JP2001138065A - Method of reproduction of electrode tip for resitance welding and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology to reproduce an electrode tip for a welding resistance whose tip form is deformed by being repeatedly used with a reproducing device of a simple construction and to increase the number of reproductions per unit time. SOLUTION: The reproducing device 6 is provided with a die 4 and an extruding pin 5. The die 4 is provided with a pair of bores 4LA and 4RA each of which decides the outer figure of a reproduced electrode tip T and is oppositely located each other, and through-holes 4LB and 4RB which penetrate through the both of the bottom parts of the bores. An extruding pin 5 is located in a manner that it slides in the through-holes and is longer than the distance between the bottom parts of a pair of the bores. With this reproducing device, a motion of force-feeding, with which the electrode tip prior to be reproduced is forcedly fed into one bore, is transmitted via the extruding pin to a motion of force-extruding with which a reproduced electrode tip housed in the other bore is forcedly extruded, thus a reproduction and a discharge are simultaneously executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for regenerating an electrode tip for resistance welding, and more particularly to a technique for efficiently regenerating an electrode tip using a simple apparatus.

[0002]

2. Description of the Related Art An electrode tip for resistance welding usually has a cylindrical shape with a rounded tip, and is made of a copper alloy having a low electric resistance. The electrode tip is used by being attached to the tip of a welding gun. The workpiece is sandwiched between a pair of electrode tips, and a current is applied between the electrode tips in the sandwiched state to weld the workpiece. During welding, the tip of the electrode tip is pressed against the workpiece. The tip of the electrode tip is heated while being pressed against the workpiece, and is worn or crushed. For this reason, the tip shape changes. At present, the electrode tip is removed from the welding gun at the time when a predetermined number of weldings are completed,
The electrode tip is replaced with a regenerated electrode tip as described later. The removed electrode tip is regenerated for the next use.
In this regeneration processing, the tip shape of the worn or crushed electrode tip is restored to the original shape. For this reproduction,
A reproducing apparatus described in Japanese Patent Application Laid-Open No. H10-34353 has been developed. In this apparatus, the electrode tip before regeneration is pressed into a bore defining the outer shape of the electrode tip after regeneration, and the tip shape of the electrode tip is formed into the bottom shape of the bore. Since the bottom shape of the bore is adjusted to the external shape before the use of the electrode tip, the electrode tip is regenerated by the above press-fitting process.

[0003]

According to the above-mentioned regenerating technique, the electrode material is not wastedly consumed compared to the technique of cutting and regenerating the electrode tip, and it can be said to be an excellent regenerating technique. However, according to the technology of pressing and regenerating an electrode tip into a bore formed in a die, it is necessary to take out the electrode tip formed in the bore from the bore. To this end, in the prior art, the die is divided into two parts, one having a through hole for forming a cylindrical side surface, and the other having a bottom having a bottom located at the outlet of the through hole and forming a tip shape. And a die having At the time of reproduction, two dies are combined to complete a reproduction bore. After the reproduction, the two dies are separated, and the regenerated electrode tip is extruded from a through hole of one of the dies. In this technique, the reproduction die must be divided into two parts and moved, which complicates the structure. Further, since the press-fitting step for regeneration and the subsequent discharge / discharge are made into one cycle, the number of pieces reproduced per time is small. An object of the present invention is to simplify the structure of a playback device and increase the number of playbacks per time.

[0004]

According to a first aspect of the present invention, there is provided a regenerating apparatus including a die and an extrusion pin. The dice has a pair of bores, each of which defines the outer shape of the regenerated electrode tip and is located facing each other. The die has a through-hole penetrating the bottoms of the pair of bores. The push pin is slidably disposed in the through hole and is longer than the distance between the bottoms of the pair of bores. According to this regenerating apparatus, the press-fitting of the electrode tip before regeneration into one bore causes the movement of pushing out the regenerated electrode tip housed in the other bore via the push-out pin. Need not be divided into two parts, and the structure of the reproducing apparatus is simplified. What is important here is the above-mentioned bores and push-out pins. As described later, a press-fit cylinder can be provided for each bore, or a single common cylinder can press-fit each bore. . Also, a die may be prepared for each bore, or a pair of bores may be provided in a common die.

According to a second aspect of the present invention, there is provided an improved method for regenerating an electrode tip by pressing an electrode tip for resistance welding before regeneration into a bore to shape the outer shape of the electrode tip. A push-out pin is inserted between the bottoms of a pair of bores, and the movement of press-fitting the electrode tip before regeneration into one of the bores is performed through the push-out pin. It is characterized in that the electrode tip before regeneration is pressed into the bore and regenerated while transmitting the pushing motion. According to this regeneration method, press-fitting for regeneration and discharge after regeneration can be performed simultaneously, and the number that can be regenerated per time increases.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows the whole of the regenerating apparatus 6 in a partially cutaway manner. A pair of pressurizing cylinders 1L, 1R, a pair of forming punches 3L, 3R, a pair of dies 4L, 4R, one A push pin 5 and the like of the book are assembled.

The main body 2 has a plurality of plates stacked and fixed with screws 2A, and large-diameter holes 2LB,
2RB, holes 2LC, 2R with a medium diameter from the center
C, holes 2LD and 2RD having a small diameter are formed on the deeper side than C. A chamber 2E having an enlarged diameter is formed between the pair of small-diameter holes 2LD and 2RD.

The pressurizing cylinders 1L, 1R are fixed to the left and right sides of the main body 2, and are respectively formed by forming punches 3L, 3R.
Is moved left and right in the large diameter holes 2LB and 2RB. As shown in FIG. 8, steps 3LA and 3RA and tapered projections 3LB and 3LB are provided at the tips of the forming punches 3L and 3R, respectively.
3RBs are formed. As shown in FIG. 7 showing a state in which the electrode tip T is regenerated in the left bore 4LA,
At the rear end of the electrode tip T, tapered projections 3LB, 3RB
Is formed, and the electrode tip T is attached to the tip of the forming punch 3L, 3R by inserting the tapered projections 3LB, 3RB into the tapered hole TA. The tapered hole TA is also used for attaching the electrode tip T to the welding gun, and the hole diameter is often increased before regeneration. By the regenerating process described later, not only the tip shape of the electrode tip T but also the hole T
The shape of A is restored to the shape before use.

As shown in FIG. 1, a pair of dies 4L and 4R are fixed in medium diameter holes 2LC and 2RC, and are pushed further by a step between small diameter holes 2LD and 2RD. Nothing. Each die 4L,
4R is provided with bores 4LA and 4RA for chip molding. The pair of bores 4LA and 4RA have a substantially cylindrical shape with a round bottom, and their axial centers coincide with each other. Bore 4LA, 4R
A small hole 2L penetrating dies 4L and 4R from the bottom of A
Small diameter holes 4LB, 4RB communicating with D, 2RD are formed. Bore 4LA, 4RA, small diameter hole 4L of die 4
B, 4RB, the small diameter holes 2LD, 2RD of the main body 2, and the chamber 2E are coaxially arranged.

The bores 4LA and 4RA coaxially arranged, the small diameter holes 4LB and 4RB of the die 4, and the small diameter hole 2L of the main body 2
One push pin 5 is inserted into each of the chambers D and 2RD and the chamber 2E. The push pin 5 has a large diameter portion 5C at the center and small diameter portions 5LA and 5RA at the left and right. The large diameter portion 5C is housed in the room 2E, and the left and right small diameter portions 5LA,
5RA is slidably guided by the small diameter holes 4LB, 4RB of the die 4 and the small diameter holes 2LD, 2RD of the main body 2, and can protrude into the bores 4LA, 4RA.

As shown in FIG. 1, when the large-diameter portion 5C of the push pin 5 moves to the left end in the chamber 2E, the right end 5RB of the right small-diameter portion 5RA of the push pin 5 is smoothly placed on the surface of the bore 4RA. Continuously, the outer shape of the electrode tip T after reproduction is defined. In this state, the left end 5LB of the push pin 5 projects into the left bore 4LA. The entire length of the push pin 5 is longer than the distance between the bottoms of the pair of bores 4LA and 4RA. As shown in FIG. 6, when the large-diameter portion 5C of the push pin 5 moves to the right end in the chamber 2E, the left end 5LB of the left small-diameter portion 5LA of the push pin 5 is smoothly placed on the surface of the bore 4LA. Continuously, the outer shape of the electrode tip T after reproduction is defined. In this state, the right end 5R of the push pin 5
B projects into the right bore 4RA. The left and right ends 5LB and 5RB of the push pin 5 are finished in a shape corresponding to the round tip shape of the electrode tip T.

As described above, this playback apparatus
It has a die and an extrusion pin. The dice has a pair of bores that respectively define the outer shape of the regenerated electrode tip and are arranged facing each other, and a through hole that penetrates through the bottoms of the bores. The extrusion pin is
It is slidably disposed in the through hole and is longer than the distance between the bottoms of the pair of bores.

Next, a reproducing method realized by the reproducing apparatus 6 will be described. FIG. 2 shows that the electrode tip T2 is regenerated in the right bore 4RA. After the regeneration, the right forming punch 3R is retracted to the right, and the regenerated electrode tip T2 is moved to the right bore 4R.
Before discharging from A, bore 4LA on the left
Shows a state in which the electrode tip T3 before reproduction is reproduced by using FIG. The electrode tip T3 to be regenerated is mounted on the left forming punch 3L. In this state, the electrode tip T
Is distorted.

FIG. 3 shows a state in which the left pressing cylinder 1L has advanced, and the tip of the chip T3 before reproduction has come into contact with the left end 5LB of the push pin 5 projecting into the left bore 4LA. FIG.
Indicates a state in which the left pressing cylinder 1L further advances, and the pushing pin 5 starts to move rightward via the chip T3 before regeneration.
The tip T2 reproduced by the push pin 5 moving rightward starts to be discharged from the right bore 4RA. FIG. 5 shows a state in which the left pressure cylinder 1L further advances, and the large-diameter portion 5C of the push pin 5 has moved to the right limit position in the chamber 2E.
At this time, the reproduced chip T2 is discharged from the right bore 4RA. As described above, at this position, the left bore 4L
The inner surface of A and the left end 5LB of the push-out pin 5 are smoothly continuous, and define the outer shape of the chip T after reproduction as a whole. Between FIG. 4 and FIG. 5, the diameter of the tapered hole TA shown in FIG. 7 is reduced and restored to the shape of the projection 3LB of the forming punch. FIG. 6 shows a state in which the left pressing cylinder 1L further advances and the electrode tip T3 is reproduced. In this state, the tip shape of the electrode tip T3 is restored to a clean rounded shape before use and reproduced. FIG. 7 shows the state in an enlarged manner, and shows a state in which both the tip and the inner hole TA have returned to the initial shape. FIG. 8 shows a state where the left forming punch 3L has retreated to the left in preparation for the regenerated electrode tip T3 to be discharged from the left bore 4LA. Next, an electrode tip T4 to be reproduced next is attached to the right forming punch 3R. This state is equivalent to the state shown in FIG. Thereafter, the states shown in FIGS. 2 to 8 are repeated in a state where the left and right sides are reversed, the electrode tip T4 is reproduced by the right bore 4RA, and at the same time, the reproduced electrode tip T3 is discharged from the left bore 4LA.

The regeneration method shown in FIGS. 2 to 8 is a method in which an electrode tip for resistance welding before regeneration is pressed into a bore to shape the outer shape of the electrode tip and regenerate the electrode tip. An extruded pin is inserted between the bottoms of a pair of bores, and the movement of press-fitting the electrode tip before regeneration into one bore is carried out in the other bore via the extrusion pin. It is understood that the electrode tip before regeneration is characterized by being pressed into the bore and regenerating while transmitting the tip pushing motion.

The above-described reproducing apparatus has a simple structure, can be miniaturized, and can be easily carried. For this reason, the electrode tip can be regenerated at the operating place of the welding device. In addition, this device is small, and when an electrode tip is set at the tip of a forming punch, a worker's finger cannot enter the gap between the tip of the electrode tip and the die, so that the safety is high. Furthermore, even if the pressurizing cylinder and the forming punch are advanced by mistake without setting the electrode tip, there is still a sufficient gap between the forming punch and the die as compared to the operator's finger in the fully advanced state,
It does not create a hazardous condition for workers.

In the reproducing apparatus shown in FIG. 1, a pair of pressurizing cylinders 1L and 1R and a pair of forming punches 3L and 3R are used.
However, the left pressing cylinder 1L and the left forming punch 3L
In contrast, the main end 2 containing the dies 4L, 4R and the extrusion pin 5 is separated, and
By adopting the structure that is inverted by 80 degrees, the right pressing cylinder and the right forming punch can be omitted. What matters is a pair of bores and an extrusion pin, and it is not necessary to use a pair of forming punches and pressure cylinders.
Further, in the reproducing apparatus of FIG. 1, a pair of dies is used for each bore, but a pair of dies may be provided in a common die. In the above-described embodiment, the extrusion push-out pin 5 is constituted by one continuous member. However, an extrusion pin may be formed by three members including the left small diameter portion 5LA, the central large diameter portion 5C, and the right small diameter portion 5RA. Obviously from the above description of operation, it is not necessary to connect these three-pieces because the compression pin is used so as to act on the extrusion pin 5, and each of them is independently shown in FIG.
It is sufficient to house it in the main body 2 so as to slide left and right inside. In particular, the central large-diameter portion 5C
It is convenient to form a rectangular parallelepiped penetrating in the direction perpendicular to the plane of the drawing.
In this case, the large-diameter chamber 2E at the center of the main body is also formed by a through-hole having a rectangular cross section that penetrates the main body 2 in a direction perpendicular to the paper surface. With this configuration, the main body can be formed from an integral block. In this case, it is preferable to provide a stopper for preventing the large-diameter portion 5C having a rectangular parallelepiped shape from dropping out of the through hole penetrating the main body. In particular, in the cross-sectional shape of the large-diameter portion 5C having a rectangular parallelepiped shape shown in FIG. 1, it is preferable that one side is longer than the other side by 0.1 mm. If the push pin is pushed into the bore and the tip of the pin should be smoothly connected to the inner surface of the bore and the pin is too long and protrudes into the bore, the shape of the rectangular parallelepiped will be large. The diameter portion 5C can be adjusted so as not to protrude by changing the short side to a posture in which the short side faces in the left-right direction. Alternatively, when the extruding pin is pushed into the bore and the tip of the pin should be smoothly connected to the inner surface of the bore and the pin is too short and collapses from the bottom of the bore, the rectangular parallelepiped large-diameter portion 5C is formed into a long-form. Can be adjusted so that it does not collapse by changing to a position facing left and right.

[0018]

According to the regenerating apparatus and the regenerating method of the present invention, it is possible to regenerate a large number of electrode tips per hour by using a small and portable apparatus, and it is possible to eliminate waste of time and resources from a welding site. it can.

[Brief description of the drawings]

FIG. 1 shows an entire reproduction apparatus according to an embodiment.

FIG. 2 shows a state of a reproduction method.

FIG. 3 shows a state following the state of FIG. 2;

FIG. 4 shows a state following the state of FIG. 3;

FIG. 5 shows a state following the state of FIG.

FIG. 6 shows a state following the state of FIG.

FIG. 7 shows an electrode tip regenerated in a bore.

FIG. 8 shows a state following the state of FIG.

[Explanation of symbols]

 1: Pressing cylinder 2: Body 3: Forming punch 4: Die 5: Extrusion pin

Claims (2)

[Claims] An apparatus for regenerating a resistance welding electrode tip comprising a die and an extrusion pin, wherein each of the dies defines an outer shape of the regenerated electrode tip, and a pair of the dies are arranged to face each other. A resistor having a bore and a through-hole penetrating through the bottoms of the bore, wherein the push pin is slidably disposed in the through-hole and longer than the distance between the bottoms of the pair of bores. Regeneration device for electrode tip for welding. 2. A method for reshaping an electrode tip by press-fitting an electrode tip for resistance welding before regeneration into a bore to regenerate the electrode tip, wherein an extrusion pin is inserted between bottoms of a pair of bores. In this case, the movement of press-fitting the electrode tip before regeneration into one bore is transmitted to the movement of pushing out the regenerated electrode tip housed in the other bore via the push-out pin. A method for regenerating an electrode tip for resistance welding, wherein the electrode tip is pressed into a bore and regenerated.