JP2002176740A - Yoke of rotary electric machine and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yoke of rotary electric machine which assures easier molding process and reduces the manufacturing cost. SOLUTION: A cylindrical portion 11 of the yoke 10 is provided with a folding-back portion 14 which is folded externally from its opening end portion 13 and is closely in contact with the external circumferential surface of the opening end portion 13. The folding-back portion 14 is provided to be in the close contact with the external circumferential surface of the cylindrical portion 11 to a magnet loading portion 11a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yoke for a rotary electric machine, and more particularly to a method of manufacturing a yoke for locally increasing the thickness of a yoke magnet mounting portion.

[0002]

2. Description of the Related Art Generally, in a motor yoke, it is necessary to increase the thickness of a magnet mounting portion in order to improve the magnetic characteristics of a motor. One of the methods is
A manufacturing method is possible in which the yoke is formed using a plate material with the same thickness as the required thickness for the magnetic characteristics of the magnet mounting part.However, since a thick material is used, the parts other than the magnet mounting part also become thick. The weight of the entire yoke is increased. This has been a problem in reducing the weight of the motor.

Therefore, conventionally, the thickness of the yoke cylindrical portion including the magnet mounting portion is increased by thickening drawing shown in FIG. 3, or the yoke cylindrical portion in the magnet mounting portion of the yoke shown in FIG. A method of covering another part processed into a ring shape was used.

More specifically, in the thick drawing, as shown in FIG. 3A, first, a rough yoke material 33 having a cylindrical portion 32 having a larger diameter than the cylindrical portion of the finished yoke is subjected to deep drawing. Process. Thereafter, as shown in the right half of FIG. 3 (b), the cylindrical portion 32 of the yoke coarse material 33 is subjected to circumferential compression processing many times until it has the same diameter as the cylindrical portion of the finished yoke.
Then, by the compression processing, the cylindrical portion 3 of the yoke coarse material 33 is formed.
As shown in the left half of FIG. 3 (b), 2 is formed into the cylindrical portion 31 of the finished yoke 30, and the thickness of the cylindrical portion 31 including the magnet mounting portion 34 is increased.

On the other hand, in the method shown in FIG.
A yoke cylinder 41 having a predetermined shape is formed from a thin plate material. Thereafter, the yoke cylinder 41 for mounting the magnet M, which has an inner diameter equal to the outer diameter of the yoke cylinder 41, is prepared in advance.
An iron ring-shaped member 43 having the same height as the magnet mounting portion 42 is attached so as to cover the outer peripheral surface 40a of the yoke cylindrical portion 41. Then, the thickness of the yoke 40 in the magnet mounting portion 42 on the magnetic characteristics is increased.

[0006]

By the way, the increase in the thickness of the magnet mounting portion 34 due to the thickening drawing has a limit due to the compression working. Generally, the material thickness is 1.3 to
The increase is only 1.5 times, which does not reach the expected increase in the thickness of the magnetic properties, and the number of compression processes is required. Was.

In the method shown in FIG. 4, the thickness of the magnet mounting portion 42 can be increased twice or more than the thickness of the plate material in terms of magnetic characteristics. However, the yoke 40 is made of two parts. As the number of parts increases, it becomes necessary to assemble two parts, leading to an increase in the cost of the motor, which is a problem.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a yoke for a rotating electrical machine and a method for manufacturing the same, which can facilitate molding and reduce manufacturing costs. It is in.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an invention according to claim 1 is provided for mounting a magnet on an inner surface of a cylindrical portion having an open end and a bottomed cylindrical shape. In the yoke of the rotating electric machine provided with the magnet mounting portion, the folded portion formed by bending the end portion of the opening end of the cylindrical portion in parallel with the axis of the cylindrical portion is in close contact with the outer surface of the magnet mounting portion. It is the gist that it is formed.

According to a second aspect of the present invention, there is provided a yoke for a rotary electric machine, wherein a magnet mounting portion for mounting a magnet is provided on an inner surface of a cylindrical portion having an open end and a bottomed cylindrical shape. A gist is formed on the outer surface of the magnet mounting portion so as to be folded from the end of the opening end of the cylindrical portion in parallel with the axis of the cylindrical portion so as to be in close contact with the magnet mounting portion. And

[0011] The invention according to claim 3 is the invention according to claim 1 or 2.
In the yoke of the rotating electric machine described in the above, the length of the folded portion is equal to or larger than the axial distance from the lower end surface of the magnet mounted on the magnet mounting portion to the end of the open end. The gist is that it is formed in.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a yoke for a rotating electric machine, wherein a magnet mounting portion for mounting a magnet is provided on an inner surface of a cylindrical portion having an open end and a bottomed cylindrical shape. A first forming step of forming a cylindrical portion having a flange portion at an open end of the cylindrical portion, and a second forming step of forming a folded portion by bending the flange portion.
And a third forming step of bringing the folded portion into close contact with the outer surface of the cylindrical portion.

(Operation) According to the first aspect of the present invention,
On the outer surface of the magnet mounting portion, a folded portion formed by bending from the end of the opening end of the cylindrical portion in parallel with the axis of the cylindrical portion is formed in close contact. Therefore, the plate thickness of the magnet mounting portion on which the folded portion is formed in close contact is increased. as a result,
The magnetic characteristics of the motor can be improved. In addition, the rigidity of the open end portion of the cylindrical portion having the folded portion closely formed can be improved.

According to the second aspect of the present invention, on the outer surface of the magnet mounting portion, a folded portion formed by bending the end of the opening end of the cylindrical portion in parallel with the axis of the cylindrical portion is provided on the magnet mounting portion. It is formed in close contact over the entire surface. Therefore, the thickness of the magnet mounting portion is the same as that of the other portion of the cylindrical portion.
Therefore, the magnetic characteristics of the motor can be reliably improved.

According to the invention described in claim 3, according to claim 1 of the present invention,
In addition to the effects of the inventions described in (2) and (3), since the folded portion is formed by completely covering the magnet mounting portion,
It is possible to reliably improve the magnetic characteristics of the motor.

According to the fourth aspect of the present invention, the magnet mounting portion can be thickened by forming the folded portion using the flange portion formed in the deep drawing forming for forming the cylindrical portion. As a result, the yoke for increasing the thickness of the magnet mounting portion can be easily formed, and the manufacturing man-hour and cost of the yoke can be reliably reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a motor as a rotating electric machine will be described below with reference to FIGS. FIG. 1 is a sectional view of a yoke of the motor according to the present embodiment. FIG. 2 is a cross-sectional view showing a method of forming the yoke of the motor shown in FIG.

As shown in FIG. 1, a yoke 10 of a motor according to the present embodiment is formed of an iron plate into a bottomed cylindrical shape, and has a circular cylindrical portion 11 having one open end and a second end of the cylindrical portion 11. And a bottom portion 12 for sealing.

The cylindrical portion 11 is folded outward from its open end 13 to form a folded portion 14 which is in close contact with the outer peripheral surface of the open end 13 as the outer surface of the cylindrical portion 11.
The folded portion 14 is formed to have substantially the same length as the axial length of the magnet mounting portion 11a for mounting the magnet 15 on the inner peripheral surface as the inner surface of the cylindrical portion 11 at the opening end 13. That is, the folded portion 14 is provided so as to be in close contact with the outer peripheral surface of the cylindrical portion 11 over the magnet mounting portion 11a. In the present embodiment, as shown in FIG. 1, the length H of the folded portion 14 is different from the length of the cylindrical portion 11.
Is equal to the axial distance h from the lower end surface 15a of the magnet 15 mounted on the inner peripheral surface of the magnet 15 to the end of the opening end 13 (H
= H).

The bottom 12 is formed in a two-stage bulge shape. The yoke 10 of the present embodiment forms the cylindrical portion 11 and the bottom portion 12 while simultaneously forming the folded portion 14.
A first forming step of forming a flange portion 16 for forming the first portion, a second forming step of forming a folded portion 14 by bending the flange portion 16, and a second forming step of forming a folded portion 14.
4 is brought into close contact with the cylindrical portion 11 and is manufactured through a third molding step. Hereinafter, a method of manufacturing the yoke 10 will be described following each molding step.

[First Forming Step] In this forming step, as shown in FIG. 2A, a first die 21 having a concave portion 20 having the same shape as the outer shape of the cylindrical portion 11 is formed. The iron thin plate material is deep drawn using the first drawing punch 22 having the same outer shape as the inner shape of the portion 11. Then, through a multi-stage deep drawing process, a coarse material of the yoke 10 having the circular cylindrical portion 11 and the two-stage bulge-shaped bottom portion 12 and the flange portion 16 is formed.

[Second Forming Step] In this forming step, the coarse material of the yoke 10 formed in the first forming step is placed on a second die 23 shown in FIG. The flange portion 16 is connected to the cylindrical portion 11 by the second bending punch 24.
Bend parallel to the axis of. By this step, the folded portion 14 is formed.

[Third Forming Step] Finally, as shown in FIG. 2C, the yoke 10 on which the folded portion 14 is formed is formed.
In a state where the rough material is sandwiched between the third die 25 and the first drawing punch 22, the folded portion 14 is pressed and formed by the third punch 26 so as to be in close contact with the outer peripheral surface of the cylindrical portion 11. At this time, the folded portion 14 is brought into close contact with the outer peripheral surface of the cylindrical portion 11 over the magnet mounting portion 11a.

Next, the features of the above-described yoke 10 and its manufacturing method will be described. (1) In the present embodiment, the cylindrical portion 11 of the yoke 10 is folded outward from the open end 13 and the folded portion 14 that is in close contact with the outer peripheral surface of the open end 13 is formed in close contact with the magnet mounting portion 11a. Have been.

Accordingly, the thickness of the magnet mounting portion 11a formed by the opening end 13 and the folded portion 14 closely contacting the outer peripheral surface of the opening end 13 is twice as large as that of the other portion of the cylindrical portion 11. Therefore, the magnetic characteristics of the motor can be improved.

Further, it is possible to improve the rigidity of the open end 13 of the cylindrical portion 11 where the folded portion 14 is formed in close contact. (2) In the present embodiment, the length H of the folded portion 14 is equal to the lower end surface 1 of the magnet 15 mounted on the inner peripheral surface of the cylindrical portion 11.
It is set to be the same as the axial distance h from 5a to the end of the open end 13 (H = h).

Therefore, since the folded portion 14 is formed by completely covering the magnet mounting portion 11a, it is possible to reliably improve the magnetic characteristics of the motor. (3) In the present embodiment, the yoke 10 forms the cylindrical portion 11 and the bottom portion 12 and, at the same time, forms a flange portion 16 for forming the folded portion 14, and bends the flange portion 16. A second forming step of forming the folded portion 14 by causing the folded portion 14 to
1 and a third molding step of making it closely adhere to the substrate.

Therefore, the magnet mounting portion 11a can be made thicker by forming the folded portion 14 using the flange portion 16 formed in the deep drawing forming of the cylindrical portion 11 and the bottom portion 12. As a result, the yoke 10 for increasing the thickness of the magnet mounting portion 11a can be easily formed, and the number of manufacturing steps and cost of the yoke 10 can be reliably reduced.

The embodiment of the present invention may be modified as follows. In the above embodiment, the cylinder 11 is formed in a circular shape. However, the cylinder 11 may be formed in a shape other than a circle, for example, a square or an ellipse. In this case, the same effect as in the above embodiment can be obtained.

In the above embodiment, the length H of the folded portion 14 is determined by the magnet 15 mounted on the inner peripheral surface of the cylindrical portion 11.
The length H of the folded portion 14 is set to be the same as the axial distance h (H = h) from the lower end surface 15a to the end of the opening end 13. The configuration may be such that the axial distance h from the lower end surface 15a of the magnet 15 mounted on the peripheral surface to the end of the opening end 13 is slightly larger (that is, H> h).
In this case, the same effect as in the above embodiment can be obtained.

The bottom 12 may be formed in a shape other than the two-stage bulge shape. In the above embodiment, the present invention is embodied in the yoke 10 of the motor, but may be embodied in another rotating electric machine other than the motor.

[0032]

As described in detail above, according to the first and second aspects of the present invention, the magnetic characteristics of the motor can be improved.

According to the invention described in claim 3, according to claim 1
In addition to the effects of the inventions described in (1) and (2), the magnetic characteristics of the motor can be reliably improved. According to the fourth aspect of the present invention, the yoke for increasing the thickness of the magnet mounting portion can be easily formed, and the number of man-hours and cost for manufacturing the yoke can be reliably reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a motor yoke according to an embodiment.

FIG. 2 is a sectional view showing a method of manufacturing the motor yoke.

FIG. 3 is a sectional view of a main part of a conventional motor yoke.

FIG. 4 is a cross-sectional view showing a conventional method for manufacturing a motor yoke.

[Explanation of symbols]

10: yoke of motor as rotating electric machine, 11: cylindrical part,
11a: magnet mounting portion, 13: open end, 14: folded portion, 15: magnet, 16: flange portion.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H002 AA07 AB06 AC04 AE08 5H615 AA01 BB01 BB14 PP01 PP07 PP28 SS02 SS03 SS18 SS19 TT05 5H622 CA02 CA05 CA10 CA12 CB05 PP05 PP19

Claims (4)

[Claims] 1. A yoke for a rotary electric machine having a magnet mounting part (11a) for mounting a magnet (15) on an inner surface of a cylindrical part (11) having an open end and a bottomed cylindrical shape. In the outer surface of the magnet mounting part (11a), a folded part (14) formed by bending the end of the open end (13) of the cylindrical part (11) in parallel with the axis of the cylindrical part (11). A yoke for a rotating electric machine, wherein the yoke is formed in close contact. 2. A yoke for a rotary electric machine having a magnet mounting portion (11a) for mounting a magnet (15) on an inner surface of a cylindrical portion (11) having an open end and a bottomed cylindrical shape. In the outer surface of the magnet mounting part (11a), a folded part (14) formed by bending the end of the open end (13) of the cylindrical part (11) in parallel with the axis of the cylindrical part (11). A yoke for a rotating electrical machine, wherein the yoke is formed in close contact with the magnet mounting portion (11a). 3. The yoke for a rotating electrical machine according to claim 1, wherein the folded portion has a length (H) which is attached to the magnet attaching portion.
A yoke for a rotary electric machine, wherein the yoke is formed to be equal to or larger than an axial distance (h) from a lower end surface (15a) of (5) to an end of the opening end (13). 4. A yoke for a rotary electric machine having a magnet mounting portion (11a) for mounting a magnet (15) on an inner surface of a cylindrical portion (11) having an open end and a bottomed cylindrical shape. In the manufacturing method of (1), a flange portion (1) is
A first forming step of forming a cylindrical portion (11) having 6); a second forming step of forming a folded portion (14) by bending the flange portion (16); and the folded portion (14). And a third forming step of closely adhering the outer surface of the cylindrical portion (11).