JPH11105688A - Vehicular brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the controllability of the total braking torque that includes regenerative braking torque and frictional braking torque in a vehicular brake system using a regenerative brake system and a hydraulic brake system. SOLUTION: For surging the total braking torque up during traction control in a vehicular brake system that uses a regenerative brake system and a hydraulic brake system, Step 8 increases both the regenerative braking torque and the hydraulic braking torque. For abating the total braking torque in the same condition, on the other hand, Steps 10 to 13 hold the hydraulic braking torque constant and decrease the regenerative braking torque. Because of excellent responsiveness of the hydraulic braking torque, increasing both the regenerative and hydraulic braking torques pushes up the total braking torque more rapidly than increasing only the regenerative braking torque. A smooth reduction trend of the regenerative braking torque, in addition, permits smooth diminution of the total braking torque to thus improve the controllability of the total braking torque.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking system including a regenerative braking system and a friction braking system.

[0002]

2. Description of the Related Art An example of a vehicular braking device including a regenerative braking device and a hydraulic braking device as a friction braking device is described in Japanese Patent Application Laid-Open No. 8-149606. A regenerative braking device is a device that applies regenerative braking torque to a wheel by regenerative braking of an electric motor, and a hydraulic braking device frictionally engages a friction member with a brake rotating body that rotates with the wheel by hydraulic pressure. This is a device for applying hydraulic braking torque to the motor. A total braking torque including a regenerative braking torque and a hydraulic braking torque is applied to the driving wheels, and a hydraulic braking torque is applied to the non-driving wheels. The total braking torque applied to the non-driven wheels is the same as the hydraulic braking torque. In the vehicle braking device, the total braking torque of the drive wheels is reduced by reducing the regenerative braking torque while the hydraulic braking torque is kept constant. Since the vehicle equipped with this vehicle braking device is a rear-wheel drive vehicle, during braking, hydraulic braking torque is applied to both the rear and front wheels, while regenerative braking torque is applied to the rear wheels. Therefore, the front and rear braking force distribution lines are located on the side where the rear wheel braking force is greater than the ideal braking force distribution line, and the rear wheels are easily locked. Therefore, if the total braking torque applied to the rear wheels is reduced with a decrease in the regenerative braking torque, the ratio of the total braking torque applied to the rear wheels to the total braking torque applied to the front wheels can be reduced. The braking force distribution line can be made closer to the ideal braking force distribution line.

As described above, in the vehicle braking device described in the above publication, the total braking torque of the drive wheels is reduced by decreasing the regenerative braking torque, but the total braking torque is changed by a change in the regenerative braking torque. In such a case, there is a case where the response delay is large and the control of the total braking torque cannot be performed satisfactorily. The control of the regenerative braking torque is performed by controlling the electric motor provided in the regenerative braking device. However, since the inertia of the electric motor and its load is large, the response is poor, and the regenerative braking torque is rapidly increased and decreased. You cannot do it. If the electric motor has a large capacity (a large capacity) capable of driving the vehicle with a margin, the regenerative braking torque can be rapidly increased or decreased. However, if the capacity of the electric motor is large enough, the weight will increase,
Another problem such as an increase in cost arises.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle braking device including both a regenerative braking device and a friction braking device, while avoiding an increase in cost while reducing the overall cost. The purpose is to improve the controllability of the braking torque. The above problem is solved by the following vehicle braking device. In the following description, each aspect of the present invention is divided into sections, numbered, and, if necessary, other sections are cited and described in the same format as the claims. This is to clarify the possibility of adopting the features described in each section in combination. (1) A regenerative braking device that applies regenerative braking torque to wheels of a vehicle by regenerative braking of an electric motor, and a friction member is frictionally engaged with a brake rotating body that rotates together with the wheels to apply friction braking torque to the wheels. Friction braking device, when changing the total braking torque including the regenerative braking torque and the friction braking torque with a large gradient, changing both the regenerative braking torque and the friction braking torque to reduce the total braking torque And a total braking torque control device that changes the regenerative braking torque while keeping the friction braking torque constant when changing the braking torque. In the vehicle braking device according to the present mode, a total braking torque including a regenerative braking torque and a friction braking torque is applied to the wheels. The total braking torque applied to the wheels can be changed by changing at least one of the regenerative braking torque and the friction braking torque,
By changing both the regenerative braking torque and the friction braking torque, compared to changing only the regenerative braking torque,
The change gradient of the total braking torque can be increased, and the response delay can be reduced accordingly. The response delay can be reduced without increasing the capacity of the electric motor provided in the regenerative braking device, so that controllability can be improved while avoiding an increase in cost. Here, the friction braking torque is controlled by controlling the pressing force when the friction member is pressed against the brake rotating body in the friction braking device. When the friction coefficient between the friction member and the brake rotating body is the same, the friction braking torque is larger when the pressing force is large than when the pressing force is small. As the friction braking device, a hydraulic braking device, an electric braking device, or the like can be used. The hydraulic braking device includes a hydraulic pressure control device that controls the pressing force of the friction member against the brake rotating body by controlling the hydraulic pressure. As the electric braking device, a voltage applied to a laminated body such as a piezoelectric element is used. To control the pressing force by controlling the expansion and contraction of the stacked body, and the motor braking device including the motor controlling device that controls the pressing force by controlling the electric motor. Etc. exist. In the former hydraulic braking device, it is relatively easy to quickly increase and decrease the hydraulic pressure, so that the pressing force can be rapidly increased and decreased. In the latter, the laminate can be rapidly expanded and contracted by controlling the voltage, so that the pressing force can be increased or decreased quickly. Also in the motor braking device, the pressing force can be quickly increased or decreased by controlling the electric motor. In the motor braking device, since the electric motor is applied to the friction member via the booster having a large boost factor, the inertia can be reduced relatively easily. In any case, the responsiveness is better in the control of the friction braking torque than in the control of the regenerative braking torque. Therefore, the responsiveness can be improved by controlling the total braking torque by controlling the friction braking torque, and the responsiveness can be improved by controlling the total braking torque by controlling both the friction braking torque and the regenerative braking torque. It can be even better. Compared to the case where the total braking torque is changed only by the change of the regenerative braking torque, the increase / decrease of the total braking torque can be switched more quickly and the gradient of the increase / decrease can be increased. On the other hand, the regenerative braking torque can be changed smoothly, so that it is suitable for gradually changing the total braking torque. When the total braking torque is gradually changed, the response may not be good. Further, when the friction braking device is a hydraulic braking device, and the fluid pressure of the wheel cylinder is gradually increased by repeating switching of the solenoid valve such as duty control of the solenoid valve, the operating noise of the solenoid valve increases. While there is a problem, the gradual change of the regenerative braking torque has an advantage that such a problem does not occur. As described above, by utilizing the difference in controllability between the regenerative braking torque and the friction braking torque, controllability of the total braking torque can be improved. The total braking torque control device in the vehicle braking device according to this section includes a braking torque changing means for changing both the regenerative braking torque and the friction braking torque, and a regenerative braking while the friction braking torque is kept constant. It can be considered that regenerative braking torque changing means for changing the torque is included. Here, the regenerative braking torque changing unit is also a friction braking torque holding unit. (2) The total braking torque control device includes traction control means for controlling the total braking torque so that the driving slip state of the wheels becomes substantially appropriate, and the traction control means sharply increases the total braking torque. When the total braking torque is gradually decreased, the regenerative braking torque is kept constant while increasing the regenerative braking torque and the frictional braking torque. The vehicle braking device according to claim 1, further comprising regenerative braking torque gradual decreasing means for gradually reducing the braking torque. In traction control,
In many cases, the total braking torque increases rapidly and decreases slowly. For example, when the driving slip state is equal to or more than the set state, the driving torque is rapidly decreased by rapidly increasing the total braking torque, and when the driving slip state tends to recover, the total braking torque is gradually reduced. Therefore, when the total braking torque is suddenly increased, both the regenerative braking torque and the friction braking torque are increased. When the regenerative braking torque is gradually decreased, the total braking torque is rapidly increased. , Can be smoothly reduced, and traction control can be favorably performed. Here, it is desirable that both braking torque increasing means increase the regenerative braking torque to an upper limit value. Although the upper limit value will be described in detail in [Embodiment of the invention], it is the maximum value that can be output under these conditions at that time, such as the rotation speed of the electric motor, the state of charge in the power storage device, the temperature, and the like. If the regenerative braking torque is set to the upper limit, there is more room for reducing the regenerative braking torque, and the energy efficiency is improved. (3) In a state where the traction control means reduces the total braking torque in a state where the regenerative braking torque is reduced to zero by the regenerative braking torque decreasing means, a reduction that reduces the friction braking torque. The braking device for a vehicle according to item (2), including a friction braking torque gradual decrease means when insufficient. From the state in which both the regenerative braking torque and the friction braking torque are applied to the wheel, the regenerative braking torque is reduced by the regenerative braking torque reducing means. However, even if the regenerative braking torque becomes zero, If it is necessary to reduce the total braking torque, that is, if it is not reached to maintain or increase the total braking torque, the friction braking torque will be reduced. In this case, the regenerative braking torque gradual decrease means may be referred to as regenerative priority gradual decrease means. (4) The traction control means sets the decreasing gradient of the total braking torque to a recovery state of the drive slip state due to both the regenerative braking torque and the friction braking torque being increased by the two braking torque increasing means. The vehicle braking device according to the mode (2) or (3), including a decreasing gradient determining means that is determined in accordance with the mode. In the traction control in which the total braking torque is gradually reduced when the driving slip state starts to recover due to the increase in the total braking torque, the decreasing gradient of the total braking torque may be determined according to the recovery state of the driving slip state. it can. For example, there is a recovery speed as one mode of the recovery situation, but when the recovery speed in the driving slip state is high, the decrease gradient is made larger than when the recovery speed is low.
When the change gradient of the drive slip is large, control for increasing the change gradient of the total braking torque is generally performed. In other words, when the recovery speed of the driving slip state is high, it can be estimated that the friction coefficient of the road surface is larger than when the recovery speed is low, and it is desirable to change the total braking torque with a large gradient. In traction control, the total braking torque is gradually reduced with the regenerative braking torque, or as described in (3), with the friction braking torque being gradually reduced. Therefore, the decreasing gradient determined by the decreasing gradient determining means is
There are cases where the regenerative braking torque has a decreasing gradient and cases where the friction braking torque has a decreasing gradient. (5) The total braking torque control device includes anti-lock control means for controlling the total braking torque so that the braking slip state of the wheel is substantially appropriate, and the anti-lock control means controls the total braking torque. In the case of abrupt decrease, both braking torque reducing means for reducing both the regenerative braking torque and the friction braking torque, and in the case where the total braking torque is gradually increased, the friction braking torque is kept constant. The vehicle braking device according to any one of the above items (1) to (4), including a regenerative braking torque gradual increasing means for gradually increasing the regenerative braking torque. In the anti-lock control, the total braking torque is often decreased rapidly and increased gradually. For example, when the braking slip state reaches a set state, the total braking torque is sharply reduced, and when the braking slip state starts to recover, the total braking torque is gradually increased. If the total braking torque is reduced, both the regenerative braking torque and the friction braking torque are reduced, and if the total braking torque is increased, the regenerative braking torque is gradually increased, so that the total braking torque is rapidly reduced and gradually increased. The anti-lock control can be performed well. (6) When the total braking torque needs to be increased in a state where the regenerative braking torque has been increased to the upper limit value by the regenerative braking torque gradual increasing means, the antilock control means slowly increases the friction braking torque. The vehicle braking device according to item (5), including a friction braking torque gradual increasing means when the increase is insufficient. Even if the regenerative braking torque reaches the upper limit, if the total braking torque still needs to be increased, the friction braking torque is increased. The regenerative braking torque gradual increase means can be referred to as regenerative priority gradual increase means. (7) The anti-lock control means determines the increasing gradient of the total braking torque as a target total braking torque which is a total braking torque intended by a driver and an actual total braking torque which is a total braking torque actually obtained. The vehicle braking device according to the mode (5) or the mode (6), further including a slowly increasing gradient determining means for determining the gradient based on the vehicle speed. When antilock control is performed in the vehicle braking device described in this section, the total braking torque of the drive wheels is increased by increasing the regenerative braking torque, but the regenerative braking torque is applied to the non-drive wheels. Therefore, it can be increased by increasing the friction braking torque. Here, if the braking slip state of the wheels and the magnitude of the total braking torque when the total braking torque is gradually increased are the same for the driving wheel and the non-driving wheel, the increasing gradient of the total braking torque in the non-driving wheel is used. And the gradient of the increase in the total braking torque in the drive wheels is desirably the same. When the friction braking device is a hydraulic braking device, the hydraulic braking torque as the friction braking torque has a magnitude corresponding to the hydraulic pressure of the wheel cylinder.
In the case where the friction braking torque is gradually increased in the non-drive wheels by repeating the short-time communication and disconnection of the wheel cylinder from the master cylinder, the pressure increase gradient of the wheel cylinder hydraulic pressure becomes the hydraulic pressure of the master cylinder. , The hydraulic pressure of the wheel cylinder, and the duty ratio of the pressure-increasing on-off valve provided between the master cylinder and the wheel cylinder. If the duty ratio of the booster on-off valve is the same, when the difference between the master cylinder hydraulic pressure and the wheel cylinder hydraulic pressure is large, the pressure increasing gradient becomes larger than when it is small,
The increasing gradient of the hydraulic braking torque increases. In the case where the regenerative braking torque is increased at substantially the same gradient as the hydraulic braking torque, the increasing gradient of the regenerative braking torque is set to the target total braking torque according to the driver's intention and the actual total braking applied to the wheels. It can be determined based on the difference from the torque.
If the values corresponding to the above-mentioned duty ratio are predetermined, it can be considered that these torque differences correspond to the above-mentioned hydraulic pressure differences. When determining the increase gradient, the actual regenerative braking torque, which is the regenerative braking torque actually obtained,
Information or the like that can estimate the magnitude of the actual regenerative braking torque, such as the number of revolutions of the electric motor, may be considered.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vehicular braking system according to an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the vehicle equipped with the vehicle braking device is a hybrid vehicle, and has a front wheel 1 as a driving wheel.
0 and 12 are driven by an electric drive device 14 and an internal combustion drive device (not shown). The electric drive device 14
And two electric motors 16, 18. The driving torque of the electric motors 16, 18 is
Is added to In the present embodiment, an electric motor is provided for each wheel. By controlling these electric motors 16 and 18 separately, it is possible to separately control the magnitude of the torque applied to each of the wheels 10 and 12. It is possible. The electric drive device 14 is also a regenerative braking device that applies regenerative braking torque to the wheels 10 and 12 by regenerative braking of the electric motors 16 and 18, and is hereinafter referred to as a regenerative braking device 14.

[0006] In addition to the regenerative braking device 14, the vehicle is provided with a hydraulic braking device 20 as a friction braking device. A pad serving as a friction member is pressed against a rotor serving as a brake rotating body that rotates together with the wheels 10 and 12 by transmitting hydraulic pressure to the wheel cylinders 22 and 24, and a hydraulic braking torque is applied to the wheels 10 and 12. Can be Both the hydraulic braking torque by the hydraulic braking device 20 and the regenerative braking torque by the regenerative braking device 14 can be applied to the wheels 10 and 12 as drive wheels.

The regenerative braking device 14 is provided with the electric motor 1
6, 18, power converters 30, 32, transmissions 34,
36, a power storage device 38, an electric motor control device 42, and the like. The electric motors 16 and 18 include a power storage device 38.
Is converted into AC by the power converters 30 and 32 and supplied. Power converters 30, 32
Includes an inverter and the like, and is controlled by the electric motor control device 42. The magnitude of the regenerative braking torque output by the electric motors 16 and 18 is controlled by current control such as slip frequency control and vector control in the inverter. Since power converters 30 and 32 are provided corresponding to electric motors 16 and 18, electric motors 16 and 18 are separately controlled by power converters 30 and 32 and regenerative braking applied to wheels 10 and 12. The magnitude of the torque will be controlled separately. The electric motor control device 42 controls the electric power conversion device 30 so that the actual regenerative braking torque output by the electric motors 16 and 18 approaches the regenerative braking torque target value represented by the information supplied from the total braking torque control device 46. , 32 are controlled. The magnitude of the regenerative braking torque can also be controlled by changing the shift speed in the transmissions 34 and 36.

[0008] The hydraulic braking device 20 is provided with the front wheels 10 and 12.
Brake cylinders 46, a linear valve device 56, a hydraulic pressure control valve device 58 for controlling the hydraulic braking torque and controlling the total braking torque including the regenerative braking torque and the hydraulic braking torque. In addition, as shown in FIG. 2, wheel cylinders 64,
66, a master cylinder 68, a constant hydraulic pressure source 70, and the like. The master cylinder 68 has two pressurizing chambers 72 and 74.
In each of the two pressurizing chambers 72 and 74, a hydraulic pressure having substantially the same magnitude according to the operating force of the brake pedal 76 is generated. One pressurizing chamber 72 is connected to the wheel cylinders 22 and 24 of the front wheels 10 and 12 as drive wheels via a liquid passage 80, and the other pressurizing chamber 74 is connected to a rear wheel via a liquid passage 82. 60, 62 wheel cylinders 64, 66 are connected. Constant pressure source 70
Includes a master reservoir 84, a pump 86, an accumulator 88, and the like. The hydraulic fluid in the master reservoir 84 is pumped up by the pump 86 and the accumulator 8
8 The accumulator 88 is configured to always store the working fluid within a set pressure range. A pressure switch (not shown) is attached to the accumulator 88, and an O switch having hysteresis of the pressure switch is provided.
The pump 86 is started and stopped according to N and OFF. The constant fluid pressure source 70 is connected to the pressurizing chamber 74, and a high-pressure hydraulic fluid is supplied to the pressurizing chamber 74 as the brake pedal 76 is depressed. Thus, the operation stroke of the brake pedal 76 can be reduced.

In the middle of the liquid passage 80, an electromagnetic on-off valve 9 is provided.
0 and 92 are provided. Solenoid on-off valve 90,
The opening and closing of 92 causes the wheel cylinders 22 and 24 to communicate with the master cylinder 68 or cuts off. When the regenerative braking cooperative control, the antilock control, and the traction control (the antilock control and the traction control are sometimes performed in parallel with the regenerative braking cooperative control) are performed by the wheel cylinders 22 and 24, the master cylinder is used. 68.

In the middle of a liquid passage 93 connecting the wheel cylinders 22, 24 and the master reservoir 84, electromagnetic on-off valves 94, 96 are provided. Solenoid on-off valves 94, 96
Is switched to the open state, the wheel cylinders 22,
24 and the master reservoir 84 are communicated. The hydraulic pressure of the wheel cylinders 22, 24 is reduced, and the hydraulic braking torque is reduced. Wheel cylinder 2
Liquid passage 9 for connecting the linear valve device 56 with the linear valve device 56
In the middle of 8, electromagnetic switching valves 100 and 102 are provided. When the regenerative braking cooperative control is performed during normal braking, the electromagnetic on-off valves 100 and 102 are kept open, and the wheel cylinders 22 and 24 and the linear valve device 5 are kept open.
6 are kept in communication. These solenoid on-off valves 100,
Check valves 104 and 106 are provided in the middle of the bypass passages respectively bypassing the flow passages 102 to allow the flow of the hydraulic fluid from the wheel cylinders 22 and 24 toward the linear valve device 56 but to prevent the flow in the opposite direction. When the depression of the brake pedal 76 is released by the check valves 104 and 106, the hydraulic fluid of the wheel cylinders 22 and 24 is returned to the master cylinder 68 via the linear valve device 56 immediately. Further, the linear valve device 56 of the liquid passage 98 and the electromagnetic on-off valves 100, 10
2, an electromagnetic on-off valve 108 is provided. The electromagnetic on-off valve 108 is kept open when regenerative braking cooperative control or traction control is performed, or when antilock control is performed on the front wheels 10 and 12, and the like.

The linear valve device 56 is provided in the middle of a liquid passage 82 connecting the pressurizing chamber 74 and the wheel cylinders 64, 66 of the rear wheels 60, 62. The liquid passage 98 is connected to the wheel cylinder side 56. Between the linear valve device 56 and the wheel cylinders 64 and 66,
An electromagnetic on-off valve 110 is provided, and a wheel cylinder 6
A check valve 112 is provided to allow the flow of hydraulic fluid in the direction from 4, 66 to the linear valve device 56, but to prevent the flow in the opposite direction. The wheel cylinder 6
Liquid passage 11 connecting master reservoirs 84 and 66
In the middle of 4, an electromagnetic on-off valve 116 is provided. The proportioning valve 118 is also provided in the fluid passage 82 so that the fluid pressure of the wheel cylinders 64 and 66 of the rear wheels 60 and 62 is controlled so as not to be higher than the fluid pressure of the wheel cylinders 22 and 24 of the front wheels 10 and 12. Have been. As shown, in the present embodiment, the rear wheels 64, 66
The hydraulic pressure of the wheel cylinders 64, 66 is commonly controlled.

Further, the constant hydraulic pressure source 70 and the linear valve device 5
An electromagnetic on-off valve 120 is provided in the middle of a liquid passage 119 (a liquid passage that bypasses the linear valve device 56) that connects the wheel cylinder 6 with the wheel cylinder side. Solenoid on-off valve 1
20 is always kept in a closed state, but is switched to an open state when traction control is performed, and high-pressure hydraulic fluid is supplied to the wheel cylinder. In the present embodiment, since the drive wheels are the front wheels 10 and 12, when the traction control is performed, the electromagnetic switching valve 120 is switched to the open state, and the electromagnetic switching valve 110 is switched to the open state.
Is switched to the closed state, and the electromagnetic switching valve 108 is switched to the open state. The hydraulic fluid from the constant hydraulic pressure source 70 is supplied to the front wheel-side wheel cylinders 22 and 24 without being supplied to the rear wheel-side wheel cylinders 64 and 66. The hydraulic pressures of the front wheel side wheel cylinders 22 and 24 are separately controlled by controlling the electromagnetic on-off valves 100 and 94 and the electromagnetic on-off valves 102 and 96 in a state where the electromagnetic on-off valves 90 and 92 are kept closed. You. The front wheels 10, 12 have wheel cylinders 22, 2,
A hydraulic braking torque of a magnitude corresponding to the magnitude of the hydraulic pressure of No. 4 is applied.

A fluid pressure sensor 122 is provided between the linear valve device 56 and the master cylinder 68 in the fluid passage 82, and a fluid pressure sensor 124 is provided near the wheel cylinder side of the linear valve device 56. . Further, the wheel cylinders 22, 2 are
The hydraulic pressures of the wheel cylinders 64 and 66 are commonly detected by the hydraulic pressure sensor 130.
The fluid pressure sensor 132 provided in the middle of the fluid passage 98 is provided for detecting a failure of the fluid pressure sensor 124. When the solenoid on-off valve 108 is kept open, the output signal of the hydraulic pressure
4 is significantly different from the output signal of the hydraulic pressure sensor 1
24 is considered abnormal.

As shown in FIG. 3, the linear valve device 56 includes a pressure-increasing linear valve 150 and a pressure-reducing linear valve 1.
52, pressure reducing reservoir 154 and check valves 156, 15
8 is included. The pressure-increasing linear valve 150 is provided in the middle of the liquid passage 82, and the pressure-reducing linear valve 152 is connected to the liquid passage 16 connecting the liquid passage 82 and the pressure-reducing reservoir 154.
It is provided in the middle of 0. In the middle of the bypass passage bypassing the pressure-intensifying linear valve 150, the above-described check valve 1
Reference numeral 56 denotes a direction in which the flow of the hydraulic fluid from the wheel cylinder to the master cylinder 68 is allowed and the flow in the opposite direction is prevented. The check valve 158 is provided in the bypass passage that bypasses the pressure reducing linear valve 152 in such a direction that the check valve 158 allows the flow of the hydraulic fluid from the pressure reducing reservoir 154 to the master cylinder 68 and prevents the flow in the opposite direction. .

The pressure-increasing linear valve 150 includes a seating valve 190 and an electromagnetic biasing device 194.
The seating valve 190 includes a valve 200, a valve seat 202, an electromagnetic biased body 204 that moves integrally with the valve 200, and the electromagnetic biased body 20 in a direction in which the valve 200 sits on the valve seat 202.
4 includes a spring 206 as an elastic member as an urging means for urging the spring 4. In addition, the electromagnetic urging device 1
94 is a solenoid 210, a holding member 212 made of resin for holding the solenoid 210, and the first magnetic path forming body 21.
4, the second magnetic path forming body 216 and the like. When a voltage is applied to both ends of the winding of the solenoid 210, a current flows through the winding of the solenoid 210 and a magnetic field is formed. Most of the magnetic flux is generated by the first magnetic path forming member 214, the electromagnetically driven member 204, the second magnetic path forming member 216, and the electromagnetically driven member 204.
And the second magnetic path forming body 216. If the voltage applied to the winding of the solenoid 210 is changed, the magnetic force acting between the electromagnetically energized member 204 and the second magnetic path forming member 216 also changes. The magnitude of the magnetic force increases with the magnitude of the voltage applied to the winding of the solenoid 210, and the relationship between the applied voltage and the magnetic force can be known in advance. Therefore, by continuously changing the applied voltage according to the relationship, the magnitude of the force for urging the electromagnetically energized member 204 can be arbitrarily changed. The force for urging the electromagnetically energized member 204 is a force of the above-described magnetic force in the direction in which the electromagnetically energized member 204 is brought closer to the second magnetic path forming member 216. Called force. The electromagnetic driving force is a force in the opposite direction to the urging force of the spring 206. The electromagnetic biasing member 20
4 is formed on the surface facing the first magnetic path forming body 216, and the first magnetic path forming body 216 is formed on the engaging projection 220.
A portion facing the electromagnetically biased member 204 is provided with an engagement recess 2.
22 are formed, and the engagement protrusions 22 are formed in accordance with a change in the relative position between the electromagnetic biased member 204 and the first magnetic path forming member 216.
The area of the opposing portion between 0 and the engagement recess 222 is changed.

Electromagnetic biasing member 204 and second magnetic path forming member 21
The magnetic resistance of the magnetic path formed by 6 changes depending on the relative position of the electromagnetically-urged member 204 and the second magnetic-path forming member 216 in the axial direction. As a result, the solenoid 210
If the voltage applied to the second magnetic path forming member 2 is constant within a range that is not so large,
The electromagnetic driving force for urging in the 16 directions
Irrespective of the relative position of the second magnetic path forming body 216 in the axial direction. On the other hand, the urging force (urging force of the spring) for urging the electromagnetically energized body 204 by the spring 206 in a direction away from the second magnetic path forming body 216 is a combination of the electromagnetically energized body 204 and the second magnetic path forming body. It increases with approach to the H.216. Therefore, the urging force (differential pressure acting force) is applied to the valve element 200 based on the hydraulic pressure difference between the inlet-side hydraulic pressure and the outlet-side hydraulic pressure.
Is not acting, the movement of the electromagnetic biased member 204 in the direction of the second magnetic path forming member 216 is caused by the spring 20.
When the urging force of No. 6 becomes equal to the electromagnetic driving force, the motor stops. As described above, when the applied voltage is increased, the valve 200 acting on the electromagnetic biased member 204 is moved to the valve seat 202.
(The resultant force of the electromagnetic driving force and the urging force of the spring) is reduced, and the valve 200 is easily separated from the valve seat 202.

The same applies to the pressure-reducing linear valve 152. However, the pressure-increasing linear valve 150 and the pressure-reducing linear valve 152 differ in the urging force of a spring that urges the valve 200 toward the valve seat 202. The spring 224 of the pressure reducing linear valve 152 is larger than the spring 206 of the pressure increasing linear valve 150. Even if the wheel cylinder pressure increases,
This prevents the working fluid from flowing to the pressure reducing reservoir 154 via the pressure reducing linear valve 152.

In any case, the pressure increasing linear valve 15
0, it is possible to control the hydraulic pressure output by the linear valve device 56 according to the voltage applied to each solenoid 210 of the pressure reducing linear valve 152. When the voltage applied to the solenoid 210 of the pressure-increasing linear valve 150 is increased, the electromagnetic driving force in the direction opposite to the urging force of the spring 206 is increased, and the valve 200 is easily separated from the valve seat 202 in the seating valve 190. Become. The hydraulic pressure output from the linear valve device 56 is increased, and the hydraulic pressure of the wheel cylinders 22 and 54 increases. Similarly, when the voltage applied to the solenoid of the pressure reducing linear valve 152 is increased, the seating valve 190 is easily opened, and the wheel cylinder hydraulic pressure is reduced. Thus, the pressure-increasing linear valve 150, the pressure-reducing linear valve 15
2, the wheel cylinder fluid pressure is controlled in accordance with the voltage applied to each solenoid 210. Controlling the voltage applied to the solenoid 210 of the pressure increasing linear valve 150 and the solenoid 210 of the pressure reducing linear valve 152 In the specification, the control of the linear valve device 56 is abbreviated.

A liquid pressure sensor 226 is provided in the middle of the liquid passage 80 extending from the pressurizing chamber 72.
Since the hydraulic pressure detected by the hydraulic pressure sensor 226 is a hydraulic pressure corresponding to the braking force intended by the driver, the target total braking based on the hydraulic pressure detected by the hydraulic pressure sensor 226 will be described later. Torque is required. A stroke simulator 228 is connected to the liquid passage 80 to prevent the stroke of the brake pedal 76 from becoming almost zero when both the solenoid on-off valves 90 and 92 are closed.

The total braking torque control device 46 is mainly composed of a computer.
22 to 132, 226, a depression force switch 250 for detecting that the brake pedal 76 is depressed,
In addition to the wheel speed sensors 252 to 258 that detect the wheel speeds of the wheels 12, 60, and 62, the rotation speed detectors 260 and 262 that detect the rotation speeds of the electric motors 16 and 18, and the charging status of the power storage device 38 are detected. Charge status detection device 26
4, an accelerator operation amount detection device 268 for detecting the operation amount of the accelerator pedal 266 (see FIG. 1) and the like are connected. The output unit is connected to the electric motor control device 42, and the solenoids of the respective solenoid on-off valves are connected. Linear valve device 56
Are connected via a drive circuit (not shown). When the operation amount detected by the accelerator operation amount detection device 268 is greater than 0, the accelerator pedal 2
66 is said to have been depressed. The accelerator operation amount detection device 268 also functions as an accelerator switch. R
The OM stores various programs such as a traction control program shown in the flowchart of FIG. 4, an antilock control program shown in the flowchart of FIG. 6, and a regenerative braking cooperative control program (not shown in the flowchart). .

Similarly, the electric motor control unit 42 is mainly composed of a computer, and the input unit includes the above-described rotation speed detection devices 260 and 262 and the accelerator operation amount detection device 2.
68 and the like, and the output units are connected to the power converters 30 and 3.
2 and the like are connected via a drive circuit (not shown). The power conversion devices 30 and 32 include an accelerator operation amount detection device 26.
8 is controlled so as to output a drive torque corresponding to the operation amount detected, or the output torque of the electric motors 16 and 18 is controlled so as to approach the regenerative braking torque target value. The information indicating the regenerative braking torque target value is:
The information is supplied from the total braking torque control device 46, and information indicating the actual regenerative braking torque is supplied to the total braking torque control device 46. The magnitude of the actual regenerative braking torque is detected based on the number of rotations of the electric motors 16 and 18, and the like. The total braking torque control device 46, based on the actual regenerative braking torque represented by the information supplied from the electric motor control device 42,
The hydraulic pressure control valve device 58 including the linear valve device 56 and a plurality of electromagnetic on-off valves is controlled.

The operation of the vehicular braking system configured as described above will be described. When the brake pedal 76 is depressed, the hydraulic pressure corresponding to the depression force is
The hydraulic fluid is generated in the pressurizing chambers 72 and 74 and supplied to the wheel cylinders 22, 24, 64 and 66. Each wheel 1
A hydraulic braking torque corresponding to the wheel cylinder hydraulic pressure is applied to 0, 12, 60, and 62, and rotation of the wheels is suppressed. When the regenerative braking cooperative control is performed, hydraulic braking torque is applied to the rear wheels 60 and 62 as non-driving wheels, and regenerative braking torque and hydraulic braking are applied to the front wheels 10 and 12 as driving wheels. And a total braking torque including the torque. The target total braking torque according to the driver's intention is determined to have a magnitude corresponding to the hydraulic pressure detected by the hydraulic pressure sensor 226. In addition, the regenerative braking torque target value is determined to a value that maximizes the energy efficiency. In the present embodiment, the power generation side upper limit determined by the rotational speed of the electric motors 16 and 18 within a range not exceeding the operation side upper limit (target total braking torque) determined according to the depression force of the brake pedal 76, The lower limit of the charging-side upper limit determined by the state of charging in the device 38 is the smaller upper limit. Information indicating the regenerative braking torque target value determined in this way is supplied to the electric motor control device 42. Further, a value obtained by subtracting the actual regenerative braking torque represented by the information supplied from the electric motor control device 42 from the target total braking torque is set as the target hydraulic braking torque. Linear valve device 5
6 is controlled so that the hydraulic braking torque corresponding to the output hydraulic pressure detected by the hydraulic sensor 124 approaches the target hydraulic braking torque.

When the driving torque applied to the front wheels 10, 12 and the total braking torque applied to the wheels 10, 12, 60, 62 become excessive with respect to the road surface friction coefficient, traction control and antilock control are performed. However, here, for convenience, traction control will be described first.
When the drive slip state of at least one of the front wheels 10 and 12 as a drive wheel becomes equal to or greater than a set state, traction control is performed. The total braking torque applied to the front wheels 10 and 12 is controlled so that the driving slip state is maintained in a substantially appropriate state. By controlling the internal combustion engine in addition to controlling the total braking torque, the driving torque applied to the front wheels 10 and 12 is controlled.
Control of the total braking torque will be described. Further, as described above, the traction control is performed on at least one of the two drive wheels 10 and 12, but the following description will be given without distinguishing the two drive wheels 10 and 12.

The traction control is started when a traction start condition is satisfied, and is ended when a traction end condition is satisfied. In the present embodiment, the traction start condition is satisfied when the drive wheel speed exceeds the target drive wheel speed. Here, the target drive wheel speed is
Since the magnitude is obtained by adding a predetermined value to the estimated vehicle speed at the time of traction, the above-described traction start condition is satisfied when the drive slip exceeds a predetermined value. In most cases, the estimated vehicle speed at the time of traction is determined based on the smaller one of the wheel speeds of the rear wheels 60 and 62 as non-driving wheels. The size is limited so as not to exceed the range of the size obtained in consideration of the upper limit value and the lower limit value. The traction end condition is satisfied when the state in which the drive slips of both drive wheels 10 and 12 are both smaller than the set value has continued for a set time or longer.

During the traction control, one of the rapid increase mode, the hold mode, and the slow decrease mode is performed according to a predetermined table based on the drive wheel speed, the drive acceleration, and the like.
One is selected. When the driving wheel speed is higher than the target driving wheel speed and the driving wheel acceleration is positive, the rapid increase mode is selected. Thereafter, when the drive wheel speed decreases by a predetermined amount from the peak, the slow decrease mode is selected. If the slowdown mode is selected, the drive wheel acceleration becomes 0 or more, and if the drive slip changes from a decreasing tendency to an increasing tendency, the holding mode is selected. In this case, the holding mode is maintained while the driving wheel speed is lower than the target driving wheel speed, but when the driving wheel speed exceeds the target driving wheel speed, the rapid increase mode is selected. During traction control,
In the hydraulic braking device 20, the electromagnetic switching valves 90 and 92 are switched to the closed state, the electromagnetic switching valve 120 is opened, the electromagnetic switching valve 108 is opened, and the electromagnetic switching valve 1 is switched to the closed state.
The electromagnetic switching valves 100 and 94 and the electromagnetic switching valves 102 and 96 are controlled in a state in which 10 is switched to the closed state. In the regenerative braking device 14, the electric motors 16, 1
8 so that the actual regenerative braking torque output by the power converter 8 approaches a regenerative braking torque target value described later.
32 is controlled.

When the rapid increase mode is selected, both the regenerative braking torque and the hydraulic braking torque are increased.
At the start of traction control, drive wheels 10 and 12
Since no braking torque is applied, regenerative braking torque and hydraulic braking torque are newly applied. In the regenerative braking device 14, the power conversion devices 30, 32
Control is performed so that the regenerative braking torque of the electric motors 16 and 18 becomes the above-described upper limit. The reason why the regenerative braking torque target value is set to the upper limit value is to maximize the energy efficiency and increase the room for reduction of the regenerative braking torque.
In the hydraulic braking device 20, the electromagnetic on-off valves 100, 10
2 is kept open, and the solenoid on-off valves 94 and 96 are closed. Wheel cylinders 22 and 2 of drive wheels 10 and 12
4, the hydraulic fluid of the constant hydraulic pressure source 70 is immediately flowed, so that the hydraulic pressure of the wheel cylinders 22, 24 is immediately increased, and the hydraulic braking torque is rapidly increased. The total braking torque will be increased with a large gradient.

When the slow decrease mode is selected, the total braking torque is reduced as the regenerative braking torque is reduced. Here, the decreasing gradient of the regenerative braking torque is determined according to the recovery speed of the driving slip state while the rapid increase mode is selected. When the recovery speed (reduction speed) of the drive slip is high, it can be estimated that the friction coefficient of the road surface is larger than when the recovery speed is low, so that the decreasing gradient of the total braking torque is increased. Further, when the change speed of the drive slip is high, control is generally performed to increase the change gradient of the total braking torque as compared with the case where the change speed is low. In a state where the hydraulic braking torque is kept constant (in a state where the electromagnetic switching valves 100, 102.94, and 96 are both kept in the shut-off state), the actual regenerative braking torque is reduced, and the total braking torque is reduced. Can be Since the regenerative braking torque can be changed more smoothly than the hydraulic braking torque, the total braking torque can be reduced smoothly.

As described above, if the driving slip state starts to recover due to the decrease in the total braking torque, the holding mode or the rapid increase mode is selected, and the total braking torque is held or increased, but the regenerative braking torque is gradually decreased. Even if it is set to 0, if the gradual decrease mode is set,
The hydraulic braking torque is slowly reduced. Solenoid on-off valve 100,
102 is switched to the closed state and the solenoid on-off valves 94 and 96
Are alternately switched between a closed state and an open state at a predetermined ratio. The hydraulic pressure of the wheel cylinders 22, 24 is reduced, the hydraulic braking torque is reduced, and the total braking torque is reduced accordingly. In the present embodiment, the switching ratio of the electromagnetic on-off valves 94 and 96 is determined so that the decreasing gradient of the hydraulic braking torque is substantially the same as the decreasing gradient of the regenerative braking torque. Since the braking torque is reduced with substantially the same gradient as that of the braking torque, the decreasing gradient of the total braking torque is kept substantially constant while the slow decrease mode is set.

When the holding mode is selected, both the regenerative braking torque and the hydraulic braking torque are maintained at the values. The current state of the electric motors 16 and 18 is maintained, and the
0, 102 and the solenoid on-off valves 94, 96 are kept closed.

The above traction control will be described with reference to the flowchart of FIG. In step 1 (hereinafter abbreviated as S1; the same applies to other steps), it is determined whether or not the accelerator pedal 266 is depressed. When the vehicle is depressed, the wheel speeds of the drive wheels are read in S2 and S3, the estimated traction time vehicle body speed and the like are calculated, and the driving slip is calculated based on the traction estimated vehicle speed. In S4, it is determined whether or not the traction control-in-progress flag is set. If the traction control-in-progress flag is not set, it is determined in S5 whether the traction start condition is satisfied.
If so, the traction control in progress flag is set in S6, and the control mode is selected in S7. When the traction start condition is satisfied, the surge mode is most often selected. S
At 8, the regenerative braking torque target value is determined to be the upper limit value, and information representing the target value is supplied to the electric motor control device 42. Further, the hydraulic pressure control valve device 58 is controlled as described above. The total braking torque is sharply increased and the driving torque is sharply reduced.

Next, when S4 is executed, the traction control flag is set, so that the determination is Y.
It becomes ES, and it is determined in S9 whether the traction end condition is satisfied. If the condition is not satisfied, the traction control is continuously performed, and in S7, the control mode is selected. When the slow decrease mode is selected, the torque decrease gradient is determined in S10.
As described above, the size is determined according to the recovery speed of the drive slip. In S11, it is determined whether or not the actual regenerative braking torque is 0. When the rapid increase mode is selected, the actual regenerative braking torque is controlled to a magnitude substantially corresponding to the upper limit value. Therefore, when S11 is executed first, the determination is NO, and in S12, The hydraulic pressures of the wheel cylinders 22 and 24 are maintained, and the regenerative braking torque target value is reduced by the decrease value. The decreasing gradient of the regenerative braking torque is decreased so as to have the magnitude determined in S10, and the value determined in this manner is the decreasing value. If the regenerative braking torque target value is reduced by the decreasing value, the actual regenerative braking torque is reduced accordingly, and the total braking torque is reduced accordingly.

If the regenerative braking torque is reduced and the drive slip changes to an increasing tendency, the holding mode is selected, and in S14, the regenerative braking torque and the hydraulic braking torque are maintained at the values. On the other hand, even if the regenerative braking torque is reduced to 0, if the slow decrease mode is set, the hydraulic braking torque is reduced in S13. With the electromagnetic on / off valves 100 and 102 kept closed, the electromagnetic on / off valves 94 and 96 are alternately switched between an open state and a closed state. The regenerative braking torque remains at zero.

If the traction end condition is satisfied, S
9 is YES, the traction control flag is reset in S15, and the regenerative braking torque target value is set to 0 and the wheel cylinder fluid pressure is set to atmospheric pressure in S16. If the start condition is not met,
Similarly, S16 is executed. Since the brake pedal 76 is not depressed, both the regenerative braking torque and the hydraulic braking torque are set to zero.

FIG. 5 shows an example of the case where traction control is performed in the vehicle brake system. When the traction control is started at time t ₁ and the rapid increase mode is selected, both the regenerative braking torque and the hydraulic braking torque are increased, so that the total braking torque is rapidly increased.
The drive torque is reduced and the drive slip is reduced. At time t _2, when the drive slip is reduced more than the set value than the peak value, gentle reduction mode is selected, the regenerative braking torque is not loose Gensa. The decreasing gradient of the regenerative braking torque in this case is a size corresponding to the reduced slope of the traction between the time Delta] t _12. Regenerative braking torque is not loose Gensa, becomes zero at a time t _3, since the gentle reduction mode is set to continue, thereafter, the hydraulic braking torque with the opening and closing of the electromagnetic valve 94, 96 As a result, the regenerative braking torque is reduced at a gradient substantially the same as the gradient. Time t
Holding mode is selected at _4, at time t _5,
The surge mode is selected again. Here, the reason why the magnitude of the upper limit value of the regenerative braking torque differs between the case where the rapid increase mode is selected first and the case where the rapid increase mode is selected next is due to the difference in the speed of the drive wheels and the like. I do.

As described above, in this embodiment, when the rapid increase mode is selected in the traction control, both the regenerative braking torque and the hydraulic braking torque are increased, so that the total braking torque is increased with a large gradient. It can be increased immediately. Since the responsiveness of the hydraulic braking torque is good, the increasing gradient of the total braking torque can be increased at the initial stage of the increase as compared with the case where only the regenerative braking torque is increased. When the slowdown mode is selected, the total braking torque is reduced by reducing the regenerative braking torque while the hydraulic braking torque is kept constant. As a result, the total braking torque can be smoothly reduced. In the traction control, the total braking torque is increased rapidly and is often decreased slowly. Therefore, according to the vehicle braking device of the present embodiment, the controllability of the total braking torque can be improved. Thus, traction control can be performed well.

When the hydraulic braking torque is changed at a large gradient, one of the solenoid valves 100 and 102 and the solenoid valves 94 and 96 may be kept open, but the change is gradual. In such a case, the solenoid on-off valve 100,
It is necessary to switch between the open state and the closed state of either the valve 102 or the electromagnetic switching valves 94 and 96. Therefore, the hydraulic braking torque will be changed step by step,
It cannot be changed smoothly. In addition, there is a problem that a loud operating noise is generated with the opening and closing of the electromagnetic on-off valve. On the other hand, the regenerative braking torque can be reduced without such a problem, and the total braking torque can be reduced while reducing the operation noise. The hydraulic braking device 20 includes a drum brake device, and if the electric motors 16 and 18 are disposed inside the drum, the installation space for the electric motor can be reduced. The electric motor in this case can be referred to as an in-wheel motor.

When the braking slip state of the wheels 10, 12, 60, 62 exceeds the set state, the anti-lock control is started. The total braking torque of each of the wheels 10, 12, 60, 62 is controlled such that the braking slip state is maintained in a substantially appropriate state. The anti-lock control is performed on both the driven wheels and the non-driven wheels. Here, the case where the anti-lock control is performed on the driven wheels will be described. The antilock control is started when an antilock start condition is satisfied, and is ended when an antilock end condition is satisfied. In the present embodiment, the start condition is that the front wheels 10, 1
(2) that the braking slip amount ΔVw of at least one wheel is further larger by the set slip amount ΔVR than the reference slip amount ΔVsn when the wheel deceleration Gw is equal to or more than the set deceleration G1 (ΔVw> ΔVsn + ΔVR);
The termination condition is that the depression of the brake pedal 76 is released or the traveling speed of the vehicle becomes equal to or lower than the set speed.

During the anti-lock control, a rapid decrease mode, a slow increase mode, a hold mode, and the like are selected according to a predetermined table based on the wheel speed and deceleration of each wheel. When the wheel speed is low and the deceleration is large, the rapid decrease mode is selected. When the wheel speed is high and the deceleration is small, the slow increase mode is selected. In the regenerative braking device 14, the power converters 30 and 32 are controlled such that a regenerative braking torque target value described later is obtained.
In the hydraulic braking device 20, the electromagnetic on-off valve 120 is closed, the electromagnetic on-off valves 90 and 92 are closed, and the electromagnetic on-off valve 1 is closed.
08 in the open state, the solenoid on-off valves 100, 1
By controlling 02, 94 and 96, the hydraulic pressures of the wheel cylinders 22 and 24 are independently controlled.

When the rapid decrease mode is selected, both the regenerative braking torque and the hydraulic braking torque are reduced.
In the regenerative braking device 14, the power converters 30 and 32 are controlled such that the target value of the regenerative braking torque becomes 0. In the hydraulic braking device 20, the electromagnetic on-off valves 100 and 102 are controlled.
Are switched to the closed state, and the electromagnetic switching valves 94 and 96 are switched to the open state. The hydraulic fluid in the wheel cylinders 22 and 24 is immediately discharged to the master reservoir 84, the hydraulic pressure is rapidly reduced, and the hydraulic braking torque is rapidly reduced.

When the slow increase mode is selected, the total braking torque is slowly increased as the regenerative braking torque is slowly increased. As the regenerative braking torque target value gradually increases, the actual regenerative braking torque is gradually increased, and the total braking torque is gradually increased. In this case, the increase gradient is determined based on a torque difference between the target total braking torque intended by the driver and the actual total braking torque, and the like. The determination is made so that the increasing gradient of the total braking torque is substantially the same between the front wheels 10, 12 and the rear wheels 60, 62. The increasing gradient of the total braking torque applied to the rear wheels 60 and 62 is determined by the hydraulic pressure of the master cylinder 68, the hydraulic pressure of the wheel cylinders 64 and 66, and the solenoid on-off valve 110
The duty ratio of the solenoid on-off valve 110 when the slow increase mode is selected is determined in advance. Therefore, the front wheels 10, 12
Is determined based on the torque difference between the target total braking torque and the actual total braking torque, and the value corresponding to the duty ratio. Even if the regenerative braking torque is slowly increased to reach the upper limit, if the slow increase mode is set, the hydraulic braking torque is slowly increased. When the electromagnetic on-off valves 94 and 96 are kept in the closed state and the electromagnetic on-off valves 100 and 102 are in the closed state and the open state, the increasing gradient of the hydraulic braking torque is substantially the same as the increasing gradient of the regenerative braking torque. Are switched at a ratio such that When the holding mode is selected, the states of the electric motors 16 and 18 are maintained at the original state, and the wheel cylinder hydraulic pressure is also maintained at that value.

As shown in the flowchart of FIG.
At 1, it is determined whether or not the brake pedal 76 is depressed. If it is depressed, it is determined whether the anti-lock control flag is set, whether the anti-lock start condition is satisfied, whether the anti-lock end condition is satisfied, and the like. During the anti-lock control, the control mode is selected in S37, and accordingly, the power converters 30 and 32 are controlled in the regenerative braking device 14, and the hydraulic pressure control valve device 58 is controlled in the hydraulic braking device 20. Controlled.

If the rapid decrease mode has been selected, S38
, The regenerative braking torque target value is determined to be 0, the electromagnetic on / off valves 100 and 102 are closed, and the electromagnetic on / off valves 94 and 9 are closed.
6 is switched to the open state. Wheel cylinder 22,
The hydraulic fluid 24 is quickly discharged into the master reservoir 84, the hydraulic pressure is rapidly reduced, and the total braking torque is rapidly reduced. If the gradual increase mode is selected, S40
In Steps -42, it is determined whether or not the actual regenerative braking torque is equal to or more than the upper limit value. If the actual regenerative braking torque is smaller than the upper limit value, the regenerative braking torque target value is gradually increased in a state where the wheel cylinder fluid pressure is maintained. The increase value is added to the regenerative braking torque target value so as to obtain the gradient determined as described above. Even if the actual regenerative braking torque reaches the upper limit, if the slow increase mode is selected, the hydraulic braking torque is slowly increased. With the electromagnetic on / off valves 94 and 96 kept closed, the electromagnetic on / off valves 100 and 102 are switched between the open state and the closed state at the determined ratio. As the hydraulic pressures of the wheel cylinders 22 and 24 gradually increase, the hydraulic braking torque is gradually increased, and the total braking torque is gradually increased. When the holding mode is selected, in S44, both the regenerative braking torque and the hydraulic braking torque are maintained at a constant magnitude.

FIG. 7 shows an example of the antilock control. If the time antilock brake control is started at t _1, rapid reduction mode is selected, both the regenerative braking torque and the hydraulic braking torque is decreased. Braking slip is recovered, at time t _2, slow increase mode is selected. Regenerative braking torque is not loose masa, but reaches the upper limit at time t _3. However, since the gradual increase mode is set at this point, the hydraulic braking torque is thereafter steadily increased. Here, the reason why the upper limit value of the regenerative braking torque during the antilock control is smaller than that before the start of the control is due to a decrease in the wheel speed or the like. Time t ₄
Holding mode is selected in, the rapid reduction mode is selected at time t _5, the total braking torque is caused to sharply again.

As described above, when the total braking torque is rapidly reduced in the antilock control, both the regenerative braking torque and the hydraulic braking torque are reduced, and when the total braking torque is gradually increased, the hydraulic braking torque is constant. , The regenerative braking torque is gradually reduced. As a result, the total braking torque can be rapidly reduced with a large gradient, or can be smoothly increased. In the anti-lock control, the total braking torque is often performed rapidly when it is decreased, and is slowly performed when it is increased. Therefore, according to the vehicular braking apparatus of the present embodiment, the anti-lock control is performed well. It becomes possible.

As described above, in the present embodiment, the traction control means and the antilock control means are included in the total braking torque control device 46, but S8 of the total braking torque control device 46 is executed. The parts and the like constitute both braking torque increasing means, and the parts that execute S10 to S13 and the like constitute regenerative braking torque gradual decreasing means.
Further, of the total braking torque control device 46, a portion for executing S38 and the like constitute a both braking torque decreasing means, and a portion for executing S40 to S43 and the like constitute a regenerative braking torque gradual increasing means.

In the above-described embodiment, the regenerative braking torque and the hydraulic braking torque are not changed even when the sudden increase mode is selected immediately after the start of the traction control or when the sudden increase mode is selected during the traction control. Although both are increased, immediately after the start, both may be increased, and only one of the regenerative braking torque and the hydraulic braking torque may be increased during control. In this case, if the regenerative braking torque is preferentially increased, wasteful release of kinetic energy can be suppressed. Similarly, also in the antilock control, when the rapid decrease mode is selected immediately after the start, both the regenerative braking torque and the hydraulic braking torque are reduced, and during the control, the regenerative braking torque and the hydraulic braking torque are reduced. Only one of them may be reduced. In this case, if the hydraulic braking torque is preferentially reduced, a decrease in energy efficiency can be suppressed.

In the traction control, any one of the rapid increase mode, the slow decrease mode, and the hold mode is selected. Alternatively, the rapid decrease mode or the like may be selected. Good. Further, one of the rapid increase mode and the slow decrease mode may be selected. Similarly, in the antilock control, in addition to the rapid decrease mode, the slow increase mode, and the hold mode, the control in which the slow decrease mode or the like is selected, and the control in which any one of the rapid decrease mode and the slow increase mode is selected. You can also. In any case, the traction control mode and the antilock control mode in the above-described embodiment are merely examples, and are not limiting.

Further, in the above-described embodiment, the regenerative braking torques of the front wheels 10 and 12 as drive wheels are controlled independently of each other, but they may be controlled in common. Since the magnitude of the hydraulic braking torque can be controlled independently by the right front wheel 10 and the left front wheel 12, the magnitude of the regenerative braking torque can be the same. In that case, the electric motors 16 and 18 are
It is not necessary to provide for every 0, 12 and one electric motor
Front wheels 10, 12 via differential gears and drive shafts
Can be connected to. It is rare that the right front wheel 10 and the left front wheel 12 are in contact with road surfaces having different friction coefficients, so that one common reason is that they can be controlled in common.

The structure of the hydraulic braking device 20 is not limited to the above embodiment, and the linear valve device 56 is not indispensable, and the hydraulic braking torque of each wheel is controlled by the control of the hydraulic control valve device 58. You can also make it. Further, a linear valve device may be provided for each wheel cylinder. In this case, the hydraulic pressure of each wheel cylinder can be controlled by controlling the linear valve device. Further, the brake switch 250 is not indispensable. If the hydraulic pressure detected by the hydraulic pressure sensors 122, 226 and the like becomes larger than 0, it can be detected that the brake pedal 72 is depressed. Similarly, an accelerator switch may be provided in addition to the accelerator operation amount detection device 268. Further, the friction braking device is not limited to the hydraulic braking device,
By controlling the electric motor, the pressing force when pressing the friction member against the brake rotating body is controlled, or by controlling the voltage applied to the laminated body such as the piezoelectric element, the expansion and contraction of the laminated body is controlled to control the pressing force. Or an electric braking device.

Although not specifically exemplified, the present invention can be carried out in various modified and improved forms based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an entire vehicle equipped with a vehicle braking device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a hydraulic braking device included in the vehicle braking device.

FIG. 3 is a partial sectional view of a linear valve device included in the hydraulic braking device.

FIG. 4 is a flowchart showing a traction control program stored in a ROM of a total braking torque control device included in the vehicle braking device.

FIG. 5 is a diagram illustrating an example of a case where traction control is performed in the vehicle braking device.

FIG. 6 is a flowchart showing an antilock control program stored in a ROM of the total braking torque control device included in the vehicle braking device.

FIG. 7 is a diagram illustrating an example of a case where antilock control is performed in the vehicle braking device.

[Explanation of symbols]

 14 Regenerative braking device 16, 18 Electric motor 20 Hydraulic braking device 22, 24, 64, 66 Wheel cylinder 30, 32 Power conversion device 38 Power storage device 42 Electric motor control device 46 Total braking torque control device 56 Linear valve device 58 Hydraulic pressure Control valve device

Claims (3)

[Claims] 1. A regenerative braking device for applying regenerative braking torque to a wheel of a vehicle by regenerative braking of an electric motor; and frictionally engaging a friction member with a brake rotating body that rotates together with the wheel to frictionally brake the wheel. When the total braking torque including the regenerative braking torque and the friction braking torque is changed with a large gradient, both the regenerative braking torque and the friction braking torque are changed to reduce the total braking torque. And a total braking torque control device that changes the regenerative braking torque while keeping the friction braking torque constant when changing at a small gradient. 2. The total braking torque control device includes traction control means for controlling the total braking torque so that the driving slip state of the wheel is substantially appropriate, and the traction control means includes a traction control means for controlling the total braking torque. Abruptly increasing, the braking torque increasing means for increasing both the regenerative braking torque and the friction braking torque, and a state in which the friction braking torque is kept constant when the total braking torque is gradually decreased. The vehicle braking device according to claim 1, further comprising: a regenerative braking torque gradual decreasing unit configured to gradually reduce the regenerative braking torque. 3. The total braking torque control device includes anti-lock control means for controlling the total braking torque so that the braking slip state of the wheel becomes substantially appropriate, and the anti-lock control means includes When the braking torque is rapidly reduced, both braking torque reducing means for reducing both the regenerative braking torque and the friction braking torque, and when the total braking torque is gradually increased, the friction braking torque is kept constant. 3. The vehicle braking device according to claim 1, further comprising: a regenerative braking torque gradually increasing unit configured to gradually increase the regenerative braking torque in a state where the vehicle is in a retracted state.