MXPA06005821A - Welding stud - Google Patents

Abstract

A welding studapparatus and method of manufacturing a welding stud are disclosed. The welding stud has a weld end constructed to be welded to a workpiece that has at least one recess formed therein. The recess decreases an effective arc area of the weld end to localize a current therethrough and increase the efficiency with which the welding stud can be welded to a workpiece.

Description

WELDING SPARROW ANTECEDENTS OF THE INVENTION The present invention relates generally to welder systems and, more particularly, to a welder stud for stud welding applications. Asparagus welding is a welding process that makes use of a current discharge located between a metal fastener and a metal work piece. A stud welding system has a power source, an asparagus gun, a pair of wires that connect the stud gun to the power source, and a stud that is welded to the work piece. In most cases, although not required, the fastener and the work piece have the same material properties. The fasteners are retained and welded in place through the use of an electromechanical device in the asparagus gun. Asparagus welding has applications in many industries. These industries include boiler manufacturing, shipbuilding, car manufacturing, and construction, to name a few. Welding an asparagus to a workpiece is an easy and effective means of securing a fastener device to a workpiece. The studs are also provided in a variety of shapes and materials so that the stud welding to a work piece can be used to differentiate between additional systems that are fixed to the work piece depending on the type of stud welded thereto. The quality of the weld joining the stud to the work piece partially determines the amount of load the stud can bear. Poor quality welding can result in weld failure between the stud and the work piece. The weld failure associated with poor weld quality is difficult to predict and is often designed by the excess welding of the stud instead of improving the welding efficiency of the weld stud. A low efficiency in the stud welding process is partially due to a low effective contact resistance between the stud and the work piece. The efficiency of the welding between the stud and the work piece is determined partly by the physical construction of the weld stud used and the condition of the interface between the weld stud and the work piece. A poor interface between the weld stud and the workpiece adversely affects the performance of the arc and can result in weld failure. The construction of the weld end of the weld stud also affects the quality of a weld between a weld stud and a work piece. If the weld end of the weld stud is poorly constructed, an incomplete weld can be formed between the weld stud and the workpiece after completion of the welding process. Therefore, it would be desirable to design a weld stud for stud welding applications that maximizes the characteristics of the arc between the weld stud and the work piece, thus maximizing welding quality and welding efficiency.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to a soldering stud that solves the aforementioned disadvantages. A soldering stud and method for manufacturing a soldering stud including at least one ledge, but preferably, a plurality of lugs formed at the weld end of the soldering stud are disclosed. The plurality of ridges locate a current that passes through the welding end of the weld stud during the welding operation. By locating the current through the welding end of the stud, the stud can be welded to a workpiece faster and with less energy than welding studs without the current location construction of the invention. Thus, according to one aspect of the invention, there is disclosed a soldering stud having a body extending between a first end and a second end. The first end is constructed to engage a welding gun by stud. At least one gap is formed at the second end which increases the effective surface area of the second end and is designed to decrease an effective arc area of the second end. Such construction allows the weld stud to be quickly and efficiently welded to a work piece. According to another aspect of the present invention, a soldering stud having a body is disclosed. The body extends from one end connector built to attach a welding gun by stud. A weld end of the weld stud, opposite the connector end, has at least one projection and is constructed to be welded to the workpiece. The projection extends outwards to separate the weld end having a non-planar surface from a work piece. Such a construction reduces the cross-sectional area of the welding end and locates the current that passes through it during a welding operation. According to a further aspect of the present invention, a method for manufacturing a soldering stud is disclosed. The method includes providing a soldering stud having a first end and a second end, forming the first end for coupling a soldering iron per stud, and forming the second end with an increased resistance to current flow as compared to a soldering stud having a nozzle and a generally flat surface on it. According to yet another aspect of the present invention, a soldering stud is disclosed. The weld stud has a first end constructed to engage a welding gun by stud. A body extends from the first end towards a face of a welding end. The weld stud includes means for locating the current density at the weld end face of the weld stud. Various other features, objects and advantages of the present invention will become apparent from the detailed description and drawings below.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate and include a preferred embodiment currently considered to carry out the invention. In the drawings: Figure 1 is a perspective view of a stud welding device according to the present invention. Figure 2 is a side view of the welding gun by stud of the Figure 1, in use. Figure 3 is a perspective view of a weld stud according to the present invention that can be used with the stud welder shown in Figure 1. Figure 4 is a cross-sectional view of the weld end of the weld stud shown in Figure 3. Figure 5 is a plan view of the weld end of the weld stud shown in Figure 4. Figure 6 is a cross-sectional view of the weld end of an alternative embodiment of a weld stud in accordance with the present invention. Figure 7 is a plan view of the weld end of the weld stud shown in Figure 6. Figure 8 is a cross-sectional view of the weld end of another alternative embodiment of a weld stud according to the present invention. Figure 9 is a plan view of the weld end of the weld stud shown in Figure 8. Figure 10 is a cross-sectional view of the weld end of yet another alternative embodiment of a weld stud according to the present invention. Figure 11 is a plan view of the weld end of the weld stud shown in Figure 10. Figure 12 is a cross-sectional view of the weld end of another alternative embodiment of a weld stud according to the present invention. Figure 13 is a plan view of the weld end of the weld stud shown in Figure 12.

DETAILED DESCRIPTION OF THE PREFERRED MODALITY Figure 1 shows a stud welding system 10 according to the present invention. The stud welding system 10 includes a box 12 enclosing the internal components of the welding power source such as a circuit board and the power source. In one embodiment, the stud welding device 10 is of such a compact construction that it includes a handle 14 for ease of transportation of the welding system from one site to another. To perform the welding process, the stud welding device 10 includes a stud welding gun 16 as well as a work clamp 18. The work clamp 18 is configured to complete the welding circuit for a work piece to be welded. The connection of the stud welding gun 16 and the work clamp 16 to the box 12 is a pair of wires 22 and 24, respectively. Before a welding operation, as shown in Figure 2, a stud 21 is placed on a working end 26 of the stud welding gun 16 and in abutting engagement with the workpiece 20. When a trigger is pressed 17 of the stud welding gun 16, a welding current develops between the welding gun 16 and the work piece 20 through the stud 21. An arm 28 of the stud welding gun 16 is used to hold the stud 21 and allow consume the asparagus 21 away from the work piece to form the arc welding by studs. The arc of the weld is formed by consuming the stud 21 from the work piece 20 as the electric current 32 passes through the stud 21 and the work piece 20. As the electric current 32 passes through the stud 21 and the workpiece 20, a welding end 34 of the stud 21 and the target point 36 of the workpiece 20 are fused. An internal tool holder 38 of the stud welding gun 16 maintains a distance, indicated by the arrows 39, between the stud 21 and the work piece 20 during the welding process. The distance 39 is determined to be the distance required to form a suitable welding arc between the stud 21 and the workpiece 20. After a predetermined time, the stud 21 is urged towards the work piece 20, thus forming a weld homogeneous between the stud 21 and the work piece 20. Although an electromechanical stud bolt gun and an asparagus welding system is shown, it is understood that this is simply by way of example. This is not intended to limit the scope of the claims presented here. An exemplary weld stud 21 is shown in greater detail in Figure 3. The weld stud 21 includes a body 40 disposed between the weld end 34 and the end of the gun 42. The end 42 of the gun is constructed to engage a gun asparagus welder as shown in Figure 2. Additionally, end 42 of the gun can be constructed to attach to a connector (not shown) after the soldering stud 21 is welded to a workpiece. As shown in Figure 3, the end 42 of the stud gun 21 includes a head 44 formed around it. It will be understood that the head 44 can be in many forms depending on the asparagus gun used and the final application of the stud. The head 44 only needs to be constructed to engage the end of the piece of the stud welding gun and adaptable to provide a further connection thereto. In the embodiment shown in Figure 3, a weld end 34 of the weld stud 21 has a plurality of shoulders 46 formed on it and oriented concentrically around a central axis 48 of the weld stud 21.

A slot 50 is formed between the adjacent shoulders 46. A nozzle 52 is formed in the center of the weld end 34 and is surrounded by a surface 54 of the weld end 34 of the spreader stud 21. U na m oreor p art the welding end 34 is occupied by the surface 54 with the nozzle 52 positioned at its center. As such, the surface 54 has a substantially non-planar construction, which provides the localized density of current during a welding process. The surface 54 decreases an effective arc area between the weld stud 21 and the work piece 20. During the welding process, an electric arc is formed as the electric current passes between the weld end 34 of the weld stud 21 and the workpiece 20. During a welding operation, the non-planar construction of the surface 54 results in an increase in the effective surface area of the welding end 34 and provides an asparagus with a reduced contact area. The contact area is defined as that area that would make contact with a work piece once it is fixed on the work piece during the welding process. The location of the current through the welding end 34 during the soldering process reduces the total amount of energy required to perform the weld resulting in more efficient welding. As shown in Figure 4, the slots 50 formed in the weld end 34 of the weld stud 21 increase the total surface area of the surface 54 and reduce the transverse surface area of the surface. As such, the slots 50 decrease the effective area of the spindle, between the spindle and a work piece. The shoulders 46 extend toward the tip 56 on the surface 54 and surround the nozzle 52, and define the contact surface between the weld stud 21 and a workpiece. The surface 54 is prologued along the weld end 34 from the nozzle 52 to the outer surface 58 of the weld stud 21. During the welding operation, the nozzle 52 ensures adequate separation between the surface 54 and a workpiece before of the initialization of the welding process. Once the welding procedure is initiated, the nozzle 52 and the tips 56 are fused. The slots 50 focus the current that travels through the surface 54 and a workpiece at the tips 56 of the shoulders 46. Such a construction creates a current density located on the surface 54 that is greater than a local current density of a soldering iron with a practically flat welding surface. Since the shoulders 46 and the nozzle 52 melt during the welding process, the slots 50 decrease until the stud and the workpiece become one. As shown in Figure 5, the shoulders 56 and the grooves 50 are generally positioned circumferentially around the nozzle 52 at the weld end 34 of the stud bolt 21. The ends 56 and the grooves 50 also generally extend from uniformly from the nozzle 52 to the outer surface 58 of the weld stud 21. As shown in FIG., the welding surface 54 is geometrically centered on the longitudinal axis 48, shown in Figure 3, of the welding stud. Such construction ensures a generally uniform arcing around the surface 54 of the welding stud 21, after the nozzle 52 melts, during the welding process. The increased resistance associated with the weld stud 21 ensures uniform welding of the studs to a workpiece in a repeatable and efficient manner, thus creating an efficient welding process. An alternative weld stud 60 is shown in Figures 6 and 7. Weld stud 60 is similar to weld stud 21 in that it includes a plurality of shoulders 64 and a plurality of grooves 66 disposed about a nozzle 68 at the weld end 62 of the weld stud 60. The grooves 66 do not extend so far into the weld end 62 of the weld stud 60, Figure 6, as the grooves 50 extend toward the weld end 34 of the weld stud 21, Figure 4. However, the end of welding 62 has a tapered perimeter 70. The tapered perimeter 70 reduces the effective surface area of the welding end 62 for a work piece during the welding process. As the picture shows 7, the welding end 62 of the welding stud 60 is similar to the welding end 34 of the welding stud 21 shown in Figure 5 in that both welding ends 34 and 62 have a plurality of grooves and generally concentric ridges around a nozzle. The tapered perimeter 70 of the welding stud 60 reduces the effective cross-sectional area of the welding end 62 during the welding process. The tapered perimeter 70 and the grooves 66 each contribute to concentrate a current passed through the solder end 62 of the soldering stud in the projections 64. As such, after the welding process is initiated and the nozzle 68 is melted. , the weld current is located, or concentrated, on the shoulders 64. Instead of the circular pattern of the grooves and shoulders of the weld studs 21 and 60, Figures 4 to 7, a weld stud, Figures 8 and 9, and another weld stud 100, Figures 10 and 11, have a pattern formed at the weld end based on a relatively simple geometric pattern. The weld stud 80, shown in Figures 8 and 9, has a cross-sectional shape that is similar to the cross-sectional shape of the weld stud 21, as shown in Figure 4. In Figure 8, a nozzle 82 is shown in FIG. is positioned on a central axis 84 of a welding end 86 of the welding stud 80. A plurality of grooves 88 and a plurality of shoulders 90 are formed on a surface 92 of the welding end 86. The surface 92 extends from the nozzle 82 to a perimeter 94 of the weld end 86 of the weld stud 80. Figure 9 shows a generally geometric pattern formed at the weld end 86 by means of the plurality of grooves and linear ridges. The welding stud 100, shown in Figures 10 and 11, has a plurality of cavities 102 formed between a plurality of adjacent shoulders 104. The cavities 102 and the shoulders 104 are formed on a surface 106 of the welding end 108 of the welding stud 100. A nozzle 110 extends beyond the surface 106 along an axis 112 of the welding stud 100 and initiates contacting the welding stud 100 with a workpiece. A cone 114 may be formed around a perimeter 116 of the surface 106 of the weld stud 100 to reduce the effective cross-sectional area of the weld end 108 of the weld stud 100. By comparing the weld studs 80 and 100, as shown in Figures 9 and 11, with the weld studs 21 and 60, as shown in Figures 5 and 6, it should be understood that the present invention discloses a weld stud having a non-planar surface between the nozzle and the perimeter of the weld end of the stud welder. Regardless of the pattern formed on the surface of the weld end, a weld stud having a series of ridges and grooves formed in the surface of the weld end is welded more efficiently to a work piece than a weld stud with a weld stud. generally flat surface. The non-planar surface provides the current density located on the shoulders during the welding process. The location of the current increases the efficiency with which the soldering stud can be welded to a work piece. If the pattern formed on the surface of the weld end forms a curvilinear pattern, as shown in Figures 5 and 7, or a rectilinear pattern, as shown in Figures 9 and 11, each of the geometric patterns fuses an asparagus Tiler that benefits from the current densities located during a welding process. The patterns shown in the Figures are merely by way of example and in no way limit the claims herein. It is also understood that the patterns of the grooves and ridges formed on the surfaces of the weld studs disclosed herein can be any etching pattern., stamping, machining, etc. Another weld stud is shown in Figures 12 and 13. A flux capsule 122, or a combination of powdered metal and flux, is encased in the weld end 124 of weld stud 120. A contact tip 126 of the weld capsule Flux 122 functions the same as the nozzle of the above embodiments and extends beyond a surface 128 of the solder end 124 of the soldering stud 120. The contact tip 126 of the flux capsule 122 is constructed to initiate contact with a solder piece. I work during a soldier operation. During the welding operation, the flux capsule 122 inhibits atmospheric contamination from contaminating the weld pool of the weld material generated during the spinning process. As such, the cartridge 1 22 ensures a high-quality, non-contaminated weld between the stud 120 and a workpiece. The surface 128 extends between a perimeter 130 of the flux capsule 122 towards a tapered perimeter 132 of the welding end 124 of the welding stud 120. After the flux capsule 122 is melted during the initialization of an arc, the current is located through of the stud 120 on the surface 128 of the soldering stud 1 20. As such, the soldering stud 120 locates a welding current on the surface 128 after initialization of the welding process melting the flux capsule 122. It will be understood that the flux capsule 122 may be incorporated in any / each of the weld studs described above to achieve the benefits of having a flux introduced into a weld. In the case of an asparagus using a flux capsule, a decrease in the amount of energy needed to weld a stud of a given diameter can be achieved when compared to the amount of energy required to weld an asparagus having a nozzle and a generally flat surface. The decrease in energy results from a higher current density through the welding stud of the work piece. In this case, the path of the minimum resistance extends through the metal portion of the stud around the flux capsule. The flux capsule, having a relatively high electrical resistance, allows relatively low current levels to flow through it. This results in the increased current density in the metal portion of the stud around the flux capsule. This construction requires lower energy levels for welding. Alternatively, it will be understood that the flux capsule can be replaced with powdered metals. Similar to the flux capsule, the powdered metals result in a decrease in the amount of energy required to gain a given diameter of stud when compared to a stud with a nozzle and flat surface. The powder metal capsule has a relatively high electrical resistance compared to the solid metal portion of the stud extending around it. The decrease in energy results from the relatively high current density through the solid metal portion of the stud and thus around the powder metal capsule. Such construction results in increased local current densities that provide efficient welding with less energy. Each of the embodiments of the present invention carry out the benefits achieved by a soldering stud having a generally non-planar welding end. The non-planar surface of the weld end results in the area of contact between the welded stud and the work surface during a weld procedure, an increase in the total surface area of the weld end, and provides a localized current density during a welding process. As such, a soldering stud constructed in accordance with the invention requires less energy to weld the stud to a workpiece compared to a soldering stud having a generally flat surface. Therefore, according to one embodiment of the present invention, a welding stud has a body extending between a first and a second end. The first end is constructed to engage an asparagus gun and the second end has at least one cavity formed therein. According to another embodiment of the present invention, a soldering stud has a body extending from a connecting end constructed to engage a stud welding gun. The weld stud has a weld end that has at least one projection and is constructed to be welded to a work piece. The projection extends outwardly to separate a greater part of the weld end having a non-planar surface of a work piece. According to a further embodiment of the present invention, a method of manufacturing a soldering stud includes providing a soldering stud having a first end and a second end, forming the first end for coupling an asparagus welder, and forming the second end with increased resistance to the flow of current according to sec. Aune srragous stencil that has a nose and a generally flat surface around it. According to a further embodiment of the present invention, a soldering stud has a first end constructed to engage a stud welding gun. The body extends from the first end towards a surface of a welding end. The weld stud includes means for locating the current density at the weld end surface of the weld stud. The present invention has been described in terms of the preferred embodiments, and it is recognized that equivalents, alternatives and modifications, other than those expressly stated, are possible and within the scope of the appended claims.

Claims (29)

1. A weld stud characterized in that it comprises: a body having a first and a second end; the first end constructed to couple an asparagus gun; and the second end has at least one cavity formed therein.

The weld stud according to claim 1, further characterized in that the cavity is designed to decrease an effective arc area of the second end for a work piece.

The weld stud according to claim 1, characterized in that it further comprises one of an encapsulated powder metal and a combination of flux and powdered metal encapsulated at the second end.

4. The welding stud according to claim 1, characterized in that it further comprises a plurality of cavities, wherein the cavities are concentric about an axis of the stud.

The welding stud according to claim 1, characterized in that it also comprises a plurality of cavities, wherein the cavities are annular grooves.

6. The welding stud according to claim 1, characterized in that it further comprises a pocket extending from the second end to a central axis of the stud to initiate contact with a workpiece and defining a space between the work piece. work and the second extreme.

The weld stud according to claim 1, further characterized in that the first end has a flange extending outward to collect the stud welding gun.

The welding stud according to claim 1, characterized in that it also comprises a plurality of cavities, wherein the cavities are geometrically centered around the second end.

The welding stud according to claim 1, characterized in that it further comprises a plurality of cavities, wherein the plurality of cavities are defined by a plurality of projections extending away from the welding stud and towards the workpiece.

10. A weld stud comprising: a connecting end constructed to engage an asparagus welding gun; a body extending from the connection end; a welding end constructed to be welded to a work piece; and characterized in that the weld end has at least one projection extending outward to separate a greater part of the weld end of a work piece, wherein the greater part of the weld end has a non-planar surface.

The weld stud according to claim 10, characterized in that it further comprises a plurality of grooves and ridges formed at the weld end to form the non-planar surface.

12. The weld stud according to claim 10, characterized in that it further comprises a combination of flux capsule and powder metal, and a powder metal capsule, within the weld end.

The weld stud according to claim 11, further characterized in that the plurality of shoulders are geometrically centered about a longitudinal axis of the weld stud.

The weld stud according to claim 11, further characterized in that the plurality of shoulders are annular.

15. The weld stud according to claim 14, further characterized in that the plurality of shoulders are concentric.

The weld stud according to claim 10, further characterized in that at least one projection includes a nozzle extending from a center of the weld end beyond a tip further outward from each of the plurality of projections.

17. The weld stud according to claim 11, further characterized in that each shoulder has a base and wherein a height of the shoulder is substantially similar to a width of the base.

18. A method for manufacturing a weld stud characterized in that it comprises the steps of: providing a weld stud having a first end and a second end; forming the first end to attach an asparagus welder; and forming the second end with increased resistance to current flow as compared to a soldering stud having a nozzle and a generally flat surface around it.

The method according to claim 18, characterized in that it further comprises the step of forming a receptacle with a combination of flux and powdered metal and a receptacle with powdered metal at the welding end.

The method according to claim 19, further characterized in that the step of forming the second end further comprises embossing a plurality of slots therein.

The method according to claim 19, further characterized in that the step of forming the second end further comprises recording a plurality of slots therein.

22. The method according to claim 19, further characterized in that the step of forming the second end further comprises machining a plurality of slots therein.

23. The method according to claim 19, further characterized in that the step of forming the first end further comprises the step of fuming the first end to couple a connector.

24. The method according to claim 19, further characterized in that the step of forming the second end increases the density of a current passing therethrough during a welding process.

25. A weld stud characterized in that it comprises: a first end constructed to engage an asparagus welding gun; a body extending from the first end towards a surface of a welding end; means for locating the current density at the surface of the weld end of the weld stud.

26. The weld stud according to claim 25, further characterized in that the means for locating the current density comprises a plurality of peaks formed on the surface of the weld end around a nozzle.

27. The soldering stud according to claim 25, further characterized in that the means for connecting the soldering stud are further constructed to couple a connector.

28. A weld stud characterized in that it comprises: a body having a first end and a second end; the first end constructed to engage in an asparagus gun; and the second end having a nozzle and constructed around it with at least one portion having a diminished arc surface area.

29. A weld stud characterized in that it comprises: a body having a first end and a second end; the first end constructed to engage in an asparagus gun; and the second end having a surface constructed with at least one projection disposed to face a workpiece and a remaining surface that is configured with a contact area that is decreased as compared to a flat surface.