Resistance welding of thermoplastic components

Abstract

Assembling two components (2) by means of resistance welding, wherein a heating element (3) which enables the components (2) to be welded together comprises conductive wires (301) placed in the joining region between the components (2). Preferably the conductive wires take the form of a metal mesh (301). A filler (S) is provided between the gaps of the metal mesh (301) and brought to a solid phase to as to fix their position. Preferably, a thermoset material, such as epoxy, is provided between the gaps of the metal mesh, and then cured in an oven so that the heating element (3) gains a rigid form. Subsequently, an electric current is applied to resistively heat the heating element (3) to thereby form a weld (4) between the two components (2).

Description

[0001] DESCRIPTION

[0002] RESISTANCE WELDING OF THERMOPLASTIC COMPONENTS

[0003] This invention relates to a welding workbench where parts are joined by resistance welding method.

[0004] Resistance welding is performed by joining two or more parts using heat generated by passing electric current through the parts. In the process, the parts to be joined are fixed and heat is generated in the area where the parts touch each other by passing electric current between them. Heat makes the parts viscous and enables them to be joined by applying pressure to the parts. In thermoplastic resistance welding, metal wires are placed in the welding area when prepregs are joined by resistance welding. The wires increase the heat energy of the polymers by means of the current given to the system, allowing them to melt and accelerate the welding process.

[0005] In the American patent document numbered US11618222B2 in the state of the art, a method regarding the resistance welding of thermoplastic fibre composite structural components for an aircraft or spacecraft is mentioned. The conductive elements used for joining fibre-reinforced thermoplastic components are covered with an insulating coating. By means of the insulating coating, short circuits are prevented with fibres embedded in the thermoplastic material. Conductive elements have an electrically insulating coating. The adhesion of the insulating coating to the conductive elements is higher than the adhesion of the components to the thermoplastic material. In this way, peeling of the coating during the pulling process can be prevented. In addition, the coating may contain an adhesive coating and thus prevents the components from coming out of the joining area during the pulling process.

[0006] By means of a welding workbench developed with the present invention, deformation of the wires located between the components during resistance welding of thermoplastic components, and deformation of the welding process are minimized.

[0007] Another aim of the present invention is to provide heating with wires of a rigid structure that are mechanically resistant for thermoplastic resistance welding. The welding workbench defined in the first claim and the claims dependent on this claim, which is realised to achieve the aim of the invention, comprises two components to be welded to each other by resistance welding process. In the welding process, a conductive heating element is placed between the two components to be joined. The heating element consists of multiple conductive elements placed in the joining area of the components parallel and / or perpendicular to each other. There is a resistance weld that applies electric current to the heating element. The electric current is applied to the elements by the resistance weld and transmitted to the components through the heating element. The temperature increases as a result of resistance heating. The temperature rises in the joining area of the components and after a while, it causes the components to melt. The components are welded to each other by diffusion as a result of their melting.

[0008] Said welding workbench comprises a filler that is filled and frozen in the gaps between the elements before the welding process. While the welding process is being carried out, the elements placed between the components can slip under the effect of high temperature and pressure and deform the joining area of the components. After the components are welded to each other, the elements remain permanently between the components. The filler is used between the gaps of the elements, thus fixing the position of the elements between the components while welding them.

[0009] In one embodiment of the invention, the welding workbench comprises components made of thermoplastic material. Thermoplastic components can be joined to each other by the resistance welding method. The welding of thermoplastic materials is carried out by means of heat generated by electrical resistance in joining two parts. The two components to be joined are pre-shaped and made suitable for welding. The surface of the components is cleaned, and the welding quality is increased. A conductive heating element, preferably a metal implant, is placed between the two components to provide the electrical resistance that will form the weld. An electric current is applied through the heating element. This current creates heating due to the resistance. The electrical energy causes the components and their surroundings to heat up. The thermoplastic components melt and join in the heated areas. When sufficient joining is achieved, the electric current is cut off and the joint is left to cool. In this process, pressure is applied to the joint to ensure that the components are joined more firmly and with better quality.

[0010] In one embodiment of the invention, the welding workbench comprises elements in the form of a wire grid. The wire grid forms the heating element and can conduct electric current with a certain resistance. When a wire grid, preferably in the form of a metal mesh, is used, it becomes easier to conduct electric current and distribute energy between the components.

[0011] In one embodiment of the invention, the welding workbench comprises a filler filled in the gaps between the elements. The filler consists of thermoset material and can preferably be epoxy. The filler filled in the gaps is cured in the oven. Thus, the heating element gains a rigid form. By means of its rigid form, the heating element that is located between the two components to be welded to each other will be located between the components without slipping, with its position fixed, and will be able to distribute heat homogeneously to the components. By means of the rigid heating element placed between the components to be welded to each other, the negative effects of the elements such as slipping from their positions under the effect of high temperature and pressure, displacement, and deformation of the components in the welded joint area are minimised during the welding process.

[0012] In one embodiment of the invention, the welding workbench comprises a filler in the form of a solution filled in the gaps between the elements and frozen. The solution filler is chemically compatible with the components and preferably consists of thermoplastic material and / or materials. When the thermoplastic solution that is located between the cavities of the elements is brought to the solid phase, the heating element gains a rigid form. By means of the rigid heating element, the elements are prevented from slipping during welding and the welding process is optimised.

[0013] In one embodiment of the invention, the welding workbench comprises elements surfaces of which in contact with the components are coated with nano-materials. The elements are preferably in the form of cylindrical wires and their outer surfaces are coated with nano-materials. Thus, their electrical conductivity and welding efficiency are increased.

[0014] In one embodiment of the invention, the welding workbench comprises elements in a cylindrical form interiors of which are emptied. When the interiors of the elements are emptied, the electric current accumulates on the outer surface of the elements, thus, when energy is given to the heating element by the resistance weld, the welding process is carried out more quickly and efficiently.

[0015] In one embodiment of the invention, the welding workbench comprises a resistance weld used for aircraft components. The components that are joined to each other by resistance welding and the resulting parts are within the precision and tolerance values that can be used in the aircraft.

[0016] In one embodiment of the invention, the welding workbench comprises elements in the form of a mesh. Filler is filled into the gaps between the elements. The elements filled with filler in the gaps by means of the oven are frozen and brought to solid form. The solid and rigid heating element is placed between the components on the workbench. Current is applied to the heating element by the weld. Thus, the components melt and bond to each other.

[0017] The welding workbench realised to achieve the aim of this invention is shown in the attached figures, and of these figures;

[0018] Figure 1 shows perspective view of the welding workbench.

[0019] Figure 2 shows schematic view of the heating element.

[0020] Figure 3 shows perspective view of the heating element.

[0021] The parts in the figures are numbered one by one and the equivalents of these numbers are given below.

[0022] 1 . Welding workbench

[0023] 2. Component 3. Heating element

[0024] 301 . Element

[0025] 4. Weld

[0026] (F) Filler

[0027] (S) Polymer solution

[0028] The welding workbench (1 ) comprises two components (2) joined together by means of resistance welding, a heating element (3) which enables the components (2) to be welded together, a plurality of electrically conductive elements (301 ) which are placed parallel and / or perpendicular to each other at least partially in the joining region between the components (2) and are included in the structure of the heating element (3), a weld (4) which applies electric current to the heating element (3) and thus enables the components (2) to be joined together in the joining region by means of the elements (301 ).

[0029] The welding workbench (1 ) that is the subject of the invention comprises a filler (F) which is filled into the gaps between the elements (301 ) and brought to solid phase before the welding process, and a heating element (3) which fixes the position of the elements (301) between the components (2) by means of the filler (F) while the components (2) are being welded.

[0030] There are two components (2) to be welded together. A conductive heating element (3) is placed between the two components (2) to be joined while the welding process is being carried out. The heating element (3) consists of multiple conductive elements (301 ) placed in the joining area of the components (2) parallel and / or perpendicular to each other. There is a weld (4) which applies electric current to the heating element (3). (Figurel )

[0031] Before the welding process, the filler (F) is filled into the gaps between the elements (301 ) and frozen. In this way, the elements (301 ) placed between the components (2) are prevented from slipping under the effect of high temperature and pressure and damaging the components (2) and the welding process in the joining area. (Figure 2, Figure 3) In one embodiment of the invention, the welding workbench (1 ) comprises components (2) containing thermoplastic material. Thermoplastic materials can be quickly joined by welding and enable the production of parts that meet certain design requirements. In the welding process, a predetermined area of the components (2) is heated using an electric current and the components (2) are melted and joined by means of the heat.

[0032] In one embodiment of the invention, the welding workbench (1 ) comprises elements (301 ) in the form of a wire grid. By means of the elements (301 ) in the form of a wire grid, the current applied by the weld (4) allows the heat energy to be distributed homogeneously in the joining area of the components (2).

[0033] In one embodiment of the invention, the welding workbench (1 ) comprises a thermoset material filler (F) filled and cured between the gaps of the elements (301 ), elements (301 ) and a heating element (3) consisting of the filler (F). The filler (F) is preferably epoxy. By means of the filler (F), deformations and / or welding errors that may occur during the welding process are minimised.

[0034] In one embodiment of the invention, the welding workbench (1 ) comprises a polymer solution (S) that is chemically compatible with the components (2) and is filled between the gaps of the elements (301 ), a heating element (3) formed by freezing the polymer solution (S) on the elements (301 ). By means of the filler (F) formed from the solution (S), a chemically compatible interface is provided with the components (2) and thus the welding efficiency increases and the heating element (3) gains a rigid form, thus eliminating possible slipping and / or deterioration errors in the welding process.

[0035] In one embodiment of the invention, the welding workbench (1 ) comprises elements (301 ) the conductivity of which is increased by coating the surface in contact with the components (2) with nano-materials. The welding process is carried out more efficiently by means of the elements (301 ) with increased conductivity.

[0036] In one embodiment of the invention, the welding workbench (1 ) comprises elements (301 ) that have a hollow cylinder shape and thus allow the electric current to accumulate on the outer surface. By means of the hollow cylinder-shaped elements (301 ), the heating element (3) easily applies heat to the components (2).

[0037] In one embodiment of the invention, the welding workbench (1 ) comprises the weld (4) used for the aircraft components (2). On the welding workbench (1 ), parts that comply with aviation standards and are used in this field are produced.

[0038] In one embodiment of the invention, the welding workbench (1 ) comprises:

[0039] - Filler (F) filled into the gaps between the elements (301 ) in the form of a mesh,

[0040] - Elements (301 ) and filler (F) brought together to solid phase in the oven,

[0041] - Heating element (3) made of elements (301 ) and filler (F) in solid phase, thus becoming rigid,

[0042] - Components (2) with a heating element (3) placed between them, and

[0043] - Weld (4) that applies current to the heating element (3) and thus enables the components (2) to melt and conjoin each other.

Claims

CLAIMS1. A welding workbench (1 ) comprising two components (2) joined together by means of resistance welding, a heating element (3) which enables the components (2) to be welded together, a plurality of electrically conductive elements (301 ) which are placed parallel and / or perpendicular to each other at least partially in the joining region between the components (2) and are included in the structure of the heating element (3), a weld (4) which applies electric current to the heating element (3) and thus enables the components (2) to be joined together in the joining region by means of the elements (301 ), characterised by a filler (F) which is filled into the gaps between the elements (301 ) and brought to solid phase before the welding process, and a heating element (3) which fixes the position of the elements (301 ) between the components (2) by means of the filler (F) while the components (2) are being welded.

2. A welding workbench (1 ) according to Claim 1 , characterised by components containing thermoplastic material (2).

3. An welding workbench (1 ) according to Claim 1 or Claim 2, characterised by elements (301 ) in wire grid form.

4. A welding workbench (1 ) according to any of the previous claims, characterised by a thermoset material filler (F) filled and cured between the gaps of the elements (301 ), elements (301 ) and a heating element (3) consisting of the filler (F).

5. An welding workbench (1 ) according to Claims 1 to 3, characterised by a filler (F) which is a polymer solution (S) that is chemically compatible with the components (2) and is filled between the gaps of the elements (301 ), a heating element (3) formed by freezing the polymer solution (S) on the elements (301 ).

6. A welding workbench (1 ) according to any of the previous claims, characterised by elements (301 ) the conductivity of which is increased by coating the surface in contact with the components (2) with nano-materials.

7. A welding workbench (1 ) according to any of the previous claims, characterised by elements (301 ) that have a hollow cylinder shape and thus allow the electric current to accumulate on the outer surface.

8. A welding workbench (1 ) according to any of the previous claims, characterised by weld (4) that is used for aircraft components (2).

9. A welding workbench (1 ) according to any of the previous claims, characterised by- Filler (F) filled into the gaps between the elements (301 ) in the form of a mesh,- Elements (301 ) and filler (F) brought together to solid phase in the oven,- Heating element (3) made of elements (301 ) and filler (F) in solid phase, thus becoming rigid,- Components (2) with a heating element (3) placed between them, and- Weld (4) that applies current to the heating element (3) and thus enables the components (2) to melt and conjoin each other.

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