Process and device for determining a temperature at a spot weld and process for evaluating the quality of the spot weld

US5726409A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Manfred Fortmann · Much, DE
• Volkhard Kunnemann · Engelskirchen, DE

Key dates

• Filing date: Feb 26, 1996
• Grant date: Mar 10, 1998
• Expiry date: Feb 26, 2016

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B23K11/115
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A process for determining a temperature at a spot weld formed between two parts being made of at least one first metal by at least one electrode being made of a second metal and being in contact with one of the parts, includes determining a first measurement value for a thermoelectric voltage between the electrode and the parts prior to forming the spot weld. A second measurement value is determined for a thermoelectric voltage between the electrode and the parts after forming the spot weld. The temperature is determined by taking both measurement values into account. A device for determining a temperature at the spot weld includes at least one volt meter for ascertaining a thermoelectric voltage between the electrode and the parts, corresponding to a temperature. A control unit records at least one first measurement value for the thermoelectric voltage prior to formation of a spot weld and at least one second measurement value for the thermoelectric voltage after the formation of the spot weld. A first memory stores the first measurement value and a second memory stores the second measurement value. A subtractor forms a difference between the first measurement value stored in the …