JPH10145996A - Rotor for magnet generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor for magnet generator in which the manufacturing cost can be reduced by decreasing the number of components and the power generation output can be increased by decreasing or eliminating the air gap between an iron arm and a permanent magnet thereby reducing loss of magnetic force. SOLUTION: The rotor 1 comprises a permanent magnet 5 arranged on the inside of an iron arm 4, and a magnet protective cover 6 arranged on the inside thereof. The magnet protective cover 6 is an annular body having substantially L-shaped crosssection with the flange part 6b thereof being secured to the open end of the iron arm 4. The magnet protective cover 6 is integrally provided with a member 6c for regulating rearward movement of the permanent magnet 5. Since magnet protective cover 6 is provided integrally with the regulating member 6c, conventional ring is not required and since the number of component is decreased, cost of the rotor 1 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the positioning of a permanent magnet in a rotor of a magnet generator. Further, the present invention relates to a technique for reducing a magnetic force loss between a permanent magnet and an iron bowl in a rotor of a magnet generator.

[0002]

2. Description of the Related Art A rotor of a conventional magnet generator is shown in FIG. The rotor J1 of the magnet generator has a boss J2 and a rivet J
3, an iron bowl J4 rotatably driven via the iron bowl J4, a permanent magnet J5 arranged in the iron bowl J4, and an iron bowl J4 arranged inside the permanent magnet J5 and at the open end side of the iron bowl J4.
And a ring-shaped magnet protection cover J6 having a substantially L-shaped cross section, which is fixed to the magnet. The rotor J1 of the conventional magnet generator is
A ring J7 is used to position the permanent magnet J5 in the axial direction of the iron bowl J4 (the axial direction of the rotating shaft).
This restricts the movement of the permanent magnet J5 to the back of the iron bowl J4.

[0003] The rotor J1 of the magnet generator is connected to an iron bowl J.
At the opening end of No. 4, a locking piece J8 for fixing the magnet protective cover J6 by plastic deformation is integrally provided. Conventional locking piece J
Reference numeral 8 is provided inside the open end of the iron bowl J4.
That is, the inner end A of the base of the conventional locking piece J8 is
And the inner end B of the open end of the slab.

[0004]

SUMMARY OF THE INVENTION As indicated above,
Since the rotor J1 of the conventional magnet generator uses the ring J7 to position the permanent magnet J5, there is a problem that the number of parts is large and the manufacturing cost is high.

[0005] The rotor J1 of the conventional magnet generator is
Since the inner end A at the base of the locking piece J8 coincided with the inner end of the opening end B of the iron bowl J4, when the locking piece J8 was plastically deformed inward, the inner end at the base of the locking piece J8 was An inwardly arcuate portion C is formed. If the circular arc portion C and the permanent magnet J5 interfere with each other, the permanent magnet J5 may be damaged. Therefore, in order to avoid the interference between the circular arc portion C and the permanent magnet J5, the inside of the iron bowl J4 is closed. A gap D having a gap width of 0.5 mm and an axial dimension of about 8 mm was provided. When such a large gap D is provided, there is a problem that the magnetic force is increased by the gap D and the power generation output is reduced.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotor of a magnet generator which can reduce the number of parts and the manufacturing cost.
Another object of the present invention is to provide a rotor of a magnet generator capable of reducing a magnetic force loss by reducing or eliminating a gap between an iron bowl and a permanent magnet and increasing power generation output.

[0007]

Means for Solving the Problems In order to achieve the above object, the rotor of the magnet generator of the present invention employs the following technical means. [Means of Claim 1] Since the regulating member provided integrally with the magnet protection cover positions the permanent magnet inside the iron bowl, the ring conventionally used becomes unnecessary. For this reason,
The number of parts is reduced as compared with the related art, and the cost of the rotor of the magnet generator can be reduced.

According to a third aspect of the present invention, the inner end of the base of the locking piece for fixing the magnet protective cover by plastic deformation is provided at a position away from the inner end of the open end of the iron bowl. Even if the piece is plastically deformed inward, the arc formed at the inner end of the base of the locking piece does not interfere with the permanent magnet. For this reason, a gap for the purpose of avoiding interference, which is conventionally formed, becomes unnecessary, and the gap can be reduced or eliminated. As described above, by reducing or eliminating the gap, the magnetic force loss is reduced, and the power generation output of the magnet generator is increased.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to examples and modifications. 1 to 5 show an embodiment. FIG. 1 is a sectional view of a rotor of a magnet generator, and FIG. 2 is an enlarged view of a main part thereof.

The magnet generator is mounted on the end of the engine of a motorcycle. A rotor 1 used for the magnet generator has a boss 2 fixed to the end of a crankshaft and driven to rotate, and a boss 2 Concentrically arranged on the outer circumference of
The boss 2 has an iron bowl 4 firmly connected by rivets 3.

The boss 2 is formed by forging a steel material and then by machining such as cutting. The boss 2 extends at right angles to the tapered portion 2a fixed to the end of the crankshaft in the outer diameter direction. And a flange portion 2 provided in a disk shape
b, and the bottom 4a of the iron bowl 4 is fixed to the flange 2b. The iron bowl 4 is made by rolling a rolled steel plate into a circular bowl shape by press working, and has a bottom 4 a joined to the flange 2 b of the boss 2. Inside the cylindrical portion 4b of the iron bowl 4, a permanent magnet 5 such as ferrite or rare earth is disposed. The permanent magnet 5 is usually composed of four 90 ° bow magnets.
Used.

Inside the permanent magnet 5, a magnet protection cover 6 is provided.
Is arranged. This magnet protection cover 6 is shown in FIGS. 3 shows a sectional view of the magnet protection cover 6, and FIG. 4 shows a view of the magnet protection cover 6 viewed from the bottom. The magnet protection cover 6 is formed by pressing a thin plate of a non-magnetic metal such as SUS into an annular shape having a substantially L-shaped cross section by pressing, and includes a cylindrical portion 6a on which the permanent magnet 5 is mounted on the outer peripheral surface, and an iron. Iron bowl 4 in contact with the open end of bowl 4
And a flange portion 6b that is fixed to the base member.

The magnet protection cover 6 is integrally formed with a positioning regulating member 6c for regulating the movement of the permanent magnet 5 to the back of the iron bowl (left side in FIG. 1). The restricting member 6c of the present embodiment is formed by cutting and bending the cylindrical portion 6a of the magnet protective cover 6, and the cylindrical portion 6c is configured such that the restricting member 6c contacts each of the plurality of permanent magnets 5. 6a
Are formed around the periphery. The regulating member 6c is
The positioning of the permanent magnet 5 is performed with the permanent magnet 5 interposed therebetween. Therefore, the regulating member 6c of this embodiment is
In order to improve the assemblability of the permanent magnet 5, the regulating member 6
The tip of c is rounded.

A liquid adhesive for adhering the permanent magnet 5 and the iron bowl 4 is dropped on the upper portion of the flange 6b in a later step. At this time, a plurality of holes 6d are formed in the flange 6b by punching to allow the liquid adhesive to penetrate into the interface between the permanent magnet 5 and the iron bowl 4 (see FIG. 4).

After the magnet protection cover 6 is attached to the inside of the iron bowl 4 together with the permanent magnet 5, the locking piece 4c provided at the end of the iron bowl 4 is crimped inward, and the plastically deformed locking is performed. The magnet protection cover 6 is fixed to the iron bowl 4 by sandwiching the flange 6b of the magnet protection cover 6 between the tip of the piece 4c and the end face of the iron bowl 4. This fixing technique will be specifically described.

The locking piece 4c is formed by cutting the end surface of the iron bowl 4 into a substantially cylindrical shape. The shape before caulking is shown by a two-dot chain line in FIG. 2, and the shape after caulking is shown in FIG. Shown by solid line. This locking piece 4c is such that its inner end A
Is provided at a position away from the inner end B of the open end of the outer side. For this reason, even if the locking piece 4c is plastically deformed inward by winding caulking, the arc portion C formed at the inner end of the root of the locking piece 4c is formed at a position outside the permanent magnet 5 at a distance,
The arc portion C due to plastic deformation does not interfere with the permanent magnet 5. As a result, the gap D (refer to the related art) for avoiding the interference, which has been formed conventionally, is basically unnecessary.

However, also in this embodiment, a gap α having a function different from that of the prior art is provided. The void α in this embodiment
Is a chamfer for guiding when the magnet is inserted, and is provided smaller than the conventional gap D. Specifically, the conventional gap D has a gap width of about 0.5 mm and an axial dimension of about 8 mm, but the gap α in this embodiment has a slope of 0.3 /
It is provided as small as 1.5 and the axial dimension is about 1.5 mm.

(Effects of the Embodiment) In the rotor 1 of the magnet generator of this embodiment, the regulating member 6c provided integrally with the magnet protection cover 6 positions the permanent magnet 5 inside the iron bowl 4. This eliminates the need for a ring conventionally used for positioning. For this reason, the number of parts is reduced as compared with the related art, and the cost of the rotor 1 of the magnet generator can be suppressed, and as a result, the cost of the magnet generator using the rotor 1 can be suppressed.

Since the inner end A at the base of the locking piece 4c for fixing the magnet protective cover 6 to the iron bowl 4 is provided at a position away from the inner end B of the opening end of the iron bowl 4, the locking piece is provided. 4c, the arc portion C due to plastic deformation remains in the permanent magnet 5
Does not interfere with For this reason, the gap α for the purpose of avoiding interference, which has been conventionally formed, is not required, but the gap α is provided as a chamfer for magnet insertion. However, since the gap α provided in the present embodiment is a chamfer for inserting a magnet, the gap α is slightly smaller than that in the related art. As described above, since the gap α is minimized, the field magnetomotive force loss due to the gap α is reduced,
As a result, the power output of the magnet generator using the rotor 1 increases.

More specifically, the conventional gap D (gap width 0.
5 mm, axial dimension 8 mm)
As shown in FIG. 5, when the rotor 1 having the gap α (inclination 0.3 / 1.5, axial dimension 1.5 mm) of the present embodiment mounted on a magnet generator and compared, Assuming that the output of the magnet generator using the conventional rotor is 100%, the output of the magnet generator using the rotor 1 of this embodiment is 120%.
%.

(Modification) In the above embodiment, the cylindrical member 6a of the magnet protective cover 6 is cut and bent to form the regulating member 6.
Although the example in which c is formed has been described, the restricting member 6c may be formed by a projection punching process for punching the cylindrical portion 6a of the magnet protection cover 6 outward.

In the above embodiment, an example was shown in which the locking piece 4c was formed in a cylindrical shape on the end face of the iron bowl 4, and was wound and caulked to fix the magnet protective cover 6 to the iron bowl 4. As shown by the dashed line in FIG. 6, the locking piece 4c is formed by undercut on the end surface of the iron bowl 4, and the locking piece 4c is press-caulked as shown by the solid line in FIG. 7, the locking piece 4c may be formed by cutting and bending the end surface of the iron bowl 4, and the magnet protection cover 6 may be bent by bending the locking piece 4c. 4 may be fixed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rotor (Example).

FIG. 2 is a sectional view showing an open end of an iron bowl (Example).

FIG. 3 is a sectional view of a magnet protection cover (Example).

FIG. 4 is a bottom view of the magnet protection cover (Example).

FIG. 5 is a graph showing the relationship between the volume of a gap and the output of a magnet generator (Example).

FIG. 6 is a sectional view showing an open end of an iron bowl (modification).

FIG. 7 is a sectional view showing an open end of an iron bowl (modification).

FIG. 8 is a sectional view of a rotor (conventional example).

[Explanation of symbols]

 Reference Signs List 1 rotor of magnet generator 4 iron bowl 4c locking piece 5 permanent magnet 6 magnet protection cover 6c regulating member A inner end of root of locking piece B inner end of open end of iron bowl α gap

Claims (3)

[Claims] 1. An iron bowl driven to rotate, a permanent magnet arranged in the iron bowl, and arranged inside the permanent magnet and fixed to the iron bowl at an opening end side of the iron bowl. A magnet protection cover having an annular shape having a substantially L-shaped cross section, wherein the magnet protection cover integrally includes a regulating member that regulates movement of the permanent magnet to the back of the iron bowl. A rotor of a magnet generator, comprising: 2. The rotor of a magnet generator according to claim 1, wherein said magnet protection cover is made of a thin plate made of metal, and said regulating member is provided by metal working. 3. The rotor of the magnet generator according to claim 1, wherein said iron bowl is integrally provided with a locking piece for fixing said magnet protection cover by plastic deformation at an open end thereof. The rotor of the magnet generator, wherein the inner end of the base of the piece is provided at a position outwardly distant from the inner end of the open end of the iron bowl.