JPS62284238A - Chassis dynamo for brake test - Google Patents

Abstract

PURPOSE:To take a brake noise test on a chassis dynamo by accurately simulating an actual run state by using the braking torque and speed reduction pattern of a brake obtained at the time of a real run test. CONSTITUTION:A brake noise test of a vehicle 10 to be inspected is taken on an actual run road and the braking torque and speed reduction pattern at this time are measured and set in a torque setter 44 and a speed reduction pattern generator 72. Then, the braking torque of the vehicle 10 to be tested which is detected by a torque sensor 18 is inputted to an actuator 52 and the hydraulic pressure of a master cylinder 26 is brought under feedback control so that the detected torque coincides with the set value in the torque setter 44. Further, the detection signal of the rotating speed sensor 74 for a dynamometer 16 is collated with the output of the speed reduction pattern generator 72 by a collator 78 and an ASR circuit 80 adjusts electric power supplied from a three-phase AC power source 84 to the dynamometer 16 so that the detection signal coincides with the speed reduction pattern.

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 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 vehicle's IQ dynamic characteristics, it gives the driver and other passengers a sense of psychological anxiety and discomfort, so it is installed especially on high-performance models. Brakes are required to suppress this noise 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 last is repeatedly performed.

Actual driving tests can directly verify whether brake squeal occurs under actual driving conditions, so extremely useful data can be obtained.

On the other hand, a brake squeal test is generally performed using vehicle speed and brake pedal depression as parameters. For this reason, the test takes several hours or even tens of hours from start to finish, which tends to cause fatigue for the last driver, which is easily affected by weather, and which requires schedule coordination with other actual driving tests on the test course. The problem was that it required

For this reason, there is a known device that uses a chassis dynamo to perform brake squeal tests indoors.
A brake squeal test is conducted by placing both the left and right wheels of the test vehicle in contact with a pair of rollers on a chassis dynamometer, and simulating actual driving conditions on these rollers.

FIG. 3 shows an example of a conventional brake testing system, in which a pair of rollers 12.12 provided corresponding to the left and right wheels 20.20 of the vehicle 10 have an inertia equivalent to the weight of the vehicle. A mechanical flywheel 14 is connected to simulate the amount of the roller 12.
A dynamometer 16 is connected to the dynamometer 16 to evaluate the braking force characteristics of the vehicle when the vehicle is accelerated or decelerated, and particularly to analyze the so-called brake squeal phenomenon that occurs when normal deceleration braking is performed from a running state.

[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 simulates an amount of inertia equivalent to that of a vehicle "m" using a mechanical flywheel 14, and sets the amount of inertia by increasing or decreasing the number of flywheels 14 connected to the rollers 12. It is carried out.

Therefore, since the inertia amount can only be set in stages, it is inevitable that a setting error will occur between the set inertia and the actual vehicle weight, and the actual braking condition on the test course There was a problem in that it could not be accurately reproduced on a chassis dynamo.

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 will be different from when actually driving on the road, and the so-called brake squeal phenomenon can be suppressed by using the chassis dynamometer. There was a problem in that it was not possible to accurately analyze the above.

In addition, even with such a conventional device, it is possible to finely simulate the inertia value by increasing the number of mechanical flywheels 14 prepared, but in this case, the installation space for the mechanical flywheels 14 becomes extremely large. This poses a problem in that the overall device becomes bulky and effective.

Second point: In such conventional devices, the driver 100 actually rides in a test vehicle that is running in a simulated manner on a chassis dynamometer and performs 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 senses of the driver 100 to control the brake pedal depression,
There is a problem in that the brake squeal analysis results vary depending on the skill level of the driver 100, and it is not always possible to conduct a brake squeal test with high accuracy.

[Purpose of the Invention] The present invention has been made in view of such conventional problems, and its purpose is to perform a vehicle brake test, especially a brake squeal test, without requiring a driver, and on the actual road. To provide a chassis dynamo for brake testing capable of accurately simulating driving with high precision.

[Means for Solving the Problems] Point of Interest When conducting a brake test on a vehicle, the inventors of the present invention consider three factors: 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
After examining these relationships, it was found that once the braking torque and deceleration pattern are determined, the remaining oil pressure is automatically determined, and when the oil pressure and deceleration pattern are determined, the remaining braking torque is automatically determined. .

In other words, the present invention uses a pair of rollers provided corresponding to both 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 the master cylinder hydraulic circuit of the brake; a torque sensor that detects the braking torque of the test vehicle; and a torque setting device that sets a desired braking torque. including,
The hydraulic pressure of the master cylinder is feedback-controlled so that the output of the torque sensor matches the set torque, and the dynamometer control device includes a speed sensor that detects the running speed of the test vehicle, and a speed sensor that detects the running speed of the test vehicle during the brake test. A deceleration pattern generator that generates a deceleration pattern, and the rotational speed of the motor 7 is feedback-controlled in accordance with the deceleration pattern.

[Function] The present invention has the above configuration, and its function will be explained next.

First of all, a brake test, especially a brake rake test, was started on the chassis dynamometer.

In this way, the hydraulic pressure corresponding to the braking torque and deceleration pattern is automatically applied to the master cylinder of the brake, and the actual running state of the vehicle can be accurately simulated to 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, if the outputs of the torque setting device and deceleration pattern generator are switched and controlled so that the brake squeal test is repeated using the braking torque and deceleration pattern as parameters, the driver will not be required to perform a long brake sniff test. This can be done automatically and with high precision without having to do so.

[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.

Composition 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 test vehicle 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.

Brakes The left and 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 oil pressure in the master cylinder 26 increases and this is applied to the caliper 3 via the brake pipe 28.
0, and the disc brake 22 is operated.

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 output of the dynamometer 16 in order to perform such a brake 22 test, particularly a brake squeal test. It is characterized by the fact that it has been provided.

12 two earth five! The brake control device 40 includes a control hydraulic circuit 42 directly connected to the hydraulic circuit of the mask cylinder 26 of the brake.
and a torque setting device 44 for setting a desired braking torque.
The hydraulic pressure of the mask cylinder 26 is feedback-controlled so that the braking torque of the test vehicle 10 detected by the torque sensor 18 and the set torque of the torque setting device 44 match.

In the embodiment, the control hydraulic circuit 42 includes a pipe 46
It is formed using a first cylinder 48 that is directly connected to the hydraulic circuit of the master cylinder 26 via a second cylinder 50 that is coaxial with the first cylinder, and a second cylinder 50 that is coaxial with the first cylinder. The hydraulic pressure of the master cylinder 26 is controlled by driving the cylinder 50 of the master cylinder 26 .

Further, the torque sensor 18 of the embodiment is formed using a load cell that uses the braking torque of the test vehicle 10 as power to measure the swinging torque of 116, and inputs its detection output to the actuator 52 via the amplifier 54. are doing.

The actuator 52 includes a verifier 56, an amplifier 58, a hydraulic tank 60, a pump 62, and a hydraulic controller 64, and provides feedback to the second cylinder 50 so that the detected output of the sensor 18 and the set value of the torque setting device 44 match. It's in control.

In this way, -! According to the brake control device 40 on the upstream side, the brake control device 40 and the brake can be connected without the need for a driver. Since the side hydraulic circuit is completely separated, the mask cylinder hydraulic pressure can be controlled from the outside without loading the brake control device 40 into the test vehicle, making it possible to easily prepare for the brake squeal test.

In general, since the brake control device 40 directly controls the hydraulic pressure of the mask cylinder 26 rather than the brake pedal 24, it is possible to control the braking horn of the brake with good responsiveness and extremely high reproducibility.

Furthermore, in the present invention, the dynamometer control device 70 includes a speed sensor that detects the running speed of the test vehicle 10, and a deceleration pattern that generates a deceleration pattern of the test vehicle 10 during a brake test. generator 72, and is configured to feedback-control the rotational speed of the power 3116 according to the deceleration pattern.

In the embodiment, the speed sensor is configured to convert the detection signal of the rotation speed sensor 74 of the dynamometer 16 into a voltage signal using a signal converter 76 and output the voltage signal.

Then, the detection signal of the rotation speed sensor 74 and the output signal of the deceleration pattern generator 72 are collated by a collation device 78, and the AS
R(Automatic 3peedROgUIat
er> is input to the circuit 80.

The ASR circuit 80 controls the SCR circuit 82 so that the rotational speed of the dynamometer 16 matches the speed signal output from the deceleration pattern generator 72, and supplies the power from the three-phase AC power source 34 to the power train 16. Adjustments are being made to the power generated.

This embodiment has the above configuration, and its operation will be explained next.

When the left and right wheels 20 of the test vehicle 10 are brought into contact with the rollers 12 and simulated running is performed 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 16, a simulated running on the rollers 12 that is equivalent to the actual running is performed. condition can be reproduced.

The present inventors investigated the following three factors: 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 was actually run on a test course and a brake test was conducted. After focusing on these relationships and examining their relationship, it was confirmed that once the braking torque and vehicle deceleration pattern are determined, the cylinder oil pressure is automatically determined.

If we control Nagiru Kawaraoka so that the rotation speed of the dynamometer 16 decreases in 5 ways compared to the actual driving route,
If a brake squeal test is performed on the test vehicle 10 on an actual running road and the braking torque and deceleration pattern at that time are measured, the braking torque is set in the torque setting device 44 and the deceleration pattern is set in the deceleration pattern generator 72. Set it to
By controlling the oil pressure of the master cylinder 26 and the rotation speed of the dynamometer 16, the same braking torque as on the actual road is applied to both the left and right wheels 20 of the test vehicle 10, allowing accurate analysis of the brake sniffing phenomenon. becomes possible.

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

According to the present invention, the deceleration pattern generator 72 is set to output the deceleration patterns sequentially according to the time schedule shown in FIG.
By setting the braking torque to be output sequentially according to the time schedule shown in Figure 2, a brake squeal test using the braking torque and deceleration pattern as parameters on the chassis dynamometer can be performed to accurately simulate actual driving. This can be done repeatedly.

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

a3. In the above-mentioned embodiments, the case where a brake squeal test was performed as a brake test was explained as an example, but the present 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 actual run can be accurately simulated on a chassis dynamometer. It becomes possible to perform a brake test.

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

[Brief Description of the Drawings] Fig. 1 is an explanatory diagram showing a preferred embodiment of the chassis dynamo for brake testing according to the present invention; Fig. 12 is an explanatory diagram of a brake squeal test pattern;
The figure is an explanatory view showing an example of a conventional chassis dynamo for brake testing. 10... Test vehicle 12... Roller 16... Dynamometer 1 B... Torque sensor 20... Wheel 22... Brake 2 (i... Master cylinder/10...
Brake control device 42 ... Control hydraulic circuit/1/l ... Torque setting device 70 ... Dynamometer control device 72 ... Deceleration pattern generator 74 ... Rotation speed sensor

Claims (3)

[Claims] (1) On a chassis dynamo that performs a brake test on a test vehicle, which includes 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 brake control device that controls the brake of the brake, and a dynamometer control device that controls the output of the dynamometer, and the brake control device includes: a control hydraulic circuit connected to a brake master cylinder hydraulic circuit; It includes a torque sensor that detects the braking torque of the inspected vehicle, and a torque setting device that sets the desired braking torque,
The hydraulic pressure of the master cylinder is feedback-controlled so that the output of the torque sensor matches the set torque, and the dynamometer control device includes a speed sensor that detects the running speed of the test vehicle, and a speed sensor that detects the running speed of the test vehicle during the brake test. A brake testing chassis dynamo, comprising: a deceleration pattern generator that generates a deceleration pattern, and feedback-controls the rotational speed of a dynamometer according to the deceleration pattern. (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.