JPH07167748A - Antilock brake inspection method - Google Patents

Abstract

PURPOSE:To accurately judge whether antilock cancellation function is proper or not by determining whether the maximum deceleration speed of a roller generated within a specific time immediately before the stop point of the roller is within a specific allowable range or not. CONSTITUTION:When inspecting a brake, each wheel of an automobile is mounted on rollers 11 and 12 and then an automobile is driven. Then, when a specific speed is reached, clutches 21 and 22 of the rollers 11 and 12 are turned off to enable the rollers 11 and 12 to be rotated independently and then a brake pedal is stepped in this state. At this time. it is judged whether the maximum deceleration speed of the rollers 11 and 12 generated within a specific time immediately before the stop time of the rollers 11 and 12 is within an allowable range or not. When antilock control is canceled at a higher speed than normally, the deceleration speed of the rollers 11 and 12 increases until the wheel begins to slip, thus accurately judging whether the antilock cancellation function is proper or not based on the maximum deceleration speed generated immediately before stopping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention runs an automobile equipped with an anti-lock brake with wheels on rollers, and when a predetermined speed is reached, the brake is operated to inspect the anti-lock brake. Regarding how to do.

[0002]

2. Description of the Related Art Conventionally, as this type of inspection method, according to Japanese Patent Application Laid-Open No. 4-305134, the braking time taken from the start of the brake operation to the stop of the roller is measured, and from the start of the brake operation. A known method is to measure the maximum deceleration of the roller that occurs within a predetermined set time and compare the measured braking time and maximum deceleration with the reference values set for each to determine the quality of the antilock brake. Has been.

If the antilock brake is normal, the deceleration of the wheels increases to a predetermined value within a set time from the start of the brake operation to start antilock control, and the wheel speed is decelerated at a substantially constant deceleration. Then, the wheels or rollers stop at a predetermined time. On the other hand, if the braking force is insufficient, the deceleration of the roller does not increase to a predetermined value within a predetermined time from the brake operation start time, and if the antilock control does not work, the deceleration greatly increases. Therefore, the quality of the antilock brake can be determined based on the maximum deceleration that has occurred within the set time and the braking time.

By the way, in the anti-lock brake, the anti-lock control is released when the pseudo vehicle speed calculated from the rotational speed of each wheel falls to a predetermined low speed, and the wheel is braked and stopped in the normal brake state. Therefore, at the time of this stop, the elastic energy stored in the inertial system composed of the wheel and the roller is released, and the deceleration of the roller once falls below the zero level. When the anti-lock release function is unsuccessful and the anti-lock control is released at a speed higher than the regular anti-lock release speed, the amount of decrease in deceleration occurring at the time of stop to below the zero level becomes large. Therefore, in the above-mentioned conventional method, the quality of the anti-lock releasing function is also determined based on the amount of decrease.

[0005]

When the antilock control is released at a speed higher than the regular antilock release speed, the wheels may slip on the roller, and in this case, the deceleration of the roller falls below the zero level. The amount of decrease in is not as large as on the left and may be determined to be normal.
The present invention has been made in view of the above points, and an object thereof is to provide an inspection method of an antilock brake capable of accurately determining whether the antilock release function is good or bad.

[0006]

[Means for Solving the Problems] In order to achieve the above object,
According to the present invention, an automobile equipped with an anti-lock brake is run with wheels on rollers, the brake is actuated when a predetermined speed is reached, and the brake is actuated until the roller stops. In the method of inspecting the anti-lock brake based on the deceleration characteristics of the roller between, whether the maximum deceleration of the roller generated within the predetermined time immediately before the stop time of the roller is within the predetermined allowable range. It is characterized by including a step of making a determination.

[0007]

When the antilock control is released at a speed higher than the regular antilock release speed, even if the wheel slips on the roller, the deceleration of the roller increases until the wheel begins to slip. Thus, the quality of the anti-lock releasing function can be accurately determined based on the maximum deceleration of the roller that has occurred within the predetermined time immediately before the stop of the roller.

[0008]

1 shows a brake inspection device, which comprises a pair of left and right rollers 1 ₁ and 1 ₁ for front wheels and a pair of left and right rollers 1 ₂ and 1 ₂ for rear wheels. , a gear box 3 ₁ obtained by connecting respective roller 1 ₁ via a respective clutch 2 ₁ between the rollers 1 _1, 1 ₁ for the front wheels, rollers 1 ₂ for the rear wheels, 1 ₂
A gear box 3 _{2 in} which the rollers 1 ₂ are connected to each other via a clutch 2 ₂ is arranged between the two gear boxes 3 ₁ , 3 ₂
Are connected via a drive shaft 4, and when the vehicle is run by mounting the wheels on the rollers, the front wheels, which are the drive wheels, rotate to rotate the roller 1 ₁ , the clutch 2 ₁ , the gear box 3 _1, and the drive shaft 4. The rear wheels are made to rotate via the gear box 3 ₂ , the clutch 2 ₂ and the roller 1 ₂ .

Each of the rollers 1 ₁ and 1 ₁ is a pair of front and rear split rollers 1a connected through a belt 5 so as to rotate synchronously.
1b, the friction coefficient of the outer peripheral surface of both split rollers 1a, 1b is set to be large, and
The rotational inertia moments of a and 1b are set to be equal to each other and the total rotational moment of inertia is set to be slightly larger than the rotational inertia moment of each wheel. I tried not to slip. Further, connecting the flywheel 6 to the rollers 1 _1, 1 ₂ of the rear split roller 1b, the divided roller 1b
And then interposed a torque meter 7 between the flywheel 6, it detects the rollers 1 _1, 1 ₂ of the deceleration as a torque,
The detection signal of the torque meter 7 is input to the monitor circuit 8 composed of a microcomputer to perform the inspection described later.

The rollers 1 ₁ and 1 ₁ for the front wheels are mounted on the fixed base 9.
Roller 1 ₂ for the rear wheels also 1 ₂ is provided on the moving freely slide board 10 before and after, a telescopic rear of the drive shaft 4 with a spline shaft 4b which is fitted to the sleeve 4a the structure and adapted to adjust the distance between the rollers 1 ₂ for the rear wheels and the roller 1 ₁ for the front wheels in accordance with the wheelbase of the motor vehicle by the movement of the slide board 10.

[0011] In the brake test, each wheel is traveling automobile placed on the rollers 1 _1, 1 _2, upon reaching a predetermined speed, the clutch 2 _1, 2 ₂ of the roller 1 _1, 1 ₂ The rollers are turned off so that the rollers 1 ₁ and 1 ₂ are independently rotated, and the brake pedal is depressed in this state.

FIG. 3 shows the rotational speed V of the wheel when the rear wheel brake having the proportioning control valve (PCV) provided in the hydraulic system is normally antilock-controlled.
, The deceleration ν of the wheel, the brake pressure P, and the torque T detected by the torque meter 7. At the start of operation of the brake, the brake pressure P is a predetermined value P
When it rises to s, the brake pressure is gradually increased by the action of PCV, and when the deceleration ν exceeds a predetermined set value νs, the increase of the brake pressure is stopped, and the pseudo vehicle speed calculated from the rotation speed of each wheel. When the wheel speed V drops below the reference speed Vs determined based on the above, the brake pressure is reduced until the deceleration ν becomes below νs, and when the wheel speed V exceeds Vs, the brake pressure is increased. After that, the above operation is repeated, and when the pseudo vehicle speed finally decreases to the predetermined low speed Vo, the antilock control is released, the wheels are braked in the normal brake state, and the wheels and the rollers are stopped.
While the antilock control is being performed, the wheels have a reference speed V
deceleration is performed at an almost constant deceleration that matches the deceleration characteristics of
No large peak change appears in the torque T. Further, when the roller is stopped, the elastic energy stored in the inertial system including the wheel, the roller, and the flywheel is released, and the deceleration ν and the torque T temporarily fall below the zero level.

The inspection process in the monitor circuit 8 is executed in the procedure shown in FIG. To describe this in detail, the torque detected by the torque meter 7 when a brake start signal is input from a control panel (not shown) is sampled at a unit time interval for a predetermined time, for example, 4 seconds (S1), and then the sampling data is sampled. series in reading (S2), and stores the time when the torque becomes _zero above a predetermined threshold level T as the operation starting time t ₀ of the brake (S3, S4). Then t ₀
At the time when the first set time ts1 (for example, 0.3 seconds) has elapsed from then, the maximum torque read up to that point is stored as the first maximum torque Tmax1 (S5, S
6). Time Then, torque is determined whether it is below zero level (S7), when it becomes less than zero level, which stores this time as the roller stop point t ₁ (S8), has elapsed further ts1 From t ₁ to the second set time ts
The maximum value of the torque read up to a time point two (eg, 0.2 seconds) before is stored as the second maximum torque Tmax2 (S9), and the torque read within the time ts2 is stored. The largest of these is the third maximum torque Tmax
It is stored as 3 (S10).

Next, from the time difference between t ₀ and t ₁ , the braking time t
Is calculated (S11), and it is determined whether the braking time t is within a predetermined allowable range between the lower limit value tL and the upper limit value tH determined according to the deceleration characteristic of the reference speed (S12).
If it is within the allowable range, it is determined to be acceptable, and if it is out of the range, it is determined to be unacceptable and NG data is created (S13). Further, it is determined whether or not Tmax1 is within an allowable range between a predetermined lower limit value TL1 and an upper limit value TH1 (S14). NG data is created (S15), and it is further determined whether Tmax2 is within the allowable range between the predetermined lower limit value TL2 and the upper limit value TH2 (S16). If it is out of the range, NG data is created as a failure (S17), and it is determined whether Tmax3 is equal to or less than a predetermined upper limit value TH3 (S18). (S19), then the pass / fail judgment data is output (S20), and the torque waveform is printed out (S21).

Since TL1 is set to a value corresponding to the deceleration at which the antilock control is started, that is, νs, and TH1 is set to a value corresponding to the maximum deceleration at which the wheels are not locked, the braking force is insufficient. When ts1 has elapsed, the torque does not increase to TL1. When anti-lock control does not work and the brake pressure increases rapidly, the torque exceeds TH1 at ts1 elapsed time, and Tmax1 is equal to TL1 and TH1. And whether the braking time t is tL and tH.
It is possible to determine whether or not the antilock control is normally performed by determining whether or not it is within the allowable range between and.

By the way, when a response delay occurs in the control of the brake pressure due to the inclusion of air in the hydraulic system, the fluctuation range of the torque becomes large, and the torque is determined based on the normal operating condition of the antilock control. It will fall outside the allowable range between TL2 and TH2. In this case, t after ts1
It may be determined whether or not all the torques at each time point before s2 are within the permissible range. However, in the brake in which the PCV is provided in the hydraulic system, the fluctuation of the deceleration is suppressed by the action of the PCV. As described above, only Tmax2 is detected and it is determined whether or not this is within the allowable range.

When the antilock control is released at a speed higher than the normal release speed V ₀ , the deceleration immediately before the wheels stop is increased, and the torque is temporarily increased as shown by the dotted line in FIG. 3 (d). To increase. Therefore, by setting a value corresponding to the torque immediately before the stop when the anti-lock control is canceled TH3 at V _0, when the anti-lock control is released at higher V ₀ the rate Tmax3 is greater than TH3 . In this case, if the wheels do not slip with respect to the rollers, the torque once increases and then drops sharply, and the amount of decrease of the torque generated at the time of stop to below the zero level becomes large. It doesn't become so big, but it is about the same as normal. However, even if the wheel slips, the torque immediately before that becomes large, and thus, by determining whether Tmax3 is TH3 or less, it can be accurately determined whether the antilock releasing function has worked normally.

[0018]

As is apparent from the above description, according to the present invention, it is possible to accurately determine the quality of the antilock releasing function.

[Brief description of drawings]

FIG. 1 is a plan view of an example of an inspection apparatus used for carrying out the method of the present invention.

FIG. 2 is a flowchart showing an example of an execution program of the method of the present invention.

FIG. 3 is a diagram showing respective changes in wheel speed, wheel deceleration, and brake pressure and a torque waveform during brake operation.

[Explanation of symbols]

1 ₁ 1 ₂ Roller 7 Torque meter 8 Monitor circuit

Claims (1)

[Claims] 1. An automobile equipped with an anti-lock brake is run with wheels on rollers, the brake is operated when a predetermined speed is reached, and the roller is stopped from the start of the brake operation. In the method of inspecting the anti-lock brake based on the deceleration characteristics of the roller during the period, whether the maximum deceleration of the roller generated within the predetermined time immediately before the stop time of the roller is within the predetermined allowable range. A method for inspecting an anti-lock brake, which comprises a step of determining