JP3216729B2 - Manufacturing method of laminated core - 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 of manufacturing a laminated iron core, and more particularly to a method of manufacturing a laminated iron core that forms a rotor piece by utilizing an inner diameter region of a stator piece where a rotor receiving hole is formed. It is.

[0002]

2. Description of the Related Art For example, a laminated iron core such as a stator A or a rotor B as shown in FIG. 8 which constitutes a stepping motor is made of an iron core piece (a stator piece and a rotor) having a predetermined shape formed by punching a band-shaped material. Pieces) in order,
It is manufactured by fixing to each other by means such as caulking.

[0003]

By the way, when manufacturing the laminated iron cores such as the stator A and the rotor B, the rotor piece is formed by utilizing the inner diameter region of the stator piece where the rotor accommodation hole is formed. A method of forming by punching is conceivable.

[0004] However, as shown in FIG.
The air gap a between the inner circumference of the rotor and the outer circumference of the rotor B is set to be extremely small, about 0.02 mm. Has only a very small width corresponding to the air gap a.

As a result, when the inner peripheral edge portion of the stator piece is punched to form a rotor receiving hole having a predetermined shape in the stator piece, the punched waste should have a thin ring shape corresponding to an air gap. Because it is extremely thin, it breaks at multiple locations, and the punched waste jumps out to the surface of the material without being dropped into the lower mold, causing so-called waste rise, which causes inconveniences such as product defects such as dimples. there were.

In order to solve the above-mentioned inconvenience, a manufacturing method in which a rotor piece and a stator piece are stamped and formed from separate strip-shaped materials by using separate mold apparatuses has been adopted. In order to manufacture a stator and a rotor in one type of stepping motor, not only two mold units and a press machine are required, but also the yield of materials is low, which leads to an increase in manufacturing costs. Was.

The present invention has been made in view of the above circumstances, and has as its object to provide a method of manufacturing a laminated core that can minimize an increase in manufacturing cost.

[0008]

Therefore, in the present invention, the first invention
In the step, the rotor piece is punched out from the inner diameter region of the stator piece into a predetermined outer shape, and in the second step, the stator piece is pressed in the plate thickness direction to make the inner peripheral edge radially inward. The above object is achieved by extruding the inner peripheral edge of the stator piece in a third step into a predetermined shape over the entire circumference to form a rotor accommodation hole. Further, in the present invention, in the first step, the inner diameter region of the stator piece is punched out into a predetermined shape so as to form a rotor accommodation hole, and the rotor piece is formed. In order to achieve the above object, the outer peripheral edge portion is extruded radially outward by pressing the outer peripheral portion in a radially outward direction, and the outer peripheral edge portion of the rotor piece is punched and formed into a predetermined shape over the entire circumference in a third step. ing.

[0009]

According to the present invention, when a rotor piece is punched and formed by utilizing the inner diameter region of the stator piece where the rotor receiving hole is formed, the punching width is widened. When the peripheral edge or the outer peripheral edge of the rotor piece is punched and formed, the punched scum is removed in a state where it is wide and connected in a ring shape, and occurrence of scum and the like is prevented beforehand. In other words, according to the present invention, it is possible to punch and form a rotor piece using an inner diameter region where a rotor housing hole is formed in a stator piece, and by using a single press and a mold device, The stator piece and the rotor piece can be stamped and formed from one strip material.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments. FIG. 1 shows an example in which a method of manufacturing a laminated core according to the present invention is implemented in a progressive die apparatus for manufacturing a laminated core for manufacturing a stator and a rotor of a stepping motor.

Various punches 10a, 10b, and 10c are mounted on the upper die holder 2 of the apparatus 1, and a rotor piece pulling punch 11, a coining punch 12, a tooth tip pulling punch 13, and a stator A single punch 10d is attached.

The apparatus 1 further includes a die 4 mounted via a lower die holder 3 and a stripper plate 5. The apparatus 1 includes working stations Sa, Sb, Sc in the order from the left in the figure. , A rotor piece removal station S1, a coining station S2, a tooth tip removal station S3, and a stator piece removal station Sd.

[0013] The rotor piece removal station S1 includes a lifter 6R for supporting the rotor piece and a pusher 7R for dispensing the rotor, while the stator piece removal station Sd includes a stationary piece removal station Sd. A lifter 6S for supporting the child piece and a pusher 7S for dispensing the stator are provided. Note that the appearances of the stator and the rotor manufactured by the device 1 are basically the same as those of the stator A and the rotor B shown in FIG.

The strip-shaped material 5 carried into the apparatus 1 having the above configuration
0 is sequentially fed from left to right in FIG. 1, and first, in the processing stations Sa, Sb, and Sc, a pilot hole, a swaged portion, and a center hole of a rotor piece are sequentially formed. .

Next, the strip material 50 is removed from the rotor piece 200 by the rotor piece removing punch 11 at the rotor piece removing station S1 as shown in FIG.
Is dropped (first step).

Here, as shown in FIG. 2, the rotor piece 200 is concentric with the stator piece 100 from the inner diameter region 100A where the rotor housing hole 101 is formed in the stator piece 100 and is formed on the outer periphery. The outer shape is cut into a predetermined shape having small teeth.

At this time, as is apparent from FIG. 3A, the inner peripheral edge portion 100i of the stator piece 100 after the rotor piece 200 has been pulled out, and the rotor accommodating hole 101 formed later by punching. A portion 100ia facing the tip of each of the small teeth 102 formed at the edge of the rotor accommodating hole 101 later has an extremely small width corresponding to the air gap between the stator and the rotor ( About 0.
02mm).

Next, the band-like material 50 is fed to the coining station S2 as described above.
2, the inner peripheral edge 100 of the stator piece 100
i is pressed in the thickness direction (second step).

Here, the coining punch 12 is provided with an annular punch surface, and as shown in FIG. 3 (a), the inner peripheral edge 100i, more specifically, the rotor accommodating hole 101 at the inner peripheral edge 100i. The area including the tip of each of the small teeth 102 formed at the edge of is pressed over the entire circumference, thereby reducing the thickness of the area.

As a result, the inner peripheral edge portion 100i of the stator piece 100 is extruded radially inward of the stator piece 100 as shown in FIG. 2 (third position from the left). Further, as shown in FIG. 3B, the inner peripheral edge portion 100i is extruded radially inward (to the right in the figure), so that a portion 100ia facing the tip of each of the small teeth 102 to be punched later is formed.
Has a much wider width than the air gap.

The range in which the inner peripheral edge 100i of the stator piece 100 is pressed will be described later.
3A, not only the area including the tip of each of the small teeth 102 formed at the edge portion, but also the central portion of each of the small teeth 102 formed later, that is, the coining punch 1 in FIG.
2 may be pressed on the left region, or may be pressed on the entire inner peripheral edge 100i of the edge that extends radially inward from the base of each of the small teeth 102.
By pressing the above-mentioned range, the inner peripheral edge 100i of the stator piece 100 is also pushed out from the state shown in FIG. 3A in the radially inward direction as shown in FIG.
It goes without saying that the width of the portion 100ia facing the tip of each small tooth 102 is much wider than the air gap. In place of the coining punch 12, a flat-shaped projection corresponding to the coining punch 12 may be provided on the lower surface of the stripper plate 5, and the stator piece 100 may be pressed by the projection. is there.

Next, the belt-shaped material 50 is removed from the inner peripheral edge 100i of the stator piece 100 by the tooth tip pulling punch 13 at the tooth tip removing station S3 as shown in FIG. 2 (right end). It is stamped and formed (third step).

As shown in FIG. 3C, a large number of small teeth 10
When the rotor accommodating hole 101 provided with the hole 2 is formed by punching, the inner peripheral edge portion 100i of the stator piece 100 becomes a punching waste 300 and is dropped. As described above, the width is much wider than the air gap.

In other words, in the conventional device H as shown in FIG. 4B, the width Lw of the stator piece W to be removed can be set only to the size of the air gap.
As is clear from FIG. 4 (a), in the device 1 embodying the present invention, in the above-described second step, the stator pieces 1
By pressing the inner peripheral edge portion 100i of 00, the punching width L can be made much wider than the size of the air gap.

As described above, since the narrowest portion 100ia of the punched waste 300 has a width much wider than the air gap, the punched waste 3
00 is dropped into the die 4 and the lower die holder 3 in a state of being connected in a ring shape without being inadvertently divided,
As a result, the occurrence of scraps and the like is suppressed as much as possible.

Further, in the conventional apparatus H shown in FIG. 4B, since the plate thickness Tw of the small teeth Wa in the stator piece W is large, the clearance Cw between the die D and the punch P must be set wide. Absent. For this reason, as shown in FIG. 5B, the area where the shear surface Fw is formed at the tip of the small teeth Wa is extremely narrow, and the area of the rotor facing the tip of the small teeth at the shortest distance is small. Had become.

On the other hand, in the apparatus 1 embodying the present invention shown in FIG. 4A, in the above-described second step,
Inner peripheral edge 10 of stator piece 100 including tip of small teeth 102
0i, the thickness T of the small teeth 102 is reduced.
Is thinner than the main body of the stator piece 100, so that the clearance C between the die 4 and the stator tooth tip withdrawal punch 13 can be set small.

It is well known that, for the same material, the smaller the clearance, the wider the shear surface is formed. As shown in FIG.
At the tip of the small tooth 102 at 0, a shear surface F is formed over a wide range, and the area of the rotor facing the tip of the small tooth at the shortest distance is manufactured by a conventional method. The electric characteristics of the stepping motor are greatly improved.

At the tooth tip removal station S3, the inner peripheral edge 100i of the stator piece 100
After the rotor accommodating hole 101 is formed by punching, the stator piece 100 of the strip-shaped material 50 is punched out by the stator stripping punch 10d at the stator stripping station Sd.

The rotor pieces 200 removed at the rotor piece removal station S1 are sequentially caulked at the receiving base 6Ra of the lifter 6R to form a completed rotor, and are received by the pusher 7R.
And then sent out of the device 1. Further, the stator pieces 100 that have been removed at the stator piece removal station Sd are sequentially caulked at the receiving base 6Sa of the lifter 6S to form a completed stator, and are discharged from the receiving base 6Sa by the pusher 7S. After that, it is sent out of the device 1.

In the method for manufacturing a laminated core shown in FIGS. 6 and 7, after a pilot hole or a caulking portion is formed in the strip material 50 ', the inner diameter of the stator piece 100' in the strip material 50 'as shown in FIG. The region 100A 'is removed, and the rotor receiving hole 10 having a predetermined shape with a large number of small teeth is provided.
1 'is formed, and the rotor piece 200' is pulled out (first step).

At this time, as is apparent from FIG. 7A, the narrowest portion between the outer peripheral edge portion 200o of the rotor piece 200 'and the rotor piece outer circumference 201 formed later, ie, the rotor A portion 200 oa facing the tip of each small tooth 202 formed on the edge of one outer periphery 201
Has a small width corresponding to the air gap between the stator and the rotor.

Next, the outer peripheral edge 200o of the rotor piece 200 'is pressed in the plate thickness direction, and as shown in FIG. 6, the outer peripheral edge 200o is pushed out of the rotor piece 200' in the radial direction. Step 2).

Here, the outer peripheral edge portion 200o is formed as shown in FIG.
As shown in FIG. 7 (a), the area including the tip of each small tooth 202 is pressed over the entire circumference by the coining punch 12 ', and is pushed outward in the radial direction (to the left in the figure), so that FIG. As shown in (b), the portion 200oa facing the tip of each small tooth 202 has a width wider than the air gap. In addition, even when the central portion of each small tooth 202 in the outer peripheral edge portion 200o or the entire area of the edge portion extending radially outward from the base of each of the small tooth portions 202 is pressed, the outer peripheral edge portion in the rotor piece 200 'is also pressed. 200o
7A is pushed outward in the radial direction from the state shown in FIG. 7A, as shown in FIG. 7B, whereby the width of the portion 200oa facing the tip of each small tooth 202 is much wider than the air gap. Needless to say,

Next, as shown in FIG. 6, an outer peripheral edge portion 200o of the rotor piece 200 'is cut out over the entire circumference, and a rotor outer periphery 201 of a predetermined shape having a large number of small teeth 202 is formed. It is formed (third step).

Here, the outer peripheral edge portion 200o of the rotor piece 200 'is punched out as a scrap 300', and as shown in FIG. 7C, the thinnest portion 200oa of the punched scrap 300 'is formed. However, since it has a much wider width than the air gap, it is dropped into the die in a state of being connected in a ring shape without being inadvertently divided, minimizing the occurrence of scraps etc. Can be

In the above-described second step, the plate thickness of the small teeth 202 is reduced by pressing the outer peripheral edge 200o of the rotor piece 200 ', which is not shown. Since the clearance between the die and the punch can be set small, the small teeth 2 on the rotor piece 200 '
In the tip portion of No. 02, a shear surface is formed over a wide range, the area facing the tip of the small teeth of the stator at the shortest distance is increased, and the electrical characteristics of the stepping motor are improved. .

In the first step described above, the rotor piece 2
From the strip material 50 'from which 00' has been removed, the stator piece 100 'is punched out in a predetermined shape by a stator piece removal punch at a stator piece removal station (not shown). Further, the stator piece 100 'and the rotor piece 200' formed in the above-described manner are sequentially caulked and joined to form a stator and rotor product, and then sent out of the apparatus.

FIGS. 1 to 7 show an example in which the present invention is applied to the manufacture of a stator and a rotor of a stepping motor, but the method of manufacturing a laminated core according to the present invention is as follows.
It goes without saying that the present invention can be effectively applied not only to the stator and the rotor of the stepping motor but also to a method of manufacturing the stator and the rotor of various electric motors.

[0040]

As described above in detail, in the method for manufacturing a laminated iron core according to the present invention, the rotor piece is punched out of the inner diameter region of the stator piece into a predetermined outer peripheral shape in the first step, and then the rotor is formed. Since the inner peripheral edge portion is extruded radially inward by pressing the stator piece in the plate thickness direction to make it thinner in the step 2, the inner peripheral edge portion of the stator piece in the third step is formed into a rotor housing hole. When punching and forming into a predetermined shape over the entire circumference to form, a sufficient punching margin can be obtained. Further, in the present invention, the inner diameter region of the stator piece is punched into a predetermined shape so as to form a rotor housing hole in the first step, and the rotor piece is formed. In the third step, when the outer peripheral edge of the rotor piece is punched into a predetermined shape over the entire circumference in the third step, , A sufficient blanking margin can be obtained. That is, according to the manufacturing method of the laminated core according to the present invention, when the rotor piece is punched and formed by using the inner diameter region where the rotor housing hole is formed in the stator piece, the inner peripheral edge of the stator piece is formed. Alternatively, since the punching width at the time of punching and forming the outer peripheral edge of the rotor piece is widened, the punching waste is wide and connected in a ring shape and is dropped, so that it is not inadvertently divided into the lower mold. Since it is dropped out, the occurrence of dregs and the like is suppressed, and thus it is possible to prevent product defects due to dregs and the like during punching and forming. In other words, according to the configuration of the present invention, the rotor piece can be stamped and formed by utilizing the inner diameter region of the stator piece where the rotor housing hole is formed without causing a product defect. It is possible to form a stator piece and a rotor piece from one strip material by using a machine and a mold device. As a result, compared to the conventional manufacturing method that required two mold units and a press machine to manufacture the stator and the rotor in one type of stepping motor, the yield of the material was significantly improved, As a result, it is possible to minimize the inadvertent increase in manufacturing cost.

[Brief description of the drawings]

FIG. 1 is an overall side sectional view conceptually showing a progressive die apparatus for manufacturing a laminated core for performing a method of manufacturing a laminated core according to the present invention.

FIG. 2 is a conceptual perspective view showing an embodiment in which stator pieces are formed in accordance with the method for manufacturing a laminated core according to the present invention.

FIGS. 3 (a), (b) and (c) are main part plan views showing stator pieces formed in accordance with the method for manufacturing a laminated core according to the present invention.

FIGS. 4 (a) and (b) are cross-sectional views of a main part showing a mold apparatus for carrying out a method for manufacturing a laminated core according to the present invention, and a mold apparatus for carrying out a conventional method for producing a laminated core. FIG.

FIGS. 5 (a) and (b) are perspective views of a main part showing a stator piece manufactured according to a method of manufacturing a laminated core according to the present invention, and manufactured according to a conventional method of manufacturing a laminated core. FIG. 6 is a perspective view of a main part showing a stator piece that has been removed.

FIG. 6 is a conceptual perspective view showing an embodiment in which a rotor piece is formed according to the method of manufacturing a laminated core according to the present invention.

FIGS. 7A, 7B, and 7C are plan views of main parts showing a rotor piece formed according to the method of manufacturing a laminated core according to the present invention.

FIG. 8 is an overall perspective view showing a stator and a rotor of the stepping motor.

FIG. 9 is an essential part perspective view showing a stator and a rotor of the stepping motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1: Progressive die apparatus for laminated iron core manufacturing, S1: Rotor piece removal station, S2 ... Coining station, S3 ... Tooth tip removal station, 11 ... Rotor piece removal punch, 12 ... Coining punch, 13 ... Tooth 50, 50 '... strip material, 100, 100' ... stator piece, 100A, 100A '... inner diameter area, 100i ... inner peripheral edge, 101, 101' ... rotor accommodating hole, 102 ... small teeth , 200, 200 '... rotor piece, 200o ... outer peripheral edge, 201 ... rotor piece outer circumference, 202 ... small teeth, 300, 300' ... punched waste.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B21D 28/02 B21D 28/06 B21J 5/02 B21J 5/06

Claims (2)

(57) [Claims] 1. A method for manufacturing a laminated iron core, wherein a rotor piece is formed by using an inner diameter region of a stator piece where a rotor housing hole is formed, wherein the rotor piece is formed from the inner diameter region of the stator piece. A first step of punching and forming a piece into a predetermined outer peripheral shape; a second step of pressing an inner peripheral edge in a radially inward direction by pressing the stator piece in a plate thickness direction to reduce the thickness; A third step of punching and forming the inner peripheral edge portion of the child piece into a predetermined shape over the entire circumference to form the rotor housing hole. 2. A method for manufacturing a laminated core in which a rotor piece is formed by using an inner diameter region of a stator piece where a rotor housing hole is formed, wherein the inner diameter region of the stator piece is formed by the rotation. A first step of punching the rotor piece into a predetermined shape to form a rotor housing hole and pressing the rotor piece in a plate thickness direction to extrude an outer peripheral edge in a radially outward direction; And a third step of punching and forming the outer peripheral edge of the rotor piece into a predetermined shape over the entire circumference.