Basic principle of fork cylinder

The fork type cylinder is a piston type actuator. In fact, it is mainly applicable to the on-off or metering control of valves with 90 ° angle. The fork type cylinder usually refers to a single cylinder, which is described in detail below.

There are many kinds of fork type cylinders, which have a good reputation in the market at present. The internal structure of the shift fork type cylinder is the front fork type and the gear type. The difference lies in whether the internal drive is fork drive or gear drive. See the figure below for the internal schematic diagram. The inside of the front fork type is smooth front fork and ball drive. Gear engagement! The working principle of the shift fork cylinder is that the ball drives the shift fork to slide, and then drives the shaft to rotate to realize the opening and closing of the valve! Because of its unique internal structure design, the structure is reduced and the volume can be reduced, so the speed is faster and the gas consumption is less! The fork cylinder can be set to normally open or normally closed!


There are also single-acting and double-acting fork cylinders. Double action means there is no spring design on the side, and single action means there is spring design on both sides! In this way, it can be recovered by the force of the spring when the power is cut off, and the valve can be closed. It can be used in dangerous industries such as petrochemical industry to avoid the failure of the working power supply under sudden conditions.

When using a fork type cylinder, first determine the torque of the valve. The safety value of water vapor or non-lubricating medium is increased by 30%; Non-lubricated dry gas medium increases the safety value by 50%; The particle powder medium transported by non-lubricating gas increases by 30%. For the operator, it is important to know that the safety value of clean and friction-free lubricating medium should be increased by 20%, and then find the double-acting fork cylinder according to the working pressure of the air source, and you can obtain accurate results.

In addition, some steam or non-lubricating media can increase the safety value by 25%; The safety value of non-lubricating dry gas medium is increased by 60%; Non-lubricated gas transports granular powder medium, and the safety value is improved; At this time, we need to know that for clean and friction-free lubricating media, increase the safety value by 20%, then look up the torque table of single-acting pneumatic actuator, check the end point of spring return, and then check the end point of air source working pressure.

The fork type cylinder should be greater than the spring return torque to obtain the accurate SA series pneumatic actuator model. Or the spring return "0 °" torque is the torque to close the valve, and the spring return "90 °" torque is the torque to open the valve. The torque corresponding to the air supply pressure "0 °" is the torque to close the valve.

The above article is about the basic principle of the fork cylinder introduced by the editor. If you are curious, please come and have a look. I'm sure it will not disappoint you. That's all for today's content. I hope it can help you.

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