JP3296902B2 - Vehicle drive system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular drive device having a motor connected to wheels via a drive shaft extending substantially in the vehicle width direction, and configured to rotate the wheels by the motor. It is.

[0002]

2. Description of the Related Art Heretofore, there has been known a vehicle drive device using a hydraulic motor or an electric motor as an auxiliary drive power source other than an engine. For example, JP-A-4-24362
No. 7 discloses a vehicle drive device provided with 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 an engine, and the other is driven by a motor. This motor is generally provided for each of the left and right wheels, and is configured to rotationally drive each wheel via a drive shaft extending in the vehicle width direction.

[0004]

However, in the conventional vehicle drive device, the motor for driving the left wheel and the motor for driving the right wheel are arranged side by side in this order on the left and right. The length of the connected drive shaft was relatively short. When the length of each drive shaft is short in this way, the displacement in the vehicle width direction of each drive shaft due to the bump and rebound of the wheel increases,
An excessive load acts on the motor connected to the drive shaft.

On the other hand, if each drive shaft is formed to be long, the above problem can be solved. However, in this case, when both drive shafts are simply arranged so as to be parallel to each other. In this case, since each motor easily interferes with the drive shaft of the other motor, it is difficult to dispose each motor. And, in order to avoid this, it is necessary to set a large space between both drive shafts or to provide an intermediate coupling mechanism such as gears, so that the space occupied by the drive device becomes large,
This limits the degree of freedom of layout of auxiliary components such as suspension links or fuel tanks.
There is a problem.

The present invention has been made in view of such circumstances, and in a vehicle drive device provided with a motor, an excessive load acts on the motor while keeping the space occupied by the drive device small. It is an object of the present invention to provide a vehicular drive device capable of suppressing the occurrence of a vehicle.

[0007]

A vehicle drive device according to the present invention achieves the above object by devising a position where a motor and a drive shaft are provided.

That is, the present invention comprises a motor connected to wheels through a drive shaft extending substantially in the vehicle width direction, and the wheels are driven to rotate by the motor. A vehicle drive device, wherein the motor for driving the left wheel is disposed on the right side and the motor for driving the right wheel is disposed on the left side with respect to the center of the vehicle body in the vehicle width direction, A pair of the drive shafts connected to the two motors are disposed so as to be in a torsion position relationship with each other.

The "motor" may be a hydraulic motor or an electric motor.

[0010] The "relationship between the twist positions" means that the two straight lines do not intersect and are not parallel to each other, but the aspect is not particularly limited. A configuration in which the drive shafts intersect in plan view from the vehicle body vertical direction (Claim 2) and a configuration in which the drive shafts cross in front view from the vehicle body longitudinal direction (Claim 3), both in plan view and in front view And the like (claim 4) can be adopted.

[0011]

As described above, according to the present invention, the motor for driving the left wheel is disposed on the right side with respect to the center of the vehicle body in the vehicle width direction, and the motor for driving the right wheel is disposed on the left side. , Each drive shaft can be formed to be long, thereby reducing the displacement of each drive shaft in the vehicle width direction due to the bump and rebound of the wheels, and imposing an excessive load on the motor. It can be prevented from acting.

Further, in the present invention, the pair of drive shafts connected to the two motors are disposed so as to be in a twisted relationship with each other. Even if the interval between them is set to be small, each motor can be easily arranged without causing interference with the drive shaft of the other motor,
Thereby, the space occupied by the driving device can be reduced. As a result, the degree of freedom in the layout of auxiliary components such as suspension links or fuel tanks can be increased.

As described above, according to the present invention, it is possible to minimize the space occupied by the driving device and to suppress the application of an excessive load to the motor.

[0014]

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 drawing, the vehicle drive system according to the present embodiment drives the front wheels 1FL, 1FR as main drive wheels by the engine 2 and the rear wheels 1RL, 1RR by the hydraulic motor M.
An apparatus for driving as auxiliary driving wheels by L and MR, which has a feature in the layout of the hydraulic motors ML and MR and their peripheral members. Before describing this, first, FIGS. The drive system for the hydraulic motors ML and MR will be described based on the above.

Description of Hydraulic System (FIG. 1) In FIG. 1, 1FL is a front left wheel, 1FR is a front right wheel, 1R
L is a left rear wheel, and 1RR is a right rear wheel. An engine 2 is disposed in front of the vehicle body, and a driving force of the engine 2, that is, a generated torque is transmitted to a differential device 5 via a clutch 3 and a manual transmission 4 having five forward speeds and one reverse speed. Then, the left front wheel 1F is output from the differential device 5 via the drive shaft 6L.
L to the drive shaft 6R
The engine driving force is transmitted to the right front wheel 1FR via the.

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

The left and right rear wheels 1RL, 1RR are
Separately from the left and right pair of hydraulic motors ML, MR
Is driven to rotate. 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).
A connection port Lb (Rb), from La (Ra) to Lb
When the high-pressure oil flows to (Rb), the rotation is in the forward direction. When the high-pressure oil flows in the opposite direction, the rotation is in the backward direction. Then, the hydraulic motors ML and MR
Are the same 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.
Degree.

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

P is a pump as a hydraulic pressure generating source. The pump P is of a variable displacement type, and has an output shaft 2 of the engine 2.
The drive pulley 13 drives the drive pulley 13, the belt 14, and the rear wheel pulley 15. The high-pressure oil pumped by the pump P from the reservoir tank 16 is discharged to a high-pressure line 18 to which a check valve 17 is connected. From this high-pressure line 18, first and second hydraulic pressure supply lines 31A and 31B connected to the check valve 10 or 32 are connected in parallel. A release line 23 extends from the reservoir tank 16.
Furthermore, each connection port La, Lb of the hydraulic motor ML (MR)
From (Ra, Rb), the parallel lines 20L, 2L,
1L (20R, 21R) is derived.

The lines 20L and 21L of the hydraulic motor ML are connected to the switching valve VVA and the lines 19 and 19L parallel to each other.
And lines 22, 22L and switching valves VVB · L, VVE
L can be selectively connected to the first supply line 31A and the release line 23 using L. 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. The supply line 31A and the release line 23 can be selectively connected.

A switching valve VVI is connected to the second common supply line 31B on the downstream side of the check valve 32, and a flow dividing valve 34 is connected on the downstream side of the check valve 32. Split valve 3
4, one branch supply line 33L branched into two
Is connected to the line 19L, and the other branch supply line 33
R is connected to line 19R.

An accumulator 41 for storing high-pressure oil pressure is connected to the high-pressure line 18. For this high pressure line 18, a line 20L (20R)
Are connected by a passage 42L (42R). This passage 42L (42R) has 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) and VVE · L (V
VE · R), VVI, the flow dividing valve 34 and the like are bypassed.

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

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

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

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

[0030]

[Table 1]

In each control mode shown in Table 1, the operating state of the valve which plays a major role will be described in detail as follows.

(1) Independent Mode As described in detail later, the independent mode controls the driving of the hydraulic motors ML and MR so that the left and right rear wheels 1 RL and 1 RR have target speeds set independently of each other. And there are two types: forward drive (drive assist) and reverse drive (braking). In this independent mode, the switching valves VVE · L,
The differential mode of VVE · R is as shown in FIG. 1, but the switching valve VVA is at the central switching position and the first supply line 31
A is shut off. The switching valve VVI is set to the open position and the second
This is a hydraulic supply mode using the supply line 31B. In this state, the switching valves VVB · L and VVB · R are controlled,
The switching of the hydraulic pressure supply direction according to the forward drive or the reverse drive (setting of the 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, which will be described later. Naturally, the rear wheels 1RL, 1RR are rotated in the direction opposite to the traveling direction of the vehicle. It does not give a large driving force.

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

(3) Hydraulic lock mode In the hydraulic lock mode, the passage resistance, that is, the variable orifice V
A deceleration force using the throttle resistance of VC · L (VVC · R) is obtained. In this hydraulic lock mode, the switching valve V
VB · L (VVB · R) is in the center switching position, the lines 20L and 21L (20R and 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 closed orifice VVC · L (VVC · R) is circulated through the closed or closed hydraulic circuit including the variable orifice VVC · L.
The throttle resistance of (VVC · R) gives a deceleration force to the vehicle. Then, the variable orifice VVC · L (VV
The opening of C · R) is controlled to decrease as the deceleration of the vehicle increases (the variable orifice V according to the deceleration).
The VC / L and VVC / R opening degrees are set in step E of FIG.
37).

(4) Accumulation mode In the accumulation mode, the hydraulic motors ML, MR are driven by the rotation of the rear wheels 1RL, 1RR accompanying the running of the vehicle, and these hydraulic motors ML, MR are made to function as pumps. It is to let. In this pressure accumulation mode, while the line 21L (21R) is connected to the reservoir tank 16, the on-off valve VVF · L (VVF · R) is opened, and the oil liquid in the reservoir tank 16 is discharged from the motor ML (M
R), and is accumulated in the accumulator 41.

(5) Stop Mode In the stop mode, the hydraulic motors ML and ML stop the vehicle when the parking brake is not operating.
The drive of the MR is controlled (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 supply line, and the supply and discharge control of the hydraulic pressure is performed by the switching valve VVB · L (VV
BR).

(6) Parking Mode The parking mode enhances the operation 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 center switching position, and the hydraulic supply / discharge line is shut off.

(7) F / S Mode The F / S mode is a fail-safe mode. When there is any abnormality, for example, when the high-pressure line 18 becomes abnormally high, the hydraulic motors ML and MR are normal. When the valve is not driven, when a certain valve is stuck, or when the oil temperature further rises to a predetermined temperature or higher, the safety valve VVG is opened and the hydraulic pressure of the high-pressure line 18 is released. You.

Description of Control System (FIG. 2) FIG. 2 shows a control system in the present invention. In the figure, U1, U2, and U3 are control units configured using a microcomputer, respectively.
Is a main control unit that controls the above-described valves VVA and the like. The control unit U2 is for ABS control (anti-lock brake control), and the control unit U3 is for traction control. S1 to S13 are sensors or switches, respectively.

The sensors S1 to S4 are provided for each wheel 1FL to 1R.
The rotation speed of R, that is, the wheel speed is detected independently, 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. In the embodiment, the sensor S5 detects the ground vehicle speed (detection of the absolute vehicle speed). The sensor S6 detects a shift position of the transmission 4, that is, a 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 depression amount of the brake pedal. The switch S11 is an ignition switch. The switch S12 detects whether the parking brake has been operated.

The sensor S13 detects a rough road (uneven road). Bad road detection is performed, for example, assuming that the sensor S13 detects the vertical stroke of the suspension.
The control unit U1 determines a case where a stroke equal to or more than a predetermined amount has occurred a predetermined number of times or more within a predetermined time as a bad road. In addition, assuming that the sensor S13 detects the vertical G (acceleration) acting on the vehicle body, the control unit U determines that the road is rough when the vertical G equal to or more than a predetermined value occurs a predetermined number of times within a predetermined time.
1 may be determined. It should be noted that the determination of the degree of the rough road may be made by changing one or more of the threshold values for the above-described rough road determination.

The signals from the sensors or the switches S5 to S13 are input to the control unit U1, and the control unit U1 controls the above-described valves VVA to VVJ. Of course, the control unit U2 is for preventing the wheels from locking during braking, and the control unit U2 controls the brake fluid pressure adjusting means 81 for independently adjusting the brakes of each wheel. . In addition, the control unit U3 includes left and right front wheels 1FL which are always driving 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, it controls a torque adjusting means 82 for adjusting the opening degree of the throttle valve of the engine 2, the ignition timing, the fuel injection amount, and the like.

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

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

First, in the main flow chart of FIG. 3, after a signal from each sensor or the like is input at D1, it is determined at D1 whether the ignition switch is ON. If the determination in D2 is NO, in D3, the safety valve VVG is opened, and the pressure in the high-pressure line 18 is released. If the determination in D2 is YES, in D4, the safety valve VVG is closed, and the high-pressure oil is supplied to the high-pressure line 18.

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

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

If the determination in D10 is YES, in D15, the drive assist using the hydraulic motors ML and MR is executed. In this case, the reverse drive is performed in the independent mode (the rear wheel is moved in the backward direction). 1RL, 1RR). If the determination in D11 is YES, in D14,
Driving assistance using the hydraulic motors ML and MR is performed. In this case, the positive drive is performed in the independent mode described below 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). Will be

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

If the determination in E26 is YES, the sequence from E27 to
The processing of E39 is performed, but this processing is based on a good road, a high μ road, and when traveling straight. Finally, are the control conditions for performing the forward drive (E28) in the independent mode, the reverse drive (E35) in the independent mode, the accumulation mode (E33, E39) or the hydraulic lock mode (E31, E37) satisfied? It is determined whether or not.

The degree of acceleration and the degree of deceleration can be determined by various known methods. For example, the degree of acceleration
It can be known from any one or a combination of any two or more of the accelerator pedal depression speed, the accelerator pedal depression amount increase amount, and the vehicle body acceleration obtained by differentiating the vehicle speed. The degree of deceleration is, for example, any one or any of a plurality of values such as a magnitude of an accelerator release speed, a magnitude of a brake depression speed, an increase in a brake depression amount, a vehicle deceleration obtained by differentiating a vehicle speed, and the like. Can be known by the combination of However, in the embodiment, at least when the accelerator return speed is high (when the accelerator release speed is high), it is determined that the deceleration is equal to or more than the slow deceleration for setting the hydraulic lock mode.

If the determination at E26 in FIG. 4 is NO,
5 is based on the premise that the vehicle is turning on a good road and a high μ road. Finally, it is determined whether or not control conditions for performing the forward drive (E42) and the reverse drive (E44) in the independent mode or the LSD mode (E45) are satisfied.

When 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. This E
If the determination at 51 is YES, the processing of E52 to E59 is performed, but this processing is performed on the premise that the vehicle is traveling straight on a good road, a low μ road, and straight ahead. Finally, it is determined whether or not 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 of E51 in FIG.
Is performed, and the process is performed on a good road, a low μ road, and at the time of turning. Finally, it is determined whether or not the control conditions for performing the normal drive (E62), the hydraulic lock mode (E65), and the LSD mode (E66) in the independent mode are satisfied.

If the determination in E24 in FIG. 4 is YES, in E71 in FIG. 8, it is determined whether or not the road is extremely bad. If the determination in E71 is NO, E71 to E86
This is a determination of the control mode on a rough road. In addition, when the determination in E71 is YES, the processing after E91 in FIG. 9 is performed, but this is the determination of the control mode on an extremely rough road.

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

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

Next, at Z3, it is determined whether or not a value obtained by subtracting the actual wheel speed VBL of the left rear wheel 1RL from the target vehicle speed VTR is higher than a predetermined speed V1. When the determination in Z3 is NO, it is determined that the drive assist by the forward drive is not necessary, and the forward drive of the left rear wheel is stopped in Z14. The processing of Z3 and Z14 is also performed independently on the right rear wheel 1RR independently of 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 a variable value that increases as the vehicle speed VA increases.

If the determination in Z3 is YES, it is determined whether or not the accelerator is fully opened in Z4. Also, if the determination in Z4 is YES, the driving assistance using the hydraulic motors ML and MR is not necessary. Then, the process shifts to Z14 (in this case, the positive drive is stopped simultaneously at the left and right rear wheels 1RL and 1RR).

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 angle. Thereafter, in Z6, the correction coefficients K1 and K2 are set. Then, in Z7, it is determined whether or not the vehicle is turning right. In this determination of Z7, YE
In the case of S, in Z9, the target wheel speed VTRL of the left rear wheel 1RL is calculated by multiplying the target vehicle speed VTR determined by Z2 by the correction coefficient K1, and similarly, the target wheel speed VTRL of the right rear wheel 1RR is calculated. If the target wheel speed VTRR is equal to the target vehicle speed V
It is calculated by multiplying TR by a correction coefficient K2.

If NO in Z7, the target wheel speeds of the left and right rear wheels 1RL and 1RR are calculated in Z8. In short, the processing of Z6 to Z9 corresponds to processing of increasing the turning outer wheel side target wheel speed and decreasing the turning inner wheel side target wheel speed. However, when the vehicle is going straight, the determination of Z7 is NO and the process proceeds to Z8. However, since the correction coefficient is set to 1 (lateral G is 0 or almost 0), the left and right rear wheels 1RL, 1RR target wheel speeds are equal to each other).

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

At Z12, it is determined whether or not a value obtained by subtracting the actual wheel speed VBL of the left rear wheel 1RL from the vehicle speed VA is smaller than a predetermined speed "-V2". This Z
The determination at 12 is that the actual wheel speed VBL of the left rear wheel 1RL is
This is to determine whether or not the speed is too high compared to the vehicle speed VA. If the determination in Z12 is YES, in Z13,
Correction for reducing the supply flow rate Q is performed so that the rear wheels maintain the predetermined slip value. Note that the processing of Z12 and Z13 is similarly performed for the right rear wheel 1RR. Z12
If the determination is NO, the routine returns without passing through Z13.

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

First, after data is input in Z21, it is determined in Z22 whether or not the reverse drive flag is 1. If the determination in Z22 is NO, Z30
In, it is checked where the current state is in an area set using the steering wheel angle and the vehicle speed VA as parameters. Thereafter, in Z31, the current state is Z30.
It is determined whether or not there is a hatched C area in the area shown in FIG. If the determination in Z31 is YES, Z3
After the reverse drive flag is set to 1 in 2, Z 21
When the determination in Z31 is NO, the process returns to Z21 without passing through Z32.

After passing through Z32, the determination of Z22 is YE
At this time, it is determined in Z23 whether or not the ABS control is currently being performed. In the determination of Z23, N
In the case of O, in Z24, it is determined whether or not the brake depression amount is large. If 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.

If 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. Thereafter, in Z27, the switching valves VVB · L, VVB · R are controlled such that the flow rate Q determined in Z26 is supplied to the left and right hydraulic motors ML, MR. Z2
After 7, the processing of Z28 and Z29 is performed. This processing corresponds to the processing of Z12 and Z13 in FIG. 10, and is a processing for correcting that the reverse driving force becomes too large.

If the determination in any of the above Z23, Z24 and Z25 is YES, after the reverse drive control is stopped in Z33, the reverse drive flag is reset to 0 in Z34.

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

First, after data is input in Z41,
In Z42, the amount of decrease in the torque applied to the front wheels 1FL and 1FR caused by the traction control of the control unit U3, that is, the amount of decrease TF in the engine 2
Is read based on a signal from the control unit U3. Thereafter, in Z43, the vehicle speed reduction amount VC according to the torque reduction amount TF is determined.

In 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 is equal to the generated torque reduction amount of the engine 2. Thereafter, in Z45, it is determined whether or not the traction control has been stopped. If the determination in Z45 is NO, the processing in Z46 to Z52 is performed. The processing of Z46 to Z52 is performed by correcting the correction coefficients F1 and F2.
, The supply flow rate QTRL, QTR for the left and right rear wheels
R, that is, the torque distribution ratio is determined. More specifically, when 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) When the vehicle is traveling 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 transition to 53 is performed.
Since they correspond to 11 to Z13, their duplicate description will be omitted.

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

When the transmission 4 is an automatic transmission (in this case, the clutch 3 is a torque converter), even if the accelerator pedal is not depressed, the operation is performed at an extremely low speed, as called creep. An operation is to be performed. In order to obtain this creep, the target vehicle speed VTR
Is set to, for example, 5 km / h, the creep speed can always be kept constant irrespective of the inclination of the road surface during stopping. Then, the target vehicle speed VTR can be selected continuously or steplessly in a manual range, for example, in the range of about 0 to 15 km / h (no creep when the target vehicle speed is 0).

Layout Diagrams of Hydraulic Motor and Its Peripheral Members FIGS. 14 and 15 are sectional views showing the layout of the hydraulic motors ML and MR and their peripheral members in the vehicle drive device according to the present embodiment as viewed from above (FIG. 15). XIV-XI
FIG. 15 is a sectional view (a sectional view taken along the line XV-XV in FIG. 14) showing the same viewed from the rear.

As shown in these figures, the floor panel 1
The rear side frames 106 extend in the vehicle front-rear direction on the lower surface near the joint with the wheel apron 104 at both ends in the vehicle width direction of the vehicle 02. A cross member 108 for supporting the panel 102 is provided. Both the rear side frame 106 and the cross member 108 have a closed sectional structure.

A suspension cross member 112 extending in the vehicle width direction is attached to both rear side frames 106. This suspension cross member 1
Numeral 12 has an inverted U-shaped cross-sectional structure, and hollow flat plates 110 are respectively joined to the lower surfaces at both ends in the vehicle width direction of the upper surface portion 112a. The suspension cross member 112 is attached to each of the rear side frames 106 at two front and rear positions on the flat plate 110. The front end 112b and the rear end 112c of the suspension cross member 112 support the other ends of a pair of front and rear suspension links (not shown) each having one end connected to each of the left and right rear wheels 1RL, 1RR. It has become.

In the cross section of the suspension cross member 112, a pair of left and right hydraulic motors ML, MR and drive shafts 11L, 11R are disposed.

In the hydraulic motors ML and MR, a hydraulic motor ML for driving the left wheel is disposed on the right side and a hydraulic motor MR for driving the right wheel is disposed on the left side with respect to the center of the vehicle body in the vehicle width direction. ing. And these hydraulic motors M
Drive shaft 11L, 11R connected to L, MR
Intersect in plan view from the top and bottom of the vehicle body,
They are parallel in a front view from the vehicle front-rear direction.
That is, these drive shafts 11L and 11R
They are arranged so as to be in a relationship of a twist position to each other.

The hydraulic motors ML and MR are
Motor mounting brackets 114, 1
16 are attached to brackets 118 and 120 joined to the rear surface portion 112 c of the suspension cross member 112 and the flat plate 110.

The suspension cross member 112
Is formed so that the front portion 112b is close to the drive shafts 11L and 11R that intersect in plan view, and the center portion in the vehicle width direction is slightly bent rearward, and is formed in front of the front portion 112a. Is the front part 112
The fuel tank 122 is arranged along the shape of b.

As described in detail above, in this embodiment, the hydraulic motor ML for driving the left wheel is disposed on the right side with respect to the center of the vehicle body in the vehicle width direction, and the hydraulic motor MR for driving the right wheel is provided. Since it is arranged on the left side, each drive shaft 11L, 11R can be formed long,
This makes it possible to reduce the displacement in the vehicle width direction of each of the drive shafts 11L and 11R due to the bump and rebound of the wheels 1RL and 1RR, thereby preventing an unreasonable load from acting on the hydraulic motors ML and MR.

Further, in the present embodiment, the pair of drive shafts 11L and 11R are disposed so as to be in a torsion position relationship with each other. Even if the interval between the 11Rs is set narrow, each hydraulic motor ML or MR
To the drive shaft 11 of the other motor MR or ML.
It can be easily arranged without causing interference with R or 11L, and thereby the space occupied by the drive device can be reduced. As a result, the degree of freedom in layout of auxiliary components such as the suspension link or the fuel tank 122 can be increased.

As described above, according to this embodiment, the hydraulic motor ML,
An unreasonable load acting on the MR can be suppressed.

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

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

As shown in these figures, the present embodiment has the same basic structure as the first embodiment, but is different from the first embodiment in that the hydraulic motors ML and MR and the drive shaft 1 are different from the first embodiment.
The arrangement positions of 1L and 11R and the structures related thereto are different.

In this embodiment, the hydraulic motor M
L and MR are such that a hydraulic motor ML for driving the left wheel is disposed on the right side and a hydraulic motor MR for driving the right wheel is disposed on the left side with respect to the center in the vehicle width direction of the vehicle body. , 11R are arranged so as to be in a relationship of a twist position with respect to each other. However, the drive shafts 11L and 11R in the present embodiment are parallel in plan view from the vehicle body up-down direction, and intersect in front view from the vehicle body front-rear direction.

Each of the hydraulic motors ML and MR has its
Motor mounting brackets 114, 1
16, the bracket is attached to a bracket 118 provided on the front surface 112b or the rear surface 112c of the suspension cross member 112 and a bracket 120 provided on the bottom surface 112d.

The suspension cross member 112
Is formed so that its upper surface portion 112a is close to the drive shafts 11L and 11R intersecting in a front view, and the center portion in the vehicle width direction is slightly bent downward, and is formed above the upper surface portion 112a. Is the upper surface portion 112
A fuel tank 122 is arranged along the shape of a.
Also, the bottom portion 11 of the suspension cross member 112
2d is recessed upward in a semi-circular shape at the center in the vehicle width direction where the drive shafts 11L and 11R intersect, and an exhaust pipe 124 is provided below and near the semi-circular concave portion of the bottom surface portion 112d. It is designed to be inserted in the front-back direction.

As described in detail above, in the present embodiment, the hydraulic motor ML for driving the left wheel is disposed on the right side with respect to the center of the vehicle body in the vehicle width direction, and the hydraulic motor MR for driving the right wheel is provided. Since it is arranged on the left side, each drive shaft 11L, 11R can be formed long,
This makes it possible to reduce the displacement in the vehicle width direction of each of the drive shafts 11L and 11R due to the bump and rebound of the wheels 1RL and 1RR, thereby preventing an unreasonable load from acting on the hydraulic motors ML and MR.

Further, in this embodiment, since the pair of drive shafts 11L and 11R are disposed so as to be in a torsion position relationship with each other, when the above configuration is adopted, both drive shafts 11L and 11R are used. Even if the interval between the 11Rs is set narrow, each hydraulic motor ML or MR
To the drive shaft 11 of the other motor MR or ML.
It can be easily arranged without causing interference with R or 11L, and thereby the space occupied by the drive device can be reduced. Then, by this, the suspension link or the fuel tank 122 and the exhaust pipe 124
The degree of freedom in the layout of auxiliary components such as the above can be increased.

As described above, according to the present embodiment, the hydraulic motor ML,
An unreasonable load acting on the MR can be suppressed.

[Brief description of the 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.

FIGS. 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 according to the first embodiment as viewed from above.

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

FIG. 16 is a view similar to FIG. 14, showing a second embodiment of the vehicle drive device according to the present invention;

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

[Explanation of symbols]

 1RL Left rear wheel 1RR Right rear wheel ML, MR Hydraulic motor 11L, 11R Drive shaft 112 Suspension cross member 122 Fuel tank 124 Exhaust pipe

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60K 17/356 B60K 17/04

Claims (4)

(57) [Claims] 1. A vehicle drive device comprising: a motor connected to wheels via a drive shaft extending substantially in a vehicle width direction, wherein the motor is configured to rotate the wheels. The motor for driving the left wheel is disposed on the right side and the motor for driving the right wheel is disposed on the left side with respect to the center in the width direction, and a pair of the drive shafts connected to both motors Are arranged so that the positions of the torsions are in a mutual positional relationship. 2. The vehicle drive device according to claim 1, wherein the pair of drive shafts intersect in a plan view. 3. The vehicle drive device according to claim 1, wherein the pair of drive shafts intersect in a front view. 4. The vehicle drive device according to claim 1, wherein the pair of drive shafts intersect in a plan view and a front view.