JPH052261B2 - - 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. 2 shows an example of a conventional brake test 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, in such conventional devices, the driver 10 is
0 actually rides on a tower and conducts a long brake squeal test.

For this reason, as in the case of the actual driving test, there was a problem in 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] In order to achieve the above object, the present invention provides a pair of rollers provided corresponding to both left and right wheels of a 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 master cylinder hydraulic circuit of the brake; a hydraulic pressure detection sensor for the control hydraulic circuit; and a hydraulic pressure setting device for setting a desired hydraulic pressure. The dynamometer control device feedback-controls the oil pressure of the master cylinder to a set value based on the output of the oil pressure detection sensor, and the dynamometer control device includes an electric inertia calculation circuit that calculates and outputs an electric inertia load corresponding to the running acceleration of the test vehicle, and a dynamometer. a torque sensor for measuring the swinging torque of the dynamometer, and the torque of the dynamometer is feedback-controlled so that the electrical inertia load and the swinging torque match.

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

The apparatus of the present invention first sets the brake oil pressure required for a brake test, particularly a brake squeal test, in the oil pressure setting device, and starts the brake test on the chassis dynamometer.

In this way, the hydraulic pressure in the master cylinder of the brake is controlled to the set value using the brake control device, and a predetermined braking torque is applied to both the left and right wheels of the test vehicle.

At this time, it is understood that if an inertia equivalent to the vehicle weight can be applied to both the left and right wheels of the test vehicle using a chassis dynamometer, braking torque equal to that on the actual driving road will be applied to both the left and right wheels of the test vehicle. be done.

In order to apply an inertial load equivalent to the vehicle weight to the vehicle under test using a chassis dynamometer, calculate the electric inertial load from the dynamometer by subtracting the fixed inertial load of the chassis dynamometer itself from the inertial load equivalent to the vehicle weight. You can supply it as such.

For this reason, the apparatus of the present invention uses a dynamometer control device to calculate the electric inertia load corresponding to the running acceleration of the test vehicle in real time, and performs feedback control on the output torque of the dynamometer.

By doing so, according to the present invention,
An inertial load equivalent to the weight of the vehicle to be tested can be applied to both left and right wheels on the chassis dyno, making it possible to accurately simulate the actual vehicle driving condition and conduct 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. For this reason,
By switching and controlling the output of the oil pressure setting device so that brake squeal tests are repeatedly performed using the brake master cylinder oil pressure as a parameter, long-term brake squeal tests can be performed automatically without the need for a driver. Moreover, it becomes possible to perform the process with high precision.

[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 master cylinder 26 of the brake, and a hydraulic setting device 44 for setting a desired hydraulic pressure. It is controlled to the desired set value.

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 second cylinder 50 is coaxial with the cylinder of the master cylinder 26, and the oil pressure of the master cylinder 26 is controlled to a desired value by driving the second cylinder 50 using an actuator 52. ing.

In order to detect the oil pressure in the master cylinder 26, an oil pressure sensor 5 is installed in the first cylinder 48.
4 is provided, and its detection output is sent to an amplifier 55.
The signal is input to the actuator 52 via.

The actuator 52 includes a collation device 56 and an amplifier 5.
8. It consists of a hydraulic tank 60, a pump 62, and a hydraulic controller 64, and controls the second cylinder 50 by feedback so that the detected output of the sensor 54 and the set value of the hydraulic setting device 44 match.

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 to a value set using the oil pressure 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 In the present invention, the dynamometer control device 70
is an electric inertia calculation circuit 72 that calculates and outputs an electric inertia load corresponding to the running acceleration α of the test vehicle 10.
and a torque sensor 18 for detecting the swinging torque of the dynamometer 16, and performs feedback control on the output of the dynamometer 16 so that the detected torque matches the calculated electric inertia load.

That is, when the test vehicle 10 is actually traveling, a value Wα obtained by multiplying the vehicle weight W1 and the acceleration α is applied to the vehicle itself as an inertial load.

Therefore, if a brake test is to be performed on the chassis dynamometer, it is necessary to apply a load corresponding to this inertial load W1α to both the left and right wheels 20 of the test vehicle 10 via the chassis dynamometer.

For this purpose, the vehicle weight of the test vehicle 10 itself must be
The value obtained by subtracting the fixed inertia W2 of the chassis dynamometer itself (the fixed inertia of the rotational drive system consisting of the rollers 12, dynamometer 16, etc.) from W1 (W1 - W2), multiplied by the acceleration α of the test vehicle 10, W3α = (W1−W2)
α is defined as an electrical inertia load, and the output torque T of the dynamometer 16 may be controlled to match this electrical inertia load.

In this way, the vehicle under test 10 has a fixed inertia load W2α of the chassis dyno, as shown in the following equation.
and the electric inertial load W3α output from the dynamometer 16 is applied as W2α+W3α=W2α+(W1−W2)α=W1α (1). As a result, test vehicle 1
It is understood that an inertial load equivalent to the weight of the vehicle is applied to 0.

The electrical inertia calculation circuit 72 of the embodiment includes a vehicle weight setter 74 and a fixed inertia setter 76 for calculating the electrical inertia load described above.

Then, from the vehicle weight W1 of the tested vehicle 10 set by the vehicle weight setting device 74, the fixed inertia W2 of the chassis dynamo is set using the fixed inertia setting device 76.
is subtracted using the subtracter 78, and the subtracted value (W1-W2) is input to the multiplier 86.

Further, the calculation circuit 72 of the embodiment includes the test vehicle 1
0 deceleration sensor, this deceleration sensor is
The output of the rotation speed sensor 80 of the dynamometer 16 is converted to the converter 8
2 is converted into a voltage signal, and then this is differentiated using a differentiator 84 to obtain the deceleration α.

Then, the multiplier 86 multiplies the output (W1-W2) of the subtracter 78 and the output α of the differentiator 84,
This value is calculated and output as electrical inertia load α (W1-W2).

Further, the torque sensor 18 of the embodiment has a dynamometer 1
It is formed using a load cell that measures the swing torque of 6, and is configured to output its detection output via an amplifier 88.

Then, the calculation output of the electric inertia calculation circuit 72 and the detected torque of the torque sensor 18 are compared by a collation device 90, and an ATR (automatic torque regulator) is used.
It is input to circuit 92.

The ATR circuit 92 controls the SCR circuit 94 so that the rocking torque of the dynamometer 16 matches the electrical inertia load calculated and output from the electrical inertia calculation circuit 72, and supplies the power from the three-phase AC power source 96 to the dynamometer 16. The power output is being adjusted.

In this way, the dynamometer control device 70 of the embodiment
performs feedback control of the output torque of the dynamometer 16 in accordance with the electrical inertia load output from the electrical inertia calculation circuit 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, if an inertial load equivalent to the vehicle weight of the test vehicle 10 is applied to both the left and right wheels 20 of the test vehicle 10, a simulated running state equivalent to actual running can be reproduced on the rollers 12.

Therefore, the device of the present invention sets the vehicle weight W1 of the tested vehicle 10 in the vehicle weight setting device 74, and sets the fixed inertia W2 of the chassis dynamo itself in the fixed inertia setting device 76.
Set.

In this way, the electrical inertia calculation circuit 72 calculates and outputs the electrical inertia load corresponding to the deceleration α of the test vehicle 10 based on the following equation, α(W1−W2) Oscillation of the dynamometer 16 Feedback control is performed so that the torque is equal to this electrical inertia load.

As a result, the inertial load applied from the chassis dynamometer to both the left and right wheels of the tested vehicle 10 via the roller 12 is the sum of the fixed inertial load W2α of the chassis dynamometer itself and the electric inertial load α (W1-W2), and this value is It is understood that the inertial load is equivalent to the vehicle weight as shown in the following equation.

αW2+α(W1-W2)=αW1 In this way, according to the device of the present invention, by electrically inertia controlling the output of the dynamometer 16, the braking applied to both the left and right wheels 20 of the test vehicle 10 on the actual driving road is applied. It becomes possible to apply a rotational load equal to the load.

Further, the device of the present invention includes a brake control device 40
A desired oil pressure is set in the oil pressure setting device 44 to control the oil pressure of the master cylinder 26. As a result, the same braking torque as on the actual road can be applied to both the left and right wheels 20 of the test vehicle 10, and it becomes possible to accurately perform a so-called brake squeal test.

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). It is also possible to analyze the brake squeal phenomenon by comparing it 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 explained above, according to the present invention, the output of the dynamometer can be electrically inertia controlled, and an inertial load equal to that during actual driving can be applied to the test vehicle, and the actual driving can be performed on the chassis dyno. It becomes possible to accurately simulate and perform brake tests.

Further, according to the present invention, since no mechanical wheels are required, the entire device can be made inexpensive.

Further, according to the present invention, since the brakes of the test vehicle are directly controlled using the brake control device, it is possible to successfully perform a brake test on the test vehicle without requiring a driver.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing a preferred embodiment of a brake test chassis dynamo according to the present invention, and FIG. 2 is an explanatory view showing an example of a conventional brake test chassis dynamo. 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...Hydraulic pressure setting Value, 70... Dynamometer control device, 72... Electric inertia calculation circuit, 74... Vehicle weight setter, 76... Fixed inertia setter, 78... Subtractor, 80... Rotation speed sensor, 84
...Differentiator, 86...Multiplier.

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. and a hydraulic pressure circuit for control, a hydraulic pressure detection sensor, and a hydraulic pressure setting device for setting a desired hydraulic pressure, and feedback-controls the hydraulic pressure of the master cylinder to a set value based on the output of the hydraulic pressure detection sensor, and the dynamometer. The control device includes: an electric inertia calculation circuit that calculates and outputs an electric inertia load corresponding to the running acceleration of the test vehicle; and a torque sensor that measures the swinging load of the dynamometer; A chassis dynamo for brake testing characterized by feedback control of the torque of a dynamometer so that the 2. The device according to claim 1, wherein the electrical inertia calculation circuit includes: a vehicle weight setting device for setting the weight of the vehicle to be tested; a fixed inertia setting device for setting the fixed inertia of the chassis dynamo; a subtracter that subtracts and outputs inertia; and an acceleration sensor that detects the running acceleration of the tested vehicle; the output of the subtracter is multiplied by the detected acceleration to obtain an electrical inertial load corresponding to the running acceleration of the tested vehicle. A chassis dynamo for brake testing that is characterized by calculation output. 3. The brake testing chassis dynamo according to claim 2, wherein the acceleration sensor is configured to differentially output the output of a rotation speed sensor of a dynamometer.