JPH07117512A - Drive device of vehicle - Google Patents

Abstract

PURPOSE:To properly set a sphere where the drive of second drive wheels consisting of rear wheels or the like is conducted by means of a second drive means. CONSTITUTION:This device possesses a first drive means 98 that is equipped with an engine 2 and drives first drive wheels consisting of either of front wheels 1FL, 1FR and rear wheels 1RL, 1RR, and a second drive means 99 that is equipped with actuators (motors ML, MR) and drives the other second drive wheels. Also, the device is provided with a TRC control unit U3 to execute traction control to control the slip of the first drive wheels in regard to a road surface by controlling drive force to be given to the first drive wheels; a TRC detecting means 100 to detect that traction control has been executed; and a main control unit U1 that outputs a control signal to operate the actuator of the second drive means 99 at the time of traction control execution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a first drive means having an engine for driving a first drive wheel composed of either front wheels or rear wheels, and an actuator for driving the other second drive wheel. And a second drive means for a vehicle.

[0002]

2. Description of the Related Art In recent vehicles, there is an increasing number of four-wheel drive vehicles that can reduce the slip of each wheel with respect to the road surface by distributing the engine output to the front and rear wheels. However, in a general four-wheel drive vehicle in which the engine is arranged in front of the vehicle body, it is necessary to arrange a propeller shaft or the like for transmitting the driving force of the engine to the rear wheel side below the floor panel. There is a problem in that, as the weight increases, the accommodation portion for the propeller shaft and the like projects toward the vehicle interior side and the vehicle interior space decreases.

In order to solve the above problems, conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-120136, two motors having different driving forces are used, and the motor operates according to the gear stage of the transmission. The type and number of items have been changed. Further, as disclosed in JP-A-57-74222, the supply amount of hydraulic pressure distributed to one hydraulic motor for driving the left and right auxiliary drive wheels is applied to the left and right auxiliary drive wheels. The function of the differential device is added by automatically controlling the load according to the road load.

Further, as disclosed in Japanese Patent Laid-Open No. 63-38031, the drive voltage of the electric motors installed on the left and right is controlled in accordance with the vehicle speed to drive the left and right wheels driven by the electric motors. It has been proposed that the force is controlled to be constant and that the drive motor is selectively driven and stopped in response to an operation of a manual switch.

[0005]

In the drive devices disclosed in the above-mentioned publications, the drive energy of the motor for auxiliary driving one of the front wheels and the rear wheels ultimately depends on the engine. It is necessary to improve fuel efficiency by limiting the period to the minimum necessary. In addition, the running characteristics of the vehicle change between the four-wheel drive state in which one of the front wheels and the rear wheels is auxiliary driven by the motor and the two-wheel drive state in which the operation of the motor is stopped. It is necessary to prevent the auxiliary driving by the motor.

The present invention has been made in view of the above points, and includes a first drive means having an engine for driving a first drive wheel composed of either front wheels or rear wheels, and a second drive means of the other. A drive device for a vehicle, comprising: a second drive means having an actuator for driving the drive wheel, wherein an area in which the second drive wheel is driven by the second drive means can be appropriately set. It is an object.

[0007]

The invention according to claim 1 is
As shown in FIG. 1, front wheels 1FL, 1FR or rear wheels 1R
First drive wheel 1FL, 1 consisting of either L or 1RR
First drive means 98 including engine 2 for driving FR
And a second drive means 99 provided with actuators ML and MR for driving the other second drive wheels 1RL and 1RR, and a drive force applied to the first drive wheels 1FL and 1FR to control a first road surface. In a vehicle drive device having a traction control means U3 for executing traction control for suppressing slip of the drive wheels 1FL, 1FR, a TRC detection means 100 for detecting execution of the traction control, and the TRC detection means 100. According to the detection signal output from the
Second drive wheel control means 101 for operating the actuators ML and MR of the drive means 99 is provided.

The invention according to claim 2 is a reduction amount detecting means 102 for detecting the reduction amount of the driving force of the first drive wheels 1FL, 1FR at the time of executing the traction control, and the above-mentioned reduction amount detecting means 102 for detecting the reduction amount. The driving force setting means 103 for setting the driving force of the second driving wheels 1RL and 1RR based on the amount of decrease in the driving force is provided.

According to the third aspect of the present invention, the driving force of the second drive wheels 1RL, 1RR is the first when the traction control is executed.
The driving force setting means 103 for limiting the driving force of the second driving wheels 1RL, 1RR so as to be smaller than the driving force of the driving wheels 1FL, FR is provided.

According to a fourth aspect of the present invention, a vehicle speed detecting means S5 for detecting a vehicle speed, a steering angle detecting means S8 for detecting a steering angle of steered wheels, the vehicle speed detecting means S5 and the steering angle at the time of executing traction control. Driving force setting means 103 for setting the driving force of the second drive wheels 1RL, 1RR according to the vehicle speed and the steering angle detected by the detecting means S8 is provided.

According to a fifth aspect of the present invention, the yaw rate detecting means S17 for detecting the yaw rate acting on the vehicle body and the yaw rate detecting means S1 for executing the traction control are executed.
The second drive wheel 1 according to the yaw rate detected by
Driving force setting means 103 for setting the driving force of RL and 1RR
And are provided.

According to a sixth aspect of the present invention, the engine control means 8 for controlling the driving force of the engine during traction control is provided.
2 and a braking force control means 81 for applying a braking force to the first drive wheels 1FL, 1FR, and the engine control means 82.
The actuators ML and MR of the second drive means 99 are operated at the same time as the operation of the.

[0013]

According to the invention described in claim 1, when the TRC detecting means 100 detects that the traction control by the traction control means U3 is executed, the second
The drive wheel control means 101 outputs an operation command signal to the actuators ML and MR of the second drive wheels 1FL and 1FR,
The auxiliary drive of the second drive wheels 1FL and 1FR will be performed.

According to the second aspect of the invention, when the traction control is executed and the driving force of the first drive wheels 1FL, 1FR decreases, the amount of decrease in the driving force is detected by the reduction amount detecting means 102. At the same time, the driving force of the second driving wheels 1RL, 1RR is set in the driving force setting means 103 according to the detected value, and the control signal corresponding to the setting value of the driving force is the actuator ML of the second driving wheels 1FL, 1FR. , MR will be output.

According to the third aspect of the invention, when the traction control is executed, the driving force of the second driving wheels 1RL, 1RR set by the driving force setting means 103 is the first driving force.
If the driving force is greater than the driving wheels 1FL and 1FR,
The driving force of the second drive wheels 1RL and 1RR is the first drive wheel 1F.
The set value is corrected so that it becomes smaller than the driving force of L and FR.

According to the invention described in claim 4, during the traction control, the second setting is made by the driving force setting means 103 in accordance with the vehicle speed and the steering angle detected by the vehicle speed detecting means S5 and the steering angle detecting means S8. Drive wheel 1RL,
By correcting the driving force of 1RR, control is performed such that the turning performance is improved during turning and the traveling stability is improved.

According to the fifth aspect of the present invention, during the traction control, the driving force of the second driving wheels 1RL, 1RR set by the driving force setting means 103 is corrected according to the yaw rate detected by the yaw rate sensor S17. As a result, the turning force acting on the vehicle body is suppressed and the traveling stability is improved.

According to the sixth aspect of the present invention, during the traction control, the control for reducing the drive torque applied to the first drive wheels 1FL, 1FR by the engine control means 82 is executed, and at the same time, the second control is performed. Drive wheel 1FL, 1
The control signal for driving FR is the second drive wheel control means 10 described above.
1 to the actuators ML and MR.

[0019]

【Example】

[Description of hydraulic system and the like (see FIG. 2)] FIG. 2 shows an embodiment of a vehicle drive device according to the present invention. In this drive device, a first drive means 98 having an engine 2 for driving a first drive wheel composed of left and right front wheels 1FL and 1FR and a second drive wheel composed of left and right rear wheels 1RL and 1RR are individually provided. Second drive means 99 having an actuator composed of driving motors ML and MR is provided.

The driving force of the engine 2 is the clutch 3,
The transmission 4, the differential device 5 and the left and right drive shafts 6L,
It is adapted to be transmitted to the left and right front wheels and rear wheels 1FL and 1FR via 6R. The left and right front wheels 1FL and 1FR, which are steered wheels, are linked to each other by a steering link 7 made of a tie rod or the like, and the steering link 7 is linked to a steering wheel 8 via a rack and pinion mechanism 9. .

The left and right rear wheels 1RL and 1RR are
The left and right drive shafts 11L, 11R are linked to the motors ML, MR via the left and right drive shafts 11L, 11R, and are connected to each other by a hydraulic clutch 12 so that they can be connected to each other. The motors ML and MR
Are the first connection ports La and Ra and the second connection port L, respectively.
b, Rb, and from the first connection ports La, Ra to the second
When high-pressure hydraulic oil is supplied to the connection ports Lb and Rb,
It is configured as a turbine that rotates in the forward direction and rotates in the reverse direction when hydraulic pressure is supplied in the opposite direction.

The motors ML and MR have the same specifications, and the total value of the maximum generated torques thereof is set to about 1/3 to 1/2 of the maximum generated torque of the engine 2. In the present embodiment, the rear wheel drive by the motors ML and MR is executed only under a predetermined condition described later, and even when the left and right front wheels 1FL and 1FR are driven by the engine, the left and right rear wheels 1RL and 1RR. May not be driven by the motors ML and MR.

The second drive means 99 has a variable displacement pump P serving as a hydraulic pressure generation source, and this pump P is connected to the output shaft 2a of the engine 2 via a drive pulley 13, a belt 14 and a driven pulley 15. Has been done. Then, the high-pressure hydraulic oil pumped up from the reservoir tank 16 by the pump P is discharged to the high-pressure line 18 in which the check valve 17 is arranged.

The high pressure line 18 has a check valve 1
0 and 32 are arranged, and the first and second hydraulic pressure supply lines 31A and 31B installed in parallel with each other are connected. A release line 23 is connected to the reservoir tank 16. Further, the motors ML and M
Lines 20L, 21L, 20R, and 21R installed in parallel with each other are connected to the respective connection ports La, Lb, Ra, and Rb of R.

The lines 20L, 2 of the left motor ML
1L is a switching valve VVA, lines 19, 19L,
Lines 22 and 22L and switching valves VVB / L and VVE
It is adapted to be selectively connected to the first hydraulic pressure supply line 31A and the release line 23 via L. Also, the lines 20R, 21R of the right motor MR
Is a switching valve VVA, lines 19 and 19R, lines 22 and 22R, and switching valves VVB / R and VVE / R
Is selectively connected to the first hydraulic pressure supply line 31A and the release line 23 via the.

Further, in the second hydraulic pressure supply line 31B, a switching valve VVI is provided downstream of the check valve 32.
Is installed, and the flow dividing valve 34 is installed on the downstream side thereof. Two branch lines 33L and 33R are connected to the shunt valve 34, and one branch line 33L is connected.
Is connected to the line 19L, and the other branch line 33R is connected to the line 19R.

The high pressure line 18 is connected to the motor ML,
It is connected to an accumulator 41 that stores high-pressure hydraulic oil that serves as driving energy for MR. In addition, in the high pressure line 18, the lines 20L and 20R are connected to the passage 42.
L, 42R, and the passages 42L, 42R
The check valves 43L and 43R and the switching valve VV.
F / L and VVF / R are provided. Both passages 42
L and 42R are the switching valves VVAL and VVB.
L, VVB.R, VVE.L, VVE.R, VVI and the shunt valve 34 are bypassed and arranged in parallel with each other.

The lines 20L and 20R and the lines 21L and 21R are communicated with each other by communication passages 51L and 51R, respectively.
Variable orifices VVC.L and VVC.R are provided respectively.

The clutch 12 has an actuator 61.
It is configured to be intermittent by. That is,
The supply line 62 of the actuator 61 is the switching valve VV.
Clutch 1 connected to the high-voltage line 18 via J
2 is engaged, the discharge line 63 of the actuator 61 is connected to the release line 23 via the switching valve VVJ, and the clutch 12 is disengaged.
The switching control is selectively performed so that the clutch 12 and the clutch 63 are both in the disengaged state.

The left and right motors ML and MR are connected to each other by a communication passage 71 having an opening / closing valve VVD. The release line 23 is connected to the check valve 17
Is connected to the high pressure line 18 via the load / unload valve VVH, and the downstream side of the check valve 17 is connected to the high pressure line 18 via the safety valve VVG.

[Description of Control Modes (Table 1)] The second drive means 99 has eight types of control modes as described later, and the operation of each valve when each control mode is executed. The states are set as shown in Table 1 below. In this Table 1, reference symbols "L" and "R" for identifying left and right
Is omitted. The load / unload valve VVH not shown in Table 1 above is controlled to be opened / closed so that the pressure in the high-pressure line 18 falls within a predetermined range between the lower limit value and the upper limit value.

[0032]

[Table 1]

In the respective control modes shown in Table 1 above, the operating states of the respective valves which perform the main functions will be described below. (1) Comprehensive mode In the comprehensive mode, the left and right rear wheels 1RL,
The drive control of the motors ML and MR is performed so that 1RR has the same rotational speed, and the positive drive that applies an auxiliary drive force in the traveling direction of the rear wheels 1RL and 1RR and the rear wheels 1RL and 1RR There are two types: reverse driving in which the braking force is applied by driving in the direction opposite to the traveling direction.

In this general mode, the clutch 12
Is closed, that is, the switching valve VVJ opens the supply line 62 and closes the discharge line 63, the switching valves VVB · L, VVB · R, VVE · L,
The operation mode of VVE · R and VVI becomes the state shown in FIG. In this state, by controlling the switching valve VVA,
Switching control of the hydraulic pressure supply direction according to the forward drive and the reverse drive of the motors ML and MR, and the first hydraulic pressure supply line 3
Control of the hydraulic oil supply flow rate to the motors ML and MR using 1A is executed.

In the reverse drive, a larger damping force is obtained than in a hydraulic lock mode described later, but it goes without saying that when the vehicle is moving forward, the rear wheels 1RL, 1RR are moved forward. It does not give a large driving force for rotating in the opposite direction to the direction, but gives an appropriate braking force to the rear wheels 1RL, 1RR.

(2) Independent Mode In the independent mode, the left and right rear wheels 1RL,
The drive control of the motors ML and MR is performed so that 1RR becomes the individually set target wheel speed. There are two types of drive, that is, forward drive and reverse drive, as in the general mode. In the independent mode, the switching valve VV
J closes supply line 62 and discharge line 6
The clutch 3 is released and the clutch 12 is released.

Further, the switching valves VVE / L, VVE / R
2 operates in the state shown in FIG. 2, but the switching valve VVA
Becomes the central switching position, and the first hydraulic pressure supply line 31
A is cut off. Further, the switching valve VVI is in the open position, and the hydraulic pressure is supplied using the second hydraulic pressure supply line 31B. In this state, the switching valves VVB · L, VVB
By controlling R, the switching control of the hydraulic pressure supply direction according to the forward drive and the reverse drive of the motors ML and MR and the control of the hydraulic pressure supply flow rate to the motors ML and MR are executed.

(3) LSD Mode The LSD mode is for obtaining an operation control function. In this LSD mode, the switching valves VVB.L, VVB.R close the lines 20L, 21L, 20R, 21R respectively, thereby completely shutting off the supply and discharge of hydraulic pressure to the motors ML, MR. . Then, by opening the on-off valve VVD to communicate the closed left and right paths of the motors ML and MR with each other, it is possible to prevent a large rotation difference between the left and right motors ML and MR. In the LSD mode, the variable orifice VV
C / L and VVC / R are fully closed.

(4) Hydraulic Lock Mode The hydraulic lock mode is to obtain the deceleration force using the passage resistance, that is, the throttle resistance of the variable orifices VVC.L and VVC.R. In this hydraulic lock mode, the switching valve V
Line 2 with VB / L and VVB / R in the central switching position
Each of 0L, 21L, 20R, and 21R is shut off, the on-off valve VVD is closed, and the variable orifices VVC · L and VVC · R are opened.

In this state, the hydraulic oil is used for the motors ML and MR.
The variable orifices VVC ・ L, VVC
-Variable orifice VV which is generated when the hydraulic pressure passes through the closed hydraulic circuit having R
A deceleration force is applied to the vehicle by the throttle resistances of C / L and VVC / R. The variable orifice VV
The opening degrees of C / L and VVC / R are controlled to be smaller as the deceleration of the vehicle is larger. In the hydraulic lock mode, the clutch 12 may be in the engaged state or the disengaged state.

(5) Pressure Accumulation Mode In the pressure accumulation mode, the motors ML and MR, which are rotationally driven by the rear wheels 1RL and 1RR during traveling, function as pumps to accumulate hydraulic oil in the accumulator 41. In this pressure accumulation mode, the lines 21L and 21R are communicated with the reservoir tank 16 and the opening / closing valve VVF /
Reservoir tank 16 with L and VVF / R open
The hydraulic oil therein is pumped up and accumulated in the accumulator 41.

(6) Vehicle Stop Mode In the vehicle stop mode, the motor M is driven according to the target vehicle speed set to 0 when the parking brake is not operating.
The vehicle is stopped by controlling the operating states of L and MR. In this case, the second hydraulic pressure supply line 31B is used as a hydraulic pressure supply line, and hydraulic pressure supply / discharge control is performed using the switching valves VVB · L and VVB · R.

(7) 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 valves VVB · L, VV
B and R are closed at the central switching position, the hydraulic pressure supply / discharge line is cut off, and the clutch 12 is engaged.

(8) F / S mode The F / S mode is a fail-safe mode, and when some kind of abnormality occurs, for example, when the high voltage line 18 becomes abnormally high, the motors ML and MR operate normally. The safety valve VVG is opened and the hydraulic pressure of the high pressure line 18 is released when the oil is exhausted, when a specific valve is stuck, or when the oil temperature rises above a predetermined temperature.

[Explanation of control system (see FIG. 3)] FIG.
The control part of the said 2nd drive means 99 is shown. The control unit includes a main control unit U1 having a built-in microcomputer, an ABS control unit U2 for anti-lock brake control, a TRC control unit U3 for traction control, and various sensors S1 to S10, S14, S.
15, S17 and various switches S11 to S13, S1
And 6 are provided.

The sensors S1 to S4 individually detect the rotational speeds of the left and right front wheels 1FL and 1FR and the left and right rear wheels 1RL and 1RR, that is, the wheel speeds. The wheels detected by the sensors S1 to S4, respectively. The speed signal is ABS
Control unit U2 to main control units U1 and T
Each is transmitted to the RC control unit U3. The sensor S5 detects the vehicle speed, and is configured to detect the absolute vehicle speed which is the ground vehicle speed in this embodiment.

The sensor S6 is a shift position of the transmission 4,
That is, the gear position is detected, and the sensor S7 is
The engine speed is detected. Also, the sensor S
Reference numeral 8 denotes an operation angle of the steering wheel, that is, a steering wheel steering angle, a sensor S9 detects an accelerator opening, and a sensor S10 detects a depression amount of a brake pedal. In addition, the switch S11
Is an ignition key switch, switch S1
2 is for detecting whether or not the parking brake is operated.

The switch S13 is a manual switch for selecting four control modes of "AUTO", "general control", "independent control" and "OFF". Further, the switch S14 detects a bad road, that is, a bumpy road. For example, when a stroke of a predetermined amount or more occurs a predetermined number of times or more within a predetermined time according to a detection value of a vertical stroke of the suspension, It is configured to determine that the road. The determination of the degree of rough road can be performed by dividing at least one of the threshold values set for each element into a plurality of sections.

The sensor S15 is a pressure sensor for detecting the pressure in the accumulator 41, that is, the accumulator pressure. The switch S16 is an emergency switch that drives the vehicle by the motors ML and MR when the engine 2 is stopped.
It is manually operated by an occupant between the F state and the ON state having various output values. further,
The sensor S17 is a yaw rate sensor that detects the angular velocity of the turning force that acts on the vehicle body about the vertical axis.

The main control unit U1 outputs control signals for controlling the valves VVA-VVJ according to the signals output from the sensors S5-S10, S14, S15, S17 and the switches S11-13, S16. It is configured to output. Further, the main control unit U1 detects the TRC detection means 100 for detecting that the traction control is executed according to the TRC control signal output from the TRC control unit U3, and the detection signal of the TRC detection means 100 according to the detection signal. Second drive wheel control means 101 for outputting a control signal for operating the motors ML and MR to the respective control valves VVG to VVJ is provided.

In the second drive wheel control means 101, during the traction control, a decrease amount for detecting the decrease amount of the drive force applied to the front wheels 1FL, 1FR according to the control signal output from the TRC control unit U3 is lowered. Quantity detecting means 102
And driving force setting means 103 for setting the driving force applied to the rear wheels 1RL, 1R by the motors ML, MR based on the detection value of the reduction amount detecting means 102.

Further, the ABS control unit U2 outputs a control signal for individually controlling the brakes of the wheels 1FL to 1RR to the brake fluid pressure adjusting means 81, so that the wheels 1FR to 1RR are applied to the wheels 1FR to 1RR during braking. The brake force is adjusted to prevent the wheels 1FL to 1RR from locking.

The TRC control unit U3 outputs a control signal for controlling the torque generated by the engine 2 when the left and right front wheels 1FL and 1FR, which are constantly driving wheels, slip excessively on the road surface during acceleration or the like. By outputting to the wheel 82, the opening of the throttle valve, the ignition timing of fuel, the fuel injection amount, etc. are adjusted, and the wheels 1
By outputting a control signal for adjusting the braking force applied to FR to 1RR to the brake fluid pressure adjusting means 81, a traction control means for suppressing the slip of the front wheels 1FL, 1FR is configured.

The main control unit U1 is provided with the wheel speed signals detected by the sensors S1 to S4,
The ABS control signal indicating that the ABS control is being performed and the μ signal indicating the road surface μ (friction coefficient) are transmitted from the ABS control unit U2, and the TRC control unit U
3 is the wheel speed signal of each of the wheels 1FL to 1RR.
It is adapted to be transmitted from the BS control unit U2.

Further, the main control unit U1 is provided with a TRC signal indicating that the traction control is being performed, a torque reduction amount signal indicating an amount of reduction of the engine torque caused by the execution of the traction control, and a road surface μ signal. Are transmitted from the TRC control unit U3. In addition,
The detection of the road surface μ can also be performed by the name control unit U1. Further, the wheel speeds detected by the sensors S1 to S4 may be directly input to the main control unit U1.

The TRC detecting means 1 of the main control unit U1 indicates that the traction control is executed in response to the TRC signal output from the TRC control unit U3.
00, the decrease amount of the driving force of the front wheels 1FL and 1FR is detected by the decrease amount detecting means 102 based on the torque decrease amount signal, and the decrease amount of the driving force detected by the detected value is detected. Rear wheel 1RL according to
The driving force of 1RR is set by the driving force setting means 103.

[Description of Main Control (See FIG. 4)] Next, the control operation of the main control unit U1 will be described with reference to the flowchart shown in FIG. When the above control operation starts, first, in step D0, signals from the respective sensors are input, and then in step D1, it is determined whether or not the ignition key switch S11 is in the OFF state. If this determination result is NO, step D
2, ignition key switch S11 is ON
If it is NO, the process proceeds to step D3, the safety valve VVG is opened to release the pressure of the high pressure line 18, and then the control operation is ended.

When it is determined YES in step D2 and it is confirmed that the ignition key switch S11 is in the ON state, in step D4,
The safety valve VVG is closed to supply high-pressure hydraulic oil to the high-pressure line 18. Then, in step D5, it is determined whether or not the ground vehicle speed detected by the vehicle speed sensor S5 is substantially 0. If YES is determined, the detection value of the sensor S6 at the gear detection position is set in step D6. Accordingly, it is determined whether the gear of transmission 4 is in the neutral position.

When it is determined YES in step D6 and it is confirmed that the gear of the transmission is in the neutral position, in step D7, the parking brake is activated according to the detection signal from the parking brake detection switch S12. Or not. When the result of this determination is YES and it is confirmed that the parking brake is in the activated state, the function of maintaining the parking state of the vehicle is enhanced by executing the control of the parking mode in step D8. To control. Further, when it is determined NO in step D7 and it is confirmed that the parking brake is not in the operating state, the vehicle stop mode control is executed in step S9.
The vehicle speed is controlled to be zero.

Further, when it is determined NO in step D5 and it is confirmed that the vehicle is in the running state, or when it is determined NO in step D6 and the gear of the transmission 4 is not in the neutral position. To step D
At 10, it is determined whether the gear of the transmission 4 is in the reverse position. If the result of this determination is NO, then in step D11 it is determined whether or not the vehicle is currently in a stuck state. The determination of the stuck state is made by, for example, the vehicle speed becoming 0 when the accelerator pedal is depressed in accordance with the detection signal of the accelerator opening detection sensor S9, and the left and right front wheels 1F detected by the wheel speed sensors S1 and S2.
It is performed depending on whether or not the rotation speed of L, 1FR is sufficiently higher than the vehicle speed.

If it is determined NO in step D11 and it is confirmed that the vehicle is not in the stuck state, a control mode other than the parking mode and the stop mode, which will be described later, is executed in step D12. After determining whether or not the control condition to be satisfied is satisfied, in step D13, it is determined whether or not the control mode is executed as described later.
Decide whether to execute the control.

If it is determined YES in step D10 and it is confirmed that the gear of the transmission 4 is in the retracted position, the motors ML and MR are used for driving in step D15. Is driven in the independent mode, and the rear wheels 1RL and 1RR are driven in the backward direction. When it is determined YES in step D11 and it is confirmed that the vehicle is in the stuck state, the motors ML and MR are determined in step D14.
The auxiliary drive of the rear wheels 1RL and 1RR is performed by utilizing.
In this case, the target vehicle speed is set to a low vehicle speed of about 10 km / h, which is a condition for releasing the stack, and the positive drive is performed in the independent mode described later.

Further, when it is determined YES in step D1 and it is confirmed that the ignition switch is in the OFF state, the clutch 12 is engaged in step D16, and then the switching valve VVJ is set in step D17. Supply line 62 and release line 6
3, the clutch 12 is maintained in the engaged position, and in step D18, a control signal for opening the safety valve VVG is output.

[Explanation of Mode Judgment Control (Refer to FIGS. 5 to 8)] Next, step D1 of the above main flow chart.
The determination operation of whether or not the control condition for executing the control mode in 2 is satisfied will be described based on the flowcharts shown in FIGS. The flow chart of the above mode determination is premised on a road surface that is not a bad road, that is, a good road.

When the above control operation starts, first, at step E24 in FIG. 5, it is determined whether or not the traction control by the TRC control unit U3 is currently being executed. If the result of this determination is NO, it is determined in step E26 whether or not the road surface is a low μ road. If the result of this determination is that the road surface is not a low μ road, At E26, it is determined whether the vehicle is currently in a straight traveling state. To determine whether the vehicle is in the straight traveling state, the lateral G acting on the vehicle body is calculated according to the steering wheel steering angle detected by the steering wheel steering angle sensor S8 and the vehicle speed detected by the vehicle speed sensor S5. It is performed depending on whether or not G is equal to or less than a preset predetermined value.

When it is determined YES in step E26 and it is confirmed that the vehicle is in the straight traveling state, the normal road control operation shown in steps E27 to E39 is executed. This control operation is premised on a straight traveling state on a good road and a high μ road.
It is configured to determine whether or not the conditions for executing the forward drive of the general mode in 28, the reverse drive in step E35 and the pressure accumulation mode in steps E33 and E39, or the hydraulic lock mode in steps E31 and E37 are satisfied. Has been done.

That is, in step E27, it is determined whether or not the vehicle is currently in the rapid acceleration operation state. If the result of this determination is YES, then in step E28
Judge that the conditions for positive drive in the general mode are met,
Rear wheels 1RL, 1 at the time of sudden acceleration in a straight state on a high μ road
By driving the RR forward, the rear wheels 1RL, 1R
The motor ML, so as to apply an auxiliary driving force to R,
Control the MR.

When it is determined NO in step E27 and it is confirmed that the vehicle is not in the rapid acceleration state, it is determined in step E29 whether or not the vehicle is in the high speed operation state, and NO is determined. If so, in step E30, it is determined whether or not the vehicle is in the slow deceleration state. If the determination result is YES, step E
In 31, it is determined that the condition of the hydraulic lock mode is satisfied, and resistance is applied to the rotation of the rear wheels 1RL and 1RR, so that the vehicle decelerates during the slow deceleration in the medium-low speed operation state when traveling straight on a high μ road. The force is controlled to gradually increase.

When it is determined NO in step E30 and it is confirmed that the vehicle is not in the slow deceleration state, it is determined in step E32 whether the vehicle is in the rapid deceleration state and YES. When it is determined, in step E33, it is determined that the pressure accumulation mode condition is satisfied, and the pressure accumulation mode control is executed. That is, at the time of sudden deceleration from the medium-low speed operation state when going straight on a high μ road, the rear wheel 1R
While giving resistance to the rotation of L and 1RR, this rear wheel 1R
Accumulation of the accumulator 41 is performed by utilizing the rotation of L and 1RR.

Further, when it is determined YES in step E29 and it is confirmed that the vehicle is in the high speed driving state, it is determined in step E34 whether the vehicle is in the rapid deceleration state, and this determination is made. If the result is YES, in step E35, it is determined that the condition for reverse driving in the general mode is satisfied, and the reverse driving control is executed. That is, the deceleration force is increased by applying a large braking force to the rotation of the rear wheels 1RL and 1RR during the rapid deceleration in the high speed operation state when the vehicle is running straight on the high μ road.

When it is determined NO in step E34 and it is confirmed that the vehicle is not in the sudden deceleration operation state, it is determined in step 36 whether the vehicle is in the slow deceleration state. If the determination result is YES, it is determined in step E37 that the condition of the hydraulic lock mode is satisfied, and the variable orifice V corresponding to the deceleration is set.
Set the VC opening. That is, the variable orifice VVC is controlled so as to slightly increase the deceleration force by giving the rear wheels 1RL and 1RR a resistance corresponding to the deceleration at the time of slow deceleration in the high-speed operation state during straight traveling on the high μ road.

When it is determined NO in step E36 and it is confirmed that the vehicle is not in the slow deceleration state, it is determined in step E38 whether or not the vehicle is in the steady operation state, and this determination is made. If the result is YES, in step E39, it is determined that the condition of the pressure accumulation mode is satisfied, and the pressure is accumulated in the accumulator. That is, when the high-speed road is in a steady state in a high-speed driving state when going straight,
While applying resistance to the rotation of the rear wheels 1RL, 1RR, the rotation of the rear wheels 1RL, 1RR is used to accumulate pressure in the accumulator 41.

Further, when the determination at step E32 and step E38 is NO, the rear wheels 1RL, 1R
It is determined that the driving condition of R is not satisfied, and the control operation is ended. That is, the rear wheels 1RL and 1RR are not driven by the second drive means 99 during steady running in the medium-low speed operation state.

The degree of acceleration and the degree of deceleration can be appropriately set by a known method. That is, it can be known by any one of the degree of acceleration, for example, the magnitude of the accelerator depression speed, the increase amount of the accelerator depression amount, the vehicle body acceleration obtained by differentiating the vehicle speed, or any combination thereof. Further, the degree of deceleration can be known from any one of the magnitude of the accelerator release speed, the increase amount of the brake depression amount, the vehicle body deceleration obtained by differentiating the vehicle speed, or any combination thereof.

If it is determined NO in step E26 and it is confirmed that the vehicle is not in the straight traveling state, the control operation shown in the flowchart of FIG. 6 is executed. This control operation is premised on turning on a good road, and finally, the condition for executing the forward drive in the independent mode in step E42, the reverse drive in step E44, or the control in the LSD mode in step E45 is satisfied. It is determined whether or not it has been done. In particular,
In step E41, it is determined whether or not the vehicle is in the sudden acceleration operation state, and if YES is determined, it is determined in step E42 that the condition for the positive drive in the independent mode is satisfied. Then, at the time of rapid acceleration accompanied by turning on a high μ road, the rear wheels 1RL and 1RR are independently driven to rotate normally to control the turning force to be assisted.

When it is determined NO in step E41 and it is confirmed that the vehicle is not in the rapid acceleration operation state, it is determined in step E43 whether the vehicle is in the deceleration operation state. If the result of this determination is YES, then in step E44, it is determined that the condition for reverse driving in the independent mode has been met. Then, during deceleration accompanied by turning on a high μ road, independent braking force is applied to each of the rear wheels 1RL, 1RR so that the deceleration force is controlled to be increased.

On the other hand, if it is determined NO in step E43 and it is confirmed that the vehicle is not in the decelerating operation state, it is determined in step E45 that the LSD mode condition is satisfied. Then, at the time of turning without acceleration / deceleration on a high μ road, control is performed so that a large turning difference is suppressed between the rear wheels 1RL and 1RR and smooth turning is performed.

Further, if it is determined YES in step E25 and it is confirmed that the road is a low μ road, the control operation shown in FIG. 7 is executed. When this control operation starts, first, in step E51, it is determined whether the vehicle is in a straight traveling state. This judgment result is YES
If it is, the processes of steps E52 to E59 are executed, but this process is premised on the straight traveling state on the low μ road which is a good road.

Finally, it is determined whether or not the conditions for executing the positive drive of the independent mode in step E55, the reverse drive of the independent mode in step E57, the hydraulic lock mode in step E54, or the control of the LSD mode in step E59 are satisfied. Whether or not it is determined.

Specifically, in step E52, it is determined whether or not the vehicle is in the high speed driving state. If YES is determined, in step E53, it is determined whether or not the vehicle is in the decelerating driving state. To judge. If the result of this determination is YES, then in step E54, it is determined that the conditions for the hydraulic lock mode have been met. Then, at the time of deceleration from the high-speed driving state in the straight traveling state on the low μ road, the deceleration force of the vehicle is controlled to be slightly increased by imparting a resistance force to the rotation of the rear wheels 1RL and 1RR.

When it is determined that the vehicle is not in the decelerating operation state when it is determined to be NO in step E53,
At step E55, it is determined that the condition for the positive drive in the independent mode is satisfied. Then, the rear wheels 1RL and 1RR are independently driven to rotate forward in a high-speed driving state in a straight traveling state on a low μ road, so that auxiliary driving is performed.

When it is determined NO in step E52 and it is confirmed that the vehicle is not in the high speed operation state, it is determined in step E56 whether the vehicle is in the rapid acceleration operation state. If the determination result is YES, then in step E57, it is determined that the condition for the positive drive in the independent mode is satisfied. Then, when the vehicle is stopped in the straight running state on the low μ road or when the vehicle is suddenly accelerated from the medium-low speed operation state, the rear wheels 1RL and 1RR are independently driven to rotate normally, so that auxiliary driving is performed.

When it is determined NO in step E56 and it is confirmed that the vehicle is not in the rapid acceleration operation state, it is determined in step E58 whether the vehicle is in the deceleration operation state. If the determination result is NO, it is determined in step E59 that the LSD mode condition is satisfied. Then, when straight traveling without deceleration on the low μ road, it is controlled so that stable running is performed while suppressing a large rotation difference between the rear wheels 1RL and 1RR. Note that the determination result in step E58 is YES.
In the case of, the control operation is terminated without establishing the operation mode.

When it is judged NO in step E51 and it is confirmed that the vehicle is not in the straight running state, the control operation shown in FIG. 8 is executed. This control operation is
It is assumed that there is no acceleration / deceleration on the low μ road. Then, finally, it is determined whether or not the conditions for executing the normal drive in the independent mode in step E62, the hydraulic lock mode in step E65, and the LSD mode control in step E66 are satisfied.

Specifically, in step E61, it is determined whether or not the vehicle is in the sudden acceleration operation state, and if YES is determined, it is determined in step E62 that the condition for the positive drive in the independent mode is satisfied. to decide. And
Rear wheel 1RL, 1RR during sudden acceleration accompanied by turning on low μ road
Is independently driven to perform normal rotation, thereby performing control for assisting the normal rotation driving force.

On the other hand, if it is determined NO in step E61 and it is confirmed that the vehicle is not in the rapid acceleration operation state, it is determined in step E63 whether the vehicle is in the high speed operation state. When the determination result is YES, it is determined in step E64 whether the vehicle is in the decelerating operation state. If the result of this determination is YES, it is determined that the conditions for the hydraulic lock D mode have been met. Then, at the time of deceleration from a high-speed operation state involving turning on a low μ road, a resistance force is applied to the rotation of the rear wheels 1RL, 1RR, so that the deceleration force is controlled to be increased.

When it is determined NO in step E64 and the vehicle is not in the deceleration operation state, or when it is determined NO in step E63 and the vehicle is not in the high speed operation state. Is step E6
At 6, it is determined that the LSD mode condition is satisfied. Then, during high-speed operation or middle-low speed operation that involves turning on a low-μ road, control is performed so that a large turning difference is suppressed between the rear wheels 1RL and 1RR and smooth turning is performed.

[Description of Execution Judgment Control (See FIG. 9)] Next, the control content of step D13 in the main flowchart shown in FIG. 4 will be described. This control finally executes and does not execute the mode that satisfies the control conditions shown in FIGS.

When the above control operation starts, first, at step W0, it is determined whether or not the conditions for executing the control of modes other than the general mode and the independent mode are satisfied. If the determination result is YES, step W
In 4, the control satisfying the condition, that is, the LSD mode, the hydraulic lock mode, or the pressure accumulation mode is executed.

When it is judged NO in step W0 and it is confirmed that the condition for executing the control in the general mode or the independent mode is satisfied, in step W1, the operation state (selected state) of the manual switch S13 is determined.
Is determined to be "OFF". If the result of this determination is YES, it is determined that the driver does not want the auxiliary driving using the motors ML and MR, and the process proceeds to step W2, where the rear wheels 1RL that use the motors ML and MR,
Prohibit 1RR drive.

On the other hand, when it is judged NO in step W1 and it is confirmed that the manual switch S13 is not "OFF", it is checked in step W3 whether the operation state of the manual switch S13 is "AUTO". judge. If the determination result is YES, in step W4, the rear wheels 1R driven by the motors ML and MR are used.
The control in the mode satisfying the control condition is executed including the auxiliary driving of L and 1RR.

When it is determined NO in step W3 and it is confirmed that the manual switch S13 is not "AUTO", it is determined in step W5 whether the control condition in the general mode is satisfied. . If the result of this determination is YES, then in step W6 it is determined whether the operating state of the manual switch S13 is the "general mode". This judgment result is YES
If it is, it is determined in step W7 whether or not the traveling road is a bad road. If YES is determined, drive control of the motors ML and MR based on the general mode is executed in step W8. To do.

Further, it is determined NO in the above step W6 and it is confirmed that the operation state of the manual switch S13 is not the "total mode", or the above step W7.
When it is determined to be YES and it is confirmed that the traveling road is a bad road, the drive control of the motors ML and MR based on the independent mode is executed in step W9.

On the other hand, when it is judged NO in step W5 and it is confirmed that the control condition based on the general mode is not satisfied, whether or not the control condition in the independent mode is satisfied in step W10. Judge, Y
If determined as ES, in step W11,
The operation state of the manual switch S13 is "independent mode"
Or not. If the determination result is YES, in step W13, drive control of the motors ML and MR based on the independent mode is executed.

When it is determined NO in step W11 and it is confirmed that the operation state of the manual switch S13 is not the "independent mode", it is determined in step W12 whether the traveling road is a bad road. If NO is determined, it is determined in step W14 whether the vehicle is in a turning state. This determination result is NO
If it is, the drive control of the motors ML and MR based on the general mode is executed in step W15.

When it is determined NO in step W10 and it is confirmed that the control condition of the independent mode is not satisfied, it is determined YES in step W12 and it is confirmed that the traveling road is a very bad road. If it is determined that the vehicle is in a turning state when YES is determined in step W14, the auxiliary drive control of the rear wheels 1RL and MR by the motors ML and MR is prohibited in step W2. To do.

[Description of Positive Drive Control in Independent Mode (Refer to FIGS. 10 and 11)] FIGS.
The details of the positive drive control in the independent mode are shown. When this control operation starts, first, in step Z0, it is determined whether or not a drive inhibition flag F, which will be described later, is 1. If the determination result is YES, the process directly returns, and if NO and it is confirmed that the flag F is 0, in step Z1, the ground vehicle speed VA and the wheel speeds VBL, VBR, etc. are determined. After inputting the signal, in step Z2, the target vehicle speed VTR is set using the accelerator opening and the shift position of the transmission 4 as parameters.

Next, in step Z3, the actual wheel speeds VBL, VBR of the left rear wheel 1RL are calculated from the target vehicle speed VTR.
It is determined whether or not the value obtained by subtracting is greater than or equal to a predetermined vehicle speed V1 set in advance. If the result of this determination is NO, it means that auxiliary drive in the forward rotation direction is not necessary, so in step Z14, forward drive of the left rear wheel 1RL is stopped. The processes of steps Z3 and Z14 are performed on the right rear wheel 1RR in the same manner as on the left rear wheel 1RL. The predetermined vehicle speed V1 is set corresponding to the limit value of the slip amount allowed during acceleration, but this value may be set to a constant value, and the higher the vehicle speed VA, the larger the variable vehicle speed VA. It may be set as a value.

If YES is determined in step Z3 and it is confirmed that the above value is equal to or higher than the predetermined vehicle speed V1, it is determined in step Z4 whether or not the accelerator opening is fully opened, and YES is determined. If it is determined, it is determined that the auxiliary drive in the forward rotation direction using the motors ML and MR is not necessary, and the process proceeds to step Z14, where the forward drive of both the left and right rear wheels 1RL and 1RR is stopped. To do.

Further, when it is determined NO in step Z4 and it is confirmed that the accelerator opening is not fully opened, in step Z5, the lateral G acting on the vehicle body is determined based on the vehicle speed VA and the steering angle of the steering wheel. Calculate Then, in step Z6, based on the lateral G, correction coefficients K1 and K2 for correcting the target vehicle speeds of the turning outer wheel and the turning inner wheel, which cause a rotation difference during turning, are set.

Then, as shown in FIG. 11, step Z
In 7, it is determined whether or not the vehicle is turning right,
If YES is determined, in step Z9,
For the target vehicle speed VTR set in step Z2,
The target wheel speed VTRL of the left rear wheel 1RL is calculated by multiplying the correction coefficient K1 set according to the lateral G by a value of 1 or more, and a lateral value of 1 or less with respect to the target wheel speed VTR. The target wheel speed VTRR of the right rear wheel 1RR is calculated by multiplying the correction coefficient K2 set according to G.

Further, the determination result of step Z7 is NO.
If it is, in step Z8, the left and right rear wheels 1R
The target wheel speeds of L and 1RR are calculated. Step Z above
By performing the processes of 6 to Z9, the control for increasing the target wheel speed on the turning outer wheel side and decreasing the target wheel speed on the turning inner wheel side is executed. When the vehicle goes straight, the determination result of step Z7 becomes NO and the process proceeds to step Z8. In this case, since the lateral G is 0 or almost 0, both the correction coefficients K1 and K2 are 1 The target wheel speeds of the left and right rear wheels 1RL and 1RR are set to be equal to each other.

Next, at step Z10, the motor M is driven according to the value obtained by subtracting the actual wheel speeds VBL, VBR of the rear wheels 1RL, 1RR from the target wheel speeds VTRL, VTRR.
The amount Q of oil supplied to L and MR is determined. This oil amount Q is
The left and right motors ML and MR are individually determined. Then, in step Z11, the switching valves VVB · L and VVB · R are set according to the set value of the oil amount Q.
Control individually.

Thereafter, in step Z12, the vehicle speed V
It is determined whether or not a value obtained by subtracting the actual wheel speed VBL of the left rear wheel 1RL from A is smaller than a preset predetermined vehicle speed "-V2". The predetermined vehicle speed "-V2" serves as a criterion for determining whether the actual wheel speed VBL of the left rear wheel 1RL is too high with respect to the actual vehicle speed VA.

If YES in step Z12, the left rear wheel 1 is operated in step Z13.
Supply oil quantity Q so that RL maintains a predetermined slip value
Correct to reduce. Incidentally, the above step Z12,
The processing of Z13 also applies to the left rear wheel 1 for the right rear wheel 1RR.
The same as for RL. If the decision result in the step Z12 is NO, the process returns without passing through the step Z13.

The positive drive control in the general mode is
The target vehicle speed VTR set in step Z2 becomes equal to the left / right rear wheel 1R because the processes of steps Z5 to Z9 are unnecessary.
The target wheel speeds VVTRL and VTRR are L and 1RR, and V is used as a switching valve used for adjusting the flow rate Q.
It is performed in the same manner as the positive drive control in the independent mode except that VA is used.

[Description of Reverse Drive Control in Independent Mode (see FIG. 12)] FIG. 12 shows details of the reverse drive control in the independent mode. When this control operation starts, first, various signals are input in step Z21, and then it is determined in step Z22 whether the reverse drive flag is 1 or not. If the result of this determination is NO, in step Z30 it is determined which of the regions where the steering angle and the vehicle speed VA are set as parameters.

Thereafter, in step Z31, it is determined whether or not the current traveling state is in the C area hatched in the area set in step Z30. If the result of this determination is YES, the reverse drive flag is set to 1 in step Z32, and the flow returns to step Z21. On the other hand, if the decision result in the step Z31 is NO, the process returns to the step Z21 without passing through the step Z32.

When the step Z32 is performed, the reverse drive flag is set to 1, so that the step Z is executed.
After YES is determined in 22, it is determined in step Z23 whether ABS control is currently being executed. If the result of this determination is NO, it is determined in step Z24 whether or not the brake depression amount is large, and if NO, then step Z25.
At, it is determined whether or not the vehicle speed VA is in a low speed operation state at a predetermined vehicle speed V3 or less.

When it is judged NO in step Z25 and it is confirmed that the vehicle is in the high speed operation state, the vehicle speed VA and the shift position of the transmission 4 are set as parameters in step Z26. After reading and setting the oil amount Q to be supplied to the motors ML and MR from the graph, in step Z27, the switching valves VVB, L2VVB, and R are individually controlled according to the set value of the oil amount Q.

After that, the processes of steps Z23 and Z29 are executed. This process corresponds to step Z1 of FIG.
The correction processing corresponds to the processing of No. 2 and Z13 and is executed to prevent the reverse driving force from becoming too large. When YES is determined in any of the steps Z23, Z24, and Z25, the reverse drive control is stopped in step Z33, and then the step Z is performed.
At 34, the reverse drive flag is reset to zero.

The reverse drive control in the general mode is
The reverse drive control in the independent mode is executed in the same manner as above, except that the VVA is used as the switching valve used for adjusting the oil amount Q.

[Description of Auxiliary Drive Control During Traction Control (see FIGS. 13 to 15)] Next, a control operation during traction control executed when the determination result in step E25 in FIG. 5 is YES It demonstrates based on the flowchart shown in FIGS.

When the above control operation is started, first, in step Z41, various control signals are input, and then in step Z42, the front wheels 1FL and 1FR are generated due to the traction control performed by the TRC control unit U3. The reduction amount of the applied torque, for example, the reduction amount TF of the engine torque detected by the reduction amount detecting means 102 is read based on the output signal from the TRC control unit U3. Then, in step Z43, the vehicle speed reduction amount VC corresponding to the torque reduction amount TF is determined.

Next, at step Z44, the driving force setting means 103 sets the amount of oil Q to be supplied to the motors ML and MR in accordance with the reduction amount VC of the vehicle speed. The oil supply amount Q is set so that the total torque generated by the motors ML and MR is the same as the engine torque decrease amount TF. Then, in step Z45, the limit value Qtr of the supplied oil amount Q is read from the graph in which the driving torque T of the front wheels 1FL and FR and the vehicle speed V or the steering angle θh are set as parameters. The limit value Qtc is set by the driving force setting means 103 such that the driving torque of the rear wheels 1RL, 1RR does not become larger than the driving torque T of the front wheels 1FL, 1FR.

Next, in step Z46, it is determined whether or not the limit value Qtr is larger than the supply oil amount Q set in step Z44. If YES is determined, the limit value Qtr is determined in step Z47. By setting the value Qtr as the amount of oil Q to be supplied to the motors ML and MR, the driving torque of the rear wheels 1RL and 1RR is set to the front wheel 1F.
Do not exceed the drive torque T of L and FR. In addition, when NO is determined in the step Z46, the oil amount Q is not rewritten and the step Z is performed.
Move to 48.

In step Z48, it is determined whether or not the traction control has been stopped. If NO is determined in step Z49, the lateral G acting on the vehicle body based on the steering angle and the vehicle speed VA is determined in step Z49. After the calculation, in step Z50, the correction coefficients F1 and F2 based on the lateral G are set. This correction coefficient F1 is lateral G
Is set to a value larger than 0.5 and the correction coefficient F2 is set to a value smaller than 0.5. , A motor ML corresponding to the turning inner wheel,
The distribution ratio of the oil supply amount Q to the MR, that is, the torque distribution ratio is set by the driving force setting means 103.

Then, as shown in FIG. 14, step Z
At 51, it is determined whether the vehicle is in a right turn state,
If the determination result is YES, in step Z52, the supply oil amount Q set in step Z44 or step Z47 is multiplied by the correction coefficient F1 to supply to the motor ML that drives the left rear wheel 1RL. The right rear wheel 1R is calculated by calculating the oil amount QTRL and multiplying the supplied oil amount Q by the correction coefficient F2.
The oil supply amount QTRR for the motor MR that drives R is calculated.

When it is determined NO in step Z51 and it is confirmed that the vehicle is not in the right turning state, it is determined in step Z53 whether the vehicle is in the left turning state. When the result is YES, in step Z54, the supplied oil amount Q set in step Z44 is multiplied by the correction coefficient F2 set in accordance with the lateral G by a value of 0.5 or less, and the result is left. Rear wheel 1RL
The amount of oil supplied to the drive motor ML is calculated, and the amount of supplied oil Q is multiplied by a correction coefficient F1 set in accordance with the lateral G with a value of 0.5 or more, thereby rear right Oil quantity Q supplied to drive motor MR of wheel 1RR
Calculate TRR.

Further, in step Z53, NO
If it is determined that the vehicle is in the straight turning state and is not in the right turning state or the left turning state,
In step Z55, 0.5 is applied to the supply oil amount Q set in step Z44 or step Z47.
By multiplying by, the oil amounts QTRL and QTRR supplied to the motors ML and MR are calculated. In this way, during turning, the driving force on the outside wheel side of the turning is increased and the driving force on the inside wheel side of the turning is reduced, and during straight traveling, a process for maintaining this state is executed.

When the vehicle is determined to be NO in step Z53, the absolute value of the yaw rate ψ detected by the yaw rate sensor S17 is greater than the preset reference yaw rate ψ ₀ in step Z56. If YES is determined, in step Z57, the correction coefficients F3 and F4 based on the detected value of the yaw rate ψ are set. In addition, when it is determined to be NO in step Z56, the correction coefficient F
Without setting 3 and F4, the step Z61 described later will be performed.
Move to.

The correction factors F3 and F4 set the distribution ratio of the oil supply amount Q to the motors ML and MR corresponding to the turning outer wheel and the correct inner wheel that cause a rotation difference when the vehicle turns, that is, the torque distribution ratio. Is a coefficient for doing. Then, the correction coefficient F3 becomes a value larger than 1, and the correction coefficient F4
Are set in accordance with the magnitude of the yaw rate ψ so as to be smaller than 1. The sign of the yaw rate ψ is set to be positive when turning right and negative when turning left.

Then, in step Z58, it is determined whether the sign of the detected value of the yaw rate ψ is positive,
If the determination result is NO, in step Z59, the correction coefficient F is set with respect to the set value of the supplied oil amount QTRL.
By multiplying 3 by correcting the oil supply amount QTRL of the motor ML driving the left rear wheel 1RL, and multiplying the set value of the oil supply amount QTRR by the correction coefficient F4, the right rear wheel 1RR The oil supply amount QTRR of the motor MR that drives the motor is corrected.

If it is determined YES in step Z58 and it is confirmed that the sign of the detected value of the yaw rate ψ is positive, in step Z60 the set value of the supply oil amount QTRL is compared with the set value. By multiplying by the correction coefficient F4, the supplied oil amount QTRL of the motor ML for driving the left rear wheel 1RL is corrected, and at the same time, the supplied oil amount Q
By multiplying the set value of TRR by the correction coefficient F3, the oil supply amount Q of the motor MR driving the right rear wheel 1RR
Correct TRR.

In this way, during the right turn when the sign of the detected value of the yaw rate ψ is positive, the driving force setting means 10 is set.
3, the driving force of the right rear wheel 1RR on the turning outer wheel side is corrected to be larger than that of the left rear wheel 1RL, and the yaw rate ψ
When the sign of the detected value is negative, the driving force of the left rear wheel 1RL on the turning outer wheel side is corrected to be larger than that of the right rear wheel 1RR. As a result, the turning force acting on the vehicle body is reduced.

After the execution of the above processing, as shown in FIG. 15, in step Z61, the oil quantity QTR after the correction is applied.
Switching valve VVB ・ L, VV depending on the set value of L, QTRR
Control B and R individually. Next, at step Z62, the actual wheel speed V of the left rear wheel 1RL is changed from the vehicle speed VA.
The value obtained by subtracting BL is a predetermined vehicle speed "-V" set in advance.
4 ”is determined. This predetermined vehicle speed "-
"V4" is a criterion for determining whether or not the actual wheel speed VBL of the left rear wheel 1RL is too large with respect to the actual vehicle speed VA.

If it is determined YES at step Z62, the left rear wheel 1 is returned at step Z63.
Supply oil quantity Q so that RL maintains a predetermined slip value
Correct to reduce. The above step Z62,
The processing of Z63 also applies to the left rear wheel 1 for the right rear wheel 1RR.
The same as for RL. If the decision result in the step Z62 is NO, the process returns without passing through the step Z63.

[Description of Traction Control (see FIG. 16)] Next, traction control executed in the TRC control unit U3 will be described with reference to the flowchart shown in FIG. When this traction control starts, first, at step T0, each wheel speed sensor S
The wheel speeds VAL to VBR detected by 1 to S4 are input, and the absolute vehicle speed VA detected by the vehicle speed sensor S5 is input in step T1.

Then, in step T2, the front wheels 1F
It is determined whether a value obtained by subtracting the vehicle speed VA from the wheel speeds VAL and VAR of L and 1FR is larger than a preset first reference value α. If the result of this determination is YES, and it is confirmed that the vehicle is traveling at a time when traction control should be executed because the slip amounts of the front wheels 1FL, 1FR driven by the engine 2 are large, then in step T3, the traction control The flag Ft is set to 1 and a TRC signal indicating that traction control is being executed is output to the main control unit U1.

Further, when it is determined NO in step T2 and it is confirmed that the value obtained by subtracting the vehicle speed VA from the wheel speeds VAL and VAR of the front wheels 1FL and 1FR is less than or equal to the first reference value α, In step T5, it is determined whether or not the flag Ft has already been set to 1, and N
If it is determined to be O, the process directly returns.

If YES in step T5, in step T6, the front wheels 1FL, 1FL, 1FL
It is determined whether or not the value obtained by subtracting the vehicle speed VA from the FR wheel speeds VAL and VAR has become smaller than zero. If NO in step T6, in step T7, the torque adjusting means 82 outputs a control signal for reducing the drive torque applied from the engine 2 to the front wheels 1FL and 1FR.
Output to and execute engine control.

As a result, the engine control by the TRC control unit U3 and the auxiliary drive control of the rear wheels 1RL, 1RR executed by the main control unit U1 according to the TRC signal are simultaneously executed. .

Then, in step T8, the front wheels 1F
It is determined whether a value obtained by subtracting the wheel speed VA from the wheel speeds VAL and VAR of L and 1FR is larger than a second reference value β set to a value larger than the reference value α, and it is determined to be YES. If so, in step S9, the front wheels 1
A control signal for applying a braking force to FL, 1FR to further reduce the driving force is output to the brake fluid pressure adjusting means 81 to execute the brake control.

When it is determined YES in step T6 and it is confirmed that the value obtained by subtracting the wheel speed VA from the wheel speeds VAL and VAR of the front wheels 1FL and 1FR is greater than 0, the traction control is executed. Since the traction control is stopped in step T10, the traction control flag Ft is reset to 0 in step T11.

As described above, when the TRC control unit U3 executes the traction control, the second drive means 99 executes the auxiliary drive control of the second drive wheel including the rear wheels 1RL and 1RR. Front wheel 1FL lowered due to execution of traction control,
The drive torque of the first drive wheel composed of 1FR is transferred from the motors ML and MR of the second drive means 99 to the rear wheels 1RL and 1RR.
Will be compensated by the driving force applied to the. Therefore, it is possible to prevent the front wheels 1FL and 1FR from slipping while the vehicle is accelerating, and effectively prevent the acceleration performance from being impaired.

The driving of the rear wheels 1RL, 1RR by the second driving means 99 is performed when the driving torque applied from the engine 2 to the front wheels 1FL, 1FR is reduced by the execution of the traction control. By utilizing the surplus drive torque, the actuator composed of the motors ML and MR of the second drive means 99 can be effectively driven. Further, since the second driving means 99 is driven at a limited time such as when the traction control is executed, the second driving means 99 is compared with the case where the rear wheels 1RL and 1RR are always driven. The durability of the engine 99 can be improved and the driving force of the engine 2 can be prevented from being wasted.

When executing the above traction control,
The front wheel 1F detected by the reduction amount detecting means 102
The driving force setting means 1 according to the amount of decrease in the driving force of L and 1FR
When the driving force set by 03 is applied from the actuator to the rear wheels 1RL, 1RR, the acceleration of the vehicle, which is reduced when the traction control is executed, is applied to the rear wheels 1RL, 1RR. It can be appropriately compensated by the driving force.

Further, as described above, the limit value Qt of the hydraulic pressure supplied to the motors ML and MR is set so that the driving force of the rear wheels 1RL and 1RR does not become larger than the driving force of the front wheels 1FL and 1FR. When the driving force of the rear wheels 1RL, 1RR is configured to be limited, an excessive driving force is applied to the rear wheels 1RL, 1RR during the traction control, causing the vehicle to oversteer. Can be reliably prevented.

Further, the vehicle speed detected by the vehicle speed detecting means comprising the vehicle speed sensor S5 and the steering wheel steering angle sensor S
When the driving force setting means 103 corrects the set value of the driving force of the rear wheels 1RL and 1RR according to the steering wheel steering angle detected by the steering angle detecting means consisting of eight, the traction control is performed. At times, the running stability can be effectively improved.

That is, at the time of traction control, the rear wheel 1
The driving force setting means 1 corresponding to the driving forces of RL and 1RR
The limit value Qtr of the amount of oil supplied to the actuator set by 03 is changed according to the detected value of the vehicle speed or the steering angle of the steering wheel, and the larger the detected value, the smaller the limit value Qtr is set. By doing so, it is possible to effectively prevent a decrease in traveling stability due to a large driving force being applied to the rear wheels 1RL and 1RR during a sharp turn.

Further, the lateral G acting on the vehicle body is calculated according to the detected values of the vehicle speed and the steering angle of the steering wheel, and depending on the magnitude of the lateral G, a turning outer wheel side and a turning inner wheel side in which a rotation difference occurs during turning. If the driving force on the turning outer wheel side is set to be larger than that on the inner wheel side by setting the distribution ratio of the oil supply amount Q to the actuators corresponding to and, the turning performance of the vehicle can be effectively improved. Can be improved.

Further, the turning force acting on the vehicle body is detected by the yaw rate detecting means including the yaw rate sensor S17, and the rear wheels 1RL, 1R are detected according to the detected value of the turning force.
When the driving force setting means 103 corrects the set value of the driving force of R so that the driving force on the turning inner wheel side is made larger than that on the outer wheel side, the turning that acts on the vehicle body during traction control is performed. The force can be set to an appropriate value to improve the running stability of the vehicle.

Further, in the vehicle drive device provided with the traction control means having the braking force control means comprising the brake fluid pressure adjusting means 81 and the engine control means comprising the torque adjusting means 82, the engine control means is If the actuators of the second drive means 99 are simultaneously operated, the drive control of the rear wheels 1RL, 1RR is executed promptly from the execution point of the traction control. It is possible to effectively prevent the occurrence of discomfort caused by the execution of.

The present invention is not limited to the above-mentioned embodiments, but includes the following modifications, for example. (1) When the mode selected by the manual switch S13, that is, the general mode or the independent mode, and the mode in which the control condition is satisfied in step D12 of FIG. 4 are different, the auxiliary using the motors ML and MR is used. It may be configured not to perform such driving.

(2) In the case of a bad road, the auxiliary driving using the motors ML and MR may be performed as in the case of a good road.

(3) The control area may be set in the general mode and the independent mode according to the rough road, prior to the selection of the manual switch S13. Further, it may be configured such that only the control in the independent mode is allowed on the bad road, while the control in the comprehensive mode is allowed on the slow road. Further, on the contrary, it may be configured such that only the control in the comprehensive mode is permitted on the bad road, while the control in the independent mode is permitted on the slow road.

(4) The left and right rear wheels 1RL and 1RR may be driven by the engine 2 and the left and right front wheels 1FL and 1FR may be driven by the motors ML and MR. An electric motor may be used instead of the actuator composed of the hydraulic motor. In this case, a battery or a capacitor that stores electric power is used as an energy storage means.

(5) When traveling straight ahead, the control based on the independent mode may be executed at low speed, and the control based on the general mode may be executed at high speed. Such settings are
Although it can be performed on a high μ road, it is preferable in order to satisfy the effect of improving running performance at low speed and the effect of improving straight running stability at high speed, particularly when configured to execute on a low μ road. Becomes

[0149]

As described above, according to the present invention, the auxiliary drive control of the second drive wheels is executed by the second drive means when the traction control is executed.
The drive torque of the first drive wheel, which is reduced by the execution of the traction control, is compensated by the drive force applied to the second drive wheel by the actuator of the second drive means. Therefore, when accelerating the vehicle, the first
It is possible to prevent the driving wheels from slipping and at the same time effectively prevent the acceleration performance from being impaired, thereby improving the running performance.

The drive of the second drive wheel by the second drive means is performed when the drive torque applied from the engine to the second drive wheel is reduced by the execution of the traction control. It is possible to effectively drive the actuator of the second drive means by utilizing. Further, since the driving of the second driving means is executed only during the traction control or the like, the durability of the second driving means is improved as compared with the case where the second driving wheels are always driven. In addition to that, there is an advantage that the fuel consumption can be improved by effectively utilizing the driving force of the engine.

When the traction control is executed,
When the driving force set by the driving force setting means is applied to the second driving wheel from the actuator according to the amount of decrease in the driving force of the first driving wheel detected by the reduction amount detecting means, The acceleration of the vehicle, which is reduced when the traction control is executed, can be appropriately supplemented to the driving force applied to the rear wheels 1RL, 1RR. Therefore, there is an advantage that the acceleration desired by the driver can be secured, and the occurrence of discomfort due to the change in the driving state can be effectively prevented.

In the case where the driving force of the second driving wheel is set by the driving force setting means so that the driving force of the second driving wheel is always smaller than the driving force of the first driving wheel. In order to prevent the vehicle from entering the oversteer state due to the driving force of the rear wheel, which is the second driving wheel, being larger than the driving force of the front wheel, which is the first driving wheel, during the traction control. be able to. Therefore, there is an advantage that while the running stability is maintained, the driving control of the second driving wheels by the second driving means can be appropriately executed to improve the running performance.

Further, when the driving force of the second driving wheel is set according to the vehicle speed detected by the vehicle speed detecting means and the steering wheel steering angle detected by the steering angle detecting means, the actuator is The drive force applied to the second drive wheel from the above is controlled more appropriately according to the driving state of the vehicle, and the running stability is reduced due to the large drive force applied to the second drive wheel during a sharp turn. There is an advantage that proper turning performance of the vehicle can be secured while preventing it.

Further, the turning force acting on the vehicle body is detected by the yaw rate detecting means, and the driving force of the second driving wheel corresponding to the detected value of the turning force is set, so that the driving force on the turning inner wheel side is set to the outer wheel. If it is configured to be larger than that on the side, turning that acts on the vehicle body due to wheel slippage, for example, when traction control is executed in a running condition on a low μ road such as a snow road. It is possible to effectively reduce the force, improve the straightness, and improve the running stability of the vehicle.

Further, in the vehicle drive device provided with the traction control means having the braking force control means and the engine control means, the engine control means and the actuator of the second drive means are simultaneously operated. In this case, since the drive control of the second drive wheel is quickly executed from the execution point of the traction control, it is possible to effectively prevent the occurrence of discomfort due to the execution of the traction control. There are advantages.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram showing a hydraulic system of the drive device.

FIG. 3 is a block diagram showing a control system of the drive device.

FIG. 4 is a main flowchart showing a control operation by the control system.

FIG. 5 is a flowchart showing a first part of a mode determination routine by the control system.

FIG. 6 is a flowchart showing a second part of the mode determination routine.

FIG. 7 is a flowchart showing a third part of the mode determination routine.

FIG. 8 is a flowchart showing a fourth part of the mode determination routine.

FIG. 9 is a flowchart showing an execution determination routine by the control system.

FIG. 10 is a first independent positive drive routine by the control system.
It is a flowchart which shows a part.

FIG. 11 is a flowchart showing a second part of the independent positive drive routine.

FIG. 12 is a flowchart showing an independent reverse drive routine by the control system.

FIG. 13 is a flowchart showing a first part of auxiliary drive control during traction control.

FIG. 14 is a flowchart showing a second part of auxiliary drive control during traction control.

FIG. 15 is a flowchart showing a third part of auxiliary drive control during traction control.

FIG. 16 is a flowchart showing a traction control operation.

[Explanation of symbols]

 1FL, 1FR front wheel (first drive wheel) 1RL, 1RR rear wheel (second drive wheel) 81 brake fluid pressure adjusting means (braking force control means) 82 torque adjusting means (engine output control means) 98 first drive means 99th 2 drive means 100 TRC detection means 101 second drive wheel control means 102 reduction amount detection means 103 drive force setting means ML, MR motors (actuators) U1 main control unit U3 TRC control means (traction control means)

Claims (6)

[Claims] 1. A first drive means having an engine for driving a first drive wheel, which comprises either front wheels or rear wheels,
Second drive means having an actuator for driving the other second drive wheel, and traction control for suppressing slippage of the first drive wheel with respect to the road surface by controlling the drive force applied to the first drive wheel. In a vehicle drive device having traction control means, TRC detection means for detecting execution of the traction control, and TR
A drive device for a vehicle, comprising: second drive wheel control means for operating an actuator of the second drive means at the time of executing the traction control according to a detection signal output from the C detection means. 2. A reduction amount detecting means for detecting a reduction amount of the driving force of the first drive wheel at the time of executing the traction control, and a second drive based on the reduction amount of the driving force detected by the reduction amount detecting means. The drive device for a vehicle according to claim 1, further comprising a drive force setting means for setting a drive force of the wheels. 3. A drive force setting means for limiting the drive force of the second drive wheel so that the drive force of the second drive wheel becomes smaller than the drive force of the first drive wheel when executing the traction control. The drive device for a vehicle according to claim 1, wherein: 4. A vehicle speed detecting means for detecting a vehicle speed, a steering angle detecting means for detecting a steering angle of steered wheels, a vehicle speed and a steering angle detected by the vehicle speed detecting means and the steering angle detecting means during execution of traction control. The drive device for a vehicle according to claim 1, further comprising drive force setting means for setting a drive force of the second drive wheel according to an angle. 5. A yaw rate detecting means for detecting a yaw rate acting on the vehicle body, and a driving force setting means for setting a driving force of the second drive wheel in accordance with the yaw rate detected by the yaw rate detecting means when executing the traction control. The drive device for a vehicle according to claim 1, further comprising: 6. An engine control means for controlling a driving force of an engine and a braking force control means for applying a braking force to a first driving wheel are provided at the time of traction control, and at the same time when the engine control means operates, The drive system for a vehicle according to claim 1, wherein the actuator of the second drive means is operated.