Repair method for a workpiece of a plastics material, repair apparatus

Patent metadata

Field	Value
Publication number	US-10857741-B2
Application number	US-201916274368-A
Country	US
Kind code	B2
Filing date	Feb 13, 2019
Priority date	Aug 17, 2016
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A repair method for a workpiece of a plastics material is provided, wherein an induction heating apparatus is positioned at a repair region of the workpiece. The induction heating apparatus comprises a magnetic field generating device and a heat source. The heat source is arranged between the magnetic field generating device and the repair region. A repair material is positioned on the repair region and heated by way of the heat source. The heat source is inductively heated by the magnetic field generating device. A temperature (T) is measured by which an application of heat to the repair material by the heat source is characterized. The temperature (T) is controlled by means of a control device. The control of the temperature (T) by the control device occurs according to a temperature profile specification, which has a heating region and a working region following the heating region.

First claim

What is claimed is:

1. Repair method for a workpiece of a plastics material:
wherein an induction heating apparatus is positioned at a repair region of the workpiece;
the induction heating apparatus comprises a magnetic field generating device and a heat source;
the heating source is arranged between the magnetic field generating device and the repair region;
a repair material is positioned on the repair region, the repair material is heated by way of the heat source arranged at the repair region; and
the heat source is inductively heated by the magnetic field generating device,
wherein a temperature is measured by which an application of heat to the repair material by the heat source is characterized,
wherein the temperature is controlled by means of a control device,
wherein the control of the temperature by the control device occurs according to a temperature profile specification,
wherein the temperature profile specification has a heating region and a working region following to the heating region,
wherein the magnetic field generating device is applied with an electric current,
wherein at least one of the electric current, an electric voltage, and electric power resulting from the application of current is a controlled variable,
wherein the application of current to the magnetic field generating device is deactivated for control pause times, and
wherein the regulation of the temperature occurs according to the temperature profile specification by way of the deactivation of the application of current with the control pause times.

2. Repair method in accordance with claim 1 , wherein at least one of the electric current, the electric voltage, and the electric power is controlled by the control device in such a way that a time profile of at least one of an effective value of the electric current, an effective value of the electric voltage, and an effective value of the electric power at least approximately corresponds to a time profile of the temperature.

3. Repair method in accordance with claim 1 , wherein the temperature profile specification is at least approximately constant within the working region.

4. Repair method in accordance with claim 1 , wherein, in the case of a thermoplastic repair material, the temperature profile specification within the heating region is monotonically increasing.

5. Repair method in accordance with claim 1 , wherein, in the case of a thermosetting repair material, the temperature profile specification within the heating region is monotonically increasing in sections.

6. Repair method in accordance with claim 1 , wherein, in the case of a thermosetting repair material, the temperature profile specification has within the heating region a plateau region in which the temperature profile specification is at least approximately constant.

7. Repair method in accordance with claim 1 , wherein, in the case of a thermosetting repair material, the temperature profile specification within the heating region has an increase starting from an initial temperature, wherein the increase is followed by a plateau region in which the temperature profile specification is at least approximately constant, and wherein the plateau region is followed by a further increase.

8. Repair method in accordance with claim 1 , wherein the temperature profile specification has a cooling region following the working region, and in particular wherein the temperature profile specification within the cooling region is monotonically falling.

9. Repair method in accordance with claim 1 , wherein an underpressure region is produced between a vacuum hood of the induction heating apparatus and the workpiece.

10. Repair method in accordance with claim 9 , wherein the control of the pressure by the control device occurs according to a specified working pressure or a specified working pressure range.

11. Repair method in accordance with claim 9 , wherein a constant spacing is produced between the magnetic field generating device and the heat source.

12. Repair method in accordance with claim 1 , wherein an application of current to the magnetic field generating device is deactivated for a pause time, and wherein within this pause time at least one of the temperature is measured and a pressure is measured, and wherein at least one of the temperature measured and the pressure measured is transmitted to the control device within the pause time.

13. Repair method in accordance with claim 12 wherein the application of current is deactivated in a clock-timed manner with a clock frequency, and wherein at least one of the temperature and the pressure is measured in a clock-timed manner with said clock frequency.

14. Repair method in accordance with claim 12 , wherein at least one of the temperature and the pressure is measured temporally offset by a first wait time after the beginning of the pause time.

15. Repair method in accordance with claim 12 , wherein a measurement of at least one of the temperature and the pressure is completed temporally offset by a second wait time before the end of the pause time.

16. Repair method in accordance with claim 1 , wherein the repair material is arranged in solid form on the repair region.

17. Repair method in accordance with claim 1 , wherein a thermal insulating layer is arranged between the magnetic field generating device and the heat source.

18. Repair apparatus on a workpiece of a plastics material, comprising:
an induction heating apparatus which is arranged at the workpiece;
a repair material which is arranged on a repair region of the workpiece;
wherein the induction heating apparatus comprises a magnetic field generating device and a heat source;
wherein the heat source is arranged between the magnetic field generating device and the repair region; and
at least one temperature sensor;
wherein the at least one temperature sensor measures a temperature by which an application of heat to the repair material by the heat source is characterized,
wherein the at least one temperature sensor is signal-operatively connected to a control device,
wherein the control device has a storage device in which a temperature profile specification is stored,
wherein the control device controls the temperature, measured by the at least one temperature sensor, according to the stored temperature profile specification,
wherein the magnetic field generating device is applied with an electric current,
wherein at least one of the electric current, an electric voltage, and electric power resulting from the application of current is a controlled variable,
wherein the application of current to the magnetic field generating device is deactivated for control pause times, and
wherein the regulation of the temperature occurs according to the temperature profile specification by way of the deactivation of the application of current with the control pause times.

19. Repair apparatus in accordance with claim 18 , wherein the induction heating apparatus comprises a vacuum hood.

20. Repair apparatus in accordance with claim 18 , wherein a thermal insulating layer is arranged between the magnetic field generating device and the heat source.

Assignees

• Deutsch Zentr Luft & Raumfahrt
• Deutsches Zentrum Fuer Luft—Und Raumfahrt E V

Inventors

• Schneider Marvin
• Kaden Markus

Classifications

• B29C73/02 Primary

  using liquid or paste-like material (B29C73/16 takes precedence) · CPC title

• B29C66/91221

  of the parts to be joined · CPC title

• B29C65/1403

  characterised by the type of electromagnetic or particle radiation (B29C65/1603 takes precedence) · CPC title

• B29C73/34

  for local heating · CPC title

• B29C2035/0811

  using induction · CPC title