JPH03253247A - Manufacture of laminated core - Google Patents

Abstract

PURPOSE:To secure the welding by laser irradiation even if the thickness of a core piece is extremely thin by irradiating every other laminated thin core piece with a laser beam so as to weld it to the core pieces positioned on both sides. CONSTITUTION:Core pieces 10, which are stamped out of hoop material 0.1mm or below in thickness into specific shapes, are laminated. A squeeze ring 7, which has a holding hole 6, is arranged below a die 4 so that the stamped core pieces may be held horizontally in the condition of close adhesion, and in the middle of this squeeze ring 7, an optical fiber chip 8 for irradiating them with laser beams are arranged. And the margins of the core pieces 1a are irradiated with laser beams for welding alternately so as to weld the core piece irradiated with laser beams to the core pieces 1a on both sides. Hereby, even in case of laminating extremely thin core pieces 1a, they can be united securely by the spot welding using a laser beam.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a method for manufacturing 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 magnetic helad cores, motor cores, etc. The present invention relates to a method of manufacturing a laminated core that is laminated and integrated.

[Prior Art] Conventionally, when manufacturing this type of laminated core, a method is known in which laminated thin plates are welded together using a laser beam. However, this welding has a large thermal effect on the surroundings, increases the magnetic resistance and hysteresis of the magnetic circuit, and
This results in a decrease in the efficiency of the magnetic circuit due to an increase in iron loss due to eddy currents and the like. In order to solve this problem, for example, Japanese Patent Publication No. 14087/1987 discloses a method. In such a conventional method, each overlapping portion of the steel plates is irradiated with a laser beam spot, and the steel plates are joined together by discontinuous welding at each overlapping portion using these spots. This method is effective when the steel plate is relatively thick, but cannot be applied when the laminated thin plates are extremely thin, such as in a magnetic helad core. For example, when the material is permalloy, the thickness of the core piece used in the magnetic head core is approximately 0.
．． It is often 1 mm or less, and in the case of amorphous, it is 0.
Even if a laser beam spot is applied to each overlapping part of such thin plates, the plate thickness is extremely thin, so it is almost impossible to perform discontinuous welding at each overlapping part. It's impossible.

In general, even though it is theoretically possible to create a minute laser spot by narrowing it down with a lens, in reality the laser beam is focused on the irradiation position using an optical fiber, so it is determined by the diameter of the optical fiber used. Practically speaking, the spot diameter will be about 0.2 mm. Therefore, if the above-mentioned method is carried out using such a laser welding method, it will essentially be in a continuous welding state similar to the conventional one, which is ultimately unsuitable for laminating extremely thin core pieces such as magnetic herad cores. It's a method.

In addition, this conventional method requires the spot diameter to be less than twice the thickness of the thin plate in order to separate blocks into arbitrary block lengths, so from this point of view as well, it is not suitable for thin plates. .

[Problem to be solved by the invention] In this way, the conventional method of welding laminated thin plates together using a laser beam is difficult to apply to an extremely thin thin plate like a magnetic head core. There is a problem.

The object of the present invention is to solve the above-mentioned problems and to reduce the thickness of the plate to approximately 0.
It is an object of the present invention to provide a method for manufacturing a laminated core that can be reliably integrated by spot welding using a laser beam even when extremely thin core pieces of about 1 mm or less are laminated.

[Means for Solving the Problem] In order to achieve the above-mentioned 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 these core pieces are stacked. It is characterized in that a laser beam is irradiated to every other side edge of the core piece for welding, and the core pieces irradiated with the laser beam are welded to the core pieces on both sides.

[Function] According to the method for manufacturing a laminated core having the above-described configuration, when the side edges of the laminated thin core pieces are irradiated with a laser spot, the core pieces adjacent on both sides are simultaneously welded. A large number of core pieces are spot welded by irradiating every other piece with a laser.

[Example] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows an example for realizing the method of the present invention when a punching die is used, and 1 shows a case where the plate thickness is Q, 1 mm, for example.
The following hoop materials such as permalloy or amorphous, la
indicates core pieces punched into a predetermined shape from this hoop material and laminated. The mold is composed of an upper mold 3 having a punch 2 for punching out the outer diameter of the core piece 1a, and a lower mold 5 having a die 4 into which the core piece 1a is punched. A squeeze ring 7 having a holding hole 6 having a shape matching the outer shape of the core piece 1a is disposed below the die 4 so that the punched core piece 1a can be held horizontally in close contact with the core piece 1a. In the middle of this squeeze ring 7, an optical fiber chip 8 for irradiating a laser beam is arranged facing the inner diameter side, and this optical fiber output unit 8 is optically connected to a laser oscillator 9 installed outside. This laser oscillator 9
is connected to the laser control device 10.

FIG. 2 shows how the core pieces 1a that have been pulled out are welded one after another. In this state, each time a sheet is pulled out, it moves downward by the thickness of one sheet. Then, every time two core pieces 1a are pulled out, that is, every other core piece, a laser beam is irradiated from the optical fiber output unit 8 toward the side edge of the core piece 1a. By doing this, parts of the core pieces 1a adjacent to both upper and lower sides of the core piece 1a irradiated with the laser beam are simultaneously welded, and this welded portion B is formed on every other piece. This welding operation is performed by a pulse operation synchronized with the upward movement of the ram of the press, that is, the punching operation. By repeating such an operation a required number of times, a magnetic held core 11 as illustrated in FIG. 3 in which a required number of core pieces 1a are laminated and integrated can be obtained.

The mold shown in Figure 1 is configured to continuously draw out a larger amount than the number of stacked products, so the number of stacked products is constantly checked and when switching to the next product, laser irradiation is applied. The laser control device 10 controls the laser 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 die 5 side. For example, 3 on the lower mold 5 side.
It is also possible to attach two optical fiber emitting units 8 to provide three welded portions B around the core piece 1a, as shown in FIG.

Furthermore, although this embodiment illustrates a case in which the laser irradiation means is incorporated into the mold, it is not necessarily incorporated into the mold. For example, the core pieces 1a may be laminated in the required number after punching with the mold. Hold the optical fiber output unit 8 with the core piece 1
Laser irradiation can be performed by moving every other piece of core piece l, or by fixing the optical fiber output unit 8,
The laser irradiation may be performed by moving every other sheet on the a side.

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

[Effects of the Invention] As explained above, in the method for manufacturing a laminated core according to the present invention, a laser beam is irradiated to every other layered thin core piece to weld it to the core pieces located on both sides. As a result, even if the thickness of the core piece is extremely thin, it can be reliably welded by laser irradiation. Furthermore, since the number of laser irradiations can be significantly reduced compared to the conventional method, costs can be reduced and working efficiency can be improved, and the electrical properties of the core pieces are less likely to deteriorate due to reliable spot welding. Furthermore, since spotting can be performed even when laser welding such a thin core piece, energy loss can be reduced compared to ordinary continuous welding. Furthermore, in the conventional example described above, in order to separate blocks into arbitrary block lengths, it is necessary to make the spot diameter less than twice the thickness of the core piece, but in the case of the present invention, it is only necessary to make the spot diameter less than three times the thickness of the core piece. Therefore, there is an advantage that it can be applied to a thinner core piece.

[Brief explanation of drawings]

The drawings show an embodiment of the method for manufacturing a laminated core according to the present invention, and FIG. 1 is a sectional view of a mold, FIG. 2 is a partially enlarged sectional view of the mold, and FIG. 3 is a perspective view of the product. FIG. 4 is a plan view illustrating spot welding locations. Symbol l is the hoop material, 1a is the core piece, 2 is the punch, 3 is the upper die, 4 is the guide, 5 is the lower die, 6 is the holding hole, 7 is the squeeze ring, 8 is the optical fiber output unit ↓ knit, 9 is the Laser oscillator, 10 laser control device,
11 is a magnetic herad core. Figure 1 Figure 2

Claims (1)

[Claims] 1. A plurality of thin core pieces punched into a predetermined shape are laminated, and a laser beam is irradiated to the side edges of every other core piece for welding, and the core is irradiated with the laser beam. A method for manufacturing a laminated core, characterized by welding a piece to core pieces on both sides.