JPH10248230A - Rotary actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a self-hold torque during the start of release operation of release torque by providing a power storing body such as a spring interposed between a moving member and a fixed portion when the moving member has stopped thereby storing a releasing force in the opposite direction of that of a self-hold force. SOLUTION: One end of a spring 19 as an elastic power storing body is fixed to an end of a peripheral wall inside a case 1 located on a center line of stoppers 18, 18, its free end is linked with both side walls 17b of a channel- shaped notch groove 17a of a moving member 17 and is bent, and release energy tending to move in the direction of stopper 18 is stored at the curved portion. Therefore, when the moving member has stopped, a hold torque T1 by self-hold in the direction of the stopper 18 is added to a release torque T2 in the direction of the stopper 18' created by the release energy of the spring 19 and this sum hold torque acts and a movement occurs in the direction of stopper 18' in conformity with a rotation torque T. By doing this, an rotary actuator having a quick operation start can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable magnet type rotary actuator for converting electric energy into rotational force, which can reciprocate at a predetermined angle and hold a position without energization, and in particular, is charged when a mover is stopped. The present invention relates to a rotary actuator that can reduce a holding torque at the time of starting.

[0002]

2. Description of the Related Art Conventionally, as a rotary actuator of this type, a configuration example shown in FIG. 4 has been known. In the same figure, (a) is a top view in which the upper electromagnetic coil and the like opposed to each other are omitted, and (b) is an electromagnetic coil 3a in FIG.
FIG. 7 is a sectional view taken along line AA ′ of FIG. As shown in the drawing, the case main body is composed of a case 1 and a mounting plate 2, and an inner bottom surface 1a of the case 1 and an inner side 2a of the mounting plate 2 are opposed to each other and have left and right electromagnetic coils 3 (3 ') and an electromagnetic coil. 3a (3a ')
Are a rectangular core 4 (4 ') and a core 4a, respectively.
(4a '), and the shaft 5 is rotatably provided by a bearing 6 (the case 1 side is not shown). Further, a permanent magnet 7 is fixed to a support member 5 a made of plastic and fixed integrally with the shaft 5. Reference numerals 8 and 8 'denote left and right stoppers of the support member 5a, respectively, so that the permanent magnet 7 stops after passing through the upper surfaces of the opposed cores 4 and 4' as shown in FIGS. 4 (a) and 4 (b). It is set on the inner surface 2a of the mounting plate 2.

[0003]

However, in the electromagnetic magnet type rotary actuator configured as described above,
4 (b), the core 4 and the permanent magnet 7 are slightly opposed to each other at an inner position than the end 7a of the permanent magnet 7, and are stopped. As shown by the characteristic curve c), although a stable region of the holding torque is obtained even at a wider rotation angle and a strong advantage against disturbances such as vibration is obtained, when the force for detachment is applied, the operation is performed. There was a problem that the starting speed was slow.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a rotary actuator in which a movable element abuts on a fixed section and is self-held. By providing an energy storage body such as a spring interposed in the power supply, a release force in a direction opposite to the self-holding force is stored, and this release torque reduces the self-holding torque at the time of starting the release operation. It is configured to increase the speed.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are main part top views showing a first embodiment of a rotary actuator according to the present invention. FIG. 1A shows a configuration of a conventional example shown in FIG.
FIG. 4 is a layout view of main parts showing a positional relationship among a case, a shaft, a bearing, a plastic-molded movable element, and a stopper, and shows a state in which the left stopper is self-held. The same parts as those in FIG. Spring 19 as elastic energy storage
Is fixed to the inner peripheral wall of the case 1 on the center line (including the center of the shaft) of the stoppers 18, 18 ′, and the free ends are formed on both side walls 17 b (1) of the U-shaped cutout groove 17 a of the mover 17.
7b '), and bends.
Accumulates departure energy to move in eight directions.

Therefore, the holding torque T1 (similar to the related art) by self-holding in the direction of the stopper 18 and the separation torque −T2 in the direction of the stopper 18 ′ generated by the separation energy of the spring 19 are added to the movable element 17. T1
A holding torque of -T2 = T acts, and the stopper 18 'moves in accordance with the turning torque T of the combined characteristic curve as shown in FIG. 1B.

FIG. 1C shows a comparison between the operation at the time of starting the movable element 17 in the conventional embodiment and the present embodiment, and shows the relationship between the rotation angle θ and the operation time t. As can be seen from the figure, the operation of the present embodiment is significantly faster than that of the conventional embodiment indicated by a broken line.

FIG. 2 is a main part top view showing a second embodiment of the rotary actuator according to the present invention.
The same reference numerals are given to the same parts. As is clear from the figure, the present embodiment employs a spring 29 as an elastic energy storing body.
This is a case where one end 29a is fixed to both sides of the support shaft 5 of the mover 27. In this case, cutouts 27a and 27a 'are provided on both sides of the free end of the mover 27. When the spring comes into contact with the stopper 28, the spring 29
9b is bent, and at this time, desorption energy is accumulated. This stored energy becomes a negative holding torque in the direction of the stopper 28 ', and when the detaching force is applied to the mover 27 by the urging of the opposite electromagnetic coil 3a', as in the first embodiment, a quick operation is performed. Stopper 28 'at start speed
(See FIGS. 1B and 1C).

FIG. 3 is a view showing a third embodiment of the present invention. FIG. 3 (a) is a top view of a main part, and FIG. 3 (b) is a side sectional view of a stopper. Are given the same reference numerals. As is apparent from FIG. 7, in the present embodiment, a light-weight coil spring 39 (39 ') is used as the elastic energy storing body, and the concave portions 38 formed in the stoppers 38, 38' are provided.
a, 38a 'and the head protrudes. As a result, the mover 37 comes into contact with the head of the coil spring 39 (or 39 ') from which the stopper 38 (or 38') protrudes, and accumulates the anti-holding torque toward the non-contact-side stopper 38 '. Therefore, also in the third embodiment, a rotary actuator whose operation starts quickly can be obtained as in the first and second embodiments.

[0010] Further, the coil spring 39 (39 ') shown in FIG.
However, it is needless to say that the same effect can be obtained even if the movable member 37 is fitted to a portion which comes into contact with the stopper 38 (38 ').

[0011]

As described above, according to the present invention, the following effects can be obtained. In the present invention, a spring as an elastic energy accumulator is provided on the fixed portion side of the mover or the case or the stopper, so that the accumulating force generated in the spring when the mover is stopped functions, and the spring is applied to the opposite stopper. The holding force at the start of rotation is reduced, and a rotary actuator that starts operation quickly can be obtained.

[Brief description of the drawings]

FIG. 1 is a top view of a main part showing a first embodiment of the present invention,
These are holding torque characteristics and operating characteristics.

FIG. 2 is a main part top view showing a second embodiment of the present invention.

FIG. 3 is a top view of a main part and a side sectional view of a stopper, showing a third embodiment of the present invention.

FIG. 4 is a top view of a main part of a conventional example, a sectional view taken along line AA 'of FIG.

[Explanation of symbols]

1 Case 2 Mounting plate 3, 3 ', 3a, 3a' Electromagnetic coil 4, 4 ', 4a, 4a' Core 5 Shaft 6 Bearing 7 Permanent magnet 8, 8 ', 18, 18', 28, 28 ', 38, 38 38 '
Stoppers 19, 29 Springs 17, 27, 37 Mover 39, 39 'Coil spring

Claims (4)

[Claims] 1. A rotary actuator in which a movable element abuts on a fixed part and is held by itself, wherein an elastic energy storage member is interposed between the fixed part and the movable element. 2. The rotary actuator according to claim 1, wherein the elastic energy storage body is a spring having one end fixed to the case and a free end moving in a U-shaped notch groove of the mover and abutting on both side walls. 3. The elastic energy storage body is a spring provided on both side surfaces of a mover, the spring having a rear end fixed near a support shaft of the mover, and a distal end provided with a gap between the spring and the mover. The rotary actuator according to claim 1, further comprising: 4. The rotary actuator according to claim 1, wherein the elastic energy storage body is a coil spring fitted to a stopper or a portion of the movable element that comes into contact with the stopper.