JPH0443805Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Summary] This invention tests the anti-skid control device early after the engine starts, thereby making the test sound of the device inconspicuous and making it possible to determine the test results before driving. It can be so.

[Industrial application field]

The present invention relates to a test circuit for automatically checking the functionality of an anti-skid control system for adjusting brake oil pressure.

[Conventional technology]

The anti-skid control device, which calculates the slip rate from the difference between wheel speed and vehicle speed and adjusts the brake oil pressure, generates a pseudo signal to operate the oil pressure adjustment device as one of its self-diagnosis functions. Check whether it is working properly. There are various timings for conducting this test, but conventionally (1)
When the power supply voltage maintains a normal value (for example, 10V or more) after the ignition (IG) switch is turned on,
Alternatively, a typical example is when the two wheel speeds first reach a certain value.

[Problem that the invention attempts to solve]

However, in method (1), if the startup of the engine (E/G) starter motor is delayed after the IG switch is turned ON (the ignition key has not been turned from the IG position to the START (ST) position), anti-skid control will be performed during that time. Since the test of the device has started, the test sound (operating sound of the solenoid) can be heard, giving the driver a sense of anxiety and discomfort.

In method (2), the test is conducted after the engine has started, so there is no problem with noise, but the test results cannot be visually confirmed unless the vehicle is running, which poses a problem for safe driving.

The present invention attempts to solve the problems of the above methods (1) and (2) by conducting a test at an early stage after starting the E/G.

[Means for solving problems]

FIG. 1 is a basic configuration diagram of the present invention, in which 1 is a battery, 2 is an IG switch, 3 is an anti-skid control device, and 31 is its comparator. The battery 1 supplies current to all loads in the vehicle. A starter motor (not shown) is one of them, and a start switch (a contact that is turned on at the above-mentioned ST position) is interposed between the starter motor and the motor. The battery 1 is not only discharged, but also charged after the E/G is started.
Therefore, the state of the E/G can be determined from the voltage _VB of the battery 1.

[Effect]

FIG. 2 is an explanatory diagram of the operation of the present invention. The battery voltage _VB takes different values depending on the switch ON, starter ON, and E/G starting states. for example
When the IG switch is ON, the voltage is 12V, but during the cranking period (t ₁ ) when the starter is ON, the voltage drops extremely to 8 to 9V. Also, if E/G starts, 14V
rise to a degree. Therefore, this cranking period and the preceding IG switch ON period are, for example, Vth
It can be distinguished by the comparator 31 of =10V. Also,
By determining the direction in which the battery voltage V _B exceeds the reference value Vth, it is possible to distinguish between the IG switch ON state and the state after E/G start. This may be determined in terms of level using another comparator with Vth'=13V or so.

The important point is to start testing the anti-skid control device after the E/G has started and it can be reliably determined. However, since this is not detected from the wheel speed, etc., in this invention, the test is conducted early after the E/G is started, and therefore, generally when the vehicle is stationary, the test sound may be mixed in with the E/G sound and may be distracting. Not only will it not become a problem, but the test results will be determined before the start of driving.

〔Example〕

FIG. 3 is a configuration diagram showing an embodiment of the present invention.
5 is a wheel speed sensor, and 5 is a hydraulic adjustment device. The anti-skid control device 3 includes an anti-skid control circuit 32 which plays a central role in control, as well as a self-diagnosis circuit 33 for testing, a power supply section 34, an output circuit 35, a monitor circuit 36, and the like.

The self-diagnosis circuit 33 is composed of a microcomputer, and checks the following three points from the output of the comparator 31 shown in FIG. (1) IG switch 2 is ON
(2) V _B must once fall below Vth, and _then Vth
(3) that the cranking period t ₁ has elapsed beyond
Thereafter, a period t ₂ in which V _B > Vth continues for several seconds;
It is. Once these three points are confirmed, the test will begin. There are two types of test signals; 1 and 2 are for checking the output circuit 35; This result can be determined from the output of the monitor circuit 36. is for testing the entire anti-skid control circuit 32, and at this time, the hydraulic adjustment device 5
works. This result can also be determined from the output of the monitor circuit 36. The final test result is displayed by sending a signal from the self-diagnosis circuit 33 to an alarm display section (not shown).

[Effect of idea]

As described above, according to the present invention, the test of the anti-skid control device can be automatically performed early after the engine starts, so the test results can be determined while the engine is stopped, and the advantage is that the test sound is not bothersome. There is.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of the present invention, FIG. 2 is an explanatory diagram of the operation of the present invention, and FIG. 3 is a configuration diagram showing an embodiment of the present invention.

Claims (1)

[Scope of utility model registration request] In an automatic test circuit for an anti-skid control device that includes an anti-skid control circuit 32 and its self-diagnosis circuit 33, a comparator 31 with a reference value Vth for detecting battery voltage _VB is provided, and the output of the comparator 31 is sent to the self-diagnosis circuit 33. When it is determined that the engine starts after the cranking period (t ₁ ) has elapsed and a certain period of time (t ₂ ) has elapsed, the control circuit 32 outputs a test signal. An automatic test circuit for an anti-skid control device, characterized in that: