JP2560550Y2 - Skew laminated iron core for rotor and mold equipment for its manufacture. - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skew laminated iron core used particularly for a rotor of a small electric motor, and a progressive die apparatus for manufacturing the same.

[0002]

2. Description of the Related Art A skew laminated iron core for an electric motor rotor is
When core pieces pressed from a strip-shaped thin sheet material (strip material) by a progressive die apparatus are sequentially dropped in an outer shape punching step, the core pieces are fixedly stacked in a predetermined number of sheets. For this purpose, each core piece is preformed with a caulking projection that forms a concave portion on the upper surface side and a convex portion on the lower surface side,
The concave and convex portions of each vertically adjacent iron core piece are connected by caulking at the same time as punching the outer shape, and a predetermined number of core pieces are provided with a separation punched hole into which the convex portion of the caulking projection is loosely fitted. And make them weigh. Further, when the punched core pieces are sequentially laminated at the same position, the thickness deviation of each core piece is accumulated, and the dynamic balance of the rotor is deteriorated, causing rotation unevenness and deteriorating magnetic performance. For this purpose, in the outer shape punching step, by rotating the outer shape punching die by a certain angle, each iron core piece is punched out while being displaced (skewed) by a certain angle at each of the vertically adjacent iron core pieces, and stacked in a skew state.

[0003] As described above, as prior art relating to a laminated iron core for a rotor to be laminated in a skew state, for example, Japanese Patent Publication No. 55-11940 and Japanese Utility Model Publication No. 53-53183 are disclosed.
There is one in the publication. In this rotor laminated core 20,
As shown in FIGS. 4 and 5, a cut-and-raised caulking projection 23 is formed along the circumferential direction of the iron core piece 21 adjacent to the skew relief hole 22 previously formed in the pole plate surface of the iron core piece 21. In the outer shape punching step, each iron core piece 21 is formed.
Skew is provided by stacking the inclined portions 23a of the caulking projections 23.

[0004]

However, the skew lamination by the caulking projections 23 of the prior art described above requires a large space in the circumferential direction. In particular, the core piece 21 such as a laminated core for the rotor of a small electric motor is required. When the width of the pole plate surface is narrow, it is not possible to secure a sufficient space for forming the skewing relief hole 22 and the caulking projection 23, and if the caulking projection 23 is unavoidably reduced in size, the crimping area decreases. Therefore, there was a disadvantage that the required caulking strength could not be obtained. Therefore, in the present invention, even when the width of the pole plate surface of the core piece is narrow, such as a laminated core for a rotor of a small motor,
An object of the present invention is to provide a skew laminated iron core for a rotor and a mold apparatus for manufacturing the same, which can form a projection for caulking in a state where a necessary crimping area is secured and can obtain sufficient caulking strength. It was done.

[0005]

The first gist of the present invention is as follows.
In each of the skew-stacked iron core pieces, a crimping projection that forms a concave portion on the upper surface side and a convex portion on the lower surface side is elongated in the radial direction, and the concave portion and the convex portion extend in the circumferential direction in the radial direction. A fitting in which the concave portion of the caulking protrusion of the lower core piece and the convex portion of the caulking protrusion of the upper iron piece that are arranged to be shifted by a desired skew amount and vertically stacked adjacent to each other are aligned in the circumferential direction. This is a skew laminated iron core for a rotor of a small electric motor which is crimped in a combined state.

A second gist of the present invention is that, before a contour punching step of successively punching each of the pressed core pieces in a laminated state at the same time as the outer contour punching, each core piece is elongated in the radial direction with respect to each iron core piece. Forming a concave portion on the upper surface side and forming a convex portion on the lower surface side. The forming process of the caulking projection includes a skew per iron core piece in a circumferential direction with respect to the die. Punches are provided in a displaced manner by an amount. In the outer shape punching step, the die side is rotated in the circumferential direction by the amount of skew per core piece to caulk the lower core piece already laminated. This is a progressive die apparatus for manufacturing a skew laminated iron core for a rotor, provided with a rotation imparting device for aligning a concave part of the projection with a convex part of a caulking projection of an upper core piece to be newly punched.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a skew laminated iron core for a rotor of a small electric motor according to the present invention and a mold apparatus for manufacturing the same will be described in detail with reference to the illustrated embodiment. This progressive die apparatus is composed of an upper die 1 and a lower die 2 arranged vertically as shown in FIG. 1, and punches a slot hole along a feeding direction F of a strip-shaped thin material (strip material) W. A process A, a punching process B for a shaft hole, a forming process C for a caulked portion, an outer shape punching and a lamination caulking process D are provided. A strip-shaped thin plate (strip material) W is intermittently and sequentially fed at a predetermined pitch in the feed direction F between the upper die 1 and the lower die 2, and the upper die 1 and the lower die 2 are used to intermittently move the AC. In each step, the desired press-forming of the strip-shaped sheet material W is performed, and in the step D, the core pieces that have been successively punched out by the external punching are caulked and fixed in a laminated state to produce a laminated core for the rotor.

[0008] The basic structure described above is the same as that of the conventional case, but the progressive die apparatus according to the present invention has a new concept to solve the conventional problem. This is performed in the caulking step D. First,
The caulking portion forming step C is divided into a measuring through hole punching step C1 and a caulking projection forming step C2. In the measuring through hole punching step C1, the punch 3a attached to the upper die 1 is included. And a die 4a formed on the lower mold 2 are provided,
A punch 3b attached to the upper die 1 and a die 4b formed on the lower die 2 are provided in a forming step C2 of the caulking projection. The punching step C1 of the measuring through hole and the forming step C2 of the swaging protrusion are performed by switching means between the punch 3a and the punch 3b by control means (not shown) so that one of them is in an operative state when the other is in an operative state. At the same time, the punch 3a cooperates with the above-described die 4a to make the through hole 11 for measurement into the first (lowest layer) core piece 11 of the laminated core 10.
a, and the punch 3b cooperates with the die 4b to form the core pieces 12 from the second to the uppermost layer of the laminated core 10.
1 to 1n are each formed with a caulking projection 15 as shown in FIGS. The caulking projections 15
Each of the core pieces 12-1n is formed by a concave portion 15a recessed on the upper surface side and a convex portion 15b protruded on the lower surface side, and the concave portion 15a and the convex portion 15b are formed around the circumference of each of the core pieces 12-1n. Are arranged in a state displaced by a desired skew amount d in the direction, and are formed in a rectangle or an ellipse in a form extending elongated in the radial direction with respect to the pole plate surface of each of the iron core pieces 12 to 1n. I have. For this reason, the caulking protrusion 15
The punch 3b and the die 4b in the forming step C2 are formed so as to be displaced in the circumferential direction by the skew amount d. The punching step C1 is also arranged with the relative positions of the punch 3a and the die 4a displaced.

Next, in the outer shape punching and laminating caulking process D, the measuring through hole 11a and the caulking protrusion 15
Each of the iron core pieces 11 to 1n formed with the die 6 is separated from the strip-shaped thin plate material W by punching the outer shape of the punch 5 attached to the upper die 1 and the die 6 attached to the lower die 2 and the lower portion thereof. The inner diameter part is successively drawn into the squeeze ring 7 that grips the outer shape of each iron core piece continuously to the side. In the lower die 2 side of the step D, the die 6 and the squeeze ring 7 are rotated before the outer shape is punched by the punch 5 to displace the already drawn core pieces by the skew amount d. Rotation applying device 8
Is provided. As the rotation applying device 8, for example, a constant rotation angle (skew angle) in which the rotation of the crankshaft of the press is synchronized with the press stroke via a cam or the like.
To a constant rotation angle that combines the rotation angle and the skew angle for eliminating the thickness deviation via an index drive, and drives the servo motor and stepping motor in synchronization with the press stroke, Conventionally known means for transmitting to the die 6 and the squeeze ring 7 using a belt, a timing gear, or the like can be used.

By providing the rotation imparting device 8, the caulking of the second core piece 12 drawn next into the measuring through hole 11a of the first core piece 11 drawn first is performed. The protruding portion 15b of the third core piece 13 is then caulked in the aligned state, and the protruding portion 15b of the third caulking projection 15 of the third core piece 13 is the caulking projection of the second core piece 12. It is caulked in the recess 15a of the 15 in an aligned state. In the following, similarly, new core pieces that are sequentially pulled out, the concave portions of the caulking projections of the lower core piece and the convex portions of the caulking projections of the upper core piece that are vertically stacked are circumferentially oriented. Is crimped in a fitting state aligned with the hole, and when a predetermined number n is punched, the measuring through-hole 11a is formed in the step C1.
The core pieces 11 for separation are punched. As a result, the laminated cores 10 are crimped together in a state where the required number of laminated layers required for one product is specified, and the space between the vertically adjacent core pieces is equal to the desired amount of skew in the circumferential direction. The layers are shifted. In addition, since the caulking projection 15 has a shape in which the convex portion 15a and the concave portion 15b are shifted, the depth of the concave portion 15a is preferably within 2/3 of the thickness of the iron core piece from the viewpoint of strength, and for example, about 1/2 is sufficient. It is.

[0011]

As described above, in the skew laminated iron core for the rotor of the present invention, the concave and convex portions of the caulking projection for fixing between the core pieces are arranged in the circumferential direction by being shifted by a desired skew amount. By laminating in a skew state, the caulking projections are elongated in the radial direction of the lamination core, so that even when the pole plate surface is narrow like a rotor of a small electric motor, it is not affected. The crimping projections can be formed in a state where a necessary crimping area is secured along the pole plate surface, and sufficient crimping strength can be obtained. In addition, the progressive die apparatus of the present invention shifts the relative position of the punch and the die in the forming process of the caulking projection in the circumferential direction by the skew amount per iron core piece, as compared with the conventional die apparatus of this type. In the outer shape punching process, the die is rotated each time new punching is performed to displace the already laminated core pieces in the circumferential direction, and the concave and convex portions of the caulking projections of the vertically adjacent core pieces are displaced. The skew laminated iron core described above can be easily manufactured with a simple configuration in which only a rotation applying device for aligning the parts is provided.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a skew laminated iron core for a rotor and a mold apparatus for manufacturing the same according to the present invention.

FIG. 2 is a plan view of the skew laminated core in FIG. 1;

FIG. 3 is an enlarged plan view of a main part of FIG. 2;

FIG. 4 is a plan view of a conventional skew laminated iron core for a rotor.

5A is a cross-sectional view in which a main part of FIG. 4 is enlarged, and FIG.
Is a plan view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper die 2 Lower die 3a 4a 5 Punch 3b 4b 6 Die 7 Squeeze ring 8 Rotation giving device 10 Laminated core 11 12 13 14 1n Iron core piece 11a Weighing through hole 15 Caulking projection 15a Depressed portion 15b (of caulking projection) Convex portion of caulking protrusion W Strip-shaped thin plate material (strip material) F Feeding direction A Punching process of strot hole B Punching process of shaft hole C Forming process of caulking portion C1 Punching process of through hole for measurement C2 Forming of caulking protrusion Process D Outline punching and lamination caulking process d Skew amount

Claims (2)

(57) [Scope of request for utility model registration] The skew-stacked core pieces each have a caulking projection which extends in the radial direction and forms a concave portion on the upper surface and a convex portion on the lower surface side. Are displaced in the circumferential direction by a desired skew amount,
It is characterized in that the concave portion of the caulking projection of the lower core piece and the convex portion of the caulking projection of the upper core piece that are vertically adjacently stacked are caulked in a fitting state aligned in the circumferential direction. Skew laminated iron core for rotor. 2. Prior to an outer shape punching step of successively punching each of the pressed core pieces in a laminated state simultaneously with the outer shape punching, a concave portion is formed on the upper surface side elongated in the radial direction with respect to each iron core piece. A step of forming a caulking projection is formed on the lower surface side, and the forming step of the caulking projection is performed by disposing a punch by displacing the die in the circumferential direction by a skew amount per core piece. In the outer shape punching step, the die side is rotated in the circumferential direction by the amount of skew per iron core piece to newly punch a concave portion of the caulking projection of the already laminated lower iron core piece. A progressive die apparatus for manufacturing a skew laminated iron core for a rotor, comprising a rotation imparting device for aligning with a convex portion of a caulking projection of an upper core piece to be removed.