JPH10184729A - Electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an attaching sound without using any friction materials by setting the holding force of an armature plate by a rubber damper to be non-uniform in a circumferential direction, making a colliding and joining time when the armature plate is adsorbed on a rotor long and reducing collision energy. SOLUTION: Respective rubber spring set values of first to third rubber dampers 18-1 to 18-3 is set to values different by about 1kg or more. When current is carried to an exciting coil in this condition, an armature plate 10 is attracted and joined to rotor friction by the rubber damper having weakest rubber damper compression deflection margin, for instance the rubber damper 18-1. Then, it is attracted and joined to the second weakest rubber damper 18-2 and, lastly, it is attracted and joined to the strongest rubber damper 18-3. Thus, an attracting and joining time is made longer than when all the rubber dampers have uniform compressing deflection margin and collision energy and an attracting sound is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch, and more particularly, to an electromagnetic clutch for intermittently transmitting driving force to a compressor provided in an air conditioner or the like for an automobile.

[0002]

2. Description of the Related Art In a conventional electromagnetic clutch, a method of holding an armature by using the elastic force of rubber is employed for the purpose of reducing the suction surface generated at the time of suction and joining at a friction surface.

[0003] The general structure of this type of electromagnetic clutch is as follows.
As shown in FIG. 7, reference numeral 1 denotes an exciting coil for generating an electromagnetic force, 2 denotes a yoke member having a U-shaped cross section, in which the exciting coil 1 is fixed with a resin material 3 and a flange 4 is provided on a side end surface. It is fixed by welding or the like, and is fixed to the compressor front plate 5 via the flange 4.

The rotor 6 is connected to the engine by a V-belt (not shown), and is rotatably supported on the compressor front plate 5 by bearings 7. The rotor 6 has a friction surface 8 formed on a side end surface, and an armature 9 is disposed coaxially with the rotor 6 with a slight space from the friction surface. On the amateur 9, a friction surface 11 is formed as an amateur plate 10 to be frictionally joined with the rotor friction surface 8. On the other hand, the hub 12 is fixed to the compressor main shaft 13 with splines 14, bolts 15, etc., and a dish-shaped damper case 16 is fixed by welding to the outside of the stopper plate 19,
An armature 9 is formed by press-fitting a rubber damper 18 whose inner side is flow-bonded to a rivet 17 and crimping the rivet 17 to the armature plate 10 inside the damper case 16.

Next, the operation of the conventional electromagnetic clutch will be described. When the exciting coil 1 is energized in the above configuration, the armature plate 10 on which the magnetic circuit is formed is attracted to the rotor 6 as shown by the dashed line in FIG. 6 is transmitted to the main shaft 13. Next, when the energization of the exciting coil 1 is stopped, the armature plate 10 is separated from the rotor 6 by the rubber spring force of the rubber damper 18, so that the transmission of the rotational power from the engine to the main shaft 13 is cut off.

[0006]

However, in the electromagnetic clutch having the above-described structure, the armature plate 10 attracts the rotor 6 and generates a collision joining sound (hereinafter referred to as an attraction sound) between the metals when the friction surface is joined. There is a problem in that a metallic noise is generated every time the clutch is sucked, which causes discomfort.
The cause of the loud suction noise is that the amateur plate 10
And the magnitude of the collision energy with the rotor 6. Various measures are used to mitigate this. For example, there is a method of arranging an annular friction material 20 made of fiber resin on the rotor friction surface 8 to reduce collision between metal surfaces and reduce suction noise. It has disadvantages such as the number of steps for bonding and the large cost of the friction material 20 itself.

An object of the present invention is to reduce the suction noise without using the friction material 20.

[0008]

SUMMARY OF THE INVENTION According to the present invention, the holding force of the armature plate by the rubber damper is set to be non-uniform in all circumferential directions, and the collision joining time when the armature plate is attracted to the rotor is extended. The point is that the collision energy is reduced and the suction sound is reduced.

According to the above configuration, it is possible to reduce the suction noise without disposing the friction material on the friction surface.

[0010]

According to the first aspect of the present invention, a rubber damper for holding an amateur plate is set to have a non-uniform holding force of 1 kg or more at each rubber damper portion. It is. According to this configuration, the collision energy at which the armature plate is attracted to the rotor is reduced, and the attraction sound can be reduced.

According to a second aspect of the present invention, the holding force of the armature by the rubber damper is set such that the compression deflection allowance of each rubber damper is set to be non-uniform by 0.1 mm or more. Is obtained.

According to a third aspect of the present invention, the holding force of the armature by the rubber damper is set such that the rubber spring hardness Hs of each rubber damper is non-uniform by 5 points or more. Is obtained.

[0013]

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

(Embodiment 1) FIG. 1 is a front view of an electromagnetic clutch according to the present invention, and FIG. 2 is a longitudinal sectional view taken along the line A--A of the electromagnetic clutch of the present invention. The point is that the set value of the rubber spring force of the damper 18 is set to a value different by 1 kg or more for every three places.

That is, as shown in Table 1, the set value of the rubber spring force of each of the first rubber damper 18-1, the second rubber damper 18-2, and the third rubber damper 18-3 is 1 kg or more every three places. The point is that they are set to different values. When the exciting coil 1 is energized in this state, the armature plate 10 has the rubber damper 18-
Suction and joining are performed on the rotor friction surface 8 from step 1, then suction and joining are performed with the weak rubber damper 18-2, and finally suction and joining are performed with the strongest rubber damper 18-3, and each rubber damper is uniformly compressed. Clearly, the suction and joining times can be set longer than in the case of having a bending allowance. With this setting,
As shown in Table 1, the collision energy at the time when the armature plate 10 is attracted to the rotor 6 is reduced, and the attraction sound can be reduced.

[0016]

[Table 1]

(Embodiment 2) FIGS. 3 and 4 are longitudinal sectional views of a rubber damper and a rivet before and after caulking. FIGS. 5 and 6 are longitudinal sectional views showing the dimensions of each rubber damper rivet. The compression deflection of the rubber damper is
The thickness a of the stopper plate 12 and the damper case 16 at the value set by the caulking portion of the damper rivet 17 and the armature plate 10, the size initially set by the damper rivet 17 alone, the damper rivet end face 17a to the rubber damper end face 18a It is the difference from the b dimension up to. The rubber elastic force at the compression deflection margin acts as a force for holding the amateur plate 10. Normally, the compression deflection allowance ab is set by the correlation between the attraction force of the electromagnetic clutch and the holding force of the armature plate 10 that withstands vibration and the like.
It is set to a constant value of about 0.3 mm. In this embodiment, as shown in FIG. 5, in the three rubber dampers, the respective compression deflection allowances are set within a range in which the attraction force of the electromagnetic clutch and the armature holding force are compatible.
8-1 Compression allowance 0.2 mm, second rubber damper 18-2
The compression allowance is 0.3 mm, the third rubber damper 18-3 has a compression allowance of 0.4 mm, and each of the three compression allowances is 0.1.
mm or more. With this setting, the same effects as in the first embodiment can be obtained as shown in Table 2 as in the first embodiment.

[0018]

[Table 2]

(Embodiment 3) FIG. 6 is a longitudinal sectional view of a rubber damper of an electromagnetic clutch according to a third embodiment of the present invention.

The difference from the second embodiment is that the rubber damper 18 has the same compression deflection allowance, and the rubber spring hardness of the rubber damper 18 is different by 5 points from each other. As a setting example of the rubber spring hardness Hs, the rubber damper 18-1 is Hs50, and the rubber damper 18-2 is Hs.
55, and the rubber damper 18-3 is Hs60. The force for holding the amateur plate 10 is determined by the compression deflection allowance of the rubber damper 18 and the rubber spring hardness Hs, and the rubber spring hardness Hs is unevenly set by five rubber dampers, each of which is at least 5 points. As shown in Table 3, the same effects as in the first embodiment can be obtained.

[0021]

[Table 3]

[0022]

As is apparent from the above embodiment, the present invention sets the holding force of the rubber damper holding the armature plate unevenly, or sets the compression deflection allowance of each rubber damper unevenly. According to this configuration, the rubber spring hardness of each rubber damper is set to be non-uniform. According to this configuration, the collision joining time when the armature plate is attracted to the rotor is lengthened, the collision energy is reduced, and the suction noise is reduced. Is achieved.

[Brief description of the drawings]

FIG. 1 is a plan view of an electromagnetic clutch according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the electromagnetic clutch according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the rubber damper according to the first embodiment of the present invention before the rivet is swaged.

FIG. 4 is a longitudinal sectional view after caulking a rubber damper and a rivet according to the first embodiment of the present invention.

5 (a) to 5 (c) are longitudinal sectional views after caulking each rubber damper and rivet according to the first embodiment of the present invention.

6 (a) to 6 (c) are longitudinal sectional views after caulking rubber dampers and rivets according to a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a conventional electromagnetic clutch.

[Explanation of symbols]

 6 rotor 9 amateur 10 amateur board 16 damper case 17 rivet 18 rubber damper 19 stopper plate

Claims (3)

[Claims] 1. A compressor having a bearing fixedly supported on an inner ring at a front end portion of a compressor body, disposed on an outer ring of the bearing, and disposed coaxially with a rotor rotatably driven by an engine via a belt. An armature fixed to the main shaft of the compressor via a rubber damper and having an armature plate movable in the axial direction, and an exciting coil for generating an electromagnetic force for frictionally joining the rotor and the armature plate are provided. An electromagnetic clutch wherein the holding force of the rubber damper of the amateur is not uniform by 1 kg or more at each rubber damper portion. 2. The electromagnetic clutch according to claim 1, wherein an armature is provided in which each of the rubber dampers has an uneven compression deflection of 0.1 mm or more. 3. The electromagnetic clutch according to claim 1, further comprising an armature having a rubber spring hardness Hs of each rubber damper portion that is not uniform by 5 points or more.