JPH03283507A - Transformer for welder and its manufacture - Google Patents

Abstract

PURPOSE:To make a current flow in a conductor effectively as a whole by splitting a primary coil of a transformer for welder and by making the coil of an insulated conductor. CONSTITUTION:To make a primary-side coil for a welder transformer, an insulated film is laminated on a sheet conductor and the film-laminated conductor is wound and then the winding is cut into very thin pieces. Coil units 39a-39d which are made up of the thinly cut coil elements 20 are so inserted into slots 32a-32d and 34a-34d which are made on a board 30 as to be connected through both ends. The slots 32a-32d and the slots 34a-34d are electrically connected with each other through conductors. Consequently, many large-surface-area primary-side coil units can be obtained. For example, four pairs of coil units, each made up of five coil elements 20, are placed parallelly in cores 40 and 42.

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 around 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 has a coil unit by further arranging a plurality of individual coils wound multiple times in parallel via an insulating member. A plurality of coil units are mounted on a board with a predetermined distance between them, and the individual coils of the plurality of coil units are electrically connected to each other by conductors provided on the board to form a primary side or a secondary side. The present invention is characterized in that a coil is formed, and a core member and a secondary coil or a 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 thin plate-shaped conductor, a second step of winding the conductor and the insulating member, and a second step of laminating the conductor and the insulating member. a third step of cutting the coil into a thin plate shape to obtain a single coil; a fourth step of placing the coils next to each other to form a coil unit; and incorporating the coil unit into a substrate and attaching the coil to another coil. The present invention is characterized in that it includes a fifth step of electrically connecting the coil unit to the core, and a sixth step of forming a welding transformer by attaching the coil unit to a core.

[Function] According to the first invention, by constructing the single-layer coil of the welding transformer with split insulated conductive wire, this The surface area of the secondary coil is significantly increased, so that the total cross-sectional area of the conductor can be relatively small.

Furthermore, according to the second invention, a single coil can be obtained simply by laminating an insulating member on a thin plate-shaped conductor and then slicing it into thin plates, and a coil unit can be manufactured by simply electrically connecting this single coil. 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 10 and the insulating film 12 are wound together as shown in FIG. Cut with. Then, the thin core material 1
4 is separated to define a space 16. As a result, the second
A single coil indicated by reference numeral 20 in the figure is obtained. One end 20a of the coil unit 20 extends horizontally in FIG. 2, and the other end 20b of the coil unit 20 also extends horizontally in the same manner as described above.

Next, the substrate 30 on which the coil unit 20 is mounted will be explained. As shown in FIG. 2, the substrate 30 has hole rows 32a to 32d on its surface side for inserting the five coil units 20 in parallel, and below the hole rows 32a to 32d. , including hole rows 34a to 34d provided parallel to the hole rows 32a to 32d. The hole row 32a and the hole row 34b are inclined and electrically connected by a wiring portion 36a made of a conductor.
b and the hole row 34C are similarly inclined and electrically connected by a wiring portion 36b made of a conductor. Furthermore, the wiring portion 36C is also connected to the hole row 32C and the hole row 34d.
electrically connected.

Therefore, five individual coils 20 are prepared, and one end 20a and the other end 20b are connected to the hole row 32a and the hole row 3.
4a respectively. Similarly, hole row 32b and hole row 3
4b1 hole row 32C and hole row 34C1 hole row 32d and hole row 34d. In addition, each coil alone 20.
As shown in FIG. 2, an insulating film 38 having substantially the same external shape as the coil unit 20 is inserted between the coils 20 and 20. That is, in the substrate 30, the hole row 32a
Five individual coils 20 are arranged in parallel between and 34a,
The five coils inserted into the hole row 32a and the hole row 34a are then connected to the five coils 20 inserted into the next hole row 32b and hole row 34b via the wiring portion 36a. electrically connected. Furthermore, the coil unit 20 in the hole rows 32b and 34b is connected to the wiring portion 36b.
It is electrically connected to the five coils 20 inserted into the hole rows 32C and 34C through the hole row 3.
2d and the coil unit 20 inserted into the hole row 34d are electrically connected through a wiring portion 36c. Note that the terminal portion 35 extends from the hole row 34a, and the five coils 20 inserted into the hole rows 32d and 34d.
connects its one end to the terminal section 37, and these terminal sections 3
5.37 is connected to an inverter section which will be described later. When each coil unit 20 is inserted into the hole rows 32a to 32d and the hole rows 34a to 34d, they are firmly fixed by soldering or the like so as to be electrically conductive.

The substrate 30 to which the coil units 39a to 39d consisting of a plurality of single 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 vertical cross-sectional view of FIG. 6, if a hole 59 is defined in advance in the conductor 52 and cooling water is conducted through the hole 59, the transformer can be effectively cooled. .

FIG. 7 shows the circuit configuration of the welding transformer constructed as described above. Reference numeral 60 is a rectifier circuit, for example,
A three-phase AC 400V power supply is connected to this rectifier circuit 60, and after obtaining a direct current with this rectifier circuit 60, a square wave is obtained with an inverter section 62, and then a predetermined direct current is taken out from the secondary side. , and supplies this to the welding gun 64.

As described above, according to this embodiment, in forming the primary coil of a welding transformer, an insulating film is laminated on a thin conductor, wound, and then cut into extremely thin pieces. Coil units 39a to 39d consisting of thinly cut coils 20 are inserted so as to be connected to hole rows 32a to 32d and 34a to 34d defined in the substrate 30 via one end and the other end thereof. Since the respective hole rows 32a to 32d and 34a to 34d are electrically connected to each other via conductors, it is possible to obtain a large number of single-layer coil units with a large surface area.

According to the embodiment, a coil unit having five turns and consisting of five individual coils 20 is arranged in parallel, and four sets of these are arranged in parallel with respect to 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 a configuration in which the secondary coil is composed of a single rectangular conductor wire, the surface area of the coil as a whole becomes significantly larger due to the plurality of conductor wires, and the surface area of the conductor is increased due to the skin effect. This makes it possible to avoid the inconvenience that current only flows. 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 invention, a single coil is obtained by laminating an insulating film on a thin metal plate as described above, winding the same, and cutting the coil into thin pieces using a cutting tool. There is. 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.

[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 when assembling a welding transformer consisting of a primary side and a secondary side with the coil itself attached to the board, and Fig. 4 is a plan view of the welding transformer shown in Fig. 3. , FIG. 5 is a front view of the welding transformer shown in FIGS. 3 and 4, FIG. 6 is a sectional view taken along line A-A in FIG. 4, and FIG. FIG. 7 is an electrical circuit diagram of the welding transformer shown in FIGS. 10... Copper sheet 12... Insulating film 14... Core material 20... Coil unit 30... Substrate 38... Insulating film 50... First diode 52... Conductor 54... ...Second diode 60...Rectifier circuit 62...Inverter section 64...Welding gun

Claims (2)

[Claims] (1) A coil unit is formed by arranging a plurality of single coils wound multiple times in parallel with an insulating member interposed therebetween, and a plurality of the coil units are mounted on a board with a predetermined distance between them, and The coils of a plurality of coil units are electrically connected to each other by the provided conductor to form a primary or secondary coil, and the core member and the secondary coil or the primary coil are connected to the coil unit. A welding transformer characterized by being placed in close proximity. (2) A first step of laminating an insulating member on a thin conductor, a second step of winding the conductor and the insulating member, and a single coil by cutting the conductor and the insulating member into thin sheets. 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 electrically connecting the coil unit to another coil unit. and a sixth step of forming a welding transformer by attaching the coil unit to a core.