JPH1143043A - Steering braking system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To commonly use one pump for the purpose of a braking system and a steering system. SOLUTION: Delivered oil out of a pump 8 driven by an engine 6, is introduced to chambers 2A and 2B at both the sides of a tire steering cylinder 2. Solenoid valves 16A, 16B, 16C and 16D are disposed to the inlet port sides of both the chambers 2A and 2B, and to the outlet port side of a reservoir 12 respectively so as to be controlled by a controller 18, so that hydraulic pressure is thereby generated in the respective chambers 2A and 2B. Wheel cylinders 24A and 24B are connected with the respective chambers 2A and 2B respectively by way of connection passages 22A and 22B. Solenoid valves 16E, 16F, 16G and 16H are provided for the upstream of the respective wheel cylinders 24A and 24B, and for the reservoir 12 side in the downstream so as to by controlled by the controller 18, so that braking pressure generated in the wheel cylinders 24A and 24B is thereby controlled. Even when one of the braking system B and a steering system S is operated while the other is during operation, no adverse effect is mutually affected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering / braking system, and more particularly to an electric control steering system for electrically controlling a steering pressure in response to an input to a driver's steering wheel, and to an input to a brake pedal. And an electric control brake system for electrically controlling the brake pressure.

[0002]

2. Description of the Related Art An electric control brake system detects a depression force or a stroke of a brake pedal with a sensor, and a controller to which a signal from the sensor is input is used.
This is a system that controls the operation of an opening / closing solenoid valve or a proportional solenoid valve to control the brake pressure.An electric control steering system detects an operating force or a steering angle of a steering wheel with a sensor, and similarly controls an opening / closing solenoid valve or a steering wheel with a controller. This is a system for controlling the steering pressure by controlling the operation of a proportional solenoid valve and the like. A steering / braking system including the electric control brake system and the electric control steering system is conventionally known.

[0003]

In a conventional steering / braking system including the above-mentioned electric control brake system and electric control steering system, since each system uses a different pump as a pressure source, there is a structural problem. It was useless and costly.

Further, in order to drive the electric control brake system and the electric control steering system by one pump, as shown in FIG. 6, for example, a brake (a brake system B is shown on the left side of FIG. 6). ), The steering oil (the right side of FIG. 6 indicates the steering system S) is operated, the discharge oil from the pump P also flows to the steering system S side, and the supply of the pressure oil to the brake side becomes insufficient. In addition, there is a possibility that the braking force may be insufficient, and similarly, if the brake is operated during the operation of the steering, there is a problem that the steering force may be insufficient. In the drawings, reference numeral 102 denotes a tire steering cylinder, 104 denotes a wheel cylinder, and 106 denotes a solenoid valve.

Further, a steering / braking system by mechanical connection, in which hydraulic oil is supplied by a single pump to a braking system and a steering system connected in series, is conventionally known. (See FIG. 7). This system includes a brake pedal 110, an open center type hydraulic brake booster (hereinafter abbreviated as a booster) 112 which is operated by the brake pedal 110 and boosts the pedal depression force and outputs the boosted brake pedal pressure. Tandem master cylinder 114, master cylinder 1
Brake cylinder 116, which operates with brake fluid pressure from 14 to generate braking force on each wheel, handle 1
18, an open center type power steering device 120 which is operated by the handle 118 and boosts and outputs a steering operation force, a pump 124 which is driven by the engine 122 and supplies hydraulic fluid to the booster 112 and the power steering device 120, It comprises a reservoir 126 for storing a hydraulic fluid, an emergency accumulator 128 and the like.

In the above system, since the booster 112 and the power steering device 120 are connected in series, when the steering wheel 118 is operated and the power steering device 120 is operated, the brake pedal 110 is depressed and operated. Then, the power steering device 1
The amount of the working fluid supplied to the handle 20 decreases and the handle 11
8 may be shocked. As described above, in the steering / braking system in which the power steering device 120 and the brake booster 112 are arranged in series, when the brake is operated during steering, the pump pressure supplied to the steering device 120 fluctuates, and When a shock occurs and the steering is performed during the operation of the brake, there is a problem that the brake pressure fluctuates similarly and a shock is applied to the brake pedal 110.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an object to drive an electrically controlled brake system and an electrically controlled steering system by using a single pump as a power source, and that the respective operations adversely affect each other. It is an object of the present invention to provide a steering and braking system without the need.

[0008]

SUMMARY OF THE INVENTION A steering and braking system according to the present invention comprises: a tire steering cylinder in which hydraulic oil discharged from a pump is introduced into chambers on both sides; An electromagnetic valve for generating hydraulic pressure in the chamber, a brake system connected to the chambers on both sides of the tire steering cylinder, and an electromagnetic valve for controlling the pressure supplied to the brake system via the tire steering cylinder. Have.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows a steering system according to an embodiment of the present invention.
FIG. 2 is a circuit diagram showing a schematic configuration of a braking system (indicated by reference numeral 1 as a whole).
The lower part of the figure shows the brake system B.

In FIG. 1, reference numeral 2 denotes a tire steering cylinder for power steering. Discharge oil from a pump 8 driven by an engine 6 is introduced into two chambers 2A and 2B defined by a piston 4. Supply passages 10A, 10B from the pump 8 to both chambers 2A, 2B of the cylinder 2, and discharge passages 1 from each chamber 2A, 2Bb to the reservoir 12.
Solenoid valves (proportional solenoid valves in this embodiment) 16A, 16B, 16C, 16D are provided in 4A, 14B, respectively. The operation of the solenoid valves 16A, 16B, 16C, 16D causes the tire steering cylinder 2 to rotate. Each room 2A, 2
A required pressure is generated in B, and the piston 4 is operated by the pressure difference between the two chambers 2A and 2B to obtain a tie rod thrust, thereby generating a necessary steering angle for the steered wheels. Both chambers 2 of cylinder 2
Solenoid valves 16A, 16B, 1 for generating pressure on A, 2B
6C and 16D are connected to the controller 18 as described later.
The operation is controlled by Both chambers 2 of these cylinders 2
A, 2B are provided with pressure sensors 20A, 20B for detecting the oil pressure of the respective chambers 2A, 2B.
The pressure detected by 0A and 20B is sent to the controller 18 as an electric signal.

The chambers 2A on both sides of the tire steering cylinder 2
2B are connecting passages 22A, 22B and proportional solenoid valves 16 provided in these connecting passages 22A, 22B, respectively.
E, 16F, 16G, 16H are connected to the wheel cylinders 24A, 24B. Each of the wheel cylinders 24A and 24B controls the operation of the upstream electromagnetic valves 16E and 16F and the downstream electromagnetic valves 16G and 16H communicating with the reservoir 12, so that the oil discharged from the pump 8 can be used to control the tire steering cylinder 2 And the required braking force can be obtained. Wheel cylinder 24A, 24B
Solenoid valves 16E, 16 for controlling the brake pressure generated in
The operations of F, 16G, and 16H are controlled by the controller 18. Each of the wheel cylinders 24A, 2
4B includes a pressure sensor 26 for detecting each pressure.
A, 26B are provided, and the pressure detected by these sensors 26A, 26B is sent to the controller 18 as an electric signal.

FIG. 2 is a diagram showing an example of a control system of the steering / braking system 1. The steering wheel 30 has a sensor 32 such as a steering angle sensor for detecting a steering angle or a torque sensor for detecting a steering torque. The steering angle or torque detected at the time of operating the steering wheel is input to the controller 18 as an electric signal, and the controller 18 responds to this signal to cause the proportional solenoid valves 16A, 16B, 16C, 16C, By controlling the operation of 16D, pressure is generated in both chambers 2A, 2B of the tire steering cylinder 2.

Further, the brake pedal 34 is provided with a sensor 36 such as a pedaling force sensor for detecting a pedaling force or a stroke sensor for detecting a pedal stroke. The pedaling force or stroke is input to the controller 18 as an electric signal, and the controller 18 controls the operation of the proportional solenoid valves 16E, 16F, 16G, and 16H on the brake system B side according to the signal to generate a brake pressure. Let it.

The operation of the steering / braking system 1 according to the above configuration will be described. When the steering / braking system 1 is not operated, the proportional solenoid valves 16E and 16F provided on the upstream side of the wheel cylinders 24A and 24B are closed to shut off the steering system S side and the brake system B side, and to perform other electromagnetic operations. Valves 16A, 16B, 16C, 16D,
16G and 16H are left open. In this state, the hydraulic oil discharged from the pump 8 passes through the solenoid valve 16A in one supply passage 10A, the one chamber 2A of the tire steering cylinder 2 and the solenoid valve 16C in the discharge passage 14A, and the other. Of the supply passage 10B, the other chamber 2B of the tire steering cylinder 2 and the solenoid valve 1 of the discharge passage 14B
The pressure is returned to the reservoir 12 via 6D, and the pressure in both chambers 2A and 2B of the tire steering cylinder 2 is zero.

When only the steering operation is performed, the controller 18 controls the solenoid valves 16A, 16B, 16C, 16D on the steering system S side in response to a signal from the steering angle sensor (or torque sensor) 32.
To operate the two chambers 2A, 2B of the tire steering cylinder 2.
The pressure is generated in both chambers 2A and 2B by narrowing the flow path on the discharge side of. The pressures in these two chambers 2A and 2B are detected by pressure sensors 20A and 20B, and the controller 18 controls the steering angle sensor (or torque sensor) 32
Each of the solenoid valves 16 is set to a value corresponding to the input from the
A, 16B, 16C, 16D are controlled to control both rooms 2A, 2B.
A pressure difference is created between them. In a conventional steering system, the pressure difference between the two chambers to obtain the required tire operating force (tie rod thrust) generates the required hydraulic pressure only in the high pressure side chamber, and the hydraulic pressure in the low pressure side chamber remains zero. In this embodiment, the pressure in the chamber on the low pressure side (for example, 2A) is increased to the pressure required for the brake operation in preparation for the operation of the brake. For example, in 2B), a pressure is generated such that a necessary pressure difference is obtained with respect to the pressure in the chamber on the low pressure side.

When a brake operation is performed during the operation of the steering, the controller 18 responds to a signal from the pedaling force sensor (or stroke sensor) 36.
Are the respective solenoid valves 16E, 16F, 1 on the brake system B side.
6G and 16H are operated, and the brake pressure is generated by squeezing the reservoir 12 side of the passages 22A and 22B connecting the two chambers 2A and 2B of the tire steering cylinder 2 and the wheel cylinders 24A and 24B. The pressure of each wheel cylinder 24A, 24B is detected by a pressure sensor 26A, 26B, and the controller 18 controls each solenoid valve so that the pressure becomes a value corresponding to the input from the pedaling force sensor (or stroke sensor) 36. 16E, 16F,
16G and 16H are controlled. At this time, since the pressure oil in both the chambers 2A and 2B of the tire steering cylinder 2 is supplied to the brake system, the pressure in the two chambers 2A and 2B does not drop below the pressure required for the steering operation. Each electromagnetic valve 16A, 16B, 16 on the steering system S side
By controlling C and 16d, the amount of oil discharged from the pump 8 introduced into the chambers 2A and 2B is adjusted.

In the steering / braking system 1 according to the present embodiment, when only the brake is operated, the solenoid valves 16A, 16B, 16C, 16 on the steering system S side.
D by operating the two chambers 2A, 2A,
2B, the same pressure required for the brake operation is generated, and the solenoid valves 16E, 16
By operating G, 16G, and 16h, the brake pressure is controlled in accordance with the depression force or stroke of the brake pedal 34.

When the steering operation is performed during the brake operation, the solenoid valves 16A, 16B, 16C, 1
By controlling 6D, a pressure corresponding to the steering angle or the torque of the steering wheel 30 is introduced so that a pressure difference between the two chambers 2A and 2B can obtain a necessary tire operating force. For example, as described above, when the same pressure required for the operation of the brake is generated when only the brake is operated, the pressure of one of the chambers 2A or 2B is increased to increase the required pressure. Generate a differential pressure.

As described above, in the steering / braking system 1 according to the present embodiment, one pump 8 is connected to the steering system S.
And the brake system B, and the overall system can be simplified. Further, the supply of the pump discharge oil to the brake system B is performed through both the chambers 2A and 2B of the tire steering cylinder 2, so that the steering wheel 30 is operated during the brake operation. Even when the brake pedal 34 is operated during the steering operation, they do not affect each other.

In this embodiment, the brake system B has two systems connected to the two chambers 2A, 2B of the tire steering cylinder 2, respectively, so that each set of the solenoid valves 16E, 16G and the electromagnetic By separately controlling the valves 16F and 16H, it is possible to make a difference between the two systems of brakes. For example, in a braking operation when the vehicle is turning, the vehicle can be stopped quickly by increasing the braking force of the outer wheels. In addition, by turning the brake on the inner wheels during turning of the vehicle without operating the brake pedal, the vehicle can be turned smoothly, and stable running can be performed. Also, at the time of anti-skid braking for preventing tire lock during brake operation, the brake pressure can be reduced only on one wheel. Further, in traction control for preventing a tire from slipping at the time of starting or the like, the drive wheels can be brake-controlled.

In the above embodiment, the solenoid valves 16A, 16B,
Although the case where the proportional solenoid valves are used as 16C, 16D, 16E, 16F, 16G, and 16H has been described, an on-off solenoid valve can be used instead of the proportional solenoid valves. When a proportional solenoid valve is used, the generated pressure is controlled by controlling the current, and in the case of an open / close solenoid valve, the generated pressure is controlled by duty-controlling the solenoid valve.

FIG. 3 shows a steering / braking system 1 according to a second embodiment. The steering system S at the top of the figure has the same configuration as the steering system S of the first embodiment. Are different from each other in the configuration of the brake system B at the bottom. In the above embodiment, two independent brake systems were connected to the chambers 2A and 2B on both sides of the tire steering cylinder 2, respectively. However, in this embodiment,
The brake system is one system. That is, the connection passage 22 from both chambers 2A and 2B of the tire steering cylinder 2
A and 22B are provided with solenoid valves 16E and 16F, respectively, and the pressure oil via these solenoid valves 16E and 16F is combined and supplied to the power cylinder 40, whereby the master cylinder 42 operates to operate the wheel cylinders 24A and 24F. 24B
To generate brake pressure. The power cylinder 40
Is connected to the reservoir 12 via a solenoid valve 16G.

As shown in FIG. 2, the steering / braking system 1 according to the second embodiment also employs a controller according to a steering angle (or torque) detected by a steering angle sensor (or torque sensor) 32. 18, the solenoid valves 16A, 16B,
By controlling the operations of 16C and 16D, pressure is generated in both chambers 2A and 2B of the tire steering cylinder 2. In addition, the controller 18 controls the operation of the solenoid valves 16E, 16F, and 16G to generate brake pressure in accordance with the pedaling force (or pedal stroke) detected by the pedaling force sensor (or stroke sensor) 36.

The operation of the steering / braking system 1 according to the second embodiment will be described. When not operating, the solenoid valves 16E,
16F, the steering system S side and the brake system B side are shut off, and the other solenoid valves 16A, 16
B, 16C, 16D and 16G are left open. In this state, the hydraulic oil discharged from the pump 8 passes through the solenoid valve 16A of one supply passage 10A, the one chamber 2A of the tire steering cylinder 2 and the solenoid valve 16C, and the other supply passage 10B To the reservoir 12 via the solenoid valve 16B, the one chamber 2B of the tire steering cylinder 2 and the solenoid valve 16D, and the two chambers 2A, 2 of the tire steering cylinder 2
The pressure in B is zero.

When only the steering operation is performed, the same operation as in the first embodiment is performed. If a brake operation is performed during the operation of the steering, the electromagnetic valve 16E or 1E connected to one of the two chambers 2A and 2B of the tire steering cylinder 2 is operated.
6F and the solenoid valve 16G on the reservoir 12 side,
The pressure in the chamber 2A or 2B is sent to the power cylinder 40, and the master cylinder 42 is operated to generate brake pressure in the wheel cylinders 24A and 24b. The controller 18 controls each of the solenoid valves 16E, 16F, 16G so that the pressure becomes a value corresponding to the input from the pedaling force sensor (or stroke sensor) 36. When the brake is operated during the steering operation, pressure may be supplied to the brake system from any of the chambers 2A and 2B. For example, the brake pressure is supplied by opening the solenoid valve 16E of the high pressure side chamber (for example, 2A) of the tire steering cylinder 2. At this time, the solenoid valves 16A and 16C on the upstream side and the downstream side of the chamber 2A are controlled to maintain the pressure so that the pressure in the chamber 2A of the cylinder 2 that supplies the pressure to the brake side does not decrease.

In the above description, the pressure is introduced from the one chamber 2A or 2B (for example, the high pressure side chamber) of the tire steering cylinder 2 to the brake side when the brake is operated. Side solenoid valves 16
The pressure may be supplied from both chambers 2A and 2B of the cylinder 2 to the brake side by controlling E, 16F and the downstream electromagnetic valve 16G. At this time, in order to prevent the pressure in both chambers 2A and 2B of the cylinder 2 from decreasing,
It goes without saying that the solenoid valves 16A and 16C and the solenoid valves 16B and 16D are controlled.

When the operation of only the brake is performed,
By controlling the solenoid valves 16A, 16B, 16C, 16D, the pressure required for the brake operation is generated in both chambers 2A, 2B of the tire steering cylinder 2 at the same pressure. At the same time, one of the solenoid valves 16E and 16F on the upstream side of the brake and the solenoid valve 16G on the downstream side are operated to generate a brake pressure, and this brake pressure is a pressure corresponding to the depression force or stroke of the brake pedal 34. The electromagnetic valves 16E, 16F, and 16G are controlled so that

When the handle 30 is operated during the operation of the brake, the solenoid valves 16A, 16B, 16
C and 16D to control both chambers 2 of the tire steering cylinder 2.
Control is performed so that the pressure difference between A and 2B becomes a value corresponding to the steering angle or torque of the steering wheel 30. For example, during operation of only the brake as described above, the tire steering cylinder 2
When the same pressure sufficient to operate the brake is generated in both chambers 2A and 2B, the pressure in one chamber 2A or 2B is increased so that a necessary differential pressure is obtained between the two chambers. .

In the first embodiment, when the brakes are operated, the pump 8 controls the two chambers 2 of the tire steering cylinder 2.
A, 2B is supplied directly to the wheel cylinders 24A, 24B to generate brake pressure, and in the second embodiment, both chambers 2A, 2A of the tire steering cylinder 2 are provided. 2B is supplied to the power cylinder 40, whereby the master cylinder 42
Is operated to generate a brake pressure in the wheel cylinders 24A and 24B.
The pressure oil may be directly introduced into the wheel cylinders 24A and 24B, or the brake pressure may be generated via the master cylinder 42. However, at present, plant hydraulic fluid is generally used as brake fluid and mineral oil is used for steering fluid. Therefore, it is preferable to convert the hydraulic fluid through the power cylinder 40 and the master cylinder 42. Further, in the second embodiment, since the pressure oil from the pump supplied from the steering system S side to the brake system B side is one system, the master cylinder 42 should be tandem and the master cylinder 42 should be two systems ahead. Is preferred for safety.

The connection system of the brake system when the steering / braking system 1 of each embodiment is applied to a vehicle will be described.
This will be described with reference to FIGS. First, the two brake systems of the first embodiment (the wheel cylinders 24A side and 24B
4) is an X pipe as shown in FIG. That is,
One system of the brake system B is connected to the right side 50A of the front wheel and the left side 51B of the rear wheel, and the other system is connected to the left side 50B of the front wheel and the right side 51A of the rear wheel. In this case, the steering / braking system 1 according to the present invention is applied to all wheels. As shown in FIG. 5, one of the two brake systems of the first embodiment is connected to the front right wheel 50A and the other is connected to the front left wheel 50B, and the rear wheels 51A and 51B are operated by the brake pedal 34. Can be connected to the master cylinder 52. In this case, the front wheels 50A, 5A
The steering / braking system 1 of the present invention is applied to 0B, and the mechanical brake system conventionally used is applied to the rear wheels 51A and 51B.

In the case of the second embodiment, since the brake system is a single system, the master cylinder 42 shown in FIG. 3 is divided into two circuits of a tandem type, one of which is connected to the right front wheel 5.
0A and the rear wheel left 51B, and the other is connected to the front wheel left 50B and the rear wheel right 51A to form an X pipe (see FIG. 4). Also in this case, the steering / braking system 1 according to the present invention is applied to all the wheels. The master cylinder 42 of the second embodiment is of a tandem type, one of which is connected to the front right wheel 50A and the other is connected to the front left wheel 50B.
Master cylinder 52 operated by brake pedal 34
(See FIG. 5). In this case, the front wheels 50A,
The steering and braking system 1 of the present invention is applied to 50B,
A conventionally used mechanical brake system is applied to the rear wheels 51A and 51B.

As described above, the present invention can be applied to various configurations. In particular, when the connection shown in FIG. 5 is performed, even when the steering / braking system 1 according to the present invention fails, Since only the rear wheels 51A and 51B can always maintain the braking performance, extremely high safety can be ensured. When the X pipe is connected as shown in FIG. 4 in the configuration of the first embodiment, there are two brake systems, and when one system fails, control of that system is stopped. ,
By controlling only one other normal system, the braking force can be secured.

In the above embodiment, the steering system S
And a brake system B using a single pump 8 as a drive source and a plurality of solenoid valves 16A, 16B,
16C, 16D, 16E, 16F, 16G, 16H
The desired tire steering angle and tire braking force are obtained by controlling by the controller 18. However, by changing the setting of the controller 18 for controlling the solenoid valve, the steering characteristic and the braking characteristic can be easily and shortened. Can be changed in time.

As a brake characteristic, a brake pressure characteristic with respect to a pedal depression force or a brake pressure characteristic with respect to a pedal stroke is stored in a plurality of types of controllers, and as a steering characteristic, a characteristic with respect to a differential pressure of a tire steering cylinder with respect to a steering wheel angle. Alternatively, a plurality of types of characteristics relating to the differential pressure of the tire steering cylinder with respect to the steering wheel torque are stored, and one of the characteristics is selected and switched under a predetermined condition.

Conditions for selecting and switching a plurality of characteristics stored in the controller 8 include, for example, 1) the loading status of the vehicle (that is, whether the vehicle is loaded or empty).
And 2) switching according to the traveling speed, that is, switching to a different characteristic during high-speed traveling than during low-speed traveling, or 3) road surface conditions, for example, low μ road or high μ road. That is, the characteristics are switched according to whether the friction coefficient (μ) between the tire and the road surface is large or small, and 4)
Depending on the driver's intention, it is possible to switch to the desired characteristic by operating the changeover switch, or 5) to switch when one of the brake systems has failed.

[0036]

As described above, according to the present invention, a tire steering cylinder in which hydraulic oil discharged from a pump is introduced into chambers on both sides, and a hydraulic pressure is applied to each chamber of the tire steering cylinder. An electromagnetic valve to be generated, a brake system connected to chambers on both sides of the tire steering cylinder, and an electromagnetic valve for controlling pressure supplied to the brake system via the tire steering cylinder. , One pump can be shared by the steering system and the brake system, and even if the operation of one system is performed while the other system is in operation, the pumps do not adversely affect each other and exhibit sufficient performance. be able to.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a steering / braking system according to one embodiment of the present invention.

FIG. 2 is a diagram showing an example of a control system of the steering / braking system.

FIG. 3 is a circuit diagram showing a configuration of a steering / braking system according to a second embodiment.

FIG. 4 is a diagram showing an example of a connection system of a brake system when the steering / braking system of each embodiment is applied to a vehicle.

FIG. 5 is a diagram showing another example of a connection system of the brake system.

FIG. 6 is a diagram showing an example of a conventional configuration in a case where hydraulic oil is supplied from one pump to an electric control brake system and an electric control steering system.

FIG. 7 is a diagram showing an example of a conventional steering / braking system by mechanical connection.

[Explanation of symbols]

 Reference Signs List 2 tire steering cylinder 2A tire steering cylinder chamber 2B tire steering cylinder chamber 4 piston 8 pump 10A supply passage 10B supply passage 12 reservoir 14A discharge passage 14B discharge passage 16A to 16H solenoid valve 18 controller 22A connection passage 22B Connection passage 24A Wheel cylinder 24B Wheel cylinder

Claims (8)

[Claims] 1. A tire steering cylinder into which hydraulic oil discharged from a pump is introduced into chambers on both sides, a solenoid valve for generating hydraulic pressure in each chamber of the tire steering cylinder, and a tire steering valve. A steering / braking system comprising: a brake system connected to chambers on both sides of a cylinder; and a solenoid valve for controlling pressure supplied to the brake system via a tire steering cylinder. 2. A tire steering cylinder in which hydraulic oil discharged from a pump is introduced into chambers on both sides partitioned by a piston, a supply passage to each chamber of the tire steering cylinder and a reservoir from each chamber. Solenoid valves that are respectively provided in the discharge passages to generate hydraulic pressure in each chamber, a wheel cylinder connected to both chambers of the tire steering cylinder via a connection passage, and an upstream side of the wheel cylinder. A solenoid valve provided on the downstream side for controlling a pressure sent from the tire steering cylinder, and a controller for controlling the operation of the solenoid valve in accordance with operation of a steering wheel and operation of a brake pedal. A steering and braking system characterized by the following. 3. The steering / braking system according to claim 1, wherein the brake system is composed of two systems independently connected to respective chambers of a tire steering cylinder. 4. The steering / braking system according to claim 1, wherein the brake system is one system connected to both chambers of a tire steering cylinder. 5. The pressure in both chambers of the tire steering cylinder is:
The steering / braking system according to claim 2, wherein the steering / braking system is transmitted to a wheel cylinder via a master cylinder. 6. The pressure in both chambers of the tire steering cylinder is
3. The steering / braking system according to claim 2, wherein the steering / braking system is supplied directly to a wheel cylinder. 7. One of the two brake systems or one obtained by branching one brake system into two circuits is connected to the right front wheel and the left rear wheel of the vehicle, and the other is connected to the all left wheels of the vehicle. The steering and braking system according to claim 3 or 4, wherein the steering and braking system is connected to the right rear wheel. 8. One of the two brake systems or one of the two brake systems divided into two circuits is connected to the right front wheel and the other is connected to the left front wheel, and the rear wheel is operated by a brake pedal. 5. The apparatus according to claim 3, wherein the master cylinder is connected to a master cylinder operated by the control means.
The steering and braking system according to 1.