JP2001231189A - Structure for securing magnet cover of electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for securing a magnet cover in which the yield of material can be increased while reducing the labor for machining. SOLUTION: An extremely thin aluminum plate is used as a magnet cover 4 for protecting a magnet 2 and the entire surface of the magnet cover 4 is enlarged and applied tightly and entirely to the inner circumferential surface of the magnet 2 and a magnet holder 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a magnet cover of a rotating electric machine.

[0002]

2. Description of the Related Art FIG. 13 is a sectional front view showing a conventional magnet type DC motor disclosed in, for example, JP-A-64-5343. FIG. 14 is a partially cut-away view showing a stator of the motor. It is a chipping side view. Such a conventional DC motor is used as a starter motor of an automobile. The DC motor includes a stator 11, an armature 13 having a commutator 12, a gear case 14, an end bracket 15, a pinion clutch 16, and a switch. 17 and the like.

[0003] The stator 11 has an auxiliary pole 19 and a permanent magnet (main magnetic pole) 20 corresponding to the set number of magnetic poles arranged side by side at appropriate intervals in the circumferential direction on the inner periphery of a yoke 18 made of a tubular steel plate. . Further, as shown in FIG. 14, a magnetic pole 21 is formed by the auxiliary pole 19 and the permanent magnet 20, and the magnetic pole 21 is fixed to the inner periphery of the yoke 18 as follows. That is, the holding brackets 22 having a U-shaped cross section, which are stamped and formed using an elastic member in advance, are fixedly arranged at equal intervals on the inner periphery of the yoke 18 in accordance with the number of magnetic poles. This fixing means may use a tack,
The holding member 22 may be fixed by providing a fixing portion on the yoke 18 itself.

[0004] Next, the auxiliary pole 19 and the permanent magnet 20 formed of mild steel are press-fitted between the holding fittings 22 with their axial end faces, for example, the faces on the commutator 12 side coincide. here,
Axial side surfaces (side surfaces extending in the axial direction) 19c and 20c of the auxiliary pole 19 and the permanent magnet 20 are formed in advance so as to face the center O of the yoke 18, and are designed so that both surfaces 19c and 20c are in close contact with each other. is there. Further, the holding bracket 22 is also formed in a substantially U-shape in advance, so that the auxiliary pole 19 and the permanent magnet 2 are formed.
0 is pressed so as to be located at a predetermined magnetic neutral point irrespective of the variation in the crossing of the component dimensions.
Magnetic poles (combination of auxiliary poles and permanent magnets) 21
Is pressed and fixed. The auxiliary pole 19 and the permanent magnet 2
0 indicates that the permanent magnet 20 is formed in an arc shape so as to conform to the inner periphery of the yoke 18 in advance, and the permanent magnet 20 is provided with chamfers 20a and 20b on the inner periphery at both ends in the axial direction.

Next, a magnetic pole cover 2 is provided on the inner peripheral side of the magnetic pole 21.
3 is arranged as follows. The magnetic pole cover 23 is, for example, a cylindrical portion 2 formed of a steel plate having a thickness of 0.15 to 0.3 mm.
3a and a flange 23b integrally formed by pressing at one end of the cylindrical portion 23a. The outer diameter of the flange 23b is set smaller than the inner diameter of the yoke 18 in advance.
The outer diameter of 3a is formed so that it can be inserted into the inner periphery of the magnetic pole 21. And when arranging the magnetic pole cover 23,
The cylindrical portion 23a is inserted from the opening side of the yoke 18 into the inner circumference of the magnetic pole 21 already held by the holding fitting 22 on the inner circumference of the yoke 18. This insertion is performed by the flange 2 of the magnetic pole cover 23.
3b until it abuts against the end face of the magnetic pole 21. In this way, the cylindrical portion 23a is inserted into the magnetic pole 21 with a stop fit.

Thereafter, a tubular elastic body (not shown) such as rubber is inserted into the inner periphery of the tubular section 23a, and the tubular elastic body is deformed under pressure to make it tightly contact the tubular section 23a. The cylindrical elastic body is pressurized so that the cylindrical portion 23a of the magnetic pole cover 23 is
At the same time, the cylindrical portion 2 is forced into the holding fitting installation space S between the magnetic poles 21 by the pressing force of the cylindrical elastic body.
3a is press-fitted and deformed so that a portion 23c of the cylindrical portion 23a projects toward the space S. Due to such plastic deformation of the magnetic pole cover 23, the magnetic pole cover 23 surrounds the inner periphery of the magnetic pole 21 while the magnetic pole 21 is formed. It is fastened and fixed to the inner periphery of the yoke 18.

This process is continued, and the magnetic pole cover 23
Is pressurized from the inside, thereby forming the chamfered portion 2 of the permanent magnet 21.
The magnetic pole cover 23 also deforms and adheres to 0a and 20b, and the cylindrical end 23d of the magnetic pole cover 23 deforms larger than the inner diameter of the magnetic pole 21 and stops at the plastically deformed portion. Also, by pressing the part 23e of the flange part 23b from the inner periphery, the part 23e of the flange is forcibly plastically deformed and cut into the concave part 24 (a groove or a knurl) provided in the yoke 18. Thereby, the magnetic pole cover 23 and the yoke 18 can be firmly fixed.

Another conventional example is disclosed in Japanese Patent Laid-Open No. 8-16 / 1996.
As shown in Japanese Patent No. 3800, FIGS. 15 to 17 show an example in which a thin metal plate is used as a magnet cover.
Shown in In the figure, 30 is a stator, 31 is a yoke, 3
2 is a magnet and 33 is a magnet cover. The magnet cover 33 has a U-shaped one end in the circumferential direction like 33a. When the magnet cover 33 is incorporated into the inner peripheral surface of the magnet 32, the magnet cover 33 is rolled and inserted, and the other end 33b is connected to the U-shape. It is structured to be inserted into the shape part 33a.

[0009]

The magnet structure of a conventional rotating electric machine is constructed as described above.
In the magnet cover disclosed in JP-A-4-5343,
When a thin plate is formed, trimming and punching are required, so that an extra material is required, and there has been a problem that the material yield is deteriorated. Also, to improve motor performance,
The clearance between the magnet and the rotor needs to be reduced to some extent, and for that purpose, an ultra-thin plate must be used for the magnet cover. However, in molding, low-cost materials such as aluminum are not suitable for molding and handling because of low strength.

Also, in the magnet cover disclosed in Japanese Patent Application Laid-Open No. 8-163800, since one end portion needs to be formed in a U-shape, there is a problem that complicated man-hours such as bending increase. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made to improve the yield of materials,
An object of the present invention is to provide a magnet cover fixing structure that can use a low-cost ultra-thin plate material and can reduce the number of processing steps.

[0012]

According to a first aspect of the present invention, a magnet cover fixing structure for a rotating electric machine uses an extremely thin aluminum plate as a magnet cover for protecting a magnet.

According to a second aspect of the present invention, the magnet cover fixing structure for a rotating electric machine is such that the entire surface of the magnet cover is expanded.

According to a third aspect of the present invention, there is provided a magnet cover fixing structure for a rotating electric machine in which a magnet cover is brought into close contact with the entire inner surface of a magnet and a magnet holder by expanding a pipe.

According to a fourth aspect of the present invention, there is provided a magnet cover fixing structure for a rotary electric machine, wherein an aluminum plate serving as a magnet cover is formed into a pipe shape by ultrasonic welding.

According to a fifth aspect of the present invention, there is provided a magnet cover fixing structure for a rotating electric machine, comprising: a ring portion provided at both ends facing each other; and a magnet holder having a plurality of connecting portions connecting the two ring portions. A stopper is provided inside one connecting portion for positioning both ends of the magnet cover.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a magnet cover fixing structure of a rotating electric machine according to an embodiment of the present invention, and FIG. 2 is a front sectional view of the same. In the figure, 1 is a yoke, 2 is a magnet arranged on the inner periphery of the yoke 1, 3 is a magnet holder for incorporating and holding the magnet 2, and 4 is a magnet cover inserted into the inner periphery of the magnet 2. FIG. 3 is a perspective view showing the magnet holder 3, and FIG. 4 is a perspective view showing the magnet cover 4. Here, chamfers 2a and 2b are provided on the inner peripheral surfaces of both ends in the axial direction of the magnet 2. As shown in FIG. 3, the magnet holder 3 includes opposed ring portions 3a and 3b disposed at both ends, and the ring portions 3a and 3b.
a, 3b, four connecting parts 3c, 3d, 3e,
3f, and all of these connecting portions 3c to 3c
A concave groove 3g is formed inside f.

As shown in FIG. 4, the magnet cover 4 is formed by rolling an aluminum ultra-thin plate material having a thickness of about 0.1 mm and joining both ends by ultrasonic welding to form a pipe. still,
The welding may be laser, resistance welding, or the like, and the joint 4a may be overlapped or butted.

In assembling, the magnet cover 4 and the magnet 2 are assembled into the magnet holder 3 and pressed into the yoke 1. Alternatively, the magnet cover 4 may be inserted after the magnet 2 alone is assembled into the magnet holder 3 and pressed into the yoke 1. Thereafter, a cylindrical elastic body (not shown) is inserted into the inside of the magnet cover 4 to compress the elastic body and push and expand the entire surface of the magnet cover 4 so that the inner periphery of the magnet 2, the entire chamfers 2a and 2b, the magnet The holder 3 is brought into close contact with the inner periphery of the ring portions 3a and 3b and the concave groove 3g inside the connecting portion. As means for expanding the magnet cover, means such as fluid force and air pressure may be used.

In the stator configured as described above, since the magnet cover 4 is formed by joining plates of a required length by ultrasonic welding to form a pipe, there is almost no waste of material and ultrasonic welding is performed. By doing so, it is possible to use an ultra-thin aluminum material, which was difficult to manufacture and handle in molding, so that the material and processing costs can be reduced. Ultrasonic welding generates less heat than laser, resistance, etc. welding, so it is suitable for heat-sensitive thin aluminum materials and has higher welding strength than other welding. Because of the tendency, peeling of the welded portion due to pipe expansion and reduction in strength are reduced. Also, since the aluminum material is easily plastically deformed, the entire surface of the magnet 2 is brought into close contact with the magnet 2 by expanding the entire surface of the magnet cover 4. For this reason, floating of the magnet cover 4 is less likely to occur, and contact with the rotor during rotation of the motor can be prevented.

Also, even if the magnet cover 4 is slightly deformed by handling before being assembled, the magnet cover 4
Since the entire surface is expanded, the deformed portion can be corrected regardless of the deformation location. Although the aluminum material is used for the magnet cover 4 in this embodiment, the deformed portion can be corrected by using a thin copper plate, for example, stainless steel.

Further, the connecting portions 3c to 3c of the magnet holder 3
By providing the concave groove 3g inside 3f, when the entire magnet cover 4 is expanded, as shown in FIG. 5, the magnet cover 4 cuts into the concave groove 3g and comes into close contact therewith. For this reason, it is possible to prevent the magnet cover 4 from rotating and falling off due to vibration or impact.

When the magnet 2 is press-fitted, a compressive force F is applied to the connecting portions 3c to 3f of the magnet holder 3 as shown in FIG. 6, so that the connecting portions 3c to 3f are formed as shown in FIG. May deform inward. As a result, the position of the magnet 2 may be displaced or the holding force may be reduced. However, as shown in FIG. 8, the deformed portions of the connecting portions 3c to 3f can be pushed outward by the entire pipe expansion and corrected. Therefore, the positional accuracy and holding force of the magnet 2 are improved.

As described above, the material yield can be improved by forming the magnet cover 4 into an extremely thin pipe shape by ultrasonic welding. Also, as the magnet cover 4,
By using a pipe obtained by ultrasonically welding an ultra-thin aluminum material, material and processing costs can be reduced. Since ultrasonic welding generates a small amount of heat, it is suitable for heat-sensitive thin aluminum materials, and has a high welding strength, so that peeling of the welded portion due to pipe expansion and a decrease in strength are reduced.

Further, by using an ultra-thin aluminum material as the magnet cover 4 and expanding the entire surface of the magnet cover 4, the magnet cover 4 comes into close contact with the entire surface of the magnet 2 and the floating of the magnet cover 4 is eliminated. Thereby, contact with the rotor can be prevented. or,
The deformation of the magnet cover 4 can be corrected by using an extremely thin aluminum material as the magnet cover 4 and expanding the entire surface of the magnet cover 4.

Further, by expanding the entire surface, the deformation of the connecting portions 3c to 3f of the magnet holder 3 toward the inner diameter side can be corrected, so that the positional accuracy and the holding force of the magnet 2 are improved. Further, by providing the concave groove 3g inside the connecting portions 3c to 3f of the magnet holder 3, the magnet cover 4 bites into the concave portion 3g by the entire tube expansion and adheres closely, so that the adhesion force of the magnet cover 4 is improved, and the vibration is improved. Rotation and falling off due to impact, etc. can be prevented. Further, by using an extremely thin metal plate as the magnet cover 4, the number of processing steps can be reduced and the cost can be reduced.

Embodiment 2 FIG. FIG. 9 is a front sectional view showing a structure for fixing a magnet cover of a rotary electric machine according to Embodiment 2 of the present invention. In the drawing, the inside of any one of connecting portions 3c to 3f of magnet holder 3 is located at the center. The projection 5 is formed. The magnet cover 4 is made of aluminum,
A very thin metal plate such as stainless steel is used. Assembling, magnet holder 3 magnet 2
And press-fit into the yoke 1. Thereafter, as shown in FIG. 10, the magnet cover 4 is rolled and inserted so that both end portions 6a and 6b of the magnet cover 4 are located at the positions of both end surfaces 5a and 5b of the protrusion 5 of the magnet holder 3, respectively. Expansion is performed in the same manner as in 1.

In the stator configured as described above, since the magnet cover 4 has a plate shape, the number of processing steps is reduced. For example, since it is only necessary to cut the roll material into a predetermined length, the processing cost can be reduced. Further, since the projections 5 are provided on the magnet holder 3 to serve as stoppers at both ends 6a and 6b of the magnet cover 4, the rotation of the magnet cover due to vibration or impact can be prevented.

The shape of the stopper may be a T-shape 7 as shown in FIG. As shown in FIG. 12, a T-shape 7 and two slots 8a, 8b are provided, and both ends 6a, 6 of the magnet cover 4 are inserted into the slots 8a, 8b.
It is good also as a structure which bends b by expanding a pipe and sinks.

[0030]

According to the magnet cover fixing structure of the rotating electric machine according to the first aspect of the present invention, since the extremely thin aluminum plate is used as the magnet cover for protecting the magnet, the material yield of the magnet cover is improved. Thus, material costs can be reduced.

According to the magnet cover fixing structure of the rotating electric machine according to the second aspect of the present invention, since the entire surface of the magnet cover is expanded, the deformation of the magnet cover can be corrected, and the positional accuracy and holding force of the magnet are improved. be able to.

According to the magnet cover fixing structure for the rotating electric machine according to the third aspect of the present invention, the magnet cover is brought into close contact with the entire inner surface of the magnet and the magnet holder by expanding the pipe, so that the floating of the magnet cover is reduced and the rotor is reduced. Contact can be prevented.

According to the magnet cover fixing structure of the rotating electric machine according to the fourth aspect of the present invention, since the aluminum plate as the magnet cover is formed into a pipe shape by ultrasonic welding, the material and the processing cost can be reduced. . In addition, since the heat generated by welding is small, it is suitable for thin aluminum materials that are vulnerable to heat.
Peeling of the welded portion and reduction in strength due to expansion are reduced.

According to the magnet cover fixing structure for a rotary electric machine according to the fifth aspect of the present invention, a magnet holder having a ring portion provided opposite to both ends and a plurality of connecting portions for connecting the two ring portions. And a stopper for positioning both ends of the magnet cover is provided inside one connecting portion, so that rotation and falling off of the magnet cover can be prevented.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a stator structure of a rotating electric machine according to Embodiment 1 of the present invention.

FIG. 2 is a front sectional view showing a stator structure of the rotary electric machine according to Embodiment 1 of the present invention;

FIG. 3 is a perspective view showing a magnet holder according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a magnet cover according to Embodiment 1 of the present invention.

FIG. 5 is a partial sectional view showing a magnet cover fixing structure according to the first embodiment of the present invention.

FIG. 6 is a partial side view showing a magnet fixing structure according to the first embodiment of the present invention.

FIG. 7 is a partial side sectional view showing a magnet fixing structure according to the first embodiment of the present invention.

FIG. 8 is a partial side sectional view showing a magnet fixing structure according to the first embodiment of the present invention.

FIG. 9 is a front sectional view showing a stator structure of a rotary electric machine according to Embodiment 2 of the present invention;

FIG. 10 is a partial side view showing a structure for fixing a magnet cover of a rotary electric machine according to Embodiment 2 of the present invention;

FIG. 11 is a partial cross-sectional view illustrating a magnecover fixed structure of a rotary electric machine according to Embodiment 2 of the present invention;

FIG. 12 is a partial cross-sectional view showing a structure for fixing a magnet cover of a rotary electric machine according to Embodiment 2 of the present invention;

FIG. 13 is a sectional front view showing a conventional electric motor.

FIG. 14 is a partial side view showing a conventional electric motor.

FIG. 15 is a side sectional view showing a conventional stator.

FIG. 16 is a sectional view showing a conventional stator.

FIG. 17 is a perspective view showing a conventional butting portion.

[Explanation of symbols]

1 yoke, 2 magnets, 3 magnet holders,
3a, 3b ring portion, 3c-3f connecting portion, 3g concave groove, 4 magnet cover.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Keiichi Uehara, Inventor 2-6-1, Otemachi, Chiyoda-ku, Tokyo Mitsubishi Electric Engineering Co., Ltd. (72) Shuichi Tamura 2-6-1, Otemachi, Chiyoda-ku, Tokyo No. 2 Mitsubishi Electric Engineering Co., Ltd. (72) Inventor Hirohisa Enoda 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Tokyo Mitsui Electric Co., Ltd. (72) Hisao Tezuka 2-2-2 Marunouchi, Chiyoda-ku, Tokyo No.3 Mitsubishi Electric Corporation F-term (reference) 5H622 CA02 CA05 CA13 PP03 PP17 PP18 5H623 AA10 BB07 GG13 GG16 GG23 JJ03 JJ06 LL05 LL08

Claims (5)

[Claims] 1. A rotating electric machine for fixing a magnet on an inner periphery of a yoke, wherein an ultra-thin aluminum plate is used as a magnet cover for protecting the magnet. 2. The magnet cover fixing structure for a rotating electric machine according to claim 1, wherein the entire surface of the magnet cover is expanded. 3. The magnet cover fixing structure for a rotating electric machine according to claim 2, wherein the magnet cover is brought into close contact with the entire inner peripheral surface of the magnet by expanding the pipe. 4. The magnet cover fixing structure for a rotating electric machine according to claim 1, wherein the magnet cover is formed in a pipe shape by ultrasonic welding an aluminum plate. 5. A ring portion provided opposite to both ends,
A magnet holder having a plurality of connecting portions for connecting the two ring portions is provided, and a stopper for positioning both ends of the magnet cover is provided inside one connecting portion. The structure for fixing the magnet cover of the rotating electric machine according to claim 3.