JP2578011B2 - Manufacturing method of laminated core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of laminating a large number of thin plates made of permalloy, amorphous or the like having a thickness of 0.1 mm or less, for use in a magnetic head core or a motor core. The present invention relates to a method for manufacturing a laminated core which is integrated by integration.

[Prior Art] Conventionally, when manufacturing this kind of laminated core, a method of welding laminated thin plates using a laser beam is known. However, this welding has a large thermal effect on the surroundings, and causes a reduction in the efficiency of the magnetic circuit due to an increase in the magnetic resistance of the magnetic circuit, an increase in hysteresis, an increase in iron loss due to overcurrent, and the like. To solve this problem, for example, Japanese Patent Publication No. 62-14087 is disclosed. In the conventional methods disclosed in these publications, spots by a laser beam are applied to the respective overlapping portions of the steel sheets, and the steel sheets are joined to each other by discontinuous welding of the overlapping portions by the spots. This method is effective when the steel plate is relatively thick,
This is not applicable when the thickness of the thin plates to be laminated like a magnetic head core is extremely thin. For example, the thickness of a core piece used for a magnetic head core is often about 0.1 mm or less when the material is permalloy or the like, and is further reduced to about 0.03 mm when the material is amorphous. Even if a laser beam spot is applied to each of the overlapping portions, the thickness of the sheet is extremely thin, so that it is almost impossible to perform discontinuous welding for each overlapping portion.

In general, even though a laser spot can theoretically be a small spot if narrowed down by a lens, the laser beam is actually focused on the irradiation position by an optical fiber, so it is determined by the diameter of the optical fiber used, Practically, the spot diameter becomes about 0.2 mm. Therefore, when the above-described method is performed by such a laser welding means, the continuous welding state is substantially the same as that of the conventional method, and eventually an unsuitable method for laminating extremely thin core pieces such as a magnetic head core. It turns out that.

In addition, in this conventional method, the spot diameter needs to be twice or less the thickness of the thin plate in order to separate the block into an arbitrary block length. is there.

[Problem to be Solved by the Invention] Therefore, the present applicant has already disclosed in Japanese Patent Application No. 2-48825 that a laser beam is irradiated on every other core piece so as to be applicable even when the core piece is thin. A method of welding core pieces was proposed. However, even in this case, since the welding portions are still close to each other, the magnetic resistance against overcurrent is not sufficient, and loss due to this is unavoidable.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method of manufacturing a laminated core that solves the above-mentioned problems, increases the magnetic resistance, reduces the occurrence of overcurrent, and improves the magnetic characteristics. Is to do.

Means for Solving the Problems In order to achieve the above object, in the method for manufacturing a laminated core according to the present invention, a plurality of thin plate-shaped core pieces punched into a predetermined shape are laminated, and The method is characterized in that laser beams are alternately and alternately shifted in a staggered manner for irradiation to the side edges of the core pieces for welding, and the core pieces irradiated with the laser beam are welded to the core pieces on both sides. Then

[Operation] According to the method of manufacturing a laminated core having the above-described configuration,
When the laser beam is radiated every other side and in a staggered manner to the side edges of the laminated thin core pieces, the adjacent core pieces are simultaneously welded on both sides, and furthermore, the distance between the welding locations is increased. The resistance increases and the occurrence of overcurrent decreases.

[Example] The present invention will be described in detail based on an illustrated example.

FIG. 1 shows an embodiment for realizing the method of the present invention in the case of using a punching die, wherein 1 is a hoop material such as permalloy or amorphous having a plate thickness of 0.1 mm or less, and 1a is a hoop material made of this material. 3 shows a core piece punched into a predetermined shape and laminated. The die is composed of an upper die 3 having a punch 2 for punching the outer diameter of the core piece 1a and a lower die 5 having a die 4 into which the core piece 1a is punched. Below the die 4,
A squeeze ring 7 having a holding hole 6 having a shape conforming to the outer shape of the core piece 1a is arranged so that the punched core piece 1a can be held horizontally in a close contact state. A set of two optical fiber chips 8 for irradiating a laser beam are arranged inward at a required position in the middle of the squeeze ring 7 with a horizontal space therebetween. Each of the laser oscillators 9 is optically connected to an externally mounted laser oscillator 9, and the laser oscillator 9 is connected to a laser controller 10.

FIG. 2 shows a state in which the pulled-out core pieces 1a are sequentially welded. The core pieces 1a drawn into the die 4 by the punch 2 have their side edges closely adhered to the inner surface of the squeeze ring 7. In this state, each time one sheet is pulled out, it moves downward by the thickness of one sheet. Then, each time two core pieces 1a are pulled out, that is, every other sheet, a laser beam is alternately irradiated from one of the two optical fiber emission units 8 toward the side edge of the core piece 1a. Thus, the core pieces adjacent to the upper and lower sides of the core piece 1a irradiated with the laser beam are formed.
A portion of 1a is welded alternately left and right, that is, in a staggered manner, and this welded portion B is formed every other sheet. This welding operation is performed by a pulse operation synchronized with the movement of the press on the ram, ie, the punching operation. By repeating such an operation a required number of times, a required number of core pieces 1a are laminated and integrated into a third piece.
A magnetic head core 11 as illustrated in the figure is obtained. Note that S indicates a spot adjustment position by a laser beam.

Since the mold shown in FIG. 1 is configured to continuously pull out a larger number of products than the number of stacked products, the number of stacked products is always checked, and when switching to the next product, laser irradiation is performed. It is controlled by the laser controller 10 so as to stop. The location of the core piece 1a to be spot-welded can be arbitrarily selected depending on the number and position of the laser irradiation means arranged on the lower mold 5 side. For example, 2
A set of three optical fiber emitting units 8 is attached,
As shown in FIG. 4, the welded portion B may be formed at three places around the core piece 1a.

Further, in this embodiment, the case where the laser irradiation means is incorporated in the mold is exemplified, but it is not necessarily incorporated in the mold.For example, after punching out with the mold, the required number of core pieces 1a are laminated. Hold the optical fiber emitting unit 8 to the core piece 1a.
Alternatively, the laser irradiation may be performed by moving every other sheet, or the optical fiber emission unit 8 may be fixed and the laser beam may be irradiated by moving the core piece 1a side every other sheet.

Although the present invention is most effective for manufacturing a magnetic head core in which extremely thin core pieces 1a are laminated, the present invention is not necessarily limited to magnetic head cores.For example, the same applies to a motor core or the like in which thin core pieces of 0.5 mm or less are laminated. Needless to say, it can be applied to

[Effects of the Invention] As described above, in the method of manufacturing a laminated core according to the present invention, a weld is formed by irradiating a laser beam to every other thin and staggered thin core pieces and forming a welded portion. Since the core pieces are welded to the core pieces located on both sides, even if the thickness of the core pieces is extremely thin, welding can be reliably performed by laser irradiation. Further, since the laser irradiation positions are arranged in a staggered manner, the distance between the welding positions is increased, the magnetic resistance is increased, and the loss due to overcurrent is small. Further, since the number of laser irradiations can be greatly reduced as compared with the conventional case, the cost can be reduced, the work efficiency can be improved, and the electrical characteristics of the core piece are not reduced by reliable spot welding. In addition, since spotting can be performed even by laser welding to a thin core piece, energy loss can be reduced as compared with general continuous welding. Further, in the above-described conventional example, the spot diameter needs to be twice or less the thickness of the core piece in order to separate the block into an arbitrary block length. Therefore, there is an advantage that it can be applied to a thinner core piece.

[Brief description of the drawings]

The drawings show an embodiment of the method for manufacturing a laminated core according to the present invention. FIG. 1 is a sectional view of a mold, FIG. 2 is a partially enlarged sectional view of the mold, FIG. FIG. 4 is a plan view illustrating a spot welding portion. Reference numeral 1 denotes a hoop material, 1a denotes a core piece, 2 denotes a punch, 3 denotes an upper die, 4 denotes a die, 5 denotes a lower die, 6 denotes a holding hole, 7 denotes a squeeze ring, 8 denotes an optical fiber emitting unit, and 9 denotes a laser oscillator. , 10 is a laser control device, and 11 is a magnetic head core.

Claims (1)

(57) [Claims] 1. A plurality of thin plate-shaped core pieces punched into a predetermined shape are laminated, and a laser beam is alternately and alternately shifted in a zigzag manner on the side edges of these core pieces for welding. And fusing the laser beam-irradiated core pieces to the core pieces on both sides.