JP5942192B2 - Resistance welding machine electrode - Google Patents

Description

  The present invention relates to an electrode for a resistance welder that can smoothly move up and down a positioning guide pin, and that can be accurately welded by preventing the bending of a horn that holds the electrode.

  Resistance welding is a process in which a workpiece is sandwiched between an upper electrode and a lower electrode, pressurized and energized, and the workpiece is melted and welded by electrical resistance heat flowing through the workpiece. It is used in various fields such as product assembly factories.

  As shown in FIG. 4, the resistance welding electrode generally includes an upper electrode 1 on an upper frame 22 of a brass C-shaped frame 21 mounted on a welding machine body 20, and a lower electrode on a lower frame 23. 2 has a structure to which each is attached. After a workpiece W (member to be welded) is set between these upper and lower electrodes 1 and 2, the upper electrode 1 is energized while being pressurized toward the lower electrode 2 by a pressurizing device (not shown), and the welding process is performed. Is called.

  Further, in order to position the workpiece W, an insulating ceramic guide pin is used. The guide pin is configured to guide and position the workpiece W at a predetermined position in the raised state, and to descend to a position where it does not interfere with the loading of the workpiece W. It is common to use force.

  However, if the coil spring is used for a long time, the elastic force of the coil spring is lowered and the guide pin is lowered, so that there is a problem that accurate positioning cannot be performed and welding failure or misalignment occurs. In addition, when the guide pin is lowered, there is a problem that iron powder or the like enters and hinders the guide pin from moving up and down.

On the other hand, in the pressurizing step, the lower frame 23 may bend downward due to the pressure applied from above, and therefore the lower electrode 2 may not be leveled with the ground. As a result, the work guided by the guide pins of the lower electrode 2 cannot be kept in a horizontal state, and there is a problem that sufficient adhesive strength cannot be obtained. In particular, in the case of a nut provided with a projection, there is a problem that if the horizontal state is not secured, the total number of projections cannot be completely welded to the iron plate as the other workpiece, resulting in a defective product. .
Furthermore, if the horizontal state is not secured, dust and spatter and other sparks will adhere to the workpiece during welding, and polishing will be required later, resulting in increased costs. In this electrode, it is difficult to bring the cooling water to the vicinity of the welded portion at the tip, and sufficient cooling cannot be performed, so that the tip electrode portion is quickly worn and the running cost is increased.

JP 2000-117455 A

  The present invention has been completed for the purpose of solving the above-described problems and providing an electrode for a resistance welding machine capable of smoothly moving up and down a positioning guide pin over a long period of time. . In addition, the horn that holds the electrode can be prevented from bending and the workpiece can be maintained in a horizontal state. As a result, the adhesive strength can be secured as specified, and dust and spatter powder can be prevented from scattering. Completed for the purpose of providing an electrode for resistance welding machines that can eliminate adhesion to electrodes and workpieces, and that can sufficiently cool the vicinity of the welded part at the tip and greatly extend the life of the tip electrode part. It has been done.

  The electrode for a resistance welding machine of the present invention, which has been made to solve the above problems, has a guide pin that can be raised and lowered at the upper end of a cylindrical electrode holder, and this electrode holder is attached to the lower side of the C-shaped frame. A resistance welder electrode, wherein a cylinder holder containing a cylinder for moving the guide pin up and down is attached to a lower end portion of the electrode holder, and a stick-like rod is attached to the lower end portion of the cylinder holder. The member is attached downward, the electrode holder, the cylinder holder and the rod member are connected in a straight line, and the lower end of the rod member is grounded to the ground.

  An annular cooling device that covers the outer periphery of the electrode holder is preferably attached to the upper part of the electrode holder, and this is the invention according to claim 2.

  Further, it is preferable that an air piping port for injecting air for blowing off dust and spatter generated during the welding process is provided in the lower part of the electrode holder, and this is the invention according to claim 3.

  In the invention according to claim 1, a cylinder holder containing a cylinder for moving the guide pin up and down is attached to the lower end portion of the electrode holder, and a stick-like rod member is provided below the lower end portion of the cylinder holder. The electrode holder, the cylinder holder, and the rod member are connected in a straight line, and the lower end of the rod member is grounded to the ground. Unlike raising by the elastic force of the coil spring, the cylinder can be moved up and down stably by the cylinder. In addition, the lower frame is prevented from bending downward during the pressurizing process during welding, so that the workpiece is always kept in a horizontal state, so that the welding strength can be increased and the projection is provided with a projecting nut. In this case, all projections can be completely welded.

  In the invention according to claim 2, since the annular cooling device that covers the outer periphery of the electrode holder is attached to the upper part of the electrode holder, the vicinity of the welded portion at the tip can be sufficiently cooled, and wear of the tip electrode portion is prevented. Running costs can be reduced.

  In the invention according to claim 3, when an air piping port for injecting air for blowing off dust and spatter generated during the welding process is provided at the lower part of the electrode holder, the air is blown out simultaneously with the end of the welding process. If controlled, dust and spatter powder can be prevented from adhering to the electrode, and the guide pin can be lifted to increase the working speed.

It is sectional drawing which shows embodiment of this invention. It is sectional drawing which shows the state which the guide pin lowered in FIG. 1 is an overall perspective view showing an embodiment of the present invention. It is a front view which shows the outline of a resistance welder.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 4, the electrode for a resistance welder of the present invention has an upper electrode 1 attached to an upper frame 22 of a brass C-shaped frame 21 attached to a welding machine body 20, while a lower frame 23 has a lower part. The electrodes 2 are attached to each other for use. And after setting the workpiece | work W (to-be-welded member) between these upper electrodes 1 and lower electrodes 2, it energizes, pressing the upper electrode 1 to the lower electrode 2 side with a pressurization apparatus (not shown). The point where the welding process is performed is basically the same as the conventional one.
In addition, the electrode for resistance welding machines of this invention is related with the lower electrode 2 among the said upper and lower electrodes.

As shown in FIG. 1, the upper end of a cylindrical electrode holder 3 made of brass is closed with a cap 4 having a hole in the center, and a ceramic guide pin 5 can be raised and lowered freely in the hole. Built in. The guide pin 5 guides and positions the workpiece W to a predetermined position in the raised state, and is lowered to a position where it does not get in the way when the workpiece W is loaded (see FIG. 2).
An air pipe port 6 for injecting air for blowing off dust and spatter generated during the welding process is provided below the electrode holder 3. This operation will be described later.

  The lower end of the electrode holder 3 is closed with a brass holder base 7. A cylindrical cylinder holder 11 is attached to the holder base 7, and a cylinder 12 for moving the guide pin 5 up and down is built in the holder base 7. 13a is an air supply port for raising the cylinder piston, 13b is an air supply port for lowering the cylinder piston, and the cylinder rod 14 is moved up and down by supplying air to these air supply ports.

A connecting rod 15 is interposed between the cylinder rod 14 and the guide pin 5, and the guide pin 5 moves up and down via the connecting rod 15 by the operation of the cylinder 12. The connecting rod 15 does not need to be fixed to the guide pin 5 and the cylinder rod 14 with screws or the like, and can simply be placed, so that assembly and maintenance can be easily performed.
As described above, in the present invention, the guide pin 5 is moved up and down by the operation of the cylinder 12 instead of the conventionally used coil spring, so that it can be operated stably and accurately even when used for a long period of time. The workpiece W can always be accurately positioned.

The lower end of the cylinder holder 11 is closed by a holder base 16 made of brass. The holder base 16 has a stick-like bar member 8 made of brass attached and integrated downward. Accordingly, the three members of the electrode holder 3, the cylinder holder 11, and the rod member 8 are connected in a straight line and extended downward. Further, the lower end of the bar member 8 is adjusted so as to contact the ground G (see FIG. 1).
Reference numeral 9 denotes a brass stick base attached to the lower end of the bar member 8.

Specifically, the position adjustment of the bar member 8 is performed by setting a work W between the upper and lower electrodes 1 and 2, and a pressurizing device (not shown) contacting the upper electrode 1 to pressurize the lower electrode 2. Using the starting position as the origin, adjustment is made so that the lower end of the bar member 8 contacts the ground G at this time.
As a result, the workpiece W is in a state of being supported straight by a single support bar composed of the lower electrode 2 and the bar member 8, so that the lower frame 23 of the C-shaped frame 21 can be moved even when pressurized from the upper electrode 1 side. It does not cause bending downward. As a result, since the lower electrode 2 is always kept in a horizontal state with the ground G, a welding process is performed in which the lower electrode 2 is evenly pressurized and has a bond strength according to the standard. Further, in the case of a nut provided with projections, all projections can be welded equally.

  Further, it is preferable that an annular cooling device 10 covering the outer periphery of the electrode holder 3 is attached to the upper part of the electrode holder 3. The cooling device 10 includes a cooling water injection pipe and a discharge pipe (not shown), and cools the outer periphery of the electrode holder 3 by circulating the cooling water along an annular shape. It is possible to extend the life of the electrode by suppressing the temperature rise at.

  Further, an air piping port 6 for injecting air for blowing off dust and spatter generated during the welding process is provided at the lower part of the electrode holder 3, and control is performed so that air is blown out simultaneously with the end of the welding process. In this case, dust and spatter powder are prevented from adhering to the electrode, and at the same time, the guide pin is lifted up. As a result, the working speed can be improved nearly twice.

In the resistance welding machine electrode of the present invention configured as described above, a cylinder holder with a built-in cylinder is attached to the lower end portion of the electrode holder, and the guide pin is moved up and down by the cylinder. Even when used for a long period of time, the guide pin can be operated stably and accurately, and the workpiece W can always be accurately positioned.
Further, even when a load is applied to the lower electrode during the welding process, the lower frame of the C-shaped frame is reliably prevented from being bent downward because it is supported straight by the rod member. As a result, the adhesive strength of the workpiece can be reliably improved, and the welding defect of the projection can be made zero. In addition, it is possible to prevent dust from spattering and other sparks from being scattered, to eliminate the work after removing the adhesion to the workpiece, and to cool the vicinity of the weld at the tip sufficiently, greatly extending the life of the tip electrode. It has the advantage that it can be extended.

DESCRIPTION OF SYMBOLS 1 Upper electrode 2 Lower electrode 3 Electrode holder 4 Cap 5 Guide pin 6 Air piping port 7 Holder base 8 Bar member 9 Stick base 10 Cooling device 11 Cylinder holder 12 Cylinder
13a Air supply port
13b Air supply port 14 Cylinder rod 15 Connecting rod 16 Holder base 20 Welding machine main body 21 C-type frame 22 Upper frame 23 Lower frame G Ground W Workpiece

Claims (3)

  A guide pin that can be moved up and down is built in the upper end portion of the cylindrical electrode holder, and this electrode holder is an electrode for a resistance welding machine attached to the lower side of the C-shaped frame. A cylinder holder containing a cylinder for moving the guide pin up and down is attached, and a stick-like rod member is attached to the lower end of the cylinder holder so as to face downward. The electrode holder, the cylinder holder, and the rod An electrode for a resistance welding machine, wherein the members are connected in a straight line, and the lower end of the bar member is grounded to the ground.   The electrode for a resistance welder according to claim 1, wherein an annular cooling device that covers the outer periphery of the electrode holder is attached to the upper part of the electrode holder.   The electrode for a resistance welder according to claim 1 or 2, wherein an air piping port for injecting air for blowing off dust and spatter generated during the welding process is provided below the electrode holder.

Images