JPH03283508A - Transformer for welder and its manufacture - Google Patents

Abstract

PURPOSE:To make a reduced-size and light-weight transformer by making a primary coil from a split insulated conductor and by electrically connecting coil elements which are obtained by slicing coaxially installed conductor and insulated member into sheets. CONSTITUTION:To make a primary-side coil for a welder transformer, an insulated film is laminated on a sheet conductor and the lamination is wound and then the winding is cut so that a specified space is made along an axis. Nextly, the winding is sliced at right angles with the axis into sheet coil elements 20. Coil units 39a-39d which are made from the sheet coil elements 20 are inserted into slots 32, 34, 36 and 37 which are made on plates 33a-33d of which a board is composed through both ends of the coil elements 20. The coil elements 20 of which the coil units 39a-39d are composed are electrically connected at the slots 32, 34, 36 and 37 when they are inserted into the slots. As a result, many large-surface-area primary-side coil units can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a welding transformer and a manufacturing method thereof;
More specifically, the present invention relates to a welding transformer and a method for manufacturing the same, which make it possible to further reduce the size and weight of a high-frequency welding transformer used in, for example, an inverter-type resistance welding machine.

[Prior Art] Conventionally, for example, welding robots that perform resistance welding have been frequently used on automobile production lines.

In this case, resistance welding is used because it is necessary to supply a large current to the object to be welded.

The welding machine for this welding robot first converts direct current into high-frequency alternating current, supplies this high-frequency alternating current to a welding transformer to step down the voltage, and then converts it to direct current again using a rectifier to feed the welding gun arm. Inverter-type DC resistance welding equipment is used. The reason for converting to high-frequency alternating current is to make the welding transformer relatively small and lightweight by utilizing the fact that the cross-sectional area of the transformer core that constitutes the welding transformer is inversely proportional to the frequency of the high-frequency alternating current.

This type of welding transformer is disclosed, for example, in Japanese Utility Model Publication No. 61-33620 filed by the present applicant.

This welding transformer is composed of a single-layer coil wound with many turns, a transformer core, and a secondary coil with two turns and a center tap.
It is in practical use at kHz.

[Problems to be Solved by the Invention] The present invention has been made in connection with such technology, and further reduces the size and weight by overcoming the skin effect that occurs when the frequency is increased. The purpose of the present invention is to provide a welding transformer and a method for manufacturing the same.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the welding transformer of the present invention forms a coil unit by arranging a plurality of individual coils in parallel with an insulating member interposed therebetween, and By fitting a single coil into a hole drilled in the board, the same turns in the same coil unit are electrically connected, and multiple coil units configured as described above are arranged on the board. to form a primary or secondary coil, and the core member and the secondary or primary coil are brought close to the coil unit.

Further, the method for manufacturing a welding transformer of the present invention includes a first step of laminating an insulating member on a conductor, a second step of cutting the conductor and the insulating member into thin plate shapes, and a step of laminating the cut conductor and the insulating member into thin plates. a third step of obtaining a single coil by cutting the insulating member along its axis; a fourth step of forming a coil unit by arranging the single coils adjacent to each other; and incorporating the coil unit into a substrate. , a fifth step of electrically connecting a coil unit to another coil unit; and a sixth step of forming a welding transformer by attaching the coil unit to a core. Features.

Further, the method for manufacturing a welding transformer of the present invention includes a first step of laminating an insulating member on a conductor, a second step of cutting the conductor and the insulating member along their axis, and a second step of laminating the conductor and the insulating member along the axis thereof. a third step of cutting a conductor and an insulating member into thin plate shapes to obtain a single coil; a fourth step of arranging the single coils adjacent to each other to form a coil unit; and incorporating the coil unit into a substrate; A fifth step of electrically connecting a coil unit to another coil unit; and a sixth step of forming a welding transformer by attaching the coil unit to a core. shall be.

[Operations] According to the first invention, by constructing the secondary coil of the welding transformer with split insulated conductive wires, this - The surface area of the secondary coil is significantly increased, so that the total cross-sectional area of the conductor can be made relatively small. Therefore, it is possible to flow a large amount of current while avoiding the occurrence of the skin effect, and it is also possible to suppress heat generation.

Furthermore, according to the second and third inventions, a single coil is obtained by slicing a coaxially provided conductor and an insulating member into thin plates, and the coil unit is formed by electrically connecting the single coil. Once manufactured, this coil unit is assembled into the core to easily obtain a welding transformer.

[Example] Next, a welding transformer and a method for manufacturing the same according to the present invention will be described in detail below with reference to the accompanying drawings.

First, a method for manufacturing the -order coil will be explained.

An insulating film 12 coated with adhesive on both sides is laminated on a thin copper sheet 10. Next, the copper sheet 10 and the insulating film 1 are attached to a core material 14 made of synthetic resin, for example.
As shown in FIG. 1, the copper sheet lO1 insulation film 12 is wound together with the core material 14, preferably with a width of 1flfl1, by using a wire cutting method or the like as shown by the broken line. disconnect. Then, the thin core material 14 is removed to define a space 16. Next, as shown by the arrow in FIG. 1, the laminate of the copper sheet 10 and the insulating film 12 is cut along its axis. This cutting width is approximately the same as the thickness of the substrate, which will be described later. As a result, a single coil indicated by reference numeral 20 in FIG. 2 is obtained.

Note that the coil unit 20 may be obtained by cutting the laminate of the copper sheet 10 and the insulating film 12 in advance along its axial direction, and then slicing it by a wire cutting method or the like.

Next, the substrate 30 on which the coil unit 20 is mounted will be explained. As shown in FIG. 3, it has a plate body 31 and plate bodies 33a to 33d fixed at right angles to the plate body 31 and spaced apart from each other by a predetermined distance. The plates 33a to 33d each have a matrix of holes 32, 34, 36 and 37. Each of the holes 32, 34, 36 and 37 has a stone-shaped hole row in a direction perpendicular to the plate 31,
In addition, a hole matrix (IJ hook) having a hole row of four turns in the longitudinal direction of the plate body 31 is defined.

Therefore, the coil unit 20 is attached to this hole matrix. First, four individual coils 20 are stacked together in four layers with an insulating film 38 in between (see FIG. 2) to form a coil unit, and this coil unit is designated by reference numeral 3.
Four pieces are prepared as shown in 9a to 39d. Then, the single coil 20 of each coil unit 39a to 39d
As shown in FIG. 4, one end 20a is connected to the other end 20b.
Insert it into the hole 32 while being deviated from the other direction. That is, the other end 20b of one single coil 20 is electrically connected to one end of the next single coil 20. In other words, the innermost winding part of the coil unit 20 is the next coil unit 20.
It is electrically connected to the innermost winding part of , and the same goes for the next outer winding part.

Figure 5 shows a coil unit (39) configured as above.
The back side of the plate 31 that electrically connects a to 39d is shown. On the back surface of the plate body 31, four terminals 31a to 31d are formed on the upper side in the figure, and
Four terminals 35a to 35d are formed on the lower side. As can be understood from the figure, the terminal 31a and the terminal 35b are connected by a conductor, and the terminal 31
b and terminal 35c1, terminal 31C and terminal 35d are also connected in the same way. The terminal 31d and the terminal 35a are electrically connected to an inverter which will be described later.

In FIG. 2, reference numeral 41a indicates a flat cable that connects the leftmost coil 20 of the coil unit 39a inserted into the hole 32 to the terminal 35a, and reference numerals 41b, 41C, and 41d
are coil units 39b, 39C, 39d and terminals 35b, 3 inserted into holes 34, 36, 37, respectively.
A flat cable is shown that electrically connects 5c and 35d, respectively. Further, reference numerals 43a to 43d indicate coil units) 3 inserted into the holes 32.34.36.37.
9a, 39b.

39C and 39d, flat cables are shown that electrically connect the leftmost coil unit 20 in the figure to the terminals 31a to 31d, respectively.

The substrate 30 to which the coil units 39a to 39d consisting of a plurality of individual coils 20 are fixed in this way is then
The cores 40, 42 are installed using the space 16 created by removing the core material 14. Then, a conductor having a rectangular cross section and forming a secondary coil is engaged with the single coil 20 forming the secondary coil. That is,
A conductor 52 having a rectangular cross section that is electrically connected to the main surface of the first diode 50 held by the plate 48 extends horizontally toward the substrate 30, and after passing through the space of the core 40, One end is bent and directed downward, and further bent and the first
It extends back toward the diode 50 side.

Then, the end portion extends parallel to the substrate 30, rises upward again, and further extends parallel to the substrate 30. Then, the second diode 5 further extends toward the substrate 30 and descends again.
4, which is in contact with a hexagonal plate 56. In this case, a bolt is inserted between the plate 56 and the plate 48 to firmly sandwich the first diode 50 and the second diode 54. Note that the center tap 58 is located at the middle portion of the conductor 52.
Let it stand up.

Next, as explained in the longitudinal cross-sectional view of FIG. 9, the transformer can be effectively cooled by defining a hole 59 in the conductor 52 in advance and allowing cooling water to flow through the hole 59. .

FIG. 10 shows the circuit configuration of the welding transformer configured as described above. Reference numeral 60 is a rectifier circuit. For example, a three-phase AC 400V power source is connected to this rectifier circuit 60. After obtaining a direct current in this rectifier circuit 60, a square wave is obtained in an inverter section 62, and then , extracts a predetermined direct current from the secondary side and supplies it to the welding gun 64.

As described above, according to this embodiment, when forming the single-layer coil of a welding transformer, an insulating film is laminated on a thin conductor, this is wound, and then a predetermined position is formed along the axis of the insulating film. The coil units 39a to 39d made up of the thinly cut coils 20 are cut into a substrate 30 via one end and the other end. Holes 32.3 defined in the plates 33a to 33d constituting the
4. Insert at 36 and 37. Each hole 32.34
．． 36 and 37 are coil units) 39a to 39d
Since the coil units 20 constituting the coil unit 20 are electrically connected through the insertion action, it is possible to obtain a large number of single-layer coil units with a large surface area.

According to this embodiment, a coil unit having four turns and consisting of four individual coils 20 is arranged in parallel, and four sets of these are arranged in parallel for the core 40 and the core 42. . As a result, the surface area of the conductor through which welding current flows increases, and a large current can flow without being inhibited by the skin effect. Moreover, in order to form a single coil, thin plate members such as copper plates are simply laminated with an insulator interposed between them, and then cut into extremely thin widths, so it is simple and extremely easy to handle. It's easy.

[Effects of the Invention] As described above, according to the first invention, the single-layer coil of the welding transformer is divided and made up of insulated conductive wires. For this reason, for example, in the prior art, compared to the case where the secondary coil is composed of a single rectangular conductor wire, the surface area of the plurality of conductor wires is significantly larger as a whole, and the surface area of the conductor is caused by the skin effect. It is possible to avoid the inconvenience that current flows only in the vicinity. That is, it becomes possible to efficiently flow current through the conductor as a whole. Furthermore, by simply inserting and fixing the coil unit configured as described above to the board, a well-balanced primary coil can be obtained, allowing stable operation during welding. I can do it.

Moreover, since the structure is simple, it is possible to manufacture the device at a low cost with few failures, and even if a failure occurs, parts can be easily replaced. Therefore,
Not only can it be made smaller as a welding transformer, but it can also be extremely lightweight.

Furthermore, according to the second and third inventions, a single coil is obtained by laminating an insulating film on a thin metal plate as described above, winding the same, and cutting it into extremely thin pieces. ing. Therefore, it is possible to obtain a single coil having an extremely large surface area.

According to the present invention, since it can be easily manufactured as described above, the manufacturing cost is also reduced, and it is possible to provide a welding transformer that is inexpensive as a whole.

In addition, in the present invention, a configuration was described in which an insulating film is laminated on a thin conductor, wound, and then sliced.
For example, a single coil with the same effect can be obtained by laminating insulating films on concentric tubular conductors with different diameters and then fitting them together, and this is of course included in the present invention. It is.

[Brief explanation of drawings]

1 is a perspective explanatory view showing the manufacturing process of a single coil constituting a welding transformer according to the present invention; FIG. 2 is a perspective view illustrating a state in which the coil shown in FIG. 1 is inserted into a substrate; The figure is a perspective explanatory view of the state before inserting the coil unit into the board as shown in Figure 1, Figure 4 is a partially omitted perspective explanatory view of the state where the coil unit is inserted into the board, and Figure 5 is the back side of the board. Figure 6 is a perspective explanatory diagram when assembling a welding transformer consisting of a primary side and a secondary side with the coil itself attached to the board, Figure 7 is a wiring diagram of Figure 6. 8 is a front view of the welding transformer shown in FIGS. 6 and 7, FIG. 9 is a sectional view taken along line A-A in FIG. 7, and FIG. , FIG. 9 is an electrical circuit diagram of the welding transformer shown in FIGS. 7, 8, and 9. 10... Copper sheet 12... Insulating film 4... Core material 0... Coil unit 0... Substrate 0... First diode 2... Conductor 4... Second diode 0... Rectifier circuit 2... Inverter section 4... Welding gun FiG, 9 Ll"1

Claims (3)

[Claims] (1) A coil unit is formed by arranging a plurality of single coils in parallel with an insulating member interposed therebetween, and the same coil unit is formed by fitting the single coil of the coil unit into a hole drilled in a substrate. A plurality of coil units configured as described above are arranged on a board to form a primary or secondary coil, and a core member and a secondary coil are connected to each other with respect to the coil unit. A welding transformer characterized by having a secondary coil or a primary coil placed close to each other. (2) A first step of laminating an insulating member on the conductor, a second step of cutting the conductor and the insulating member into thin plates, and cutting the cut conductor and the insulating member along their axis. a third step of forming a coil unit by placing the coil units next to each other, a fourth step of forming a coil unit by arranging the coil units next to each other, and incorporating the coil unit into a substrate and connecting the coil unit to another coil unit. A method for manufacturing a welding transformer, comprising: a fifth step of electrically connecting the coil unit to a core; and a sixth step of forming a welding transformer by attaching the coil unit to a core. (3) A first step of laminating an insulating member on the conductor, a second step of cutting the conductor and the insulating member along their axis, and cutting the cut conductor and the insulating member into thin plates. a third step of forming a coil unit by placing the coil units next to each other, a fourth step of forming a coil unit by placing the coil units next to each other, and a step of incorporating the coil unit into a substrate and connecting the coil unit to another coil unit. A method for manufacturing a welding transformer, comprising: a fifth step of electrically connecting the coil unit to a core; and a sixth step of forming a welding transformer by attaching the coil unit to a core.