JPH05229418A - Braking force controller - Google Patents

Abstract

PURPOSE:To secure the controllabitity of a brake, in a braking force controller equipped with a simulation control means. CONSTITUTION:This is a braking force controller which is equipped, between a simulation control means 46 and a master cylinder 1, with a check valve 43, which allows only the communication from the master cylinder to the simulation control means, and a relief valve 44, which allows the communication from the simulation control means side to the master cylinder side when the difference of pressure between both ends gets at a specified value or more, being arranged in parallel with this check valve.

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, as a device that does not impair the brake operation feeling in the brake pedal when adjusting the pressure of the wheel cylinder, the master cylinder and the wheel cylinder are separated from each other, and the master cylinder side is set according to the output pressure of the master cylinder when the brake is operated. It is conceivable to provide simulation control means for changing the volume and adjusting the pressure on the wheel cylinder side according to the brake operating force. The simulation control means controls the wheel cylinder pressure according to the brake operating force when the brake is operated. The master cylinder and the wheel cylinder are separated at this point, and the wheel cylinder can be simply controlled according to the brake operating force, and slip prevention control and the like can be added depending on the rotational speed of the wheel. Further, when the pressure of the master cylinder increases, the volume of the chamber connected to the master cylinder increases, and a brake pedal feeling without a feeling of strangeness can be obtained.

When the simulation control means is provided, since the master cylinder pressure and the volume secured by the simulation control means are unique, it is important to secure the controllability of the brake.

Therefore, it is an object of the present invention to ensure the controllability of the brake in the braking force control device equipped with this simulation control means.

[0007]

The means used in the present invention to solve the above-mentioned problems are a check valve between the simulation control means and the master cylinder, which permits only communication from the master cylinder to the simulation control means. The relief valve is provided in parallel with the check valve and allows the communication from the simulation control means side to the master cylinder side when the pressure difference between both ends becomes equal to or more than a predetermined value.

[0008]

According to the above-mentioned means, when the brake pedal is depressed, the fluid can be made to flow from the master cylinder to the simulation control means through the check valve. Therefore, the simulation control means operates to adjust the pressure of the wheel cylinder.

Here, when the brake pedal is slightly returned, the pressure difference between both ends of the relief valve is below a predetermined value, and the relief valve does not open. Also, since the check valve does not flow the fluid from the simulation control means to the master cylinder, the pressure on the simulator control means side is maintained. When the brake pedal is further returned, the pressure difference between both ends of the relief valve exceeds a predetermined value and the relief valve opens, so that the fluid flows from the simulation control means to the master cylinder, and the braking force of the wheel cylinders is reduced by the simulation control means. Therefore, hysteresis can be provided on the side where the brake pedal is depressed and the side where the brake pedal is released. By providing the hysteresis in this way, the controllability of the brake can be secured.

[0010]

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 simulation control device 46, which is a simulation control means, is connected to the wheel cylinder 8 via a wheel cylinder side pipe 19. A check valve 43 and a relief valve 44 are provided in parallel between the master cylinder side pipe 45 of the simulation control device 46 and the master cylinder side pipe 17 connected to the master cylinder 1. The check valve 43 is the master cylinder side pipe 17
Is a non-return valve that allows only communication from the pipe to the master cylinder side pipe 45. The relief valve blocks the communication from the master cylinder side pipe 17 to the master cylinder side pipe 45, and opens when the pressure in the master cylinder side pipe 45 becomes higher than the pressure in the master cylinder side pipe 17 by a predetermined value or more. Communication from the side pipe 45 to the master cylinder side pipe 17 is allowed.

A simulator valve 4 as a simulator means is interposed between the master cylinder side pipe 45 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 and its peripheral circuit are constructed as shown in FIG.

In FIG. 2, the relief valve 44 is a spring 44.
It is biased toward the wheel cylinder by b. The relief valve 44 has a slit 44a in its valve seat portion. Therefore, both ends of the relief valve 44 are not completely shut off.

The simulator valve 4 includes a hollow cylinder 26, a hollow piston 27 that slides in the cylinder 26,
A simulator piston 28 that slides inside the piston 27 is provided. The internal space of the cylinder 26 is divided by the piston 27 into a first chamber 34 (see FIGS. 3 and 4) on the right side of the piston 27 in the figure and a second chamber 35 on the left side of the figure. The piston 27 is biased toward the first chamber by a spring 33 that is a biasing means provided in the second chamber 35.
A seal 3 is provided on the sliding surface between the cylinder 26 and the piston 27.
8 and 39 are provided 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. Third room 36
Communicate with the first chamber 34 through the communication passage 27a. Third
A stem 30 is arranged in the room. The stem 30 is
A protrusion 30a extending to the first chamber in the communication passage 27a,
The valve body 31 is made of an elastic body capable of blocking the third chamber from the communication passage 27a, and the spring 32 is provided to bias the stem 30 main body to the right in the figure. The cylinder 26 is provided with three ports. The first port 26a is provided facing the first chamber, and is connected to the master cylinder side pipe 45. The second port 26c is provided facing the second chamber,
It is 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 45 via the orifice 25. A check valve 24 is provided in parallel with the orifice 25. Check valve 24
Blocks the flow of fluid from the master cylinder side pipe 45 to the third port 26b. The piston 27 has a notch 27 for communicating the second chamber 35 with the third port 26b in the state shown in FIG.
b is provided.

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, acceleration, etc. 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 apparatus having the above structure, when the brake pedal 16 is not depressed, the master cylinder side pipe 1
Since the pressures at 7 and 45 have dropped, the piston 27 of the simulator valve 4 is urged by the spring 33 to move to the position (first position) shown in FIG. Since the electronic control unit 15 has zero brake operation force, 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-second port 26c-second chamber 35-notch 27b.
-Third port 26b-Orifice 25 and check valve 24
-Master cylinder side pipe 45-Slit 44a-Flows to the master cylinder 1 via the 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 via the check valve 43, but since the pressure is introduced into the second chamber 35 via the orifice 25, the pressure in the first chamber 34 is temporarily reduced. Pressure is in the second chamber 3
Pressure higher than 5. 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.
Since the port 26b is closed and the master cylinder cut valve 5 is also closed, the second chamber 35 is closed and the piston 27 is fixed at the position (second position) shown in FIG. In this state, the valve body 31 of the stem 30 is not closed,
The third chamber 36 and the first chamber 34 communicate with each other. Therefore, the master cylinder side pipe 17-check valve 43-master cylinder side pipe 45-first port 26a-first chamber 34
-The master cylinder pressure is applied to the third chamber 36 via the communication passage 27a.
Will be introduced to. 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 brake pedal 1
The force required to step 6 increases as the pedal is depressed, and a good brake pedal feeling is obtained. On the other hand, the electronic control unit 15 opens the pressure control cut valve 6 and opens the pressure control valve 7
Is controlled, 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.

The flow of fluid from the master cylinder side pipe 17 to the simulation controller 46 is allowed by the check valve 43. However, with respect to the flow in the reverse direction, the check valve 43 is closed and the relief valve 44 is not opened unless there is a pressure difference of a predetermined value or more, so that hysteresis occurs. Due to this hysteresis effect, even if the brake pedal is slightly loosened, the braking force hardly changes, and the controllability is good. The slit 44a of the relief valve 44 does not have to be provided in particular, but by providing the slit 44a in the relief valve 44, it is possible to follow up even a slow brake pedal operation with a delay.

[0025]

As described above, in the present invention, since the controllability of the brake can be secured, a good brake operation feeling can be obtained.

[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 adjustment 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 1st chamber 35 2nd chamber 36 3rd chamber 37 4th chamber 38, 39 seal 40 acceleration sensor 41 pressure sensor (wheel cylinder pressure detection means) 42 wheel speed sensor 43 check valve 44 relief valve 44a slit 44b Spring 45 Master cylinder side piping 46 Simulation control device (simulation control means)

Claims (2)

[Claims] 1. A simulation control means for dividing a master cylinder from a wheel cylinder, changing the volume of the master cylinder side according to the output pressure of the master cylinder during brake operation, and adjusting the pressure of the wheel cylinder side according to the brake operation force. In the braking force control device further comprising, between the simulation control means and the master cylinder,
A check valve that allows only communication from the master cylinder to the simulation control means, and a check valve that is arranged in parallel with the check valve and that allows communication from the simulation control means side to the master cylinder side when the pressure on the simulation control means side exceeds a predetermined value. A braking force control device, comprising: a relief valve that allows the braking force. 2. The master cylinder cut valve, wherein the simulation control means divides the space between the master cylinder and the wheel cylinder into a master cylinder side pipe and a wheel cylinder side pipe, and can open and close the communication between the pipes. Simulator means installed in the pipe, pressure adjusting means for adjusting the pressure value according to an instruction, communication between the pressure control valve and the wheel cylinder side pipe, which is connected to the pressure adjusting means and the wheel cylinder side pipe Cut valve for pressure control that can open and close, brake operating force detecting means for detecting brake operating force, wheel cylinder pressure detecting means for detecting supply pressure value to wheel cylinder, and master cylinder cut valve, pressure adjusting means, pressure Connected to control cut valve, brake operation force detection means, wheel cylinder pressure detection means And a control means capable of controlling opening and closing of the master cylinder cut valve and the pressure control cut valve, and capable of instructing the pressure adjusting means to output a predetermined pressure, wherein the control means controls the brake operating force. When not detected, 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 used as the brake operating force. When the wheel cylinder pressure detecting means detects that the wheel cylinder pressure has decreased in response to a pressure instruction to the pressure adjusting means at the time of detecting the brake operating force, the master cylinder cut valve is adjusted. The simulator means is a hollow cylinder and is slidably disposed in the cylinder. A piston that divides the interior of the cylinder into a first chamber and a second chamber, and the cylinder is provided to face the first chamber,
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. The braking force control device according to claim 1, wherein: