KR20130035074A - Contact tip for arc welding and its manufacturing method - Google Patents

Abstract

The present invention relates to an arc welding contact tip and a method for manufacturing the same, and specifically, to improve the structure and material of the contact tip to maintain the same level of conductivity as before, and to improve the strength of the wear and the like compared to the conventional electrode wire It relates to a technology that can prevent the shaking and the like.
For this reason, the present invention relates to a technology that can prevent welding defects due to unnecessary shaking of the electrode wire and minimize the inconvenience of frequent replacement.

Description

Contact tip for arc welding and its manufacturing method {CONTACT TIP FOR ARC WELDING AND ITS MANUFACTURING METHOD}

The present invention relates to a contact tip used for arc welding, and in particular, to improve the mechanical strength of the product by improving the manufacturing method according to the improvement of the material and structure, which can extend the life of the product as well as lower the welding failure rate It's about technology.

In general, the electrode wire used for arc welding is used in such a manner that the contact tip of a separate hollow tube form is drawn out to the outside by a corresponding consumption length each time it is consumed.

At this time, the contact tip used was phthalate copper or precipitation hardening copper alloy, which has about 99% copper having excellent conductivity. Since copper is almost the majority of the components, the conductivity is excellent while the wear resistance and heat resistance are high. There is a low problem.

Therefore, in the process of repeatedly drawing the electrode wire through the inside, the inner surface of the contact tip is worn out due to friction, and the diameter of the hollow part is increased.

This causes the electrode wire to shake irregularly in the hollow part, which is a major cause of welding failure.

Due to this problem, the contact tip must be replaced periodically after a certain period of time, which causes a secondary problem that causes economic loss and hassle due to replacement work.

Republic of Korea Patent No. 0794691 (2008.01.08) Korea Patent Registration No. 0561202 (2006.03.08)

The present invention has been proposed to solve this problem,

The present invention provides a contact tip and a method of manufacturing the same to reduce welding defects by improving the material and maintaining the same level of conductivity as the conventional one, while improving the strength of wear and the like, thereby preventing the shaking of the electrode wire.

In addition to this, it is intended to provide a contact tip and a method of manufacturing the same, which can prolong the life of the product and minimize the inconvenience of frequent replacement.

Various embodiments of the present invention for this purpose,

An outer tube forming process for preparing an outer tube having copper as a main component, a powder mixing process for mixing copper powder and carbon nanotube powder, and mixing the mixed powder into a hollow tube form in the outer tube Powder inserting process, sintering process for sintering the mixed powder to be molded into inner tube of hollow tube shape, inserting the outer tube and inner tube into a mold and simultaneously extruding the capillary molding process for manufacturing the capillary, drawing the capillary And a shape processing step of processing the shape by cutting or rolling.

And a diameter adjusting process performed between the capillary forming process and the shape processing process to reduce the diameter of the outer tube and the inner tube through at least one of the drawing process, the forging process, and the rolling process. can do.

In addition, the sintering process may be carried out under pressure and molding pressure of about 800 ~ 950 ℃ and 0.5 ~ 3.0ton / cm 2 of the mixed powder.

And the capillary forming process is made of the extrusion temperature of 900 ~ 980 ℃, the pressing force of 5 ~ 10ton / cm2, the extrusion diameter ratio of 20 ~ 50: 1, the outer tube of the outer tube is 40 ~ 80mm and the inner tube of The inner diameter may be made of 20 ~ 60mm.

In addition, the diameter adjustment process may be made so that the outer tube outer diameter of the mother tube is 6 ~ 16mm, the inner diameter of the inner tube is 0.8 ~ 8mm.

And the arc welding contact tip produced through this method,

It consists of a hollow tube type outer tube mainly composed of copper, and a hollow tube type inner tube inserted into the outer tube, wherein the inner tube is sintered in a mixed state of copper powder and carbon nanotube powder. It is characterized by consisting of a structure.

In addition, the inner tube may be made of copper powder 92 ~ 97wt%, carbon nanotube powder 3 ~ 8wt%.

The present invention having these various embodiments,

Basically, the contact tip is made of a double tube type, but as the carbon nanotube powder is added to the inner tube which is in direct contact with the electrode wire, high conductivity and high strength are simultaneously realized.

The change in diameter due to friction with the electrode wire is minimized, which has the advantage of minimizing welding failure rate and product replacement cycle.

1 is a process chart showing the overall manufacturing process
Figure 2 is a schematic diagram showing the outer tube forming process
3 is a schematic view showing a powder mixing process
4 is a schematic view showing a sintering process
Figure 5 is a schematic cross-sectional view of the sintering process
6 is a schematic view showing a maternal forming process
Figure 7 is a schematic diagram of the capillary produced through the capillary molding process
8 is a schematic view of the diameter of the capillary is adjusted through the diameter adjustment process
9 is a cross-sectional view of the contact tip completed through the shape machining process

Hereinafter, a detailed configuration and effects thereof will be described with reference to the configuration shown in the drawings.

Arc welding contact tip manufacturing method according to the present invention is largely as shown in Figure 1 outer tube forming step (S100) and powder mixing step (S200), mixed powder insertion step (S301), sintering step (S300) ), The capillary molding process (S400), diameter control work (S500) and shape processing process (S600) is configured.

First, the outer tube forming process (S100) is a process of manufacturing an outer tube 100 serving as an outer casing of the contact tip, and the outer tube 100 is a method similar to a method of manufacturing a contact hollow in the form of a conventional simple hollow tube. More specifically, the manufacturing method of the outer tube can be made in various ways,

For example, an alloy containing 99 wt% of copper, 0.8 wt% of Cr, and 0.2 wt% of Zr and an alloy containing 99 wt% of copper and 1.0 wt% of Cr are melted and extruded to form a hollow tube, followed by drawing, forging, etc. There is a way to go through the heat treatment.

0.8~0.4wt%를함유하는 합금을 가스분무법으로 분말형태로 제조한 후 산화-환원-압출-인발-냉간단조 등을 통해 제조하는 방식으로도 진행될 수 있다.In addition to this, copper 99.2 ~ 99.6wt%,

The alloy containing 0.8 ~ 0.4wt% may be prepared by powder spraying by gas spraying, followed by oxidation-reduction-extrusion-drawing-cold forging.

As described above, the outer tube manufactured as shown in FIG. 2 has a hollow tube shape, that is, a hollow portion 110 is formed therein in a state in which both ends are open, and the material is made of an alloy form mainly composed of copper.

When the outer tube forming step (S100) is completed, the powder mixing step (S200) is carried out.

Powder mixing process (S200) is a process of preparing and mixing the materials for forming the inner tube 200 to be described later,

In this case, copper powder and carbon nanotube powder are used as the prepared metal powder.

The mixing ratio between the copper powder (C1) and the carbon nanotube powder (C2) is 92 to 97 wt% of the copper powder and 3 to 8 wt% of the carbon nanotube powder.

The metal powders thus prepared are pulverized and mixed with each other through mechanical alloying, which will be described in more detail.

When the copper powder (C1) and the carbon nanotube powder (C2) at the same time between the crushing pressure roller (1) rotating in the opposite state as shown in Figure 3 and the copper powder (C1) by the crushing pressure roller (1) As the carbon nanotube powder (C2) is crushed to be in close contact with each other at the same time, as shown in the enlarged view of FIG. 3, the carbon nanotube powder is mixed in an integrated state.

For reference, such a mechanical alloying method may be modified in other ways in addition to the method using a crushing pressure roller, if the copper powder and carbon nanotube powder (C2) can be mixed in an integrated state.

The mixed powder C thus made is filled in the outer tube 100 as shown in FIG. 4 through the mixed powder insertion process S301.

At this time, the mixed powder (C) is filled along the inner wall surface of the outer tube 100, the final filled powder is also in the form of a hollow tube empty inside.

When the mixed powder insertion step (S301) is completed, the sintering step (S300) is performed.

The sintering process (S300) is a process of solidifying the mixed copper powder and carbon nanotube powder to a completely integrated state, and is divided into a compression molding step (S310) and a heating and pressing step (S320).

Among them, the compression molding step (S310) is a process of compressing the mixed powder (C) at a constant pressure to be in a first solidified state, and a general powder compression molding method is used.

In addition, the heating and pressing step S320 is a process of secondly heating the mixed powder C that has undergone compression molding so as to solidify the powder particles in a state where the powder particles are completely solidified with each other. ) Is heated in the vacuum and reducing atmosphere to 800 ~ 950 ℃ and at the same time applying a pressing force of 0.5 ~ 3.0ton / cm 2 to proceed to the sintered body.

Of course, the heating temperature and the pressing force is not limited to the above values, and may be variously modified depending on the amount of the mixed powder or the mixing ratio between each powder.

When the sintering process (S300) is performed in this way, the mixed powder C is formed into an inner tube 200 having a hollow tube structure in which copper powder and carbon nanotube powder are mixed, and the inner tube 200 is an outer tube. It is inserted inside the to have a double tube structure as a whole.

At this time, the outer diameter of the outer tube 100 as shown in Figure 5 is 120 ~ 200mm and the inner diameter of the inner tube is 30 ~ 80mm and the ratio of the cross-sectional area of the outer tube 100 and the inner tube 200 is the outer tube 3-6: inner tube It becomes 1

For reference, the ratio of the diameter and the cross-sectional area of the outer tube 100 and the inner tube 200 may be variously modified depending on the overall length.

When the sintering process (S300) is completed, the maternal tube forming process (S400) is performed.

The capillary molding process (S400) is a process of integrating the outer tube 100 and the inner tube 200 having a double tube structure with each other and simultaneously molding them to an appropriate diameter.

More specifically, as shown in FIG. 6, when the assembly between the outer tube 100 and the inner tube 200 is put into the extrusion die 2 and then pushed out by the compression rod 3, the enlarged view and the [FIG. 7] Like this, the outer tube 100 and the inner tube 200 are extruded in the form of a mother tube through the extrusion hole 4 at the same time.

In this case, the outer tube 100 and the inner tube 200 are extruded in a state in which the hollow tube shape is maintained by the mandrel 5 connected to the compression rod 3.

And the outer diameter of the outer tube 100 is the same as the diameter of the extrusion hole 4 and the inner diameter of the inner tube 200 is the same as the diameter of the core rod 5, the overall inner diameter is reduced than before the extrusion process do.

In addition, the outer tube 100 and the inner tube 200 are integrated with each other by the compressive force generated during the extrusion process, and thus the final extruded mother tube 300 has the outer tube 100 and the inner tube 200 having an integrated state. It has a double tube structure.

For reference, when explaining the extrusion conditions, the extrusion temperature is 900 ~ 980 ℃, the pressing force is 5 ~ 10ton, the extrusion speed is set to 10 ~ 30mm / sec.

And the extrusion ratio, that is, the ratio of the diameter of the mother tube passed through the extrusion hole to the outer diameter of the mother tube before passing through the extrusion hole is 20 ~ 50: 1. Due to this extrusion ratio, the final extruded capillary 300 has an outer diameter of 40 to 80 mm and an inner diameter of the inner tube 200 to 20 to 60 mm as shown in FIG. 7.

For reference, the extrusion conditions and the diameter of the final extruded capillary can be variously modified without being limited to the above values.

When the capillary molding process (S400) is completed, the diameter adjustment process (S500) is subjected to.

Diameter adjustment process (S500) is a process of reducing the inner and outer diameter to an appropriate level again by processing the extruded capillary 300 and at the same time increasing the strength,

Cold drawing, swaging, and rolling the entire mother pipe 300 so that the outer diameter of the outer tube 100 to 6 ~ 16mm as shown in Figure 8 and the inner diameter of the inner tube 200 to 0.8 ~ 8mm Proceed.

Through this diameter adjustment process (S500) the outer diameter of the parent tube 300 is maintained at the same level as the outer diameter of the existing contact tip and the inner diameter of the inner tube 200 is almost the same level as the diameter of the electrode wire (6).

If the diameter of the capillary in the capillary molding process (S400) can be processed to the above level, and sufficient strength can be secured only by extrusion molding, the diameter adjusting process (S500) may be omitted.

When the diameter adjustment step (S500) is completed, the shape processing step (S600) is passed.

Shape processing process (S600) is a process to have a functional shape by cutting the outer tube 100 through a cutting or rolling process, such as after cutting the parent tube 300 of a simple hollow tube type to a certain length as shown in FIG. to be.

Shape processing of the capillary by the shape processing step (S600) can be processed into a variety of shapes depending on the length of use or method.

The contact tip 1000 finally completed through this process is inserted into the inner tube 200 in the outer tube 100 made of copper as a main raw material as shown in [Fig. Reference numeral 200 is a form of a structure in which the copper powder and the carbon nanotube powder are mixed and molded.

Carbon nanotubes, which are used as raw materials of the inner tube, are materials having both high conductivity and high strength. The carbon nanotubes are alloyed with copper, so that the inner surface of the inner tube 200 is repeatedly formed with the electrode wire 6. Even when contacted, wear and the inner tube inner diameter is increased to minimize the phenomenon.

That is, the present invention is characterized in that the contact tip has a double tube structure as a whole, and improves the components of the inner tube in which direct friction with the electrode wire is prevented, thereby preventing the reduction of life due to wear.

In another aspect, the present invention is characterized in that the contact tip is made of a double pipe structure so that the carbon nanotubes are contained only in the inner tube which is in direct contact with the electrode wire, thereby preventing unnecessary waste of the carbon nanotubes.

The following <Example Table> shows the mechanical property difference according to the mixing ratio of the copper and carbon nanotubes constituting the inner tube 200 (CNT: abbreviation of Carbon Nano Tube)

GRADE
ingredient
Mixing ratio (vol%) Tensile Rate (psi) Compressive strength (psi) Elongation (%) Hardness (HRB) Conductivity (IACS) Softning termper (℃)
CNT3

CNT 3, Cu 97
75.000
70.000
10
75
90
800
CNT5

CNT 5, Cu 95
80.000
75.000
8
80
85
800
CNT8

CNT 8, Cu 92
85.000
80.000
5
85
80
800

As can be seen from the above table, the higher the carbon nanotube (CNT) content of the inner tube 200, the higher the mechanical properties, but the lower the conductivity.

Therefore, as described above, the present invention has a high conductivity and a high strength ratio at the same time by supplementing the mechanical properties such as strength, hardness, and tensile strength, which are weaknesses of copper, by adding carbon nanotubes as the main component of copper having high conductivity. I would have to.

The above-described features of the present invention can be practiced by various modifications and combinations by those skilled in the art, but such modifications and combinations produce a contact tip in a double tube structure and contain carbon nanotubes in the inner tube in direct contact with the electrode wire. According to the configuration and the purpose to be able to reinforce the strength of the weakness of the copper while maintaining the high conductivity of the copper according to be determined to be included in the protection scope of the present invention.

100: outer tube 200: inner tube
C1: copper powder C2: carbon nanotube powder
300: mother pipe S100: outer tube forming process
S200: Powder Mixing Process S300: Sintering Process
S400: Capillary molding process S500: Diameter control process

Claims (7)

Outer tube forming process for producing an outer tube having copper as the main component and having a hollow tube shape,
Powder mixing process for mixing copper powder and carbon nanotube powder,
A sintering process of filling the mixed powder into the outer tube and sintering the mixed powder to form a hollow tube-shaped inner tube;
Capillary molding process for producing a capillary tube by extruding the outer tube and the inner tube at the same time,
Shape processing process for processing the shape by cutting or rolling the capillary
Arc welding contact tip manufacturing method comprising a.
In claim 1,
Between the capillary forming step and the shape hole processing step,
Diameter adjusting process for reducing the diameter of the outer tube and the inner tube through any one or more of the drawing process, drawing processing, forging processing, rolling process
Arc welding contact tip manufacturing method further comprising a. In claim 1,
The sintering step,
After press-molding the mixed powder is made in the atmosphere of about 800 ~ 950 ℃ temperature and pressure of 0.5 ~ 3.0ton / cm2
Method for manufacturing contact tip for arc welding. In claim 1,
The capillary molding process,
Extrusion temperature of 900 ~ 980 ℃, pressing force of 5 ~ 10ton / cm2, extrusion diameter ratio of 20 ~ 50: 1,
The mother tube has an outer diameter of 40 to 80 mm and an inner diameter of the inner tube is 20 to 60 mm.
Method for manufacturing contact tip for arc welding. The method according to claim 2 or 4,
The diameter adjusting process,
The outer tube outer diameter of the mother tube is 6 to 16mm, the inner diameter of the inner tube is made to be 0.8 ~ 8mm
Method for manufacturing contact tip for arc welding. Outer tube in the form of a hollow tube mainly composed of copper,
Consists of an inner tube of the hollow tube shape inserted into the outer tube,
The inner tube has a structure in which copper powder and carbon nanotube powder are sintered in a mixed state.
Arc welding contact tip. In claim 1 or 6,
The inner tube is composed of copper powder 92 ~ 97wt%, carbon nanotube powder 3 ~ 8wt%
Arc welding contact tip.

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