The contact resistance at the faying surface is influenced by the electrode force
. A higher pressure between the welding wheels demands a high current in order to achieve the same melting of the weld as compared to that for lower pressure settings.
Furthermore the cylinder pressure is responsible for the electrode force
and can be adjusted as well.
The parameters of the spot welding process like constant welding current, constant electrode force / -pressure a.s.o.
Further the cylinder pressure is responsible for the electrode force and can be adjusted as well.
Who: Huntingdon Fusion Techniques Limited (Stukeley Meadows, England) What: Robot cell resistance welder electrode force gauge
Why you should care: The electrode force gauge allows welding robots to self-test at selected intervals to make sure that force is still within predetermined levels so that weld quality does not become unacceptable and require re-work.
A programmable, low-friction air cylinder can adjust electrode force
parameters in 100-pound increments, ensuring the integrity of weld strength.
At first, the weld time and electrode force were kept constant and varying the weld current subsequently.
The result from  has shown that the increasing of the weld time and electrode force increases the tensile shearing strength, that is, weld area.
Normally, the parameters monitored for weld quality detection are classified into two types: one is the parameters related to the power input (e.g., welding current, electrode tip voltage, or dynamic resistance) of the welding process and the other is the one related to mechanical response, such as dynamic electrode displacement, applied electrode force and acoustic emission.
Figure 4 shows [Z.sub.r](t) of resistance spot welding processes creating good and bad welds when welding low carbon steel plates (specimens: two plates are welded, for each with size of 150 x 70 x 0.5 mm, welding parameters: current time 0.1s, electrode force 1.35 kN, welding current 4.5 ~ 8.0 kA) .