JPH0595018U - Resistance welding transformer - Google Patents

Abstract

(57) [Abstract] [Purpose] A transformer for welding used in a resistance welding machine, and to a structure of a secondary coll thereof. [Structure] A water-cooled secondary coil having a winding number of at least 2 turns or more is stacked with a primary coil in which an insulating material is arranged and a band-shaped conductor is wound, and an iron core is provided between the coil conductors formed by the stacking. In the inserted resistance welding transformer, the secondary coil is formed by bending one conductive member to form a continuously wound loop portion of two turns or more. As a result, compared to the conventional two-turn secondary coil in which U-shaped coil pieces having a two-part structure are connected in an N-shape via a connecting conductor, water leakage from the connecting portion is prevented, and the number of parts and material A simple and inexpensive secondary coil can be easily manufactured, improving the durability and safety of the product and significantly reducing the weight, size and cost.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a resistance welding transformer used in, for example, a portable spot welder, and particularly to a structure of a secondary coil which constitutes a loop circuit of at least 2 turns or more.

[0002]

[Prior Art]

 FIG. 1 shows the internal structure of a conventional transformer of this type. FIG. 2 shows a cross section of the laminated structure of the primary coil and the secondary coil. FIG. 3 shows a connection structure of a two-turn loop portion of a conventional secondary coil. FIG. 4 is a plan view of FIG. FIG. 5 is a side view of the terminal side of the transformer, showing a connection portion of a loop portion wound between two split coil pieces constituting a secondary coil via a connection conductor.

In the above drawings, the secondary coil 2 used in this type of transformer 1 includes a connecting conductor 3 between the terminal sides of two split coil pieces 2A and 2B formed by bending a conductive member into a substantially U shape. It is connected to form a loop circuit of two turn coils. A cooling water passage 4 is formed inside each of the divided coil pieces 2A and 2B, and the cooling water passage 4 communicates with a cooling water passage 5 opened inside the connection conductor 3 to start the secondary coil. Cooling water is supplied from either the port 6 or the port 7 at one of the end and the coil end, and the temperature of the secondary coil 2 is prevented from rising by the cooling water flowing in the secondary coil.

On the inner side and the outer side of the secondary coil 2, a primary coil 8 in which a strip-shaped member is wound is stacked with an insulator S 1 disposed. The iron core 9 is inserted between the coil conductors in which the primary coil and the secondary coil are stacked. Terminal plates 11 and 12 are connected to the start and end ends of the secondary coil, respectively, and the iron core and the entire coil are covered with a trans cover 10 except for the terminal plates 11 and 12.

[0005]

[Problems to be Solved by the Invention] Conventionally, when a loop portion of a secondary coil of two turns or more is formed on the terminal side of a transformer, two split coil pieces 2A bent in a U shape, The connecting conductor 3 was connected between the terminals of 2B by means of brazing, soldering or arc welding. For this reason, skilled techniques are required for the soldering, soldering, and arc welding, and it takes time to install the connecting conductor, and sometimes the connecting part is incomplete. And this causes water leaks and causes a fatal accident. In addition, conventionally, a connection conductor was required, resulting in an increase in the number of parts, a processing man-hour for the cooling water passage, and a material cost. Moreover, the structure was complicated and upsized, and there were still problems in reducing the weight and cost of the transformer. It was

[0006]

[Means for Solving the Problems]

 The present invention takes the following technical means as an improvement measure for solving the above problems. That is, a transformer for resistance welding, in which an insulator is arranged on a secondary coil having a winding number of at least 2 turns or more, primary coils are stacked, and an iron core is arranged on the coil conductor formed by stacking In particular, in a transformer in which the secondary coil is a water-cooled type, the secondary coil is formed by bending one conductive member to continuously form a loop portion of two turns or more. It is characterized by

[0007]

[Action]

 According to the structure of the secondary coil of the present invention, one conductive member is bent to form a winding loop portion of two turns or more. Since it is not necessary to connect the split coil pieces with connecting conductors, it is possible to drastically eliminate fatal accidents caused by water leakage from the incomplete connection part in the winding loop part, and the number of parts and material cost are reduced. Moreover, the manufacturing of a simple secondary coil is simplified, and the transformer weight is reduced, the size is reduced, and the cost is reduced.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 6 is a front view showing an embodiment of the secondary coil of the present invention. FIG. 7 is a side view. In this case, the other components (primary coil, iron core, terminal plate, transformer cover, etc.) except the secondary coil are basically the same as the structure of the conventional transformer, and therefore detailed description thereof is omitted.

The secondary coil 20 of the present invention is an example of a case where a 2-turn loop circuit is constructed here, and a 2-turn loop is formed by mechanically bending one conductive member 21. -Pop part 22 is formed continuously. The secondary coil 20 has a cooling water passage 23 inside, and the cooling water is made to flow through the water hole to effectively cool the secondary coil 20. Although not shown in the drawing, a secondary coil having two or more turns can also be easily manufactured by mechanically bending a cooling pipe connected to the outer periphery of one conductive member in advance. The terminal board is fixed to the end surface of the secondary coil by means of bonding, etc. as usual.

8 and 9 show changes in the winding shape of the loop portion 22 of the secondary coil. In the case of FIG. 8, the bending shape of the secondary coil is an example in which it is bent in a hook shape according to the combination with other parts. FIG. 9 shows the bent shape of the loop portion in consideration of the space saving on the terminal side of the transformer. In this case, the bending structure of the secondary coil is such that the side face a of the loop portion 22 is bent inward at about 90 °, the end edge is bent centering on the fulcrum a, and the end edge of the loop portion is fulcrumed. The secondary coil is bent outward at the center of b, and then the side b is bent approximately 90 ° laterally to form the loop portion of the secondary coil in an N shape. The primary coil 25 is laminated on the secondary coil via the insulator 24. If the secondary coil having the loop portion formed in this way is used, as shown in FIG. 10, the dimension of the loop portion projecting to the terminal side, that is, the width h of the secondary coil is the loop portion. By bending the side surface of 22 inward by approximately 90 °, it can be shortened and the transformer can be made smaller.

[0012] The resistance welding transformer of the present invention is used in the same manner as in the conventional case, by suspending this transformer on the ceiling and connecting the spot welding gun with the secondary cable, so that the robot or human can freely use the welding gun. To perform welding, or carry out welding with a robot equipped with a welding machine that has a transformer and spot welding gun integrated into one unit. This transformer is also used in a multi-spot welding machine that welds multiple locations with one energization.

[0012]

[Effect of the device]

 As described above, since the secondary coil of the present invention is formed by bending the winding loop portion of a coil of two turns or more from one conductive member, it is not used in the conventional art. There is no need for the two split coil pieces and connection conductors that were previously used, and therefore the work of connecting the split coil pieces with a connection conductor is also eliminated, and there is no need to process the cooling water passage of the connection conductor or Leaks can be completely eliminated. Also, a simple secondary coil with a low number of parts and low material cost can be easily manufactured. As a result, the durability and safety of the resistance welding transformer can be improved, and the weight, size and cost of the transformer can be further promoted.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structural example of a conventional welding transformer used in a resistance welding machine.

FIG. 2 is an enlarged cross-sectional view of a coil laminated structure portion taken along the line AA of FIG.

FIG. 3 shows a structure of a conventional secondary coil.

FIG. 4 is a plan view of a secondary coil having a conventional structure.

FIG. 5 is a side view showing, in an enlarged manner, a connection conductor connected between the terminal sides of the split coil pieces that constitute the secondary coil of the conventional structure.

FIG. 6 is a front view showing the structure of the secondary coil of the present invention.

FIG. 7 is a side view showing the terminal side of the secondary coil of the present invention.

FIG. 8 is a side view showing another structural example of the secondary coil of the present invention by bending.

FIG. 9 is a side view showing another embodiment of the bent shape of the loop portion in the transformer of the present invention.

FIG. 10 is a view taken along the line BB of FIG. 9, in which an intermediate portion thereof is crushed.

[Explanation of symbols]

 20 Secondary Coil 21 One Conductive Member 22 Winding Loop Part 23 Cooling Water Passage 24 Insulator 25 Primary Coil

[Procedure amendment]

[Submission date] January 21, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

Claims (1)

[Scope of utility model registration request] 1. A resistance welding transformer comprising a secondary coil having at least 2 turns or more turns and an insulator placed on the primary coil, and a coil conductor formed by stacking the iron core. In a transformer in which the secondary coil is a water-cooled type, the secondary coil is formed by bending one conductive member to form a continuously wound loop portion of two turns or more. A resistance welding transformer.