JP2568201B2 - Electromagnetic clutch - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch that receives a belt driving force of a driving source and transmits a rotational force to a driven shaft.

[Prior Art] Conventionally, an electromagnetic clutch has been used as a power transmission device for various devices such as a vehicle cooling compressor. In this type of electromagnetic clutch, generally, a rotor with a pulley that inputs a rotational force by a belt drive of a drive source is rotatably fitted to a part of the main body of a driven device (for example, a compressor) through a bearing, while the pulley is rotated. The armature is fixed to the rotary shaft of the driven unit through an elastic member so as to face the rotor with a magnet, and the rotor with a pulley and the armature are magnetized by an exciting coil to frictionally engage the two. Is transmitted to the rotating shaft of the driven equipment via the rotor with pulley and the armature.

Further, when roughly classifying a rotor with a pulley used in such an electromagnetic clutch, for example, as disclosed in Japanese Utility Model Application Laid-Open No. 61-523, the clutch part and the pulley part constituting the rotor with a pulley are separated from each other. There is a method in which the clutch section and the pulley section are integrally formed, and the pulley section is part of the magnetic path, as disclosed in Japanese Patent Laid-Open No. 58-134233.

[Problems to be solved by the invention]

By the way, among the rotors with a pulley of an electromagnetic clutch in the above-mentioned conventional technology, the former type has a pulley and a clutch portion, etc., which are molded separately from each other. Since the clutch part and the bearing storage part are separate and fixed, the rigidity is weaker than the integrated type in which the pulley part and the clutch part, etc. are integrally molded with respect to the belt tension from the drive source, and this rigidity is improved. In order to do so, the wall thickness of the parts must be made relatively thick, which tends to increase the weight. On the other hand, in the latter case,
Although it has excellent rigidity, the conventional pulley and clutch are integrated, because the pulley is part of the magnetic circuit, so the pulley must always be placed facing the exciting coil. As a result, there is a restriction on the arrangement (alignment) of the pulley portion with respect to the clutch portion of the rotor, the exciting coil, etc., and the degree of freedom in design tends to be limited to a narrow range. This cannot fully cope with the present situation that the arrangement of the pulleys differs depending on the type of vehicle on which the vehicle is mounted, and improvement thereof has been desired. Also, while the pulley diameter differs depending on the type of vehicle installed, the excitation coil placed on the inner circumference side of the pulley section is standardized.Therefore, when the pulley section doubles as a magnetic circuit, the larger the pulley diameter, the larger the pulley diameter becomes. It is necessary to increase the wall thickness to keep the size of the magnetic gear between the inner circumference of the pulley and the outer circumference of the excitation coil to an acceptable size.Therefore, the larger the pulley diameter, the greater the degree of weight reduction of the rotor as a whole. I got it.

The present invention has been made in view of the above points, and an object thereof is to have excellent rigidity, to secure a degree of freedom in designing with respect to a pulley diameter and a disposition property of a pulley portion, and to improve molding processability. An object of the present invention is to provide an electromagnetic clutch that is improved and has excellent magnetic characteristics.

[Means for Solving Problems] In order to achieve the above object, the present invention configures an electromagnetic clutch as follows. Hereinafter, in order to facilitate understanding of the present invention, reference will be made to the reference numerals of the embodiment shown in FIG.

That is, according to the present invention, the rotor 3 with a pulley, which is rotatably fitted to the main body part 9 of the driven device P via the bearing 7, and inputs the rotational force by the belt drive of the drive source.
An armature 4 fixed to the rotary shaft of the driven device P facing the rotor 3 with pulley, and an exciting coil 6a for magnetizing the rotor 3 with pulley 3 and armature 4 to frictionally engage them. In the electromagnetic clutch, the rotor with pulley 3 has a frictional engagement surface 3b 'facing the armature 4
And a pulley portion 3a arranged on the outer periphery of the clutch portion 3b, and an inner cylindrical portion protrudingly provided on the opposite side of the friction engaging surface 3b 'of the clutch portion 3b for fitting and holding the bearing 7.
3c, and an outer cylindrical portion 3d arranged concentrically with the inner cylindrical portion 3c outside the inner cylindrical portion 3c, the clutch portion 3b,
The pulley portion 3a and the inner cylindrical portion 3c are made of an integrally formed body integrally formed of a magnetic member, while the outer cylindrical portion 3d is a magnetic annular member which is formed separately from the integrally formed body in advance. The cylindrical portion 3d is fitted into the annular recess 13 formed on the back surface of the frictional engagement surface of the clutch portion 3b of the one-piece molded body, and is plastically coupled to the one-piece molded body by the plastic flow of the outer peripheral edge of the ring-shaped recess, Also, the exciting coil 6a is interposed between the outer circumference of the inner cylindrical portion 3c and the inner circumference of the outer cylindrical portion 3d, and the inner cylindrical portion 3c and the outer cylindrical portion 3d form a part of the magnetic circuit of the exciting coil 6a. Set to configure.

[Action]

The electromagnetic clutch having such a configuration is an exciting coil.
When 6a is excited, the inner cylindrical portion provided on the rotor with pulley 3
The clutch part 3b and the armature 4 together with 3c and the outer cylindrical part 3d constitute a magnetic circuit, and the armature 4 is attracted to the friction engagement surface 3b 'of the clutch 3b of the rotor 3 with pulley, and the belt rotational force of the drive source is increased. It is transmitted to the rotary shaft 10 side of the driven device P via the rotor with pulley 3 and the armature 4.
Then, the tension (rotational torque) received from the belt
Is added to the inner cylindrical portion 3c for fitting and holding the pulley portion 3a, the clutch portion 3b, and the bearing 7, but is not directly added to the outer cylindrical portion 3d forming the magnetic circuit due to its structure. Therefore, since the members 3a, 3b, 3c that receive the tension are integrally formed, the clutch input rotating body can be excellent in rigidity even with the minimum necessary thickness structure.

Further, according to the present invention, since the outer cylindrical portion 3d is configured in place of the pulley portion 3a as a part of the magnetic circuit based on the exciting action of the exciting coil 6a, it is not necessary to use the pulley portion 3a also as the magnetic circuit. As a result, the pulley part 3a is excited by the exciting coil 6a.
Therefore, it is not necessary to always dispose them facing each other, and the restriction on the arrangement of the pulley portion 3a can be removed. That is, the pulley portion 3a can be arranged on the side opposite to the exciting coil 6a with respect to the clutch portion 3b as shown in FIG. 1, or can be arranged in parallel on the exciting coil 6a side, and the pulley portion 3a can be designed freely. You can secure the degree. Further, even if the pulley diameter is increased, it is not necessary to increase the thickness as in the conventional case. Therefore, the pulley arrangement and the pulley diameter can be arbitrarily designed according to the vehicle type to be mounted. Moreover, the pulley portion 3a, the clutch portion 3b, and the inner cylindrical portion 3
Since the integral molded body made of c is also molded separately from the outer cylindrical portion, the shape of the integral molded body has a relatively simple structure, the molding process can be easily performed, and the molding process can be improved.
Furthermore, since the outer cylindrical portion 3d is plastically coupled to the integral molded body that will be the rotor portion 3 with pulleys by plastic flow, the mechanical strength of the coupling between the outer cylindrical portion 3d and the integral molded body is increased, and heat is applied. Since the non-coupling method is adopted, the magnetic resistance of the coupling portion is reduced, and the portion of the rotor portion with pulley 3 that constitutes the magnetic circuit is an integrally molded product except for this plastic coupling portion. The characteristics can be improved.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view showing a mounting state of an electromagnetic clutch according to an embodiment of the present invention, FIG. 2 is a sectional view of a rotor with a pulley of the electromagnetic clutch, and FIGS. 3 (a) and 3 (b) are sectional views. 2 is an enlarged sectional view of a portion A of FIG. 4, and FIGS. 4 (a) to 4 (e) are perspective views, FIG. 5 and FIG.
The drawing is a cross-sectional view showing another embodiment of the rotor with pulley.

In FIG. 1, reference numeral 1 denotes an electromagnetic clutch, and the electromagnetic clutch 1 in the present embodiment exemplifies what is applied to a vehicle air conditioning compressor. The electromagnetic clutch 1 is roughly classified into a hub (output rotating body) 2 connected to a rotating shaft 10 of the compressor P,
Rotor with pulley (input rotor) 3 connected to a vehicle engine, which is a drive source, by a multiple V-belt (not shown)
An armature 4 arranged at a position opposed to the rotor 3, a leaf spring 5 for connecting the armature 4 to the hub 2, and an exciting device 6 for frictionally engaging the rotor 3 and the armature 4. Etc.

The rotor with pulley 3 includes a clutch portion 3b having a friction engagement surface facing the armature 4, a pulley portion 3a arranged on the outer periphery of the clutch portion 3b, and a friction engagement surface 3 of the clutch portion 3b.
An inner cylindrical portion 3c protrudingly provided on the opposite side of b'for fitting and holding the bearing 7, and the inner cylindrical portion 3c having a diameter larger than that of the inner cylindrical portion 3c.
3c and an outer cylindrical portion 3d arranged concentrically, and among these rotor elements, the pulley portion 3a, the clutch portion 3b, and the inner cylindrical portion 3c are integrally formed of a magnetic material, and The outer cylindrical portion 3d is molded of a magnetic material separately from the integrally molded body of the rotor elements 3a, 3b, 3c. And the outer cylindrical part
3d is fixed to the integrally formed body of the rotor elements 3a, 3b, 3c by plastic coupling. Then, the rotor 3 with a pulley configured as described above is rotatably fitted to the outer periphery of the cylindrical protrusion 9 provided at one end of the housing 8 of the compressor P via the bearing 7.

Further, the pulley portion 3a has a cylindrical shape, and multiple small V-shaped grooves 3a 'are formed on the outer periphery thereof, and multiple V-belts are hung on the V-shaped grooves 3a'. The outer ring 7a of the bearing 7 is positioned and fixed on the inner circumference of the inner cylindrical portion 3c, and the inner ring 7b is positioned and fixed on the outer circumference of the cylindrical protrusion 9.

The exciting device 6 is composed of an exciting coil 6 and a U-shaped core 6b arranged on the inner and outer circumferences of the coil 6, and the exciting device 6 has an outer circumference of an inner cylindrical portion 3c and an outer circumference of an outer cylindrical portion 3d of the rotor 3. And a small gear gap, and is fixed to one end of the housing 8 of the compressor P by a fitting 11. 12 is an elongated hole for determining the path of the magnetic circuit.

The electromagnetic clutch constructed as described above operates as follows.
When the exciting coil 6a installed in the exciting device 6 is energized,
Due to the magnetomotive force of the exciting coil 6a, the core 6b of the exciting device 6
And a magnetic flux is generated along the magnetic circuit of the inner cylindrical portion 3c of the rotor 3 → the clutch portion 3b → the armature 4 → the clutch portion 3b → the core 6b of the exciter 6 and the outer cylindrical portion 3d, causing the armature 4 to move to the leaf spring 5 The clutch portion 3b of the rotor 3 against the spring force of
To be frictionally engaged. As a result, power is applied to the drive source transmitted to the rotor 3 by the armature 4 → the leaf spring 5
→ The hub 2 → The rotary shaft 10 is used for transmission to operate the compressor P. When the exciting coil 6a is not energized, the spring force of the leaf spring 5 operates so as to keep the armature 4 separated from the clutch portion 3b.

Therefore, according to the present embodiment, the tension (rotational torque) received from the belt is applied to the inner cylindrical portion 3c for fitting and holding the pulley portion 3a, the clutch portion 3b, and the bearing 7, but the outer cylindrical portion forming the magnetic circuit. It does not directly join part 3d. Therefore, since the members 3a, 3b, 3c that receive the tension are integrally formed, the clutch input rotating body can be excellent in rigidity even with the minimum necessary thickness structure.

Further, since the outer cylindrical portion 3d constitutes a part of the magnetic circuit based on the exciting action of the electromagnetic coil 6a in place of the pulley portion 3a,
There is no need to use the pulley section 3a for the magnetic circuit,
As a result, it is no longer necessary to dispose the pulley portion 3a facing the exciting coil 3a at all times, and the restriction on the arrangement of the pulley portion 3a can be removed. That is, as shown in FIG. 1, the pulley portion 3a is arranged on the side opposite to the exciting coil 6a (outer cylindrical portion 3d) with respect to the clutch portion 3b, or as shown in FIG. Side by side in the same direction as part 3d,
As shown in FIG. 6, the pulley portion 3a can be arranged bidirectionally, the degree of freedom of the arrangement of the pulley portion 3a can be secured, and even if the pulley diameter is increased, it is necessary to increase the wall thickness as in the conventional case. Disappears. Therefore, the pulley arrangement and the pulley diameter can be arbitrarily designed according to the vehicle type to be mounted. Moreover, since the integrally molded body including the pulley portion 3a, the clutch portion 3b, and the inner cylindrical portion 3c is also molded separately from the outer cylindrical portion 3d, the shape of the integrally molded body has a relatively simple structure and the molding process is easy. It is possible to improve the molding processability.

As described above, the pulley diameter of the electromagnetic clutch and the disposition property of the pulley portion can be easily changed depending on the mounted vehicle.

Next, a method of manufacturing the rotor with pulley 3 will be described with reference to FIGS. 4 (a) to 4 (e). As shown in FIG. 4, first,
The material is punched into a disc shape with a circular hole in the center by an iron plate (a). Next, the cylindrical pulley portion 3a and the inner cylindrical portion 3c are extruded by cold forging (b). At this time, the pulley portion 3a, the inner cylindrical portion 3c, and the clutch portion 3b are formed to have almost the same wall thickness. Next, an arcuate hole 12 is formed in the clutch portion 3b of the member.
Then, the multiple V-groove pulley portion 3a 'is formed by punching and rolling on the outer surface of the pulley portion 3a (c). On the other hand, the outer cylindrical portion 3d
Is cut from a drawn pipe material or the like as shown in (d), and is fitted into an annular recess 13 formed on the back surface of the friction engagement surface of the clutch portion 3b as shown in (c) above and outside the annular recess. It is plastically connected to the integral molded bodies 3a, 3b, 3c by the plastic flow of the peripheral edge (e).

According to the manufacturing method as described above, it is possible to manufacture a rotor with a pulley with a high yield of materials by a relatively simple process. Further, since the pulley portion 3a and the inner cylindrical portion 3c for accommodating the bearing 7 are simultaneously molded from the same member, the accuracy of concentricity is improved. Furthermore, in the state before rolling the pulley V groove,
Since a large space is created on the inner circumference of the pulley portion 3a (in other words, the outer cylindrical portion 3d is a separate body), the inner surface of the pulley portion 3a can be used as a receiving surface of the rolling piece, so that the rolling accuracy is improved. .

As another effect, since the rotor 3 with pulley is subjected to cold forging processing to increase the hardness of the member, it is excellent in wear resistance. Since the outer cylindrical part 3d is a separate body,
The layout of 12 can be made larger than the inner diameter of the outer cylindrical portion 3d, and the performance of the torque transmitted to the driven machine is improved. Furthermore, since the material of the outer cylindrical portion 3d and the material of the input rotary member can be made different, extremely low carbon steel with good magnetic performance can be used for the outer cylindrical portion, magnetic resistance is reduced and torque performance is improved.

Next, a plastic coupling method suitable for fixing the outer cylindrical portion 3d to the main body of the rotor with pulley 3 will be described with reference to FIG.
This will be described with reference to (b). A plurality of V-shaped grooves 14 are formed near the end of the outer cylindrical portion 3d on the press-fitting side, and are pressed into the annular recess 13 of the clutch portion 3d (a). Next, a part 15 of the clutch part 3b near the outer circumference of the outer cylindrical part 3d is plastically deformed by pressure with an annular die, so that the clutch part 3b of the rotor with pulley 3 flows into the groove 14 of the outer cylindrical part 3d. By doing so, both members are firmly plastically coupled. According to this coupling method, the joint area of both members is increased, so that not only mechanical strength but also magnetic resistance is reduced and performance is improved as compared with mere press fitting.
Further, during processing, since heat is not applied to the rotor with pulley 3 and the outer cylindrical portion 3d, deformation due to joining is less than welding, so
Dimensional accuracy is improved.

〔The invention's effect〕

As described above, according to the present invention, by integrally molding the clutch portion, the pulley portion, and the inner cylindrical portion of the pulley with rotor of the electromagnetic clutch, the outer cylindrical portion that is rigid with respect to the belt tension is used, Further, by making this a separate body, it is possible to provide an electromagnetic clutch having flexibility in pulley diameter and pulley disposition, excellent manufacturing workability, and excellent magnetic characteristics.

[Brief description of drawings]

1 is a sectional view of an electromagnetic clutch showing an embodiment of the present invention, FIG. 2 is a sectional view of a rotor with a pulley used in the above embodiment, and FIGS. 3 (a) and 3 (b) are A of FIG. Part enlarged cross section,
FIGS. 4 (a) to 4 (e) are explanatory views showing the manufacturing process of the rotor with pulleys, and FIGS. 5 and 6 are sectional views showing other examples of the rotor with pulleys. 1 ... Electromagnetic clutch, 3 ... Rotor with pulley, 3a ... Pulley section, 3b ... Clutch section, 3b '... Friction engagement surface, 3c ...
… Inner cylinder, 3d …… Outer cylinder (magnetic annular member), 4
...... Armature, 6a …… Excitation coil, 7 …… Bearing, 9 …… Part of main body of driven equipment (cylindrical protrusion), 10 ・ ・ ・
… Rotation axis, P… Driven device (compressor).

Claims (1)

(57) [Claims] 1. A pulley-equipped rotor that is rotatably fitted to a part of a main body of a driven device via a bearing, and receives a rotational force by driving a belt of a drive source. In an electromagnetic clutch comprising an armature fixed to a rotating shaft of a driven device, and an exciting coil that magnetizes the rotor with pulley and the armature to frictionally engage the two, the rotor with pulley has the armature. A clutch portion having a frictional engagement surface facing the clutch portion, and a pulley portion arranged on the outer periphery of the clutch portion,
An inner cylindrical portion that projects from the side opposite to the friction engagement surface of the clutch portion to fit and hold the bearing, and an outer cylindrical portion that is concentrically arranged with the inner cylindrical portion outside the inner cylindrical portion. The clutch portion, the pulley portion, and the inner cylindrical portion are made of an integral molded body integrally molded with a magnetic member, while the outer cylindrical portion is made of a magnetic material that is molded separately from the integral molded body. In the annular member, the outer cylindrical portion is fitted into an annular recess formed on the back surface of the friction engagement surface of the clutch of the integrally molded body, and is plastically coupled to the integrally molded body by the plastic flow of the outer peripheral edge of the annular recess. The excitation coil is interposed between the outer circumference of the inner cylindrical portion and the inner circumference of the outer cylindrical portion, and the inner cylindrical portion and the outer cylindrical portion constitute a part of a magnetic circuit of the excitation coil. It is characterized by being set to Electromagnetic clutch.