JPH0256601B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for allowing two measuring axes of a wide range dimension measuring device to slide in parallel with good straightness.

If two measuring axes are required to measure two points such as the outer diameter, inner diameter, and width of a wide-range length measuring device, the measurement axis center is not on the line of the measurement part, so the method that does not comply with Atsbe's principle will not be able to handle the two measurement axes. In order to obtain high accuracy, the measurement axes must be parallel to each other and slide with good straightness.

Normally, the sliding bearing of the cylindrical measuring shaft is a sliding bearing with the inner surface of the cylinder as the contact surface, or a rolling bearing with rolling balls interposed therebetween.The casing is made with a precision hole drilled with a jig boring machine, etc. Fit or press-fit the bearings so that there are no gaps. In this case, it is not easy to machine the two holes in parallel, with good straightness, and with minute dimensional tolerances, and the longer the holes, the more difficult it becomes. Furthermore, when a bearing is fixed in this hole, if it is fitted with a clearance, it will be tilted, and if it is press-fitted, it will also be tilted, making it difficult to arrange it with good parallelism.

The present invention is characterized in that the two measurement axes can slide in parallel and with high precision in straightness, and can be manufactured at low cost.

Next, examples of the present invention will be described.

FIG. 1 is a front view as viewed from the arrows, showing the structural principle of the present invention.

FIG. 2 shows a side view.

Reference numeral 1 denotes the housing of the length measuring instrument, and the measurement axis is cylindrical sliding bearings 2 and 3, which slide in parallel within 4 and 5. As mentioned above, cylindrical sliding bearings include sliding bearings and rolling bearings, but when straightness accuracy is particularly required, rolling bearings that apply a preload via rolling balls to the fitting part are recommended. bearings are suitable. Fingers 6 and 7 are provided at one end of the measuring shaft and have contacts 8 and 9 at their tips. Note that the measurement axis may be provided with a signal source such as a touch sensor or a proximity switch instead of a contact, or a detector such as a differential transformer that outputs the amount of dimensional displacement in analog form.

A digital scale 10 is attached to the other end of the measuring shaft 3, and a reading head 11 is attached to the other end of the measuring shaft 2, so that the relative displacement of the measuring shaft is detected by the digital scale. The cylindrical sliding bearings are in contact with each other along the generatrix line at 12 parts, and also on the reference planes 13, 1 in the housing 1.
4, are fixed with presser perforators 15 and 16, presser plates 17 and 18, and presser screws 19 and 20. The fixing method is not necessarily limited to this example, and adhesive fixing is also possible.

If it is desired to increase the distance between the two bearings, as shown in FIG. 3, a parallel block 21 with a desired thickness and good parallelism accuracy is sandwiched between the 12 parts and pressed together, thereby obtaining the desired shaft distance.

In general, the outer surface of the cylinder and the reference plane can be easily machined with good straightness, so according to the present invention, the parallel measuring axes of the wide-range dimension measuring device can be machined with much better parallelism and straightness than with conventional methods. It has the characteristics of being able to be moved and manufactured at low cost.

Although the present invention belongs to the structure of Patent Application No. 57-027786 (February 23, 1982), it can be widely applied beyond the scope of the original patent application.

[Brief explanation of the drawing]

1 and 3 are front views taken in the direction of the arrows in FIG. 2, showing the principle of the structure of the present invention. Figure 2 is a side view. 1: Housing, 2, 3: Measuring axis, 4, 5: Cylindrical sliding bearing, 6, 7: Finger, 8, 9: Contact, 10: Digital scale, 11: Reading head, 12: Pressure contact part, 13 , 14: Reference plane, 1
5, 16: Pressing perilla, 17, 18: Pressing plate, 1
9, 20: Cap screw, 21: Parallel block.

Claims (1)

[Claims] 1. Wide-range dimensional measurement in which two cylindrical sliding bearings for measuring axes that operate in parallel are pressed against each other along the generatrix and fixed against two planes of the inner wall of the casing. Long vessels. 2. A wide range of cylindrical sliding bearings for two measurement axes that operate in parallel are pressed against each other along the generatrix line with a parallel block in between, and are fixed against two planes of the inner wall of the housing. Dimension measuring device.