Air Cylinders’ Drive System Full Stroke Time & Stroke End Velocity Glossary of Terms: Cylinder’s Motion Characteristics (1) Piston start-up time It is the time between the solenoid valve is energized (de-energized) and the piston (rod) of a cylinder starts traveling. The accurate judgement is done by the start-up of acceleration curve. (2) Full stroke time It is the time between the solenoid valve is energized (de-energized) and the piston (rod) of a cylinder is reached at the stroke end. (3) 90% force time It is the time between the solenoid valve is energized (de-energized) and the cylinder output is reached at 90% of the theoretical output. (4) Mean velocity Values which devided stroke by “full stroke time”. In the sequence or diaphragm, it is used as a substituting expression for “full stroke time”. (5) Max. velocity It is the maximum values of the piston velocity which occurs during the stroke. In the case of Graph (1), it will be the same values as “stroke end velocity”. Like Graph (2), when lurching or stick-slipping occurs, it shows substantially larger values. (6) Stroke end velocity It is the piston velocity when the piston (rod) of a cylinder is reached at the stroke end. In the case of a cylinder with adjustable cushion, it says the piston velocity at the cushion entrance. It is used for judging the cushion capability and selecting the buffer mechanism. (7) Impact velocity It is the piston velocity when the piston (rod) of a cylinder is collided with the external stopper at the stroke end or arbitrary position. (Reference) Balancing velocity: If a cylinder having enough longer stroke is driven by meter-out, the latter half of a stroke will be in an uniform motion. Regardless of the supply pressure or a load, the piston speed for this time will be dependent only on the effective area S [mm2] of the exhaust circuit and the piston area A [mm2] . Balancing velocity = 1.9 x 105 x (S/A) [mm/s] is estimated with this formula. Full stroke time Piston start-up time Acceleration Speed Time 0 0 90% force time Exhaust chamber pressure Supply chamber pressure Stroke Graph (1) Note) These definitions are harmonized with SMC “Model Selection Software”. Stroke end velocity Full stroke time Piston start-up time Acceleration Speed Time 0 0 0 Max. speed 90% force time Exhaust chamber pressure Supply chamber pressure Stroke Graph (2) Stroke end velocity Front matter 39