Other dimensionless variables and parameters remain unchanged, only changing
the dimensionless B value. The theoretical and experimental results are shown in
Figs. 8.23, 8.24, and 8.26. In the actual measurement process, different B values are
obtained by changing the inlet flow coefficient C v1 only and keeping the outlet flow
coefficient C v2 unchanged. From Figs. 8.23, 8.24, 8.25 and 8.26, it can be clearly
seen that with the increase of B value, the amount of compressed gas entering the
working chamber ① of the cylinder increases, while the p 1 =p s value rises sharply,
and the piston starts to move after reaching a certain value. At this time, if the B value
is relatively small (as shown in Fig. 8.23, B ¼ 0:436), the piston with a certain speed
will continuously increase the volume of cylinder chamber ①. If the gas supply is
insufficient to keep up with the requirements of piston acceleration, the pressure p 1
decreases faster than that of B value. For this reason, the piston velocity always
Fig. 8.21 Piston motion
characteristics at different gas
state change processes (I)
Fig. 8.22 Piston motion
characteristics at different gas
state change processes (II)
8.2 Structure and Characteristics of Actuators
25