JPH07260425A - Apparatus for measuring run out of rotor - Google Patents

Abstract

PURPOSE:To detect run out of a rotor accurately by irradiating a rotating object with light from a plurality of directions, detecting the quantity of transmitted light at a quantity of light detecting section, and then detecting the rotational angle of the object at a rotational angle detecting section. CONSTITUTION:A gauge pin 10 is irradiated with a parallel light emitted from light emitting sections 50, 52. A photointerrupter 92 detects a mark put on the gauge pin 10 and a rotational angle operating section 94 operates the rotational angle of the gauge pin 10 based on the detection signal. Displacement of the detected rotational angle is then determined in two directions based on the variation in the quantity of light received by optical sensors 80-83 and a rotational angle outputted from the rotational angle operating section 94. The displacement thus operated is fed to a basic circle operating section 112 and a vector generating section 114. The operating section 112 determines the position and the eccentricity of the rotational shaft of gauge pin which are fed to the vector generating section 114. The vector generating section 114 operates the run out vector of the gauge pin based on the displacement in two directions and an output from the section 112. A printer/display 116 displays a Lissajous's figure, the eccentricity and the run out vector delivered from the sections 112, 114.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shake measuring device for a rotating body such as a rotating shaft for measuring the shake caused by the rotation of the rotating body.

[0002]

2. Description of the Related Art In recent years, with the progress of high precision and miniaturization of various devices and equipment, the rotation device and the rotating body have little fluctuation,
High precision is required. For example, a drill that makes holes for wiring in a printed wiring board not only affects the hole position and the accuracy of the holes that are made when the runout is large, but also affects the number of boards that can be drilled at one time. Brings up costs. For this reason, there is an increasing demand for a technique for detecting a shake associated with the rotation of a rotating body with high accuracy.

Conventionally, the shake in the direction (radial direction) orthogonal to the rotation axis of the rotating body has generally been measured by a capacitance type or a magnetic type. FIG. 8 shows a conventional capacitance type shake measuring device. As shown in FIG. 8, this capacitance type shake measuring apparatus has an electrode 14 arranged in the vicinity of a round bar-shaped gauge pin 10 as an object to be measured, and the gauge pin 10 is rotated as shown by an arrow a to A capacitance C between the electrode 10 and the electrode 14 is detected. The capacitance C between the two is the gauge pin 10 and the electrode 14
Fluctuates depending on the distance d between

## EQU1 ## It is obtained as C = f (d).

The capacitance C between the gauge pin 10 and the electrode 14 is temporally stored by the converter 16, which converts it into a time series function signal C (t) corresponding to the capacitance. Input to the conversion circuit 18. And the conversion circuit 1
8 converts the function signal C (t) into a distance function signal d (t) and sends it to the maximum value holding circuit 20 and the minimum value holding circuit 22. The maximum value holding circuit 20 holds the maximum value of the function signal d (t) of the distance output from the conversion circuit 18, that is, the value when the gauge pin 10 is farthest from the electrode 14,
The minimum value holding circuit 22 holds the minimum value of the distance function signal d (t) output from the conversion circuit 18. These maximum value and minimum value are input to the subtraction circuit 24, and the subtraction circuit 24 calculates the difference between the two and outputs it as the shake amount. The same applies to the case of the magnetic deflection measuring device.

By the way, the causes of the radial runout of the rotating body are mainly composed of the eccentricity and the axial runout.
The amount of eccentricity occurs when the center of rotation does not coincide with the center of the rotating body. In addition, the axial center runout is such that the center of rotation changes due to the rotation of the rotating body, and it indicates so-called rotational accuracy, and can be expressed by the magnitude and direction of the runout (= runout vector). The Lissajous method is often used as a method of measuring the rotation accuracy, and its principle is as shown in FIG.

The Lissajous method is, for example, a master ball 2
6 is slightly eccentric and attached to the rotary spindle 28,
Rotate as indicated by arrow 30. Then, in the vicinity of the master ball 26, for example, the capacitance type electrode 1 as described above.
The detectors 32 and 34 composed of the converter 4 and the converter 16 are arranged in two orthogonal directions, and the voltage value or the current value corresponding to the electrostatic capacitance C measured by the detectors 32 and 34 is set by the amplifiers 36 and 38. After amplification, the arithmetic units 40 and 42
This is a method of obtaining the displacement amount of the master ball 26 in two orthogonal directions and displaying it on the oscilloscope 44. Then, the rotation accuracy is evaluated by discretizing the measurement data in two directions to remove the eccentric amount contained in the data and then obtaining a Lissajous figure as shown in FIG. 10 in which the variation amount is superimposed on the basic circle. . In the evaluation of the rotation accuracy using this Lissajous figure, the width of the Lissajous figure obtained by a plurality of rotations usually represents reproducibility, and the difference between the maximum radius and the minimum radius with respect to the center of the basic circle is the rotation accuracy.

[0007]

However, in the conventional shake measuring device as shown in FIG. 8, the distance between the gauge pin 10 and the electrode 14 must be made small in view of the measuring principle. It is difficult and it takes time to install the electrode 14. In addition, the electrode 14 is correct and the gauge pin 1
There is a problem that high-precision measurement cannot be performed unless the direction of rotation is 0. On the other hand, in the evaluation of the rotation accuracy by the Lissajous figure, it is difficult to find the direction and magnitude of the shake at any rotation angle of the rotating body unless the start point and the end point of the shake vector are clearly indicated. Can't judge accurately. For this reason, in the case of using the Lissajous figure, determining the shake of the axial center only by the radial variation of the Lissajous figure lacks the accuracy of the shake evaluation.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a shake measuring apparatus for a rotating body capable of detecting the shake of the rotating body with high accuracy. Another object of the present invention is to significantly reduce the detection time of shake of the rotating body. further,
An object of the present invention is to separate the shake amount into an eccentric component and a shake vector component so that a shake vector at an arbitrary rotation angle can be easily obtained. The object of the present invention is to reduce the influence of the shape accuracy of the rotating body.

[0009]

In order to achieve the above-mentioned object, a shake measuring apparatus for a rotating body according to the present invention comprises a plurality of rotating bodies, which are arranged in the same plane orthogonal to the rotation axis of an object to be measured. A light emitting portion, a plurality of light amount detecting portions, which are provided at opposing positions corresponding to the respective light emitting portions on the side opposite to the respective light emitting portions of the DUT, and which receive the light emitted by the light emitting portion, A rotation angle detection unit that detects the rotation angle of the measured object,
It has a configuration including a shake amount calculation unit that obtains a shake amount at an arbitrary rotation angle of the object to be measured based on detection signals of the rotation angle detection unit and each of the light amount detection units.

The shake amount calculation unit is provided with a basic circle calculation unit and a vector generation unit which are separately obtained into a shake vector indicating the magnitude and direction of the shake at an arbitrary rotation angle of the object to be measured and an eccentric amount. To Further, the plurality of light emitting portions are a pair in which the optical axes of the emitted light are orthogonal to each other, and three light emitting portions can be provided around the object to be measured at 120 degree intervals. Then, each light emitting unit is configured by a light source and a lens that converts the light emitted by the light source into parallel light. The parallel light emitted by this lens is made larger than the width of the object to be measured, and each light amount detection unit is composed of a pair of optical sensors arranged in line symmetry with respect to the optical axis of the light emitted by the corresponding light emission unit. It is desirable to do.

As a light source forming the light emitting portion,
Although a light emitting diode, a semiconductor laser, various laser devices, and various lamps can be used, it is desirable to use the light emitting diode or semiconductor laser from the standpoint of stability of emitted light, space and life. Further, as the light sensor forming the light amount detection unit, a photodiode, a phototransistor, a solar cell, a photoconductive cell, or the like can be used. However, due to the stability of the relationship between the received light amount and the output, the photodiode is used. Alternatively, a phototransistor is preferable.

[0012]

The apparatus for measuring shake of a rotating body according to the present invention constructed as described above irradiates a rotating object to be measured with light from a plurality of directions, and detects the amount of light passing through the object to be measured. To receive light. Then, the light receiving area of the light amount detecting section changes when the object to be measured shakes due to the rotation, and the detected value also changes. Therefore, it is possible to obtain displacement amounts in multiple directions of the measured object from the detection signals of the plurality of light amount detection sections at any rotational angle of the measured object detected by the rotation angle detection section. , It is possible to obtain the shake of the measured object at an arbitrary rotation angle. Moreover, unlike the conventional capacitance type and magnetic type, it is not necessary to place electrodes and the like in close proximity to the object to be measured, and the detector can be placed easily, and the shake measurement can be performed with high accuracy and extremely easily and quickly. It is possible to ask.

Further, when the shake amount calculation unit is provided with a basic circle calculation unit and a vector generation unit to obtain a shake vector in which the eccentric amount is separated from the shake amount, the shake of the object to be measured at an arbitrary rotation angle. It is possible to easily obtain the size and direction of the object, and to grasp the shake state of the object to be measured in detail and accurately.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a shaker for rotating body according to the present invention will be described in detail with reference to the accompanying drawings. Figure 1
FIG. 3 is a block diagram of a shake measurement device for a rotating body according to an embodiment of the present invention.

In FIG. 1, a pair of light emitting portions 50 and 52 are provided.
The light sources 54 and 56 constituting the above are provided in the same plane orthogonal to the axis 58 of the round bar-shaped gauge pin 10 that is the object to be measured, and as shown in FIG.
The optical axes 64 and 66 of 0 and 62 are arranged so as to be orthogonal to each other. Then, in front of each of the light sources 54 and 56, a collimator lens 68 that constitutes the light emitting portions 50 and 52,
70 is provided, and the light 60 emitted from the light sources 54 and 56,
It is possible to irradiate the gauge pin 10 with 62 as parallel light 72, 74. These collimating lenses 6
8, 70 may be composed of one lens,
It may be configured as a lens system in which a plurality of lenses are combined, and collimated light 72, 74 larger than the width of the gauge pin 10 which is the object to be measured, that is, the diameter of the gauge pin 10 is emitted.

Light amount detecting portions 76 and 78 are arranged on the side of the gauge pin 10 opposite to the light sources 54 and 56. The light amount detection units 76 and 78 are a pair of optical sensors 80 and 81 and a photo sensor 8 each of which is composed of a photodiode or the like.
2 and 83, the optical sensors 80 and 81 are arranged in line symmetry with respect to the optical axis 64, and the optical sensors 82 and 83 are arranged.
Are arranged in line symmetry with respect to the optical axis 66. The detection signals of these optical sensors are input to the amplifiers 86 to 89 of the signal processing device 90 which is the shake amount calculation unit. In addition, the signal processing device 90, together with the reflection type photo interrupter 92, a rotation angle calculation unit 94 that constitutes a rotation angle detection unit that detects the rotation angle of the gauge pin 10.
Is provided. The rotation angle calculation unit 94 includes a waveform shaping circuit 96 that shapes the output of the photo interrupter 92,
The rotation angle calculator 98 calculates the rotation angle of the gauge pin 10 based on the pulse output from the waveform shaping circuit 96.

The signal processing device 90 is further provided with differential amplifiers 100 and 102. The differential amplifier 100 differentially amplifies and outputs the outputs of the amplifiers 86 and 87, and the differential amplifier 102 differentially amplifies and outputs the outputs of the amplifiers 88 and 89. The outputs of the differential amplifiers 100 and 102 are taken into the sampling circuits 104 and 106 in synchronization with the sampling signal output from the rotation angle calculator 98, and are used as displacement signals at the rotation angle obtained by the rotation angle calculator 98 as a basis. It is input to the circle calculation unit 112 and the vector generation unit 114. The base circle calculation unit 112 calculates the eccentric amount of the gauge pin 10 from the displacement output signal. Then, the vector generation unit 1
Reference numeral 14 calculates a shake vector from the displacement signal and the eccentricity amount obtained by the basic circle calculation unit 112. Further, the displacement signal is sent as Lissajous data to the printer / display device 116 together with the eccentricity amount obtained by the basic circle calculation unit 112 and the shake vector obtained by the vector generation unit 114, and the Lissajous figure, the eccentricity amount, and the shake vector are sent to the printer and Displayed on the display device.

The operation of the embodiment constructed as described above is as follows. First, the relationship between the position of the gauge pin 10 and the displacement output will be described. The relationship between the position of the gauge pin 10 and the displacement output signal is expressed as shown in FIG. 4, for example. That is, when the center of the gauge pin 10 is on the optical axis 64, for example, the light receiving amounts of the optical sensors 80 and 81 are equal, and the displacement output signal becomes zero. As the gauge pin 10 moves from the optical axis 64 to the optical sensor 80 side, the light receiving amount of the sensor 80 decreases and the output signal decreases, and the light receiving amount of the optical sensor 81 increases and the output signal increases. The output signal of the differential amplifier 102 that amplifies the difference between the two increases gradually, and the displacement signal that is output also increases. When the gauge pin 10 is further swung toward the optical sensor 80 side and the parallel light 72 is applied to the optical sensor 81 side of the optical sensor 80, the displacement signal gradually decreases from the maximum value V _MAX . When the gauge pin 10 swings toward the optical sensor 81, the displacement signal changes to the minus side in the same manner as described above.

A mark for obtaining a rotation reference signal is provided at one location on the peripheral surface of the gauge pin 10. When the gauge pin 10 is attached to a chuck or the like of a rotating device and rotated as indicated by an arrow a, this mark is displayed on the photo interrupter 92.
The detection signal of the photo interrupter 92 is input to the waveform shaping circuit 96 of the rotation angle calculation unit 94. When the signal from the photo interrupter 92 is input, the waveform shaping circuit 96 outputs a reference pulse signal as shown in FIG. 3 (1). Then, the rotation angle calculator 98 creates a sampling signal at a certain time interval based on the reference signal output from the waveform shaping circuit 96, converts this to a signal of the rotation angle Δθ, and inputs it to the sampling circuits 104 and 106.

The outputs of the differential amplifiers 100 and 102 are input to the sampling circuits 104 and 106 in synchronization with the sampling signal output from the rotation angle calculator 98. And
The rotation angle of the gauge pin 10 obtained by the rotation angle calculator 98,
The displacement of the gauge pin 10 at the rotation angle of the gauge pin 10 determined by the rotation angle calculator 98 from the outputs of the differential amplifiers 100 and 102, that is, from the measurement center where the optical axes 64 and 66 of the rotation axis 58 of the gauge pin 10 intersect. X-axis direction, Y
Axial displacement amounts S _xi and S _yi (FIGS. 3 (3) and (4)) are obtained, and the displacement amounts are input to the basic circle calculation unit 112 and the vector generation unit 114.

The basic circle calculation unit 112 calculates the deviation amount (deviation amount) of the rotation center with respect to the measurement center by the least squares method from the displacement amounts S _xi and S _yi of the gauge pin at the rotation angle of the gauge pin 10, and calculates the eccentricity. The amount (difference between the rotation center and the cross-sectional center of the gauge pin 10) is calculated to obtain the basic circle, and the calculated deviation amount and eccentric amount of the rotation center are sent to the vector generation unit 114. The vector generation unit 114
The shake vector is calculated based on the displacement amount and the output of the basic circle calculation unit 112, and is output to the printer / display device 116.

FIG. 5 is a diagram showing how to obtain the shake vector E. In the case of the embodiment, the X axis of FIG. 5 is aligned with the optical axis 64, and the Y axis is aligned with the optical axis 66. Now, at the rotation angle θ _i , the displacement amount of the gauge pin 10 in the X-axis direction obtained based on the detection signals of the optical sensors 82 and 83 is S _{xi.
Therefore} , it is assumed that the displacement amount in the Y-axis direction obtained based on the detection signals of the optical sensors 80 and 81 is S _yi . Then, the rotation center C with respect to the measurement center O obtained by the basic circle calculation unit 112
If the position of is (C _x , C _y ),

## EQU2 ## S _xi = C _x + e ₀ cos θ _i + E _ix

## _EQU3 ## S _yi = C _y + e ₀ sin θ _i + E _iy holds. Here, e ₀ is the amount of eccentricity (the distance between the rotation center and the cross-sectional center of the gauge pin), and E _ix and E _iy
Is a shake vector E, that is, the X component and Y of the shake of the shaft center.
With ingredients.

When the above equation is rearranged for E _ix and E _iy ,

[ _Equation 4] E _ix = S _xi −C _x −e ₀ cos θ _i

[ _Equation 5] E _iy = S _yi −C _y −e ₀ sin θ _i .

Therefore, the shake magnitude | E | and the shake direction (vector direction) α _i are

[Equation 6] | E | = (E _ix ² + E _iy ² ) ^1/2

It can be obtained as α _i = tan ⁻¹ (E _iy / E _ix ).

However, the deviations C _x and C _y from the sensor origin O to the center of rotation C and the eccentricity e ₀ are measured values S _xi and S _yi at arbitrary rotation angles θ _i , and the central coordinates (C _x , C _y). ), By applying the least squares method to a circle of radius e ₀ .
Note that reference numeral 130 in FIG. 5 indicates a trajectory drawn by the shake.

As described above, the displacement amount is output as Lissajous data together with the eccentricity amount obtained by the basic circle calculation unit 112 and the shake vector obtained by the vector generation unit 114 to the printer / display device 116, and the Lissajous figure, the eccentricity amount. The shake vector is displayed on the printer and the display, and is stored in the external storage device as needed.

In the above embodiment, the optical axis 64,
The case where the pair of light emitting portions 50 and 52 in which 66 is orthogonal to each other is provided has been described, but as shown in FIG.
The two light emitting portions 134a, 134b, 134c and the light amount detecting portions 136a, 136b, 136c may be arranged around the gauge pin 10 at intervals of 120 degrees. By arranging the three light emitting parts and the light amount detecting parts at 120-degree intervals in this way, the states of the shake vectors in the 45-degree direction and the 135-degree direction with respect to the X axis can be known in detail, and the accuracy is higher. A shake can be measured. Further, in the above-described embodiment, the case where each light amount detecting unit 76, 78 is configured by the pair of optical sensors 80, 81 and the optical sensors 82, 83 has been described, but each light amount detecting unit 76, 78 is shown in FIG. 7. As shown in FIG.
The shake may be detected by a so-called radius method in which the parallel light 140 is irradiated to one end side of the gauge pin 10.
Further, in the above-mentioned embodiment, the case where the object to be measured is the gauge pin 10 has been described, but the object to be measured may be various drive shafts, spheres and the like.

[0028]

As described above, according to the present invention, the rotating object to be measured is irradiated with light from a plurality of directions, and the amount of light passing through the part to be measured is detected. By detecting the rotation angle of the object to be measured by the rotation angle detecting unit while detecting the rotation angle of the object to be measured, the shake of the object to be measured at an arbitrary rotation angle can be highly accurately and extremely easily and quickly obtained.

Further, since the eccentricity component is separated and the shake amount and direction at any rotation angle of the measured object are obtained by the vector generation section of the shake amount calculation section, the shake state of the measured object is detailed. It can be used to improve the rotating device. Further, since the parallel light emitted from the lens is made larger than the width of the object to be measured and the light amount is detected by a pair of optical sensors arranged in line symmetry with respect to the optical axis, the shape accuracy of the object to be measured can be improved. The influence can be reduced, and the measurement accuracy can be further improved.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a shake measurement device for a rotating body according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an arrangement state of a light emitting portion and a light amount detecting portion of the embodiment.

FIG. 3 is a diagram showing an example of sampling timings and displacement amounts in the X-axis direction and the Y-axis direction in the embodiment.

FIG. 4 is a diagram showing an example of a relationship between a position of a gauge pin and a displacement signal according to the embodiment.

FIG. 5 is a diagram illustrating a method of obtaining a shake vector.

FIG. 6 shows a case where three light emitting parts and three light quantity detecting parts are provided,
It is a top view which shows those arrangement states.

FIG. 7 is a diagram showing a principle of shake measurement by a radius method.

FIG. 8 is a diagram illustrating the principle of a conventional electrostatic capacitance type shake measuring method.

FIG. 9 is a diagram illustrating the principle of shake measurement by the Lissajous method.

FIG. 10 is an example of a Lissajous figure for evaluating shake.

[Explanation of symbols]

10 object to be measured (gauge pin) 50, 52 light emitting part 54, 56 light source 68, 70 collimating lens 76, 78 light amount detecting part 80 to 83 optical sensor 90 signal processing device 92, 94 rotation angle detecting part (photo interrupter,
Rotation angle calculation unit) 112 Basic circle calculation unit 114 Vector generation unit

Claims (5)

[Claims] 1. A plurality of light emitting portions arranged in the same plane orthogonal to the rotation axis of a rotating object to be measured, and a plurality of light emitting portions on the side opposite to the light emitting portions of the object to be measured. A plurality of light amount detection units which are provided at corresponding facing positions and receive the light emitted by the light emission unit, a rotation angle detection unit which detects the rotation angle of the object to be measured, the rotation angle detection unit and the respective light amounts. A shake measurement device for a rotating body, comprising: a shake amount calculation unit that obtains a shake amount at an arbitrary rotation angle of the measured object based on a detection signal from a detection unit. 2. A basic circle calculation unit for obtaining a shake vector indicating an amount of eccentricity due to the center of the object to be measured not coinciding with the center of rotation and a shake magnitude and direction at an arbitrary rotation angle. The shake measurement device for a rotating body according to claim 1, further comprising: and a vector generation unit. 3. The shake measuring apparatus for a rotating body according to claim 1, wherein the plurality of light emitting portions are a pair in which optical axes of emitted light are arranged to be orthogonal to each other. 4. The shake measuring apparatus for a rotating body according to claim 1, wherein the plurality of light emitting portions are three arranged at intervals of 120 degrees around the object to be measured. 5. Each of the light emitting portions includes a light source and a lens that collimates the light emitted by the light source, and makes the parallel light emitted by the lens larger than the width of the object to be measured. 5. The light amount detecting section comprises a pair of optical sensors arranged in line symmetry with respect to the optical axis of the light emitted by each light emitting section. Rotational shake measurement device.