JPH05203530A - Tire-uniformity measuring method - Google Patents

Abstract

PURPOSE:To measure the uniformity of a tire simply and accurately by providing a displacement detecting sensor on the passive surface directly beneath a vehicle body, and detecting the vertical displacement of the vehicle body through the sensor. CONSTITUTION:A displacement detecting sensor 7 is provided on a floor surface 1 located on the axial line of the tread of a wheel 6 directly beneath a vehicle 5. The sensor 7 is connected to an amplifier 8. The amplifier 8 is connected to a display device 9. A motor 4 is driven, and a roller 3 is rotated at a very low speed. The wheel 6 is made to follow and rotated. At this time, the weight balance of a tire is not affected by the rotation of the wheel at this rotating speed of the roller 3. The low speed is set in such a way that intrinsic vibration does not occur in the suspension of the vehicle 5. When the wheel 6 is rotated, the body of the vehicle 5 is vertically moved by the eccentricity including the amount of the attaching eccentricity and the uniformity of the wheel 6. The displacement is detected with the sensor 7 and converted into the specified electric quantity. The result is inputted into the amplifier 8. The displacement is stabilized by this measurement, and the tire uniformity can be detected readily and accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire uniformity measuring method capable of easily and accurately measuring tire uniformity.

[0002]

2. Description of the Related Art Since tire uniformity is related to riding comfort and safety during high speed running of an automobile, its measurement is essential. Conventionally, this type of measuring method includes a so-called off-the-car method, in which the tire is removed from the vehicle for measurement, and a so-called on-the-car method, in which the tire is attached to the vehicle for measurement.

Among these, as an on-the-car type, for example, in Japanese Patent Laid-Open No. 59-217129, a vehicle body is jacked up so that a wheel is lightly placed on a roller, and the wheel is rotated through the roller so that the weight of the tire is reduced. Balance measurement, then attach a predetermined balance weight to the unbalance position, correct the above unbalance, and then lower the jack,
A method of rotating a wheel through rollers to measure tire uniformity is shown.

[0004]

However, this measuring method requires an operation of raising and lowering the vehicle body at the time of measurement, which complicates the work and also detects the vertical displacement of the tire, thereby making the tire uniform. Since there is an irregular and unstable operation of the tire, the displacement of the tire becomes unstable, and it is difficult to detect the displacement, and there is a problem that an accurate measurement result cannot be obtained. .

An object of the present invention is to solve the above problems and to provide a tire uniformity measuring method capable of easily and accurately measuring the tire uniformity.

[0006]

Therefore, in the tire uniformity measuring method of the present invention, the wheels of the vehicle to be inspected mounted on the rollers are rotated at a low speed, and the vertical displacement on the vehicle side is detected by a sensor. In a tire uniformity measuring method for measuring tire uniformity, a displacement detection sensor is installed on an immovable surface immediately below the vehicle body, and the vertical displacement of the vehicle body is detected through the sensor, so that the tire uniformity can be easily and accurately measured. It is characterized by being able to measure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. In FIG. A roller 3 is rotatably housed in the pit 2.

The roller 3 is linked to a motor 4, and a predetermined wheel 6 of the vehicle 5 to be inspected, in the embodiment, a front wheel which seriously affects the steering wheel operation during traveling is placed on the upper surface of the roller 3.

Directly below the vehicle 5 to be inspected, on the floor surface 1 located on the axis of the tread of the wheel 6, a non-contact type displacement detection sensor 7 utilizing, for example, ultrasonic waves or a laser is installed. The distance between the vehicle body and the lower surface of the vehicle body 5 to be inspected can be continuously measured.

The displacement detection sensor 7 converts the distance into a predetermined amount of electricity and inputs it to an amplifier 8, and inputs the signal amplified by the amplifier 8 to a display device 9 such as an oscilloscope or a recorder, and the device The vibration waveform 10 can be displayed at 9.

An appropriate mark (not shown) is provided at an arbitrary position on the side surface of the wheel 6, and a position detector (not shown) capable of detecting the position of the mark near the wheel 6 is provided.
Is provided, the signal is input to the amplifier 8, and the display device 9
It is desirable to display the position of the wheel 6 for each rotation.

In addition, reference numerals 11 and 12 in the drawing denote pulleys provided on the roller 3 and the motor 4, around which a belt 13 is wound, and 14 is a tread plate installed at the opening of the pit 2.

FIG. 2 shows another embodiment of the present invention, in which the same reference numerals are used for the components corresponding to those of the above-mentioned embodiment. In this embodiment, instead of the non-contact type displacement detection sensor 7, a contact type displacement detection sensor 7 is adopted, and as the sensor 7, a known torque bridge having a coil and a sliding contact is used. The upper and lower ends are at a predetermined position of the vehicle body and the floor surface 1.
It is characterized in that it is pivotally attached to and to detect the vertical displacement of the vehicle body. As the contact type displacement detection sensor 7, a linear sliding type potentiometer, a differential transformer, a spring scale, or the like can be used in addition to the above.

Although the motor 4 is driven as the rotating means of the wheel 6 in the above embodiment, the vehicle 5 to be inspected may be directly driven and rotated.

[0015]

In the tire uniformity measuring method thus constructed, the vehicle 5 to be inspected is put into a test site of an automobile production plant, moved to the test equipment side, and the test wheels 6 are placed on the rollers 3.

Next, a displacement detection sensor 7 is installed on the floor surface 1 located on the axis of the tread of the wheel 6 just below the vehicle 5 to be inspected, the sensor 7 is connected to the amplifier 8, and the amplifier 8 is used as a display device. Connect to 9. In this case, when the non-contact type displacement detection sensor 7 is used, there is no trouble of fixing the sensor 7 to the floor surface 1 and the vehicle body, so that the preparatory work can be easily performed.

When a series of preparatory work is completed, the motor 4 is driven to rotate the roller 3 at an extremely low speed so that the wheels 6 follow the rotation. In this case, the rotation speed of the roller 3 is set to such a low speed that the weight balance of the tire is not affected by the rotation of the wheels 6 and the suspension of the vehicle 5 to be inspected does not perform its own amplitude operation.

Thus, when the wheel 6 rotates, the vehicle body of the vehicle 5 to be inspected moves up and down due to the eccentricity and the uniformity including the mounting eccentricity of the wheel 6, and its displacement is detected by the displacement detection sensor 7, which is a predetermined value. It is converted into an electric quantity and input to the amplifier 8.

As described above, according to the present invention, the displacement is stable because the measurement is performed through the displacement of the vehicle body as compared with the conventional measuring method for detecting the displacement of the wheel 6 which operates irregularly and unstablely. In addition, this can be detected easily and accurately as compared with the one under rotation.

The above signal is amplified by the amplifier 8 to a predetermined amount,
This is input to the display device 9, and the vibration waveform 1 is applied to the device 9.
0 is displayed. The vibration waveform 10 is represented as a composite waveform in which the eccentricity including the mounting eccentricity of the wheel 6 and the influence of tire uniformity are combined. Therefore, by analyzing this waveform, the tire uniformity waveform and its characteristics can be known.

For example, the eccentricity waveforms of the wheels 6 (tires) and their data, which are individually measured before assembling the wheels 6, are input and placed in the display device 9 in advance, and the input data is based on the data and the waveforms. The tire uniformity waveform and its data are obtained by comparing and calculating the waveform.

Therefore, if the acceptance uniformity reference value of the tire uniformity is obtained by an experiment or the like and is input to the display device 9 in advance, it can be determined whether or not the tire uniformity is acceptable.

[0023]

As described above, the tire uniformity measuring method according to the present invention is provided with the displacement detecting sensor on the immovable surface immediately below the vehicle body and detects the vertical displacement of the vehicle body through the sensor to detect the tire uniformity. Because you can measure the Mity,
Compared with the conventional method of detecting the displacement of a wheel that rotates irregularly and unstablely and rotates, the vertical displacement is regular and stable, and the displacement can be detected easily and accurately.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 immovable surface 3 roller 5 vehicle under test 6 wheel 7 displacement detection sensor

Claims (1)

[Claims] 1. A tire uniformity measuring method in which a wheel of a vehicle to be inspected mounted on a roller is rotated at a low speed, a vertical displacement on the vehicle side is detected by a sensor, and tire uniformity is measured. A method for measuring tire uniformity, wherein a displacement detection sensor is installed on an immovable surface, and vertical displacement of the vehicle body is detected through the sensor.