Patent ID: 7392734
Filing Date: 2008-07-01
Classification: F15B

Abstract:
1. An actuator using a fluid cylinder, comprising: a fluid cylinder having a cylinder chamber and a piston slidably disposed in the cylinder chamber so as to partition the cylinder chamber into a first chamber and a second chamber; a first choke valve device disposed between a fluid pressure source and the first chamber to adjust a fluid pressure in the first chamber; and a second choke valve device disposed between the fluid pressure source and the second chamber to adjust a fluid pressure in the second chamber, each of the first choke valve device and the second choke valve device including a supply valve mechanism that permits the fluid to flow in the input direction from the fluid pressure source to the corresponding chamber and a discharge valve mechanism that permits the fluid to flow in the output direction from the chamber to the fluid pressure source, at least the discharge valve mechanism being capable of varying the opening of the valve, wherein both of the supply valve mechanism and the discharge valve mechanism are constructed within a hybrid valve mechanism that comprises a pressure control valve mechanism; a one-way valve mechanism that permits the fluid to flow only in the input direction from the fluid pressure source to the corresponding chamber side through the pressure control valve mechanism; and a two-way valve mechanism that permits the fluid to flow in the two directions; i.e., in the input direction from the fluid pressure source to the chamber through the pressure control valve mechanism and in the output direction from the chamber to the fluid pressure source, the two-way valve mechanism being arranged so that the opening of the valve can be varied depending on the pressure of the fluid supplied from the fluid pressure source.