JPS59109801A - Micrometer - Google Patents

Abstract

PURPOSE:To improve the wear resistance of a screw driving part, to hold the precision for a longer time and to reduce the cost by constituting the screw driving part of a spindle, which is moved back from and forth to an anvil, with ceramics. CONSTITUTION:A male screw part 7 provided on the side of a spindle 5 is constituted with ceramic materials, and plural male screw pieces 13 cut from a male screw member 23 which consists of the same materials as the male screw part 7 and has the same pitch as the male screw part 7 are attached to the inside circumferential face of an inner sleeve 4 to a female screw part to be engaged with the male screw part 7. In case that these male screw pieces 13 are attached to the inner sleeve 4, they are fixed with screw parts on the inside by an adhesive or the like. By this constitution, the production is made easy, and the precision is held for a longer time, and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a micrometer, and many measuring instruments employ precise screw structures. This is because, for example, when used in the drive section of a micrometer, the structure is convenient for not only ensuring accuracy but also for obtaining a constant measuring force. In other words.

This is because the relative position between two interlocking objects can be fixed at any position. But on the other hand.

It can also be said to be the part that is most likely to wear out because it receives the force from the measuring force. Therefore, it is desired to enhance wear resistance while maintaining initial accuracy.

Recently, it has been proposed to use ceramics in measuring instruments due to their advantages such as wear resistance, light weight, low thermal expansion, and electrical insulation. However, it is desirable that the micrometers mentioned above be made into ceramics. This is because it is extremely difficult to obtain a precise screw structure that satisfies workability and economy from ceramic materials. does not apply. Therefore, due to accuracy problems, grinding must be used, but small diameters, such as those with a diameter of 12
Since there is no existing machine that can grind female threads of mrn or less, it is impossible to obtain a thread structure made of the same material, that is, a thread structure with male and female threads. On the other hand, if the diameter is made large, the practical value decreases in terms of accuracy, economy, and operation due to the nature of the micrometer.

Therefore, conventionally, as a measuring device using ceramic,
For example, as described in Japanese Patent Application Laid-open No. 57-19604 (a situation in which the sliding main scale and vernier scale are only made of ceramic, a separate means for maintaining a constant measuring force must be added) occurs, resulting in low practical value.

SUMMARY OF THE INVENTION An object of the present invention is to provide a micrometer in which a screw drive part of a spindle that moves forward and backward with respect to an anobile is made of ceramic.

Therefore, in the present invention, the frame body includes an anvil,
In the micrometer, the micrometer is provided with a spindle that can move forward and backward with respect to the anvil, and is driven by a screw on the spindle, wherein the male screw portion provided on the spindle side is made of a ceramic material, and the frame main body side A plurality of male threaded pieces cut out from a male threaded member of the same type and thread pitch as the male threaded part are placed on the inner circumferential surface of the frame body where the male threaded part is located. The above objective is achieved by arranging and configuring the system.

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows the micrometer of this embodiment. In the figure, an anvil 2 made of a ceramic material is fixed to one end of a U-shaped frame main body 1 on the inner surface facing the other end. Further, at the other end of the frame main body 1, the inside of a cylindrical outer sleeve 3 is integrally fixed to the outer surface thereof, and a cylindrical inner sleeve 4 is interposed inside the frame body 1, and a ceramic side slant is formed on the inside. A spindle 5 is inserted into the punishment building 2 so that it can move forward and backward. On the outer circumferential surface of the penalty sleeve 3,
A scale 6 at 0.5 increments is carved along the axial direction.

Further, the spindle 5vc has a male threaded portion 7 with a pitch of 0.5 warts formed in a range from approximately the center to a slightly front side of the outer end, and has a male threaded portion 7 at the outer end that slides on the outside of the outer sleeve 3. Freely mating lath spindle 5
A simple 8 and an operation knob 9, which rotate integrally with each other, are respectively attached. On the outer circumferential surface of the inner end of the simple 8, a scale 10 is engraved by dividing the outer circumference into 50 equal parts. Moreover, the operation knob 9 is equipped with a ratchet mechanism inside, and when a measurement pressure of a certain pressure or more is applied to the spindle 5,
It is designed to idle relative to the single 8 and spindle 5vc.

In addition, as shown in FIG. 2, the inner league 4 has an end fixed to the frame main body 1 side and an end opposite to the end, that is, an outer end, at intervals of 120 degrees in the circumferential direction. 3
A split groove 11 is formed along the axial direction, and a threaded portion 12 is formed on the outer peripheral surface of the outer end of the book, and a threaded portion 12 is formed on the inner peripheral surface of the outer end.
Three male threaded pieces 13 made of a ceramic material are provided at positions □ at 20 degree intervals to be screwed into the male threaded portion 7 of the spindle 5, respectively. A taper nut 14 for expanding or contracting the inner diameter of the outer end portion of the inner league 4 in the radial direction is screwed into the threaded portion 12. Thereby, the clearance between the male threaded portion 7 of the spindle 5 and the male threaded piece 13 can be adjusted.

Here, a method for manufacturing the male screw piece 13 will be explained. For this purpose, as shown in FIG.
1 is cut to a predetermined length to form two male threaded members 22 and 23, and this -10,000 male threaded member 23 is cut in the axial direction to produce a plurality of circumferentially divided male threaded pieces 13. Ru. To attach the inner sleeve 4iC, which is made of the 13 male threaded pieces, to the inner sleeve 4iC, the inner sleeve 4iC is fixed with the threaded portion inside, for example, by adhesive. As a result, a female threaded portion made of ceramic that is screwed into the male threaded portion 7 is formed.

Note that the other male threaded member 22 can also be used as the male threaded portion γ. In this case, the spindle 5 may be constructed by connecting a shaft of a predetermined length to both ends of the male threaded member 220, or
Alternatively, it may be formed in advance into the shape of the spindle 5 when manufacturing the male threaded shaft 21.

A micrometer constructed in this way.

Use it in the same way as a regular micrometer.

That is, when the simple 8 is rotated, the spindle 5 moves forward and backward relative to the anvil 2 according to the thread pitch of the male threaded portion 7 and the male threaded piece 13.

When the object to be measured is held between the anvil 2 and the spindle 50, the distance between the anvil 2 and the spindle 5, that is, the dimension of the object to be measured, is indicated by the scale 6. It can be read and taken from scale 10.

Therefore, according to this embodiment, the male threaded portion 7 provided on the spindle 511111 is made of a ceramic material, and the female threaded portion that is screwed with the male threaded portion T is made of the same material and has the same thread pitch as the male threaded portion 7. Since the male threaded member 23 is constructed by attaching the plurality of cut out male threaded pieces 13 to the inner circumferential surface of the inner sleeve 4, it is possible to provide a micrometer in which the screw driving portion is a ceramic ring. Since this can improve the wear resistance of the drive section, the initial measurement accuracy of the micrometer can be maintained over a long period of time.

In particular, in this embodiment, a male threaded member 23 made of a ceramic material is cut in the axial direction to form a plurality of male threaded pieces 13 divided in the circumferential direction, and these male threaded pieces 13 are used as inner sleeves made of female threaded material. 4 to form a female screw member, it is now possible to manufacture a small diameter female screw for a ceramic ring, which has been difficult in the past. Furthermore, since only the male thread machining is required, manufacturing is extremely easy, and improvements in accuracy and cost can be expected.

In addition, since the three male threaded pieces 13 are arranged on the inner circumferential surface of the inner sleeve 4, it is possible to easily manufacture female threads with different diameters as long as the thread pinch is the same. Since the joint surface can be made smaller, the sliding resistance can be reduced. In addition, Inner League 4
Since the diameter can be changed, the clearance between the male threaded portion 7 and the male threaded piece 13 can be adjusted. In addition, since ceramic materials have electrical insulating properties, for example, even if an electric encoder is used in the detection section, magnetic problems will not occur, and as a result, various detection means can be used.

Therefore, reading accuracy can be improved.

In the above embodiment, the entire spindle 5 is made of ceramic, but only the male threaded portion r may be made of ceramic. Further, the materials of the male threaded portion 7 and the female threaded portion may have different components as long as they are included in ceramic. Also.

In the above embodiment, the three male threaded pieces 13 are arranged in the inner sleeve 4 to form the female threaded portion, but the number of male threaded pieces 13 may be at least two or more. Furthermore, as for the type of micrometer, in addition to the structure in which the spindle 5 moves forward and backward relative to the anvil 2 without rotating as in the above embodiment, there is also a so-called straight movement type in which the spindle moves forward and backward relative to the anvil 2 without rotating. It may also be a micrometer.

As described above, according to one aspect of the present invention, it is possible to provide a micrometer in which the screw drive portion of the spindle that advances and retreats with respect to the anobile is made of ceramic.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, FIG. 2 is an enlarged perspective view of the main part thereof, and FIG. 3 is an explanatory view showing the manufacturing process of the male screw piece. DESCRIPTION OF SYMBOLS 1...Frame body, 2...Anvil, 5...Spindle, 7...Male thread part, 13...Male thread piece, 2
3...Male thread member. Agent: Patent attorney Minoru Kinoshita (and 1 other person)

Claims (1)

[Claims] (1) In a micrometer in which the frame body is provided with an anvil and a spindle capable of advancing and retracting with respect to the anvil, and the spindle is of a screw drive type, the male threaded portion provided on the spindle side is made of ceramic material. and a female threaded part provided on the frame main body side and screwed with the male threaded part,
A micrometer characterized in that a plurality of male threaded pieces cut out from a male threaded member of the same type and pitch as the male threaded portion are arranged on the inner circumferential surface of the frame body where the male threaded portion is located. .