JPS595232Y2 - electromagnetic spring clutch - Google Patents

Description

[Detailed description of the invention] In this invention, by energizing the electromagnetic coil built into the input rotor, the armature is magnetically attracted to the side surface of the manually powered rotor, and the armature is rotated as a unit. This invention relates to a so-called electromagnetic spring clutch that transmits and cuts off power from a human-powered rotor to an output rotor by tightening coil springs whose ends are hooked to an output rotor.

Generally, in this type of electromagnetic spring clutch, as shown in a longitudinal side view in FIG. The input rotor 1 is integrally fixed to a mounting flange 3 fixed by bolts, and is rotatably supported by a bearing 4 interposed on a boss portion 3a of the mounting flange 3.

The armature 5, which is disposed opposite to the side surface of the input rotor 1, is magnetized by the magnetic flux generated when a voltage is applied to the electromagnetic coil 2, and is magnetically attracted to the human-powered rotor 1.

The armature has a coil spring tightening surface 1b formed by the outer circumferential surface of a boss protruding from the side surface of the input rotor 1, and a coil spring tightening surface 6a formed by the outer circumferential surface of the output rotor 6. One end 7a of a coil spring 7, which is arranged so as to wrap around these coil spring winding surfaces 1b and 6a, is hooked.

The other end 7b of this coil spring 7 is hooked to the output rotor 6.

Ends 7a and 7b of the coil spring 7 form an outward hook portion and an inward hook portion, respectively, and are engaged with a notch 5a on the inner peripheral surface of the armature 5 and a notch 6b on the outer peripheral surface of the output rotor 6. has been done.

The output rotor 6 is fixed to, for example, an input shaft 8 of a compressor with bolts 9, and is further connected to an armature 5.
It also includes a spring cover 10 that surrounds the coil spring 7, has an open end that serves as an outer guide for the armature 5, and is fixed to the side of the output rotor 6 by welding or the like.

The armature 5 is connected to the output rotor 6 via the coil spring 7 and is held as an output rotor side member regardless of the rotation of the input rotor 1 until it is magnetically attracted to the input rotor 1 side by energization. .

Once the rudder and armature 5 are magnetically attracted to the input rotor 1, they rotate together with the input rotor 1 and work to tighten the coil spring 7.
are the seaming surface 1b of the input rotor 1 and the seaming surface 6 of the output rotor 6.
A is tightly wound, and the two are integrally connected and rotated to drive the input shaft 8 of the compressor.

A conventional electromagnetic spring clutch configured and operated as described above is installed, for example, in the engine compartment of an automobile together with a compressor, and is operated by controlling the energization of the electromagnetic coil 2 by a detection device for the temperature inside the vehicle and the vehicle speed. However, the current situation is that they are constantly subjected to unexpected external forces such as vibrations from the engine or car.
For this reason, the armature 5 may resonate between the spring cover 10 and the input rotor 1 when the clutch is OFF, and furthermore, when the power to the electromagnetic coil 2 is cut off, the armature 5 may not be able to completely separate from the input rotor, causing the compressor to It had various drawbacks, such as the addition of an extra load.

This idea was based on the above-mentioned viewpoints,
To provide an electromagnetic spring clutch that is resistant to vibration, quickly and reliably disconnects the armature from the input rotor, and achieves stable operation without being affected by dust. This device is characterized in that a magnetic blocking layer is formed along the outer circumferential surface of the armature release permanent magnet embedded in the magnet.

Next, the electromagnetic spring clutch of this invention will be explained by way of examples with reference to the drawings.

In the description, the same structures and members as those of the conventional electromagnetic spring clutch described earlier will be described with the same reference numerals.

FIG. 2 shows an embodiment of the electromagnetic spring clutch of this invention in a partially enlarged longitudinal sectional side view.

In the drawings, 1 is an input rotor, 1a is an opening space, 1
b is a coil spring wrapping surface, 2 is an electromagnetic coil, 3 is a mounting flange, 3a is a boss portion, 4 is a bearing, 5 is an armature, 6 is an output rotor, 6a is a coil spring wrapping surface,
Reference numeral 7 denotes a coil spring, each of which performs the same function as in the conventional electromagnetic spring clutch explained with reference to FIG.

As shown in the figure, a permanent magnet 11 for armature release is embedded in the back surface of the armature 5 which is inserted into the open end of the spring cover 10 and comes into contact with the side thereof, so that the magnetic force of the permanent magnet does not flow directly to the armature 5. As such, voids 12 are formed along the outer peripheral surface as a magnetic blocking layer.

In order to effectively utilize the magnetic force of the permanent magnets to reliably pull back and hold the armature 5 to the spring cover 10, it is preferable to embed a plurality of permanent magnets 11 in the back surface of the armature 5 at appropriate intervals.

In addition, although FIG. 3a shows a state in which the permanent magnet 11 is simply buried in the back of the armature 5 in a longitudinal sectional side view of the main part, in this case, the magnetic flux of the permanent magnet 11 flows into the armature 5 in a short-circuited state between Φ1 and the spring. There are two ways of flowing, Φ2 flowing through the cover 10, and the magnetic effect becomes very weak.

On the other hand, as shown in the figure, in order to prevent a magnetic short circuit between the permanent magnet 11 and the armature 5, the magnet 1
When a gap 12 is provided as a magnetic blocking layer on the outer peripheral surface of 1,
The magnetic flux Φ2 is now effectively utilized.

Further, FIG. 1C shows a case where the shape of the void 12 as the magnetic blocking layer is changed to another shape, and this void is formed by counterbore.

Furthermore, in order to completely block the magnetic flux, a gap is formed by counterbore along the outer circumferential surface of the permanent magnet 11, and this gap is filled with a non-magnetic material 13 such as resin to form a magnetic blocking layer. The case of formation is shown.

The electromagnetic spring clutch of this invention, which has the above-mentioned configuration, has a permanent magnet for releasing the armature embedded in the back of the armature with a magnetic blocking layer formed thereon, so that the magnetic flux of the permanent magnet effectively flows to the spring cover. is securely held in the spring cover, and resonance caused by clutch vibration is prevented.
Effective armature operation is ensured, and since the permanent magnet is interposed between the closed armature and spring cover, dust is prevented from entering, resulting in a simple structure and excellent effects. It is something that is brought about.

[Brief explanation of drawings]

Fig. 1 is a vertical side view showing an example of a conventional electromagnetic spring clutch, Fig. 2 is a partially enlarged longitudinal side view showing an example of the electromagnetic spring clutch of this invention, and Fig. 3a is a case where no magnetic blocking layer is formed. Fig. 3 is a longitudinal sectional side view of the main part showing the manner in which the permanent magnet is embedded; FIG. In the drawings, 1... Input rotor, 5... Armature, 6... Output rotor, 7... Coil spring, 10... Spring cover, 11
. . . Permanent magnet, 12 . . . Air gap as magnetic blocking layer, 13 . . . Nonmagnetic member as magnetic blocking layer.

Claims (1)

[Scope of utility model registration request] A coil spring 7 faces the outer peripheral surface of the boss portion of the input rotor 1 and has one end hooked to the armature 5 and the other end hooked to the output rotor 6, and a permanent magnet for releasing the armature on the back side facing the spring cover 10. 11 is embedded therein, and a spring cover 10 is integrally fixed to the output rotor 6 and includes the armature 5 and the coil spring 7, and the armature 5 is magnetically attracted to the input rotor 1 to cause the coil spring 7 to be In an electromagnetic spring clutch that is wound tightly around the boss portion of the rotor 1 and transmits torque from the manual rotor side to the output rotor side, magnetic blocking layers i2 and 13 are formed along the outer peripheral surface of the armature release permanent magnet 11. Features an electromagnetic spring clutch.