JPS5811944Y2 - spring type electromagnetic clutch - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a spring-type electromagnetic clutch coupled between a rotating machine and a prime mover for intermittently driving, for example, a refrigerant compressor of an automobile air conditioner. .

Conventionally, as a spring type electromagnetic clutch, for example,
As shown in Japanese Patent No. 8947, a coil spring is provided with an electromagnetic coil on one side of a drive pulley and a clutch plate on the other side, and wound around the shaft of the pulley and the shaft of a rotated body with a gap. When one end is engaged with the clutch plate and the other end is engaged with the shaft of a rotated body and the electromagnetic coil is excited, the clutch plate engages with the friction surface of the pulley and rotates, thereby being engaged with the clutch plate. A structure has been proposed in which a coil spring is tightly wound around a shaft portion so that the drive pulley and the rotated body are rotationally connected.

However, in the above-mentioned electromagnetic clutch, as shown in FIG. 1, one end of the coil spring 4 is bent in the radial direction of the coil spring and is locked in a notch 40 on the inner peripheral edge of the annular clutch plate 5. , (1) The winding diameter of the coil spring 4 is regulated by the inner diameter of the clutch plate 5, which restricts size and weight reduction.
2) From the viewpoint of the strength of the bent part, it is necessary to use a coil spring with a rectangular cross section that is taller than it is wide.
Miniaturization of the coil spring itself is also restricted.

(3) When the clutch plate is connected, the friction surface of the pulley abuts, and when it is released, the cover abuts against the surface. If both sides wear out after long-term use, the clutch plate and the end of the coil spring will come into contact with each other when the clutch is connected. There are problems such as the engagement area becomes small, excessive force is applied to the end of the coil spring, or the coil spring may come off from the clutch plate.

The purpose of this invention is to solve the above problem by bending the end of the coil spring in a direction parallel to the winding axis of the coil spring so that it is engaged with a notch in the inner peripheral edge of the clutch plate. This paper proposes a spring-type electromagnetic clutch.

For this reason, the configuration of the present invention includes a rotary drive body 2 having a shaft portion 13 and a friction surface 15 perpendicular to the axis thereof, and the shaft portion 13.
a rotated body 3 having a cylindrical cover 9 that covers the outer circumferential side of the shaft portion 25 and the shaft portion 13 adjacent to each other on an extension thereof; and an annular clutch plate disposed facing the friction surface 15 of the rotary drive body 2. 5, which is wound around each of the shaft parts 13, 25 at intervals in a space between each of the shaft parts 13, 25 and the cylindrical cover 9, and has one end attached to the clutch plate 5 and the other end. A spring-type electromagnetic clutch comprising a coil spring 4 whose ends are respectively locked to the rotated body 3, and an electromagnetic biasing means for frictionally engaging the clutch plate 5 with the friction surface 15 of the rotary drive body 2, A notch 40 provided on the inner peripheral edge of the clutch plate 5
A locking piece 4a formed by bending the end of the coil spring 4 parallel to the center axis of the coil spring is engaged with the locking piece 4a.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of the spring type electromagnetic clutch based on this invention is demonstrated based on the illustrated Example.

FIG. 2 shows an embodiment of an electromagnetic clutch that is attached to a refrigerant compressor of an automobile air conditioner, in which a plurality of left end flange portions 21 a of a cylindrical body 21 are attached to an end wall of the refrigerant compressor (not shown). It is fixed with several bolts.

A bearing 6 for supporting the pulley 2, which is a rotary drive body, is fitted onto the cylindrical body 21, and its right end is supported by a chrysanthemum washer and a nut 7 so as not to move in the axial direction. The portion 13 is supported so as not to move in the axial direction.

A housing 1 consisting of an annular body having a U-shaped cross section and supporting an electromagnetic coil 19 is inserted into an annular groove 18 having a U-shaped cross section formed on the left end surface of the pulley 2 with a slight gap therebetween. It is fixedly supported by the flange 21a.

An endless belt 12, which is hung in a groove 2a on the outer peripheral surface of the pulley 2, is engaged with a pulley on the rotating shaft of the engine.

The pulley 2 has a circumferentially long slit 11 between the groove 2a and the cylindrical shaft part 13, and the wall part perpendicular to the axis is thin, and the clutch plate 5 engages and disengages from the right end surface of the pulley 2. It constitutes surface 15.

The clutch plate 5 is provided with a pair of notches 40 on the inner peripheral edge,
These include the cylindrical shaft portion 13 of the pulley and the shaft portion 25 of the rotated body.
One end of the two coil springs 4 lightly wound around engages,
The clutch plate 5 is supported slidably in the axial direction.

The clutch plate 5 holds a flange portion 9a of a cylindrical cover 9 that accommodates the coil spring 4, and includes an annular leaf spring 27 curved in a waveform in the circumferential direction, and a bolt 28 slidably supported on the flange portion 9a. or connected with rivets and spring 27
It is separated from the friction surface 15 by the force of .

Inside the immovable cylindrical body 21, the main shaft of the refrigerant compressor and the key 8 are installed.
A cylindrical rotatable body 3, which is rotatably coupled through the cylindrical body 3, is inserted through the cylindrical body 3.

The rotated body 3 is connected to the aforementioned shaft portion 25 via the flange portion 3a.
The shaft portion 25 has a circumferential surface continuous with the cylindrical shaft portion 13 of the pulley 2.

The end of the coil spring 4 bent radially inward is inserted into a notch 26 that is cut into the outer end of the shaft portion 25 and covered with the end wall portion of the cylindrical cover 9 that is fixed to the flange portion 3a with bolts (not shown). part is locked.

As shown in FIG. 3, the important structure of the present invention is that one end of the coil spring 4 is bent outward parallel to the winding axis of the coil spring 4, that is, the center axis to form a locking piece 4a. , this locking piece 4a is engaged with a notch 40 on the inner peripheral edge of the clutch plate 5 at right angles to the plate surface of the clutch plate.

As described above, the other end of the coil spring 4 is located within the notch 26 of the flange portion 3a and is locked so that it does not move in the direction of the central axis. The locking piece 4a extends perpendicularly toward the friction surface of the notch 40 and has dimensions such that it does not engage with the friction surface.
always provides a sufficiently large engagement area.

A split tube 22 made of a thin metal plate is rotatably supported on the shaft portion 13 so as not to slide in the axial direction, so that the coil spring 4 is wound smoothly.

Next, to explain the operation of the spring-type electromagnetic clutch according to the present invention, the pulley 2 is moved around the immovable cylindrical body 21 by the endless V-belt 12 that is stretched between the pulley and the pulley of the drive shaft of the engine (not shown). be rotated.

When the electromagnetic coil 19 is not energized, the clutch plate 5 is separated from the friction surface 15 of the pulley by the force of the spring 27.

The coil spring 4 lightly engages with the inner circumferential surface of the cover 9 due to the spring action of increasing its winding diameter, and similarly, the split tube 22 engages with the shaft portion 13, leaving a slight gap between it and the spring 4. is forming.

Therefore, the rotated body 3 does not rotate. When the electromagnetic coil 19 is excited, a magnetic circuit is generated between the housing 1 made of paramagnetic material, the pulley 2, and the clutch plate 5 as shown by the broken line in FIG. will be combined.

Therefore, the clutch plate 5 rotates together with the pulley 2, and the coil spring 4, which is locked in the notch 40 of the clutch plate, is tightened, and the split tube 22 is wound around the cylindrical shaft portion 13.

In this way, the rotational force of the pulley 2 is transmitted to the rotated body 3 via the clutch plate 5 and the coil spring 4, and the refrigerant compressor is driven.

In the present invention, as described above, in a spring-type electromagnetic clutch, one end of the coil 4 is placed parallel to the winding axis of the coil spring 4, that is, parallel to the center axis of the coil spring 4, in the notch 40 provided on the inner peripheral edge of the clutch plate 5. The ends of the coil springs 4 extend in a direction perpendicular to the friction surfaces of the clutch plates 5 and have a length sufficiently longer than the thickness of the clutch plates 5. Provide a meeting point.

Therefore, both sides of the clutch plate 5 are worn out, and the pulley 2
The friction surface 15 of the clutch plate 5 is worn out when the clutch is operated.
Even if the amount of displacement of the coil spring 4 toward the friction surface 15 of the pulley 2 increases, the end of the coil spring 4 will not reach the notch 40 of the clutch plate 5.
There is no risk of only partial engagement or loss of engagement.

In other words, since a sufficiently large engagement area is provided between the notch 40 and the coil spring 4, the surface pressure is small and the wear of the engagement portion can be suppressed accordingly.

Furthermore, since the inner diameter of the clutch plate 5 can be made approximately the same size as the inner diameter of the coil spring 4, a wider friction surface can be obtained compared to conventional electromagnetic clutches, or the outer diameter of the clutch plate can be reduced by that amount. Can be made smaller.

Further, the coil spring 4 is not limited to a cross-sectional shape having a thickness greater than its width, and there are no particular limitations to the diameter of the clutch plate.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the engagement portion between the clutch plate and the coil spring in a conventional spring-type electromagnetic clutch, FIG. FIG. 3 is a perspective view showing an engaging portion between a clutch plate and a coil spring. 1: Housing, 2: Pulley, 3: Rotated body, 4: Coil spring, 5: Clutch plate, 9: Cylindrical cover, 13: Cylindrical shaft, 15: Friction surface 19: Electromagnetic coil, 25: Shaft,
27: Leaf spring, 40: Notch.

Claims (1)

[Scope of utility model registration request] A rotary drive body 2 having a shaft portion 13 and a friction surface 15 perpendicular to the axis thereof, and a shaft portion 2 adjacent to the shaft portion 13 on an extension thereof.
5 and a rotated body 3 having a cylindrical cover 9 covering the outer peripheral side of the shaft portion 13, an annular clutch plate 5 disposed opposite to the friction surface 15 of the rotary drive body 2, and each of the above-mentioned details. 13
．． 25 and the cylindrical cover 9, and are wound around each of the shaft parts 13, 25 at intervals, one end of which is attached to the clutch plate 5, and the other end of which is attached to the rotated body 3. In a spring-type electromagnetic clutch comprising a coil spring 4 to be locked and an electromagnetic biasing means for frictionally engaging the clutch plate 5 with the friction surface 15 of the rotary drive body 2, a spring-type electromagnetic clutch is provided on the inner peripheral edge of the clutch plate 5. A spring-type electromagnetic clutch characterized in that a locking piece 4a formed by bending an end of the coil spring 4 parallel to the central axis of the coil spring is engaged in the notch 40.