JPS6058401B2 - Inner diameter micrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The object of the present invention is to provide a method for measuring the inner diameter of small diameters, for example, 6 millimeters or less.
The object of the present invention is to improve the inner diameter micrometer described in Japanese Patent No. 29594.

The inner diameter micrometer disclosed in Japanese Patent Publication No. 49-29594 consists of a main body to which an arm is connected, and a body that rotates within this main body.
It consists of a longitudinally movable control shaft and two concentric cones driven by the control shaft, the two cones having at least one measuring key movable at right angles to the axis. The measuring key is provided at the tip of the arm, and the measuring key is provided at the tip of the arm. at one end of which the contact is controlled in displacement by one of the two cones, and at the other end disposed in the body there is a support whose displacement is controlled by another cone. holds the department.

In this prior art, the two cones specifically mean a conical helical inclined part, and the helical thread carrying the support part of the measuring key and the contactor is not parallel to the axis of rotation, but as a whole. It has a conical slope.

. Therefore, when displacing the contactor and the support part of the measuring key in the radial direction, the spiral lines of the two corresponding conical spiral inclined parts are such that the inclination of the inclined surfaces and the distance in the radial direction between them are They must coincide in point and must also be exactly proportional to the axial and rotational displacements of the micrometer screw. It is not always easy to accurately manufacture the above three types, and therefore there are problems with their measurement accuracy, ease of manufacture, and measurement range. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an inner diameter micrometer which solves the above-mentioned drawbacks, has excellent measurement accuracy, is easy to manufacture, and has a further expanded measurement range.

In order to increase the measuring capability of the internal diameter micrometer shown in the above patent publication, while retaining the basic advantage of being able to measure deep internal diameters and very small diameters, the internal diameter micrometer of the present invention provides a The tip forms a smooth cone that controls the displacement of the measurement key contact, and the other end of the control shaft has a generatrix parallel to the rotation axis that controls the displacement of the measurement key support. By adjusting the measuring micrometer screw that fits into the thread cut into the main body, the smooth cone and the spiral inclined part having a generatrix parallel to the axis of rotation can be formed. It is driven in the rotational and axial direction, so that the measurement is smoothed only by a smooth conical movement, and the helical ramp moves in the radial direction of the measuring key without any influence on the measurement. It has the characteristic of ensuring only the displacement of .

Since the inner diameter micrometer of the present application has almost the same structure as the inner diameter micrometer described in the above-mentioned patent publication, only new elements necessary for understanding the present invention will be described in the following description of the embodiments. Therefore, each element already written in the said patent publication is designated by the same reference numeral. In the figure, a shoulder portion 7 of an arm 6 is connected to a main body 1 of the measuring instrument, and is fixed to the main body 1 via a holding plate 8 with several screws 9. The outer peripheral wall of arm 6 is 3
A longitudinal groove is cut into the radial slot 1.
3, 14 and 15, which can be seen at the free end of the arm 6, at the flange 7 and at the body 1, respectively.

Contacts 24 are located within these longitudinal grooves and radial slots.
A plurality of new measuring keys 23 are housed therein, each consisting of three parts: an elongated core 25 and a support 26, which is radially tightened by a ring-shaped spring 22. These measuring keys 23 are arranged on a smooth conical body 27 concentrically arranged on the rod 10 and on a spiral inclined part 28 having a generatrix parallel to the axis of rotation.
4 and a support 26 at its ends, the rotational and longitudinal movement of this rod is controlled by a control shaft 2 on which the rod 10 and these smooth cones 27 are supported.
and are firmly connected via a measuring micrometer 29 on a spiral inclined portion 28 having a generatrix parallel to the axis of rotation.

The front cone 27 is a smooth cone, and the sliding surface 30 of the contact 24 of the measuring key is in contact with its side surface, that is, its entire length from its top to its base.

The rear shaft end of the control shaft has the shape of a spiral slope having a generatrix parallel to the rotation axis, and the support surface of the support portion 26 abuts on the spiral.

Each rotation of the driving micrometer screw displaces the cone in the longitudinal direction by a value approximately S equal to the advance of the helical inclined portion, and the value measured each rotation is the angle of the inclined portion. Contrary to the above-mentioned patent publication, which is only directly related to displacement, the contact is such that the angular and axial displacements are exactly proportional and also abuts against the inclined generatrix of the smooth cone. always equal to the radial displacement of the support 26 tangent to the helical slope parallel to the common axis of the two cones and the generatrix in the child 24 -
In order to effect a radial displacement, the measuring micrometer screw 21 is adjusted with maximum accuracy on the sliding surface 30 of the corresponding thread of the measuring instrument body.

In the drawing, this measuring micrometer screw is shown without an adjusting device, but this adjusting device can be formed by known means, such as a ring with a radial clamping force. In FIG. 2, the ends of three contacts 24 are arranged in slots 13 in the outer circumferential wall of arm 6, and at only a short distance the three contacts are concentrated on the conical axis, so that their base It can be seen that it forms a slope of 120cm.

By using a smooth cone to control the displacement of the contact, the sliding surface 30 can be extended to the apex of the cone, and the radial stroke can respond to the maximum extent to the radius of the base of the cone 27. This means that the present internal diameter micrometer has the ability to measure up to the maximum diameter determined by the cone; It cannot be implemented with a helical ramp of the dimensions required to do so.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the invention, and FIG. 2 is an enlarged sectional view taken along line 1--1 in FIG. 1... Main body, 2... Control axis, 6... Arm, 10
... Rod, 13, 14, 15 ... Slot, 23
... Measuring key, 24 ... Contact, 25 ... Elongated core, 26 ... Support part, 27 ... Smooth cone, 28 ... Spiral with generatrix parallel to rotation axis slope,
29...Micrometer screw for measurement.

Claims (1)

[Claims] 1. A main body 1 having an arm 6 fixed to the main body, a control shaft 2 movable in the rotation direction and longitudinal axis direction of the main body, and at least one control shaft movable perpendicularly to the control shaft. Measurement key 2
3, the measuring key comprising an elongated core 25 guided over at least part of the length of the core in slots 13, 14, 15 formed in the body and along the arms; The measuring key carries a contact at one of the two ends of the measuring key disposed at the end of the arm, and a support at the other end placed in the main body, and further comprises: A micrometer for internal diameter measurement, driven by a control axis and having a smooth cone 27 arranged at the end of the arm for controlling the displacement of the contact of the measuring key, with a generatrix parallel to the control axis; a helical ramp having a diameter is located in the body coaxially with the smooth cone and is driven by the control shaft for controlling the displacement of the support of the measuring key; It is driven in the rotational and axial direction by a measuring screw 29 of the micrometer formed in and adjusted by means of a screw, so that the measurement is carried out only by a smooth conical movement and the helical ramp A micrometer for measuring inner diameter, characterized in that the micrometer ensures only radial displacement of the measuring key without affecting the measurement in any way. 2. The contact comprises support means in contact with the smooth cone, the support means having a length approximately equal to the length of the generatrix of the smooth cone, thereby reducing the radial stroke of the contact. 2. An internal diameter micrometer according to claim 1, characterized in that the diameter is equal to half the diameter of the base of the smooth cone.