The mini cylinder determines the push and pulls forces on the piston rod according to the amount of force required for the job. Therefore, when selecting the cylinder, the output force of the cylinder should have a little margin. If the cylinder diameter is too small, the output force will not be enough, and the cylinder will not work normally; however, if the cylinder diameter is too large, it will not only make the equipment bulky and expensive but also increase the air consumption and cause energy waste. When designing the fixture, a force-increasing mechanism should be used as much as possible to reduce the size of the cylinder.
There are intake and exhaust ports on the end cover of the mini cylinder, and some also have a buffer mechanism in the end cover. The rod side end cover is provided with a sealing ring and a dust ring to prevent air leakage from the piston rod and prevent external dust from mixing into the cylinder. There is a guide sleeve on the end cover of the rod side to improve the guiding accuracy of the cylinder, bear a small amount of lateral load on the piston rod, reduce the bending amount when the piston rod is extended, and prolong the service life of the cylinder. Guide bushes usually use sintered oil-impregnated alloy and forward-inclined copper castings. In the past, malleable cast iron was commonly used for end caps. Now, in order to reduce weight and prevent rust, aluminum alloy die-casting is often used. Microcylinders are made of brass.
The inner diameter of the cylinder barrel represents the output force of the cylinder. The piston should slide smoothly back and forth in the cylinder, and the surface roughness of the inner surface of the cylinder should reach Ra0.8um. For the steel tube cylinder, the inner surface should also be plated with hard chrome to reduce frictional resistance and wear and prevent rust. In addition to using high-carbon steel pipes, the cylinder barrels are also made of high-strength aluminum alloys and brass. Mini cylinders are available with stainless steel tubes. For cylinders with magnetic switches or those used in corrosion-resistant environments, the cylinder barrel should be made of stainless steel, aluminum alloy, or brass.
