JPS628436Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electromagnetic clutch for limited rotation.
The automatic drive source for the feeding device is generally a geared motor with a high reduction ratio, and it is impossible to rotate this manually. Therefore, a clutch is required between the output side and the driven side of the geared motor to disconnect the two. The electromagnetic clutch used as this clutch uses a general power transmission type such as a friction type or a mesh type, but in this case, the general power transmission type is designed to handle infinite rotation. Therefore, the static coil type requires a rotor, and the rotating coil type requires a slip ring, etc., which increases the number of parts and has high precision parts, resulting in a large volume and high cost as a whole. It existed. However, feeding devices generally have a finite rotation speed, such as tables in machine tools, power windows, scanning machines in office machines, traversers in winding machines, and automatic doors, and the number of revolutions used is low and the required torque is large. . SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electromagnetic clutch that is used for limited forward and reverse rotation and is simple and inexpensive to manufacture.

The configuration of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

2 is a geared motor, and a pinion gear 4 fixed to its output shaft meshes with a gear 8 rotatably fitted to the output shaft 6 via a ball bearing. Reference numeral 10 denotes a ring-shaped leaf spring fixed to the gear 8 with a screw, and the leaf spring 10 has an armature 12 formed in the center thereof with a shaft hole into which the output shaft 6 is loosely fitted. It is fixed with rivets. Reference numeral 14 denotes a magnetic pole member fitted and fixed to the square portion 6' of the output shaft 6, and a yoke member 16 having the same shape as the armature 12 is fixed to this. Friction surfaces or projections and depressions for engagement are formed on opposing surfaces of the outer circumferential portion of the yoke member 16 and the outer circumferential portion of the armature 12. Reference numeral 18 denotes a coil wound around a bobbin disposed on the outer periphery of the magnetic pole member 14, and a terminal 20 to which the winding start and end of the coil are connected is fitted and fixed into a through hole formed in the yoke member 16. There is. A lead wire 22 has a flat two-core structure and is made of a spring-like shape-retaining elastic member. A core at one end of the lead wire 22 is attached to the terminal 20 and electrically connected to the winding start end and the winding end end of the coil 18. The other end of the lead wire 22 is connected to a terminal (not shown) provided on a fixing member (not shown), and the terminal is connected to a power source via a switch or the like. The lead wire 2
2, the diameter of the spring-like ring expands and contracts in accordance with the finite rotational movement of the yoke member 16, and this expansion and contraction change prevents twisting at both ends of the lead wire 22.

Next, the operation of this embodiment will be explained.

The finite rotation of the output shaft of the geared motor 2 is controlled by the armature 12 through the pinion 4, gear 8, and leaf spring 10.
is transmitted to. When the coil 18 is energized, the armature 12 resists the elasticity of the leaf spring 10 and is pressed against its outer circumference by magnetic force, so that the finite rotational movement of the armature 12 is transferred to the output shaft 6 via the yoke member 16. communicated. The ring size of the lead wire 22 changes according to the finite rotational movement of the yoke member 16, and the lead wire 22 is twisted due to the finite rotational movement of the yoke member 16, or
There is no load on the rotational movement of the yoke member 22. When the coil 18 is de-energized by turning the switch OFF, the tensile force of the leaf spring 10 separates the outer circumference of the armature 12 from the outer circumference of the yoke member 16 for a predetermined period of time, thereby disengaging the electromagnetic clutch. The output shaft 6 is now in a state where it can be rotated manually.

As described above, the present invention has the advantage that since the spring-like lead wire is connected to the yoke member, a rotor or slip ring is not required, and therefore the structure is simple and can be manufactured at low cost.

[Brief explanation of the drawing]

The figures show a preferred embodiment of the present invention, with FIG. 1 being a sectional view, FIG. 2 being a rear view, and FIG. 3 being a front view. 2...Geared motor, 4...Pinion gear,
6... Output shaft, 8... Gear, 10... Leaf spring, 1
2... Amateur, 14... Magnetic pole member, 16...
Yoke member, 18... Coil, 20... Terminal, 2
2...Lead wire.

Claims (1)

[Scope of utility model registration request] A shaft hole for connecting the output shaft 6 is formed, and a magnetic pole member 14 with a coil 18 installed on the outside is connected to a limited rotation drive system via a leaf spring 10, and the output shaft 6 is loosely fitted in the center part. an armature 12 that has a hole for
and a yoke member 1 which is fixedly attached to the magnetic pole member 14 and whose outer peripheral portion faces the outer peripheral portion of the armature 12.
6, a terminal 20 electrically connected to the coil 18 and protruding from the yoke member 16, and the terminal 2
0, and has an elastic shape retention property whose length is set according to the finite rotation range of the yoke member 16 so that the diameter of the ring expands and contracts with the finite rotational movement of the yoke member 16. An electromagnetic clutch characterized by comprising a spring-shaped lead wire 22.