JP2003130175A - Driving power distributing system to left and right hand sides of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove an adverse effect in a vehicle maneuverability, which is caused by growing weight imbalance of vehicle for a conventional system, because of the position of the center of gravity for conventional vehicle being too far from that of a vehicle unit as a whole. SOLUTION: This system is equipped with a differencial gear case 24, to which a rotating driving power of a drive shaft 21 is transmitted through gears, a differencial gear system which distributes and transmitters the input driving power into the differencial gear case into a left and right axel 28, 29, a hydraulic motor 31 for supplying a relative rotating power between the left and the right axles whenever it needs, and a hydraulic pump 34 to rotate and drive the hydraulic motor. A spur gear 47 is formed in one body with the outer periphery of the differencial gear case, and the hydraulic pump and a flow path switching valve 35 are arranged parallely to the left and the right hand axles to connect the pump axle 49 with the spur gear 47 through an idle gear 49 and a driving gear 49a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle left / right driving force distribution device capable of positively controlling a distribution ratio of driving force to left / right wheels.

[0002]

2. Description of the Related Art As a lateral driving force distribution device of this type, a device disclosed in Japanese Patent Application Laid-Open No. 3-50028 has been conventionally devised.

As shown in FIG. 6, this left / right driving force distribution device includes a drive shaft 2 connected to a propeller shaft of an engine (not shown) in a differential carrier 1.
The drive pinion 3 provided at the tip of the drive shaft 2, the ring gear 5 fixed to the outer periphery of the differential case 4 constituting the differential gear and meshed with the drive pinion 3, and the rotational force of the differential case 4 are The planetary gear 6 and the sun gear 7 of the planetary gears to be transmitted are accommodated,
The planetary gear 6 absorbs the difference in rotational speed between the left and right axles 8 and 9.

Further, a radial plunger type hydraulic pressure for applying a relative rotational force between the left and right axles 8 and 9 at a position axially adjacent to the differential device in the differential carrier 1. A motor 10 is provided.

Further, the hydraulic motor is provided at a position opposite to the drive shaft 2 which sandwiches the differential device.
In addition, a radial plunger type hydraulic pump 11 for appropriately supplying / discharging hydraulic oil via a supply / discharge passage (not shown) is provided. This hydraulic pump 11 has a direction perpendicular to the axles 8 and 9,
That is, a cylinder block provided at the tip of the housing 12a of the drive transmission mechanism 12 arranged in series with the drive shaft 2 and housed inside the pump casing 11a, or a plurality of radial blocks formed on the cylinder block. And a plunger provided slidably in each cylinder. The drive transmission mechanism 12 is provided with a pump drive shaft 14 provided with a hypoid gear 13 that meshes with the ring gear 5 in a housing 12a, and an end portion of the pump drive shaft 14 via a connecting flange 15. The pump shaft 16 of the hydraulic pump 11 is connected. Further, at the outer end portion of the hydraulic pump 11, a flow passage switching valve (not shown) that appropriately switches the supply / discharge passage is provided.

The hydraulic pump 11 is used when the vehicle turns.
By operating the hydraulic motor 10 via the flow path switching valve, the outer wheel is given a larger rotational force than that of the inner wheel, or the inner wheel is provided with a larger rotational force than that of the outer wheel so that the vehicle is yawed. It is designed to generate a moment.

[0007]

However, in the conventional left / right driving force distribution device, the hydraulic pump 1 is used.
Since 1 is provided on the tip side of the drive transmission mechanism 12 that extends long in the direction orthogonal to the axles 8 and 9, this center of gravity position is sufficiently separated from the center of gravity position of the entire unit of the left and right power distribution device. It will be in the position. For this reason, the weight balance of the vehicle body may be deteriorated and the mobility of the vehicle may be adversely affected, and a large installation space is required, which leads to an increase in the size of the entire device, which increases the weight of the vehicle and It is forced to deteriorate the mountability.

Further, since the hydraulic pump 11 is provided on the tip end side of the drive transmission mechanism 12 as described above, the distance between the hydraulic pump 10 and the hydraulic motor 10 is increased, and the supply between the hydraulic pump 11 and the hydraulic motor 10 is increased. As the exhaust passage becomes longer, the handling of the pipe becomes complicated. Furthermore, since the high-pressure pipe must be provided outside the device, there is a technical problem that the hydraulic oil easily leaks from the connection point or the like.

[0009]

The present invention has been devised in view of the technical problems of the above-mentioned conventional apparatus. The invention according to claim 1 is a rotational drive of a propeller shaft connected to the engine side. The differential case in which the force is transmitted via the gear gears, the differential device that distributes and transmits the driving force input to the differential case to the left and right axles, and the relative rotational force is applied between the left and right axles as necessary. A left and right driving force distribution device for a vehicle, comprising: a hydraulic motor for driving the hydraulic motor; and a hydraulic pump for rotationally driving the hydraulic motor, wherein a spur gear for driving the hydraulic pump is provided on an outer periphery of the differential case. There is.

According to a second aspect of the present invention, the hydraulic pump is arranged parallel to the left and right axles, and the pump shaft of the hydraulic pump is linked to the spur gear via a predetermined gear. Is characterized by.

Therefore, according to the present invention, the hydraulic pump can be arranged parallel to the axle on the side of the differential carrier in which the differential case is accommodated.
The hydraulic pump, the flow path switching valve and the like can be integrated into a unit. As a result, the entire structure can be made compact, and the center of gravity can be moved closer to the center of the vehicle and lower. As a result, the vehicle body can be reduced, the mountability on the vehicle body is improved, the weight balance of the vehicle body is improved, and the motility of the vehicle is not adversely affected, and stable traveling performance can be secured.

According to a third aspect of the present invention, a planetary gear mechanism is provided between the motor shaft of the hydraulic motor and the left and right axles to which a necessary rotational driving force is applied from the motor shaft. Is characterized by.

According to another aspect of the invention, the hydraulic pump comprises a plurality of cylinders radially formed inside a cylinder block, and a plunger provided in each cylinder slidably in the radial direction. And a hydraulic pressure supply / discharge passage for supplying / discharging hydraulic pressure from the hydraulic pump to / from the cylinder to slide the plunger, the hydraulic supply / discharge passage being connected to two positions of the cylinder. .

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each embodiment of a left and right driving force distribution device for a vehicle according to the present invention will be described in detail with reference to the drawings.

1 to 3 are general configuration diagrams of a first embodiment of a left-right driving force distribution device according to the present invention. A differential device of a vehicle accommodated in a differential carrier 20 is a so-called planetary gear. It is a gear type, and the rotational force of a propeller shaft (not shown) connected to the engine side is applied from the drive shaft 21 to the drive pinion 22 and the ring gear 2.
3 is transmitted to the differential case 24, and the rotational force of the differential case 24 is evenly distributed to the left and right axles 28 and 29 by the plurality of planetary gears 26 and the sun gear 27 via the ring gear 25 on the inner peripheral side, and the planetary gear 26 has Due to the rotation, the rotation speed difference between the left and right axles 28, 29 is absorbed. Further, each planetary gear 26 is rotatably supported by supporting bodies 26b on both sides via a support shaft 26a.

That is, the differential case 24 is mounted on the differential carrier 20 fixed to the vehicle body by the bearing 3
While being rotatably supported via 0a and 30b,
A planetary gear 26 is rotatably attached to the support body 26b inside the differential case 24, and a sun gear 27 meshed with the planetary gear 26 is coupled to one axle 28. Further, the support 26b is provided with side covers 40, 41 of the hydraulic motor 31 as described later.
Is connected to the other axle 29 via.

The left / right driving force distribution device applies a relative rotational force between the left and right axles 28, 29 at a position adjacent to the differential device in the differential carrier 20 in the axial direction. The radial plunger type hydraulic motor 31 is disposed, and a pair of supply / discharge passages 32, 33 for appropriately sucking / discharging the hydraulic fluid to / from the hydraulic motor 31 are formed inside the differential carrier 20. .

Further, the differential carrier 20
At a position opposite to the drive shaft 21 of the radial plunger type hydraulic pump 34 for supplying / discharging the working hydraulic pressure to / from the hydraulic motor 31 via the supply / discharge passages 32, 33.
And a flow path switching valve 35 for switching the flow path of the hydraulic oil discharged or sucked from the hydraulic pump 34 is provided on the outer side of the hydraulic pump 34.

Specifically, the hydraulic motor 31 will be described.
Is a radial plunger type, and as shown in FIG.
Is connected to a reservoir tank 36 via a flow path switching valve 35, and the supply and discharge of hydraulic fluid can be switched by operating the flow path switching valve 35 by a controller (not shown). Cylinder block 38 held so as to be movable back and forth in the radial direction via 38a
And a cam ring 39 that is arranged in the outer peripheral region of the cylinder block 38 and engages with the tip of each plunger 37. On both sides of the cam ring 39, one side cover has a boss portion 40a that extends in the axial direction. 40 and 41 are integrally connected. Further, the cylinder block 38 and the side covers 40, 41 are provided with a ball bearing 42.
They are rotatably supported relative to each other via a and 42b.

The side covers 40 and 41 are mounted on the differential carrier 2 by bearings 43a and 43b.
0 is rotatably supported, and the boss portion 40a of the one side cover 40 is splined to the support body 26b. Therefore, the cam ring 39 and the side cover 4
The motor case constituted by 0 and 41 always rotates integrally with the differential case 24.

Further, each cylinder hole 38a formed radially in the cylinder block 38 accommodates a spring 44 for urging each plunger 37 toward the cam ring 39, and one end surface of each cylinder hole 38a is accommodated. An internal passage 45 communicating with the supply / discharge passage 3 is formed with an opening.
The working fluid can be supplied to and discharged from each of the cylinder holes 38a through the inner passages 45 from the second and the third passages 33.

The inner passages 45 are arranged in pairs in the circumferential direction at intervals of one, and when the working fluid is supplied to one of the groups, the working fluid is discharged from the other group. It is supposed to be done. The profile of the inner peripheral surface of the cam ring 39 imparts a continuous rotary motion from the plunger 37 to the cam ring 39 when the hydraulic fluid is alternately supplied to and discharged from one set and the other set of the internal passage 45 described above. It is set to be done.

A rotatable roller 46 is attached to the tip of each plunger 37.
It comes into contact with the inner peripheral surface of the cam ring 39 through.

On the other hand, as shown in FIGS. 1 and 2, a variable displacement radial plunger pump is used as the hydraulic pump 34, and a side portion of the differential carrier 20 is parallel to the axles 28, 29. The differential case 24 is rotationally driven to operate the pump.

That is, a spur gear 47 is integrally formed on the outer periphery of the differential case 24.
7 is a differential carrier 20 and a hydraulic pump 34.
The rotational force is transmitted to a drive gear 49a of a pump shaft 49, which will be described later, of the hydraulic pump 34 via an idle gear 48 provided inside a gear case 48 provided between

The hydraulic pump 34 has a cylinder block 52 in which a plurality of plungers 51 are provided in a cylinder hole 52a so as to be able to move forward and backward in a radial direction at one end side of a pump casing 50 extending substantially parallel to the differential carrier 20. And a cam ring 53 that is arranged in the outer peripheral area of the cylinder block 52 and engages with the tip of each plunger 51.
It has and. The cylinder block 52 is formed integrally with the pump shaft 49, is rotatably supported by the pump casing 50 by a bearing 58, and is internally connected to a first end surface of each cylinder hole 52a. While the passage 55 is opened, second communication passages 56 that communicate with the other end surface of the cylinder hole 52a are formed. Then, the first and second communication paths 5
The hydraulic pressure is supplied to and discharged from the hydraulic motors 5, 56 to the hydraulic motor 31 through the supply and discharge passages 32, 33. Also,
Each cylinder hole 52a communicates with the reservoir tank 36 via the first and second communication passages 55, 56 and the intake pipe 57. Further, the openings of the first and second communication passages 55, 56 on the cylinder hole 52a side are formed in a long hole shape along the circumferential direction of the cylinder hole 52a.

A pressure control valve 59 is provided between the pump casing 50 and the flow path switching valve 35 to control the discharge pressure from each cylinder hole 52a to a constant value. The black and white arrows displayed in the supply / discharge passages 32 and 33 indicate the flow direction of the hydraulic oil when the driving torque of the hydraulic motor 31 is changed to the left or right.

In the other end of the pump casing 50, that is, between the pump shaft 49 and the drive gear 49a,
A one-way clutch 60 is provided which operates the hydraulic pump 34 only when the vehicle is traveling forward and stops the pump function when traveling backward. That is, the hydraulic pump 34
Since the power is transmitted from the propeller shaft through the differential case 24, it is rotationally driven not only when the vehicle travels forward, but also when it travels backward. The operation of the hydraulic pump 34 is stopped at the time of traveling in reverse so that the pump function is not adversely affected.

Therefore, in the hydraulic pump 34, while the vehicle is traveling forward, the idle shaft 48 meshed with the spur gear 47 with the rotation of the differential case 24, and the pump shaft 49 via the drive gear 49a meshed therewith. The rotation causes the cylinder block 52 to rotate, and the plungers 51 move forward and backward to operate the pump.

The operation of the left-right driving force distribution device will be briefly described below. When the flow path switching valve 35 is in the neutral position, both supply / discharge passages 32, 33 of the differential carrier 20 are connected to the reservoir tank 36. Since they communicate with each other, the motor case of the hydraulic motor 31 and the cylinder block 38 are in a free rotation state. Therefore, at this time, equal driving force is transmitted from the propeller shaft to the left and right axles 28, 29 through the differential device. Therefore, the torque is distributed to each axle 28, 29 in the same manner as in a general vehicle.

From this state, when the flow path switching valve 35 is switched to, for example, one side by the control of the controller, one supply / discharge passage 3 of the differential carrier 20.
1 communicates with the hydraulic pump 34, and the other supply / discharge passage 32 communicates with the reservoir tank 36. As a result, high-pressure hydraulic fluid is supplied from one of the supply / discharge passages 31 to the internal passage 45 of half of the cylinder block 38, and the hydraulic fluid is supplied from the other half of the internal passages 45 of the cylinder block 38 to the other supply / discharge holes. Then, the plunger 37 on the cylinder block 38 relatively rotates the cam ring 39 in one direction at this time.

As a result, the diff cover 24 and the sun gear 27 rotate in the same direction via the support 26b splined to the boss portion 40a of the side cover 40, and a rotational force is applied to the left axle 28. Therefore, the rotational force of the hydraulic motor 31 directly acts between the left and right axles 28, 29 to cause a rotation difference. As a result, the axle 28 on the left side is accelerated and the axle 29 on the right side is decelerated, and the driving force of the drive shaft 21 is distributed to the axles 28, 29 on the left and right according to the ratio of the acceleration and deceleration.

Further, when the flow path switching valve 35 is switched to the other side by the control signal of the controller, the action opposite to that described above, that is, the other supply / discharge passage 32 communicates with the hydraulic pump 34, The supply / drain passage 31 communicates with the reservoir tank 36. As a result, the high-pressure hydraulic fluid is supplied from the other supply / discharge passage 32 to the other half of the internal passages 45 of the cylinder block 38, and the hydraulic fluid is supplied from the other half of the internal passages 45 of the cylinder block 38 to the other supply / discharge. The plunger 37 on the cylinder block 38 causes the cam ring 39 to relatively rotate in the other direction. As a result, the axle 29 on the right side is accelerated, while the axle 28 on the left side is decelerated, contrary to the above, and the driving force of the drive shaft 21 is applied to the left and right axles 28, 29 at a rate according to this acceleration / deceleration. Will be distributed.

Further, according to this embodiment, since the spur gear 47 is formed on the outer periphery of the differential case 24, the hydraulic pump 32 is arranged on the side of the differential carrier 20 in parallel with the axles 28, 29. Therefore, as shown in FIG. 2, the hydraulic pump 34 and the flow path switching valve 35 are
Also, the pressure control valve 59 can be integrated into a unit. As a result, the entire structure can be made compact, and the center of gravity can be moved further toward the center of the vehicle body and at a lower position. As a result, the vehicle body can be reduced, the mountability on the vehicle body is improved, the weight balance of the vehicle body is improved, and the motility of the vehicle is not adversely affected, and stable traveling performance can be secured.

Further, by unitizing the above-mentioned components, it is possible to form almost all of the supply / discharge passages 32, 33 in the pump casing 50 and the differential carrier 21. It is possible to prevent the hydraulic oil from leaking, which is likely to occur when a high-pressure pipe is used outside.

The cylinder hole 5 of the hydraulic pump 34
Since the first and second communication passages 55 and 56 can be formed with respect to 2a, respectively, the passage cross-sectional area can be expanded, and the suction and discharge efficiency at high pump rotation speed can be improved. In addition, pump noise can be reduced and reliability can be improved by improving suction and discharge efficiency when the pump temperature is low. Further, since the opening shape of both the communication passages 55 and 56 on the cylinder hole 52a side is formed in the elongated shape, the suction and discharge efficiency can be further improved without changing the size of the unit.

Further, due to the increase of the suction and discharge passages (communication passages), the pressure balance at the time of sliding of each plunger 51 in each cylinder hole 52a becomes good, and as a result, the amount of hydraulic oil leak is reduced. In addition, the wear resistance due to the sliding can be improved.

Further, in this embodiment, the hydraulic pump 34
Since the structure of (1) is of a radial plunger type, it can be operated at an extremely high rotation speed, and it becomes possible to obtain a pump discharge pressure that meets a sufficient use condition.

FIGS. 4 and 5 show a second embodiment of the present invention. In this embodiment, a planetary gear mechanism 60 is provided on the right axle 28 that is the motor shaft of the hydraulic motor 31. That is, a carrier 63 that rotatably supports a plurality of planetary gears 62 via respective support shafts 61 is arranged and fixed to the cylinder block 38 on the side cover 40 side, and at the center of each planetary gear 62. A sun gear 63 fixed to the axle 28 is provided. Further, each planetary gear 62 is meshed with a tooth portion 40b formed on the inner peripheral surface of the side cover 40.

Therefore, according to this embodiment, when the hydraulic motor 31 is rotationally driven by using the hydraulic pump 34 as a hydraulic power source, the side covers 40 and 41 are rotated in accordance with the left or right rotation of the cam ring 39. Rotational torque is transmitted from the sun gear 63 to the axle 2 via each planetary gear 62.
The transmission rotational torque can be increased or decreased as required by the planetary gear mechanism 60. As a result, the hydraulic motor 31 can be applied to various types of vehicles simply by changing the size of the planetary gear mechanism 60 without changing the volume of the hydraulic motor 31, which is highly versatile.

The present invention is not limited to the configuration of each of the above-described embodiments. For example, the differential device may be configured by a bevel gear type instead of the planetary gear type, and the hydraulic motor 31 or the like. The structure of the hydraulic pump 34 may be a vane type pump instead of the radial plunger type. Further, the spur gear 47 provided on the differential case 24 may be formed integrally with the differential case 24 or may be provided separately.

[0042]

As is apparent from the above description, claim 1
According to the invention described in (1), since the spur gear is formed on the outer periphery of the differential case, the degree of freedom in layout of the hydraulic pump and the like is improved, and the mountability on the vehicle body is improved.

Further, since the spur gear allows the reduction ratio with the hydraulic pump to be freely set, it can be applied to various vehicles.

According to the second aspect of the present invention, since the hydraulic pump can be arranged parallel to the axle on the side of the differential carrier in which the differential case is accommodated, the hydraulic pump and the flow path switching valve can be arranged. Etc. can be integrated into a unit. As a result, the entire structure can be made compact and the center of gravity can be moved closer to the center of the vehicle. As a result, the vehicle body can be reduced, the mountability on the vehicle body is improved, the weight balance of the vehicle body is improved, and the motility of the vehicle is not adversely affected, and stable traveling performance can be secured.

Moreover, since the respective supply / discharge passages can be formed in the pump casing or the differential carrier by unitizing each component, it is likely to occur when a high-pressure pipe is used outside. It becomes possible to prevent the leakage of hydraulic oil. Further, the total length of each supply / discharge passage can be shortened and the handling becomes easy.

According to the invention described in claim 3, by providing the planetary gear mechanism between the hydraulic motor and the axle,
Since the rotational drive torque of the hydraulic motor can be freely set, it can be applied to various types of vehicles simply by changing the size of the planetary gear mechanism without changing the volume of the hydraulic motor. , Versatile.

According to the fourth aspect of the invention, since two communication passages are formed in the cylinder hole of the hydraulic pump, the passage sectional area can be increased.
Pump noise can be reduced and reliability can be improved by improving the suction and discharge efficiency when the pump is rotating at high speed and improving the suction and discharge efficiency when the pump is at low temperature.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a side view showing a part of the same embodiment in section.

FIG. 3 is a schematic view of the same embodiment.

FIG. 4 is a sectional view showing a second embodiment.

FIG. 5 is a schematic diagram of the same embodiment.

FIG. 6 is a cross-sectional view showing a conventional device.

[Explanation of symbols]

20 ... Differential Carrier 21 ... Drive shaft 22 ... Drive pinion 23 ... Ring gear 24 ... Differential case 28, 29 ... Axle 31 ... Hydraulic motor 32, 33 ... Supply and discharge passage 34 ... Hydraulic pump 35 ... Flow path switching valve 47 ... spur gear 48 ... Idol gear 49 ... Pump shaft 50 ... Pump casing 59 ... Pressure control valve 60 ... Planetary gear mechanism

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Claims (4)

[Claims] 1. A differential case in which the rotational driving force of a propeller shaft connected to the engine side is transmitted via a gear wheel, and a differential device for distributing and transmitting the driving force input to the differential case to the left and right axles. A left and right driving force distribution device for a vehicle, comprising: a hydraulic motor that applies a relative rotational force between the left and right axles as necessary, and a hydraulic pump that rotationally drives the hydraulic motor, wherein: A left-right driving force distribution device for a vehicle, comprising a spur gear for driving the hydraulic pump. 2. The hydraulic pump is arranged parallel to the left and right axles, and the pump shaft of the hydraulic pump is linked to the spur gear via a predetermined gear. A left-right driving force distribution device for a vehicle as described in. 3. A planetary gear mechanism is provided between a motor shaft of the hydraulic motor and the left and right axles to which a necessary rotational driving force is applied from the motor shaft. A left-right driving force distribution device for a vehicle as described in. 4. The hydraulic pump comprises a plurality of cylinders radially formed inside a cylinder block, and a plunger slidably provided in each cylinder in a radial direction.
A hydraulic pressure supply / discharge passage for supplying / discharging hydraulic pressure from the hydraulic pump into / from the cylinder to slide the plunger, the hydraulic supply / discharge passage being connected to two positions of the cylinder. The lateral driving force distribution device for a vehicle according to any one of 1 to 3.