JPH07164900A - Driving device for vehicle - Google Patents

Abstract

PURPOSE:To simplify a fitting structure of a hydraulic motor and a hydraulic pump disposed in the rear of a car body as engine auxiliary driving means and to make the same in a compact size. CONSTITUTION:A hydraulic motor ML for driving a left wheel and a hydraulic motor MR for driving a right wheel are disposed in such a manner as to butt each other in the inner end part in the car width direction, a hydraulic pump P for supplying oil pressure to the respective hydraulic motors ML, MR is disposed near in front of the butt part of the hydraulic motors ML, MR, a bracket 108 is fitted to the brackets 110L, 110R of the respective hydraulic motors ML, MR, and further the hydraulic pump P is connected to its driving source through a propeller shaft 14. Thus, the paired hydraulic motors ML, MR and the hydraulic pump P are formed in a compact unit, and the unit can be installed on a car body through motor mount brackets 112L, 112R of the hydraulic motors ML, MR and a pump mount bracket 114 of the hydraulic pump P.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a hydraulic motor connected to a wheel via a drive shaft extending substantially in the vehicle width direction, and a vehicle drive device configured to rotationally drive the wheel by the hydraulic motor. It is about.

[0002]

2. Description of the Related Art Conventionally, a vehicle drive device using a hydraulic motor or an electric motor as an auxiliary driving force source other than an engine has been known. For example, JP-A-57-7422
Japanese Unexamined Patent Publication No. Hei 4 (1999) -264 discloses a vehicle drive device equipped with a hydraulic motor as the auxiliary drive force source.
Japanese Patent Laid-Open No. 243627 discloses a vehicle drive device including an electric motor as the auxiliary drive force source.

In such a vehicle drive device, one of the front and rear wheels is driven by the engine and the other is driven by the motor. The above-mentioned motor is generally provided for each of the left and right wheels, and is adapted to rotationally drive each wheel via a drive shaft extending in the vehicle width direction.

[0004]

In the vehicle drive device having the hydraulic motor as the auxiliary driving force source, a hydraulic pump for supplying hydraulic pressure to the pair of left and right hydraulic motors is required. The pump is generally provided near the output shaft of the engine. For example, in a so-called FF type vehicle, a hydraulic pump is generally arranged in the front part of the vehicle body together with an engine. Therefore, the FF type vehicle is provided with hydraulic piping for sending hydraulic pressure from the hydraulic pump arranged at the front part of the vehicle body to each hydraulic motor arranged at the rear part of the vehicle body. Also, hydraulic piping for sending hydraulic pressure from the hydraulic pump arranged at the rear portion of the vehicle body to each hydraulic motor arranged at the front portion of the vehicle body is provided. In each of these cases, long hydraulic piping is required,
Due to the hydraulic piping space, there is a problem in that the layout of the vehicle body is greatly restricted and a pressure loss in the hydraulic piping becomes large.

On the other hand, the hydraulic pump and the pair of hydraulic motors are arranged on the same side in the front and rear of the vehicle body, and the hydraulic pump is connected to the engine output shaft through a propeller shaft extending in the vehicle longitudinal direction. Then, although a space for disposing the propeller shaft is newly required, since the long hydraulic pipe as described above is not necessary, the above problem can be solved.

However, in this case,
Since the hydraulic pump is also arranged at the front or rear of the vehicle body on which the pair of hydraulic motors are arranged, the mounting on these vehicle bodies is devised to simplify and compact the mounting structure. It is desirable to plan.

The present invention has been made in view of the above circumstances, and when a pair of hydraulic motors and hydraulic pumps are arranged on the same side of the front and rear of the vehicle body, they are attached to the vehicle body. It is an object of the present invention to provide a vehicle drive device that can be simplified and made compact.

[0008]

According to the vehicle drive device of the present invention, the arrangement of the pair of hydraulic motors and the hydraulic pumps is devised, and the hydraulic pumps are attached to the respective hydraulic motors. The above-mentioned purpose is achieved.

That is, the present invention provides a vehicle drive device comprising a hydraulic motor connected to a wheel through a drive shaft extending substantially in the vehicle width direction, the hydraulic motor being configured to rotationally drive the wheel. The invention according to claim 1 is based on the premise that the hydraulic motor for driving the left wheel and the hydraulic motor for driving the right wheel project from each other at inner ends of the respective hydraulic motors in the vehicle width direction. Hydraulic pumps that are arranged so as to be matched with each other and that supply hydraulic pressure to the respective hydraulic motors are arranged near the abutting portion of the respective hydraulic motors and are attached to the respective hydraulic motors and drive the hydraulic pumps. It is characterized in that it is connected to a driving force source via a propeller shaft. The invention according to claim 2 is characterized in that the hydraulic motor for driving the left wheel and the right motor. The wheel drive hydraulic motors are arranged apart from each other in the vehicle width direction, and hydraulic pumps that supply hydraulic pressure to the respective hydraulic motors are arranged between the respective hydraulic motors. And a driving force source for driving the hydraulic pump via a propeller shaft, the invention according to claim 3 is characterized in that: The hydraulic motors for driving the right wheels are arranged apart from each other in the vehicle width direction, and hydraulic pumps that supply hydraulic pressure to these hydraulic motors are provided between the hydraulic motors and to the hydraulic motors. On the other hand, a propeller shuff arranged at a position displaced in the longitudinal direction of the vehicle body, attached to each of the hydraulic motors, and inserted between the pair of hydraulic motors as a driving force source for driving the hydraulic pumps. The are coupled via, it is characterized in.

The "driving force source" is typically an engine, but is not particularly limited, and may be a motor or other driving force source.

[0011]

As described above, in the invention described in claim 1, the hydraulic motor for driving the left wheel and the hydraulic motor for driving the right wheel are the inner ends in the vehicle width direction of these hydraulic motors. And a hydraulic pump that supplies hydraulic pressure to each of the hydraulic motors is disposed near the abutting portion of each hydraulic motor and is attached to each hydraulic motor and drives the hydraulic pump. The pair of hydraulic motors and hydraulic pumps can be attached to the vehicle body as a unit because they are connected to the driving force source via a propeller shaft.
For this reason, it is not necessary to mount each hydraulic motor or hydraulic pump on the vehicle body, and the mounting structure on the vehicle body can be simplified. Further, since the hydraulic pump and the respective hydraulic motors are extremely close to each other, the hydraulic pipes can be eliminated or can be made extremely short, which makes the pair of hydraulic motors and hydraulic pumps compact as a whole. Can be configured. Moreover, this can improve the operation response of each hydraulic motor.

Further, in the invention according to claim 1,
Since the pair of hydraulic motors are arranged so as to abut against each other at the vehicle width direction inner end, the left and right drive shafts can be formed to be long, and as a result, bump rebound of the wheel can be achieved. Along with this, the axial load input to each drive shaft can be reduced to prevent an unreasonable load from acting on each hydraulic motor.

The pair of hydraulic motors need only be arranged so as to abut each other at the inner ends in the vehicle width direction, and it is not necessary to join them, but they may be joined together. However, by doing so, the mounting rigidity of the pair of hydraulic motors and hydraulic pumps to the vehicle body can be improved.

According to the second aspect of the invention, the hydraulic motor for driving the left wheel and the hydraulic motor for driving the right wheel are spaced apart from each other in the vehicle width direction, and the hydraulic pressure is supplied to each of these hydraulic motors. The hydraulic pumps to be installed are mounted between the hydraulic motors and attached to the hydraulic motors, and are connected to a driving force source for driving the hydraulic pumps via a propeller shaft. The pair of hydraulic motor and hydraulic pump can be attached to the vehicle body as a unit. Therefore, it is not necessary to mount each hydraulic motor or hydraulic pump on the vehicle body, and the mounting structure on the vehicle body can be simplified. Further, since the hydraulic pump and the respective hydraulic motors are extremely close to each other, the hydraulic pipes can be eliminated or can be made extremely short, which makes the pair of hydraulic motors and hydraulic pumps compact as a whole. Can be configured. Moreover, this can improve the operation response of each hydraulic motor.

Further, in the invention according to claim 2,
Since the hydraulic pump is arranged between the pair of hydraulic motors, the lengthening of the left and right drive shafts is sacrificed as compared with the invention of claim 1, but the pair of hydraulic motors and hydraulic pumps It is possible to further reduce the size of the vehicle body in the front-rear direction.

According to the third aspect of the invention, the hydraulic motor for driving the left wheel and the hydraulic motor for driving the right wheel are spaced apart from each other in the vehicle width direction, and the hydraulic pressure is supplied to each of these hydraulic motors. Hydraulic pumps are installed between the hydraulic motors and at positions displaced relative to the hydraulic motors in the front-rear direction of the vehicle body, are attached to the hydraulic motors, and the pair of driving force sources drive the hydraulic pumps. Since the hydraulic motors of (1) and (2) are connected via a propeller shaft that passes through, the pair of hydraulic motors and hydraulic pumps can be attached to the vehicle body as a unit, as in the first aspect of the invention. Therefore, it is not necessary to mount each hydraulic motor or hydraulic pump on the vehicle body, and the mounting structure on the vehicle body can be simplified. Further, since the hydraulic pump and the respective hydraulic motors are extremely close to each other, the hydraulic pipes can be eliminated or can be made extremely short, which makes the pair of hydraulic motors and hydraulic pumps compact as a whole. Can be configured. Moreover, this can improve the operation response of each hydraulic motor.

Further, in the invention according to claim 3,
The pair of hydraulic motors are arranged so as to be spaced apart from each other in the vehicle width direction, but the spacing dimension is sufficient as long as the dimension that allows the propeller shaft to be inserted is secured, so it is not as great as the invention of claim 1. Although not provided, the left and right drive shafts can be made longer than in the second aspect of the invention.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram showing a first embodiment of a vehicle drive device according to the present invention.

As shown in the figure, in the vehicle drive system according to this embodiment, the front wheels 1FL, 1FR are driven by the engine 2 as main drive wheels, and the rear wheels 1RL, 1RR are hydraulic motors M.
A device that is driven by L and MR as auxiliary drive wheels, and is characterized by the layout of the hydraulic motors ML and MR and its peripheral members. Before describing this, first, referring to FIGS. A drive system of the hydraulic motors ML and MR will be described based on the above.

Description of hydraulic system, etc. (FIG. 1) In FIG. 1, 1FL is the left front wheel, 1FR is the right front wheel, 1R
L is the left rear wheel, and 1RR is the right rear wheel. An engine 2 is arranged in front of the vehicle body, and a driving force of the engine 2, that is, a generated torque is transmitted to a transfer 5 equipped with a differential device via a clutch 3 and a manual transmission 4 having five forward gears and one reverse gear. To be done. Then, the engine driving force is transmitted from the transfer 5 to the left and right front wheels 1FL and 1FR via the drive shafts 6L and 6R, and the universal joint 1
3, the engine driving force is transmitted to the hydraulic pump P (which will be described later) via the propeller shaft 14 extending in the vehicle front-rear direction and the universal joint 15.

The left and right front wheels 1FL and 1FR which are the steered wheels are linked by a steering link 7 such as a tie rod, and the steering link 7 and the steering wheel 8 are linked through a rack and pinion mechanism 9.

The left and right rear wheels 1RL, 1RR are the engine 2
Separately independently of, a pair of left and right hydraulic motors ML, MR
It is designed to be driven by rotation. That is,
The left rear wheel 1RL is rotationally driven by a hydraulic motor ML via a drive shaft 11L, and the right rear wheel 1RR is rotationally driven by a hydraulic motor MR via a drive shaft 11R.

The hydraulic motor ML (MR) is of a turbine type (impeller type) and has a first connection port La (Ra) and a second connection port La (Ra).
It has a connection port Lb (Rb), from La (Ra) to Lb
When the high-pressure oil liquid flows to (Rb), the rotation is in the forward direction, and when the high-pressure oil liquid flows in the opposite direction, the rotation is in the backward direction. And the hydraulic motors ML and MR
Have the same specifications as each other, and the total value of the maximum generated torque is 1/3 to 1/2 of the maximum generated torque of the engine 2.
It is considered as a degree.

In this embodiment, the hydraulic motors ML, M
The rear wheel drive by R is executed only under a predetermined condition described later. That is, even when the left and right front wheels 1FL and 1FR are driven by the engine 2, the left and right rear wheels 1RL and 1RR may not be driven by the hydraulic motors ML and MR.

P is a pump as a hydraulic pressure generation source. The hydraulic pump P is of a variable capacity type and is driven by the engine 2 via a propeller shaft 14. The high-pressure oil liquid pumped up from the reservoir tank 16 by the hydraulic pump P is discharged to the high-pressure line 18 to which the check valve 17 is connected. From the high-pressure line 18, first and second hydraulic pressure supply lines 31A and 31B connected to the check valve 10 or 32 and parallel to each other are led out. Further, a release line 23 is led out from the reservoir tank 16. Further hydraulic motor ML
From each connection port La, Lb (Ra, Rb) of (MR),
Parallel lines 20L, 21L (20R, 21R)
Has been derived.

Lines 20L and 21L of the hydraulic motor ML are parallel to the switching valve VVA, and lines 19 and 19L parallel to each other.
And lines 22 and 22L and switching valves VVB / L and VVE
-By using L, it is possible to selectively connect to the first supply line 31A and the release line 23. Similarly, the lines 20R and 21R of the hydraulic motor MR use the switching valve VVA, the lines 19 and 19R and the lines 22 and 22R which are parallel to each other, and the switching valves VVB · R and VVE · R to make the first line. The supply line 31A and the release line 23 can be selectively connected.

To the second common supply line 31B, a switching valve VVI is connected downstream of the check valve 32 and a flow dividing valve 34 is connected further downstream. Shunt valve 3
One branch supply line 33L branched into two by 4
Is connected to the line 19L and the other branch supply line 33
R is connected to line 19R.

An accumulator 41 for storing a high pressure oil pressure is connected to the high pressure line 18. For this high-pressure line 18, line 20L (20R)
Are connected by a passage 42L (42R). In this passage 42L (42R), a check valve 43L (43
R) and the switching valve VVF · L (VVF · R) are connected. The passages 42L and 42R are parallel to each other, and each of the valves VVA, VVB · L (VVB · R), VVE · L (V
VE / R), VVI, the shunt valve 34, etc. are bypassed.

The above line 20L (20R) and line 21
The L (21R) is communicated with the communication passage 51L (51R), and the variable orifice VVC · L (VVC · R) is connected to the communication passage 51L (51R).

The left and right hydraulic motors ML and MR are connected to each other by a communication passage 71, and an on-off valve VVD is connected to the communication passage 71.

The release line 23 is located upstream of the check valve 17 (hydraulic pump P with respect to the high pressure line 18).
Side), and is connected via a load / unload valve VVH, and is connected via a safety valve VVG on the downstream side of the check valve 17.

Description of Control Modes (Table 1) In this embodiment, as will be described later, there are a total of seven control modes, and the operating states of the above-mentioned valves when each mode is executed are summarized below. Are shown in Table 1. In this table, the symbols "L" and "R" for identifying the left and right are omitted. The load / unload valve VVH not shown in Table 1 is controlled to be opened / closed so that the pressure in the high pressure line 18 falls within a predetermined pressure range between a lower limit value and an upper limit value.

[0034]

[Table 1]

In the respective control modes shown in Table 1, the operating states of the valve, which plays a major role, will be specifically described as follows.

(1) Independent Mode In the independent mode, as will be described in detail later, the drive control of the hydraulic motors ML and MR is performed so that the left and right rear wheels 1RL and 1RR respectively have target rotational speeds set independently of each other. There are two types: forward drive (drive assistance) and reverse drive (braking). In this independent mode, the switching valve VVE ・ L,
Although the differential mode of VVE · R is set to the state shown in FIG. 1, the switching valve VVA is set to the central switching position and the first supply line 31 is used.
A is cut off. The switching valve VVI is set to the open position and the second
The hydraulic pressure is supplied using the supply line 31B. In this state, control the switching valves VVB / L and VVB / R,
Switching of the hydraulic pressure supply direction according to forward drive or reverse drive (setting of forward and reverse directions of the hydraulic motors ML and MR) and the supply flow rate to the hydraulic motors ML and MR are controlled.

In the reverse drive, a larger deceleration is obtained than in the hydraulic lock mode described later, but it goes without saying that the rear wheels 1RL, 1RR rotate in the direction opposite to the traveling direction of the vehicle. It does not give a great driving force.

(2) LSD mode The LSD mode obtains an operation limiting function and is a switching valve V
VB / L (VVB / R) is line 20L, 21L (20
R and 21R) are both closed to completely cut off the supply and discharge of hydraulic pressure to and from the hydraulic motor ML (MR). Then, the on-off valve VVD is opened, and both hydraulic motors ML and MR are
And the closed left and right hydraulic paths are communicated with each other to prevent a large rotation difference between the left and right hydraulic motors ML and MR. In this LSD mode, the variable orifice VVC.L (VVC.R) is fully closed.

(3) Hydraulic lock mode The hydraulic lock mode is used for the passage resistance, that is, the variable orifice V.
The deceleration force is obtained by using the throttle resistance of VC · L (VVC · R). In this hydraulic lock mode, the switching valve V
VB.L (VVB.R) is in the central switching position, lines 20L, 21L (20R, 21R) are shut off, and the on-off valve VVD is closed. Then, the variable orifice VVC · L (VVC · R) is opened. In this state, the oil liquid changes according to the rotation of the hydraulic motor ML (MR).
The variable orifice VVC · L (VVC · R) is circulated in a closed closed hydraulic circuit formed including the variable orifice VVC · L (VVC · R).
The throttle resistance of (VVC · R) gives a deceleration force to the vehicle. Then, the variable orifice VVC · L (VV
The opening degree of C / R is controlled so as to decrease as the deceleration of the vehicle increases (the variable orifice V corresponding to the deceleration V
Set the opening of VC / L and VVC / R by step E in FIG.
37).

(4) Pressure Accumulation Mode In the pressure accumulation mode, the hydraulic motors ML and MR are driven by the rotation of the rear wheels 1RL and 1RR as the vehicle travels, these hydraulic motors ML and MR function as pumps, and the accumulator 41 accumulates pressure. It is what makes me. In this pressure accumulation mode, the line 21L (21R) is communicated with the reservoir tank 16, while the opening / closing valve VVF · L (VVF · R) is opened, so that the oil liquid in the reservoir tank 16 is transferred to the hydraulic motor ML.
It is pumped up by (MR) and accumulated in the accumulator 41.

(5) Stopping Mode In the stopping mode, the hydraulic motor ML is used to stop the vehicle when the parking brake is not operating.
The drive control of the MR is performed (the drive of the hydraulic motors ML and MR is controlled so that the vehicle speed becomes the target vehicle speed 0).
In this case, the second supply line 31B is used as the hydraulic pressure supply line, and the hydraulic pressure supply / discharge control is performed by the switching valve VVB · L (VV
B ・ R) is used.

(6) Parking Mode The parking mode enhances the action of maintaining the parking state when the parking brake is operated. That is, in the parking mode, the switching valve VVB · L
(VVB · R) is set to the closed position of the central switching position, and the hydraulic pressure supply / discharge line is cut off.

(7) F / S mode The F / S mode is a fail-safe mode, and when there is any abnormality, for example, when the high pressure line 18 becomes abnormally high, the hydraulic motors ML and MR are normal. The safety valve VVG is opened to release the hydraulic pressure in the high pressure line 18 when the valve is no longer driven, when a certain valve is stuck, or when the oil temperature rises above a predetermined temperature. It

Description of Control System (FIG. 2) FIG. 2 shows a control system according to the present invention. In the figure, U1, U2 and U3 are control units each configured by using a microcomputer.
Is a main control unit for controlling the above-mentioned valves VVA and the like. The control unit U2 is for ABS control (antilock brake control), and the control unit U3 is for traction control. Further, S1 to S13 are sensors or switches, respectively.

The sensors S1 to S4 are used for the wheels 1FL to 1R, respectively.
The rotation speed of R, that is, the wheel speed is independently detected, and the wheel speed detected by each of the sensors S1 to S4 is transmitted from the control unit U2 to the control units U1 and U3. The sensor S5 detects the vehicle speed, and in the embodiment, detects the ground vehicle speed (absolute vehicle speed detection). The sensor S6 detects the shift position of the transmission 4, that is, the gear position. The sensor S7 detects the engine speed. The sensor S8 detects the steering angle of the steering wheel. The sensor S9 detects the accelerator opening. The sensor S10 detects the amount of depression of the brake pedal. The switch S11 is an ignition switch. The switch S12 is for detecting whether or not the parking brake is operated.

The sensor S13 detects a bad road (uneven road). For the rough road detection, for example, the sensor S13 detects the vertical stroke of the suspension,
The control unit U1 determines that a bad road is generated when a stroke of a predetermined amount or more occurs a predetermined number of times within a predetermined time. In addition, the control unit U determines that the sensor S13 detects up and down G (acceleration) acting on the vehicle body and that when the up and down G above a predetermined number occurs a predetermined number of times or more within a predetermined time, it is a bad road.
It may be configured such that 1 determines. The determination of the degree of rough road may be made by changing one or more of the threshold values for the rough road determination.

The signals from the sensors or switches S5 to S13 are input to the control unit U1, and the control unit U1 controls the above-mentioned valves VVA to VVJ. Of course, the control unit U2 is for preventing the wheels from being locked at the time of braking, and the control unit U2 controls the brake fluid pressure adjusting means 81 for independently adjusting the brake of each wheel. . In addition, the control unit U3 uses the left and right front wheels 1FL, which are constantly driven wheels during acceleration,
When the slip on the road surface of 1FR becomes excessive,
At least the engine output (torque generated by the engine 2) is reduced, and for example, the torque adjusting means 82 for adjusting the opening of the throttle valve of the engine 2, the ignition timing, the fuel injection amount, etc. is controlled.

From the control unit U2 to the control unit U1, in addition to the wheel speed signals detected by the sensors S1 to S4, A
The ABS signal indicating that the BS control is being executed and the μ signal indicating the road surface μ (friction coefficient) are transmitted. Further, a wheel speed signal is transmitted from the control unit U2 to the control unit U3. Further, from the control unit U3 to the control unit U1, a TRC signal indicating that the traction control is being executed, a torque reduction amount signal indicating a reduction amount of the engine torque performed by the traction control, and a road surface μ signal are transmitted. It The detection of the road surface μ can be performed by the control unit U1, and the sensors S1 to S can be used.
Each wheel speed detected in 4 may be directly input to the control unit U1.

Description of Flowchart (FIG. 3) Next, the control content of the control unit U1 will be described with reference to the flowcharts in FIG. In the following description, D, E, W, and Z indicate steps.

First, in the main flow chart of FIG. 3, after signals from the respective sensors are input at D1, it is determined at D1 whether or not the ignition switch is ON. When the determination in D2 is NO, the safety valve VVG is opened and the pressure in the high pressure line 18 is released in D3. On the other hand, when the determination in D2 is YES, the safety valve VVG is closed and the high pressure hydraulic pressure is supplied to the high pressure line 18 in D4.

At D5, it is judged if the vehicle speed (vehicle speed to ground) is substantially zero. If YES in the determination of D5, it is determined in D6 whether or not the gear position of the transmission 4 is neutral. If YES in the determination of D6, it is determined in D7 whether or not the parking brake is operated. When the determination in D7 is YES, the parking mode control is executed in D8. D
When the determination in No. 7 is NO, the control in the vehicle stop mode is executed in D9.

If NO in D5 and NO in D6, the transmission 4 is set in D10.
It is determined whether or not the gear position of is the reverse position. D1
When the determination result in 0 is NO, in D11, it is determined whether or not the stack is currently in progress. Whether or not this is the stack is determined to be the stack, for example, when the accelerator is stepped on, the vehicle speed is almost 0, and the rotation speeds of the front left and right wheels 1FL, 1FR are sufficiently higher than the vehicle speed. Can be determined. When the determination in D11 is NO, in D12, as will be described later, it is determined whether or not to execute a control mode other than the parking mode and the stop mode.

If YES in the determination in D10, drive assistance using the hydraulic motors ML and MR is executed in D15, but in this case, reverse drive is performed in the independent mode (rear wheel in the backward direction). Drive 1RL, 1RR). If YES in the determination of D11, in D14,
Drive assist using the hydraulic motors ML and MR is executed, but in this case, normal drive is performed in the independent mode described later in which the target vehicle speed is set to a low vehicle speed (for example, about 10 km / h which is a stack release condition). Be seen.

Description of Flowchart (FIGS. 4-9) Details of D12 in FIG. 3 are shown in the flowcharts of FIGS. First, at E23 in FIG.
It is determined whether or not the traction control by the control unit U3 is being performed. When the determination in E23 is NO, in E24, it is determined whether or not the vehicle is currently traveling on a rough road.
When the determination in E24 is NO, in E25, it is determined whether or not the road surface is low μ. N in the judgment of E25
When it is O, it is determined in E26 whether or not the vehicle is currently traveling straight ahead. In the present embodiment, whether or not the vehicle is going straight is determined by calculating the lateral G based on the steering angle and the vehicle speed.
When the lateral G is less than or equal to a predetermined value, it is determined that the vehicle is traveling straight ahead.

When the determination in E26 is YES, E27 to
The processing of E39 is performed, but this processing is premised on a good road, a high μ road, and a straight road. And finally, whether the control conditions for performing the positive drive (E28) in the independent mode, the reverse drive (E35) in the independent mode, the pressure accumulation mode (E33, E39) or the hydraulic lock mode (E31, E37) are satisfied. It is determined whether or not.

The degree of acceleration and the degree of deceleration can be made by various known methods. For example, the degree of acceleration is
It can be known by any one or a plurality of combinations of the accelerator pedal depression speed, the accelerator pedal depression amount, the vehicle body acceleration obtained by differentiating the vehicle speed, and the like. Further, the degree of deceleration is, for example, one or any of an accelerator release speed, a brake depression speed, an increase amount of the brake depression amount, a vehicle deceleration obtained by differentiating the vehicle speed, and the like. It can be known by the combination of. However, in the embodiment, at least when the accelerator return speed is fast (the accelerator release speed is fast), it is determined that the deceleration is not less than the slow deceleration for setting the hydraulic lock mode.

If NO in the determination at E26 in FIG.
5 is performed, but FIG. 5 is premised on a good road, a high μ road, and during turning. Then, finally, it is determined whether or not the control conditions for performing the forward drive (E42) and the reverse drive (E44) in the independent mode or the LSD mode (E45) are satisfied.

If the determination at E25 in FIG. 4 is YES, the processing shown in FIG. 6 is performed. In FIG. 6, first, E5
At 1, it is determined whether or not the vehicle is traveling straight ahead. This E
When the result of the determination in step 51 is YES, the processes of E52 to E59 are performed, but this is a process on the assumption that the road is a good road, a low μ road, and is straight ahead. Then, finally, it is determined whether or not the control conditions for performing the forward drive (E55) and the reverse drive (E57) in the independent mode, the hydraulic lock mode (E54), and the LSD mode (E59) are satisfied.

If NO in the determination at E51 in FIG.
The process shown in (1) is performed, but this process is performed on a good road, a low μ road, and on the assumption that the vehicle is turning. Then, finally, it is determined whether or not the control conditions for performing the positive drive (E62) in the independent mode, the hydraulic lock mode (E65), and the LSD mode (E66) are satisfied.

If the result of the determination in E24 of FIG. 4 is YES, then in E71 of FIG. 8, it is determined whether or not the road is a bad road. When the determination in E71 is NO, E71 to E86
However, this is the determination of the control mode on a slow road. Further, when the determination in E71 is YES, the processes after E91 in FIG. 9 are performed, but this is the determination of the control mode on a bad road.

Description of Flowchart (FIG. 10) FIG. 10 shows the details of the positive drive control in the independent mode.

First, after the data is input in Z1, the target vehicle speed VTR is set in Z2 using the accelerator opening and the shift position of the transmission 4 as parameters.

Next, at Z3, it is judged if the value obtained by subtracting the actual wheel speed VBL of the left rear wheel 1RL from the target vehicle speed VTR is greater than the predetermined speed V1. If the determination of Z3 is NO, it is determined that the drive assistance by the normal drive is not necessary, and the normal drive of the left rear wheel is stopped at Z14. The processes of Z3 and Z14 are performed independently for the right rear wheel 1RR and separately for the left rear wheel 1RL. The predetermined speed V1 is set to a speed indicating a slip amount sufficient for acceleration, but may be a constant value, or may be set to a variable value so that the vehicle speed VA increases as the vehicle speed VA increases.

When the determination of Z3 is YES, it is determined whether or not the accelerator is fully open in Z4. Even when the determination of Z4 is YES, the drive assistance using the hydraulic motors ML and MR is not necessary. Then, the process proceeds to Z14 (in this case, the right and left rear wheels 1RL, 1RR are simultaneously stopped for normal driving).

If the determination in Z4 is NO, in Z5, the lateral G acting on the vehicle body is calculated based on the vehicle speed VA and the steering wheel steering angle. After that, the correction coefficients K1 and K2 are set in Z6. Then, at Z7, it is determined whether or not the vehicle is making a right turn. YE by this Z7 discrimination
At S, the target wheel speed VTRL of the left rear wheel 1RL is calculated at Z9 by multiplying the target vehicle speed VTR determined at Z2 by the correction coefficient K1, and similarly, at the right rear wheel 1RR. The target wheel speed VTRR is the target vehicle speed V
It is calculated by multiplying TR by the correction coefficient K2.

If NO in Z7, the target wheel speeds of the left and right rear wheels 1RL, 1RR are calculated in Z8. After all, the processing of Z6 to Z9 corresponds to the processing of increasing the target wheel speed on the outer wheel turning side and slowing the target wheel speed on the inner wheel turning side. However, when going straight, the determination in Z7 is NO and the process moves to Z8. At this time, since the correction coefficient is 1 (lateral G is 0 or almost 0), the left and right rear wheels 1RL, The target wheel speeds of 1RR are equal to each other).

After Z8 or Z9, in Z10, the rear wheel 1RL is changed from the target wheel speed VTRL (VTRR).
The amount Q of oil supplied to the hydraulic motor ML (MR) is determined according to the value obtained by subtracting the actual wheel speed VBL (VBR) of (1RR). The oil liquid amount Q is independently determined for the left and right hydraulic motors ML and MR. Then, at Z11, the switching valves VVB · L and VVB · R are independently controlled so that the determined oil liquid amount Q is realized.

At Z12, it is judged if the value obtained by subtracting the actual wheel speed VBL of the left rear wheel 1RL from the vehicle speed VA is smaller than the predetermined speed "-V2". This Z
The determination of 12 is that the actual wheel speed VBL of the left rear wheel 1RL is
It is determined whether the vehicle speed is too high compared to the vehicle speed VA. If YES in Z12, in Z13,
Correction is performed to reduce the supply flow rate Q so that the rear wheels maintain the predetermined slip value. The processing of Z12 and Z13 is similarly performed for the right rear wheel 1RR. Z12
When the determination is NO, the routine returns without passing through Z13.

Description of Flowchart (FIG. 11) FIG. 11 shows details of reverse driving in the independent mode.

First, after the data is input in Z21, it is determined in Z22 whether the reverse drive flag is 1 or not. If NO in this determination of Z22, Z30
At, in the area set with the steering wheel steering angle and the vehicle speed VA as parameters, it is confirmed where the current state is. Then, in Z31, the current state is Z30.
It is determined whether or not the area C is in the hatched area C. If YES in the determination of Z31, Z3
After the reverse drive flag is set to 1 in 2
If NO in the determination of Z31, the process returns to Z21 without passing through Z32.

After passing through Z32, the determination of Z22 is YE.
At S23, it is determined at Z23 whether ABS control is currently being performed. N is judged by this Z23
When it is O, it is determined in Z24 whether or not the brake depression amount is large. When the determination in Z25 is NO, it is determined in Z25 whether the vehicle speed VA is at a low vehicle speed equal to or lower than the predetermined value V3.

When the determination in Z25 is NO, in Z26, the supply flow rate Q to the hydraulic motors ML and MR is determined using the vehicle speed VA and the shift position of the transmission 4 as parameters. After that, in Z27, the switching valves VVB · L and VVB · R are controlled so that the flow rate Q determined in Z26 is supplied to the left and right hydraulic motors ML and MR. Z2
After 7, the processing of Z28 and Z29 is performed. This processing corresponds to the processing of Z12 and Z13 of FIG. 10, and is processing for correcting the reverse driving force becoming too large.

When YES is determined in any of Z23, Z24, and Z25, the reverse drive control is stopped in Z33, and the reverse drive flag is reset to 0 in Z34.

Flowchart (FIG. 12) FIG. 12 is executed when the determination in E23 of FIG. 4 is YES, and the drive using the hydraulic motors ML and MR when the traction control is executed by the control unit U3. Auxiliary (right and left independent positive drive) control.

First, after data is input in Z41,
At Z42, the reduction amount of the torque applied to the front wheels 1FL, 1FR caused by the traction control of the control unit U3, that is, the generation torque reduction amount TF of the engine 2 is increased.
Are read based on the signal from the control unit U3. After that, in Z43, the vehicle speed reduction amount VC corresponding to the torque reduction amount TF is determined.

At Z44, the supply liquid amount Q to be supplied to the hydraulic motors ML and MR is determined according to the vehicle speed reduction amount VC. The supply flow rate Q is determined so that the total generated torque of the hydraulic motors ML and MR becomes the same as the generated torque reduction amount of the engine 2. After that, in Z45, it is determined whether or not the traction control is stopped. If NO in Z45, the processes of Z46 to Z52 are performed. The processing of Z46 to Z52 is performed by the correction coefficients F1 and F2.
Supply flow rate QTRL, QTR to the left and right rear wheels
R, that is, the torque distribution ratio is determined. More specifically, during turning, the torque distribution amount on the turning outer wheel side is made larger than the torque distribution amount on the turning inner wheel side (Z49, Z5).
1) At the time of going straight, the torque distribution ratio to the left and right rear wheels is made equal (Z52).

After Z49, Z51 or Z52, Z
The process of shifting to 53 is performed, and this process is performed by Z in FIG.
Since it corresponds to 11 to Z13, the duplicated description will be omitted.

Description of Flowchart (FIG. 13) FIG. 13 shows the control contents of the vehicle stop mode in D9 of FIG. First, after the data is input in Z61, it is determined in Z62 whether or not the accelerator is depressed. In the case of NO in this determination of Z62, after the target vehicle speed VTR is set to 0 in Z63, the actual wheel speeds VBL, VBR of the left and right rear wheels 1RL, 1RR become the target vehicle speed VTR in Z64. , The supply flow rates to the hydraulic motors ML and MR are feedback-controlled (right and left independent control).

By the way, when the transmission 4 is an automatic transmission (in this case, the clutch 3 is a torque converter), even if the accelerator is not stepped on and operated at an extremely low speed, as is called creep. The operation is designed to be performed. To obtain this creep, target vehicle speed VTR
If, for example, is set to 5 km / h, the creep speed can always be kept constant regardless of the inclination of the road surface while the vehicle is stopped. Then, the target vehicle speed VTR can be manually selected, for example, in the range of 0 to 15 km / h in a continuously variable manner or in a stepless manner (when the target vehicle speed is 0, no creep occurs).

Layout of the hydraulic motor and its peripheral members
DOO 14 and 15, the cross-sectional view (FIG. 15 showing a look the hydraulic motor ML in the vehicle driving apparatus according to the first embodiment, the layout of MR and its peripheral members from above XI
FIG. 15 is a cross-sectional view taken along line V-XIV) and a cross-sectional view showing the same when viewed from the left (cross-sectional view taken along line XV-XV in FIG. 14).

As shown in these figures, the rear side frames 10 are respectively provided on the lower surfaces of both end portions of the floor panel in the vehicle width direction.
2 extends in the front-rear direction of the vehicle body, and a cross member 104 that connects them and supports the floor panel is provided between the two rear side frames 102. Both the rear side frame 102 and the cross member 104 have a closed cross-section structure.

Both ends of a suspension cross member 106 extending in the vehicle width direction are attached to both the rear side frames 102. The suspension cross member 106 has an inverted U-shaped cross-section structure, and hydraulic motors ML and MR for driving the rear wheels 1RL and 1RR and drive shafts 11L and 11R are provided in the cross section.
Is provided.

The hydraulic motors ML and MR are arranged so as to abut each other at the inner ends of the hydraulic motors ML and MR in the vehicle width direction. The hydraulic pump P that supplies hydraulic pressure to each of the hydraulic motors ML and MR is located in front of the abutting portion of the hydraulic motors ML and MR such that the joint portion with the propeller shaft 13 is located at the front end portion. They are arranged adjacent to each other and attached to each of these hydraulic motors ML and MR. This mounting is performed by the bracket 10 provided at the rear end of the pump P.
8 and the brackets 110L and 110R provided on the front portions of the hydraulic motors ML and MR, respectively, are bolted at two points. As a result, the hydraulic pump P and the hydraulic motors ML and MR can be attached to the vehicle body as a unit.

Motor mount brackets 112L and 112R are provided at the lower rear portions of the hydraulic motors ML and MR, respectively, and a pump mount bracket 114 is provided at the upper portion of the hydraulic pump P. Then, with the motor mount brackets 112L and 112R butted against each other, the suspension cross member 1
Bracket 11 provided on the inner surface of the rear surface portion 106c of 06
6 and the pump mount bracket 1
14 is the front portion 10 of the suspension cross member 106.
By mounting it on a bracket 118 provided on the outer surface of 6b, the hydraulic pump P and the hydraulic motors ML and MR are mounted on the vehicle body as the above-mentioned unit.

The mounting of the vehicle body as this unit is carried out by inserting the above unit into the inverted U-shaped cross section from below the suspension cross member 106.
The front surface portion 106b and the rear surface portion 10 of the suspension cross member 106 are provided within a range that does not affect the insertion work.
Bottom plate 120 connecting 6c at the lower end of the inverted U-shaped cross section
Are provided respectively to improve the rigidity of the suspension cross member 106. Further, both ends of the suspension cross member 106 are formed so as to be stepped up together with the bottom plate 120, and the lower surface of the bottom plate 120 at each of these stepped parts has a front side of the pair of front and rear suspension links 122, 124. The vehicle width direction inner ends of the suspension links 122 are connected to each other via brackets 126. On the other hand, the inner ends of the rear suspension links 124 in the vehicle width direction are connected to each other via brackets 128 provided on the outer surface of the rear surface portion 106c of the suspension cross member 106.

The suspension cross member 106
In order to improve rigidity, both sides of the attachment portion to the rear side frame 102 and the periphery of the attachment portion to the suspension link 124 are formed to have a wide width, and the attachment portion of the suspension cross member 106 to the rear side frame 102 has the portion. Is joined to form a closed section. The portions of the suspension cross member 106 other than the both side portions are formed to have a minimum width necessary for attaching the hydraulic pump P and the hydraulic motors ML and MR to the vehicle body as a unit.
A sufficient space for disposing a fuel tank, a muffler, etc. can be secured before and after the suspension cross member 106. In this embodiment, the fuel tank 132 is provided in front of the suspension cross member 106.
The rear end portion is arranged so as to extend immediately before the hydraulic pump P. The fuel tank 132 has a saddle-shaped bottom surface to avoid interference with the propeller shaft 14. Also, suspension cross member 1
A notch portion 134 for avoiding interference with the hydraulic pump P is formed in the vehicle width direction central portion of the front surface portion 106b of No. 06.

As described above in detail, in the present embodiment, the hydraulic motor ML for driving the left wheel and the hydraulic motor MR for driving the right wheel are located at the inner ends of the hydraulic motors ML, MR in the vehicle width direction. A hydraulic pump P, which is arranged so as to abut against each other and supplies hydraulic pressure to each of the hydraulic motors ML and MR, is arranged near the abutting portion of each of the hydraulic motors ML and MR, and the hydraulic motors ML and MR are provided. And a transfer 5 that drives the hydraulic pump P are connected via a propeller shaft 14, so that the pair of hydraulic motors ML and MR and the hydraulic pump P can be attached to the vehicle body as a unit. Therefore, it is not necessary to mount each hydraulic motor ML, MR or each hydraulic pump P on the vehicle body, and the mounting structure on the vehicle body can be simplified. Further, since the hydraulic pump P and the respective hydraulic motors ML and MR are extremely close to each other, the hydraulic pipes can be eliminated or can be made extremely short, whereby the pair of hydraulic motors ML and MR and The hydraulic pump P can be made compact as a whole, and the operation response of each hydraulic motor ML, MR can be improved.

Further, in this embodiment, since the pair of hydraulic motors ML and MR are arranged so as to abut each other at their inner ends in the vehicle width direction, the left and right drive shafts 11L and 11R are lengthened. It is possible to reduce the axial load input to the drive shafts 11L and 11R along with the bump rebound of the rear wheels 1RL and 1RR to reduce the hydraulic motors ML and
It is possible to prevent an unreasonable load from acting on the MR.

In the present embodiment, the pair of hydraulic motors ML and MR are simply arranged so as to abut each other at their inner ends in the vehicle width direction, but they are joined together. However, by doing so, the pair of hydraulic motors ML, M
It is possible to improve the mounting rigidity of the R and the hydraulic pump P on the vehicle body.

Next, a second embodiment of the present invention will be described.

16 and 17 are sectional views showing the layout of the hydraulic motors ML and MR and their peripheral members in the vehicle drive system according to this embodiment as seen from above (XVI-XVI line sectional view of FIG. 17). FIG. 17 is a cross-sectional view (a cross-sectional view taken along the line XVII-XVII in FIG. 16) viewed from the left.

As shown in these figures, the basic construction of this embodiment is the same as that of the first embodiment, but the hydraulic motor ML,
The positional relationship between the MR and the hydraulic pump P and the configuration associated therewith are different from those in the first embodiment.

That is, in this embodiment, the hydraulic motor ML for driving the left wheel and the hydraulic motor MR for driving the right wheel are used.
Are spaced apart from each other in the vehicle width direction, and a hydraulic pump P that supplies hydraulic pressure to these hydraulic motors ML and MR.
Are arranged between the hydraulic motors ML and MR and attached to the hydraulic motors ML and MR.

Each hydraulic motor ML, M of the hydraulic pump P
For mounting to the R, a pair of brackets 136L and 136R provided on both sides of the hydraulic pump P are attached to the hydraulic motors ML,
This is done by bolting at three points to the inner end surface of the MR.

These hydraulic pump P and hydraulic motor M
For mounting on the vehicle body as a unit of L and MR, the motor mount brackets 138L and 138R provided on the lower portions of the hydraulic motors ML and MR are attached to the bracket 14 provided on the inner surface of the bottom plate 120 of the suspension cross member 106.
The pump mount bracket 142 provided on the upper part of the hydraulic pump P while being attached to the 0L and 140R,
This is done by attaching to a bracket 144 provided on the inner surface of the upper surface portion 106a of the suspension cross member 106.

The hydraulic pump P and the hydraulic motor ML,
To mount the MR unit on the vehicle body, mount the unit from the rear of the suspension cross member 106 in the reverse U direction.
The rear surface portion 10 of the suspension cross member 106 is formed by inserting the suspension cross member 106 in the letter-shaped cross section.
A notch 146 for insertion is formed over a wide area in the center of the vehicle 6c in the vehicle width direction. On the other hand, in the present embodiment, the bottom plate 120 is provided so as to close not only both sides of the suspension cross member 106 in the vehicle width direction but also the central portion thereof, so that the rigidity of the suspension cross member 106 is ensured. It has become.

Also in this embodiment, the portions of the suspension cross member 106 other than the both side portions are formed to have the minimum width necessary for mounting the hydraulic pump P and the hydraulic motors ML and MR as a unit on the vehicle body. As a result, a sufficient space for disposing the fuel tank, the muffler, and the like can be secured before and after the suspension cross member 106. In this embodiment,
A fuel tank 132 is arranged in front of the suspension cross member 106 so that its rear end portion extends just before the hydraulic pump P, that is, just before the front surface portion 106b of the suspension cross member 106. It should be noted that the bottom surface of the fuel tank 132 is formed in a saddle shape in order to avoid interference with the propeller shaft 14, and that the front surface portion 106b of the suspension cross member 106 interferes with the hydraulic pump P at the center portion in the vehicle width direction. The point that a notch portion 134 for avoiding is formed is the same as in the first embodiment.

As described in detail above, also in this embodiment, as in the first embodiment, the pair of hydraulic motors ML and MR and the hydraulic pump P can be attached to the vehicle body as a unit. It is not necessary to mount the motors ML, MR or the hydraulic pumps P on the vehicle body, and the mounting structure on the vehicle body can be simplified. Further, since the hydraulic pump P and the hydraulic motors ML and MR are extremely close to each other, the hydraulic piping can be eliminated or can be made extremely short.
The L, MR and the hydraulic pump P can be configured compactly as a whole, and the operation response of each of the hydraulic motors ML, MR can be improved.

Moreover, in this embodiment, since the hydraulic pump P is arranged between the pair of hydraulic motors ML and MR, the left and right drive shafts 11 are different from those in the first embodiment.
Although the lengths of L and 11R are sacrificed, the pair of hydraulic motors ML and MR and the hydraulic pump P can be further downsized in the vehicle body front-rear direction.

Next, a third embodiment of the present invention will be described.

18 and 19 are sectional views showing the layout of the hydraulic motors ML, MR and their peripheral members in the vehicle drive system according to this embodiment as seen from above (XVIII-XVIII line sectional view of FIG. 19). FIG. 19 is a cross-sectional view (a cross-sectional view taken along line XIX-XIX in FIG. 18) viewed from the left.

As shown in these figures, the basic structure of this embodiment is the same as that of the first embodiment, but the hydraulic motor ML,
The positional relationship between the MR and the hydraulic pump P and the configuration associated therewith are different from those in the first embodiment.

That is, in this embodiment, the hydraulic motor ML for driving the left wheel and the hydraulic motor MR for driving the right wheel are used.
Are spaced apart from each other in the vehicle width direction, and a hydraulic pump P that supplies hydraulic pressure to these hydraulic motors ML and MR.
Between the hydraulic motors ML and MR and each hydraulic motor M
A pair of hydraulic motors ML, which are arranged at positions displaced toward the rear of the vehicle body with respect to L and MR, are attached to the hydraulic motors ML and MR, and which have a propeller shaft 14 connecting the hydraulic pump P and the engine 2 to each other. It is arranged so as to pass through between the MRs.

Each hydraulic motor ML, M of the hydraulic pump P
The mounting to R is performed by a motor mount bracket 148L provided on the inner end surface of each hydraulic motor ML, MR in the vehicle width direction,
A pair of brackets 150L and 150R provided on both sides of the hydraulic pump P with the 148R butted against each other.
Is connected to the brackets 152L and 152R provided on the rear end surfaces of the hydraulic motors ML and MR and extending rearward and downward by bolts at three points.

When mounting the hydraulic pump P and the hydraulic motors ML and MR as a unit on the vehicle body, the motor mount brackets 138L and 138R provided under the hydraulic motors ML and MR are attached to the bottom plate 120 of the suspension cross member 106. By mounting the brackets 140L and 140R provided on the inner surface and mounting the motor mount brackets 148L and 148R to the bracket 154 provided on the inner surface of the front surface portion 106b of the suspension cross member 106, the motor mount brackets 148L and 148R are abutted against each other. Has become.

The hydraulic pump P and the hydraulic motor ML,
To mount the MR unit on the vehicle body, mount the unit from the rear of the suspension cross member 106 in the reverse U direction.
The rear surface portion 1 of the suspension cross member 106 is designed to be inserted into the letter-shaped cross section.
The notch 146 for insertion is formed over a wide area in the center of the vehicle width direction of 06c. The bottom plate 120 covers not only both sides of the suspension cross member 106 in the vehicle width direction but also the center thereof. Is provided in the same manner as in the second embodiment.

Also in this embodiment, the portions of the suspension cross member 106 other than the both side portions are formed to have the minimum width required to mount the hydraulic pump P and the hydraulic motors ML and MR as a unit on the vehicle body. As a result, it is possible to secure a sufficient space for disposing the fuel tank, the muffler and the like in front of and behind the suspension cross member 106. In this embodiment, since the hydraulic pump P is provided at the rear of the suspension cross member 106, the rear end of the fuel tank 132 has the front portion 106b of the suspension cross member 106.
Is arranged so as to extend immediately before. It should be noted that the bottom surface of the fuel tank 132 is formed in a saddle shape in order to avoid interference with the propeller shaft 14, and that the front surface portion 106b of the suspension cross member 106 interferes with the hydraulic pump P at the center portion in the vehicle width direction. The point that a notch portion 134 for avoiding is formed is the same as in the first embodiment.

As described in detail above, also in the present embodiment, as in the first embodiment, the pair of hydraulic motors ML and MR and the hydraulic pump P can be attached to the vehicle body as a unit, and therefore, the respective hydraulic pressures can be attached. It is not necessary to mount the motors ML, MR or the hydraulic pumps P on the vehicle body, and the mounting structure on the vehicle body can be simplified. Further, since the hydraulic pump P and the hydraulic motors ML and MR are extremely close to each other, the hydraulic piping can be eliminated or can be made extremely short.
The L, MR and the hydraulic pump P can be constructed compactly as a whole. Moreover, this can improve the operation response of each hydraulic motor ML, MR.

Moreover, in the present embodiment, the hydraulic pump P is arranged between the pair of hydraulic motors ML and MR, but the spacing dimension allows the propeller shaft 14 and the universal joint 15 to be inserted therethrough. Since it is sufficient if the dimensions are secured, the drive shafts 11L, 1L on the left and right, which are not so large as those in the first embodiment, are compared with those in the second embodiment.
The length of 1R can be increased.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of a vehicle drive device according to the present invention.

FIG. 2 is a block diagram showing a control system in the first embodiment.

3 to 13 are flowcharts showing the contents of hydraulic motor control in the first embodiment.

FIG. 14 is a cross-sectional view showing the layout of the hydraulic motor and its peripheral members in the first embodiment as viewed from above.

FIG. 15 is a sectional view showing the layout of the hydraulic motor and its peripheral members in the first embodiment as viewed from the left.

FIG. 16 is a view similar to FIG. 14 showing a second embodiment.

FIG. 17 is a view similar to FIG. 15, showing a second embodiment.

FIG. 18 is a view similar to FIG. 14 showing a third embodiment.

FIG. 19 is a view similar to FIG. 15 showing the third embodiment.

[Explanation of symbols]

1RL Left rear wheel 1RR Right rear wheel ML, MR Hydraulic motor P Hydraulic pump 11L, 11R Drive shaft 14 Propeller shaft 106 Suspension cross member 108, 110L, 110R bracket 112L, 112R Motor mount bracket 114 Pump mount bracket 132 Fuel tank 136L, 136R Bracket 138L, 138R Motor mount bracket 142 Pump mount bracket 148L, 148R Motor mount bracket 150L, 150R, 152L, 152R Bracket

Claims (3)

[Claims] 1. A vehicle drive device comprising a hydraulic motor connected to a wheel via a drive shaft extending substantially in the vehicle width direction, the vehicle drive device being configured to rotationally drive the wheel by the hydraulic motor. The hydraulic motors for driving the wheels and the hydraulic motors for driving the right wheels are arranged so as to abut each other at the vehicle width direction inner ends of these hydraulic motors. A hydraulic pump to be supplied is disposed in the vicinity of the abutting portion of each hydraulic motor, is attached to each hydraulic motor, and is connected to a driving force source for driving the hydraulic pump via a propeller shaft. And a vehicle drive device. 2. A vehicle drive device comprising a hydraulic motor connected to a wheel via a drive shaft extending substantially in the vehicle width direction, the vehicle drive device being configured to rotationally drive the wheel by the hydraulic motor. The hydraulic motors for driving the wheels and the hydraulic motors for driving the right wheels are arranged so as to be separated from each other in the vehicle width direction, and a hydraulic pump that supplies hydraulic pressure to each of these hydraulic motors is A vehicle drive device, characterized in that the vehicle drive device is mounted between the hydraulic motors and is connected to a drive force source for driving the hydraulic pumps via a propeller shaft. 3. A vehicle drive device comprising a hydraulic motor connected to a wheel via a drive shaft extending substantially in the vehicle width direction, the vehicle drive device being configured to rotationally drive the wheel by the hydraulic motor. The hydraulic motors for driving the wheels and the hydraulic motors for driving the right wheels are arranged so as to be separated from each other in the vehicle width direction, and a hydraulic pump that supplies hydraulic pressure to each of these hydraulic motors is Between the pair of hydraulic motors and a driving force source for driving the hydraulic pumps, which is disposed between the hydraulic motors in the longitudinal direction of the vehicle body and is attached to the hydraulic motors. A drive device for a vehicle, wherein the drive device is connected via a propeller shaft.