JPH04105536A - Manufacture of laminated core - Google Patents

Abstract

PURPOSE:To completely spot weld a plurality of core pieces by laminating a plurality of the pieces, and intermittently irradiating the side edges of the core pieces with a laser beam, to spot welding them. CONSTITUTION:A core piece 1a punched in a die 4 by a punch 2 is moved downward by thickness of one piece each time its side edge is brought into close contact with the inner surface of a squeezing ring 7. Each time the piece 1a is punched, laser beams are alternately irradiated from two sets of optical fiber irradiating units 8 toward the side edges of the pieces. Thus, parts of the pieces adjacent to both upper and lower sides of the piece 1a irradiated with the beams are alternately fusion-bonded laterally, and formed at each one piece. According to this method, since the welding pitch of laminating direction is of the degree of the thickness of the one piece, even if the alignment accuracy of the spot welding position is roughly set, the spot welding of the pieces can be completely conducted.

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 formed by laminating and integrating layers.

[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,
No. 087 and the like are disclosed. In the conventional methods disclosed in these publications, each overlapping portion of the steel plates is irradiated with a laser beam spot, and the steel plates are joined by discontinuous welding at each overlapping portion using these spots. This method is effective when the thickness of the steel plate is relatively thick, but it is not applicable when the thickness of the laminated thin plates is extremely thin, such as in a magnetic helad core9. The thickness of the core piece is often about 0.1 mm or less when the material is permalloy or the like, and even thinner, about 0.03 mm when the material is amorphous. Furthermore, even when irradiated with a laser beam spot, the plate thickness is extremely thin, so it is almost impossible to perform discontinuous welding at each overlapped portion.

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 laser welding means, it will essentially be in the same continuous welding state as in the past, which is ultimately not suitable for laminating extremely thin core pieces such as magnetic helad cores. do not have.

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 it is not suitable for thin plates. be.

Therefore, in Japanese Patent Application Nos. 2-48825 and 2-167547, the applicant has already set the welding pitch of the core piece so that it can be applied even when the core piece is thin and so that the magnetic properties can be improved. We proposed a method to make the thickness of the plate more than twice the thickness t.

[Problem to be solved by the invention] Each of these methods has excellent advantages such as being able to improve magnetic properties, but as mentioned above, when the welding pitch is 2
Because of this, extremely high precision is required for positioning the welding point, and even a slight deviation in position will cause problems such as incomplete spot welding of adjacent core pieces and weakening of adhesion. have.

The purpose of the present invention is to improve such problems by making it possible to perfectly spot weld core pieces together even if the positioning accuracy of the welding points is not very high, thereby increasing mass productivity and increasing the adhesion force. An object of the present invention is to provide a method for manufacturing a laminated core that can be reinforced.

[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. This method is characterized by spot welding by intermittently irradiating laser beams at multiple locations on the side edges of the core piece.

[Operation] In the method for manufacturing a laminated core having the above-described configuration, welding is performed by intermittently switching the welding portions at a plurality of locations at predetermined timings.

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

FIG. 1 shows an embodiment for realizing the method of the present invention using a punching die, and FIG. 2 shows a cross-sectional view of the die. In the drawings, 1 indicates, for example, a plate thickness of 0.
A hoop material such as permalloy or amorphous having a diameter of 1 mm or less, and la indicates a core piece punched into a predetermined shape from the hoop material 1 and laminated. The mold consists of an upper mold 3 having a bunch 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 drawn.

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 necessary places in the middle of this squeeze ring 7,
A set of two optical fiber output units 8 for irradiating laser beams are arranged horizontally at intervals and facing inward, and each optical fiber output unit 8 is optically connected to a laser oscillator 9 installed outside. and connect this laser oscillator 9 to the laser control device 10, respectively.

FIG. 3 shows a sectional view taken along the line m--2 in FIG. 1, and shows an example of the arrangement of four sets of optical fiber output units 88 to 8d that emit laser beams toward the inner surface of the squeeze ring 7.

FIG. 4 shows a magnetic helad core manufactured by this method, with A-D representing welding points.

In this case, the fiber output units 88 to 8d in FIG.
Of these, 8a and 8d and 8b and 80 each form a pair, and the welding pitch in the lamination direction is approximately the thickness of one core piece. Then, spot weld parts B and 6 in Figure 4 at the same time, then weld parts A and D at the same time with a one-pitch shift, and weld parts B and 0 with a further one-pitch shift. Repeat sequentially.

In order to intermittently irradiate multiple locations with laser irradiation, for example, as shown in FIG. Divide into 1/4,
The divided laser beams are sent to shutters 13a to 1, respectively.
3d and lenses 14a to 14d, the optical fiber 1
5a to 15d, each optical fiber output unit 88 to 8
d, and the welding area is exposed to the shutters 13a to 13.
3d allows selection intermittently. shutter 1
In order to drive 3a to 13d intermittently, for example, a solenoid may be used as a drive source and the components 3a to 13d may be operated intermittently.

As shown in FIGS. 1 and 2, the die 4 is
The core piece 1a pulled out moves downward by the thickness t of one piece each time the core piece 1a is pulled out, with its side edge in close contact with the inner surface of the squeeze ring 7. Each time one core piece 1a is pulled out, laser beams are alternately irradiated from each of the two optical fiber output units 8 toward the side edges of the core piece 1a. In this manner, portions of the core pieces 1a adjacent to the upper and lower sides of the core piece 1a irradiated with the laser beam are welded alternately left and right, that is, in a staggered manner, and this welded portion is formed one by one. 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 in which a required number of core pieces 1a are laminated and integrated can be obtained.

The mold is configured to continuously draw out a larger amount than the number of stacked products, so the laser control device constantly checks the number of stacked products and stops laser irradiation when switching to the next product. 10. 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.

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. Alternatively, the optical fiber output unit 8 may be fixed and the core piece la side may be moved to perform laser irradiation.

In addition, various modifications other than the above-mentioned embodiment can be considered regarding the welding location and the welding timing. For example, in the example, there are four welding points A-D, or five welding points.
More than one location is also possible. Regarding the timing of spot welding, in the example, the welding location was changed for each irradiation, but as shown in FIG.
After irradiating twice in a row, switch the welding point and weld part B to n times.
The irradiation may be performed several times in succession.

Further, in the embodiment, a case is shown in which the shutter 13 is used as a means for intermittently selecting the welding location, but instead of using the shutter, a moving mirror or the like may be used to adopt a time-sharing method. In this case, there is an advantage that energy can be saved compared to a method using a shutter.

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 also be applied to motor cores in which thin core pieces of 0.5 mm or less are laminated, for example. , it goes without saying that it can be similarly applied.

[Effects of the Invention] As explained above, in the method for manufacturing a laminated core according to the present invention, the welding pitch in the lamination direction is about the thickness of one core piece, so the alignment accuracy of spot welding points is rough. However, the core pieces can be perfectly spot welded together. Therefore, it is possible to strengthen the fixing force and improve workability. Further, since spot welding is performed for each thickness of the core pieces, each core piece is lowered one by one each time a core piece is pulled out, so that the welding position can be automatically and accurately set. Furthermore, since a plurality of welding locations are switched at predetermined timing, deterioration of magnetic properties can also be prevented.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for manufacturing a laminated core according to the present invention, FIG. 1 is a configuration diagram of an apparatus for carrying out the present invention, FIG. 2 is a partially enlarged sectional view of a mold, and FIG. 3 is III in Figure 1.
4 is a perspective view of the product, FIG. 5 is a configuration diagram of an optical system, and FIG. 6 is an explanatory diagram of another example of a welding location. 1 is a hoop material, 1a is a core piece, 2 is a punch, 3 is an upper die, 4 is a die, 5 is a lower die, 6 is a holding hole, 7 is a squeeze ring, 8 is an optical fiber output unit, and 9 is a laser oscillator. , 10 is a laser control device, 11 is a total reflection mirror 1
2 is a beam splitter, 13 is a shutter, 14 is a lens, and 15 is an optical fiber. Patent applicant: Kuroda Seiko Co., Ltd. Figure 3 Figure 4 Figure 1 Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] 1. It is characterized by laminating a plurality of thin plate-shaped core pieces punched into a predetermined shape and performing spot welding by intermittently irradiating laser beams at multiple locations on the side edges of these core pieces. Method for manufacturing a laminated core.