JPH113831A - Manufacture of laminated iron core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely separate a laminated iron core comprising thin single plates. SOLUTION: At a single plate 33 at the lowest stage of an iron core 32 laminated on an iron core 30, a downward protruding part 15 positioned near a caulking projection 19 is formed. Since, near the projection 19, a gap occurs between iron cores 30 and 32 laminated together, an interference in the projections 19 between the iron cores 30 and 32 is suppressed even the single plate is thin, thus, the iron cores 30 and 32 are separated with sure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated iron core used for a transformer or the like.

[0002]

2. Description of the Related Art Conventionally, as a core of a transformer, a laminated steel single plate has been used. In manufacturing the iron core, the veneers are joined by a caulking method or a welding method, and the completed iron cores are sequentially stacked.

[0003] The single plate generally has a thickness of 0.27 m.
m to 0.50 mm is used. In this case, the joining of the single plates and the separation of the iron core by the caulking method are performed as shown in FIG. In this figure, the uppermost veneer 51 of the iron core 50 is shown.
Single plates 53, 54, and 55 of the iron core 52 are sequentially laminated on the top.

The veneers 51, 54 and 55 have downward projections 5 on them.
6, the through holes 57 are respectively formed in the veneer 53, the projections 56 of the veneer 54 are formed in the through holes 57 of the veneer 53, and the projections 56 of the veneer 55 are formed in the upper surface recesses of the protrusions 56 of the veneer 54. By press-fitting, the single plates 53, 54, 55 are integrated.

Here, the protrusion amount of the protrusion 56 is set to about 1.2 times the plate thickness in order to increase the area of the fitting portion 58 between the protrusion 56 of the veneer 54 and the side edge of the through hole 57 of the veneer 53. １1.4 times. Therefore, the tip of the protrusion 56 of the veneer 54 slightly projects into the upper surface recess of the protrusion 56 of the veneer 51, but the fitting portion 59 between the protrusion 56 and the upper surface recess of the protrusion 56 of the veneer 51.
Is significantly smaller than the fitting portion 58 with the side edge of the through hole 57, the single plate 51 and the single plate 53 are not joined, and the two iron cores 50 and 52 are separated.

[0006] In recent years, in transformers incorporated in home electric appliances and OA equipment, an iron core having excellent harmonic characteristics has been required in order to prevent heating and burning due to harmonic currents and occurrence of abnormal noise. In the production, the plate thickness is 0.20 m
m or less must be used.

In order to laminate such single plates and join them to separate the iron core, it is conceivable to adopt a configuration as shown in FIG. 9 to which the above technique is applied. In this figure, veneers 63 to 68 of an iron core 62 are sequentially laminated on a top veneer 61 of an iron core 60.

A downward projection 69 is formed on each of the veneers 61, 65 to 68, and a through hole 70 is formed on each of the veneers 63, 64. The projection 69 of the veneer 65 is formed through the through hole 70 of the veneer 64. The projections 69 of the veneers 66 to 68 are press-fitted into the through holes 70 of the veneer 63 into recesses on the upper surface of the projections 69 overlapping thereunder.

By this press-fitting, fitting portions 71 and 72 are formed between the projection 69 of the veneer 65 and the side edges of the through holes 70 of the veneers 64 and 63, respectively. A fitting portion 73 is formed between the tip of the projection 69 of the veneer 65 projecting downward and the upper surface recess of the projection 69 of the veneer 61.

The reason why the through holes 70 are formed in the two single plates 63 and 64 is to reduce the area of the fitting portion 73 that hinders separation of the two iron cores 60 and 62.

[0011]

However, in the configuration shown in FIG. 9, the area of the fitting portion 73 and the fitting portions 71, 72
Is small, the separation between the veneer 61 and the veneer 63 is not stable, and the veneer 6
There is a problem that 3, 64 is easily peeled off.

Therefore, the present invention provides a method for manufacturing a laminated iron core by integrating laminated thin veneers by a caulking method.
An object of the present invention is to provide a technique that can reliably separate stacked iron cores.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of stacking a plurality of veneers, press-fitting a projection formed on the veneer to a lower veneer, and fitting these protrusions. A laminated iron core is formed by integrating the plates, and in the method of manufacturing a laminated iron core in which the completed laminated iron cores are sequentially stacked, in the configuration of the laminated iron core, the lowermost single plate of each laminated iron core is A downward projection located near the projection is formed.

When such a convex portion is formed, a gap is generated between the vertically stacked laminated iron cores in the vicinity of the caulking projection, so that the two iron cores can be reliably separated.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows an entire processing line for a laminated iron core. In this processing line, the steel strip 2 set in the uncoiler 1 is inserted between the pair of feed rolls 4 and 4 via the leveler 3, and the steel strip 2 is fed into the press device 5 with the rotation of the feed roll 4. The steel strip 2 is punched out by the press device 5 to form a single veneer continuously, and the veneer is laminated to form a laminated iron core.

As a method of feeding the strip 2, there are a feeding method in which the feed roll 4 is provided in front of the press device 5 and a tension method in which the feed roll 4 is provided behind the press device 5. From the workability of feeding into the press device 5 and the advantage of the scrap processing of the residual material punched by the press device 5,
Generally, a sending method is adopted.

When the thin steel strip 2 having a thickness of 0.20 mm or less is fed into the press device 5 by such a feeding method, since the steel strip 2 has a weak stiffness, it is vertically moved in front of the press device 5. In some cases, a feeding failure may occur such that the strip 2 is not inserted horizontally into a guide or the like of the press device 5.

In order to prevent this feeding failure, as shown in FIGS. 2 and 3, a groove 6 is formed on the outer periphery of each feed roll 4, and a guide plate 7 extending in the front-rear direction is inserted into the groove 6.
The strip 2 is inserted between the two guide plates 7. In this case, the width of the guide plate 7 is smaller than the width of the strip 2 so that the strip 2 and the feed roll 4 come into contact with each other and an even feeding force is transmitted from the feed roll 4 to the strip 2. In addition, it is necessary that the width of the steel strip 2 be equal to or larger than a dimension capable of effectively preventing the bending in the width direction. When a steel plate is used as a material, the thickness of the guide plate 7 is 1 mm or more. The width of the guide plate 7 from the feed roll 4 to the press device 5 is preferably wider than the portion inserted into the groove 6.

Next, the working process in the press device 5 will be described with reference to FIGS. The press device 5 is provided with a lifting frame 9 above the die 8 and the first stage 1
0, a second stage 11 and a third stage 12 are formed.

In the first stage 10, as shown in FIG. 4, a pair of punches 13 are provided on the lifting frame 9 so as to be able to come and go, and the die 8 is formed with a recess 14 corresponding to the punches 13. . When the punch 13 is pressed in a state where the punch 13 is projected from the lifting frame 9, the steel strip 2 has a downward projection 15.
Are formed as a pair.

In the second stage 11, a punch 16 is provided on the lifting frame 9, and a die hole 17 corresponding to the punch 16 and a concave portion 18 corresponding to the projection 15 are formed in the die 8. The amount of protrusion of the punch 16 from the lifting frame 9 can be adjusted. When the punch 16 is pressed in a state where the amount of protrusion is limited, a downward projection 19 is formed on the steel strip 2. 19 is dropped into the die hole 17 and a through hole (not shown) is formed in the steel strip 2. In addition, the convex portion 15 formed on the first stage 10
When the lifting frame 9 is lowered, it is fitted into the recess 18 and does not collapse by pressing.

In the third stage 12, as shown in FIG. 5, a punch 20 is mounted on the lifting frame 9 and a punch 2 is mounted on the die 8.
0 are provided, and die holes 2 are provided.
A holding ring 22 is provided below 1. In the third stage 12, the strip 2 is punched by a punch 20 in accordance with the pressing operation, and the punched portion is laminated as a single plate on the die hole 21 and the holding ring 22, and the projection 1
9 is press-fitted to the lower veneer and these veneers are integrated to form an iron core.

The completed iron cores are sequentially stacked, and when the lowermost iron core comes off the retaining ring 22, the retaining ring 22
The pedestal 23 supporting the iron core is moved down, and the lowermost iron core is dispensed. Thereafter, the pedestal 23 is raised again and presses the iron core in the die hole 21 and the holding ring 22 upward. I do.
By repeating these steps, a laminated iron core is manufactured continuously.

FIG. 6 shows details of the crimped portion of the single plate in the third stage 12. As shown in FIG. In this drawing, veneers 33 to 38 of an iron core 32 are sequentially laminated on the uppermost veneer 31 of the iron core 30.

The single plates 31, 35 to 38 are the second stage 1
1, the veneers 33 and 34 have through holes 39 formed in the second stage 11, respectively.
The projection 19 of 5 is press-fitted into the through-hole 39 of the veneer 33 via the through-hole 39 of veneer 34, and the projections 19 of veneers 36 to 38 are press-fitted into the upper surface recess of the projection 19 overlapping below.

Due to this press-fitting, fitting portions 40 and 41 are formed between the projections 19 of the veneer 35 and the side edges of the through holes 39 of the veneers 34 and 33, respectively. A fitting portion 42 is formed between the tip of the projection 19 of the veneer 35 protruding from the veneer 35 and the upper surface recess of the projection 19 of the veneer 31.

The single plate 33 has a pair of convex portions 15 formed on the first stage 10.
Are located on both sides of the projection 19. Due to the presence of the convex portion 15, an interval is generated between the iron cores 30 and 32, and the area of the fitting portion 42 is reduced.
Since the difference between the areas 0 and 41 increases, both iron cores 30 and 32
Are reliably separated.

The height of the projections 15 is affected by the thickness of the veneer, the height of the projections 19, and the number of veneers in which the through holes 39 are formed. / 2 or more.

[0029]

EXAMPLE In the processing line shown in FIG. 1, a steel strip 2 having a thickness of 0.10 mm and a width of 46 mm was set on an uncoiler 1, and the steel strip 2 was guided to a feed roll 4 via a leveler 3.

As shown in FIGS. 2 and 3, a groove 6 was formed in the feed roll 4, and a guide plate 7 was inserted into the groove 6. The groove 6 was 12 mm wide and 3 mm deep, and the guide plate 7 was 10 mm wide and 2 mm thick.

When the strip 2 is inserted between the guide plates 7 and 7 and the feed roll 4 is rotated, the strip 2 is fed into the press device 5 and punching is started at 100 SPM. Since the waving phenomenon did not occur in the strip steel 2 at, the machining speed was increased to 300 SPM and machining was continued.

In the press device 5, the processing in the first stage 10 and the second stage 11 shown in FIG.
In the U-shaped iron core as shown in the three places of both feet and back,
A 1 × 5 mm rectangular through hole 39 and a 2 × 3 mm rectangular convex portion 15 having a height of 0.06 mm at positions 6 mm before and after the rectangular through hole 39.
Are formed at the third stage 12 shown in FIG.
When a laminated iron core was manufactured by punching into a single plate having a thickness of 41 mm and a length of 41 mm and a width of 13 mm and press-fitting the pyramid-shaped projections 19 with each other, the stacked iron cores were surely separated. Similar results were obtained even when the projections 19 were conical.

[0033]

As described above, according to the present invention, the downwardly projecting portion located near the crimping projection is formed on the lowermost veneer of each stacked iron core. In the vicinity, there is a gap between the iron cores stacked vertically, and even when the veneer is thin, interference between the protrusions between the iron cores is suppressed, and the iron cores are reliably separated.

Thus, an iron core for a transformer with less harmonic distortion can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a processing line for manufacturing a laminated iron core.

FIG. 2 is a longitudinal sectional side view showing a feed roll.

FIG. 3 is a partially cutaway front view of the above.

FIG. 4 is a view showing a state of forming a projection and a projection in the manufacturing method according to the present invention

FIG. 5 is a diagram showing a state in which the iron cores are stacked in the embodiment.

FIG. 6 is an enlarged view showing a swaged portion of the iron core according to the first embodiment;

FIG. 7 is a plan view showing a processing state of a bottom veneer of the iron core according to the embodiment;

FIG. 8 is an enlarged view showing a caulked portion of a conventional iron core in which thick veneers are laminated.

FIG. 9 is an enlarged view showing a caulked portion of an iron core obtained by laminating thin veneers by the same technology.

[Explanation of symbols]

 15 Protrusion 19 Projection 30, 32 Iron core

Claims (1)

[Claims] 1. A laminated iron core is formed by laminating a plurality of veneers, press-fitting a projection formed on the veneer to a lower veneer, and integrating these veneers. In the method for manufacturing a laminated iron core in which laminated iron cores are sequentially stacked, in the configuration of the laminated iron core, a downwardly projecting portion located in the vicinity of the protrusion is formed on the lowermost veneer of each laminated iron core. A method for producing a laminated iron core.