JPH1099975A - Welding method by pin-pull electrode, and chip forming cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the welding by a pin-pull type electrode which is excellent in continuous spot welding and versatile by cutting an alloy layer formed on a pin-pull tip surface by a cutting blade arranged in a bottom recessed part of a cutter to recycle a tip of the electrode. SOLUTION: A cutter 10 for forming a pin-pull type electrode tip is held between electrodes of a resistance welding machine, and when a base 1 is turned in the direction of the arrow by a turning mechanism through a notch 11 for turning in the pressurized condition, an electrode tip is cut in a pin-pull shape concentric in the vertical direction by spiral cutting blades 3-6 formed on the forming cutter 10. A tip surface of the pin-pull shape electrode tip is also cut by a cutting blade 8 formed on a bottom surface of a recessed part 2 corresponding to the pin-pull in a center part in the cutting process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method using a pimple-type electrode tip suitable for welding electrodes of a resistance welding machine, particularly a plated steel plate, and a cutter for forming.

[0002]

2. Description of the Related Art The tip shape of an electrode tip for resistance welding is roughly classified into a dome shape and a pimple type having an "navel" at an electrode tip. The generally used dome shape wears the tip end surface during welding of plated steel sheet, and also forms an alloy layer on the tip end surface of the chip, resulting in poor weldability. Must be removed and molded. On the other hand, in the case of the pimpled electrode, the "navel" at the tip is turned up in a mushroom shape during the welding process (self-regenerating function), so that the alloy layer does not accumulate. However, in order to effectively use a pimple-type electrode tip, its dimensional elements are extremely important. In the state where an object to be welded is sandwiched by welding pressure, a "navel" having a minimum diameter and a predetermined height necessary for welding is used.
The self-regenerating function does not work sufficiently unless electrodes are formed concentrically in the vertical direction. As disclosed in Japanese Utility Model Publication No. Hei 7-56140, as a forming cutter mechanism that satisfies the dimensional element at the tip of the electrode, the two electrodes are rotated by being pressed between two opposing electrode tips of a resistance welding machine by welding pressure. A cutter for simultaneously forming a tip, a bottomed concave portion corresponding to the navel diameter and the height of the navel of the pimple-shaped electrode tip, and It can be formed by a cutter mechanism for forming a pimple-type electrode tip in which horn-shaped depressions having cutting blades provided radially at intervals on the surface are formed concentrically.

[0003]

In the pimpled electrode, the "navel" at the tip is turned up in a mushroom shape during the welding process (self-regenerating function). The alloy layer does not accumulate on the tip of the pimple and there is no need to cut the electrode tip. Although it is an ideal electrode having a high continuous hitting property, its dimensional element is extremely important and its suitability is narrow, so that it has a problem that it lacks versatility. In other words, the work to be welded has various requirements such as base metal components, plating types, plating thicknesses, welding conditions, etc., even if the thickness is the same depending on the purpose of use. Must be selected. The pimple diameter is the minimum diameter required for the work to be welded and the allowable dimensional tolerance is as narrow as 1 mm or less.If it is small, the welding area is insufficient, and if it is large, self-regeneration is not sufficiently performed in the process of continuous hitting and it gradually progresses to the tip of the electrode tip. Alloy layers accumulate and cause poor welding. Therefore, the diameter of the pimple varies depending on the workpiece, and the selection of the forming cutter for forming the pimple needs to correspond to various pimple dimensions, and the management is complicated and the use is restricted.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention uses a forming cutter having a pimple diameter slightly larger than a required minimum diameter and cuts a tip end surface of the pimple to reduce the bottom surface of the cutter. In addition, a cutting edge is arranged to supplement the lack of the self-regeneration function in the welding process by cutting the tip of the pimple to provide versatility in selecting the pimple diameter.Specifically, the cutting edge is provided between the electrode tips of the resistance welding machine. A cutter for simultaneously forming the two electrode tips by being rotated while being clamped by pressurization of a welding machine. The navel diameter and the height of the navel and the height of the pimpled electrode tip are formed at the center of both surfaces of the disk member having the minimum required thickness. And a conical recess having a cutting blade in the bottom recess and a cutting blade provided on the surface following the bottom recess.

[0005]

When the cutter for forming a pimple-type electrode tip according to the present invention having the above structure is sandwiched between both electrode tips of a resistance welding machine and rotated in the direction of the arrow while being pressed, the cutting blade arranged on the cutter is used. The upper and lower electrode tips are concentrically cut to a predetermined pimple diameter and height, and the electrode tip faces are also cut by the cutting edge of the bottom recess. Accordingly, the resistance welding machine is mounted with the electrodes whose top and bottom are concentric with the predetermined pimple diameter and height and the tip end surface of which is also cut out. If the pimple diameter is set slightly larger than the ideal minimum diameter, the self-regenerating function does not work sufficiently during the welding process and the alloy layer gradually accumulates on the tip surface of the electrode tip. Thus, the alloy layer on the tip surface of the electrode tip is cut and removed, and the pimple at the tip of the electrode is regenerated to the initial state including the tip surface. In other words, if the tip end surface of the pimple electrode is cut and removed, even if the self-regenerating function is insufficient to some extent, it is possible to perform welding with high continuous hitting properties utilizing the characteristics of the pimple electrode. Therefore, the setting of the pimple diameter can be freely set to some extent as long as it is equal to or larger than the welding diameter.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a conventional welding with a pimple electrode,
In the case of a plated steel plate with a thickness of 0.8 mm to be welded, the optimal pimple diameter with the pimple electrode is φ6.5, height 1 mm,
With this diameter and height, there is no shortage of welding area and the "navel" at the tip of the pimple electrode turns up in a mushroom shape during the welding process (self-regenerating function). Approximately 20,000 welding points can be continuously welded until the "navel" disappears, and there is no need to cut the electrode front surface even during molding.
Only the height needs to be cut down to 1 mm. In the welding method of the present invention, the pimple diameter for the plated steel plate having a thickness of 0.8 mm to be welded is set to φ8 and 3 mm in height. (Combined use of 0.8 mm and 2 mm) Since the diameter of the pimple is φ8, the self-regenerating function does not work sufficiently in the process of continuous spot welding, and the alloy layer gradually accumulates on the electrode tip surface to improve the weldability. Since it becomes worse, step-up is carried out at appropriate times as in the case of the conventional dome-shaped electrode, and about 20,000 spot welding is performed. (In this welding process, the pimple disappears, the tip surface of the electrode also collapses, and the alloy layer accumulates thickly.) The electrode is cut and formed by a forming cutter and a forming method described below to regenerate the pimple.

An embodiment of the molding cutter and the molding method according to the present invention will be described below in detail with reference to the drawings. Reference numeral 10 denotes a cutter for molding a pimpled electrode tip according to the present invention. Both surfaces (upper and lower surfaces in the figure) of the base 1 are depressed surfaces corresponding to the longitudinal cross-sectional shape of the pimple-shaped electrode to be formed, and concave portions 2 and 2a corresponding to pimple are formed in the center.
Is arranged. On the surface of the recessed surface, spiral cutting blades 3 to 6, 3a to 6a are formed concentrically along the rotation direction indicated by arrow 12 and four in the circumferential direction at equal intervals. Cutting blades 8, 8a are also formed on the bottom surfaces of the concave portions 2, 2a. The pimple-type electrode tip forming cutter 10 according to the present invention having the above-described configuration is sandwiched between both electrode tips of the resistance welding machine (not shown), and the base 1 is pressed through the rotary notch 11 in a pressurized state. If it is rotated in the direction of the arrow by a rotation mechanism (not shown), the spiral cutting blade 3 formed on the molding cutter 10 is rotated.
-6, 3a-6a, the electrode tip is cut and formed into a pimpled shape concentric with the top and bottom. In this cutting process, the tip surface of the pimpled electrode tip is also cut by the cutting blades 8, 8a formed on the bottom surfaces of the concave portions 2, 2a corresponding to the pimples at the center.

[0008]

As described above, in the pimpled electrode tip of the present invention, the tip of the electrode is a pimpled electrode having a minimum required pimple diameter or more, and a forming cutter having a cutting edge arranged on the bottom portion in the process of continuous spot welding is welded. The electrode tip is rotated while being clamped by the pressurization of the machine, and both electrode tips are formed at the same time, and the lack of self-regeneration function in the welding process is removed by cutting the tip of the pimple, giving versatility to the selection of the pimple diameter.
Specifically, the electrode tip of the resistance welding machine is rotated while being sandwiched by pressurization of the welding machine, and the cutter for simultaneously forming the two electrode tips, that is, at the center of both surfaces of the disk member having the minimum necessary thickness. A bottom recess corresponding to the navel diameter and the height of the navel of the pimple-type electrode tip, and a cutting blade in the bottom recess, and a cutting blade provided in the horn-shaped recessed surface corresponding to the longitudinal cross-sectional shape of the pimple-type electrode are provided. It is characterized by being formed concentrically. Therefore, the self-regenerating function of the electrode tip, which is a feature of the pimpled electrode, is slightly sacrificed, and the accumulated portion of the progressive alloy layer at the tip of the electrode tip is impulsively produced in the process of forming pimples by the molding cutter of the present invention. The bottom can also be removed and removed, so the welding conditions can be used as if using a conventional dome-shaped electrode, without having to worry about selecting the ideal pimple diameter. It has the effect of being able to perform welding with a pimple-type electrode having high continuous hitting properties and versatility.

[0009]

[Brief description of the drawings]

FIG. 1 is a front view of a molding cutter of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2, 2a Bottom concave part at the center part 3-6, 3a-6a Spiral cutting edge 8-8a Bottom cutting edge 10 Molding cutter 11 Notch for rotation 12 Arrow indicating rotation direction

Claims (2)

[Claims] In the process of continuous spot welding using a pimple electrode of a resistance welding machine, the electrode tip is pinched and rotated by welding pressure and cut and formed by a forming cutter for simultaneously forming pimples on both electrode tips. At the tip of the tip, the pimple with the minimum pimple diameter is formed, and the alloy layer formed on the tip of the pimple in the welding process is cut and removed by the cutting blade arranged in the concave part of the cutter bottom to regenerate the electrode tip and continuously hit the electrode. The welding method using pimple electrodes is continued. 2. A cutter for simultaneously forming both electrode tips by pinching and rotating between electrode tips of a resistance welding machine by welding pressure, wherein a pimple-type electrode is provided at the center of both surfaces of a disk member having a minimum required thickness. A horn-shaped dent corresponding to the shape of the tip of the tip and a bottom dent corresponding to the navel diameter and the height of the navel are formed concentrically, and a cutting blade is provided on the horn-shaped dent surface and the bottom dent. For forming a pimpled electrode tip.