KR102067935B1 - Flat head tip dressor for spot welding - Google Patents

Abstract

The present invention discloses a flat head tip dresser for spot welding. The present invention includes a dressing tool having a polishing groove in a circumferential direction, in which the flat head tip of the flat head tip can be inserted into the outer circumference thereof, the cutting groove having a cutting edge; A tip guide rotatably supporting the dressing tool and guiding the flat head through the polishing groove of the dressing tool while the flat head tip moves tangentially to the dressing tool; And an actuator for rotating the dressing tool. The tip guide is formed so as to correspond to the polishing groove of the dressing tool, and has a guide groove in which the flat head is inserted and moves as a radius of the dressing tool. It can be polished simply as it moves along the groove. The dressing tool may be configured in various forms, for example, it may be composed of a diamond wheel or a milling cutter with diamond powder deposited on its surface, or may be configured to have a plurality of cutting edges in the form of splines in the grinding groove.
The present invention enables simple and precise dressing of the flat head tip without warping or increasing the flat head or generating burrs.

Description

Flat head tip dressor for spot welding}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip dresser for spot welding, and more particularly, to a narrow cap of a joint such as a short flange of an automobile door frame, the welding is generally performed with a cap tip. Flat head tip dresser for spot welding, which makes it possible to precisely grind the so-called flat head tip, which has a flat end on the plate for welding impossible parts, without deformation such as burr or warping. It is about.

As is well known, spot welding is a type of electric resistance welding in which an electric current is applied to a base material to be welded to melt the base material with an electric resistance heat generated at the contact portion, and at the same time, an external force is applied. ) Is applied in a point-like manner, like a rivet joint, by applying a current while pressing the two electrodes coaxially.

This spot welding is not only fast, but also has a narrow heating range, so there is little residual stress or deformation. Therefore, the spot welding has a high stability of the joints. Mainly used.

 For this purpose, spot welding is generally equipped with an electrode tip on a servo gun, which is an automation equipment, and is usually installed in an industrial robot to automatically perform welding while moving.

On the other hand, since the electrode tip for spot welding must not only have excellent conductivity, but also be able to withstand the pressure sufficiently, alloys of copper and chromium or beryllium, tungsten, etc. are used.

However, because the electrode tip is subjected to high heat and pressure during welding, repeated welding above a certain RV due to the characteristics of copper deforms the pressurized portion of the electrode tip or forms an oxide film, and may cause scratches when the panel is melted. It is also often the case that some of the parts are pressed against the electrode tips.

In this case, the current density is lowered, which causes welding failure or strong sparking, which causes damage to the panel. Therefore, after welding a certain number of RBI or more, the pressing portion of the electrode tip should be regularly dressed through the tip dresser to restore the shape and remove the oxide film.

On the other hand, in recent years, a method of reducing the weight of the vehicle body has been attempted to reduce fuel consumption of an automobile, and as a part thereof, as shown in FIGS. 1A and 1B, for example, a welding flange (for example, a door frame D) (hereinafter referred to as “short”) The width b) is reduced. Accordingly, a problem arises in that welding is not possible with a cap tip Tc for general vehicle body welding, as shown by a virtual line.

That is, in general, in the vehicle assembly line, a cap tip Tc having rounded ends having a diameter of 13 mm and 16 mm is used, and the fixing tip supporting the rear has no problem, but the movable tip has a width (b). Access to this narrowed short flange (F) is impossible to perform welding.

To solve this problem, the present inventors form a circular head H1 having a diameter reduced to correspond to the width b of the short flange F, which is reduced at the end of the electrode tip T1, as shown in FIG. The welding was attempted, but the mechanical strength of the circular head H1 was weak, resulting in a problem that the circular head H1 was bent due to heat and pressing force generated during welding.

Accordingly, the present inventors planarly process both sides of the circular electrode tips as shown in FIGS. 1B and 3 so as to stably weld the short flange F having a narrow width while effectively preventing the buckling of the circular head H1. Thus, a so-called flat head tip T having a flat head H formed flat at a thickness corresponding to the width b of the shot flange F was developed.

By the way, such a flat head tip (T) can be easily welded to the short flange (F), the following problems in the dressing performed after a certain RBI.

First, when dressing using, for example, a conventional Auto Tip Dresser (ATD) as disclosed in Patent Document 1, the flat head H of the flat head tip T is twisted as shown in FIG. Not only did deformation occur, but also the tip was turned in the direction of rotation of the cutter holder, causing the mounting position of the movable tip to be displaced.

In addition, a burr is generated in a direction opposite to the rotation direction of the cutter holder, and the burr may generate sparks during welding, causing damage to the flange F, and may cause welding failure.

Such problems are caused by the conventional auto tip dresser cutter holder having a concave circle corresponding to the outer shape of the cap tip Tc and rotating in the circumferential direction, whereas the flat head tip T has both sides of the flat head H. It is presumed to be due to the fact that a flat surface is formed so that a space is formed between both sides of the flat head H and the cutter holder of the auto tip dresser, so that the cutting force of the cutter acts in the circumferential direction.

Second, when the flat head tip T was polished several times while being pressed and moved by a predetermined distance with respect to the rotating diamond block, a deformation in which the flat head H width (thickness) of the flat head tip T increased was rather increased. The chip was stuck in the diamond block, resulting in improper dressing.

In addition, since only the tip of the flat head H is in contact with the rotating diamond block, the flat both sides of the flat head H cannot be dressing.

Korea Patent Registration 10-1271463

The present invention has been made in view of the above-mentioned conventional problems, and the flat head is formed flat on the end so that the welded portion of the base material to be joined is narrow so that a welded object cannot be welded with a general cap tip. It is an object of the present invention to provide a flat head tip dresser for spot welding, which can precisely grind the flat head tip having without burr or distortion.

Another object of the present invention is to provide a flat head tip dresser for spot welding, which can be reliably polished to both flat sides of the flat head while essentially preventing the deformation of the flat head from increasing in width by dressing.

The flat head tip dresser for spot welding according to the present invention for achieving the above objects is provided with a grinding groove in the circumferential direction in which the flat head tip of the flat head tip can be inserted in the outer circumference, and the cutting edge is provided in the grinding groove. Having a dressing tool; A tip guide rotatably supporting the dressing tool and guiding the flat head through the polishing groove of the dressing tool while the flat head tip moves tangentially to the dressing tool; An actuator for rotating the dressing tool (actuator); characterized in that it comprises a.

According to one preferred feature of the present invention, the tip guide is formed to correspond to the polishing groove of the dressing tool, and has a guide groove in which the flat head is inserted and moves in the radial direction of the dressing tool, and part of the polishing groove of the dressing tool is a guide groove. By protruding by a predetermined gap, the flat head tip can be simply polished while moving along the guide groove.

The dressing tool may be configured in various forms, for example, it may be composed of a diamond wheel or a milling cutter with diamond powder deposited on its surface, or may be configured to have a plurality of cutting edges in the form of splines in the grinding groove.

Here, the spline-shaped cutting edge may be preferably configured to be inclined by a predetermined angle with respect to the center of the dressing tool for easier cutting.

In addition, according to another preferred feature of the invention, the tip guide is further provided with a suction hole (suction hole) in communication with the support hole of the dressing tool can be connected to the chip suction means, thereby scattering fine chips generated during polishing It is possible to effectively eliminate the possibility of polishing trouble caused by the chip while effectively preventing the damage.

According to the flat head tip dresser for spot welding according to the present invention, dressing is performed while the flat head tip of the flat head tip passes through the polishing groove of the dressing tool in the radial direction, and the dressing tool also rotates in the radial direction of the tip. Since the flat head is polished, there is no fear of warping the flat head and the occurrence of burrs can be effectively prevented.

In addition, since the flat head is inserted into the guide groove of the tip guide and moves in the radial direction of the dressing tool, the flat head tip can be dressed correctly through the polishing groove of the dressing tool without flow, and both sides of the flat head can be ground together. It becomes possible.

In particular, since the grinding groove of the dressing tool is configured to correspond to the width of the flat head, there is no possibility that the width of the flat head is increased by dressing as in the prior art, and thus the flat head of the flat head tip is initialized. As can be precisely polished.

In addition, through the suction hole formed in the tip guide, it is possible to reliably collect and remove fine chips generated during polishing, which can reliably prevent the polishing defects caused by the chips as well as the chips scattered to the surroundings to contaminate the surroundings. You can also solve the problem.

Figure 1a is a rear view showing a door frame of a vehicle consisting of a short flange,
1B is a cross-sectional view taken along the line AA of FIG. 1A,
Figure 2 is a side view showing the problem of the electrode tip constituting a circular head of reduced diameter for short flange welding,
3 is a perspective view of a flat head tip for short flange welding;
4 is a plan view showing the problem of the flat head tip dressing through the conventional auto tip dresser,
5 is a perspective view showing a flat head tip dresser according to the present invention;
6 is a partially cut plan view of the flat head tip dresser according to the present invention;
7 is a cross-sectional view taken along the line BB of FIG.
8 is a perspective view showing a dressing tool of a flat head tip dresser according to the present invention;
9 is a perspective view showing another embodiment of the dressing tool of the flat head tip dresser according to the present invention;
10 is a front view of the dressing tool shown in FIG. 9;
11 is a front view showing another embodiment of the dressing tool of the flat head tip dresser according to the present invention;
12 is a cross-sectional view taken along line CC of FIG. 11;
13 is a front view showing another form of the dressing tool shown in FIG.
14 is a perspective view showing a state in which the flat head tip dresser according to the present invention is mounted on a conventional auto tip dresser.

Specific features and other advantages of the flat head tip dresser for spot welding according to the present invention will become more apparent from the following description of the preferred embodiment with reference to the accompanying drawings.

5 to 8, the flat head tip dresser 1 for spot welding according to the present invention includes a dressing tool 10 which is rotated and has a cutting edge or a cutting part on its outer periphery, and the dressing tool 10 is rotatable. It is configured to include a tip guide 20 for guiding the flat head tip T to move in the tangential direction of the rotating dressing tool 10 while supporting it, and an actuator 30 for rotating the dressing tool 10.

The dressing tool 10 may be configured in various forms, and may be any form as long as the flat head tip T may be dressing.

For example, as shown, a diamond wheel-shaped polishing head 11, in which diamond powder, which functions as a cutting edge, is electrodeposited on the surface to polish the flat head tip T, so that the polishing head 11 can rotate It may be provided with a shaft 12 connected to the actuator 30.

On the outer circumference of the polishing head 11, a polishing groove 13 having a predetermined depth is formed in the circumferential direction so that the tip of the flat head H of the flat head tip T moving in the tangential direction thereof can be inserted therein.

Preferably, the grinding groove 13 is formed in a width corresponding to the thickness of the flat head tip (T) to cover the tip of the flat head (H) of the flat head tip (T) to move during polishing flat head tip (T) The front end face (welding part) and both sides of the flat head H can be polished together while preventing the flow of metal.

The tip guide 20 is fixed on the base 40 and has a tool support hole 21 for rotatably supporting by inserting the polishing head 11 of the dressing tool 10. A guide groove 22 is formed on the upper surface of the tip guide 20 to guide the flat head H of the flat head tip T through the polishing groove 13 of the dressing tool 10 in a tangential direction. .

The guide groove 22 is formed in the tangential direction of the dressing tool 10 so as to correspond to the position of the polishing groove 13 of the dressing tool 10, and the flat head H of the flat head tip T is stable when polishing. It is preferable that the flat head is formed to a depth enough to insert the flat head (H).

This guide groove 22 communicates partially intersect with the tool support hole 21. Accordingly, a portion of the dressing tool 10 may be exposed into the guide groove 22 to polish the flat head H of the flat head tip T.

Here, the guide groove 22 is formed at least as large as a predetermined gap than the grinding groove 13 of the dressing tool 10 so that the grinding groove 13 of the dressing tool 10 is the guide groove 22 of the tip guide 20. It makes contact with the tip of the flat head (H) of the flat head tip (T) moving in.

On the other hand, such a tip guide 20 may be preferably provided with a suction hole 23 for collecting fine chips generated during polishing. The suction hole 23 is formed to communicate with the tool support hole 21 for supporting the dressing tool 10, and is connected to a chip suction means (not shown) to prevent chip generated during polishing from being scattered to the outside. To be collected.

The actuator 30 may be used in various forms, for example, may be configured as an air motor that is easy to control. The actuator 30 is mounted on the base 40 by a fixed block 32.

The rotary shaft 31 of the actuator 30 is arranged coaxially with the tool support hole 21 of the tip guide 20 so as to be electrically connected to the shaft 12 of the dressing tool 10.

Next, operation | movement of the flat head tip dresser 1 for spot welding by this invention comprised in this way is demonstrated.

First, the flat head tip T, which is mounted on a servo gun (not shown) and performs welding over a predetermined predetermined score, is moved to the tip guide 20 guide groove 22 of the dresser 1 of the present invention. At this time, the movement of the flat head tip (T) can be made automatically by a robot equipped with a servo gun.

Subsequently, the actuator 30 of the dresser 1 is operated to rotate the dressing tool 10 fixed to the rotary shaft 31 thereof, and the flat head tip T is bottomed of the guide groove 22 of the tip guide 20. In the direction tangential to the dressing tool 10 along the guide groove 22 while properly pressing in the direction.

At this time, the flat head tip (T) is the flat head (H) is inserted into the guide groove 22 of the tip guide 20, so moving so that the dressing tool 10 exposed to the guide groove 22 while moving very stably. It can pass through the grinding | polishing groove 13 of correctly.

Then, the dressing tool 10 is polished in contact with the tip of the flat head H of the flat head tip T, which moves to be inserted into the polishing groove 13, and the polishing is, for example, the flat head tip T. It can be performed twice or more by reciprocating at least once.

The flat head tip T dressing in this way is made by dressing by passing through the grinding groove 13 of the dressing tool 10 while moving along the guide groove 22 formed in the width corresponding to the thickness of the flat head H. In addition, since the dressing tool 10 is polished while rotating in the same radial direction as the moving direction of the flat head tip T, the dressing tool 10 can be precisely restored to the initial state without warping or increasing the width of the flat head H and generation of burrs. Can be.

9 and 10 show another embodiment of a dressing tool 50 that can be used in the flat head tip dresser 1 for spot welding according to the present invention.

The dressing tool 50 of this embodiment has a structure in which the polishing head 51 is a milling cutter in the configuration of the above-described embodiment, and the polishing groove 53 formed in the circumferential direction on the outer circumference of the polishing head 51 is a milling cutter. It is formed to a depth shallower than the groove 55 formed between the cutting edge 54 of the.

Accordingly, cutting edges 54 are formed on both the bottom and both sides of the grinding groove 53 to grind together the tip and sides of the flat head H of the flat head tip T, which is inserted into the grinding groove 53 and passes therethrough. Can be.

Embodiments of such a configuration also have the same effect as the above-described embodiment.

11 and 12 show another embodiment of a dressing tool 60 that can be used in the flat head tip dresser 1 for spot welding according to the invention.

The dressing tool 60 of this embodiment has a structure in which the cutting head 64 is provided in the form of a spline in the polishing groove 63 in which the polishing head 61 is formed in the circumferential direction on the outer circumference.

The cutting edge 64 is provided on both the bottom and both sides of the grinding groove 63 to grind together the tip and sides of the flat head H of the flat head tip T passing through the grinding groove 53. have.

The cutting edge 64 of this embodiment may be preferably formed to be inclined at a predetermined angle α with respect to the center of the dressing tool 60, as shown in FIG. In this case, the cutting edge 64 is inclined in contact with the flat head (H) of the flat head tip (T) at the time of polishing to minimize the cutting resistance can be more easily dressing.

Embodiments of such a configuration can also exhibit the same effect as the above-described embodiments.

Meanwhile, although the flat head tip dresser 1 for spot welding according to the present invention may be used alone, it may be preferably provided with a conventional auto tip dresser A as shown in FIG. 14. .

In this case, the general cap tip (Tc) and the flat head tip (T) can be dressing in one dresser (D), it is more advantageous to improve the work efficiency of spot welding.

10, 50, 60: dressing tools 11, 51, 61: polishing head
12, 52, 62: shaft 13, 53, 63: abrasive groove
54, 64: cutting edge 20: tip guide
21: tool support hole 22: guide groove
23: suction hole 30: actuator
31: rotating shaft 40: base
T: flat head tip H: flat head
Tc: Cap Tip A: Auto Tip Dresser
D: Door frame F: Short flange

Claims (7)

A dresser for grinding a flat head tip having a flat head of predetermined thickness provided at a tip end thereof,
A dressing tool having a polishing groove in a circumferential direction, in which the flat head tip of the flat head tip can be inserted in an outer circumference thereof, and having a cutting edge in the polishing groove;
A tip guide rotatably supporting the dressing tool and guiding the flat head through the polishing groove of the dressing tool while the flat head tip moves in a tangential direction of the dressing tool;
An actuator for rotating the dressing tool;
The tip guide is formed to correspond to the polishing groove of the dressing tool, and has a guide groove in which the flat head is inserted and moves in the radial direction of the dressing tool, and a part of the polishing groove of the dressing tool protrudes into the guide groove by a predetermined gap. ,
The dressing tool is made of a milling cutter having a grinding groove on the outer circumference,
And a suction hole communicating with the support hole of the dressing tool in the tip guide, the flat head tip dresser for spot welding being connected to the chip suction means. The method according to claim 1,
Flat head tip dresser for spot welding, characterized in that the dressing tool is made of a diamond wheel having a grinding groove on the outer circumference. The method according to claim 1 or 2,
The dressing tool has a flat head tip dresser for spot welding, characterized in that the polishing groove has a plurality of cutting edges in the form of splines. The method according to claim 3,
Flat head tip dresser for spot welding, characterized in that the cutting edge is formed to be inclined at a predetermined angle with respect to the center of the dressing tool. delete delete delete

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