Weld Heads for Resistance Welding

Resistance Welding Equipment - Weld Heads

Weld heads play a significant role in producing high-quality resistance welds. They come in variety of shapes, sizes, and modes of force application as listed below:

Manual Weld Heads
In manual heads, the force is applied by the operator, typically with a foot pedal. They are commonly used in welding of small parts and are often limited to 20 lbs maximum force. Manual heads are well suited for welding very small parts that need careful alignment prior to welding; the parts are usually small enough that they have to be viewed through the microscope. In the hands of an experienced operator, the manual head is a robust tool. One of the limitations of manual heads is the difficulty in controlling the rate of force application and maximum force applied; both are critical for weld consistency and hence require proper welder training.
Pneumatic Heads
Air driven heads are the most common type of heads in manufacturing and automation. The force is applied by an air-cylinder and the weld head can be controlled by the welding power supply. As with manual heads, the pneumatic heads have to be set properly to control the rate of air flow and maximum pressure.
Servo Heads
Servo or motorized heads are increasing in popularity and can replace pneumatic heads in automation. An additional feature of servo heads is that they are independent of the air supply on the factory floor.
Cam Driven Heads
Weld heads that are operated by a cam are only found on high-speed machines and are used for welding contacts to bimetal strips. Such machines can run at the rate of up to 300 parts per minute.
Electromagnetic Heads
Electromagnetic heads are fancier versions of servo heads and are completely controlled by the power supply. Such heads do not have a spring and the force is directly programmed from the controller. However, the voice coil technology that they operate on has limited their application to 20 lbs of welding force.