JPH0626752Y2 - Electromagnetic clutch - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an electromagnetic clutch that connects and disconnects a rotational torque transmission by energizing and deenergizing an exciting coil.

[Conventional technology]

The electromagnetic clutch consists of a yoke in which an exciting coil is provided in an annular groove, a rotor having a U-shaped annular groove that is loosely mounted in the annular groove of the yoke from the opening end side, and the anti-open end of the rotor. The armature is supported by a spring member and has a friction surface facing the side friction surface, and a predetermined air gap is provided between the friction surface of the rotor and the friction surface of the armature when rotation transmission is released. It is formed.

With this configuration, when a voltage is applied to the exciting coil and a magnetic flux is generated, the magnetic attraction force magnetically couples the rotor and the armature against the spring force of the spring member, and the rotational torque is transmitted. To be done.

When the voltage application to the exciting coil is released from this state, the spring force of the spring member separates the friction surface of the armature from the friction surface of the rotor, and the transmission of the rotational torque is cut off.

By the way, in this type of electromagnetic clutch, between the friction surfaces of these members within the coupling time from the magnetic attraction of the armature to the rotor to the complete coupling of the armature and the rotor and transmission of rotation. There is a problem that vibration noise is generated by the frictional engagement, and the vibration resonates to generate an uncomfortable audible sound (hereinafter referred to as a squeaking sound).

FIG. 5 and FIG. 6 are waveform charts showing the operating characteristics of the conventional electromagnetic clutch, and the waveform indicated by reference numeral 1 shows the rotational speed of the driven side compressor shaft on which the electromagnetic clutch is mounted as the output waveform of the tachogenerator. 0 to 4000
Looking in the rpm range. The waveform indicated by reference numeral 2 is the current waveform of the electromagnetic clutch, and the time 0 to P is the suction time of the armature. Further, the waveform indicated by reference numeral 3 is the output waveform from the sound level meter, and the loudness and the generation timing of the squealing noise are observed by the magnitude of the amplitude. There
Frequency analysis of sound and overall value (equivalent noise level) are observed by FFT (Fast Fourier Transform) device. Note that this waveform is obtained by averaging the waveform of the waveform 3 at the time Q for several tens of times. As described above, in the conventional electromagnetic clutch, it is understood that an unpleasant squeaking sound is generated due to the vibration generated within the engagement time.

Therefore, as a means for suppressing such squeal noise, an electromagnetic clutch in which a resin ring as a vibration damping material is attached to the outer circumference of a rotor with an adhesive has been proposed.
It is disclosed in Japanese Patent No. 5027. This electromagnetic clutch not only improves the operating characteristics by electrical control, but also prevents the generation of squeaking noise during frictional engagement between the armature and the rotor. A ring made of a resin agent is fitted and fixed to the outer circumference of the flange.

[Problems to be solved by the device]

However, such a conventional electromagnetic clutch cannot obtain a sufficient bonding area because the resin ring is bonded as described above as a squeal noise generation preventing means, and there is a risk that the resin will come off. In addition to the problem of unreliability, when the generation of noise is not completely prevented, mounting the electromagnetic clutch on the car cooler causes a problem of deteriorating the environment in the engine room.

The present invention has been made in view of the above points, and an object thereof is to provide an electromagnetic clutch in which a resin as a vibration damping material is firmly fixed and reliability is improved.

[Means for Solving the Problems]

In order to achieve such an object, according to the present invention, a magnetic flux path portion formed of an annular groove having a U-shaped cross section in which the exciting coil internal portion of the yoke is loosely fitted, and a belt groove outside the magnetic flux path portion. And a rotor integrally formed with a pulley portion having an armature, and an armature whose friction surfaces are opposed to the rotor,
The annular groove formed between the magnetic flux path portion of the rotor and the pulley portion and opening in the axial direction was filled with resin.

[Operation] When a voltage is applied to the exciting coil and a magnetic flux is generated, the magnetic attraction force magnetically couples the rotor and the armature against the spring force of the spring member, and the rotational torque is transmitted. When the voltage application to the exciting coil is released from this state, the spring force of the spring member separates the friction surface of the armature from the friction surface of the rotor, and the transmission of rotational torque is interrupted. In the electromagnetic clutch that operates in this manner, since the vibration damping resin is filled in the annular groove of the rotor, the vibration at the time of magnetic coupling is damped and the squeaking noise is reduced.
The resin adhesion area is large and there is no risk of the resin coming off.

〔Example〕

1 to 3 show an example in which the electromagnetic clutch according to the present invention is used for power transmission and disconnection between an engine and a compressor, and FIG. 1 is a longitudinal sectional view thereof, FIG. 2 and FIG.
The figures are waveform charts showing the operating characteristics of the electromagnetic clutch corresponding to FIGS. 5 and 6. In the drawing, a yoke 1 fixed to the engine side is formed in an annular shape having a U-shaped cross-section that opens in the axial direction, and an exciting coil 2 formed in an annular shape and connected to a power source is formed in an annular groove 1a. Is fixed inside with resin. Also, the know part 3 on the engine side
A rotor, generally designated by 4, is rotatably supported via a bearing 5. The rotor 4 has a magnetic flux path portion formed in an annular shape having a U-shaped cross section into which the annular portion of the yoke 1 is engaged. 6 and a pulley portion 7 welded to the circumferential surface of the magnetic flux path portion 6.
And are integrally formed. The magnetic flux path portion 6 is formed of an outer pole 6a, an inner pole 6b, and a substrate 6c, and a thick step 6d is formed at the end of the outer pole 6a on the substrate 6c side. Further, an annular groove having a generally U-shaped cross-section opening in the axial direction is formed between the pulley portion 7 and the magnetic flux path portion 6, and the outer peripheral surface of the pulley portion 7 is provided between the pulley portion 7 and the pulley on the compressor side. A plurality of V-grooves 7a for stretching the belt are formed. A resin 8 for vibration damping is filled in an annular groove formed between the pulley portion 7 and the magnetic flux path portion 6, and the resin 8 is a step portion 6d formed on the outer pole 6a. By disposing, the separation from the annular groove is restricted.

On the other hand, an armature hub 11 is fixed to the tip of the rotary shaft 10 protruding from the engine side by spline fitting and bolts 12.
An armature 13 having friction surfaces opposed to the rotor 4 is elastically held by a leaf spring 14.

The operation of the electromagnetic clutch configured as above will be described. When a voltage is applied to the exciting coil 2 while the rotating shaft 10 of the engine is rotating, magnetic flux is generated in a path that bypasses the armature 13 from the outer pole 6a and returns to the outer pole 6a via the inner pole 6b. The magnetic attraction force causes the armature 13 to be magnetically attracted to the friction surface of the rotor 4 against the spring force of the leaf spring 14, and the rotation of the rotating shaft 10 is transmitted to the rotor 4 via the armature hub 11 and the armature 13. , And is transmitted to the compressor by a belt stretched around the pulley portion 7 of the rotor 4.

When the voltage application to the exciting coil 2 is released from this state and the magnetic flux disappears, the armature 13 is separated from the friction surface of the rotor 4 by the spring force of the leaf spring 14, the transmission of the rotational torque is cut off, and the compressor stops. .

As described above, during the transmission of the rotational torque, both the armature 13 and the rotor 4 are magnetically attracted to the rotor 4 and the rotation of the armature 13 and the rotor 4 is completely coupled to each other within the coupling time. Member 1
There is a problem that vibrational noise is generated due to frictional engagement between the friction surfaces 3 and 4, and an unpleasant squeal is generated due to resonance of this vibration. On the other hand, in the present device, since the vibration damping resin 8 is filled in the annular groove between the magnetic flux path portion 6 of the rotor 4 and the pulley portion 7, the vibration at the time of magnetic coupling is attenuated and the squealing noise is reduced. Is less likely to occur.

2 and 3 are waveform charts showing the operation characteristics of the electromagnetic clutch in the present device, and as is clear from comparison with FIGS. 5 and 6, the output waveform of the noise level meter during the connecting time is shown. The amplitude becomes small, the peak near 5 KHz disappears, and the noise level is reduced by 10 dB or more, and the environment is not deteriorated even when mounted in the engine room as in this embodiment. Further, in this device, the resin 8 is filled in the annular groove, and the adhesion area is large, so that the resin does not come off. Particularly in this embodiment, since the outer pole 6a, which is a part of the annular groove filled with the resin, is provided with the thick step 6d, the resin 8 does not come off.

4 (a), (b), (c), (d), and (e) are vertical cross-sectional views of the outer peripheral portion of the rotor as another embodiment of the present invention. First, in the embodiment shown in FIG. 4 (a), an annular groove filled with resin is opened on the side opposite to the armature, and an annular groove 6e is formed on the outer pole 6d which is the outer wall of the annular groove.
Is provided. This prevents the resin from coming off.

Further, in the one shown in FIG. 4 (b), the V groove of the pulley portion 7 is provided with only one line as indicated by reference numeral 7b in the drawing, and the resin 8 is provided with the outer peripheral member of the pulley portion 7 and the V groove 7b. The annular groove surrounded by the outer wall and the outer pole 6a is filled from the opening on the armature 13 side. The step 6d is provided on the outer pole 6a as in the embodiment shown in FIG.
By doing so, the contact area of the resin 8 is large and the step 6
Since the movement is restricted by d, the resin 8 does not come off from the annular groove.

In the embodiment shown in FIG. 4 (c), an annular groove filled with the resin 8 is opened on the side opposite to the armature, and the outer pole 6a surrounding this annular groove is provided with an annular groove 5c. . By doing so, the contact area of the resin 8 is large and the movement is restricted by the groove 6c, so that the resin 8 does not separate from the annular groove.

Furthermore, in the embodiment shown in FIG.
The magnetic flux path portion 6 and the pulley portion 7 are integrally formed, and the pulley portion 7 is provided with a plurality of V grooves 7a.
A caulking piece 7c to be caulked after the resin 8 is filled is provided at the opening end of the outer member surrounding the annular groove filled with. By doing so, the contact area of the resin 8 is large,
Since the movement of the resin 8 is restricted by the caulking piece 7c, the resin 8
Does not separate from the annular groove. When the outer pole 6a is shorter than the pulley 7 in the axial direction, the outer pole 6a
A crimping piece may be provided on the side, and when the pulley portion 7 and the outer pole 6a have the same length in the axial direction, a crimping piece may be provided on both members.

Further, in the embodiment shown in FIG. 4 (e), only one V-groove 7b is provided, and the outer peripheral member of the pulley portion 7 as a member surrounding the annular groove filled with the resin 8 has an annular shape. An annular protrusion 7d that projects into the groove is provided, and the annular groove is open to the armature 13 side. By doing so, the contact area of the resin 8 is large, and the movement of the resin 8 is restricted by the protrusion 7d, so that the resin 8 does not separate from the annular groove.

[Effect of device]

As is apparent from the above description, in the present invention, the magnetic flux path portion is formed of an annular groove having a U-shaped cross section in which the exciting coil inner portion is loosely fitted, and the belt groove is provided outside the magnetic flux path portion. A rotor integrally formed with a pulley portion and an armature having friction surfaces opposed to the rotor are provided, and in an annular groove formed between the magnetic flux path portion of the rotor and the pulley portion and opening in the axial direction. Since the resin filled in the annular groove has a sufficient adhesive area, the resin does not separate from the annular groove, and the quality reliability is improved.

[Brief description of drawings]

1 to 4 show an example in which the electromagnetic clutch according to the present invention is used for power transmission and disconnection between an engine and a compressor, and FIG. 1 is a longitudinal sectional view, FIG. 2 and FIG.
The figures are waveform charts showing the operating characteristics of the electromagnetic clutch corresponding to FIGS. 5 and 6, and FIGS. 4 (a), (b), (c), (d), and (e) of the present invention, respectively. FIG. 5 and FIG. 6 are longitudinal sectional views of the outer peripheral portion of the rotor as another embodiment, which are waveform diagrams showing the operating characteristics of the conventional electromagnetic clutch. 1 ... Yoke 2 ... Excitation coil 4 ... Rotor 6 ...
... magnetic flux path section, 6a ... outer pole, 6b ... inner pole, 6c ... substrate, 7 ... pulley section, 7a, 7b ... V groove, 8 ... resin, 13 ... armature.

Claims (1)

[Scope of utility model registration request] 1. A magnetic flux path portion formed of an annular groove having a U-shaped cross section into which an exciting coil inner portion of the yoke is loosely fitted, and a pulley portion having a belt groove outside the magnetic flux path portion are integrally formed. A rotor and an armature whose friction surfaces are opposed to each other, and a resin is filled in an annular groove formed between the magnetic flux path portion of the rotor and the pulley portion and opening in the axial direction. Characteristic electromagnetic clutch.