JP3366052B2 - Comparative length measuring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a part having a relatively simple shape, such as a dimension between walls parallel to X, Y, and Z axes. A comparative measurement method that can directly measure and measure the diameter of cylinders and holes, etc. with a block gauge that conforms to the measurement data, and directly display numerical values equivalent to measurement data in a constant temperature room under standard conditions. . 2. Description of the Related Art Conventionally, various three-dimensional coordinate measuring machines have been used for measuring the size or shape of a work, and are widely used due to their wide adaptability and advanced automation equipment. In general, such a precision measuring instrument is often used in a constant temperature room, and its operation requires considerable skill. In addition, the price of the apparatus itself is very expensive. . [0003] As means for measuring the dimensions of the object to be measured,
Reference workpiece (master) built within the tolerance of the workpiece
A comparison measuring machine that determines the quality of a work by comparing coordinate values at corresponding points between the master and the work to be measured has been put to practical use. It is necessary to manufacture a master having good quality in advance, accurately measure the master, and collect its reference dimension data. [0004] The production of the above master is troublesome to cope with low-volume production parts of other types, and requires precise measurement in a constant temperature chamber. In order to respond to the measurement of various products, it is effective to use a block gauge whose measured value in a standard state is already guaranteed. According to the present invention, an object to be measured (hereinafter referred to as a "workpiece") is measured by X, Y, and Z.
Set on the surface plate so as to be parallel to any of the axial directions,
Only the reference length that matches each of the measurement
A block gauge of a simple shape to be provided is fixed at a predetermined position on the surface plate so as to be parallel to a direction of a corresponding main part of the work, and a probe equipped with a measuring mechanism is connected to a X. The relative movement in the Y and Z axis directions measures the block gauge and a predetermined portion of the work corresponding thereto, and a standard value obtained by measuring the block gauge and an actual measurement value obtained by measuring the predetermined portion of the work corresponding thereto. By performing the comparison operation, the actual size of the required portion of the work or the error size with respect to the block gauge is displayed. 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 measured value of the block gauge in this state is compared with the standard size of the gauge. By recognizing, the size at the corresponding part of the workpiece to be compared and measured is to be displayed as the actual size or the tolerance size at the standard environmental temperature of the measurement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In describing an embodiment of the present invention, referring to the drawings, a table 2 slidable in the X-axis direction on a base 1 of a machine is equipped as an X-axis slider. The platen 3 is fixed on the upper part. At the top of the surface plate 3, a suitable jig 4
Work 6 as an object to be measured using the
Is held in a predetermined direction. On one side of the surface plate 3 (left side in the drawing), the block gauge 7 _L conforming to the longitudinal dimension L of the workpiece under side, also the block gauge 7 _H conforming to the height H workpiece cylindrical portion, further work cylinder the gauge block 7 _D conforms to the diameter D of parts, fixed in accordance with the measurement direction of the respective workpiece 6. Needless to say, the number of block gauges is increased or decreased as needed in accordance with the number of measurement points on the work 6. A column 8 corresponding to the table 2 is erected at the rear of the center of the base 1, and a Y-axis slider 9 is provided above the Y-axis slider 9 which is orthogonal to the X-axis and freely movable in the Y-axis direction.
Erection. On the front side of the Y-axis slider 9, there is provided, via a support frame 10, a holder 12 for 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. A probe 13 is mounted on the extended lower end of the Z-axis slider 11 so that the probe 14 corresponds to the work 6 and the block gauge 7 on the surface plate 3, and the probe 14 contacts the measurement points. Enables three-dimensional movement. The table 2 is driven relative to the base 1 in the X-axis direction, the Y-axis slider 9 is driven relative to the column 8 in the Y-axis direction, and the Z-axis slider 1
1 is driven in the Z-axis direction by a linear actuator, a motor, an encoder, and the like, and is connected to a multi-axis controller 15 having a servo function. And the Z-axis driving device 18. The above multi-axis controller 15
Is connected to a teaching box 19 so that necessary data input from these can be stored in the ROM device 20 as well. The amount of relative movement of the probe 13 in the X-axis direction with respect to the base 3 is determined by the X
Detected by the axis scale 21 and Y of the probe 13
The relative movement amount in the axial direction and the Z-axis direction
Y-axis scale 22 associated with axis slider 9 and Z-axis scale 2 associated with holder 12 and Z-axis slider 11
3 respectively. The read signals from these X, Y, and Z axis scales 21, 22, and 23 are transmitted through the respective X, Y, and Z axis amplifiers 24, 25, and 26 shown in FIG. Axis counters 27, 28,
29, and is counted here. The probe touch signal from the probe 13 is
0 and each counter 2 via the interface 31
Since each of the counters is input to the motherboard 32 equipped with 7, 28, and 29, each counter outputs X ·
It is possible to latch the Y and Z axis movement readings. There is a data processing device 33 connected to the multi-axis controller 15 and the motherboard 32.
Further, an operation display panel 34 is connected to the data processing device 33. The data processing device 33 includes an input device such as a keyboard 35, and the output unit includes a display 36,
A 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 configuration, first, the work 6 is held at a predetermined position on the surface plate 3 by an appropriate jig 4 and a 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, a block gauge 7 suitable for a required measurement portion size of the work 6 is fixed to one side space 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 gauge 7 _H is in a state of standing on a surface plate, further blocks gauges 7 _D corresponding to the diameter D of the workpiece cylindrical portion are respectively fixed so as to be parallel to the X axis of the device (or Y axis). After the above-mentioned preparation work is completed, the measurement work is started. The driving program necessary for the measurement operation of the probe 13 is stored in the multi-axis controller 15 by the teaching box 19 (or the keyboard 35) in advance.
First probe 13 is moved to the block gauge mounting portion of the base 3, and several touch the Y-axis direction that the measuring element 14 on the measuring surface of the gauge blocks 7 _L, and the average calculating the coordinate readings of both the touch surface This is registered as the display length of the block gauge 7 _L (the length at the standard environmental temperature of 20 ± α ° C. ). 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 tracing stylus 14 touches the front and rear wall surfaces of the lower part of the work from 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. For measurement of the height H of the cylindrical portion of the work 6 (the step between the lower portion of the work and the upper surface of the cylindrical portion), the probe probe 14 is touched to the upper surface of the lower work portion and the upper surface of the cylindrical portion. , and calculates the Z-axis coordinate readings respectively, compared to the block gauge 7 narrowing already reference value taken for _H, and displays an error value for the measured values and standard dimensions of the height H. Further, the measurement of the diameter D of the work cylinder is performed by touching the outer periphery of the cylinder under the condition that the Z-axis coordinate value of the probe tracing stylus 14 is fixed. There are several methods for selecting this measurement point. Touch the three points on the circumference to
A method of geometrically calculating the respective X and Y coordinate values to obtain the diameter and center coordinate value of the cylindrical portion, or two points of moving the probe 13 on a Y-axis coordinate line passing through a substantially center position of the cylindrical portion and touching the cylindrical portion. Is calculated, the Y-axis value of the center coordinate value is obtained, 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 probe comes into contact with the cylindrical portion is obtained. A method of calculating a value, or a method of calculating an X / Y coordinate measurement value at four or more points on the circumference by a least square method to obtain an average value of the diameter and a coordinate value of the center of the circle, etc. However, it is practical to use the least squares method statistically for errors. [0016] As described above, the comparative length measurement according to the present invention.
The method does not require the production of an accurate master based on the production drawing of the workpiece, and generally uses a block gauge whose accuracy has been approved as a means for taking in reference dimension data.・ Accurate length measurement according to the accuracy of the Y and Z axis scales is possible. Needless to say, the block gauge accuracy, axis scale accuracy and resolution are both 1 μm.
There is no difficulty in selecting components because the following performances are readily available. In particular, the apparatus according to the present invention, when registering a reference value serving as a comparison measurement base, measures the actual measured length of the block gauge and its display value (the measured standard state when the block cage is manufactured) regardless of the environmental temperature at the time of measurement. (Length at 20 ± α ° C) to the device and calculate the coordinate value based on these values. Therefore, the absolute length and error value in the standard condition must be accurately measured and displayed. Can be. In addition, the registration of the reference actual measured value in the block gauge is performed by re-registering at any time by the above-mentioned sampling operation even if the environmental temperature changes during the measurement work, and converting the dimensional operation value to the display value of the block gauge. Because the comparative measurement is performed,
It is possible to effectively reduce a decrease in length measurement accuracy due to a temperature change. Also, in the case of the present invention, the work is a main part of the measurement.
Set so that is parallel to any of the X, Y, and Z axis directions
And a block of a length suitable for the main measurement part of the workpiece
Set the gauge parallel to the direction of the corresponding measurement
Measurement work and measurement values
The calculation is simplified.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a comparative length measuring device showing one 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 device showing one embodiment of the present invention. FIG. 4 is a perspective view showing an example of the arrangement of a work and a block gauge on a surface plate. [Description of Signs] 2 Table (X-axis slider) 3 Surface plate 6 Workpiece (measurement object) 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 processing unit 34 Operation display panel

Claims (1)

(57) [Claims] [Claim 1] An object to be measured (hereinafter, referred to as a work) is set on a surface plate such that a main portion of the object to be measured is parallel to any of the X, Y, and Z axis directions. , Only the standard length that fits each of the measurement
The block gauge of the simple shape to be provided is fixed at a predetermined position on the surface plate so as to be parallel to the direction of the corresponding measurement main part of the work. Y
Relative movement in the Z-axis direction measures the block gauge and the corresponding location on the workpiece, and compares the standard value obtained by measuring the block gauge with the actual measurement value obtained by measuring the corresponding location on the workpiece. A comparative length measurement method characterized by displaying the actual dimensions of the required part of the work or the error dimensions with respect to the block gauge.