JP2541861B2 - Welding transformer and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a welding transformer and a method for manufacturing the same, and more specifically, for example, a high frequency welding transformer used in an inverter resistance welding machine. Downsizing,
The present invention also relates to a welding transformer and a manufacturing method thereof, which enables weight reduction.

[Prior Art] Conventionally, for example, a welding robot by resistance welding has been widely used in an automobile production line. As a welding machine for this welding robot, an inverter that once converts an alternating current into a high frequency alternating current, supplies this high frequency alternating current to a welding transformer to reduce the voltage, then converts the alternating current again using a rectifier and supplies it to a welding gun arm. Type AC resistance welding equipment is adopted. 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 constituting the welding transformer is in inverse proportion to the frequency of the high-frequency alternating current.

A welding transformer of this type is disclosed, for example, in Japanese Utility Model Publication No. 61-33620, which is an application filed by the present applicant. This welding transformer has a primary coil wound many turns,
It is composed of a transformer core and a secondary coil having a center tap with two turns, and is put to practical use at several hundred Hz to 1 kHz.

[Problems to be Solved by the Invention] The present invention has been made in connection with such a technique, and further miniaturization and weight reduction can be achieved by overcoming the skin effect generated when the frequency is further increased. An object of the present invention is to provide a welding transformer and a manufacturing method thereof.

[Means for Solving the Problems] In order to solve the above problems, in the welding transformer of the present invention, a plurality of coil units formed by laminating a plurality of conductors that mutually insulate each other are interposed via an insulating member. A coil unit is formed by arranging them side by side, and an end portion of the coil unit is fitted into a hole portion formed in a second substrate fixed substantially orthogonally to the first substrate, One end and the other end of the conductors of the corresponding layers are connected in series between the adjacent coil units and between the adjacent coil units, and are further laminated between the adjacent coil units and between the adjacent coil units. It is characterized in that the conductors of the respective layers are respectively connected in parallel to form one of a primary side coil and a secondary side coil, and a core member is mounted via a space defined by 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, and a laminated body of the conductor and the insulating member is formed into a thin plate shape along a direction substantially orthogonal to the axial direction thereof. A second step of cutting the laminated body of the cut conductor and the insulating member with a predetermined cutting width along the axial direction of the laminated body, and cutting the laminated body into a plurality of coil units; Corresponding between adjacent coil units and between adjacent coil units by fitting the ends of the conductors forming the coil units into the holes formed in the second substrate fixed orthogonally to each other. Connecting the conductors of the layers to each other in series, and connecting the conductors of the laminated layers in parallel between the adjacent coil units and between the adjacent coil units to connect one of the primary side coil and the secondary side coil. A third step of forming, characterized by having a, a fourth step of forming a welding transformer by mounting the core member via the space portion defined in said coil unit.

[Operation] According to the first aspect of the invention, the primary coil of the welding transformer is composed of split insulated conductors, so that the primary coil is composed of a single rectangular conductor wire as compared with the conventional one. Has a significantly larger surface area, and therefore the total cross-sectional area of the conductor can be made relatively small. Therefore, generation of the skin effect can be avoided, a large amount of current can be passed, and heat generation can be suppressed.

Further, according to the second aspect of the invention, the coil unit is manufactured by slicing the conductor and the insulating member provided coaxially into a thin plate to obtain a coil unit, and electrically connecting the coil unit. At the same time, this coil unit is incorporated into the core member, and a transformer for welding can be easily obtained.

[Embodiment] 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 of manufacturing the primary coil will be described.

An insulating film (12) having adhesive on both sides is laminated on a thin copper sheet (10). For example, as shown in FIG.
A core material 14 made of synthetic resin is wound in a state of being laminated in six layers together with the copper sheet 10 and an insulating film 12 interposed between the copper sheets adjacent to each other, and then, as shown by a broken line, By using the wire cutting method or the like, the copper sheet 10 and the insulating film 12 together with the core material 14 are preferably cut into a width of 1 mm. Then, the thin core material 14 is removed to define the space portion 16. Then, as indicated by the arrow in FIG.
A laminate of the copper sheet 10 and the insulating film 12 is cut along the axial direction. This cutting width is almost the same as the thickness of the substrate described later. As a result, the coil alone shown by reference numeral 20 in FIG. 2 is obtained.

The coil unit 20 may be obtained by previously cutting the laminate of the copper sheet 10 and the insulating film 12 along the axial direction thereof, and then slicing it by a wire cutting method or the like.

Next, the substrate 30 for mounting the coil unit 20 will be described. As shown in FIG. 2, the substrate 30 includes an elongated first substrate 31 and a second substrate 33a fixed so as to be orthogonal to the first substrate 31 and separated from each other by a predetermined distance.
To 33d. The second substrates 33a to 33d have matrix-shaped holes 32, 34, 36 and 37, respectively. Each of the holes 32, 34, 36 and 37 has a hole row corresponding to conductors stacked in six layers along a direction orthogonal to the first substrate 31, and a first row for forming a coil unit of 6 turns. One substrate 31 defines a hole matrix having seven rows of holes along the longitudinal direction.

Therefore, the coil unit 20 is attached to the hole matrix. First, two coil units 20 and two insulating films 38 are alternately laminated in four layers to form coil units 39a to 39d (see FIG. 2).
Four pieces to 39d are prepared as shown in FIG. And
As shown in FIG. 4, the coil unit 20 of each of the coil units 39a to 39d is inserted into the hole 32 with one end 20a being displaced from the other end 20b. That is, by inserting the other end 20b of the coil unit 20 and the one end 20a of another coil unit 20 adjacent thereto into the same hole 32, the other end 20b of one coil unit 20 becomes the next coil. One end 20a of the unit 20
Connected to make direct contact with. Therefore, the coil alone
The innermost wound portion of 20 is electrically connected to the innermost wound portion of the next coil unit 20, and the next outer wound portion is also connected in the same manner.

FIG. 5 shows the coil unit 39 configured as above.
The rear surface side of the first substrate 31 for electrically connecting a to 39d is shown. On the back surface of the first substrate 31, four terminals 31a to 31d are formed on the upper side and four terminals 35a to 35d are formed on the lower side in the drawing, respectively. As is clear from the figure, the terminals 31a and 35b are connected by conductors, and the terminals 31b and 35c and the terminals 31c and 35d are also connected in the same manner.
The terminal 31d and the terminal 35a are electrically connected to an inverter unit described later.

In this case, as shown in FIG. 10, the conductors of the respective layers connected in series with each other between the adjacent coil units and between the adjacent coil units are connected in parallel.

In FIG. 2, reference numeral 41a indicates a flat cable for connecting the coil unit 39a inserted into the hole 32 to the terminal 35a on the leftmost coil unit 20 in the drawing, and reference numerals 41b, 41c and 41d has holes 3
4 shows flat cables for electrically connecting the coil units 39b, 39c, 39d inserted in 4, 36, 37 and the terminals 35b, 35c, 35d, respectively. Further, reference numerals 43a to 43d
Is the coil unit 39 inserted in the holes 32, 34, 36, 37.
A flat cable for electrically connecting the rightmost coil unit 20 of a, 39b, 39c and 39d in the figure to terminals 31a to 31d, respectively.

In this way, the substrate 30 to which the coil units 39a to 39d each including the plurality of coil units 20 are fixedly attached to the core 4 using the space 16 generated by removing the core member 14 next.
Wear 0 and 42. Then, the conductor having a rectangular cross section which constitutes the secondary coil is engaged with the single coil 20 which constitutes the primary coil. That is, the conductor 52 having a rectangular cross section, which is electrically connected to the main surface of the first diode 50 held by the plate body 48, extends horizontally toward the substrate 30 side, and the core 40
After passing through the space part, it is bent at one end to be directed downward, and further bent so as to return to the first diode 50 side. Then, the end portion thereof extends parallel to the substrate 30, then rises upward again, and further extends parallel to the substrate 30. And again,
After extending toward the substrate 30 and descending again, it contacts a hexagonal plate 56 that contacts the second diode 54. In this case, a bolt is inserted between the plate body 56 and the plate body 48, and the first
The diode 50 and the second diode 54 are firmly sandwiched. The center tap 58 is set up in the middle of the conductor 52.

Next, as described in the longitudinal sectional view of FIG. 9, if a hole 59 is defined in the conductor 52 in advance and cooling water is made to flow through this hole 59, this transformer can be effectively cooled. .

Fig. 10 shows the circuit configuration of the welding transformer configured as described above. Reference numeral 60 is a rectifier circuit, for example,
A power supply of three-phase AC 400V is connected to the rectifier circuit 60, and after obtaining an AC by the rectifier circuit 60, a square wave is obtained by the inverter unit 62, and then the welding transformer according to the present embodiment is used. Take a predetermined AC current from the secondary side and
Supply this to 64.

As described above, according to the present embodiment, in forming the primary coil of the welding transformer, the insulating film is laminated on the thin plate-shaped conductor, which is wound, and then a predetermined length is set along the axis thereof. It cuts so as to define a gap, and then cuts very thinly so as to be orthogonal to the axis, and the coil units 39a to 39d composed of this thinly cut coil unit 20.
Holes 32, 34, 36 and 37 defined in the second substrates 33a to 33d forming the substrate 30 through one end and the other end thereof.
To insert. In each of the holes 32, 34, 36 and 37, since the coil unit 20 constituting the coil units 39a to 39d is electrically connected through the insertion action, as a result, a large number of primary surfaces having a large surface area are formed. A side coil unit can be obtained.

According to this embodiment, the coil unit 39a having the six turns and including the coil unit 20 in which six conductor layers are laminated is provided.
4 to 39d are arranged in parallel, and the coil unit 39a
The core 40 and the core 42 are mounted through the space defined by the reference numerals 39 to 39d. As a result, the surface area of the conductor through which the welding current flows is increased, and a large current can be passed without being hindered by the skin effect. Moreover, in order to form the coil alone, since thin plate members such as copper plates are simply laminated through the insulator and the width is cut extremely thin,
It is simple and easy to handle.
[Advantages of the Invention] As described above, according to the first aspect of the invention, the primary coil of the welding transformer is divided and configured by the insulated conductive wire. For this reason, for example, in the prior art, the surface area of the primary coil of the plurality of conductors is significantly increased as a whole as compared with the one in which the primary coil is composed of one rectangular conductor wire, and therefore only the conductor surface vicinity is provided by the skin effect. It is possible to avoid the inconvenience that a current flows. That is, it becomes possible to efficiently flow current to the conductor as a whole. Moreover, a balanced primary coil can be obtained simply by inserting the coil unit configured as described above into the board and then fixing it, so that the operation can be stably performed during welding. You can

Further, since the structure is simple, it is possible to manufacture at a low cost with few failures, and even if a failure occurs, it is possible to easily replace the parts. Therefore, not only can the size of the welding transformer be reduced, but also the weight can be greatly reduced.

Furthermore, according to the second invention, the coil alone is laminated with the insulating film on the thin metal plate body as described above,
This is wound and then cut into extremely thin pieces. Therefore, it is possible to obtain a single coil having an extremely large surface area at once.

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

In the present invention, the structure in which the insulating film is laminated on the thin plate conductor, wound and then sliced is described. For example, concentric tubular conductors having different diameters are laminated and then fitted together. By combining them, it is possible to obtain a single coil having the same effect, and it goes without saying that this is also included in the present invention.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view showing a manufacturing process of a coil unit constituting a welding transformer according to the present invention, and FIG. 2 is a perspective explanatory view showing a state in which the coil unit shown in FIG. 1 is inserted into a substrate. 1 is a perspective explanatory view of the state shown in FIG. 1 before inserting the coil alone into the substrate, FIG. 4 is a partially omitted perspective explanatory view of the state where the coil alone is inserted into the substrate, and FIG. Wiring diagram, FIG. 6 is a perspective explanatory view when assembling a welding transformer composed of a primary side and a secondary side with the coil alone attached to a substrate, and FIG. 7 is a welding diagram shown in FIG. Plan view of the transformer for welding, FIG. 8 is a front view of the transformer for welding shown in FIGS. 6 and 7, FIG. 9 is a sectional view taken along the line AA of FIG. 7, and FIG. FIG. 9 is an electric circuit diagram of the welding transformer shown in FIG. 9. 10 …… Copper sheet, 12 …… Insulation film 14 …… Core material, 20 …… Coil alone 30 …… Board, 50 …… First diode 52 …… Conductor, 54 …… Second diode 60 …… Rectifier circuit, 62 …… Inverter section 64 …… Welding gun

Claims (2)

(57) [Claims] 1. A coil unit is formed by arranging a plurality of coil units, each of which is formed by laminating a plurality of mutually insulating conductors, in parallel with each other with an insulating member interposed therebetween, and is fixed substantially orthogonal to a first substrate. By fitting the ends of the coil units into the holes formed in the formed second substrate, the ends of the conductors of the corresponding layers between the adjacent coil units and between the adjacent coil units are mutually connected. And the other end are connected in series, and further, between adjacent coil units and between adjacent coil units, the conductors of each laminated layer are connected in parallel to form one of the primary side coil or the secondary side coil. A core transformer is attached to the coil unit through a space defined by the coil unit. 2. A first step of laminating an insulating member on a conductor, and cutting the laminated body of the conductor and the insulating member into a thin plate shape along a direction substantially orthogonal to an axial direction thereof, and the cutting. A second step of obtaining a plurality of coil single bodies by cutting a laminated body of a conductor and an insulating member along an axial direction thereof with a predetermined cutting width, and a second step of being orthogonally fixed to a first substrate. By fitting the end portions of the conductors forming the coil unit to the holes formed in the substrate of, the conductors of corresponding layers are connected in series between the adjacent coil units and between the adjacent coil units. And a third step of forming a primary side coil or a secondary side coil by connecting the conductors of the stacked layers in parallel between adjacent coil units and between adjacent coil units, and Koi 4 to form the welding transformer by mounting the core member via the space portion defined in the unit
And a method for manufacturing a welding transformer.