JPS62284239A - Chassis dynamo for for brake test - Google Patents

Abstract

PURPOSE:To take a brake squeak test on a chassis dynamo by accurately simulating an actual run state by using the braking torque and speed reduction pattern of a brake which are obtained at the time of an actual run test. CONSTITUTION:The brake squeak test of a vehicle 10 to be tested is taken on an actual run road to measure the speed reduction pattern and braking torque at the time, and they are set in a speed reduction pattern generator 44 and a torque setter 72. Then, the detection signal of the rotating speed sensor 66 for as dynamometer 16 which detects the running speed of the vehicle 10 to be tested is inputted to an actuator 52 during the test and the hydraulic pressure of a master cylinder 26 is controlled so that the detection signal coincides with the output of the speed reduction pattern generator 44. further, the braking torque of the vehicle to be tested which is detected by a torque sensor 18 and the set torque in the torque 72 are collated by a collator 78 which each other and an ART circuit 78 controls electric power supplied from a three-phase AC power source 82 to the dynamometer 16 so that the detected torque coincides with the set torque.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to the improvement of a chassis dynamometer for testing brakes, particularly a chassis dynamometer for testing brake squeal.

[Prior Art] As vehicle performance improves, vehicle brakes are also required to have higher performance, and in particular, it is required to effectively suppress brake squeal that occurs during vehicle braking.

Although this type of brake squeal does not have any effect on the braking characteristics of the vehicle, it causes psychological anxiety and discomfort to the driver and those around them, so it is especially important for brakes installed on high-performance models. It is required to suppress this as much as possible, and for this reason, various brake squeal tests have been conducted in the past.

As one of such brake squeal tests, actual driving tests have been widely conducted in the past, in which a test vehicle is actually driven on a test course and brake tests are repeatedly performed.

Actual driving tests can directly verify whether or not brake squeal occurs under actual driving conditions, so extremely useful data can be obtained.

On the other hand, brake squeal tests are generally conducted repeatedly using vehicle running speed 1u- and brake pedal depression as parameters. It takes time, tends to cause driver fatigue, is susceptible to the effects of weather, and has the following problems: It requires schedule adjustment with other actual driving tests on the test course. Was.

For this reason, we have traditionally used a chassis dynamo for play-1.
There is also a known device that performs a brake squeal test indoors.This device brings both the left and right wheels of the vehicle under test into contact with a pair of rollers on the chassis dynamometer, and detects brake squeal on these rollers (simulating actual driving conditions). Tests are being conducted.

Figure W33 shows an example of a conventional brake test chassis dive, in which both left and right wheels 2 (1, 2
A pair of rollers 12.12 provided corresponding to 0,
A mechanical flywheel 14 is connected to simulate an amount of inertia equivalent to the weight of the vehicle, and a dynamometer 16 is connected to the roller 12 to evaluate the braking force characteristics of the vehicle during acceleration and deceleration of the vehicle, especially in driving conditions. We are currently analyzing the so-called brake sniffing phenomenon that occurs during normal deceleration braking.

[Problems to be Solved by the Invention] However, such conventional devices have various problems described below, and effective countermeasures have been desired.

First, such a conventional device uses a mechanical flywheel 14 to simulate the amount of inertia equivalent to the weight of the vehicle, and increases or decreases the amount of inertia by increasing or decreasing the number of flywheels 14 connected to the rollers 12. I am setting the number +1.

Therefore, since the inertia amount can only be set in stages, it is inevitable that a setting error will occur between the set inertia amount and the actual vehicle t11. There was a problem in that it was not possible to accurately reproduce the braking condition of the engine on the engine.

As a result, with such conventional devices, even if the vehicle generates the same braking force as when the vehicle is actually driving, the deceleration friction will be different from that when the vehicle is actually driving on the road, and the so-called brake squeal phenomenon can be suppressed from the chassis. There was a problem in that it was not possible to accurately analyze dynamo soil.

In addition, even with such a conventional device, it is possible to finely simulate the amount of inertia by increasing the number of mechanical flywheels 14 to be prepared. There is a problem in that the installation space becomes extremely large, and the entire device becomes bulky and effective.

Second, in such a conventional device, the driver 100 actually rides in a test vehicle running a simulated chassis dyno Morhi and conducts a brake squeal test for a long period of time.

Therefore, as in the case of the actual driving test, the driver 10
There was a problem in that it easily caused fatigue.

Furthermore, since such conventional devices rely on the driver's 100's senses to control the brake pedal pressure, variations occur in the brake squeal analysis results depending on the skill level of the driver 100. There was a problem that the sniff test was not convex.

[Object of the Invention] The present invention was made in view of the above-mentioned conventional problems, and its purpose is to perform vehicle brake tests: 1) (brake squeal test) without the need of a driver; To provide a chassis dynamo for brake testing capable of accurately simulating actual road running with high precision.

[Means for Solving Problem 1] 5" + 1 point When the present inventors perform a brake test on a vehicle (S, the oil pressure in the master cylinder of the brake, the braking torque of the vehicle, and the deceleration pattern of the vehicle) Focusing on the relationship between these three elements, we examined these relationships and found that once the braking torque and deceleration pattern are determined, the remaining oil pressure is automatically determined, and once the oil pressure and deceleration pattern are determined, the remaining braking torque was found to be determined automatically.

In addition to accurately simulating actual driving conditions, the present invention has a pair of rollers provided corresponding to the left and right wheels of the test vehicle, and a dynamometer connected to each of these rollers. A chassis dynamo that performs a brake test on a test vehicle includes: a brake control device that controls the brakes of the test vehicle; and a dynamometer control device that controls the output of the dynamometer.

The brake control device includes a control hydraulic circuit connected to a brake master cylinder hydraulic circuit, a speed sensor that detects the running speed of the test vehicle, and a deceleration pattern that generates a deceleration pattern of the test vehicle during a brake test. a generator, which feedback controls the hydraulic pressure of the master cylinder so that the traveling speed of the test vehicle matches the deceleration pattern, and the dynamometer control device includes a torque sensor that detects the braking torque of the test vehicle;゛Includes a torque setting device for setting a desired braking torque,
The present invention is characterized in that the output of the dynamometer is feedback-controlled so that the output of the torque sensor and the set torque match.

[For f+] The present invention has the above configuration, and its operation will be explained next.

Start the rake test on the chassis dynamometer.

In this way, hydraulic pressure corresponding to the braking torque and deceleration pattern is automatically applied to the master cylinder of the brake, making it possible to accurately simulate the actual running state of the vehicle and perform a brake test.

In particular, the device of the present invention uses a brake controller to control brake master cylinder oil pressure without the need for a driver. Therefore, in order to repeat the brake squeal test using the braking torque and deceleration pattern as parameters, it is possible to cut off the output of the I/luke setting device and the deceleration pattern generator for a long time. This makes it possible to perform a brake squeal test automatically and accurately without the need for a driver.

[Example] Next, a preferred example of the present invention will be described based on the drawings. Note that the same reference numerals are given to the members corresponding to those of the conventional device, and the explanation thereof will be omitted.

Structure FIG. 1 shows a preferred example of the chassis dynamo for brake testing according to the present invention, in which both the left and right wheels 20.20 of the vehicle to be tested 10 are brought into contact with a pair of rollers 12.12, and the chassis dynamometer is The actual driving of the test vehicle 10 is simulated.

Before brake Re h Both right wheels 20.20 are provided with brakes depending on the type of vehicle. For example, when a disc brake 22 is provided as such a brake,
When the brake pedal 24 is stepped on, the hydraulic pressure in the master cylinder 26 increases, which is transmitted to the caliper 30 via the brake pipe 28, thereby operating the disc brake 22.

In order to perform such a brake 22 test, particularly a brake squeal test, the present invention provides a brake control device 40 that controls the brakes of the test vehicle 10, and a dynamometer control device 70 that controls the power a-+1e output. It is characterized by having the following.

Brake control device The brake control device 40 includes a control hydraulic circuit 42 directly connected to the hydraulic circuit of the master cylinder 26 of the brake.
and a deceleration pattern generator 44 that generates a deceleration pattern of the test vehicle to be applied during a brake test, and a master generator 44 that generates a deceleration pattern of the test vehicle that is applied during a brake test so that the running speed of the test vehicle 10 detected by a speed sensor (to be described later) matches the deceleration pattern. The hydraulic pressure of the cylinder 26 is feedback-controlled.

Real/I [I! In the example, the control hydraulic circuit 42 uses a first cylinder 48 directly connected to the hydraulic circuit of the master cylinder 26 via a pipe 46, and a second cylinder 50 coaxial with the first cylinder. The hydraulic pressure of the master cylinder 26 is controlled by driving the second cylinder 50 using the actuator 52 .

Further, in this embodiment, the speed sensor is a dynamometer 1.
The detection signal of the rotation speed sensor 66 of No. 6 is converted into a voltage signal using a signal converter 68, and the signal is outputted to the actuator 52.

The actuator 52 includes a verifier 56, an amplifier 58, a hydraulic tank 60. Consisting of a pump 62 and a hydraulic controller 64, the detection output of the sensor 18 and the deceleration pattern generator 44
The second cylinder 50 is feedback-controlled so that the output of the second cylinder 50 matches the output of the second cylinder 50.

In this way, the brake control device 1<+ (
According to the present invention, the brake control device 40 and the register cylinder 26 are connected via the pipe 46 (), and the brake control device 40 and the brake-side hydraulic circuit are completely separated, so that the brake control device 40 is connected to the test vehicle. The master cylinder oil pressure can be controlled from the outside without having to load the brakes, making it easy to prepare for brake squeal tests.

Furthermore, since the brake control device 40 directly controls the oil Fj- of the master cylinder 26 instead of the brake pedal 24, the braking force of the brake is controlled so that the response tl Ju <
t can be controlled with extremely high reproducibility.

Further, in the present invention, the dynamometer control device 70 includes a torque setting device 72 for setting a desired braking torque, and a torque setting device 18 for detecting the braking torque of the test vehicle 10. The rotational speed of the dynamometer 16 is controlled by a feed balance so that the braking torque of the tested vehicle detected by the torque sensor Fj18 and the torque setting device 72 (') +f2 constant torque match. 'In the embodiment, the torque sensor 18 detects the braking torque of the test vehicle 10 using a dynamometer 1.
It is formed using a load cell that measures the swing torque of 6, and outputs its detection output via an amplifier 74.

Then, the detection signal of the torque sensor 18 and the set torque of the torque setting device 72 are verified by a verification device 76, and the ATR
(Automatic Torque Regu-
Iter) circuit 78.

Then, the ATR circuit 78 controls the SCR circuit 80 so that the detected torque of the torque sensor 18 and the set torque of the torque setting device 72 match, and
Direction is supplied from to the dynamometer 16? t< )J is being adjusted.

In this way, it becomes possible to control the test vehicle one step at a time without requiring a driver based on the dynamometer control on the downstream side.

j1 Kawamoto The embodiment has the above configuration, and its operation will be explained next.

When both the left and right wheels 20 of the test vehicle 10 are brought into contact with the rollers 12 and the vehicle is run in a simulated manner on the rollers 12, each rotating roller 12 functions as an endless flat road instead of an actual road surface.

At this time, by applying a rotational load equal to the load applied to both the left and right wheels 20 of the test vehicle 10 on the actual running route through the rollers 12 using the dynamometer 10, a simulated run equivalent to the actual running is performed on the rollers 12. It is possible to reproduce the ti state.

The present inventors have determined the hydraulic pressure of the brake master cylinder, the deceleration pattern of the test vehicle 10, and the braking torque when the test vehicle 10 is actually run on a test course and a brake test is performed. After looking at the factors and examining their relationships, it was confirmed that once the braking torque and vehicle deceleration pattern are determined, the cylinder oil pressure is automatically determined.

Therefore, when carrying out a brake squeal test on the test vehicle 10 on the chassis inamo, a brake squeal test is conducted on the test vehicle 10 on the actual running road, and the deceleration pattern at that time is compared. Once the braking torque has been measured, the deceleration pattern is set in the deceleration pattern generator 44, the braking torque is set in the torque setting device 72, and the oil pressure of the master cylinder 26 and the rotation of the dynamometer 16 are measured. By controlling the number, both left and right wheels 2 of the test vehicle 10
0, the same braking torque as on the actual road is applied, making it possible to accurately analyze the so-called brake squeal phenomenon.

FIG. 2 shows measurement data obtained when a brake squeal test was repeatedly conducted on an actual driving road using braking torque and deceleration pattern as parameters.

According to the present invention, before the deceleration pattern generator 44:
By setting the deceleration pattern to be outputted sequentially according to the time schedule shown in FIG. 2, and setting the setting device 72 so that the braking torque is outputted sequentially according to the time schedule shown in FIG. The above brake squeal test using braking torque and deceleration pattern as parameters can be repeated by accurately simulating actual driving.

In addition, in order to control the braking force of the brake, the device of the present invention can collect measurement data from a brake test conducted using a chassis dynamo and measurement data from a so-called brake unit test (a test conducted without the brake mounted on the vehicle). It is also possible to analyze the brake squeal phenomenon by comparing the results with the above.

In addition, although the said Example demonstrated the case where the brake squeal test was performed as an example of a brake test, this invention is not limited to this and can also be used for other brake tests.

[Effects of the Invention] As described above, according to the present invention, it is possible to perform a brake test on a test vehicle, particularly a brake squeal test, without requiring a driver.

In particular, according to the present invention, if the braking torque and deceleration pattern when a test vehicle is actually run and a brake test is performed, the brake test is performed by accurately simulating the actual run on a chassis dynamometer. It becomes possible to do this.

Further, according to the present invention, since a mechanical flywheel is not required, the entire device can be made small and inexpensive.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a preferred embodiment of the brake test chassis dynamo according to the present invention, Fig. 2 is an explanatory diagram of a brake squeal test pattern, and Fig. 3 is an example of a conventional brake test chassis dynamo. It is an explanatory diagram. 10 ... Test vehicle 12 ... Roller 16 ... Dynamometer 18 ... Torque sensor 20 ... Wheel 22 ... Brake 26 ... Master cylinder 40 ... Brake control device 42 ... - Control hydraulic circuit 44 ... Deceleration pattern generator 66 ... Rotation speed sensor 70 ... Dynamometer control device 72 ... Torque setting device

Claims (1)

[Scope of Claims] A chassis dynamometer that performs a brake test on a test vehicle, including a pair of rollers provided corresponding to both left and right wheels of the test vehicle, and a dynamometer connected to each of these rollers, respectively. , a brake control device that controls the brakes of the test vehicle, and a dynamometer control device that controls the output of the dynamometer, and the brake control device includes: a control hydraulic pressure connected to a brake master cylinder hydraulic circuit; a circuit; a speed sensor that detects the running speed of the tested vehicle; and a deceleration pattern generator that generates a deceleration pattern of the tested vehicle during a brake test, the driving speed of the tested vehicle matching the deceleration pattern. the dynamometer control device includes: a torque sensor that detects the braking torque of the test vehicle; and a torque setting device that sets a desired braking torque;
A chassis dynamo for brake testing, characterized in that the output of the dynamometer is feedback-controlled so that the output of the torque sensor matches the set torque. (2) A chassis dynamo for brake testing in the apparatus according to claim (1), wherein the torque sensor is formed using a load cell that measures the swinging torque of a dynamometer. (3) The device according to any one of claims (1) and (2), characterized in that the speed sensor is formed using a rotation speed sensor that detects the rotation speed of a dynamometer. Chassis dynamo for brake testing.