This invention generally relates to manufacturing, and more specifically relates to precision welding.
Modern manufacturing relies on the ability to reliably precise attach disparate pieces together in an automated fashion. One commonly used technique is welding. Welding is the heating of metals, causing them to melt and flow together. The heat used to weld together materials can be applied through electricity or other means. In processes that require high degrees of precision, a laser can be used to accurately melt the pieces together.
One technical challenge that arises in precision laser welding is the ability to consistently weld pieces together that do not fit tightly together. For example in some situations it is necessary to weld a tab into a slot. The tab is placed in the slot and then subjected to the welder, which causes the materials to melt and flow together. This welding process thus makes a permanent physical connection between the tab and the slot.
Unfortunately, it can be difficult to consistently weld a thin tab to a relatively wide slot. This difficulty occurs because of the propensity for the thin tab to move within the slot if it cannot be held fixed in place. In particular, if the tab is not firmly pressing against one side of the slot when the laser weld occurs, the materials may not flow together sufficiently to create a solid weld between the tab and the side of the slot. These failures negatively impact reliability and can dramatically reduce the yield of the welding system.
While this problem can be alleviated in some circumstances by narrowing the width of the slot or widening the thickness of the tab, this cannot be done in all applications. For example, in some applications the minimum width of the slot is determined by the manufacturing process used to create the slot. For example, if the slot is created by a punch, then the minimum width of the slot may be determined by the minimum thickness for which a punch can be reliably used. Likewise, the thickness of the tab may be limited to the thickness of the material from which the tab is created.
All of these applications require the ability to reliably weld a relatively thin tab into a relatively wide slot. Thus, what is needed is an improved system and method for welding a relatively thin tab into a relatively wide slot that improves the reliability and yield of the system.
The present invention provides a system and method for reliably welding a relatively thin tab into a relatively wide slot. The system and method forms a protrusion on the tab. When the tab with the protrusion is inserted into the slot, the protrusion causes the tab to be firmly pressed against one side of the slot. With the tab pressed firmly against the side of the slot, the tab can then be welded to the slot. Because the tab is pressed firmly against the side of the slot during welding, the reliability of the welding process is improved.
The present invention is applicable to all welding procedures, but is particularly applicable to laser welding used in precision manufacturing. In those applications, the protrusion causes the tab to be firmly held against the side of the slot while the laser welds the tab and slot together.