JPH0869932A - Method for grounding secondary circuit of welding transformer for resistance welding - Google Patents

Abstract

PURPOSE: To obtain a simple method for grounding the secondary circuit of a welding transformer for resistance welding formed by integrally molding a resin so as to reduce the weight and cost of the transformer. CONSTITUTION: In a method for grounding secondary circuit of welding transformer for resistance welding, lead wires for grounding are respectively held between a primary coil 1 and secondary coils 2 through insulating thin plates 3 while one ends of the lead wires are brought into contact with parts of the secondary coils 2 in a coil block composed of the primary coil 1, secondary coils 2, and thin plates 3. In an iron core clamping plate on the primary input side, the need of an insulating resin is eliminated from the other part than the four corners of a necessary part so as to reduce the weight and cost of the secondary circuit and the leader lines are guided to the space formed by eliminating the resin. Then grounding resistors are connected to the front ends of the lead wires and the resistors are positioned in the space in attachable/ detachable states as necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a welding transformer in a resistance welding machine.

[0002]

2. Description of the Related Art Conventionally, a method of grounding a secondary circuit of a welding transformer of this type has been such that a screw for connecting a lead wire is provided at a root portion of a secondary output terminal, and a lead wire connected to that portion is secondarily output. A general method is to connect to a grounding resistor mounted inside the iron core clamping plate on the terminal side and ground the other end of the resistor.

However, according to this method, in a transformer in which all the main parts of a transformer often seen recently are resin-molded, the grounding resistor is also molded at the same time, and the above-mentioned grounding resistor cannot be removed. .

[0004]

In the method of grounding the secondary terminal of the welding transformer according to the above-mentioned prior art, even if the grounding resistor becomes defective, it is molded together, so that the grounding resistor can be removed. There was a problem that I could not.

The grounding method according to the present invention has been proposed in view of these problems. Therefore, the object of the present invention is to provide a structure in which the grounding lead wire can be connected to the secondary coil by a simple method, and the grounding resistor connected to the lead wire has a removable structure. There is.

[0006]

In order to achieve the above object, a method for grounding a secondary circuit of a welding transformer for resistance welding according to the present invention proposed will be described. As shown in FIG. The method of pulling out the grounding connection wire from the coil is to connect it to a part of the secondary coil side when assembling the coil block with a thin insulating plate between the primary coil and the secondary coil. A portion of the lead wire where the insulation coating is removed from the tip portion is abutted, the lead wire is sandwiched by the primary coil, the secondary coil, and the insulating thin plate, and in that state, the resin is fixed with an insulating mold resin, A means of connecting a grounding resistor to the tip and grounding is used.

Further, in addition to the above, as shown in FIG. 3, the primary input side iron core tightening plate portion is provided with a space in which a grounding resistor can be arranged and the grounding resistor is detachable. Provide a welding transformer.

That is, the invention of claim 1 is a method for continuously pulling out a grounding lead wire from a secondary circuit, in which a lead wire for direct connection is brought into contact with a secondary coil wheel and a thin plate for insulation is interposed, Provided is a method in which an insulating resin is molded and fixed after being sandwiched between a primary coil and the secondary coil.

According to a second aspect of the present invention, the secondary circuit grounding lead wire of the first aspect is fixed to a secondary coil, and a grounding resistor is connected to the other end of the lead wire to ground. In order to secure the space for arranging the ground resistor,
At the stage before resin molding, as shown in FIG. 2, a mold resin reducing metal fitting is mounted and molded, then the metal fitting is removed, and a ground resistor is arranged in the removed space. Further, the present invention provides a method for manufacturing a resistance welding transformer, characterized in that an effort is made to reduce the amount of mold resin corresponding to the space portion excluding the mold resin reducing metal fitting.

[00010]

According to the present invention, in the method of grounding the secondary circuit of the welding transformer for resistance welding according to the first aspect of the present invention, the part of the secondary coil is insulated from the grounding lead wire. Abutting the stripped portion, when assembling the wire wheel block after that, through the primary wire wheel and the insulating thin plate,
It is held by the secondary wheel. After that, it is completely fixed by molding with an insulating molding resin.

According to the invention of claim 2, in addition to the invention of claim 1, a mounting place of a grounding resistor mounted on the other end of the grounding lead wire is secured in the primary input terminal side iron core clamping plate. Therefore, as shown in FIG. 2, the resin is removed by the resin for molding reduction so that the resin for molding is not filled in that portion.

Further, according to the second aspect of the present invention, a mold resin reducing metal fitting is provided for resin reduction in addition to the grounding resistor mounting portion to reduce the amount of the mold resin, thereby achieving weight reduction and cost reduction. There is.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an exploded perspective view for explaining an essential part of a method for grounding a secondary circuit of a resistance welding transformer according to an embodiment of the present invention. When actually assembling into a wire ring block of a welding transformer, one thin insulating plate and one primary wire are added to the outside of the secondary wire 2 in Fig. 1 and taping is performed with insulating tape. It is integrated as a wheel block.

In FIG. 1, 1 is a primary wire wheel, 2 is a secondary wire wheel, 3 is a thin insulating plate, 4 is a grounding lead wire,
Reference numeral 5 denotes a groove portion in which the secondary wire wheel is processed to have unevenness for slipping the lead wire.

The portion 5 is a groove portion in which unevenness is processed to prevent the grounding lead wire from slipping. The insulating coating on the tip portion of the grounding lead wire 4 is peeled off at this portion, and the peeled portion is the portion 5 After contact with the secondary wire wheel 2 and the insulating thin plate 3
The primary wire wheel 1 is sandwiched between the two and then resin-molded to completely fix it.

In comparison with the example before that of the conventional integral molding type, for example, in which only the wire ring block was molded, in the conventional example, a crimp terminal is attached to the grounding lead wire, and then two bolts, nuts, etc. are attached. It was fastened near the secondary output terminal of the next wheel. It can be said that it is much simpler than this method.

FIG. 2 is a perspective view of the transformer for welding as seen from the direction of the iron core clamping plate on the primary input terminal side in the pre-stage of filling the molding resin. In FIG. 2, 11 is a metal mold reducing metal fitting, 12 is a wire ring block, 13 is a primary input side iron core clamping plate, 14 is a transformer case, and 15 is a secondary output terminal side iron core clamping plate. .

FIG. 3 is a state diagram in which the mold resin reducing metal fitting 11 is removed after the molding resin is filled. The reference numerals in FIG. 3 are the same as in the description with reference to FIG. 1
Part 6 is a space for mounting an insulation resistor, and part 17 is a space for the purpose of weight reduction and cost reduction. In addition, 1
In the portion 8 the upper end of the integrated molding resin is shown.

The portion 18 does not mean simply the upper end portion of the molding resin, but this portion plays an important role. That is, the role of deciding and fixing the relative position of the wire wheel block 12 with respect to the iron core fastened by both the iron core fastening plates 13 and 15 and the primary input terminal side iron core fastening plate 13 is shared. are doing. Therefore, in the integral-mold type resistance welding welding transformer of the present invention, the push bolt and the like from the clamping plate portion for fixing the coil block, which is used in the conventional transformer, is not attached to the primary input terminal side. It is not used in the iron core tightening plate part.

The other end of the lead wire 4 shown in FIG. 1 is attracted to the ground resistor mounting space 16 shown in FIG. 3 and is connected to a ground resistor (not shown) arranged in that space. Connected. Further, the other end of the resistor is grounded. As is clear from the above description, the grounding resistors arranged in the 16 spaces can be freely attached and detached, maintenance is facilitated, and the grounding resistors can be replaced at any time when they are out of order.

Needless to say again, the space 16,
As a result of the elimination of the molding resin in the parts 17 and 17, the volume of the molding resin reducing metal fitting 11 is surely reduced in weight and price as compared with the conventional integrally molded transformer.

FIG. 4 is a circuit connection diagram of an embodiment showing a method of grounding a secondary circuit of a welding transformer for conventional resistance welding.
101 is a welding transformer, 1 is a primary coil, 2 is a secondary coil, and 4 is a grounding lead wire. The leading end of the lead wire is connected near the secondary output terminal, the lead wire is connected to the grounding resistor 102, and is grounded from the other end of the grounding resistor.

FIG. 5 is a circuit connection diagram showing a method of grounding a secondary circuit of a welding transformer for resistance welding according to an embodiment of the present invention. The reference numeral numbers for explanation correspond to those in FIG. The grounding lead wire 4 is connected to the intermediate portion of the secondary coil wheel 2, and is connected to the grounding resistor 102 from this, and the state of being grounded is displayed.

[0024]

As described above in detail, in the present invention, in the method of manufacturing the welding transformer for resistance welding, how efficiently the secondary circuit is grounded, and how much the mold resin other than the necessary amount is used. By eliminating the above, it is possible to provide a lightweight and low-priced transformer.

(1) A method in which a grounding lead wire is brought into contact with a part of the secondary wire wheel and the lead wire is sandwiched between the secondary wire wheel and the primary wire wheel via a thin insulating plate. After that, by a method of completely fixing with a molding resin, a series of operations performed by conventional technology, such as crimping the crimp terminal to the end of the lead wire and attaching it, and connecting it to the secondary circuit with a fastening member There is an outstanding effect that is unnecessary.

(2) Further, by connecting the grounding resistors to the other ends of the lead wires described in (1) above and disposing them in the space for mounting the grounding resistors, the resistors are If something goes wrong, it can be removed at any time.

At the same time, by securing a space for mounting the grounding resistor, and by securing another space for the purpose of weight reduction and cost reduction, the mold having a volume corresponding to the space portion is secured. The resin is reduced, and there is an effect that the weight and the cost can be surely reduced as compared with the conventional integral mold type transformer.

From the above, it can be said that the technology according to the present invention is a drastic improvement in comparison with the transformer according to the prior art.

[0029]

[Brief description of drawings]

FIG. 1 is an exploded perspective view for explaining an essential part relating to a grounding method of a secondary circuit of a welding transformer for resistance welding according to an embodiment of the present invention.

FIG. 2 is a perspective view of a resistance welding welding transformer according to an embodiment of the present invention, in which a pre-stage of filling with a molding resin is viewed from the direction of the iron core clamping plate on the primary input terminal side.

FIG. 3 is a perspective view showing a state in which the mold resin reducing metal fitting is removed after filling the molding resin according to the embodiment of the present invention.

FIG. 4 is a circuit connection diagram of an embodiment showing a method of grounding a secondary circuit of a welding transformer for conventional resistance welding.

FIG. 5 is a circuit connection diagram showing a grounding method of a secondary circuit of a welding transformer for resistance welding according to an embodiment of the present invention.

[Explanation of symbols]

1 Primary wire wheel 2 Secondary wire wheel 3 Insulating thin plate 4 Grounding lead wire 5 Lead wire with unevenness on the secondary wire ring Anti-slip groove 11 Mold resin reduction metal fitting 12 Wire wheel block 13 Primary input terminal side Iron core tightening plate 14 Transformer case 15 Secondary output terminal side iron core tightening plate 16 Space for mounting grounding resistor 17 Space for weight reduction 18 Upper end of mold resin 101 Welding transformer for resistance welding 102 Grounding Resistor

Claims (2)

[Claims] 1. A method for manufacturing a resin-molded welding transformer for resistance welding, in which, when grounding a secondary circuit, a primary wire wheel and a secondary wire wheel are combined to form a wire wheel block. A welding transformer secondary for resistance welding, characterized in that a grounding lead wire is sandwiched between the insulating plate and the secondary coil, which are laminated on opposite surfaces of the secondary coil via an insulating plate. Circuit grounding method. 2. A method of manufacturing a resin-molded welding transformer for resistance welding, in which a grounding lead wire is drawn out according to the method of claim 1 with respect to grounding of a secondary circuit, and a grounding resistor attached to the tip of the lead wire. Welding transformer secondary for resistance welding characterized in that resin is removed by inclusions so that the molding resin is not filled in the clamping plate portion for the iron core on the primary input terminal side to secure the mounting location. Circuit grounding method.