JPH0333515A - Electromagnetic clutch - Google Patents

Abstract

PURPOSE:To effectively prevent vibration of an armature and reduce assembling manhour by providing an extended part extending a plate spring in one body for connecting the inner ring or the outer ring of the armature with a hub, and forming projections on the extended part. CONSTITUTION:A plate spring 43 for the inner ring and a plate spring 44 for the outer ring are fixedly secured to a hub 104 with common rivets 47. The plate spring 43 for the inner ring is provided with an extended part 48 formed in one body from the fixed part of the hub to the outer ring 42 of an armature. The extended part 48 is provided with projecting parts 49, 50 respectively contacting with the armature inner ring 41 and the outer ring 42. These projecting parts are pressed against the inner ring 41 and the outer ring 42 of the armature at no working of a clutch, and appropriate reaction forces are generated on the plate spring 43, 44. Thus, at no working of the clutch, vibration of the armature is effectively prevented, and assembling manhour can be reduced due to saving of parts number.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a motor which is disposed between a driving device and a driven device, and is configured to intermittently transmit rotation from the driving device to the driven device. The present invention relates to an electromagnetic clutch suitable for, for example, a compressor used in a vehicle air conditioner.

[Conventional technology]

Conventionally, a typical dry single-plate electromagnetic clutch consists of a stator that generates magnetic force, a rotor supported by bearings to be rotated by the rotational force from the drive source, and a disc-shaped clutch that can be moved in the axial direction by the magnetic force of the stator. It consists of a single armature.

When an electromagnetic clutch with such a structure is used, for example, in a compressor of a vehicle air conditioner (2), it connects a stator attached to the compressor that generates magnetic force, and a rotary connection to the compressor via a bearing. The rotor is freely attached, and the hub is attached to the compressor and has an armature that is movable in the axial direction by the magnetic force of the stator.The friction surface of the armature, which is provided opposite to the friction surface of the rotor, is The rotor is attracted by the generated magnetic force, and the torque transmitted from the drive device is transmitted to the compressor, which is the driven side.

Normally, the armature is connected to the hub by a leaf spring, and when the armature is attracted to the rotor by the magnetic force of the stator, the leaf spring is deflected, allowing the armature to move in the axial direction and engaging the rotor friction surface. It has become.

In the above-mentioned type of clutch, the friction surface of the armature needs to be sufficiently large according to the torque to be transmitted, so the armature tends to be large and the weight of the armature is also relatively large. Therefore, when the armature (3) moves in the axial direction and comes into contact with the rotor friction surface when the clutch is operated, the armature collides with the rotor with a large inertial force, causing an impact noise. Various measures have been taken to reduce the above-mentioned impact noise, but generally when the armature becomes large, it is not integrated, but is divided into two annular members, an inner ring and an outer ring, and each is connected to the hub with a leaf spring. A method is being taken to do so.

In this case, by slightly changing the spring constants of the leaf springs that connect the inner and outer rings to the hub, the inner and outer rings contact the rotor with a time difference, dispersing impact noise and reducing the weight of the armature that collides with the rotor. It has the effect of reducing impact noise by dividing it into two parts.

[Problem to be solved by the invention]

As a result of dividing the armature into an inner ring and an outer ring as described above, impact noise during operation is reduced, but as a result, armature vibration when the clutch is not operating has become a problem. In other words, when the clutch is not operating, the inner ring of the armature,
The outer ring is held in the neutral (4) position of the leaf spring, and is not stable because it is not receiving any axial force.When vibration is applied from the outside, the leaf spring and armature resonate, and the armature contacts the rotor friction surface. There is a problem of so-called chattering, which generates vibration noise. In order to prevent this chuckling,
In Japanese Patent No. 2293, a separate connecting plate is provided which is fixed to the hub together with the leaf spring, and the connecting plate is provided with a plurality of protrusions. When the clutch is not operating, the projections contact the armature inner and outer rings, slightly biasing the armature toward the rotor, creating an initial reaction force in the leaf spring that holds the armature, and stabilizing the positions of the armature inner and outer rings. . However, in the above-mentioned known technology, it is necessary to separately provide a dedicated connecting plate in order to bias the armature inner ring and outer ring to obtain an appropriate spring reaction force, resulting in problems such as an increase in the number of parts and an increase in the number of assembly steps. In view of the above problems, the present invention
The object of the present invention is to provide an electromagnetic clutch having a structure that effectively prevents armature chattering without increasing the number of parts or man-hours.

5) [Means for Solving the Problems] According to the present invention, there is provided an electromagnetic clutch in which a stopper for preventing chattering of the armature is formed on the leaf spring itself that holds the armature inner ring or outer ring.

That is, the present invention includes an armature consisting of two mutually independent annular members, an inner ring and an outer ring, and each of the inner ring and outer ring is connected to a hub fixed to a rotating shaft so as to be movable in the axial direction, In an electromagnetic clutch that is brought into frictional engagement with a rotor friction surface by actuation of a stator excitation coil, the leaf spring that connects at least one of the inner ring or the outer ring of the armature and the hub extends integrally from the hub connection side end. The extension part is formed with a protrusion that presses the armature inner ring and the outer ring, respectively, and presses the armature inner ring and outer ring, respectively, when the clutch is not in operation, and presses the armature inner ring and outer ring, respectively, and presses the armature inner ring and outer ring, respectively, and presses the armature inner ring and outer ring, respectively, and presses the armature inner ring and outer ring, respectively, when the clutch is not operated. It is characterized by generating a moderate initial reaction force.

(6) [Function] According to the present invention, with the above configuration, when the clutch is not activated, the inner ring and outer ring of the armature are pressed against the projections as the stopper formed on the leaf spring, so that the leaf spring returns to the neutral position. The armature is held in a state where a moderate initial reaction force is generated in the leaf spring, so even if vibration is applied from the outside, the armature does not vibrate and chattering does not occur.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIGS. 1 and 2, 100 is a housing of the compressor, and 101 is a rotating shaft of the compressor. Reference numeral 10 denotes a stator housing made of a magnetic material, in which an excitation coil 2 is embedded with epoxy resin 13. This excitation coil 12 is connected to an external power source via a lead wire (not shown). Further, a flange 11 is connected to the stator housing 10, and the stator housing 10 is fixed to the compressor housing 100 by a circlip 102 via the flange 11. A magnetic rotor 20 is integrally formed with a pulley 21, and is rotatably mounted on the compressor housing 100 via a bearing 30. The outer ring 31 of the bearing 30 is press-fitted into the rotor 20, and the inner ring 32 is fitted into the compressor housing 100, and the circlip 103 is attached to the housing 100.
is fixed. The friction surface 22 of the rotor 20 is provided with elongated sections 23 and 24 for the purpose of cutting off the magnetic field, so that the magnetic flux generated by the operation of the excitation coil can be efficiently used when the armature is attracted.

An armature 40 is arranged to face the rotor friction surface 22 with a small gap therebetween, and the armature 40 is made of a magnetic material, and each armature has an annular inner ring 41 formed separately.
and the outer ring 42. Further, the rotating shaft 101
A hub 104 is fixed to the hub 104 by bolts 105. The inner ring 41 and the outer ring 42 of the armadure are each connected to a plurality of inner ring leaf springs 43 and (8) outer ring leaf springs 44 (in this embodiment, each is a flexible spring means) via rivets 45 and 46. The inner ring leaf spring 43 and the outer ring leaf spring 44 are fixed to the hub 104 with the inner ring leaf spring 43 facing down using a common rivet 47. ing.

As shown in FIG. 1, the inner ring leaf spring 43 includes an extension 48 that is integrally formed from the hub fixing part to the armature outer ring 3I at a certain angle with respect to the inner ring fixing part, and the extension part 48 has a rivet 47. A cantilever beam is used as a fixed end, and a stopper 48 is formed on the lower surface of the extension to press the armature inner ring 41 and outer ring 42, respectively, when the clutch is not in operation, by means of protrusions 49 and 50 formed, for example, by stamping. are doing.

The rotor 20 is rotationally driven by an automobile engine (not shown) via a belt and a pulley 21, and when the clutch is activated, when the excitation coil 12 is energized, a magnetic flux is generated as shown by the broken line 1 in FIG. Inner ring 4
A suction force is applied to the rotor 1 and the outer ring 42 in the direction of the rotor 20. As a result, the leaf spring 4344 is elastically deflected, and the armature inner ring 41 and outer ring 42 (9) move toward the rotor 20, coming into close contact and frictionally engaging with the rotor friction surface 22, and transmitting the rotational force of the rotor 2G to the leaf spring 4344. The signal is transmitted to the rotating shaft 101 via the rotating shaft 101.

During the engagement operation between the friction surfaces 22 of the inner ring 41 and the outer ring 42, by setting the spring constants of the inner ring leaf spring 43 and the outer ring leaf spring 44 to different values, the rotor friction surface 22 is Inner ring 4
3 and the outer ring 44 can have a slight difference.

Thereby, the engagement between the loaf friction surface and the armature is performed in two stages, and it is possible to reduce the collision noise between the armature and the friction surface and to alleviate the shock when the clutch is engaged.

In addition, when stopping the operation of the clutch, the magnetic flux disappears when the power to the excitation coil 12 is stopped, and the armature inner ring 41 and outer ring 42 are separated from the rotor friction surface 22 by the restoring force of the leaf springs 43 and 44, respectively. Rotational force is no longer transmitted. In this armature return operation, the protrusions 49.50 formed on the extension portion 48 of the inner ring plate spring 43
acts as an elastic stopper for the inner ring 41 and the outer ring 42 to stop the inner ring and the outer ring (10). At the same time, even after the stop, the inner ring and the outer ring are pressed with an appropriate force, and the leaf springs 43 and 44 are set to the required initial axial direction. Provides a reaction force to prevent the plate spring and armature from resonating due to external vibrations and causing chattering.

The initial reaction force of the leaf springs 43, 44 can be set to an appropriate value by changing the heights of the protrusions 49, 50. Further, in this embodiment, the protrusions 49 and 50 are formed on the leaf spring by stamping, but other means may be used, for example, by drilling holes at the protrusion positions on the leaf spring extension and attaching protrusions made of rubber or resin. It's good as well.

〔Effect of the invention〕

The present invention provides an extension part that is an integral extension of a leaf spring that connects the inner ring or outer ring of the armature and the hub, and forms a projection on the extension part to serve as a stopper that presses against the inner ring and outer ring. By generating an appropriate reaction force in the leaf spring without installing any parts, it is possible to effectively prevent armature vibration when the clutch is not operating, and the number of parts is saved.
This has the effect of reducing assembly man-hours.

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[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of an electromagnetic clutch according to the present invention;
FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1. 101...rotation axis, 104.../%bu, 10
... Stator winding, 12... Excitation coil, 20... Rotor, 22...
Friction surface, 30... Bearing, 40... Armature, 41... Armature inner ring, 42... Armature outer ring, 43... Leaf spring for inner ring, 44... Leaf spring for outer ring,
45.46.47...Rivet, 48...Extension part, 49.50...Protrusion. (12) Fig. 1 41... Armature inner ring 42... Armature outer ring 43... Inner ring plate spring 44... Outer ring plate spring 45, 46, 47... Rivet 48... Extension part 49 .50... Protrusion 12... Excitation coil 20... Rotor 22... Friction surface 30... Bearing 41... Armature inner ring 42... Armature outer ring 43... Inner ring plate spring 44.・・Plate spring for outer ring 45.47・Rivet 48・Extension part 49.50・Protrusion

Claims (1)

[Scope of Claims] 1. A stator having an excitation coil, a rotor rotationally driven by a drive source and having a friction surface on one side, and a friction surface opposite to the friction surface of the rotor, the rotor and The armature comprises two mutually independent annular members, an inner ring and an outer ring, coaxially arranged around a rotating shaft with a predetermined gap between them, and the inner ring and outer ring of the armature are fixed to the rotating shaft. In an electromagnetic clutch connected to a hub so as to be movable in the axial direction via a plurality of leaf springs, the leaf spring that connects the hub to at least one of the inner ring or the outer ring of the armature is located at the side end of the hub fixing part. The extension part is provided with a protrusion that abuts the armature inner ring and the outer ring, respectively, and the protrusion part is configured to contact the armature inner ring when the clutch is not operated. An electromagnetic clutch characterized in that the leaf spring is pressed against the outer ring to generate an appropriate reaction force in the leaf spring.