JPH09239562A - Cutter for electrode tip dresser - Google Patents

Abstract

(57) [Abstract] [Problem] It is possible to easily adjust the pressing force, to enable quick dressing, and to prevent clogging by cutting chips during cutting.
To provide a cutter for an electrode tip dresser which can achieve a long life of the electrode tip, has a simple cutting edge shape, is easy to manufacture, and is inexpensive. SOLUTION: The cutting portion 22 is characterized by having an uneven surface and at least one through hole 25 penetrating to the other end surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cutter for an electrode tip dresser that cuts the tip of an electrode tip of a spot welding device by a cutting portion and corrects (dresses) the cutting into a predetermined shape.

[0002]

2. Description of the Related Art In general, spot welding is a method in which a plurality of objects to be joined are set in a stacked state and the objects to be joined are joined together by energizing them while sandwiched between a pair of electrode tips.

In this case, the objects to be joined are pressed by the electrode tip, because the objects to be joined are brought into contact with each other so that electricity can flow reliably when electricity is applied. It is also to assist the mutual bonding of the objects to be joined.

However, if the objects to be welded are sandwiched by the electrode tip and welded, the electrode tip receives the applied pressure and the Joule heat generated at the time of energization.
Under these influences, if the tip of the electrode tip is deformed, or if the object to be bonded is surface-treated by plating or coating, impurities such as the surface-treated coating adhere to the tip of the electrode tip. I have something to do.

If spot welding is carried out using such a deformed electrode tip or an electrode tip to which impurities are attached, the current density flowing through the objects to be joined is reduced, and there is a risk of spot welding and other welding defects. For example, if welding is performed using a deformed electrode tip, the contact area between the object to be joined and the electrode tip increases, so the current density decreases, and the current does not flow to the extent that sufficient weld occurs at the contact portion. Spot welding occurs due to insufficient current, resulting in spot peeling. This is also the case when an electrode tip with impurities attached is used.

Therefore, in general, the electrode tip is
A material that is not easily deformed, for example, a Cr-Cu alloy or the like is used or cooled by cooling water to prevent deformation and adhesion of impurities as much as possible.

However, if spot welding is performed many times,
Since the electrode tip is inevitably deformed and adhered with impurities, if it is welded a predetermined number of times, the tip is dressed regularly, and the tip of the electrode tip is always kept in a prescribed shape or in a state of no impurities, and welding quality is improved. To prevent the decline of.

An electrode tip dresser as shown in FIG. 4 is used for this dressing. In this electrode tip dresser 10, a tip 13 of an electrode tip dresser is attached to the tip of an arm 12 horizontally projected from a main body 11, and the tip of a pair of upper and lower electrode tips W, W is rotated by rotating the cutter 13. Each part Wa is cut into a predetermined shape.

A cutter 13 conventionally used for the electrode tip dresser 10 is, for example, as shown in FIG. 5, a boss portion 14 which is partially chamfered so as to be held by the arm 12, and the boss portion. Cutting portions 15 and 15 provided so as to project from both upper and lower end surfaces of the portion 14, and the electrode tip W
And a communication hole 16 opened for the purpose of finishing the pressurizing surface.

As shown in FIG. 6A, the upper surface a of the plurality of radially arranged cutting blades 17 forming the cutting portion 15 extends sharply from the outer peripheral edge toward the center, and the tips thereof are the above-mentioned. A pair of cutting blades 17a tapered so as to end at the end surface of the boss portion 14 and each upper surface a as shown in FIG. 6B.
Is sharply extended from the outer peripheral edge toward the center direction, and is composed of a pair of cutting blades 17b that are tapered so that their tip portions are connected to the central cutting blade portion 18 having a narrow width. A so-called relief groove b is formed on the upper surface a of each cutting edge 17 in order to improve the sharpness. Incidentally, 18a is a groove portion for forming the central cutting edge portion 18.

[0011]

However, since the conventional cutter 13 having such a configuration has a complicated shape as a whole including the cutting edges 17 and the like, it is not easy to form the cutter itself. It is expensive.

Further, when cutting from both the upper and lower directions, the cutting chips are clogged inside, so it is necessary to remove them by air blowing.

Further, because the relief groove b and the like improve the cutting performance, the sharpness is good. For this reason, if the pressure of the electrode tip W against the cutter 13 is increased, the tip portion Wa of the electrode tip is worn. It is intense and has a short life. In particular, when spot-welding an object to be joined that has been surface treated such as plating, it is necessary to frequently perform dressing to remove impurities adhering to the tip of the electrode tip. If the cutter with good sharpness is used for the dressing performed for the purpose, there is a problem that the tip of the electrode tip is worn quickly and the life of the electrode tip becomes extremely short. Also,
If the pressure is weakened, dressing may be insufficient, so it is extremely difficult to adjust the pressure of the electrode tip W.
The time required for one dressing becomes long.

The present invention has been made in view of the above problems. It is possible to easily adjust the pressing force, to perform quick dressing, to prevent clogging by cutting chips during cutting, and to prevent electrode chips from being clogged. An object of the present invention is to provide a cutter for an electrode tip dresser that can achieve a long life, has a simple cutting edge shape, is easy to manufacture, and is inexpensive.

[0015]

According to a first aspect of the present invention for achieving the above object, a tip portion of an electrode tip for spot welding, which is rotatably attached to an electrode tip dresser and is pressure-welded, is provided. In a cutter for an electrode tip dresser having a cutting portion to be dressed, the cutting portion has a surface of an abutting portion, at which at least one end of the rod-shaped body is in pressure contact, which is an uneven surface, and the corresponding abutting portion. At least one through hole penetrating to the other end surface of the main body is opened.

In this way, since the cutting portion has the uneven surface, the sharpness of the cutter is somewhat lowered, but there is no fear of excessive or insufficient dressing, and the pressure applied to the cutter by the electrode tip can be adjusted. This makes the electrode tip easier and has a longer life. Moreover, since the shape of the cutting portion is simple, the manufacture of the cutter itself is easy and the cost is low.

According to the second aspect of the present invention, since the surface of the abutting portion is a file-like uneven surface that is capable of removing the coating adhered to the tip of the electrode tip during spot welding, the cutting powder generated during dressing Also, the amount is minute and small, and there is no need for air blow.

According to the third aspect of the present invention, since the contact portion has a concave curved surface into which the tip portion of the electrode tip fits, impurities attached to the tip portion of the electrode tip can be smoothly dressed and removed.

In the invention according to claim 4, since the through hole formed in the abutting portion penetrates to the other surface, chips can be easily discharged, and the side surface of the through hole coincides with the central axis of the main body. Therefore, no dressing residue occurs.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is an overall perspective view of a cutter for an electrode tip dresser according to an embodiment of the present invention, FIG. 2A is a plan view of FIG. 1, and FIG. 2B is a sectional view taken along line BB of FIG. 2A. In the description, the same reference numerals are used for the members common to the members shown in FIGS.

A cutter 20 for an electrode tip dresser according to the present embodiment shown in FIG. 1 has a cutting portion 22 for dressing the tip portion Wa of an electrode tip at the upper and lower ends of a main body 21 having a generally flat columnar shape. On the outer peripheral surface of the main body 21, the cutter 20 is attached to the arm 1 of the electrode tip dresser 10.
A chamfered portion 23 is formed so that the chamfered portion 23 can be easily attached to and rotated.

The cutting portion 22 has the tip Wa of the electrode tip.
Has an abutting portion 24 to be pressed into contact therewith, and the corresponding abutting portion 24 is provided with a plurality of through holes 25 penetrating to the other end surface of the main body 21. The inner upper surface side of these contact portions 24 is a concave surface into which the tip end portion Wa of the electrode tip W is fitted during spot welding, and the lower surface side is a flat surface (see FIG. 2B). Moreover, the surface of each of the abutting portions 24 is an uneven surface, and the uneven surface corrects the deformation of the electrode tip tip portion Wa to prevent the deterioration of the welding quality, and the surface-treated object to be bonded such as plating. Impurities that adhere when spot welding is performed are easily removed.

Here, the roughness of the uneven surface may be set to be different between the case of correcting the deformation of the tip of the electrode tip and the case of removing the adhering impurities. Two
It is preferable to use a punched surface with a punch on the surface of No. 4. For example, a large number of dots having a diameter of 0.2 to 1.0 mm and a depth of 0.2 to 1.0 mm may be formed.

In particular, when used for removing adhered impurities, the tip of the electrode tip is frequently dressed. Therefore, the surface roughness of the contact portion 24 is prevented so that the tip Wa of the electrode tip is not worn by this dressing. It is preferable to make it fine. For example, a file-like fine concavo-convex surface capable of removing the coating adhered to the tip end Wa of the electrode tip W is preferable, and specifically, a medium-to-fine filed level is preferable, and in some cases, so-called satin finish. It may be a finely textured surface with a degree of treatment.

With this configuration, even when the tip portion Wa of the electrode tip is pressed against the contact portion 24, the pressure force can be easily adjusted, and the tip portion of the electrode tip is not damaged by the adjustment of the pressure force. It is also possible to remove only the attached impurities.

In the contact portion 24 on the upper surface side of the present embodiment, the electrode tip tip portion Wa bulges like a dome,
This is a concave surface so that it can be easily fitted, but the shape of this concave surface may be appropriately changed and used according to the shape of the tip end Wa of the electrode tip W. For example, the shape of the electrode tip tip Wa is frustoconical. In this case, it may be formed in such a shape that this truncated cone can be fitted. Further, as shown in the lower surface of FIG. 2B, it may be a flat surface.

A plurality of through holes 25 are formed in the abutting portion 24, one of which has a side surface 25a of the main body 1.
It is preferably formed so as to coincide with the central axis O of the.
With this configuration, when the dressing is performed, the contact portion 24 also contacts the axial center portion of the tip end portion Wa of the electrode tip W, and the portion where the dressing is not performed does not occur, so that the electrode tip can be reliably formed. The entire tip can be dressed. Further, these through holes 25 are opened so that the distances r1 to r4 from the axis center O to the respective center positions are different, and when the cutter rotates, the edge portion of each through hole surely contributes to the dressing. I am trying to get it. Moreover, since the surface of the contact portion 24 is uneven in this cutter, there is no possibility that cutting chips generated during dressing will enter the uneven surface and cause clogging. When the holes 25 are opened, the cutting chips can be discharged to the outside through the through holes 25, so that the cutting chips can be discharged more smoothly and the clogging preventing effect is further enhanced.

Next, the operation of the above embodiment will be described.
When forming the cutter 20, it is generally performed as follows. As a material to be used, a relatively inexpensive columnar ordinary tool steel is used, and the tool steel is cut into a predetermined length to form the main body 21.

Then, both ends or one end of the main body 21 are machined by using a drilling machine, a lathe or the like, and a concave contact portion 2 corresponding to the shape of the tip Wa of the electrode tip W is formed.
4 is formed.

After this machining, the surface of the abutting portion 24 is punctured with a punch to form an uneven surface with a predetermined roughness, and finally the entire main body 21 is hardened by carburizing and quenching, etc. A cutter 20 for a dresser can be formed.

As described above, in forming the cutter 20 of the present embodiment, there is no complicated processing unlike the conventional cutter for the electrode tip dresser, and only the simple machining is performed. Therefore, the cost of the cutter itself is reduced. It can be greatly reduced compared to the conventional one.

Cutter 20 for this electrode tip dresser
In order to dress each tip portion Wa of the electrode tip W into a predetermined shape using, the cutter 20 is first attached to the tip portion of the arm 12 of the electrode tip dresser 10 shown in FIG. This attachment is performed by fitting the chamfered portion 23 of the cutter 20 into a chuck portion (not shown) built in the arm 12 side.

On the other hand, a pair of upper and lower electrode tips W, W attached to the welding gun are arranged coaxially with the cutter 20. In some cases, an adapter (not shown) may be attached to the arm 12 and the electrode tip W may be eccentrically attached to perform dressing.

In this state, a switch of a drive source such as a motor is turned on, the cutter 20 is rotated at a predetermined rotation, and the tip portions Wa of the pair of upper and lower electrode chips W, W are brought into contact with each other.
The tip end portion Wa is dressed by being pressed against 4 with a predetermined pressing force.

In this case, the cutter 20 of the present embodiment
Is the upper surface a of each cutting edge 17 like the conventional cutter 13.
Is sharply extended from the outer peripheral edge toward the center, and the relief groove b for improving the sharpness is not formed. Therefore, the sharpness of the cutter is slightly reduced, but even if the applied pressure is increased, the electrode The tip W itself is not shaved off in a large amount, and the pressure applied to the cutter of the electrode tip is easily adjusted. Therefore, even in an automatic spot welding line performed by using a plurality of robots, it is not necessary to strictly adjust the pressing force of the electrode tip W attached to each welding robot, so that the automatic welding line can be fully automated. It will be relatively easy.

Further, since the side surface 25a of the through hole 25 of the cutter 20 is aligned with the central axis O, even the central portion of the electrode tip tip portion Wa can be dressed, and the entire electrode tip tip portion can be reliably held. Will be able to dress.

When the tip ends Wa of both electrode tips are dressed in a predetermined shape in this manner, cutting chips are generated.
Since this cutting powder becomes extremely fine, it is discharged to the outside by the centrifugal force of the cutter 20, and
Even if it stops inside, it is discharged through the through hole 25, so there is no risk of clogging. This is the same for both the upper and lower cutters 20.

The present invention is not limited to the above-mentioned embodiment, but can be variously modified. For example,
In the above-described embodiment, when forming the roughness of the uneven surface, a punch is used to form a spot on the surface of the contact portion 24. However, not only such a spot but also parallelism by machining or the like is used. It can also be formed by a groove or ridge, or a cross groove or ridge.

Further, the abutting portions 24 above and below the main body 21
May have a dome shape or a flat shape, or may have different shapes.

[0040]

EXAMPLE An example of the cutter 20 for an electrode tip dresser according to the present invention will be described below.

A) The cylindrical main body 21 has a diameter of 28 m.
m SK steel was used. b) A concave contact portion 24 having a diameter of 21 mm was formed on one end of the main body, and the other end was a flat surface. The concave contact portion 24 is
The radius of curvature was 15 mm. c) Four through holes 25 having a diameter of 4 mm are formed in the main body at positions eccentric to each other. The distance from the axis center 0 to the center of each through hole 25 was 2, 4, 6, 8 mm. d) A large number of spots having a diameter of about 0.5 mm and a depth of about 0.5 mm were formed on the cut portions 22 at both ends of the main body 21 by using punches. e) The quenching is flame quenching and the hardness is HRC5.
It became about 0. The time required to produce the cutter 20 for the electrode tip dresser is about 2 hours, and it can be produced in about 1/3 the time of the conventional cutter.

Cutter 20 for this electrode tip dresser
Made of Cr-Cu alloy with a diameter of 16 mm,
An electrode tip W with a tip Wa having a diameter of about 5 mm was dressed. Dressing was performed while variously adjusting the pressure applied to the cutter 20 of the electrode tip W in the range of 100 to 400 Kgf, but neither excessive cutting nor insufficient cutting of the electrode tip W occurred. In addition, the cutting powder during cutting was smoothly discharged from the groove 25 to the outside by centrifugal force, and there was no need to blow air.

[0043]

As described above, according to the first aspect of the invention, since the cutting portion has an uneven surface and has at least one through hole penetrating to the other end surface of the cutter, Although the sharpness is somewhat reduced, the pressure of the electrode tip on the cutter can be adjusted without fear of excessive dressing, the life of the electrode tip is extended, and the shape of the cutting part is simple, so the cutter itself can be manufactured. It will be easier and cheaper.

According to the second aspect of the present invention, the unevenness on the surface of the contact portion is a filed uneven surface that can remove the coating adhered to the tip of the electrode tip during spot welding. It is also fine and has a small amount, and there is no need for air blow.

According to the third aspect of the present invention, since the contact portion is a concave curved surface into which the tip portion of the electrode tip is fitted, the impurities attached to the tip portion of the electrode tip are smoothly dressed,
Can be removed.

According to the fourth aspect of the invention, since the through hole formed in the abutting portion penetrates to the other surface, it becomes easy to discharge the cutting chips, and the side surface of the through hole is aligned with the central axis of the main body. Therefore, no dressing residue will occur.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention.

2A is a plan view of FIG. 1, and B is a cross-sectional view taken along line BB of FIG. 2A.

FIG. 3 is an overall perspective view of an electrode tip dresser.

FIG. 4 is a perspective view of a conventional cutter for an electrode tip dresser.

5 is a sectional view taken along the line AA of FIG. 4, and B is FIG.
It is sectional drawing which follows the BB line of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Electrode tip dresser, 20 ... Cutter for electrode tip dresser, 21 ... Main body, 22 ... Cutting part, 24 ... Abutting part, 25 ... Through hole, 25a ... Side surface, O ... Central axis, W ... Electrode tip, Wa … The tip of the electrode tip.

Claims (4)

[Claims] 1. An electrode tip having a cutting portion (22) rotatably attached to an electrode tip dresser (10) and dressing a tip portion (Wa) of an electrode tip (W) for spot welding which is pressure-welded. In the dresser cutter, the cutting portion (22) has an uneven surface on the contact portion (24) to which the tip portion (Wa) provided at least at one end of the rod-shaped main body (21) is pressed, and A cutter for an electrode tip dresser, characterized in that at least one through hole (25) penetrating to the other end surface of the main body (21) is opened in the contact portion (24). 2. The cutter for an electrode tip dresser according to claim 1, wherein the abutting portion (24) is a file-like uneven surface that is capable of removing a coating film attached during spot welding. . 3. The electrode tip dresser according to claim 1, wherein the abutting portion (24) has a concave surface into which the tip portion (Wa) of the electrode tip (W) is fitted. cutter. 4. A side surface (25a) of the through hole (25) is the main body.
The cutter for an electrode tip dresser according to claim 1 or 2, which is formed so as to coincide with the central axis (O) of the (21).