Induction welding process and device for parts made of composite materials

Patent metadata

Field	Value
Publication number	US-9770892-B2
Application number	US-201514623143-A
Country	US
Kind code	B2
Filing date	Feb 16, 2015
Priority date	Feb 18, 2014
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A device comprising at least one pressure generation unit and a heating unit, the heating unit comprising a two-sided inductor and being configured to generate a uniform alternating magnetic field in an assembly comprising two parts made of composite materials comprising carbon fibers embedded in a resin and a field absorber. The field absorber is configured to absorb the magnetic field and comprising a ferromagnetic material. The field absorber is arranged at the contact walls of the two parts, so as to heat them to at least a transformation temperature of the resin.

First claim

The invention claimed is:

1. An induction welding process for at least two parts made of composite materials comprising carbon fibers embedded in a resin and oriented in a main direction belonging to a principal plane, said process comprising the following steps:
forming at least one field absorber configured to absorb a magnetic field and comprising a ferromagnetic material;
forming an assembly comprising the parts to be welded and the at least one field absorber arranged at contact walls of the parts;
generating, over a predefined period, a uniform alternating magnetic field in the assembly with a two-sided inductor having two walls, in a direction of incidence, so as to heat the contact walls of the assembly up to a temperature referred to as the process temperature; and
tilting at least one of the following elements: the assembly and the two-sided inductor, so as to orient the direction of incidence of the magnetic field in relation to the principal plane at an angle other than 90° and other than zero while the walls of the two-sided inductor are parallel.

2. The process according to claim 1 , further comprising a step of applying a contact pressure on the assembly.

3. The process according to claim 2 , further comprising:
stopping the generation of the magnetic field; and,
cooling the assembly and maintaining the contact pressure, after the generation of the magnetic field in the assembly has been stopped.

4. The process according to claim 1 , wherein the process temperature is defined between a transformation temperature of the resin and a temperature above this resin transformation temperature of at least 50° C.

5. The process according to claim 1 , wherein during the generating step, the assembly is moved relative to the two-sided inductor following a displacement speed, the generation time of the magnetic field in the assembly being controlled according to the displacement speed.

6. The process of claim 1 wherein the walls each include at least one coil, and wherein a distance between the two walls is substantially equal to a radius of one of the coils.

7. An induction welding process for at least two parts made of composite materials comprising carbon fibers embedded in a resin and oriented in a main direction belonging to a principal plane, said process comprising:
forming at least one field absorber configured to absorb a magnetic field and comprising a ferromagnetic material;
forming an assembly comprising the parts to be welded and the at least one field absorber arranged at contact walls of the parts;
generating, over a predefined period, an alternating magnetic field in the assembly with two-sided inductor having two walls, in a direction of incidence, so as to heat the contact walls of the assembly up to a temperature referred to as the process temperature; and
tilting at least one of the assembly and the two-sided inductor, so as to orient the direction of incidence of the magnetic field in relation to the principal plane at an angle other than 90° and other than zero while the walls of the two-sided inductor are parallel;
stopping the generation of the magnetic field; and,
cooling the assembly, after the generation of the magnetic field in the assembly has been stopped.

8. The process according to claim 7 , wherein the process temperature is defined between a transformation temperature of the resin and a temperature above this resin transformation temperature of at least 50° C.

9. The process according to claim 7 , wherein the generation of the alternating magnetic field step, the assembly is moved relative to the two-sided inductor following a displacement speed, the generation time of the magnetic field in the assembly being controlled according to the displacement speed.

10. The process of claim 7 , wherein the magnetic field is uniform.

11. The process of claim 7 wherein the walls each include at least one coil, and wherein a distance between the two walls is substantially equal to a radius of one of the coils.

Assignees

• Airbus Operation (S A S )
• Airbus Operations Sas

Inventors

• Chotard Florian
• Collart Cyrille
• Trichet I Didier
• Fouladgar Javad

Classifications

• B29C66/91651 Primary

  by controlling or regulating the heat generated by Joule heating or induction heating · CPC title

• B32B37/06 Primary

  characterised by the heating method · CPC title

• B32B2310/00

  Treatment by energy or chemical effects · CPC title

• B29C65/3668

  characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special induction coils · CPC title

• B29C66/932

  by measuring the speed · CPC title