JPS6327584B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electromagnetic spring clutch coupled between a rotating machine and a prime mover for intermittently driving a refrigerant compressor of an automobile air conditioner, etc. It is related to.

Conventional structure and its problems The conventional general electromagnetic spring clutch is
As shown in Fig. 2 and Fig. 2, the bearing 1
An annular excitation coil 3 fixed to a fixed frame is disposed inside the input hub 2 which rotates and is mounted on a shaft. It is set up. 5 is an output hub fixedly mounted on the output shaft 6 facing the input hub 2; 7 is an armature plate provided facing the through hole 4; The spring holding drum 9 is inserted between a notch provided therein and a bent portion on the outer periphery of the spring holding drum 9. Due to the weak acting force of the spring 8, the spring holding drum 9 comes into contact with a flange portion of a spring holding drum 9 fixed to the output hub 5 so as to rotate on the same axis, and is held rotatably and slidably. 10 is a coil spring formed into a coil shape, and is wound around the spring holding drum 9. An outward hook 11 bent outward is provided at the beginning of winding of the coil spring 10, and an inward hook 12 bent inward is provided at the end of winding. This coil spring 10 is located outside of the winding surface 13 of the input hub 2 and the winding surface 14 of the output hub 5, and is fitted into the armature plate 7. Further, the outward hook 11 is inserted into the hook insertion hole 15 of the armature plate, and the inward hook 12 is inserted into the hook insertion hole 15 of the armature plate.
is engaged in the hook insertion hole 16 of the output hub 5.

In the conventional electromagnetic spring clutch configured as described above, when the excitation coil 3 is excited, the armature plate 7 is attracted against the acting force of the spring 8 and rotates together with the input hub 2, and at the same time the armature plate 7 rotates together with the input hub 2. The outward hook 11 of the coil spring 10, which is engaged in the hook insertion hole 15 of the plate 7, also rotates. Therefore, since the inward hook 12 of this coil spring 10 is engaged with the hook insertion hole 16 of the output hub 5, the coil spring 10 tightens the winding surfaces 13 and 14 of the input hub 2 and the output hub 5. The output hub 5 rotates. That is, the rotational force applied to the input hub 2 is transmitted to the output hub 5.

Next, when the excitation coil 3 is de-energized, the attracted armature plate 7 moves away from the input hub 2 due to the force of the spring 8 and comes into contact with the flange portion of the spring holding drum 9. Further, the coil spring 10 expands to create a gap with the winding surface 13 of the input hub 2, thereby cutting off the rotational force.

However, in the above configuration, the spring 8 that applies an axial force to the armature plate 7 is provided outside the armature plate 7, and the spring 8 is annular, which makes it difficult to remove material, and the spring 8 has to be bent in order to provide the spring action. This requires processing and has the problem of varying spring characteristics. Moreover, the mounting means for the spring 8 requires bending, etc., resulting in poor workability. Another problem is that the electromagnetic spring clutch becomes large.

Purpose of the Invention In view of the above-mentioned problems, the present invention provides a leaf spring that applies an axial force to the armature body, is located inside the armature body, one end of this leaf spring is in contact with the armature body, and the other end is connected to the output hub. We have created a small electromagnetic spring clutch that is inexpensive and provides stable spring action by providing a step with the above-mentioned abutment part on the body and fixing it with machine screws, etc., making it a plate spring that requires no bending and has good material removal. This is what we provide.

Structure of the Invention The present invention provides shaft-side friction surfaces provided on the outside of an input hub and an output hub, respectively, and a coil spring provided within these friction surfaces and engaged with an armature body and the output hub. and an excitation coil that attracts the armature body to the input hub, and one end of the excitation coil that is located inside the armature body and applies an acting force in the direction of pulling the armature plate away from the input hub contacts the armature body, and the other end is the output coil. It consists of a leaf spring fixed to the hub body, and when the excitation coil is energized, the coil spring is expanded through the armature body, and the coil spring is pressed against each of the above-mentioned shaft center side friction surfaces to input rotational force from the hub. The power is transmitted to the output hub, and when it becomes de-energized, the armature body is separated from the input hub by the force of the leaf spring to cut off the transmitted force, making it possible to create a leaf spring that uses small materials, can be easily removed, and does not require bending. This has the advantage that the leaf spring can be easily attached.
Another advantage is that the electromagnetic spring clutch can be made compact.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a cross section of an electromagnetic spring clutch in a first embodiment of the invention. Further, FIG. 4 is a cross section taken along line AA in FIG. 3. 2
1 is a small screw 23 attached to the fixed frame 22 of the refrigerant compressor.
24 is an input hub that is rotatably fixed to the fixed frame 22 via a bearing 25 and fixed in the axial direction by retaining rings 26 and 27. V groove 2
8, which is connected to a drive shaft pulley of an engine (not shown) by a V-belt (not shown). Further, a cylindrical shaft-side friction surface 29 is provided at the outer end of the input hub 24, and a plurality of arc-shaped through holes 31 are bored in the inner end surface 30 thereof. Reference numeral 32 denotes an output hub body, which is fixed to the output shaft 33 of the refrigerant compressor with bolts 34 or the like. The outer cylindrical portion of the output hub body 32 is provided with an axial friction surface 35 having approximately the same diameter as the axial friction surface 29 of the input hub 24, and the inner cylindrical portion is provided with a notch 36. It is provided. Reference numeral 37 denotes an armature body having a notch 38. This armature body 37 is fitted into the stepped portion of the output hub body 32 so as to be rotatable and slidable in the axial direction, and one end is inserted into the inside of this armature body 37. A weak acting force is applied to the side opposite to the input hub 24 by a leaf spring 40 which is in contact with the output hub body 32 and whose other end is fixed to the output hub body 32 by means of fixing means such as machine screws 39 with a step between the other end and the abutting portion. Reference numeral 41 denotes a coil spring 41 formed in a coil shape so as to be unwound with respect to the rotational direction of the input hub 24, and each end of the coil spring 41 at the beginning and end of winding is bent inward. Inward hooks 42 and 43 are formed, and the inward hook 42 at the beginning of winding engages with the notch 38 of the armature body 37, and the inward hook 43 at the end of winding engages with the notch 3 of the output hub body 32.
It is locked at 6. Further, the coil spring 41 is wound on the outer circumferential surface of the armature body 37 and a part of the output hub body 32, with a gap interposed between the shaft center side friction surfaces 29 and 35, respectively.

The operation of the electromagnetic spring clutch constructed as described above will be explained below. The input hub 24 rotates via a bearing 25 because a V-groove 28 provided in the input hub 24 and a driving pulley of an engine (not shown) are connected by a V-belt (not shown). When the excitation coil 21 is not energized, the armature body 37 is separated from the end surface 30 of the rotating input hub 24 due to the weak acting force of the leaf spring 40.
Further, the coil spring 41 is wound around the outer peripheral surface of the armature body 37 and a part of the output hub body 32, and forms a small gap between the shaft center side friction surfaces 29 and 35. Therefore, no rotational force is transmitted to the output hub body 32, and the output shaft 33 is not driven.

When the excitation coil 21 is energized, a magnetic circuit shown by the broken line in FIG. match. Therefore, the armature body 37 rotates together with the input hub 24. Therefore, the inward hook 42 of the coil spring 41 engaged in the notch 38 of the armature body 37 rotates in a direction to unwind the coil spring 41. However, the inward hook 43 at the other end of the coil spring 41 is engaged in the notch 36 provided in the output hub body 32, and at this time, the output hub body 32 is still
does not rotate due to the load on the refrigerant compressor. Next, when the inward hook 42 further rotates, the coil spring 41 is unwound and expanded, and comes into pressure contact with the shaft-side friction surfaces 29 and 35. At this time, coil spring 4
1 and the shaft center side friction surface 2 of the input hub 24
9 and the shaft center side friction surface 35 of the output hub body 32 are frictionally engaged with each other, and the rotational force of the input hub 24 is transmitted to the output hub body 32, and the rotational force of the input hub 24 is transmitted to the output shaft 33 of the refrigerant compressor.
is driven against its load.

When the excitation coil 21 is de-energized, the armature body 37 is moved away from the end face 30 of the input hub 24 under the action of the leaf spring 40, and the coil spring 41 is subjected to centrifugal force due to the return force of the winding diameter becoming smaller. It moves away from the shaft-side friction surfaces 29 and 35 against the above-mentioned forces, and wraps around the outer circumferential surface of the armature body 37 and a part of the output hub body 32 in the original position. Therefore, transmission of rotational force is interrupted.

As described above, according to this embodiment, since the leaf spring 40 is provided inside the armature body 37, material removal can be improved with less material, and the leaf spring does not require bending, and can be easily fixed by fixing means such as machine screws. Can be fixed to.

In this embodiment, the number of leaf springs 40 is three, but the number is not limited, and it goes without saying that they may be formed integrally.

Effects of the Invention As described above, the present invention provides a leaf spring inside the armature body, thereby making it possible to create a leaf spring that requires less material, has good material removal, and does not require bending. It also becomes easier,
The armature body also has a small diameter, is inexpensive, easy to assemble, and can be made compact, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional electromagnetic spring clutch, FIG. 2 is a perspective view of the spring shown in FIG. 1, FIG. 3 is a sectional view of an electromagnetic spring clutch according to an embodiment of the present invention, and FIG. A sectional view taken along line A-A in the figure is shown. 21... Excitation coil, 24... Input hub, 32
... Output hub body, 37 ... Armature body, 40
...Plate spring, 41...Coil spring.

Claims (1)

[Claims] 1. An annular excitation coil fixed to a fixed frame, an input hub that attracts the armature body by excitation of the excitation coil, and an output bubble body that rotates on the same axis as the rotation axis of the input hub. , a coil spring having one end fixed to the armature body and the other end fixed to the output hub body; and the cylinder of the input hub, which is located outside the coil spring and faces the coil spring, forming an axial-side friction surface. a cylindrical portion of the output hub body, which has an axial friction surface having approximately the same diameter as the axial friction surface; one end is fixed to the output hub body, and the other end is inside the armature body. an electromagnetic spring clutch comprising a leaf spring in contact with the input hub, the leaf spring biasing the armature body in a direction pushing the armature body away from the input hub;