JPH06165447A - Manufacture of laminated iron core - Google Patents

Abstract

PURPOSE:To provide a manufacture of a laminated iron core, which can easily and surely remove a means for temporarily fixing each iron core with the next, which may cause the iron loss, generating an eddy current, from the laminated iron core, concerning the method of manufacturing a laminated iron core such as a motor core, a transformer core, etc. CONSTITUTION:Thin plates 11b to 11n for iron cores died as desired are stamped out in order as iron cores 21 into a mold by outline stamping, and also each iron core 21 stacked in this mold is temporarily fixed with temporarily fixing means 15 and 17, using one part within an unnecessary thin part 12 for removal, and this temporarily fixed stacked iron core 14 is taken out of the mold, and then the regular fixation of the stacked iron core 14 by a fixing means 29 and the removal by stamping of temporarily fixed unnecessary thin parts for removal are performed. And, the temporarily fixed unnecessary thin parts 12 for removal are stamped once in the condition that they are pulled out half or completely from the thin plates for iron cores before stamping of outline, and then they pushed back into stamp holes 19, and are set and held in press-fit condition to the thin plates 11b to 11n for iron cores.

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 iron core such as a motor core or a transformer core by joining a predetermined number of iron cores punched from a strip-shaped thin plate material in a laminated state.

[0002]

2. Description of the Related Art When manufacturing a laminated core of this type,
For example, while intermittently transferring the strip-shaped thin plate material with a progressive die device, the core thin plate portion of the strip thin plate material is sequentially subjected to a desired die-cutting process in each process, and then the core thin plate portion is subjected to an outer diameter. It is punched by a punching punch, separated from the strip-shaped thin plate material, and sequentially withdrawn into the die, and the removed iron cores are joined in a laminated state by a predetermined number of sheets by caulking joining means provided in advance in the iron core. The automatic laminating method is used. As a general caulking coupling means therefor, for example, as shown in JP-A-58-116033, a cut-and-raised portion is provided in advance in each iron core, or JP-A-
As in Japanese Patent Laid-Open No. 9-37103, punching projections (doughs) are provided, and the iron cores are sequentially punched from a strip-shaped thin plate material by an outer diameter punching punch, and are punched out into a die under pressure, and vertically adjacent to each other in a stacked state. The iron cores are connected by caulking with raised portions or punched protrusions. However, in the above-mentioned general caulking coupling means, the coupling portion such as the cut-and-raised portion and the punch-out projection is left as it is when the motor is assembled by subsequently inserting the shaft into the shaft hole, for example. However, there is a problem that an eddy current or the like is generated in the caulking connection portion, and the efficiency is reduced by several percent due to iron loss.

As one of means for solving this problem,
For example, a method of manufacturing a laminated iron core according to JP-A-55-13665 is known. As shown in the outline of FIG. 6, this manufacturing method includes a removed thin plate portion which is finally removed as scrap in the iron core 1 such as the shaft hole 3 and the slot portion 2 and is unnecessary as the laminated iron core 7. For the whole
The iron cores 1a to 1n are punched in a half-blanked state in advance, for example, half-blanked holes 6a to 6n corresponding to the shaft holes 3, and projecting portions that are connected to the bottom side by the outer peripheral edge portions of the half-blanked holes. 5b to 5n are formed in advance. When these cores are separated from the strip-shaped thin plate material by the outer diameter punch and sequentially dropped into the die, the protrusions 5 of the vertically adjacent cores 1 are press-fitted into the semi-drilled holes 6. After taking out a predetermined number of laminated iron cores 7 that have been fitted and caulked and tentatively fixed to each other by this caulking, from the die, main fixing is performed by a separate means, and the caulked-connected shaft hole 3 portion is removed. The shaft is attached to the shaft hole 3 by removing it by press punching.

[0004]

However, like the latter, an unnecessary portion of each iron core 1, for example, the projection 5 and the half-drilled hole 6 provided on the whole of the thin plate portion for the shaft hole are temporarily fixed by caulking. When the caulked and joined thin plate portion for an axial hole is subsequently punched and removed, there are the following problems. As described above, in order to press fit the outer diameter of the protruding portion 5 to the inner diameter of the half-drilled hole 6 and crimp the iron cores 1 together, the inner diameter dimension d ₁ of the half-drilled hole 6 is set to the outside of the protruding portion 5. It is necessary to make it smaller than the diameter dimension ₂ , and in order to punch out and remove this caulked joint from the laminated iron core 7, a half-blanked portion of this caulked joint, that is, a portion connected to the iron core side is completely separated. Therefore, a large press or the like is required because the punching force increases. That is, it is not easy to punch the caulked joint portion from the laminated iron core 7 in which a large number of iron cores 1 are stacked, and burrs are easily generated in the punched holes, so that additional machining in a separate process is required. is necessary. Therefore, in the present invention, a method of manufacturing a laminated iron core that can eliminate iron loss due to eddy currents generated from the joint portions of the respective iron cores, which is a problem of the prior art as described above, and facilitate removal of unnecessary portions including the joint portions. 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, desired thinned iron core thin plate portions are sequentially dropped into the mold as outer cores by outer diameter punching. Along with this, unnecessary removal of the iron cores stacked in the mold is temporarily fixed by temporarily fixing each iron core by a part of the thin plate portion, and after taking out the temporarily fixed laminated core from the mold. , The main fixation of the laminated iron core by the main fixation means and the removal and removal of the temporarily fixed removal thin plate portion are performed, and the unnecessary removal thin plate portion that is temporarily fixed is removed from the iron core thin plate portion before the outer diameter punching. After punching once in the half-punched state or the completely punched state, it is pushed back into the punched hole and press-fitted and held in the thin plate portion for the iron core. 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 groove into which the caulking projection can be press-fitted, on the upper surface side, respectively, by the outer diameter punching. When the iron cores are sequentially pulled out into the mold, the caulking projections and the caulking concave grooves of the vertically adjacent iron cores are caulked together. Another temporary fixing means irradiates the removed thin plate portions of the iron cores stacked in the mold with laser light to partially weld the removed thin plate portions by laser welding. Further, the laminated iron core is a laminated iron core of a motor rotor, the removal thin plate portion that is temporarily fixed is used as a shaft hole thin plate portion that becomes a rotor shaft hole, and the thin plate portion for shaft hole of the temporarily fixed laminated iron core is pressed. The rotor shaft is pressed by using a pressing force such as the above, so that the thin plate portion for the shaft hole is separated and removed, and the main fixing is performed by press-fitting the rotor shaft into the rotor shaft hole at the same time.

[0006]

EXAMPLES A method for manufacturing a laminated core according to the present invention will be described below in detail with reference to the examples shown in FIGS. FIG. 1 (a) shows that a thin plate portion 11 for an iron core of a strip-shaped thin plate material 10 is punched as an iron core 21 after being subjected to a desired punching process by a progressive die device (not shown), and finally a figure. 5 (f) is a plan view showing a process of manufacturing the laminated core 14 of the motor rotor 13 as shown in FIG.
[Fig. 3] is a front view showing a main part by breaking.

In the first step, in order to separate the connecting portions of the first iron core 21a of the laminated core 14 from the beginning of stacking and the second and subsequent iron cores 21b to 21n among the respective iron cores 21, the rotor shaft is separated. As shown in FIG. 5A, the first iron core is provided with a plurality of (three in the embodiment) separation holes 15 for separation, which are formed inside the thin plate portion 12 for the shaft hole to be the holes 16. 21
The so-called weighing-out is performed in which the iron core thin plate portion 11a to be a is bored. In the second step, the separation holes 15 are formed in the iron core thin plate portions 11b to 11n, which are the second and subsequent iron cores 21b to 21n of the laminated iron core 14 among the iron cores 21.
The caulking coupling portion 17 is formed so as to project at the same position as that, and a large number of slot portions 1 are provided around the outer periphery of the axial plate thin plate portion 12.
8 is stamped on all the thin plate portions 11 for the iron core. As shown in the enlarged view of FIG. 5 (a), the caulking coupling portion 17 has a caulking projection 17 a partially protruding toward the bottom surface of the iron core thin plate portions 11 b to 11 n, and the iron core thin plate portion 11. The caulking protrusion 17a is provided in a part of the upper surface side and is slightly smaller in diameter than the caulking projection 17a. The caulking groove 17b has the same diameter as the separating hole 15.

In the third step, the shaft hole thin plate portion 12 is punched in each iron core thin plate portion 11 in a half-blanked state,
As a result, the thin plate portion 12 for the shaft hole is cut and raised in such a manner that it projects toward the bottom surface side of the thin plate portion 11 for each iron core, and a half-drilled hole 19 is formed on the upper surface side of the thin plate portion 11 for each iron core. .
As shown in the enlarged view of FIG. 5B, the thin plate portion 12 for the shaft hole and the half-drilled hole 19 are located at the beginning of stacking of the laminated iron core 14.
In the iron core thin plate portion 11a serving as the first iron core 21a, the shaft hole thin plate portion 12a in which the separation hole 15 is formed is cut and raised, and the half-drilled hole 19a is formed in the upper portion thereof. In the iron core thin plate portions 11b to 11n that are the second and subsequent iron cores 21b to 21n, the axial hole thin plate portions 12b to 12n in which the crimping coupling portion 17 is formed by the crimping projection 17a and the crimping groove 17b are formed. It is cut and raised and half-drilled holes 19b to 19n are formed in the upper part thereof.

In the fourth step, the thin plate portion 12 for the shaft hole, which has been cut and raised in the third step and is in the half-blanked state, is flat-pressed from the bottom side of the thin plate portion 11 for the iron core and pushed back (pushed back) into the half-blanked hole. ). The pushed back axial plate 12 is
When pressed flat, the connecting portion with the iron core thin plate portion 11 is sheared and is almost separated, and is press-fitted into the half-blank hole 19. As shown in detail in FIG. 5 (c) in an enlarged manner, the outer peripheral surface of the shaft hole thin plate portion 12a has an iron core thin plate portion 11a.
The outer peripheral surfaces of the shaft hole thin plate portions 12b to 12n are respectively supported by the pressure contact connecting portions 20 with the iron core thin plate portions 11b to 11n. The fifth step is a play (idle) step provided for balancing the mold apparatus without any special work.

In the sixth step, as shown in FIG. 2, the iron core thin plate portion 11 is punched by the outer diameter punching punch 22 and the iron cores 21 separated from the strip-shaped thin plate material 10 are sequentially inserted into the punching holes 24 of the die portion 23. Be pulled out. As shown in the enlarged view of FIG. 5D, the iron cores 21 drawn into the hole 24 are separated from the first hole 21a of the first iron core 21a, which is the first hole, for separation. The second iron core 21 pulled into the
The crimping protrusion 17a of b is fitted in a press-fitted state and crimped together, and each of the third and subsequent iron cores 21c to 21n
In the caulking groove 17b of the iron core 21 that has been pulled out first, the caulking protrusion 17a of the iron core 21 that has been pulled out later is fitted and press-fitted in the caulking connection. The caulking force at that time is generated by the resistance force due to the interference between the inner diameter of the punching hole 24 of the die portion 23 and the outer diameter of the iron core 21 and the pressing force of the outer diameter punching punch 22 in the punching direction. In this way
Iron cores 2 that are pulled out one after another and are vertically adjacent to each other in a laminated state
Reference numeral 1 denotes a core 21a in which a caulking projection 17a and a caulking concave groove 17b provided in a shaft hole thin plate portion 12 are caulked to each other via a caulking joint portion 17, and then a separation hole 15 is formed in the iron core 21a. When the iron is pulled out, the iron core 21 pulled out first
Since it is not caulked with n, the laminated core 14 obtained by separating and laminating a predetermined number of sheets is obtained.

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

In the seventh step, the temporarily fixed laminated iron core 14 is placed on the base 28 having the shaft insertion hole 28a formed therein as shown in FIG. 4, and the rotor is pressed by a pressing force by a press or the like. The shaft 29 presses the upper surface of the shaft hole thin plate portion 12. As a result, as shown in detail in FIG. 5 (e), the shaft hole thin plate portion 12 provided with the caulking coupling portion 17 is provided.
Is a press-connecting connecting portion 20 for each core 21 of the laminated core 14.
Is pushed out into the shaft insertion hole 28a in a state of being separated from the rotor core, and the rotor shaft 29 is press-fitted into the rotor shaft hole 16 formed thereafter, while the caulking joint portion 17 is replaced, and the iron cores 21 are sequentially fixed to each other. 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 penetrates through the rotor shaft hole 16, the main fixation of the laminated core 14 by the rotor shaft 29 is completed,
As shown in FIG. 5 (f), the motor rotor 13 is completed.

The present invention is not limited to the above embodiments, but various modifications can be made within the scope of the invention. For example, in the sixth step, the back pressure block 26 at the tip of the fluid cylinder is removed through the vent hole 2 for caulking.
4, the back pressure block 26 is pushed down by one sheet each of the iron cores 21 every time the iron cores 21 are sequentially pulled out by being pressed by the outer diameter punching punch 22 from the lower surface side of the iron cores 21. When the predetermined number of iron cores 21 necessary for the laminated iron core 14 are pulled out or the back pressure block 26
When is pressed down by a predetermined distance corresponding to the height of the laminated core 14, the laminated core 14 may be discharged out of the mold by detecting this and driving the fluid cylinder. By doing so, it is possible to eliminate the possibility that the shaft hole thin plate portion 12 may be pushed out at the time of caulking and coupling in the above-described embodiment. Further, as a die structure, a die rotating means is provided on the die side in a portion corresponding to the sixth step, and so-called skew rotation known in the related art or so-called rolling for eliminating plate thickness deviation at the time of stacking is provided. You can also

Further, in the above embodiment, the shaft hole thin plate portion 12 which becomes the rotor shaft hole 16 as an unnecessary removal thin plate portion temporarily fixed.
Although the caulking joint portion 17 is provided in a part of the inside, the caulking joint portion is provided in a part of the other unnecessary removal thin plate portion that is punched and scrapped, such as the slot portion and the air guide hole. May be. Further, in the above embodiment, the unnecessary removal thin plate portion that is temporarily fixed by press-fitting the rotor shaft 29, that is, the shaft hole thin plate portion 12 is cut off, and the permanent fixing of the laminated core 14 by the rotor shaft 29 is simultaneously performed. Alternatively, the removed thin plate portion may be separated after the main fixing. In this case, a fixing means such as bolting is used for the final fixing. For example, when bolting, a through hole is previously formed in the thin plate portion 11 for the core, and the bolt is tightened through this through hole. Then, the laminated core 14 is permanently fixed,
After that, the removed thin plate portion is cut off as in the embodiment.
Further, in the above-mentioned embodiment, the method of temporary fixing is explained by caulking. However, the present invention is not limited to this, and the removed thin plate portion of each iron core 21 laminated in the mold is irradiated with laser light such as YAG laser. The heat energy of the laser light is used for welding to perform temporary fixing, and the unnecessary removed thin plate portion including the welded portion may be removed from the temporarily fixed laminated iron core as in the case of the embodiment. Further, in the above-mentioned embodiment, the so-called push-back method in which the thin plate portion 12 for the shaft hole, which is the unnecessary thin plate portion in the third and fourth steps, is pushed back after being half-punched is used. You may push it back from. Further, in the embodiment, the laminated iron core of the motor rotor has been described as an example, but the same method can be applied to laminated iron cores such as the stator and the 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 thin strip portion of each core, and the thin strip portion is removed. The push-back method allows almost all of the separated parts to be fitted and held in the laminated iron core in a press-fitted state, and the removal thin plate part from the part that is press-fitted and fitted when the laminated iron core is finally fixed. In the final laminated iron core product that has been separated and removed, 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, iron loss does not occur due to the generation of eddy current due to the residual caulked joint, and a laminated core having excellent characteristics can be obtained. Further, as compared with the case of unexamined Japanese Patent Laid-Open No. 55-13665, the entire unnecessary thin plate portion is half-blanked to form a caulking joint portion for temporary fixing, and the thin plate portion to be removed is later removed by press punching. Since it is easily removed without requiring a large punching force, and there is no occurrence of a residual portion or burrs and no post-processing is required, a high-quality laminated core product can be manufactured with good workability. However, since the temporary fixing is provided in a part of the removed thin plate portion, the temporary fixing means by welding of the laser beam can be used in addition to the caulking. Further, when manufacturing a laminated core of a motor rotor, a temporary fixing means is provided on the shaft hole thin plate part that becomes the rotor shaft hole, and the rotor shaft thin plate part is separated by press fitting the rotor shaft with a relatively small pressing force. The removal and the main fixation by the rotor shaft can be performed at the same time.

[Brief description of drawings]

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

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

FIG. 3 is a perspective view of a laminated iron core taken out from the mold of FIG.

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

FIG. 5 is a longitudinal cross-sectional view of a main part for explaining the processing state of the iron core in each of the above steps.

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

[Explanation of symbols]

10 Strip-shaped thin plate member 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-drilled hole 20 Pressure Contact Connection Part 21 Iron Core 22 Outer Diameter Punching Punch 23 Die Part 24 Die Hole 25 Piston Rod 26 Back Pressure Block 27 Detection Switch 28 Base 29 Rotor Shaft

Claims (4)

[Claims] 1. A desired die-cut thin plate portion for an iron core is sequentially pulled out as an iron core into a mold by punching with an outer diameter, and a part of the unnecessary removed thin plate portion of each iron core stacked in the die is removed. After temporarily fixing each iron core with temporary fixing means using, and taking out the temporarily fixed laminated iron core from the mold, the permanent fixing of the laminated iron core by the permanent fixing means and the punching removal of the temporarily fixed removed thin plate portion are performed. The unnecessary removal thin plate portion that is temporarily fixed is punched from the thin plate portion for an iron core before the outer diameter punching in a half punched state or a completely punched state and then pushed back into the punching hole, A method of manufacturing a laminated core, comprising fitting and holding the parts in a press-fitted state. 2. As the temporary fixing means, a caulking projection is provided from a part of a bottom surface side of the removal thin plate portion, and a caulking concave groove into which the caulking projection can be press-fitted is provided on an upper surface side, respectively. The method for manufacturing a laminated iron core according to claim 1, wherein when the iron cores are sequentially pulled out into the mold by the outer diameter punching, the vertically adjacent iron cores are caulked with the caulking grooves and the caulking concave grooves. . 3. The temporary fixing means, wherein the removed thin plate portions of the iron cores stacked in the mold are irradiated with laser light to partially weld the removed thin plate portions by laser welding.
The method for manufacturing a laminated core according to 1. 4. The laminated iron core is a laminated iron core of a motor rotor, wherein the temporarily fixed removal thin plate portion is a shaft hole thin plate portion which becomes a rotor shaft hole, and the temporarily fixed laminated iron core shaft hole thin plate is formed. 4. The portion is pressed by the rotor shaft by using a pressing force of a press or the like, so that the thin plate portion for the shaft hole is cut off and removed, and the main fixing by press-fitting the rotor shaft into the rotor shaft hole is simultaneously performed. 2. A method for manufacturing a laminated core according to any one of 1.