JPH07274421A - Rotor of magnetic generator - Google Patents

Abstract

PURPOSE:To adequately mount a magnet to a yoke where a reluctor is expansion-formed while avoiding a decrease in inner radius. CONSTITUTION:In a rotor of a magnet generator where a plurality of arc-shaped magnets 20 are located at regular intervals within the inner periphery of a yoke where a reluctor is expansion-formed in a part of a cylindrical wall outside the radial direction, a radius Ra of a central portion 22a in peripheral direction of the outer periphery of each magnet is set larger than a radius ra of the inner periphery of a yoke cylindrical wall 12, and a radius Rb of both the ends 22b in peripheral direction is set smaller than the radius ra of the inner periphery of the yoke cylindrical wall. By doing this, if the roundness of the yoke is degraded due to the expansion of the reluctor, then the central portion 22a at the outer periphery of the magnet always comes in contact with the inner periphery of the cylindrical wall of the yoke, so that the magnet is not deviated to the center direction of the yoke. Since the inner diameter of a group of magnets is not reduced, interference of the rotor with the stator of generator can be avoided and thus it is not required to make an air gap larger between the rotor and stator of generator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of a magnet generator, and more particularly to improvement of a permanent magnet fixing structure, for example, rotation of a magnet generator mounted on a small or special vehicle such as a motorcycle or a buggy. Regarding what is effective for children.

[0002]

2. Description of the Related Art Generally, in a small or special vehicle such as a motorcycle or a buggy, a magnet generator using a permanent magnet (hereinafter referred to as a magnet) such as a ferrite magnet is used.

In this type of magnet generator, a rotor is constructed by arranging and fixing a plurality of magnets at equal intervals on the inner circumference of a yoke, and a coil is wound around a radial salient pole portion of a core. The rotor is driven by the engine to rotate around the electron emitter, thereby inducing an electromotive force in each magnetic pole coil of the electron emitter. Has been done.

In the conventional rotor of this type of magneto-generator, a plurality of arc-shaped magnets are arranged at the inner circumference of a cylindrical yoke, and the outer peripheral surface of the magnet contacts the inner peripheral surface of the yoke. It is arranged so as to contact. In order to make the outer peripheral surface of the magnet adhere to the inner peripheral surface of the yoke, the radius of the outer circumference of the magnet and the radius of the inner circumference of the yoke are designed to be as equal as possible.

Further, as a rotor of a conventional magnet generator of this type, in order to supply an ignition signal to an ignition device of an engine, a reductor is radially outwardly stamped on a part of a cylindrical wall of a yoke. Some of them are bulged. When the rotor is driven by the engine and rotates around the electrons, the reluctor bulged in the yoke is arranged close to the outside of the rotor of the magneto generator. By passing through (Pulsa),
An ignition signal generator is configured to generate an ignition signal and supply it to an engine ignition device.

[0006]

However, the present inventor has clarified that the rotor of the conventional magneto-generator has the following problems. From the viewpoint of rotor manufacturing efficiency, it is advantageous to reduce the number of magnets and magnetize one magnet with multiple poles. Further, from the relationship between the output of the magneto generator and the effective use of the magnet, it is advantageous that the neutral portion of the magnet (the portion that does not generate the magnetic force of the magnet) is small. From these points, it is advantageous that the circumferential length of the magnet (hereinafter referred to as the circumferential length) is long. On the other hand, when the reluctor is bulged and formed on the yoke by punching with a press, the cylindrical wall of the reluctor section receives a pulling force in the bulging direction due to this punching, so that the inner circumference of the yoke of the reluctor section and its surroundings is increased. Is deformed in a direction to be smaller than the radius of the inner circumference of the yoke before stamping, and the circularity of the yoke is reduced. When a magnet having a long circumference is arranged on the inner circumference of the reluctor portion of the yoke and the peripheral portion of which the roundness is lowered, both ends of the outer circumference of the magnet come into contact with the inner circumference of the yoke. Since the magnets are biased toward the center of the yoke, the inner diameter of the magnet group is partially reduced when a plurality of magnets are mounted inside the yoke. When the inner diameter of the magnet group becomes small, the rotor that swirls around the electron emission is likely to interfere with the electron emission. Therefore, in order to avoid this interference, the gap (air gap) between the electron-emitting device and the rotor is set to be large in advance in terms of design. However, when this air gap becomes large, the output (power generation capacity) of the magneto generator decreases.

An object of the present invention is to solve the above-mentioned problems, and it is possible to properly mount a magnet on a yoke having a bulged reluctor while avoiding reduction of the inner diameter of the magnet group. An object of the present invention is to provide a rotor of a magnet generator capable of setting a small air gap between and.

[0008]

In the rotor of a magneto generator according to the present invention, a plurality of arc-shaped magnets are arranged at intervals on the inner circumference of a cylindrical yoke, and the outer peripheral surface of the yoke is formed. In the rotor of the magneto generator, which is in contact with the inner peripheral surface and has the reluctor bulging outward in the radial direction on a part of the cylindrical wall of the yoke, the radius of the outer periphery of each magnet at the central portion in the circumferential direction. Is set to be larger than the radius of the inner circumference of the yoke, and both ends of the outer circumference of the magnet are set to be separated from the inner circumference of the yoke.

[0009]

According to the above means, even if the circularity of the yoke is lowered as described above, the central portion of the outer circumference of the magnet comes closer to the state of being in contact with the inner circumference of the yoke. Therefore, the magnet can be prevented from being biased toward the center of the yoke. Therefore, it is possible to prevent the inner diameter of the magnet group from becoming small when a plurality of magnets are mounted in the yoke, and thus to prevent the rotor from interfering with the electron emission. Therefore, it is not necessary to set a large air gap between the rotor and the electrons.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an enlarged partial plan view showing the relationship between a yoke and a magnet of a rotor of a magnet generator according to an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) explain the operation. FIG. 3A and 3B show a rotor of a magnet generator according to an embodiment of the present invention, FIG. 3A is a plan view, and FIG. 3B is a front sectional view taken along line bb of FIG.

In the present embodiment, the rotor of the magneto-generator according to the present invention comprises a yoke, a plurality of magnets, and a cylindrical magnet cover.

The yoke 11 is integrally formed by a magnetic material into a circular cylindrical shape whose upper surface is open and whose lower surface is closed. The cylindrical wall 12 of the cylindrical shape has a reluctor 1 facing the pulsar 39.
3 has a predetermined width in the circumferential direction and the axial direction, and is formed to bulge outward in the radial direction by stamping with a press. A shaft hole 15 for inserting a boss (not shown) directly connected to the engine is provided in the lower surface closing wall 14 of the yoke 11 at the center thereof. A pair of circular holes 16 used for attaching the yoke positioning jig are formed on the concentric circles with a phase difference of 180 degrees. Further, a plurality of elliptical holes 17 (12 in this embodiment) for inserting a magnet positioning jig are provided on the outer peripheral portion of the closing wall 14 of the yoke 11, and are equidistantly arranged in the circumferential direction on a concentric circle. Has been drilled.

In this embodiment, the cylindrical wall 12 of the yoke 11 is
Since the reluctor 13 is formed so as to bulge outward in the radial direction in a part of, the cylindrical wall 12 of the yoke 11 receives the pulling force in the bulging direction, and the cylindrical wall of the reluctor 13 and the peripheral portion thereof receives a pulling force.
As shown in FIG. 2, the radius rb of the reluctor 13 in the cylindrical wall 12 of the yoke 11 and the cylindrical wall portion of its peripheral portion is smaller than the radius ra of the perfect circle.

Further, the bottom surface of the closing wall 14 of the yoke 11 is provided with a plurality of convex portions 18 (in this embodiment, eight) for fixing the cover, a group of circular holes 16 and a group of elliptical holes 17. They are arranged at equal intervals in the circumferential direction on the concentric circles between them, and a part of the closing wall 14 is pushed up from the outer surface so as to project inward in the axial direction. This convex portion 18 is projected on the cover. It is configured so that it can be caulked by being inserted into the fixing hole.

The closed wall 14 of the yoke 11 is provided with a plurality of female screw holes 19 for attaching a cooling fan, which are provided at equal intervals in the circumferential direction on a concentric circle near a group of circular holes 16.

The magnet 20 has a height equal to or less than the depth of the yoke 11 and is integrally formed into a substantially rectangular parallelepiped having a circular arc shape curved along the inner circumference of the yoke 11 in the width direction. Inclined surface portions 23 are formed on both left and right ends of an arc-shaped inner peripheral surface (hereinafter, referred to as abdominal surface) 21 of the magnet 20 so as to approach an outer peripheral surface (hereinafter, referred to as a rear surface) 22 as they go to the left and right end portions. Has been done. The rising side surfaces 24 and 24 on both sides are formed so as to be at right angles to the tangent to the normal line passing through the center of the yoke 11, and the upper surface 25 and the lower surface 26 are formed parallel to each other.

In the present embodiment, the rotor of the magneto generator is configured to use four magnets 20. That is, the total circumferential length L of the back surface 22 of one magnet 20 is set to about 1/4 of the inner circumferential length of the yoke cylinder wall 12, which is relatively long. Therefore, it is advantageous in terms of manufacturing efficiency and magnet effective efficiency.

In the present embodiment, the arc-shaped rear surface 22 of the magnet 20 is preset with different radii of curvature in the central portion 22a and both end portions 22b, 22b in the circumferential direction. That is, the circumferential center portion 2 of the back surface 22
The radius Ra in 2a is set to be larger than the radius ra preset on the inner circumference of the cylindrical wall 12 of the yoke 11 by design. In addition, both circumferential ends 22b, 22b of the back surface 22
The radius Rb at is smaller than the radius ra preset on the inner circumference of the cylindrical wall 12 of the yoke 11. Here, a preset radius ra on the inner circumference of the yoke cylinder wall 12 is set.
Corresponds to the radius ra when the yoke cylinder wall 12 is a perfect circle. By the way, the circumferential length La between the inner contact points of both the circular arc drawn by the radius Ra of the back surface central portion 22a and both arcs drawn by the radius Rb of the back end portions 22b is about 2 of the total circumferential length L of the back surface 22.
It is set to / 3.

The abdominal surface 21 of the magnet 20 is formed in an arc shape with a circle defining the inner circumference of the cylindrical wall 12 of the yoke 11 as a concentric circle, and the radius Rc of the abdominal surface is the cylindrical surface 12 of the yoke.
The radius ra of the inner circumference of the magnet 20 is set smaller by the amount that defines the radial thickness of the magnet 20. Since the magnet 20 is manufactured by being compacted by a molding die and then baked, the outer shape of the magnet 20 can be freely set by setting the structure of the molding die in advance.

The cover 30 is made of a metal material such as a thin iron plate and is integrally formed by drawing and pressing. The cover 30 is formed into a cylindrical shape that is press-fitted into the cylinder formed by the magnet 20 group. An outer flange portion 32 is formed at one end (hereinafter, referred to as an upper end) of the cylindrical wall 31 of the cover 30 in a circular donut shape protruding outward in the radial direction.

Before assembling, an inner collar portion 33 is integrally formed in a circular donut shape at the lower end of the cylindrical wall 31 of the cover 30. The inner diameter of the inner flange portion 33 is smaller than the arrangement diameter of the group of convex portions 18 arranged on the yoke 11 and equal to or slightly larger than the arrangement diameter of the circular holes 16, 16. In the radial middle portion of the inner flange portion 33, the same number of fixing holes 34 as the convex portions 18 group of the yoke 11 (8 in this embodiment) are arranged so that each of them is aligned with the convex portion 18 group of the yoke 11. It is opened in each of the fixing holes 34
Are formed so that the respective convex portions 18 can be inserted respectively.

A notch 3 is formed on the inner peripheral edge of the inner flange 33.
A plurality of (5 in this embodiment) 5 are formed in a substantially semi-circular shape, and the yoke 1 is formed by the group of the notches 35.
One group of circular holes 16 and one group of female screw holes 19 can be appropriately escaped. Further, a rigidity-imparting portion 36 is formed by bending and bending over the entire circumference including the cutout portion 35 at the inner peripheral edge of the inner flange portion 33. The rigidity imparting portion 36 is formed by bending the inner peripheral edge portion of the inner flange portion 33 axially inwardly at a constant height over the entire circumference by drawing or the like, so that sufficient rigidity is imparted when the cover 30 is press-fitted. Has become.

Next, a brief description will be given of the work of assembling the rotor of the magneto-generator by the components having the above-mentioned structure. First, a plurality (four in this embodiment) of magnets 20 are
The cover 30 is arranged in a circular ring shape in the yoke 11 and is press-fitted.

Since the rigidity imparting portion 36 is formed on the inner collar portion 33 of the cover 30, the cover 30 is properly fitted. In the state after the fitting, the cover 30 is in a state in which the inner flange portion 33 of the cover 30 is in contact with the bottom surface of the closing wall 14 of the yoke 11 and the outer flange portion 32 is in contact with the upper surface 25 of the magnet 20 group. Further, when the cover 30 is press-fitted, the first bulging portion 37 is formed between the magnets 20 group, and the magnets 20 group is relatively positioned in the circumferential direction and prevented from rotating.

Further, by press-fitting the cover 30, the outer peripheral surface of the cover 30 becomes the inner peripheral surface 2 of the magnet 20.
1 and the inclined surface portion 23, the group of magnets 20 is pushed outward in the radial direction.
The second circumferential center portion 22a is pressed against the inner circumferential surface of the yoke cylinder wall 12, and the radial positioning is performed. In this state, the back surface 22 of each magnet 20 is in a state of being pressed against the inner peripheral surface of the yoke cylinder wall 12 at the circumferential center portion 22a thereof, so that the cover 30 defined by the inner diameter Rc of each magnet 22 is The inner diameter is concentric with the inner diameter ra of the yoke cylinder wall 12.

Subsequently, the protruding end portion of the convex portion 18 of the yoke 11 inserted into the fixing hole 34 of the cover 30 is caulked. The cover 30 is formed on the entire circumference of the inner flange 33 by the group of the protrusions 18 after the caulking process.
It is in a state of being fixed in a circular ring shape to the closing wall 14 of. In this state, the magnet group 20 is circumferentially positioned and prevented from rotating with respect to the yoke 11.

Next, a plastic tool (not shown) is inserted into the inside of the cover 30, and the space between the yoke closing wall of the cylindrical wall 31 of the cover 30 and the end surface of the magnet on the yoke closing wall side is annularly outwardly oriented. Or at least a second swelling portion 38 swelling is formed at the yoke closing surface side end surface portion of each magnet, and the magnets 20 are axially positioned and fixed. After that, the plastic tool is extracted upward from the inside of the cover 30. Through the above steps, the rotor of the magneto generator shown in FIG. 3 is manufactured.

By the way, as shown in FIG. 2A, the radius of curvature R'of the rear surface 22 'of the magnet 20' is made as equal as possible to the radius ra of the perfect circle of the yoke cylinder wall 12. In the case of the conventional example, when the magnet 20 ′ is arranged on the inner circumference of the bulging and deformed yoke 11, the magnet 20 ′ is arranged largely deviated inward in the radial direction. That is, as shown in FIG. 2 (a), both ends of the magnet back surface 22 ′ are brought into contact with the inner circumference of the portion of the yoke cylinder wall 12 that has been bulged and deformed to have a small inner diameter rb, The gap G ′ formed between the magnet back surface 22 ′ and the inner circumference of the yoke cylinder wall 12 becomes large, and the magnet 20 ′ is largely deviated toward the center of the yoke cylinder wall 12 by the eccentric amount E. And this magnet back 2
The gap G ′ formed between 2 ′ and the inner circumference of the yoke cylinder wall 12 becomes larger as the entire circumferential length of the magnet 20 ′ becomes longer and the bulging deformation of the yoke cylinder wall 12 becomes larger. Become.

However, in this embodiment, the arc-shaped rear surface 22 of the magnet 20 has a radius Ra at the central portion 22a in the circumferential direction set to be larger than the radius ra preset on the inner circumference of the cylindrical wall 12 of the yoke 11. In addition, since the radius Rb at both ends 22b, 22b in the circumferential direction is set to be smaller than the preset radius ra on the inner circumference of the cylinder wall 12 of the yoke 11, the magnet 20 bulges and deforms. Even if it is arranged on the inner circumference of the wall 12, the magnet 20
It is possible to avoid the phenomenon in which the elements are arranged inwardly in the radial direction. That is, as shown in FIG. 2B, the yoke cylinder wall 12 is bulged and deformed so that the inner diameter is small.
The back of the magnet comes into contact with the inner circumference of the part
The gap G formed between the magnet back surface 22 and the inner circumference of the yoke cylinder wall 12 is small because the two ends of the center part 22a in the circumferential direction of the second cylinder 22a are located. Almost no bias in the direction. The gap G formed between the magnet back surface 22 and the inner circumference of the yoke cylinder wall 12 is constant and does not increase even when the total circumferential length L of the magnet 20 increases, and the yoke cylinder wall 1
It is always constant regardless of the degree of decrease in roundness of 2.

According to the above embodiment, the following effects can be obtained. (1) In the unlikely event that a reluctor is bulged on the cylinder wall of the yoke,
Even if the circularity decreases in the direction in which the inner radius of the yoke of the cylindrical wall of the reluctor and its surrounding parts becomes smaller than the inner radius of the yoke of that part, the central part of the magnet back surface is Since the state where the magnet is always in contact with the inner circumference of the cylinder wall is approached, it is possible to prevent the magnet from being biased toward the center of the yoke cylinder wall.

(2) According to the above (1), it is possible to prevent the inner diameter of the magnet group from becoming small when a plurality of magnets are mounted in the yoke, so that the rotor interferes with the emitted electrons. It is possible to prevent such a situation from occurring, and it is not necessary to set a large air gap between the rotor and the electrons.

(3) According to the above (2), since the volume of the emitted electrons can be set large, the power generation capacity of the rotor of the magnet generator can be enhanced. Moreover, since the air gap can be set small, the magneto-generator can be made compact and lightweight.

(4) Even in the case of a magnet having a long total circumference, since the central portion of the back surface of the magnet comes closer to the state of abutting against the inner circumference of the yoke cylinder wall, the magnet is biased toward the center of the yoke cylinder wall. Can be prevented. As a result, it is possible to use a magnet with a long total circumference, so it is possible to improve the manufacturing efficiency of the rotor of the magnet generator, and by setting the neutral part of the magnet to a minimum, the magnet is maximized. It can be used and the power generation capacity of the magnet generator can be enhanced.

(5) With the engine running,
The cylindrical wall of the yoke receives a centrifugal force acting on the magnet and is greatly distorted at the part between the adjacent magnets, but the action point is different from the conventional case where both ends of the magnet were in contact with the inner circumference of the yoke. Can be separated from each other, so that the distortion of the yoke cylinder wall can be reduced and the change in the gap between the pulsar and the reluctor can be suppressed.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the radii at both ends of the back surface of the magnet in the circumferential direction are not limited to be set smaller than the radius on the inner circumference of the yoke, and may be formed to be the same as the radius of the inner circumference of the yoke or formed in a straight line.

[0037]

As described above, according to the present invention,
It is possible to properly mount the magnet on the yoke in which the reluctor is bulged while avoiding reduction of the inner diameter of the magnet group.

[Brief description of drawings]

FIG. 1 is an enlarged partial plan view showing a relationship between a yoke and a magnet of a rotor of a magneto generator that is an embodiment of the present invention.

FIG. 2A and FIG. 2B are plan views for explaining the operation.

3A and 3B show a rotor of a magneto-generator according to an embodiment of the present invention, in which FIG. 3A is a plan view and FIG. 3B is bb of FIG.
It is a front sectional view which follows a line.

[Explanation of symbols]

11 ... Yoke, 12 ... Cylindrical wall, 13 ... Reactor, 14 ... Closure wall, 15 ... Shaft hole, 16 ... Circular hole, 17 ... Elliptical hole, 18
... Convex part, 19 ... Female screw hole, 20 ... Magnet, 21 ... Arc-shaped inner peripheral surface (abdominal surface), 22 ... Outer peripheral surface (rear surface), 22
a ... Central part in the circumferential direction, 22b ... Both end parts in the circumferential direction, 23 ... Inclined surface part, 24 ... Standing side surface, 25 ... Top surface, 26 ... Bottom surface, 30 ... Cover, 31 ... Cylindrical wall, 32 ... Outer collar part, 33
... Lower collar portion, 34 ... Fixing hole, 35 ... Notch portion, 36 ... Stiffness imparting portion, 37 ... First bulging portion, 38 ... Second bulging portion, 3
9 ... Pulsa.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Taka ▼ Junichi Se 1268-1 Hirosawa-cho, Kiryu-shi, Gunma Mitsuba Electric Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. A cylindrical yoke has a plurality of arc-shaped magnets arranged at intervals on the inner periphery thereof, and an outer peripheral surface of the magnet abuts on the inner peripheral surface of the yoke. In a rotor of a magnet generator in which a reluctor is partially formed to bulge outward in the radial direction, the radius of the outer circumference of each magnet in the circumferential center is set to be larger than the radius of the inner circumference of the yoke. A rotor for a magneto-generator, characterized in that both ends of the outer circumference are set apart from the inner circumference of the yoke.