JPH05306963A - Instrument for measuring amount of unbalance of automobile wheel - Google Patents

Abstract

PURPOSE:To obtain a high resolution even with an inexpensive sensor by respectively providing press rollers in front and rear of a driving roller which rotates an automobile wheel and detecting the variation of the wheel pressing pressure of the press rollers by means of the sensor while the wheel is rotated. CONSTITUTION:When an automobile 7A is stopped and fixed on a driving roller 20 and press rollers 25 and 26 provided in front and rear of the roller 20, the axle load of the automobile 7A is applied to the roller 20. At the same time, the pressing pressures P of the rollers 25 and 26 are also applied to a wheel 12A through a sliding body 44. Under such a condition, the tire of the wheel 12A follows the rotation of the roller 20 driven by a driving motor 23 and, when the amount of unbalance exists in the rotating system of the wheel 12A, a centrifugal force (f) is generated. When the force (f) is generated, a load is applied to the wheel 12A in the centrifugal direction and the force (f) is applied to the rollers 20, 25, and 26 supporting the wheel 12A in addition to the load already applied to the rollers. A first and second sensors 37 and 38 measure the amount of unbalance of the rotating system by detecting and measuring the force (f) applied to the rollers 25 and 26. In addition, since the resolution can be expressed by a specific equation, miscellaneous elements resulting from the nonuniform wall thickness, out of roundness, etc., of the tire can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle wheel unbalance amount measuring apparatus for measuring a centrifugal unbalance amount existing in a wheel rotating system which causes a shake or shimmy generated when a vehicle runs at high speed.

[0002]

2. Description of the Related Art The centrifugal unbalance amount existing in the rotating system of the wheel of an automobile causes stains and shakes that occur during high speed running. Therefore, we are trying to reduce the amount of unbalance by centrifugally balancing the wheels with the tires mounted and the tire mounting parts of the car individually. However, when the wheels are attached, the amount of unbalance is usually increased in the entire rotating system due to the problem of misalignment at the time of attachment and the directionality of the slightly remaining unbalance.

In order to reduce this, it is sufficient to measure the unbalanced amount again with the wheels attached to the vehicle, and a device for measuring the unbalanced amount of the axle system in the state where the vehicle is actually lifted and the wheels idle is commercially available. Has been done.

However, such a commercially available device is practical in terms of lifting a wheel and how the amount of unbalance measured in a completely idle state is related to the occurrence of the above-mentioned stains and shakes. However, it is difficult to use, especially in automobile production lines and large maintenance plants, even though it is highly necessary.

Therefore, in order to solve the above problems, the applicant has previously proposed an embodiment of a vehicle vibration detecting device shown in FIGS. 7 to 9, for example. In this embodiment, the vehicle body load (axial load) is applied to the wheels of the vehicle, and one supporting roller receives all the axial load of one wheel.

[0006] However, when explaining this embodiment in detail, 1 is a pit formed on the floor surface. This pit 1 is provided in an inspection line where vehicle running noise, vibration, engine diagnosis, etc. are performed. Reference numeral 2 denotes a plurality of motor supporting bases respectively installed in the front and rear pits 1, and these motor supporting bases 2 have a required height. Reference numeral 3 denotes a plurality of drive motors provided on the upper surface of each motor support base 2.

Reference numeral 4 denotes a plurality of sensor support bases installed separately from the motor support base 2 in the pit 1. The sensor support bases 4 are lower than the motor support bases.

Reference numeral 5 is sandwiched between the sensor support base 4 and the roller support plate 6 provided above the sensor support base, and detects vibration of the vehicle 7. A plurality of vibration detection members. These vibration detecting members 5 are plate-shaped members having a plurality of sensors at the corners of the upper surface, etc., and are appropriately integrally attached to the sensor support bases 4 and the roller support plates 6.

Numeral 8 is provided on the upper surface of the roller support plate 6 via bearings 9, respectively, and is rotated by a driving force of each driving motor 3 via a power transmission means 10 such as a belt or a chain and holding means. A plurality of vibration transmission rollers for rotating a front wheel 12 and a rear wheel 13 of the vehicle 7 fixedly held by 11. As the holding means 11, in this embodiment, two lift devices appropriately buried in the floor surface F are used. These lift devices 11
A support portion 11b that engages with the underfloor of the vehicle 7 is provided at the tip of the operating rod 11a.

Reference numeral 14 is a pit cover plate, 15 is a central processing unit that is electrically connected to the vibration detecting member 5 and has operation buttons, a control panel, etc., and 16 is an electrical connection with the central processing unit 15. A television-type display device connected to
Reference numeral 17 denotes a sheet-shaped or block-shaped vibration-damping member that is laid on the inner wall surface of each pit 1 so as not to be affected by vibrations generated from other peripheral devices.

In the above structure, first, the vehicle 7 is placed on the floor F.
While traveling on, get on the front and rear vibration transmission rollers 8. Next, when the front wheels 12 and the rear wheels 13 of the vehicle 7 ride on the respective vibration transmission rollers 8, the vehicle body is supported by the holding means 11 so that the vehicle body does not move.

After that, each drive motor 3 is started.
In this case, the drive motors 3 can be driven simultaneously or individually. When the drive motor 3 is driven, the driving force is transmitted to each vibration transmission roller 8 via the power transmission means 10. Front wheel 1 of vehicle 7
2 and the rear wheel 13 are independently rotated by the rotation of each vibration transmission roller 8, but the rotational force is gradually increased,
For example, when traveling on a general highway at 120 km / h, a state close to actual traveling is reproduced.

Thus, the front wheels 12 and / or the rear wheels 1
Abnormal vibrations generated while 3 is rotating at a constant speed or acceleration / deceleration pass through the respective vibration transmission rollers 8 and the respective vibration detection members 5
Is transmitted to each. Then, the vibration of the front wheels 12 and / or the rear wheels 13 detected by each vibration detection member 5 is sent to the central processing unit 15 as a vibration signal (frequency), and the shake or shimmy of the vehicle can be analyzed or analyzed. Become. The data processed by the central processing unit 15 is displayed on the display unit 16.

However, the above-mentioned embodiment has the following problems. That is, in general, a sensor for measuring centrifugal force is applied with vehicle gravity (Wc) applied to an axle and gravity (Ws) of a measuring device, and centrifugal force (f) is applied on the sensor, so that high resolution is required. Then, it is mathematically known that this resolution is obtained by the following Equation 1.

[0015]

[Equation 1]

The problem here depends on the type of car, but in the above embodiment, for example, Wc is 300 to 500 kg,
While Ws is around 100 kg, f is 100 to 2
Since it is about 00N, the sensor measures the amount of change of 2 to 5% of the total amount, which makes the signal handling extremely difficult.

Generally, a sensor or a measuring instrument has a fixed minimum measuring unit for the entire measuring width. The price of will increase significantly. In the case of a sensor, the so-called required resolution is increased, or the signal-to-noise ratio (SN ratio) is deteriorated, which is disadvantageous in that it becomes expensive in any case.

[0018]

SUMMARY OF THE INVENTION The present invention, in view of the above-mentioned conventional drawbacks and the problems of the above-mentioned embodiment of the prior application, can obtain a high resolution even when the same sensor is used.
Since the detected signal is easy to handle, it is possible to use an inexpensive sensor, so that the device can be finally manufactured at low cost, and the device can be clean without being affected by noise generated from the driving device. An object of the present invention is to obtain a device for measuring an unbalance amount of a vehicle wheel, which can obtain a waveform and can be easily installed in a production line of a factory or a car maintenance shop.

[0019]

An apparatus for measuring an unbalanced amount of a vehicle wheel according to the present invention is a drive for supporting a wheel to receive an axial load of the vehicle and rotating the wheel by a driving force of a driving motor. A roller, a plurality of pressing rollers opposite to each other for pressing the wheels before and after the drive roller, and a pressing roller mounted on at least one roller supporting member of the pressing roller. And a sensor that detects a change in the pressing force applied to the wheel during rotation.

[0020]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

In the description of each embodiment of the present invention, the same parts as those of the above-mentioned embodiment of the prior application will be denoted by the same or similar reference numerals and overlapping description will be omitted.

First, in the embodiment shown in FIGS. 1 to 6, reference numeral 20 receives the axial load (which means the weight of the vehicle added to one tire) Wc of the automobile 7A via the wheels 12A, and , A support base 22 forming a part of the support member 21
The driving force of the driving motor 23 installed on the upper surface of the wheel 12
A drive roller for rotating A. This drive roller
20 is located directly under the wheel 12A, and is pivotally attached to the support member 21 via a bearing 24 for a drive motor which constitutes a part of the support member 21 as shown in FIG.

Reference numerals 25 and 26 denote wheels 1 in front of and behind the drive roller.
2A is a plurality of pressing rollers that are opposed to each other to press them. In this embodiment, the pressing rollers 25 and 26 are arranged with a phase angle α of 90 degrees, and even if a centrifugal force (± f) is applied to the sensor described later, the pressing rollers 25 and 26 do not separate from the wheel 12A. Such a pressing force (Pf), for example, if the centrifugal force is ± 10 Kg, the wheel 12A is pressed with a force of at least 10 Kg or more.

27 and 28 are roller supporting members 29 and 30.
It is a front and back support stand that constitutes a part of. Fitting portions 31 and 32 are formed on the upper ends of the support bases 27 and 28, respectively, toward the center of the wheel 12A. Further, at the upper end portions of the support bases 27 and 28, storage portions 34 for the pressure adjusting device 33, which communicate with the fitting portions 31 and 32 in the intersecting direction, are formed.

Reference numerals 35 and 36 are also roller support members 2.
These are front and rear bearings that respectively constitute a part of 9, 30.
The lower ends of the bearings 35 and 36 are loosely fitted in the fitting portions 31 and 32. The front and rear pressing rollers 25, 26 are pivotally attached to the front and rear roller support members 29, 30 via these bearings 35, 36, respectively.

37 and 38 are front and rear pressing rollers 2
5 and 26 are first and second sensors that detect changes in the pressing force of the rotating wheel 12A that are respectively received by 5 and 26. In the present embodiment, these first and second sensors 37, 38 minimize the mass between the wheel and the pressing roller so that unnecessary force other than centrifugal force such as inertial force accompanying the movement of the pressing roller is not applied. Front and rear bearings 35, 3
6 are fixedly attached to the lower ends thereof.

Reference numerals 39 and 40 denote contact portions or contact members for a sliding body, which will be described later, fixedly provided at the lowermost ends of the front and rear bearings 35 and 36 via a sensor. The lower end surfaces of these contact members 39, 40 are formed in a tapered shape.

As described above, the pressure adjusting device 33 includes a motor 42 having a male screw shaft 41 fixedly provided on the supports 27 and 28, and a female screw member 43 screwed to the male screw shaft 41, as shown in FIG. The sliding member 44 has a casing shape, and the upper wall surface of the leading end portion of the sliding member is tapered so as to correspond to the tapered surfaces of the contact members 39 and 40. Therefore, the sliding body 44 moves back and forth in the direction of the arrow by the driving force of the motor 42, whereby the bearing 35 having the pressing rollers 25, 26,
36 moves up and down.

By the way, in this embodiment, the front and rear bearings 35,
Although the first and second sensors are attached to both of the rollers 36, respectively, it is not always necessary to provide both of the first and second sensors on the roller support members 29 and 30, and the sensor may be attached to either one. However, when a plurality of sensors are provided as in the present embodiment, the waveform shaping and the abnormal waveform detection are facilitated by combining the measured values detected by the sensors.

The first and second sensors 37, 38
Is preferably mounted on the lower end portions of the bearings 35 and 36 so that an unnecessary force other than the centrifugal force does not act. However, as in the embodiment of the prior application, a sandwich is provided between the upper support base and the lower support base. You may intervene in the shape.

In the above structure, the automobile 7A is mounted on the driving roller 20 and the front and rear pressing rollers 25 and 26.
When the vehicle gets in and is fixed by the lift device 11, the vehicle 7A is mounted on the drive roller 20 as shown in FIG.
The axial load Wc of the (wheel 12A) is applied, and the pressing force (Pf) of the front and rear pressing rollers 25, 26 is applied to the wheel 12A via the sliding body 44 of the pressure adjusting device 33. ..

Therefore, when the drive motor 23 is started and the drive roller 20 rotates, the tire rotates following the rotation of the drive motor 20. If there is an unbalanced amount in the rotation system of the wheel 12A including the tire, the centrifugal force is generated. A force f is generated.

By the way, since the wheels of an automobile are generally supported by a spring system, they are microscopically free-moving shafts that do not have a supporting portion, and so-called pestle movement is possible. Therefore, the front and rear bearings 35 and 36 can follow the roundness of the tire, that is, can slightly move in the centrifugal direction of the tire.
1 and 32 are provided.

When the centrifugal force f is generated, a load is applied in the centrifugal direction. Therefore, in addition to the load up to that point, the centrifugal force is also applied to the portion (drive roller, pressing roller) supporting the wheel 12A. Therefore, the first and second sensors 29, 30 are connected to the front and rear pressing rollers 3
Centrifugal force f applied via 7 and 38 is detected and measured.

However, since the centrifugal force f is in the minus direction when the centrifugal force is applied to the opposite side of the measuring portion, the change in the load generated by one rotation of the wheel becomes a sine curve. Since the magnitude of the centrifugal force is proportional to the peak value of the curve in the sine curve, the unbalance amount of the rotating system can be measured, and the axial load Wc and the centrifugal force f of the vehicle at this time can be measured. The vector concept is as shown in FIG. 6, and the resolution is Equation 2 below. As a result, it is possible to eliminate miscellaneous elements due to uneven thickness of the tire, roundness, and the like.

[0036]

[Equation 2]

[0037]

As is apparent from the above description, when the concept of the invention, the measured values and the like of the embodiment of the prior application and the embodiment of the present invention are compared, the results are shown in Table 1 below. Therefore, since the present invention can use a low-resolution sensor (inexpensive sensor), an inexpensive device can be finally manufactured.

[0038]

[Table 1]

[Brief description of drawings]

[Figure 1]

FIG. 3 is an explanatory diagram showing an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a main part of the present invention.

FIG. 5 is a schematic explanatory diagram for explaining the basic concept of the present invention.

FIG. 6 is an explanatory view showing the vector concept of the axial load Wc and the centrifugal force f of the present invention.

FIG. 7

FIG. 9 is an explanatory diagram showing an example of a prior application.

[Explanation of symbols]

 20 ... Drive roller, 12A ... Wheel, 7A ... Automobile, 21 ... Support member, 23 ... Drive motor, 25,26 ... Pressing roller, 29,30 ... Roller support member, 31,32 ... Fit part, 33 ... Pressure adjustment Device, 34 ... Storage section, 35, 36 ... Bearing, 37 ... First sensor, 38 ... Second sensor, 39, 40 ... Contact member, 44 ... Sliding body.

Claims (2)

[Claims] 1. A drive roller for supporting a wheel to receive an axle load of an automobile and rotating the wheel by a drive force of a drive motor.
A roller, a plurality of pressing rollers arranged to press the wheels before and after the drive roller, and at least one roller supporting member of the pressing rollers, and the pressing roller receives the rollers. An unbalance amount measuring device for an automobile wheel, comprising: a sensor that detects a change in a pressing force of a rotating wheel. 2. The unbalanced amount measuring device for an automobile wheel according to claim 1, wherein the sensor is fixedly mounted on a lower end portion of a bearing of the pressing roller supporting member.