JPS6339466B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application This invention relates to a brake booster, and more particularly to a brake booster used as an actuator in a brake control device of an automobile having an electronic information processing device. be.

(b) Prior art and its problems Conventional automotive brake control devices have a structure in which the hydraulic pressure that acts on the brakes depends only on the magnitude of the force applied to the brake pedal by the driver. Although a large deceleration can be obtained in the above case, a larger pedal force is required to obtain the same deceleration as in the above case with a full load.
In addition, the effectiveness of the brake also changes due to changes in the slope of the road, changes in the friction coefficient of the brake friction material, etc. Therefore, the driver needs a driving technique that changes the pedal force according to changes in the various driving situations in which the vehicle is placed.

Therefore, the applicant has developed a brake control device that does not require the above-mentioned driving technique, that is, a brake control device that can always obtain a constant brake effectiveness with a constant pedal force, regardless of changes in the various driving conditions in which the automobile is placed. We have applied for a patent specifically for the brake control device (Japanese Patent Application No. 128737-1981).

The brake control device according to the above patent application is
As shown in the figure, an actuator 2 that operates a master cylinder 1, a pump 3 for generating hydraulic pressure acting on the actuator 2, an accumulator 4 for the hydraulic pressure generated by the pump 3, and an accumulator 4 for generating the hydraulic pressure. It has a control valve 6 for controlling. It also has a vehicle deceleration detection sensor 7 and an electronic information processing device 8 such as a microprocessor that controls the control valve 6 to achieve a preset effect based on the input signal from the sensor 7. Further, the magnitude of the depression force on the brake pedal 9 is detected by a control input detection sensor 10 provided on the actuator 2, and this is input to the information processing device 8. In FIG. 1, 11 is a liquid tank, 12 is a brake cylinder, and 13 is a wheel.

In the above-mentioned brake control device, the desired relationship between the depression force on the brake pedal and the vehicle deceleration is input into the processing device 8 in advance, and the actual vehicle deceleration is detected by the detection sensor 7.
The control valve 6 is controlled from the processing device 8 so that the desired deceleration is obtained by comparing the brake control input data detected by the brake control input data.

Therefore, according to the above-mentioned brake control device, it is possible to always obtain a constant brake effectiveness with a constant pedal force regardless of changes in driving conditions.

On the other hand, conventionally known brake boosters are
Using vacuum pressure, hydraulic pressure, etc. as a driving source, the master cylinder is actuated by an output that increases in proportion to the pedal force, and the reaction force of the force acting on the master cylinder is sensed by the driver via a reaction disk. However, since this device is configured to be operated only by the driver's pedal effort, it cannot be controlled from the electronic information processing device as described above.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a brake booster having a structure suitable for use as an actuator in the above-mentioned electronic information processing apparatus.

(C) Means for Solving the Problems The brake booster of the present invention includes a piston inserted into a cylinder, a pressure chamber for moving the piston between the piston and the cylinder, and a pressure chamber in the pressure chamber. a control valve is interposed in the passage, one end of the piston shaft of the piston is an input shaft that connects to a brake pedal, the other end is an output shaft that engages a master cylinder, and the input This configuration has an input detection sensor attached to the shaft.

With the above configuration, the brake control input signal is input to the electronic information processing device, and the pressure from the pressure source is controlled by the control signal from the device, and an appropriate output is input to the master cylinder through the output shaft. This allows a force equal to the sum of the pedal force acting on the input shaft and the assisting force acting on the piston to be applied to the master cylinder.

(d) Embodiment FIG. 2 shows a state in which a brake booster 20 according to an embodiment of the present invention is combined with a master cylinder 21.

This brake booster 20 includes a cylinder 23,
It includes a piston 24, an input shaft 25 as a piston shaft, and an output shaft 26.

The cylinder 23 has a large diameter part 28 and a small diameter part 29 formed by a step part 27 formed on the input side.
It is divided into. The piston 24 consists of a large diameter part 30 that slides within the large diameter part 28 and a small diameter part 31 that slides within the small diameter part 29. By interposing seals 32 and 33 in these sliding contact parts, ,
A hydraulic chamber 34 is formed.

Two passages 35, 35' are formed in the cylinder 23 and communicate with the hydraulic pressure chamber 34, and each passage 35,
35' communicate with valve chambers 36 and 36', respectively. In the valve chambers 36, 36', plungers 39,
39' is inserted, and this plunger 39,
Each passage 35, 35' is closed by the tip needle portion 37, 37' of 39'. In addition, each valve chamber 36,
36' is connected to an inlet port 40 for connecting to the high pressure side of the pressure source and an outlet port 41 for connecting to the low pressure side of the pressure source.

A coil spring 42 is inserted into the large diameter portion 28 of the cylinder 23, and one end of the coil spring 42 is connected to the piston 2.
4, and the other end engages with the body of the master cylinder 21 connected to the cylinder 23 by a bolt 43, thereby constantly urging the piston 24 toward the input side.

The small diameter portion 31 of the piston 24 is connected to the piston 2
4 protrudes from the rear end of the cylinder 23 in the most retracted state as shown in the figure, and its tip and the cylinder 23
Boots 44 are attached between the two.

Further, a rearwardly open space 45 is formed in the small diameter portion 31 of the piston 24, and the input shaft 25 passes through the space 45. Further, an output shaft 26 is provided protruding from the front surface of the large diameter portion 30 of the piston 24, and the distal end ball portion of the input shaft 25 is inserted into a recess formed in the output shaft 26 from the space 45 side, and the tip of the input shaft 25 is inserted into the recess. By caulking a part of the piston 2 to prevent it from coming off.
4, an input shaft 25 is swingably connected to the input shaft 25. The input shaft 25 has a pipe-shaped control input detection section 46 in the middle thereof, and a control input detection sensor 47 using a strain gauge is attached to the detection section 46 so that its lead wire is drawn out through the inside of the input shaft 25. I have to. In addition, the output shaft 26 also has a pipe-shaped output detection section 4 in the middle thereof.
8, and an output detection sensor 49 using a strain gauge is attached to the detection portion 48, and its lead wire passes through the piston 24, passes through the inside of the input shaft 25, and is similarly drawn out to the outside. .

Inserting the lead wire inside the input shaft 25 in this way reduces the clearance between the input shaft 25 and the piston small diameter portion 31 due to the swinging of the input shaft 25 when the brake is applied. This has the effect of preventing contact between the lead wire and the piston small diameter portion 31 that occurs when the lead wire is passed through.

Note that the tip of the output shaft 26 is engaged with the primary piston 51 of the master cylinder 21.

Next, the operation of the brake booster will be explained.

This brake booster 20 is used by being incorporated into a brake control device, as indicated by the symbol with a bracket in FIG. That is, each electromagnetic valve 38 and the control input detection sensor 47 are electrically connected to the information processing device 8, and the input port 40
is connected to the high pressure side, and the output port 41 is connected to the low pressure side.

Now, when the driver steps on the brake pedal 9, the input shaft 25 pushes the piston 24, and the output shaft 26, which is integrated with the piston 24, operates the primary piston 51 of the master cylinder 21 to generate brake fluid pressure. The brake cylinder 12 is actuated by the hydraulic pressure to reduce the rotational speed of the wheel 13. The deceleration of the vehicle due to a decrease in the rotational speed of the wheels 13 is determined by the information processing device 8 based on the signal from the deceleration detection sensor 7 .

On the other hand, since the magnitude of the brake pedal force is continuously input to the information processing device 8 by the control input detection sensor 47, the information processing device 8 can reduce the brake pedal force corresponding to the pedal force input and stored in advance. The data regarding the speed and the deceleration actually detected by the deceleration detection sensor 7 are compared.

As a result, if the deceleration is small relative to the pedal effort, a control signal is output to the solenoid valve 38 to activate it. Due to the operation of the solenoid valve 38, the plunger 3
9 retreats, thereby opening the passage 35 and increasing the pressure in the hydraulic chamber 34, causing the piston 24 to move forward. Since the brake fluid pressure increases as the piston 24 moves forward, the electromagnetic valve 38 is returned to its original state when a state in which deceleration commensurate with the pedal effort is detected is detected.

Furthermore, if the driver reduces the pedal force while braking, the balance between the pedal force and deceleration will be lost, so a control signal is sent from the information processing device 8 to the solenoid valve 38' on the output port 41 side, and this solenoid valve 38' is The actuation opens the passage 35' and reduces the pressure in the hydraulic chamber 34. In this case, the liquid flowing out from the output port 41 returns to the liquid tank 11.

Note that if the signal of the output detection sensor 49 is input to the information processing device 8, the output of the sensor 49 and the control input detection sensor 47
If the output of By comparing the magnitudes of the signals, it is possible to detect a malfunction in the information processing device 8, and a warning can be issued to the driver.

However, even in such a failure state, the device of the present invention has an integrated input shaft 25, piston 24, and output shaft 26, and the output shaft 26 engages with the primary piston 51 of the master cylinder 21. Therefore, it is possible to ensure a braking function based only on pedal force.

In addition, as a modification of the above embodiment, the same effect can be obtained by using a spool valve instead of the plunger needle valve type solenoid valves 38, 38'.

Furthermore, it is obvious that the input/output detection section is not limited to the illustrated structure, and any type of sensor that converts force into an electric signal can be used.

In addition, in the control by the information processing device 8, if the time delay from when the driver depresses the brake pedal 9 to when the required deceleration is obtained is too large, the time delay from the time of the previous brake operation or including the previous brake operation may be determined. The vehicle deceleration relative to the current output of this device is estimated by referring to the output information obtained by the output detection sensor during previous brake operations and the deceleration information obtained by the deceleration detection sensor. The above-mentioned time delay can be shortened by controlling the output of the present device from the information processing device through the control valve so that the deceleration becomes a preferable deceleration corresponding to the current pedal depression force.

Since the brake booster of the present invention has the configuration described above, by using it as an actuator of a brake control device using an electronic information processing device, it is possible to maintain a constant pedal force regardless of changes in driving conditions. It is possible to obtain a constant brake effectiveness.

[Brief explanation of drawings]

Figure 1 is a block diagram of the brake control device, Figure 2
The figure is a sectional view of an embodiment of the invention. 20... Brake booster, 21... Master cylinder, 23... Cylinder, 24... Piston, 25... Input shaft, 26... Output shaft, 34... Hydraulic pressure chamber, 35, 3
5'... Passage, 37... Needle portion, 38, 38'... Solenoid valve, 45... Space, 47... Control input detection sensor, 49... Output detection sensor.

Claims (1)

[Claims] 1. A piston is inserted into a cylinder, a pressure chamber for moving the piston is provided between the piston and the cylinder, a passage connected to a pressure source is communicated with the pressure chamber, and a an input shaft that connects one end of the piston shaft of the piston to the brake pedal through a valve, and an output shaft that engages the other end of the piston shaft with the master cylinder, and an input detection sensor that continuously detects pedal depression force on the input shaft. A brake booster equipped with a. 2 A hydraulic pressure source is used as the above pressure source, and a passage connecting the high pressure side of the hydraulic pressure source and the pressure chamber and a passage connecting the low pressure side and the pressure chamber are provided, and a control valve is interposed in each passage. A brake booster according to claim 1. 3. The brake booster according to claim 1, wherein the piston has a space open to the input side, and the input shaft passes through the space.