JPH02304222A - Electromagnetic connection device - Google Patents

Abstract

PURPOSE:To reduce the overall size of a device and reduce impact noise by forming an armature with a plastic layer and magnetic material plates located on both sides of the plastic plate, with the armature having a slit and opposing a rotor with a gap in the axial direction of the rotor. CONSTITUTION:A number of slits 7a are formed side by side in the radial direction at a portion of a rotor 7 corresponding to an exciter coil 4. An armature 20 has a slit 20a and opposes the rotor 7 with a gap (g) in the axial direction of the rotor 7. An exciter coil 5 is provided for bringing the armature 20 into press contact with the rotor 7. The armature 20 is integrally formed with a first and a second armatures 20a, 20b formed in a disk shape with a magnetic material and a plastic layer 20d interposed between the armatures. Thus the overall size of the device is reduced and the cost of the device is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic coupling device used in a cooling compressor of an automobile or the like.

[Conventional technology]

FIG. 2 is a partially cutaway front view of a conventional electromagnetic coupling device of this kind used in a compressor. In FIG. An excitation coil 4, which is formed in an annular shape and is connected to a power source by a lead wire (not shown), is housed in the annular groove 3a and is fixed with resin 5. Further, a rotor 7 formed in an annular shape with a U-shaped cross section is rotatably fitted into the cylindrical nose portion 6 protruding from the compressor body 1 via a bearing 8 so as to be crowned by the yoke 3. There is. In the part of the rotor corresponding to the excitation coil 4, a plurality of arc-shaped slits 7a serving as demagnetizing parts are arranged circumferentially in parallel in two rows in the radial direction. Reference numeral 7b denotes a pulley integrally formed on the outer periphery of the rotor, and a belt is stretched between this pulley 7b and a pulley on the drive side (not shown), and the rotor 7 is rotationally driven from the drive side. There is.

A boss 10 formed in a cylindrical shape with a collar is fixed with a key on a rotating shaft 9 protruding from the compressor main body l.
A disk-shaped plate 11 and a plurality of leaf springs 12 are fixed to the flange of the boss 1O with rivets 13. Numeral 14 is a bolt that fixes the plate 11 to the rotating shaft 9.

An annular armature 15 is fixed to the free end of the leaf spring 12 with a rivet 16, and the armature 15 has a plurality of arc-shaped slits 15a arranged circumferentially. , are provided at radially intermediate portions of the two rows of slits 7a. When the excitation coil 5 is not energized, a gap is formed between the rotor 7 and the armature 15, as indicated by the symbol g in the figure. lla
is a stopper that protrudes from the outer periphery of the plate 11 and restricts the end of movement of the armature 15 to maintain the gap g.

With this configuration, when the yoke 7 is rotated on the nose portion 6 by being driven from the driving side,
When a voltage is applied to the excitation coil 4, a magnetic flux Φ is generated in a magnetic path that detours around the slits 7a and 15a, which serve as magnetic interruption parts, in a zigzag pattern, as shown by the dotted line in the figure, and the armature 15 is pulled into a plate due to its attractive force. The rotation of the rotor is caused by armature 15. being attracted by the rotor against the elastic force of the spring 12 and coming into contact with its friction surface. Leaf spring 12. It is transmitted to the rotating shaft 9 via the plate 11 and the boss IO. The rotation of the rotating shaft 9 rotates the compressor, providing cooling capacity.

When the voltage is removed from the excitation coil 4 in this state, the magnetic flux Φ disappears and the armature 15 is separated from the rotor 7 by the elastic force of the temporary spring 12 and returns to its original position, maintaining the air gap g. , rotational transmission between the yoke 7 and the rotating shaft 9 is cut off.

[Problem to be solved by the invention]

However, such conventional electromagnetic coupling devices have the following problems. That is, if the material of the plate 11 is a magnetic material, when the armature 15 is about to be attracted to the rotor, the magnetic flux Φ will flow through the three rows of slits. It is supposed to pass through the gap g four times by bypassing a and 15a, but since the magnetic resistance of the gap g is large, it becomes easy to pass through to other magnetic parts, and leakage magnetic flux is generated. That is,
This leakage magnetic flux is transmitted to the armature 15, as indicated by the symbol Φ1 in the figure. Stopper lla, plate 11゜boss 10
It is distributed to the compressor main body l through.

Due to this leakage, the current when attracting the armature 15 increases, and the gap g wears out and becomes larger.
In order to avoid this, if the magnetomotive force is increased or the material of the plate 11 is made of stainless steel, which is a non-magnetic material, the problem of increasing the size and cost of the device arises. there were. In addition, as the current for attraction increases, the impact energy when the armature 15 comes into contact with the rotor 7 increases, and this appears as a loud impact sound, which causes discomfort to the driver every time the device operates. There was a problem. In an attempt to avoid this, the gap g is made smaller, but since it is difficult to achieve machining accuracy for the rotor 7 and armature 15, these may swing and interfere with each other when no voltage is applied, and the friction surface There were problems such as uneven wear and burnout.

The present invention has been made in view of the above points, and an object of the present invention is to provide a small, inexpensive electromagnetic coupling device with low impact noise.

[Means to solve the problem]

In order to solve this object, in the present invention, the armature is formed of a resin layer and magnetic plate bodies on both sides thereof.

[For production]

When the armature is attracted, a lot of magnetic flux is consumed by the air gap, so the magnetism in the iron part is not saturated, and the magnetic flux from the rotor side is blocked by the resin layer of the armature and returns to the rotor side, causing leakage magnetic flux. Furthermore, the impact noise generated when the armature is attracted to and contacts the rotor is absorbed by the armature's resin layer and becomes smaller.

〔Example〕

FIG. 1 is a partially cutaway front view showing an embodiment of the electromagnetic coupling device according to the present invention. In FIG. In this annular groove 3a, an excitation coil 4, which is formed in an annular shape and is connected to a power source by a lead wire (not shown), is fixed with a resin 5 and housed. Further, a rotor 7 formed in an annular shape with a U-shaped cross section is rotatably fitted into a cylindrical nose portion 6 protruding from the compressor body 1 via a bearing 8 so as to be crowned by the yoke 3. There is. In the part of the rotor corresponding to the excitation coil 4, a plurality of arc-shaped slits 7a serving as demagnetizing parts are arranged circumferentially in parallel in two rows in the radial direction. 7b
is a boob formed almost integrally with the outer periphery of the rotor,
A belt is stretched between the pulley 7b and a boot on the driving side (not shown), and the rotor 7 is rotationally driven from the driving side.

A post 10 formed in a cylindrical shape with a collar is fixed with a key on a rotating shaft 9 protruding from the compressor main body 1.
A disk-shaped plate 11 and a plurality of leaf springs 12 are fixed to the collar of the post IO with rivets 13. Numeral 14 is a bolt that fixes the plate 11 to the rotating shaft 9.

An annular armature 20 is fixed to the free end of the leaf spring 12 with a rivet 16, and the armature 20 has a plurality of arc-shaped slits 2OA arranged circumferentially.・The two rows of slits mentioned above? It is located at a radially intermediate portion of a. The armature 20 is integrally formed with a first armature 20b and a second armature 20c on both sides, which are formed into a disc shape from a magnetic material, and a resin layer 20d interposed between them. Between the armature 25 and the rotor 7 configured in this way, a gap is formed which is indicated by the symbol g in the figure when the excitation coil 5 is not energized. It is held by a stopper 11a that restricts the end of the movement of 20.

The operation of the electromagnetic coupling device configured as above will be explained. When a voltage is applied to the excitation coil 4 while the yoke 7 is being driven from the driving side and rotating on the nose portion 6,
As shown by dotted lines in the figure, slits 7a and 2 serve as magnetic interruption parts.
A magnetic flux Φ is generated in the magnetic path that detours around 0a in a zigzag pattern, and due to its attractive force, the rear armature air 20 is attracted to the rotor tough against the elastic force of the leaf spring 12 and comes into contact with its friction surface.
Rotation of the rotor is done by Amana Koa 20. It is transmitted to the rotating shaft 9 via the leaf spring 12, the plate 11, and the post IO. The compressor rotates by 90 rotations of the rotating shaft, providing cooling capacity.

When the voltage is removed from the excitation coil 4 in this state, the magnetic flux Φ disappears and the armature 20 is separated from the rotor 7 by the elastic force of the leaf spring 12 and returns to its original position, maintaining the air gap g. , rotational transmission between the yoke 7 and the rotating shaft 9 is cut off.

In the electromagnetic coupling device that operates in this way, when the armature 20 is attracted to the rotor, a magnetic flux Φ is generated in the air gap g.
Since the magnetism of the iron part is not saturated due to the large consumption of As such, it is blocked by the resin layer 20d and does not flow to the second armature 20c. Therefore, even if the plate 11 is made of a magnetic material, leakage magnetic flux Φ1 as in the conventional case does not occur.

Further, when the armature 20 is attracted and comes into contact with the rotor 7, a collision sound is generated and the armature 2o vibrates, but this vibration is absorbed by thermal energy in the resin layer 20d, so that the impact noise is reduced.

Wear.

Note that when the armature 20 is attracted, the gap g disappears, so the magnetic flux in the iron portion approaches saturation, and the magnetic flux also flows to the second armature 20c, so that performance does not deteriorate.

〔Effect of the invention〕

As is clear from the above explanation, in the electromagnetic coupling device according to the present invention, the armature is formed of a resin layer and magnetic plate bodies on both sides of the resin layer, so that when the armature is attracted to the rotor, the magnetic flux is transferred to the resin layer. Since it is blocked by the layer, leakage magnetic flux becomes difficult to flow and there is no need to increase the magnetomotive force, so the excitation coil can be made smaller than before, making it possible to downsize the entire device and provide the device at a low cost. In addition, a magnetic material can be used for the stopper for the armature. In addition, the sound of impact against the rotor that occurs when the armature is sucked is absorbed by the resin layer of the armature and becomes smaller, so there is no discomfort and the working environment is improved.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of an electromagnetic coupling device according to the present invention, and FIG. 2 is a partially cutaway front view of a conventional electromagnetic coupling device. 3... Yoke, 4... Excitation coil, 7...
Rotor, 7a, 15a...Slit, 20...
Armature, 20b...First armature, 20
c...Second armature, 20d...Resin layer,
g...Gap.

Claims (1)

[Claims] a rotor having a plurality of slits arranged in parallel in the radial direction;
An electromagnetic coupling device comprising an armature having a slit and facing the rotor with a gap in the axial direction, and an excitation coil that brings the armature into pressure contact with the rotor. An electromagnetic coupling device characterized in that it is formed from a plate body.