Pneumatic Automatic Spot Welding Machine for Stainless Steel with Foot Pedal Operation

Introducing the Hwashi WL-CD-7K Double-Head Capacitor Discharge Spot Welder — a precision energy-storage welding system engineered for high-quality spot welding on stainless steel cookware, hardware, metal furniture, and coated materials. Featuring tandem dual-head discharge, capacitor energy storage technology, and pneumatic pressurization, this machine delivers clean, mark-free welds on both sides simultaneously — zero grinding required.

The WL-CD-7K is a double-head capacitor discharge (CD) spot welding machine designed for manufacturers who demand impeccable weld appearance and structural strength. Unlike conventional AC spot welders, the capacitor discharge principle stores energy slowly and releases it instantly — in less than 20 milliseconds — concentrating massive current through the weld point with minimal heat diffusion.

The dual-head tandem welding configuration solves a critical challenge: welding workpieces coated with paint, PET protective film, or plating without damaging the surface finish. Both heads discharge simultaneously, completing two weld points in a single stroke — doubling throughput without doubling cycle time.

With 800kg pneumatic electrode force, 4500J energy output, and digital voltage control accurate to ±1V, the WL-CD-7K delivers consistent, repeatable welds across long production runs. No water cooling required for the transformer — reducing operating costs and maintenance complexity.

The WL-CD-7K operates on the capacitor discharge welding principle — "slow charge, instant release":

1. Charging Phase — A small-power transformer charges the capacitor bank (42,000µF) to a preset voltage (0–425V adjustable), drawing minimal current from the grid
2. Discharge Phase — Once the target voltage is reached, the capacitor bank releases stored energy through the welding transformer in a burst lasting less than 20ms, producing peak currents up to thousands of amperes
3. Weld Formation — The concentrated energy melts and fuses the metal at the contact point before heat can diffuse into surrounding material, resulting in minimal deformation and discoloration
4. Dual-Head Tandem — Both welding heads fire simultaneously from opposite sides, ensuring balanced pressure and eliminating weld marks on one side of the workpiece