3-position operating actuator and permanent-magnet eddy-current deceleration device
View Patent ↗A braking actuator uses a single cylinder without using a spring to achieve a 3-position operation. A partition plate and an intermediate check plate are affixed within a cylinder at suitable intervals in the axial direction. Inserted movably in the axial direction of the cylinder are a first piston disposed between a pressing lid and the intermediate check plate, a second piston disposed between the intermediate check plate and the partition plate, and a third piston disposed between the partition plate and a pressing lid. A rod which is axially movable within the cylinder has a base end attached to the third piston and a tip end which extends outside from the cylinder through the partition plate, the second piston, the intermediate check plate, the first piston, and the pressing lid. A stopper affixed to a middle portion of the rod moves the first piston or the second piston.
1. A 3-position operating actuator comprising:
a cylinder having both ends closed by pressing lids which are integral with or separate from the cylinder;
a partition plate and an intermediate check plate affixed within the cylinder at suitable intervals in an axial direction;
a first piston axially movable within the cylinder between one of the pressing lids and the intermediate check plate;
a second piston axially movable within the cylinder between the intermediate check plate and the partition plate;
a third piston axially movable within the cylinder between the partition plate and the other of the pressing lids;
a rod axially movable within the cylinder, wherein the rod has a base end attached to the third piston and a tip end which extends outside from the cylinder through the partition plate, the second piston, the intermediate check plate, the first piston, and one of the pressing lids; and
a stopper affixed to a middle portion of the rod to move the first piston or the second piston when the rod moves.
2. The 3-position operating actuator according to claim 1 , further comprising:
a first passageway formed in the other of the pressing lids for supplying or discharging a fluid between the other of the pressing lids and the third piston;
a second passageway, a third passageway, and a fourth passageway formed in an outer peripheral wall of the cylinder for supplying or discharging a fluid between the third piston and the partition plate, between the partition plate and the second piston, and between one of the pressing lids and the first piston; and
a nozzle installed in the cylinder for releasing to atmosphere a fluid inside a space formed by the intermediate check plate and the second piston.
3. A 3-position operating actuator according to claim 2 , further comprising electromagnetic valves directly connected to the other of the pressing lids.
4. A 3-position operating actuator according to claim 3 , wherein the electromagnetic valves comprise a normally closed, single-acting electromagnetic valve having two ports and a normally open, single-acting electromagnetic valve having two ports.
5. A permanent-magnet eddy-current deceleration device comprising the 3-position operating actuator according to claim 1 used as an actuator of a braking ON-OFF switching device.
6. The permanent-magnet eddy-current deceleration device according to claim 5 , wherein the actuator and a magnetic rotation mechanism are connected via a lever.