Abstract
Pneumatic cylinders are used widely as low-cost actuators in various automatic assembly machines. Recently, high-speed driving of pneumatic cylinders have become an important subject of research, since these machines must be driven at high-speeds.
The authors have analyzed dynamic behavior of a pneumatic cylinder driven at a high-speed. It was found that the velocity response of the piston as well as the pressure response of the air in the cylinder chamber showed an oscillatory behavior when the pneumatic cylinder was driven at a high-speed, especially in the meter-out circuit. From an application of this oscillatory behavior, a new method of driving a pneumatic cylinder at a high-speed has been proposed. In this new driving method, the piston will be driven ideally, meaning that the response will be fast while the velocity at the end of the cylinder will be low, and the impact will be at an acceptable level.
In this report, the basic equations expressing the dynamic characteristics of pneumatic cylinders are normalized, and generalized conditions are derived for high-speed driving of the pneumatic cylinders with the proposed method. These conditions mean the generalized optimum relations between the adjustable orifice and load. From these relations, it is possible to adjust the optimum orifice areas for high-speed driving of pneumatic cylinders.
