JPH05201328A - Braking force control device - Google Patents

Abstract

PURPOSE:To obtain a brake force control device which does not mar the brake operation feeling with a brake pedal during the adjustment of the pressure of a wheel cylinder. CONSTITUTION:A cut valve 5 and a simulator means 4 are provided between a master cylinder and a wheel cylinder, whereby the piston 27 and the simulator 29 inside the simulator means 4 are arranged. At normality, the cut valve 5 is shut off, and the simulator is operated to control the pressure of a wheel cylinder. At pressure abnormality of the wheel cylinder, the cut valve 5 is opened, and the piston 27 is shifted to shut off a stem 30, whereby the pressure of the master cylinder and the pressure of the wheel cylinder are balanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling a braking force of an automobile or the like to brake the automobile or the like.

[0002]

2. Description of the Related Art Conventionally, there has been developed a device for adjusting a braking force in order to improve the braking performance of a vehicle according to a brake operation of the vehicle. For example, Japanese Examined Patent Publication No. 2-21982 and Japanese Examined Patent Publication No. 2-46426 disclose a technique in which the deceleration of the vehicle corresponds to the brake operating force when the brake is operated. These techniques control the operation of a booster arranged between the brake pedal and the master cylinder to assist the brake operating force.

[0003]

However, in the conventional technology, when the operation of the booster is controlled, the reaction is transmitted to the brake pedal, so that the user's feeling of braking operation is impaired.

Therefore, an object of the present invention is to obtain a device which does not impair the brake operation feeling in the brake pedal when adjusting the pressure of the wheel cylinder.

[0005]

In order to solve the above problems, the first means used in the present invention divides the space between the master cylinder and the wheel cylinder into a master cylinder side pipe and a wheel cylinder side pipe, A master cylinder cut valve that can open and close communication between them, simulator means installed in the master cylinder side piping, pressure adjusting means that adjusts the pressure value according to instructions, and connection to the pressure adjusting means and wheel cylinder side piping And a pressure control cut valve capable of opening and closing the communication between the pressure control valve and the wheel cylinder side pipe,
Brake operating force detection means for detecting the brake operating force,
Connected to the wheel cylinder pressure detecting means for detecting the supply pressure value to the wheel cylinder, the master cylinder cut valve, the pressure adjusting means, the pressure control cut valve, the brake operating force detecting means and the wheel cylinder pressure detecting means, and the master cylinder cutting The control means is capable of controlling the opening and closing of the valve and the pressure control cut valve, and is capable of instructing the pressure adjusting means to output a predetermined pressure. The control means communicates the master cylinder cut valve when the brake operation force is not detected, shuts off the master cylinder cut valve when the brake operation force is detected, communicates the pressure control cut valve, and outputs the pressure adjusting means. The pressure is adjusted according to the brake operating force, and when the wheel cylinder pressure detecting means detects that the wheel cylinder pressure has decreased in response to the pressure instruction to the pressure adjusting means when detecting the brake operating force, the master cylinder cut It is characterized by opening the valve. The simulator means is provided with a hollow cylinder, a piston that is slidably arranged in the cylinder and divides the cylinder into a first chamber and a second chamber, and a cylinder facing the first chamber. At the same time, the first port connected to the master cylinder and the second port provided on the cylinder facing the second chamber and connected to the master cylinder cut valve and the piston are urged toward the first chamber. The urging means communicates with the first chamber, and the volume of the simulator chamber changes according to the pressure in the first chamber, and the communication between the first chamber and the simulator chamber is opened and closed according to the movement of the piston, and the piston is the first Valve means which is opened when biased toward the chamber.

In the first means, the simulator chamber is arranged in a space provided inside the piston, and the simulator piston which divides the space into a third chamber and a fourth chamber, and the first chamber and the third chamber. A communication passage that communicates with each other and a simulator that is provided in the fourth chamber and elastically deforms according to the movement of the simulator piston may be provided. This is the second means.

[0007] In the second means, a valve means is provided in the third chamber, and a valve body capable of blocking a communication passage from the third chamber,
A protrusion extending through the communication passage to the first chamber and a spring for urging the valve body on the side that shuts off the communication passage from the third chamber are provided, and protrude when the piston is urged toward the first chamber. Part comes into contact with the wall surface of the first chamber to move the valve body against the spring to communicate between the third chamber and the communication passage, and the piston is connected to the second chamber.
The valve body may be urged by a spring when moving to the chamber side to shut off the communication between the third chamber and the communication passage. This is the third
The means.

In the first means, the simulator means is further provided with a third port provided between the first port and the second port of the cylinder, and an orifice connected between the first port and the third port. And a second position in which the piston communicates between the second port and the third port, a second position in which the third port is shut off and the valve means is opened, and a third port is shut off. The valve means is closed and the first
The third position, which slides depending on the pressure in the chamber, may be movable with respect to each other. This is the fourth means.

[0009]

According to the first means, the piston of the simulator means is biased toward the first chamber by the biasing means when there is no brake operating force. In this state, the valve means is opened, and the master cylinder and the simulator chamber are in communication via the first port.

When the brake operation is performed here, the control means shuts off the master cylinder cut valve. Although the pressure from the master cylinder is applied to the first chamber of the cylinder via the first port, the communication from the second chamber of the cylinder to the wheel cylinder is blocked, the second chamber is sealed, and the piston does not move by a predetermined amount or more. The valve means is then open. Therefore, the master cylinder and the simulator chamber communicate with each other, and the volume of the simulator chamber changes in accordance with the pressure from the master cylinder, so that a comfortable brake operation can be obtained. On the other hand, the control means communicates the pressure control cut valve and sends a pressure instruction to the pressure control means. Therefore, the pressure in the wheel cylinder is adjusted to the pressure designated by the control means according to the brake operating force. If the control means adjusts the designated pressure according to the deceleration of the vehicle, the road surface condition, etc., it becomes possible to obtain high-performance braking performance. Various controls such as conventionally known anti-skid brake control can be added only by changing the program of the control means.

If the pressure adjusting means cannot control the wheel cylinder internal pressure sufficiently due to a failure of the pressure adjusting means or a rupture of a pipe around the pressure adjusting means, the wheel cylinder internal pressure decreases. In this case, the wheel cylinder pressure detection means detects the pressure drop, and the control means opens the master cylinder cut valve. At this time, the wheel cylinder and the second chamber of the cylinder communicate with each other via the master cylinder cut valve, and the pressure in the second chamber decreases. Therefore, the piston moves until the pressures in the first chamber and the second chamber are balanced. Therefore, the pressures of the master cylinder and the wheel cylinder become the same. On the other hand, since the piston moves, the valve means is closed and the simulator chamber is isolated from the master cylinder.
Therefore, as in the conventional normal brake operation, the wheel cylinder pressure changes in accordance with the rise of the master cylinder pressure, and the same braking performance as the conventional one can be obtained.

According to the second means, the master cylinder pressure is introduced into the third chamber when the valve means is open. Third
The simulator piston moves according to the chamber pressure,
Since the elastically deformable simulator is arranged in the fourth chamber, the volume of the third chamber increases or decreases according to the pressure value applied to the pressure in the third chamber, and the simulator effect of the brake operation is obtained. Since the simulator chamber is provided inside the piston, the entire simulator means can be miniaturized.

According to the third means, the piston is the first
When it moves to the chamber side, the protrusion hits the wall of the first chamber and prevents the valve body from closing. When the piston moves to the side of the second chamber, the protruding portion becomes free, the valve body is closed by the spring, the communication passage is shut off from the third chamber, and the simulator chamber is sealed and separated. In addition to the second means, the valve means is housed inside the piston, so that the simulator means can be further miniaturized.

According to the fourth means, at the start of the brake operation, the second chamber communicates with the master cylinder via the third port and the orifice. When the pressure of the master cylinder increases, the first chamber and the second chamber communicate with each other through the orifice, so that the pressure on the first chamber side increases and the piston moves toward the second chamber. When the piston moves by a predetermined amount and reaches the second position, the third port is blocked by the piston, so that the second chamber is sealed and the piston does not move further toward the second chamber. In this state, the valve means is open, so that the above-mentioned simulation effect can be obtained.

When the wheel cylinder internal pressure decreases due to a failure of the pressure adjusting means or the like, the pressure in the second chamber decreases, and the piston moves further toward the second chamber (third position). Even in this state, since the third port is blocked, the same effect as the first means can be obtained.

When the brake operation is stopped, the pressure in the master cylinder decreases, and the piston moves toward the first chamber due to the pressure in the second chamber and the urging means (first position). At this time, the third port is opened, and the fluid in the second chamber or the wheel cylinder is returned to the master cylinder via the orifice. A check valve that allows only the flow of fluid from the third port to the master cylinder may be provided in parallel with the orifice.

[0017]

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

In FIG. 1, when the brake pedal 16 is stepped on, the pressure in the master cylinder 1 increases, and the brake pressure is applied to the master cylinder side pipe 17. A pedaling force sensor 3, which is an operation force detecting means for detecting a brake operation force, is provided close to the brake pedal 16. The pressure sensor 2 detects the pressure in the master cylinder 1.

A simulator valve 4, which is a simulator means, is interposed between the master cylinder side pipe 17 and the intermediate pipe 18. The master cylinder cut valve 5 is interposed between the wheel cylinder side pipe 19 connected to the wheel cylinder 8 and the intermediate pipe 18. The master cylinder cut valve 5 is a normally open electromagnetic valve, and is closed by being switched by a signal from an electronic control unit 15 which is a control means. The wheel cylinder side pipe 19 has a wheel cylinder side pipe 1
A pressure sensor 41, which is a wheel cylinder pressure detecting means for measuring the pressure of 9 or the wheel cylinder pressure, is provided.

The pump 12 is driven by a motor 13 and pumps fluid from a reservoir 14 to generate fluid pressure. The motor 13 rotates according to a signal from the electronic control unit 15. The fluid pressure generated by the pump 12 is accumulated in the accumulator 9 via the check valve 10.

The accumulator pressure is detected by the pressure sensor 11. The pressure control valve 7, which is a pressure adjusting means, responds to a signal from the electronic control unit 15 with respect to the conduit 20.
Either the pipeline 21 connected to the accumulator 9 or the pipeline 22 connected to the reservoir is connected.
By switching the pressure control valve 7, the pressure in the conduit 20 is adjusted. The pipe line 20 is connected to the wheel cylinder side pipe 19 via the pressure control cut valve 6. The pressure control cut valve 6 is a normally closed electromagnetic valve, and is opened by being switched by a signal from an electronic control unit 15 which is a control means.

The simulator valve 4 is constructed as shown in FIG. In FIG. 2, the simulator valve 4 is
A hollow cylinder 26, a hollow piston 27 that slides inside the cylinder 26, and a simulator piston 28 that slides inside the piston 27 are provided. The internal space of the cylinder 26 is defined by the piston 27 so that the first chamber 34 on the right side of the piston 27 in the drawing is shown.
(See FIGS. 3 and 4) and the second chamber 35 on the left side of the drawing. The piston 27 is biased toward the first chamber by a spring 33 that is a biasing means provided in the second chamber 35. Seals 38 and 39 are provided on the sliding surface between the cylinder 26 and the piston 27 to prevent fluid leakage between the first chamber and the second chamber. The inner space of the piston 27 is divided into a third chamber 36 on the right side of the simulator piston 28 in the figure and a fourth chamber 37 on the left side of the figure. An elastically deformable simulator 29 is arranged in the fourth chamber 37. Rubber or the like may be used as the simulator 29. The third chamber 36 communicates with the first chamber 34 through the communication passage 27a. The stem 30 is arranged in the third chamber.
The stem 30 includes a protruding portion 30a extending into the first chamber inside the communication passage 27a, a valve body 31 made of an elastic body capable of blocking between the third chamber and the communication passage 27a, and a stem 30 main body urged rightward in the drawing. It is composed of a spring 32. The cylinder 26 is provided with three ports. First port 2
6a is provided facing the first chamber and is connected to the master cylinder side pipe 17. The second port 26c is provided facing the second chamber and connected to the intermediate pipe 18. The third port 26b is provided between the first port 26a and the second port 26c. The third port 26b is connected to the master cylinder side pipe 17 via the orifice 25. A check valve 24 is provided in parallel with the orifice 25. The check valve 24 blocks the flow of fluid from the master cylinder side pipe 17 to the third port 26b. The piston 27 is provided with a notch 27b which connects the second chamber 35 and the third port 26b in the state shown in FIG.

In FIG. 1, the electronic control unit 15 receives signals from the pedal force sensor 3 and the pressure sensors 2, 41 and 11. In addition, a wheel speed sensor 42 that detects the rotation speed of the wheels and an acceleration sensor 40 that detects the acceleration of the vehicle are provided.
The electronic control unit 15 includes a microcomputer, and is shown in FIG.
It operates according to the flow chart of. The electronic control unit 15 starts when the power is turned on, and first executes the initialization step 100. Here, the input / output terminals of the microcomputer are set and the memory is initialized.
Next, in the input processing step 102, inputs from sensors such as the pedaling force sensor 3, the pressure sensors 2, 41 and 11, the wheel speed sensor 42, and the acceleration sensor 40 are received, and data processing is performed. In step 103, the brake operating force determined from the output data of the pedal force sensor 3 is compared with the predetermined value F1. F1
Is a value corresponding to zero brake operation force, and is set to a value slightly higher than zero to prevent malfunction. When the brake operation force is less than or equal to the predetermined value F1, the control flag is turned off in step 104, zero is substituted for the timer T in step 105, the motor 13 is stopped in step 106, and the master cylinder cut valve is opened. 5 is opened and the pressure control cut valve 6 is set to be closed. Then, in step 108, the motor 13, the master cylinder cut valve 5, and the pressure control cut valve 6 are output according to the settings. When the brake operation force exceeds the predetermined value F1 in step 103, steps 109 and thereafter are executed. In step 109, the state of the control flag is determined. When the braking force first exceeds the predetermined value F1, the control flag is off at that point, so the control flag is updated to on in step 110, and the timer T is set to the integer value T0 in step 111. Then, in step 112, the motor 13 is rotated, the master cylinder cut valve 5 is closed, and the pressure control cut valve 6 is opened.

Thereafter, in step 114, the control value of the pressure control valve is set according to the brake operating force, the acceleration and the like. In step 108, the pressure control valve 7 is controlled to output the control value set in the pressure control valve 7. When the state in which the brake operating force exceeds the predetermined value F1 continues, the control flag is turned on, so step 113 is executed and the value of the timer T is decremented by 1. When the control flag is on for the number of times T0, the value of the timer T is 0.
Becomes At this time, the determination routine of steps 107 and 115 branches to step 116, and the timer T
Is again set to T0. At this time, step 11
If the wheel cylinder pressure has decreased by a predetermined amount α or more from the control value instructed in 7, the motor 13, the pump 12
Alternatively, the hydraulic circuit around it may be defective. In this case, in step 118, the motor 13 is stopped, the master cylinder cut valve 5 is opened, and the pressure control cut valve 6 is opened.
Set to close. Next, in step 119, the output process is continued.

In the device of the above construction, when the brake pedal 16 is not depressed, the wheel cylinder side pipe 1
Since the pressure of 7 has dropped, the piston 27 of the simulator valve 4 is urged by the spring 33, and the piston 27 of FIG.
To the position (first position) shown in. Electronic control unit 15
Since the brake operating force is zero, the master cylinder cut valve 5 is opened. In this state, the fluid in the wheel cylinder 8 is wheel cylinder side pipe 19-intermediate pipe 18-
Flow to the master cylinder 1 via the second port 26c-second chamber 35-notch 27b-third port 26b-orifice 25 and check valve 24-master cylinder side pipe 17,
The wheel cylinder 8 does not exert braking force.

When the brake pedal 16 is depressed, the pressure in the master cylinder side pipe 17 increases. This pressure is introduced into the first chamber 34 and the second chamber 35, but since the pressure is introduced into the second chamber 35 via the orifice 25, the pressure in the first chamber 34 is temporarily changed to the second chamber 35. Higher than the pressure of. Therefore, the piston 27 moves against the bias of the spring 33. On the other hand, the electronic control means 15 detects the brake operating force and closes the master cylinder cut valve 5. Therefore, when the piston 27 reaches the position (second position) shown in FIG. 3, the third port 26b is closed by the piston 27 and the master cylinder cut valve 5 is also closed, so that the second chamber 35 is sealed. Then, the piston 27 is fixed at the position (second position) shown in FIG. Stem 3 in this state
The valve body 31 of 0 is not closed, and the third chamber 36 and the first chamber 34
Are in communication. Therefore, the master cylinder pressure is introduced into the third chamber 36 via the master cylinder side pipe 17-first port 26a-first chamber 34-communication passage 27a. When the pressure in the third chamber 36 increases, the simulator piston 28
Receives the pressure in the left direction in the drawing and presses the simulator 29. Since the simulator 29 elastically deforms according to the pressing force, the volume in the third chamber 36 changes according to the master cylinder pressure. Therefore, the force required to depress the brake pedal 16 increases as the pedal is depressed, and a good brake depression feeling is obtained. On the other hand, since the electronic control unit 15 opens the pressure control cut valve 6 and controls the pressure control valve 7,
The wheel cylinder internal pressure is adjusted to a value output by the electronic control unit 15 via the wheel cylinder side pipe 19.

Disconnection between the electronic control unit 15 and the motor 13,
When a failure of the motor 13, a failure of the pump 12, a stick of the check valve 10, a failure of the accumulator 9, a failure of the pressure control valve 7, a rupture of the pipes 20, 21 or the like occurs, the electronic controller 15 is also controlled. Wheel cylinder 8 regardless
It is dangerous because the internal pressure does not rise and the wheels are not braked. Therefore, as described above, the electronic control unit 15 opens the master cylinder cut valve 5 and closes the pressure control cut valve 6 when the wheel cylinder internal pressure does not increase with respect to the output value. Second chamber 35 of the simulator valve 4
Communicates with the wheel cylinder 8, so the pressure in the second chamber 35 decreases. Therefore, the piston 27 is the master cylinder 1
Move until the pressure of and the wheel cylinder 8 are balanced,
The state shown in FIG. 4 (the third position) is obtained. In this state,
Since the protruding portion 30a of the stem 30 separates from the wall surface of the first chamber, the valve body 31 hits the wall surface of the third chamber 36, and the third chamber 36
And the communication passage 27a is shut off. The third port 26b remains closed. Therefore, in this state, the third chamber is closed and the simulator effect is not given to the master cylinder side. Since the piston 27 comes to slide according to the pressure difference between the first chamber and the second chamber, when the brake pedal is further depressed, the piston 27 moves to the left side in the drawing and the wheel cylinder pressure is increased. As a result, even if a failure occurs near the pump 12 or the pressure control valve 7, the wheel cylinder pressure corresponding to the conventional master cylinder pressure can be obtained and high braking performance cannot be obtained, but normal braking is possible. Become.

[0028]

As described above, according to the present invention, it is possible to freely adjust the braking force while maintaining a good brake operation feeling. Further, even when the pressure adjusting means does not generate the expected pressure due to a failure or the like, normal braking can be performed.

Furthermore, if the second means and the third means are used, a small simulation means can be obtained, and there is an effect of weight reduction and cost reduction.

Further, by using the fourth means, the fluid given to the wheel cylinder can be returned to the master cylinder again.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a simulator valve of the control device of FIG.

3 is a sectional view showing the operation of the simulator valve of FIG. 2 during braking.

FIG. 4 is a cross-sectional view showing the operation of the simulator valve of FIG. 2 during an abnormality

5 is a flowchart of the electronic control device of FIG.

[Explanation of symbols]

 1 master cylinder 2 pressure sensor 3 pedal force sensor (brake operating force detection means) 4 simulator valve (simulator means) 5 master cylinder cut valve 6 pressure control cut valve 7 pressure control valve (pressure adjusting means) 8 wheel cylinder 9 accumulator 10 reverse Stop valve 11 Pressure sensor 12 Pump 13 Motor 14 Reservoir 15 Electronic control device (control means) 16 Brake pedal 17 Master cylinder side pipe 18 Intermediate pipe 19 Wheel cylinder side pipe 20, 21, 22 Pipe line 24 Check valve 25 Orifice 26 Cylinder 26a 1st port 26b 3rd port 26c 2nd port 27 Piston 27a Communication passage 27b Notch 28 Simulator piston 29 Simulator 30 Stem (valve means) 30a Projection part 31 Valve body 32 Spring 33 Spline (Biasing means) 34 first chamber 35 second chamber 36 third chamber 37 the fourth chamber 38, 39 seal 40 acceleration sensor 41 pressure sensor (wheel cylinder pressure detecting means) 42 wheel speed sensors

Claims (4)

[Claims] 1. A master cylinder cut valve that divides a space between a master cylinder and a wheel cylinder into a master cylinder side pipe and a wheel cylinder side pipe, and can open and close communication between both pipes, which is interposed in the master cylinder side pipe. Simulator means, pressure adjusting means for adjusting a pressure value according to an instruction, pressure control that is connected to the pressure adjusting means and the wheel cylinder side pipe, and is capable of opening and closing communication between the pressure control valve and the wheel cylinder side pipe Cut valve, brake operating force detecting means for detecting brake operating force, wheel cylinder pressure detecting means for detecting a supply pressure value to the wheel cylinder, the master cylinder cut valve, pressure adjusting means, pressure control cut valve, brake Connected to the operating force detection means and wheel cylinder pressure detection means, the master cylinder cut And a control means capable of controlling opening and closing of a pressure control cut valve, and capable of instructing the pressure adjusting means to output a predetermined pressure, wherein the control means is a device for controlling a brake operating force. When detecting the brake operating force, the master cylinder cut valve is communicated, when the brake operating force is detected, the master cylinder cut valve is shut off, the pressure control cut valve is communicated, and the output pressure of the pressure adjusting means is adjusted according to the brake operating force. The master cylinder cut valve is opened when the wheel cylinder pressure detecting means detects that the wheel cylinder pressure has decreased in response to the pressure instruction to the pressure adjusting means when the brake operating force is detected. The simulator means is a hollow cylinder, and is arranged so as to be slidable in the cylinder. A piston for partitioning the first chamber and the second chamber, with Mokeraru facing the first chamber in said cylinder,
A first port connected to the master cylinder, the cylinder facing the second chamber, and
A second port connected to the master cylinder cut valve, an urging means for urging the piston toward the first chamber side, and a second port connected to the first chamber, the volume of which changes in accordance with the pressure in the first chamber. A simulator chamber; and valve means that opens and closes the communication between the first chamber and the simulator chamber according to the movement of the piston and is in an open state when the piston is biased toward the first chamber side. A braking force control device. 2. The simulator chamber is arranged in a space provided inside the piston, and the simulator chamber includes a simulator piston that divides the space into a third chamber and a fourth chamber, and the first chamber. The braking force control device according to claim 1, further comprising: a communication passage that communicates with the third chamber, and a simulator that is provided in the fourth chamber and elastically deforms in response to movement of the simulator piston. 3. The valve means is provided in the third chamber, and the valve means is a valve body capable of blocking the communication passage from the third chamber, and a protrusion extending to the first chamber through the communication passage. And a spring for urging the valve body on the side that shuts off the communication passage from the third chamber, and the piston is the first
When urged toward the chamber, the protrusion abuts against the wall surface of the first chamber to move the valve body against the spring, thereby communicating between the third chamber and the communication passage, and the piston moves toward the first chamber. 3. The braking force control device according to claim 2, wherein the valve body is biased by a spring when moving to the two-chamber side to shut off between the third chamber and the communication passage. 4. The simulator means further comprises a third port provided between the first port and the second port of the cylinder, and an orifice connected between the first port and the third port. The piston has a first position for communicating between the second port and the third port, a second position for shutting off the third port and opening the valve means, and a shutoff for the third port and the valve means. The braking force control device according to claim 1, wherein the braking force control device is in a closed state and is movable with respect to a third position that slides according to the pressure in the first chamber.