Method for connecting two joining elements

Patent metadata

Field	Value
Publication number	US-2019105847-A1
Application number	US-201716087492-A
Country	US
Kind code	A1
Filing date	Mar 23, 2017
Priority date	Mar 24, 2016
Publication date	Apr 11, 2019
Grant date	—

Abstract

The present invention relates to a method for connecting two joining elements, these elements being connected by means of a thermally activatable adhesive with a flat heating element arranged therein, by suitable heating of the adhesive. The invention also relates to an assembly produced in this way from two joining elements and to an arrangement designed for carrying out a corresponding method.

First claim

1 . A method for connecting two joining elements, comprising the steps of:
a) providing the two joining elements, b) providing a thermally activatable adhesive, c) providing a flat heating element, d) arranging the heating element in the adhesive, e) arranging the heating element and the adhesive between the joining elements, f) heating the adhesive by applying electrical power to the heating element while at the same time measuring the temperature of the adhesive, the extent to which electrical power is applied to the heating element being controlled in dependence on the temperature measured, the measurement of the temperature of the adhesive being performed by determining the resistance of the heating element.

2 . The method as claimed in claim 1 , wherein the resistance is determined by means of measuring the voltage and current intensity, with a time difference between the measurement of the current intensity and the measurement of the voltage of ≤10 ms, preferably ≤1 ms, more preferably ≤100 μs and particularly preferably ≤10 μs.

3 . The method as claimed in claim 1 , wherein the control of the electrical power is performed in dependence on a temperature-resistance dataset, which comprises data materially and geometrically specific to the heating element used.

4 . The method as claimed in claim 3 , wherein the geometry-dependent characteristic data of the heating element required for the temperature calculation are determined by means of an automatic resistance measurement, before or during the heating.

5 . The method as claimed in claim 1 , wherein the control of the electrical power is performed in dependence on a time-temperature curve.

6 . The method as claimed in claim 1 , wherein the control of the electrical power takes place with a maximum delay of ≤1000 ms, preferably ≤500 ms, more preferably ≤250 ms.

7 . The method as claimed in claim 1 , wherein the adhesive is solid in the non-activated state.

8 . The method as claimed in claim 1 , wherein the adhesive is a thermoset in the cured state.

9 . The method as claimed in claim 1 , wherein at least one of the joining elements, preferably both joining elements, is/are a plastic or consists of other non-metallic materials.

10 . The method as claimed in claim 1 , wherein at least one joining element is selected from the group consisting of bolts, angles, plates, holders and fittings.

11 . An arrangement designed for carrying out the method as claimed in claim 1 , comprising
(i) contacts for contacting a heating element for applying electrical power, (ii) a thermally activatable adhesive in which a flat heating element is arranged and (iii) a control unit for controlling the electrical power in dependence on the temperature of the adhesive.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Lühring Andreas
• Kleemeier Malte

Classifications

• B29C65/8215

  Tensile tests · CPC title

• B29C66/91651

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

• C09J163/00

  Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins · CPC title

• F16B11/006

  by gluing (gluing of plastics material B29C65/48) · CPC title

• C09J5/06

  involving heating of the applied adhesive · CPC title