JP2005054944A - Vehicular driving force distributing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular driving force distribution device capable of performing the torque control between right and left wheels or between front and rear axles, having the differential limit function, and capable of enhancing the traveling stability and the dynamic performance of a vehicle. <P>SOLUTION: A hydraulic motor 8 is a radial piston type hydraulic motor, and a motor case 25 is connected to a right wheel axle 17, and a cylinder block 28 is connected to a left wheel axle 16 in a relatively rotated to each other. In a hydraulic system to drive the hydraulic motor 8, a hydraulic pump 50 supplies and discharges working fluid as high-pressure oil in a reservoir 70 to pipe passages 48a and 48b via a hydraulic valve unit 60. The hydraulic valve unit 60 has a relief valve 61, a directional control valve 62 and ON-OFF valves 63 and 64 to shut off communication of pipe passages 48a and 48b with the hydraulic motor 8. The driving force is distributed between the right and left wheels by changing over the directional control valve 62, and the differential limit function between the right and left wheels is obtained by shutting off the ON-OFF valves 63 and 64. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a driving force distribution device for a vehicle that appropriately distributes driving force between left and right wheels and between front and rear axes.

  In recent years, various techniques for positively controlling torque distribution between front and rear wheels or between left and right wheels to improve running stability of a vehicle have been proposed and put into practical use.

For example, Japanese Patent Laid-Open No. 2001-199255 discloses an input shaft that is provided on the input side of a housing and is driven to rotate by a vehicle engine, and a driving force from the input shaft that is provided on the output side of the housing. A differential mechanism that distributes and transmits to the shaft, and a differential mechanism that is provided at the output side of the housing together with the differential mechanism. A vehicle left / right driving force distribution device including a reversible hydraulic motor to be applied is disclosed.
JP 2001-199255 A

  However, although the technique of Patent Document 1 described above can control the torque between the left and right wheels, since there is no differential limiting function, it can be used for roads with large irregularities, when crossing steep slopes, or when traveling on a split μ road. There is a problem that it is not possible to sufficiently secure the driving force and improve the running stability and exercise performance.

  The present invention has been made in view of the above circumstances, and has not only torque control between left and right wheels or front and rear shafts, but also has a differential limiting function, and improves vehicle running stability and motion performance. An object of the present invention is to provide a driving force distribution device for a vehicle capable of performing

  The present invention provides a differential mechanism provided between one rotating shaft and the other rotating shaft, and provided between the one rotating shaft and the other rotating shaft, and the one rotating shaft and the other rotating shaft. A hydraulic motor that causes relative rotation of the rotating shaft of the hydraulic motor, a hydraulic pump that generates hydraulic pressure to the hydraulic motor, and a hydraulic pipe line between the hydraulic motor and the hydraulic pump. In a vehicle driving force distribution device including a hydraulic valve unit that discharges, the hydraulic fluid between the hydraulic motor and the hydraulic pump is prohibited from moving the hydraulic oil in the hydraulic pump, and the hydraulic pressure is reduced. It is characterized by a control valve that suppresses the rotation of the motor.

  The vehicle driving force distribution device according to the present invention has not only torque control between the left and right wheels or between the front and rear shafts but also a differential limiting function, which can improve the running stability and motion performance of the vehicle. It becomes.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment of the present invention, FIG. 1 is a cross-sectional view of a main part showing a left / right driving force distribution device for a vehicle, FIG. 2 is a cross-sectional view for explaining a differential mechanism, and FIG. Sectional drawing explaining a hydraulic motor, FIG. 4 is explanatory drawing of the hydraulic circuit which operates a hydraulic motor.

  In FIG. 1, reference numeral 1 denotes a housing of a driving force distribution device. The housing 1 is a stepped cylindrical input housing portion 2 located on the input side, and is integrated with the input housing portion 2 located on the output side. It is mainly comprised from the stepped cylindrical output housing part 3 provided and extended in the left-right direction.

  The output housing part 3 includes a cylindrical body part 4 located in the center, a stepped cylindrical cover part 5 provided on the left side of the body part 4, and a stepped part provided on the right side of the body part 4. It is comprised from the cylindrical cover part 6. FIG.

  The output housing part 3 is provided inside the body part 4 and is provided with a stepped cylinder part 7 between the cover part 6 and a hydraulic motor 8 described later between the cover part 6 and the stepped cylinder part 7. Is rotatably arranged.

  The stepped cylinder part 7 is formed to extend in the axial direction from the right cover part 6 side toward the left cover part 5 side, and the tip side of the stepped cylinder part 7 avoids interference with the input gear 9 described later. Thus, the diameter is reduced.

  In FIG. 1, reference numeral 10 denotes a propulsion shaft as an input shaft rotatably provided in the input housing portion 2 of the housing 1, and the propulsion shaft 10 is a crankshaft (not shown) of an engine mounted on the vehicle. And is driven to rotate by the engine. Further, the propulsion shaft 10 is provided with an input gear 9 on the tip end side extending into the body portion 4 of the output housing portion 3, and the input gear 9 meshes with a ring gear 11 described later.

  In FIG. 1, reference numeral 12 denotes a differential mechanism portion that is located on the cover portion 5 side and is rotatably provided in the output housing portion 3. The differential mechanism portion 12 is constituted by, for example, a planetary gear device. A ring gear 11 that meshes with the input gear 9 is fixed to the outer peripheral side of a differential case (hereinafter referred to as a differential case) 13 that forms an outer shell by bolts or the like.

  In this way, the differential case 13 is rotationally driven by the propulsion shaft 10 via the input gear 9 and the ring gear 11, and the driving force at this time is the left and right wheel shafts 16, 17 by the sun gear 14 and the carrier 15, which will be described later. Is distributed and transmitted.

  As shown in FIG. 2, the differential mechanism section 12 includes an internal gear 18 formed over the entire circumference of the differential case 13, a carrier 15 provided in the differential case 13 so as to be relatively rotatable, A plurality of planetary gears 20, 20,... Rotatably supported by the carrier 15 via the support shaft 19 and meshed with the internal gear 18, and the carrier 15 via the support shaft 21 so as to mesh with the planetary gears 20. And the other planetary gears 22 that are rotatably supported, and the sun gear 14 that meshes with each planetary gear 22 and is rotatable relative to the carrier 15.

  The sun gear 14 is splined so as to rotate integrally with the left wheel shaft 16, and the rotation of the differential case 13 (for example, the rotation in the direction of arrow A in FIG. 2) is via a pair of planetary gears 20 and 22, respectively. This is transmitted to the sun gear 14 as rotation in the same direction. In addition, the revolution of the planetary gears 20 and 22 is transmitted to the carrier 15 via the support shafts 19 and 21, whereby the carrier 15 is also rotated in the same direction as the differential case 13.

  When the vehicle travels straight, the rotational force on the differential case 13 side is evenly distributed to the sun gear 14 and the carrier 15 via the planetary gears 20 and 22, and the sun gear 14 and the carrier 15 are left at the same rotational speed. The right wheel shafts 16 and 17 are driven to rotate.

  Further, when steering the vehicle (turning), the sun gear 14 and the left and right wheels (not shown) are rotated so that one of the wheel shafts 16 and 17 rotates faster than the other due to a reaction force received from the road surface. The rotational force on the differential case 13 side is transmitted to the carrier 15 with different rotation ratios. As a result, the wheel on the inner side of the turn has a relatively low rotational speed, and the wheel on the outer side of the turn has a higher rotational speed and exhibits a differential function that enhances the cornering performance of the vehicle.

  Further, in FIG. 1, reference numeral 23 denotes a stepped sleeve that constitutes a part of the differential mechanism portion 12, and this sleeve 23 uses bolts 24 (see FIG. 2) and the like on the end face side of the carrier 15. The rotation of the carrier 15 is fixed, and the rotation of the carrier 15 is led out to the motor case 25 (right wheel shaft 17) described later. And the spline 23a is formed in the inner peripheral side of the sleeve 23, This spline 23a is couple | bonded with the cylindrical connection part 26b of the other side case 26 mentioned later.

  On the other hand, the left wheel shaft 16 is formed by using a single shaft member, and the right wheel shaft 17 is constituted by a motor case 25 and a joint flange 27 described later. Further, the left wheel shaft 16 has a small-diameter spline shaft portion 16a at one end inserted into the output housing portion 3, and the spline shaft portion 16a is fixed to the center side of a cylinder block 28 described later. It is connected.

  The left wheel shaft 16 has a large-diameter joint flange portion 16b at the other end protruding outside the output housing portion 3, and another spline shaft is provided at an intermediate portion between the joint flange portion 16b and the spline shaft portion 16a. A portion 16c and a circular seal step portion 16d are formed. The spline shaft portion 16c is fitted on the inner peripheral side of the sun gear 14 so as to rotate integrally with the sun gear 14, and transmits the rotation of the sun gear 14 to the joint flange portion 16b side of the left wheel shaft 16. is there.

  For this reason, the left wheel shaft 16 is formed with a relatively large diameter from the joint flange portion 16b to the spline shaft portion 16c, and has sufficient rigidity to transmit a large driving force to an external wheel. . On the other hand, the portion extending from the position of the spline shaft portion 16c to the spline shaft portion 16a on the distal end side only needs to transmit a relatively small driving force generated in a cylinder block 28 of the hydraulic motor 8 described later, and therefore has a relatively small diameter. Is formed. Further, a seal member 29 described later is in sliding contact with the outer peripheral side of the seal step portion 16d to prevent oil leakage and mixing as described later.

  On the other hand, the hydraulic motor 8 is a reversible hydraulic motor that is positioned on the right cover portion 6 side and is rotatably provided in the output housing portion 3. The hydraulic motor 8 is, for example, a radial piston hydraulic motor. The motor case 25, the cylinder block 28, the piston 30, the passage block 31, and the like are mainly configured.

  The hydraulic motor 8 is disposed side by side in the left-right direction in the output housing portion 3 with respect to the differential mechanism portion 12, and is configured to accommodate the passage block 31 between the cylinder block 28 and the differential mechanism portion 12. Yes. The hydraulic motor 8 is rotated relative to the left and right wheel axles 16 and 17 by supplying and discharging pressure oil from a hydraulic pump 50 described later to relatively rotate the motor case 25 and the cylinder block 28. Apply rotational force.

  The motor case 25 of the hydraulic motor 8 is rotatably provided in the output housing portion 3 and constitutes an outer rotating body of the hydraulic motor 8. As shown in FIG. 3, the motor case 25 is formed as a covered cylindrical body, and includes a one-side case 32 in which an output shaft portion 32b is integrally formed on the center side of the lid portion 32a, a cam ring 33, and an other-side case 26. The cam ring 33 is sandwiched and integrated between the one case 32 and the other case 26 using a plurality of bolts 34, 34,.

  The entire motor case 25 including the one-side case 32, the cam ring 33, and the other-side case 26 has a covered stepped cylindrical body extending in the axial direction from the position of the cylindrical connecting portion 26b to the position of the output shaft portion 32b. The right wheel shaft 17 is configured together with the outer joint flange 27. In this case, the output shaft portion 32b of the one-side case 32 protrudes outward from the right cover portion 6 of the output housing portion 3, and the joint flange 27 is splined to the protruding end side.

  As shown in FIG. 3, the cam ring 33 of the motor case 25 is formed with a cam surface 33 a on the inner peripheral side, and this cam surface 33 a receives a driving force from the piston 30 via each roller 35 described later. Thus, a relative rotational force indicated by the X direction arrow or the Y direction arrow in FIG. 3 is generated between the motor case 25 and the cylinder block 28.

  The other case 26 is formed as a stepped cylindrical body having a diameter reduced to approximately two stages, and extends in the axial direction toward the differential mechanism section 12 with the cylinder block 28 sandwiched between the one case 32. The cylindrical extending portion 26a is formed, and the cylindrical connecting portion 26b is extended from the distal end side of the cylindrical extending portion 26a toward the inner peripheral side of the sleeve 23. The cylindrical connecting portion 26b is configured such that the outer peripheral side engages with the spline 23a of the sleeve 23 from the inside to rotate the motor case 25 (the right wheel shaft 17) integrally with the sleeve 23 of the differential mechanism portion 12. .

  The cylinder block 28 constituting the inner rotating body of the hydraulic motor 8 is formed as a rotor made of a flat stepped cylindrical body, and is provided in the motor case 25 so as to be rotatable via a plurality of bearings and the like. Further, a fitting hole into which the spline shaft portion 16a of the left wheel shaft 16 is fitted in a non-rotating state is formed as a bottomed hole on the center side of the cylinder block 28.

  Here, as shown in FIG. 3, a plurality (eight in this embodiment) of cylinders 36, 36,... Are formed in the cylinder block 28. ,... Are slidably inserted.

  Further, the cylinder block 28 is formed with a plurality of oil passages 37 (37a, 37b, 37c, 37d, 37e, 37f, 37g, 37h) individually communicating with the respective cylinders 36. These oil passages 37 are described later. By sequentially communicating with the supply / discharge passages 38 (38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h, 38i, 38j) of the passage block 31, the external pressure oil is supplied to and discharged from the cylinders 36. It is something to be made. Each piston 30 reciprocates in the cylinder 36 by the pressure oil supplied to and discharged from the cylinder 36 to generate the rotational force of the hydraulic motor 8.

  Each roller 35 is rotatably provided at the projecting side end portion of each piston 30 via a support shaft 39, and each roller 35 is biased toward the cam surface 33 a of the cam ring 33 by each spring 40. Has been provided. That is, each spring 40 is disposed between the cylinder 36 and the piston 30 and constantly urges the piston 30 in a direction in which the piston 30 protrudes from the cylinder 36. Each roller 35 slides along the cam surface 33a of the cam ring 33 to compensate for smooth relative rotation between the cylinder block 28 and the cam ring 33 (motor case 25).

  The passage block 31 for supplying and discharging the pressure oil to and from each cylinder 36 of the cylinder block 28 is formed as a stepped cylinder and is located on the outer peripheral side of the left wheel shaft 16 and on the other side of the motor case 25. In the cylindrical extending part 26a of the case 26, for example, a knock pin, a key groove or the like is used to prevent rotation. The passage block 31 rotates integrally with the motor case 25 and holds the cylinder block 28 so as to be relatively rotatable with the lid portion 32a of the one side case 32 or the like.

  In the passage block 31, a plurality of (10 in the present embodiment) supply / discharge passages 38 (38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h, 38i, 38j) are provided at regular intervals in the circumferential direction. These supply / discharge passages 38 are alternately arranged on a virtual circle concentric with the left wheel shaft 16 so as to be alternated. Then, on the end face side of the passage block 31 that is in sliding contact with the end face of the cylinder block 28, as shown by the broken lines in FIG. 3, the switching valve portion that alternately communicates with the respective oil passages 37 of the cylinder block 28. It constitutes.

  Further, on the outer peripheral side of the passage block 31, annular oil grooves 41, 42 individually communicating with the supply / discharge passages 38 are formed, and the annular oil grooves 41, 42 are separated from each other in the axial direction of the passage block 31. Arranged.

  The annular oil grooves 41 and 42 of the passage block 31 are provided with oil holes 43 and 44 formed in the cylindrical extending portion 26 a of the other case 26 and the supply and discharge formed in the stepped cylindrical portion 7 of the output housing portion 3. The hydraulic oil communicates with the ports 45 and 46 and is configured to guide the pressure oil from the supply and discharge ports 45 and 46 to the respective supply and discharge passages 38.

  With this configuration, for example, in FIG. 3, the hydraulic motor 8 applies hydraulic pressure from the hydraulic pump 50 to the respective oil passages 37 b, 37 d, and 37 g from the supply and discharge passages 38 b, 38 d, and 38 h in FIG. The cam ring 33 (the motor case 25) is changed to an arrow in the Y direction with respect to the cylinder block 28 by draining oil from the respective oil passages 37c, 37f, and 37h to the hydraulic pump 50 side through the respective supply / discharge passages 38i. Relative rotation.

  Conversely, the hydraulic pressure from the hydraulic pump 50 is applied to the oil passages 37c, 37f, 37h from the supply / discharge passages 38c, 38g, 38i, and 37b, 37d via the supply / discharge passages 38b, 38d, 38h. , 37g, the cam ring 33 (motor case 25) is rotated relative to the cylinder block 28 in the X direction arrow.

  Further, all the oil passages 37 (37a, 37b, 37c, 37d, 37e, 37f, 37g, all the way from all the supply / discharge passages 38 (38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h, 38i, 38j), 37h), the relative rotation between the cam ring 33 (motor case 25) and the cylinder block 28 is prohibited, that is, the left wheel shaft 16 and the right wheel shaft 17 are prohibited. Differential between the two is prohibited and the differential limiting function is exhibited.

  On the other hand, reference numeral 47 is a seal member provided between the stepped cylindrical portion 7 of the output housing portion 3 and the motor case 25 of the hydraulic motor 8, and this seal member 47 is constituted by, for example, a double lip seal, The other side case 26 is mounted between the cylindrical extending portion 26 a and the stepped cylindrical portion 7 with a tightening margin. The seal member 47 separates, for example, lubricating oil on the differential mechanism portion 12 side and pressure oil (operating oil) on the hydraulic motor 8 side between the output housing portion 3 and the motor case 25, Oil leakage and mixing are prevented.

  Further, the seal member 29 provided between the seal step portion 16 d of the left wheel shaft 16 and the motor case 25 is constituted by a double lip seal or the like, like the seal member 47, and the cylinder of the other case 26. The extending portion 26a and the seal step portion 16d are mounted with a tightening margin. The seal member 29 separates, for example, the lubricating oil on the differential mechanism 12 side and the hydraulic oil on the hydraulic motor 8 side from each other between the left wheel shaft 16 and the motor case 25, Leakage and mixing are prevented.

Next, a hydraulic drive system for operating the hydraulic motor 8 will be described with reference to FIG. 1 and FIG.
This hydraulic system is mainly composed of a hydraulic pump 50, a hydraulic valve unit 60, and a reservoir 70.

  The hydraulic pump 50 supplies and discharges hydraulic oil in the reservoir 70 as high-pressure oil to and from the pipes 48a and 48b via the hydraulic valve unit 60. The hydraulic pump 8 directly generates a tire torque difference. For example, 30 MPa high pressure oil can be generated. The power is taken out from the differential case 13 through a gear train (not shown), and is arranged at the rear part of the body part 4 of the output housing part 3.

  As shown in FIG. 1, the distal ends of the pipes 48 a and 48 b are connected to supply / discharge ports 45 and 46 formed in the stepped cylinder portion 7 of the output housing portion 3.

  The hydraulic valve unit 60 includes ON-OFF valves 63 and 64 as control valves for cutting off the communication between the relief valve 61, the direction control valve 62, and the pipes 48a and 48b.

  The relief valve 61 controls the hydraulic pressure generated by the hydraulic pump 50 to a necessary pressure (line pressure), has a pressure adjusting solenoid part 61a, and is output from the controller 80 described later to the solenoid part 61a. The relief set pressure is appropriately controlled according to the current value of the control signal or the pulse duty.

  The direction control valve 62 is a direction control valve provided in the middle of the pipes 48a and 48b. The direction control valve 62 includes, for example, an electromagnetic direction control valve at a 4-port 3 position, and switches the direction of the pressure oil supplied to and discharged from the hydraulic motor 8.

  That is, the direction control valve 62 has solenoid parts 62a and 62b on the right and left sides, and a control signal is output from the controller 80 to the solenoid parts 62a and 62b. Specifically, as shown in FIG. 4, the directional control valve 62 is switched from the neutral position (A) to the left and right switching positions (B) and (C). ) To switch the direction of the pressure oil supplied to and discharged from the hydraulic pump 50 to the hydraulic motor 8. Further, while the directional control valve 62 is held at the neutral position (A), by stopping the supply and discharge of pressure oil, the hydraulic motor 8 is substantially stopped, and the rotation output generated by the hydraulic motor 8 is invalidated. To do.

  The ON-OFF valve 63 is interposed in a pipe line 48 a between the direction control valve 62 and the hydraulic motor 8, and normally holds the pipe line 48 a at a position where it communicates. 48a can be shut off. The ON-OFF valve 63 is interlocked with the ON-OFF valve 64.

  The ON-OFF valve 64 is interposed in a pipe line 48b between the directional control valve 62 and the hydraulic motor 8, and normally holds the pipe line 48b in a position where it communicates. 48b can be cut off. The ON-OFF valve 64 is interlocked with the ON-OFF valve 63.

  That is, when the controller 80 operates the ON-OFF valves 63 and 64 to shut off the pipes 48a and 48b, all the supply / discharge passages 38 (38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h, 38i). , 38j), the supply and discharge of the hydraulic oil is prohibited to all the oil passages 37 (37a, 37b, 37c, 37d, 37e, 37f, 37g, 37h). As a result, the relative rotation between the cam ring 33 (motor case 25) and the cylinder block 28 is prohibited, and the differential between the left wheel shaft 16 and the right wheel shaft 17 is prohibited and the differential limiting function is exhibited. The

  The reservoir 70 stores hydraulic oil and is released to the atmosphere. Depending on the capacity, the reservoir 70 is disposed in the rear bumper or the rear trunk.

  The controller 80 outputs a signal to the direction control valve 62 according to the driving state of the vehicle to vary the left and right driving force distribution, or outputs a signal to the ON-OFF valves 63 and 64 to perform differential operation. A restriction function is added.

  For example, when the vehicle travels straight, the rotational force on the differential case 13 side is evenly distributed to the sun gear 14 and the carrier 15 via the planetary gears 20 and 22, and the sun gear 14 and the carrier 15 have the same rotational speed. Since the left and right wheel shafts 16 and 17 are rotationally driven, the vehicle is driven to travel through the left and right wheels.

  Further, when the steering operation (turning) of the vehicle is performed, the sun gear 14 and the carrier 15 have a differential case so that one of the wheel shafts 16 and 17 rotates faster than the other due to the reaction force received by the left and right wheels from the road surface. The rotational forces on the 13th side are transmitted with different rotation ratios, so that the wheels on the inside of the turn have a relatively low rotational speed, and the wheels on the outside of the turn have a higher rotational speed to improve the cornering performance of the vehicle. be able to.

  By the way, since the driving force distribution to the left and right wheel shafts 16 and 17 by the differential mechanism section 12 depends on the reaction force received from the road surface by the left and right wheels, for example, when slip occurs. In some cases, the function of distributing the driving force is lost and the running stability of the vehicle cannot always be improved. Thus, when the differential rotation of the left and right wheel shafts 16 and 17 by the differential mechanism section 12 increases, this is detected by wheel speed sensors or the like (not shown) of the left and right wheels, and the ON-OFF valve 63, 64, and the pipes 48a and 48b are shut off, all the oil passages 37 (37a, 38i, 38j, 38h, 38i, 38j) are supplied from all the supply / discharge passages 38 (38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h, 38i, 38j). 37b, 37c, 37d, 37e, 37f, 37g, and 37h), the supply and discharge of the hydraulic oil is prohibited. As a result, the relative rotation between the cam ring 33 (motor case 25) and the cylinder block 28 is prohibited, and the differential between the left wheel shaft 16 and the right wheel shaft 17 is prohibited and the differential limiting function is exhibited. The This prevents the vehicle from becoming unstable due to slipping or the like.

  Further, when the vehicle turns, the controller 80 outputs a control signal to the direction control valve 62 and the relief valve 61. For example, the controller 80 switches the direction control valve 62 from the neutral position (A) to the switching position (B) or (C). By switching to, the pressure oil from the hydraulic pump 50 is supplied to and discharged from the hydraulic motor 8 in the output housing portion 3 via the pipe lines 48a and 48b.

  As a result, the hydraulic motor 8 in the output housing section 3 causes pressure oil to flow into each cylinder 36 in the cylinder block 28 via the supply / discharge passage 38 of the passage block 31 and each oil passage 37 of the cylinder block 28. When supplied and discharged, the piston 30 is reciprocated in each cylinder 36, whereby the motor case 25 of the hydraulic motor 8 and the cylinder block 28 rotate relative to each other.

  As a result, the rotational forces due to the relative rotation of the motor case 25 and the cylinder block 28 are applied in opposite directions between the left and right wheel axles 16 and 17, and the drive force distribution is increased on the side of the turning outer wheel. The driving force applied from the propulsion shaft 10 to the differential mechanism portion 12 is positively distributed to the left or right wheel shaft 16 or 17 on the turning outer wheel shaft according to the rotational force of the hydraulic motor 8. . And by the driving force distribution at this time, a yaw moment can be actively generated in the vehicle, and the running stability and sufficient turning performance of the vehicle can be ensured.

  Thus, according to the first embodiment of the present invention, the ON-OFF valves 63 and 64 that cut off the communication of the pipes 48a and 48b are connected to the pipes between the direction control valve 62 and the hydraulic motor 8, respectively. Since the hydraulic motor 8 is interposed in the roads 48a and 48b, the hydraulic motor 8 has a function of differential limitation as well as a positive driving force distribution between the left and right wheel shafts 16 and 17, and the running stability and motion of the vehicle. The performance can be improved.

  Next, FIG. 5 is an explanatory diagram of a hydraulic circuit for operating the hydraulic motor according to the second embodiment of the present invention. In the second embodiment of the present invention, only the hydraulic circuit for operating the hydraulic motor is different from the first embodiment, and other configurations are the same as those in the first embodiment. The description is omitted.

  That is, as shown in FIG. 5, in the second embodiment of the present invention, the pipes 48a and 48b between the directional control valve 62 and the hydraulic motor 8 include two pipes 48a and 48b. An ON-OFF valve 65 is provided as an integrated control valve capable of simultaneously disconnecting communication.

  By adopting the integrated ON-OFF valve 65 in this way, the same effects as those of the first embodiment can be obtained. Further, compared with the first embodiment, the number of parts, cost and weight can be reduced, and the hydraulic valve The size reduction of the unit 60 is achieved.

  Next, FIG. 6 is an explanatory diagram of a hydraulic circuit for operating a hydraulic motor according to the third embodiment of the present invention. In the third embodiment of the present invention, only the hydraulic circuit for operating the hydraulic motor is different from the first embodiment, and other configurations are the same as those in the first embodiment. The description is omitted.

  That is, as shown in FIG. 6, in the third embodiment of the present invention, an ON-OFF valve 63 as a control valve is provided in the oil passage between the direction control valve 62 and the reservoir 70, and the direction control valve 62 and the reservoir An ON-OFF valve 64 as a control valve is interposed in an oil passage between the pipes 48a and 48b, and the pipes 48a and 48b are configured to be able to communicate with each other at the same time by cooperating with the ON-OFF valves 63 and 64. Yes.

  As described above, according to the third embodiment of the present invention, it is possible to obtain the same effect as that of the first embodiment.

  Next, FIG. 7 is an explanatory diagram of a hydraulic circuit for operating a hydraulic motor according to a fourth embodiment of the present invention. In the fourth embodiment of the present invention, only the hydraulic circuit for operating the hydraulic motor is different from the third embodiment, and other configurations are the same as those in the third embodiment. The description is omitted.

  That is, as shown in FIG. 7, in the fourth embodiment of the present invention, two conduits 48a and 48b are provided in the oil passage between the directional control valve 62 and the hydraulic motor 8 and the reservoir 70. At the same time, an ON-OFF valve 65 as an integrated control valve in which the ON-OFF valves 63 and 64 in the third embodiment are integrated is provided.

  By adopting the integrated ON-OFF valve 65 in this way, the same effects as those of the third embodiment can be obtained. Further, compared with the third embodiment, the number of parts, cost and weight can be reduced, and the hydraulic valve The size reduction of the unit 60 is achieved.

  Each embodiment of the present invention has been described by taking the final reduction gears of the left and right wheel shafts 16 and 17 as an example, but it can be applied to a center differential device provided between the front and rear rotating shafts. Nor.

  In each embodiment of the present invention, the differential mechanism unit 12 is described as being configured using a planetary gear device or the like. However, the differential mechanism unit 12 is configured using other, for example, bevel gears. May be.

Sectional drawing which shows the principal part which shows the left-right driving force distribution apparatus of the vehicle by 1st Embodiment of this invention Sectional drawing explaining a differential mechanism part as above Same as above, sectional view explaining hydraulic motor Same as above, explanatory diagram of hydraulic circuit for operating hydraulic motor Explanatory drawing of the hydraulic circuit which operates the hydraulic motor by the 2nd Embodiment of this invention Explanatory drawing of the hydraulic circuit which operates the hydraulic motor by the 3rd Embodiment of this invention Explanatory drawing of the hydraulic circuit which operates the hydraulic motor by the 4th Embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 8 Hydraulic motor 12 Differential mechanism part 16 Left wheel shaft 17 Right wheel shaft 25 Motor case 28 Cylinder block 30 Piston 31 Passage block 33 Cam ring 33a Cam surface 35 Roller 48a Pipe line 48b Pipe line 50 Hydraulic pump 60 Hydraulic valve unit 61 Relief valve 62 Directional control valve 63 ON-OFF valve (control valve)
64 ON-OFF valve (control valve)
70 reservoir 80 controller

Agent Patent Attorney Susumu Ito

Claims (2)

A differential mechanism provided between one rotating shaft and the other rotating shaft;
A hydraulic motor that is provided between the one rotary shaft and the other rotary shaft, and causes the one rotary shaft and the other rotary shaft to perform relative rotation;
A hydraulic pump for generating hydraulic pressure to the hydraulic motor;
In a vehicle driving force distribution device including a hydraulic valve unit that intervenes in a hydraulic pipe line between the hydraulic motor and the hydraulic pump to supply and discharge hydraulic oil,
A control valve that inhibits movement of hydraulic oil in the hydraulic pump and suppresses rotation of the hydraulic motor is interposed in a hydraulic pipe line between the hydraulic motor and the hydraulic pump. Driving force distribution device.   2. The vehicle driving force distribution device according to claim 1, wherein the one rotation shaft and the other rotation shaft are at least one of a left and right rotation shaft and a front and rear rotation shaft.

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