JPH0221235A - Vibration test method and apparatus for vehicle - Google Patents

Abstract

PURPOSE:To detect the damage of the abnormal part of a vehicle beforehand and to perform an automatic test after the cooling time confirming to a temp. rise by emergently stopping vibration when an acceleration detection value is shifted from a predetermined range or when a temp. detection value is out of a predetermined range. CONSTITUTION:Acceleration sensors 31-34 are mounted on respective suspension lower arms 6 and temp. sensors 41-44 are mounted on the outer cylinders 7 of shock absorbers. An apparatus main body 9 starts driving with respect to a vibration stand 9a at a predetermined vibration level corresponding to the detection values of the sensors 31-34 and acceleration is monitored continuously on and after by an acceleration judge means 11 and, when the acceleration value is shifted from a predetermined range, vibration is stopped and an alarm is generated from an abnormality alarm means 14. A temp. change is monitored continuously by a temp. judge means and, when friction heat reaches an upper limit, vibration is stopped and air is sent to perform cooling. When a temp. rise speed judge means 13 detects the abnormality rapid temp. rise of each shock absorber, an alarm is generated from the means 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vibration test method and device for a vehicle, in which a vibration test is performed while the vehicle is placed on a vibration table and air is blown to the wheels. be.

(Prior art) Conventionally, in such a vibration test, a predetermined vibration state is set by detecting acceleration with an acceleration sensor, and then the vibration is repeatedly applied within a time range in which the temperature of the shock absorber does not rise excessively. A limit switch was placed below the bottom of each body near the four wheels to detect abnormal descent.

(Problem to be solved by the invention) As a result, the test was brought to an emergency stop when the limit switch was activated due to damage to the suspension or body, but it was not possible to detect and prevent these abnormalities before they occurred. Ta. There were also problems in terms of test efficiency.

Therefore, the present invention provides a vibration testing method and device for a vehicle that can detect damage to abnormal parts of a vehicle due to the addition of vibration and that can automatically repeat the vibration test after a cooling period corresponding to a temperature rise. The purpose is to provide.

[Means to solve the problem]

In order to achieve this object, the present invention installs an acceleration sensor on the suspension lower arm portion of each wheel, and a temperature sensor on each shock absorber portion. If the temperature exceeds or falls below the predetermined range, the excitation will be brought to an emergency stop, and if the temperature detected by any of the temperature sensors exceeds the predetermined upper limit, the system will continue to blow air until the temperature drops to the predetermined temperature. The vibration is interrupted, and when the rate of increase in the temperature detection value of any one of the temperature sensors exceeds a predetermined upper limit, the vibration is brought to an emergency stop.

A device for carrying out this method is a well-known vehicle vibration testing device in which the vehicle is placed on a vibration table and the vehicle is subjected to vibration at a predetermined level while blowing air to each wheel. , an acceleration sensor and a temperature sensor are respectively attached as described above, and an acceleration determining means (11) for determining whether one of the detected acceleration values is above or below a predetermined range, and one of the temperature temperature determination means (12
), and temperature increase rate determining means (
13), when it is determined that the detected acceleration value is above or below a predetermined range, the excitation is brought to an emergency stop, and when it is determined that the detected temperature value has exceeded the upper limit, the temperature is set to a predetermined value. Vibration on/off control means (excitation on/off control means) which interrupts the vibration in the air blowing state until it is determined that the temperature has decreased, and then stops the vibration in an emergency when it is determined that the rate of increase in the detected temperature value exceeds the upper limit value. 15) and an abnormality notification means (14) that provides notification when both emergency stops are added.

[Effect]

If the detected acceleration value deviates above or below a predetermined range due to an abnormality in the shock absorber or undercarriage, vibration is applied or an emergency stop is performed, allowing the abnormality to be detected before fatal damage occurs.

During the vibration test, the detected temperature value of the shock absorber gradually increases due to frictional heat, and when it reaches a predetermined temperature, the vibration is interrupted until the shock absorber is cooled to a predetermined low temperature to avoid abnormal heating. , then the excitation is resumed. Further, an emergency stop is also performed when an excessive temperature rise rate is detected due to an abnormality in the shock absorber portion.

The vibration testing device includes vibration on/off control means (15
) is the acceleration determining means (11) and the temperature determining means (IZ
) The vibration excitation is interrupted or an emergency stop is performed depending on the result of the judgment, and when an emergency stop is made, an abnormality notification means (14) notifies the user to that effect.

(Embodiment of the Invention) FIGS. 1 and 2 show a vibration testing apparatus for a vehicle according to an embodiment of the present invention.

In FIG. 1, four wheels 2. 24 are placed on a vibration table 9a driven by the vibration test apparatus main body 9. Acceleration sensors 3I to 34 are attached to each suspension lower arm 6, and temperature sensors 4 to 34 are attached to the outer cylinder 7 of the shock absorber. .about.44 are respectively attached (see FIG. 2).

Acceleration determining means 11 follows the acceleration sensors 31 to 34, and generates an emergency stop signal by detecting that any one of the detected acceleration values of each acceleration sensor is above or below a range of, for example, 30G to 25G. Temperature sensors 41-4. is followed by a temperature determining means 12, which detects when the detected temperature value of the front wheels 22, 22 reaches, for example, 55°C, or when the detected temperature value of the rear wheels Z3, z4 reaches, for example, 70°C, and applies vibration. Outputs an interruption signal, and also sets the front and rear wheels to 40 degrees Celsius, for example.
It detects that the current is decreasing and outputs an excitation restart signal.

Reference numeral 13 denotes a temperature increase rate judgment means, which measures the time from the start or resumption of excitation to reach the above-mentioned upper temperature limit, and generates an emergency stop signal if the time is faster than a predetermined time by about 20%. .

Reference numeral 15 denotes an excitation on/off control means for the apparatus main body 9, which emergency stops the excitation drive of the apparatus main body 9 in response to emergency stop signals from the acceleration determining means 11 and the temperature rise rate determining means;
The vibration driving is interrupted according to the judgment result of the temperature judgment means 12.

Reference numeral 14 denotes an abnormality notification means, which reports an abnormality by sound or display in response to the emergency stop signal from the acceleration judgment means 11 and the temperature rise rate judgment means I3.

These data on acceleration and temperature over time and abnormal data are stored in the data recording/output means 16 and output when necessary.

Each of these units 11 to 13 is a personal computer,
It is composed of a microcomputer, etc.

Moreover, each part 11-13.15 can also be comprised by a hard logic circuit.

During the test, acceleration sensors 3° to 34° were used as before.
In response to the detected value, the apparatus main body 9 starts driving the vibration table 9a at a predetermined vibration level. Thereafter, according to the present invention, changes in acceleration are continuously monitored by the acceleration determining means 11, and if the shock absorber loses its damping function due to damage to the oil seal due to frictional heat, or if the wheel is damaged due to damage to the suspension parts. Because the behavior changes, it is detected that the acceleration exceeds or falls below a predetermined acceleration range. If such abnormality symptoms are detected, an emergency stop signal is generated to stop the vibration excitation, and
An alarm is generated from the abnormality notification means 14.

Similarly, temperature changes are continuously monitored by the temperature determining means 12, and the frictional heat generated by the piston and cylinder in the shock absorber portion gradually increases over several tens of minutes, and when it reaches the upper limit, an excitation interruption signal is output. Excitation is interrupted and only air cooling is performed.

When the temperature drops to a predetermined value, a vibration restart signal is output, and the vibration is re-excited while the air continues to be blown.

When the temperature rise rate determining means 13 detects an abnormally rapid temperature rise of the shock absorber, it outputs an excitation emergency stop signal, causes the abnormality notification means 14 to issue an alarm, and brings the test to an emergency stop.

In addition, in the above-mentioned example, the acceleration, temperature range, etc.
It can be automatically corrected according to the ambient temperature, and can also be automatically changed according to the external settings of the car model. It is also conceivable that the temperature rise rate determining means 13 may perform more accurate monitoring by storing a normal temperature rise curve and comparing it with the actually measured temperature rise. The temperature sensor can also be attached to part A in FIG. 2, avoiding the coil spring part.

(Effects of the Invention) As described above, according to the present invention, in contrast to conventional limit switches that detect abnormalities by monitoring acceleration or temperature changes, abnormalities are detected at the symptom stage of abnormality occurrence before fatal damage occurs. can detect defects. This also prevents secondary damage. Furthermore, by continuously monitoring the temperature change of the shock absorber and controlling the excitation on and off, it is possible to conduct an excitation test safely without wasting time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a vehicle vibration testing apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of a wheel portion showing the state in which the sensor is installed. l...Vehicle, 21-24...Wheel, ~34.
...Acceleration sensor, 4. ~44... Temperature sensor 6.
...Suspension lower arm, 7...Shock absorber outer cylinder.

Claims (1)

[Claims] 1) A vehicle vibration test method in which a vehicle is placed on a vibration table and the vehicle is vibrated while blowing air to each wheel, in which an acceleration sensor is attached to a suspension lower arm portion of each wheel. In addition, a temperature sensor is installed on the shock absorber portion of each wheel, and when the detected acceleration value of any of the acceleration sensors exceeds or falls below a predetermined range, the vibration is brought to an emergency stop. When the temperature detection value of any one of the temperature sensors exceeds a predetermined upper limit, the vibration is interrupted in the ventilation state until the temperature drops to a predetermined temperature value, and the temperature detection value of any of the temperature sensors is An excitation test method for a vehicle, characterized in that the excitation is brought to an emergency stop when the rising speed exceeds a predetermined upper limit. 2) In a vehicle vibration test device that places a vehicle on a vibration table and vibrates the vehicle while blowing air to each wheel, an acceleration sensor is attached to the suspension lower arm of each wheel, and a temperature sensor is attached to the shock absorber portion of each of the temperature sensors; Temperature determination means for determining whether any of the detected temperature values exceeds a predetermined upper limit and whether or not the temperature drops to a predetermined temperature after exceeding the upper limit; temperature increase rate determination means for determining whether or not the rate of increase exceeds a predetermined upper limit; and when it is determined that the detected acceleration value exceeds or falls below the range, the vibration is brought to an emergency stop; Furthermore, when it is determined that the temperature detection value has exceeded the upper limit value, the vibration is interrupted in the air blowing state until it is determined that the temperature has decreased to the predetermined temperature value, and the rate of increase in the temperature detection value is further increased. A vehicle for use in a vehicle, characterized in that it comprises: an excitation on/off control means that makes an emergency stop of the excitation when it is determined that the upper limit has been exceeded; and an abnormality notification means that gives an alarm when both of the emergency stops occur. Vibration test equipment.