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    • 专利摘要:
    ABSTRACT OF THE DISCLOSURE A supply pump (100) includes a housing (3) that has a tappet receivingChamber (13), which receives a plunger drive mechanism (50), and oil for lubricatingrespective lubricating portions of the plunger drive mechanism (50) is temporarilyretained in the tappet receiving chamber (13). ln the housing (3), a communicationhole (53) opens in an inner peripheral wall surface of a tappet guide (12) and guidesthe oil from a tappet upper side chamber (41) into a tappet lower side chamber (42) atthe time of upwardly moving a tappet (16). _29-
    公开号:SE539463C2
    申请号:SE1650049
    申请日:2016-01-18
    公开日:2017-09-26
    发明作者:Kuroda Akihiro
    申请人:Denso Corp；
    IPC主号:
    专利说明:

    LUBRICATING DEVICE FOR INTERNAL COMBUSTION ENGINE TECHNICAL FIELDThe present disclosure relates to a Iubricating device for an internal combustion engine.
    BACKGROUND A tappet Iubricating device has been previously proposed as a Iubricatingdevice of an internal combustion engine, which has a housing that includes a receivingchamber where oil for lubricating respective lubricating portions of a drive mechanismis retained. ln the tappet lubricating device, oil for lubricating respective lubricatingportions of a plunger drive mechanism is retained in a tappet receiving chamber of ahousing of a supply pump installed to an internal combustion engine.
    Here, the plunger drive mechanism is a converting mechanism that convertsrotation of a cam of a camshaft into reciprocation of a plunger and includes a tappet(used as a lifter), a roller of the tappet, and a roller pin (a rotational shaft of the roller)(see, for example, JP2008-286124A).
    FIG. 5 indicates a structure of a typical plunger pump that is used as a supplypump having the above described plunger drive mechanism.
    The supply pump is constructed to pressurize and pump fuel, which is drawninto a pressurizing chamber 105 through a fuel suction valve 104, when a plunger 103is reciprocated in a cylinder 102 along a contour of a cam 101 of a camshaft. ln the plunger drive mechanism, when the cam 101 is rotated through rotationof the camshaft, a roller pin 107 and a tappet 108 are reciprocated through a roller 106in a top-to-bottom direction in the drawing. The upward and downward movement ofthe tappet 108 described above is transmitted to the plunger 103, so that the plunger103 is reciprocated in the top-to-bottom direction of the drawing in the cylinder 102. ln the supply pump, slide movement occurs at a contact portion between theplunger and the tappet. Therefore, in order to limit wearing and seizing at the contactportion between the plunger and the tappet, oil is circulated and supplied in a tappetreceiving chamber of the plunger drive mechanism.
    For example, the oil is supplied to the contact portion between the plunger 103and the tappet 108, so that an oil film is formed between the plunger 103 and thetappet 108 to lubricate the contact portion between the plunger 103 and the tappet _1_ 108.
    The oil is also supplied to a contact portion between the cam 101 and the roller106, a contact portion between the roller pin 107 and the tappet 108, and a roller bushplaced between the roller 106 and the tappet 108.
    Furthermore, a seal member 110 is installed in the supply pump to sealbetween the pressurizing chamber 105, which is formed at one axial end of thecylinder 102, and a tappet upper side chamber 109 of a tappet receiving chamber. ln the supply pump, as shown in FIG. 5, when the roller 106 is raised along thecam 101, the tappet 108 is moved upward along with the plunger 103. When thetappet 108 is moved upward, a volume of the tappet upper side chamber 109 of thetappet receiving chamber, which is located on the plunger side of the tappet 108, isreduced. ln this way, the oil, which is retained in the tappet upper side chamber 109, iscompressed, so that a pressure in the tappet upper side chamber 109 is increased.
    Therefore, the seal member 110, which liquid-tightly seals between the tappetupper side chamber 109 and the pressurizing chamber 105 through a clearance, maybe damaged, or a roller contact surface 111 of the cam 101 may be damaged. Thus,there will be a disadvantage, such as deterioration in a sealing performance of the sealmember 110 or wearing of the roller contact surface 111 of the cam 101. ln order to avoid the above disadvantage, a pressure release passage, whichreleases a pressure (an oil pressure) in the tappet upper side chamber 109, isrequired. However, in many cases, a sufficient flow passage cross-sectional area ofthe pressure release passage cannot be ensured due to interference between thepressure release passage and another component or a fuel flow passage. ln view of the above disadvantage, JP2008-286124A discloses a supply pumpthat has a communication oil passage, which communicates between the tappet upperside chamber and a cam/shaft receiving chamber and is formed in a tappet guide of ahousing as a pressure release passage for releasing the pressure in the tappet upperside chamber. ln this case, the communication oil passage, which is communicated with thetappet upper side chamber, opens in a bottom surface, which is different from a tappetslide surface of the tappet guide, to form a large space of the cam/shaft receivingchamber. ln this way, the amount of change in the volume of the cam/shaft receivingchamber relative to the amount of change in the volume of the tappet upper sidechamber becomes very small. Thereby, the pressure of the tappet upper side chamber _2_ cannot be easily decreased, so that oil suctioning effect for suctioning the oil from thetappet upper side chamber into the cam/shaft receiving chamber is small.
    Thus, in the supply pump of JP2008-286124A, the oil suctioning effect, whichis exerted by the upward movement of the tappet, cannot be expected too much, andthe pressure increase of the tappet upper side chamber cannot be sufficiently limited.
    SUMMARY The present disclosure addresses the above disadvantage, and it is anobjective of the present disclosure to provide a lubricating device for an internalcombustion engine, being capable of sufficiently limiting pressure increase of a plungerside chamber, which is located on a plunger side of a partition portion of a tappet.
    According to the present disclosure, there is provided a lubricating device foran internal combustion engine, including a camshaft, a high pressure fuel pump, and ahousing. The camshaft includes a cam and is rotatable synchronously with an outputshaft of the internal combustion engine. The high pressure fuel pump includes aplunger and a drive mechanism. The plunger is reciprocatable along a contour of thecam. The drive mechanism converts rotation of the cam into reciprocation of theplunger to reciprocate the plunger. The high pressure fuel pump pressurizes the fueldrawn through the reciprocation of the plunger. The housing includes a receivingchamber, which receives the drive mechanism. Oil is retained in the receivingchamber. The drive mechanism includes a roller, which contacts the cam, and atappet, which is integrally movably connected to the roller and reciprocates integrallywith the plunger. The tappet includes a partition portion, which partitions the receivingchamber into a plunger side chamber and a cam side chamber. The housing includesa guide, which is configured into a tubular form and guides the tappet in a reciprocatingdirection of the tappet, and a communication hole, which communicates between theplunger side chamber and the cam side chamber. The cam side chamber is a firstvolume variable chamber that is formed by a roller contact surface of the cam, an innerperipheral surface of the guide, and a cam side surface of the tappet.
    According to the present disclosure, there is also provided a lubricating devicefor an internal combustion engine, including a camshaft, a high pressure fuel pump, avalve device, and a housing. The camshaft includes a first cam and a second cam andis rotated synchronously with an output shaft of the internal combustion engine. Thehigh pressure fuel pump includes a plunger and a first drive mechanism. The plunger _3_ is reciprocatable along a contour of the first cam. The first drive mechanism convertsrotation of the first cam into reciprocation of the plunger to reciprocate the plunger.The high pressure fuel pump pressurizes the fuel drawn through the reciprocation ofthe plunger. The valve device includes a valve and a second drive mechanism. Thevalve is reciprocatable along a contour of the second cam. The second drivemechanism converts rotation of the second cam into reciprocation of the valve toreciprocate the valve. The valve device opens and closes a port opening of theinternal combustion engine. The housing includes a first receiving chamber, whichreceives the first drive mechanism, and a second receiving chamber, which receivesthe second drive mechanism. Oil is retained in the first receiving chamber and thesecond receiving chamber. The first drive mechanism includes a first roller, whichcontacts the first cam, and a first tappet, which is integrally movably connected to thefirst roller and reciprocates integrally with the plunger. The second drive mechanismincludes a second roller, which contacts the second cam, and a second tappet, whichis integrally movably connected to the second roller and reciprocates integrally with thevalve. The first tappet includes a first partition portion, which partitions the firstreceiving chamber into a plunger side chamber and a first cam side chamber. Thesecond tappet includes a second partition portion, which partitions the secondreceiving chamber into a valve side chamber and a second cam side chamber. Thehousing includes a communication hole, which communicates the plunger side chamber with the valve side chamber or the second cam side chamber.
    BRIEF DESCRIPTION OF THE DRAWINGS The drawings described herein are for illustration purposes only and are notintended to limit the scope of the present disclosure in any way.
    FIG. 1 is a cross-sectional view showing a schematic structure of an enginehaving a supply pump according to a first embodiment of the present disclosure; FIG. 2 is a cross-sectional view taken along line ll-ll in FIG. 1; FIG. 3 is a cross-sectional view showing the schematic structure of the enginehaving the supply pump according to the first embodiment; FIG. 4 is a cross-sectional view showing a schematic structure of an enginehaving a supply pump according to a second embodiment of the present disclosure;and FIG. 5 is a cross-sectional view showing a schematic structure of a supply _4_ pump of a prior art technique.
    DETAILED DESCRIPTION Embodiments of the present disclosure will be described with reference to theaccompanying drawings.(First Embodiment) FIGS. 1 to 3 show a tappet lubricating device of a first embodiment, in whichthe principle of the present disclosure is applied.
    The lubricating device for an internal combustion engine of the presentembodiment is a system that circulates and supplies engine oil (lubricant oil:hereinafter referred to as oil) to respective corresponding parts (lubricating parts, suchas sliding parts and bearing parts) of an internal combustion engine (a vehicle driveengine: hereinafter referred to as an engine), such as a diesel engine, installed in anengine room of a vehicle, such an automobile.
    This system includes an oil pump (not shown), which is installed to a cylinderblock of the engine, and the tappet lubricating device, which circulates and suppliesthe engine oil (the lubricating oil: hereinafter referred to as the oil) outputted from theoil pump to respective lubricating portions of the plunger drive mechanism of thesupply pump.
    The oil pump is rotated synchronously with rotation of a crankshaft (outputshaft) of the engine to forcefully circulate the oil in an oil circulation path (includingrespective lubricating portions of the engine and the supply pump). This oil pumpdraws the oil, which is stored in an oil storage chamber of an oil pan and thenpressurizes and discharges the drawn oil to the oil circulation path.
    Details of the tappet lubricating device will be described later.
    The engine includes the cylinder block, in which a plurality of cylinders isformed, and a cylinder head, which is joined to an upper portion of the cylinder block.The engine also includes a crankcase, which is formed at a lower portion of thecylinder block, and the oil pan, which is formed integrally with the lower portion of thecrankcase.
    A fuel supply device, which supplies the fuel to the engine, is formed by acommon rail type fuel injection system known as a fuel injection system of, forexample, the diesel engine.
    This common rail type fuel injection system includes a fuel filter, a low pressure _5_ fuel pump (hereinafter referred to as a feed pump), the supply pump, a common rail,and a plurality of fuel injection valves (injectors).
    The supply pump is a high pressure pump that pressurizes and discharges thefuel drawn into a fuel pressurizing chamber (described later) through reciprocation of aplunger (described later) in a cylinder configured into a cylindrical form.
    The supply pump 100 includes a camshaft 1, which is rotated in apredetermined direction synchronously with rotation of the crankshaft of the engineand, a housing 3, which rotatably supports the camshaft 1.
    The supply pump 100 includes a cylinder body 4, which is secured to an upperportion of the housing 3 with fixing elements, such as bolts, and a plunger 6, which isreciprocated in a cylinder barrel 5 of the cylinder body 4.
    The camshaft 1 is rotated by the crankshaft of the engine. The camshaft 1 isrotatably supported by the housing 3 through two metal bushes 9. A cam 11, whichhas at least one cam mountain (cam lobe), is integrally installed to an outer peripheralsurface of the camshaft 1. The cam 11 is rotatably received in a cam/shaft receivingchamber 10 of the housing 3 along with the camshaft 1.
    The camshaft 1 is coupled to the crankshaft in such a manner that thecamshaft 1 makes one rotation when the crankshaft makes two rotations.
    A tappet guide 12, which is configured into a cylindrical form, is formed in theinside of the housing 3.
    Here, in a case where the reciprocating direction of the plunger 6 is assumedto be a top-to-bottom direction, a tappet receiving chamber 13, which receives theplunger drive mechanism 50 for reciprocating the plunger 6 in the top-to-bottomdirection, is formed. The oil, which lubricates the respective lubricating portions of theplunger drive mechanism 50, is temporarily retained in the tappet receiving chamber13.
    The housing 3 is formed integrally with the cylinder head or the cylinder blockof the engine. Specifically, the housing 3 is integrally formed in the cylinder head orthe cylinder block of the engine. Alternatively, the housing 3 may be fixed to a pumpreceiving portion of the cylinder head or the cylinder block of the engine with fixtureelements, such as bolts.
    A slide surface 12b, along which an outer peripheral surface 16a of a tappet 16of the plunger drive mechanism 50 reciprocates and slides, is formed in an innerperipheral surface (also referred to as an inner peripheral wall surface) 12a of the _6_ tappet guide 12 of the housing 3.
    The plunger drive mechanism 50 includes a tappet roller 14, a roller pin 15, atappet (a tappet body) 16, and a roller bush 17. The tappet roller 14 contacts an outerperipheral surface (cam profile) of the cam 11 of the camshaft 1. The roller pin 15rotatably supports the tappet roller 14. The tappet 16 is connected to the tappet roller14 in an integrally movable manner through the roller pin 15. The roller bush 17 isplaced between the tappet roller 14 and the roller pin 15.
    Details of the plunger drive mechanism 50 will be described later.
    The cylinder barrel 5, which is configured into a cylindrical tubular form, isformed in the cylinder body 4 such that the slide surface of the plunger 6 isreciprocatable and is slidable along the cylinder barrel 5. Afuel pressurizing chamber19 is formed at one axial end of the cylinder barrel 5 (a radially outer side of thecamshaft 1).
    A suction valve receiving chamber, which is communicated with an outlet sideof the feed pump, is formed in the cylinder body 4. Afuel suction valve, which opensand closes a fuel suction flow passage (described later) located on an upstream sideof the fuel pressurizing chamber 19, is received in an inside of the suction valvereceiving chamber. The fuel suction valve includes a spool valve 21, which is placedon one axial side (the upper side in the drawing) of the cylinder barrel 5 of the cylinderbody 4.
    The fuel suction valve includes a valve body 22, which reciprocatably andslidably supports the spool valve 21, and a return spring 23, which urges the spoolvalve 21 in a valve closing direction.
    A receiving recess (receiving hole), which opens toward an outside, is formedin the cylinder body 4. A fuel discharge valve having a check valve structure isreceived in a deep side (pressurizing chamber side) of this receiving recess. The fueldischarge valve includes a valve (a valve element) 24, which opens and closes a fueldischarge flow passage (described later), and a return spring 25, which urges the valve24 in the valve closing direction.
    A fuel suction flow passage includes a fuel suction flow passage 26a, a fuelsuction hole 26b, and a valve receiving chamber (a valve element receiving chamber)26c. The fuel suction flow passage 26a is communicated with an inlet port (suctionport) that receives the fuel from the feed pump. The fuel suction hole 26b iscommunicated with the fuel suction flow passage 26a. The valve receiving chamber _7_ 260 0ommuni0ates between the fuel su0tion hole 26b and the fuel pressurizing0hamber 19.
    The fuel dis0harge flow passage includes a fuel dis0harge hole 27a, adis0harge valve re0eiving 0hamber 27b, a fuel dis0harge hole 270, and an outlet port(dis0harge port). The fuel dis0harge hole 27a is 0ommuni0ated with the fuelpressurizing 0hamber 19. The dis0harge valve re0eiving 0hamber 27b is0ommuni0ated with the fuel dis0harge hole 27a. The fuel dis0harge hole 270 is0ommuni0ated with the dis0harge valve re0eiving 0hamber 27b. The outlet port(dis0harge port) opens toward the outside.
    The supply pump 100 in0ludes the plunger drive mechanism 50, whi0h ispla0ed between the 0am 11 of the 0amshaft 1 and the plunger 6.
    A spring seat 31 is installed to an outer peripheral surfa0e of a lower end partof the plunger 6 shown in the drawing. Furthermore, a spring re0eiving portion 32,whi0h is 0onfigured into a tubular form, is formed at a lower end part of the 0ylinderbody 4 shown in the drawing. A plunger spring 33, whi0h urges the plunger driveme0hanism 50 against the outer peripheral surfa0e (profile) of the 0am 11, is installedbetween an upper end surfa0e of the spring seat 31 and a deep side surfa0e of thespring re0eiving portion 32.
    Atappet 0onta0t portion 34, whi0h is 0onfigured into a flange form, is formed ata lower end part of the plunger 6 shown in the drawing.
    Furthermore, the supply pump 100 in0ludes a seal member 35, whi0h is0onfigured into a tubular form and liquid-tightly seals a gap (0learan0e) between anouter peripheral surfa0e of an intermediate part of the plunger 6 and an innerperipheral surfa0e of the lower end part of the 0ylinder barrel 5 of the 0ylinder body 4.The seal member 35 limits outflow of the fuel from the fuel pressurizing 0hamber 19 tothe tappet re0eiving 0hamber 13 through the 0learan0e. The outflow of the fuel fromthe fuel pressurizing 0hamber 19 to the tappet re0eiving 0hamber 13 would result inmixing of the fuel into the oil.
    The plunger drive me0hanism 50 in0ludes the tappet roller 14, the roller pin 15,and the tappet 16.
    The tappet roller 14 is rotatably supported by an outer peripheral surfa0e of theroller pin 15. The tappet roller 14 re0ipro0ates the plunger 6 in the re0ipro0atingdire0tion along the 0ontour of the 0am mountain of the 0am 11 and dire0tly 0onta0ts the 0am mountain of the 0am 11.
    The roller pin 15 is installed to the tappet roller 14 such that the roller pin 15extends through the tappet roller 14 in the axial direction of the tappet roller 14. Theroller pin 15 includes projecting shaft portions 36, which project outward from two endsurfaces, respectively, of the tappet roller 14 in the axial direction of the rotational axisof the tappet roller 14.
    When the tappet roller 14 is rotated about the roller pin 15 in a circumferentialdirection, seizing may possibly occur between the tappet roller 14 and the roller pin 15.Because of this reason, the roller bush 17, which is configured into a cylindrical tubularform, is placed between an inner peripheral surface of the tappet roller 14 and an outerperipheral surface of the roller pin 15.
    Furthermore, a roller contact surface 37, which slidably contacts the outerperipheral surface of the tappet roller 14, is formed in the outer peripheral surface ofthe cam 11 of the camshaft 1.
    The tappet 16 converts the rotation of the cam 11 into the reciprocation of theplunger 6 in the top-to-bottom direction to reciprocate the plunger 6. The tappet 16 isreciprocatably and slidably supported by the tappet guide 12 of the housing 3. Thetappet 16 is connected to the tappet roller 14 in an integrally movable manner throughthe roller pin 15. Furthermore, the tappet 16 is constructed to reciprocate integrallywith the plunger 6, the tappet roller 14, and the roller pin 15.
    The tappet 16 includes a partition wall (also referred to as a partition portion)43 that partitions the tappet receiving chamber 13 of the housing 3 into a tappet upperside chamber 41 and a tappet lower side chamber 42, which are located on an upperside and a lower side, respectively, of the partition wall 43 in an axial direction of anaxis of the plunger 6. The tappet upper side chamber 41 receives the tappet contactportion 34 of the plunger 6, the spring seat 31, and the plunger spring 33. The tappetlower side chamber 42 receives the tappet roller 14, a support wall 44 of the tappet 16,the roller pin 15, the roller contact surface 37 of the cam 11.
    The tappet upper side chamber 41 is a second volume variable space (plungerside chamber) that is formed by a tappet side surface (a lower surface in the drawing)4a of the cylinder body 4, a tappet side surface (a lower end surface in the drawing)35a of the seal member 35, the inner peripheral surface 12a of the tappet guide 12,and a plunger side surface (an upper end surface in the drawing) 43a of the partitionwall 43 of the tappet 16. That is, the tappet upper side chamber 41 is surrounded bythe tappet side surface 4a of the cylinder body 4, the tappet side surface 35a of the _9_ seal member 35, the inner peripheral surface 12a of the tappet guide 12, and theplunger side surface 43a of the partition wall 43 of the tappet 16.
    The tappet upper side chamber 41 is placed on a tappet/plunger upwardlymoving side of the partition wall 43 of the tappet 16, i.e., on the plunger 6 side of thepartition wall 43 of the tappet 16. The tappet upper side chamber 41 is communicatedwith the tappet lower side chamber 42 through a minute clearance formed between theinner peripheral surface 12a of the tappet guide 12 and the outer peripheral surface16a of the tappet 16. A volume of the tappet upper side chamber 41 is reduced at thetime of upwardly moving the tappet 16 and the plunger 6. The volume of the tappetupper side chamber 41 is increased at the time of downwardly moving the tappet 16and the plunger 6.
    The tappet lower side chamber 42 is a first volume variable space (cam sidechamber), which is defined by the outer peripheral surface (the roller contact surface37) of the cam 11, the inner peripheral surface 12a of the tappet guide 12, and the camside surface (the lower end surface in the drawing) 43b of the partition wall 43 of thetappet 16. That is, the tappet lower side chamber 42 is surrounded by the rollercontact surface 37 of the cam 11, the inner peripheral surface 12a of the tappet guide12, and the cam side surface 43b of the partition wall 43.
    The tappet lower side chamber 42 is located on the tappet/plunger downwardlymoving side of the partition wall 43 of the tappet 16, i.e., on the cam 11 side of thepartition wall 43 of the tappet 16. The tappet lower side chamber 42 is communicatedwith the cam/shaft receiving chamber 10 through a flow restriction passage (discussedlater). The tappet lower side chamber 42 is communicated with the oil storagechamber of the oil pan through the flow restriction passage and the cam/shaft receivingchamber 10. A volume of the tappet lower side chamber 42 is increased at the time ofupwardly moving the tappet 16 and the plunger 6. The volume of the tappet lower sidechamber 42 is decreased at the time of downwardly moving the tappet 16 and theplunger 6.
    The tappet contact portion 34 of the plunger 6 directly contacts the uppersurface, i.e., the plunger side surface 43a of the partition wall 43.
    The tappet 16 includes a cylindrical peripheral wall, which axially projects froman outer peripheral portion of the partition wall 43 toward the plunger side (the upperside in the drawing).
    The tappet 16 includes the support wall 44, which is configured into a tubular _10- form and axially projects from the outer peripheral portion of the partition wall 43toward the cam 11 side (the lower side in the drawing). lnsertion holes 45, into whichthe projecting shaft portions 36 of the roller pin 15 are rotatably inserted, are formed inthe support wall 44. A roller receiving chamber 46, which rotatably supports the tappetroller 14, is formed in the inside of the support wall 44. The roller receiving chamber46 is included in the tappet lower side chamber 42.
    The projecting shaft portions 36 of the roller pin 15 may be fixed to the supportwall 44. Furthermore, the space below the support wall 44 of the tappet 16 shown inthe drawing may be formed as the tappet lower side chamber 42. ln such a case, theroller receiving chamber 46 is not included in the tappet lower side chamber 42.
    Next, details of the tappet lubricating device of the present embodiment will bebriefly described with reference to FIGS. 1 to 3.
    The tappet lubricating device is the system that circulates and supplies the oilto the respective lubricating portions of the plunger drive mechanism 50 of the supplypump 100 and includes oil supply passages 51, 52, a communication hole 53 and aflow restriction passage 54.
    Here, the lubricating portions of the plunger drive mechanism 50 may include,for example, a contact portion between the tappet contact portion 34 of the plunger 6and the partition wall 43 of the tappet 16, a contact portion between the roller contactsurface 37 of the cam 11 and the tappet roller 14, a slide portion (slide clearance)between the tappet guide 12 and the tappet 16, a slide portion (slide clearance)between the tappet roller 14 and the roller bush 17, and a slide portion between theroller pin 15 and the roller bush 17.
    The oil supply passage 51 is formed in the housing 3. An upstream end of theoil supply passage 51 in a flow direction of the oil is connected to the outlet side of theoil pump. Adownstream end of the oil supply passage 51 in the flow direction of the oilopens in the inner peripheral surface 12a of the tappet guide 12 of the housing 3, sothat the oil supply passage 51 communicates between the outlet of the oil pump andthe tappet receiving chamber 13. ln this way, the oil is temporarily retained in thetappet receiving chamber 13.
    The oil supply passage 52 is formed in the partition wall 43 of the tappet 16.An upstream end of the oil supply passage 52 in the flow direction of the oil isconnected to a downstream end of the oil supply passage 51. A downstream end ofthe oil supply passage 51 in the flow direction of the oil opens in the wall surface of the _11- roller receiving Chamber 46 of the tappet 16 (i.e., the cam side surface 43b of thepartition wall 43) and supplies the oil into the roller receiving chamber 46.
    The communication hole 53, which communicates between the tappet upperside chamber 41 and the tappet lower side chamber 42, is formed in the housing 3. Asshown in FIG. 2, this communication hole 53 includes an opening 53a, which opens inthe wall surface of the tappet upper side chamber 41, and an opening 53b, whichopens in the wall surface of the tappet lower side chamber 42. The openings 53a, 53bof the communication hole 53 open only in the inner peripheral surface 12a (the slidesurface 12b) of the tappet guide 12 or a plane (the plane being extending along anextension line that extends from the slide surface 12b in the top-to-bottom direction)that is the same as a plane of the slide surface 12b. This plane may be a curved planeor a planar plane. For instance, this plane may be a curved plane in the case wherethe inner peripheral surface 12a is the curved surface. Alternatively, this plane may bea planar plane in a case where the inner peripheral surface 12a is a planar surface.
    The communication hole 53 is bent into a V shape at an intermediate sectionbetween the upstream end and the downstream end in the flow direction of the oil.
    The communication hole 53 is an oil pressure relief passage that has apassage cross-sectional area, which is larger than a passage cross-sectional area ofthe minute clearance (slide clearance) defined between the inner peripheral surface12a of the tappet guide 12 and the outer peripheral surface 16a of the tappet 16.
    The flow restriction passage 54 is an oil passage that communicates betweenthe cam/shaft receiving chamber 10 of the housing 3 and the tappet lower sidechamber 42 of the tappet guide 12. The flow restriction passage 54 is formed betweenthe surface (the outer peripheral surface, two annular end surfaces) of the cam 11 ofthe camshaft 1 and the tappet guide 12. The cam 11 is received in the lower portion(the opening side) of the tappet lower side chamber 42 in the drawing, so that thepassage cross sectional area of the lower portion (opening side) of the tappet lowerside chamber 42 is reduced in the flow restriction passage 54. ln this way, a flowresistance of the oil is increased at the time of passing through the flow restrictionpassage 54.
    Furthermore, the oil, which is supplied from the tappet lower side chamber 42to the roller contact surface 37 of the cam 11, is in a free-flowing state.
    (Operation of First Embodiment)Next, the operation of the supply pump 100 used in the common rail fuel _12- injection system of the present embodiment will be briefly described with reference toFIGS. 1 to 3.
    When the camshaft 1 of the supply pump 100 is rotated synchronously withrotation of the crankshaft of the engine, the tappet roller 14 is reciprocated in the top-to-bottom direction (making upward and downward movement, vertical movement)along the outer peripheral surface (the cam profile) of the cam 11.
    This motion of the tappet roller 14 is transmitted to the tappet 16 through theroller pin 15, so that the tappet 16 is reciprocated in the top-to-bottom direction of thedrawing (making upward and downward movement, vertical movement) in the tappetreceiving chamber 13.
    This motion of the tappet 16 is directly transmitted to the plunger 6, andthereby the plunger 6 is reciprocated in the top-to-bottom direction of the drawing(making upward and downward movement, vertical movement).
    Then, when the plunger 6 at, for example, the top dead center is moveddownward, a volume of the fuel pressurizing chamber 19 is increased, and thereby thefuel pressure in the fuel pressurizing chamber 19 is reduced. When the fuel pressureof the fuel suction flow passage becomes larger than a sum of the urging force of thereturn spring 25 of the fuel suction valve and the fuel pressure of the fuel pressurizingchamber 19, the spool valve 21 of the fuel suction valve is opened. That is, the spoolvalve 21 is lifted from a tapered seat surface of the valve body 22, so that the fuelsuction flow passage is opened. ln this way, the fuel, which is discharged from thefeed pump, is drawn into the fuel pressurizing chamber 19 through the inlet port, thefuel suction flow passage 26a, the fuel suction hole 26b, and the valve receivingchamber 26c in this order.
    Then, when the plunger 6 begins to move upward after reaching the bottomdead center, the volume of the fuel pressurizing chamber 19 is reduced, and the fuelpressure of the fuel pressurizing chamber 19 is increased. When the fuel pressure ofthe fuel suction flow passage becomes lower than the sum of the urging force of thereturn spring 25 of the fuel suction valve and the fuel pressure of the fuel pressurizingchamber 19, the spool valve 21 of the fuel suction valve is closed. That is, the spoolvalve 21 is seated against the tapered seat surface of the valve body 22 to close thefuel suction flow passage, and at the same time the fuel pressure of the fuelpressurizing chamber 19 is further increased. At this time, the fuel is pressurized and is compressed at the high pressure in the fuel pressurizing chamber 19. _13- When the fuel pressure of the fuel pressurizing chamber 19 is increased to apressure that equal to or higher than the valve opening pressure of the fuel dischargevalve, the valve 24 of the fuel discharge valve is opened. ln this way, the highpressure fuel is pumped from the fuel pressurizing chamber 19 to the common railthrough the fuel discharge flow passage (the fuel discharge hole 27a, the dischargevalve receiving chamber 27b, the fuel discharge hole 27c, and the outlet port in thisorder).
    When each of the injectors is valve opened at a given injection timing, the highpressure fuel, which is accumulated in the common rail, is injected into thecorresponding one of the cylinders of the engine at predetermined timing.
    (Advantage of First Embodiment) Here, in the supply pump 100 used in the common fuel injection system, whenthe tappet roller 14 is moved onto the cam mountain of the cam 11 of the camshaft 1,the roller pin 15 and the tappet 16 are moved upward along with the plunger 6.
    When the tappet 16 is moved upward, the volume of the tappet lower sidechamber 42, which is located on the cam 11 side of the partition wall 43 of the tappet16 in the tappet receiving chamber 13 is increased. ln contrast, the volume of thetappet upper side chamber 41, which is located on the plunger 6 side of the partitionwall 43 of the tappet 16, is reduced. ln this way, the oil, which is retained in the tappetupper side chamber 41, is compressed, so that the pressure in the tappet upper sidechamber 41 is increased. ln this way, wearing of the roller contact surface 37 of the cam 11 may possiblydisadvantageously occur. Furthermore, a seal lip of the seal member 35, which liquid-tightly seals between the fuel pressurizing chamber 19 and the tappet upper sidechamber 41 through a clearance, may possibly be lifted from the outer peripheralsurface (the seal surface) of the plunger 6 due to an increase in the pressure of thetappet upper side chamber 41, and thereby the sealing performance for sealingbetween the fuel pressurizing chamber 19 and the tappet upper side chamber 41 maypossibly be disadvantageously deteriorated. ln view of the above disadvantages, the supply pump 100 of the presentembodiment includes the housing 3 that has the tappet receiving chamber 13, whichreceives the plunger drive mechanism 50, and the oil for lubricating the respectivelubricating portions of the plunger drive mechanism 50 is temporarily retained in thetappet receiving chamber 13. The housing 3 is formed integrally with the cylinder head _14- or the cylinder block of the engine.
    The communication hole 53 is formed in the housing 3, which receives thesupply pump 100. The communication hole 53 opens in the inner peripheral wallsurface of the tappet guide 12 and guides the oil from the tappet upper side chamber41 into the tappet lower side chamber 42 at the time of upwardly moving the tappet 16.
    The communication hole 53 directly communicates between the tappet upperside chamber 41 and the tappet lower side chamber 42. The tappet upper sidechamber 41 is formed by the tappet side surface 4a of the cylinder body 4, the tappetside surface 35a of the seal member 35, the inner peripheral surface 12a of the tappetguide 12, and the plunger side surface 43a of the partition wall 43 of the tappet 16.The tappet lower side chamber 42 is formed by the roller contact surface 37 of the cam11, the inner peripheral surface 12a of the tappet guide 12, and the cam side surface43b of the partition wall 43 of the tappet 16. ln this way, the amount of change in the volume of the tappet upper sidechamber 41 and the amount of change in the volume of the tappet lower side chamber42 become generally equal to each other, or the amount of change in the volume of thetappet lower side chamber 42 becomes larger than the amount of change in thevolume of the tappet upper side chamber 41. Thereby, the oil suctioning effect at thetappet lower side chamber 42 becomes large. ln this way, the volume of the tappetupper side chamber 41 is reduced in response to the upward movement of the tappet16. ln contrast, when the volume of the tappet lower side chamber 42 is increased, theoil, which is retained in the tappet upper side chamber 41, flows into the tappet lowerside chamber 42 through the communication hole 53. Thus, the pressure increase inthe tappet upper side chamber 41 can be sufficiently limited.
    Thereby, wearing of the roller contact surface of the cam 11 may be limited.Furthermore, it is possible to limit the reduction in the sealing performance for sealingbetween the fuel pressurizing chamber 19 and the tappet upper side chamber 41 _(Second Embodiment) FIG. 4 shows a fuel injection system (second embodiment), in which thepresent disclosure is applied. ln the following discussion, the components, which are similar to those of thefirst embodiment, will be indicated by the same reference numerals and will not bedescribed further for the sake of simplicity.
    The lubricating device for the internal combustion engine according to the _15- present embodiment includes: an oil pump (not shown) that draws and pumps engineoil (lubricating oil, hereinafter referred to as oil), which is stored in an oil storagechamber of an oil pan; a first tappet lubricating device that circulates and supplies theoil to the respective lubricating portions of the plunger drive mechanism 50 of thesupply pump 100; a second tappet lubricating device that circulates and supplies theoil to respective lubricating portions of an intake valve drive mechanism (or simplyreferred to as a drive mechanism) 210a of an intake valve device 200a; and a thirdtappet lubricating device that circulates and supplies the oil to respective lubricatingportions of an exhaust valve drive mechanism (or simply referred to as a drivemechanism) 210b of an exhaust valve device 200b. The intake valve device 200a andthe exhaust valve device 200b cooperate together to form an intake and exhaust valvedevice 200.
    Similar to the first embodiment, the supply pump 100 includes the camshaft 1,the housing 3, the cylinder body 4, the plunger 6, and the plunger drive mechanism 50.The plunger drive mechanism 50 includes the tappet roller 14, the roller pin 15, thetappet 16, and the roller bush 17.
    The cam 11 of the camshaft 1 serves as a first cam of the present disclosure.The tappet roller 14 of the plunger drive mechanism 50 serves as a first roller of thepresent disclosure. The roller pin 15 serves as a first pin. The tappet 16 serves as afirst tappet of the present disclosure.
    Similar to the first embodiment, the tappet 16 includes the partition wall 43,which partitions the tappet receiving chamber 13 of the housing 3 into the tappet upperside chamber 41 and the tappet lower side chamber 42.
    The partition wall 43 of the tappet 16 serves as a first partition portion of thepresent disclosure. The tappet lower side chamber 42 serves as a first cam sidechamber of the present disclosure.
    The intake and exhaust valve device 200 includes a camshaft 2 and thehousing 3. The camshaft 2 is rotated in a predetermined direction synchronously withrotation of the crankshaft (the output shaft) of the engine. The housing 3 is commonwith the supply pump 100 and rotatably supports the camshaft 2. The intake andexhaust valve device 200 includes a stem (hereinafter referred to as an intake valvestem) 7 of an intake valve (air intake valve) and the intake valve drive mechanism210a. The intake valve stem 7 opens and closes an opening (port opening) of an airintake port. The intake valve drive mechanism 210a reciprocates the intake valve stem _16- 7 in the top-to-bottom direction. The intake and exhaust valve device 200 furtherincludes a stem (hereinafter referred to as an exhaust valve stem) 8 of an exhaustvalve and the exhaust valve drive mechanism 210b. The exhaust valve stem 8 opensand closes an opening (port opening) of an exhaust port. The exhaust valve drivemechanism 210b reciprocates the exhaust valve stem 8 in the top-to-bottom direction.
    At least one air intake port, which is independently connected to a combustionchamber of corresponding one cylinder, is formed in the cylinder head of the engine.The intake valve, which opens and closes the opening of the intake port of thecorresponding cylinder, is formed at a combustion chamber side end portion of theintake port of the cylinder.
    At least one exhaust port, which is independently connected to the combustionchamber of the corresponding one cylinder, is formed in the cylinder head. Theexhaust valve, which opens and closes the opening of the exhaust port of thecorresponding cylinder, is formed at a combustion chamber side end portion of theexhaust port of the cylinder.
    The cam/shaft receiving chamber 10 of the housing 3 is placed on the upperside of the oil storage chamber of the oil pan.
    The camshaft 2 is rotated by the crankshaft of the engine. The camshaft 2 isrotatably supported by the housing 3 through three metal bushes 59. An intake cam61, which has at least one cam mountain, and an exhaust cam 71, which has at leastone cam mountain, are integrally assembled to the outer peripheral surface of thecamshaft 2.
    The camshaft 2 is coupled to the crankshaft of the engine in such a mannerthat the camshaft 2 makes one rotation when the crankshaft makes two rotations.
    The intake cam 61 of the camshaft 2 serves as a second cam of the presentdisclosure.
    An intake valve spring 60 is installed between the cylinder head of the engineand a flange (hereinafter referred to as a tappet contact portion) 62 of the intake valvestem 7. The intake valve spring 60 urges the intake valve drive mechanism 210aagainst the outer peripheral surface (the cam profile) of the intake cam 61.
    An exhaust valve spring 70 is installed between the cylinder head and a flange(hereinafter referred to as a tappet contact portion) 72 of the exhaust valve stem 8.The exhaust valve spring 70 urges the exhaust valve drive mechanism 210b againstthe outer peripheral surface (the cam profile) of the exhaust cam 71. _17- Here, in a case where the reciprocating direction of the intake valve is definedas a top-to-bottom direction, a tappet receiving chamber 63, which receives the intakevalve drive mechanism 210a that reciprocates the intake valve in the top-to-bottomdirection, is formed in the inside of the housing 3. Furthermore, in a case where thereciprocating direction of the exhaust valve is defined as the top-to-bottom direction, atappet receiving chamber 73, which receives the exhaust valve drive mechanism 210bthat reciprocates the exhaust valve in the top-to-bottom direction, is formed in theinside of the housing 3.
    The oil, which lubricates the respective lubricating portions of the intake valvedrive mechanism 210a and the respective lubricating portions of the exhaust valvedrive mechanism 210b, is temporarily retained in the tappet receiving chambers 63,73.
    The intake valve drive mechanism 210a includes a tappet roller 64, a roller pin65, a tappet 66, and a roller bush 67. The tappet roller 64 contacts an outer peripheralsurface (cam profile) of the intake cam 61 of the camshaft 2. The roller pin 65 rotatablysupports the tappet roller 64. The tappet 66 is connected to the tappet roller 64 in anintegrally movable manner through the roller pin 65. The roller bush 67 is placedbetween the tappet roller 64 and the roller pin 65.
    The lubricating portions of the intake valve drive mechanism 210a may include,for example, a contact portion between the tappet contact portion 62 of the intakevalve stem 7 and the partition portion (describe later) of the tappet 66, a contactportion between the intake cam 61 and the tappet roller 64, a slide portion (slideclearance) between the tappet roller 64 and the roller bush 67, and a slide portionbetween the roller pin 65 and the roller bush 67.
    The exhaust valve drive mechanism 210b includes a tappet roller 74, a rollerpin 75, a tappet 76, and a roller bush 77. The tappet roller 74 contacts an outerperipheral surface (cam profile) of the exhaust cam 71 of the camshaft 2. The rollerpin 75 rotatably supports the tappet roller 74. The tappet 76 is connected to the tappetroller 74 in an integrally movable manner through the roller pin 75. The roller bush 77is placed between the tappet roller 74 and the roller pin 75.
    The lubricating portions of the exhaust valve drive mechanism 210b mayinclude, for example, a contact portion between the tappet contact portion 72 of theexhaust valve stem 8 and the partition portion (describe later) of the tappet 76, acontact portion between the exhaust cam 71 and the tappet roller 74, a slide portion _18- (slide clearance) between the tappet roller 74 and the roller bush 77, and a slideportion between the roller pin 75 and the roller bush 77.
    The tappet roller 64 is rotatably supported by an outer peripheral surface of theroller pin 65. The tappet roller 64 reciprocates the intake valve stem 7 in thereciprocating direction along the contour of the cam mountain of the intake cam 61 anddirectly contacts the cam mountain of the intake cam 61.
    The roller pin 65 is installed to the tappet roller 64 such that the roller pin 65extends through the tappet roller 64 in the axial direction of the tappet roller 64. Theroller pin 65 includes projecting shaft portions 69, which project outward from two endsurfaces, respectively, of the tappet roller 64 in the axial direction of the rotational axisof the tappet roller 64.
    The tappet 66 converts the rotation of the intake cam 61 into the reciprocationof the intake valve in the top-to-bottom direction of the intake valve. The tappet 66 isreciprocatably received in the tappet receiving chamber 63 of the housing 3. Thetappet 66 is connected to the tappet roller 64 in an integrally movable manner throughthe roller pin 65. Furthermore, the tappet 66 is constructed to reciprocate integrallywith the intake valve stem 7.
    The tappet 66 includes a partition wall (a partition portion) 83 that partitions thetappet receiving chamber 63 of the housing 3 into a tappet upper side chamber 81 anda tappet lower side chamber 82.
    The tappet upper side chamber 81 is a valve side chamber located on theintake valve stem 7 side of the partition wall 83 of the tappet 66.
    The tappet lower side chamber 82 is a second cam side chamber that islocated on the intake cam 61 side of the partition wall 83 of the tappet 66.
    The tappet contact portion 62 of the intake valve stem 7 directly contacts anupper surface of the partition wall 83.
    The tappet 66 includes a support wall 84, which is configured into a tubularform and extends from an outer peripheral portion of the partition wall 83 toward thelower side in the drawing. lnsertion holes 85, into which the projecting shaft portions69 of the roller pin 65 are rotatably inserted, are formed in the support wall 84. A rollerreceiving chamber 86, which rotatably supports the tappet roller 64, is formed in theinside of the support wall 84.
    The projecting shaft portions 69 of the roller pin 65 may be fixed to the supportwall 84. _19- The tappet contact portion 72 of the exhaust valve stem 8 directly contacts anupper surface of the tappet 76.
    The tappet 76 includes a support wall 304, which is configured into the tubularform and extends from the outer peripheral portion of a partition wall (partition portion)303 of the tappet 76 toward the lower side in the drawing. lnsertion holes 95, intowhich projecting shaft portions 309 of the roller pin 75 are rotatably inserted, areformed in the support wall 304. A roller receiving chamber 96, which rotatablysupports the tappet roller 74, is formed in the inside of the support wall 304. Thepartition wall 303 partitions the tappet receiving chamber 73 of the housing 3 into atappet upper side chamber 97 and a tappet lower side chamber 98.
    The projecting shaft portions 309 of the roller pin 75 may be fixed to thesupport wall 304.
    Next, details of the first to third tappet lubricating devices will be brieflydescribed with reference to FIG. 4.
    The first tappet lubricating device is a system that circulates and supplies theoil to the respective lubricating portions of the plunger drive mechanism 50 of thesupply pump 100. The second tappet lubricating device is a system that circulates andsupplies the oil to the respective lubricating portions of the intake valve drivemechanism 210a of the intake and exhaust valve device 200. The third tappetlubricating device is a system that circulates and supplies the oil to the respectivelubricating portions of the exhaust valve drive mechanism 210b of the intake andexhaust valve device 200.
    The first and second tappet lubricating devices include oil supply passages 91,92 and a communication hole 93.
    The oil supply passage 91 is formed in the housing 3. Similar to the oil supplypassage 51 of the first embodiment, an upstream end of the oil supply passage 91 in aflow direction of the oil is connected to the outlet side of the oil pump. A downstreamend of the oil supply passage 91 in the flow direction of the oil opens in the innerperipheral surface 12a of the tappet guide 12 of the housing 3, and the oil supplypassage 91 communicates between the outlet of the oil pump and the tappet receivingchamber 13. ln this way, similar to the first embodiment, the oil is temporarily retainedin the tappet receiving chamber13.
    The oil supply passage 92 is formed in the partition wall 43 of the tappet 16.An upstream end of the oil supply passage 92 in the flow direction of the oil is _20- connected to the downstream end of the oil supply passage 91. A downstream end ofthe oil supply passage 92 in the flow direction of the oil opens in the wall surface of theroller receiving chamber 46 of the tappet 16 and supplies the oil to the slide portionsamong the tappet roller 14, the roller pin 15 and the roller bush 17.
    A partition wall portion 94, which partitions between the tappet receivingchamber 13 and the tappet receiving chamber 63, is formed in the housing 3. Thecommunication hole 93, which communicates between the tappet upper side chamber41 and the tappet receiving chamber 63, is formed through the partition wall portion 94. ln a case where a phase difference between the cam 11 and the intake cam 61is 180 degrees, the tappet upper side chamber 41 is formed in the housing 3 such thatthe tappet upper side chamber 41 is communicated with the tappet upper sidechamber 81 of the tappet receiving chamber 63 through the communication hole 93.Furthermore, the communication hole 93 communicates between the tappet upper sidechamber 41 and the tappet upper side chamber 81 along a straight line in a commonplane. Alternatively, in a case where a vertical position of an upstream end of thecommunication hole 93, which opens in the inner peripheral surface 12a of the tappetguide 12, is different from a vertical position of a downstream end of thecommunication hole 93, which opens in the wall surface of the tappet upper sidechamber 81, the communication hole 93 may communicate between the tappet upperside chamber 41 and the tappet upper side chamber 81 along a tilted line or along acurved line.
    As discussed above, the engine, which has the supply pump 100 and theintake and exhaust valve device 200 of the present embodiment, includes the housing3 where the oil is temporarily retained in the tappet receiving chamber 13, whichreceives the plunger drive mechanism 50 of the supply pump 100, and the tappetreceiving chamber 63, which receives the intake valve drive mechanism 210a of theintake and exhaust valve device 200. Similar to the first embodiment, the housing 3 isformed integrally with the cylinder head or the cylinder block of the engine.
    The housing 3, which receives the supply pump 100 and the intake andexhaust valve device 200, particularly, the partition wall portion 94 of the housing 3,which partitions between the tappet receiving chamber 13 and the tappet receivingchamber 63, is provided with the communication hole 93 that extends through thepartition wall portion 94 in the left-to-right direction of the drawing, which isperpendicular to the top-to-bottom direction. _21- The communication hole 93 directly communicates between the tappet upperside chamber 41, which is located on the plunger 6 side of the partition wall 43 of thetappet 16, and the tappet upper side chamber 81, which is located on the intake valvestem 7 side of the partition wall 83 of the tappet 66. Furthermore, the communicationhole 93 has an opening 93a, which opens in the wall surface of the tappet upper sidechamber 41, and an opening 93b, which opens in the wall surface of the tappet upperside chamber 81. The opening 93a of the communication hole 93 opens in the innerperipheral surface 12a (the slide surface 12b) of the tappet guide 12 or the plane (theplane being extending along the extension line that extends from the slide surface 12bin the top-to-bottom direction) that is the same as the plane of the slide surface 12b.
    Furthermore, the communication hole 93 is an oil pressure relief passage thatopens in the inner peripheral wall surface of the tappet guide 12 and guides the oilfrom the tappet upper side chamber 41 into the tappet upper side chamber 81 at thetime of upwardly moving the tappet 16. ln this way, the amount of change in the volume of the tappet upper sidechamber 41 and the amount of change in the volume of the tappet upper side chamber81 become generally equal to each other, or the amount of change in the volume of thetappet upper side chamber 81 becomes larger than the amount of change in thevolume of the tappet upper side chamber 41. Thereby, the oil suctioning effect at thetappet upper side chamber 81 becomes large. ln this way, the volume of the tappetupper side chamber 41 is reduced in response to the upward movement of the tappet16. ln contrast, when the volume of the tappet upper side chamber 81 is increased,the oil, which is retained in the tappet upper side chamber 41, flows into the tappetupper side chamber 81 through the communication hole 93 of the housing 3. Thus,the pressure increase in the tappet upper side chamber 41 can be sufficiently limited.
    Thereby, wearing of the roller contact surface of the cam 11 may be limited.Furthermore, it is possible to limit the reduction in the sealing performance for sealingbetween the fuel pressurizing chamber 19 and the tappet upper side chamber 41.(Modifications) ln the first and second embodiments, the drive mechanism, which reciprocatesthe plunger of the high pressure fuel pump, is applied in the plunger drive mechanism,which reciprocates the plunger of the supply pump used in the common rail fuelinjection system. Alternatively, the drive mechanism, which reciprocates the plunger ofthe high pressure fuel pump, may be applied in a plunger drive mechanism, which _22- reciprocates a plunger of a distributor fuel injection pump or an in-line fuel injectionpump that is used in a fuel injection device having no common rail. ln the first and second embodiments, the present disclosure is applied to thesupply pump 100 that has the fuel suction valve, which adjusts the quantity of the fueldrawn into the pressurizing chamber. Alternatively, the present disclosure may beapplied to a supply pump that has an electromagnetic valve, which adjusts a quantityof fuel drawn into a pressurizing chamber.
    An electromagnetic pump delivery control valve (PCV) of a normally closedtype or an electromagnetic pump delivery control valve (PCV) of a normally open typemay be used as the electromagnetic valve. ln place of the PCV, an electromagneticsuction control valve (SCV) may be used. ln the second embodiment, there is discussed the example where thecommunication hole 93, which communicates between the tappet upper side chamber41 of the plunger drive mechanism 50 and the tappet upper side chamber 81 of theintake valve drive mechanism 210a, is formed in the partition wall portion 94 of thehousing 3. However, in a case where the phase difference between the cam 11 andthe exhaust cam 71 is 180 degrees, the communication hole, which communicatesbetween the tappet upper side chamber 41 of the plunger drive mechanism 50 and thetappet upper side chamber 97 (the exhaust valve stem 8 side chamber) of the exhaustvalve drive mechanism 210b, may be formed in the partition wall portion of the housing3. ln the second embodiment, the camshaft 1 and the camshaft 2 may be formedseparately from each other and cooperate together to serve as a camshaft of thepresent disclosure. Alternatively, the camshaft 1 and the camshaft 2 may be formedintegrally as a one-piece camshaft, which serves as the camshaft of the presentdisclosure. Also, the camshaft 1 or the one-piece camshaft described above may beprovided separately from the supply pump 100. ln the second embodiment, the intake valve drive mechanism 210a and theexhaust valve drive mechanism 210b are driven by the common camshaft 2.Alternatively, the intake valve drive mechanism 210a and the exhaust valve drivemechanism 210b may be driven by separate camshafts (second and third camshafts),respectively.
    The drive mechanism may be a drive mechanism of a type where the rollerand the tappet directly slide relative to each other. _23- ln the first and second embodiments, the feed pump is connected at thelocation that is on the upstream side of the intake port of the high pressure fuel pumpin the flow direction of the fuel. Alternatively, a feed pump, in which the camshaft 1 isrotated in response to rotation of the crankshaft of the engine to pump the lowpressure fuel from the fuel tank through the intake port of the high pressure fuel pump,may be received in the pump housing of the high pressure fuel pump.
    Furthermore, the tappet 16 may be formed integrally with the plunger 6. ln the second embodiment, the communication hole 93 communicatesbetween the tappet upper side chamber 41 of the tappet receiving chamber 13 and thetappet upper side chamber 81 of the tappet receiving chamber 63. Alternatively, thecommunication hole 93 may communicate between the tappet upper side chamber 41of the tappet receiving chamber 13 and the tappet lower side chamber 82 of the tappetreceiving chamber 63, if desired. ln the second embodiment, the plunger drive mechanism 50 serves as a firstdrive mechanism of the present disclosure, and the tappet receiving chamber 13serves as a first receiving chamber of the present disclosure, which receives the firstdrive mechanism, i.e., the plunger drive mechanism 50. The cam 11, the tappet roller14, the tappet 16, and the partition wall 43 serve as the first cam, the first roller, thefirst tappet, and the first partition portion, respectively, of the present disclosure.Furthermore, the intake valve device 200a is placed next to the supply pump (highpressure fuel pump) 100 having the plunger drive mechanism (first drive mechanism)50, and the intake valve device 200a serves as a valve device of the presentdisclosure having the intake valve drive mechanism 210a as the second drivemechanism. The tappet receiving chamber 63 serves as a second receiving chamber,which receives the second drive mechanism, i.e., the intake valve drive mechanism210a. The intake cam 61, the tappet roller 64, the tappet 66 and the partition wall 83serve as the second cam, the second roller, the second tappet, and the secondpartition portion, respectively, of the present disclosure.
    Alternatively, the exhaust valve device 200b may be placed next to the supplypump 100 to serve as the valve device of the present disclosure having the exhaustvalve drive mechanism 210b as the second drive mechanism, and the intake valvedevice 200a may be placed on the other side of the exhaust valve device 200b, whichis opposite from the plunger drive mechanism 50 in the axial direction of the camshaft1, 2, to serve as a valve device having the third drive mechanism (the intake valve _24- drive mechanism 210a). ln such a case, if the phase difference between the cam 11and the exhaust cam 71 is 180 degrees, the communication hole 93 may communicatebetween the tappet upper side chamber 41 of the tappet receiving chamber 13 to thetappet upper side chamber (serving as a valve side chamber) 97 of the tappetreceiving chamber 73. Also, in such a case, the exhaust cam 71, the tappet roller 74and the tappet 76 serve as the second cam, the second roller and the second tappet,respectively, of the present disclosure. _25-
    权利要求:
    Claims (7)
    [1] 1. A Iubricating device for an internal combustion engine, comprising:a camshaft (1) that includes a cam (11) and is rotatable synchronously with anoutput shaft of the internal combustion engine;a high pressure fuel pump (100) that includes:a plunger (6), which is reciprocatable along a contour of the cam (11);anda drive mechanism (50), which converts rotation of the cam (11) intoreciprocation of the plunger (6) to reciprocate the plunger (6), wherein the highpressure fuel pump (100) pressurizes the fuel drawn through the reciprocation of theplunger (6); anda housing (3, 12) that includes a receiving chamber (13), which receives thedrive mechanism (50), wherein oil is retained in the receiving chamber (13), wherein:the drive mechanism (50) includes:a roller (14), which contacts the cam (11); anda tappet (16), which is integrally movably connected to the roller (14)and reciprocates integrally with the plunger (6); characterized in thatthe tappet (16) includes a partition portion (43), which partitions the receivingchamber (13) into a plunger side chamber (41) and a cam side chamber (42);the housing (3, 12) includes:a guide (12), which is configured into a tubular form and guides thetappet (16) in a reciprocating direction of the tappet (16): anda communication hole (53), which communicates between the plungerside chamber (41) and the cam side chamber (42); andthe cam side chamber (42) is a first volume variable chamber that is formed bya roller contact surface (37) of the cam (11), an inner peripheral surface (12a) of theguide (12), and a cam side surface (43b) of the tappet (16).
    [2] 2. The Iubricating device according to claim 1, wherein: the housing (3, 12) includes a slide surface (12b), along which an outerperipheral surface (16a) of the tappet (16) is reciprocatable and is slidable; the communication hole (53) opens only in the slide surface (12b) or a planethat is the same as a plane of the slide surface (12b). 26
    [3] 3. The lubricating device according to claim 1 or 2, comprising: a cylinder (4, 5) that reciprocatably and slidably supports the plunger (6); and a seal member (35), which is configured into a tubular form and seals a gapbetween an outer peripheral surface of the plunger (6) and an inner peripheralsurface of the cylinder (4), wherein: the plunger side chamber (41) is a second volume variable chamber that isformed by a tappet side surface (4a) of the cylinder (4, 5), a tappet side surface (35a)of the seal member (35), the inner peripheral surface (12a) of the guide (12), and a plunger side surface (43a) of the tappet (16).
    [4] 4. A lubricating device for an internal combustion engine, comprising:a camshaft (1, 2) that includes a first cam (11) and a second cam (61) and isrotated synchronously with an output shaft of the internal combustion engine;a high pressure fuel pump (100) that includes:a plunger (6), which is reciprocatable along a contour of the first cam(11); anda first drive mechanism (50), which converts rotation of the first cam(11) into reciprocation of the plunger (6) to reciprocate the plunger (6), wherein thehigh pressure fuel pump (100) pressurizes the fuel drawn through the reciprocation ofthe plunger (6);a valve device (200a) that includes:a valve (7), which is reciprocatable along a contour of the second cam(61); anda second drive mechanism (210a), which converts rotation of thesecond cam (61) into reciprocation of the valve (7) to reciprocate the valve (7),wherein the valve device (200a) opens and closes a port opening of the internalcombustion engine; anda housing (3, 12) that includes:a first receiving chamber (13), which receives the first drive mechanism(50); anda second receiving chamber (63), which receives the second drivemechanism (210a), wherein:oil is retained in the first receiving chamber (13) and the second receiving 27 Chamber (63);the first drive mechanism (50) includes:a first roller (14), which contacts the first cam (11); anda first tappet (16), which is integrally movably connected to the firstroller (14) and reciprocates integrally with the plunger (6);the second drive mechanism (210a) includes:a second roller (64), which contacts the second cam (61 ); anda second tappet (66), which is integrally movably connected to thesecond roller (64) and reciprocates integrally with the valve (7); characterized in thatthe first tappet (16) includes a first partition portion (43), which partitions thefirst receiving chamber (13) into a plunger side chamber (41) and a first cam sidechamber (42);the second tappet (66) includes a second partition portion (83), whichpartitions the second receiving chamber (63) into a valve side chamber (81) and asecond cam side chamber (82); andthe housing (3, 12) includes a communication hole (93), which communicatesthe plunger side chamber (41) to the valve side chamber (81) or the second cam sidechamber (82).
    [5] 5. The lubricating device according to claim 4, wherein the housing (3) includes aguide (12), which is configured into a tubular form and guides the first tappet (16) in a reciprocating direction of the first tappet (16).
    [6] 6. The lubricating device according to claim 4 or 5, wherein: the housing (3, 12) includes a slide surface (12b), along which an outerperipheral surface (16a) of the first tappet (16) is reciprocatable and is slidable; the communication hole (93) opens in the slide surface (12b) or a plane that isthe same as a plane of the slide surface (12b).
    [7] 7. The lubricating device according to any one of claims 4 to 6, wherein: in a case where a phase difference between the first cam (11) and the secondcam (61) is 180 degrees, the plunger side chamber (41) is communicated with thevalve side chamber (81) through the communication hole (93). 28
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    同族专利:
    公开号 | 公开日
    JP6394413B2|2018-09-26|
    US9739185B2|2017-08-22|
    US20160215663A1|2016-07-28|
    ITUB20160098A1|2017-07-20|
    JP2016133102A|2016-07-25|
    SE1650049A1|2016-07-23|
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    DE102017212498A1|2017-07-20|2019-01-24|Robert Bosch Gmbh|Piston pump, in particular high-pressure fuel pump for an internal combustion engine|
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    CN111069892B|2020-01-14|2021-02-26|安徽微威胶件集团有限公司|Automatic assembling equipment for O-shaped ring of automobile air conditioner|
    法律状态:
    2021-08-31| NUG| Patent has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    JP2015010000A|JP6394413B2|2015-01-22|2015-01-22|Lubricating device for internal combustion engine|
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