Design of pneumatic control circuit of locking cylinder

The control circuit of the locking cylinder should be considered according to its installation form and locking method. The control circuits of several different installation forms are listed below for reference during design.​


2.1 Horizontal installation control circuit Figure 5 is a control circuit for a spring-locked cylinder installed horizontally. The locking release signal of the circuit and the two signals of the cylinder are designed to be synchronized, that is, two two-position five-way single electric control solenoid valves are used to simultaneously Controls locking, releasing and cylinder action. Therefore, this loop has high safety.






Figure 6 is a control circuit for a horizontally installed cylinder with pneumatic locking or spring-pneumatic combined locking. It uses a two-position five-way single electronically controlled solenoid valve to control the locking release action, and a three-position five-way neutral pressurized double An electronically controlled solenoid valve is used to control the movement of the cylinder. The pressure regulating valve B must be installed on the intake and exhaust pipeline of the rodless cavity of the cylinder, and a one-way valve is connected in parallel next to it.





The relationship between the adjusted pressure PA and PB when the cylinder is in equilibrium is as follows:





2.2 Vertically upward installation control circuit Figure 7 is a control circuit for a spring locking cylinder installed vertically upward. It uses a two-position three-position normally closed single electric control solenoid valve to control the locking and releasing actions, and a three-position five-way neutral position Pressurized dual electronically controlled solenoid valves control cylinder action. The electronic control system should send out the locking release signal first or at the same time as the two signals of the cylinder. If the release signal of the two-position three-way solenoid valve lags behind the signal that controls the extension of the piston rod of the cylinder, the piston rod will rush out. During actual installation, a compact two-position three-way solenoid valve can be installed directly on the air inlet with the help of a joint to keep the locking delay time as short as possible. Pressure regulating valve B must be installed on the intake and exhaust pipeline of the cylinder rod cavity, with a one-way valve connected in parallel next to it.





Figure 8 is a control circuit for a pneumatic locking or spring-pneumatic combined locking cylinder installed vertically upward. It uses a two-position five-way single electric control solenoid valve to control the locking release action, and two two-position three-way normal-way single electric control solenoid valves. The solenoid valve controls the movement of the cylinder, and the pressure regulating valve must be installed on the intake and exhaust lines of the cylinder's rod cavity.





The relationship between the adjusted pressure PA and PB when the cylinder is in equilibrium is as follows:





2.3 Vertically downward installation control circuit Figure 9 is a control circuit for a spring locking cylinder installed vertically downward. It uses a two-position three-position normally closed single electric control solenoid valve to control the locking release action, and two two-position three-position normally closed single solenoid valve to control the locking release action. The through-type single solenoid valve controls the action of the cylinder. The pressure regulating valve B must be installed on the intake and exhaust pipeline of the cylinder rodless cavity.





Figure 10 is a control circuit for air pressure locking or spring and air pressure combined locking installed vertically downward. It uses a two-position five-way single electric control solenoid valve to control the locking release action, and a three-position five-way neutral pressurized double electric solenoid valve. The control solenoid valve controls the movement of the cylinder. The pressure regulating valve B must be installed on the intake and exhaust pipeline of the cylinder rodless cavity, and a one-way valve is connected in parallel next to it.






The relationship between the adjusted pressure PA and PB when the cylinder is in equilibrium is as follows:




To sum up, the spring locking method usually uses a two-position three-way normally closed single solenoid valve to control the locking release action: air pressure locking or spring-air pressure combined locking method, usually a two-position five-way single solenoid valve is used to control the locking release action. An electronically controlled solenoid valve controls the locking and releasing action. Because the original state of this cylinder is in a locked state, no matter what locking method is used at this time, the cylinder's two-way stroke action control circuit must be designed as a dual-chamber air intake type, with a three-position five-way neutral pressurized dual electric control circuit. When the solenoid valve controls the two-way stroke action of the cylinder, the pressure regulating valve B should be installed on the pipeline between the solenoid valve and the cylinder, and a one-way valve should be connected in parallel with the pressure regulating valve. The connection direction of the one-way valve should be according to the exhaust pipe connected to the cylinder cavity. Consider air circulation. When several such cylinders are compactly installed and require simultaneous locking and release, a solenoid valve can be used to control the locking and releasing action.