SYSTEM AND METHOD FOR FORMING A WELD ALONG A LENGTH

A technique for creating a weld along a joint. A method begins by positioning a first edge of a first member proximate to a second edge of a second member to form the joint, wherein the joint is to be welded along the length from a first position on the joint to a second position on the joint. A clamping ring of a refill spot welding apparatus is placed to surround an unwelded portion of the length. The clamping ring contacts a top surface of the first member and a top surface of the second member. A first refill spot weld process is performed with the refill spot welding apparatus to join the first member and the second member at a first spot weld on the joint.

TECHNICAL FIELD

In general, the present invention relates to tailored metal blanks and, in particular, a technique for completing a weld along a length during production of the tailored metal blanks.

BACKGROUND

Metal blanks, and in particular sheet metal blanks, may be manufactured for a particular application. For example, tailored metal blanks are often created for various applications in the automotive industry. Such tailored metal blanks may be created by joining two or more metal blanks together via a welding process or other joining process. Often, the welding process used to join the two or more metal blanks creates a weld that ends prior to the end of the joint. Such welds that are not fully incorporated to the end of the joint can cause problems with the integrity and strength of the weld joint.

SUMMARY

In various, non-limiting embodiments, a technique is provided for forming a weld for a length of a joint. The technique includes positioning a first edge of a first member proximate to a second edge of a second member to form the joint, wherein the joint is to be welded along the length from a first position on the joint to a second position on the joint. A clamping ring of a refill spot welding apparatus is placed to surround an unwelded portion of the length. The clamping ring contacts a top surface of the first member and a top surface of the second member. A first refill spot weld process is performed with the refill spot welding apparatus to join the first member and the second member at a first spot weld on the joint.

In another embodiment, a method for forming a weld includes positioning a first edge of a first member proximate to a second edge of a second member to form a joint, where the joint is to be welded along a length from a first position on the joint to a second position on the joint. A welding process is performed to form the weld on the joint along a portion of the length, where the weld includes a retract hole. Additional material is placed on top of the retract hole. A clamp ring of a refill spot welding apparatus is placed to surround the additional material and the retract hole. A refill spot weld process is performed with the refill spot welding apparatus to fill the retract hole with material from the additional material.

In another embodiment, a method for forming a weld for a length of a joint includes positioning a first edge of a first member proximate to a second edge of a second member to form the joint. At least one clamping ring of a refill spot welding apparatus is placed to surround an unwelded portion of the length, where the clamping ring contacts a top surface of the first member and a top surface of the second member. At least one refill spot weld process is performed with the refill spot welding apparatus to join the first member and the second member at one or more spot welds on the joint.

These and other features of this invention will be evident when viewed in light of the drawings, detailed description and appended claims.

DETAILED DESCRIPTION

A tailored blank formed from multiple pieces (e.g. metal blanks) has many applications, specifically within the automotive industry and in general various manufacturing industries. However, certain techniques used to join the multiple pieces can leave an unwelded portion at the edge of a weld joint. It is to be appreciated that when joined via certain processes the systems and methods can leave a section of inadequately joined material. For example, the area that can be welded may be different than the remainder of the seam using a plunge and retract of the weld. In accordance with various techniques described herein, an end welding technique and system is used to complete a weld for a length of a joint. In certain other embodiments, a refill spot welding process can be applied at multiple locations along a length of a joint to combine pieces together.

These and other advantages of the techniques provided herein will be apparent to one of ordinary skill in the art.

With reference to the drawings, like reference numerals designate identical or corresponding parts throughout the several views. The inclusion of like elements in different views does not mean a given embodiment necessarily includes such elements or that all embodiments of the invention include such elements. The examples and figures are illustrative only and not meant to limit the invention, which is measured by the scope and spirit of the claims. Moreover, it should be understood that the drawings may not depict features to scale. The drawings may enlarge or exaggerate certain features to facilitate visualization.

FIG. 1depicts a first member100and a second member102joined together by a weld104at a joint. Each of the first member100and the second member102can be made of a metal including, but not limited to, aluminum, steel, stainless steel, nickel, copper, titanium, cast iron, a metal alloy, or a combination of different metals. Each of the first member100and the second member102can include a respective shape, size, length, thickness, height, width, surface finish, among others. The first member100and the second member102can be made of the same material or they can be made of different materials. In certain embodiments, the first member100and the second member102can together form a tailored blank. For example, the tailored blank can be formed from two or more members, wherein the members are joined by a welding operation. It is to be appreciated that the tailored blank can include a shape and each member that forms the tailored blank can include respective properties (e.g., shape, size, length, width, height, weight, thickness, composition, surface finish, surface pattern, etc.). The systems and methods described herein facilitate fabricating a tailored blank with one or more welds while mitigating discontinuities, defects and other welding issues.

A welding system (discussed in more detail below) can be utilized to perform a weld between the first member100and the second member102to create a portion of a tailored blank. In particular, the first member100can be positioned such that a first edge of the first member100is proximate to and/or aligned with a second edge of a second member102to form a joint106in accordance with the portion of the tailored blank to be created. As depicted inFIGS. 1-3, the first member100and the second member102can be positioned in a non-overlapping arrangement. It should be appreciated that in certain embodiments, the first member100and the second member102can be positioned to be overlapping. It is to be further appreciated that there may be one or more welds to perform to create the tailored blank and/or there may be two or more members to attach. The joint106can be welded along a length108from a first position on the joint106to a second position on the joint106. The length108can include at least one of the entire length of a joint106from the first end110of the joint106to the second end112of the joint106, a length from a first end110to a position on the joint106between the first end110and the second end112, a length from a position on the joint106between the first end110and the second end112to the second end112, or a length from a first position to a second position where both positions are along the joint106in between the first end110and the second end112. A weld process can be performed by a welding system to form the weld104on the joint106along a portion of the length108such that the length108includes a welded portion114and an unwelded portion116. The weld process can be, but is not limited to, formed by friction stir welding, laser welding, or another joining process. It is to be appreciated that the welding process can be selected with sound engineering judgment without departing from the scope of the subject disclosure. A top view of a tailored blank having a representative weld104is shown inFIG. 2and a bottom view of the tailored blank having the representative weld104is shown inFIG. 3.

FIG. 4displays a cross-sectional view of a representative refill friction stir spot welding apparatus118(hereinafter refill spot welding apparatus). It is to be appreciated that the techniques of the refill spot welding apparatus can be performed with various tools or devices and such tools and devices can be selected with sound engineering judgment without departing from the scope of the subject disclosure. The welding system that performs a weld between at least the first member100and the second member102can further utilize a refill spot welding apparatus118. The refill spot welding apparatus118can be utilized to complete the weld104for a desired length108of the joint106by performing a spot weld that covers the unwelded portion116. The refill spot welding apparatus118includes a clamping ring120(also referred to as a non-rotating collar), a rotating shoulder122, and a probe124. The refill spot welding apparatus118can be mounted on a console, coupled to a robotic arm, a table, a fixture, among others and can further be operated by a controller, manually operated, or a combination thereof. In particular, the welding spot apparatus118, having a cylindrical shape, can be configured with a diameter that corresponds to the length of the unwelded portion116. In another embodiment, the refill spot welding process can be one or more stations or locations in order to cover a length of the unwelded portion. In other words, the systems and methods can include multiple refill spot welding stations (e.g., side-to-side, within proximity of one another, etc.) to be used to cover and repair the length of the unwelded portion. It is to be appreciated that the shape of the welding spot apparatus118can be selected or fabricated with any suitable shape to allow the unwelded length116to be at least one of covered, surrounded, or encased by the clamping ring120. The clamping ring120can contact a top surface of both the first member100and the second member102and provide a downward force to the first member100and the second member102on a supported table or other fixture to restrain the first member100and the second member102from movement. Once clamped, the rotating shoulder122and the probe124can perform the spot weld on the unwelded portion116(as described in more detail below). It is to be appreciated that the clamping ring120can be selected based on sound engineering judgment and may be include various dimensions (e.g., height, length, width, thickness, size, shape, among others). For example, the clamping ring120may be a non-ring shape based on the process or materials for the welding system.

Turning now toFIG. 5, a flow diagram depicting a method500of a technique for completing a weld104for a length108of a joint106is illustrated. At reference numeral502, a first edge of a first member100is positioned proximate to a second edge of a second member102to form a joint106. The first edge of the first member100and the second edge of the second member102can be positioned to be non-overlapping. For example, the first edge and the second edge can be aligned with each other to create a butt joint between the first member100and the second member102. The joint106can be welded along a length108from a first position on the joint106to a second position on the joint106. As previously described, the first position and the second position can be selected based on sound engineering judgment and may be located anywhere on the joint106including the first end110of the joint106, the second end112of the joint106, or any point therebetween. For example, the first position or the second position can be dependent on a shape of the tailored blank the first member and the second member will form.

At reference numeral504, a welding process is performed to form a weld104on the joint106along a portion of the length108such that the length108includes a welded portion110and an unwelded portion112. For example, the weld process can be, but is not limited to, friction stir welding, laser welding, other welding techniques, or another joining process such as brazing or soldering.

At reference numeral506, the clamping ring120of a refill spot welding apparatus118is placed to surround the unwelded portion112of the length108. Once placed, the clamping ring120functions by contacting the surfaces of both the first member100and the second member102and applying pressure to clamp the first member100and the second member102in place. The clamping ring120also functions to contain material flow within the clamping ring120throughout the refill spot welding process. In certain embodiments, the first member100and the second member102can be placed on an anvil126or other supporting member to provide support to the first member100and the second member102and to prevent material deformation during the refill spot welding process. In an embodiment, the anvil126can be customized with a specific shape based on the welding project or blanks being used. In certain embodiments, the clamping ring120of the refill spot welding apparatus118is placed to surround only a portion of the unwelded portion112of the length108.

At reference numeral508, a refill spot welding process is performed with the refill spot welding apparatus118. In particular, the refill spot welding process can include the steps as follows. The process can include activating the rotating shoulder122and the probe to generate heat through friction until the member material reaches a plastic state. It is to be appreciated that the variables (e.g., speed of rotation, rate of movement of probe, time of applying rotation, among others) of the spot welding process can be selected based on the parameters of at least one of the first member100or the second member102. After the member material reaches a plastic state, the method includes retracting the probe124while the rotating shoulder122plunges into the surface of both the first member100and the second member102. Next, the method includes reversing directions of the rotating shoulder122and the probe124to return the rotating shoulder122and the probe124to their starting position. In certain embodiments, the movements of the rotating shoulder122and the probe124are interchanged such that the rotating shoulder122initially retracts and the probe124plunges into the surface of the first member100and the second member102. After the shoulder122and the probe have returned to the starting position, the method includes releasing the clamping ring120from the first member100and the second member102and removing the refill spot welding apparatus118from the first member100and the second member102.

FIGS. 6-9illustrate the refill spot welding system that performs portions of the method inFIG. 5. It should be appreciated that the system displayed inFIGS. 6-9is just one example of a system that can be used to perform the method, and can be assembled with sound engineering judgment. As shown inFIG. 6, the rotating shoulder122and the probe124contact the first member100and the second member102to surround the unwelded portion112of the length108. In an embodiment, the refill spot welding system can perform the technique in multiple locations, for example, if the probe124does not surround the entire unwelded portion112of the length108. The rotating shoulder122and the probe124generate heat through friction until the member material reaches a plastic state. As shown inFIG. 7, the probe124then retracts while the rotating shoulder122plunges into the surface of both the first member100and the second member102. The retraction of the probe124creates a volume128for material displaced by the plunging rotating shoulder122to flow. The rotating shoulder122and the probe124then reverse directions to return to the starting position. During this stage, the probe124forces the material back into a cavity formed in the surfaces of the first member100and second member102by the rotating shoulder122while the rotating shoulder122is retracting. The rotating shoulder122and the probe124eventually return to the starting position as shown inFIG. 8.

Turning now toFIG. 9, the clamping ring120is released from the first member100and the second member102, and the refill spot welding apparatus118is removed. The unwelded portion116of the length has been welded by the refill spot welding apparatus118to complete the weld104along the length108by forming a spot weld130. Following the refill spot welding process, the completed weld104includes the original welded portion114and the spot weld130. In the embodiment shown inFIG. 9, the spot weld130completes the weld104for the length108that extends to the second end112of the joint106. However, it should be appreciated that the desired length108can end at a second position on the joint106before the second end112of the joint106.

Turning now toFIGS. 10 and 11, in certain embodiments when a first member1000and a second member1002are joined together at a joint1006by a friction stir welding process, a resulting weld1004may include a retract hole1007.FIG. 10is a top side view of a portion of a tailored blank andFIG. 11is a bottom view of the portion of the tailored blank. The retract hole1007is a result of the material not flowing into the space left from where the friction stir welding tool is retracted at the end of the weld1004. In these embodiments, additional material1009can be added to the retract hole1007prior to a refill spot welding process. In an embodiment, the additional material1009can be a slug. The additional material1009can be made of any material designed to fill the retract hole1007, including a metal such as aluminum, steel, stainless steel, cast iron, an alloy, or a combination of such materials. In certain embodiments, the additional material1009is selected to match the material of the corresponding first member1000and/or second member1002. In other embodiments, the additional material1009is selected to differ in material from the first member1000and/or second member1002. The size and shape of the additional material1009can be selected using sound engineering judgment, taking into consideration the size of the retract hole, and the diameter of the clamping ring120of the refill friction spot welding apparatus118. In one embodiment, the additional material1009is selected to be a shape and size large enough to fill the retract hole once welded, but small enough to be surrounded by the clamping ring120of the refill friction spot welding apparatus118.

Turning now toFIG. 12, a flow diagram depicting a method1200illustrates a technique for completing a weld1004having a retract hole1006. At reference numeral1202, a first edge of a first member1000is positioned proximate to a second edge of a second member1002to form a joint1006. For example, the first edge and the second edge can be aligned with each other to create a butt joint between the first member1000and the second member1002. The joint1006is to be welded along a length1008from a first position on the joint106to a second position on the joint106. As previously described, the first position and the second position can be selected based on sound engineering judgment and may be located anywhere on the joint1006including the first end1010of the joint1006, the second end1012of the joint1006, or any point therebetween.

At reference numeral1204, a welding process is performed to form a weld1004on the joint1006along a portion of the length1008. In certain embodiments, the nature of the welding process creates a weld1004with a length1008that includes a welded portion1014having a retract hole1007. In an embodiment, the welding process is a friction stir welding process.

At reference numeral1206, an additional material1009is placed on top of the retract hole1007. At reference numeral1208, the clamp ring120of a refill spot welding apparatus is placed to surround the additional material1009and the retract hole1007. At reference numeral1210, a refill spot weld process is performed with the refill spot welding apparatus120. The refill spot welding process involves the rotating shoulder122plunging into the additional material1009, and in certain embodiments, a portion of the first member1000and the second member1002, which causes the material from the additional material1009to fill the volume of the retract hole1007.FIG. 13illustrates two examples of a weld1004having a refill spot weld1030that incorporates the material from the additional material1009into the retract hole1007.

As shown inFIGS. 14-18, multiple refill spot welds can be used to create a weld along a length of a weld joint. Turning now toFIG. 14, a first member1402and a second member1404are abutted to create a joint1406. The first member1402and the second member1404can be positioned to be non-overlapping. It should be appreciated that in certain embodiments, the first member1402and the second member1404can be positioned to be overlapping. The first member1402and the second member1404can have the same thickness or different thicknesses. As depicted inFIG. 15, a first spot weld1408can be created at a position along the joint1406. In one embodiment, the first spot weld1408is formed at an edge of the joint1406.

In one embodiment, a length of the joint can be welded with spot welds created in different passes. For example, as shown inFIG. 16, a first set of spot welds1410can be created along a length of the joint1406. The first set of spot welds1410includes multiple individual spot welds (e.g. first spot weld1408) that are staggered to create a gap1412between successive individual spot welds along the joint1406. It should be appreciated that the first set of spot welds1410can span the entire length of the joint1406, or it can span a portion of the entire length of the joint1406. In certain embodiments, the individual spot welds of the first set of spot welds1410can be made by a single spindle welder such as the refill spot welding apparatus118. In these embodiments, the single spindle (each spindle can include a clamping ring120, a rotating shoulder122, and a probe124) can perform the first spot weld1408and then be repositioned at the subsequent locations of the desired welds along the joint1406. In another embodiment, the first member1402and the second member1404can be repositioned with respect to the spindle so that the single spindle can perform the subsequent locations of the desired welds along the joint1406.

In other embodiments, multiple individual spot welds of the first set of spot welds1410can be made simultaneously by a refill spot welding apparatus having multiple spindles. In these embodiments, the positions of the multiple spindles can be fixed as to produce a fixed gap1412, or the positions of the multiple spindles can be adjustable to allow a user to select the size of the gap1412between subsequent spot welds of the first set of spot welds1410. In one embodiment, the position of each spindle on the refill spot welding apparatus can be adjusted individually to allow for varying gap1412sizes in between welds. In another embodiment, the position of each spindle is adjusted to create a uniform gap1412size in between welds. The spindles can also be swapped out for spindles of varying sizes. For example, the refill spot welding apparatus can be modified to include multiple spindles of different sizes and/or varying sized gaps1412. In one embodiment, the refill spot welding apparatus having multiple spindles can form the entire first set of welds1410simultaneously in one welding operation. In another embodiment, the refill spot welding apparatus having multiple spindles can form a portion of the first set of welds1410simultaneously and then be repositioned along the joint1406to form a subsequent portion of the first set of welds1410. In certain embodiments, a refill spot welding apparatus can be modified to allow the addition or removal of spindles. In these embodiments, a user can add or remove spindles to choose and customize the number of spot welds per set of welds. It should be appreciated that the embodiments described above with respect to the creation of the first set of welds1410can also be applied to subsequent passes of welds such as, for example, the second set of welds1414.

In certain embodiments, additional passes of spot welds can be applied to create a continuous weld. Turning now toFIGS. 17 and 18, a second set of spot welds1414can be created along a length of the joint1406. The second set of spot welds1414includes second individual spot welds that are applied to fill in the gaps (e.g. gap1412) between successive welds of the first set of spot welds1410. For example, a second spot weld1416can be applied adjacent to the first spot weld1408, or it can be applied overlapping the first spot weld1408to at least partially encompass the gap1412. The second set of spot welds1414includes multiple additional spot welds that are applied to fill in the remaining gaps between successive welds of the first set of spot welds1410, which completes a continuous weld1418along the joint1406. The continuous weld1418(e.g. a fully incorporated weld) can therefore span the entire length of the joint1406from edge to edge, or it can span a portion of the joint1406. It should be appreciated that multiple individual spot welds of the second set of spot welds1414can be formed with a single spindle welder such as the refill spot welding apparatus118or simultaneously by a refill spot welding apparatus having multiple spindles, as discussed above with respect to the first set of welds1410.

The second set of spot welds1414can also be applied in a manner such that the individual welds only partially fill in the gap1412between successive welds of the first set of spot welds1410. In these embodiments, additional passes of welds can be performed in order to complete a continuous weld1418along the joint. The larger the gap1412between successive welds of the first set of spot welds1410, the greater the number of weld passes will be needed to completely fill the gaps1412.

It should be appreciated that the continuous weld1418can also be formed in a single pass. In such an embodiment, each successive spot weld of the first set of spot welds1410is applied at the edge of a previous spot weld, or overlapping the previous spot weld. In other words, the first set of spot welds1410can include individual successive spot welds with no gap1412in between.

Turning now toFIG. 19, a joint1406can be welded using a first end spot weld1902applied to a first end of the joint1406and a second end spot weld1904applied to an opposing end of the joint1406. In this embodiment, a length of the joint1406in between the first end spot weld1902and the second spot weld1904is unwelded.

Turning now toFIG. 20, a method2000for forming a weld along a length of a joint1406is depicted. At reference numeral2002, a first1402and second member1404are positioned to form a joint1406to be welded along a length from a first position on the joint to a second position on the joint. The first member1402and second1404can be positioned in a non-overlapping manner. At reference numeral2004, a first refill spot weld process is performed with a refill spot welding apparatus to create a first set of spot welds1410along the length. The first set of spot welds1410includes a plurality of first individual spot welds. During the first refill spot weld process, a plurality of gaps1412of unwelded material may be left between successive first individual spot welds. At reference numeral2006, a second refill spot weld process is performed with the refill spot welding apparatus to create a second set of spot welds1414along the length. The second set of spot welds1414includes a plurality of second individual spot welds that can be positioned to at least partially encompass the plurality of gaps1412.

It is to be appreciated that various features or aspects of the embodiments described herein can be utilized in any combination with any of the other embodiments.

As utilized herein, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form. Further, as used herein, the term “exemplary” is intended to mean “serving as an illustration or example of something.”

Illustrative embodiments have been described, hereinabove. It will be apparent to those skilled in the art that the above devices and methods may incorporate changes and modifications without departing from the general scope of the claimed subject matter. It is intended to include all such modifications and alterations within the scope of the claimed subject matter. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.