Patent Application
20080152919
The present invention relates to the use of resistive implant welding for structural welds in automotive applications.
The joining together of two or more plastic components to form a weld or joint is frequently required during the manufacturing automobile components. As the use of plastic material in automotive applications increases there exists a greater need for more ways of welding together such components. One particular requirement is that the weld formed must have a sufficient amount of weld strength. In particular, in vehicle tailgates, such as pick-up truck tailgates the component must be designed to withstand great loads. In order to meet load requirements, composite tailgates are designed as a hollow structure having several reinforcement ribs and flange supports in combination with reinforcement sheets. For tailgates that are formed of thermoplastic composites, the various reinforcement sheets and supportive ribs of the tailgate are fused together using adhesives specially formulated to have high weld strength. The use of such adhesives does add to the length of the manufacturing time due to the time it takes to cure the weld. Also, the adhesives can be costly and contribute to the overall cost of producing the tailgate. Yet other adhesives are less costly and have a faster cure time, they require surface treatments (e.g., corona treatment or plasma treatment) to increase the surface energy of welding faces. These surface treatments are a secondary operation and difficult to control and increase part cost. Therefore, there exists a need to form welds between thermoplastic components that will decrease manufacturing time by reducing the time needed to form the weld, as well as eliminate costly adhesives.
A fused component having a first portion and second portion made of polymer material. Between the first portion and second portion is a conductor and a weld line is formed between said first portion and said second portion along the surface area of the conductor. The weld line has a strength of equal to or greater than 800 psi. The fused component formed can be any type of automotive component such as a tailgate, running board, roof rail, liftgate, front end carrier, decorative panels or airbag deployment doors.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring now to
The conductor 22 comes into contact with an energy source 24 which can be copper contacts or conductors that energize the conductor 22. The conductor 22 can be wire mesh or some other type of electrically conductive material capable of generating heat when an electrical current is applied. Additionally the conductor 22 can be a single wire. When the upper platen 14 moves down and compresses the first portion 18 and second portion 20 the energy source 24 applies energy to the conductor 22 which causes the conductor to heat up. The heating of the conductor 22 causes the first portion 18 and second portion 20 to weld together as molten material flows around the wire mesh conductor 22. The heating of the conductor 22 causes portions 18 and 20 to start melting. The pressure applied force on the molten portions 18 and 20 causes the molten portions to flow around the wire mesh conductor and mix together. The heat generated by the conductor 22 combined with the pressure applied by the upper platen 14 to the lower platen 16 causes the weld line to form.
After the pressing and energizing operation has occurred for a predetermined time period the first portion 18 and second portion 20 will be allowed to solidify by cooling to form a weld line. During the forming process the surfaces of the first portion 18 and second portion 20 that are exposed to the conductor 22 are heated and melt or weld the first and second portions together. The conductor 22 will remain in the fused component 10 at the weld line. The use of wire mesh as the conductor 22 provides holes for the molten plastic material of the first and second components 18, 20 to cure together. The weld line formed between the first portion 18 and second portion 20 will have a high weld strength, that has been shown to be equal or greater than the type of weld strength obtained using adhesives or mechanical fasteners. Furthermore, the manufacturing time for forming the weld between the first portion 18 and second portion 20 is much shorter than the manufacturing time forming a similar weld using adhesives.
Referring to
Referring now to
The embodiment disclosed in
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
