Circuit for measuring the voltage drop between the welding electrodes of a resistance welding machine
US4939335A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 25, 1989 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | May 25, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K11/309
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
What is described is a circuit for measuring the effective voltage drop at the welding position (30) between the welding electrodes (14,16) of a resistance seam welding machine. A first measuring loop (40) for measuring a first loop voltage is secured to the lower welding arm (28) close to the lower welding electrode (16) and is in communication with the upper welding electrode (14) through a sliding contact (44). The second measuring loop (60) is taken close to the welding electrodes (14,16) through the head portion of the Z-rail (12). The conductor turns (42,62) of both measuring loops, which lead to an evaluation circuit (48), are twisted together. Thus the stray effects picked up in the two measuring loops are the same. The difference between the two loop voltages formed in the evaluation circuit (48) is the effective voltage drop which is further processed in the usual manner to monitor the quality of the welding seam produced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.