Selection of cylinder should be based on working requirements and conditions, the correct choice of cylinder type. Following is an example of single piston rod double-acting cylinder to introduce the selection steps of
air cylinder actuator.
(1) Cylinder diameter. The output force of the cylinder is determined according to the load force of the cylinder, and the cylinder diameter is calculated accordingly.
(2) Cylinder stroke. The stroke of cylinder is related to the occasion of use and the stroke of mechanism, but the full stroke is not usually used.
(3) Strength and Stability Calculation of Cylinder
(4) Installation form of cylinder. The installation form of cylinder depends on the installation position and use purpose. In general, the fixed cylinder is used. When it is necessary to rotate continuously with the working mechanism (such as lathe, grinder, etc.), the rotary cylinder should be selected. When the piston rod needs arc swing besides linear motion, the pin-type cylinder is selected. When there are special requirements, the corresponding special cylinder should be selected.
(5) The cushioning device of the cylinder. The speed of the piston determines whether the buffer device should be used.
(6) Magnetic switch. When the pneumatic system adopts electrical control mode, the cylinder with magnetic switch can be selected.
(7) Other requirements. If the cylinder is working in the harsh environment such as dust, it is necessary to install a dust cover at the extension end of the piston rod. When no pollution is required, oil-free or oil-free lubrication cylinders should be selected.
Key Points of Cylinder Selection
1. Determine the load F and load rate according to the load state and load movement state of the
air cylinder actuator, and then determine the use pressure P according to the principle that the use pressure should be less than 85% of the air source pressure. For single-acting cylinder, the ratio of rod diameter to cylinder diameter is 0.5, and for double-acting cylinder, the ratio of rod diameter to cylinder diameter is 0.3-0.4. According to the formula, the cylinder diameter D can be obtained, and the D value can be standardized. If D size is too large, mechanical expansion mechanism can be used.
2. According to the actual running distance of the cylinder and transmission mechanism, the stroke of the
China air cylinder actuator can be pre-selected. In order to facilitate installation and debugging, it is appropriate to increase the calculated distance by 10-20 mm, but not too long, so as to avoid increasing the gas consumption.
3. Determine the type and installation form of cylinder according to the purpose of use and installation position. Refer to relevant manuals or product samples.
4. The motion speed of piston (or cylinder) mainly depends on the diameter of intake and exhaust port of cylinder and the inner diameter of pipe. The size of connecting thread of intake and exhaust port of cylinder is used as the reference. Gas-liquid damper cylinder can be used to achieve slow and steady motion. The velocity of ordinary cylinder is about 0.5-1 m/s. Buffer cylinder or buffer cylinder should be selected for high-speed cylinder.
Maintenance and maintenance methods of cylinders:
1. When the
air cylinder actuator is repaired and reassembled, the parts must be cleaned, especially to prevent the sealing ring from being cut and damaged, and pay attention to the installation direction of the dynamic sealing ring.
2. In use, it is necessary to check regularly whether there are abnormal phenomena in all parts of the cylinder, whether there are loosening in the connecting parts, etc. The movable parts of the cylinder installed by the pin type should be regularly lubricated.
3. When the
China air cylinder actuator is not used for a long time, all the machined surfaces should be coated with rust-proof oil, and the intake and exhaust ports should be dust-proof and blocked.
4. When the cylinder is repaired and reassembled, the parts must be cleaned and the dirt must not be brought into the cylinder. In particular, it is necessary to prevent the sealing ring from being sheared, damaged and pay attention to the installation direction of the dynamic sealing ring.
5. Establish a monthly, seasonal and annual maintenance system for cylinders.
6. When the
China air cylinder actuator is working, the piston will impact the cylinder head, and the cushion seal ring of the cylinder head is a vulnerable part. If the cushion seal ring is seriously damaged, it will make the cylinder not be well sealed before the end of the journey, so the cushion plunger and cushion seal ring will lose their cushioning effect. When using cylinders for a long time, the sealing rings should be replaced and lubricating grease should be added at the same time.