Proporational flow control valve and pilot-operated check valve integrated therewith

Patent metadata

Field	Value
Publication number	US-11009896-B2
Application number	US-201916502249-A
Country	US
Kind code	B2
Filing date	Jul 3, 2019
Priority date	Jul 3, 2019
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

An example valve includes: a first port fluidly coupled to a chamber of an actuator; a second port fluidly coupled to a reservoir; a third port configured to provide an output pilot fluid signal and receive an input pilot fluid signal; a fourth port fluidly coupled to a source of fluid; a main poppet configured to be subjected to a first fluid force of fluid received at the first port acting on the main poppet in a proximal direction to cause the main poppet to be seated at a main poppet seat to block fluid flow to and from the first port; a piston configured to move axially to contact the main poppet; and a spool that is axially movable between a first position and a second position to operate the valve in either a pilot-operated check valve mode of operation or a proportional flow control mode of operation.

First claim

What is claimed is:

1. A valve comprising:
a plurality of ports comprising: (i) a first port configured to be fluidly coupled to a hydraulic actuator, (ii) a second port configured to be fluidly coupled to a reservoir, (iii) a third port configured to provide an output pilot fluid signal and receive an input pilot fluid signal, and (iv) a fourth port configured to be fluidly coupled to a source of fluid;
a main poppet configured to be subjected to a first fluid force of fluid received at the first port acting on the main poppet in a proximal direction to cause the main poppet to be seated at a main poppet seat to block fluid flow to and from the first port;
a piston configured to move axially to contact the main poppet; and
a spool that is axially movable between a first position and a second position, wherein the valve is configured to operate in two modes of operation: (i) a pilot-operated check valve mode of operation in which the spool is in the first position that allows the input pilot fluid signal to apply a second fluid force on the piston in a distal direction opposite the proximal direction, thereby causing the piston to unseat the main poppet off the main poppet seat to fluidly couple the first port to the second port, and (ii) a proportional flow control mode of operation in which the spool is subjected to fluid received at the fourth port to move the spool to the second position at which the spool blocks the second port and the main poppet is unseated off the main poppet seat, thereby causing the fourth port to be fluidly coupled to: (a) the first port to provide fluid flow thereto, and (b) the third port to provide the output pilot fluid signal to be communicated externally.

2. The valve of claim 1 , further comprising:
a main sleeve comprising the second port;
a housing having a cylindrical cavity in which the main sleeve is at least partially disposed, wherein the housing comprises the third port and the fourth port; and
a nose piece disposed at least partially in the main sleeve, wherein the nose piece comprises the first port and forms the main poppet seat on an interior surface of the nose piece.

3. The valve of claim 2 , wherein the nose piece further comprises a plurality of cross-holes disposed in a circumferential array about the nose piece and configured to fluidly couple (i) the first port to the second port when the spool is in the first position and the main poppet is unseated off the main poppet seat, and (ii) the fourth port to the first port when the spool is in the first position and the main poppet is unseated off the main poppet seat.

4. The valve of claim 1 , wherein the spool comprises:
a cross-hole configured to be fluidly coupled to the third port when the spool is in the first position and a channel that is fluidly coupled to the cross-hole and configured to receive a portion of the piston therein, such that the input pilot fluid signal is communicated from the third port through the cross-hole to the channel to apply the second fluid force on the piston in the distal direction.

5. The valve of claim 1 , further comprising:
a first spring configured to apply a biasing force on the main poppet in the proximal direction; and
a second spring configured to apply a respective biasing force on the piston in the proximal direction.

6. The valve of claim 1 , further comprising:
a second poppet configured to block fluid flow from the fourth port when the second poppet is seated at a poppet seat, wherein the second poppet is configured to be subjected to a third fluid force of fluid received at the fourth port acting on the second poppet in the proximal direction;
a dart disposed, at least partially, within the second poppet, wherein the dart is configured to be seated on a dart seat formed on an interior surface of the second poppet, and wherein the dart is configured to move axially within the second poppet; and
a solenoid actuator having an armature coupled to the dart such that axial motion of the armature causes the dart to move axially off the dart seat, thereby causing the third fluid force to move the second poppet to follow the dart and allow fluid received at the fourth port to push the spool toward the second position.

7. The valve of claim 6 , further comprising:
a solenoid coil; and
a pole piece, wherein when the valve is in the pilot-operated check valve mode of operation, the solenoid coil is de-energized and the second poppet blocks the fourth port, and wherein when the solenoid coil is energized, a solenoid force is applied to the armature and the dart coupled thereto, thereby causing the armature and the dart to move axially in the proximal direction toward the pole piece to operate the valve in the proportional flow control mode of operation.

8. The valve of claim 6 , further comprising:
a sleeve disposed adjacent to the spool, wherein the sleeve has a cylindrical cavity in which the second poppet is axially movable and wherein the sleeve forms the poppet seat on a respective interior surface.

9. The valve of claim 6 , wherein the second poppet includes a pilot feed orifice configured to fluidly couple the fourth port to a chamber formed within the second poppet, wherein pressurized fluid from the fourth port is communicated to the chamber through the pilot feed orifice, and wherein when the dart is unseated off the dart seat, fluid in the chamber is allowed to flow out of the chamber thereby reducing pressure level therein and allowing the second poppet to be unseated off the poppet seat by pressurized fluid of the fourth port.

10. A hydraulic system comprising:
a source of fluid;
a reservoir;
an actuator having a first chamber and a second chamber therein;
a pilot-operated check valve comprising: (i) a load port fluidly coupled to the second chamber of the actuator, and (ii) a pilot port, wherein the pilot-operated check valve is configured to allow fluid flow from the load port to the reservoir when a pilot fluid signal is received at the pilot port; and
a valve comprising: (i) a first port fluidly coupled to the first chamber of the actuator, (ii) a second port fluidly coupled to the reservoir, (iii) a third port configured to provide an output pilot fluid signal to the pilot port of the pilot-operated check valve and receive an input pilot fluid signal, and (iv) a fourth port fluidly coupled to the source of fluid, and wherein the valve further comprises:
a main poppet configured to be subjected to a first fluid force of fluid received at the first port acting on the main poppet in a proximal direction to cause the main poppet to be seated at a main poppet seat to block fluid flow to and from the first port,
a piston configured to move axially to contact the main poppet, and
a spool that is axially movable between a first position and a second position,

wherein the valve is configured to operate in two modes of operation: (i) a pilot-operated check valve mode of operation in which the spool is in the first position that allows the input pilot fluid signal to apply a second fluid force on the piston in a distal direction opposite the proximal direction, thereby causing the piston to unseat the main poppet off the main poppet seat to fluidly couple the first port to the second port, and (ii) a proportional flow control mode of operation in which the spool is subjected to fluid received at the fourth port to move the spool to the second position at which the spool blocks the second port and the main poppet is unseated off the main poppet seat, thereby causing the fourth port to be fluidly coupled to: (a) the first port to provide fluid flow to the first chamber of the actuator, and (b) the third port to provide the output pilot fluid signal to be

Assignees

• Sun Hydraulics Llc

Inventors

• Zähe Bernd
• Borja Andy

Classifications

• F15B11/042 Primary

  by means in the feed line {, i.e. "meter in"}(F15B11/046, F15B11/05 take precedence) · CPC title

• F15B2211/351

  Flow control by regulating means in feed line, i.e. meter-in control · CPC title

• F15B13/043

  with electrically-controlled pilot valves · CPC title

• F15B13/0403

  a secondary valve member sliding within the main spool, e.g. for regeneration flow (F15B13/0418 takes precedence) · CPC title

• F15B2211/3057

  having two valves, one for each port of a double-acting output member · CPC title