JP6456753B2 - Method and apparatus for manufacturing rotor laminated core - Google Patents

Description

  The present invention relates to a method for manufacturing a rotor laminated core in which iron core pieces are punched from a steel plate and sequentially laminated, and a manufacturing apparatus therefor.

In the manufacture of a rotor for an electric motor or a generator, as shown in FIGS. 3A and 3B, a plurality of core pieces 90 punched from a steel plate (thin strip material) are caulked and joined or rolled up. Therefore, a squeeze ring 92 is provided below the lower mold 91 used for punching the iron core piece 90.
The inner diameter of the squeeze ring 92 is set to be slightly smaller than the outer diameter of the iron core piece 90, thereby applying a side pressure to the iron core piece 90 and holding the iron core piece 90 with its frictional force. The inner peripheral shape of the squeeze ring 92 is a perfect circle as shown in FIG.

In the above-described punching process of the steel sheet, a punch (not shown) and a die 93 processed into a perfect circle shape are used so that the shape of the iron core piece 90 becomes a perfect circle shape. However, even if this punch and die 93 are used, the shape of the core piece 90, which is a punched product, becomes an elliptical shape with the rolling direction of the steel plate as the major axis due to the influence of processing strain when the steel plate is rolled. Is well known.
For this reason, when the elliptical core piece 90 is held by the squeeze ring 92 having a perfect circle shape, there is a problem that a large lateral pressure is applied to the long axis side of the core piece 90 and the core piece 90 is swelled.

Thus, when waviness occurs in the iron core piece 90, the flatness of the rotor core (rotor laminated iron core) in which the iron core pieces 90 are laminated is deteriorated and the thickness deviation varies. Therefore, when fixing a permanent magnet in the magnet insertion hole of such a rotor core, if the rotor core is sandwiched between molds and an attempt is made to fill the magnet insertion hole with resin, it will be from between the laminated core pieces. Resin leaks.
Thus, for example, Patent Document 1 proposes a technique for correcting the roundness of the cutting blade of the punching die so as to suppress the ovalization of the iron core piece and making the iron core piece almost a perfect circle.

Japanese Patent Laid-Open No. 10-24333

However, it takes time and labor to correct the cutting blade of the punching die, and the processing cost also increases.
In addition, since the quality of the steel sheet also varies, in the case of a steel sheet having a large thickness variation, the tendency of the core piece to become elliptical also greatly varies. For this reason, as a result, waviness occurs in the iron core piece, and the above problem cannot be solved.

  SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a method for manufacturing a rotor laminated iron core and a manufacturing apparatus for the same that can prevent the occurrence of undulation with good workability and can manufacture a product of stable quality. The purpose is to do.

A method for manufacturing a rotor laminated core according to the first aspect of the present invention is the method of punching iron core pieces sequentially from a steel plate with a punch and a die, and then drawing into the squeeze ring by a squeeze ring disposed below the die. In the method for manufacturing a rotor laminated core in which the dropped iron core pieces are sequentially laminated,
The long axis side end portion of the elliptical iron core piece punched out by the punch and the die is positioned in a recessed region formed in the inner wall of the squeeze ring, and the iron core pieces are sequentially placed in the squeeze ring. Laminate.

In the method for manufacturing a rotor laminated core according to the first invention, the squeeze ring is rotated about the axis of the squeeze ring together with the die each time a predetermined number of the core pieces are dropped into the squeeze ring. It can be driven.
Here, the squeeze ring is preferably rotated 90 degrees or 180 degrees about its axis.

An apparatus for manufacturing a rotor laminated core according to the second aspect of the present invention is provided below a die that is paired with a raising and lowering punch, and an iron core piece punched and removed from a steel plate by the punch and the die. In an apparatus for manufacturing a rotor laminated iron core having squeeze rings that are sequentially laminated,
On the inner side wall of the squeeze ring, a recessed region is formed in which a long axis side end portion of the elliptical iron core piece punched by the punch and the die is positioned.

In the rotor laminated core manufacturing apparatus according to the second aspect of the invention, the squeeze ring rotates about the axis of the squeeze ring each time a predetermined number of the core pieces are pulled into the squeeze ring together with the die. It can be made drivable.
Here, it is preferable that the recessed area is formed every 90 degrees or 180 degrees around the axis of the squeeze ring.

In the manufacturing method and the manufacturing apparatus for a rotor laminated core according to the present invention, the long-axis side end of the punched elliptical core piece is positioned in the recessed area of the squeeze ring, and the core piece is placed in the squeeze ring. Since the layers are sequentially laminated, the large side pressure generated on the long axis side of the iron core pieces can be suppressed and further eliminated compared to the conventional case.
Therefore, it is possible to prevent the occurrence of the undulation of the iron core piece economically with good workability and to manufacture a product with stable quality.

(A) is explanatory drawing of the manufacturing method of the rotor laminated core which concerns on one embodiment of this invention, (B) is a top view of the squeeze ring of the manufacturing apparatus of the rotor laminated core which applies the manufacturing method. It is a top view of the squeeze ring which concerns on a modification. (A) is explanatory drawing of the manufacturing method of the rotor lamination | stacking iron core which concerns on a prior art example, (B) is a top view of the squeeze ring used for the manufacturing method of the same rotor lamination | stacking iron core.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
First, the rotor laminated core (rotor) 10 manufactured with the manufacturing method of the rotor laminated core which concerns on one embodiment of this invention is demonstrated, referring FIG. 1 (A).

The rotor laminated core 10 is configured by laminating a plurality of annular (predetermined shapes) core pieces 11.
The iron core piece 11 has an annular integral structure. In addition, the core piece has a split structure in which a plurality of arc-shaped core pieces can be connected in a ring shape, or a part of the plurality of arc-shaped core pieces in the circumferential direction is connected by a connecting portion, and the connecting portion is folded. A structure that can be bent into an annular shape may be used.

The core piece 11 is formed by punching from a steel plate (thin strip material) made of an electromagnetic steel plate or amorphous material having a thickness of about 0.10 to 0.5 mm, for example. The iron core piece may be punched from a single steel plate, or may be punched in a state where a plurality of steel plates (for example, two or more) are stacked.
The core pieces 11 and 11 adjacent to each other in the stacking direction are connected by caulking, but any of resin (thermosetting resin (for example, epoxy resin) or thermoplastic resin), adhesive, and welding can be used. It can also be connected using 1 or 2 or more.

A shaft hole (not shown) is formed in the center of the rotor laminated core 10, and a through hole formed in the stacking direction of the rotor laminated core 10 is formed around the shaft hole (shaft hole). A plurality of permanent magnet insertion holes are formed. Fixing the permanent magnet in the magnet insertion hole is preferably performed using the resin described above.
The shaft hole is provided with a key (projection) (not shown) protruding inward.

Next, a rotor laminated core manufacturing apparatus (hereinafter also simply referred to as a manufacturing apparatus) 20 according to an embodiment of the present invention will be described with reference to FIGS.
The manufacturing apparatus 20 includes a punch (not shown) that moves up and down, a die 21 that is fixedly disposed to be paired with the punch, and a squeeze ring 22 provided below the die 21, and an iron core in the squeeze ring 22. Swelling of the piece 11 is prevented and a product with stable quality can be manufactured. This will be described in detail below.

The die 21 and the squeeze ring 22 are provided on the lower mold 23.
Specifically, the die 21 and the squeeze ring 22 are fixedly supported by a die holder (not shown), and a rotation driving means (toothed pulley or gear) is provided on the die holder.
Therefore, by this rotation driving means, the squeeze ring 22 and the die 21 together with the die 21 squeeze ring 22 each time a predetermined number of iron core pieces 11 are dropped into the squeeze ring 22 (one or two or more, and so on). Can be driven to rotate around the axis (in this case, rotationally driven every 180 degrees).

The inner peripheral contour shape (cross-sectional shape) of the die 21 is a perfect circle shape, and the outer peripheral contour shape (cross-sectional shape) of the punch is also a perfect circular shape. Thereby, the outer peripheral outline shape of the iron core piece 11 punched from the steel plate using the punch and the die 21 should be a perfect circle shape.
However, as described above, the shape of the iron core piece 11 becomes an elliptical shape with the rolling direction of the steel plate as the major axis due to the influence of processing strain when the steel plate is rolled.
Therefore, the following squeeze ring 22 is used instead of the conventional squeeze ring whose inner peripheral contour shape is a perfect circle.

The squeeze ring 22 is configured to sequentially stack the core pieces 11 punched and removed from the steel sheet by the punch and the die 21 and perform caulking and rolling (rotating and stacking).
The squeeze ring 22 has a cylindrical shape, and an inner diameter of a virtual circle 25 having a minimum inner diameter in plan view is slightly smaller than an outer diameter of the iron core piece 11 (an inner diameter of the die 21). It is set small (for example, about several tens of μm or less). The virtual circle 25 corresponds to a perfect circular inner peripheral contour formed in a conventional squeeze ring indicated by a one-dot chain line in FIGS. 1A and 1B (FIGS. 3A and 3B). reference).

On the inner side wall of the squeeze ring 22, a recessed area 26 is formed for positioning the end on the long axis side of the elliptical core piece 11 punched out by the punch and die 21.
Specifically, the recessed area 26 is formed in the stacking direction of the core pieces 11 as shown in FIG. 1 (A), and the axial center of the squeeze ring 22 as shown in FIG. 1 (B). Are formed at positions facing each other, that is, at positions of every 180 degrees (here, a total of two places). The dent region 26 can be formed by performing relief processing (dent processing) or the like on a conventional squeeze ring whose inner peripheral contour shape is a perfect circle.

The indented region 26 passes through the inner peripheral surface 27 in plan view so that the arc-shaped inner peripheral surface 27 does not come into contact with the end on the long axis side of the elliptical core piece 11 (becomes the maximum inner diameter). The inner diameter of the virtual circle 28 is slightly larger (for example, about several tens of μm or less) than the inner diameter of the virtual circle 25 described above.
The recessed area 26 has an inner peripheral surface 27 that does not completely contact the end of the elliptical core piece 11 on the long axis side (the inner diameter of the virtual circle 28 is larger than the width of the core piece 11 on the long axis side). However, if a product with stable quality can be produced even if a slight (smaller than the conventional) undulation occurs in the elliptical core piece 11, the end of the core piece 11 on the long axis side You may contact the part.

In addition, the recessed area 26 has an inner peripheral surface 27 formed in an arc shape, but is not particularly limited as long as the contact with the end on the long axis side of the elliptical iron core piece 11 can be suppressed and further prevented. For example, an elliptic arc shape or a polygonal shape can be used.
The squeeze ring 22 is rotated 180 degrees around the axis of the squeeze ring 22 together with the die 21 each time a predetermined number of core pieces 11 are pulled out of the squeeze ring 22 (180 degree rollover). However, the present invention is not limited to this, and for example, the following configuration may be adopted.

The squeeze ring 30 shown in FIG. 2 has substantially the same function as the squeeze ring 22 described above, and the squeeze ring 30 is rotated 90 degrees together with the die each time a predetermined number of core pieces are removed from the squeeze ring 30. Drive (90 degree rollover).
For this reason, the inner wall of the squeeze ring 30 has an elliptical iron core piece 11 punched by a punch and a die at positions every 90 degrees centering on the axis of the squeeze ring 30 (here, a total of four points). A recessed area 31 (having substantially the same function as the recessed area 26) is formed in which the end on the long axis side is located.

As described above, the squeeze ring 22 for performing 180-degree roll-over and the squeeze ring 30 for performing 90-degree roll-over have been described as the squeeze ring for performing caulking and rolling, but the present invention is not limited thereto. A squeeze ring that performs (360 / n) degree transposition including these may be used. Note that “n” is a positive divisor of 360 (eg, 2-6, 8-10, 12).
In this way, by using a squeeze ring in which a recessed area is provided for each rolling angle, it is possible to cope with rolling other than 90-degree rolling and 180-degree rolling described above.

Next, a method for manufacturing a rotor laminated core according to an embodiment of the present invention will be described with reference to FIGS.
First, the steel plate is conveyed between the punch and the die 21.
At this time, the squeeze ring 22 is arranged so that the recessed area 26 is located at the end on the long axis side of the iron core piece 11 that becomes elliptical by punching (that is, the formation position of the opposed recessed area 26). And the conveying direction of the steel plate are matched.

Next, the core pieces 11 are sequentially punched out of the steel plate by the punch and the die 21 that are moved up and down, and the core pieces 11 that are dropped into the squeeze ring 22 are sequentially stacked by the squeeze ring 22.
At this time, every time a predetermined number of iron core pieces 11 are dropped into the squeeze ring 22, the squeeze ring 22 is driven to rotate 180 degrees (90 degrees in FIG. 2) about the axis of the squeeze ring 22 together with the die 21. .
Thereby, the end of the long axis side of the elliptical core piece 11 punched out by the punch and die 21 is positioned in the recessed area 26 of the squeeze ring 22, and the core pieces 11 can be sequentially stacked in the squeeze ring 22.

  From the above, by using the manufacturing method and the manufacturing apparatus of the rotor laminated core of the present invention, for example, it is possible to cause undulation in the core piece without correcting the punch or die as in the prior art. Can be prevented. Further, even if the steel sheet has a large fluctuation in thickness, no undulation is generated in the iron core piece, so that stable production is possible (the difference in quality depending on the production lot of the steel sheet can also be handled).

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, a case where a method and an apparatus for manufacturing a rotor laminated iron core according to the present invention are configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the present invention.
For example, in the method and apparatus for manufacturing a rotor laminated core according to the present invention, it is possible to further suppress the undulation of the core piece by using a corrected punch or die.
Further, in the above-described embodiment, the case where the squeeze ring is driven to rotate together with the die each time a predetermined number of iron core pieces are removed from the squeeze ring has been described, but the squeeze ring was removed without being driven to rotate. A plurality of core pieces can be caulked and joined in sequence.

DESCRIPTION OF SYMBOLS 10: Rotor laminated iron core, 11: Iron core piece, 20: Manufacturing apparatus of rotor laminated iron core, 21: Die, 22: Squeeze ring, 23: Lower mold | type, 24: Inner peripheral surface, 25: Virtual circle, 26: Recess Area, 27: inner peripheral surface, 28: virtual circle, 30: squeeze ring, 31: recessed area

Claims (6)

In the manufacturing method of the rotor laminated core, in which the core pieces are sequentially punched from the steel plate by the punch and the die, and the core pieces that are dropped into the squeeze ring are sequentially laminated by the squeeze ring disposed below the die.
The long axis side end portion of the elliptical iron core piece punched out by the punch and the die is positioned in a recessed region formed in the inner wall of the squeeze ring, and the iron core pieces are sequentially placed in the squeeze ring. A method for producing a rotor laminated iron core, characterized by being laminated.   2. The method for manufacturing a rotor laminated core according to claim 1, wherein the squeeze ring is rotated about the axis of the squeeze ring together with the die each time a predetermined number of the core pieces are removed from the squeeze ring. A method for producing a rotor laminated core, characterized by comprising:   3. The method of manufacturing a rotor laminated core according to claim 2, wherein the squeeze ring is rotated 90 degrees or 180 degrees about its axis. In an apparatus for manufacturing a rotor laminated core having a squeeze ring that is provided below a die that is paired with a raising and lowering punch and sequentially laminates the punch and the core pieces punched and removed from the steel plate by the die,
An inner wall of the squeeze ring is formed with a recessed region for positioning a long axis side end of the elliptical iron core piece punched by the punch and the die. manufacturing device.   5. The manufacturing apparatus for a rotor laminated iron core according to claim 4, wherein the squeeze ring is driven to rotate about the axis of the squeeze ring each time a predetermined number of the core pieces are dropped into the squeeze ring together with the die. An apparatus for manufacturing a rotor laminated iron core, characterized in that it is possible.   6. The rotor laminated core manufacturing apparatus according to claim 5, wherein the recessed region is formed every 90 degrees or 180 degrees around the axis of the squeeze ring. apparatus.

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