Valve with memory wire function

Abstract

A valve with a memory wire function, in which a pin actuated by a memory wire is moved against the force of a return spring to switch a movable switching element located inside a valve housing between a closed position and an open position, wherein the memory wire undergoes a change in length when current is applied, thereby effecting the switching process, and wherein the valve automatically remains in the closed position or returns to it when de-energized.

Description

1. Purpose of the invention The invention relates to a valve system that switches between two stable switching states by means of a memory wire actuator (shape memory alloy, MMI). The aim is to provide an energy-efficient, bistable, and fail-safe valve for liquids and gases in technical, industrial, building services, and safety-related applications. 2. Technical problem Conventional valves often require: • a continuous energy supply (e.g., solenoid valves), • complex mechanical drives (motors, gearboxes), • high power consumption, • low reliability in the event of a power failure. Therefore, there is a need for a valve that: • can be operated without continuous current, • has a defined fail-safe position, • requires minimal mechanical effort, • is compact and inexpensive to manufacture. 3. Technical field The invention lies in the field of fluid technology, in particular: • Valve technology, • Safety technology, • Building technology (water, gas), • Smart home systems, • Laboratory and medical technology, • Microfluidics. 4. Object of the invention The task is to provide a valve that: • operates bistably, • can be switched electrically by means of a memory wire, • assumes a defined closed position when de-energized, • requires few components, • is suitable for various media and pressure ranges. 5. Solution to the task The task is solved by a valve that: • has a ball or a movable switching element, • assumes two stable positions (A = closed, B = open), • is switched by a memory wire actuator and a return spring, • only requires electrical energy during the switching process, • automatically remains in position A when de-energized. 6. Solution approach of the invention The memory wire shortens when power is supplied and moves a pin that transfers the ball from position A to position B. When the power is switched off, the memory wire expands again, and the spring returns the pin to its starting position. Due to its position and gravity, the ball remains in position B until the next switching process occurs. Fig. 1 shows the closed state (position A). Fig. 2 shows the open state (position B). 7. Components 7.1 Mechanical Module • Valve body • Ball or movable switching element • Seat surfaces for positions A and B • Pin / slider • Return spring • Guide elements • Seals (optional) 7.2 Electrical Module • Memory wire (SMA wire) • Electrical connections (+ / -) • Control board (optional) • Thermal fuse (optional) • Position sensor (optional, e.g. Hall sensor) 8. Functionality and advantages • Bistability: Valve remains in its last position even without power. • Fail-safe: Without power → position A (closed). • Very low energy consumption: Power is only used during switching. • Silent operation: No solenoids or motors. • Compact design: Few components. • High reliability: Mechanically simple, low susceptibility to failure. • Wide range of applications: Water, gas, technical fluids. 9. Compatibility with standard products The valve can be integrated into: • Standard pipe systems (1 / 4", 3 / 8", 1 / 2", etc.) • Smart home modules • Sensor / actuator units • Safety shutdowns. 10. Summary of the advantages • Energy efficient • Bistable • Fail-safe • Simple design • Low cost • Long lifespan • Universally applicable • Low noise • Miniaturizable 11. State of the art and comparison Known solutions: • Solenoid valves (high power consumption, not bistable) • Motorized valves (complex, expensive) • Thermal valves (slow, imprecise) None of these systems combines: • Memory wire actuation • Bistability • Fail-safe closing function • Minimal energy consumption • Mechanical simplicity 12. Comparison to the state of the art / today Compared to today's systems, the invention offers: • lower power consumption, • higher reliability, • lower noise levels, • simpler construction, • better miniaturization. 13. Degree of innovation The combination of: • memory wire, • bistable ball mechanism, • spring-assisted return, • fail-safe locking logic represents a novel technical solution that is not known in the prior art. 14. Ergonomic and sustainable features • Low energy consumption → sustainable operation • Simple manufacturing → low material costs • Long lifespan → less maintenance • Quiet operation → suitable for residential areas • Compatible with smart home systems → modern integration

Claims

A valve with a memory wire function, in which a pin actuated by a memory wire is moved against the force of a return spring to switch a movable switching element located inside a valve housing between a closed position and an open position, wherein the memory wire undergoes a change in length when current is applied, thereby effecting the switching process, and wherein the valve automatically remains in the closed position or returns to it when de-energized. Valve according to claim 1, characterized in that the memory wire is designed as a shape memory alloy which shortens when heated by an electric current. Valve according to one of the preceding claims, characterized in that the switching element is held in the open position by gravity or by a mechanical detent geometry. Valve according to one of the preceding claims, characterized in that the return spring returns the pin to the starting position after the current is switched off. Valve according to one of the preceding claims, characterized in that the memory wire only requires electrical energy during the switching process. Valve according to one of the preceding claims, characterized in that the valve is bistable and remains in the last reached position without continuous current. Valve according to one of the preceding claims, characterized in that the valve is designed as a fail-safe system, wherein the closed position forms the de-energized basic position. Valve according to one of the preceding claims, characterized in that the memory wire can be controlled via a control board or an external control unit. Valve according to one of the preceding claims, characterized in that a position sensor, preferably a Hall sensor or a limit switch, is provided for detecting the position of the switching element. Valve according to one of the preceding claims, characterized in that the valve is suitable for liquids, gases or technical fluids. Valve according to one of the preceding claims, characterized in that the memory wire can be replaced by an alternative shape memory structure, for example by an FGL band or an FGL spring. Valve according to one of the preceding claims, characterized in that the valve is miniaturizable and can be used in microfluidic or medical applications. Valve according to one of the preceding claims, characterized in that the valve can be integrated into standard pipe systems. Valve according to one of the preceding claims, characterized in that the valve operates quietly because no electromagnetic or rotary actuators are used. Valve according to one of the preceding claims, characterized in that the valve can be combined with smart home or security systems.

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