I. Introduction
In recent years, handheld laser welding machines have been widely used in sheet metal processing, stainless steel fabrication, and aluminum alloy welding. As their application scope continues to expand, higher requirements have been placed on equipment stability, operational safety, and welding consistency.
Within the overall system, the solenoid valve, although small in size and relatively low in cost, performs a critical control function. Its operating condition has a direct impact on welding quality and the safe operation of the entire machine.
II. Basic Concept of Solenoid Valves
A solenoid valve is an automatic control component that uses the energizing and de-energizing of an electromagnetic coil to control the on/off flow of fluids (gas or liquid).
In handheld laser welding machines, solenoid valves are primarily used to control shielding gas or auxiliary gas circuits, enabling automated and precise control of the welding process.
III. Main Functions of Solenoid Valves in Handheld Laser Welding Machines
1. Precise Control of Shielding Gas Flow
During laser welding, the weld zone requires a continuous and stable supply of shielding gas (such as argon or nitrogen) to isolate it from ambient air and prevent oxidation, discoloration, or porosity in the weld seam.
Based on welding signals, the solenoid valve automatically opens or closes the gas circuit to achieve:
Synchronous gas supply at the start of welding
Timely gas shutoff at the end of welding
Prevention of unnecessary gas consumption during idle periods
This precise control ensures welding quality while effectively reducing shielding gas usage.
2. Coordinated Control Between Welding Action and Gas Supply
Handheld laser welding machines typically receive welding commands from the torch trigger or the control system. In this process, the solenoid valve acts as an “actuator.” The control logic is as follows:
Trigger pressed → control signal output → solenoid valve opens → shielding gas flows
Trigger released → control signal interrupted → solenoid valve closes → gas flow stops
This coordinated mechanism ensures that gas is supplied before laser emission, preventing the laser from directly acting on the workpiece without protection and thereby reducing welding defects.
3. Improved Welding Stability and Consistency
Stable shielding gas flow is a key factor in achieving consistent weld formation. When used in conjunction with a pressure regulation system, the solenoid valve helps maintain uniform gas supply conditions for each welding cycle, minimizing fluctuations caused by manual operation or response delays. This contributes to:
Improved consistency of weld appearance
Reduced rework rates
Enhanced stability in batch welding operations
4. Enhanced Overall Equipment Safety
In abnormal situations such as emergency stops, system alarms, or torch disconnection, the control system can immediately cut power to the solenoid valve, causing the gas circuit to shut off instantly. This helps to:
Prevent continuous gas leakage
Avoid safety risks caused by abnormal gas flow
Work together with the laser source to form multiple safety interlock protections
IV. Impact of Solenoid Valve Selection on Welding Performance
Solenoid valves used in handheld laser welding machines generally need to meet the following requirements:
Fast response time to ensure synchronization between welding action and gas supply
Good sealing performance to prevent gas leakage and unstable pressure
High durability to withstand frequent on/off cycles
Compatibility with common shielding gases such as argon and nitrogen
If the solenoid valve quality is inadequate, issues such as delayed gas supply, weld oxidation, or excessive gas consumption may occur, indirectly affecting welding quality.
V. Conclusion
Although the solenoid valve is not a core optical component of a handheld laser welding machine, it plays an indispensable role in gas control, safety interlocking, and welding stability.
Reliable solenoid valve performance is essential for achieving high-quality laser welding and ensuring long-term stable operation of the equipment. Proper selection and regular maintenance of the solenoid valve provide a solid foundation for reliable handheld laser welding machine performance.