JP6214317B2 - Length measuring instrument - Google Patents

Description

  The present invention relates to a contact-type length measuring device including a spindle that comes into contact with an object to be measured.

  A length measuring device is known which measures a length by contacting a measuring object with a spindle which is movable in the axial direction provided with a scale and reading a displacement from a reference position generated in the axial direction of the spindle from the scale. . Such a length measuring device is also referred to as a displacement measuring device, a displacement detector, a dial gauge, a linear gauge, a micrometer (electric micrometer), or the like.

  For example, a measuring element that comes into contact with a measurement object is provided at the tip of the spindle, and a length measuring device provided at a position where the scale protrudes in the radial direction from the main body of the spindle is provided at a substantially intermediate portion of the spindle (for example, , See Patent Document 1).

Japanese Utility Model Publication No. 55-51739

  As in the invention described in Patent Document 1, by providing the scale at a position protruding in the radial direction from the main body of the spindle, the size of the length measuring device must be increased particularly in the radial direction of the spindle.

  In view of the above problems, an object of the present invention is to provide a length measuring device that is small in size and easy in structure.

  In order to achieve the above object, according to the present invention, a spindle that abuts on an object to be measured and slides in an axial direction according to the object to be measured, and a scale portion provided integrally with the spindle are provided. In a length measuring device that calculates the displacement of the spindle in the axial direction by reading the scale of the scale unit and measures the length of the object to be measured, a concave portion is formed in the spindle, and the scale portion is located in the concave portion on the outer peripheral surface of the spindle. It is installed so as not to protrude radially outward from.

  Here, the spindle is supported by the main body case via a bearing that is spaced apart in the axial direction, and a recess is formed between the two bearings.

  In addition, the recess is provided with an opening penetrating in the radial direction of the spindle, and the scale reading unit that reads the scale includes a light emitting element that emits light from one opening end of the opening toward the scale unit, and a scale unit. The light receiving element may be disposed so as to face the light emitting element so as to sandwich the light receiving element, and the light receiving element that receives light transmitted through the scale portion may be received. The scale portion may be provided so as to close the opening.

  In addition, the scale reading unit for reading the scale is a light emitting element that emits light toward the scale unit, a light receiving element that is installed on the same side as the light emitting element with respect to the scale unit, and that receives the light reflected by the scale unit, May be configured.

  According to the present invention, it is possible to realize a small length measuring device having a simple structure. That is, according to the present invention, the scale portion is installed in the recess formed in the spindle so as not to protrude radially outward from the outer peripheral surface of the spindle. The size in the direction can be reduced. As a result, the scale reading unit for reading the scale is provided with a scale unit so as to block the opening formed in the recess, and the scale unit is sandwiched between the scale reading unit and the light emitting element. Thus, it is possible to configure the light emitting element that emits light and the light receiving element that receives the light reflected by the scale portion on the same side with respect to the scale portion. In addition, by arranging the bearings on both ends of the scale portion, the movement of the scale portion is stabilized, the scale reading accuracy is improved, and high-precision measurement can be performed.

It is sectional drawing of the axial direction of the length measuring device by the Example of this invention. It is sectional drawing of the radial direction of the length measuring device by the Example of this invention. It is a top view which shows the spindle in the length measuring device by the Example of this invention. It is a side view of the length measuring device by the Example of this invention. It is a perspective view (the 1) of the length measuring device by the Example of this invention. It is a perspective view (the 2) of the length measuring device by the Example of this invention.

  FIG. 1 is a sectional view in the axial direction of a length measuring device according to an embodiment of the present invention, FIG. 2 is a sectional view in the radial direction of a length measuring device according to an embodiment of the present invention, and FIG. FIG. 4 is a side view of a length measuring device according to an embodiment of the present invention, and FIGS. 5 and 6 are length measurements according to the embodiment of the present invention. It is a perspective view of a vessel. Hereinafter, components having the same reference numerals in different drawings mean components having the same functions.

  The length measuring device 1 according to the embodiment of the present invention includes a spindle 11, a bearing 12, a scale unit 13, a scale reading unit 14, a measuring element 15, a spring 16, and a rotation preventing means 17.

  The spindle 11 includes a slide shaft 11-1 and a probe shaft 11-2. The slide shaft 11-1 can slide in the axial direction on the main body case 31 by two bearings 12 spaced apart in the axial direction. It is supported. The base end portion of the probe shaft 11-2 is fixed to the tip of the sliding shaft 11-1. The slide shaft 11-1 and the measuring element shaft 11-2 have a substantially circular cross section along the radial direction. The probe shaft 11-2 has a smaller diameter than the sliding shaft 11-1.

  A cap 18 is provided on the front end side (rightward in FIG. 1) of the main body case 31. The base end side of the tracing stylus shaft 11-2 (leftward in FIG. 1) is covered with the cap 18.

  Between the bearings 12 of the sliding shaft 11-1, a recess 22 that is recessed in the radial direction with respect to the outer peripheral surface of the sliding shaft 11-1, and an opening that penetrates from the bottom surface of the recess 22 in the radial direction of the spindle 11. Part 21 is formed. The recess 22 is formed by cutting a part of the outer peripheral surface of the sliding shaft 11-1 into a flat shape.

  The measuring element 15 is provided at the tip of the measuring element shaft 11-2 of the spindle 11 and abuts on the measurement object.

  The scale unit 13 is configured as a plate-like light transmission type scale on which a scale is formed. The scale part 13 is installed in the recess 22 so as not to protrude from the outer peripheral surface of the sliding shaft 11-1 and to close the opening 21. Therefore, the scale portion 13 does not protrude radially outward from the outer peripheral surface of the sliding shaft 11-1.

  The scale reading unit 14 is opposed to the light emitting element 14-1 such as an LED that irradiates light toward the scale unit 13 and the light emitting element 14-1 with the scale unit 13 interposed therebetween, and is transmitted through the scale unit 13. A light receiving element 14-2 that receives light is provided, and the light emitting element 14-1 and the light receiving element 14-2 are fixed to the main body case 31 side. The light emitted from the light emitting element 14-1 passes through the opening 21 and the scale part 13, and then reaches the light receiving element 14-2 and is received by the light receiving element 14-2. The scale reading unit 14 reads the scale drawn on the scale unit 13 using the light received by the light receiving element 14-2, and outputs the scale to an external computing device (not shown). When the spindle 11 slides in the axial direction, the scale unit 13 also moves together with the spindle 11, so that the scale read by the scale reading unit 14 changes. The external calculation device calculates the displacement of the spindle 11 in the axial direction using the scale change information obtained from the scale reading unit 14.

  The spring 16 urges the spindle 11 between the base end side (leftward in FIG. 1) of the sliding shaft 11-1 and the main body case 31 in a direction in which the spindle 11 slides to the front end side (rightward in FIG. 1). It is provided as follows. The sliding of the spindle 11 toward the base end side is performed elastically against the urging force of the spring 16.

  The rotation preventing means 17 includes a rotation prevention pin 17-1 provided on the sliding shaft 11-1 and a rotation prevention guide 17-2 provided on the main body case 31. The locking pin 171-1 protrudes from the main body case 31 outward in the radial direction of the sliding shaft 11-1. The anti-rotation guide 17-2 is provided on both sides of the opening groove on the body case provided so that the anti-rotation pin 17-1 can pass therethrough, and forms a slit into which the anti-rotation pin 17-1 is inserted. The pin 17-1 is allowed to move in the axial direction and is guided not to move in the radial direction. As a result, the spindle 11 is restricted from rotating in the radial direction and is allowed to move in the axial direction.

  In the length measuring instrument 1 having the above-described configuration, when the measurement object comes into contact with the measuring element 15, the spindle 11 slides following the measurement object, and the scale unit 13 moves integrally with the spindle 11, The scale at this time is read by the scale reading unit 14. Since the scale unit 13 also moves together with the spindle 11, the scale read by the scale reading unit 14 changes. Using the scale change information obtained from the scale reading unit 14, the displacement of the spindle 11 in the axial direction can be calculated, and the length of the measurement object can be measured.

  As described above, according to the present invention, the scale portion 13 is installed in the recess 22 without protruding outward in the radial direction from the outer peripheral surface of the sliding shaft 11-1. Therefore, the size of the length measuring instrument 1 can be reduced with a simple structure. In particular, by providing the scale portion 13 so as to close the opening portion 21 formed in the recess 22, the light transmission type scale is incorporated into the spindle 11 (sliding shaft 11-1), so the length measuring device 1 is compact. Can be formed. In addition, since the bearings 12 are disposed on both ends of the scale unit 13, the movement of the scale unit 13 is stabilized, the scale reading accuracy can be improved, and high-precision measurement can be performed.

  In the illustrated embodiment, the opening 21 is provided in the vicinity of the intermediate portion of the sliding shaft 11-1, but it may be located at a position shifted from the intermediate portion as long as it is between the bearings 12.

  In the illustrated embodiment, the scale unit 13 is configured as a light transmission type scale, but the scale unit 13 may be configured as a light reflection type scale. In this case, for example, a three-dimensionally carved scale on a metal plate capable of reflecting light, a scale colored in a color different from the metal plate, or the like may be provided in the recess 22. However, since it is not necessary to transmit light, the opening 21 is unnecessary. When the scale unit 13 is configured as a light reflecting scale, the light receiving element may be installed on the same side as the light emitting element.

  Moreover, you may comprise the scale part 13 as an electromagnetic scale, a magnetic scale, or an electrostatic capacitance type scale. In this case, the scale reading unit 14 may have a known reading configuration in accordance with the aspect of the scale unit 13.

  In the illustrated embodiment, the rotation prevention pin 17-1 in the rotation preventing means 17 is provided on the sliding shaft 11-1, and the rotation prevention guide 17-2 is provided on the main body case 31, but as an alternative example, The anti-rotation pin 17-1 is provided on the inner wall surface of the main body case 31 so as to protrude radially inward, and the anti-rotation guide 17-2 is realized as a groove provided on the outer peripheral surface of the sliding shaft 17-2. May be.

DESCRIPTION OF SYMBOLS 1 Length measuring device 11 Spindle 11-1 Sliding shaft 11-2 Measuring element shaft 12 Bearing 13 Scale part 14 Scale reading part 14-1 Light emitting element 14-2 Light receiving element 15 Measuring element 16 Spring 17 Anti-rotation means 17-1 Around Stopping pin 17-2 Non-rotating guide 18 Cap 21 Opening 22 Recessed part 31 Body case

Claims (3)

A spindle that abuts on the object to be measured and slides in the axial direction according to the object to be measured, and a scale unit provided integrally with the spindle, and by reading the scale of the scale unit, In a length measuring device that calculates the displacement in the axial direction and measures the length of the measurement object,
An opening that penetrates the spindle in the radial direction is formed in the spindle ,
The scale portion is installed in the opening ,
The scale reading unit for reading the scale is installed facing the light emitting element so that the light is emitted from one opening end of the opening toward the scale part, and the scale part is interposed therebetween. A light receiving element that receives light transmitted through the scale portion , and
A length measuring instrument characterized by The spindle is supported by the main body case via a bearing that is spaced apart in the axial direction.
The length measuring device according to claim 1, wherein the opening is formed between both the bearings. The length measuring device according to claim 1, wherein the scale portion is installed so as not to protrude radially outward from an outer peripheral surface of the spindle.

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