JPH052260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a chassis dynamometer for testing brakes, and particularly to 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 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 cars. It is required to suppress this as much as possible, and for this reason, various brake squeal tests have been carried out in the past.

As one of such brake squeal tests, an actual driving test has conventionally been widely conducted, in which a test vehicle is actually driven on a test course and the brake test 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, brake squeal tests are generally repeated using vehicle running speed and brake depression amount as parameters. For this reason, it takes several hours or even tens of hours from the start to the end of the test.
These problems tend to cause test driver fatigue, are susceptible to the effects of weather, and require scheduling adjustments with other actual driving tests on the test course.

For this reason, there is a known device that performs a brake squeal test indoors using a chassis dynamometer.This device brings both the left and right wheels of the vehicle under test into contact with a pair of rollers on the chassis dynamo, and the brake squeal test is performed on these rollers under actual driving conditions. We are conducting a brake squeal test by simulating this.

FIG. 3 shows an example of a conventional brake testing chassis dynamometer, in which a pair of rollers 1 are provided corresponding to both left and right wheels 20, 20 of a vehicle 10.
2 and 12 are connected to a mechanical flywheel 14 that simulates an amount of inertia equivalent to the weight of the vehicle, and a dynamometer 1 is connected to the roller 12.
6 is connected to evaluate the braking force characteristics of the vehicle during acceleration and deceleration, 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 the vehicle weight 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. I'm going.

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 weight, and the actual braking on the test course will be different. condition,
There was a problem that it could not be accurately reproduced on a palm dynamo.

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

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 prepared, but in this case, the installation space for the mechanical flywheels 14 becomes extremely large. There was a problem in that the overall size of the device became large and effective.

Second point: In such a conventional device, the driver 10 is
0 actually rides on a tower and conducts a long brake squeal test.

Therefore, as in the case of the actual driving test, there was a problem that the driver 100 was likely to become fatigued.

Furthermore, in such conventional devices, driver 1
Since the driver 100 relies on his/her sense of feeling to control the brake pedal pressure, there will be variations in the brake squeal analysis results depending on the skill level of the driver 100.
There was a problem that it was not always possible to perform 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 and performing accurate driving.

[Means for Solving the Problems] Points of Interest When conducting a vehicle brake test, the present inventors investigated three factors: the oil pressure in the brake master cylinder, the vehicle control torque, and the vehicle deceleration pattern. Focusing on the relationship between the It was found that it is fixed.

The present invention focuses on these points and uses the braking torque and deceleration pattern of the brakes during the actual driving test to accurately simulate the actual driving condition,
This system is characterized by being able to perform brake tests, especially brake squeal tests, on a chassis dynamo.

Configuration That is, the present invention provides a chassis dynamometer for performing 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 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. 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; A deceleration pattern generator that generates a deceleration pattern of the vehicle, and the rotational speed of the dynamometer is feedback-controlled in accordance with the deceleration pattern.

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

The device of the present invention first sets the combination of brake braking torque and deceleration pattern required for a brake test, especially a brake squeal test, in a torque setting device and a deceleration pattern generator, respectively, and then starts a brake test on a 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 perform a brake test by accurately simulating the actual running state of the vehicle.

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. For this reason,
Brake squeal tests are conducted repeatedly using braking torque and deceleration pattern as parameters.
By switching and controlling the outputs of the torque setting device and deceleration pattern generator, it becomes possible to perform a long brake squeal test automatically and with high precision without requiring 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.

Configuration FIG. 1 shows a preferred example of the brake testing chassis dynamometer according to the present invention, in which both left and right wheels 20, 20 of a test vehicle 10 are connected to a pair of rollers 12,
12 to simulate the actual running of the test vehicle 10 on the chassis dynamometer.

Brake The left and right wheels 20, 20 are provided with brakes depending on the type of vehicle. For example, if a disc brake 22 is provided as such a brake, when the brake pedal 24 is depressed,
The hydraulic pressure in the master cylinder 26 increases and 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
Dynamometer control device 70 that controls the output of the dynamometer 16
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 brake master cylinder 26 and a torque setting device 44 for setting a desired braking torque.
The hydraulic pressure of the master cylinder 26 is feedback-controlled so that the braking torque of the test vehicle 10 detected by the brake controller 12 matches the torque set by the torque setting device 44.

In the embodiment, the control hydraulic circuit 42 includes a first cylinder 48 that is directly connected to the hydraulic circuit of the master cylinder 26 via a pipe 46, and a first cylinder 48 that is directly connected to the hydraulic circuit of the master cylinder 26 via a pipe 46.
The master cylinder 26 is formed using a second cylinder 50 that is coaxial with the cylinder of the master cylinder 26, and is configured to control the hydraulic pressure of the master cylinder 26 by driving the second cylinder 50 using an actuator 52.

Further, the torque sensor 18 of the embodiment is formed using a load cell that measures the braking torque of the test vehicle 10 as the swinging torque of the dynamometer 16.
The detection output is input to the actuator 52 via the amplifier 54.

The actuator 52 includes a collation device 56 and an amplifier 5.
8, a hydraulic tank 60, a pump 62, and a hydraulic controller 64, and a second
The cylinder 50 is under feedback control.

In this way, the brake control device 4 of the embodiment
According to 0, without the need for a driver,
It becomes possible to feedback-control the oil pressure of the master cylinder 26 so that the braking torque becomes the value set using the torque setting device 44.

In particular, according to the present invention, the brake control device 40 and the master cylinder 26 are connected via the pipe 46, and the brake control device 40 and the brake side hydraulic circuit are completely separated. The master cylinder oil pressure can be controlled from the outside without loading the vehicle, making it easy to prepare for brake squeal tests.

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

Dynamometer control device Furthermore, in the present invention, the dynamometer control device 70
includes a speed sensor that detects the traveling speed of the test vehicle 10, and a deceleration pattern generator 72 that generates a deceleration pattern of the test vehicle 10 during a brake test, and the rotation speed of the dynamometer 16 is determined by the deceleration pattern. It is configured to perform feedback control according to the

In an embodiment, the speed sensor is a dynamometer 1
The detection signal of the rotation speed sensor 74 of 6 is sent to the signal converter 7
6 to convert it into a voltage signal and output it.

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 an ASR (Automatic Speed Regulator) is used.
It 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 the ASR circuit 80 controls the SCR circuit 82 so that the rotation speed of the dynamometer 16 matches the speed signal outputted by the deceleration pattern generator 72, and the speed signal is supplied from the three-phase AC power source 34 to the dynamometer 16. The power is being adjusted accordingly.

In this way, the dynamometer control device 70 of the embodiment
The rotation speed of the dynamometer 16 is feedback-controlled in accordance with the deceleration pattern output from the deceleration pattern generator 72.

Function The present embodiment has the above configuration, and its function 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 oil 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.

Therefore, on the chassis dynamometer, the test vehicle 1
When performing a brake squeal test of 0, test vehicle 1
If hydraulic pressure is applied to the master cylinder 26 so that the braking torque applied to the chassis dynamo from 0 to a predetermined value is controlled so that the rotation speed of the dynamometer 16 is decelerated in the same way as on the actual traveling route, the actual traveling route can be changed. It becomes possible to perform an accurately simulated brake squeal test.

For this reason, the test vehicle 1
0 brake squeal test and measure the braking torque and deceleration pattern at that time, the braking torque is set in the torque setting device 44, the deceleration pattern is set in the deceleration pattern generator 72, and the master cylinder 26 By controlling the hydraulic pressure and the rotation speed of the dynamometer 16, both the left and right wheels 20 of the test vehicle
The same braking torque as on the actual driving road is applied to
It becomes 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, the deceleration pattern generator 72 is set to output the deceleration pattern sequentially according to the time schedule shown in FIG. 2, and the setting device 44 is set to output the braking torque according to the time schedule shown in FIG. By setting the brakes to be output sequentially according to a schedule, it is possible to repeatedly conduct a brake squeal test using braking torque and deceleration pattern as parameters on the chassis dynamometer, accurately simulating actual driving.

Furthermore, 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 actual run is accurately simulated on a chassis dynamometer to perform the brake test. 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 a 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 explanatory diagram showing an example of a conventional brake test chassis dynamo. It is. DESCRIPTION OF SYMBOLS 10... Test vehicle, 12... Roller, 16... Dynamometer, 18... Torque sensor, 20... Wheel, 22... Brake, 26... Master cylinder, 40... Brake control device, 42... Hydraulic circuit for control, 44... Torque setting 70... Dynamometer control device, 72... Deceleration pattern generator, 74... Rotation speed sensor.

Claims (1)

[Claims] 1. A chassis dynamo for performing a brake test on a test vehicle, which includes 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, 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 circuit connected to a brake master cylinder hydraulic circuit. a torque sensor that detects the braking torque of the test vehicle; and a torque setting device that sets a desired braking torque, and feedback controls the hydraulic pressure of the master cylinder so that the output of the torque sensor and the set torque match. The dynamometer control device includes: a speed sensor that detects the running speed of the test vehicle; and a deceleration pattern generator that generates a deceleration pattern of the test vehicle during a brake test, and controls the rotation speed of the dynamometer to A brake testing chassis dynamo characterized by feedback control according to a deceleration pattern. 2. The brake testing chassis dynamo according to claim 1, wherein the torque sensor is formed using a load cell that measures the swinging torque of a dynamometer. 3. The brake test chassis dynamo according to claim 1, wherein the speed sensor is formed using a rotation speed sensor that detects the rotation speed of a dynamometer.