Three-stage hydraulic actuator and method of operating the same

Patent metadata

Field	Value
Publication number	US-10151330-B2
Application number	US-201414558232-A
Country	US
Kind code	B2
Filing date	Dec 2, 2014
Priority date	Dec 3, 2013
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

Disclosed herein is a three-stage hydraulic actuator. The three-stage hydraulic actuator includes a pressurizing chamber, a distribution chamber and an acceleration chamber. The pressurizing chamber has therein separated spaces respectively charged with compressed gas and compressed oil. The distribution chamber is provided to communicate with the pressurizing chamber and is charged with oil pressurized by the compressed oil charged into the pressurizing chamber. The acceleration chamber communicates with the distribution chamber through a distributing orifice. An acceleration piston is installed in the acceleration chamber and is moved forward when the pressurized oil is supplied from the distribution chamber to the acceleration chamber.

First claim

What is claimed is:

1. A three-stage hydraulic actuator, comprising:
a pressurizing chamber having therein separated spaces respectively charged with compressed gas and compressed oil charged into the pressurizing chamber;
a distribution chamber communicating with the pressurizing chamber, the distribution chamber being charged with oil pressurized by the compressed oil charged into the pressurizing chamber;
a slider disposed in the distribution chamber, to be slidable while an outer circumferential surface of the slider makes contact with an inner surface of the distribution chamber; and
an acceleration chamber communicating with the distribution chamber through a distributing orifice, with an acceleration piston installed in the acceleration chamber, the acceleration piston being moved forward when an oil inlet disposed perpendicular to the distribution chamber on a first end of the acceleration chamber supplies compressed oil from a starting accumulator into the acceleration chamber in a first compressed oil supplying operation which begins to open the distributing orifice, and the acceleration piston being accelerated further forward in a second compressed oil supplying operation in which the pressurized oil which is charged in the distribution chamber is supplied from the distribution chamber to the acceleration chamber through the distributing orifice when the distributing orifice begins to open as a result of the first compressed oil supplying operation, whereby a mass connected to the acceleration piston is accelerated,
wherein the distributing orifice is closed or opened by sliding of the acceleration piston, a side surface of the acceleration piston closes the distributing orifice, and an opening capacity of the distributing orifice becomes larger as the acceleration piston is moved forward,
wherein the compressed oil is discharged from the acceleration chamber through an oil outlet disposed on the acceleration chamber, at a position adjacent to the oil inlet,
wherein compressed gas is supplied from a returning accumulator into the acceleration chamber or discharged from the acceleration chamber through a returning gas port disposed on a second end of the acceleration chamber, and
wherein the pressurizing chamber comprises a plurality of pressurizing chambers arranged in parallel to each other, and lower ends of the pressurizing chambers are connected to the distribution chamber.

2. The three-stage hydraulic actuator as set forth in claim 1 , wherein another slider is installed in the pressurizing chamber so as to be slidable while an outer circumferential surface of said another slider makes contact with an inner surface of the pressurizing chamber,
wherein the compressed gas and the compressed oil are charged into the spaces separated from each other by said another slider.

3. The three-stage hydraulic actuator as set forth in claim 2 , wherein
a gas port is provided on an upper end of the pressurizing chamber so that the compressed gas is supplied into or discharged from the pressurizing chamber through the gas port,
an oil port is provided on a lower end of the pressurizing chamber so that the compressed oil is supplied into or discharged from the pressurizing chamber through the oil port, and
said another slider slides between the gas port and the oil port.

4. The three-stage hydraulic actuator as set forth in claim 2 , wherein a stopper is provided between the pressurizing chamber and the distribution chamber so that downward movement of said another slider is limited by the stopper.

5. The three-stage hydraulic actuator as set forth in claim 1 , wherein an oil port is provided on a lower end of the distribution chamber so that compressed oil is supplied into the distribution chamber through the oil port.

6. The three-stage hydraulic actuator as set forth in claim 1 , wherein the starting accumulator comprises a plurality of starting accumulators arranged in parallel to each other.

7. The three-stage hydraulic actuator as set forth in claim 1 , wherein the compressed gas comprises nitrogen gas.

8. A method of operating a three-stage hydraulic actuator comprising a pressurizing chamber having therein separated spaces respectively charged with compressed gas and compressed oil charged into the pressurizing chamber, a distribution chamber communicating with the pressurizing chamber, the distribution chamber being charged with oil pressurized by the compressed oil charged into the pressurizing chamber, the pressurizing chamber comprising a plurality of pressurizing chambers arranged in parallel to each other, and lower ends of the pressurizing chambers are connected to the distribution chamber, a slider installed in the distribution chamber so as to be slidable while an outer circumferential surface of the slider makes contact with an inner surface of the distribution chamber and an acceleration chamber communicating with the distribution chamber through a distributing orifice, with an acceleration piston installed in the acceleration chamber, the method comprising:
a gas charging operation of charging compressed gas into an upper portion of the pressurizing chamber;
a first oil charging operation of charging compressed oil into the distribution chamber;
a second oil charging operation of charging compressed oil into a lower portion of the pressurizing chamber;
an acceleration-piston driving operation of supplying, by an oil inlet disposed perpendicular to the distribution chamber on a first end of the acceleration chamber, compressed oil from a starting accumulator into the acceleration chamber and beginning to move the acceleration piston forward which begins to open the distributing orifice;
an acceleration operation of accelerating the acceleration piston further forward by supplying compressed oil charged in the distribution chamber into the acceleration chamber through the distributing orifice formed between the distribution chamber and the acceleration chamber when the distributing orifice begins to open as a result of the acceleration-piston driving operation, thus accelerating a mass connected to the acceleration piston;
an acceleration-piston returning operation of returning the acceleration piston to an initial position thereof by supplying compressed gas from a returning accumulator into the acceleration chamber through a returning gas port provided on a second end of the acceleration chamber, and discharging compressed oil from the acceleration chamber through an oil outlet provided on the acceleration chamber at a position adjacent to the oil inlet, the distributing orifice being closed or opened by sliding of the acceleration piston, and a side surface of the acceleration piston closing the distributing orifice, an opening capacity of the distributing orifice becoming larger as the acceleration piston is moved forward.

9. The method as set forth in claim 8 , wherein a pressure of the compressed gas charged in the second oil charging operation is higher than a pressure of the compressed gas charged in the gas charging operation.

10. The method as set forth in claim 8 , wherein a speed of the mass is controlled by a pressure of the compressed gas charged into the pressurizing chamber in the second oil charging operation.

Assignees

• Agency Defense Dev

Inventors

• Kim Taehyeong
• Kim Yoonjae
• Shul Changwon
• Ha Jaechang

Classifications

• F15B15/224

  having a piston which closes off fluid outlets in the cylinder bore by its own movement · CPC title

• F15B1/24 Primary

  with rigid separating means, e.g. pistons · CPC title

• F15B2211/212

  the pressure sources being accumulators · CPC title

• F15B15/221

  for accelerating the stroke, e.g. by area increase · CPC title

• G01M7/08

  Shock-testing · CPC title