What is squeeze time in resistance welding?

What is squeeze time in resistance welding?

Squeeze Time is the time interval between the initial application of the electrode force on the work and the first application of current. Squeeze time is necessary to delay the weld current until electrode force has built up to the desired level.

What is squeeze time?

Squeeze time is the period of time programmed into the weld controller, typically between the command to close the electrode and the beginning of weld time (sometimes referred to as the programmed squeeze time).

What is the difference between hold time and squeeze time?

Initially, during the squeeze time, the electrodes clamp the sheets to be welded under the action of the electrode force, preset by the welding engineer. The hold time is the time during which the electrode force is maintained after the welding current flow ends, its purpose being to consolidate the weld.

What is squeeze type resistance spot welding?

To explain it just a bit deeper it is a weld that typically bonds two or more panels/parts together by creating an electrical resistance between two electrodes. The electrodes don’t touch, they attempt to pass current through the location, thereby heating the metals to a point of welding them together.

What is off time in spot welding?

Off Time. In Resistance Welding, Off Time denotes the amount of time in which the Electrodes open after the Welding Sequence and remain open prior to the welding sequence automatically repeating.

How long does it take to weld one spot?

Forcing a large current through the spot will melt the metal and form the weld. The attractive feature of spot welding is that much energy can be delivered to the spot in a very short time (approximately 10–100 milliseconds).

What is the meaning of squeeze in?

: to find time for (someone or something) I can squeeze you in after my one o’clock appointment. The teacher tried to squeeze in a few more lessons before school vacation.

What is meant by weld time?

Definition. For a typical weld, weld time is the amount of time welding current flows through the metal. Weld time is long when it exceeds applicable specifications.

What is hold time in welding?

The duration of electrode force application at the end of the welding cycle to permit solidification of the weld.

Why is hold time required?

In the meantime it is necessary to maintain a stable value at the input to ensure a stable value at node W, which in turn translates to the output, defining the reason for hold time within a flop. A finite positive setup time always occurs, however hold time can be positive, zero, or even negative.

What does Strsw stand for?

When performing squeeze type resistance spot welds (STRSW), it is always important to make sure the tips are properly dressed. Failure to do so can result in an inferior weld.

Why is squeeze time important in resistance welding?

Short squeeze time can lead to expulsion and the electrodes being damaged, running hot, inconsistent nuggets and erratic weld quality. Long squeeze time extends the total weld time and could mean fewer parts per shift. Selection of the proper squeeze time is important for the efficient production of quality parts.

What should the current be for resistance welding?

The optimum value of these parameters varies with the type of metal and its thickness. For commonly used low-carbon steel 1/16″ thick, a typical value of current is 10,000 amps, for a time of 1/4 second, and 600 pounds electrode force.

Why do you need a long squeeze time?

Long squeeze time extends the total weld time and could mean fewer parts per shift. Selection of the proper squeeze time is important for the efficient production of quality parts. Every welding machine or weld gun operates differently be it powered by pneumatic cylinders or servo.