JPH1143038A - Antilock brake control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To search the cause of a functional trouble closely by providing an electric control unit having the function of writing brake operation, antilock control execution and initial check execution in a nonvolatile memory. SOLUTION: When a brake pedal 10 is operated, a master cylinder 11 supplies a brake fluid to a wheel brake 14 for imparting a braking force to a wheel through a hydraulic passage 12 to impart a brake hydraulic pressure. Each output of a wheel speed detector 20, an electric motor current detector 21 and a brake switch 22 is inputted to an electric control unit 19. The electric control unit 19 is provided with a microcomputer to start the execution of a program when the ignition switch of a vehicle is switched from OFF to ON. An initial check is performed for a prescribed electric system to judge whether a failure is present therein or not. When the failure is present, a countermeasure to the failure content is taken.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-lock brake control device for a vehicle, and more particularly to an anti-lock brake control device for facilitating investigation of a cause of a sensual abnormal phenomenon that could not be grasped by a conventional failure detection function. About.

[0002]

2. Description of the Related Art In general, an anti-lock brake control device for a vehicle is electrically connected to a hydraulic passage for guiding a hydraulic pressure to a wheel brake from a hydraulic pressure generating device for generating a hydraulic pressure corresponding to a brake pedal depression force. A hydraulic modulator controlled to
An electric control unit is provided for electrically controlling the hydraulic modulator based on the slip state of the wheels during vehicle braking. This electric control unit includes an EEPROM (Electrically as a writable nonvolatile memory).
Erasable Programmable Read Only Memory) and one of the couplers for connecting a monitor tester that can read the data written in the non-volatile memory. When the ignition switch is turned on, failure of the specified electrical system (disconnection, short circuit) , Poor contact, etc.), and then continuously checks for the presence of these failures and for the failure of the computer, and when a failure occurs, takes a prescribed action corresponding to the content of the failure that occurred. It has a function of writing the content of the fault that has occurred in the nonvolatile memory. When a failure occurs, the anti-lock brake control device specifies the content of the failure by connecting the monitor tester to the electric control unit via the coupler and reading the content of the failure written in the nonvolatile memory. be able to.

[0003]

However, among the contents where the user complains of a problem, there is a problem sensuously determined which is not detected by the above-described failure check function. The content of such a defect is information only in the words of the user, and in many cases, even if the product in which the defect occurred is collected and investigated, the cause cannot be specified.

[0004] For example, when there is a complaint that a stepping stroke of a brake pedal suddenly increases during vehicle braking, the situation in which this problem occurs is as follows.
(A) During normal braking, (b) After starting antilock control,
(C) Three patterns at the end of the antilock control can be considered.

[0005] In the pattern (b), liquid leakage to the pressure reducing circuit, air remaining in the pressure reducing circuit, and liquid leakage to the outside can be considered, and the cause can be investigated.

However, in many cases, it is not possible to grasp which of the above patterns the situation at the time of occurrence of the problem.
Since there is no clue to the cause, the cause cannot be determined.

An object of the invention of this application is to provide an anti-lock brake device capable of investigating the cause of a sensual defect that cannot be detected by the conventional failure check function.

[0008]

According to a first aspect of the present invention, there is provided an electric motor which is disposed in a hydraulic passage for guiding a hydraulic pressure from a hydraulic pressure generating device for generating a hydraulic pressure corresponding to a brake pedal depression force to a wheel brake. A hydraulic pressure modulator that is electrically controlled, and an electric control unit that electrically controls the hydraulic pressure modulator based on a slip state of wheels during vehicle braking,
An anti-lock brake control device comprising: a nonvolatile memory writable by the electric control unit; and one of a coupler for connecting a monitor tester capable of reading data written in the nonvolatile memory, wherein the electric control unit Has a function of writing the brake operation, execution of the antilock control, and execution of the initial check into the nonvolatile memory.

Specifically, the electric control unit writes the number of times of the brake operation, the execution of the antilock control, and the execution of the initial check into the nonvolatile memory, or executes the brake operation, the execution of the antilock control, and the execution of the initial check. Write to the non-volatile memory in time series.

In such an anti-lock brake control device, when a failure that cannot be detected by the failure check function occurs, the monitor tester is connected to the electric control unit via the coupler, and the brake operation, the anti-lock and the The information on the number of times of execution of the control and the execution of the initial check or the time-series information is read out, and it is possible to grasp which of the above three patterns the situation at the time of occurrence of the trouble, and to investigate the cause thereof.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an antilock brake device according to the present invention will be described with reference to the drawings.

In FIG. 1, a brake pedal 10 is operatively connected to a master cylinder 11 as a hydraulic pressure generator. When the brake pedal 10 is depressed, the master cylinder 11 is A brake fluid is supplied to a wheel brake 13 (not shown) for applying a braking force, and a brake fluid pressure is applied.

A normally open on-off solenoid valve 14A
And a normally closed opening / closing solenoid valve 14B.
A control valve 14 for controlling the discharge and re-supply of the brake fluid to the wheel 3 and for reducing and re-increasing the brake fluid pressure in the wheel brake 13 is provided. When the brake is operated with the brake pedal 10 depressed, the on-off solenoid valve 14
When both A and 14B are turned on (energized), the brake fluid in the wheel brake 13 is discharged and the brake fluid pressure in the wheel brake 13 is reduced. Thereafter, the open / close solenoid valve 14A is turned on and the open / close electromagnetic valve is opened. By turning off the valve 14B, the supply and discharge of the brake fluid into the wheel brake 13 is stopped, and the brake fluid pressure in the wheel brake 13 is maintained. After the brake fluid pressure in the wheel brake 13 is reduced, the opening / closing solenoid valve 14B is turned off and the opening / closing solenoid valve 14
By repeatedly turning off and on A, the brake fluid is intermittently resupplied into the wheel brake 13 and the brake fluid pressure in the wheel brake 13 is increased again in a stepwise manner.

An auxiliary reservoir 15 for storing the brake fluid discharged from the inside of the wheel brake 13 at a low pressure (several atmospheric pressures) is connected to the open / close electromagnetic valve 14B of the control valve 14.
The brake fluid in the auxiliary reservoir 15 is returned to the fluid pressure path between the control valve 14 and the master cylinder 12 by a pump 17 driven by an electric motor 16. During operation of the pump 17 by the electric motor 16, the auxiliary reservoir 15
When all of the brake fluid in the
The value of the current flowing through the current rises sharply to a low current value. Therefore, when the electric motor 16 is turned on, it can be determined whether or not all of the brake fluid in the auxiliary reservoir 15 has been pumped by detecting whether or not the electric motor current has become equal to or less than a predetermined value. Although not shown, the pump 16 has a suction valve and a discharge valve.

Control valve 14, auxiliary reservoir 15, pump 1
6. The electric motor 17 forms a hydraulic modulator MOD.

Control valve 14, auxiliary reservoir 15, pump 1
6. The electric motor 17 and the check valve 18 are
OD.

Opening / closing solenoid valves 14A, 14B of the control valve 14
Are connected to an electric control unit 19, and on / off of each is controlled. The electric motor 16 is also connected to the electric control unit 19 and its on / off is controlled. Outputs of a wheel speed detector 20, a motor current detector 21, and a brake switch 22 (switched from off to on in response to depression of a brake pedal) are input to the electric control unit 19.

The electric control unit 19 includes a microcomputer, and when an ignition switch (not shown) is switched from off to on in the vehicle, execution of a program corresponding to the flowchart of FIG. 2 is started.

When the execution of the program shown in FIG. 2 starts, the microcomputer is first initialized in step 101. Then, in step 102, an initial check is performed for a predetermined electric system. In step 103, it is determined whether or not there is a failure. If there is a failure, the process proceeds to step 104, where a measure corresponding to the content of the failure (lighting of an alarm lamp, EEPROM, , And an instruction to prohibit antilock control is performed.

If the result of the determination in step 103 is that there is no failure, the routine proceeds to step 105, where the wheel speed detector 2
0, input processing from the motor current detector 21 and the brake switch 22 is performed, and then a failure check is performed in step 106. If there is a failure in step 106, the process proceeds to step 104, and if there is no failure, the process proceeds to step 107, where antilock control processing is performed.
It returns to step 105.

FIG. 3 shows a program which is started when the electric control unit 19 is connected to a battery (not shown). The program records the number of times of brake operation, the number of times of initial check, and the number of times of execution of antilock control. When the execution of the program of FIG. 3 is started, first, in step 201, the count value A of the number of times of brake operation, the count value B of the number of times of initial check execution, and the count value C of the number of times of execution of antilock control are returned to zero. At 202, it is determined whether or not each of the brake operation, the initial check execution, and the antilock control execution has occurred, and if so, the count value thereof is incremented by 1 at step 203, and at step 204, the EEP is executed.
After writing to the ROM, the process returns to step 202. In step 202, brake operation, initial check execution,
If it is determined that there is no execution of the antilock control, the process returns to step 202.

FIG. 4 shows a program started by the execution of the initial check, in which the brake operation, the execution of the initial check, and the execution of the antilock control are recorded in time series. When the execution of the program in FIG. 4 starts,
First, in step 301, the record D of the brake operation and the record E of the execution of the antilock control are erased.
In step 2, it is determined whether or not the brake operation and the execution of the anti-lock control have been performed. If so, the data is written to the EEPROM in step 303, and then the ignition switch (I / G) is turned off in step 304. It is determined whether or not it is, and if so, the process is terminated; otherwise, the process returns to step 302 to continue the process. If it is determined in step 302 that neither the brake operation nor the execution of the antilock control is performed, the process proceeds to step 30.
Return to 2.

[0023]

As described above in detail, according to the invention of this application, the electric control unit can obtain the number-of-times information or the time-series information about the brake operation, the execution of the antilock control, and the execution of the initial check. Therefore, when a failure that is not detected by the failure check function occurs, the situation at the time of occurrence of the failure can be grasped, and the cause can be investigated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an antilock control process according to the embodiment of FIG. 1;

FIG. 3 shows the number of brake operations in the embodiment of FIG. 1,
It is a flowchart which shows the process which records the antilock control execution frequency and the initial check execution frequency. You.

FIG. 4 is a flowchart showing a process of recording a brake operation, execution of an anti-lock control, and execution of an initial check in a time series according to the embodiment of FIG. 1;

[Explanation of symbols]

 11 Master cylinder (hydraulic pressure generator) 13 Wheel brake 19 Electric control unit MOD Fluid pressure modulator

Claims (1)

[Claims] 1. A hydraulic pressure modulator interposed in a hydraulic pressure passage for guiding a hydraulic pressure from a hydraulic pressure generating device for generating a hydraulic pressure corresponding to a brake pedal depression force to a wheel brake, and electrically controlled;
An electric control unit that electrically controls the hydraulic modulator based on a slip state of wheels at the time of vehicle braking, wherein the electric control unit writes data to a nonvolatile memory and data written to the nonvolatile memory. An anti-lock brake control device comprising one of a readable monitor tester connection coupler, the electric control unit having a function of writing brake operation, anti-lock control execution, and initial check execution to the nonvolatile memory. An anti-lock brake control device, comprising: