JPS5872704A - Three-position changeover hydraulic actuator - Google Patents

Abstract

PURPOSE:To obtain highly reliable three changeover a positions with infallible operation in such a way that two pistons which are slidable to each other are inserted into the inside of a cylinder, and pressure operation chambers are formed at both ends by the pistons. CONSTITUTION:Pistons 3, 7 are inserted into a cylinder 5, operation chambers 10, 14 are partitioned at both ends, and an atmospheric air chamber 6 is formed in the center. A hollow rod 12 of the piston 7 is fitted around a piston rod 17 which is fitted to the piston 3, an output rod 20 is extended from the hollow rod 12 to the outside of the cylinder 5, and it is pushed and energized by a spring 4. Pressured fluid is introduced through inlet ports 8, 2 into the operation chambers 10, 14. In case where the both operation chambers 10, 14 are communicated to the atmospheric air, the both pistons 3, 7 occupy the positions as shown in the figure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention operates a clutch in three positions, for example, in a rear wheel two-axle drive vehicle, a drive switching position between one and two axles, and a position where a rear wheel difference of 171M is locked. The present invention relates to a three-position switching fluid actuator used in various cases.

An object of the present invention is to selectively supply pressurized fluid to the f moving chambers disposed at both ends of the screws 1 to 3.
The purpose of the present invention is to provide a hydraulic actuator that can be switched to two positions.For this reason, the configuration of the present invention is to provide a hydraulic actuator that can be switched to two positions. The hollow rod of the second piston is externally supported so as to be able to slide relative to the rod connected to the first piston within a predetermined range. Then, attach the first screw to the cylinder! A stopper for regulating the operating range of the first screw is provided between the second screw and the cylinder. A spring is provided to bias the second pistons in a direction to separate them from each other, and an output rod protruding outward from the atmospheric chamber is supported on the hollow rod of the second screw.

The present invention will be explained based on an example.
:The fluid pressure actuator according to the present invention has two screws inside the cylinder 5 whose both ends are closed! -n 3.7
are fitted to define working chambers 14.10 at both ends, and an atmospheric chamber 6 connected to the atmosphere through an opening 13 in the center. Screw! - The rings 3 and 7 are connected to each other by a rod 17 so as to be movable relative to each other by a fixed distance. That is, the piston 3 is attached to the left end of the rod 17 with the retaining ring 15.
It is fixed with. On the other hand, screw I/N7 is rod 17.
The boss portion 12 is slidably supported between a stepped portion 18 of the rod 17 and a retaining ring 19 fixed to the rod 17. The operating range of the piston 3 is restricted by a retaining ring 16 fixed to the inner wall of the cylinder 5.

A spring 4 is interposed between the stepped portion of the cylinder 5 and a seven flange 21 formed on the boss portion 12. Further, a rod 20 extending outward from the opening 13 is coupled to the boss portion 12, and the tip thereof is connected to a drive switching mechanism for the rear wheel axle. An inlet 2.8 is provided in each end wall of the cylinder 5 for supplying pressure fluid to the working chamber 14.10.

Note that the right end of the rod 17 is slidably supported by the end wall of the cylinder 5 and covered by the cover 9;
There is no problem even if the rod 17t1 is clipped at the retaining ring 19 portion.

Next, to explain the operation of the device of the present invention, as shown in FIG. towards fJ
The piston 3 is urged against the retaining ring 19 as a stopper to urge the rod 17 to the right, and the piston 3 is brought into contact with the retaining ring 16 as a collar. This state is the position where the zero point 20 is shifted to the farthest right.

Next, when pressurized fluid is supplied from each port 2.8 to the working chambers 14.10, the screws 1-31i remain in contact with the retaining ring 16, and the screws 1-7 resist the force of the spring 4. It then moves to the left and stops when it collides with the stepped portion 18 of the rod 17. This position becomes the first stage operation position of the rod 20.

Next, when the working chamber 14 is opened to the atmosphere and pressurized fluid is roughly supplied from the inlet 8 to the IY moving shaft 10, the rod 17 and the screw I-needle 3 are pushed leftward by the piston 7, and the rod 17 is actuated. It stops when it collides with the end wall of the chamber 14. This position becomes the second stage operation position of the rod 20.

Conversely, when returning the rod 20 to its original position, first supply pressure fluid to the working chamber 14, the rod 20 returns to the first operating position, and then only or both working chambers 14
．． When the rod 10 is released into the atmosphere, the force of the spring 4 causes the rod 2 to
0 is returned to its original position.

As mentioned above, the present invention is simply a matter of fitting two screws that can slide against each other inside a cylinder, and forming pressure working chambers at both ends with these pistons. The structure is simple, the operation is reliable, and three highly reliable switching positions can be obtained, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a fluid pressure actuator according to the present invention. 5- 2.8: Inlet 3, 7: Piston 4 Two springs 5 Niji cylinder 6: Atmospheric chamber 10, 14: Working chamber 16.19:
Retaining ring 17, 20: Rod 18: Danbeta Patent applicant 1 = Jidosha Co., Ltd. agent Patent attorney Toshio Yamamoto 61

Claims (1)

[Claims] Inside the cylinder is the first. A second screw is fitted to partition a pressure working chamber at both ends and an atmospheric chamber at the center, and the hollow rod of the second piston is fitted within a predetermined range to the rod connected to the first piston. The first piston is supported externally so as to be relatively slidable, a stopper is provided on the cylinder to restrict the operating range of the first piston, and the first piston is disposed between the second piston and the cylinder. 1ill the second piston to each other
A fluid pressure actuator for three-position switching, characterized in that a spring biased in the direction of lii is provided, and an output rod protruding outward from the atmospheric chamber is supported on a hollow rod of the second screw. .