JP2001194186A - Rotation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation detector capable of improving earthquake resistance and humidity resistance. SOLUTION: This rotation detector 4 has a rotating detection body 7 mounted to a rotary shaft 3 protruded from the outer frame 2 of a rotation driving device 1, a fixed detection body 8, a surface mount element 9, and a substrate 6 mounted to the outer frame 2 of the rotation driving device 1, wherein the substrate 6 together with the surface mount element 9 is molded with a resin 10 except the detection surface of the fixed detection body 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detector for detecting a rotation position, a rotation speed, and the like of a rotary drive device such as a motor used as a drive device of a machine tool or the like.

[0002]

2. Description of the Related Art A conventional rotation detector is constructed as shown in FIG. In the figure, 1 is a rotary drive device such as a motor or a rotary disk drive device, 2 is an outer frame of the rotary drive device 1, 3 is a rotary shaft projecting from the outer frame 2,
Reference numeral 4 denotes an optical rotation detector, which comprises a substrate 6 mounted on the outer frame 2 via a mounting member 5 formed of a screw, and a rotating disk having a slit (not shown) mounted on the rotating shaft 3. It comprises a rotation detector 7 and a fixed detector 8 composed of a light emitting element 8a attached to the substrate 6 and a light receiving element 8b attached to the substrate 6. Reference numeral 9 denotes a surface mount element fixed to the substrate 6 with only solder, and is directly exposed on the substrate 6 to the outside air. In such a configuration, when the rotation shaft 3 of the rotation drive device 1 is driven, the rotation detection body 7 rotates together with the rotation shaft 3. In addition, light is emitted from the light emitting element 8a of the fixed detection body 7, and this light passes through the slit of the rotation detection body 7 and is cut off at a portion without the slit, so that the rotation driving device 1, the rotation position, the rotation speed and the like are detected.

[0003]

However, such a conventional rotation detector has the following problems. (1) A solder crack occurs on the substrate 6 due to the vibration of the electric motor in which the rotation detector 4 is incorporated or the machine in which the electric motor is incorporated, or the surface mount element 9 on the substrate 6 due to the lack of solder.
May fall. (2) If the surrounding environment is a place with high humidity, the circuit of the substrate 6 is short-circuited due to dew condensation, and as a result, a malfunction of the circuit is caused. In the worst case, the rotation detector 4 may be broken. (3) In an environment with high humidity, the corrosion of the substrate 6 is likely to progress. The present invention has been made to solve such a problem, and an object of the present invention is to provide a rotation detecting device capable of greatly improving earthquake resistance and moisture resistance.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a rotation detector attached to a rotating shaft projecting from an outer frame of a rotary drive, a fixed detector and a surface mount element. A rotation detector having a substrate mounted on an outer frame of the rotation driving device, wherein the substrate is molded with a resin together with a surface mount element except for a detection surface of the fixed detection body.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a detector showing an embodiment of the present invention, and FIG. 2 is a plan sectional view taken along line AA in FIG. The configuration of the rotation detector of the present invention is basically the same as the configuration of the conventional rotation detector, except that the entire substrate 6 is made of resin 10.
The difference is that it was molded with. On the substrate 6, the surface mount element 9 and the light receiving element 8b fixed on the substrate 6 with solder are molded together with the resin 10, but the detection surface of the fixed detection body 7,
That is, the light emitting surface of the light receiving element 8b is not molded because it interferes with light emission. Also, the joining portion of the surface of the substrate 6 with the mounting member 5 is not molded, so that the dimensional tolerance in the thickness direction is reduced, and the screw as the mounting member 5 can be tightened in the plane of the substrate 6. And a stable tightening force can be obtained. Thereby, the reliability of mounting the substrate is improved. With such a configuration, even if the vibration caused by the drive of the rotary drive device 1 or the drive of the machine tool or the like in which the rotary drive device 1 is incorporated occurs on the substrate 6, the solder There is no generation of cracks and no drop of the surface mount element 9. Further, since the surface mount element 9 does not come into contact with the outside air, short circuit of the circuit due to dew condensation and corrosion of the substrate 6 do not occur. In the above-described embodiment, the optical rotation detector is shown as an optical rotation detector.

[0006]

As described above, according to the present invention, since the entire substrate is molded with resin, it is possible to greatly improve the earthquake resistance and moisture resistance of the rotation detector. is there.

[Brief description of the drawings]

FIG. 1 is a side view of a detector showing an embodiment of the present invention.

FIG. 2 is a plan sectional view taken along line AA in FIG.

FIG. 3 is a side view showing a structure of a detector according to the related art.

[Explanation of symbols]

 Reference Signs List 1 rotation drive device, 2 outer frame, 3 rotation axis, 4 rotation detector, 5 mounting member, 6 substrate, 7 rotation detector, 8 fixed detector, 8a light emitting element, 8b light receiving element, 9 surface mounting element, 10 resin

Claims (3)

[Claims] 1. A rotation detecting body attached to a rotating shaft protruding from an outer frame of a rotary driving device, and a substrate having a fixed detecting body and a surface mount element, the substrate being mounted on the outer frame of the rotary driving device. The rotation detector according to claim 1, wherein the substrate is molded with a resin together with a surface mount element except for a detection surface of the fixed detection body. 2. The rotation detector of the rotation detector is constituted by a rotating disk attached to a rotating shaft, and the fixed detector is attached to a light emitting element attached to the outer frame and to the substrate. A light receiving element, and
The substrate is attached to the outer frame by an attachment member so as to be located on the side of the rotating disk opposite to the rotation driving device, and the substrate is molded with a resin together with a surface mount element, except for the light emitting surface of the light receiving element. The rotation detector according to claim 1, wherein: 3. The rotation detector according to claim 2, wherein the mounting member is formed of a screw, and the substrate is molded with a resin except for a joint portion of the surface with the screw.