JP4030701B2 - Iron core manufacturing method and iron core manufacturing apparatus suitable for the method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an iron core such as a motor or a transformer, and a manufacturing apparatus suitable for the method.
[0002]
[Prior art]
When manufacturing laminated iron cores such as motors and transformers using non-oriented electrical steel sheets, in general, electrical steel sheets are made into unit iron cores by shearing or punching, then laminated, and then bolted, caulked, welded Or it adheres by adhesion | attachment etc.
After the laminated iron core is fixed, it is subjected to processing such as a winding coil assembling process, and finally the transformer is assembled. The laminated iron core is weakly fixed, and if it is unwound to a unit iron core, the efficiency of coil winding work is reduced, so the laminated iron core needs to be firmly fixed.
[0003]
By the way, when fixing by bolting, it is necessary to provide a through hole through which the bolt passes in the laminated iron core, and when a through hole is provided in the laminated iron core, the magnetic properties of the laminated iron core deteriorate. Similarly, when the laminated iron core is fixed by welding, the magnetic properties of the laminated iron core may deteriorate due to thermal distortion in the welded portion.
In the case of fixing with an adhesive, a liquid adhesive is poured between the steel plates using the capillary phenomenon and then fixed, but it is difficult to evenly pour the adhesive. There is a problem that it is difficult to treat the adhesive remaining on the laminated end surface of the iron core.
[0004]
Furthermore, methods such as bolting, welding and adhesives have the problem that the steel plate is punched into the unit iron core in the punching process and then the laminated surfaces are aligned and fixed, which increases the assembly process and increases costs. .
[0005]
Therefore, at present, fixing by caulking, which can fix a laminated iron core at the same time as punching, is common. The caulking method is characterized in that it can be fixed in a punching die and has a very high production efficiency. However, it is difficult to firmly fix with caulking, and the laminated iron core may be displaced during assembly of the transformer, or the magnetic characteristics may be deteriorated due to caulking.
[0006]
When the adhesive coating with adhesive ability is punched and laminated on the surface of the steel sheet, and the laminated iron core is fixed by heating and pressing, there is no deterioration of the magnetic properties seen in welding, etc. Since it is large, a firmly fixed iron core can be obtained.
[0007]
However, when a laminated iron core is fixed using a magnetic steel sheet having a conventional adhesive coating, it has been necessary to apply pressure in a heating furnace for heating and pressurization. Therefore, various studies have been made on a method for obtaining a laminated iron core in a short time. JP-A-11-147141 discloses a punched unit iron core as a unit below a mold. A technique of laminating on an iron core lamination part, heating the laminated unit iron cores, and applying pressure using a male mold is disclosed.
This technique has dramatically improved the process of laminating and fixing steel sheets with an adhesive coating.
[0008]
[Problems to be solved by the invention]
However, in the technique disclosed in Japanese Patent Application Laid-Open No. 11-147141, it is necessary to operate intermittently for each iron core, although a dramatic improvement in efficiency is seen as compared with the conventional fixing method. There was a problem that the iron core fixing efficiency by the caulking was not achieved.
The present invention solves such problems, and has a method that has an efficiency substantially equal to the iron core fixing efficiency by caulking when manufacturing an iron core using an electromagnetic steel sheet having such an adhesive coating. Is to provide.
[0009]
[Means for Solving the Problems]
Means of the present invention for solving the above-mentioned problems are as follows.
(1) When manufacturing an iron core by laminating magnetic steel sheets coated with an insulating coating that exhibits adhesive ability by heating and pressing the surface, the unit iron core punched by the local heating means after punching is used. In the method of heating and pressurizing to integrate the iron core , a non-volatile liquid is dropped on the surface of the unit iron core every predetermined number of times to cancel the adhesive ability of the unit iron core, thereby continuously punching the laminated iron core The manufacturing method of the laminated iron core characterized by sticking .
[0010]
( 2 ) A punching part for punching the supply member into a predetermined shape, a laminating part for laminating the punched unit iron core, a local heating device for heating the laminated iron core, and a punching die for pressing the laminated iron core An apparatus for producing a laminated iron core, comprising a dual-use pressure punch, and comprising a separation device that drops a non-volatile liquid on the surface of the unit iron core every predetermined number to offset the bonding ability of the unit iron core .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific modes for carrying out the present invention will be described.
In the present invention, the surface of the electromagnetic steel sheet used for the iron core needs to have an insulating coating that exhibits adhesive ability by heating and pressurization, a so-called adhesive coating. The adhesive coating does not necessarily have to be applied to both surfaces of the steel plate, and may be partial. Further, the electromagnetic steel sheet used for the laminated iron core may be a non-oriented electrical steel sheet or a directional electrical steel sheet, and a general steel sheet may be used as the electromagnetic steel sheet.
[0012]
Although it does not specifically limit as an adhesive film used by this invention, The thing which expresses adhesive ability by heating and pressurizing in the range of 150 to 300 degreeC which has an organic resin as a main component is suitable. is there. More specifically, a modified or mixed epoxy resin, acrylic resin, or phenol resin is preferable.
[0013]
In the present invention, it is necessary to use an apparatus for punching a unit iron core with a punching die for processing the unit iron core. After punching with a punching die, a laminated iron core that is continuously laminated on a laminated portion is used. When fixing by heating and pressurizing, the laminated iron core is fixed at a production efficiency comparable to the caulking method by offsetting the adhesive ability of the unit core for each predetermined number of sheets.
[0014]
As the heating means, electric heating, induction heating, dielectric heating, electromagnetic wave irradiation, direct contact heating, and the like can be used. Although there is no particular limitation, direct contact heating with an electric heater is simple and suitable.
In the present invention, by installing the heating device in the iron core laminated portion, it is possible to quickly heat the punched unit iron core to a temperature range where the adhesive ability is exhibited.
[0015]
Next, as a method of applying pressure to fix the iron core, a pressure punch is used in the present invention, but the pressure punch can be used also as a male die of a punching die. In this case, when the predetermined number of punches is reached, it is possible to apply a large pressure to the laminated iron core by making the male stroke larger than the normal punch stroke, thereby further increasing the fixing strength. it can. Moreover, in order to make the fixed laminated iron core stronger, after this step, it may be heated under pressure again.
[0016]
Next, in the present invention, in order to continuously produce a laminated iron core, after a predetermined number of unit iron cores are laminated, the bonding ability of the adhesive coating of the unit iron core positioned between the next laminated iron cores is offset. . Thereby, it becomes possible to improve the manufacturing efficiency of an iron core significantly by heating and pressurizing a laminated iron core continuously. If the adhesive ability of the adhesive coating between the iron cores is not offset, there is a problem that the iron cores adhere to each other and a predetermined stacking height cannot be obtained.
[0017]
In the present invention, it is effective to provide a convex portion on the surface of the steel sheet as a method of offsetting the adhesive ability. If convex portions exist on the surface, the adhesive coatings do not adhere to each other, and therefore the adhesive coatings do not adhere to each other, so that the laminated iron core can be separated.
[0018]
As a method for forming a convex portion on the surface of a steel plate, for example, there is a method of forming the convex portion by using a half punching die for every predetermined number of sheets. The arrangement, number, size, shape, and height of the protrusions on the surface of the steel plate are not particularly limited. The number and size of the pressure punch can be maintained.
[0019]
The shape of the convex portion is not particularly limited, but a circular shape or a square shape is preferable in consideration of the mold life. There is no problem if the height of the convex portion is larger than the film thickness of the adhesive coating, but it is generally within a range of 50 μm to 300 μm. In addition, depending on the intended use of the laminated iron core, it is possible to attach a convex portion having a thickness greater than the plate thickness.
In addition, when removing a convex part at a post process, it is suitable to use a small particle etc. as a convex part. Specifically, for example, a convex portion formed by attaching small particles of silicon rubber, for example, every predetermined number can be easily removed after fixing.
[0020]
In addition, as a method of canceling the adhesive ability, it is effective to drop the nonvolatile liquid on the surface where the adhesive ability is desired to be canceled every predetermined number of sheets. Generally, the temperature required for fixing the adhesive coating is between 150 ° C. and 250 ° C. However, if it functions as a liquid in this temperature range, the adhesive ability can be offset. Specifically, the adhesive ability can be offset by dropping silicon grease, a high boiling point organic solvent, heat resistant oil, or the like onto the surface of the steel sheet. In addition, when the viscosity of the liquid is high, it is possible to make it adhere to the surface of the adhesive coating instead of dropping.
[0021]
The location of the device that gives the function of offsetting the adhesive ability is not particularly limited, but may be provided independently inside the mold, or may be a punching die or a punching die that punches into a predetermined shape. It may also be used as a pressure punch. In particular, when the convex portion is formed on the surface of the steel plate by a semi-punching die, it is preferable that the die maintenance can be simplified by using both the punching die and the pressure punch.
[0022]
In the present invention, a heat insulating member can be installed between the punching die and the heating device. Generally, the temperature required for fixing the adhesive coating is between 150 ° C. and 250 ° C. However, since the punching mold requires very high accuracy, what is the heated part so that the mold does not expand? It is necessary to prevent heat from being transmitted through the heat insulating member or the gap. The heat insulating member used here is desirably a material having high heat resistance such as ceramics, but is not particularly limited.
[0023]
【Example】
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
[Example 1]
FIG. 1 shows a cross-sectional view of a state in which a magnetic steel sheet 1 is punched, laminated and bonded to a unit core shape of a transformer core. In the figure, 1 is a magnetic steel sheet (supply member), 2 is a male die pressure punch for punching the supply member 1 into a unit iron core, and 3 is grease on the surface of the supply member every predetermined number of unit iron cores. 4 is a mold base, 5 is a holding base that holds the heating device 6 and is installed at a predetermined position, 6 is a heating device, 7 is a laminated iron core receptacle, and 8 is a laminated iron core. Since the grease dropped every predetermined number is located between the unit iron cores 29, the unit iron cores with the grease are not adhered even when heated and pressurized. 9 is a pedestal provided opposite to the grease supply mold 3, 10 is a female mold facing the male mold 2 of the punching die, 11 is a grease supply pipe, 12 is a grease supply tank, 3 is a grease supply mechanism, 11 and 12. Reference numeral 23 denotes a laminated iron core fixed to a predetermined number.
[0024]
The unit iron core punched by the pressure punch 2 serving as the male die of the punching die and dropped into the hole formed in the female die 10 of the punching die is laminated on the cradle 7. When the iron core 8 is stacked from above and descends to the point where it comes into contact with the heating device 6 held by the support 5 of the heating device, it is heated by the heating device 6 and is heated to a temperature of 200 ° C. at which the adhesive film exhibits adhesive ability. Is done. The laminated iron core 8 is pressed by the punching die male pressure punch 2 and moves downward each time the unit iron core is supplied. It is moving downward.
[0025]
When the portion where the electromagnetic steel sheet is punched into the laminated iron core is positioned immediately below the grease supply mold 3, the grease supply mold 3 descends and silicon grease is dropped onto the steel sheet surface. Silicon grease is supplied from the supply tank 12 through the supply pipe 11. The supply mold 3 for dropping silicon grease is held by a padding base 9 so that a certain amount of grease can be dropped. When the portion where the silicon grease is dropped is punched into the unit iron core and laminated on the upper part of the laminated iron core 8, it adheres to the lower laminated iron core, but adheres to the upper laminated iron core with silicon grease. Because the performance is offset, it does not adhere.
A predetermined number of laminated iron cores that have been fixed arrive at the cradle 7. As the laminated iron core moves downward, the cradle 7 is gradually lowered. When the laminated iron core is lowered by exactly one laminated iron core, the fixed laminated iron core 23 is paid out.
[0026]
[Example 2]
Another embodiment of the present invention will be described with reference to FIG.
FIG. 2 shows a cross-sectional view of a state in which the magnetic steel sheet 13 having an adhesive coating in the unit core shape of the motor core is punched and laminated, and then heated and pressurized to be bonded.
In the figure, 13 is a magnetic steel plate, 14 is a male die of a guide hole punching die, 15 is a male die of an inner peripheral punching die, and 16 is a male of a half punching die that forms a convex portion on the surface of the steel plate every predetermined number. A die, 17 is an outer punching male combined pressure punch, 18 is a laminated iron core, and a convex portion provided every predetermined number is located between the unit iron cores 29. The iron core is not bonded. Reference numeral 19 denotes a heating device, 20 denotes a peripheral punching die female die, 21 denotes a heat insulating member, 22 denotes a laminated iron core holder that holds the laminated iron core 18 by applying pressure from the side surface, and 23 is fixed to a predetermined number. A laminated iron core is shown. Reference numeral 24 denotes a spring for adjusting the pressing force of the pressure punch, 25 denotes a die receiving base, 26 denotes a female die facing the male die of the half punching die, and 16 and 26 are provided with convex portions on the surface of the steel plate every predetermined number. Form. Reference numeral 27 denotes an inner peripheral punching die female die, and 28 denotes a guide hole punching die female die.
[0027]
The electromagnetic steel sheet 13 in a coiled state is continuously fed into the apparatus of the present invention by a feeding device as a supply member. The supply member 13 fed with the guide pins by the guide hole punching dies 14 and 28 with high precision is punched on the inner peripheral side by the inner peripheral punching dies 15 and 27 and is used as a male die for the outer peripheral punching die. It is conveyed to just below the pressure punch 17.
[0028]
The unit iron cores punched by the outer peripheral punching dies 17 and 20 are pushed into the holes formed in the female peripheral punching die. The unit iron cores that have been pushed in are stacked one after another on the laminated iron core receiving table 22 that holds the laminated iron core 18 by a side pressure to form a part of the laminated iron core. The laminated iron core is heated up to a temperature of 200 ° C. at which the bonding ability is exhibited by the heating device 19.
[0029]
When a predetermined number of punches are punched, convex portions are formed on the surface of the steel sheet by the half punching dies 16 and 26. At this time, a concave portion is formed on the back surface of the convex portion. When the member portion including the convex portion is positioned directly below the outer peripheral punching die male die 17, the unit iron core having the convex portion is laminated. Since the adhesive coatings are dissociated on the convex portion side, the laminated iron core does not adhere, but in the concave portion, most of the surface of the adhesive coating adheres and adheres. Since the laminated iron core 18 is supplied with unit iron cores one after another, the laminated iron core 23 pushed out from the cradle 22 and fixed from inside the mold is discharged.
[0030]
【The invention's effect】
According to the present invention, the iron core can be continuously fixed by the punching line of the laminated iron core, the laminated iron core can be separated very efficiently, and the electromagnetic steel sheet having the adhesive film can be bonded in a short time. The workability of the iron core fixing process can be greatly improved.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the method of the present invention, in which a magnetic steel sheet having an adhesive coating is punched into a unit iron core, silicon grease is adhered to every predetermined number of sheets, laminated, heated, and then heated during pressurization. Explanatory drawing which shows a state.
FIG. 2 shows another embodiment of the method of the present invention, in which a magnetic steel sheet having an adhesive coating is punched into a unit iron core, a convex portion is formed on the surface of the steel sheet every predetermined number, and then laminated and heated. Illustration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 13: Hoop-shaped electromagnetic steel plate 2: Male die pressurizing press for punching die 3: Grease supply die for press-bonding to the steel plate surface every predetermined number of sheets 4: Receiving base 5: Support base 6 holding a heating device 19: Heating device 7: Pressurizing press cradle 8, 18: Laminated iron core 9: Grease supply type padding base 10: Punching die female die 11: Grease supply pipe 12: Grease supply tank 14: Guide hole punching die Male die 15: Male die for inner peripheral punching 16: Male die for half punching die that forms a convex portion on the surface of the steel plate every predetermined number 17: Pressure punch for outer peripheral punching die 20: Peripheral punching die Female die 21: Heat insulating member 22: Laminated iron core cradle 23: Laminated iron core 24 fixed and separated for each predetermined number of sheets 24: Pressure punch spring 25: Mold base 26: Half-molding mold for forming convex portions Female die 27: inner peripheral die 28 female die 28: guide hole Bled mold of the female 29: separation portion of the laminated iron core

Claims (2)

When manufacturing iron cores by laminating magnetic steel sheets coated with an insulating coating that exhibits adhesive ability by heating and pressing on the surface, after punching, the unit iron core punched by the local heating means is heated. In the method of pressing and integrating the iron core , a non-volatile liquid is dropped onto the surface of the unit iron core every predetermined number of times to offset the adhesive ability of the unit iron core, thereby continuously sticking the punched laminated iron core A method for producing a laminated iron core, comprising: A punching part for punching the supply member into a predetermined shape and a laminated part for laminating the punched unit iron cores, a local heating device for heating the laminated iron cores, and a punching die combined pressure for pressing the laminated iron cores An apparatus for producing a laminated iron core, comprising a punch and provided with a separating device that drops a non-volatile liquid onto the surface of a unit iron core every predetermined number of times to offset the bonding ability of the unit iron core.

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