A high-frequency solenoid valve is a solenoid valve that can quickly switch its working state, and its response time is a key indicator to measure its performance.
I. High frequency solenoid valve response time range
- Extremely fast type: under ideal experimental conditions, the response time of some high-end high-frequency solenoid valves can reach 1 – 3 milliseconds. This type of ultra-fast response solenoid valve is usually used in scientific experimental equipment that requires extremely high time accuracy, such as certain high-precision physical experimental instruments, which need to accurately control the flow of gas or liquid in a very short time.
- Fast type: High-frequency solenoid valves in general industrial applications have a response time of mostly between 5 and 20 milliseconds. For example, in an automated electronic component manufacturing line, high-frequency solenoid valves used to control tiny gas flows need to be opened and closed quickly to ensure the accuracy and efficiency of the production process.
II. Factors affecting the response time of high-frequency solenoid valves
1. Solenoid system feature
Coil turns and inductance
• The more turns a coil has, the greater its inductance. According to the law of solenoid induction, inductance opposes the change of current. When the solenoid valve receives an opening signal, the larger inductance will prolong the time it takes for the current to rise enough to generate sufficient solenoid force, thereby delaying the opening action of the valve core. For example, a high-frequency solenoid valve with too many turns in the coil may have a response time several milliseconds slower than a solenoid valve with a reasonable number of turns.
• Inductive effects. To reduce the effect of inductance on response time, when designing a high-frequency solenoid valve, engineers will accurately calculate the number of coil turns based on the specific operating frequency of the solenoid valve and the required solenoid force to balance the solenoid force and response speed.
Magnetic field strength and materials
• The magnetic permeability of the core material directly affects the magnetic field strength. Materials with high magnetic permeability (such as pure iron, Permalloy, etc.) can generate a stronger magnetic field under the same current, so that the valve core is subjected to a greater electromagnetic force, thereby speeding up the movement of the valve core and shortening the response time.
• The uniformity of the magnetic field distribution is also important. If the magnetic field is unevenly distributed, the electromagnetic force on the valve core will be uneven, which may cause the valve core movement to be blocked and prolong the response time. By optimizing the magnetic circuit structure of the solenoid valve, such as adopting a reasonable core shape and magnetic pole layout, the magnetic field distribution can be made more uniform and the response speed can be improved.
2. Valve core structure and feature
Spool quality and shape
• The smaller the mass of the spool, the greater the acceleration under electromagnetic force and the shorter the response time. For example, a valve core made of lightweight alloy material has less inertia than a traditional heavier metal valve core and can move faster in response to changes in solenoid force.
• The shape of the valve core also affects its resistance to movement. A valve core designed with a reasonable shape such as a streamlined shape will experience less resistance when moving in the fluid medium, which helps to improve the response speed. For example, in some high-frequency solenoid valves that need to work in viscous liquid environments, optimizing the shape of the valve core can significantly reduce the impact of liquid resistance on response time.
Friction between valve core and valve seat
• The friction between the valve core and the valve seat is an important factor affecting the response time. Too much friction will hinder the movement of the valve core and prolong the response time. The friction coefficient between the valve core and the valve seat can be reduced by fine processing and special treatment (such as grinding, coating, etc.) on the surfaces of the valve core and the valve seat. For example, plating a layer of hard chrome or using a ceramic coating on the surface of the valve core can effectively reduce friction and speed up the movement of the valve core.
3. Working medium feature
Fluid viscosity
• When the working medium is a fluid, the viscosity of the fluid has a significant impact on the response time of the high-frequency solenoid valve. Fluids with high viscosity (e.g., heavy oils, highly concentrated glues, etc.) will create greater resistance to the movement of the spool. In this case, even if the solenoid force is sufficient, the movement of the spool is slowed down by the viscous effect of the fluid, resulting in a longer response time.
• On the contrary, low-viscosity fluids (such as water, air, etc.) have less resistance to the movement of the valve core. Which is beneficial to improving the response speed of the solenoid valve. For example, in a high frequency solenoid valve system with air as the working medium, its response time will be much faster than the same solenoid valve system with high viscosity oil as the medium.
Fluid pressure
• The pressure of the working fluid also affects the response time of the high-frequency solenoid valve. Under high pressure conditions, the valve core needs to overcome greater fluid pressure to open or close, which may increase response time. For example, in a high-frequency solenoid valve with a self-balancing pressure structure, fluid pressure can assist the valve core to return to its initial position faster during the closing process.
4. Driving circuit performance
Supply voltage and current
• Higher supply voltage can provide a larger initial current. Allowing the coil to build up sufficient electromagnetic force to drive the valve core more quickly, thereby shortening the response time. However, too high a voltage may damage the coil and other electrical components of the solenoid valve, so it is necessary to select a suitable power supply voltage based on the rated parameters of the solenoid valve.
• The output current feature of the power supply are also important. If the internal resistance of the power supply is too large and cannot provide sufficient current at the moment the solenoid valve is started, the electromagnetic force will rise slowly, affecting the response time. For example, a power supply with a small and unstable output current will significantly increase the response time of a high-frequency solenoid valve.
Response frequency of the circuit
• The response frequency of the drive circuit needs to match the operating frequency of the high-frequency solenoid valve. If the response frequency of the circuit is too low, it will not be able to provide enough energy to the solenoid valve in time to maintain high-frequency opening and closing actions, which will result in a longer response time. In some high-speed automatic control systems, a dedicated drive circuit with a high response frequency is required to cooperate with the work of the high-frequency solenoid valve to ensure that the solenoid valve can respond to the control signal quickly and accurately.
