How to select a cylinder to meet application conditions

Cylinder selection

1. Type selection

Correctly select the type of cylinder according to the working requirements and conditions. If the cylinder is required to reach the end of the stroke without impact and impact noise, a buffer cylinder should be selected;if it is required to be light weight, a lightweight cylinder should be selected;if the installation space is narrow and the stroke is short, a thin cylinder can be selected;if there is a lateral load, a cylinder with a guide rod can be selected;requirements For high braking accuracy, a locking cylinder should be selected;if the piston rod is not allowed to rotate, a cylinder with rod rotation function should be selected;in high temperature environments, a heat-resistant cylinder must be selected;in corrosive environments, a corrosion-resistant cylinder must be selected. In harsh environments such as dust, it is necessary to install a dust cover on the extended end of the piston rod. When pollution-free is required, no oil supply or oil-free lubrication cylinder should be selected.





2. Installation form
Determined based on installation location, purpose of use and other factors. In general, fixed cylinders are used. When it is necessary to rotate continuously with the working mechanism (such as lathes, grinders, etc.), a rotary cylinder should be used. When the piston rod is required to move in an arc in addition to linear motion, a pin-type cylinder is selected. When there are special requirements, the corresponding special cylinder should be selected.

3. The size of the force
That is, the choice of cylinder diameter. The thrust and pulling force output by the cylinder are determined according to the load force. Generally, the cylinder force required according to the external load theoretical balance condition is selected, and different load rates are selected according to different speeds, so that the cylinder output force has a slight margin. If the cylinder diameter is too small, the output force is insufficient, but if the cylinder diameter is too large, the equipment will be bulky, cost will increase, air consumption will increase, and energy will be wasted. When designing the clamp, the force expansion mechanism should be used as much as possible to reduce the overall size of the cylinder.

4. Piston stroke
It depends on the occasion of use and the stroke of the mechanism, but generally the full stroke is not selected to prevent the piston and cylinder head from colliding. If used in a clamping mechanism, etc., a margin of 10 to 20 mm should be added based on the calculated stroke.

5. Movement speed of piston
It mainly depends on the input compressed air flow rate of the cylinder, the size of the cylinder inlet and exhaust port and the inner diameter of the duct. High-speed movement is required and a large value should be taken. The cylinder movement speed is generally 50~800㎜/s. For high-speed moving cylinders, a large inner diameter air inlet pipe should be selected;for load changes, in order to obtain a slow and steady movement speed, a throttle device or a gas-liquid damping cylinder can be used, which makes it easier to achieve speed control. When selecting a throttle valve to control the cylinder speed, please note: when the horizontally installed cylinder pushes the load, it is recommended to use the exhaust throttle speed regulation;when the vertically installed cylinder lifts the load, it is recommended to use the intake throttle speed regulation;the movement at the end of the stroke is required to be smooth To avoid impact, a cylinder with a buffer device should be used.





Cylinder selection


Procedure 1: Select the cylinder type according to the operation mode:
The cylinder operation modes include double-action, single-action spring press-in and single-action spring press-out.

Procedure 2: Select other parameters:
1. The selected cylinder bore size is determined based on the relevant load, air pressure and direction of action;
2. Select the moving distance of the workpiece in the cylinder stroke;
3. Select the cylinder series;
4. Different series of selected cylinder installation types have different installation methods, mainly including basic type, foot type, flange type, U-shaped hook, and shaft lug type;
5. Select the buffer: no buffer, rubber buffer, air buffer, hydraulic shock absorber;
6. Select the magnetic switch, which is mainly used for position detection and requires a built-in magnetic ring in the cylinder;
7. Select cylinder accessories including related joints.


The above is an introduction to how to select a cylinder to meet the application conditions. If you want to know more relevant information, please log on to Sunway Pneumatic www.diancifa.cc.