JPS63266331A - Unbalance correcting method for wheel - Google Patents

Abstract

PURPOSE:To correct the unbalance of a wheel by a correcting work of once without being subjected to the influence from a hanging mechanism, by executing an unbalance correction, based on only the amplitude in the forward and backward direction of an under-spring constituting member. CONSTITUTION:A balanced wheel is hung to a real car, a weight is attached to a position in the prescribed peripheral direction of a rim of the wheel, and thereafter, the wheel is rotated at prescribed speed on a rotary drum 1. Subsequently, a rotational phase detected by a position detector 2, and a displacement in the forward and backward direction of a lower arm (b) being an under-spring constituting member detected by a displacement detector 3 are recorded, and by deriving the amplitude with regard to a weight of each weight, a tuning charge is prepared. Next, a wheel (a) hung to a car to be tested is placed on the rotary drum 1 and rotated, and a rotational phase and a displacement in the forward and backward direction of the lower arm (b) are recorded. Thereafter, a phase angle of an unbalance position of the wheel (a) and the amplitude are derived, and the weight of the corresponding weight is attached to an unbalance position of the rim of the wheel (a).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for correcting unbalance of wheels of an automobile or the like.

(Prior art) If a wheel is unbalanced, it will move up and down while rotating.
It is known that vibrations occur in the longitudinal direction and the direction of the turning angle.

In general, vibrations in the vertical and longitudinal directions are caused by weight imbalance in the circumferential direction of the wheel (static anno 9 lance), and imaging in the direction of turning angle is caused by an it unbalance in the width direction of the wheel (dynamic unbalance). This is thought to be caused by Detects the amplitude of the unsprung component in three directions: the vertical direction, the longitudinal direction, and the turning angle direction, and calculates the amount of quiet unbalance from the amplitude in the vertical direction and the longitudinal direction, and the amount of working unbalance from the amplitude in the turning angle direction. We proposed a method for correcting imbalances in which weights corresponding to these unbalance amounts are attached to each unbalance position on the wheel rim.

(Problem to be Solved by the Invention) However, even with the method described above, the unbalance of the wheels is not necessarily corrected, and the need for re-correction still arises.As a result of the inventor's analysis, the cause is The following points were found.

In other words, the vertical vibration of the unsprung component is affected by the suspension function of the suspension mechanism and the uniformity of the tires, and a unique relationship cannot be established between the vertical amplitude and the amount of static noise of the wheel. Furthermore, the vibration in the direction of the turning angle is affected by the vertical vibration of the nine wheels due to static imbalance using the gyroscopic action as a medium, as well as the compliance of the suspension mechanism in the direction of the turning angle. Even though there is no unambiguous relationship between the amplitude and the amount of dynamic unbalance of the wheels, weights are selected based on these amplitudes.

The present invention has focused on the above points, and aims to solve the problems of the prior application and provide a method for correcting the imbalance.

In order to achieve the above object, the present invention detects the unbalance of the wheels suspended on the vehicle body while the wheels are placed on a rotating drum and rotated. In the method of correcting unbalance based on the detection result, wheel unbalance is detected as an amplitude in the longitudinal direction of an unsprung component other than the wheel,
From the relationship between the amplitude in the longitudinal direction obtained in advance and the weight weight, select the weight way corresponding to the detected value of the amplitude,
The weight T is characterized by being attached to the unbalanced position of the rim of the wheel.

(Function) The longitudinal vibration of the unsprung components is hardly affected by the vertical direction or turning angle direction and the different suspension mechanism, and the static unbalance of the wheel causes longitudinal vibration. appear directly.

Therefore, there is a unique relationship between the amplitude in the longitudinal direction and the amount of silent unbalance of the wheel, and by attaching a weight corresponding to the amplitude, the static unbalance is corrected, and the static unbalance caused by the silent unbalance is corrected. The vertical and longitudinal vibrations of the shaft are suppressed, and furthermore, the vibrations in the turning angle direction, which are caused by the vertical and longitudinal vibrations using the gyroscopic action as a medium, are also suppressed.

(Example) Referring to FIGS. 1 to 3, (1) is a rotating drum mounted on a wheel at suspended on the body of an automobile, and (2) is a reflective tape a1 attached to a wheel a. A phase detector consisting of a phototube that detects the rotational phase of the wheel (2), and (3) an optical displacement detector that detects the longitudinal displacement of the unsprung horizontal bottom member, for example, the lower arm b; (3
) is provided so as to be movable in three orthogonal axes directions of up, down, forward, left, and right, and when the wheel a is placed on a rotating drum (1), the displacement detector (3) is placed opposite the front or rear surface of the lower arm b. Move to a predetermined measurement position and perform displacement detection.

To explain this in more detail, a machine frame (4) is erected inside the arrangement part of the rotating drum (1), and a cylinder (5a) is attached to the machine frame (4) along the guide rail (5b). a second table (6) that supports a first table (5) that is moved up and down by a cylinder, and a second table (6) that is moved back and forth along a guide rail (6b) by a cylinder (6a) on the first table (5);
A third table (7) is mounted on the second table (6) and is moved left and right by a Zeel screw L7b with a handle L7B'.
A spring plate (9) that comes into contact with the front or rear surface of the lower arm b is provided on the support stand (8) on the third table (7), and a spring plate (9) that comes into contact with the stay (8a) on the support stand (8) is provided. Spring plate (9)
The displacement detector (3)
and the third table (7) is fixed to the Zeel screw (7h) with the lock handle (7c) adjusted in the horizontal direction, and the wheel a is placed on the rotating drum (1). After placing the spring plate (9) on the front or rear surface of the lower arm b, the first table (5) is raised to the regular position and the second table (6) is advanced toward the lower arm b to the regular position. The spring plate (9) is brought into pressure contact with the lower arm b so that it vibrates in the longitudinal direction together with the lower arm b, and the displacement detector (3) detects the longitudinal displacement of the lower arm b. The displacement detector (3) includes a light source (3a) that irradiates the object to be measured with a beam of light, and a plurality of light receivers that form an image of scattered light from the object to be measured. The imaging section (3b) is arranged obliquely to the optical axis of the light source r3a3, and the displacement of the object to be measured is determined by the bright spot position in the imaging section (3b). This is detected as a change in , and is conventionally known, so a detailed explanation thereof will be omitted.

When correcting the unbalance of the wheel a, a tuning chart as shown in FIG. 4 is created in advance showing the relationship between the longitudinal amplitude of the lower arm b and the weight weight gw.

The tuning chart is created by suspending nine balanced wheels on an actual vehicle, attaching weights to the rims of the wheels at predetermined positions in the circumferential direction, and then rotating the wheels at a constant speed on a rotating drum (1). The rotational phase detected by the phase detector (2) and the longitudinal displacement of the lower arm b detected by the displacement detector (3) are recorded with a two-pen recorder, and this is repeated by changing the weight of the weight. This is done by finding the amplitude from the maximum value of displacement for each weight and plotting it.

By the way, the phase where the displacement in the longitudinal direction is maximum is when the weight attachment point matches the horizontal line in the longitudinal direction passing through the axle, but due to the time lag of the recorder, etc., on the recording paper,
After the weight attachment point reaches a phase that matches the horizontal line, a predetermined phase difference exists and the displacement reaches its maximum, and this phase difference is determined as the correction angle P. Next, wheel a suspended on the test vehicle is placed on the rotating drum (1), wheel a is rotated at the same speed as above, and the two-pen recorder is used to record the rotation phase and the front and back of lower arm b. The displacement in the direction is recorded.

The X-rays and yllIFi in Fig. 5 are lines representing the rotational phase and displacement, respectively, and each time the wheel a rotates once and the reflective tape al attached to it passes the front of the phase detector (2). A pulse waveform appears in the X-ray, and the displacement in the direction approaching the displacement detector (3) from the generation point of this Norse waveform becomes maximum y
? If the length on the recording paper up to the peak point of FM is Y1, and the generation interval on the recording paper of the pulse waveform is X, then the reflective tape al
The phase angle 2 of the peak point is as follows:
Then, the phase angle Q of the unlocked lance position of wheel a is Z
From the correction angle P and the correction angle P, calculate the amplitude from the wave height at the peak point of the y-line, select the weight t of the weight corresponding to this amplitude using the tuning chart, and set this weight. Figure 6 shows the unbalance of the left and right front wheels of the eight experimental vehicles (■ to ■) before correction and after correction using the above method, as shown in the longitudinal amplitude in the radial direction. It is shown in polar coordinates with the phase angle taken in the circumferential direction.The X mark is before the correction, and the * mark is after the correction, and it can be seen that the unbalance of the wheel has been significantly corrected.

In addition, the table below shows the measurement results of the amplitude of the lateral vibration of the steering wheel (corresponding to the amplitude in the direction of the turning angle) of the above experimental vehicle, and shows that the lateral vibration of the steering wheel can be significantly suppressed by correcting the unbalance using only the longitudinal amplitude. I understand.

(Effects of the Invention) As described above, according to the present invention, the unbalance is corrected based only on the longitudinal amplitude of the unsprung component where the unbalance of the wheel directly appears, and the unbalance is not affected by the suspension mechanism. First, the unbalance of the wheels can be corrected to the extent that there is no practical problem with a single correction operation, which has the effect of improving productivity.

[Brief explanation of the drawing]

Fig. 1 is a front view of essential parts of an example of an unbalance detection device used for carrying out the present invention, Fig. 2 is a side view thereof, Fig. 3 is a plan view thereof, and Fig. 4 is a line indicating a tuning chart tracker. 5 is a diagram showing detection data by the phase detector and the displacement detector, and FIG. 6 is a polar coordinate graph showing the experimental results. a...Wheel b...Lower arm (unsprung component) (1)...Rotating drum (2)...Phase detector (3)...2 people outside the displacement detector

Claims (1)

[Claims] In this method, the unbalance of the wheel is detected while the wheel suspended on the vehicle body is placed on a rotating drum and rotated, and the unbalance is corrected based on the detection result. The amplitude is detected in the longitudinal direction of the unsprung component, and a weight corresponding to the detected amplitude is selected based on the relationship between the predetermined amplitude in the longitudinal direction and the weight weight, and the weight is used to determine the unbalance of the wheel rim. A method for correcting wheel imbalance, which is characterized by installing the wheel in a certain position.