JP3252858B2 - Electronic control brake device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled brake device for electrically controlling a brake pressure.

[0002]

2. Description of the Related Art As a conventional technique of this type, there is, for example, Japanese Patent Publication No. 2-49943, which discloses a technique in which a stroke simulator is connected to a pipe connected to a wheel cylinder. An electromagnetic valve that can control the communication with the stroke simulator, a pressure switch that detects the hydraulic pressure of the servo brake system, a pressure measuring device that detects the hydraulic pressure of the wheel cylinder pressure, an electromagnetic valve, a pressure switch, and pressure measurement A control device electrically connected to the device, wherein when the servo brake system fails, the control device detects the failure by a signal output from the pressure switch, and the control device shuts off the solenoid valve. Thus, the master cylinder and the wheel cylinder communicate with each other without passing through the stroke simulator.

[0003]

However, in the above prior art, when the servo brake system has failed, the control device detects the failure by a signal output from the pressure switch, and the control device shuts off the solenoid valve. Since the master cylinder and the wheel cylinder communicate with each other without passing through the stroke simulator, the conductor connecting the pressure switch and the control device and the conductor connecting the control device and the solenoid valve are disconnected. If the device itself breaks down, the solenoid valve cannot be driven, and the master cylinder and the stroke simulator may not be shut off.

Accordingly, an object of the present invention is to make it possible to reliably shut off the master cylinder and the stroke simulator when the servo brake system fails.

[0005]

Configuration of the Invention

[0006]

Means for Solving the Problems The technical means adopted in the present invention to solve the above technical problems is a hydraulic pressure generating device for generating a hydraulic pressure according to the depression force of a brake pedal, and a hydraulic pressure generator for the brake pedal. a pedal force detection means for detecting a pedaling force, and the power pressure source for generating a power hydraulic pressure boosts the brake fluid to a predetermined pressure, which can control fluid pressure disposed between the power pressure source and the wheel cylinder receiving a valve means, and the stroke simulator disposed in the conduit connecting with the hydraulic pressure generator and the wheel cylinders, disposed between the stroke simulator and the line power pressure of the power pressure source
Sometimes communication between stroke simulator and hydraulic pressure generator
And does not operate when the power pressure of the power pressure source is not supplied
And shut off the stroke simulator and hydraulic pressure generator
A cut valve that, said hydraulic pressure generator when in and receiving power pressure of the power pressure source is disposed on the wheel cylinder side than the stroke simulator of the conduit
Shut off the wheel cylinder and remove the power pressure source
When the work pressure is not supplied, it is not activated and the hydraulic pressure is generated.
A bypass valve communicating the device with the wheel cylinder ;
Electronic control blanking and a control means for outputting a control signal to said valve means based on the signal output from the <br/> pedal force detection means is electrically connected to said pedal force detection means and the valve means
It is a rake device .

[0007]

The above technical means operates as follows. In normal operation, the power pressure is supplied from the power pressure source to the bypass valve, so that the fluid pressure generator and the wheel cylinder are shut off, and the hydraulic pressure corresponding to the brake pedal depression force detected by the pedal force detection means is reduced. The power is supplied from the power pressure source to the wheel cylinder under the control of valve means.

As for the pedal depression force, the hydraulic pressure generated by the hydraulic pressure generating device according to the pedal depression force can obtain a predetermined stroke by operating the stroke simulator.

In addition, when the power hydraulic pressure fails, the power hydraulic pressure is not supplied to the bypass valve and the cut valve , so that the bypass valve and the cut valve do not operate, and the hydraulic pressure generator and the wheel cylinder communicate directly with each other. The pressure generator and the stroke simulator do not communicate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments to which the present invention is applied will be described below in detail with reference to the accompanying drawings.

In this embodiment, two systems are used for front and rear piping. However, since the rear piping is the same except that the booster cylinder 13 is not interposed with the front piping, the description of the rear piping is omitted. .

In FIG. 1, an electronically controlled brake device 1
Is composed of a tandem master cylinder (hereinafter simply referred to as a master cylinder) 2a and a booster 2b, and a hydraulic pressure generator 2 for generating a hydraulic pressure according to the pedaling force of the user by the brake pedal 3; A treading force sensor 8 for detecting a treading force, wheel cylinders 50 a and 51 a disposed on wheels 50 and 51, an accumulator 5 in which a predetermined power pressure is accumulated by a pump 4, and a power pressure accumulated in the accumulator 5. Linear valves 6a and 6b for supplying to wheel cylinders 50a and 51a based on predetermined conditions; a stroke simulator 7 connected to a pipe 20 connecting master cylinder 2a and wheel cylinders 50a and 51a; Valve 9 for controlling the communication between the cylinder and the stroke simulator 7
And a G sensor 10 for detecting front and rear G of the vehicle, an electronic control electrically connected to the pedaling force sensor 8, the linear valves 6a and 6b, and the G sensor 10.
A unit (hereinafter simply referred to as an ECU) 40 is basically provided.

The accumulator 5 controls the hydraulic pressure generated by the pump 4 driven by the motor 4 a by a check valve 11.
Through the ECU 40 so as to be maintained at a predetermined pressure based on a signal output from the pressure sensor 12.
Controls the motor 4a.

Pipe line 20 connected to master cylinder 2a
Is provided with a booster cylinder 13 on its upstream side,
A pipe 20g is branched downstream from a portion where the pressure intensifying cylinder 13 is provided. The pressure-increasing cylinder 13 controls the power pressure of the accumulator 5 via the pipe line 20q.
a, the piston 13b is located on the right side in the figure, and increases the hydraulic pressure sent from the master cylinder 2a when the power pressure from the accumulator 5 is no longer supplied.

A switching valve 14 is provided in the pipe line 20, and the switching valve 14 is electrically connected to an EC.
U40, and when driven, communicates the pipeline 20 with the pipeline 20a to communicate the master cylinder 2a with the stroke simulator 7, and when not driven, communicates with the pipeline 20 and the pipeline 20a. The master cylinder 2a and the wheel cylinder 50a are directly connected to each other via the pipe 20b by communicating with the master cylinder 2a. The switching valve 14 is operated when an ignition switch (not shown) is turned on. When the engine is driven, the line 20 is always connected to the line 2.
0a.

The cut valve 9 is disposed between the switching valve 14 and the stroke simulator 7 and communicates only when the power pressure is applied from the accumulator 5. If the power pressure is not supplied, both are shut off.

The stroke simulator 7 includes a first piston 7a and a second piston 7b, a first spring 7c and a second spring 7d for urging both pistons rightward in the drawing, and a rubber cushion member 7e. The first piston 7a and the second piston 7b move leftward in the drawing against the urging force of the first spring 7c and the second spring 7d by the hydraulic pressure supplied from the master cylinder 2a, and It moves further while bending the member 7e. The relationship between the pedal stroke and the pedal depression force obtained by the stroke simulator 7 can be changed as appropriate depending on the biasing force of the spring and the diameter of the piston.

The pipeline 20a is branched from a bypass 20c which branches and joins the pipeline 20g.
It merges with the pipeline 20b on the downstream side via the line c.

A check valve 15a is connected to the bypass passage 20c.
And a bypass valve 16a are arranged in parallel. The bypass valve 16a is connected to the accumulator 5 via a line 20m.
When the power pressure is applied from the, the communication with the pipeline 20b is interrupted, and when the power pressure is not applied from the accumulator 5, the communication with the pipeline 20b is established. On the downstream side of the check valve 15a, the power pressure from the accumulator 5 is supplied at the time of braking, so that when the bypass valve 16a is in a closed state, the oil in the pipe line 20a passes through the bypass path 20c. It is not supplied to the pipeline 20b.

A cut valve 17a is provided in the pipe 20b downstream of the junction of the bypass 20c and the pipe 20b. The cut valve 17a is electrically connected to the ECU 40 and The ECU 40 is driven by the ECU 40 during the control of the quad brake system (hereinafter, simply referred to as ABS) or the control of the traction control system (hereinafter, simply referred to as TRC). Thus, the oil in the bypass 20c is prevented from being supplied to the pipeline 20b, and is not driven during normal braking.

A pressure sensor 18a is disposed downstream of the cut valve 17a in the pipe 20b, and a pipe 20d branches. The pressure sensor 18a is connected to the line 2
The ECU 4 detects the hydraulic pressure (pressure of the wheel cylinder 50a) in the ECU 4 and electrically connects the detected signal.
0 is output.

The line 20d has a cut valve 19a and a linear valve 6a arranged in series.
The communication between the linear valve 6a and the pipeline 20b is controlled by an electrically connected ECU 40. Linear valve 6
a is E based on the signal output from the pedaling force sensor 8.
A voltage corresponding to the depression force of the brake pedal 3 is output from the CU 40, and the power pressure supplied from the accumulator 5 via the line 20f according to the output voltage is communicated to the line 20d or the reservoir 21. Is supplied to the pipeline 20e. Also, the cut valve 19a
When the depression force of the brake pedal 3 is detected by the depression force sensor 8, the ECU 40 outputs a voltage corresponding to the depression force to the linear valve 6a from the ECU 40 and simultaneously outputs the voltage to the cut valve 19a.
A signal is output from the CU 40. During braking, the accumulator 5 and the wheel cylinder 50a communicate with each other via the linear valve 6a and the cut valve 19a.

The pipeline 20g is branched from a bypass 20h, which branches off at one end and merges with the 20g again. A switching valve 22 is provided in parallel with the bypass 20h. The switching valve 22 operates when an ignition switch (not shown) is turned on, and always shuts off the line 20g when the engine is driven.

A cut valve 17b is provided in the pipe 20g downstream of the junction of the pipe 20g and the bypass 20h, and the cut valve 17b is electrically connected to the ECU 40. The wheel cylinder 50 is driven by the ECU 40 during the ABS control and is involved in the ABS control.
This prevents the oil in the bypass 20h from being supplied to the pipe 20g due to the pressure reduction in b, and is not driven during normal braking.

A pressure sensor 18b is disposed downstream of the cut valve 17b in the line 20g, and a line 20i is branched. The pressure sensor 18b is connected to the line 2
The ECU 4 detects the fluid pressure (pressure of the wheel cylinder 50b) in the ECU 4 and electrically detects the detected signal.
0 is output.

The conduit 20i is provided with a cut valve 19b and a linear valve 6b arranged in series.
The communication between the linear valve 6b and the pipeline 20i is controlled by the ECU 40 which is electrically connected. Linear valve 6
b is E based on the signal output from the pedaling force sensor 8.
A voltage corresponding to the depression force of the brake pedal 3 is output from the CU 40, and the power pressure supplied from the accumulator 5 via the pipe 20j according to the output voltage is communicated to the pipe 20i or the reservoir 21. This is supplied to the pipeline 20k which merges with the pipeline 20e. When the depression force of the brake pedal 3 is detected by the depression force sensor 8, the cut valve 19b outputs a voltage corresponding to the depression force from the ECU 40 to the linear valve 6b, and simultaneously outputs a signal to the cut valve 19b. During braking, the accumulator 5 and the wheel cylinder 50
b communicate with each other via the linear valve 6b and the cut valve 19b.

A check valve 15b is connected to the bypass passage 20h.
And a bypass valve 16b are arranged in parallel. The bypass valve 16b is connected to the accumulator 5 via the line 20n.
When the power pressure is being applied to the bypass line, the communication between the bypass passage 20h and the pipeline 20g is cut off. When the power pressure is not being applied from the accumulator 5, the bypass passage 20h and the pipeline 2g are disconnected.
0 g is communicated. Further, on the downstream side of the check valve 15b, since the power pressure from the accumulator 5 is supplied at the time of braking, the downstream side becomes high pressure,
When the bypass valve 16b is closed, the oil in the bypass passage 20h is not supplied to the pipeline 20g.

In the line 20f, a cut valve 24 is disposed between the junction with the line 20n and the accumulator 5, and the line 2 is connected between the cut valve 24 and the accumulator 5.
0p is branched. When the depression force of the brake pedal 3 is detected by the depression force sensor 8, the cut valve 24
A signal is output from 0 and driven, and the line 20f is communicated during braking.

The pipe 20p has an orifice 25 and a cut valve 26 arranged in parallel. The cut valve 26 is connected to the pipe 20p when the power pressure of the accumulator 5 is applied.
When the power pressure of the accumulator 5 is not applied, the line 20p is communicated.
Also, since the pipe 20p is connected to the pipe 20e via the cut valve 26, the liquid chamber 13a communicates with the reservoir 21 when the cut valve 26 is in communication. Pipe 20p
Is in communication with the pipe line 20p through the orifice 25, and is in constant communication with the liquid chamber 13a of the pressure-intensifying cylinder 13.

The pressure sensor 27 monitors whether a hydraulic pressure corresponding to the depression force of the brake pedal 3 detected by the depression force sensor 8 is generated from the master cylinder 2a.

Wheel speed sensors 23a and 23b, which are electrically connected to the ECU 40, are provided on the wheels 50 and 51, and detect the wheel speeds of the wheels 50 and 51. The ECU 40 calculates a reference speed and an estimated vehicle speed that serve as a reference for the control.

The G sensor 10 detects the acceleration / deceleration in the front-rear direction of a vehicle, which is conventionally known as a switch type or a linear sensor type.

Next, the operation of this embodiment will be described.

First, the operation during normal braking will be described.
When the ignition switch is turned on, the switching valve 1
4 communicates the pipeline 20 with the pipeline 20a. Cut valve 9,
The cut valves 9 are connected to the bypass valves 16a, 16b and the cut valve 28 by the power pressure of the accumulator 5, and the bypass valves 16a, 16b and the cut valve 28 are closed. When the brake pedal is depressed by the driver, the pressure-intensifying cylinder 13,
Hydraulic pressure is supplied to the stroke simulator 7 via the pipe 20, the switching valve 14, the pipe 20a, and the cut valve 9.
By operation of the stroke simulator, a pedal stroke corresponding to a predetermined pedaling force is obtained as shown in FIG. Also, the cut valves 19a, 19b
Then, a signal is output to the linear valves 6a, 6b and the cut valve 24, and the power pressure is supplied from the accumulator 5 to the linear valves 6a, 6b via the cut valve 24. Linear valve 6
Since the ECU 40 outputs a voltage corresponding to the pedal depressing force obtained by the pedaling force sensor 8, the wheel cylinders a and 6 b are arranged so that the power pressure from the accumulator 5 can be obtained at a predetermined vehicle deceleration corresponding to the pedal depressing force. 50a, 5
1a is supplied via cut valves 19a and 19b. The voltage output from the ECU 40 to the linear valves 6a and 6b is determined by the G sensor 10 and the pressure sensors 7, 18a and 18b.
Is determined based on the signal output from the.

Next, the operation during the ABS control and the TRC control will be described.

When it is determined from the signals output from the wheel speed sensors 23a and 23b that the wheels are slipping, the ECU 40 outputs signals to the cut valves 17a and 17b and the linear valves 6a and 6b to output the signals to the pipeline 20b. , And outputs a voltage to the linear valves 6a and 6b based on predetermined conditions to increase and decrease the fluid pressure (wheel cylinder pressure) in the pipelines 20d and 20i to perform ABS control and TRC control.

Here, the operation when the power pressure is no longer supplied from the accumulator 5 due to a failure or a failure in the pipeline will be described.

Since no power pressure is supplied from the accumulator 5, the cut valve 9 and the bypass valves 16a and 16b are not supplied.
Then, the cut valve 26 becomes inactive. Therefore, the cut valve 9 cuts off the communication between the stroke simulator 7 and the pipeline 20a. By-pass valves 16a and 16b allow the bypass passage 20c to communicate with the pipeline 20b and the bypass passage 20h with the pipeline 20g. By the cut valve 26, the liquid chamber 13a of the pressure-intensifying cylinder 13 communicates with the reservoir 21 via the line 20q, the cut valve 26, and the line 20e, so that the pressure-increasing cylinder 13 can be pressurized. As a result, the master cylinder 2a and the wheel cylinders 50a, 50
0b is in direct communication with the wheel cylinder 5
The oil supplied to Oa and 50b has been pressurized by the booster 2b and the pressure-intensifying cylinder 13.

[0039]

According to the present invention, since the power pressure is supplied from the power pressure source to the bypass valve in the normal state, the connection between the hydraulic pressure generating device and the wheel cylinder is cut off, and the brake detected by the pedaling force detecting means is provided. The hydraulic pressure according to the pedaling force is supplied from the power pressure source to the wheel cylinder under the control of the valve means, and the pedaling force is determined by the hydraulic pressure generated by the hydraulic pressure generator according to the pedaling force. Since a predetermined stroke can be obtained by the operation of the accelerator, a pedal stroke matching the pedal depression force can always be obtained, and a change in the amount of liquid consumed due to a change in μ due to wear of the brake pad or deterioration of the flexible hose, etc.
A braking force corresponding to the pedaling force can always be obtained.

By changing the setting of the stroke simulator, it is possible to obtain a desired relationship between the pedal effort and the pedal stroke.

Further, when the power hydraulic pressure fails, the power hydraulic pressure is not supplied to the bypass valve and the cut valve , so that the bypass valve and the cut valve do not operate, and the hydraulic pressure generating device and the wheel cylinder communicate directly with each other. The pressure generator and the stroke simulator do not communicate with each other,
The hydraulic pressure can be reliably transmitted to the wheel cylinder .

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration of an electronic control brake device according to the present embodiment.

FIG. 2 is a characteristic diagram showing a relationship between a pedal depression force and a pedal stroke in the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic control brake device 2 ... Hydraulic pressure generating device 3 ... Brake pedal 5 ... Accumulator (power hydraulic pressure source) 6a ... Linear valve (valve means) 7 ... Stroke shimyu Rator 9: Cut valve 16a: Bypass valve 50a: Wheel cylinder 40: ECU (control means)

Claims (1)

(57) [Claims] 1. A hydraulic pressure generating device for generating a hydraulic pressure corresponding to a pedaling force of a brake pedal, a pedaling force detecting means for detecting a pedaling force of a brake pedal, and a power hydraulic pressure generated by increasing a brake fluid to a predetermined pressure. Power pressure source, hydraulically controllable valve means disposed between the power pressure source and the wheel cylinder, and a stroke disposed in a pipe connecting the hydraulic pressure generator and the wheel cylinder. A stroke simulator provided between the stroke simulator and the pipeline and receiving a power pressure of a power pressure source.
And the hydraulic pressure generator to communicate the power pressure of the power pressure source.
Inactive when there is no supply and stroke simulation
And a cut valve for shutting off the fluid pressure generator and the cutoff valve, the cut valve being disposed closer to the wheel cylinder than the stroke simulator of the pipeline and receiving the power pressure of the power pressure source .
Shut off the hydraulic pressure generator and the wheel cylinder
When the power pressure of the power pressure source is not supplied.
Actuating the hydraulic pressure generating device and the wheel cylinder
An electronic control unit that includes a bypass valve that communicates with the control unit and a control unit that is electrically connected to the pedaling force detection unit and the valve unit and outputs a control signal to the valve unit based on a signal output from the pedaling force detection unit. Control braking device.