JP6010976B2 - Manufacturing method of laminated iron core - Google Patents

Description

The present invention relates to a method for manufacturing a laminated core suitable as a stator core of a rotating electrical machine such as an automotive alternator.

(Conventional technology)
Conventionally, as this type of laminated iron core and its manufacturing method, various laminated structures and manufacturing methods for efficiently realizing the laminated structure have been developed and put into practical use. The basic laminated structure is that a plurality of core sheets made of thin plate-like magnetic materials are stacked, and the core sheets stacked in layers above and below are joined together by a plurality of caulking means formed on the core sheet itself. When manufacturing the laminated core for a cylindrical wound core such as the stator core, for example, a caulking means is processed in advance on a long core sheet, and the core sheet is spirally wound. A method is adopted in which a cylindrical laminated core is formed by winding and laminating in a shape, and the upper and lower core sheets are bonded to each other by caulking means.

  Here, what is important is the strength of the laminated core, that is, how to devise the caulking means in order to firmly bond the core sheets of each layer. At present, the tongue piece bent by punching and its punching A technique of bonding to each other using holes is preferred. The caulking means at each location is generally provided with one tongue piece, but from the idea that the coupling strength can be improved by increasing the number of tongue pieces, as an effective measure for improving the strength. Also, caulking means in which a pair of (two) tongue pieces are provided at one place has been studied (for example, see Patent Document 1).

(Problems of conventional technology)
However, as shown in FIG. 9, when the caulking means SH is provided for each core sheet R of the laminated core Q, the one described in Patent Document 1 is punched into a pair of tongue pieces S1 and S2. At the same time, a pair of punching holes H1 and H2 are formed, and an uncut portion T is provided between the pair of tongue pieces S1 and S2. However, by increasing the number of tongue pieces, the occupation area W of the caulking means SH increases. However, since the effective magnetic path area of the laminated core Q is reduced accordingly, the effect of improving the strength cannot be expected so much at the expense of the magnetic characteristics of the laminated core.

The main reasons are as follows.
First, even if the occupation area W of the caulking means SH is the same area, the effective length of each tongue piece S1, S2 is limited by the ratio between the pair of tongue pieces S1, S2 and the uncut portion T. .
Secondly, when the pair of tongue pieces S1 and S2 is caulked (pressed and deformed) with a caulking tool, for example, the pair of tongue pieces S1 and S2 are bifurcated into the pair of holes H1 and H2 in order to simultaneously press and deform the pair of tongue pieces S1 and S2. However, even in this case, the stroke of the caulking tool is restricted by the interference with the uncut portion T, and the tongue pieces S1 and S2 can be sufficiently spread (rolled). Can not.

  Of course, the latter (second) problem may be solved by caulking the pair of tongue pieces S1 and S2 individually one by one, but there is a possibility of causing a quality problem that the laminated core Q is distorted. In addition, there are cost problems such as an increase in the number of manufacturing steps and a complicated manufacturing apparatus, which is not practical.

Utility Model Registration No. 3046084

  On the other hand, in recent years, as rotary electric machines have been pursued to be smaller and higher performance and lower cost, thin core magnetic plates with excellent characteristics tend to be adopted in the core core, which is the core part. While keeping in mind that it is an essential issue to effectively utilize the limited area of the caulking means to secure high bond strength and reduce costs, a laminated core having a laminated core with high bond strength and Realization of a method for manufacturing the laminated core at a low cost is eagerly desired.

  The present invention has been made in view of the above-described problems, and improves the bonding strength between core sheets by caulking means that can be caulked positively and sufficiently without increasing the occupied area of the caulking means. Thus, an object of the present invention is to provide a production method capable of obtaining a laminated iron core having a laminated core having a high bond strength and capable of producing the laminated iron core at low cost by caulking means efficiently.

The invention according to claim 1 ( a method for manufacturing a laminated core) is characterized by caulking means (consisting of a pair of rectangular tongue pieces and a hole) formed on the core sheet. A pair of rectangular tongue pieces that are punched out of the core sheet and bent, each tongue piece is connected to the core sheet at the root portion that is one end, and the core sheet extends to the tip portion that is the other end. It is separated from and is folded and formed so as to be opposed to a double door. Moreover, the hole formed by punching out the pair of tongue pieces is configured as a single opening that accommodates the pair of tongue pieces without drawing each other.
Then, the core sheets stacked in layers above and below are formed by the tongues of the core sheet on the upper layer side being fitted into the holes of the core sheet on the lower layer side and being pressed into the caulking means of the core sheet on the lower layer side. Are connected. In addition, the pair of tongue pieces are characterized in that the tip portions are spread and press-fitted thinner than the root portions.

According to the above manufacturing method , the caulking means is composed of a pair of tongues facing each other in a double-spread shape and a single-opening hole that can utilize the punched hole as it is. Since the tongue piece can be formed by effectively utilizing it, it is possible to secure a tongue piece having a long effective length. Moreover, since the hole portion is configured as a single opening that accommodates the pair of tongue pieces without drawing each other, the pair of tongue pieces can be press-fitted simultaneously and sufficiently, and the caulking means is highly coupled. Strength can be secured.

BRIEF DESCRIPTION OF THE DRAWINGS It shows typically the automotive alternator which applies the laminated iron core by the manufacturing method of this invention, (a) is a half sectional view which shows the whole structure of an alternating current generator, (b) is A- of (a). It is a front view of the upper half part which shows the form of a stator core single-piece | unit along A section (Example 1). The principal part of the laminated iron core by the manufacturing method of this invention is shown, (a) is a top view, (b) is BB sectional drawing of (a) (Example 1). It is the schematic diagram which showed the basic manufacturing process in the manufacturing method of the laminated core of this invention in process order (Example 1). FIG. 3 shows one embodiment of a core sheet for explaining the first step of FIG. 3, (a) is a plan view, (b) is an enlarged plan view of a portion C (caulking means portion) of (a), (c) ) Is a cross-sectional view taken along the line XX of (b), and (d) is a cross-sectional view showing the final form in the first step of the caulking means (Example 1). FIG. 4 is used for explaining the second step and the third step in FIG. 3, and shows a manufacturing process of the laminated core when the core sheet shown in FIG. 4 is used, and (a) shows a laminated layer obtained in the second step. (B), (c) is a longitudinal cross-sectional view showing two modes of the caulking step performed in the third step (Example 1). FIGS. 3A and 3B are vertical sectional views showing two modes of a caulking process performed in the third process (Example 1). The other Example of the core sheet | seat used for description of the 1st process of FIG. 3 is shown, (a) is an enlarged plan view of a caulking means part, (b) is YY sectional drawing of (a). Example 2). 7 is used to explain the second step and the third step when the core sheet shown in FIG. 7 is used. (A) is a longitudinal sectional view of the laminated core obtained in the second step, and (b) is the third step. It is a longitudinal cross-sectional view which shows the crimping process implemented (Example 2). It is sectional drawing of the core sheet with which it uses for description of the crimping means currently examined conventionally (conventional example).

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

[Example 1]
In Example 1, the manufacturing method of the present invention is applied to a stator core of an automotive alternator (alternator).

[Basic configuration of AC generator]
As shown in FIG. 1A, the AC generator G has a rotor GR attached to a rotary shaft GA driven by an engine, and a stator GS carried by a housing GH. In the stator GS, an annular (cylindrical) stator core E as shown in FIG. 1B is used as an iron core to which a stator coil (multiphase winding) D is mounted. This stator core E is provided with a large number of teeth (teeth, protrusions) E1 and slots (grooves) E2 around which a stator coil D is wound on the inner peripheral side, and the teeth E1 are connected in an annular shape on the outer peripheral side. It is composed of a cylindrical laminated iron core (commonly called a wound iron core) 1 having a connecting portion E3. The connecting portion E3 is a non-winding portion around which the stator coil D is not wound, and is provided with a caulking means 3 which will be described in detail later.

[Basic structure of laminated core 1 (stator core E)]
As shown in FIGS. 2 (a) and 2 (b), the laminated iron core 1 is formed by stacking a plurality of core sheets 2 made of a thin plate-like magnetic material, and the core sheets 2 stacked in layers above and below are core sheets. 2 is composed of a cylindrical laminated core 4 joined by a plurality of caulking means 3 punched and formed on itself.

Each core sheet 2 includes a plurality of protrusions (teeth) 2a and grooves (slots) 2b around which the stator coil D is wound on the inner peripheral side, and a connecting portion that connects the protrusions 2a in an annular shape on the outer peripheral side. The connecting portion 2c, which is a non-winding portion, is provided with a plurality of caulking means 3 having an occupied area W in a developed state in the circumferential direction.
In the present embodiment, when the caulking means 3 is provided in the connecting portion 2c, the caulking means 3 is particularly disposed at a position corresponding to the protruding portion 2a.

Each caulking means 3 has a caulking portion 5 formed by punching from the core sheet 2 and a hole portion 6 formed by punching the caulking portion 5, and the caulking portion 5 includes: It is comprised by a pair of tongue pieces 5a and 5b.
The pair of tongue pieces 5a and 5b are connected to the core sheet 2 at the root portion 51 which is one end portion of each tongue piece 5a and 5b, and from the core sheet 2 to the tip end portion 52 which is the other end portion. It is separated and folded so as to be opposed to a double door.
The hole 6 is configured as a single opening that accommodates the pair of tongue pieces 5a and 5b without drawing each other.
The occupying area W of the caulking means 3, that is, the developed length in the circumferential direction, is the length from the root of one tongue piece 5a to the root of the other tongue piece 5b, that is, the circumferential length of the hole 6. The pair of tongue pieces 5a and 5b are provided so as to make the most effective use of the occupied area W and to make the effective length as long as possible.

Then, the core sheet 2 stacked in the upper and lower layers has the tongue pieces 5a and 5b of the core sheet 2 on the upper layer side inserted into the hole 6 of the core sheet 2 on the lower layer side, and is press-fitted and rolled. Thus, it is press-fitted into the caulking means 3 (the tongue pieces 5a and 5b and the hole 6) of the core sheet 2 on the lower layer side with a sufficient area while tilting deeply over multiple layers. Therefore, the core sheets 2 of each layer are firmly bonded by the caulking means 3, and the laminated core 4 having a high bonding strength (high caulking strength) is obtained.

[Detailed structure of laminated core 1 and method of manufacturing the same]
Hereinafter, the characteristic structure of the laminated iron core 1 (stator iron core E) shown in FIG. 2, particularly the detailed structure of the caulking means 3 and the function thereof will be described together with the manufacturing method.

The laminated core 1 is manufactured based on a manufacturing process roughly divided into four processes as shown in FIG.
In FIG. 3, first, in the first first step, a thin plate-like sheet (for example, a steel plate sheet) 10 made of a long (band-like) magnetic material is sequentially put into the pressing devices 11 and 12, and divided into two in the length direction. Then, a pressing process for producing two continuous core sheets 2 by constant-size press molding or continuous press molding is performed. Next, as a second step, the core sheet 2 is spirally wound by the winding device 20, and is wound with a predetermined number of turns (number of laminations) to form the original shape 4 a of the laminated core 4. Steps are carried out, and subsequently, as a third step, the core 4 of each layer is formed by putting the original shape 4a of the laminated core 4 into the caulking device 30 and positively caulking (pressing deformation) the caulking means 3. A caulking step for producing the laminated core 4 firmly bonded is performed. Finally, as a fourth step, finishing steps such as various moldings and deburring for shaping the laminated core 4 into a predetermined shape are performed by various devices (not shown). In addition, since the laminated core 4 with high caulking strength is obtained in the third step, the welding step (joining between the core sheets 2) of the laminated core 4 can be omitted in the fourth step.

Next, the details of each of the above manufacturing steps will be described with reference to FIGS.
[First step (pressing step)]
In this step, the long core sheet 2 that is divided into two parts from the thin plate sheet 10 and has the form shown in FIGS. 4A to 4C is produced.
Caulking means 3 is punched and formed in the core sheet 2 together with the projecting portion 2a and the groove portion 2b in a connecting portion 2c forming a non-winding portion where no winding is wound. Here, when the long core sheet 2 is divided into two from the thin plate sheet 10, a method of dividing the caulking means 3 before punching and a method of dividing the caulking means 3 after punching and forming can be considered. This method can also be adopted.

As shown in FIG. 4 (a), the caulking means 3 is provided corresponding to the protruding portion 2a. However, depending on the required caulking strength of the final laminated core 4, the same number or an appropriate interval as the protruding portion 2a is provided. In this embodiment, as shown in FIG. 1B, it is provided at 12 locations at intervals of 30 ° on the entire circumference.
Each caulking means 3 has a caulking portion 5 (a pair of tongue pieces 5a and 5b) and a hole portion 6 (single opening) deployed in the length direction, and has an occupied area W. Yes.
The caulking means 3 can also be disposed by expanding the caulking portion 5 (a pair of tongue pieces 5a and 5b) and the hole portion 6 (single opening) in the radial direction.

  As shown in FIGS. 4B and 4C, the relationship between the pair of tongue pieces 5a and 5b and the hole portion 6 is that the tongue pieces 5a and 5b facing each other in a double-spread shape are rectangular as a whole. Although it has a shape, it has a tapered shape in which the width increases from the root portion 51 to the tip portion 52, and the hole portion 6 formed by the punched hole naturally has a narrow width at both end portions 61. It has a rhombus shape.

In particular, in the present embodiment, as shown in FIG. 4 (d), with respect to the pair of tongue pieces 5a and 5b, the tip portions 52 of the tongue pieces 5a and 5b are accommodated in the holes 6, and A bent portion 53 that is bent in a curved shape is formed from the root portion 51 to the tip portion 52 of the pieces 5a and 5b.
4 (d), after first forming the forms shown in FIGS. 4 (b) and 4 (c) by press molding, the tip portion 52 is pushed into the hole 6 while forming the bent portion 53. However, it is possible to manufacture the bent portion 53 at the same time while half-cutting the tip portion 52 (not completely punching out, but only about half the plate thickness). It can also be produced by this process.

Thus, the first step is completed, and the pair of tapered tongue pieces 5a and 5b having a long effective length can be formed by making the best use of the occupation area W of the caulking means 3.
If the punching allowance is excluded, the total maximum length of the pair of tongue pieces 5a and 5b can be made substantially the same as the length of the occupied area W.

[Second step (winding step)]
In this step, the long core sheet 2 is wound and laminated in a plurality of layers in a spiral manner so that the position of the caulking means 3 of the core sheet 2 that overlaps in the vertical direction matches, and the laminated core 4 having a desired thickness is formed. The original shape 4a is produced. Specifically, as shown in FIG. 5A, the core sheet 2 is wound and laminated so that the bent portions 53 overlap each other. In this winding process, each layer is tightly wound. Even if the tongue pieces 5a and 5b are rotated, the tip portions 52 are accommodated in the holes 6 and do not protrude as shown in FIG. 4C. It is possible to prevent each layer from being hindered and to smoothly wind each layer. Of course, the tongue pieces 5a and 5b can also be prevented from buckling or breaking.

[Third step (caulking step)]
In this step, as shown in FIG. 3, the original shape 4a of the laminated core 4 is put into a caulking device 30 including a slot guide 31, a die (lower die) 32, a punch (upper die) 33, etc. The laminated core 4 is produced by caulking each caulking means 3 with the die 32 and the punch 33 while guiding the groove 2 b with 31.

In this caulking step, according to the present invention, the core sheet 2 of each layer is firmly bonded by press-fitting the pair of tongues 5a and 5b on the upper layer side into the hole 6 on the lower layer side, and the laminate has high caulking strength. A core 4 is obtained. The outline of the mechanism is as follows.
As shown in FIGS. 4B and 4C, the pair of tongue pieces 5a and 5b has a tapered shape with a large width at the tip portion 52, and the hole portion 6 has a rhombus shape. The area can be increased and the caulking force can be increased simultaneously. That is, first, the peripheral length of the tongues 5a and 5b is increased by the amount corresponding to the taper, and the surface area increases, so that the contact area (caulking area) between the mating hole 6 and the tongues 5a and 5b to be caulked. ) Increases. Second, the rhombus-shaped hole 6 has both end portions 61 formed by punching holes in the base portion 51 having a small width of the tongue pieces 5a and 5b, and has a narrow width. However, as a result of the tip portion 52 being press-fitted into the hole 6, the tip portion 52 tilts with the root portion 51 as a base point, so that the wide tip portion 52 side is press-fitted into the narrow hole portion. The caulking force can be increased according to the press-fitting allowance (fitting allowance).
Furthermore, since each of the tongue pieces 5a and 5b has a long effective length, the tongue pieces 5a and 5b are deeply tilted and rolled over multiple layers and sequentially press-fitted into the caulking means 3 of the core sheet 2 on the lower layer side.
As described above, the laminated core 4 can ensure high caulking strength.

  Specifically, in the caulking step, the distal end portion 52 is pressed and spread toward the root portion 51 side while the bent portion 53 of each tongue piece 5a, 5b is pushed inward from the outer side of the laminated core 4. As the method, as shown in FIG.5 (b), the convex side of the bending part 53 is located upward (when the pressing start side of each tongue piece 5a, 5b is upward and the pressing end side is downward), First caulking (convex caulking) and second caulking (concave caulking) with the concave side of the bent portion 53 positioned upward as shown in FIG. 5 (c). Either can be selected and adopted.

The first method shown in FIG. 5 (b) is the same as the procedure shown in FIG. 6 (a). The laminated core 4 is placed on the die 32 so that the convex side of the bent portion 53 faces upward. While pressing the periphery of the caulking means 3 with the punch 33a, the bending portion 53 is pressed from the convex side with the press-fitting punch 33b, and the press-fitting punch 33b is press-fitted into the hole 6.
According to such a method, each tongue piece 5a, 5b is pressed with the tip portion 52 facing downward toward the root side (circumferential direction) while the convex side of the bent portion 53 is deformed in the opposite direction (concave direction). By moving, the tip portion 52 having a downward steep inclination angle on the upper layer side is inclined with respect to the presser punch 33a. The core sheet 2 can be reliably press-fitted without a gap.

The second method shown in FIG. 5 (c) is the same as the procedure shown in FIG. 6 (b). The laminated core 4 is placed on the die 32 so that the concave side of the bent portion 53 faces upward. While pressing the periphery of the caulking means 3 with the punch 33a, the bending portion 53 is pressed from the concave side with the press-fitting punch 33b and the press-fitting punch 33b is press-fitted into the hole portion 6.
According to this method, each tongue piece 5a, 5b is moved by being pressed and moved toward the root side (circumferential direction) with the upward tip portion 52 while the bent portion 53 is pushed along the concave side. Since the upper end portion 52 of the upper layer side is gently inclined while extending in the opposite direction, the upper tongue portions 5a and 5b can be pressed into the lower layer side caulking means 3 in a wide area. .
Therefore, even if any caulking method is selectively employed, a good high caulking strength can be obtained.
Moreover, since the hole 6 is a single opening, the pair of tongue pieces 5a and 5b can be caulked simultaneously with the single press-fitting punch 33b, and the stroke of the press-fitting punch 33b can be freely selected. .

[Fourth process (finishing process)]
The laminated core 4 thus obtained is subjected to various forming processes for shaping and maintaining a predetermined shape such as the roundness of the laminated core 4 and finishing processes such as deburring to complete the final laminated core 1. . The deburring means that the protruding portion generated in the third step, that is, a part of the lower-layer side tongue pieces 5a and 5b extends downward from the end face of the laminated core 4 as shown in FIGS. 6 (a) and 6 (b). There are a method of positively removing the protruding portion, and a method of deleting the protruding portion and a method of pushing into the hole 6.

[Winding process]
As shown in FIG. 1, the laminated iron core 1 completed as described above has a stator coil (winding) D attached to a tooth E1 (protruding portion 2a) to form a stator GS. However, the caulking means 3 does not become an obstacle. In other words, the caulking means 3 is located at the connecting portion E3 (the connecting portion 2c) where the stator coil D is not wound, and the caulking means 3 is not limited to the stator coil D even during winding. And the stator coil D is not damaged by the caulking means 3.

[Effect of Example 1]
The main effects in the structure and production of the laminated core 1 described above are summarized and listed below.
(1) The caulking means 3 is composed of a pair of tongue pieces 5a and 5b that are opposed to each other in the form of double doors and a hole 6 having a single opening that can utilize the punched hole as it is. Accordingly, since the tongue pieces 5a and 5b can be formed by making the most effective use of the entire occupation area W of the caulking means 3, the tongue pieces 5a and 5b having a long effective length (caulking pieces that can be caulked across multiple layers). ) Can be secured.
Such a structure can minimize the occupation area W of the caulking means 3 and minimize the sacrifice of the effective magnetic path area of the laminated core 1, and can contribute to resource saving by reducing waste material due to punching, Can be expected to have an accompanying effect such as omitting the welding process of the laminated core 4.

(2) Since the pair of tongue pieces 5a and 5b have a tapered shape in which the width of the tip portion 52 is large and the hole portion 6 has a rhombus shape, the caulking area and the caulking force are simultaneously increased. be able to. That is, by increasing the peripheral length of the tongue pieces 5a and 5b by an amount corresponding to the taper, the caulking area is increased, and the rhomboid hole 6 has both end portions 61 of the width of the tongue pieces 5a and 5b. Since the narrow base portion 51 is formed and the width is narrowed, the caulking force can be increased by press-fitting the wide end portion 52 into the narrow hole portion.
The taper shape of the pair of tongue pieces 5a and 5b is positively formed, and the taper shape specifications (taper angle and maximum width) are determined by the material of the core sheet 2, the plate thickness, and the final thickness. Of course, it is set as appropriate according to the caulking strength to be secured.

(3) As shown in FIGS. 5B and 5C, the pair of tongue pieces 5 a and 5 b are press-fitted with the tip portion 52 being thinner than the root portion 51 in the caulking step. Therefore, the pair of tongue pieces 5a and 5b of the upper core sheet 2 can be deeply inclined into the hole 6 of the lower core sheet 2 and spread over multiple layers.

(4) In the laminated iron core 1 on which the winding is mounted, the caulking means 3 is arranged at a location where the winding of the core sheet 2 is not mounted. For example, when the caulking means 3 is disposed on the projecting portion 2a, the winding and the caulking means 3 interfere with each other, so that the caulking means 3 damages or cuts the winding, resulting in faults such as poor insulation or disconnection accidents. However, such a failure can be suppressed.
In this embodiment, the caulking means 3 is disposed on the connecting portion 2c corresponding to the protruding portion 2a.
Since the connecting portion 2c corresponding to the groove portion 2b is also a non-winding portion where no winding is mounted, it may be disposed here.

(5) In particular, when the laminated iron core 1 is a cylindrical wound iron core, the caulking means 3 is deployed in the circumferential direction. When the caulking means 3 is deployed in the radial direction, the occupied area W of the caulking means 3 is reduced due to the restriction of the radial dimension of the connecting portion 2c. On the other hand, the occupied area W is effectively utilized by utilizing the space of the connecting portion 2c. Large caulking means 3 can be provided.

[Example 2]
In this second embodiment, the construction of the caulking means 3 and the caulking method thereof are particularly devised as another embodiment of the manufacturing method of the laminated core 1 .
The following description will be made with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same or equivalent part as Example 1, and description is abbreviate | omitted.

As shown in FIG. 7 (a), the caulking means 3 is formed in the connecting portion 2c of the core sheet 2, and a pair of tongue pieces 5a and 5b facing each other in a double-spread shape are rectangular as a whole. The taper has a large width from the root portion 51 to the tip portion 52, and the hole 6 formed by the punched hole has a rhombus shape.
Accordingly, the basic structure of the caulking means 3 is substantially the same as that of the first embodiment, but the caulking means 3 and the caulking method in the second embodiment have the following characteristics.

The feature point of Example 2 is demonstrated with the manufacturing method implemented at the 1st process-3rd process shown in FIG.
First, in the first step (pressing step), when the pair of tongue pieces 5a and 5b and the hole 6 are formed by punching, the pair of tongue pieces 5a and 5b, as shown in FIG. It is punched in a half-cut state within a range smaller than the plate thickness (about half of the plate thickness), and is bent into an L shape having a flat portion 54 so as to face the tip portion 52. By this half-cutting process, each tongue piece 5a, 5b has a flat portion 54 (including the tip portion 52) bent into an L shape from the root portion 51 without protruding completely from the hole portion 6. Half of it is housed in 6. That is, the above half-drawing configuration is one means for accommodating the tip end portions 52 of the tongue pieces 5 a and 5 b in the hole portion 6.
When the pair of tongue pieces 5a and 5b has a half-punch configuration, the waste material inevitably has a predetermined interval V between the front end portions 52 facing each other due to a subsequent process (caulking process). Therefore, the total maximum length of the pair of tongue pieces 5 a and 5 b is shorter than the total length of the occupation area W of the caulking means 3.
However, the above-described half-punch configuration can be formed in such a manner that the pair of tongue pieces 5a and 5b are completely punched out and then returned to the half-pull state.

  Then, in the second step (winding step), the core sheet 2 is spirally wound a predetermined number of times so that the tongue pieces 5a and 5b of the upper core sheet 2 fit into the holes 6 of the lower core sheet 2. The laminated core 4 having the original shape 4a as shown in FIG. 8A is produced. At this time, since the distal end portion 52 of each tongue piece 5a, 5b is accommodated in the hole 6, when the core sheet 2 is wound spirally, each tongue piece 5a, 5b becomes an obstacle to the winding operation of each layer. Thus, each layer can be wound smoothly. Of course, each tongue piece 5a, 5b does not buckle or break.

In the subsequent third step (caulking step), the periphery of the caulking means 3 of the laminated core 4 is pressed by the die 32a and the presser punch 33a, and the flat portions 54 (including the tip portion 52) of the tongue pieces 5a and 5b are laminated. 4, while the press-fitting punch 33 b and the moving die 32 b are lowered (moved in the stacking direction) while being sandwiched between the press-fitting punch 33 b and the moving die 32 b from the both end face sides, the central punch 33 c is further press-fitted into the central part of the hole 6 To do.
The stacked core sheets 2 can prevent the overlapping portions from being lifted by sandwiching the flat portion 54, and can make the core sheets 2 that overlap vertically overlap each other. Further, by translating the flat portion 54 in the laminating direction, each of the tongue pieces 5a and 5b is pushed down as indicated by an arrow at the tip portion 52, and in particular, the root portion 51 is pulled and spreads thinly. And is press-fitted in a large area with respect to the caulking means 3 on the lower layer side.

  Thus, also in the second embodiment, substantially the same effects as those of the first embodiment can be obtained in terms of structure and manufacturing.

As described above, the two embodiments have been described in detail, but the features common to the structural and manufacturing aspects of the laminated iron core 1 are organized and summarized below.
○ [Structural surface of laminated core 1]
(1) The pair of tongue pieces 5a and 5b are opposed to each other in a double-spread shape by connecting each tongue piece to the core sheet 2 at the root portion 51, and cutting and bending the tip portion 52. The hole 6 is configured as a single opening that accommodates the pair of tongue pieces 5a and 5b without defining each other.
(2) Each tongue piece 5a, 5b has a tapered shape in which the width increases from the root portion 51 to the tip portion 52, and the hole 6 has a rhombus shape in which both end portions 61 are narrow.
(3) Each of the tongue pieces 5a and 5b is press-fitted with the distal end portion 52 being thinner than the root portion 51 (Example 1).
(4) Each tongue piece 5a, 5b is press-fitted with the root portion 51 extending thinner than the tip portion 52 (Example 2).
(5) When the winding (stator coil D) is mounted on the laminated core 1, the caulking means 3 is disposed at a location (projecting portion 2 a) where the winding is not mounted on the core sheet 2.
(6) When the laminated iron core 1 is the wound iron core 1 formed in a cylindrical shape by spirally winding and laminating the long core sheet 2, the core sheet 2 is arranged on the inner peripheral side. And a plurality of projecting portions 2a for mounting windings (stator coil D) on the outer periphery, and a connecting portion 2c for connecting the projecting portions 2a in an annular shape on the outer peripheral side, respectively. It is deployed in the direction.

○ [Manufacturing surface of laminated core 1]
(1) In the first step, a hole 6 is formed as a single opening for accommodating the pair of tongue pieces 5a and 5b without drawing each other, and in the third step, the press-fitting punch 33b is inserted into the hole 6. , 33c is pressed into a pair of tongue pieces 5a and 5b to simultaneously roll the core sheets 2 of the laminated core 4 together.
(2) In the first step, as the pair of tongue pieces 5a and 5b, the tapered tongue pieces 5a and 5b having a large width from the root portion 51 to the tip portion 52 are formed, and the hole portion 6 has a rhombic hole. The portion 6 is formed, and in the third step, the wide portions of the tongue pieces 5a and 5b located on the upper layer side are press-fitted into the narrow portions of the hole portions 6 located on the lower layer side.
(3) A case where the long core sheet 2 is produced in the first step, and the long core sheet 2 is spirally wound and laminated in the second step to form the cylindrical laminated core 4. Includes a step of storing the tip portions 52 of the tongue pieces 5a and 5b in the hole 6 as a pre-step (first step) of the second step.
(4) In the first step, in punching and forming the pair of tongue pieces 5a and 5b, the pair of tongue pieces 5a and 5b are half-punched or completely punched within a range smaller than the plate thickness of the core sheet 2, and then half-punched Returning to the state, the method includes a step of forming an L-shape having a flat portion 54 while facing the tip portion 52 (Example 2).
(5) The first step includes a step of forming a bent portion 53 bent in a curved shape from the root portion 51 to the tip portion 52 with respect to the pair of tongue pieces 5a and 5b. In the third step, A step of pressing and extending the tip portion 52 toward the root portion 51 while pushing the bent portion 53 inward from the outer side of the laminated core 4 (Example 1) is provided.
(6) In the third step, the L-shaped tongue pieces 5a and 5b are press-fitted along the laminating direction of the laminated core 4 in a state where the flat portions 54 are sandwiched from both end face sides of the laminated core 4. A step of pulling and spreading the root portion 51 is provided (Example 2).
(7) As a post-process after performing the third step, a step of removing a portion protruding from the end face of the laminated core 4 of the tongue pieces 5a, 5b is provided.

[Modification]
Although the manufacturing method of the present invention has been described in detail with respect to an example in which the manufacturing method of the present invention is applied to a stator core of an automotive alternator (alternator), the application range of the laminated core 1, the arrangement, shape, size, and number of caulking means 3 are as follows. Various modifications can be made without departing from the spirit of the present invention.

  For example, the laminated iron core 1 is not a wound iron core as described above, but a laminated iron core of a type in which a plurality of disk-shaped core sheets are laminated to form a laminated core, such as an armature iron core (rotor iron core) of an electric motor. Can be applied. Moreover, it is applicable also to laminated iron cores other than rotary electric machines, such as a transformer, which comprises a laminated core by laminating a plurality of rectangular core sheets.

In the case of the laminated iron core as described above, since the core sheet 2 is not wound and laminated, the caulking means 3 keeps the pair of tongue pieces 5a and 5b as shown in FIG. 52 can be used while completely protruding from the hole 6.
Also in the case of the laminated iron core as described above, disposing the caulking means 3 in the non-winding portion is an effective means for preventing damage to the winding.

  Furthermore, since the caulking means 3 can increase the effective length of the pair of tongue pieces 5a and 5b, the shape of the tongue pieces 5a and 5b and the hole 6 may be a simple rectangular shape like a rectangle.

  DESCRIPTION OF SYMBOLS 1 ... Laminated iron core, 2 ... Core sheet, 3 ... Caulking means, 4 ... Laminated core, 5 ... Caulking part, 5a, 5b ... Tongue piece, 6 ... Hole part, 51 ... Root part, 52 ... Tip part.

Claims (4)

A plurality of core sheets (2) made of thin magnetic material are stacked, and the core sheets (2) stacked in layers above and below are joined by a plurality of caulking means (3) formed on the core sheet itself. A method for producing a laminated iron core (1),
The caulking means (3) has a caulking part (5) punched out from the core sheet (2) and a hole (6) formed by punching out the caulking part (5). And
The caulking portion (5) is composed of a pair of tongue pieces (5a, 5b) having a rectangular shape as a whole,
The pair of tongue pieces (5a, 5b) are connected to the core sheet (2) at the root portion (51) where each tongue piece is one end portion, and the tip end portion (52) which is the other end portion. ) Is separated from the core sheet (2) and bent to form a double-sided facing,
The hole (6) is configured as a single opening that accommodates the pair of tongue pieces (5a, 5b) without defining each other;
In the core sheet (2) stacked in layers above and below, the tongues (5a, 5b) of the upper core sheet (2) are fitted into the holes (6) of the lower core sheet (2). , By being pressed into the caulking means (3) of the core sheet (2) on the lower layer side, and
The tongue piece (5a, 5b) has a distal end portion (52) that is thinner than a root portion (51) and is press-fitted into the laminated core. In the manufacturing method of the laminated iron core (1) of Claim 1,
The tongue pieces (5a, 5b) have a tapered shape in which the width increases from the root portion (51) to the tip portion (52),
The said hole (6) has comprised the rhombus shape, The manufacturing method of the laminated iron core characterized by the above-mentioned . In the manufacturing method of the laminated iron core (1) of Claim 1 or 2 ,
Winding (D) is attached to this laminated iron core (1),
The method of manufacturing a laminated iron core, wherein the caulking means (3) is disposed at a location (2c) where the winding (D) is not mounted on the core sheet (2) . In the manufacturing method of the laminated iron core (1) of Claim 3 ,
This laminated iron core (1) is a wound iron core (1) formed into a cylindrical shape by laminating a plurality of the long core sheets (2) in a spiral shape, and laminating them.
The core sheet (2) has a plurality of projecting portions (2a) for mounting the winding (D) on the inner peripheral side, and a connecting portion (2c) for annularly connecting the projecting portions (2a) on the outer peripheral side. Have
The method for manufacturing a laminated core, wherein the caulking means (3) is arranged in a circumferential direction in the connecting portion (2c) .

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