MXPA97002412A - Contact point for solder - Google Patents

Abstract

The present invention relates to contact tip for welding having a conduit for a wire electrode in the center thereof, comprising a tip body and a tip end which are separable from each other by a structure of the type foscate or type tapered, the tip body is composed of brass, aluminum, chromed copper, copper with zirconium, chromium plated copper with zirconium or phosphor bronze, the conduit for wire in the tipped body has a diameter of 1.03-1.50 times the diameter of the wire, The wire conduit at the tip end has a diameter of 1.03-1.25 times the diameter of the wire

Description

CONTACT POINT FOR WELDING FIELD OF THE INVENTION This invention relates to improved contact tips for use in arc welding.

DESCRIPTION OF THE RELATED ART The contact tips for use in an automatic arc welder or in a semiautomatic arc welder have a conduit for wire that serves to feed a wire electrode, which is formed in the center of an arrow-like member formed normally of copper alloy, which is a conductive material. The wire electrode passes through the wire conduit. The arc welding is done at one end of the wire electrode that is being supplied. Meanwhile, the leading end of the soldering contact tip is exposed to high temperatures at the time of the arc welding and, therefore, it seriously wears out. Because the wire electrode is supplied through the wire conduit, the shape of the conduit, in a front opening portion, is inclined to change from its original circular shape to an oval shape, due to abrasion between the electrode wire and the conduit. If the shape of the front opening portion of the wire duct is deformed, the supply of the wire electrode to the welding portion becomes unstable. Consequently, the wire deviates from its proper position, so that favorable arc welding is impossible. Additionally, splashes or similar substances stick or adhere easily to the walls of the wire conduit, thereby making it difficult to carry out the welding operation. Consequently, several technologies have been proposed to solve the above problem. For example, as shown in the Japanese Utility Model Issue No. ShoßO-20372 and the Japanese Utility Model Issued No. Sho62- 169774, a ring made of an abrasion resistant material is embedded or sealed at the front end of the contact tip for welding that is subject to severe wear. Japanese Patent Laid-Open No. Shoßl-115683 and Japanese Laid-open Patent No. Sho63-188477 have disclosed technologies for covering a front end portion of the contact tip with a ceramic lid. Japanese Published Patent No. Hei6-285645 has disclosed a technology for coating a surface of the contact tip with a heat resistant resin. Japanese Patent Laid-Open No. Hei5-261551 has disclosed a technology in which the end portion of the contact tip is structured in double tubes, while an inner conduit portion for wire is from a ceramic tube. Japanese Published Patent No. Hei5-277742 and Japanese Patent Laid No. Hei6-650 have disclosed technologies in which the entire contact tip is constructed with double tubes. The technologies to fit or seal the abrasion-resistant material within the contact tip for welding, disclosed in the Japanese Utility Model Issued No. Sho60-203372 and the Japanese Utility Model Issued No. Sho62-169774 have the problem of that cracks, loosening, etc. will probably occur. in a portion in which the ring is fitted or sealed. In addition, these technologies have production problems and do not present an excellent production performance (accuracy). Technologies for covering the leading end of the contact tip with a ceramic cap, disclosed in Japanese Patent Laid-Open No. Shoßl-115683 and Japanese Patent Laid-open No. Sho63-188477 and, the technology for coating the surface of the tip of contact with a heat resistant resin disclosed in Japanese Published Patent No. Hei6-285645 are effective to prevent splashes from adhering to the surface of the contact tip to a certain degree, without 87/40 However, they are not able to solve fundamental problems, such as deformation of the wire conduit and wear, and are limited in terms of improving durability. In this way, these technologies are not usable in a practical way. In addition, the technologies for providing the double tube structure that increase the durability of the wire conduit presented in Japanese Published Patent No. Hei5-261551 and Japanese Patent Laid No. Hei5-277742 have the problem that the production methods are complicated and, in this way, increase the cost of production. Thus, these technologies have not been developed for their actual application.

SUMMARY OF THE INVENTION In accordance with the foregoing, an objective of the present invention is to solve the above problems and provide contact points with which their production is facilitated and which allow the production to be carried out at a low cost, obtaining contact tips of excellent durability According to one aspect of the present invention, welding contact tips are provided which comprise a tip body and a tip end, which are separable from each other by a screw-type or a conical-type-engaging structure, the body of The tip is composed of brass, aluminum, chromed copper, copper with zirconium, chromium-plated copper with zirconium or phosphor bronze, the conduit for wire in the tipped body has a diameter of 1.03-1.50 times the diameter of the wire, the conduit for wire at the tip end it has a diameter of 1.03-1.25 times the diameter of the wire. The present invention has been proposed with the idea that the total cost of production can be reduced by (1) constructing or manufacturing the contact tip with the tip body and the tip end separately and (2) making the body tip of brass, aluminum, chromed copper, copper with zirconium or phosphor bronze. The total cost of consumer parts, such as the contact tip for welding, is determined not only by the unit price of production but also by its durability (frequency of replacement or replacement). For example, if the replacement frequency decreases because the durability is improved, the total cost decreases even if the unit price is reasonably higher. The contact tip for welding in accordance with the present invention is capable of increasing the durability by more than double and decreasing the cost of production, so that a tremendous reduction of the total cost can be obtained.

The effects of this cost reduction can obviously be recognized when a soft material, such as brass, aluminum, is applied to the tip body that is larger than the tip end. Consequently, the cost of the material can be reduced. In addition, because drilling and the like can be conducted more easily, the cost required for processing can be reduced. If a soft material is to be used to make a hole that forms a relatively long wire conduit, the precision in the processing is better compared to the case where hard material is used. In addition, the use of a soft material allows to guide the wire gently, thus having effects in the reduction of wear (to improve the durability). The reason why the diameter of the wire conduit of the tip body is set at 1.03-1.50 times the diameter of the wire is as follows. If the diameter of the wire conduit is less than 1.03, it is difficult to pass the wire through the conduit. If this is greater than 1.50, the electrical conduction deteriorates. Furthermore, if the separation between the wire and the duct is very large, conversely the contact between the wire and the duct is not smooth, so that wear is considered to be severe.

If the diameter of the wire conduit at the tip end is set at 1.03-1.25 times the diameter of the wire, the electrical conduction is secured and, at the same time, the wire can be passed smoothly. In addition, it is possible to suppress or eliminate the deviation of the welding point that can occur if the wire conduit is very large. Because the tip body and the tip end are separable from each other by means of the screw-type or snap-in type structure, if the tip end subjected to severe heat wear is worn, only the tip can be replaced of tip, assuring in this way a high efficiency of operation. In accordance with another aspect of the present invention, solder contact tips are provided wherein the tip end is composed of copper, chrome-plated copper, chromium-plated copper with zirconium, copper with zirconium, tungsten with silver, tungsten with copper, copper with dispersed alumina, copper with beryllium or copper with beryllium and nickel. Because the tip end is composed of this material, the wear resistance of the tip end can be imed. If the hard material is applied only to the relatively small tip end, the cost of material can be suppressed and additionally the essing cost can be suppressed. In addition, because the wire conduit is short, even the hard material can ensure high drilling precision, so that the abrasion resistance caused when the wire passes through can be reduced. In accordance with a further aspect of the present invention, solder contact tips are ided, wherein the wire conduit of the tip end is 3-20 mm long. In the case where the tip end is composed of hard material, if the length of the wire duct is more than 20 mm, boring or precise drilling becomes difficult, so that the resistance to abrasion with respect to the wire tends to increase. If the length of the wire conduit is less than 3 mm, the actual length of the tip end decreases. Thus, the thermal influences at the time of welding easily reach the tip body and, in addition, the tip of the blade is subjected to serious heat wear and the ease of handling of this component is eliminated. That is, this very short length is not favorable. In accordance with yet another aspect of the present invention, welding contact tips are ided wherein an extended conical portion that is open, with a gradually extending duct area, is formed in an end portion on a imal side of the conduit for the tip end wire. If the extended conical portion is formed, it effectively prevents the wire from being trapped and fixed when the wire is supplied from the wire conduit, in the tip body, to the wire conduit, at the tip end. In accordance with yet another aspect of the present invention, brazing contact tips are ided wherein a rear end of the tip end and a forward end of the tip body each have a thread portion and a contact face, contact faces, from which the thread portion is excluded, are in contact with each other and have a contact area that is greater than 10% of the rear face of the tip end or of the front face of the nose body. If the contact area is less than 10%, the heat conduction between the tip body and the tip end is deteriorated, so that the cooling effect of the tip end at the time of welding is reduced and the electrical conduction It is affected in a harmful way. In accordance still with a further aspect of the present invention, welding contact tips are ided wherein a round portion is formed at the periphery of the end face of the tip end. This round portion makes it difficult for splashes or similar materials generated at the time of welding to stick or adhere to the tip end. In accordance still with a further aspect of the present invention, welding contact tips are ided, wherein die markings are ided on the end face of the tip end. If the die markings are ided on the end face of the tip end, and if the tip end is prepared for forming, it is possible to make the die markings at the same time as the adjustment, thus eliminating particular marking edures by die BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front view of the welding contact tip in accordance with the present invention; Figure 2 is a sectional view of a tip body; Figure 3 is a sectional view of a tip end; Figure 4 is an enlarged view of Figure 3; Figure 5 is a complete, perspective view showing an example of a structure in which a round portion is formed on the front end face of the tip end; Figure 6 is an explanatory view showing an example of the structures in which the contact faces are formed in a bottom face of a screw hole and an end face of a male screw portion; Figure 7 is an explanatory view showing an example of a structure in which the tip body is coupled to the tip end, by the conical nesting method.

DESCRIPTION OF THE PREFERRED ODALITIES The embodiments of the present invention will be described with reference to the accompanying drawings. As shown in Figure 1, a welding contact tip according to the present invention comprises a tip body 1 and a tip end 2. The contact tip for welding is composed by connecting the tip body and the tip end 2, so that they are integrated with each other. Only the tip end 2, which is subjected to a 7/40 serious wear caused by automatic arc welding or semiautomatic arc welding, may be replaced with another. As shown in Figure 2, the tip body 1 is a relatively large shaft or arrow-like part having, along its axis, a conduit 3a for wire. A screw hole 4 communicating with the wire conduit 3a is formed in the center of the forward portion of the tip body 1. On the rear side of the tip body 1, a mounting portion 9 which is a screw portion male is formed to mount the contact tip for welding on a torch (not shown). As shown in Figure 3, the tip end 2 is a relatively small part provided with a male screw portion 5 projecting backward from a rear face thereof. A conduit 3b for wire is formed along its axis and the male screw portion projecting from the rear face can be coupled with the screw hole 4, at the front end face of the tip body 1. Then if the portion of screw 5 of the tip end 2 is inserted into the screw portion 4 of the tip body 1, the tip body 1 is connected to the tip end 2, such that a contact face 6 in the 87/40 front side of the tip body 1 comes into contact with a contact face 7 on the rear side of the tip end 2. Consequently, the conduction of heat and the electrical conduction between the tip body 1 and the end of tip 2 are secured by means of these contact faces 6, 7. The contact face 6 of the tip body 1 is a section of the front face portion of the tip body, excluding a section of the screw hole 4. The contact face 7 of the tip end 2 is a section of the rear face portion of the tip end 2, excluding a section of the male screw portion 2. Assuming that a bottom face m of the screw hole 4 of the tip body 1 and the rear end face n of the male screw portion 5 of the tip end 2 can be constructed, so that the bottom face of the hole m is adjustment with the rear end face n, as shown in Figure 6, the contact faces 6, 7 are connected to each other by engagement with the male screw portion 5. Then, to ensure sufficient heat conduction and electrical conduction, the contact faces 6 (o), 7 (or n) are constructed to have an area greater than 10% of the front face of the tip body 1 and the rear face of the tip end 2, respectively. The female thread of the tip body 1 and the 7/40 male end tip screw 2 can be reversed. In addition, the method of coupling between the two components can be of the snap-fit type, as shown in Figure 7, instead of the threaded type. In the case of the type of screw shown in Figures 1-5, when the male screw portion 5 of the tip end 2 fits into the screw hole 4 of the tip body 1, both the conduit 3a, and the cable 3b can be aligned precisely. In this way, the welding wire can be fed smoothly through the conduits 3a, 3b for wire. On the back side of the wire conduit 3b of the tip end 2, an extended conical portion 8b is formed that opens rearward, with its duct area expanded. Also, on the back side of the wire conduit 3a of the tip body 1, an extended conical portion 8a is formed which opens rearwardly with its extended conduit area. Accordingly, when the wire passes from the rear end of the tip body 1, a front end of the wire can be fed smoothly through the same portions. On the surfaces of the tip body 1 and the tip end 2 flat portions 10 a, 10 b respectively are formed for insertion in a tightening tool, such that the tip body 1 and the end 87/40 tip 2 can be safely inserted into each screw-in portion. Then, the flat portions 10a, 10b can be tightened by a key or the like, so that the tip body 1 and the tip end 2 can be tightened securely. In accordance with the present invention, the tip body 1 is made of brass, copper, aluminum, chromed copper, copper with zirconium, chromium-plated copper with zirconium or phosphor bronze. The tip end 2 is made of copper, chromed copper, chromium-plated copper with zirconium, copper with zirconium, tungsten with silver, tungsten with copper, copper with dispersed alumina, copper with beryllium or copper with beryllium and nickel. There are effective combinations of materials for the reduction of the total cost, in terms of the relation between the durability and the cost of production, which are provided as a result of the repeated experimentation with diverse materials made by this inventor. Table 1 shows the result of the durability test and a relationship with prices from the point of view of comparison with a contact tip for conventional integrated type welding. 7/40 Table 1. (Summary of results of the durability test with various materials) 87/40 Notes regarding Table 1 Note 1: If the tip end is made of copper, tungsten with silver or tungsten with copper, conventionally you can get almost the same unit price when manufacturing the brass top body. Note 2: If the tip end is brass, conventionally you can get almost the same unit price by making the brass tip body. However, the days are shorter, so this is not practical. The unit price based on days (obtained by dividing the unit price by the days of duration) is obtained from the days of duration obtained from the result of the durability test and from a relation between the tip body 1 and the tip end 2. In the case of a contact tip of conventional integrated type costs about 120 yen for the case of chromed copper and about 150 yen for the case of chromium-plated copper with zirconium. If as mentioned in this invention, the separate type is used, the total cost of the tip body 1 and the tip end 2 can be equal to or less than about 120 yen, which is the cost for the conventional integrated type. From the above, a particularly effective combination is that the tip body 1 is made of brass and the 7/40 tip end 2 is chromed copper or chrome-plated copper with zirconium. In this case, the unit price based on days is from 54 to 55 yen, which is a cost reduction of more than twice the conventional price. The diameter of the duct 3a for wire in the tip body 1 is 1.03-1.50 times the diameter of the wire and the diameter of the duct 3b for wire at the tip end 2 is 1.03-1.25 times the diameter of the wire. The foregoing has been proven by the inventor herein as a result of experiments with various combinations of the wire diameter of the tip body 1 and the diameter of the tip end wire 2. Table 2 shows a summary of the results of the experiment. 7/40 Table 2 Summary of the results of the conduit wheel for wire) Consequently, if the diameter of the conduit 87/40 for tip 1 body wire is less than 1.03 times the diameter of wire, it is difficult to feed the wire. If this is less than 1.50 times the diameter of the wire, sufficient electrical conduction can not be ensured thereby providing an unfavorable condition. In addition, if the diameter of the wire conduit at the tip end is less than 1.03 times the diameter of the wire, it is difficult to pass the wire. If it is more than 1.25 times, a deviation of the welding point will probably occur so that it is impossible to carry out the welding in a precise manner. With respect to the diameter of the wire conduit allowing or enabling more stable welding, the diameter of the wire conduit of the tip body 1 is within the range of 1.05-1.30 times the diameter of the wire and the diameter of the wire conduit of the wire. Tip end 2 is within the range of 1.05-1.15 times the diameter of the wire. The length s of the wire conduit of the tip end 2 is 3-20 mm. The reason is the following, if the length of the tip end 2 is less than 3 mm, it is very likely that a defect such as wear, melting and the like will extend into the wire conduit 3 of the tip body i. Also, if the length of the tip end 2 is shorter, 87/40 reduces processing performance and handling performance. If the length s of the conduit 3b for wire is greater than 20 mm it is difficult to ensure the precision in the processing of the conduit 3b for wire. In addition, the tip end 2 becomes larger, so that the performance in terms of cost is reduced. As described above, the area of the contact face 6 (area m of Figure 6) on the front side of the tip body 1 is greater than 10% of the total area of the front face of the tip body 1. If it is less than 10%, the heat conduction is deteriorated, so that the cooling of the tip end 2 is not effected uniformly. In addition, inappropriate electrical conduction is likely to occur. If it is more than 10%, these defects do not occur. The ratio of the contact area on the contact face 6 (m) of the tip body 1 is the same for the tip end 2. The area of the contact face (n in Figure 6) on the front side of the end of the contact tip 7 is more than 10% of the total area of the front face of the tip end 2. The shape of the forward end of the tip end 2 can be flat as shown in Figure 3. However, it is more favorable if it is provided a round portion r in the entire interval. This round portion r provided around the front end repels splashes generated during welding and makes it difficult to 87/40 splashes stick or adhere to it. Consequently, the reduction of the quality of the welding due to the alterations of the gas flow is suppressed. To prevent splash adhesion, the outer surface of the tip end 2 can be electroplated with nickel, hard chromium or the like. In addition, diemarks can be provided on the end face. These die markings i include, for example, the name of the producer, the production number, the product number and the like. If the die marks i are provided on the end face, they can be provided at the same time as the tip end 2 is prepared for the next processing. In this way, a particular process can be omitted to provide the diemarks as seen in conventional products, thus simplifying the processing operation, which leads to the reduction of the production cost. The external shapes of the tip body 1 and the tip end 2 may be circular, dodecagonal, hexagonal, tetragonal, pentagonal, with transverse planes or the like. 7/40 Industrial Applicability The contact tip for welding improves the durability of the contact tip for arc welding and the quality of the welding produced with it, thereby greatly reducing the total cost of the welding operation. 87/40

Claims (7)

CLAIMS;

1. Contact tip for welding that has a conduit for a wire electrode in the center thereof, comprises a tip body and a tip end that are separable from each other by a threaded or conical-type structure that can be engaged, the body The tip is composed of brass, aluminum, chromed copper, copper with zirconium, chromium plated copper with zirconium or phosphor bronze, the conduit for wire in the tipped body has a diameter of 1.03-1.50 times the diameter of the wire, the conduit for wire at the tip end it has a diameter of 1.03-1.25 times the diameter of the wire. The soldering contact tip according to claim 1, wherein the tip end is composed of copper, chromium-plated copper, chromium-plated copper with zirconium, copper with zirconium, tungsten with silver, tungsten with copper, copper with dispersed alumina, copper with beryllium or copper with beryllium and nickel. 3. The soldering contact tip according to claim 1 or 2, wherein the wire conduit of the tip end is 3-20 mm long. 4. The soldering contact tip according to claims 1-3, wherein an extended conical portion that opens with an extended conduit area is 87/40 forms in an opening portion, on a proximal side of the cable conduit of the tip end. 5. The soldering contact tip according to claims 1-4, wherein a rear end of the tip end and a front end of the tip body each have a thread portion and a contact face, the faces of contact, from which the thread portion is excluded, are in contact with each other and have a contact area that is greater than 10% of the rear face of the tip end or the front face of the tip body. The soldering contact tip according to claims 1-5, wherein a round portion is formed at the periphery of the end face of the tip end. 7. The soldering contact tip according to claims 1-6, wherein die markings are provided on the end face of the tip end. 7/40