Optimizing the electrical contact points of a self-locking push switch is crucial for reducing electrical resistance and improving conductivity. This requires coordinated improvements across multiple dimensions, including material selection, structural design, surface treatment, and manufacturing processes, to achieve a balance between contact stability and low resistance.
Material selection is the foundation for optimizing contact points. Contact points must utilize metal materials with high conductivity and low resistivity, such as silver alloys or silver-plated copper-based materials. Silver, due to its excellent conductivity and oxidation resistance, is an ideal material for contact points, but its cost is relatively high. Therefore, silver-nickel alloys or silver-cadmium oxide composites are often used to maintain conductivity while reducing costs. Furthermore, silver plating of copper-based materials can further enhance surface conductivity and reduce contact resistance. The proper balance between material hardness and elasticity is also crucial. Excessively soft materials are prone to wear, while excessively hard materials can lead to poor contact. Optimal performance requires composition adjustment.
Structural design directly impacts the contact area and pressure distribution of the contact points. Self-locking push switches typically utilize dual or multi-point contact designs. This increases the effective contact area, reducing the current density per unit area and thus reducing resistance. For example, a curved contact surface design allows the contacts to create a larger contact area when pressed, while maintaining stable contact pressure through a resilient structure. Furthermore, the spacing and arrangement of the contacts should be optimized to prevent loosening due to vibration or temperature fluctuations, ensuring long-term reliability.
Surface treatment is a key measure for reducing contact resistance. The contact surface requires precision polishing or electroplating to eliminate microscopic irregularities and reduce the actual contact resistance. Gold or silver plating creates a dense conductive layer, preventing oxidation corrosion and reducing surface roughness. For high-frequency applications, chemical deposition or physical vapor deposition techniques can be used to create a more uniform and thinner coating, further improving conductivity. Furthermore, the contact surface can be coated with a conductive lubricant to reduce friction and wear, maintaining a low resistance state.
The manufacturing process impacts contact performance throughout its lifecycle. Precision stamping or injection molding ensures dimensional accuracy and shape consistency of the contacts, preventing poor contact due to machining errors. Automated assembly reduces manual intervention and ensures a precise fit between the contacts and components such as the spring and housing. For example, high-precision mold control can achieve contact point flatness tolerances down to the micron level, thereby improving contact stability. Furthermore, heat treatment eliminates internal material stress, enhancing the contact's elasticity and fatigue resistance.
Spring design is crucial for maintaining stable contact pressure. The spring in a self-locking push switch must provide a moderate positive force to ensure a tight fit while preventing material fatigue caused by excessive pressure. Wave springs or shaped springs are often used in contact point support structures due to their uniform elasticity and long life. The selection of spring materials must also balance strength and elasticity, such as stainless steel or phosphor bronze. Heat treatment can be used to optimize their mechanical properties to ensure stable contact pressure even under long-term vibration or shock conditions.
Environmental compatibility is crucial for ensuring long-term contact reliability. Contacts must be corrosion-resistant, high-temperature, and low-temperature resistant to adapt to diverse usage scenarios. For example, in humid or salt-spray environments, the contact surface requires a sealed structure or anti-corrosion coating to prevent oxidation corrosion and increased resistance. For high-temperature applications, the contact material must have a high melting point and thermal stability to prevent loosening due to thermal expansion. In addition, the design of contact points needs to take into account the changes in material dimensions caused by temperature changes, and ensure contact stability by reserving gaps or adopting elastic compensation structures.
