JPH11142295A - Unit test device of wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a unit test device of wheels capable of performing evaluation on road noise. SOLUTION: A wheel 10 is supported by a supporting base 12 with sufficient rigidity via a load sensor 14. The supporting base 12 is supported via a supporting spring 16 by a seating 18 provided on a surface plate 20. The supporting spring 16 interrupts the input of the vibration of the surface plate 20 and the seating 18 to the supporting base 12. By this, the output of the load sensor 14 is not affected even if the surface plate 20, etc., have resonance frequencies within a frequency range of 50-500 Hz in regard to road noise. In addition, the mass of the supporting base 12 and the spring constant of the supporting spring 16 are set so that the resonance frequency of the system formed of the supporting base 12 and the supporting spring 16 is not in the frequency range of road noise. by such a constitution, it is possible to measure axle load caused by vibration which occurs at the plane of grounding of a wheel 10 at a satisfactory S/N ratio and to perform accurate evaluation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for testing the characteristics of a wheel by itself, and more particularly to a test apparatus for evaluating road noise generated due to the ground surface of a wheel and unevenness of a road surface.

[0002]

2. Description of the Related Art A surface that contacts the road surface of a wheel (tread surface).
Are formed with irregularities called tread patterns to prevent slippage and improve drainage. Further, various irregularities also exist on the road surface on which the vehicle travels.
With the rolling of the wheel, the wheel vibrates due to the unevenness,
This vibration is transmitted to the vehicle body through the components that make up the axle and the suspension, and enters the vehicle body as sound and enters the vehicle interior. This sound has a frequency of 50-500H called road noise.
z, and since this frequency is in a frequency range in which a human sense is relatively sharp, it becomes noise that can be heard. In particular, when the frequency of the input from the ground point of the wheel matches the resonance frequency of the wheel or suspension components, the sound generated is close to a pure sound, so even if the noise level is not so high, it can be heard by the ear. This may give the passenger an unpleasant sensation.

[0003] In order to evaluate the wheels with respect to the road noise, there is known a method in which a test is performed on a single wheel using an apparatus fixed on a surface plate, not in a state where the vehicle is mounted.

[0004]

However, a support system such as a surface plate on which the test apparatus is installed is generally 200
There is a resonance point in the frequency range of 300 Hz, which is included in the frequency range of the road noise of 50 to 500 Hz, so that there is a problem that the evaluation of the wheel with respect to the road noise cannot be accurately performed.

Japanese Patent Laying-Open No. 54-162303 discloses a device for measuring the response of a wheel to an input in the left-right direction, but does not disclose any technique for suppressing vibration of a system supporting the wheel. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and a wheel unit test apparatus in which a resonance frequency of a system supporting a wheel to be tested does not affect a frequency range to be evaluated. In particular, it is an object to provide an axle input test device.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a wheel unit test apparatus according to the present invention is a test apparatus for performing a wheel unit test on vibration input from a wheel to an axle. An axle that rotatably supports the axle, a load sensor that measures the load applied to the axle, a support that supports the axle, a pedestal that is fixed to be able to be positioned on a surface plate, and the support and the pedestal A support spring interposed therebetween to support the support base; and a drum that is in contact with an outer peripheral portion of the wheel and that is rotationally driven by a drive source.

[0008] Then, the resonance frequency of the vibration system formed by the support spring and the support table is outside the frequency band to be tested, and the vibration of the pedestal and the base plate transmits the signal to the support table. To prevent this, the spring constant of the support spring and the mass of the support base are adjusted. This makes it possible to detect the axle load resulting from the wheel contact surface input in the frequency range of interest with a sufficient S / N.

[0009]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a wheel unit testing apparatus according to the present embodiment. The wheel 10 includes an annular tire having a tread surface that actually contacts the road surface, and a wheel that supports the tire. The wheel is coupled to a wheel hub rotatably supported on the axle via bearings. The axle is a support 12 with high mass and high rigidity.
And is supported via a load sensor 14. The load sensor 14 includes a piezoelectric load converter and outputs an electric signal proportional to the load to the axle. The support base 12 is supported by a base 18 via a support spring 16 which is a coil spring.

The pedestal 18 is a base 2 fixed on a surface plate.
2, a Y-direction slider 24 slidable on the base 22 in the left-right direction (hereinafter, referred to as Y direction), and a Y-direction slider 2 slidable in the up-down direction (hereinafter, referred to as Z direction).
4 has a pedestal head 26 disposed thereon. The support spring 16 described above is fixed to the pedestal head 26. A direction orthogonal to the Y direction and the Z direction is defined as an X direction, and positive and negative directions are determined as shown in the figure, and a three-dimensional coordinate system is set.

The Y-direction slider 24 is provided with a Y-direction adjusting screw 2.
8, the position in the Y direction can be adjusted. By adjusting the Y-direction position, the pedestal head 26, the support table 12, and the wheels mounted on the Y-direction slider 24 are positioned in the Y direction. The pedestal head 26 is movable along a guide 30 extending in the Z direction, and the amount of movement is controlled by a hydraulic actuator 32. The pedestal head 26 is moved by the hydraulic actuator 32 to the Y-direction slider 2.
When it is moved to a desired position with respect to 4, it is fixed at that position by the fixed shaft 34.

The wheel 10 is in contact with a cylindrical drum 36 simulating a road surface, and the drum 36 can be driven to rotate in both forward and reverse directions around its cylindrical axis by an electric motor (not shown). The relative position between the wheel 10 and the drum 36 is adjusted by moving the slider 24 in the Y direction and by moving the pedestal head 26 in the Z direction. The movement of the pedestal head 26 applies a load corresponding to the vertical load when the wheel 10 is mounted on the vehicle. Further, a counter mass 38 corresponding to the mass of the wheel 10 and a counter spring 40 are provided at an end of the support base 12 opposite to the side where the wheel 10 is mounted. By adjusting the position of the lower end of the counter spring 40, the support base 12 can be kept horizontal.

The support spring 16 includes a platen 20 and a pedestal 18.
Has a sufficiently low spring constant so as not to transmit the vibration to the support table 12. In addition, the counter mass 38 and the wheel 1
0, the resonance frequency of the vibration system formed by the support base 16 and the support spring 16 is set to a frequency band 50 of the road noise.
The masses of the support spring 16 and the support base 12 are set so as not to be set to 500 Hz.

FIG. 2 shows the load sensor 14 when the wheels are not mounted.
The figure shows the measurement results of the load transmissibility of the load detected by the load sensor 14 with respect to the vibrating force when is applied in the Z direction. From this result, it can be seen that the peak generated by the elastic resonance of the present device occurs at 500 Hz or more, and a good S / N axle load can be measured in the range of 50 to 500 Hz, which is the frequency range of road noise. Recognize.

The test is performed as follows. The vertical load corresponding to mounting on the actual vehicle is adjusted by moving the pedestal head 26 in the Z direction. At this time, the mass of the counter mass 38 is changed according to the mass of the wheel 10 to be mounted. Also,
The counter spring 40 is adjusted so that the support base 12 is kept horizontal. Next, it is assumed that the surface of the drum 36 simulates a road surface where traveling is assumed. The drum 36 is rotated by the electric motor, the axle load is measured based on the output of the load sensor 14 at this time, and the wheels 10 are evaluated.

FIG. 3 shows a result obtained by assuming a case where the wheel gets over the protrusion and mounting the protrusion on the surface of the drum 36 and measuring. Axle loads are detected separately in the X, Y, and Z directions, and their frequency is analyzed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a wheel unit test apparatus of the present embodiment.

FIG. 2 is a diagram showing a result of studying the rigidity of the device of the present embodiment.

FIG. 3 is a diagram showing a measurement result by the apparatus of the present embodiment.

[Explanation of symbols]

10 wheels, 12 support base, 14 load sensor, 16
Support spring, 18 pedestals, 20 stool, 36 drums.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Nakagawa 41-Cho, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. No. 41, Yokomichi, Toyota Central Research Laboratory Co., Ltd. (72) Inventor Yasuaki Tsurumi, 41, Nagakute-cho, Aichi-gun, Aichi Prefecture 1 Toyota Town, Toyota City Inside Toyota Motor Corporation

Claims (1)

[Claims] 1. A wheel unit test apparatus for performing a wheel unit test on a vibration input from a wheel to an axle, comprising: an axle for rotatably supporting the wheel; and a load sensor for measuring a load applied to the axle. A support pedestal supporting the axle; a pedestal fixed to be positionable on a surface plate; a support spring interposed between the support pedestal and the pedestal to support the support pedestal; and an outer peripheral portion of the wheel And a drum that is rotationally driven by a drive source, and a pedestal such that a resonance frequency of a vibration system formed by the support spring and the support table exists outside a frequency band to be tested. A wheel unit test apparatus, wherein a spring constant of the support spring and a mass of the support table are adjusted so as to prevent transmission of vibration of the surface plate to the support table.