• 专利附录
  • 专利说明
  • 权利要求
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    • 专利摘要:
    pneumatic radial tire for passenger vehicle. it is a pneumatic radial tire for a passenger vehicle, having: a cross-sectional width sw and an outside diameter od controlled under an appropriate sw-od ratio; and an optimized setting of a part of his crown.
    公开号:BR112014010358B1
    申请号:R112014010358-5
    申请日:2012-11-02
    公开日:2021-07-20
    发明作者:Kohei Hasegawa；Isao Kuwayama
    申请人:Bridgestone Corporation；
    IPC主号:
    专利说明:

    FIELD OF TECHNIQUE
    [0001] The present invention relates to a radial tire for a passenger vehicle. FUNDAMENTALS OF THE TECHNIQUE
    [0002] Diagonal tires that have relatively narrow cross-sectional widths were predominantly used on vehicles until around 1960 because vehicles at that time were relatively light, had relatively low cruising speed required of them, and therefore did not exert much strain on the vehicles. tires. However, radial tires with wide, flat structures are prevalent these days due to the fact that good steering stability on the high-speed course, as well as good wear resistance, is required of tires as the nets of roads are developed and vehicle speed increases (eg PTL 1).
    [0003] However, the increasing widths of tires decrease the free spaces in a vehicle and worsen the comfort in them. This is becoming a big problem because electric vehicles that have been developed for use in recent years, in particular, must have enough space to accommodate drive units such as a motor to control the torque of rotating tires around the drive shafts. and, in this sense, ensuring sufficient space around their tires is increasingly important.
    [0004] Furthermore, there has been an increasing demand for better fuel efficiency in recent years as people become more concerned about environmental issues. It is conventionally known that increasing the diameter and width of a tire is effective in terms of decreasing the rolling resistance value (RR value) of the tire for the best fuel efficiency of the tire. Increasing the diameter and width of a tire, however, also increases the tire width and air resistance of a vehicle, thereby resulting in an increase in the resistance experienced by the vehicle and too much load on the tire.
    [0005] In this sense, decreasing the diameter and width of a tire to reduce its weight results, then, in worsening the controllability of the tire.CITATION LISTPatent LiteraturePTL 1: JP-A 07-040706 SUMMARY OF THE INVENTION Problems of the Technique
    [0006] It is, in general, difficult to achieve good fuel efficiency, good comfort in a vehicle (free space in a vehicle) and other good performances of a tire simultaneously in a compatible manner, as described above. A technique to comprehensively improve these performances in a compatible way, therefore, was demanded.
    [0007] The present invention aims to solve the problems described above and an object of it is to provide a radial tire for a passenger vehicle in which the durability and wear resistance of the tire have been improved with the guarantee of high fuel efficiency and ample space free in a vehicle. Solution to Problem
    [0008] The inventors of the present invention have studied intensively to solve the problems described above.
    [0009] As a result, the inventors first discovered that by reducing a tire width and increasing a tire diameter or, more specifically, controlling a cross section width SW and an outside diameter OD of a radial tire under an appropriate SW-OD ratio it is very effective in terms of ensuring good fuel efficiency and ample headroom for a vehicle using the radial tyre.
    [0010] Furthermore, the inventors have again found that it is effective to optimize the configuration of a crown portion of a radial tire that has small width and large diameter in terms of improving the tire's durability and wear resistance.
    [0011] The present invention was designed based on the aforementioned findings and the main structural features are as follows.
    [0012] (1) A radial tire for a passenger vehicle, provided with a carcass consisting of plies such as radially arranged carcass cords and provided in a toroidal shape through a pair of bead parts, a strap consisting of at least one belt layer, and at least one belt reinforcement layer such as a rubber coated cord layer extending in the circumferential direction of the tyre, the belt and the belt reinforcement layer being provided on the outer side in the radial direction of the tyre. carcass tire, characterized by the fact that: since SW and OD represent the cross-sectional width and outer diameter of the tire, respectively, SW and OD satisfy a formula shown below:OD > - 0.0187 x SW2 + 9, 15 x SW - 380; and, given that, in a cross section in the tire width direction: m1 represents an imaginary line that passes through a point P on a tread surface in the tire's equatorial plane and extends parallel to the tire width direction. tire; m2 represents an imaginary line passing through a ground contact end E and extending parallel to the tire width direction; LCR represents a distance in the radial direction of the tire between line m1 and line m2; and TW represents a tire tread width, an LCR/TW ratio < 0.045. ADVANTAGEOUS EFFECT OF THE INVENTION
    [0013] According to the present invention, it is possible to provide a radial tire for a passenger vehicle that has excellent durability and wear resistance, ensuring high fuel efficiency and ample space available in a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS
    [0014] Figure 1 is a view showing a cross-sectional width SW and an outer diameter OD of a tire.
    [0015] Figure 2A is a view showing a vehicle provided with tires of the present invention with large diameters and narrow widths fitted to it. Figure 2B is a view showing a vehicle having conventional tires fitted to it.
    [0016] Figure 3 is a schematic cross-sectional view of a half-part of a radial tire used in a test in the present invention.
    [0017] Figure 4A is a graph showing the relationships between SW and OD observed in the test tires of the present invention and in conventional test tires.
    [0018] Figure 4B is a graph showing a relationship between SW and OD observed in test tires of the present invention and in conventional test tires.
    [0019] Figure 5 is a graph showing a relationship between the rolling resistance value and the air resistance value in each of the test tires.
    [0020] Figure 6 is a schematic cross-sectional view of a half-part of a radial tire according to an embodiment of the present invention. DESCRIPTION OF MODALITIES
    [0021] How a radial tire for a passenger vehicle of the present invention (which tire will be referred to as simply a "tire" hereinafter) was envisioned will be described below.
    [0022] First, the inventors of the present invention paid attention to a fact that a SW tire cross-sectional width (see Figure 1) of a radial tire smaller than that of a conventional radial tire ensures ample free space in a vehicle , ample space to accommodate a drive member in the vicinity of the vehicle's inner side of the particular tire (see Figures 2A and 2B).
    [0023] A tire SW tire cross-section width of a radial tire smaller than that of a conventional radial tire also has a good effect of reducing an air resistance value (Cd value) of the vehicle because an area of the tire seen in front of it decreases.
    [0024] However, there is a demerit in this case that a rolling resistance value (RR value) of the tire increases due to an increase in deformation magnitude of a tread ground contact portion when the pressure of tire's internal air remains the same.
    [0025] The inventors of the present invention, in view of the situation mentioned above, found that the problem can be solved by using the inherent characteristics of a radial tire. Specifically, the inventors of the present invention realized that, in the case of a radial tire having a tread deformation magnitude smaller than a diagonal tyre, it is possible to make the radial tire less affected by a hard and, road surface. then, reduce a rolling resistance value (RR value) of it when the inner air pressure remains the same by increasing the outer diameter OD (see Figure 1) of the radial tire compared to the conventional radial tire. Furthermore, the inventors of the present invention also realized that an increase in OD outside diameter of a radial tire enhances the tire's loading capacity. Still additionally, an increase in outer diameter of a radial tire increases the height of the drive axles to widen a space under the chassis, as shown in Figure 2A, thereby allowing the vehicle to maintain ample spaces for a car trunk. , drive units and the like.
    [0026] In short, reducing the width and increasing the outer diameter of a tire effectively ensures ample space in a vehicle, respectively, even though they are in a trade-off in terms of a rolling resistance value (RR value) . Reducing the tire width also successfully lowers an air resistance value (Cd value) of a vehicle.
    [0027] In view of this, the inventors of the present invention have intensively studied to optimize a relationship between a tire cross-section width and an outside diameter of a tire such that an air resistance value (Cd value) and a resistance value of bearing (RR value) of a vehicle improves compared to a conventional radial tyre.
    [0028] Specifically, the inventors of the present invention, paying attention to a relationship between a SW tire cross-sectional width and an OD outside diameter of a tire, performed a test that includes fitting test tires of various tire sizes ( some of them were non-standard products) on a vehicle and measure an air resistance value (Cd value) and a rolling resistance value (RR value) for each type or size of test tires. A condition satisfied by SW and OD when both an air resistance value and a rolling resistance value were higher than those of the conventional radial tire was empirically deduced based on the measurement results.
    [0029] The results of the experiment from which the optimal relationship between SW and OD was obtained will be described in detail hereafter.
    [0030] Figure 3 is a schematic cross-sectional view, in the tire width direction, of a tire used in the aforementioned test. Figure 3 shows only a half-part with respect to the equatorial plane of the tire CL tire. The other half part of the tire basically shares the same structure as the half part and therefore its illustration will be omitted.
    [0031] Figure 3 shows a tire in a state in which the tire has been mounted with an edge and inflated at the prescribed air pressure for each vehicle in which the tire must be fitted without load exerted on it.
    [0032] A plurality of pneumatic radial tires, each having a pair of bead parts 1 and a carcass 2 radially arranged to extend in a toroidal shape through the pair of bead parts 1 as shown in Figure 3, was prepared as test tires of various tire sizes.
    [0033] The tire shown in an exemplary manner in Figure 3 has the carcass 2 made of organic fibers, a belt 3 made up of at least one layer of the belt (two layers of the belt 3a, 3b in Figure 3) and a tread 4 such that the belt 3 and the tread 4 are provided on the outer side in the radial direction of the tire of a part of the crown of the carcass 2 in this order. The two strap layers 3a, 3b shown in Figure 3 are slanted strap layers provided that the strap strands of one layer intersect the strap strands of the other layer alternately and that the strap strands of each layer are slanted at an angle of slope in the range of ±20° to ±75° with respect to the equatorial plane of the CL tire. In addition, the tire shown exemplarily in Figure 3 has at least one belt reinforcement layer 5 (a single layer in Figure 3) as a rubber-coated cord layer in which the cords are spirally wound along the plane. tire CL to extend substantially in the circumferential direction of the tire such that the belt reinforcement layer 5 is disposed on the outer side in the radial direction of the tire of the belt layer 3.
    [0034] The reinforcement layer of the strap 5 can be formed by using the custom-made cords or organic fibers such as nylon, Kevlar® or the like. The brace reinforcement layer 5 shown in an exemplary manner in Figure 3 includes the cords made of nylon and provided with Young's modulus: 3.2 GPa and fineness: 1400 dtex such that the cords are implanted in the brace reinforcement layer in the amount of cord implantation of 50 (quantity of cords/50 mm). The "Young's modulus" represents the Young's modulus to be determined by a test in accordance with JIS L1017 8.5 a) (2002) and calculated in accordance with JIS L1017 8.8 (2002) in the present invention. The same structural principles as described are applied to each of the test tires of the present invention.
    [0035] A plurality of main grooves 6, each extending in the circumferential direction of the tyre, are formed on the tread 4 (a main groove in each part by half of the tire shown exemplarily in Figure 3).
    [0036] In the tire as shown by way of example in Figure 3, a ratio W1/W2 of a width W1 in the direction of the tire width of the belt reinforcement layer 5 with respect to a width W2 in the direction of the tire width of the layer of the strap 3a which has the width in the narrowest tire width direction among the layers of the strap 3 strap is 1.1. Such strap layer as strap layer 3a may occasionally be referred to as "the narrowest width strap layer" hereinafter. The "width W1" and "width W2" described above each represent a corresponding width measured in a state in which the tire has been mounted with a rim and inflated to the prescribed air pressure for each vehicle in which the tire is to be fitted no load exerted on it.
    [0037] Furthermore, an LCR/TW ratio of an LCR distance with respect to a tread width TW, as defined above, is 0.05 on the tire as shown in Figure 3.
    [0038] Numerous test tires with various widths in cross section and outside diameters were prepared based on the tire structures described above.
    [0039] First, a tire with tire size: 195/65R15 was prepared as Reference Tire 1, whose tire size is used in vehicles of the most common types and then suitable for comparison of tire performances. Also prepared as Reference Tire 2 was a tire with tire size: 225/45R17, which is what is called an “inch-up” (diameter increase) version of the Reference Tire 1.
    [0040] Furthermore, other test tires (test tires 1 to 52 and conventional test tires 1 to 9) of various tire sizes were prepared. These test tires were each mounted with a rim, inflated to an internal pressure of 220 kPa and subjected to the tests described below.
    [0041] Table 1 shows the relevant characteristics of the respective test tires.
    [0042] With regard to tire sizes, a variety of tire sizes, including the conventional sizes prescribed by JATMA (The Japan Automobile Tire Manufacturers Association, Inc.) in Japan, TRA (THE TIRE AND RIM ASSOCIATION INC.) in the United States , ETRTO (European Tire and Rim Technical Organisation) in Europe and the like and those beyond these conventional sizes have been extensively studied.
    [0043] Table 1-1



    [0044] Table 1-2


    [0045] Rolling resistance was measured by: mounting each of the test tires described above with a rim to obtain an inflated tire rim mounting at the internal pressure as shown in Tables 21 and 2-2; exert in the rim and tire assembly the maximum load prescribed for a vehicle in which the tire is fitted; and run the tire at the drum rotation speed of 100 km/hour to measure a rolling resistance of the tire.
    [0046] The evaluation results have been shown as index values relative to “100” of Reference Tire 1. The lowest index value represents the lowest rolling resistance.<value (Cd) Vehicle air resistance>
    [0047] Air resistance was determined by: mounting each of the test tires described above with a rim to obtain an inflated tire rim mounting at the internal pressure as shown in Tables 2-1 and 2-2; fit rim and tire mount onto a 1,500cc displacement vehicle; and blasting air into the tire at a speed corresponding to 100 km/hour and measuring an air pressure value experienced by the tire by a scale installed on the ground under the tire. The results were converted to the index values relating to “100” of the Tire reference 1 for the evaluation. The smallest index value represents the smallest air resistance.
    [0048] The results of the evaluation are shown in Tables 2-1, 2-2 and in Figures 4A, 4B.
    [0049] Table 2-1



    [0050] Table 2-2



    [0051] It was revealed from the test results shown in Tables 2-1 and 2-2, in Figure 4A and in Figure 5 that a radial tire satisfactorily exhibits low air resistance value (Cd value) and value of rolling resistance (RR value) in a compatible manner in a state where the tire is fitted to a vehicle, compared to the Reference Tire 1 which has the tire size: 195/65R15 as the conventional tire, when the tire has a tire size that satisfies the following formulas (whose formulas will be referred to as “ratio formulas (1)” hereinafter), provided that SW and OD represent the cross-sectional width and outside diameter of the tire, respectively.SW /OD < 0.26 when SW < 165 (mm); eOD > 2.135 x SW + 282.3 when SW > 165 (mm)
    [0052] Figure 4A shows limits (limits according to linear equations) that differentiate the test tires each exhibiting a good effect of reducing both the rolling resistance value (RR value) and the air resistance value ( Cd value) of it in a way compatible from the test tires that do not cause the effect in a satisfactory manner. Specifically, one of the limits consists of a line that expresses OD = (1/0.26) x SW when SW < 165 (mm) and a line that expresses OD = 2.135 x SW + 282.3 when SW > 165 (mm) ).
    [0053] It was revealed from the test results shown in Tables 2-1 and 2-2, in Figure 4B and in Figure 5 that a radial tire satisfactorily exhibits low air resistance values (Cd value) and rolling resistance value (RR value) in a compatible manner in a state where the tire is fitted to a vehicle, compared to the Reference Tire 1 which has the tire size: 195/65R15 as the conventional tire, when the tire, inflated to internal pressure > 250 kPa, has a tire size that satisfies the following formula (which formula will be referred to as “ratio formula (2)” hereinafter), provided that SW and OD represent the width of the cross section and the outside diameter of the tire, respectively.OD > - 0.0187 x SW2 + 9.15 x SW - 380
    [0054] Figure 4B shows a limit (a limit according to a quadratic equation) that differentiates the test tires each exhibiting a good effect of reducing both the rolling resistance value (RR value) and the resistance value. air (Cd value) from it in a compatible manner from the test tires which do not cause the effect in a satisfactory manner. Specifically, the limit is constituted by a quadratic curve that expresses OD = - 0.0187 x SW2 + 9.15 x SW - 380.
    [0055] Furthermore, the inventors of the present invention have found that test tires 1 to 7 and 17, each satisfying SW/OD < 0.24, more reliably obtain the good effect mentioned above than the other test tires , as shown in Tables 2-1, 2-2 and Figures 4A and 5.
    [0056] Then, the following tests were performed for each of the test tires 1 to 18 in order to assess the fuel efficiency and comfort (degree of free space) of a vehicle in which the tire was fitted.<Economy of fuel in use>
    [0057] A test was performed based on the JOC 8 test cycle prescribed by Ministry of Land, Infrastructure, Transport and Tourism (MLIT) of Japan.
    [0058] The evaluation results were shown as the index values relative to “100” of the Reference Tire 1. The higher index value represents the best fuel efficiency.<Comfortability>
    [0059] Each of the test tires was fitted to a vehicle that is 1.7 m wide and the resulting width of the rear trunk was measured. The evaluation results were shown as the index values relative to “100” of the Reference Tire 1. The higher index value represents the best comfort.
    [0060] The test results thus obtained are shown in Table 3 below.
    [0061] Table 3


    [0062] It is understood from Table 3 that some of the test tires that do not satisfy neither the ratio formula (1) nor the ratio formula (2) (see Figures 4A and 4B) exhibited worse results than the benchmark 1 in at least one of fuel efficiency and comfort. In contrast, test tires 1 to 7, 12 and 17 (see Figures 4A and 4B) that satisfy at least one of ratio formulas (1) and ratio formula (2) unanimously exhibited the best results than the benchmark Tire 1 in both fuel efficiency and comfort.
    [0063] The inventors of the present invention revealed from the findings described above that it is possible to reduce both the air resistance value and the rolling resistance value of a radial tire in a state where the tire is fitted to a vehicle and also enhances fuel efficiency and vehicle comfort by adjusting the tire's SW cross-section width and tire OD outside diameter to satisfy the ratio formulas (1) and/or the ratio formula (2) mentioned above.
    [0064] In this regard, the inventors of the present invention have noted that the tire that satisfies the ratio formulas (1) and/or the ratio formula (2) mentioned above experiences a problem inherent in a tire having a narrow width and a large diameter that: a force input (pressure) from a road surface increases due to a narrower width or a decrease in a contact area with the tire floor, thereby increasing a tread deflection rate in the direction tire radial to increase the amount of tension between the belt and the belt reinforcement layer when the tire is rotated, which facilitates the occurrence of separation between the belt and the belt reinforcement layer to worsen the tire durability and also causes the shear force generated in the rubber between the belt to settle on the belt reinforcement layer non-uniform in the circumferential directions of the tire width, i.e., it makes the contactor pressure distribution non-uniform, for p improve the wear resistance properties of the tyre. The inventors did a thorough study to solve this problem and found a tire structure that could solve the problem.
    [0065] Tire structure for improving the durability and wear resistance of a radial tire for a passenger vehicle that satisfies the ratio formulas (1) and/or the ratio formula (2) mentioned above, then discovered, will be described hereafter.
    [0066] Figure 6 is a schematic cross-sectional view, in the tire width direction, of a tire according to an embodiment of the present invention. Figure 6 shows only a half-part with respect to the equatorial plane of the tire CL tire. The other half part of the tire basically shares the same structure as the half part and therefore its illustration will be omitted.
    [0067] Figure 6 shows a tire in a state in which the tire has been mounted with an edge and inflated at the prescribed air pressure for each vehicle in which the tire must be fitted without load exerted on it.
    [0068] As shown in Figure 6, it is established that, in a cross section in the tire width direction: P represents a point on a tread surface in the equatorial plane of the tire CL; m1 represents an imaginary line that passes through a point P and extends parallel to the tire width direction; m2 represents an imaginary line that passes through a ground contact edge E and extends parallel to the tire width direction; tire; LCR represents a distance in the radial direction of the tire between the m1 line and the m2 line; and TW represents a tire tread width, an LCR/TW ratio is equal to or less than 0.045. The tire shown illustratively in Figure 6 is different from the tire shown illustratively in Figure 3 in this regard.
    [0069] In the tire shown as an example in Figure 6, a W1/W2 ratio of a width W1 in the direction of the tire width of the belt reinforcement layer 8 with respect to a width W2 in the direction of the tire width of the layer strap with the narrowest width 7a of the two layers of strap 7a, 7b constituting strap 7 satisfies 0.8 < W1/W2 < 1.05. The tire shown by way of example in Figure 6 is different from the tire shown by way of example in Figure 3 in this sense as well.
    [0070] It is extremely important that the LCR/TW ratio is equal to or less than 0.045 in the tire of the present invention, as described above.
    [0071] Other structures and the like of the tire shown in Figure 6 are basically the same as those of the tire shown in Figure 3.
    [0072] The "width W1 in the tire width direction of the belt reinforcement layer 8" represents a width in the tire width direction of the belt reinforcement layer that has the width of the tire width direction narrowest in a in which case there are a plurality of band reinforcement layers.
    [0073] An effect of the present invention will be described hereinafter.
    [0074] According to the present invention, a part of the tire tread crown is made flat and an area of contact with the ground thereof increases so that an input of force (pressure) from a road surface is softened and a tread deflection rate in the tire's radial direction decrease to improve the tire's durability and wear resistance by adjusting the LCR/TW ratio to be in the aforementioned range.
    [0075] The LCR/TW ratio > 0.045 fails to ensure a satisfactorily large ground contact area, thereby increasing a tread reflection rate to worsen tire durability and wear resistance, as described above. The LCR/TW ratio < 0.04 is preferable in terms of more reliability to get good durability and wear resistance of the tire.
    [0076] On the other hand, the LCR/TW ratio > 0.025 is preferable in terms of avoiding deterioration of the ground contact properties and ensuring good performances in directional power, wear resistance and fuel efficiency of the tire .
    [0077] The Young's modulus of the strands of the reinforcement layer of the strap 8 is preferably > 15,000 MPa in the present invention.
    [0078] Young's modulus of the strand reinforcement layer cords 8 > 15,000 MPa intensifies the stiffness of the tire ring to suppress its deformation in the circumferential direction of the tire, thereby suppressing its deformation in the tire width direction , too, due to the inability to compress the rubber.
    [0079] As a result, a relatively wide region in the circumferential direction of the tire from a contact surface of the ground is deformed by an input of force in the direction of the width of the tire from a road surface, whereby the surface of Ground contact assumes a configuration where the length of ground contact in the circumferential direction of the tire does not change as much in the direction of the tire width.
    [0080] In this way, the wear resistance and partial turn power of the tire are improved in this case.
    [0081] In this sense, the very high Young's modulus of cords of the reinforcement layer of the belt 8 decreases the length of contact with the tread floor as a whole and worsens the maximum turning force. The Young's modulus of cords of the reinforcement layer of the belt 8 is therefore preferably < 30,000 MPa.
    [0082] In addition, each belt layer 7a, 7b is an inclined belt layer that includes the belt cords that extend to be inclined at an angle > 45° with respect to the circumferential direction of the tire and the belt 7 consists of a plurality of the slanted strap layers 7a, 7b such that the strap strands of one slanted strap layer intersect the strap strands of the other slanted strap layer alternatively.
    [0083] The belt layer preferably has the structure described above because the belt cords arranged to be inclined at a large angle with respect to the circumferential direction of the tire decreases out-of-plane bending stiffness in the circumferential direction of the tread tire , increases the elongation in the circumferential direction of the rubber tire when a tread floor contact surface is deformed and then successfully suppresses a decrease in the tire's floor contact length, thereby improving the directional power and the partial wear resistance of the tyre.
    [0084] In this sense, the angle of inclination of the belt strands of the belt layer with respect to the circumferential direction of the tire is preferably < 75° in terms of avoiding deterioration of the ground contact properties and ensuring good performances in power change of direction, wear resistance and fuel efficiency of the tyre.
    [0085] In the tire of the present invention, a W1/W2 ratio of a width W1 in the direction of the tire width of the belt reinforcement layer 8 with respect to a width W2 in the direction of the tire width of the belt layer with the width narrower 7a of the two layers of the strap 7a, 7b making up the strap 7 preferably satisfies 0.8 < W1/W2 < 1.05, as shown in Figure 6.
    [0086] The ratio W1/W2 is preferably < 1.05 because a width of the reinforcement layer of the strap is made substantially equal to or slightly narrower than a width of the layer of the strap with the narrowest width, which not only decreases the stiffness of the belt reinforcement layer to reduce the tension generated due to the difference in stiffness between the belt and the belt reinforcement layer and also suppress the deterioration of tire durability caused by tension, as well as causing the shear force generated in the rubber between the belt lays the uniform belt reinforcement layer in the circumferential direction of the tire to further improve the wear resistance properties of the tire. Furthermore, the W1/W2 ratio < 1.05 improves the tire's ground contact properties, thereby improving the tire's turn power, turn force and fuel efficiency as well.
    [0087] On the other hand, the W1/W2 ratio > 0.8 prevents a belt reinforcement layer width from being too narrow, satisfactorily ensures high ring stiffness and thus reliably achieves good wear resistance and power tire direction change.
    [0088] The width W2 is preferably 0.85 to 1.10 times the size of the tread width TW.
    [0089] The tire of the present invention preferably has the air volume > 15,000 cm3 because a tire for a passenger vehicle must have an air volume > 15,000 cm3 in order to reliably have the minimum loading capacity essentially required for a car of passenger walking on public roads. Examples
    [0090] The test tires of Examples 1 to 5 and the test tires of Comparative Examples 1 to 4 were prepared and subjected to the tests described below to evaluate the various performances of the tires in order to confirm an effect of the present invention.
    [0091] Specifically, each of the test tires of Examples 1 to 5 and Comparative Examples 1 to 4 has a pair of bead parts and a casing provided to extend in a toroidal shape through the pair of bead parts, as per shown in Figure 3 and Figure 6, respectively.
    [0092] In addition, the test tire has a belt consisting of two belt layers, a belt reinforcement layer, and a tread provided on the outer side in the radial direction of the carcass tire in that order.
    [0093] The two layers of the strap are slanted strap layers provided such that the strap cords of one layer intersect the strap cords of the other layer alternatively and that the cords such as the strap cords of each layer extend to be slanted in a tilt angle of ±60° with respect to the circumferential direction of the tire.
    [0094] The strap reinforcement layer cords are made of nylon and extend substantially in the circumferential direction of the tire.<Rolling resistance (RR value)>
    [0095] Rolling resistance was measured by: inflating each of the test tires to the air pressure as prescribed for each vehicle on which the tire was to be fitted; exert on the tire 80% of the maximum load prescribed for a vehicle in which the tire should be fitted; and run the tire at the drum rotation speed of 100 km/hour to measure a rolling resistance of the tire.
    [0096] The evaluation results were shown as index values relative to “100” from Comparative Example 3. The lowest index value represents the lowest rolling resistance.<Durability>
    [0097] Durability was measured by: inflating each of the test tires to the air pressure as prescribed for each vehicle on which the tire was to be fitted; exert on the tire the maximum load prescribed for the vehicle in which the tire should be fitted; subject the tire to a drum durability test at a high speed, ie run the tire on a drum under the conditions mentioned above and increase the speed from 120 km/hour gradually by 10 km/hour every 5 minutes until the tire has a problem; record the speed at which the problem occurred as a measurement value to assess the tire's durability. The evaluation results are shown as index values relative to “100” representing the speed at which a problem occurred in the tire from Comparative Example 3. The higher index value represents the best durability.
    [0098] The turn power of each test tire was measured by using a flat belt type tire testing apparatus to measure its turn characteristics at air pressure and under maximum load as prescribed for each vehicle on which the tire was to be fitted, at the drum rotation speed of 100 km/hour.
    [0099] The then measured turn power values were converted into index values with respect to the “100” turn power value of the tire Comparative Example 3 for evaluation. The largest index value represents the greatest and, therefore, most preferable power of turn. <Wear resistance>
    [00100] The wear resistance of each test tire was determined by: running the tire 30,000 km on a drum testing machine at 80 km/hour at air pressure and under maximum load as respectively prescribed for each vehicle on which the tire was to be fitted; and measuring a depth of groove remaining after running on the drum as a wear resistance value. The wear resistance value so measured was converted into index values with respect to the wear resistance value “100” of the tire from Comparative Example 3 for evaluation. The highest index value represents the best wear resistance.
    [00101] The relevant characteristics and evaluation results of the respective test tires are shown in Table 4.

    [00102] It is understood from Table 4 that the tires of Examples 1 to 5 unanimously exhibit the lowest rolling resistance values and better or longer durability, directional power and wear resistance values of the than the tires in Comparative Examples 1 and 3.
    [00103] Furthermore, it is understood from the comparison of Example 2 with Comparative Example 2 in Table 4 that the tire of Example 2 in which the SW and OD ratio was optimized exhibits a lower and better rolling resistance value or greater durability, directional power and wear resistance values than the tire in Comparative Example 2.
    [00104] Still further, it is understood from the comparison of Example 2 with Comparative Example 4 in Table 4 that the tire of Example 2 in which the LCR/TW ratio was optimized exhibits lower rolling resistance value and better or longer durability, directional power and wear resistance values than the tire in Comparative Example 4.
    [00105] LIST OF REFERENCE NUMBERS
    [00106] 1 Part of bead;
    [00107] 2 Carcass
    [00108] 3 Strap
    [00109] 3rd Strap layer with narrowest width
    [00110] 4 Tread
    [00111] 5 Strap reinforcement layer
    [00112] 6 Main groove
    [00113] 7 Strap
    [00114] 7th Strap layer with the most width
    [00115] 8 Strap reinforcement layer
    [00116] TW Tread width
    [00117] CL Equatorial plane of the tire
    [00118] E End of contact with ground.narrow
    权利要求:
    Claims (7)
    [0001]
    1. Radial tire for a passenger vehicle, having a carcass (2) made up of plies such as carcass cords arranged radially and provided in a toroidal shape over a pair of bead parts (1), a strap (3) made up of fur. at least one belt layer, and at least one belt reinforcement layer (5) such as a rubber coated cord layer extends in the circumferential direction of the tire, the belt and the belt reinforcement layer being provided on the outer side in the direction carcass tire radial, characterized by the fact that: since SW and OD represent the cross-sectional width and outer diameter of the tire, respectively, SW and OD satisfy a formula shown below: OD > - 0.0187 x SW2 + 9.15 x SW - 380; and, given that, in a cross section in the tire width direction: m1 represents an imaginary line that passes through a point P on a tread surface in the tire's equatorial plane and extends parallel to the tire width direction. tire; m2 represents an imaginary line passing through a ground contact end E and extending parallel to the tire width direction; LCR represents a distance in the radial direction of the tire between line m1 and line m2; and TW represents a tire tread width, an LCR/TW ratio < 0.045; and a W1/W2 ratio of a W1 width, in the direction of the tire width of the belt reinforcement layer, with respect to a W2 width, in the direction of the tire width of the belt layer having the narrowest width among the at least a layer of strap constituting the strap satisfies 0.8 < W1/W2 < 1.05.
    [0002]
    2. Radial tire for a passenger vehicle, according to claim 1, characterized in that SW/OD < 0.24.
    [0003]
    3. Radial tire for a passenger vehicle, according to claim 1 or 2, characterized in that the Young's modulus of the cords of the belt reinforcement layer is > 15,000 MPa.
    [0004]
    4. Radial tire for a passenger vehicle according to any one of the preceding claims, characterized in that each strap layer is an inclined strap layer that includes strap cords that extend to be inclined at an angle > 45° with respect to the circumferential direction of the tyre, and the belt is made up of a plurality of tapered belt layers, such that the belt cords of one tapered belt layer intersect the belt cords of the other tapered belt layer alternately.
    [0005]
    5. Radial tire for a passenger vehicle, according to any one of the preceding claims, characterized by the fact that the LCR/TW ratio > 0.025.
    [0006]
    6. Radial tire for a passenger vehicle, according to any one of the preceding claims, characterized in that the width W2 is 0.85 to 1.10 times greater than the tread width TW.
    [0007]
    7. Radial tire for a passenger vehicle, according to any one of the preceding claims, characterized in that a tire size is one of: 105/50R16, 115/50R17, 125155R20, 125/65R19, 135/45R21, 135 /55R20, 135/60R17, 135/65R13,145/45R21, 145/55R20, 145/60R16, 145/65R19, 155/45R18,155/45R21, 155/55R19, 155/55R21, 155/60R17, 155/65R13 ,155/65R18, 155/70R17, 165/45R22, 165.55R16, 165/55R18,165/55R19, 165/55R20, 165/55R21, 165/65R19, 165/70R18,175/45R23, 175/55R19, 175 /55R22, 175/60R18, 175/65R15,185/45R22, 185/50R16, 185/50R20, 185/60R17, 185/60R20.195/55R19, 195/65R17, 205/55R16, 205/60R16, 205/60R18 ,215/54R21, 215/60R17, 225/65R17.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR2082137A5|1970-03-04|1971-12-10|Englebert|
    JPS567888B2|1976-04-16|1981-02-20|
    JPS5340903A|1976-09-22|1978-04-13|Yokohama Rubber Co Ltd:The|Automotive tire|
    SE7807695L|1978-07-10|1980-01-11|Ifm Akustikbyran Ab|VEHICLE DECK|
    JPS60148702A|1984-01-13|1985-08-06|Bridgestone Corp|Pneumatic tyre of vehicle|
    US4688615A|1985-05-28|1987-08-25|The Goodyear Tire & Rubber Company|Reinforcing structure for a rubber article|
    EP0370699B1|1988-11-21|1993-06-02|Sumitomo Rubber Industries Ltd.|Vehicle tyre|
    JP2800943B2|1989-10-02|1998-09-21|住友ゴム工業株式会社|Pneumatic tire|
    JP2800944B2|1989-10-12|1998-09-21|住友ゴム工業株式会社|Pneumatic tire|
    JP2878356B2|1989-12-26|1999-04-05|株式会社ブリヂストン|Heavy duty pneumatic tires|
    JPH03213404A|1990-01-16|1991-09-18|Sumitomo Rubber Ind Ltd|Spare tire|
    US5178703A|1990-10-24|1993-01-12|Sumitomo Rubber Industries, Ltd.|Breaker with wound band|
    JP3426289B2|1993-07-28|2003-07-14|株式会社ブリヂストン|High performance flat pneumatic radial tire|
    JPH07242105A|1994-03-04|1995-09-19|Bridgestone Corp|Pheumatic tire for heavy cargo|
    FR2719525B1|1994-05-06|1996-06-07|Michelin & Cie|Spare wheel and its tire.|
    BG61716B1|1995-09-08|1998-04-30|"Видахим" Ад|Pneumatic tyre for agricultural purposes|
    JP3165651B2|1996-02-14|2001-05-14|住友ゴム工業株式会社|Pneumatic radial tire|
    JPH10109502A|1996-10-07|1998-04-28|Yokohama Rubber Co Ltd:The|Pneumatic radial tyre|
    US6481479B1|1997-08-25|2002-11-19|The Goodyear Tire & Rubber Company|High aspect agricultural or off-road tire|
    JP4266053B2|1998-12-28|2009-05-20|株式会社ブリヂストン|Pneumatic tire|
    JP2001121915A|1999-10-25|2001-05-08|Bridgestone Corp|Pneumatic tire|
    JP2001171318A|1999-12-17|2001-06-26|Toyo Tire & Rubber Co Ltd|Pneumatic radial tire|
    AT294713T|2001-04-16|2005-05-15|Michelin Soc Tech|ELASTIC SELF-WEARING TIRE WITH CROP WEAVE INSERT|
    JP4436146B2|2004-02-03|2010-03-24|住友ゴム工業株式会社|Passenger car tires|
    JP4540487B2|2005-01-13|2010-09-08|株式会社ブリヂストン|Pneumatic tire|
    JP4959194B2|2006-01-13|2012-06-20|株式会社ブリヂストン|Pneumatic tire|
    WO2008102667A1|2007-02-23|2008-08-28|Bridgestone Corporation|Pneumatic radial tire|
    JP5410038B2|2007-12-17|2014-02-05|株式会社ブリヂストン|Pneumatic tire|
    JP2009279948A|2008-05-19|2009-12-03|Bridgestone Corp|Pneumatic tire|
    JP2010047191A|2008-08-22|2010-03-04|Bridgestone Corp|Treated member and radial tire|
    JP5249843B2|2009-04-22|2013-07-31|株式会社ブリヂストン|Pneumatic tire|
    JP5714832B2|2010-03-29|2015-05-07|株式会社ブリヂストン|tire|
    JP5758911B2|2010-11-15|2015-08-05|株式会社ブリヂストン|Pneumatic radial tire for passenger cars|JP6175427B2|2012-04-24|2017-08-02|株式会社ブリヂストン|Pneumatic tire|
    JP6196494B2|2013-08-09|2017-09-13|住友ゴム工業株式会社|Pneumatic tire|
    US10836213B2|2013-10-29|2020-11-17|Bridgestone Corporation|Tire|
    CN105682939B|2013-10-29|2018-10-19|株式会社普利司通|Tire|
    JP2015093551A|2013-11-11|2015-05-18|住友ゴム工業株式会社|Pneumatic tire|
    JP6348713B2|2014-01-09|2018-06-27|住友ゴム工業株式会社|Pneumatic tire|
    JP5928524B2|2014-05-20|2016-06-01|横浜ゴム株式会社|Pneumatic tire|
    JP5928525B2|2014-05-20|2016-06-01|横浜ゴム株式会社|Pneumatic tire|
    EP3130483B1|2014-05-29|2018-08-01|Bridgestone Corporation|Pneumatic tire|
    JP6480699B2|2014-10-03|2019-03-13|株式会社ブリヂストン|Run flat tire|
    JP6408333B2|2014-10-03|2018-10-17|株式会社ブリヂストン|Run flat tire|
    JP6480698B2|2014-10-03|2019-03-13|株式会社ブリヂストン|Run flat tire|
    JP6587825B2|2015-05-13|2019-10-09|株式会社ブリヂストン|Pneumatic tires for passenger cars|
    FR3042740B1|2015-10-27|2017-11-24|Michelin & Cie|PNEUMATIC WORKING LAYER COMPRISING MONOFILAMENTS AND GROOVED ROLLING BELT|
    CN111016545A|2019-12-31|2020-04-17|安徽佳通乘用子午线轮胎有限公司|Radial tire capable of resisting lateral sliding abrasion of tire|
    法律状态:
    2018-12-04| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-11-05| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-10-06| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application [chapter 6.1 patent gazette]|
    2021-05-11| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-07-20| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 02/11/2012, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    JP2011-241672|2011-11-02|
    JP2011241672|2011-11-02|
    PCT/JP2012/007052|WO2013065322A1|2011-11-02|2012-11-02|Pneumatic radial tire for passenger car|
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