JPH0514883U - Non-contact measuring device for minute runout of rotating shaft - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to use the two-input method to accurately measure the amount of runout and the runout state in one measurement. [Structure] The input sections 1a and 1b and the amplification sections 2a and 2b have two input circuits, and a comparison circuit 3 compares respective signals to enable analysis of a state of runout.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a non-contact measuring device for a small amount of runout of a rotating shaft, and more particularly to a non-contact measuring device for immediately measuring the eccentricity of a rotating shaft holding a cutting tool for drilling during rotation. ..

[0002]

[Prior Art]

 As shown in FIG. 5, a conventional non-contact measuring device for a small amount of runout of a rotary shaft has an input section 1a, an amplification section 2a, and an output section 5.

Instead of the cutting tool for drilling on the rotating shaft, a cylindrical reference rod made of metal is used and rotated at a constant speed. At this time, in the space near the reference bar, the input unit 1a detects the amount of change in perspective where the reference rod approaches or moves away by an amount corresponding to the amount of core runout, and the detection signal from the input unit 1a is input to the amplification unit 2a. Then, by amplifying and amplifying the result and outputting it to the output unit 5, the minute core runout amount of the rotating shaft was measured.

[0004]

[Problems to be solved by the device]

 With the non-contact type measuring device for small amount of runout of the rotating shaft as described above, since the input signal is one signal, it is possible to measure the amount of runout in concentric circles, but in the case of elliptical runout, it is accurate. There is a problem that it is difficult to measure such a minute amount of core deviation in one measurement.

An object of the present invention is to provide a non-contact type measuring device for a small amount of core deviation of a rotating shaft, which enables accurate measurement of a minute amount of core deviation even in the case of elliptical center deviation. There is something to do.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the non-contact measuring device for minute runout amount of a rotating shaft according to the present invention, two inputs are arranged in a plane perpendicular to the rotating shaft and orthogonal to the rotating shaft. Section, two amplification sections for amplifying the input signals from the input section, a comparison circuit for comparing the output signals from the amplification sections, and an output switch for selecting the output signals from the amplification section and the comparison circuit. And an output unit for displaying the output signal selected by the output switching unit.

[0007]

[Action]

 In the present invention, the input is a two-input type, and accurate measurement of the amount of runout and the runout state is performed by one measurement.

[0008]

【Example】

 Next, the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.

FIG. 2A is a side view showing a first embodiment of a measuring mechanism according to the present invention, and FIG. 2B is a plan view of the same. FIG. 4 is an output waveform diagram.

The circuit configuration of the present invention will be described with reference to FIG. In FIG. 1, the perspective change amount of the rotating measurement reference rod 8 is detected independently by the input unit 1a and the input unit 1b, and the respective signals are amplified by the amplification unit 2a and the amplification unit 2b.

Further, the comparison circuit 3 detects only the displacement difference between the amplified signals. The output switching unit 4 selects whether to output the signal of the amplification unit 2a, output the signal of the amplification unit 2b, or output the signal of the comparison circuit 3 and display the signal on the output unit 5. To do.

Next, a first embodiment of a measuring mechanism according to the present invention will be described with reference to FIGS. 2 (a) and 2 (b).

In FIG. 2A, the measurement reference rod 8 is held in advance by the tool holding mechanism 7 at the tip of the rotary shaft 11 and is rotating at a constant speed.

The amount of displacement of the measurement reference rod 8 due to the center deviation is detected by an input unit (capacitance type displacement detector) 1 a installed on the fixed table 10 on the processing table 9.

As shown in FIG. 2B, an input unit (capacitance type) installed at a position orthogonal to the input unit 1 a on a plane perpendicular to the rotation axis of the measurement reference rod 8. The displacement detector 1b detects the amount of displacement of the reference rod 8 for measurement due to the runout.

The input units (capacitance displacement detectors) 1 a and 1 b measure the displacement amount of the capacitance due to the runout of the reference rod 8. Therefore, the distance from the reference unit 8 to the input units 1a and 1b is the closer to the measurement value, the more accurate the measured value. Therefore, when the expected runout amount is about 10 μm, the reference rod 8 is set to It is desirable that the thickness is about 100 μm so that it does not come into contact with 1a and 1b.

The signal input to each of the capacitance type displacement detectors is processed by the device body 6 and displayed on the output unit 5.

(Embodiment 2) FIGS. 3A and 3B are views showing Embodiment 2 of the present invention.

In FIG. 3A, the measurement reference rod 8 is held in advance by the tool holding mechanism 7 at the tip of the rotary shaft 11 and is rotating at a constant speed.

A change due to center deviation of the measurement reference rod 8 is detected by an input unit (laser type displacement detector) 1a installed on a fixed base 10 on the processing base 9.

As shown in FIG. 3B, an input unit (laser type displacement detection) installed at a position orthogonal to the input unit 1 a on a plane perpendicular to the rotation axis of the measurement reference rod 8. Device) 1b to detect the amount of displacement of the reference rod 8 for measurement due to runout.

The input sections (laser type displacement detectors) 1 a and 1 b need a laser projector 12 on the opposite side of the reference rod 8 in between.

The amount of change in the boundary position between the region that transmits the laser light projected from the laser projector 12 and the region that blocks the laser light is measured. The distance from the reference rod 8 to the input portions 1a and 1b is preferably about 30 mm, which is different from the capacitance type displacement detector in the above-described embodiment in that a large detection distance can be obtained.

The signals respectively input by the input sections (laser type displacement detectors) 1 a and 1 b are processed by the apparatus main body 6 and displayed on the output section 5.

Next, the output waveform will be described with reference to FIG.

When the center runout is concentric circles, the signal of the input unit 1a shown in (a) and the signal of the input unit 1b shown in (b) are 90 ° out of phase and have the same amplitude. Therefore, the signal output from the comparison circuit 3 is circular.

However, in the case of an eccentric eccentricity, as shown in (c), the signals of the input section 1a and the input section 1b have different amplitudes, and the output from the comparison circuit 3 becomes an ellipse. ..

[0029]

[Effect of the device]

 As described above, according to the present invention, even in the case of elliptical center runout, there is an effect that it is possible to accurately measure the minute runout amount at one time.

With this, by early detection and early countermeasure of the defect of the rotary shaft, it becomes possible to improve the drilling accuracy and reduce the damage of the cutting tool.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.

2A is a side view showing a first embodiment of a measuring mechanism according to the present invention, and FIG. 2B is a plan view thereof.

3A is a side view showing a second embodiment of the measuring mechanism according to the present invention, and FIG. 3B is a plan view of the same.

FIG. 4 is an output waveform diagram.

FIG. 5 is a circuit configuration diagram showing a conventional example.

[Explanation of symbols]

 1a, 1b Input part 2a, 2b Amplifying part 3 Comparison circuit 4 Output switching part 5 Output part 6 Device body 7 Tool holding mechanism 8 Measurement reference rod 9 Machining table 10 Fixing table 11 Rotating shaft 12 Laser light projector

Claims (1)

[Scope of utility model registration request] 1. An input unit arranged in a plane perpendicular to a rotation axis and orthogonal to the rotation axis, two amplification units amplifying an input signal from the input unit, respectively. A comparison circuit that compares output signals from the amplification unit, an output switching unit that selects output signals from the amplification unit and the comparison circuit, and an output unit that displays the output signal selected by the output switching unit. A non-contact type measuring device for a small amount of runout of a rotating shaft.