JP3505877B2 - Electromagnetic device and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electromagnetic equipment used in electric / electronic equipment.

[0002]

2. Description of the Related Art A conventional electromagnetic device, here, a typical reactor will be described with reference to the drawings.
FIG. 11 is a sectional view of a conventional reactor. As shown
In the conventional reactor, the first iron cores 1 formed by laminating electromagnetic steel plates are inserted into the coils 2 respectively, and two coils are arranged in parallel, and two of these and another electromagnetic steel plate are laminated. The second iron core 4 is abutted through the core gap spacer 3 to form a square-shaped magnetic path and is fixed by the metal fitting 5 (see, for example, Japanese Patent Application Laid-Open No. 7-22258).

Further, in the first and second iron cores 1 and 4, as means for fixing the laminated electromagnetic steel sheets, there is TIG welding for welding the surface layer, and other fixing means such as adhesion and extrusion pressure welding are also conceivable. From the aspect of certainty of
The G welding method was common.

The TIG welding method, which is a block fixing means for the first and second iron cores 1 and 4, will be described below. FIG. 12 is a configuration explanatory view of a first iron core in a conventional reactor, FIG. 13 is an upper surface explanatory view thereof (welding surface side plan view), FIG.
Although it is the same front view, as shown in the figure, TIG welding is usually performed at two points ab and cd in order to maintain the bonding strength. At this time, due to manufacturing variations, the positions of the upper and lower weld beads 20 and 21 cannot completely match with each other in the magnetic flux direction, and the size A may deviate.

In that case, when operating as a reactor, the first
The iron core 1 of 1 is short-circuited by one turn in the path of ab-c-d, and the cross-section A × is included in the magnetic flux flowing in the first iron core 1.
The potential proportional to the amount of magnetic flux interlinking with B is the short-circuit path ab-
It occurs within cd. Then, this potential and the short circuit path a−
A short-circuit current determined by the electric resistance value of b-c-d flows through this short-circuit path, and the loss increases. Here, the cross-sectional area A × B is a projected cross-sectional area where the magnetic flux vertically links the short-circuit paths ab-c-d.

On the other hand, FIG. 15 is a block diagram of the second iron core of the conventional reactor. When the TIG welding method is used as the block fixing means of the second iron core 4, the second iron core 4 is The surface of the hypotenuse was TIG welded at two places.

[0007]

However, in the first iron core 1, the heat generation amount of the reactor increases due to the above loss and exceeds the allowable temperature upper limit value, and in an extreme case, it may cause an overheating accident. Become. In addition, if this is attempted to be suppressed, there is no choice but to use an expensive low-loss grade iron core, or the wire diameter of the coil 2 must be made large, which is extremely disadvantageous in terms of cost or external dimensions. Had brought. Further, there is an economical disadvantage in the welding work speed because the laminated surfaces are TIG welded.

On the other hand, in the case of the second iron core 4, although the problem of loss due to magnetic flux does not occur, as in the case of the first iron core, the welding work time is long and the amount of heat generated during welding is large, which is economical. In addition, it was a disadvantageous manufacturing process.

The present invention is intended to solve such conventional problems, and an object thereof is to provide a reactor excellent in performance, economy and productivity.

[0010]

In order to achieve the above object, an electromagnetic device of the present invention comprises an iron core laminated with electromagnetic steel sheets and fixed by projection welding, and a coil located around the iron core. Is.

Further, two first iron cores having coils around them are provided in parallel, and the first iron cores are abutted with the second iron cores at both ends thereof to form a square-shaped magnetic path. And at least the first iron core is formed by stacking electromagnetic steel sheets and fixing them by projection welding.

The first iron core is formed by projection welding at one location. The first iron core is obtained by performing projection welding at a plurality of places in the magnetic flux direction.

Further, the second iron core has a trapezoidal cross section whose lower base is a side abutted with the first iron core, and projection welding is applied to a corner formed by the upper base and the oblique side.

In the method for manufacturing an electromagnetic device of the present invention, a first step of providing a projection on at least one location of an electromagnetic steel sheet, a second step of laminating a plurality of the electromagnetic steel sheets, and projection welding are performed. The method further comprises a third step of fixing a plurality of the electromagnetic steel plates to form an iron core, and a fourth step of providing a coil around the iron core.

[0015]

By adopting the above-mentioned structure, in the electromagnetic equipment of the present invention, the projected cross-sectional area that obstructs the magnetic flux is reduced, which makes it possible to reduce the loss and also because the projection welding is performed. The time can be shortened, and due to this, heat diffusion during welding is small and workability is improved.

Further, it is possible to have the same strength as the conventional one by only performing welding at one place by projection welding, and while maintaining the same strength, it is possible to reduce the projected cross-sectional area that obstructs the magnetic flux, thereby resulting in loss. It is possible to reduce the welding time, shorten the welding time, and improve the workability.

Further, by performing projection welding at a plurality of places in the magnetic flux direction, it is possible to suppress the increase in loss while improving the strength.

Further, the second iron core has a trapezoidal cross section whose lower base is a side abutted with the first iron core, and projection welding is applied to a corner portion formed by the upper base and the oblique side to generate a magnetic flux. The magnetic steel sheet can be fixed without hindering.

The method of manufacturing an electromagnetic device according to the present invention comprises performing a first step of providing a projection on at least one location of an electromagnetic steel sheet, a second step of laminating a plurality of the electromagnetic steel sheets, and projection welding. Since a third step of fixing a plurality of the electromagnetic steel plates to form an iron core and a fourth step of providing a coil around the iron core are provided, the time required for welding can be shortened, and thereby, welding can be performed. There is little diffusion of heat at the time, improving workability,
It is possible to manufacture an electromagnetic device in which the projected cross-sectional area that obstructs the magnetic flux is reduced and the loss is reduced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same components as those of the related art are designated by the same reference numerals and the description thereof will be omitted. Further, in the present embodiment, a reactor will be described as one of the electromagnetic devices, but it goes without saying that the present invention is not limited to the reactor and can be applied to a transformer, a motor core, or the like.

FIG. 1 is a structural explanatory view of a first iron core of a reactor according to an embodiment of the present invention. In the figure, 6 is a cylindrical welded body formed by projection welding.

In order to manufacture the first iron core 1 which is fixed to the electromagnetic steel plate (for example, silicon steel plate) 7 with the cylindrical welded body 6 as described above, one electromagnetic wave forming the first iron core 1 is manufactured. As shown in FIG. 2, which is a configuration diagram of the steel plates 7, projections 8 are provided on the laminated surface of each electromagnetic steel plate 7. The thickness of the electromagnetic steel sheet 7 is 0.5 mm, the vertical dimension is 49.5 mm, and the horizontal dimension is 27.
It was 4 mm. Further, FIG. 3 is a sectional view of the electromagnetic steel plate 7, but in the present embodiment, the diameter D of the projection 8 and the height H of the projection 8 are shown.
(Displayed as D dimension × H dimension) is 1.5 × 0.
7, 2.0 x 0.9, 2.5 x 1.1 (unit mm) 3
Created a type. FIG. 4A is a diagram in which electromagnetic steel plates are stacked (laminated). In this way, the electromagnetic steel plates 7 are stacked and projection-welded, and a cross-sectional view of the electromagnetic steel plates after welding is shown in FIG. 4B. Thus, the first iron core 1 is formed.

The projection welding method is a resistance welding method in which a hemispherical or frustoconical projection is press-formed at an arbitrary position on the surface of a plate-shaped workpiece, and welding current is concentrated on the projection to perform welding. Is.

When the first iron core 1 is formed, the protrusions 8 provided for each of the electromagnetic steel sheets are stacked and weighted.
As shown in FIG. 5, which is a configuration diagram of a projection welding machine used in one embodiment of the present invention, projection welding is performed by a resistance welding machine 12 having an upper electrode 9, a lower electrode 10 and a positioning frame 11, and as a result, FIG. As in (b),
A welded body 6 that splices all of the laminated electromagnetic steel sheets 7 was generated.

FIG. 6 is an enlarged view of a main part of the projection welding machine, showing the upper electrode 9, the lower electrode 10 and the positioning frame 11 of the resistance welding machine 12 in an enlarged manner. In the positioning frame 11, the projections 8 are melted by resistance heat during projection welding, and the electromagnetic steel plates 7 are likely to settle and move in the directions in which they closely contact each other, and the block right angle accuracy after welding is within ± 0.1 mm. The clearance dimension C was 0.03 to 0.05 mm.

As described above, in order to solve the performance problem of reducing loss, as shown in FIG.
Each of the iron cores 1 is subjected to projection welding penetrating in the laminating direction of the electromagnetic steel plates 7 at one location so that the fixing means is one columnar welded body 6 so that a one-turn short-circuit path does not occur.

Further, in order to solve the problems in terms of economy and production, it is a short work by performing projection welding rather than sequentially welding the entire length by TIG welding.
Since the welding current concentrated in the projection part is passed, the heat is less diffused and the workability is improved.

In the above first iron core 1, 1
Although the projection welding of only points is performed and the number of the cylindrical welded bodies 6 is one, it is also possible to perform projection welding at a plurality of points.

That is, FIG. 7 is a view showing another embodiment of the electromagnetic steel plate constituting the first iron core of the reactor in one embodiment of the present invention, in which the projection 16 similar to the one-point projection welding is 6 to 7 mm. A block was also provided in which two pieces were provided apart from each other, and the welding strength in the rotational direction was increased with respect to the mating surface of the laminated electromagnetic steel sheet 15 (two-point welding in the central portion). Further, a block having an outer peripheral portion of the two protrusions 16 was also prepared by setting the interval between the two protrusions 16 to 21.4 mm (outer peripheral portion two-point welding).

Next, after welding each of the above, the reactor was assembled into a reactor similar to the conventional one, and the relation between the increase / decrease in iron loss and the welding method was evaluated. In each reactor, the second iron core is formed by laminating the electromagnetic steel sheets 17 as shown in FIG. 8 which is a configuration diagram of the electromagnetic steel sheets forming the second iron core of the reactor in one embodiment of the present invention, and the welding strength is From the point of view of the above, projection welding was performed at two points, and the projection position was selected at a position that does not affect the loss, that is, a corner between the upper base of the trapezoid and the hypotenuse. Reference numeral 18 is a protrusion. As a result, what is formed is an iron core as shown in FIG. 9, which is a configuration explanatory view of the second iron core of the reactor in one embodiment of the present invention.

FIG. 10 is an iron loss comparison diagram. If the welding points are the same, the iron loss increases as the diameter of the projection increases, and if the welding points are different, the iron loss value also changes. ,
It can be seen that the iron loss is suppressed at any welding point as compared with the conventional one.

That is, as shown by the mark ● in FIG. 10, the melting area of the conventional TIG welding method is equivalent to the area of a circle having a diameter of 1.5 mm in terms of welding strength, and the iron loss caused by the TIG welding is , The iron loss due to the projection welding at one point in the center shown by the triangle is the same welding area as the projection diameter 1.5m
Compared with m, the projection welding of the present invention is advantageous with a difference of 0.2 W to 0.8 W including the □ mark and the ○ mark indicating other welding positions. Welding strength is increased to 2.0,
When compared at 2.5 mm, the difference is 0.2 to 1.1 W.

As described above, among the various welding methods, fixing the laminated electromagnetic steel sheet of the reactor only by the projection welding method is very effective for reducing the iron loss.

The spot resistance welding method, in which the welding point is similar to that of the projection welding method, is applied to the electromagnetic steel sheet 2
It is known that welding of three sheets is the limit, and simultaneous welding is impossible when 38 to 113 sheets of electromagnetic steel sheets are laminated as in the present invention.

In this way, if the iron core is fixed by performing projection welding at one point on the central portion of the laminated surface as in this embodiment, the one-turn short circuit path is not formed and no loss due to this is generated. Further, even if two-point projection welding is performed, the position of the projection 16 is positioned by the mold, so the positional deviation between the two points can be made extremely small (usually within 0.3 mm), and is almost the same as in the case of one-point projection. It can be suppressed to a low loss close to that of the conventional welding, and the loss can be reduced as compared with the conventional welding.

Further, by adopting the projection welding method, the welding speed can be made higher than that of TIG welding, and the diffusion of welding heat is small, so that the workability is also improved.

When the reactor of the present invention is used in an electric / electronic device such as an air conditioner, since the iron loss is low and the power loss is small, a large energy saving effect can be obtained.

[0038]

As is apparent from the above description, the electromagnetic device of the present invention reduces the projected cross-sectional area that obstructs the magnetic flux, thereby reducing the loss and performing projection welding. The time taken for welding can be shortened, and this also reduces the diffusion of heat during welding,
Workability is improved.

Further, the projection welding at one location can reduce the projected cross-sectional area that obstructs the magnetic flux while maintaining the same strength as the conventional one, thereby reducing the loss , shortening the welding time and improving the workability. Can be improved.

Further, by projection welding at a plurality of locations in the magnetic flux direction, it is possible to suppress the increase in loss while improving the strength.

The second iron core has a trapezoidal cross section whose lower base is the side abutted with the first iron core, and projection welding is applied to the corners formed by the upper base and the hypotenuse to generate magnetic flux. The magnetic steel sheet can be fixed without hindering.

Further, in the method of manufacturing an electromagnetic device of the present invention, the time required for welding can be shortened, and the heat diffusion at the time of welding is reduced, the workability is improved, and the projected cross-sectional area that obstructs the magnetic flux is reduced. It is possible to manufacture an electromagnetic device with reduced power loss and reduced loss.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a first iron core of a reactor according to an embodiment of the present invention.

FIG. 2 is a structural diagram of an electromagnetic steel plate forming the first iron core.

FIG. 3 is a sectional view of the same electromagnetic steel sheet.

FIG. 4 (a) is a stack of the electromagnetic steel sheets.
Sectional view (b) is a sectional view of the electrical steel sheet after welding

FIG. 5 is a configuration diagram of a projection welding machine used in an embodiment of the present invention.

FIG. 6 is an enlarged view of a main part of the projection welding machine.

FIG. 7 is a diagram showing another mode of the electromagnetic steel sheet forming the first iron core of the reactor in one embodiment of the present invention.

FIG. 8 is a configuration diagram of an electromagnetic steel sheet forming a second iron core of the reactor according to the embodiment of the present invention.

FIG. 9 is a structural explanatory view of a second iron core of a reactor according to an embodiment of the present invention.

Fig. 10 Iron loss comparison chart

FIG. 11 is a sectional view of a conventional reactor.

FIG. 12 is a structural explanatory view of the first iron core.

FIG. 13 is an explanatory view of the same top surface.

FIG. 14 is a front view of the same.

FIG. 15 is a configuration diagram of a second iron core of a conventional reactor.

[Explanation of symbols]

1 first iron core 2 coils 4 second iron core 6 welded body 7,15,17 Magnetic steel sheet 8, 16, 18 protrusions

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Minato 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Kazushige Takashima 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. In-house (56) Reference JP 5-101944 (JP, A) JP 50-45902 (JP, A) JP 5-111222 (JP, A) JP 6-267759 (JP, A) ) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01F 27/24 B23K 11/14 H01F 27/245 H01F 37/00 H01F 41/02

Claims (6)

(57) [Claims] 1. An electromagnetic device comprising: an iron core laminated with electromagnetic steel plates having a protrusion near the center thereof and fixed by projection welding; and a coil positioned around the iron core. 2. A square-shaped magnetic path having two first iron cores each having a coil on the periphery thereof arranged in parallel, and the first iron cores abutting the second iron cores at both ends thereof. And at least the first iron core is formed in the central portion.
Electromagnetic equipment that is made by stacking electromagnetic steel sheets with protrusions in the vicinity and fixing them by projection welding. 3. The first iron core is formed by projection welding.
The electromagnetic device according to claim 2, wherein the electromagnetic device is applied at a specific location. 4. The electromagnetic device according to claim 2, wherein the first iron core is formed by performing projection welding at a plurality of positions in the magnetic flux direction. 5. The second iron core has a trapezoidal cross section whose lower base is a side abutting against the first iron core, and projection welding is applied to a corner formed by the upper base and the hypotenuse. Electromagnetic equipment. 6. A first step of providing a projection at least at one location near a central portion of an electromagnetic steel sheet, a second step of laminating a plurality of the electromagnetic steel sheets, and a plurality of the electromagnetic steel sheets obtained by performing projection welding. The third that sticks to form an iron core
And a fourth step of providing a coil around the iron core, the method of manufacturing an electromagnetic device.