JP3294348B2 - Manufacturing method of laminated core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated core such as a motor core or a transformer core by combining a predetermined number of cores punched from a strip-shaped sheet material in a laminated state.

[0002]

2. Description of the Related Art When manufacturing this type of laminated core,
For example, while the strip-shaped sheet material is intermittently transported by a progressive die apparatus, a desired die-cutting process is sequentially performed on the iron-sheet thin portion of the strip-shaped sheet material in each process, and then the outer diameter of the iron-sheet thin portion is reduced. A so-called die in which a predetermined number of cores are punched out by a punch and separated from the strip-shaped thin sheet material and sequentially dropped into a die, and the cores thus cut out are joined in a stacked state by a predetermined number of sheets by caulking coupling means provided in advance on the core. An automatic lamination method is used. As a general caulking means for this purpose, for example, a cut and raised portion is provided in advance in each iron core as disclosed in Japanese Patent Application Laid-Open No. 58-116033,
As described in JP-A-9-37103, a projection (a dowel) is provided, and the core is sequentially punched from a strip-shaped thin plate material by an outer diameter punch, dropped into a die under a pressurized state, and vertically adjacent to each other in a laminated state. The cores are caulked and connected with a cut-out portion or a projection. However, in the above-described general caulking coupling means, the coupling portion such as the cut-and-raised portion or the projection is left as it is when the motor is assembled by, for example, inserting a shaft into a shaft hole. However, there is a problem that an eddy current or the like is generated in the caulked joint portion, and the efficiency is reduced by several percent due to iron loss.

[0003] As one of means for solving this problem,
For example, a method of manufacturing a laminated iron core according to Japanese Patent Application Laid-Open No. 55-13665 is known. As shown in the outline of FIG. 6, this manufacturing method finally removes the scrap inside the iron core 1 such as the shaft hole 3 and the slot portion 2 and removes the unnecessary thin plate portion as the laminated iron core 7. For the whole
The cores 1a to 1n are punched in advance in a half-punched state, and half-punched holes 6a to 6n corresponding to, for example, the shaft hole 3, and protruding parts which are connected to the bottom side through the outer peripheral edges of the half-punched holes. 5b to 5n are formed in advance. When these cores are cut off from the strip-shaped sheet material by the outer diameter punch and are sequentially dropped into the die, the protruding portions 5 of the vertically adjacent cores 1 are pressed into the half punched holes 6. After taking out a predetermined number of laminated cores 7 that are fitted and caulked and temporarily fixed to each other by the caulking connection from the inside of the die, they are permanently fixed by another means, and the caulked and connected shaft holes 3 are removed. The shaft is attached to the shaft hole 3 by removing by press punching.

[0004]

However, as in the latter case, an unnecessary portion of each iron core 1, for example, a protrusion 5 provided on the entire thin plate portion for a shaft hole and a half-drilled hole 6 are temporarily fixed by caulking, In the case where the caulked and connected thin plate portion for the shaft hole is subsequently punched and removed, there are the following problems. As described above, in order to press-fit the outer diameter of the protrusion 5 into the inner diameter of the half-drilled hole 6 and to caulk and connect the respective cores 1, the inner diameter d1 of the half-drilled hole 6 is determined by the outer diameter of the protrusion 5 It is necessary to make it smaller than the dimension d2 , and in order to remove this caulked joint from the laminated iron core 7, it is necessary to completely remove the semi-cut portion of the caulked joint, that is, the part connected to the iron core side. Punching is required, and the punching force increases, so a large press or the like is required. That is, it is not easy to punch out the above-mentioned swaged joint portion from the laminated core 7 in which a large number of cores 1 are stacked, and burrs and the like are easily generated in the punched holes. is necessary. Therefore, in the present invention, a method of manufacturing a laminated core capable of eliminating iron loss due to eddy current generated from a joint portion of each core, which is a problem of the prior art, and facilitating removal of an unnecessary portion including the joint portion. The purpose is to provide.

[0005]

In the method of manufacturing a laminated iron core according to the present invention for solving the above-mentioned problems, a desired die-cut thin-plate portion for an iron core is sequentially dropped as an iron core into a die by punching an outer diameter. At the same time, each core is temporarily fixed by a temporary fixing means using a part of the unnecessary removed thin plate portion of each core stacked in the mold, and the temporarily fixed laminated core is taken out from the mold. The permanent thinning of the laminated core by the permanent fixing means and punching and removal of the temporarily thinned removed thin plate portion are performed, and the unnecessary thin thin plate portion temporarily fixed is removed from the thin core portion before punching the outer diameter. The sheet is once punched in a half-punched state or a completely punched state, then pushed back into the punched hole, and fitted and held in the iron core thin plate in a press-fit state. Further, the temporary fixing means is provided with a caulking projection from a part of the bottom surface side of the removal thin plate portion, and a caulking concave groove on the upper surface side where the caulking projection can be press-fitted, and the outer diameter punching is performed. When the cores were sequentially dropped into the mold, the caulking projections and the caulking concave grooves of the vertically adjacent cores were caulked. Further, another temporary fixing means irradiates the removed thin plate portions of the respective iron cores stacked in the mold with laser light, and partially welds the removed thin plate portions by laser welding. Further, the laminated core is a laminated core of a rotor for a motor, the removed thin plate portion temporarily fixed is used as a thin plate portion for an axial hole serving as a rotor shaft hole, and the thin plate portion for a shaft hole of the temporarily fixed laminated core is pressed. The rotor shaft is pressed using a pressing force such as that described above, so that the separation and removal of the thin plate portion for the shaft hole and the permanent fixing by press-fitting the rotor shaft into the rotor shaft hole are performed simultaneously.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a laminated core according to the present invention will be described below in detail with reference to the embodiments shown in FIGS. FIG. 1A is a diagram illustrating a state in which the iron core thin plate portion 11 of the belt-shaped thin plate material 10 is punched as an iron core 21 after performing a desired die cutting process using a progressive die apparatus (not shown). FIG. 1B is a plan view showing a step of manufacturing the laminated iron core 14 of the motor rotor 13 as shown in FIG.
FIG. 3 is a front view of the same part, which is cut away.

In the first step, the rotor shaft is separated from the cores 21 in order to separate the joint between the first core 21a at the start of stacking of the laminated cores 14 and the second and subsequent cores 21b to 21n. A plurality of (three in this embodiment) through-holes 15 for separation are formed inside the thin plate portion 12 for shaft holes, which become holes 16, and the first iron core as shown in detail in FIG. 21
The so-called weigh-out is performed on the iron core thin plate portion 11a to be a. In the second step, the separation holes 15 are formed in the core thin plates 11b to 11n to be the second and subsequent cores 21b to 21n of the laminated core 14 among the cores 21.
And a plurality of slot portions 1 are formed around the outer periphery of the thin plate portion 12 for the shaft hole.
8 is punched out from all the iron core thin plate portions 11. The caulking connection portion 17 includes a caulking protrusion 17a partially projecting toward the bottom surface side of the iron core thin plate portions 11b to 11n as shown in an enlarged detail in FIG. It is provided with a caulking concave groove 17b which is formed in a part on the upper surface side and has a slightly smaller diameter than the caulking projection 17a. The caulking groove 17b is formed to have the same diameter as the separating hole 15.

In the third step, the thin plate portion 12 for the shaft hole is punched from the thin plate portion 11 for each iron core in a half-punched state.
Thus, the thin plate portion 12 for the shaft hole is cut and raised so as to protrude toward the bottom surface side of the thin plate portion 11 for each iron core, and a half hole 19 is formed on the upper surface side of the thin plate portion 11 for each iron core. .
As shown in an enlarged detail in FIG. 5B, the thin plate portion 12 for the shaft hole and the half-drilled hole 19 are located at the beginning of the stacking of the laminated core 14.
In the core thin plate portion 11a to be the second iron core 21a, the shaft hole thin plate portion 12a in which the separation hole 15 is formed is cut and raised to form a half-drilled hole 19a in an upper portion thereof, and the laminated core 14 is formed. In the core thin plate portions 11b to 11n to be the second and subsequent iron cores 21b to 21n, the shaft hole thin plate portions 12b to 12n in which the swaging coupling portion 17 is formed by the swaging protrusion 17a and the swaging concave groove 17b. It is cut and raised to form half-holes 19b to 19n in the upper part.

In the fourth step, the shaft hole thin plate portion 12 cut and raised in the third step is pressed halfway from the bottom side of the iron core thin plate portion 11 and pushed back into the half hole (pushed back). ). The pushed back thin plate portion 12 for the shaft hole is
When pressed flat, the connection portion with the iron core thin plate portion 11 is sheared and pressed into the half-drilled hole 19 in a state where it is almost cut off. As shown in an enlarged manner in FIG. 5 (c), the outer peripheral surface of the shaft hole thin plate portion 12a is
And the outer peripheral surfaces of the shaft hole thin plate portions 12b to 12n are supported by the pressure contact connecting portions 20 with the iron core thin plate portions 11b to 11n, respectively. The fifth step is an idle (idle) step provided for balancing the mold apparatus without performing any special operation.

In the sixth step, as shown in FIG. 2, each core 21 cut out from the strip-shaped thin plate material 10 by punching out the core thin plate portion 11 by the outer diameter punching punch 22 is sequentially inserted into the punched hole 24 of the die portion 23. Be pulled out. As shown in an enlarged detail in FIG. 5D, each of the cores 21 drawn into the cutout holes 24 is placed next to the separation hole 15 of the first drawn core 21a. The second iron core 21 pulled into
The crimping projections 17a are fitted and press-fitted in a press-fit state, and the third and subsequent cores 21c to 21n
The crimping projections 17a of the core 21 pulled out from the rear are inserted into the caulking recessed grooves 17b of the iron core 21 drawn in earlier in a press-fit state, and are connected by caulking. The caulking force at that time is generated by a resistance force due to a margin between the inside diameter of the hole 24 of the die portion 23 and the outside diameter of the iron core 21 and a pressing force of the outside diameter punching punch 22 in the drawing direction. In this way,
Each iron core 2 which is pulled out one after another and vertically adjacent in a stacked state
Reference numeral 1 denotes an iron core 21a which is caulked and connected to each other via a caulking joint 17 formed by a caulking projection 17a and a caulking concave groove 17b provided in the shaft hole thin plate portion 12, and then has a separation hole 15 formed therein. When the core is pulled out, the iron core 21 pulled out earlier
Since n is not caulked, the laminated cores 14 separated and stacked in a predetermined number are obtained.

When the inside of the hole 24 is filled with the plurality of laminated iron cores 14 temporarily fixed in a stacked state as described above, the piston rod of the fluid cylinder installed below the hole 24 is provided. The bottom surface of the first laminated iron core 14 is in contact with the upper surface of the back pressure block 26 provided at the end of the first 25. In this state, when a new laminated core 14 is further pushed in from above, the first laminated core 14 on the back pressure block 26 is pushed out from the hole 24 and the back pressure block 26
Is activated. The fluid cylinder driven by the detection signal of the detection switch 27 lowers the back pressure block 26, and
The laminated iron cores 14 are taken out, and the laminated iron cores 14 are discharged to the outside via discharging means (not shown). As shown in FIG. 3, the laminated iron core 14 is formed such that the rotor shaft hole 16 is partially cut out, and then the shaft hole thin plate portion 12 is pushed back.
And the thin plate portion 12 for the shaft hole.
The iron cores 21 vertically adjacent to each other are temporarily fixed to each other by the caulking joint portion 17 provided at the bottom.

In a seventh step, the temporarily fixed laminated iron core 14 is placed on a base 28 provided with a shaft insertion hole 28a as shown in FIG. 4, and the rotor is pressed by a pressing force such as a press. The upper surface of the shaft hole thin plate portion 12 is pressed by the shaft 29. As a result, as shown in detail in FIG. 5E, the shaft hole thin plate portion 12 provided with the caulking connection portion 17 is provided.
Is connected to each of the cores 21 of the laminated core 14 by the press-connecting connection portions 20.
The cores 21 are pushed out into the shaft insertion holes 28a in a state where they are separated from each other, and the rotor shafts 29 are press-fitted into the rotor shaft holes 16 formed thereafter, and the cores 21 are successively fixed to each other in place of the caulked joints 17. I will do it. Therefore, when the shaft hole thin plate portion 12 is completely removed from the laminated core 14 and the rotor shaft 29 passes through the inside of the rotor shaft hole 16, the permanent fixing of the laminated core 14 by the rotor shaft 29 is completed,
As shown in FIG. 5F, the motor rotor 13 is completed.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist. For example, in the sixth step, the back pressure block 26 at the distal end of the fluid cylinder is removed by a hole 2 for caulking.
The back pressure block 26 is disposed at an upper position in the inner surface 4 and is pressed by the outer diameter punching punch 22 from the lower surface side of the iron core 21, and the back pressure block 26 is pushed down by one sheet of the iron core 21 every time the iron core 21 is pulled out. When the required number of cores 21 are pulled out of the laminated core 14 or when the back pressure block 26
When is pressed down by a predetermined distance corresponding to the height of the laminated core 14, this may be detected and the fluid cylinder may be driven to discharge the laminated core 14 out of the mold. In this manner, it is possible to eliminate the possibility that the shaft hole thin plate portion 12 may be pushed out during the caulking connection in the above-described embodiment. Further, as the mold structure, a die rotating means is provided on the die side in a portion corresponding to the sixth step so as to provide a so-called turning stack for eliminating a conventionally known skew rotation and a thickness deviation at the time of lamination. You can also.

Further, in the above embodiment, the shaft hole thin plate portion 12 which becomes the rotor shaft hole 16 as the unnecessary thin plate portion to be temporarily fixed is used.
Although the caulking joint 17 is provided in a part of the inside, the caulking joint is provided in a part of another unnecessary removing thin plate part which is punched and scrapped like a slot part or a wind guide hole. May be. Further, in the above embodiment, the unnecessary thin plate portion, which is temporarily fixed by press-fitting of the rotor shaft 29, that is, the separation of the thin plate portion 12 for the shaft hole, and the permanent fixing of the laminated core 14 by the rotor shaft 29 are simultaneously performed. Alternatively, after the permanent fixation, the removed thin plate portion may be separated. At this time, fixing means such as bolting or the like is used for permanent fixing. For example, in the case of bolting, a through hole is previously formed in the thin plate portion 11 for an iron core, and bolting is performed through this through hole. To perform the final fixation of the laminated iron core 14,
Thereafter, the removed thin plate portion is cut off in the same manner as in the embodiment.
Further, in the above-described embodiment, the method of the temporary fixing is explained by the method of caulking. However, the present invention is not limited to this. For example, a laser beam such as a YAG laser is applied to the removed thin plate portion of each iron core 21 laminated in the mold. Then, the temporary fixing is performed by welding using the heat energy of the laser beam, and the unnecessary thin plate portion including the welded portion may be removed from the temporarily fixed laminated core later as in the case of the embodiment. In the above-described embodiment, the so-called push-back method is adopted in which the shaft-portion thin plate portion 12 which is an unnecessary thin plate portion in the third and fourth steps is half-punched and then pushed back. You may be made to push back from. Further, in the embodiment, the laminated core of the motor rotor has been described as an example, but the same method can be applied to a laminated core such as a stator or a transformer of the motor.

[0015]

As is apparent from the above description, in the method for manufacturing a laminated core according to the present invention, a portion for temporarily fixing the laminated core is provided in a part of the unnecessary removed thin plate portion of each core, and the removed thin plate portion is provided. Is almost completely separated by the push-back method so that the laminated iron core is fitted and held in a press-fit state, and the removed thin plate portion is removed from the press-fitted part when the laminated iron core is fully fixed. In the final laminated core product, the removed thin plate portion including the temporarily fixed portion is completely removed. Therefore, unlike the case of the manufacturing method generally performed in the prior art, the core loss does not occur due to the generation of the eddy current due to the remaining of the caulked joint, and a laminated core having excellent characteristics can be obtained. Also, as compared with Japanese Patent Application Laid-Open No. 55-13665, the unnecessary unnecessary thin plate portion is formed into a half-blanked shape to form a caulking connection portion for temporary fixing, and the removed thin plate portion is later removed by press punching. A high quality laminated iron core product can be manufactured with good workability because it is easily removed without the need for a large punching force, and there is no need for post-processing without the generation of residual portions or burrs. Of course, since the temporary fixing is provided in a part of the removal thin plate portion, a temporary fixing means by welding of a laser beam is also possible in addition to the caulking connection. Further, when manufacturing a laminated iron core for a motor rotor, a temporary fixing means is provided on the shaft hole thin plate portion serving as the rotor shaft hole, and the shaft hole thin plate portion is separated by press-fitting the rotor shaft with a relatively small pressing force. Removal and permanent fixing by the rotor shaft can be performed simultaneously.

[Brief description of the drawings]

FIG. 1 is a process diagram of an embodiment in which an iron core of a motor rotor is punched by using a method of manufacturing a laminated iron core according to the present invention.

FIG. 2 is a sectional view of an essential part of a mold used in a sixth step in FIG.

FIG. 3 is a perspective view of a laminated core taken out of the mold of FIG. 2;

FIG. 4 is a vertical cross-sectional view for explaining a seventh step of removing the unnecessary portion of the shaft hole thin plate portion, which is an unnecessary portion, from the laminated core and permanently fixing the shaft hole thin portion.

FIG. 5 is a vertical sectional view of an essential part for explaining a state of machining the iron core in each step described above.

FIG. 6 is an explanatory diagram of a method for manufacturing a laminated core according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Strip-shaped thin plate material 11 Iron core thin plate part 12 Shaft hole thin plate part 13 Motor rotor 14 Laminated iron core 15 Separation hole 16 Rotor shaft hole 17 Caulking connection part 17a Caulking protrusion 17b Caulking concave groove 18 Slot part 19 Half hole Reference Signs List 20 Press-connecting portion 21 Iron core 22 Outer diameter punching punch 23 Die portion 24 Drilling hole 25 Piston rod 26 Back pressure block 27 Detection switch 28 Base 29 Rotor shaft

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 15/02 B21D 28/02 B21D 28/10 B21D 39/03

Claims (4)

(57) [Claims] 1. An unnecessary thin sheet portion for punching and removing after lamination is provided on an iron sheet part of a strip-shaped sheet material, and the unnecessary thin sheet part is half-punched or completely punched from the iron sheet part before the outer diameter punching. After punching once in the state, it is pushed back into the punched hole and fitted in a press-fit state, the outer shape sheared against the iron core thin plate portion is supported by the press-contact connecting portion, and the outer diameter of the iron core thin plate portion from the band-shaped thin plate material is changed. The cores are sequentially drawn out as a core into the mold by punching and laminated, and each core is temporarily fixed by a temporary fixing means by caulking a part inside the outer shape of the unnecessary removed thin plate portion, and the temporarily fixed laminated core is removed. A method for manufacturing a laminated core, comprising: after being taken out from a mold, performing permanent fixing of the laminated core and punching and removing of a removed thin plate portion by a permanent fixing means. 2. The temporary fixing means by caulking connection comprises: a caulking projection having a part inside the outer shape of the removed thin plate portion projecting to the bottom side; and an upper surface side at which the caulking projection can be press-fitted. A crimping groove, and when the cores are successively dropped into the mold as a result of the outer diameter punching, the crimping protrusions and the crimping grooves of the vertically adjacent cores are crimped and connected. Item 4. The method for producing a laminated core according to Item 1. 3. An unnecessary thin sheet portion for punching and removing after lamination is provided in the thin sheet part for the core of the strip-shaped thin sheet material, and the unnecessary thin sheet part is half-punched or completely punched from the thin sheet part for the core before the outer diameter punching. After punching once in the state, it is pushed back into the punched hole and fitted in a press-fit state, the outer shape sheared against the iron core thin plate portion is supported by the press-contact connecting portion, and the outer diameter of the iron core thin plate portion from the band-shaped thin plate material is changed. The cores are sequentially dropped into the mold by punching and laminated, and the respective cores are temporarily fixed by a temporary fixing means for irradiating a part of the unnecessary removed thin plate portion with a laser beam and laser-welding, and temporarily laminated. A method for manufacturing a laminated core, comprising: after the core is taken out of the mold, performing permanent fixing of the laminated core and punching and removing of the removed thin plate portion by the permanent fixing means. 4. The laminated core is a laminated core of a motor rotor, wherein the removed thin plate portion is a shaft hole thin plate portion serving as a rotor shaft hole, and a part of the shaft hole thin plate portion is fixed by the temporary fixing means. The thin plate portion for the shaft hole is pressed against the temporarily fixed laminated core by a rotor shaft using a pressing force such as a press, and the thin plate portion for the shaft hole is removed by disconnecting the press-connecting portion, and the rotor is inserted into the rotor shaft hole. The method for manufacturing a laminated iron core according to any one of claims 1 to 3, wherein the permanent fixing by press-fitting the shaft is performed simultaneously.