JPH01259211A - Diameter measuring instrument for circularity measuring machine - Google Patents

Abstract

PURPOSE:To prevent the drift error of a 1st detector which contacts an outer periphery by using a bidirectional type of (+) and (-) for the 1st detector and using the detector for circularity measurement and diameter measurement, and measuring the diameter of a work without rotating it. CONSTITUTION:A master piece 10 is set on a turntable 2, a horizontal arm 6 is moved to make the contactor 13 of the 1st detector 12 abut on the right flank of the master 10, and a read of a 2nd detector 8 is found. Then the 1st detector 12 is moved to the left flank of the master 10, the contactor 13 is made to but on the left flank of the master 10, and a read D2 of the 2nd detector 8 is found. The error (e) of the device is found from those two reads D1 and D2 and the size D of the master 10 which is already known. Then the master 10 is detached and the work is set; and said operation is performed similarly to measure the diameter size of the work, thereby correcting said error (e).

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a roundness measuring device which is also equipped with a device for measuring the diameter of a cylindrical body with high precision.

Prior Art> Fig. 5 shows a conventional roundness measuring device, in which a rotary table 2 is vertically installed on a table 1, and a cylindrical body 3 to be measured (hereinafter referred to as a workpiece) is placed upright on the rotary table 2. set. A column 4 is vertically erected on the table 1, and a sliding body 5 is provided thereon so as to be freely movable up and down and fixed.

A first detector 7 for outer circumference measurement is attached to the tip i (left side in the figure) of a horizontal arm 6 that horizontally passes through the sliding body 5. Then, move the horizontal arm of the first detector 7 horizontally as appropriate, apply the contact of the detector to the side surface of the cylinder, and fix it. Rotate the rotary table 2 and measure the outer peripheral shape from the displacement of the output of the detector 7. to find the roundness.

At this time, there is a desire to know the actual dimensions on the recorded figure by knowing the diameter of the workpiece at that position with high precision, similar to the measurement of roundness.

Therefore, in the conventional method, as shown in the figure, a U-shaped support arm is provided on the right side of the sliding body 5, and a diameter reading Q'S2 detector 8 for diameter measurement is installed horizontally on this support arm. Read position. Then, stand the master piece on the rotary table 2, apply the contact of the first detector 7 to the side, and then the first detector 7
Adjust the horizontal position of the arm 6 so that the output of indicates the zero point, take the reading of the second detector 8 at that time, and set the rotary table to 180 degrees.
Rotate by ° and take the same measurements as above again to find the correction value for the known diameter value of the mask. Then, the workpiece 3 is mounted on the rotary table 2, and the diameter of the workpiece is detected in the same manner. However, here, the center axis of the column 4, the rotation center of the turntable 2, and the center of the warp 23 do not necessarily coincide,
Furthermore, since the center of rotation and the vertical movement of the detector are not parallel, errors will inevitably occur and cannot be completely corrected. In particular, the first detector 7 uses a differential transformer, but time drift occurs due to the elapse of time between measuring the mask and measuring the workpiece, making correction difficult. Therefore, there was a drawback that highly accurate measurements were not possible.

<Object of the present invention> In the present invention, the first detector in contact with the outer periphery is
)(-) bidirectional type, used for measuring roundness and diameter, and measuring the diameter without rotating the workpiece. The purpose of this is to prevent mechanical errors and first detector drift errors as much as possible.

<Example> In FIG. 1, the horizontally movable arm 6 passing through the sliding body 5
A support frame 11 curved into a hook shape is provided at the left end of the support frame 11, and a first detector 12 is attached to this in a downward direction. At this time, the detector contact 13 is positioned on the center line of the second detector 8 on the right.

As shown in FIG. 2, the 11 detector 12 has a spring 15, 16 for applying pressure force to bias the contact 13 left and right with respect to the probe lever 14. Balance is maintained at that point, and the output of the differential transformer 17 at that point is made zero. That is, it has a detection function in both left and right directions, and uses this to first measure roundness.

Next, the order in which diameter measurements are performed using this device will be explained. First, set the master piece 10 on the rotating table 2,
By moving the horizontal arm 6 from right to left through the sliding body 5! @1 Place the contact 13 of the detector 12 on the right side of the master piece.

Since the vicinity of the zero point of the detector output is an equilibrium point and is unstable, the reading r) of the second detector 8 is obtained at the point where the planting soil α is output, which is slightly deviated from this point. Next, in FIG. 1, the first detector 12 is moved to the left side of the master 10, and moved horizontally to apply the contact 13 to the left side of the master from left to right. At this time, the points where the contacts touch are defined as diameter points in the front and back. Then, at the time when the detected value shows 1 α, the second detector 8 reads D2, and according to the known size of the master, the error value e=l of this device is obtained.
Find D, -D21-D. Next, remove the master, set the workpiece, and measure the diameter by moving +α from right to left and 1α from left to right in the same way.
Perform error correction for e.

Note that if the workpiece is curved, such as a crankshaft, it is not possible to press the first detector 12 from above as shown in Figure 1, so a detector with a contact formed thereon as shown in Figure 4 is used. By placing the workpiece horizontally and sandwiching it at the diameter position, it is possible to detect the roundness and diameter value of the cylindrical part of the workpiece.

Effects> In the present invention, a special bidirectional type first detector is used, and it is also possible to measure roundness using this as in the conventional case. And when measuring the diameter, there is no need to rotate the workpiece.
Measurement is performed only by horizontal movement of the detector. and! Even if time drift F occurs in the differential transformer of @1 detector, (+)(-
) Since the diameter is detected as a difference in the direction, drift errors are also canceled, and measurement with less error is easily possible.

In addition, by rotating the workpiece and combining it with the roundness shape of the workpiece, it is possible to measure the average diameter, etc., and exhibits excellent practical effects.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of the diameter measuring device of the present invention, Fig. 2 is an explanatory diagram of the configuration of the first detector used in the invention, Fig. 3 is an explanatory diagram of its measurement, and Fig. 4 is an explanatory diagram of the configuration of the first detector used in the invention. FIG. 5 is an explanatory view of the structure of a conventionally widely used roundness measuring device, and an explanatory view of a case where a diameter measuring device is attached to the same. 1...Table 2...Turnable table 3. Workpiece 4
...Column 5...Sliding body 6...Horizontal arm 7
...Conventional first detector 8...Diameter reading second detector 11...Support frame 12...First of the present invention
Detector 13...Contact 14...Sensor lever Is, 1G...Spring 17...Differential transformer patent applicant Tokyo Seimitsu 71 Co., Ltd.

Claims (3)

[Claims] (1) In a roundness measuring machine, there is a horizontal arm that guides the contact of the first detector horizontally and diametrically with respect to the cylindrical workpiece, and a first detector that is installed at the tip of this arm. The first method allows the contactor of the device to touch two points at the diametrical position.
A diameter measuring device for a roundness measuring machine comprising a support frame for a detector and a second diameter reading detector for detecting the amount of horizontal movement of a horizontal arm. (2) The measuring device according to claim 1, wherein the measuring device is a single detector in which the probe lever of the first detector is of a two-way type (+) and (-). (3) The measuring device according to claim 1 or 2, wherein the contact lever of the first detector that contacts the diameter is a clamp type that contacts the work at the diameter position.