JPH0656348B2 - Tire balance measurement method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of performing balance measurement when correcting an imbalance of a tire.

(Prior Art) The balance measurement of tires is performed in a state where the tire is removed from the axle of the vehicle and in a state where it is attached to the axle, and the present invention is intended for the latter case. An on-the-car balancer device is therefore used for the measurement, which device rotates the tire by means of a drive rotor,
The centrifugal force generated at a predetermined speed and its phase are measured, and the unbalance amount is calculated from the rotational speed. However, the on-the-car balancer device is equipped with a drive rotor that rotates the tires.
In the case of a car, the rear wheel can be rotated by its own engine without rotating the tire by the drive rotor. However, if the engine spins the wheels,
Since the output of the engine is too large, it is difficult to maintain the same rotation speed as when traveling on a road, and inevitably the rotation speed becomes uneven. Generally, measurement is done by a signal from the accelerator operator,
Even if the rotation speeds at the time of measurement are different, the measurement speeds are the same, so the measurement error is large, and it is impossible to correct the balance accurately. (Object of the Invention) As described above, when the tire balance is corrected by rotating the tire by driving the engine of the vehicle using the on-the-car balancer device, the above-mentioned problems exist. The present invention aims to solve this problem and provides a method capable of performing more accurate balance measurement.

(Structure of the present invention) When only the tire is rotated by driving the engine of the vehicle, there is no load when traveling on the road and the inertia energy is very small, so it is virtually impossible to rotate the tire at a constant speed. Is. Therefore, the present invention is a method for performing accurate balance correction on the assumption that there is unevenness in the tire rotation speed. Therefore, first, the axle of the tire to be measured is lifted, the axle is supported by the pickup device, and the tire is kept in the air. Here, the pickup device may have a structure in which the pickup is supported through a leaf spring to which a strain gauge is attached, but may be a device in which a vibration sensor that is commonly used is attached.

In this state, operate the engine, depress the accelerator to increase the rotation speed of the tire, and measure at the stage when it reaches a certain speed, but the rotation speed at the start of measurement is stored and it is constant with respect to that speed. In order to suppress the speed fluctuation within the range, the height is displayed based on the speed at the start of measurement. Then, for the balance measurement of the tire that is rotating while fluctuating within a certain range, a system that selectively adopts the measured value only at the time when the reference speed at the time of starting the measurement is used. By the way, by selecting and adopting only the reference speed, the magnitude and phase of the unbalance amount are measured. First, the first measurement is performed to obtain the phase of the unbalance amount, and A known reference weight is attached to the position of phase 0 and the second measurement is performed to obtain the magnitude and phase of the unbalance amount. Know the actual tire unbalance amount and its position from these two measurements,
Attach the required balance weight.

Hereinafter, embodiments of the tire balance measuring method according to the present invention will be described in detail with reference to the drawings.

(Embodiment) FIG. 1 is a main body of an on-the-car balancer device, in which a driving roller 2 is directly connected to a motor 1 and is rotated by driving the motor 1. The outer surface of the drive roller 2 is formed with an inclined surface 9 which is inclined at a constant angle, and is considered so as to easily contact the outer surface of the tire. The drive roller 2
Is for pressing the tire to rotate the tire at a high speed. However, when measuring the balance of the front wheels of an FF vehicle, it is necessary to use the drive roller 2 because the front wheels are rotationally driven by the engine. However, since it is useless to manufacture a device for front wheels of FF vehicles, a device that can be applied to other vehicle types will be used. Then, the rotational speed of the tire rotationally driven by the engine is measured by the infrared sensor 8. The device also includes a brake shoe 3 and a brake lever 4 for stopping the drive roller 2 that rotates at a high speed.
Are provided to move the device, wheels 7, 7, ...
Is attached, and the front handle 5 and the rear handle 6 are attached.

On the other hand, FIGS. 2 and 3 show a pickup portion of the on-the-car balancer device, and the wheel to be measured is supported by the pickup device. In the figure, a frame 10 is supported by three rollers 11, 11 and 11. A handle 12 is swingably connected to the frame 10, and the handle 10 is arranged at an appropriate position of a wheel bearing portion. Therefore, a pickup 13 for supporting the bearing portion is mounted on the frame 10. By the way, the pickup 13 has pin holes 15 and 1 in which pins 14 are to be inserted so that the height thereof can be adjusted.
5 ... Are bored at a constant pitch, and are supported by two leaf springs 16, 16 extending horizontally from a base 17. Of course, a strain gauge (not shown) is attached to the leaf spring 16 so that the displacement acting on the pickup 13 can be detected.

FIG. 4 shows the operation panel 18 of the on-the-car balancer device body.
The operation panel 18 will be described in the order of measurement using the apparatus. First, PC, LT, TB are selected according to the left / right (LR) of the tire to be measured and the vehicle type. Here, button PC is for passenger cars, LT is for light trucks, TB
Is for trucks and buses. Turn on the power switch 19, select L for the left tire, and PC for passenger cars to select, and press the MEAS button 1 to perform the first measurement. In this case, when the rotation speed of the tire is lower than the reference measurement speed, L, L, L
The display of L is displayed, and conversely, if it is high, the display of H, H, H is displayed. Therefore, if the accelerator depression amount of the vehicle is adjusted to a predetermined rotation speed according to an instruction from the measurer, only vibration data generated according to the rotation speed is collected.

FIG. 5 shows the rotation speed of the tire with time as the horizontal axis. In this way, the rotation speed of the tire due to the accelerator operation with the engine as the driving source changes with time.
Therefore, in the present invention, the electronic circuit is configured to collect only the rotational speed data existing in a certain speed range from the measured data, obtain the stable average value of the data, and display the average value on the display panel 20. However, the structure of such an electronic circuit is not particularly limited. Therefore, when the first measurement is completed, it is necessary to compare the measured data with the known balance weight attached to obtain the initial amount of imbalance, and therefore the central display panel 20 has, for example, 3
0g is displayed, the lamp 21 lights up at 24:00,
The TEST lamp of 2 also lights up. That is, the above display indicates the following procedure, and a reflective tape for detecting the rotation speed is attached to the side surface of the tire,
The lamp display means that the reflection tape is aligned with the phase display position, a weight of 30 g is attached, and the TEST push button of 2 is pressed. Therefore, according to these instructions, the second measurement is performed. Of course, the second measurement is made to match the rotation speed of a certain range as in the first measurement,
Only vibration data at the rotation speed is collected. In this way, the true unbalance amount is calculated from the unbalance amount and the respective phases by the first and second measurements, and the weight amount is displayed on the display board 20, and the phase is arranged around the phase ramps 21, 21 ...・ Displayed with.

FIG. 6 is a vector display of the relationship between the unbalance amount and the phase at each measurement. First, the unbalance amount of the first measurement is F ₀ and the phase is α. Next, a known weight is attached to the position of phase 0, and the unbalance amount caused by the vibration when the second measurement is performed is F _1, and the phase at that time is β. Here, since F _T is a vibration component due to a known test weight, it is easy to calculate F ₀ from α and β with reference to the F _T. Therefore, for example, 15 g is displayed on the display plate 20, the phase lamp 21 is turned on at a predetermined position, and CHECK of 3 is also turned on at the same time. According to these lamp indications, a correction weight (for example, 15 g) is attached to a predetermined position where the phase lamp 21 is turned on, and the test weight 30 g is removed.
Press the CHECK button of to make the third measurement. As a result, if the unbalance is within a certain allowable value (for example, within 5 g), the OK lamp is displayed. If the FINE button is pressed, the actual amount of unbalance is displayed on the display board 20.

As described above, the tire balance measuring method according to the present invention is a method of measuring the amount of unbalance by relative comparison with the test weight attached to the tire, but in the measurement, a constant range of the tire rotation speed. The following effects can be obtained by collecting the vibration data of only the speed range within and displaying the average value.

(Effect) When performing balance measurement by rotating the tire with the engine driven, the rotation speed of the tire is not constant but fluctuates, but only vibration data in the speed range within a certain range is collected. Therefore, very accurate balance measurement can be performed. Therefore, it is very effective for balance measurement of FF vehicles.

[Brief description of drawings]

FIG. 1 shows the main body of the on-the-car balance device, FIGS. 2 and 3 are pickup devices, FIG. 2 is a plan view, FIG. 3 is a front view, FIG. 4 is an operation panel, and FIG. 5 is a tire. 6 shows the state of fluctuation of the rotational speed of FIG. 1 …… Motor 2 …… Drive rotor 3 …… Brake shoe 4 …… Brake lever 5 …… Front handle 6 …… Rear handle, 7 …… Wheels 8 …… Infrared sensor, 9 …… Inclined surface 10 …… Frame, 11 …… Roller 12 …… Handle, 13 …… Pickup 14 …… Pin, 15 …… Pin hole 16 …… Plate spring, 17 …… Pane 18 …… Operating panel, 19 …… Power switch 20 …… Display Plate, 21 ... Phase ramp

Claims (1)

[Claims] 1. An on-the-car balancer device for measuring the balance of a tire while the tire is mounted on an axle of a car, the tire being rotated by an engine of the car,
A tire balance characterized in that the rotation of the tire is detected by a sensor, vibration data of only a certain speed range of fluctuating rotation speeds is collected, and the average value of the data is displayed to indicate the amount of unbalance of the tire. Measuring method.