JPH0143602Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an inner diameter measuring device, and particularly to an inner diameter measuring device that can universally measure inner diameters of different dimensions.

For example, when measuring workpieces A, B, etc. with different design dimensions accurately and efficiently, a guide with a predetermined clearance is used to position the contacts provided in the diametrical direction in the correct position. Must be inserted safely. Conventionally, therefore, a method has been adopted in which separate measuring devices having guides corresponding to the dimensions A, B, etc. are prepared and replaced depending on the workpiece. However, when the measurement of a workpiece is changed, in order to quickly respond and measure the change, it is desirable that one measuring device can be applied universally to the workpieces A, B, and so on.
The object of the present invention is to provide a device that enables general-purpose measurements with a simple mechanism and operation.

In FIG. 1, two probe levers 4 having probes 2 and 3 at their tips in the diametrical direction (however, the upper and lower detection mechanisms are the same, so the upper one will be explained) are connected to a thin wall portion 5. The right side 6 of the lever is rotated using the lever as a fulcrum, and the tip of the right side 6 is connected to the core of the differential transformer 7. Since the probe lever has a long left side and a short right side of the fulcrum, the amount of displacement of the contacts 2 and 3 is reduced and transmitted to the differential transformer, so the measurement range becomes larger. In order to protect the contactor 2 at the tip of the probe lever 4, a triangular small guide 9 with an inclined surface is attached to the tip, allowing the contactor to enter the hole to be measured without any trouble. do. However, this alone does not necessarily ensure that the contacts 2 and 3 enter the correct diametrical position, so a guide is required, but in the present invention, a movable guide is provided to suit different workpiece dimensions.

This movable guide 10, as shown in FIGS. 2 and 3,
The fixed guide 11 at the tip of the measuring device (left end in Figure 3) enters a radial cross-shaped groove provided at a 45° angle to the diameter direction made by the contacts 2 and 3, allowing each to enter and exit radially independently. It is said that Each movable guide 10 is pulled toward the center by a spring 12. In addition, each movable guide is provided with two rollers 13 and 14 inside, and these rollers 13 and 1
4 is pressed against two square cam plates 15 and 16 by a spring 12. As shown in FIG. 4, the square cam plate simultaneously pushes out the rollers in contact with it by its rotation, or serves as a stopper when the rollers retreat toward the center. The movable guide 10 is thereby expanded or contracted.
Since the two cam plates 15 and 16 are fixed to the central shaft 17 at the same relative position, when the shaft 17 is rotated forward and backward, the four movable guides 10 simultaneously move in and out by the same amount in parallel. A rotary encoder 18 detects the entrance/exit position of the movable guide based on the rotation angle of the shaft 17. Also, 19 is the axis 17
A dog that is screwed together and has a large diameter protrusion on the outer periphery,
20 and 21 are opened and closed by being pushed by the protrusion of the dog,
This is a limit switch that regulates the rotation angle of the shaft 17, that is, the maximum and minimum positions of the movement of the movable guide 10 in and out. Although not shown in the figure, a motor capable of forward and reverse rotation is connected to the shaft 17.

When measuring a workpiece of dimension A in the above structure, first, the shaft 17 is rotated to move the movable guide 10 to the minimum dimension position where the limit switch 20 is closed, and then stopped. Next, insert this device into the master of the measurement dimensions. At this time, the contacts 2 and 3 enter the hole without any trouble by the small guide 9 having a triangular slope at the tip thereof, and the contacts are pushed in until they reach the master dimension, and a corresponding measurement signal is output. The rotation angle of the plate cam corresponding to this output is determined in advance, and the shaft 17 is rotated while the angle is detected by a rotary encoder, and the shaft 17 is stopped at a predetermined angle, that is, at a position where the movable guide has a constant clearance from the master. The contactor is set by a biasing means and a stopper (not shown) so that it can be opened and closed over the entire measurement range regardless of the movable guide. Next, adjust the zero point and measure the A dimension workpiece. The measurement dimension is B
When changing the dimensions, use the same procedure to change the settings. Note that it is also possible to automate these operations.

In the above embodiment, the cam plate is square and there are four movable guides, but the cam plate is a polygon of triangular or larger.
The number of movable guides may correspond to the number of sides of the polygon. However, for practical purposes, triangular and quadrangular shapes are preferred. Further, the detector is not limited to the differential transformer type, and other types such as a pneumatic type or an electric capacitance type can also be used.

As explained above, according to the device of the present invention,
Within a specified range, the same device can respond to changes in measurement diameter without the need to replace the guide, reducing the number of man-hours required for setup changes and reducing procurement costs for replacement parts. It is possible to save money, and furthermore, it is possible to have several types of workpieces with different sizes run on the same production line, and other great effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the detection part of the device of the present invention;
2 is a front view, FIG. 3 is a sectional view showing a movable guide mechanism, and FIG. 4 is a sectional view taken along the line - in FIG. 3. 2, 3...Contact element, 4...Detector lever, 7...
Differential transformer, 9...Small guide, 10...Movable guide,
11... fixed guide, 13, 14... roller, 15,
16... Square cam plate, 17... Central shaft, 18...
...Rotary encoder, 19...Dog, 2
0,21...Limit switch.

Claims (1)

[Scope of utility model registration request] In an inner diameter measuring device that has a probe tip in the diametrical direction and measures a diameter dimension by displacement thereof, a plurality of movable guides are provided at equal intervals and radially at positions shifted from the diametrical direction; Two rectangular cams are fixed at the same relative position to the tip of a center shaft that can be rotated in forward and reverse directions, and change the movable guide from the inside to the outside, and a roller is provided between the movable guide and the cam. An inner diameter measuring device consisting of.