JP2535171Y2 - Rotary encoder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for holding and fitting a rotary encoder to a rotary shaft using a thin slit disk.

[0002]

2. Description of the Related Art Many optical rotary encoders use a thin slit disk. The slit disk is made by photo-etching or the like, and there is a limit to the accuracy of the mounting hole with the rotating shaft. Normally, it is used as it is, but in the case of high-resolution encoders, the mounting holes are used after reaming.

[0003]

As described above, there is a problem in that the mounting hole is subjected to secondary processing and the accuracy of the diameter of the rotating shaft must be increased, which increases the cost. An object of the present invention is to make the concentricity with the rotating shaft high with a rough rotary encoder structure.

[0004]

The slit disk of the present invention is provided with three or more convex portions in the mounting hole, and the convex portion that makes partial contact with the rotating shaft has a spring structure with an arc-shaped slit. The purpose is to eliminate play with the rotating shaft by a structure in which the diameter is made smaller than the diameter of the rotating shaft and press-fitted.

The first means of the present invention is of the inscribed type. In a rotary encoder using a thin slit disk, the inner circumference of the slit disk fitted with the rotary shaft has a three-dimensional shape for contact with the rotary shaft. There are more than two convex parts, the convex parts are arranged in equal divisions, an arc-shaped slit A is formed on the same circumference on the outer circumference side, and A and a slit are formed on the same circumference on the outer circumference side. By forming the arc-shaped slits B so as to alternately overlap, a narrow support portion that gives elasticity in the radial direction is formed, the convex portion has a spring action, and the diameter of the inscribed circle of the convex portion is the diameter of the rotating shaft. It is a structure that is made smaller and fitted to the rotating shaft.

The second means of the present invention is of a circumscribed type, and has three or more convex portions on the outer peripheral portion of an index slit disk opposed to the slit disk, and the convex portions are arranged in equal parts. By forming an L-shaped slit groove and an internal slit therein, a narrow support portion for giving elasticity in the radial direction is formed, a convex portion has a spring action, and a diameter of a circumscribed circle circumscribing the convex portion, The index slit disk house that holds the index disk is larger than the inner diameter of the index slit disk house, and is fitted to the index slit disk house.

[0007]

1 and 3 show an embodiment of the present invention, and FIG. 2 is a structural view of an optical rotary encoder. Rotary axis 1
And slit disk 2 and flange 3 for holding the slit disk
The rotating shaft 1 is supported by a bearing 5a attached to an index slit disk house 4 and a bearing 5b attached to a light emitting element house 6. The index slit disk house has an index slit disk 7 and a light receiving element 8. The light emitting element house has a light emitting element 9 at a position facing the light receiving element.

FIG. 1 is a plan view of the slit disk 2 of FIG. Protrusions 10 are provided at four locations on the inner circumference of the slit disk 2, and arc-shaped slits 11 are provided at four locations on the same circumference outside the projections. Slits 12 are provided at four locations. The protrusion is a slit
The remaining support portions 13 and 14 separated by the slit 11 and the slit 12 have a sufficiently small width to provide a spring action, and the diameter of the inscribed circle of the convex portion is made smaller than the diameter of the rotary shaft 1 so that the rotary shaft can be rotated. To be fitted.

FIG. 3 shows an example of the index slit disk 7, and in FIG. 3 (a), three convex portions 15 are provided on the outer periphery thereof. The structure of the projection is such that the side and inside of the projection are separated by a slit 16 and a slit 17 is further added.
It is supported by 8b. The index mounting disk is fitted by making the diameter of the circumscribed circle of the projection larger than the index mounting hole 19 of the index slit disk house 4.

FIG. 3B shows another example of the index slit disk. The index slit disk 20 has a convex portion 21 on the outer periphery, and the convex portion is a slit passing through its side and inside.
22 and a U-shaped slit 23 surrounding a part of the slit 22, and is supported by a sufficiently narrow S-shaped support portion 24. The circumscribed circle of the projection is larger than the index mounting hole 19 and is fitted.

[0011]

[Effect of the Invention] In the case of etching, the mounting hole of the slit disk has a certain degree of variation, and can play with the shaft. In the present invention, since the mounting hole is press-fitted by a spring action, play can not be performed, and concentricity accuracy can be improved. In addition, since the distortion at the time of press-fitting can be removed at the spring portion, the warpage of the slit disk does not occur. Since the mounting hole has a spring structure, the accuracy of the shaft diameter can be made rough and the cost can be reduced.

Since the outer peripheral contact portion of the index slit disk has a spring structure, the accuracy of the index mounting hole can be made rough and the cost can be reduced. Also, the index mounting hole can be held only by the spring pressure, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a slit disk of the present invention.

FIG. 2 is a sectional view of an optical rotary encoder.

FIG. 3 is a plan view of the index slit disk of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation axis 2 Slit disk 3 Flange 4 Index slit disk house 5 Bearing 6 Light emitting element house 7 Index slit disk 8 Light receiving element 9 Light emitting element 10 Convex part 11 Slit 12 Slit 13 Support part 14 Support part 15 Convex part 16 Slit 17 Slit 18 Support 19 Hole 20 Index Slit Disk 21 Convex 22 Slit 23 Slit 24 Support

Claims (2)

(57) [Scope of request for utility model registration] In a rotary encoder using a thin plate-shaped slit disk, an inner periphery of the slit disk fitted with a rotary shaft has three or more convex portions for contacting with the rotary shaft, and the convex portions have three or more convex portions. An arc-shaped slit A is formed on the same circumference on the outer circumference side, and the slit A is formed on the same circumference on the outer circumference side so that the A and the slit alternately overlap. Thereby, a narrow support portion that has elasticity in the radial direction is formed, and the convex portion has a spring action, and the diameter of the inscribed circle of the convex portion is smaller than the diameter of the rotating shaft, and fitted to the rotating shaft. A rotary encoder, characterized in that: 2. An index slit disk opposed to a slit disk has three or more convex portions on an outer peripheral portion, and the convex portions are equally divided and arranged, and an L-shaped slit groove and a slit are formed therein. By making, a narrow support part that gives elasticity in the radial direction is formed, the convex part has a spring action, and the diameter of the circumcircle of the convex part is larger than the inner diameter of the index slit disk house that holds the index disk. A rotary encoder characterized by being enlarged and fitted to an index slit disk house.