JPH0456668A - Brake pedal stroke compensating device - Google Patents

Abstract

PURPOSE:To compensate the liquid pressure of main liquid passages automatically so as to maintain normal liquid pressure by supplying the liquid quantity shortage by a liquid supply device at the time of detecting the liquid pressure of the main liquid passages of a braking device failing to reach the liquid pressure corresponding to the stroke of a brake pedal. CONSTITUTION:A brake pedal 1 is provided with a potentiometer 3 for measuring the brake pedal stroke, and a stroke quantity detection signal is inputted into a control device 24. Three-way connectors 11 are respectively interposed in two lines of main liquid passages 10, connected to a master cylinder M/C, reaching wheel cylinders W/C. Liquid pressure sensors 12 for detecting the liquid pressure of the main liquid passages 10 are fitted into the respective three-way connectors 11, and these liquid pressure detection signals are also inputted into the control device 24. The control device 24 then compares the stroke position detection signal with the liquid pressure detection signals so as to compute the liquid quantity shortage in the main liquid passages 10, and drives/controls the pump 17 of a supply device 16 so as to compensate the liquid quantity shortage in the main liquid passages 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic foot brake system for automobiles.

[Conventional technology]

The pedal force generated by depressing the brake pedal pressurizes the fluid in the master cylinder through a vacuum booster or a hydraulic booster, and this pressurized fluid pressure is transmitted to the foil cylinder to brake the wheels.

Conventionally, the brake fluid pressure is determined by the brake pedal stroke (depression amount), a force τ
, paper lock, etc., it may not be possible to generate the hydraulic pressure equivalent to the stroke.

By the way, as a brake device that is equipped with a hydraulic pressure increase device and can apply a hydraulic pressure higher than the hydraulic pressure generated in the master cylinder to the wheel cylinder, there is one described in Japanese Patent Application Laid-Open No. 63-20256.

As shown in FIG. 4, the brake device described in the above-mentioned publication uses a brake pedal 1 formed to open and close a pedal switch 30 to pressurize the fluid in a master cylinder M/C, and a bushing rod. 2 is provided with a pedal force sensor 31.

Then, from the master cylinder M/C to the foil cylinder W/
A liquid absorber 34 is connected to a position of the main liquid path 10 leading to C near the master cylinder M/C via an electromagnetic on-off valve 35.

Further, a change valve 38 is inserted in the main liquid path 10 at a position closer to the wheel cylinder W/C. The change valve 38 is connected to a hydraulic pressure ζ pressurized by an electrically controlled hydraulic pressure source 41 via an electromagnetic hydraulic pressure control valve 42 .

In the brake system shown in FIG. 4, when the brake pedal 1 is depressed, the main controller controls the electromagnetic on-off valve 35 based on a signal from the pedal switch 30.

Further, when the brake pedal is depressed, hydraulic pressure is generated in the master cylinder M/C, but at the same time, the pedal force sensor 31 detects the pedal force, and the main control unit 1 is activated by the electrically controlled hydraulic pressure source 41.
The pump 17 and the electromagnetic hydraulic pressure control valve 42 are operated.

Then, a hydraulic pressure 75ζ higher than the hydraulic pressure of the master cylinder M/C is transmitted from the pump 17 to the change valve 38.

The high hydraulic pressure sent from the pump 17 acts on the change valve 38. This change valve 38 is connected to the master cylinder M/C and the wheel cylinder W/C.
and connects the pump 17 of the electrically controlled hydraulic pressure source 41 to the foil cylinder W/C. and,
The hydraulic pressure of the pump 17, which is higher in pressure than the hydraulic pressure of the master cylinder M/C, is transmitted to the wheel cylinder W/C to brake the wheels.

Furthermore, the change valve 38 allows the wheel cylinder W/
The hydraulic pressure of the master cylinder M/C cut off from C is transferred to the liquid absorber 34 through the electromagnetic on-off valve 35 which is kept open in order to obtain a normal brake operation feeling.
It is designed to be absorbed by

[Problem to be solved by the invention]

The conventional brake device shown in FIG. 4 increases the hydraulic pressure according to the force applied to the brake pedal, the deceleration of the car, etc., and uses the master cylinder to control the force f, which can set the required brake operating force. The M/C shuts off the pressure fluid to the main fluid path lO, and the fluid pressure is transferred from the separate electrically controlled fluid pressure source 41 to the main fluid path 1.
Since the structure is such that the change valve 38. Pump 17° Liquid absorber 34. The number of components such as the electromagnetic on-off valve 35 has increased, and the piping structure has become complicated.The present invention has been made in view of the above points, and compensates for the hydraulic pressure equivalent to the brake pedal stroke with a simple configuration. The technical challenge is to make it possible.

[Means to solve the problem]

The present invention provides a brake device configured to transmit hydraulic pressure generated in a master cylinder to a wheel cylinder through a main hydraulic path when a brake pedal is depressed, which is provided with a stroke measuring means for measuring a brake pedal stroke amount. , a hydraulic pressure detecting means for detecting the hydraulic pressure in the main liquid path is provided, and a measurement signal from the stroke measuring means and a detection signal from the hydraulic pressure detecting means are compared to detect a shortage of liquid in the main liquid path. The structure has a liquid supply device that calculates the amount of liquid and supplies this insufficient liquid amount to the main liquid path. [Function] In the above, a potentiometer that outputs the amount of movement as a displacement of a voltage value is used as the stroke measuring means. be able to. A hydraulic pressure sensor can be used as the hydraulic pressure detection means.

Further, the comparison of the detection signals is performed by a comparison section in the control device including, for example, a CPU. The calculation of the amount of insufficient liquid is performed by the calculation section.

In the above, when the brake pedal is depressed, hydraulic pressure is generated in the master cylinder M/C, and this hydraulic pressure is transmitted to the wheel cylinder W/C through the main hydraulic path to brake the wheels.

At the same time, the signal from the potentiometer, which measures the brake pedal stroke, and the signal from the hydraulic pressure sensor, which measures the hydraulic pressure in the main fluid path, are input to the comparison section of the control device. The results are sent to the arithmetic unit.

In the calculation section, the hydraulic pressure in the main hydraulic path is determined by the brake pedal.
When maintaining the hydraulic pressure corresponding to the stroke and ν,
Although no operation command signal is output to the liquid supply device, if the comparison section determines that there is a lack of liquid pressure, the calculation section calculates the insufficient liquid pressure and sends a command signal to the liquid supply device consisting of a motor M, a pump, etc. When the liquid is delivered, the liquid supply device operates and supplies the insufficient liquid pressure to the main liquid path.

〔Example〕

1 to 3 are explanatory diagrams of a brake pedal stroke compensation device according to an embodiment of the present invention.

In this embodiment, a bushing rod 2 connected to a brake pedal 1 is connected to a piston of a tandem master cylinder M/C via a vacuum or hydraulic booster 5.

The master cylinder M/C includes a foil cylinder W/C.
There are two main liquid paths 10 that reach the water.

The brake pedal 1 includes a brake pedal
A potentiometer 3 for measuring stroke is provided, and a stroke amount detection signal from this potentiometer 3 is input to a control device 24.

The potentiometer 31 is also used as a brake switch, and also functions as a lighting switch for a brake lamp, etc. (not shown).

A three-way connector 11 is inserted into each of the two main liquid passages 10, and a hydraulic pressure sensor 12 for detecting the hydraulic pressure of the main liquid passage 10 is attached to the three-way connector ll. There is. A detection signal from the hydraulic pressure sensor 12 is input to the control device 24.

A pressure increasing liquid path 20 for supplying pressurized liquid from the pump 17 of the liquid supply device 16 to the main liquid path 1o is connected to each of the three-way connectors 11.

This pressure increasing liquid path 20 is integrated into one liquid path in the middle thereof, and its end constitutes a part of the liquid supply device 16 and is connected to the discharge port of a pump 17 driven by a motor M. . In addition, in the middle part of the pressure increasing liquid path 20,
A check valve 18 that allows liquid to be supplied from the pump 17 to the main liquid path 1o is inserted in each case.

The suction port of the pump 17 is a suction side liquid path 19, which is connected to the tank 6 of the master cylinder M/C.
).

The control device 24 includes a comparison section 24a that compares the stroke position detection signal from the potentiometer 3 and a detection signal from the hydraulic pressure sensor 12, and a calculation section 24b that calculates the hydraulic pressure to be added based on the comparison result. is provided.

In addition, the control device 24 is equipped with an A/D converter, a memory for storing data and arithmetic expressions, and the like.

The motor M of the liquid supply device 16 is driven and controlled by a control signal from the control device 24 to drive the pump 1.
7 is also activated to supply the insufficient liquid amount to the main liquid path 10.

Here, to explain the relationship between the brake pedal stroke amount and the hydraulic pressure using FIG. 2, when the brake pedal 1 is depressed and the stroke amount of the brake pedal 1 is A, the detection signal generated by the potentiometer 3, That is, the generated voltage value is B.

At this time, if the brake fluid pressure detected by the fluid pressure sensor 12 is C, and the intersection of the extended lines of B and C is on the setting line in FIG.・Equivalent to a stroke.

However, if the brake fluid pressure detected by the fluid pressure sensor 12 is, for example, E, and the intersection of the extended lines of B and E is F, which is not on the set line, then the brake fluid pressure is insufficient by P. Become.

At this time, the control device 24 outputs a control signal to the motor to correct the insufficient fluid pressure P in the main fluid path lO, and drives the pump 17 to maintain the fluid pressure in the main fluid path lo to a predetermined level. Increase by minute P.

This will be explained below based on the flow shown in FIG.

First, the control device 24 repeats a loop while constantly monitoring the voltage value (switch signal) from the potentiometer 3 that functions to close the brake switch until it detects that the switch signal is turned on (step 301).

Then, when it detects that the switch signal is turned on, the brake pedal
Read the stroke amount and import it into memory (302)
.

Subsequently, the control device 24 connects the main fluid path 10 from the fluid pressure sensor 12.
Read the hydraulic pressure and import this value into memory (303)
.

Then, the comparator 24a in the control device 24 compares the two values and determines whether the converted value of the brake pedal stroke amount is lower than the actual hydraulic pressure (304).

Here, if the actual liquid pressure in the main liquid path 10 is an appropriate pressure, the loop from step 301 is repeated again. When the fluid pressure in the main fluid path 10 is low, the calculation unit 24b calculates the fluid pressure correction amount P, and sends a control signal to the motor M to increase the pressure of the brake fluid in the main fluid path 10 (30
5).

By repeating the above control, a hydraulic pressure corresponding to the stroke amount of the brake pedal is compensated in the main hydraulic path 10.

Moreover, since the insufficient amount of liquid is supplied to the main liquid path 10 without blocking the main liquid path 1o, it is a change valve.

There is no need for members such as electromagnetic on-off valves, and the structure can be made smaller and less prone to failure.

Moreover, since it is a mechanism that simply compensates the brake fluid pressure in the main fluid path 10, there is no problem in using it in combination with a brake anti-lock system or a traction system.

Furthermore, the use of a potentiometer that also serves as a brake switch reduces the number of parts.

〔Effect of the invention〕

According to the present invention, when the hydraulic pressure in the main hydraulic path of the brake device has not reached the hydraulic pressure corresponding to the brake pedal stroke,
Since the liquid supply device supplies the insufficient amount of liquid to the main liquid path, the paper lock etc. automatically compensates for the liquid pressure in the main liquid path that does not reach the desired liquid pressure and restores normal liquid pressure. can be maintained.

[Brief explanation of drawings]

1 to 4 are diagrams for explaining a brake pedal stroke compensating device according to an embodiment of the present invention, in which FIG. 1 shows a circuit diagram and FIG. 2 shows a line between a brake pedal stroke and brake fluid pressure. FIG. 3 is a flowchart of the operating circuit of the present invention, and FIG. 4 is a circuit diagram of a conventional brake device in which the brake operating force can be freely set. 1... Brake pedal 3... Potentiometer 1o... Main fluid path IZ... Fluid pressure sensor 16.
...Liquid supply device 24...Control device Fig. 1

Claims (1)

[Claims] (1) In a brake device configured to transmit hydraulic pressure generated in a master cylinder by depression of a brake pedal to a wheel cylinder through a main hydraulic path, a stroke measuring means for measuring the amount of brake pedal stroke is provided, and A liquid pressure detection means for detecting the liquid pressure in the main liquid path is provided, and a measurement signal from the stroke measuring means and a detection signal from the liquid pressure detection means are compared to determine the amount of insufficient liquid in the main liquid path. A brake pedal stroke compensator comprising a liquid supply device that calculates the amount of insufficient liquid and supplies the amount of insufficient liquid to the main liquid path.