JPS618668A - Rotating disc for speed detection - Google Patents

Abstract

PURPOSE:To provide mechanical strength, to attain high division, and to improve stability in size by providing projection and recessed parts to the outer peripheral plane part of the rotary disk made of a transparent resin material, and coating the recessed parts with a paint and constituting opaque parts. CONSTITUTION:Recessed parts 2 and projection parts 3 are provided to the outer peripheral plane part of the rotary disk 1 made of the transparent resin material. Then, the paint is applied over the outer peripheral plane part and dried, and paint on projection surfaces 3 is removed with a solvent to constitute transparent and opaque parts. The disk 1 having those transparent and opaque parts alternately is rotated between a light emitting and a photodetecting element to detect the rotating speed. Thus, the projection parts of the outer peripheral plane part of the transparent disk 1 is coated with the paint to constitute the transparent and opaque parts, so the problem of a burr treatment and a run of resin during resin formation is eliminated to increase the mechanical strength, attain high division, and improve the stability in size.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotating disk that can be used as a sensor for detecting the speed of a motor or the like.

Conventional Structure and Problems In recent years, speed detectors have been frequently used to control the speed of motors.

A conventional rotating disk for speed detection will be described below with reference to the drawings. As a rotating disk for speed detection, conventionally a glass plate with slits printed on it, a metal plate with slits cut out by etching or press processing, or a resin rotating disk as shown in Figs. 2 and 3 are used. Hole 22 in plate 21
Currently, the one provided with a groove 23 is used.

The rotation and operation of the disk 21 configured as described above will be explained below. On the outer peripheral plane part of this rotating disk 21,
A light emitting element and a light receiving element (
As the rotary disk 21 rotates, the transparent part and the opaque part constituted by the hole 22 or the groove 23 cross the light emitted from the light emitting element, and the light receiving element A signal proportional to the rotational speed of the rotating disk 20 is generated.

However, in the above configuration, when forming the holes 22 or grooves 23 in the resin rotating disk 21 by molding, paring treatment becomes a problem, and at the same time there are problems in terms of resin flow and mechanical strength. , it had problems such as difficulty in high resolution.

Purpose of the Invention The purpose of the present invention is to solve these problems and to economically produce a rotating disk for speed detection that is highly divisible, has mechanical strength, and has good dimensional stability. .

Composition of the Invention The rotating disk for speed detection of the present invention is a rotating disk made of a transparent resin material, and has □ uneven portions on the flat surface of the outer periphery, and paint is applied to the recessed portions to make these portions opaque and alternately transparent. - It is configured to detect the rotational speed by making it opaque, thereby achieving the above purpose.

'Description of Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a front view and a side view of a rotating disk for speed detection in an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a rotating disk made of transparent synthetic resin, and recessed portions 2 and convex portions 3 are alternately provided on the outer circumferential flat surface. The rotating disk 1 with the above structure is molded from a transparent resin material, and can be easily made transparent by providing unevenness, applying paint to the flat outer circumference, and removing the paint on the convex surface with a solvent after drying.・It is possible to form opaque areas.

The operation of the speed detection rotary disk of this embodiment configured as described above will be explained below. By using the rotating disk 1 having transparent and opaque parts alternately, this part can be rotated in the gap between the light emitting and light receiving elements and the rotation speed can be detected.

A speed detection rotating disk with good flow and high division has been realized.

Effects of the Invention As is clear from the above explanation, the present invention provides an uneven portion on the outer circumferential flat surface of the rotating disk for speed detection, and forms a transparent/opaque portion by applying paint to the recessed portion. It eliminates the problems of paring treatment and resin flow that occur during molding, and has the excellent effects of high mechanical strength and high divisibility.

As a result, it is possible to produce a rotating disk for speed detection at a low cost with improved dimensional stability.

[Brief explanation of drawings]

1A and 1B are a front view and a side view of a rotating disk according to an embodiment of the present invention, and FIGS. 2 and 3 are front views of a conventional rotating disk for speed detection. 1... Rotating disc, 2... Concavity, 3...
...Protrusion. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure Cα) (b) Figure 2 Figure 3

Claims (1)

[Claims] A rotary disk for speed detection, which is made of a transparent resin material and has concave and convex portions alternately provided on the outer circumferential flat surface thereof, and paint is applied to the concave portions so that the convex portions are transparent and the concave portions are opaque.