JP7121962B1 - Electrode tip shaping jig and electrode tip shaping device - Google Patents

Abstract

Kind Code: A1 When the tip of an electrode tip is stretched and shaped into a regular shape, shaping can be performed while avoiding the formation of a scarf piece, thereby improving the efficiency of the shaping work. To efficiently form and weld a good welding nugget when electric resistance welding is performed with the shaped electrode tip by shaping an alloy layer formed on the tip end face of the electrode tip with a required thickness left. A shaping section corresponding to each shaping region set at the distal end of the electrode tip is sequentially press-contacted to perform stretching and shaping as the patient enters the shaping chamber. When the tip surface of the electrode tip reaches the bottom surface of the shaping chamber, the alloy layer generated on the tip surface is scraped off by the tip surface shaping part that presses against the tip surface so that the required layer thickness remains, and the tip surface is pressed. Extend and shape. Further, the electrode tip is shaped into a regular shape by cutting with a cutting blade which is in pressure contact with the outer peripheral edge of the distal end. [Selection drawing] Fig. 4

Description

The present invention relates to an electrode tip shaping jig and an electrode tip shaping apparatus for shaping and regenerating an electrode tip that has been swollen and deformed by electric resistance welding into a regular shape. An extension residual piece (hereinafter, an extension residual piece is referred to as a scarf piece in the present invention) protruding along the outer peripheral surface toward the base end side of the electrode tip from the side is formed to extend in the radial direction. The present invention relates to an electrode tip shaping jig and an electrode tip shaping apparatus for shaping an electrode tip into a regular shape while preventing an alloy layer formed on the distal end face from being broken and leaving a predetermined thickness of the alloy layer formed on the tip end face.

In the present invention, the term "shaping" is different from the concept of polishing and shaping, in which the bulging deformed portion of the electrode tip is shaped into a regular shape by grinding or cutting. means to shape. In addition, in the present invention, the "regular shape" originally means an unused electrode tip shape (including one before electric resistance welding) , but the electrode tip shaped in the present invention has an axial length It is somewhat shortened, and an alloy layer with a predetermined layer thickness remains on the distal end face, and the shape does not completely match the unused electrode tip, and includes a shape that approximates it.

As an electrode tip attached to a welding gun and used for electric resistance welding, it prevents the workpiece from being damaged excessively due to pressure contact with the workpiece (workpiece), and also applies a large current to the workpiece effectively and stably. Copper, copper alloys, and the like, which have low electrical resistance and are easily plastically deformed, are used because they need to be energized.

For this reason, as the number of welding operations increases, the tip of the electrode tip bulges, deforms (increases in diameter) and wears due to pressure contact with the work, and the metal of the base material of the tip evaporates and wears due to sputtering. . An alloy layer of copper, which is the base material of the electrode tip, and the work material or its plating material is formed on the front end face of the electrode tip.

When the tip of the electrode tip is deformed, there is a tendency for the vicinity of the center of the tip surface to become concave. Not only does it require a larger current than when using an electrode tip that is not melted, but a large current flows around the edge of the tip of the electrode tip, forming a ring-shaped welding nugget in which the center is not completely melted. As a result, there is a problem that high-quality electric resistance welding cannot be performed.

In addition, when electric resistance welding is performed with an alloy layer formed on the tip surface of the electrode tip, the alloy layer has a higher electrical resistance than the copper or copper alloy that is the base material of the electrode tip, and is welded to the workpiece. There is a problem that the current cannot be effectively applied to form a high-quality weld nugget for welding, resulting in poor welding quality.

In order to solve the above problem, conventionally, the bulging deformed portion of the electrode tip was polished (cut) by an electrode polishing machine to return it to its normal shape. As a result, the welding cost increases, and the electrode tip needs to be replaced more frequently, resulting in troublesome and time-consuming problems.

The present applicant proposed an electrode tip shaping jig disclosed in Patent Document 1 in order to solve the above-described drawbacks of the conventional electrode tip polishing apparatus. The electrode tip shaping jig rotates as an electric motor is driven, and presses the respective outer peripheral surface forming protrusions against the outer peripheral surface of the distal end portion of the electrode tip to press and stretch the bulging deformed portion into a normal shape. After shaping, the deformed portion stretched by the rotating tip face shaping projection is piled up on the tip face of the electrode tip and flattened so that it can be shaped into a regular shape.

However, when the electrode tip is shaped into a regular shape by the above-described electrode tip shaping jig, one shaping protrusion is pressed against the entire outer peripheral surface of the distal end portion. There is a problem that the rotation resistance increases and the shaping work cannot be performed efficiently.

In addition, part of the distal end portion is pushed out around the outer periphery on the opposite side (base end side of the electrode tip) from the outer peripheral surface forming protrusion that presses against the outer peripheral surface of the distal end portion of the electrode tip, generating a scarf piece and rotating. It becomes a resistance and causes a problem that the shaping work cannot be performed efficiently.

That is, when the scarf piece is formed, the scarf piece acts as a rotational resistance, making it impossible to perform the shaping work efficiently. There is a problem that it takes time and the shaping work efficiency deteriorates.

Even if the scarf piece is left as it is, the problem can be solved by rotating the electrode tip shaping jig using a high-torque electric motor. It has a problem of becoming

Furthermore, in order to form a good quality weld nugget between the workpieces, the current applied to the outer peripheral side is increased with respect to the current applied to the central portion of the tip end surface of the electrode tip at the initial stage of current application. It is desirable to form the weld nugget to extend from the center to the center.

In order to meet the above requirements, it is necessary to regenerate the electrode tip so that the alloy layer as a resistance layer remains somewhat in the central portion of the tip surface of the electrode tip. Since most of the alloy layer formed on the tip surface of the electrode tip is removed by grinding (cutting), it is necessary to perform electric resistance welding after trial hitting the electrode tip after remanufacturing. There is an inefficiency problem.

JP 2010-149187 A

The problem to be solved is that the conventional shaping jig presses one shaping projection onto the entire outer peripheral surface of the distal end portion, which increases the rotational resistance of the electrode tip shaping jig, making the shaping work more efficient. It is in the point where it cannot go to.

Moreover, when the tip of the electrode tip is straightened into a regular shape, a scarf piece is formed as a residual portion of the straightening, which acts as a rotational resistance, and the electrode tip cannot be efficiently regenerated.

Furthermore, the shaping work must be interrupted in order to cut off and remove the formed scarf piece, resulting in poor shaping work efficiency.

Furthermore, since most of the alloy layer formed on the tip surface of the electrode tip is removed during the shaping work, when performing electric resistance welding with the shaped electrode tip, welding cannot be performed immediately, and welding cannot be performed. It is in the point that work efficiency worsens.

The electrode tip shaping jig according to claim 1 comprises a shaping chamber having a recessed cup-shaped inner peripheral surface into which the tip of the electrode tip can be inserted, and a notched outer peripheral side of the shaping chamber except for a part of the bottom surface of the shaping chamber. The notch is provided on the inner peripheral surface of the shaping chamber corresponding to at least the proximal side and distal side shaping regions assumed at the distal end of the electrode tip, respectively, and the deformed portions are formed by pressing the corresponding shaping regions. and at least two or more shaping portions that are extended to the side of the shaping chamber, and are provided on the bottom surface of the shaping chamber and extend in the radial direction, and are pressed against the front end surface of the electrode tip to scrape part of the alloy layer formed on the front end surface. A distal surface shaping section that shapes the distal surface shaping region on the distal surface while dropping it into either a planar shape, a curved surface shape, or a combination of these surfaces, and a tip surface shaping portion provided on the notch surface of the notch portion, and enters the shaping chamber. and a cutting blade for cutting at least the stretched surplus portion on the outer periphery of the distal end of the electrode tip, and each shaping portion for each shaping region assumed at the distal end of the electrode tip as it enters the shaping chamber. are sequentially pressed to stretch and shape the deformed portion toward the base end side and the distal end side, and when the tip surface of the electrode tip reaches the bottom surface of the shaping chamber, the tip surface shaping unit presses against the tip surface. While scraping off the alloy layer so that the alloy layer remains with a required layer thickness, the tip surface is flattened, curved, or combined, and pressed to at least the outer periphery of the tip side. The most important feature is that the electrode tip is shaped into a regular shape by cutting the excess stretched portion on the outer periphery of the distal end side with a cutting blade.

An electrode tip shaping apparatus according to claim 7 is provided with a rotating disk provided with a boss detachably mounted in a state in which the electrode tip shaping jig according to any one of claims 1 to 5 is detachably mounted at the center thereof. a holder that rotatably supports the rotating disk; an electric motor that is connected to the rotating disk and rotates it; and a guide shaft that supports the holder so that it can move in a direction coinciding with the axis of the electrode tip shaping jig. , The electrode tip whose tip part is deformed by electric resistance welding and the alloy layer is generated on the tip surface is inserted into the shaping chamber of the electrode tip shaping jig that rotates with the drive of the electric motor. For each shaping area assumed to be at least the distal side and the proximal side of the distal end of the tip, the corresponding shaping part is pressed in order and stretched in the respective directions of the proximal side and the distal side for shaping. When the tip surface of the electrode tip reaches the bottom surface, the alloy layer formed on the tip surface by the tip surface shaping portion that presses against the tip surface is scraped off so that the alloy layer remains with a required layer thickness. The most important method is to form the electrode tip into a regular shape by extruding and shaping the tip surface into a flat surface, a curved surface, or a combination of these surfaces, and cutting the outer periphery of the tip with a cutting blade that presses against the outer periphery of the tip. Characterized by

An electrode tip shaping apparatus according to claim 8 is provided with a rotating disk provided with a boss detachably mounted in a state in which the electrode tip shaping jig according to claim 6 is prevented from rotating at the center, and the rotating disk. a holder that is rotatably supported; an electric motor that is connected to and rotates a turntable;
a guide shaft supporting the holder movably in a direction coinciding with the axis of the electrode tip shaping jig; A pair of opposed members, in each shaping chamber of the electrode tip shaping jig that rotates with the drive of the electric motor, in which the tip portion is deformed by electric resistance welding and an alloy layer is generated on the tip surface. The electrode tips are advanced with their axes aligned with each other, and the corresponding shaping portions are sequentially pressed against each shaping region assumed at least on the distal end side and the proximal end side of the distal end portion of each electrode tip. The alloy layer is formed on the tip face by the tip face shaping section that presses against the tip face when the tip face of the electrode tip reaches the bottom face of the shaping chamber by stretching and shaping in the respective directions of the end side and tip side. is scraped off so that the alloy layer remains with the required layer thickness, and the tip surface is extruded and shaped into a flat surface, a curved surface, or a combination of these surfaces, and the cutting edge is pressed against the outer periphery of the tip. The most important feature is that the outer circumference is cut to shape the electrode tip into a regular shape.

According to the present invention, by providing a plurality of shaping sections corresponding to a plurality of shaping regions assumed on the outer peripheral surface of the distal end portion of the electrode tip, it is possible to efficiently perform the shaping work while avoiding an increase in rotational resistance. can.

In addition, when shaping the distal end of the electrode tip, it is possible to shape while avoiding the formation of a scarf piece, which becomes a rotational resistance, thereby improving the efficiency of the shaping work.

Further, by shaping the electrode tip while leaving the alloy layer formed on the front end surface of the electrode tip with a required thickness, the welding operation can be performed immediately, and the welding operation can be made more efficient.

It is a partially exploded perspective view showing an outline of an electrode tip shaping device. 1. It is the front view which looked at the electrode tip reproduction|regeneration apparatus from the arrow A direction of FIG. 1 is an overall perspective view of an electrode tip shaping jig; FIG. FIG. 4 is a plan view of an electrode tip shaping jig; FIG. 5 is a vertical cross-sectional view taken along line BB of FIG. 4; FIG. 5 is a vertical sectional view taken along line BC of FIG. 4; It is explanatory drawing which shows the regular-shaped electrode tip. FIG. 10 is an explanatory view showing an electrode tip before shaping with a deformed distal end. FIG. 5 is an explanatory diagram showing a shaping state of a tip-side shaping region; FIG. 11 is an explanatory diagram showing a shaping state of a base-side shaping region; FIG. 4 is an explanatory diagram showing a shaping state of a tip end surface; FIG. 12 is an enlarged explanatory view of a portion indicated by an arrow D in FIG. 11; It is explanatory drawing which shows the cutting range by a cutting blade. FIG. 14 is an enlarged explanatory view of a portion indicated by an arrow E in FIG. 13;

As it enters the shaping chamber, each shaping section is pressed against each shaping region assumed at the distal end of the electrode tip, and deformed portions are stretched and shaped toward the proximal side and the distal side, and the distal end of the electrode tip is shaped. When the surface reaches the bottom surface of the shaping chamber, the alloy layer generated on the tip surface by the tip surface shaping part that presses against the tip surface is scraped off so that the alloy layer remains with a required layer thickness. is extruded and shaped into a flat surface, a curved surface, or a composite surface thereof, and at least the excess portion of the extruded portion on the outer periphery of the distal end side is cut with a cutting blade that is in pressure contact with the outer periphery of the distal end side to shape the electrode tip into a regular shape. is the best embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, an electrode tip shaping device 1 is provided at the tip of an arm (not shown) of a conventionally known articulated electric resistance welder (not shown), which is called a so-called welding robot. It is placed at the movement origin position (standby position) of the welding gun (not shown). A pair of mounting arms are provided on the frame of the welding gun at an appropriate interval so as to be movable toward and away from each other. Matchingly opposed and interchangeably attached.

These electrode tips 7 and 9 are moved toward and away from each other by, for example, an air cylinder connected to one mounting arm or a feed screw mechanism connected to a numerically controllable servo motor or the like, and are positioned between them. , For example, a work such as a plurality of galvanized steel sheets that are superimposed (none of them are shown. The work is not limited to the above-mentioned galvanized steel sheet.). Electric resistance welding is performed by a welding current applied as a

Each of the electrode tips 7 and 9 has a boss that can be inserted into a mounting shaft (not shown) provided on the mounting arm. (Cr-Cu), etc., when not in use, as shown in Fig. 7, the outer periphery of the tip portion extends in a curved shape with a required outer diameter and a gradually decreasing diameter toward the tip when not in use. , the tip surface is formed to be substantially flat or curved with a predetermined curvature (FIG. 7 shows the case where the tip surface is flat).

When the number of times of electric resistance welding reaches a predetermined number, as shown in FIG. is an alloy layer of the metal composition of the electrode tips 7 and 9 and the metal composition of the work (for example, if the work is a galvanized steel plate, it is a YCr-Zn layer, a BCr-Zn layer, and an Fe-Zn layer, but the metal material of the work and the alloy layer composition is determined by the metal material plated on the surface.) is generated. The alloy layer has a higher electrical resistance than the copper or copper alloy that is the base material of the electrode tips 7 and 9 .

The electrode tip shaping device 1 pushes out the bulging deformed portions of the tip portions of the electrode tips 7 and 9 attached to the welding gun, which is moved to the movement origin position when the electric resistance welding reaches a predetermined number of times, to form a regular shape. It is a device that reshapes and reproduces. The electrode tip shaping apparatus 1 includes an electrode tip shaping jig 11 which is rotatably supported with an axis coinciding with the center axis of the electrode tips 7 and 9, and an attachment hole in which the electrode tip shaping jig 11 prevents rotation. A rotating disk 13 which is detachably inserted and is rotated by being connected to an electric motor 18 provided on a holder 17; It consists of a stationary platen 15 for retaining the jig 11, and a holder 17 which rotatably supports the rotating platen 13, covers the upper and lower peripheral edges of the rotating platen 13, and is provided with an electric motor 18.

A base end portion of the holder 17 is axially movably supported by at least a pair of guide shafts 21 provided on the main body 19, and a compression spring 23 is attached to each guide shaft 21 with the base end portion therebetween. is biased so as to be positioned in the axially intermediate portion of the guide shaft 21 by the elastic force of .

As shown in FIGS. 3 to 6, the electrode tip shaping jig 11 is made of cemented carbide (high-speed steel), ceramics, or the like, and is inserted into the mounting hole 13a of the rotating disk 13 so as to prevent rotation. It is formed in a prismatic shape (the figure shows a hexagonal prismatic shape, but it is not limited to this shape), and the inner diameter (electrode cup-shaped shaping chambers 25 and 27 (inner diameters larger than the outer diameters of the tips 7 and 9) (in the following description, the upper and lower shaping chambers are mirror-symmetrical, so only the upper shaping chamber will be described; Description of the lower shaping chamber is omitted.) is provided in mirror symmetry with respect to the axial direction. In addition, the electrode tip shaping jig 11 is rotated, for example, clockwise as shown in the drawing as the electric motor is driven to rotate.

A notch 29 is formed on a part of the outer periphery of the electrode tip shaping jig 11 and is open at a predetermined angle, leaving the center of the bottom of each of the shaping chambers 25 and 27. be. An engaging recess 29b is formed in the central portion of the notch surface 29a located on the upper side in the rotational direction of the notch 29 (the partition wall between the shaping chambers 25 and 27). A hole 29c is formed.

Also, on the inner peripheral surfaces of the shaping chambers 25 and 27 on the opposite side of the notch 27, there is formed a chip discharge hole 31 extending in the axial direction of the electrode tip shaping jig 11 and penetrating the partition between them. be done.

A first shaping portion 33 is formed on the inner peripheral surfaces of the shaping chambers 25 and 27 on the upper side in the rotation direction of the cutting waste discharge hole 31 so that the radius of curvature of the ridgeline thereof matches the radius of curvature of the leading end side shaping region a. When shaping the electrode tips 7 and 9 whose distal end portions are bulging and deformed, the deformed portions bulged out by being pressed against the tip side shaping region a are pushed and shaped toward the distal end face side.

On the inner peripheral surfaces of the shaping chambers 25 and 27 corresponding to the downstream side in the rotation direction of the chip discharge hole 31, the second shaping portion 35 has a ridgeline with a radius of curvature that matches the radius of curvature of the proximal side shaping region b. When shaping the electrode tips 7 and 9 deformed to bulge, the deformed portions bulged out by being pressed against the base end side shaping region b are pushed and shaped toward the base end side.

On the bottom surfaces of the shaping chambers 25 and 27 where the notch 27 is not formed, a distal end surface shaping portion 37 is formed so as to curve and extend in the radial direction at a location deviated from the center of rotation. The distal end surface shaping portion 37 is formed in a curved or flat shape corresponding to the curved surface or flat surface of the distal end surface of the electrode tips 7 and 9 having a normal upper surface, and is formed in a curved or flat shape to be inserted into the shaping chambers 25 and 27. 9, and if the workpiece is a galvanized steel plate, for example, chromium-zinc (YCr-Zn layer, BCr-Zn layer) and iron-zinc alloy (Fe- Zn layer), the alloy layer with high hardness (YCr-Zn layer, Fe-Zn layer) is scraped off so that only the alloy layer with low hardness (BCr-Zn layer) remains, and the tip surface is curved as required. Shape into a face or plane.

A cutting blade 39 is screwed to the notch surface 29 a of the notch portion 29 so that the downstream end surface of the blade portion 39 a in the rotational direction is aligned with the center line of the electrode tip shaping jig 11 . The cutting blade 39 is formed of, for example, high-speed steel, cemented carbide, ceramics, etc., and conforms to the shape of the tip portion of the electrode tips 7 and 9 having a normal shape on the inner peripheral surface side except for a part of the tip surface. After locking a locked portion 39b provided in the central portion of the surface facing the notch surface 29a with the blade portion 39a, the screw 39d inserted into the through hole 39c is screwed. It is fixed by screwing it into the hole 29c.

The cutting blade 39 is operated at a timing slightly delayed from the timing at which the tip surfaces of the electrode tips 7 and 9 entering the shaping chambers 25 and 27 abut against the tip surface shaping portion 37 and are shaped into a regular shape. 1. The surplus portion pushed out toward the distal end portion by the shaping portion 33 and part of the alloy layer on the distal end surface are cut away to prevent generation of scarf fragments.

Next, the operation of shaping the electrode tips 7 and 9 by the electrode tip shaping jig 11 configured as described above will be described. For convenience of explanation, FIGS. 9 to 12 show the shaping action of the electrode tip 7 by the shaping chamber 25 positioned above. , illustration is omitted.

The electrode tips 7 and 9 attached to the welding gun of the electric resistance welder are press-fitted to the workpiece during the electric resistance welding and the heat generated during the electric resistance welding causes the electrode tips 7 and 9 to have the regular shape shown in FIG. In comparison, the tips of the electrode tips 7 and 9 are crushed and deformed to swell (large diameter), and the tip surfaces are deformed by abrasion and melting due to metal evaporation due to pressure contact with the work and metal sputtering. . (See Figure 8)

In FIG. 8, the solid line indicates a state in which the tip end portions of the electrode tips 7 and 9 are crushed to have a large diameter or is partially worn, and the normal shape is indicated by a dashed line. In the case where the workpiece is a galvanized steel plate, an alloy layer with low hardness (BCr-Zn layer) and an alloy layer with high hardness are formed on the tip surfaces of the electrode tips 7 and 9 that have been subjected to electric resistance welding a predetermined number of times. A layer (YCr-Zn layer, Fe-Zn layer) is produced.

The alloy layer is determined by the metal material of the workpiece and the metal material plated on the surface of the workpiece, and is not limited to the alloy layer.

As described above, the electrode tips 7 and 9, which have expanded and deformed as described above, change their contact area with respect to the work, making the pressure contact force with respect to the work non-uniform, and making it difficult to keep the current value applied to the work constant. Therefore, the welding nuggets formed between the works cannot be formed uniformly and with high quality, and the electric resistance welding quality is degraded. In order to solve this problem, it is necessary to reshape the distal end portions of the electrode tips 7 and 9 that have deformed to bulge into a shape close to the regular shape shown in FIG.

The shaping work of the electrode tips 7 and 9 is performed, for example, when the number of times of welding reaches a predetermined number, when a plurality of shots of welding work for one workpiece is completed, when welding work for a required number of workpieces is completed, or when the following operations are performed. This is performed during standby after the welding gun 3 is returned to the movement origin position under circumstances such as until the work is brought into the required welding position.

The electrode tip 7 is moved so that the axes of the electrode tip shaping jig 11 and the shaping chambers 25 and 27 of the electrode tip shaping jig 11 rotate clockwise as shown in FIG. When the electrodes 9 are moved toward each other by a predetermined movement amount and are advanced, the deformed portion swelled by the first shaping portion 33 presses against the tip side shaping region a of the outer peripheral surface of the tip portion of the electrode tips 7 and 9. to the tip side and shape it. (See Fig. 9)

At this time, the other second shaping portion 35, the distal end surface shaping portion 37, and the cutting blade 39 are in a non-contact state with respect to the outer periphery of the distal end portion of the electrode tip 7 or 9, and the electrode tip shaping jig 11 It avoids becoming a rotation resistance of.

Next, when the distal end portions of the electrode tips 7 and 9 are further advanced into the respective shaping chambers 25 and 27, the deformed portion is formed by the second shaping portion 35 which is in pressure contact with the base end side shaping region b of the outer peripheral surface of the distal end portion. is pushed to the proximal end and shaped. (See Fig. 10)

At this time, the other first shaping portion 33, the tip surface shaping portion 37 and the cutting blade 39 are in a state of non-contact with the outer peripheral surfaces of the tip portions of the electrode tips 7 and 9 that are entering, and the electrode tip shaping jig It avoids becoming 11 rotation resistance.

For convenience of explanation, the shaping action by the first and second shaping sections 33 and 35 has been described individually, but in reality, the boundary portions of the regions of the distal end portions of the electrode tips 7 and 9 are combined. It will act and carry out shaping work.

Further, when the electrode tips 7 and 9 are advanced into the shaping chambers 25 and 27 so that their tip surfaces are in pressure contact with the tip surface shaping section 37, the tip surface shaping section 37 press-contacts with the tip surface, thereby increasing the electric resistance. Among the chromium-zinc (YCr-Zn layer, BCr-Zn layer) and iron-zinc alloy (Fe-Zn layer) generated on the tip surface during welding, the relatively hard alloy layer (YCr-Zn layer, While scraping off the Fe-Zn layer), the relatively low hardness alloy layer (BCr-Zn layer) is scraped off so that it remains with a predetermined layer thickness (0.05 to 0.15 mm). It is shaped into one of these composite surfaces. (See Figures 11 and 12)

At the time of shaping the distal ends of the electrode tips 7 and 9 by the first and second shaping sections 33 and 35 and the distal end surface shaping section 37, a part of the surplus portion that is pushed out is deformed as the electrode tip shaping jig 11 rotates. A scarf piece that is stretched proximally is generated. In particular, the surplus portion that is pushed out toward the outer peripheral side of the distal end face by the distal end shaping portion 37 tends to easily become a scarf piece.

Part of the surplus portion pushed out by the first and second shaping portions 33 and 35 and the tip surface shaping portion 37 is shown in FIGS. ), the electrode tips 7 and 9 entering the shaping chambers 25 and 27 of the electrode tip shaping jig 11 are cut by a cutting blade 39 that is in proximity to or in contact with the outer peripheral surface of the distal end portion of the electrode tips 7 and 9, and cut through the notch 29. The generation of scarf pieces can be avoided by discharging to the outside through the squeegee, and the electrode tips 7 and 9 can be shaped into a shape approximating a normal shape.

In addition, the tip surfaces of the electrode tips 7 and 9, in which the alloy layer deposited and formed by the tip surface shaping section 37 is shaped into a plane shape, a curved shape, or a combination thereof with a predetermined layer thickness, are in contact with the outer peripheral side thereof. The remaining alloy layer is cut by the cutting blade 39 . As a result, an alloy layer having a predetermined layer thickness remains in a predetermined range (1/4 to 1/2 of the diameter of the tip surface) from the center of the tip surface shaping region c of the tip surface of the electrode tips 7 and 9. is formatted with

In addition, the cutting blade 39 is positioned near the distal end side shaping region a in the distal end side shaping region a and the proximal end side shaping region b in the distal end face shaping region c outside the distal end face shaping region c with respect to the distal end periphery of the electrode tip 7 or 9. , and does not approach or contact the proximal side of the proximal side shaping region b. Scarf fragments are avoided by cutting the majority.

Further, when the first and second shaping portions 33 and 35 and the tip surface shaping portion 37 are pressed against the tip portion (including the tip surface and the outer periphery of the tip surface) of the electrode tip 7 and 9, the electrode tip 7・A portion of the bulging portion at the tip of 9 is scraped off while being stretched. At that time, cutting chips remain in the above-described cutting waste discharge hole 31 or are discharged to the outside through the notch 29, resulting in an obstacle during the shaping process (rotational resistance of the electrode tip shaping jig 11). avoiding becoming

As described above, in the electrode tips 7 and 9 which are shaped into a regular shape with the alloy layer having a predetermined thickness remaining in the tip face shaping region c of the tip face, the tip face shaping region in the electrode tip 7 and 9 The alloy layer remaining on c becomes the resistive layer. The remaining alloy layer is shaped by the tip surface shaping section 37 and the cutting blade 39 so as to remain with a predetermined layer thickness and a predetermined area.

For this reason, when the work is electric resistance welded, the welding current applied to the work via the electrode tips 7 and 9 is larger than the tip surface shaping region c where the alloy layer remains. A current distribution is formed as follows.

As a result, the workpiece is first heated at a portion corresponding to the outer peripheral side of the tip surface, and then heated and melted at a portion corresponding to the tip surface shaping region c, i.e., from the outside toward the center, so that uniform A high-quality weld nugget that is uniform in heating state and size is formed and welded.

In the present embodiment, the first and second shaping portions corresponding to the expected shaping regions of the tip portions of the electrode tips 7 and 9 are sequentially brought into pressure contact for shaping, thereby increasing the rotational resistance during shaping. can be prevented and the shaping work can be performed efficiently.

Of the alloy layers formed on the tip end surfaces of the electrode tips 7 and 9, the alloy layers with high hardness are scraped off, while the alloy layers with low hardness are removed by a required layer thickness. It can be shaped into a flat shape or a curved shape while remaining. Can be welded to quality.

A cutting blade 39 that presses against the outer periphery of the tip of the electrode tip 7 or 9 cuts the outer periphery of the tip including the outer edge of the tip surface, preventing the formation of a scarf fragment during shaping, and improving the efficiency of the shaping work. It can be carried out.

The above description relates to the electrode tip shaping apparatus 1 and the electrode tip shaping jig, which are provided with respective shaping chambers 19 and 21 on both sides in the axial direction of the electrode tip shaping jig 11 to simultaneously shape a pair of opposing electrode tips 7 and 9. 11, the electrode tip shaping jig may be provided with one shaping chamber to shape and regenerate electrode tips one by one.

In the above description, the shaping regions are assumed to be formed on the distal end side and the proximal end side of the electrode tips 7 and 9, respectively, and the corresponding shaping portions are provided. In addition to the above, for example, an intermediate portion between the distal end side and the proximal end side may be assumed, and another shaping portion may be provided on the inner peripheral surface of the shaping chamber 25/7 corresponding to the intermediate portion.

1 Electrode tip regeneration device 7/9 Electrode tip 11 Electrode tip shaping jig 13 Rotating plate 15 Fixed plate 17 Holder 18 Electric motor 19 Body 21 Guide shaft 23 Compression springs 25/27 Shaping chamber 29 Notch 29a Notch surface 29b Relation Retaining recess 29c Screw hole 31 Chip discharge hole 33 First shaping part 35 Second shaping part 37 Tip face shaping part 39 Cutting blade 39a Blade part 39b Locked part 39c Through hole 39d Screw

Claims (8)

An electrode tip with an alloy layer formed on the distal end surface of which the distal end portion is bulging and deformed by electric resistance welding is moved from the distal end surface toward the base end side with either a flat distal end surface or a curved surface with a required curvature. In an electrode tip shaping jig that shapes into a regular shape with a curved outer peripheral surface that gradually increases in diameter,
a shaping chamber having a cup-shaped concave inner peripheral surface into which the tip of the electrode tip can enter;
a notch portion in which the outer peripheral side of the shaping chamber is notched except for a part of the bottom surface;
Provided on the inner peripheral surface of the shaping chamber corresponding to at least the proximal side and distal side shaping regions assumed at the distal end of the electrode tip, and presses against the corresponding shaping regions to extend the deformed portion to each side. at least two shaping sections;
Extending in the radial direction on the bottom surface of the shaping chamber, and scraping off a part of the alloy layer formed on the tip surface by pressing against the tip surface of the electrode tip, the tip surface shaping region on the tip surface is flattened and curved. a tip surface shaping section for shaping into either a planar shape or a composite planar shape thereof;
a cutting blade provided on the notch surface of the notch portion for cutting at least the excess portion of the outer periphery of the distal end portion of the electrode tip that has entered the shaping chamber;
with
As it enters the shaping chamber, each shaping section is pressed against each shaping region assumed at the distal end of the electrode tip, and deformed portions are stretched and shaped toward the proximal side and the distal side, and the distal end of the electrode tip is shaped. When the surface reaches the bottom surface of the shaping chamber, the alloy layer generated on the tip surface by the tip surface shaping part that presses against the tip surface is scraped off so that the alloy layer remains with a required layer thickness. is extruded and shaped into a flat surface, a curved surface, or a composite surface thereof, and at least the excess portion of the extruded portion on the outer periphery of the distal end side is cut with a cutting blade that is in pressure contact with the outer periphery of the distal end side to shape the electrode tip into a regular shape. Electrode tip shaping jig. In claim 1,
Shaping regions set at the distal end of the electrode tip are at least a distal side shaping region and a proximal side shaping region, and respective shaping sections provided on the inner peripheral surface of the shaping chamber corresponding to these respective shaping regions An electrode tip shaping jig that can be shaped by being stretched to the proximal end side and the distal end side. In claim 1,
At least each of the shaping portions and the cutting blades is arranged so that when one shaping portion or cutting blade is pressed against the distal end portion of the electrode tip, the other shaping portion or cutting blade is not in contact with the electrode tip. electrode tip shaping jig. In claim 1,
The tip surface shaping section shapes the tip surface of the electrode tip into a planar shape, a curved shape, or a combination thereof with the alloy layer remaining. An electrode tip shaping jig that cuts and shapes the outer periphery of the tip of the electrode tip. In claim 1,
The distal end face shaping part is an electrode tip shaping jig that curves and extends in the radial direction at a position deviated from the center on the bottom surface of the shaping chamber. In any one of claims 1 to 5,
An electrode tip shaping jig in which two shaping chambers are arranged in mirror symmetry to enable shaping of a pair of opposing electrode tips. a turntable provided with a boss detachably mounted in a state in which the electrode tip shaping jig according to any one of claims 1 to 5 is detachably mounted in the central part;
a holder that rotatably supports the rotating disk;
an electric motor connected to and rotated by the turntable;
a guide shaft supporting the holder movably in a direction coinciding with the axis of the electrode tip shaping jig;
with
An electrode tip whose tip is deformed by electric resistance welding and an alloy layer is formed on the tip surface is inserted into the shaping chamber of the electrode tip shaping jig that rotates with the drive of the electric motor, and the tip of the electrode tip is inserted into the shaping chamber. For each shaping area assumed at least on the distal side and the proximal side of the shaping chamber, the corresponding shaping part is pressed in order and stretched in the respective directions of the proximal side and the distal side to shape it, and the electrode tip is placed on the bottom of the shaping chamber When the tip surface reaches the tip surface, the tip surface is flattened while scraping off the alloy layer generated on the tip surface by the tip surface shaping part that presses against the tip surface so that the alloy layer remains with the required layer thickness. , an electrode tip shaping device for shaping the electrode tip into a regular shape by stretching and shaping either a curved surface or a composite surface thereof, and cutting the outer periphery of the tip with a cutting blade that presses against the outer periphery of the tip. a turntable provided with a boss detachably mounted in a state in which the electrode tip shaping jig according to claim 6 is detachably mounted at the center thereof;
a holder that rotatably supports the rotating disk;
an electric motor connected to and rotated by the turntable;
a guide shaft supporting the holder movably in a direction coinciding with the axis of the electrode tip shaping jig;
an elastic member that biases the holder supported by the guide shaft so as to be positioned at an axially intermediate portion of the guide shaft;
with
In each shaping chamber of the electrode tip shaping jig that rotates with the drive of the electric motor, a pair of electrode tips facing each other, the tip end portions of which are deformed by electric resistance welding and the alloy layer is formed on the tip end face, are placed in each shaping chamber. The corresponding shaping portions are sequentially press-contacted with respect to the respective shaping regions assumed to be at least the distal side and the proximal side of the distal end portion of each electrode tip, and the proximal side and the distal side are formed. It is shaped by stretching in each direction, and when the tip surface of the electrode tip reaches the bottom surface of the shaping chamber, the alloy layer generated on the tip surface by the tip surface shaping section that presses against the tip surface. While scraping off so that the required layer thickness remains, the tip surface is extruded and shaped into a flat surface, a curved surface, or a combination of these surfaces, and the outer circumference of the tip is cut with a cutting blade that is pressed against the outer circumference of the tip. An electrode tip shaping device that shapes the tip into a regular shape.

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