JPH06294641A - Comparative length measuring equipment - Google Patents

Abstract

PURPOSE:To measure the dimensions at important points of a work precisely without requiring any master or a thermostatic bath by fixing a block gauge having length matching the measuring part of the work to one side on a surface plate and comparing the measurements between the block gauge and the work. CONSTITUTION:A work 6is secured to a predetermined point of a surface plate 3 in parallel with any one of X, Y, Z axes of the equipment by means of a jig 4 and a clamp mechanism 5. A block gauge 7 matching, in dimensions, the measuring part of the work 6 is secured in parallel with any one of X, Y, Z axes (reference moving axis) of the equipment. A driving program required for measuring operation of a probe 13 is stored in a multispindle controller through a keyboard. Upon starting the operation, the probe 13 is shifted to the block gauge 7 and touches the block gauge 7 several times. The measurements are averaged and registered as a reference value. Subsequently, the probe 13 is shifted to the work 6 which is then measured and the measurement is compared with a registered reference value and the error is displayed 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to determine a required position in a work having a relatively simple shape, for example, a dimension between wall surfaces parallel to the X, Y, and Z axes, a diameter of a cylinder, and a circular hole. The present invention relates to a comparative length measuring device capable of directly displaying the numerical value equivalent to the measurement data in a standard temperature-controlled room by performing a comparative length measurement with a block gauge suitable for this.

[0002]

2. Description of the Related Art Various three-dimensional coordinate measuring machines have been used in the past to measure the size or shape of a work, and due to their wide adaptability and highly automated equipment, they are commonly used. In addition, this type of precision measuring instrument is often used in a temperature-controlled room, requires a considerable amount of skill in its operation, and in addition, the price of the device itself is very expensive.

In addition, as a means for measuring the size of the object to be measured,
Reference measurement object (master) made within the manufacturing tolerance of the measurement object
Is prepared in advance, and a comparative measuring machine that determines the quality of the work by comparing the coordinate values at the corresponding points of this master and the measured work has also been put into practical use. It is necessary to prefabricate a good master of the above, to perform precise measurement of the master, and to collect the reference dimension data thereof.

[0004]

The production of the above-mentioned master is difficult to deal with small-lot production parts of other types and requires precise measurement in a temperature-controlled room. In order to support the measurement, it is an effective means to use a block gauge whose measured value in the standard state is already guaranteed.

[0005]

Therefore, according to the present invention, a block gauge having a length adapted to a measurement main part of a work is provided on one side of the same plate for holding a work as an object to be measured. Of the reference movement axes (X, Y, Z coordinate axes) of, are fixed according to any direction, and standard environmental temperature conditions (20 ± α
The feature is that the dimensions of the block gauge at (° C) are adopted as a reference value, and the corresponding main part of the work is measured using this value as a reference length.

[0006]

[Operation] That is, it is determined that the work held on the surface plate and the block gauge are under the same environmental temperature, and the length measurement value of the block gauge in this state is recognized as the standard gauge size. According to the above, the dimension of the corresponding portion of the workpiece to be comparatively measured is to be displayed as an actual dimension or a tolerance dimension under the standard environmental temperature of measurement.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in order to show an embodiment of the present invention, a table 2 slidable on a base 1 of a machine base in the X-axis direction is equipped as an X-axis slider, and fixed on the upper side. Fix the board 3. At the top of the surface plate 3, a suitable jig 4
Using the clamp mechanism 5 and the workpiece 6 as the object to be measured
Is held in a predetermined orientation. On the other hand, on one side (left side in the drawing) of the surface plate 3, a block gauge 7 _L that matches the vertical dimension L of the lower part of the work, and a block gauge 7 _H that matches the height H of the work cylinder part, The block gauges 7 _D that match the diameter D of the section are fixed in accordance with the measurement direction of the work 6. Of course, the number of block gauges may be increased or decreased depending on the number of measurement-required points on the work 6.

A column 8 corresponding to the table 2 is provided upright in the rear of the center of the base 1, and a Y-axis slider 9 which is movable in the Y-axis direction orthogonal to the X-axis is provided above the column 8.
Erection. On the front side of the Y-axis slider 9, there is provided a holding body 12 of a Z-axis slider 11 which is orthogonal to the X-axis and the Y-axis and is freely movable in the Z-axis direction via a support frame 10. A probe 13 is attached to the extended lower end of the Z-axis slider 11, and the probe 14 is made to correspond to the work 6 and the block gauge 7 on the surface plate 3, and the probe 14 that abuts on these measurement points. Enables three-dimensional movement.

Further, the table 2 is driven in the X-axis direction with respect to the base 1, the Y-axis slider 9 is driven in the Y-axis direction with respect to the column 8, and the Z-axis slider 1 mounted on the holding body 12.
The driving of 1 in the Z-axis direction is constituted by a linear actuator, a motor and an encoder, and is connected to a multi-axis controller 15 having a servo function. Each of the X-axis driving device 16 and the Y-axis driving device 17, And the Z-axis drive device 18. The above multi-axis controller 15
A teaching box 19 is connected to the above, and the necessary data input from these is also stored in the ROM device 20.

The relative movement amount of the probe 13 with respect to the surface plate 3 in the X-axis direction is determined by the X-axis provided on the base 1 and the table 2.
Detected by the axis scale 21, and Y of the probe 13
The amount of relative movement in the axial direction and the Z-axis direction is
The Y-axis scale 22 associated with the axis slider 9 and the Z-axis scale 2 associated with the holder 12 and the Z-axis slider 11.
3 are detected respectively. The read signals from these X, Y, Z axis scales 21, 22, 23 are passed through the respective X axis amplifier 24, Y axis amplifier 25, and Z axis amplifier 26 shown in FIG. Each axis counter 27, 28,
It is input to 29 and is counted here, but the probe touch signal from the probe 13 is input to the probe amplifier 3
0 and each counter 2 via the interface 31
Since it is input to the motherboard 32 equipped with 7, 28, 29, each counter has X.
It is possible to latch the Y / Z axis movement amount read value.

Further, there are the multi-axis controller 15 and the data processing device 33 connected to the mother board 32,
Further, an operation display panel 34 is connected to the data processing device 33. The data processing device 33 has an input device such as a keyboard 35, and the output unit has a display 36,
The printer 37 is connected as needed. Operation display panel 3
The display 4 and the display 36 are arranged, for example, as shown in FIG.

In the case of this embodiment having such a structure, first, the work 6 is held at a predetermined position on the surface plate 3 by an appropriate jig 4 and clamp mechanism 5. At this time, if the main measurement point of the work 6 is set so as to be parallel to any of the X, Y, and Z axes of the device, the measurement work and the calculation of the measurement value are simplified. Next, the block gauge 7 suitable for the required measurement portion size of the work 6 is fixed to the space portion on one side of the surface plate 3,
Block this method, for example, block gauges 7 _L corresponding to the lower side dimension L of the workpiece 6, as the length measurement unit is parallel to the Y axis of the device, also corresponding to the height H of the workpiece cylindrical portion The gauge 7 _H is set up on the surface plate, and the block gauges 7 _D corresponding to the diameter D of the work cylindrical portion are fixed so as to be parallel to the X axis (or Y axis) of the apparatus.

After the above preparatory work is completed, the measuring work is started. Since the driving program necessary for the measurement operation of the probe 13 is stored in the multi-axis controller 15 in advance by the teaching box 19 (or the keyboard 35), when the measurement work start command is issued,
First, the probe 13 moves to the block gauge mounting portion of the surface plate 3, touches the probe 14 on the measurement surface of the block gauge 7 _L several times from the Y-axis direction, and averages the coordinate readings of both touch surfaces. Then, this is registered as the display length of the block gauge 7 _L (length at standard environmental temperature). Such sampling operation, the height direction of the block gauge 7 _H, also made to the measurement surface of the block gauge 7 _D, are incorporated into the device as the reference data for each.

Next, the measurement of the work 6 is started, and first, the probe probe 14 touches the front and rear wall surfaces of the work lower side in the Y-axis direction. Calculates the contact point readings coordinate value, the comparison with the block gauge 7 narrowing already reference value takes the _L, the measured value and the decrement value for the standard dimensions of the longitudinal dimension (error amount) in the operation display panel 34 or display 36 indicate. In order to measure the height H of the cylindrical portion of the work 6 (the step between the lower side of the work and the upper surface of the cylindrical portion), the probe probe 14 is touched on the upper surface of the lower side of the work and the upper surface of the cylindrical portion. , The respective Z-axis coordinate read values are calculated and compared with the incorporated reference value of the block gauge 7 _H , and the measured value of the height H and the error value with respect to the standard dimension are displayed.

The diameter D of the cylindrical portion of the workpiece is measured by touching and rotating the outer circumference of the cylindrical portion under the condition that the Z-axis coordinate value of the probe probe 14 is fixed. There are several methods to select this measurement point, but touch three points on the circumference to
A method of geometrically calculating each X / Y coordinate value to obtain the diameter and center coordinate value of the cylindrical portion, or moving the probe 13 on the Y-axis coordinate line passing through the approximate center position of the cylindrical portion and touching the cylindrical portion. The Y-axis value of the center coordinate value is calculated, the Y-axis value of the center coordinate value is calculated, the operation in the X-axis direction at this Y-axis coordinate value is given to the probe 13, and the X-axis coordinate at which the probe contact point abuts the cylindrical portion. A method of calculating values, or a method of calculating the XY coordinate measurement values at four or more points on the circumference by the least-squares method to obtain the average value of the diameter and the coordinate value of the center of the circle. However, it is practical to use the least squares method in terms of error statistics.

[0016]

As is clear from the above, the comparative length measuring apparatus according to the present invention does not require the production of an accurate master based on the production drawing of the work, and is generally used as a means for incorporating the reference dimension data. Since a block gauge whose accuracy is officially certified is used, accurate length measurement can be performed according to this gauge accuracy and the accuracy of the X, Y, and Z axis scales. However, the accuracy of the above block gauge, the accuracy of the axis scale, and the resolution are 1μ.
Since products with performance of m or less can be easily obtained, there is no difficulty in selecting components.

In particular, the present apparatus, when registering the reference value serving as the comparative length measurement base, regardless of the environmental temperature at the time of measurement,
Measured length of block gauge and its display value (length at 20 ± α ° C in standard measurement state when manufacturing block gauge)
Is input to the apparatus and the coordinate value is calculated with these values as a reference, so that the absolute length and error value in the standard state can be accurately measured and displayed. In addition, the registration of the standard measured value in the block gauge is a numerical value obtained by re-registering at any time by the sampling operation described above even if the environmental temperature during measurement work changes, and converting the dimension calculation value to the display value of the block gauge. Thus, since the comparative length measurement is performed, it is possible to effectively reduce the decrease in the length measurement accuracy due to the temperature change.

[Brief description of drawings]

FIG. 1 is a front view of a comparative length measuring apparatus showing an embodiment of the present invention.

FIG. 2 is a side view corresponding to FIG.

FIG. 3 is a block circuit diagram of a comparative length measuring apparatus showing an embodiment of the present invention.

FIG. 4 is a perspective view showing an arrangement example of a work and a block gauge on a surface plate.

[Explanation of symbols]

 2 table (X-axis slider) 3 surface plate 6 work (object to be measured) 7 block gauge 9 Y-axis slider 11 Z-axis slider 14 probe probe 15 multi-axis controller 21 X-axis scale 22 Y-axis scale 23 Z-axis scale 33 data Processor 34 Operation display panel

Claims (1)

[Claims] 1. A three-dimensional measurement in which a probe provided in a measuring mechanism is moved relative to an object to be measured (hereinafter referred to as a work) supported on a surface plate in X, Y, and Z axis directions orthogonal to each other. In this method, a block gauge with a length that fits the measurement part of the work is fixed at a predetermined position on the surface plate, and the measured value of this block gauge and the corresponding predetermined location of the work are measured. A comparative length measuring device capable of displaying the actual size of the required part of the work or the error size with respect to the block gauge by comparing and calculating the value.