JP5047860B2 - Rotary encoder - Google Patents

Description

  The present invention relates to a rotary encoder that provides a click feeling when a shaft rotates.

Conventionally, as a technology in such a field, there is Japanese Utility Model Publication No. 5-52719. The rotary encoder described in this publication is related to a rotating shaft supported by a case, a disk that rotates integrally with the rotating shaft, and has a gear-shaped notch on the outer peripheral surface, and a gear-shaped notch. A cylindrical roller to be joined, and a lever that supports the roller and presses the roller against a gear-like step by a spring are provided. When the disc rotates with the rotation of the rotating shaft, the roller rolls on the outer peripheral surface of the disc, and the rotational torque of the rotating shaft changes abruptly each time the roller engages with the gear-shaped notch. A click feeling is obtained.
Japanese Utility Model Publication No. 5-52719

  However, the above-described conventional rotary encoder has the following problems. That is, if the cylindrical roller tilts even a little due to mounting errors during assembly or external impacts, the corners of the roller get caught on the inner surface of the gear-shaped notch, preventing proper engagement between the roller and the notch. Therefore, a click feeling is impaired. Furthermore, since the pressing force by the spring is concentrated on the corners of the roller, there is a problem that the roller and gear-shaped notches are easily worn, and the durability of the rotary encoder is lowered.

  An object of the present invention is to provide a rotary encoder capable of obtaining a good click feeling and improving durability.

  The present invention provides a rotary encoder having a rotating shaft supported by a housing and a rotation detecting unit that detects the rotation of the shaft, and is provided in an annular shape around the shaft, and a tooth portion that rotates integrally with the shaft; A barrel-shaped roller that is engaged with the tooth portion, and a roller support means that is provided on the housing and has a shaft portion that pivotally supports the roller, and that biases the roller toward the tooth portion by elastic force. Features.

  The roller applied to the rotary encoder of the present invention has a barrel shape, and both ends of the roller are reduced in diameter. Therefore, even if the roller is inclined, both ends are not caught on the wall surface of the tooth gap between the teeth, and the roller and the tooth A good click feeling can be obtained by properly engaging the part. Furthermore, since the barrel-shaped roller has a sufficient contact area with the wall surface of the tooth gap even when inclined, excessive concentration of the roller with respect to the wall surface of the tooth groove is suppressed, and the rotary encoder The durability of the tooth portion can be improved. Moreover, since a wider contact area can be obtained compared to a spherical roller, it is optimal as a roller shape for obtaining a click feeling.

  Further, the housing is provided with a support column that extends in the same direction as the extending direction of the rotation axis of the shaft, and a boss provided at the tip of the support column, and the roller support means is orthogonal to the rotation axis. A rotating arm that pivots around the boss, and has a shaft hole in which the roller is pivotally supported at one end and the boss is inserted at the other end. And a coil spring that urges the rotating arm in the rotating direction.

  According to such a configuration, the coil spring and the rotating arm can be easily assembled to the housing, and the rotating arm is biased in the rotating direction by the elastic force of the coil spring, so that the roller has a predetermined spring force on the wall surface of the tooth groove. Is pressed. This makes it possible to obtain a click feeling with a small number of parts and a simple configuration.

  In addition, the housing is provided with a slit, and the roller support means extends in parallel with the rotation axis, and the roller is pivotally supported on one end side, and the insertion portion to be inserted into the slit is provided on the other end side. It is preferable to have a leaf spring and a claw portion which is cut and raised outward from the plane of the insertion portion and pressed against the wall surface of the slit.

  According to such a structure, a leaf | plate spring can be fixed to a housing by one touch by inserting the insertion part of a leaf | plate spring in a slit. Also, the elastic force of the leaf spring allows the roller to be pressed against the wall surface of the tooth gap, and the leaf spring is less likely to be displaced in the width direction than in the thickness direction, so that the leaf spring extends in parallel to the rotation axis. As a result, the roller can be structured so as not to easily tilt.

  According to the present invention, good click feeling can be obtained and durability can be improved.

  Hereinafter, preferred embodiments of a rotary encoder according to the present invention will be described in detail with reference to the drawings.

[First embodiment]
As shown in FIG. 1, the rotary encoder 1 includes a housing 10 including a body 11 and a lid portion 12, and a shaft 2 is rotatably provided in the housing 10. A retaining ring 3 is fitted to the outer peripheral surface of the shaft 2, and the retaining ring 3 abuts against the inner wall surface of the housing 10. Further, the end 2 a of the shaft 2 is urged by a leaf spring 4 provided on the lid 12. With such a configuration, the shaft 2 is prevented from coming off.

  One end of the shaft 2 protrudes outside the housing 10 and is used as a rotation input unit for rotating the shaft 2, and the other end of the shaft 2 is press-fitted into the center of the rotor 5 inside the housing 10. . The rotor 5 includes a cylindrical rotor body 5a, an annular flange portion 5b protruding in the radial direction at the end of the rotor body 5a, and a comb tooth portion 5c provided annularly along the periphery of the flange portion 5b. have. The comb tooth portion 5c is composed of a plurality of comb teeth protruding toward the lid portion 12 in the direction of the axis L of the shaft 2, and a slit having a predetermined width is formed between the comb teeth.

  The circuit board 6 is fixed to the inner surface of the lid 12. The circuit board 6 is fixed with a rotation detector 20 that detects the rotation of the shaft 2. The rotation detector 20 includes a light emitting element 21 that emits light and a light receiving element that receives the light emitted by the light emitting element 22. 22. The light emitting element 21 and the light receiving element 22 are arranged to face each other with the comb tooth portion 5c interposed therebetween.

  In the rotary encoder 1, when the shaft 2 is rotated, the comb teeth 5 c of the rotor 5 are rotated, and the comb teeth and slits alternately pass between the light emitting element 21 and the light receiving element 22. The light 21 is received by the light receiving element 22 as strong and weak pulse light, and the amount of rotation of the shaft 2 is detected based on the received light.

  As shown in FIGS. 2 and 3, tooth portions 5 d extending along the axis L direction of the shaft 2 are arranged in parallel on the outer peripheral surface of the rotor body 5 a. A tooth groove 5e that is recessed in an arc shape is formed between the tooth portions 5d, and the tooth groove 5e is in the same direction as the extending direction of the rotation axis L of the shaft 2 by a roller support mechanism (roller support means) 30. A barrel-shaped roller 7 pivotally supported by the shaft is engaged. In FIG. 2, illustration of the flange portion 5 b and the comb tooth portion 5 c in the rotor 5 is omitted to clarify the main part.

  As shown in FIGS. 4 and 5, the body 11 is formed with a support 11 a for supporting a roller support mechanism 30 including a rotating arm 31 and a coil spring 32, and this support 11 a is a rotation axis of the shaft 2. It extends in the same direction as the extending direction of L. A columnar boss portion 11b is provided at the tip of the column 11a.

  A rod-shaped shaft portion 31a that supports the roller 7 is fixed to one end side of the rotating arm 31, and a shaft hole 31b is formed on the other end side. By inserting the shaft hole 31b of the rotating arm 31 into the boss portion 11b, the rotating arm 31 is supported so as to be rotatable around the boss portion 11b. Further, a screw hole 11c is formed at the tip of the boss portion 11b, and the head screw 8 is screwed into the screw hole 11c. The head of the head screw 8 prevents the shaft hole 31b of the rotating arm 31 from being detached from the boss portion 11b.

  The coil spring 32 is wound around the support 11 a and one end is locked to the wall surface of the body 11. And the other end is contact | abutted to the rotation arm 31, and the roller 7 is pressed against the tooth | gear part 5d by urging | biasing the rotation arm 31 in a rotation direction with an elastic force.

  In the thus configured rotary encoder 1, when the rotor 5 is rotated by the rotation of the shaft 2, the roller 7 rolls on the outer peripheral surface of the rotor body 5a, and the shaft every time the roller 7 is engaged with the tooth groove 5e. Since the rotational torque of 2 changes abruptly, a click feeling associated with the rotation of the shaft 2 is obtained (see FIG. 2).

  Further, the rotating arm 31 and the coil spring 32 can be easily assembled to the boss portion 11b and the column 11a, respectively. By this assembly, the roller 7 is pressed against the wall surface of the tooth groove 5e by a predetermined spring force, so that the roller 7 is engaged with the tooth groove 5e, and the click feeling is reduced with a simple structure with a small number of parts. Make it possible to get.

  As shown in FIG. 3, the rotary encoder 1 employs a barrel-shaped roller 7. Even if the roller 7 is inclined with respect to the tooth portion 5d due to an attachment error at the time of assembly or an impact from the outside, both ends are reduced in diameter, so both ends are wall surfaces of the tooth groove 5e between the tooth portions 5d. The roller 7 and the tooth portion 5d are appropriately engaged with each other without being caught on the surface, and a good click feeling can be obtained.

  Furthermore, since the barrel-shaped roller 7 has a sufficient contact area with the wall surface of the tooth groove 5e even when inclined, excessive concentration of the roller 7 on the wall surface of the tooth groove 5e is suppressed. The durability of the tooth portion 5d can be improved. Moreover, since a wider contact area can be obtained compared to a spherical roller, it is optimal as a roller shape for obtaining a click feeling.

[Second Embodiment]
The rotary encoder according to the second embodiment is different from the first embodiment only in the configuration of the body and the roller support mechanism. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 6 and 7, the body 41 is provided with an L-shaped slit portion 41a, and the roller support mechanism 50 has a rod-shaped shaft portion 51a that pivotally supports the roller 7 at one end. A leaf spring 51 having an L-shaped insertion part 51b at the end is provided. The leaf spring 51 extends in parallel with the rotation axis L of the shaft 2 by inserting the insertion portion 51b into the slit portion 41a, and the same direction as the extending direction of the rotation axis L in the shaft 51a. The roller 7 is pivotally supported.

  Further, the insertion part 51b of the leaf spring 51 is provided with claw parts 51c and 51d cut and raised outward from the plane. The claw portions 51c and 51d can be engaged with the leaf spring 51 by being pressed against the wall surface of the slit portion 41a, and the leaf spring 51 can be fixed to the body 41 with one touch.

  In the rotary encoder configured as described above, the roller 7 can be pressed against the wall surface of the tooth groove 5 e by the elastic force of the leaf spring 51. Further, since the leaf spring is less likely to be displaced in the width direction than in the thickness direction, the leaf spring 51 is extended in parallel to the rotation axis L of the shaft 2 so that the roller 7 does not easily tilt. Can do.

[Third Embodiment]
The rotary encoder according to the third embodiment is different from the first embodiment only in the configuration of the body and the roller support mechanism.

  As shown in FIG. 8, the lever 61 provided in the roller support mechanism has a shaft portion 61a that pivotally supports the barrel-shaped roller 7 at one end and a shaft hole 61b at the other end. The lever 61 is inserted into a rod-shaped shaft portion (not shown) provided in the body with the shaft hole 61b, and is supported so as to be rotatable around the shaft portion, and by the elastic force of a spring (not shown). By being urged in the rotation direction, the roller 7 is pressed against the wall surface of the tooth gap 5e. This makes it possible to obtain a click feeling with a simple configuration with a small number of parts.

  It goes without saying that the present invention is not limited to the embodiment described above. For example, the rotary encoder 1 is not limited to the optical type of the rotor 7 and the rotation detection unit 20, but may be a mechanical type or a magnetic type. Further, the rod-shaped shaft portion may rotate integrally with the roller. In this case, the roller support mechanism is provided with a bearing for supporting the shaft portion.

It is sectional drawing which shows 1st Embodiment of the rotary encoder which concerns on this invention. It is a perspective view which shows the rotary encoder of FIG. It is a principal part enlarged view which shows the engagement state of a roller and a tooth | gear part. It is a perspective view which shows the roller support mechanism of FIG. It is sectional drawing which shows the roller support mechanism of FIG. It is a perspective view which shows the body applied to 2nd Embodiment. FIG. 7 is a perspective view of the roller support mechanism shown in FIG. 6. It is a perspective view which shows the roller support mechanism applied to 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rotary encoder, 2 ... Shaft, 5 ... Rotor, 5c ... Comb tooth part, 5d ... Tooth part, 5e ... Tooth groove, 7 ... Roller, 10 ... Housing, 11, 41 ... Body, 11a ... Strut, 11b ... Boss , 12: Lid, 20: Rotation detector, 21: Light emitting element, 22: Light receiving element, 30: Roller support mechanism (roller support means), 31: Rotating arm, 31a, 51a, 61a ... Shaft part, 32 ... Coil spring, 41a ... Slit part, 51 ... Leaf spring, 51b ... Insertion part, 51c, 51d ... Claw part, 61 ... Lever.

Claims (3)

In a rotary encoder having a rotating shaft supported by a housing and a rotation detecting unit for detecting rotation of the shaft,
A tooth portion that is provided in an annular shape around the shaft, and rotates integrally with the shaft;
A barrel-shaped roller engaged with the tooth portion;
A rotary encoder, comprising: a shaft portion that is provided in the housing and supports the roller, and includes roller support means that urges the roller toward the tooth portion by an elastic force. The housing is provided with a support column that extends in the same direction as the extending direction of the rotation axis of the shaft, and a boss portion provided at the tip of the support column,
The roller support means is
The shaft extends in a direction orthogonal to the rotation axis, and has a shaft hole in which the roller is pivotally supported on one end side and the boss portion is inserted on the other end side, and rotates around the boss portion. A rotating arm that moves,
The rotary encoder according to claim 1, further comprising a coil spring wound around the support column and biasing the rotating arm in a rotating direction. The housing is provided with a slit,
The roller support means is
A leaf spring that extends parallel to the rotational axis, has the roller pivotally supported on one end side, and has an insertion portion on the other end side that is inserted into the slit,
The rotary encoder according to claim 1, further comprising a claw portion that is cut and raised outward from a plane of the insertion portion and is pressed against a wall surface of the slit.

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