JP3071629B2 - Automatic dimension measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic dimension measuring instrument, and more particularly, to a displacement probe, the displacement probe being supported so as to be movable in the same direction as the detection direction of the displacement probe, and the displacement of the displacement probe being digitally measured. And a length measuring means for detecting the size of the workpiece by calculating a detection amount and a movement amount of the displacement probe.

[0002]

2. Description of the Related Art To automatically measure a work having a wide measurement range, a touch probe (an electronic probe that outputs a signal at the moment of contact with the work) is attached to a detection end of a length measuring means having a wide measurement range. A method of detecting the position at the moment of contact with the workpiece by a length measuring means, and a method of attaching a displacement probe (an electronic probe capable of measuring a certain range) to a detection end of the length measuring means having a wide measuring range to detect the displacement probe And the amount of movement of the displacement probe (the amount detected by the length measuring means) is calculated to measure the size of the work. However, since the method using the touch probe cannot measure the measurement points continuously, a method using a displacement probe is used when it is desired to measure the measurement points continuously, such as measuring the shape of the work. In this case, the main body of the measurement is usually the length measuring means, and the displacement probe is used so as to detect an amount of the length measuring means that cannot follow the change of the work measurement surface. Therefore, the position of the displacement probe is controlled so that the output signal from the displacement probe is close to a predetermined value, and the deviation from the value is detected by the displacement probe. Further, a digital method is generally used for the length measuring means having a wide measurement range, and an analog signal is generally used for a control circuit for controlling the position of the displacement probe.

[0003] An example using a conventional automatic dimension measuring instrument is "Automatic dimension measuring instrument" which is described in "J.
No. ". This automatic dimensional shape measuring instrument
A displacement probe is configured by a lever mechanism that detects the displacement of the detector that abuts on the workpiece using an analog method such as a differential transformer.The displacement probe is supported so that it can move up and down in the same direction as the detection direction. Is detected by digital length measuring means. Also,
The work is moved by another horizontal moving means, thereby measuring the shape of the work. In this case, the analog signal output from the displacement probe is converted into a digital signal by the A / D converter, is calculated with the digital signal output from the length measuring means, and is output as a measured value. Further, the analog signal (voltage) output from the displacement probe is sent to the control unit of the vertical drive means of the displacement probe, and the analog signal output from the displacement probe has a predetermined value (in this case, zero).
The position of the displacement probe is controlled so as to be near.

[0004]

However, according to the method disclosed in Japanese Utility Model Publication No. Sho 61-26881, the output signal (analog) of the displacement probe is converted into a digital signal by an A / D converter, and then is converted into a digital signal by a length measuring means. There is the following problem because it is calculated with an output signal (digital). That is, if an analog signal is converted into a digital signal by an A / D converter, it takes a long time to convert the digital signal, so that a time lag occurs between the two signals, so that the work dimension detection data cannot be accurately calculated.
It is difficult to speed up the measurement because the speed of taking in the measurement data is limited by the conversion time of the A / D converter.

The present invention has been made in view of such circumstances, and has a displacement probe and the displacement probe supported so as to be movable in the same direction as the detection direction of the displacement probe, and the displacement amount of the displacement probe is digitally determined. A length measuring means for detecting the length of the workpiece by calculating the amount of movement and the amount of movement of the displacement probe. It is an object of the present invention to be able to measure a work dimension accurately and at a high speed.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a displacement probe, the displacement probe being supported so as to be movable in the same direction as the detection direction of the displacement probe, and the displacement amount of the displacement probe being digital. A length measuring means for detecting by a method, an automatic dimension measuring device for measuring the size of a workpiece by calculating a detection amount and a movement amount of the displacement probe, and (a) a digital signal and an analog signal for the displacement probe. Output both signals. (B) A control unit is provided for controlling the position of the displacement probe so that the analog output signal of the displacement probe is close to a predetermined value. (C) An arithmetic unit for calculating a digital output signal of the displacement probe and an output signal of the length measuring means is provided. (D) A data output unit for calculating and outputting measurement data from the calculated signal is provided. The configuration was as described above.

The displacement probe includes: a displacement probe; and a length measuring means for supporting the displacement probe so as to be movable in the same direction as the detection direction of the displacement probe and detecting a moving amount of the displacement probe in a digital manner. An automatic size measuring device for measuring the size of the workpiece by calculating the amount of detection and movement of the probe is used. (A) The displacement probe outputs digital signals. (B) A D / A converter for converting an output signal of the displacement probe into a corresponding analog signal is provided. (C) A control unit is provided for controlling the position of the displacement probe so that the analog signal output from the D / A converter is close to a predetermined value. (D) An operation unit for calculating an output signal of the displacement probe and an output signal of the length measuring means is provided. (E) A data output unit for calculating and outputting measurement data from the calculated signal is provided. The configuration was as described above.

[0008]

According to the present invention, since the output signal of the displacement probe is a digital signal, it can be directly calculated with the output signal of the length measuring means. Therefore, the detection amount and the movement amount of the displacement probe can be calculated at a high speed, and the work dimensions can be measured accurately and at a high speed. Further, when the displacement probe outputs both a digital signal and an analog signal, an analog output signal is directly input to the control unit, and when the displacement probe is only a digital method, the output signal of the displacement probe is After being converted into an analog signal by the D / A converter, the analog signal is input to the control unit, and the position of the displacement probe is controlled so that the output signal of the displacement probe becomes close to a predetermined value.

[0009]

FIG. 3 is an overall view of an embodiment of an automatic size and shape measuring machine using the automatic size measuring device according to the present invention. The structure of the automatic dimension measuring apparatus shown in FIG. 3 is obtained by rotating the above-mentioned conventional automatic dimension measuring apparatus by 90 ° in the vertical direction. Although the displacement is detected, the automatic dimensional shape measuring machine shown in FIG. 3 detects the displacement of the work in the horizontal direction. In FIG. 3, a column 22 is erected on a base 21 and
The length measuring means 40 is provided vertically. The length measuring means 40 includes a guide 41, a slider 42 provided on the guide 41 so as to be movable in the horizontal direction, a feed screw 43 provided on the guide 41, a feed nut 44 fixed to the slider 42, and a motor for rotating the feed screw 43. 45, a scale 46 provided on the slider 42, a detection head 47 provided on the guide 41, and a holder 48 for supporting the displacement probe 30. Further, the displacement probe 30 supported by the holder 48 is provided with a detector 30a, and the tip of the detector 30a can be detected at least in the measurement direction (X direction left and right) of the displacement probe 30. Furthermore, the base 21
Is provided with a work mounting table 23, and the work 10 is fixed to the work mounting table 23. As a result, when the motor 45 is driven, the feed screw 43 is rotated, the slider 42 is driven via the feed nut 43, and the displacement probe 30 is driven right and left in the X direction, so that the measurement surface 10
a and 10b are measured, and the amount of movement of the displacement probe 30 is measured by the scale 46 and the detection head 47 of the length measuring means 40.
The amount of calculation of the detected amount of the displacement probe 30 and the amount of movement of the displacement probe 30 (the detected amount of the length measuring means 40) is the measured value of the workpiece 10.

FIGS. 4, 5 and 6 show an outline of the structure of a first embodiment of the displacement probe 30. FIG. 4 is a central cross-sectional view in a direction perpendicular to the detection direction, FIG. 5 is a cross-sectional view taken along the line EE of FIG. 4, and FIG.
It is FF sectional drawing of. 4, 5, and 6, the displacement probe 30 </ b> A forms a parallel link mechanism in which an upper plate 31, vertical plates 32 and 32, and a lower plate 33 are connected by a cruciform leaf spring 34. The lower plate 33 is horizontally movable. As shown in FIG. 5, a coil 35 is fixed below the upper plate 31, and a core 36 loosely inserted into the coil 35 is fixed above the lower plate 33. 36 constitutes a differential transformer. Thereby, the horizontal position of the detector 30a with respect to the upper plate 31 is detected, and an analog signal is output. Further, FIG.
As shown in FIG. 7, an optical scale 37 is fixed above the lower plate 33, and a detection head 38 for detecting the position of the optical scale 37 is fixed below the upper plate 31. Thus, the horizontal position of the detector 30a with respect to the upper plate 31 is detected, and a digital signal is output. Therefore, in the displacement probe 30A, the horizontal position of the detector 30a is simultaneously detected by the two detectors, and both analog and digital signals are output.

Further, the displacement probe 30B according to the second embodiment
In the case where there is no analog detecting means for the displacement probe 30A and only the digital detecting means shown in FIG.
It is not shown again. That is, the displacement probe 30B is the same parallel link mechanism as the above-described displacement probe 30A, and the optical scale 37 is fixed above the lower plate 33, and the detection head 38 for detecting the position of the optical scale 37 is connected to the upper plate 31.
It is fixed to the lower side of. Thus, the horizontal position of the detector 30a with respect to the upper plate 31 is detected, and a digital signal is output.

FIG. 1 and FIG. 2 are block diagrams showing the control relationship of such an automatic dimension measuring device. Example 1 shown in FIG.
Is a displacement probe 30A (displacement probe having both digital and analog detection means). The digital signal of the output signal of the displacement probe 30A is sent to the arithmetic unit 52 as it is, and the length measurement means is used. It is calculated with 40 output signals. The calculated signal is sent to the data output unit 53 and output as a measured value. Also,
An analog signal (usually a voltage) of the output signal of the displacement probe 30A is sent to the control unit 51, and the control unit 51 controls the motor 35 so that the analog signal output from the displacement probe 30A becomes close to a predetermined value. It drives to control the position of the displacement probe 30A.

The block diagram of the second embodiment shown in FIG. 2 is for the displacement probe 30B (digital system only). The output signal of the displacement probe 30B is sent to the arithmetic unit 52 as it is, and the output signal of the length measuring means 40 and Is calculated. The calculated signal is sent to the data output unit 53 and output as a measured value. The output signal of the displacement probe 30B is converted into an analog signal (usually a voltage) by the D / A converter 54 and sent to the control unit 51. The control unit 51 outputs the analog signal output from the D / A converter 54. The motor 35 is driven so that the position of the displacement probe 30B is controlled so that is close to a predetermined value.

When the shape of the work 10 is measured by the automatic dimensional shape measuring machine having the above-described configuration, the operator is required to measure the work 1
0 is fixed to a predetermined position and posture of the work table 23, and when the start switch is turned on, the detector 30a comes into contact with the measurement surface of the work 10 and an output signal of the displacement probe 30 (an analog signal in the case of the displacement probe 30A). Is as it is,
In the case of the displacement probe 30B, the D / A converter 54 converts the signal into an analog signal, and the motor 45 is driven so that the position of the displacement probe 30 is controlled so that) becomes close to a predetermined value. When the output signal from the displacement probe 30 approaches a predetermined value, the output signal (digital) of the displacement probe 30 at that time and the output signal of the length measuring means 40 are calculated, and the measured value is output. When the measurement of one measurement point is completed, the length measuring means 40 is moved up and down to measure another measuring point of the workpiece 10, but the measurement is performed while moving the length measuring means 40 up and down. May be stopped. When the measurement is performed while moving the length measuring means 40 in the vertical direction, the continuous shape of the measurement surface of the workpiece 10 can be measured.

In this case, instead of moving the length measuring means 40 in the vertical direction, a vertical drive mechanism may be provided on the work placing table 23 to drive the work table 23 up and down. Alternatively, a rotational drive mechanism may be provided on the work placing table 23, or a drive mechanism perpendicular to the plane of the paper may be provided to measure the rotational direction of the work 10 or the shape perpendicular to the plane of the paper. In any case, the shape of the work 10 is measured by relatively moving the work 10 and the displacement probe 30 and the length measurement means 40 in directions different from the detection directions of the displacement probe 30 and the length measuring means 40.

In the embodiment shown in FIG. 3, an example is described in which the automatic dimensional measuring device according to the present invention is used for an automatic dimensional shape measuring device. However, the present invention is not limited to this and may be used for other measuring devices. . Further, the displacement probe 30 of the first and second embodiments has been described with respect to the case of the parallel link mechanism using the cruciform leaf spring 34 as a fulcrum. However, the present invention is not limited to this. Alternatively, the present invention can be applied to a guide using a linear bearing or an air bearing which makes the detector 30a freely movable in the horizontal direction, or a guide using a lever mechanism or the like as in the conventional example. Further, in the embodiment, the case where the detection direction is the horizontal direction has been described,
The present invention can also be applied to a case where the detection direction is the up and down direction as in the automatic size and shape measuring device described in the conventional example.

[0018]

As described above, according to the automatic dimension measuring device according to the present invention, the displacement probe 30 and the displacement probe 30 are movable in the same direction as the detection direction of the displacement probe 30.
And a length measuring means 40 for detecting the amount of movement of the displacement probe 30 in a digital manner, and measuring the size of the workpiece by calculating the amount of movement and the amount of detection of the displacement probe 30. The configuration was as described above. Thus, since the output signal of the displacement probe 30 is a digital signal, it can be directly calculated with the output signal of the length measuring means 40. Therefore, it is possible to provide an automatic dimension measuring device capable of calculating the detection amount and the movement amount of the displacement probe 30 at a high speed, and measuring the work size accurately and at a high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of an automatic dimension measuring device according to the present invention.

FIG. 2 is a block diagram of a second embodiment of the automatic dimension measuring device according to the present invention.

FIG. 3 is an overall view of an embodiment of an automatic dimension measuring device using the automatic dimension measuring device according to the present invention.

FIG. 4 is a schematic cross-sectional view of a structure of a displacement probe according to a first embodiment of the present invention, which is taken at a center perpendicular to a detection direction.

FIG. 5 is a sectional view taken along line EE of FIG. 4;

FIG. 6 is a sectional view taken along line FF of FIG. 4;

[Explanation of symbols]

 10 Work 21 Base 22 Column 23 Work table 30 Displacement probe 30a Detector 35 Coil 36 Core 37 Optical scale 38 Detection head 40 Length measuring means 51 Control section 52 Calculation section 53 Data output section 54 D / A converter

Claims (2)

(57) [Claims] 1. A displacement measuring device comprising: a displacement probe; and a length measuring means for supporting the displacement probe so as to be movable in the same direction as the detection direction of the displacement probe and detecting a moving amount of the displacement probe in a digital manner. In an automatic dimension measuring device that measures a dimension of a work by calculating a detection amount and a movement amount of a probe , the displacement probe is an optical scale and a read head.
And a digital sensor for outputting a digital signal.
And outputs the analog signal at Sa, and differential transformer type
A control unit that includes an analog sensor, outputs the digital signal to a calculation unit, outputs the analog signal to a control unit, and controls the position of the displacement probe so that the analog signal is close to a predetermined value; An automatic dimension measuring device, comprising: a calculation unit for calculating a signal and an output signal of the length measuring means; and a data output unit for calculating and outputting measurement data from the calculated signal. 2. A displacement measuring apparatus comprising: a displacement probe; and a length measuring means for supporting the displacement probe so as to be movable in the same direction as the detection direction of the displacement probe and detecting a moving amount of the displacement probe in a digital manner. In an automatic dimension measuring device that measures a dimension of a work by calculating a detection amount and a movement amount of a probe, the displacement probe may be an optical scale and a read head.
And a digital sensor for outputting a digital signal.
And service, and the D / A converter for converting an analog signal corresponding to the output signal of the displacement probe, the digital signal to the calculation unit, and outputs the analog signal to the control unit, the analog signal is a predetermined value A control unit that controls the position of the displacement probe so as to be in the vicinity; a calculation unit that calculates the digital signal and an output signal of the length measurement unit; and a data output that calculates and outputs measurement data from the calculated signal. And an automatic dimension measuring device, comprising: