JPH054579Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to an electromagnetic coupling device for interrupting power transmission to a vehicle's supercharger, etc., and in particular, relates to an electromagnetic coupling device that effectively functions as an electromagnetic clutch. It is something.

[Prior Art] In recent years, luxury cars have been equipped with a supercharger, or supercharger, and when the engine reaches a predetermined rotational speed, the supercharger is driven by an electromagnetic clutch. This electromagnetic clutch has a rotor equipped with an excitation coil and an annular armature, which is movable toward and away from the rotor. This armature uses an outer holding plate having a substantially cross-shaped flange, and when an inner holding plate is provided substantially concentrically with the outer holding plate through an elastic member such as cushion rubber, the elastic member twists and deforms during operation. The application of force can be effectively prevented, which is advantageous from the viewpoint of improving durability.

[Problems to be solved by the invention] However, when this approximately cross-shaped flange is used, unlike a retaining plate having a circular flange,
It becomes impossible to arrange only the cushion rubber portion so as to correspond to the excitation coil, and a portion where the holding plate and the excitation coil overlap inevitably occurs. As a result, magnetic leakage occurs from the excitation coil to the holding plate when the turbocharger is driven, which reduces the adhesion force of the rotor to the armature, which in turn causes a reduction in the transmitted torque, impairing the basic performance of the electromagnetic clutch itself. There is an inconvenience that it may be damaged. In this case, since the armature generally has a hole formed therein that corresponds to the pole of the excitation coil, magnetic leakage will occur directly to the holding plate through this hole, making the above situation even worse. It's getting old.

Therefore, this invention was devised to eliminate the above-mentioned drawbacks. It suppresses magnetic leakage to the holding plate of the excitation coil, prevents a decrease in transmission torque, maintains the inherent basic performance, and does not require a large mechanism. It is an object of the present invention to provide an electromagnetic coupling device that has excellent effects and requires a simple configuration.

[Means for Solving the Problems] This invention consists of a rotor that is rotationally driven by a drive source, and a rotor that is provided opposite to the friction surface of the rotor and that is movable toward and away from the friction surface. an annular excitation coil that includes the rotor and the armature in a magnetic circuit and that attracts and moves the armature to the friction surface of the rotor when energized; and an annular exciting coil that is attached to the armature and has a substantially cross-shaped hole inside. an outer holding plate having a flange surrounding the hole; and an outer holding plate having a substantially cross-shaped outer shape similar to the hole;
A flange corresponding to the flange is formed on the outer periphery and is attached to the outer holding plate via an elastic member that connects the flange and a gap between the flanges, and its rotation as the armature is attracted causes deformation of the elastic member. In the electromagnetic coupling device, the electromagnetic coupling device is provided with an inner holding plate for coupling the drive unit, which transmits the transmission while allowing the armature to transmit the information, and the armature includes a hole portion formed of a row of circular arc-shaped slits provided on the same circumference, and which interrupts the magnetic circuit in the armature. and a through hole for blocking the magnetic circuit in these retaining plates is formed at a position corresponding to the hole of the outer retaining plate or the inner retaining plate, and the hole and the through hole cooperate. It adopts a configuration characterized by preventing magnetic leakage.

[Effects of the invention] According to this invention, a relief part for blocking magnetic leakage is formed on the holding plate within the area where this and the excitation coil overlap, so that magnetic leakage of the excitation coil with respect to the holding plate is effectively prevented. The transmission torque is suppressed and the specified transmission torque is secured, the inherent basic performance is maintained in just the right amount, and the relief part only needs to have a simple configuration.It goes without saying that it is advantageous in terms of cost, and it is compact without increasing the size. For practical purposes, it is fine to leave it as is.
This makes it possible to provide an excellent electromagnetic coupling device.

[Embodiment] An embodiment in which this invention is applied to a supercharger for an automobile will be described below with reference to FIGS. 1 to 3.

Figures 1a and 1b are front views showing an electromagnetic clutch as an electromagnetic coupling device of this invention, and its A-O-
It is a longitudinal cross-sectional view along the A line. This electromagnetic clutch is used to connect and disconnect the transmission of engine driving force to an automobile's supercharger.

In Fig. 1b, 1 is a supercharger housing, 2 is a stator housing made of a magnetic material, and an excitation coil 3 wound in a cylindrical shape inside a plastic winding body 3a is disposed inside the stator housing. 3a
It is fixed to the stator housing 2 by caulking. This excitation coil 3 is connected to an external power source by lead wires a and b as shown in FIG. 2, and when energized, a magnetic circuit is connected as shown by the solid line i in FIG. It is beginning to form.

A rotor 5 is connected to a pulley 6 by welding or the like, and is rotatably mounted on the housing 1 via a bearing. An annular armature 8 is provided opposite the sliding surface 5a of the rotor 5, and an outer holding plate 10 is fixed to the armature 8 with rivets 9. This armature 8 has, for example, six arc-shaped holes 50 formed intermittently at equal angular intervals, corresponding to the poles of the excitation coil 3. And this outer holding plate 1
0 is connected to an inner holding plate 12 via a cushion rubber 11 that is an elastic member.

Now, one example of the outer holding plate has a circular outer periphery, a substantially cross-shaped hole inside, and a short cylindrical flange 10d having a substantially cross shape formed around the hole. There is. Inner holding plate 12
has an outer shape similar to the hole of the outer holding plate 10, and has a flange 12d corresponding to the flange 10d on the outer periphery. The inner holding plate 12 has a flange 12d arranged concentrically within the outer holding plate 10 with a predetermined spacing apart from the flange 10d. Cushion rubber 11 is provided between each flange 10d, 12d of these outer holding plate 10 and inner holding plate 12 in the manner described above.

In this case, the armature 8 is attached to the inner holding plate 12.
A plurality of arc-shaped through holes 51 corresponding to the hole portions 50 are formed intermittently. This through hole 51 acts as a relief part for blocking magnetic leakage, and the inner holding plate 1
2 in the thickness direction and communicates with the hole 50.

Here, the outer holding plate 10 and the inner holding plate 12 are fixed to the cushion rubber 11 in the following manner.

That is, the outer holding plate 10 and the inner holding plate 12
, that is, the flange 10 of the outer holding plate 10
d inner surface and the flange 12d of the inner retaining plate 12
An adhesive is applied to the outer surface of the mold, and the outer holding plate 10 and the inner holding plate 12 coated with the adhesive are filled into a mold with a predetermined distance apart. Then, unvulcanized rubber is filled between the outer holding plate 10 and the inner holding plate 12 in the mold, and then the mold is closed and heated, and the outer holding plate 10 and the inner holding plate 12 are bonded with adhesive. and the cushion rubber 11 are bonded together, and the cushion rubber 11 is molded into a predetermined shape. Note that the inner holding plate 12 acts as a member for connecting the drive unit, and a hexagonal bolt is connected to a rotating shaft 13a connected to a propeller (not shown) of a supercharger through a hub 13 that is integrated with the inner holding plate 12. It is joined and fixed at 14. And hub 1
3 and the rotating shaft 13a are connected by a key 13b. In this case, serrations, splines, or the like may be used instead of the key 13b.
The outer holding plate 10 and the armature 8 are connected by a plurality of rivets 9 provided on the outer holding plate 10, as shown in FIG. 1a. Incidentally, symbols H and J indicate holes formed in the cushion rubber 11, which act as relief for the deformation force applied to the cushion rubber 11.

Next, the operation of the above configuration will be explained.

When the supercharger is driven, the exciting coil 3 is energized, a magnetic flux is generated as shown by the solid line i in FIG. As a result, the cushion rubber 11 is elastically bent, and the armature 8 moves in the axial direction together with the outer holding plate 10, and is brought into close contact with the sliding surface 5a of the rotor 5 by suction.

Since the rotor 5 is driven by an automobile engine (not shown) via a pulley 6 and a belt (not shown), when the rotor 5 and armature 8 are attracted to each other, the driving force is transmitted to the armature 8. The rotation is transmitted to the outer holding plate 10 via the rivet 9, and further transmitted to the propeller of the supercharger via the cushion rubber 11, the inner holding plate 12, the hub 13 and the rotating shaft 13a in this order.

By the way, a magnetic circuit is generated when the excitation coil 3 is energized, but since the through hole 51 is formed in the outer holding plate 10, the magnetic flux of the magnetic circuit avoids the through hole 51 as shown by the loop of solid line i in FIG. 1b. Generate as follows. Therefore, magnetic leakage from the excitation coil 3 to the outer holding plate 10 is effectively suppressed, and the reduction in torque transmitted from the rotor 5 to the armature 8 is minimized, so that the basic performance of the electromagnetic clutch is maintained without fail.

While exhibiting such a valuable effect, the relief part only needs to be formed by forming a simple hole 51 in the outer holding plate 10 as in the above embodiment, which is advantageous in terms of cost as well as reducing the overall cost. The structure does not become larger in any way, and the compactness of the conventional structure can be maintained without any problems.

When the excitation coil 3 is cut off, power transmission by the electromagnetic clutch is cut off. At this time, the armature 8 returns to its original position separated by a predetermined gap from the sliding surface 5a of the rotor 5 due to the restoring force of the cushion rubber 11. In addition, in the case of the above embodiment, the outer holding plate 10 and the inner holding plate 12
Since the flanges 10d and 12d are each formed in a cross shape, these outer retaining plates 10 and inner retaining plates 12 have durability that will not succumb to torsional deformation that occurs when the armature 8 is connected to the rotor 5 by adsorption. become.

It should be noted that the area in which the magnetic shielding relief part is formed may be within the area where the outer holding plate 10 and the excitation coil 3 overlap, and for example, it may be formed in an L-shaped area as shown by diagonal lines in FIG. 1a. (For convenience, it is indicated by the symbol Q in FIG. 1a).

Further, the relief portion may be formed not only on the outer holding plate 10 but also on the inner holding plate 12, for example, in a circular shape within a region R shown with diagonal lines in FIG. 1a. However, in this case, since the magnetism from the excitation coil 3 is difficult to reach the inner holding plate 12, the inner holding plate 12
The relief part 2 is not necessarily required and may be provided as necessary.

In addition, the relief part for magnetic shielding is not limited to the arc-shaped through hole 51, but it goes without saying that it can be set to any shape, and it is not limited to holes such as through holes, but only parts corresponding to these positions. In short, it may be made of a non-magnetic material as long as it has a magnetic blocking effect. Further, the clutch of the present invention is well suited for application to a compressor for a vehicle air conditioner that generates a particularly large torsional deformation force on the outer holding plate or the inner holding plate.

[Brief explanation of the drawing]

Figures 1a and b are a front view of the right half showing the structure of an embodiment of the electromagnetic clutch as an electromagnetic coupling device of this invention, and a longitudinal cross-sectional view taken along line A-O-A, and Figure 2 is the entire electromagnetic clutch. FIG. 3 is a perspective view of the armature and its surroundings. In the figure, 3... excitation coil, 5... rotor, 8...
... Armature, 10 ... Outer holding plate, 10d ...
Flange, 11... cushion rubber (elastic member),
12...Inner holding plate, 12d...Flange, 50
...Hole part, 51...Through hole.

Claims (1)

[Claims for Utility Model Registration] A rotor 5 rotationally driven by a drive source, an armature 8 provided opposite to the friction surface of the rotor 5 and movable in directions toward and away from the friction surface. , an annular excitation coil 3 that includes the rotor 5 and the armature 8 in a magnetic circuit and attracts and moves the armature 8 to the friction surface of the rotor 5 when energized; an outer holding plate 10 having a hole and a flange 10d surrounding the hole; an outer holding plate 10 having a substantially cross-shaped outer shape similar to the hole, and a flange 12d corresponding to the flange 10d formed on the outer periphery; Said flange 10d
and a drive unit connecting device that is attached to the outer holding plate 10 via an elastic member 11 that connects the gap between the flanges 12d, and whose rotation is transmitted as the armature 8 is attracted while allowing the elastic member 11 to deform. In the electromagnetic coupling device, the armature 8 is provided with a hole 50 that is formed of a row of arc-shaped slits provided on the same circumference and that interrupts the magnetic circuit within the armature 8, A through hole 51 is formed at a position corresponding to the hole 50 of the outer holding plate 10 or the inner holding plate 12 to interrupt the magnetic circuit in these holding plates, and the hole 50 and the through hole 51 are connected to each other. An electromagnetic coupling device characterized by preventing magnetic leakage.