Rotary actuator vibration control mechanism

Abstract

To provide a rotary actuator vibration control mechanism that both reduces vibration during operation and contributes to simplifying the overall structure. In this rotary actuator vibration control mechanism, a continuous shock absorbing member that is integrally formed together with a stopper and an engagement means is laid out in a rotary actuator comprising the following: a case; a rotor that is disposed inside said case and swings back and forth; an output shaft that supports said rotor and outputs the force of the swinging thereof to the outside; the aforementioned stopper, which prescribes the movement path of the rotor inside the case; and the aforementioned engagement means, which engages with an externally attached device disposed outside the case. The shock absorbing member is designed such that the stopper is formed by the molded body that forms the shock absorbing member, and is also designed so as to cover the entire engagement means. The shock absorbing member may be designed such that an integral molded body covers contact parts of both the stopper and the engagement means in a continuous manner, or may be changed to a design in which both are integrally formed by the shock absorbing member.

Claims

1. A rotary actuator oscillation control mechanism for a rotary actuator comprising: a case; a rotor arranged in the case and oscillates in a predetermined rotary angle by a driving means; an output shaft that holds the rotor in the case and outputs oscillation force thereof to the outside as axial rotation; a stopper arranged inside the case and limits the movement of the rotor; and an engagement means arranged at an outside of the case and engages the case with an external mounting device; the rotary actuator oscillation control mechanism is characterized in that a shock-absorbing member is integrally formed as one continuous piece to both the stopper and the engagement means.

2. The rotary actuator oscillation control mechanism according to claim 1 characterized in that the shock-absorbing member is configured to cover a contact member of the stopper and a contact member of the engagement means as one continuous piece.

3. The rotary actuator oscillation control mechanism according to claim 1 characterized in that the shock-absorbing member is configured such that either one of the stopper or the engagement means is formed as a body of the shock-absorbing member, and the shock-absorbing member formed integrally with the body while covering a contact surface of the other.

4. The rotary actuator oscillation control mechanism according to claim 1 characterized in that both the stopper and the engagement means are integrally formed by the shock-absorbing member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a partially cut-out perspective view illustrating the actuator according to an embodiment 1.

(2) FIG. 2 is a perspective view showing the actuator according to the embodiment 1.

(3) FIG. 3 is a cross-sectional side view of the actuator according to the embodiment 1.

(4) FIG. 4 is a side view of the actuator according to the embodiment 1.

(5) FIG. 5(A) is a cross-sectional side view and FIG. 5(B) is a partially cut-out side view respectively showing the actuator of an embodiment 2.

(6) FIG. 6(A) is a perspective view and FIG. 6(B) is an assembly perspective view showing the conventional anti-vibration actuator mechanism.

EMBODIMENTS OF THE INVENTION

(7) In the following, embodiments 1 and 2 of an actuator arranged with the vibration-control mechanism of the present invention are described in detail with reference to the accompanying drawings.

Embodiment 1

(8) First, an actuator 1A according to the embodiment 1 will be described.

(9) The actuator 1A is configured with: a case 2 having a protrusion 23 as an engaging means for engaging the frame f of the mounting device; an electromagnetic coil 3 that is a component of a driving means and is arranged on the inner side of the case 2; a rotor 5 including permanent magnets 52 facing an electromagnetic coil 3 with a predetermined gap; an output shaft 4 that supports the rotor 5 in a cantilevered manner as well as outputs the swinging force of the rotor 5 to the outside; a stopper 61 defining a movement of the rotor 5; and a shock-absorbing member 6 disposed integrally on the stop and the engagement means.

(10) The case 2 shown in the drawings is comprised of a main body 21 having upper open (upward) and a bottomed cylindrical body, and a lid 22 that is compatible with the opening of the upper part of the main body 21, thereby configuring a sealed box shape having an internal cavity by closing of the lid 22. The lid 22 is provided with a through-hole 25 through which the output shaft 4 penetrates, and a slit 24 formed by partially cutting the surrounding of the protrusion 23 in a groove-like notching. Further, a boss 22a which engages with a through hole f3 of the frame f of the mounting device is provided with a shape formed by building a ring around the edge of the through hole 25.

(11) Two rectangular columnar protrusions 23, 23 are oppositely laid at a predetermined interval at a side wall 21a of the main body 21 of the case 2 opposite to the penetration position of the output shaft 4. The protrusion 23 serves as an engagement means with the frame f of the mounting device, and its periphery is covered with the shock-absorbing member 6. Around the base of the protrusion 23, a notched groove 26 is formed in the lid 22 and the side wall 21a, and a slit 24 is formed contiguously to the groove 26 to penetrate into the case.

(12) Near the center on the inner bottom surface 21b of the case body 21 is arranged with an electromagnetic coil 3 of a cylindrical shape and a predetermined height. The output shaft 4 is disposed in the erected state at a position not interfering with the electromagnetic coil 3. The output shaft 4 serves as an output shaft of the actuator 1A, and is configured to be rotatable with respect to the lid 22.

(13) In the present embodiment, the output shaft 4 is a convex unit extending to the outside from the case. However, it can be a concave unit without extending to the outside (not shown). In such a situation, an input shaft of the mounting device will be fitted to the fitting portion for driving force.

(14) Further, the rotor 5 of the thick plate shape is attached to the output shaft 4 in a cantilevered manner. As shown in FIG. 3, the rotor 5 has a shape of substantially hexagonal in front view. A contact member 51 protruding toward the case wall 21a is integrally formed at a position of one corner of the hexagonal shape opposite to the output shaft 4. In the rotor 5, a permanent magnet 52 facing the electromagnetic coil 3 is disposed and a back yoke 53 is disposed on the back side.

(15) With this configuration, the rotor 5 actively oscillates by a predetermined rotary angle by an electromagnetic interaction between the electromagnetic coil 3 and the permanent magnet 52, and the swing force from the output shaft 4 is supplied to the outside as an output.

(16) Next, the shock-absorbing member 6 serving as a principal object according to the present invention will be described.

(17) The shock-absorbing member 6 is integrally formed by: two contact portions 62 and 62 each having a rectangular cylindrical shape that are oppositely laid; a strip-like connecting portion 63 which connects the contact portions 62; a stopper 61 that extends from the lower outer portion of each of the contact portions 62 and further extends to be counter to and perpendicular with the extending direction of the connecting portion 63 (arrangement direction of output shaft 4). In the embodiment, the shock-absorbing member 6 is formed of rubber material (hereinafter referred to as vibration-proof rubber) that alleviates or absorbs vibrations and impacts.

(18) The shock-absorbing member 6 formed as above is arranged so that the contact portions 62 each having a tubular shape is mounted so as to fit from above the protrusions 23 in a state in which the main body 21 is closed with the lid 22. In this situation, the connecting portion 63 is substantially in close contact with a flat wall 21c formed on the side wall 21b of the case body 21 at a position opposite to the output shaft 4, and is properly retained in conformance with the notched groove 26. Also, due to this attachment, the stopper 61 is inserted through the gap of the slit 24 and is held at a predetermined position. Thus, the case 2 is sealed as the stopper 61 fits to the slit 24.

(19) The protrusions 23 as shown are fitted into the engagement opening f3 of the frame f when the actuator is assembled with the mounting device. Accordingly, the actuator 1A is prevented from relative rotation against the frame f caused by reaction forces of the rotary movement of the rotor 5.

(20) The protrusion 23s as the engaging means, by being attached with the shock-absorbing member 6 as described above, are covered at the contact portions 23a with the shock-absorbing member 6. This allows to mitigate transmission of reaction forces (rotational force in the reverse direction to the rotation direction of the rotor) from the rotor 5 via the shock-absorbing member 6 by avoiding direct contacts between the protrusions 23 and the frame f of the mounting device.

(21) Further, the stopper 61 disposed at a predetermined position in the inside of the case 2 limits the movement of the rotor 5 by colliding with the contact member 51 of the rotor 5. Further, since the stopper 61 is formed by the shock-absorbing member 6, it can alleviate or absorb the impact of the collision. As to a layout arrangement of the stopper 61 constituting the shock-absorbing member 6 functioning as a stopper, it is appropriately determined depending on a desired rotary oscillation angle of the rotor 5 and arrangement of the contact member 51 (1 or 2 points arrangement) in relation to the rotor 5.

(22) Further, the boss 22a of the case 2 formed around the output shaft, as shown in FIG. 4, is configured to engage with the frame f of the mounting device, similar to the protruding member 23 and the contact member 62. The boss 22a retains and positions the actuator 1a as a whole. On the other hand, the protrusion 23 and shock-absorbing member 6 constituting as engagement means function to prevent the relative rotation by the reaction forces of the actuator 1A as well as to suppress the vibration.

(23) In the actuator 1A according to the present invention, by arranging the shock-absorbing member 6 as described above, the shock-absorbing member of the protrusion 23, which conventionally would need to be separately provided from the shock-absorbing member of the stopper 61, can not only be integrally formed, and but also makes it possible to omit a stopper of stiff material.

(24) Here, description will be made as to the basic configuration of the drive means of the actuator 1A configured as described above.

(25) The drive means of the actuator 1A is a common technology and details thereof are disclosed in the Patent Document 1 by the present applicant, and therefore its detailed description will be omitted.

(26) Thus, the outline of the configuration used in this embodiment is as follows.

(27) In the actuator 1A, in the case of a non-energized state, the rotor 5 maintains a stopped state by the magnetic attraction between one of the permanent magnets 52 and the core (not shown) of the electromagnetic coil 3, and by the restriction of the stopper 61. Next, when an electric current is introduced to the electromagnetic coil 3, and the electromagnetic coil 3 is energized thereby generating a magnetic force. Thus, the rotor 5 moves to the opposite direction when energized magnetic force exceeds the magnetic force of the permanent magnet 52 which has been attracted to the core. The coupling/decoupling of the energization to the electromagnetic coil 3 promotes the reciprocating motion of the rotor 5, and the oscillation is outputted from the output shaft 4 as the rotary oscillation force.

Embodiment 2

(28) Next, the actuator 1B of an embodiment 2 will be described. Constituent elements having the same functionality as those in the actuator 1A of the embodiment 1 are designated by the same reference numerals, and detailed description thereof is omitted.

(29) The actuator 1B shown in FIG. 5 is a modified example of the actuator 1A of the embodiment 1, which has a different configuration of a case 2b, rotor 5b and a shock-absorbing member 6b.

(30) The shock-absorbing member 6b used in the actuator 1B is molded as a unitary body in a block shape based on the specification to function as the stopper and an engagement means described above. The block-shaped shock-absorbing member 6b (hereinafter referred to as block member) has a substantially rectangular body, and is arranged at the side wall 21a of the case 2 at a position opposite to the output shaft 4, and is further arranged at the position to interfere with the movement locus of the contact member 51b to be described below. In the substantially central position of the block member 6b, an insertion hole 64 that is substantially parallel with the axial direction of the output shaft 4 is opened with a predetermined depth. Incidentally, the insertion hole 64 may be a through-hole or a bottomed hole. In addition, although not shown, it may be configured as a male screw or one-way insertion receptor depending on specifications of a mounting device. The block member 6b has shoulder portions 65 on both sides of the insertion hole 64 as viewed (drawing) from the front.

(31) Moreover, the case 2 and its inner portion is arranged with the rotor 5b cantilevered by the output shaft 4 in the same manner as in the embodiment 1. The rotor 5b extending radially (or to the side wall 21a of the case 2) with the output shaft 4 as a center has two protruding contact members 51b at a predetermined distance.

(32) The block member 6b of the embodiment 2 configured as described above has the insertion hole 64 that receives and fits a pawl portion f2 that is bent and protruded from the frame f, which prevents the relative rotary oscillation of the actuator 1B by the reaction force of the swing. The block member 6b further includes two contact members 51b, 51b arranged at a distance that alternately contact with the shoulder portions 65, 65 to function as a stopper. Thus, the rotary angle during the oscillation of the rotor 5b, i.e., a reciprocating stroke movement is defined.

(33) As a result, since the block member 6b is formed of a shock-absorbing member, the impact force at the time of contact of the contact member 51 and reaction force from the claw portion f2 can be reduced or attenuated.

(34) Due to the above configuration, the block member 6b can provide a stopper and an engagement means by an integrally molded body, and secure a sufficient shock-absorbing area for an effective shock-absorbing member even when miniaturized. Moreover, the number of components can be reduced, and assembling efficiency, durability and reliability are improved, and further economical effects such as reduction of the component cost and manufacturing cost can also be expected.

DESCRIPTION OF REFERENCE SYMBOLS

(35) 1A actuator of embodiment 1 1B actuator of embodiment 2 2, 2b case

(36) 23 protrusion (engagement means) 3 electromagnetic coil (component of drive means) 4 output shaft 5, 5b rotor

(37) 51, 51b contact member 6 shock-absorbing member 6b block member (shock-absorbing member of embodiment 2)

(38) 61 stopper

(39) 62 contact portion

(40) 63 connecting portion

(41) 64 insertion hole

(42) 65 shoulder portion