JP3490695B2 - Method for manufacturing rotor of magnet generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a rotor of a magnet generator, for example, manufacturing a rotor of a magnet generator used for small vehicles such as motorcycles, outboard motors and portable generators. Regarding what is effective in the method.

[0002]

2. Description of the Related Art Generally, as a magnet generator, a rotor in which a plurality of magnets are arranged at equal intervals on an inner peripheral surface of a substantially bowl-shaped yoke, and a plurality of generator coils are provided inside a rotor yoke. There is a case in which the electrons are radially arranged, the electrons are fixed to the outer shell of the engine, etc., and the rotor is fitted to the rotation shaft of the engine. In this magneto-generator, the rotor is rotated around the generator by the rotation of the rotating shaft driven by the engine and relatively moves in the magnetic field of the magnet of the rotor, so that the electromotive force is generated in the generator coil. Will be induced.

As a rotor used in such a magneto-generator, a boss member which is formed in a substantially cylindrical shape having a flange on the outer periphery and a tapered inner peripheral surface is formed in the hollow portion of the cylindrical shape, And a yoke in which a boss member insertion opening opened in the bottom wall of the yoke is formed, and the boss member is inserted into the boss member insertion opening of the yoke and the inner main surface of the flange is the bottom of the yoke. Some are fixed to the yoke while being in close contact with the outer surface of the wall. The rotor of this magneto-generator has a taper outer peripheral surface formed at one end of the rotary shaft and a taper inner peripheral surface of the boss member, which is taper-joined to the rotary shaft (crankshaft) of the engine. It is fixed by being held by a screw member.

[0004]

In the rotor of the above-mentioned magnet generator, the fastening screw member that holds the taper coupling between the rotary shaft and the boss member by repeating the rotation and stop of the rotary shaft of the engine. So-called torque reduction may occur.

Therefore, in the rotor of the above-mentioned magnet generator, in order to prevent the occurrence of this torque down, the taper inner peripheral surface of the boss member is ground after cutting to roughen the taper inner peripheral surface of the boss member. Measures have been taken to improve the hardness and to increase the hardness of the tapered inner peripheral surface of the boss member by subjecting the tapered inner peripheral surface of the boss member to induction hardening.

However, even if these measures are taken, torque down may occur depending on the engine specifications.

An object of the present invention is to provide a method of manufacturing a rotor of a magneto generator capable of reliably preventing torque down.

[0008]

A method for manufacturing a rotor of a magneto generator according to the present invention is formed in a substantially cylindrical shape having a flange on the outer periphery, and a tapered inner peripheral surface is formed in the hollow portion of the cylindrical shape. Boss member and a yoke having a substantially bowl shape and having a boss member insertion opening formed in the bottom wall thereof, and the boss member is inserted into the boss member insertion opening of the yoke to form a main inside of the flange. In the method for manufacturing a rotor of a magneto-generator, the surface of which is fixed in close contact with the outer surface of the bottom wall of the yoke, in the taper of the boss member before the rotation shaft is taper-coupled to the inner peripheral surface of the taper. The taper outer peripheral surface of the jig is pressed against the peripheral surface to crush the projection formed on the taper inner peripheral surface.

According to the above-mentioned means, since the projection formed on the tapered inner peripheral surface of the boss member is crushed in advance by the jig, the rotary shaft is taper-coupled to the tapered inner peripheral surface of the boss member and the fastening screw member. It is possible to prevent a torque down that the fastening screw member loosens after being fastened.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows main steps of a method of manufacturing a rotor of a magneto generator according to an embodiment of the present invention, (a) is a front sectional view before inserting a jig, ( b) is (a)
2B is an enlarged cross-sectional view of the portion b, and FIG. 6C is a front cross-sectional view when the jig is inserted. FIG. 2 is a front sectional view before inserting the rotary shaft,
(B) is an enlarged cross-sectional view of part b of (a), and (c) is a front cross-sectional view of the rotary shaft coupling.

In this embodiment, the rotor (hereinafter referred to as the rotor) 10 of the magnet generator according to the manufacturing method of the present invention.
Includes a yoke 11 and a boss member 20. The yoke 11 is made of a magnetic material and has one end face (hereinafter referred to as the upper face).
Is integrally formed into a substantially bowl shape with an open bottom and a closed lower surface. A boss member insertion port 14 is concentrically formed in a bottom wall (hereinafter, referred to as a yoke bottom wall) 13 that closes a lower surface of a cylindrical side wall 12 of the yoke 11. A fitting portion 15 is provided around the boss member insertion opening 14 in the yoke bottom wall 13,
The yoke bottom wall 13 is curved by burring so as to project in a short cylindrical shape. Fitting part 15
Female serrations 16 are formed on the inner circumference of the.

The boss member 20 is made of a structural material having a large mechanical strength such as steel, and is formed in a substantially cylindrical shape having a circular ring-shaped flange on the outer peripheral side at one end. That is, the boss member 20 has a cylindrical body portion 21.
And a flange 22 projecting radially outward on the outer periphery of the lower end portion thereof. A tapered inner peripheral surface 23 is formed in the middle of the cylindrical hollow portion of the main body portion 21 of the boss member 20 so that the diameter gradually increases toward the flange 22 side. A cylindrical inner peripheral surface-shaped insertion hole 24 is provided in front of the tapered inner peripheral surface 23.
And a female screw hole 25 is formed in front of the insertion hole 24.

Flange 22 of main body 21 of boss member 20
Male serrations 26 are formed on the outer periphery of the side end portions.
The boss member 20 is inserted into the fitting portion 15 of the boss member insertion opening 14 from the outer surface (hereinafter, referred to as the lower surface) side of the yoke bottom wall 13 with the side opposite to the flange 22 as the front side, and the male serration 26 is inserted into the female serration 16. By being press-fitted and serrated, the yoke bottom wall 13 is serrated. By this serration coupling portion, the inner periphery of the fitting portion 15 of the boss member insertion port 14 and the outer periphery of the boss member 20 are firmly fixed against rotation and coupled. After this,
A buckling caulking portion 27 is formed on the outer periphery of the main body portion 21 at a position on the opposite side of the flange 22 of the serration coupling portion, and is sandwiched between the yoke bottom wall 13 and the flange 22 to firmly secure the axial free movement. Being prevented.

On the other hand, as shown in FIG.
The rotation shaft of the engine to which the rotor 10 is attached (hereinafter,
It is called the axis of rotation. ) 30, a tapered outer peripheral surface 31 is formed, and the tapered outer peripheral surface 31 is set to be taper-coupled to the tapered inner peripheral surface 23 of the boss member 20. A male screw portion 32 is formed in front of the tapered outer peripheral surface 31 of the rotary shaft 30, and a nut 33 as a fastening screw member is screwed to the male screw portion 32 with a washer 34 interposed therebetween.

Here, the taper inner peripheral surface 23 of the boss member 20.
When the taper inner peripheral surface 23 before the rotary shaft 30 is fitted into the above is finely observed, as shown in FIG.
The minute protrusions 28 are formed in the shape of a saw blade. The protrusions 28 are formed after cutting or polishing the tapered inner peripheral surface 23. In this state, if the taper outer peripheral surface 31 of the rotating shaft 30 is taper-coupled to the taper inner peripheral surface 23 and the male screw portion 32 is fastened by the nut 33, torque down may occur due to a mechanism described later.

Therefore, in the present embodiment, FIG.
As shown in (c), the tapered outer peripheral surface 42 of the jig 40 is fitted into the tapered inner peripheral surface 23 before the rotary shaft 30 is taper-coupled to the tapered inner peripheral surface 23. The jig 40 is a punch in which a tapered outer peripheral surface 42 is formed at the tip of a cylindrical main body 41, and the tapered outer peripheral surface 42 is set so as to be taper-coupled to the tapered inner peripheral surface 23 of the boss member 20.

The taper outer peripheral surface 42 of the jig 40 is the boss member 2.
When the pressing force is applied to the jig 40 after being fitted into the tapered inner peripheral surface 23 of 0, the protrusion 28 is crushed.
At this time, when the rotor 10 is coupled to the rotary shaft 30, a pressing force equal to or greater than the tightening load of the nut 33 fastened to the male screw portion 32 of the rotary shaft 30 is applied to the jig 40.

Thereafter, when the taper outer peripheral surface 42 of the jig 40 is pulled out from the taper inner peripheral surface 23 of the boss member 20 as shown in FIG. 2A, the protrusion 28 of the taper inner peripheral surface 23 is released. The pointed portion is in a crushed state as shown in FIG. 2 (b).

Thereafter, as shown in FIG. 2C, the tapered outer peripheral surface 31 of the rotary shaft 30 is taper-joined to the tapered inner peripheral surface 23 of the boss member 20. Subsequently, the nut 33 is screwed into the male screw portion 32 with the washer 34 interposed therebetween,
It is fastened with the specified tightening load. When the tapered outer peripheral surface 31 of the rotary shaft 30 is taper-joined to the tapered inner peripheral surface 23 after the pointed end of the protrusion 28 on the tapered inner peripheral surface 23 of the boss member 20 is crushed in this way, the rotor 10 It is possible to prevent the nut 33 from loosening and torque down occurring when the engine is driven by the engine.

As shown in FIG. 3A, a force in the rotational direction is generated between the tapered inner peripheral surface 23 and the tapered outer peripheral surface 31, which are in a stable state due to the axial force of the nut 33, due to the angular acceleration of the engine. Occurs, and when this rotational force exceeds the frictional force generated on the seat surface of the nut 33, the boss member 20 rotates minutely.

At this time, the taper inner peripheral surface 2 of the boss member 20.
As shown in FIG. 3B, the axial force acting on the boss 3 causes the boss member 20 to rotate and move in the direction of biting into the rotary shaft 30. That is, the nut 33 loosens and moves in the direction in which torque down occurs. By this biting action, the vertical resistance of the boss member 20 increases, and a new frictional force that opposes the rotation direction is generated, so that the boss member 20 enters the next stable state. It can be said that the movement at this time is a kind of stick-slip phenomenon.

Looking at the surface of the taper inner peripheral surface of the conventional rotor, the surface of the taper inner peripheral surface has a saw-toothed surface shape having minute protrusions. If the angular acceleration of the engine acts on the inner peripheral surface of the taper through the rotation axis in the state where the inner peripheral surface of the taper has a saw-toothed surface shape, the surface of the inner peripheral surface of the taper is eroded by the biting action. The sawtooth wave front of is crushed and flattened by the normal force from the rotation axis. The larger the level of this flattening, the larger the biting amount of the rotating shaft = the torque reduction width.

On the other hand, the rigidity of the sawtooth wave surface on the surface of the inner peripheral surface of the taper becomes weaker as the surface roughness becomes rougher and the hardness becomes lower, so that biting into the rotating shaft due to angular acceleration of the engine easily occurs. Become. Therefore, if the surface roughness and hardness are increased, the torque reduction amount will be reduced.

However, even if the surface roughness is finished to about 3 s, the sawtooth wavefront remains, so that torque reduction cannot be completely eliminated. Therefore, in the present embodiment, after the tapered inner peripheral surface 23 is cut or polished, the tapered outer peripheral surface 31 having the same shape as the rotating shaft 30 is pressed against the tapered inner peripheral surface 23 to obtain a specified stroke. The protrusion 28 of the taper inner peripheral surface 23 is crushed by applying pressure up to. Here, the specified stroke is the amount of sinking of the rotating shaft 30 with respect to the reference surface of the boss member 20 after the “specified tightening torque + actual machine maximum angular acceleration test”.

The present invention is not limited to the above-mentioned embodiment, and within the scope not departing from the gist thereof,
It goes without saying that various changes can be made.

For example, the amount of processing is adjusted so that the surface on which the reference gauge is inserted on the inner peripheral surface of the taper is subjected to the roller burnishing process, and then the projection 2 is adjusted by adjusting the processing amount.
8 may be crushed.

[0027]

As described above, according to the present invention,
Since the protrusion formed on the tapered inner peripheral surface of the boss member is crushed in advance, even if the angular acceleration of the engine acts on the rotor after the rotary shaft is taper-coupled to the tapered inner peripheral surface of the boss member, the fastening screw It is possible to prevent the member from loosening and torque down.

[Brief description of drawings]

FIG. 1 shows a main part process of a method for manufacturing a rotor of a magneto-generator according to an embodiment of the present invention, (a) is a front sectional view before a jig is inserted, and (b) is (a). 2B is an enlarged cross-sectional view of the portion b, and FIG. 6C is a front cross-sectional view when the jig is inserted.

FIG. 2 is a front sectional view before insertion of a rotary shaft, FIG. 2B is an enlarged sectional view of part b of FIG. 2A, and FIG.

FIG. 3 is a schematic diagram for explaining a mechanism of occurrence of torque reduction, in which (a) shows an initial stable state and (b) shows a stable state after the rotational force is increased.

[Explanation of symbols]

10 ... Rotor, 11 ... Yoke, 12 ... Side wall, 13 ... Bottom wall, 14 ... Boss member insertion port, 15 ... Fitting part, 16 ... Female serration, 20 ... Boss member, 21 ... Main body part, 22 ... Flange, 23 ... taper inner peripheral surface, 24 ... insertion hole, 25 ... female screw hole, 26 ... male serration, 27 ... buckling caulking portion,
28 ... Protrusion, 30 ... Rotation axis, 31 ... Tapered outer peripheral surface, 32
... Male screw portion, 33 ... Nut, 34 ... Washer, 40 ... Jig, 41 ... Main body, 42 ... Tapered outer peripheral surface.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-34758 (JP, A) JP-A-5-7970 (JP, A) Actual flat 1-123462 (JP, U) Actual flat 3- 60622 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 21/22 H02K 15/03

Claims (3)

(57) [Claims] 1. A boss member which is formed in a substantially cylindrical shape having a flange on the outer periphery and has a tapered inner peripheral surface formed in the hollow portion of the cylindrical shape, and a boss member which is formed in a substantially bowl shape and is formed on the bottom wall of the boss member. A magnet generator having a yoke having an insertion opening and a boss member is inserted into the boss member insertion opening of the yoke and the inner main surface of the flange is fixed in close contact with the outer surface of the bottom wall of the yoke. In the method of manufacturing a rotor of a machine, before the rotation shaft is taper-coupled to the tapered inner peripheral surface, the tapered outer peripheral surface of the jig is pressed against the tapered inner peripheral surface of the boss member to form the tapered inner peripheral surface. A method for manufacturing a rotor of a magnet generator, comprising crushing the formed protrusions. 2. The rotation of the magneto-generator according to claim 1, wherein the taper outer peripheral surface is pressed by applying a force equal to or greater than a tightening load when the rotary shaft is taper-coupled to the taper inner peripheral surface. Child manufacturing method. 3. A boss member which is formed in a substantially cylindrical shape having a flange on the outer circumference and has a tapered inner peripheral surface formed in the hollow portion of the cylindrical shape, and a boss member which is formed in a substantially bowl shape and is formed on the bottom wall of the boss member. A magnet generator having a yoke having an insertion opening and a boss member is inserted into the boss member insertion opening of the yoke and the inner main surface of the flange is fixed in close contact with the outer surface of the bottom wall of the yoke. In the method of manufacturing a rotor of a machine, before the rotary shaft is taper-coupled to the taper inner peripheral surface, roller burnishing is performed on the taper inner peripheral surface and tightening when the rotary shaft is taper-coupled to the taper inner peripheral surface. A method for manufacturing a rotor of a magnet generator, which comprises applying a force equal to or more than a load.