JPH0122492B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a clutch rotor for an electromagnetic clutch, and more particularly to a method of manufacturing a clutch rotor for an electromagnetic clutch that is suitable for reducing the diameter.

[Prior Art] Generally, as shown in FIG. 3, an electromagnetic clutch has an iron ring-shaped clutch rotor 3 rotatably supported on the outer periphery of a cylindrical convex portion 1a of a fixed portion 1 via a radial bearing 2. , is assembled with a gap between the ring-shaped excitation coil device 4 fixedly held on the fixed part 1, and the tip of the driven shaft 5 rotatably supported on the fixed part 1 through the inside of the cylindrical protrusion 1a. A magnetic hub 6 is attached to the rotor 3 while being prevented from rotating with a key or the like, and an iron ring-shaped armature 8 is attached to the hub 6 via, for example, three leaf springs 7.
It has a structure in which it faces the shaft end surface 3a of the driven shaft 5 at a distance and is movable in a direction parallel to the driven shaft 5. Then, the V applied to the V groove 3b of the rotor 3
When the rotor 3 is rotated via a belt (not shown) and the coil 9 of the excitation coil device 4 is energized, the armature 8 is moved to the shaft end surface 3 of the rotor 3 by the magnetic force generated thereby.
a to transmit rotational force to the driven shaft 5, but when the coil 9 is de-energized, the adsorption force disappears, so the armature 8 is separated from the shaft end surface 3a of the rotor 3 by the restoring force of the leaf spring 7. The rotation transmission to the driven shaft is cut off.

Here, slits 10 and 11 are provided on two different circumferences on the shaft end surface 3a of the rotor 3, and slits 10 and 11 are provided on the opposing armature 8 at appropriate positions between the slits 10 and 11 on the short shaft surface of the rotor 3. A slit 12 is provided in the. In this way, when the excitation coil 9 is energized, the magnetic flux from the excitation coil device 4 is made to meander to form a zigzag magnetic circuit φ.

Conventionally, the clutch rotor 3 having such a structure has been manufactured by first using a hot forged material 30 as shown in FIG.
By cutting the shaded part 30a, the rotor shaft end face 3
After forming the V groove 3b and the positioning portion 3c with respect to the radial bearing 2, slits 10 and 11 are formed by press punching.

[Problems to be Solved by the Invention] However, in the conventional manufacturing method using hot forging described above, when reducing the outer diameter _D3 of the clutch rotor 3, the trepanning portion 20a of the rotor 3,
Inner diameter of the U-shaped part consisting of 20b and the bottomed part
The distance between D ₄ and D ₅ is narrowed, and accordingly, the distance between the outer circumferential slit 10 and the inner circumferential slit 11 provided on the short axis surface 3a is also narrowed.

The friction surface area (particularly 8a and 8b) determined by the relative positional relationship with the slit 12 provided in the opposing armature 8 is reduced, resulting in a reduction in the transmitted torque.

In addition, in order to increase the transmitted torque, it is sufficient to increase the diameter D ₂ of the shaft end surface 3a of the rotor 3 and the armature diameter D ₁ , but this also requires increasing the outer diameter of the rotor forging material, which increases the cost. This was a contributing factor.

On the other hand, in the hot forging or cold forging manufacturing method, forging the hot forging material or the cold forging material,
Not only does it require costly machining such as cutting, but it also requires the trouble of having to set the trepanning parts 20a and 20b of the rotor 3 to be narrow from the beginning in order to reduce the diameter of the rotor 3. There is.

Furthermore, the trepanning parts 20a and 20 of the rotor 3
If b is set to be narrow, the die used for forging must be made thinner, and
Since the length of the mold becomes relatively long, the strength of the mold inevitably decreases, resulting in a disadvantage that the life of the mold is shortened. Note that shortening the length of the mold increases the amount of cutting in the depth direction, which poses a problem of complicating the processing process and increasing the cost of the product.

As described above, in the conventional method of manufacturing clutch rotors by hot forging or cold forging, cutting is required in various places, which not only makes the processing method complicated, but also makes the mold used for the forging elongated. However, because of its limitations, it was not suitable for reducing the diameter of the rotor.

Therefore, in view of the above drawbacks, the technical problem of the present invention is to reduce the cutting process as much as possible, and to extend the life of the mold without the need to set the rotor's tread pan part to be narrow from the beginning. It is an object of the present invention to provide a method of manufacturing a clutch rotor for an electromagnetic clutch that can be improved.

[Means for Solving the Problems] According to the present invention, the clutch rotor for an electromagnetic clutch is rotatably driven by an external drive source, and the armature is disposed opposite to the clutch rotor. In a method of manufacturing a clutch rotor of an electromagnetic clutch, the clutch rotor has a ring-shaped groove for receiving an excitation coil forming a magnetic circuit therein, and a flange protruding from a peripheral surface of the clutch rotor near the armature side end,
Processing a hollow ring-shaped plate material into a U-shaped cross section,
A bottomed portion and a trepanning portion extending from an edge of the bottomed portion to form an opening surface are formed, and a space defined by the bottomed portion and the trepanning portion is used as the ring-shaped groove for receiving the excitation coil. On the other hand, the flange is formed by subjecting at least the opening surface side of the trepanning part to a press drawing process so that the bottomed part side of the trepanning part protrudes relatively from the opening surface side. A method of manufacturing a clutch rotor for an electromagnetic coil is obtained.

[Examples] Examples of the present invention will be described below with reference to the drawings.

As shown in FIG.
The groove diameter is _D3 ), and the extension thereof has a flange, that is, an outer peripheral protruding end 3e (the diameter is _D6 ) at the intersection with the shaft end surface 3a,
An outer circumferential slit 13 and an inner circumferential slit 14 are provided on the inside thereof, and a flange, that is, an inner circumferential protruding end 3g (diameter:
D ₇ ) is provided.

The inner diameter D ₈ of the bearing holding portion 3 f is larger than the diameter D ₇ of the inner circumferential projecting end 3 g, and axial positioning with respect to the radial bearing 2 is performed at this portion.

Further, the armature 8' facing the shaft end surface 3a of the rotor 3 is provided with a slit 15 between the outer peripheral slit 13 and the inner peripheral slit 14 of the shaft end surface 3a, and two circumferential grooves 16 are provided on the friction surface. By providing four friction surfaces 8c, 8d, 8e, 8f
is formed.

When the excitation coil 9 is energized, the excitation coil device 4
The magnetic flux from
→Friction surface 8e→Friction surface 8f→Short shaft surface 3a→Inner peripheral protruding end 3g→Bearing holding portion 3f→Excitation coil device 4 A zigzag magnetic circuit is created, and the armature 8' is attracted to the rotor shaft end surface 3a.

Most of the rotor 3' is formed by press working, except for the inner diameter finishing cutting process of the V-groove 3b and the bearing holding part 3f.

Furthermore, since the outer circumferential slit 13 can be formed larger than the diameter D ₄ of the U-shaped cross section, the magnetic flux from the excitation coil 9 is guided to the outer circumferential side of the shaft end surface 3a, and at the same time, it is guided to the outer circumferential side of the armature 8'. This makes it possible to take a detour to the desired position.

Furthermore, since the distance between the outer circumferential slit 13 and the inner circumferential slit 14 can be set large, the areas of the armature friction surfaces 8c, 8d, 8e, and 8f are increased, and the transmitted torque is increased.

Here, the manufacturing process of the rotor 3' of the present invention will be explained with reference to FIG.

(a) First, a plate material is press punched into a hollow ring shape.

(b) A hollow ring-shaped plate material is deep drawn into a U-shaped cross section to form a bottomed portion 21 and a trepanning portion 20 extending from the edge of the bottomed portion 21 to form an opening surface.
a, 20b are formed. As a result, a ring-shaped groove 15 that receives the excitation coil 4 is formed.

(c) Slits 13 and 14 are press punched on the inner and outer circumferential sides of the bottomed portion 21, respectively.

(d) The trepanning parts 20a and 20b are press-drawn to reduce the diameter of the rotor 3' by compressing them in the axial direction and forming the rotor shaft end face 3a.
An outer circumferential protruding end 3e that protrudes beyond the pulley portion 3d and an inner circumferential protruding end 3g that protrudes inward from the bearing holding portion 3d are formed near the inner and outer circumferences of the bearing.

As a result, according to the present embodiment, the diameter of the rotor can be freely selected from a large diameter to a small diameter by press drawing, and thus the raw material can be easily produced. Therefore, the dimensions of the mold can be selected regardless of the reduction in the diameter of the rotor, so the life of the mold can be improved.

The outer peripheral protrusion 3e can increase the friction area.

By providing the protrusion 3g without changing the thickness of the inner wall 3f, the magnetic properties can be improved.

By providing the protrusions 3e and 3g, the strength of the rotor 3' can be improved.

Since the thickness of the material plate can be kept to the minimum necessary, the material yield is improved.

The machining process has been simplified, making it possible to reduce the manufacturing cost of the rotor 3'.

[Effects of the Invention] As explained above, according to the present invention, since press drawing is used, the cutting process is reduced as much as possible,
Furthermore, since it is not necessary to set the tread pan portion of the rotor in a narrow state from the beginning, it is possible to provide a method of manufacturing a clutch rotor for an electromagnetic clutch that can improve the life of the mold.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 2 is a drawing showing the press drawing process of a rotor used in the invention, Fig. 3 is a longitudinal sectional view of a conventional example, and Fig. 4 is a longitudinal sectional view of an embodiment of the present invention. FIG. 2 is a diagram showing a conventional forged material. 2...Radial bearing, 3'...Rotor, 3e,
3g...flange, 4...excitation coil device, 8...
... Armature, 15 ... Ring-shaped groove, 20a,
20b...Trepan part, 21...Bottomed part.

Claims (1)

[Claims] 1 A clutch rotor for an electromagnetic clutch rotationally driven by an external drive source, which has a ring shape for receiving an excitation coil forming a magnetic circuit including the clutch rotor and an armature arranged to face the clutch rotor. In a method for manufacturing a clutch rotor of an electromagnetic clutch having a groove and a flange protruding from the circumferential surface near the armature side end of the clutch rotor, a hollow ring-shaped plate material is processed to have a U-shaped cross section, and a bottomed portion is formed. a trepanning part extending from the edge of the bottomed part to form an opening surface; a space defined by the bottomed part and the trepanning part is the ring-shaped groove for receiving the excitation coil; The electromagnetic device is characterized in that the flange is formed by performing press drawing on at least the opening surface side of the trepanning part, and making the bottomed part side of the trepanning part protrude relatively from the opening surface side. Method of manufacturing clutch rotor for clutch.