JPH09168868A - Transformer for inverter resistance welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a secondary transformer structure having a reduced number of part items a simplified assembly process and a reduced secondary inductance in the transformer for inverter resistance welding machine. SOLUTION: Secondary coil members 22, 24 are arranged at one side (right side) as viewing from a rectifying element mounting face 30b of a heat dissipating member 30 and first/second transformer output terminals 14A, 14B are arranged at other side (left side), a first external connecting member 64 is protruded from one end part of a cathode common connecting plate 48 and is extended up to the first transformer output terminal 14A, a second external connecting member 68 is extended from a third projecting piece like connecting part 38c of a center tap member 38 existing at one side of the heat dissipating member 30 through the front face of the rectifying element mounting face 30b up to the second transformer out put terminal 14B of at other side of the heat dissipating member 30.

Description

Detailed Description of the Invention

[0010]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding transformer with a rectifying element used in an inverter type resistance welding machine.

FIG. 8 shows a circuit configuration of a main part of the inverter type resistance welding machine. In a welding transformer (transformer for an inverter resistance welding machine) 100, a primary coil 102 and a secondary coil 104 are wound around a core 106. On the primary side, both terminals of the primary coil 102 are directly connected to a pair of transformer input terminals 108A and 108B. On the secondary side, both terminals of the secondary side coil 106 are connected to one output terminal 114A via the rectifying elements 110 and 112, respectively, and the center tap 1 of the coil 106 is connected.
18 is connected to the other output terminal 114B.

DC power obtained by rectifying an AC voltage of commercial frequency by a rectifier circuit (not shown) is input to the input terminal of the inverter 116. The inverter 116 is
It is composed of a switching element such as a giant transistor, and converts the input direct current into a pulsed (rectangular wave) high frequency alternating current by a high frequency switching operation. The switching operation of the inverter 116 is performed by the control circuit 1
It is controlled by a control signal from 18.

The high frequency alternating current output from the inverter 116 is applied to the primary coil 102 of the transformer 100,
In the secondary coil 104 of the transformer 100, a stepped down high-frequency high-frequency alternating current is obtained. This secondary coil 104
The high-frequency AC generated in the transformer 110 and 112 is rectified alternately every half cycle, so that the transformer output terminal 1
14A and 114B can obtain DC power with the 114A side being the positive electrode and the 114B side being the negative electrode. As a result, a DC secondary current (welding current) I flows through the materials to be welded 124, 126 via the welding electrodes 120, 122, and the materials to be welded 124,
The weld of 126 is metallurgically joined by Joule heat.

In the medium-sized inverter type resistance welding machine, the transformer input terminals 108A and 108B of the welding transformer 100 are used.
1 to 2 kHz from the inverter 108,
AC voltage of 300 V and 40 to 200 amps is input, and the transformer output terminal 114 of the welding transformer 100 is input.
A DC welding current I of, for example, 2 to 6 kiloamperes is supplied to the materials to be welded 124 and 126 from A and 114B.

9 and 10 show a secondary side transformer structure in a conventional inverter type resistance welding machine transformer. 9 and 10 are a side view and a perspective view of this conventional secondary side transformer structure.

In this welding transformer, the secondary coil is composed of U-shaped coil members 130 and 132 made of two thick copper plates arranged in two layers. These U-shaped coil members 130 and 132 are each mounted around a core (not shown) as a single-turn coil, and both ends or notches are directed toward the center of the transformer.

The upper coil member 130 is connected to one anode common connecting member 134 made of a copper plate at one end (the front end in FIGS. 9 and 10) and the other end (see FIGS. 9 and 10), it is connected to a center tap member 136 made of a copper plate at the inner end). The lower coil member 130B has the center tap member 1 at one end (the front end in FIGS. 9 and 10).
36, and the other end (inner end in FIGS. 9 and 10) is connected to the other anode common connection member 138 made of a copper plate.

Common anode connection members 134 and 13
8 is a support part 134a, 138a having a flat plate shape, and a support part 134 for connecting to the ends of the coil members 130, 132.
a and 138a, connecting portions 134b and 138b having an L-shaped cross section that extend toward the coil side from the outer end portions thereof (138b is hidden and hidden in FIGS. 9 and 10), and a plurality of connecting portions are arranged on the opposite side. Pair of L-shaped connecting portions 134c and 13 fixed to the inner surface of the supporting portions 134a and 138a for connecting to the anode terminal of the diode 140 of FIG.
And 8c.

First and second common anode connecting member 1
34, 138 connecting portions 134c, 138c having an L-shaped cross section
On the opposite side, first and second cathode common connecting members 142 and 144 made of a copper plate and having U-shaped cross-sections have L-shaped connecting portions 134c and 138 having opposite protruding side portions.
It is fixed to the inner side surface of the common connection plate 146 made of a copper plate so as to abut the protruding side portion of c.

Common cathode connecting member 14 having a U-shaped cross section
A predetermined number (eight in one surface in the illustrated example) of diodes 140 are attached and fixed to each surface of the protruding side portions of 2, 144 with their cathode terminals facing (connected). The anode terminal of each diode 140 has an L-shaped cross-section connecting portion 134c or 138c on the opposite side via a connecting piece 141 of a copper plate.
Is connected to each surface of the protruding side portion.

The rear surface (inner surface) of the heat dissipation member 150 made of aluminum is adhered and fixed to the outer surface of the common connection plate 146. A heat radiation fin 150a having a comb-shaped cross section is provided on the surface (outer surface) of the heat radiation member 150.

The base end portions of the pair of external connection members 154 and 156 are joined to the bent portions at both ends of the common connection plate 142. These external connection members 154 and 156 are the heat dissipation members 1
From the side of 52 to the front of the heat radiation fin 150a, the front end portions 154b and 156b are integrally united with each other at the center of the front face and project toward the front side to form one transformer output terminal (114A).

On the other hand, the base end portion of the external connection member 158 is connected to the lower end portion of the center tap member 136. The external connecting member 158 is connected to the common anode connecting member 13
4, 138, diode 140, cathode common connection members 142 and 144, common connection plate 146, and heat dissipation member 15
It goes around the front of the radiating fin 150a via the bottom of 0, and the tip part 158a protrudes to the front of the front at a position slightly lower than the center part of the front and forms the other transformer output terminal (114B).

Although not shown, the core is made of a "day" -shaped silicon steel plate member. A pair of "E" -shaped silicon steel plate members or a pair of "E" -shaped silicon steel plate members and an "I" -shaped silicon steel plate member prepared by dividing the "day" character into two in the vertical direction are prepared, The primary side coil is wound around the central protruding portion of the "E" -shaped member, the secondary side coil member is attached on (surrounding) it, and both members are united to form a "day" -shaped core. A transformer assembly is constructed by tightening the outer peripheral surface of the with a band.

[0160]

This type of transformer is
Since it is often mounted on the tip of the robot arm,
It is customary to take out the transformer output terminals (114A, 114B) from one end of the transformer in the axial direction. In the above-mentioned conventional transformer, the transformer output terminal (114
A, 114B) external connection members (154, 15)
6) and the tip portion (154a, 1) of the external connection member 158.
56a) and 158a have a structure in which the radiating fins 150a project forward from the front surface.

In the above-mentioned conventional transformer, the heat dissipation member 1
Reference numeral 50 denotes a large amount of heat generated by each diode 140, which is connected to the common cathode connecting members 142 and 144 and the common connecting plate 14.
The heat is absorbed through 6 and the absorbed heat is radiated to the outside air from the heat radiation fin 150a. In order to enhance the heat dissipation effect, it is often practiced to supply air for cooling air to the heat dissipation fins 150a by a fan (not shown). However, the external connection members (154, 156), 158 are
Since it covers 50a, the heat dissipation action of the heat dissipation fin 150a is hindered.

Further, in the above-mentioned conventional transformer, the pair of external connection members 154, 156 are turned from the upper end portion and the lower end portion of the common connection plate 146 to the front surface of the heat radiation fin 150a, and the tip end portions of the both external connection members 154, 156 are rotated. 154a,
156a is integrally joined. As described above, the pair of upper and lower external connection members 154 and 156 are used because the applied voltage applied to the large number (64) of diodes 140 vertically arranged at the back of the common connection plate 146 is applied to the upper side and the lower side. This is to equalize with. These external connection members 154, 1
Waxing is used for joining the tip portions 154a and 156a of the 56. Bolt connection and resistance welding cannot be used. With bolt connection, the surface contact is uneven,
This is because electrolytic corrosion is likely to occur. In addition, the external connection members 154 and 156 made of copper plates have a small resistance value, a high thermal conductivity, and do not generate sufficient heat even when an electric current is applied.
Resistance welding is not possible. In that respect, the brazing can satisfactorily bond the copper plates together. However, brazing is very labor intensive and has skill.

Further, these external connecting members 154, 156
Has a long conductor length, and therefore forms a large loop with the other external connection member 158, thereby increasing the secondary-side inductance.

In the above conventional transformer, the Schottky diode 140 is used as the rectifying element. Since there is no large-capacity Schottky diode, the required rectifying element capacity is secured by connecting the required number of existing small-capacity Schottky diodes in parallel. Further, in order to attach these many diodes 140, the anode common connection member 134 is provided with connection portions 134b and 138b having an L-shaped cross section, or the common connection plate 14 is connected.
6, the cathode common connection members 142 and 144 having a U-shaped cross section
It has a structure to fix. In general, the above-mentioned conventional transformer has a complicated structure, a large number of parts and assembling steps, and is troublesome to maintain.

The present invention has been made in view of the problems of the prior art, and has a small number of parts and a simple assembly process,
It is an object of the present invention to provide a transformer for an inverter type resistance welding machine having a small secondary side inductance.

[0220]

In order to achieve the above object, a transformer for a resistance welding machine according to the first aspect of the present invention is configured such that AC power from an inverter is input to a primary coil and a secondary coil is input. In the inverter type resistance welding machine transformer that outputs DC power from the rectifying element connected to
A heat radiating member having a rectifying element mounting surface, a first radiating member mounted on the rectifying element mounting surface of the heat radiating member via a conductive common connecting plate, and one terminal of each of which is connected to the common connecting plate. A second rectifying element, first and second secondary side coil members arranged laterally on one side of the heat radiating member when viewed from the rectifying element mounting surface, and connected to each other via a center tap member; A conductive member extending from one lateral side of the heat dissipation member to the front surface of the rectifying element mounting surface for electrically connecting the end of the first secondary coil member to the other terminal of the first rectifying element. A first internal connecting member and an end of the second secondary coil member electrically connected to the other terminal of the second rectifying element from one lateral side of the heat radiating member. Conductive material that extends to the front of the rectifying element mounting surface 2 internal connection members, first and second output terminals arranged on the other lateral side of the heat dissipation member when viewed from the rectifying element mounting surface, and the common connection plate electrically connected to the first output terminals. An electrically conductive first external connecting member protruding from one end of the common connecting plate and extending to the other lateral side of the heat radiating member to connect to the second output terminal. And a conductive second external connection member extending from one lateral side of the heat dissipation member to the other lateral side of the heat dissipation member via the front surface of the rectifying element mounting surface for electrical connection. And

The second inverter resistance welding machine transformer of the present invention is the same as the first inverter resistance welding machine transformer, wherein the one terminal and the other terminal of each of the rectifying elements are different from each other. The rectifying element is provided on each of a pair of opposing surfaces.

[0240] Further, a third inverter type resistance welding machine transformer of the present invention is the above-mentioned second inverter type resistance welding machine transformer, wherein the first rectifying element and the second rectifying element are the above-mentioned ones. On the rectifying element mounting surface of the heat dissipating member, one or a plurality of them are arranged side by side in the lateral direction at mutually spaced positions in the longitudinal direction.

The fourth inverter type resistance welding machine transformer of the present invention is the inverter type resistance welding machine transformer according to any one of the first to third aspects, wherein the heat dissipation member is opposite to the rectifying element mounting surface. The side surface has a fin for heat dissipation.

[0260]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIGS. 1 and 2 show the overall construction of an inverter type resistance welding machine transformer according to an embodiment of the present invention. FIG. 1 is a plan view of this transformer, and FIG. 2 is a side view of this transformer.

This welding transformer is housed in the casing 10. The input terminals 12A and 12B are attached to one side surface of the housing 10, and the output terminals 14A and 14B are attached from the opposite side surface.
Has been taken out. The input terminals 12A and 12B are connected to the output terminal of the inverter 116 (FIG. 8), and the output terminal 1
4A and 14B are connected to welding electrodes 120 and 122 (FIG. 8).

In the housing 10, the transformer unit 16 is provided at a position closer to the input terminals 12A and 12B from the center. The transformer unit 16 includes a core 18
The primary side coil member 20 of the compound winding and the secondary side coil members 22 and 24 of the single winding are integrally attached to each other. Both ends of the primary side coil member 20 have cables 26A and 2A, respectively.
It is connected to the input terminals 12A and 12B via 6B.

The core 18 is made of a "day" -shaped silicon steel plate member as in the conventional case. For example, prepare a pair of "E" -shaped silicon steel plate members that are formed by dividing the "Sun" character in two in the vertical direction,
The primary side coil member 20 is provided on the central protruding side of the “E” -shaped member.
Is wound, and the secondary side coil members 22 and 2 are wound around (wound)
4, the "E" -shaped members are abutted against each other to form the "Sun" -shaped core 18, and the outer peripheral surface of the core 18 is fastened with the band 18a, whereby the transformer unit 16 is assembled.

The transformer unit 16 and the output terminal 14A,
A plurality of rectifying elements 28 made of large-capacity silicon diodes, a heat radiating member 30 made of aluminum, a fan 32 for supplying air for air cooling to the heat radiating member 30, and the like are arranged between the heat radiating member 14B and 14B. There is. In addition, the housing 1
Vents (not shown) are provided on the side surface of the No. 0.

FIGS. 3 to 7 show the secondary side transformer structure in the transformer of this embodiment. 3 is a side view of the secondary transformer structure, FIGS. 4 and 6 are perspective views of the secondary transformer structure viewed from different directions, and FIGS. 5 and 7 are diagrams of the secondary transformer structure viewed from different directions. It is the partial cutaway perspective view seen.

Each of the secondary coil members 22 and 24 is made of a thick copper plate, and has both ends or notches bent in a U-shape toward the center of the transformer so that the center side of the core 18 (see FIG. (Not shown) are wound in parallel.

The first secondary coil member 22 has a base of the first common anode connecting member 34 having an L-shaped cross section and made of a copper plate at one end portion (upper end portion in FIGS. 4 and 5) 22a. The end portion (short side portion) 34a is connected with a bolt 36, and the other end portion (lower end portion in FIGS. 4 and 5) 2
At 2b, the bolt is connected to the first projecting piece-like connecting portion 38a of the center tap member 38 made of a copper plate (FIG. 7).

The second secondary coil member 24 has a bolt 42 attached to the second projecting piece-like connecting portion 38b of the center tap member 38 at one end portion (upper end portion in FIGS. 4 and 5) 24a. And a second end having an L-shaped cross section made of a copper plate at the other end (lower end in FIGS. 4 and 5).
Base portion (short side portion) 44a of the common anode connecting member 44 of
To the bolt 46 (FIG. 7).

The heat dissipating member 30 has a rectangular heat dissipating substrate 30a, and one flat surface of the substrate 30a is attached to the rectifying element mounting surface 3.
0b and the heat radiation fin 30c having a comb-shaped cross section on the opposite surface
Is provided. First and second secondary side coil member 2
2, 24 are arranged on one lateral hand (right hand in FIGS. 4 and 5) when viewed from the rectifying element mounting surface 30b of the heat dissipation member 30.

The rectifying element mounting surface 30b of the heat dissipating member 30.
Through the cathode common connection plate 48 made of a copper plate.
Large-capacity silicon diodes 50, 52, 54, 5
6 are detachably attached by bolts 58. Each of the diodes 50, 52, 54, 56 has a box-shaped casing made of resin, and plate-shaped cathode terminals 50a, 52a, 54a, 56 provided on the bottom surface of the casing.
a is closely attached (connected) to the cathode common connection plate 48.

Each diode 50, 52, 54, 56
Two plate piece-shaped anode terminals 50b, 52b, 54b, 56b having screw holes are provided on the upper surface of the casing of FIG.

The first diodes 5 arranged side by side in the upper half of the rectifying element mounting surface 30b of the heat dissipation member 30.
The anode terminals 50b and 52b of 0 and 52 have an intermediate portion or a tip portion (long side portion) of the first common anode connecting member 34.
34b is connected by a bolt 60.

The anode terminals 54b and 56b of the second diodes 54 and 56 arranged side by side in the lower half of the rectifying element mounting surface 30b are connected to the middle or tip of the second common anode connecting member 44. Part (long side part) 44b is bolt 6
2 connected.

In the other lateral hand (left hand in FIGS. 4 and 5) as viewed from the rectifying element mounting surface 30b, one end 48a of the cathode common connecting plate 48 is bent at a right angle along one end surface of the heat dissipation member 30, A base end portion (short side portion) 64 of the first external connecting member 64 having an L-shaped cross section is provided on the bent end portion 48a.
a is fixed by a bolt 66. The long side portion 64a of the first external connecting member 64 projects vertically (to the front of the left hand) from the bent end portion 48a of the common cathode connecting plate 48, and constitutes the first transformer output terminal 14A. There is.

The center tap member 38 has a third projecting piece-like connecting part 38c projecting to the outside of the first secondary coil member 22 at a position close to the first projecting piece-like connecting part 38a. ing. The base end portion 68a of the second external connecting member 68 is fixed to the third projecting piece-like connecting portion 38c with a bolt 70. The intermediate portion 68b of the second external connecting member 68 extends straight to the other lateral hand (left hand) via the front surface of the rectifying element mounting surface 30b of the heat dissipation member 30, and the cross section L from the end of the intermediate portion 68b. A letter-shaped tip 68c extends forward. The tip portion 64c of the second external connection member 68
Constitute the second transformer output terminal 14B.

The circuit configuration of the transformer according to this embodiment is equivalent to the circuit configuration of the welding transformer 100 shown in FIG. A high-frequency AC pulse is input from the inverter 116 to the input terminal 12
When applied to the primary coil member 20 via A, 12B and the cables 26A, 26B, a high frequency AC pulse due to an induced electromotive force is generated via the core 18 between the terminals 22a, 24b of the secondary coil members 22, 24. Occurs in.

In a half cycle in which the AC pulse on the secondary side has a positive polarity, a forward voltage is applied to the first diodes 50 and 52, and a reverse voltage is applied to the second diodes 54 and 56. . When the first diodes 50 and 52 become conductive, the first secondary coil member 22 → the first common anode connecting plate 34 → the first diodes 50 and 52 → the common cathode connecting plate 48 → the first external connecting member 64 → first transformer output terminal 14A (64b) → welding electrode 120 → materials 124 and 126 to be welded → welding electrode 122 → second transformer output terminal 14B (68c) → second external connecting member 68 → center tap member 38 → Secondary current flows through the path of the second secondary side coil member 24.

In a half cycle in which the secondary side AC pulse has a negative polarity, a reverse voltage is applied to the first diodes 50 and 52, and a forward voltage is applied to the second diodes 54 and 56. . When the second diodes 54 and 56 become conductive, the second secondary coil member 24 → the second common anode connecting plate 44 → the second diodes 54 and 56 → the common cathode connecting plate 48 → the first external connecting member 64 → first transformer output terminal 14A (64b) → welding electrode 120 → materials 124 and 126 to be welded → welding electrode 122 → second transformer output terminal 14B (68c) → second external connecting member 68 → center tap member 38 → Secondary current flows in the path of the first secondary coil member 22.

The secondary coil members 22 and 24 are single-turn coils and have extremely low inductance, and most of the secondary conductive members including the secondary coil members 22 and 24 are copper having a low resistance value. Since it is configured, a considerably large secondary current flows in the secondary side circuit. Therefore, each diode 5
0, 52, 54 and 56 generate a considerable amount of heat. The heat generated by each of the diodes 50, 52, 54, 56 is absorbed by the heat radiation member 30 via the cathode common connection plate 48, and is radiated from the heat radiation fins 30c of the heat radiation member 30 to the atmosphere. The air supplied from the air cooling fan 32 to the heat radiation fins 30c enhances the heat radiation effect.

In the transformer of this embodiment, the secondary coil members 22 and 24 are arranged on one lateral side (right side in FIGS. 4 and 5) of the heat dissipation member 30 when viewed from the rectifying element mounting surface 30b, and the other side is arranged. Sideways (left hand in Figures 4 and 5)
The transformer output terminals 14A and 14B are arranged on the transformer output terminals 14A and 14B so that the first external connecting member 64 projects from one end portion 48a of the cathode common connecting plate 48 which is adjacent to one side surface of the heat radiating member 30 on the transformer output terminals 14A and 14B side. The heat dissipation member 3 while extending to the first transformer output terminal 14A.
The third external connecting member 68 from the third projecting piece-like connecting portion 38c of the center tap member 38 present on one lateral side (right hand) of 0 passes through the front surface of the rectifying element mounting surface 30b and the other side of the heat radiating member 30. It is configured to extend to the second transformer output terminal 14B of the horizontal hand (left hand).

With such a structure, the radiating fin 3 is secured while ensuring the basic (standard) form of the transformer in which the secondary coil member and the transformer output terminal are arranged on both sides of the radiating member.
The heat dissipation effect is enhanced without placing any conductive member around 0c, the number of parts is reduced as much as possible, and the transformer structure is downsized and simplified as much as possible.

Also, one end 4 of the cathode common connection plate 48
The first external connection member 64 that connects 8a to the first transformer output terminal 14A is configured to have a minimum length and has a small voltage drop, so that the voltage applied to the diodes 50, 52, 54, 56 is substantially the same. There is no variation. Therefore, it is not necessary to pull out another first external connection member 64 from the end portion on the opposite side of the cathode common connection plate 48. This eliminates the step of joining two copper plates (connection members) by brazing.

Since the loop formed between the first external connecting member 64 and the second external connecting member 68 is small, the secondary side inductance is small.

Further, in the transformer of the present embodiment, a total of four large-capacity silicon diodes 50 to 56 are used for the rectifying element, and a total of four rectifiers are used.
And a rectifying capacity equivalent to 64 Schottky diodes 140 in FIG. 10) is obtained.

[0520] Incidentally, the rectifying element mounting surface 30 of the heat dissipating member 30.
The number, arrangement position, arrangement pattern, etc. of the diodes mounted on b are selected according to the magnitude of the used current.
It is also possible to reverse the direction of the diode (positional relationship between the anode and the cathode) depending on the structure of the diode and the specifications of the secondary circuit.

The structure of the heat dissipating member 30 in the above-described embodiment, particularly the structure of the heat dissipating fins 30c, is an example, and various heat dissipating structures can be adopted. The shapes of the secondary coil members 22 and 24 and the center tap member 38 can be variously modified, and the individual members can be integrally formed or can be further subdivided.

Also, if necessary, the transformer output terminal 14
A (64b) and 14B (68c) may be arranged not in the side opposite to the secondary side coil members 22 and 24 as viewed from the heat dissipation member 30 but in a substantially perpendicular direction (for example, upward in FIGS. 4 and 5). It is possible.

[0550]

As described above, according to the inverter type resistance welding machine transformer of the present invention, the secondary coil member is provided on one side of the heat radiating member as viewed from the rectifying element mounting surface provided on the heat radiating member. By arranging and arranging the transformer output terminal on the other side, and providing the secondary side coil member, the rectifying element, the heat dissipation member, and the conductive connecting member for connecting between the transformer output terminals at the optimum position or the optimum route, The number is small, the assembling process is simplified, and the secondary side inductance can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing the overall configuration of an inverter type resistance welding machine transformer according to an embodiment of the present invention.

FIG. 2 is a side view showing the overall configuration of a transformer according to an embodiment.

FIG. 3 is a side view showing a secondary-side transformer structure in an example.

FIG. 4 is a perspective view showing a secondary side transformer structure in the embodiment.

FIG. 5 is a partially cutaway perspective view showing a secondary side transformer structure in an example.

FIG. 6 is a perspective view showing a secondary side transformer structure in the embodiment.

FIG. 7 is a partially cutaway perspective view showing a secondary side transformer structure in an example.

FIG. 8 is a circuit diagram showing a circuit configuration of a main part of an inverter type resistance welding machine.

FIG. 9 is a side view showing a secondary side transformer structure in a conventional inverter type resistance welding machine transformer.

FIG. 10 is a perspective view showing a secondary-side transformer structure of a conventional inverter type resistance welding machine transformer.

[Explanation of symbols]

 14A (64b) 1st transformer output terminal 14B (68c) 2nd transformer output terminal 20 Core 22 Primary side coil member 22 1st secondary side coil member 24 2nd secondary side coil member 30 Radiating member 30b Rectification Element mounting surface 34 First anode common connecting member 38 Center tap member 44 Second anode common connecting member 48 Cathode common connecting member 50, 52 First diode 54, 56 Second diode 64 First external connecting member 68 Second external connection member

Claims (4)

[Claims] 1. A transformer for an inverter resistance welding machine, wherein AC power from an inverter is input to a primary side coil, and DC power is output from a rectifying element connected to a secondary side coil. A member, first and second rectifying elements that are attached to the rectifying element attachment surface of the heat radiating member via a conductive common connection plate, and each one of the terminals is connected to the common connection plate, First and second secondary side coil members, which are arranged on one lateral side of the heat dissipation member when viewed from the rectifying element mounting surface and are connected to each other via a center tap member, and the first secondary side coil A conductive first internal connection extending from one lateral side of the heat dissipating member to a front surface of the rectifying element mounting surface for electrically connecting an end portion of the member to the other terminal of the first rectifying element. Members, The second secondary coil member extends from one lateral side of the heat radiating member to the front surface of the rectifying element mounting surface for electrically connecting the end of the second secondary coil member to the other terminal of the second rectifying element. A conductive second internal connection member, first and second output terminals arranged on the other side of the heat dissipation member when viewed from the rectifying element mounting surface, and the common connection plate for the first output. A conductive first external connecting member that protrudes from one end of the common connecting plate and extends to the other lateral side of the heat dissipation member for electrically connecting to a terminal, and the center tap member includes the second external connecting member. A conductive second external connection member that extends from one lateral side of the heat dissipation member to the other lateral side of the heat dissipation member via the front surface of the rectifying element mounting surface for electrically connecting to the output terminal. Inverter type resistor characterized by comprising: Transformer for contact machine. 2. The inverter according to claim 1, wherein the one terminal and the other terminal of each of the rectifying elements are provided on a pair of opposing surfaces of the rectifying element, respectively. Type resistance welding machine transformer. 3. The first rectifying element and the second rectifying element are arranged side by side in the vertical direction on the rectifying element mounting surface of the heat dissipation member, and one or more of them are arranged side by side. The inverter type resistance welding machine transformer according to claim 2, wherein the transformer is used. 4. The transformer for an inverter resistance welding machine according to claim 1, wherein the heat dissipation member has a fin for heat dissipation on a surface opposite to the rectifying element mounting surface. .