JPH0469286B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a reverse acting electromagnetic spring clutch used for force transmission.

(Prior Art) As a transmission mechanism for rotational motion, etc., there is a reverse action electromagnetic spring clutch that is in a transmission state when the electromagnetic coil is de-energized and releases the transmission when the electromagnetic coil is energized. As this technology, the special public
It is disclosed in Publication No. 3016. This reverse action electromagnetic spring clutch includes an output boss which is a rotating body, a coil spring whose one end is fixed to the output boss, and a coil spring which is adjacent to the output boss and rotates around the rotation axis of the output boss. an input-side boss that rotates the coil spring, the input-side boss having a cylindrical clutch surface that is coaxial with the coil spring and that is frictionally connected by winding at least a portion of the coil spring; A coil spring type clutch comprising a collar to which the other end is fixed, the collar having an axial surface provided on the input side boss in a direction parallel to the rotating shaft and an axial surface facing opposite to the input side boss. , the coil spring has an inner diameter that does not contact the cylindrical clutch surface in a relaxed state, and the coil spring exerts an axial force between the output boss and the collar, and the coil spring exerts an axial force between the output boss and the collar, The force presses the axial surface on the collar toward the axial surface on the input-side boss, and the frictional contact between both surfaces transmits the rotational force of the input-side boss to the collar, and at the same time, the coil A spring is wound around the cylindrical clutch surface of the input boss to transmit frictional force, whereby the input boss gradually transmits power to the output boss; The clutch is provided with an electromagnetic coil or the like for separating the clutch from the input-side boss against the pressing force of the coil spring to disconnect the clutch.

(Problems to be Solved by the Invention) However, the above-mentioned conventional technology has the following problems.

During clutch transmission, the axial surface of the collar on the input-side boss side is pressed toward the axial surface of the opposing input-side boss. This pressing transmits the rotational force of the input side boss to the collar, and the winding of the coil spring also transmits the force to the output side boss. Therefore, it is actually necessary to attach a friction plate to the opposing axial end surfaces of the collar and the input boss in order to ensure high frictional force. Furthermore, since frictional force is always acting during transmission, there is a problem of significant wear. Further, since the coil spring requires an axial force to constantly press the collar toward the input boss, it is necessary to wind the coil spring intermittently. Furthermore, the coil spring has to be fixed at one end to the collar and at the other end to the output boss, making processing and assembly troublesome.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a reverse action electromagnetic spring clutch that does not require frictional force during transmission and has a simple structure.

(Means for Solving the Problems) The present invention for solving the above problems has the following configuration.

That is, a field core formed of a magnetic material and having a U-shaped cross section, a first rotating shaft rotatably disposed within the field core perpendicular to the back wall surface of the field core, and a center hole. In the field core, the field core is formed into a ring shape,
an electromagnetic coil disposed externally on the first rotating shaft; a second rotating shaft rotatably disposed with its axis aligned with the first rotating shaft; and a cylindrical shape made of a magnetic material. and is arranged in the center hole of the electromagnetic coil, is rotatably fitted onto the first rotation shaft and the second rotation shaft, is movable in the axial direction, and has an inner end surface facing the back wall surface of the field core. an armature arranged so as to be able to come into contact with each other; an armature disposed between the armature and the first rotating shaft and the second rotating shaft, one end of which is fixed to the armature; A coil spring having an inner diameter that can be wound around the outer peripheral surfaces of the rotating shaft and the second rotating shaft, and a through hole formed of a magnetic material, provided at the open end of the field core, and into which the armature etc. can be loosely inserted. or a flange formed of a magnetic material and provided at a predetermined position of the armature to close the open end of the field core when the armature moves toward the field core, and the coil spring is When the electromagnetic coil is not energized, the first rotating shaft and the second rotating shaft, one of which is rotating due to an external force, are connected by winding, and when the electromagnetic coil is energized, a coil spring is formed. The armature rotating integrally with the first rotation shaft and the second rotation shaft is attracted by the electromagnetic coil, and the inner end surface of the armature comes into contact with the back wall surface of the field core, and the rotation of the armature is braked. This feature is characterized in that the inner diameter of the coil spring expands, loosens the tightness between the first rotating shaft and the second rotating shaft, and releases the connection.

(effect) The action will be explained with reference to FIG.

FIG. 1a shows the state before the electromagnetic coil 12 is energized. The coil spring 22 has one end fixed to the armature 16 and is in tight contact with the first rotating shaft 20 and the second rotating shaft 18, so that
If an external force is applied to the second rotating shaft 18, the first
The rotating shaft 20 and the second rotating shaft 18 rotate together.

Next, when the electromagnetic coil 12 is energized, a magnetic circuit is formed as shown by the broken line A as shown in FIG. , the rotation of the armature 16 is stopped due to the frictional force. However, the first rotation axis 2
0 and the second rotating shaft 18, the coil spring 22 loosens, expands in diameter, and releases the connection between the first rotating shaft 20 and the second rotating shaft 18, so that only the second rotating shaft 18 receives external force. rotates and the first rotation axis 20
rotation can be stopped.

(Embodiment) A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

First, the configuration will be explained with reference to FIG. 1a.

A field core 10 is made of a magnetic material, has a cylindrical shape, and is provided with a through hole 26 of an appropriate size on one end surface, through which a bearing 24 and a first rotating shaft 20, which will be described later, can be connected. Insert. The other end face is formed into an opening. field core 1
The shape of 0 does not have to be cylindrical, for example, even if it is formed by bending a steel plate with a U-shaped cross section,
It is only necessary to ensure sufficient magnetic force. Reference numeral 12 denotes an electromagnetic coil, which is formed into a ring shape with a center hole. The electromagnetic coil 12 is fixed inside the field core 10 with adhesive, resin, or the like. A yoke 14 is made of a magnetic material and is connected to the field core 10.
A through hole is provided in the center of the hole to cover the opening of the armature 16, and a through hole is formed in the center thereof to allow the armature 16 and the like to be loosely inserted thereinto. The yoke 14 may be fixed by press-fitting into the opening of the field core 10 or by caulking. A bearing 24 constitutes a part of the field core 10, is made of iron-based oilless metal which is a magnetic material, and is fixed into the through hole 26 of the field core 10 by press-fitting or caulking. Reference numeral 20 denotes a first rotating shaft, and a coil spring 22, which will be described later, rotates the second rotating shaft 1.
8, the rotational force is transmitted to a transmitted member (for example, a shaft, etc.) connected to the first rotating shaft 20.

18 is a second rotating shaft, which is similar to the first rotating shaft 2.
0 is rotatably fitted on the outside.

An armature 16 is made of a magnetic material and has a cylindrical shape, and is disposed within the center hole of the electromagnetic coil 12. The armature 16 is fitted around the first rotating shaft 20 and the second rotating shaft 18 so as to be freely slidable. Reference numeral 22 denotes a coil spring, which is wound tightly in order to connect the first rotating shaft 20 and the second rotating shaft 18 in the normal state, that is, when the electromagnetic coil 12 is not energized. It is hooked into a slit 17 cut into the outer edge of the armature 16. The length of the slit 17 is made long enough to prevent the hooking portion of the coil spring 22 from coming off when the armature 16 is attracted.

C-rings 28 and 30 position members such as the field core 10 and the second rotating shaft 18 on the first rotating shaft 20. The C-rings 28, 30 can be fixed by carving a groove in a predetermined position of the first rotating shaft 20 and fitting the C-rings 28, 30 therein. E-rings or collars may be used instead of the C-rings 28, 30.

Next, the operation will be explained.

In a normal state, as shown in FIG. 1a, the first rotating shaft 20 and the second rotating shaft 18 are connected by being tightened by a coil spring 22. Therefore, the second
When an external force is applied to the rotating shaft 18 of the rotary shaft 18 and the second rotating shaft 18 rotates in a predetermined direction, that is, in the direction in which the coil spring 22 is tightened, the first rotating shaft 20 and the second rotating shaft 18 rotate as one. do. Yotsutte 1st
The rotating shaft 20 can transmit force to a transmitted member (not shown) connected to the first rotating shaft 20.

Next, when the electromagnetic coil 12 is energized, a magnetic circuit as shown by the broken line A is formed around the field core 10 and the like, as shown in FIG. 1b. Then, the armature 16 is attracted, and its inner end surface comes into contact with the inner surface of the bearing 24 forming the back wall surface of the field core 10. Therefore, the bearing 24 and the armature 16
Due to the frictional force with the inner end surface of the armature 16
A brake is applied to the rotation. At this time, since one end of the coil spring 22 is hooked to the slit 17 of the armature 16, the rotation of the coil spring 22 is also braked. But the second
The rotating shaft 18 and the first rotating shaft 20 receive an external force,
Since the coil spring 22 continues to rotate, the coil spring 22 receives a force from the end hooked to the armature 16 to expand its diameter, and the second rotating shaft 18 is loosened. Then, the connection between the first rotating shaft 20 and the second rotating shaft 18 is gradually released, and the rotation of the first rotating shaft 20 and the transmitted member (not shown) stops.

In this embodiment, the yoke 14 is connected to the field core 1.
Although it is fixed at 0, it may be formed into a flange shape and provided at an appropriate position on the armature 16.

Furthermore, the shape of the field core 10 may be any shape as long as sufficient magnetic force can be ensured.

Further, the bearing 24 may not be provided if the friction of the armature 16 or the like is small.

Furthermore, instead of the first rotating shaft 20, a shaft or the like to which rotational force is directly transmitted can be formed into a predetermined shape and attached.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and the shape of the armature air may be polygonal instead of cylindrical, etc., in accordance with the spirit of the invention. Of course, many further improvements can be made without departing from the above.

(Effects of the Invention) When the reverse action electromagnetic spring clutch according to the present invention is used, the connection between the first rotating shaft and the second rotating shaft is achieved only by the tightening force of the coil spring itself. There is no need to provide a coil spring, and the structure that loosens the coil spring
A simple configuration is sufficient, in which the inner end surface of the armature is brought into contact with the inner wall surface of the field core using an electromagnetic coil, and the rotation of the armature is braked by the frictional force, so the coil spring can be tightened immediately regardless of the rotational position of the armature. It is possible to loosen it. In addition, wear occurs only when the armature is attracted by the electromagnetic coil and the rotation of the armature is braked, which can suppress wear compared to conventional models that constantly wear.
A spring clutch with a long life can be provided. Coil springs do not require axial force, so there is no need for intermittent winding, and any type of coil spring can be used as long as it can tighten the first and second rotating shafts under normal conditions. It has sex. Furthermore, since the other end of the coil spring does not need to be hooked anywhere, machining and assembly are simple, which is technically and economically advantageous.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a reverse action electromagnetic spring clutch according to the present invention. In addition, in the drawing, 10... field core, 12
... Electromagnetic coil, 14 ... Yoke, 16 ... Armature, 18 ... Second rotating shaft, 20 ... First
Rotating shaft, 22... coil spring.

Claims (1)

[Scope of Claims] 1. A field core formed of a magnetic material and having a U-shaped cross section, and a first rotating shaft rotatably disposed within the field core perpendicular to the back wall surface of the field core. an electromagnetic coil formed in a ring shape having a center hole and disposed within the field core so as to fit around the first rotation shaft; and an electromagnetic coil that is rotatable with its axis aligned with the first rotation shaft. a second rotating shaft arranged in the first rotating shaft and the second rotating shaft; an armature arranged to be movable in the axial direction and such that its inner end surface can come into contact with the rear wall surface of the field core;
a coil spring disposed between the rotary shaft and the rotary shaft, one end of which is fixed to the armature, and having an inner diameter capable of wrapping around the outer peripheral surfaces of the first rotary shaft and the second rotary shaft in a normal state; A yoke made of a magnetic material, provided at the open end of the field core, and having a through hole into which the armature etc. can be loosely inserted, or a yoke made of a magnetic material, when the armature moves in the direction of the field core. and a flange provided at a predetermined position of the armature to close the open end of the field core, and the coil spring has one side rotating under an external force when the electromagnetic coil is de-energized. The rotary shaft and the second rotary shaft are connected by tightening, and when the electromagnetic coil is energized, the armature rotates integrally with the first rotary shaft and the second rotary shaft via the coil spring. It is attracted by the electromagnetic coil, and the inner end surface of the armature comes into contact with the inner wall surface of the field core, and the rotation of the armature is braked, so that the inner diameter of the coil spring expands and the inner end surface of the armature comes into contact with the inner end surface of the field core. A reverse action electromagnetic spring clutch characterized in that the connection is released by loosening the winding.