JPH0442033A - Reexamination of brake tester - Google Patents

Abstract

PURPOSE:To make it possible to reexamine only intended items simply and quickly by pushing a foot brake and detecting the fluctuation of braking force when there are disqualified items after the examination of all test items regardless of the success and disqualification. CONSTITUTION:In a brake tester, the slip rate of each driving wheel of load cells 10A... is converted and measured in response t a load. Based on the measured voltage values, a microcomputer 12 sequentially examines the items of tire drag, braking force of a foot brake and parking holding force of a side brake with a judging circuit. After the end of the examination, the brake is pushed and the reexamination operation is started when there is the disqualified measured item based on the success and the disqualification of all items. For each item. the reexamination is performed for the disqualified item and the next item is examined when the item is successful in sequence. Only the disqualified item is examined. Thus, the reexamination can be conducted safely and quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for re-inspecting a brake tester, and in particular, inspects side slip, speed, brake, etc. while sequentially entering and placing a vehicle on an inspection table. The present invention relates to a method for re-inspecting a brake tester used in a comprehensive vehicle automatic test system configured to perform tests sequentially and continuously.

``Prior art'' Conventionally, for example, a wheel base measuring device, a side slip tester, a wheel load measuring device, a brake speed meter tester, a headlight tester, etc. are arranged along the vehicle approach direction on an inspection table, and the vehicle is placed on the inspection table. A vehicle automatic comprehensive test device is known that performs the various tests described above while sequentially moving the vehicle to predetermined inspection positions after entering the vehicle.

A brake tester built into this type of test equipment, for example, places each tire on a pair of brake rollers consisting of a drive roller and an idle roller, drives the brake roller via a motor, and tests the tires and brakes in this state. Using a measuring device such as a load cell that detects the slip rate between the rollers, first, the clutch is placed in an idle state to measure drag (pass/fail judgment), and then the braking force is measured by stepping on the foot brake (pass/fail judgment). ), and finally the parking holding force (pass/fail judgment) by pulling the handbrake.
The system is configured to perform each of the following items, and is configured to use a timer or a push button to proceed through each of the determination items.

“The technical problem that the invention aims to solve” However,
In the method of progressing through the judgment items using the timer, the driver in the test vehicle (those conducting the test) has a strong sense of being chased by the machine, and also because he cannot proceed to the next judgment item until the time is up. Not only does this have the drawback of time loss, but it is also extremely difficult to re-inspect in the event of a failure.

On the other hand, the push-button method is reliable because each time a test item is completed, the driver presses a push button near the vehicle to move on to the next test item, but the driver leans forward and presses the push button on the side of the vehicle. If the button is not pressed, it is impossible to move on to the next test item or perform a re-inspection, which not only forces the driver to make unnecessary movements but also delays the entire test time.

In view of the drawbacks of the prior art, it is an object of the present invention to provide a reexamination method that allows reexamination to be performed quickly and easily without any time loss.

Another object of the present invention is to provide a re-inspection method for a brake tester that allows the re-examination of desired test items to be carried out promptly without being overtaken by machines or without causing time loss. do.

"Technical Means for Solving the Problem" In order to achieve the technical problem, the present invention: ■ Inspects all test items regardless of whether each of the test items of drag, braking force, and parking holding force pass or fail. Process.

■Step of detecting the change in braking force by stepping on the foot brake if there is at least one failed test item after inspecting all the test items mentioned above.■After detecting the change in the previous braking force, proceed to re-inspection operation. This paper proposes a method for re-inspecting a brake tester, which is characterized by a transition process.

"Operation" According to this invention, the re-inspection can be carried out safely and quickly because the re-inspection can be started simply by stepping on the foot brake for braking force test without pressing the push button provided outside the vehicle. I can do it.

In addition, the present invention does not require re-inspection for each test item (instead of re-inspecting each test item, all test items are inspected regardless of whether each test item passes or failed, and then the re-inspection operation is performed, making re-inspection complicated). There's nothing to do.

"Example" The following is an example of the present invention based on the drawings. do not have.

1 to 4 all relate to embodiments of a brake tester incorporated in a vehicle automatic comprehensive test system. First, the overall circuit configuration will be explained based on FIG. 1. IOA...
is the measured voltage value V that corresponds to the load on the slip rate of each drive wheel.
The voltage value Vsi is converted into si and measured by the load cell.
is amplified by the amplifier IIA and sent into the microcomputer 12.

FIG. 2(A) shows a judgment circuit built into the microcomputer 12. First, the pass/fail judgment of the drag measurement is performed by a reference voltage setting circuit 21 that sets the pass/fail judgment standard, the base*voltage VB and the measured voltage value Vsi. a comparator 22 for comparing
AND circuit 24. Consisting of a timer 25 and a control circuit 26, when the measured voltage value Vsi is less than or equal to the reference voltage V9, an inverted signal inverted by the inverter 23 is output to the AND circuit 23, and the signal is output to the AND circuit 24 within a predetermined time set by the timer 25. Accordingly, when inversion signals for all the drive wheels 1 are obtained, a drag pass signal can be output.

Judgment for braking force/parking measurement is made by a reference voltage setting circuit 27 that sets a pass/fail judgment standard similarly to the circuit described above, a comparator 28 that compares the reference voltage with the measured voltage value Vsi, and an AND circuit. 29, and the control circuit 26, the measured voltage value Vsi of all the drive wheels is a reference voltage vf.
In the case of 3 or more or less than 3, the increase/decrease of the braking force is determined based on the signal output from each AND circuit.

As mentioned above, the configuration in which the comparison signals of all the drive wheels are ANDed improves accuracy, but there are many cases where the result is a failure or a re-examination is required.Therefore, as shown in Figure 2 (B), The measured voltage value Vsi for each driving wheel is added by the adder 31 and the added value Vt is added to the reference voltage setting circuit 33.34.
It is preferable to compare the reference voltages vI:lI and vBl, and to determine whether or not the drag measurement is successful or to determine whether the braking force is increased or decreased based on the comparison signal.

Next, the measurement operation will be explained step by step with reference to FIG. 3 which shows the fluctuation state of the slip ratio in each determination item, and the flowchart of FIG. 4 which shows the order of measurement.

First, as shown in FIG. 1, with each tire 1 placed on a pair of brake rollers consisting of a drive roller 2 and an idle roller 3, the brake rollers 2 are driven, and then the clutch is placed in an idle state. Depending on the situation, carry out drag measurements.

In drag measurement, the timer 25 is activated at the same time as the clutch is put into the idle state, and by the time the timer 25 times up, all of the driving wheels 1 or the sum value Vt of the driving wheels 1 have reached the reference voltage (2). r VBr ``T:II'
Drag measurement is repeated in the circuit until it becomes equal to or less than the vB' value (STEPI). Then, after the time-up is reached or the drag pass signal is output, the braking force is measured.

Braking force measurement is performed by stepping on the foot brake to determine whether or not the braking force has increased above the reference voltage vG++'Q' value. Holding force is reference voltage V. , -' value or more, and after the rise, release the foot brake and the holding force becomes the reference voltage vl:
bvl: Determine whether the value has fallen below the l'' value. (S
TEP 3) Then, it is determined whether all of the measurement items have passed or not. 5TEP 4) If there are any measurement items that have failed, step on the foot brake again (STEP 5). Then, the braking force determination circuit determines that the brake pedal has been stepped on, and a retesting operation is performed. (
STEP 6) In this case, if the braking force measurement fails, it is not possible to judge whether the foot brake is rising or falling, so as shown in the judgment circuit, the comparative outputs of each drive wheel are taken, and one of them is determined to be the base voltage. It is also possible to judge whether or not the voltage has risen from v lead I' (or, in the case of a circuit using an adder 31, a special reference voltage c for retesting may be set).

After moving on to the re-testing operation, it is determined whether the drag measurement passes or not, and if it fails, the re-test is performed, and if it passes, the next measurement item, braking force measurement, is performed (STEP 7).
), Furthermore, if the braking force measurement passes, the process moves to parking measurement (5TEP8), and only the measurement items that fail can be inspected. (STEP 9) ``Effects'' As described above, according to the present invention, by simply stepping on the foot brake, only the desired test items can be re-examined easily and quickly. In order to perform a retest operation after completing all parking test items,
Also, there is no time loss.

It has various effects such as

[Brief explanation of drawings]

Figures 1 to 4 all relate to embodiments of a brake tester incorporated into a vehicle automatic comprehensive testing system, with Figure 1 being an overall block diagram, and Figures 2 (A) and 2 (B) being circuit configuration diagrams of main parts. , FIG. 3 is an action diagram showing the fluctuation state of the slip ratio in each judgment item, and FIG. 4 is a flowchart showing the measurement order. Patent applicant: Toyota Motor Corporation Anzen Jidosha Co., Ltd. Figure 2 CB) f

Claims (1)

[Claims] In the re-inspection method of the brake tester, which is configured to be able to sequentially inspect each test item of tire drag, braking force of foot brake, and parking holding force of handbrake, all test items are tested regardless of whether each test item passes or fails. A re-inspection of a brake tester characterized in that if there is at least one failed test item after performing the above-mentioned test, a change in braking force is detected by stepping on a foot brake, and the re-inspection operation is performed. Method