• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a hydraulic system (1) for an industrial truck with a hydraulic lifting device (2) and at least one further hydraulic consumer (4; 4a; 5), where for feeding the lifting device (2) and the additional consumers a double pump device is arranged, which was and one comprises a displacement unit (7; 8), which is connected to an electric machine (9,10). The object of providing such a hydraulic system, which enables a high turning power of the industrial truck, is provided according to the invention in that both displacement units (7, 8) can be used individually or together (4; 4a, 5) in a pump operation for feeding the lifting device ( 2) and the additional consumers, where the displacement units (7, 8) each operate as a pump and the associated electrical machines (9, 10) operate as a motor, where at least one displacement unit (7, 8) in lowering operation of the lifting device (2) for energy recovery works as a motor and the associated electrical machines (9, 10) as a generator and a by-pass lowering line drawn from the lifting device (2) to a container (12). (40) is arranged, in which a lowering valve (41) is arranged. 1
    公开号:SE1251088A1
    申请号:SE1251088
    申请日:2012-09-27
    公开日:2013-03-28
    发明作者:Stephan Scharf
    申请人:Still Gmbh；
    IPC主号:
    专利说明:

    15 20 25 30 35 40 is used by a pump operation for volume flow generation in lifting operation of the lifting device and for feeding the additional consumers. This makes it possible to achieve maximum volume flow requirements in lifting position and volume flow requirements at power peaks through the pump operation of the two displacement units, so that the displacement unit as pump and motor can be reduced in prior art in stroke volume, thereby providing a simpler construction with the hydraulic system according to the invention. With the by-pass lowering line which goes from the lifting device to the container and the lowering valve arranged therein, it also becomes possible that in lowering operation of the lifting device in addition to the volume flow, which for useful lowering and for energy recovery drives the motor-displacing unit, which drives it as generator driven the electric machine, lead an additional volume flow to the container, so that it becomes possible, with the lowering valve in the bypass lowering line, to achieve a maximum permitted lowering speed of the lifting device and thus a high turning speed of the industrial truck. With the invention, the displacement unit driven as a pump and motor can be adapted with respect to the maximum speed to the maximum lifting speed, which is generally lower than the maximum permitted lowering speed. The additional lowering valve in the bypass line thus enables the maximum permitted lowering speed at low extra cost.
    According to a preferred embodiment of the invention, the displacement unit drivable as a pump and motor has a first connection, with which an intake filter and a shut-off valve open in the direction of the first connection, in particular a return spring valve, which communicates with a container and with a container opening. valve, in particular a return spring valve, and a return filter is connected to the container. With such shut-off valves, in pump operation of the displacement unit for feeding the lifting device in lifting operation and / or for feeding the additional consumers, a suction of pressure medium from the container over the suction filter and in motor operation during utilization for energy recovery ensures a flow of pressure medium from the motor the constriction unit over the return filter in the container.
    A common supply of the lifting device in lowering operation and / or the additional consumers through the two displacement units driven in pump operation and a useful lowering operation through motor operation of the displacement unit can be achieved in a simple manner, when according to a preferred embodiment of the invention the pump and motor drivable displacement unit has a second displacement unit. connection, which can be connected to a supply line drawn to the lifting device and the additional consumers as well as to a useful lowering line of the lifting device.
    In particular, the second connection of the displacement unit drivable as a pump and motor is provided with a switching valve device, which in a first switching position connects the second connection to the supply line and in a second switching position to the useful lower line. In the first switching position of the switching valve device, a supply of the lifting device in lifting operation and / or the additional consumers is thus provided in a pump operation by the displacement unit by a connection to the supply line. The second switching position of the switching valve device makes it possible in a simple manner in a motor operation of the displacement unit through a connection with the useful lowering line a useful lowering operation with an energy recovery. Depending on a simple coupling construction, it is advantageous when the by-pass lowering branch branches off from the useful lowering line. The volume flow in the lowering position of the lifting device can thus in a simple manner be conducted either completely or partially over the useful lowering line and the by-pass lowering line to the container.
    Particularly advantageously according to an embodiment of the invention, the switching valve device is controlled depending on the load pressure of the lifting device. Preferably, in lowering operation at low load pressure, for example a lowering without load or with small load, no energy recovery takes place through a useful lowering operation, as as a rule the available load pressure is not sufficient to overcome the friction in the motor-driven displacement unit. In such a lowering operation of the lifting device, the load pressure being below the limit load value, the switching valve device is controlled in the first switching position, in which the connection of the useful lowering line to the displacement unit is switched off and the lowering operation of the lifting device is controlled exclusively by controlling the lowering valve. The immersion volume flow is here completely conducted over the immersion valve to the container. If the load pressure exceeds the limit load pressure value, a control immersion drive can lead to energy recovery through a control of the switching valve device in the second switching position, in which the useful lower line is connected to the displacement unit.
    According to a preferred embodiment of the invention, the lowering valve is controlled depending on the speed of the displacement unit driven as a pump and a predetermined lowering speed for the lifting device.
    In this case, the preference is controlled in lowering operation of the lifting device during a useful lowering operation to the maximum speed of the displacement unit, exclusively by a corresponding speed control or regulation of the displacement unit operating as a motor in useful lowering operation, thereby enabling efficient energy recovery. In this case, the immersion volume stream flows exclusively over the utility immersion line to the container.
    With particular advantage, according to an embodiment of the invention, a further control of the lowering valve takes place after the maximum speed of the displacement unit has been reached. If the maximum speed of the displacement unit during a lowering operation is not sufficient to provide a predetermined lowering speed during a lowering operation, by further controlling the lowering valve an additional lowering flow can be conducted over the bypass lowering line to the container, so that a further increase in lowering speed up to maximum permitted lowering speed can be achieved. Further advantages and features of the invention are explained in more detail in connection with the embodiment shown in the schematic figure.
    The figure shows the wiring diagram for a hydraulic system 1 for an industrial truck, in particular an industrial truck which is battery-electrically powered.
    The hydraulic system 1 comprises a lifting device 2, which at least comprises a hydraulic lifting cylinder 3, with which a load receiving means (not shown) of the industrial truck for lifting and lowering a load is in active connection. The hydraulic system 1 comprises, in addition to the lifting device 2, at least one further hydraulic consumer 4, 4a, for example a tilt drive device (Ty. Neigeantrieb) for a lifting device and / or an auxiliary drive device, for example a side sliding device for the load receiving device. The hydraulic system 1 shown further comprises a hydraulic control device as additional hydraulic consumers 5 of the industrial truck.
    At the hydraulic system 1 according to the invention, for feeding the lifting device 2 and the additional consumers 4, 4a, 5, a double pump device 6 is arranged, which consists of two hydraulic displacement units 7, 8, each of which is in active connection with an electric machine 9, 10.
    The electric machines 9, 10 are connected to a no longer illustrated drive battery for the industrial truck.
    The displacement units 7, 8 are in the embodiment shown designed with a constant displacement volume.
    In the embodiment shown, the constriction unit 7 is designed as a pump, which is driven by the electric machine 9 designed as a motor. The constriction unit designed as a pump 7 communicates with a suction side by means of a suction line 11 with a container 12 and feeds a supply line 13.
    The supply line 13 is connected to a supply line 14 drawn to the lifting device 2 and the additional consumers 4, 4a, 5. In the supply line 14 a preferred valve 25 is arranged for preferred feeding of the additional consumer 5 designed as a control device, which ensures the preferred supply of the control device. . Downstream of the priority valve 25, the supply line 14 branches into a supply line drawn to the additional consumers 4, 4a and a lifting line 27 drawn to the lifting device 2. In the lifting line 27 a lifting valve 28 is arranged for controlling the lifting movement of the lifting device 2.
    The lift valve 28 is designed as a control valve which can be throttled in intermediate positions with a locking position 28a and a lifting position 28a designed as a flow-through position. The lifting valve 28 is actuated by means of a spring 29 in the locking position 28a and is manoeuvrable in the direction of the lifting position 28a by means of an electric operating means 30, in particular a proportional magnet.
    The displacement unit 8 is in the embodiment shown drivable as a pump and motor. The electric machine 10 in this case operates in the pump operation of the displacement unit 8 as motor for operation of the displacement unit 8 and in motor operation as generator, which is driven by the motor-driven displacement unit 8 and supplies electrical energy back into the drive battery.
    The displacement unit 8 which can be driven by pump and motor is drivable in two directions of rotation and has different directions of rotation in pump operation and in motor operation.
    The constriction unit 8 which can be driven as a pump and motor has a first connection, which by means of an intake filter 16 and a shut-off valve 16 opening in the direction of the first connection, in particular a spring-loaded valve, communicates with the container 12. The first connection of the constriction unit 8 is further connected by a the opening opening shut-off valve 17 of the container 12, in particular a spring-loaded valve, and a return filter 18 in connection with the container 12.
    At the first connection of the displacement unit 8, in this case a pressure medium line 20 is connected, which branch is in a branch line 21 drawn to the container 12 and a branch line 22 drawn to the container, the branch line 21 the shut-off valve 16 and the suction filter 15 being arranged and in the branch line 22 the shut-off valve 17 and the return filter 18.
    The displacement unit 8 which can be driven as a motor and pump has a second connection, which in pump operation of the displacement unit 8 can be connected by means of a supply line 31 to the supply line 14 serving for feeding the lifting device 2 and the additional consumers 4, 4a, 5 and in motor operation of the displacement unit 8. motor operation can be connected to a useful lowering line 32 of the lifting device 2. For controlling the second connection of the displacement unit 8 to the useful lowering line 32 for motor operation or the supply line 31 for pump operation of the displacing unit, a switching valve device 33 designed as a switching valve is arranged. with the supply line 31 and switches off the payload line 32 and in a second switching position 33b the pay line 32 connects to the second connection of the displacement unit 8 and switches off the supply line 31. The switching valve device 33 is actuated in the embodiment which is shown by means of a spring 34 in the first coupling position 33a and is by means of an electric operating means 35, in particular a coupling magnet operable in the second coupling position 33b. The hydraulic system 1 according to the invention further comprises a by-pass lowering line 40 for the lifting device 2, which leads to the container 12 and in which a lowering valve 41 is arranged. The lowering valve 41 is designed as a control valve which can be throttled in intermediate positions with a locking position 41a and a lowering position 41b which is designed in the flow-through position. The lowering valve 41 is actuated by means of a spring 42 in the locking position 41a and is operable in the direction of the lowering position 41b by means of an electric operating means 43, in particular a proportional magnet.
    In order to achieve a largely load-independent lowering speed, a pressure wave 50 can be arranged in series with the lowering valve 41.
    An electronic control device (not shown) is responsible for control in connection with the electric machines 9, 10, the lifting valve 28, the lowering valve 41 as well as with the switching device 33. For controlling the operation, the control device is connected to operating means, for example joysticks, with which the lifting device 2 and the additional consumers 4, 4a , 5 are controllable. Furthermore, the control device is in communication with a pressure sensor, which senses the load pressure of the lifting device 2.
    The two displacement units 7, 8 can be driven independently of each other by the two electric machines 9, 10.
    By corresponding pump operation, a displacement unit can be produced individually or together by the displacement unit 7, or 8, which in the supply line 14 serves as a lifting drive of the lifting device 2 and / or for feeding the additional consumers 4, 4a, 5.
    In pump operation of the displacement unit 8, the displacement unit 8 is driven to produce a volume flow in the supply line 31 of the motor operating electric machine 10.
    The switching valve device 33 is located for pump operation of the constriction unit 8 in the switching position 33a shown in the first figure, whereby the volume flow generated by the constriction unit 8 as well as the volume flow generated by the constriction unit 7 in pump operation remains in the supply line 14. 4, 4a, 5. The displacement unit 8 acting as a pump sucks in pump operation over the intake filter 15 and the shut-off valve 16 pressure medium from the container 12. In lifting operation of the lifting device 8, the lifting movement of the lifting device 2 takes place by corresponding control of the lifting valve 28.
    In the hydraulic system 1 according to the invention, the lowering movement of the lifting device 2 can be controlled or regulated individually over the lowering valve 41 or motor drive of the displacement unit 8 or together by the lowering valve 41 and motor drive of the displacement unit 8. In useful lowering operation in a motor operation the motor displacement unit 2 is driven the utility means 32 flowing the pressure medium, so that in connection with the electric machine 10 operating as a generator, an energy recovery takes place. For the useful lowering operation and thus motor operation of the narrowing unit 8, the switching valve device 33 is controlled in the second switching position 33b, so that the pressure medium flowing from the useful lowering line 32 from the lifting device 2 flows to the second connection of the narrowing unit 8 and can drive it. From the first connection, the pressure medium flows over the shut-off valve 17 and the return filter 18 into the container 12.
    The switching valve device 33 is controlled in this case depending on the load pressure of the load device 8. At low load pressure below a predetermined limit load pressure value during a lowering movement, for example a lowering movement without load or with low load, no useful lowering and no energy recovery by motor operation of the displacement unit 8 and a generator operation of the electric motor 10 takes place and the lifting device 2 lifting movement 41 is controlled depending on a predetermined lowering speed. The switching valve device 33 is in this case in the first switching position 33a, in which the connection of the useful lower line 32 with the constriction unit 8 is switched off. If a load attacking the lifting cylinder 3 exceeds a predetermined limit load pressure value, which is sensed, for example, by the pressure sensor, a reduction in efficiency takes place with an energy recovery through the motor operation of the displacement unit 8 and the generator operation of the electric machine 10. The pump-displacing displacement unit 8 is driven by the volume flow flowing away in the useful lowering line 32 from the lifting device 2 and the pressure medium flows over the shut-off valve 17 and the return filter 18 away from the container 12.
    The lowering speed of the lifting device 2 in useful lowering operation is controlled by corresponding control or regulation of the speed of the electric machine 10 operating as a generator.
    If in a useful lowering operation the maximum speed of the electric machine 10 operating as a generator and thus the maximum speed of the displacement unit 8 driven as a motor is not sufficient to achieve a lowering speed predetermined by the display device, by further controlling the lowering valve 41 in the lowering direction 41b over the bypass lowering line 40 to the container 12. The control of the lowering valve 41 in this case depends on the speed of the displacement unit 8 driven as a pump, so that the lowering valve 41 in the lowering position 41b except in pump operation of the narrowing unit 8 in useful lowering operation has a supporting effect. to achieve a desired lowering speed and predetermined at the operating device.
    The hydraulic system 1 according to the invention enables a useful lowering operation with an energy recovery through the motor operation of the displacement unit 8 while simultaneously controlling an additional consumer 4, 4a, 5, which is fed by the displacement unit 7 driven by the pump with pressure means. By throttling the operation, the throttling operation of the pressure medium flowing out of the lifting device 2 and a corresponding heat input in the pressure medium can be avoided. In this way a reduction of the viscosity of the pressure medium is effectively avoided, so that leakage at control valves and gap seals can be effectively avoided. In commercial energy recovery, the energy recovery of the potential load in electrical energy, which is fed back to a drive battery of a battery-electrically powered industrial truck or to an industrial truck powered by an internal combustion engine, can be temporarily stored in a battery, the efficiency and energy balance of the industrial truck.
    By the parallel operation of the lowering valve 41 in the useful lowering operation of the motor-driven constriction unit 8, high lowering speeds can easily be achieved by an additional volume flow flowing to the container 12 in the by-pass lowering line 40. If the displacement unit 8 with respect to maximum speed is designed for a maximum lifting speed of the lifting device 2, which is generally less than a maximum permitted lowering speed, with the hydraulic system 1 according to the invention a maximum permitted lowering speed can be achieved and achieved, so that with the hydraulic system 1 according to the invention a high turning power for the industrial truck and an efficient industrial truck are provided.
    The invention is not limited to the embodiment in which only the displacement unit 8 is operated as a pump and motor for a useful lowering operation. Unless during a service lowering operation no further consumers 4, 4a, 5 are operated, both displacement units 7, 8 can be used in a pump operation and generator operation of the electric machines 9, 10 for energy recovery. A reduction in efficiency with a pump operation of both constriction units 9, 10 may also be possible, as a supply of one or more actuated additional consumers 4, 4a, 5 is made possible by corresponding valves, provided that the load pressure and volume flow from the lifting device 2 in utilization operation is sufficient to supply the controlled additional consumers 4, 4a, 5.
    权利要求:
    Claims (1)
    [1]
    A hydraulic plant for an industrial truck with a hydraulic lifting device and at least one additional hydraulic consumer, where for feeding the lifting device and the additional consumer a double pump device is provided, each comprising a hydraulic displacement unit, which is in connection with an electric machine, characterized in that the two constriction units (7, 8) in a pump operation can each be used individually or together for feeding the lifting device (2) and the additional consumers (4; 4a, 5), where the constriction units ( 7, 8) each operates as a pump and the associated electric machines (9, 10) as a motor, where at least one displacement unit (7, 8) in lowering operation of the lifting device (2) for energy recovery works as a motor and the associated electric machines (9, 10). 10) operates as a generator and a by-pass lowering line (40) drawn from the lifting device (2) to a container (12) is arranged, in which a lowering valve (41) is arranged. Hydraulic system according to Claim 1, characterized in that the displacement unit (7, 8) which can be operated as a pump and motor has a first connection, which by means of an intake filter (15) and a shut-off valve (16) opening in the direction of the first connection, in particular a spring-loaded valve. and a return filter (18) communicates with the container (12). Hydraulic system according to Claim 1 or 2, characterized in that the displacement unit (7, 8) which can be operated as a pump and motor has a second connection, with which a supply line (14) is drawn to the lifting device (2) and the further consumers (4; 4a; 5). ) can also be connected to a payload (32) of the lifting device (2). Hydraulic system according to Claim 3, characterized in that the second connection of the constriction unit (7; 8) which can be operated as a pump and motor is provided with a switching valve device (33), which in a first switching position (33a) connects the second connection to the supply line (14). and in a second switching position (33b) the second connection connects to the utility lowered line (32). Hydraulic system according to one of Claims 1 to 4, characterized in that the by-pass lowering line (40) branches off from the useful lowering line (32). Hydraulic system according to Claim 4 or 5, characterized in that the switching valve device (33) is controlled depending on the load pressure of the lifting device (2). Hydraulic system according to claim 6, characterized in that in a lowering operation of the lifting device (2), where the load pressure is below a limit load pressure value, the switching valve device (33) is controlled in the first switching position (33a), in which the connection ) is switched off, and the lowering operation of the lifting device (2) is controlled exclusively by controlling the lowering valve (41). Hydraulic system according to one of Claims 1 to 7, characterized in that the lowering valve (41) is controlled depending on the speed of the displacement unit (7; 8) driven as a pump and a predetermined lowering speed of the lifting device (2). Hydraulic system according to one of Claims 1 to 8, characterized in that the lowering operation in useful lowering operation of the lifting device (2) is controlled up to the maximum speed of the displacement unit (7; 8) exclusively by a corresponding speed control or control of the displacement unit 7 ; 8). Hydraulic system according to Claim 9, characterized in that after a maximum speed has been reached at the displacement unit (7; 8), a further control of the lowering valve (41) takes place. 10
    类似技术:
    公开号 | 公开日 | 专利标题
    US9228599B2|2016-01-05|Hydraulic circuit for construction equipment
    US9476437B2|2016-10-25|Boom driving device
    JP2013545941A|2013-12-26|Hybrid hydraulic system for industrial process
    US20130312399A1|2013-11-28|System for driving working machine
    RU2529298C2|2014-09-27|Hydraulic system and method of hydraulic fluid feed to hydraulic system
    US20080152513A1|2008-06-26|Hydraulic circuit arrangement with recovery of energy
    Murrenhoff et al.2014|An overview of energy saving architectures for mobile applications
    EP2842905A1|2015-03-04|Energy regeneration type forklift hydraulic system
    CN103790874A|2014-05-14|Valveless hydraulic servo system and control method thereof
    CN202833365U|2013-03-27|Hydraulic source return circuit energy-saving control system
    US9759317B2|2017-09-12|Closed hydraulic circuit
    CN201559977U|2010-08-25|Belt self-control tensioner of belt conveyer
    CN205370937U|2016-07-06|Hydraulic power unit
    CN202402395U|2012-08-29|Device for testing multi-way valve
    SE1251088A1|2013-03-28|Hydraulic plant for an industrial truck
    CN107061385B|2021-03-12|Hydraulic constant pressure system for mobile working machine
    CN103062140A|2013-04-24|Hydraulic device on basis of confluence control mode
    CN105782166A|2016-07-20|Energy-saving type hydraulic pump durability testing table with hydraulic analog loading
    CN106321537A|2017-01-11|Hydraulic control system and corresponding movable working equipment
    CN205047555U|2016-02-24|Sensitive hydraulic luffing drive control system of ship unloaders disproportional load
    SE1351533A1|2014-06-22|Hydrostatic drive system for a mobile working machine with pressurized cooling
    CN203427615U|2014-02-12|Open type walking system
    CN104067032B|2016-10-12|Hydraulic pressure closed loop system
    CN102912822B|2015-09-16|A kind of excavator cooling system and excavator
    CN208634147U|2019-03-22|A kind of driving motor directly drives the hydraulic energy-saving system of pump control cylinder with differential effect
    同族专利:
    公开号 | 公开日
    DE102011053958A1|2013-03-28|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE4317782C2|1993-05-28|1996-01-18|Jungheinrich Ag|Hydraulic lifting device for battery-powered industrial trucks or the like|CN108975235B|2017-05-31|2020-11-06|北谷电子有限公司|Power system of lifting device and control method thereof|
    法律状态:
    2016-07-12| NAV| Patent application has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    DE201110053958|DE102011053958A1|2011-09-27|2011-09-27|Hydraulic system of industrial truck e.g. battery-electrically operated industrial truck, has bypass drain line which is guided from lifting device to container, for arrangement of lowering valve|
    [返回顶部]