JP3369893B2 - Manufacturing method of laminated magnetic pole core for stator - 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 magnetic pole core for a stator, which is formed from a low-grade cold-rolled thin sheet material for lamination, and more specifically, to a constituent member of the laminated magnetic pole core. Stator lamination with in-line (on-line) partial heat treatment process that partially heats the interlocking magnetic pole core member in the middle shape of a certain magnetic pole core piece to improve the magnetic characteristics around the slots of the magnetic pole core piece The present invention relates to a method for manufacturing a magnetic pole core.

[0002]

2. Description of the Related Art Conventionally, a thin strip material of a high-grade silicon steel plate is generally used as a strip-shaped material of a laminated magnetic pole iron core which is required to have magnetic characteristics because of its good magnetic characteristics. . However, the laminated magnetic pole core formed by using the thin strip material of the silicon steel plate has a problem that it is relatively expensive because of high material cost. Therefore, a laminated magnet iron core has recently been used in which a low-priced low-grade strip material such as cold rolled thin plate material (SPCC) is heat-treated to grow crystal grains to improve magnetic characteristics. Then, the heat treatment of the iron core is carried out by placing a predetermined number of magnetic pole core pieces into a laminated magnetic pole core by connecting the magnetic pole core pieces with caulking projections or by placing individual magnetic pole core pieces in a state of being aligned and pressurized in a heating container. It is being appreciated.

[0003]

However, in the former method in which the laminated magnetic pole core pieces are placed in a heating container and subjected to heat treatment, the internal residual stress retained in the magnetic pole core pieces is released by heating. However, there has been a problem that the peripheral portion of the caulking projection formed on the magnetic pole core piece swells in a direction opposite to the direction in which the caulking projection is driven, and the heat-treated laminated magnetic pole piece deforms. Further, in the latter method of performing heat treatment in a state where individual magnetic pole core pieces are aligned and pressed, a new process is provided in which a large number of magnetic pole core pieces are aligned and pressed in a heating container, and a work step of laminating and welding. Therefore, there is a problem that workability is significantly reduced. The present invention has been made in view of the above circumstances, using a low-priced cold-rolled thin sheet material for lamination, and performing partial heating in a state of a connected magnetic pole core member that is an intermediate shape of the magnetic pole core pieces, and heat treatment. It is an object of the present invention to provide a method of manufacturing a laminated magnetic pole iron core for a stator, which improves the workability of

[0004]

A method according to the above-mentioned object.
The method for manufacturing a laminated magnetic pole iron core for a stator described above is a method of forming a desired shape of a magnetic pole iron core piece by pressing a thin plate material made of cold-rolled steel for lamination, and then laminating a predetermined number of the magnetic pole iron core pieces. A method of manufacturing a laminated magnetic pole core for a child, comprising:
A shape processing step of manufacturing an intermediate-shaped connecting magnetic pole core member having an annular connecting portion that connects the tip ends of the magnetic pole teeth of the magnetic pole core piece in an annular shape from the thin strip material, and heating the connecting magnetic pole core member. It is transferred intermittently to a processing furnace and is heat-treated by high-frequency induction heating coils provided on the front and back sides of the portion corresponding to the plurality of magnetic pole teeth formed in an annular shape, and the magnetic field around the slot including the magnetic pole teeth is magnetically processed. A partial heat treatment step for improving the characteristics and a separate processing step for removing the annular connecting portion by performing a processing for separately forming the tip end portions of the magnetic pole teeth of the connecting magnetic pole core member processed in the partial heat treating step. And the outer peripheral shape of the magnetic pole core pieces is punched out from the separated magnetic pole core members of the annular coupling portion, and a predetermined number of the magnetic pole core pieces are sequentially laminated to form a desired laminated magnetic pole core. And a laminating process step for machining. The method for manufacturing a laminated magnetic pole core for a stator according to a second aspect is the method according to the first aspect, wherein the front and back surfaces are arranged corresponding to a plurality of annular magnetic pole teeth of the coupling magnetic pole core member. The high frequency induction heating coil is arranged concentrically, and a dust core can be inserted inside the coil for heating. The method for manufacturing a laminated magnetic pole iron core for a stator according to claim 3 is the method according to claim 1 or 2, wherein the shape processing step and the lamination processing step include:
Each of them is provided with a processing station to form a press working line of the laminated magnetic pole iron core for a stator, which is directly or via a loop device, and further, in the middle of the processing station between the shape processing step and the lamination processing step, Partial heating stations for performing the processing of the partial heating process are arranged to form an integrated line as a whole.

In the method for manufacturing a laminated magnetic pole iron core for a stator according to any one of claims 1 to 3, an intermediate shape having an annular connecting portion for connecting the tip end portions of the magnetic pole teeth of the magnetic pole core piece from the thin strip material in an annular shape. After the connecting magnetic pole iron core member is pressed, it is conveyed to a heat treatment furnace, and the magnetic pole teeth are included by the high-frequency induction heating coils provided on the front and back sides of the portions corresponding to the plurality of annular magnetic pole teeth. The periphery of the slot is heated to improve the magnetic characteristics. Therefore, the amount of heat applied is smaller than that in the case where the entire connecting magnetic pole iron core member is put in the furnace, and the inner tip portions of the magnetic pole teeth are connected by the annular connecting portion, so that the thermal strain is small and the length is short. The required part can be heated in time. As a result, the heat treatment is performed in a state in which the surroundings are restrained, and distortion of the magnetic pole teeth in the cooled state is eliminated, resulting in a flatter surface. Then, by heating the peripheral portion of the slot including the magnetic pole teeth, distortion occurs in the tip end portion of each magnetic pole tooth and the annular connecting portion connecting them, but the annular connecting portion is removed in the next separation processing step, Since it forms the inside of the magnetic pole teeth,
It is possible to form a laminated core piece without distortion or dimensional deviation on the inner circle. Particularly, in the method for manufacturing a laminated magnetic pole core for a stator according to claim 2, the front and back high-frequency induction heating coils arranged concentrically corresponding to a plurality of annular magnetic pole teeth of the connecting magnetic pole core member are concentrically arranged. Furthermore, since the dust core can be inserted into the inner side of the core during heating, efficient heating can be performed even at a relatively low frequency. In the method of manufacturing a laminated magnetic pole core for a stator according to claim 3, since the line of the partial heat treatment step is included in a part of the press working line, continuous work including the heat treatment step is possible.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is a process diagram of a method for manufacturing a laminated magnetic pole core for a stator according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a heat treatment state of a connecting magnetic pole core member, and FIG. 3 is a diagram of the present invention. FIG. 4 is a flow chart of a method of manufacturing a laminated magnetic pole core for a stator according to one embodiment, and FIG. 4 is an enlarged view of the drawing shown in FIG. 1.

A thin strip material made of a cold-rolled steel sheet for lamination having a width wider than the diameter of the laminated magnetic pole core for the stator to be produced was prepared and passed through a predetermined roller leveler or the like to remove the internal residual stress. After that, as shown in FIG. 1 (A), pilot holes 11 are formed in the side circumference of the thin strip material 10 at the pitch of the magnetic pole core pieces to be formed, and a through hole 12 is formed in the center of the holes. A plurality of caulking projections 13 are formed by pressing. The inner diameter of the through hole 12 is slightly smaller than the inner diameter of the stator laminated magnetic pole iron core to be manufactured, and the annular connecting portion 15a for connecting the inner end portions (tip portions) of the magnetic pole teeth 14 described below is formed. It can be formed.

Next, as shown in FIG. 1B, a predetermined number of slots 15 forming the magnetic pole teeth 14 are radially formed around the through hole 12 by press working. As a result, the radially inner ends of the magnetic pole teeth 14 are connected to each other by the annular connecting portion 15a, and these are sequentially punched into the thin strip material 10, whereby the connecting magnetic pole core member 16 is formed. It is formed (above, shape processing step). The predetermined number of slots 15 may be sequentially formed using a single press machine, or a plurality of press machines arranged in parallel may be driven simultaneously or with a slight time shift,
A plurality of sets of a predetermined number of slots 15 may be simultaneously molded.

Next, the connecting magnetic pole core member 16 manufactured through the above steps is put into a heat treatment furnace and heat treatment is performed. The heat treatment furnace in this case is filled with, for example, an inert gas such as nitrogen, so that the heat treatment of the coupled magnetic pole iron core member 16 does not oxidize. This state,
As shown in FIGS. 1C and 2, coils 17 and 18 for induction heating are arranged above and below the connecting magnetic pole core member 16. In this embodiment, there are four pairs of upper and lower coils 17 and 18, which are arranged concentrically with each other, and the axis thereof coincides with the axis of the through hole 12.

The coils 17 and 18 are made of copper pipes, cooling water flows inside, and a dust core 19 vertically driven by a cylinder (not shown) is arranged at the center of the coil. It can be energized in a state of being penetrated into the inside 18. Also,
A plurality of coils 17 and 18 (four in this embodiment)
The magnetic pole teeth 14 of the connecting magnetic pole core member 16 are provided at the same time.
And its surroundings can be heated.

Accordingly, as shown in FIG. 3, in the shape processing station 20, the slot 15 forming the magnetic pole core piece is punched out by the progressive die and is gradually carried out. The coupled magnetic pole core member 16 is the first loop device. It is conveyed via 21 to a partial heating station 22 equipped with the heat treatment furnace. In the partial heating station 22, after confirming that the four continuous through holes 12 are arranged at the positions of the four coils 17 and 18, the dust core 19 is pulled down, and the high frequency current is applied to the four coils 17 and 18. Energize and ring connection 15
a, the magnetic pole teeth 14 and the surroundings thereof are partially heated. The heating time is determined in accordance with the feed speed of the connected magnetic pole core member 16 sent from the shape processing station 20, but the shape processing station 20 sequentially carries out the punching process for forming the magnetic pole core pieces. In the case of the above, the feeding pitch time can be made multiple times (four times in this embodiment) (the above is the partial heat treatment step).

Through the above steps, a circle M is shown in FIG.
Connecting magnetic pole core member 1 which has been partially heated up to the range
6 is cooled sufficiently in a cooling zone located downstream of the partial heating station 22 and then the second loop device 2
It is carried in to the separation processing station 24 via 3. In the separation processing station 24, as shown in FIG. 1 and FIG. 4D, the tips of the magnetic pole teeth 14 whose tips are connected by the annular connecting portion 15a are pressed by a predetermined diameter,
The annular connecting portion 15a is punched out to separate the tips of the magnetic pole teeth 14 as shown in FIGS. 1 and 4E.

In this case, the annular connecting portion 15a which has been slightly deformed by the partial heat treatment is removed, and the inscribed circle of the magnetic pole teeth 14 radially arranged becomes a perfect circle, so that the final product for the stator is formed. The accuracy of the laminated magnetic pole core is improved, whereby the gap between the laminated magnetic pole core and the laminated core for a rotor can be minimized, and a more efficient rotating machine can be provided (the above is the separation processing step). The connected magnetic pole core member 16 after the above steps is conveyed to the next laminating processing station 25, and as shown in FIG. 1 (F), the outer periphery is punched to obtain a predetermined number of magnetic pole core pieces 26. Sequentially stacked, the magnetic pole core pieces 26 that are vertically adjacent to each other are connected to the caulking projections 13,
Complete the laminated magnetic pole core for the stator. 1 and 4 (G)
Indicates a thin strip material after the magnetic pole core piece 26 is punched out,
The punched hole 27 is formed (above, the lamination processing step).

In the laminated magnetic pole core for a stator manufactured as described above, the magnetic properties of the magnetic pole teeth 14 partially heated in the partial heating station 22 are improved, and the magnetic pole teeth 14 are restrained in the surroundings. And its surroundings are heated,
During the cooling process, the material itself of the magnetic pole core piece 26 is pulled, so that the magnetic pole core piece 26 can be manufactured without being deformed or distorted by heating. Further, in the partial heating station 22, since a plurality of magnetic pole core pieces 26 to be finally formed are simultaneously subjected to the heating treatment, it is possible to take a long heating time, and as a result, the partial heating station 22 is made to have a laminated magnetic pole core. It is possible to go online in the manufacturing process of the press processing line. Then, in the partial heating station 22, the dust core (iron core) 19 is attached to the coil 1
7 and 18 and the connected magnetic pole iron core member 16 perform high frequency current in a relatively low frequency region for wave induction heating, so that there is a large radius heating portion and the magnetic pole teeth are relatively long. However, it is heated smoothly.

In the above embodiment, the dust core 19 is inserted and the heat treatment is performed. However, depending on the type of the magnetic pole teeth and the diameter of the magnetic pole core piece, the dust core is omitted and a high frequency current in a higher frequency range is generated. It is also possible to carry out induction heating by flowing it, which simplifies the apparatus. Further, in the above-described embodiment, the shape processing step, the partial heat treatment step, the separation processing step, and the lamination processing step are performed online, but the partial heat treatment step is performed by setting the connecting magnetic pole core member to a predetermined length. The present invention is also applicable to the case where is offline. Note that the caulking projection 13 is omitted in FIG. 4.

[0016]

In the method for manufacturing a laminated magnetic pole core for a stator according to claims 1 to 3, a plurality of press-worked intermediate-shaped connecting magnetic pole core members are conveyed to a heat treatment furnace and formed into a plurality of annular shapes. The high-frequency induction heating coils provided on the front and back sides of the portion corresponding to the magnetic pole teeth heat the peripheral portion of the slot including the magnetic pole teeth, so compared to the case where the entire connecting magnetic pole core member is placed in the furnace. Since a small amount of heat is applied and the inner end portions of the magnetic pole teeth are connected by the annular connecting portion, heat treatment with less thermal strain can be performed. Moreover, since the high frequency induction heating is used for heating, it is possible to heat the magnetic pole teeth and the necessary portions around the magnetic pole teeth within a short time, which results in a heat treatment with the surroundings being restrained. The generation of distortion of the magnetic pole teeth in the cooled state is eliminated. Then, by partially heating the magnetic pole teeth and the annular connecting portion, distortion occurs in the tip end portion of each magnetic pole tooth and the annular connecting portion connecting them, but the annular connecting portion is removed in the next separation processing step, Since the inner sides of the magnetic pole teeth are formed, it is possible to manufacture a laminated core piece without distortion or dimensional deviation in the inner circle. Particularly, in the method for manufacturing a laminated magnetic pole core for a stator according to claim 2, the front and back high-frequency induction heating coils arranged concentrically corresponding to a plurality of annular magnetic pole teeth of the connecting magnetic pole core member are concentrically arranged. Placed in
Further, since the dust core can be inserted inside the heating core at the time of heating, efficient heating can be performed even at a relatively low frequency, and as a result, the heating process can be performed more evenly over all the magnetic pole teeth. In the method of manufacturing a laminated magnetic pole iron core for a stator according to claim 3, since the line of the partial heat treatment step is included in a part of the press working line, continuous work including the heat treatment step is possible, and the production is performed. It is possible to improve efficiency.

[Brief description of drawings]

FIG. 1 is a process drawing of a method of manufacturing a laminated magnetic pole core for a stator according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a heat treatment state of a linked magnetic pole core member.

FIG. 3 is a flow chart of a method of manufacturing a laminated magnetic pole core for a stator according to an embodiment of the present invention.

FIG. 4 is a partially enlarged view of the drawing shown in FIG.

[Explanation of symbols]

10: Thin strip material, 11: Pilot hole, 12: Through hole,
13: Caulking protrusion, 14: Magnetic pole teeth, 15: Slot,
15a: annular connecting portion, 16: connecting magnetic pole iron core member, 17:
Coil, 18: Coil, 19: Dust core, 20: Shape processing station, 21: First loop device, 22: Partial heating station, 23: Second loop device, 24:
Separation processing station, 25: Laminating processing station,
26: Magnetic pole core piece, 27: Hole

Continuation of the front page (56) Reference JP-A-7-177710 (JP, A) JP-A-4-22157 (JP, A) JP-A-62-228490 (JP, A) JP-A-57-45914 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 15/02

Claims (3)

(57) [Claims] 1. A method for manufacturing a laminated magnetic pole core for a stator, comprising forming a required shape of a magnetic pole core piece by pressing a thin strip material made of cold-rolled steel for lamination and laminating a predetermined number of the magnetic pole core pieces. A shape processing step of manufacturing an intermediate-shaped connecting magnetic pole core member that includes an annular connecting portion that connects the tip ends of the magnetic pole teeth of the magnetic pole core piece in an annular shape from the thin strip material; The iron core member is intermittently transferred to a heat treatment furnace, and high frequency induction heating coils are provided on the front and back sides of the portions corresponding to the plurality of annular magnetic pole teeth, respectively.
Heat treatment, a partial heat treatment step to improve the magnetic properties of the slot periphery including the magnetic pole teeth are separated form the distal ends of the magnetic pole teeth of the connecting pole core member treated with the partial heat treatment step A step of removing the annular connecting portion by performing a machining step, and forming the outer shape of the magnetic pole iron core piece by punching from the separated connecting magnetic pole iron core member of the annular connecting portion, and predetermining the magnetic pole iron piece. And a lamination processing step of forming required lamination magnetic pole cores by sequentially laminating the same. 2. The high-frequency induction heating coils on the front and back sides arranged corresponding to a plurality of annular magnetic pole teeth of the connecting magnetic pole core member are arranged concentrically, and further inside thereof, at the time of heating. The method for manufacturing a laminated magnetic pole core for a stator according to claim 1, wherein a dust core can be inserted. 3. The shape processing step and the lamination processing step each include a processing station to form a press processing line for a stator laminated magnetic pole core directly or through a loop device, and The partial heating station for performing the processing of the partial heating processing step is arranged between the processing stations of the shape processing step and the lamination processing step to form an integrated line as a whole. Alternatively, the method for manufacturing a laminated magnetic pole core for a stator according to 2 above.