Proportional fluid flow control valve configured to generate a pressure-boosted pilot fluid signal

Patent metadata

Field	Value
Publication number	US-10648488-B1
Application number	US-201916246924-A
Country	US
Kind code	B1
Filing date	Jan 14, 2019
Priority date	Dec 10, 2018
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

An example valve includes: a piston movable between a neutral position and an actuated position, wherein in the neutral position: a second port of the valve is fluidly coupled to a first port, and a third port is fluidly decoupled from the second port; a solenoid actuator sleeve movable between an unactuated state and an actuated state, wherein in the actuated state, the solenoid actuator sleeve allows pilot fluid to apply a fluid force on a piston in a distal direction; a first feedback spring; and a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move to the actuated position based on a relationship between the fluid force and the biasing force.

First claim

What is claimed is:

1. A valve comprising:
a housing comprising: (i) a first port, (ii) a second port, (iii) a third port, wherein the third port comprises a pilot cross-hole and an inlet flow cross-hole, and (iv) a fourth port;
a piston disposed in the housing and axially movable between a neutral position and an actuated position, wherein in the neutral position the second port is fluidly coupled to the first port;
a solenoid actuator sleeve that is axially movable between an unactuated state and an actuated state, wherein in the unactuated state, the solenoid actuator sleeve blocks the pilot cross-hole of the third port and allows the fourth port to be drained to the first port, and in the actuated state, the solenoid actuator sleeve is configured to allow the pilot cross-hole to be fluidly coupled to: (i) the fourth port to provide a pilot fluid signal to the fourth port, and (ii) the first port to allow pilot fluid to apply a fluid force on the piston in a distal direction, wherein the pilot fluid signal to the fourth port has a higher pressure level than the pilot fluid applying the fluid force on the piston;
a first feedback spring; and
a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move axially to the actuated position based on a relationship between the fluid force and the biasing force, and wherein in the actuated position the inlet flow cross-hole of the third port is fluidly coupled to the second port, whereas the second port is fluidly decoupled from the first port.

2. The valve of claim 1 , wherein the solenoid actuator sleeve comprises an orifice configured as a flow restriction, wherein when the solenoid actuator sleeve is in the actuated state: (i) a portion of fluid received via the pilot cross-hole flows through the orifice to a pilot chamber formed within the housing, wherein fluid in the pilot chamber applies the fluid force on the piston in the distal direction, and (ii) another portion of fluid received via the pilot cross-hole forms the pilot fluid signal and flows to the fourth port without passing through the orifice, causing pressure level of the pilot fluid signal provided to the fourth port higher than a respective pressure level of fluid in the pilot chamber.

3. The valve of claim 2 , wherein the orifice is a first orifice, and wherein the piston comprises a second orifice disposed in series with the first orifice, and wherein the second orifice fluidly couples the pilot chamber to the first port.

4. The valve of claim 1 , wherein the first feedback spring and the second feedback spring are disposed in a chamber formed within the solenoid actuator sleeve, wherein the piston comprises a proximal piston portion disposed within the chamber of the solenoid actuator sleeve, and wherein the first feedback spring and the second feedback spring cooperate to apply the biasing force in the proximal direction on the proximal piston portion of the piston.

5. The valve of claim 4 , further comprising:
a slidable spring cap that is slidably accommodated about an exterior peripheral surface of the proximal piston portion, wherein a proximal end of the first feedback spring rests against the slidable spring cap, whereas a distal end of the first feedback spring rests against an interior surface of the solenoid actuator sleeve; and
a proximal spring cap coupled to the proximal piston portion, wherein a proximal end of the second feedback spring rests against the proximal spring cap, whereas a distal end of the second feedback spring rests against the slidable spring cap.

6. The valve of claim 1 , wherein the fourth port comprises a pilot signal cross-hole, wherein the solenoid actuator sleeve comprises an annular groove formed in an exterior peripheral surface of the solenoid actuator sleeve, wherein in the unactuated state of the solenoid actuator sleeve, the annular groove is fluidly decoupled from the pilot signal cross-hole, and wherein in the actuated position of the solenoid actuator sleeve, the annular groove fluidly couples the pilot cross-hole of the third port to the pilot signal cross-hole to provide the pilot fluid signal to the fourth port.

7. The valve of claim 1 , further comprising:
a pilot chamber formed within the housing between the solenoid actuator sleeve and the piston, wherein the pilot fluid is communicated from the pilot cross-hole to the pilot chamber to apply the fluid force on the piston in the distal direction, wherein the piston comprises a main chamber therein, wherein the main chamber is fluidly coupled to the first port, wherein the piston further comprises an orifice, wherein the orifice fluidly couples the pilot chamber to the main chamber.

8. The valve of claim 7 , wherein as the solenoid actuator sleeve moves axially to the actuated state, a pilot flow path is formed to allow pilot fluid flow from the third port through the pilot cross-hole, the pilot chamber, the orifice, and the main chamber to the first port.

9. The valve of claim 1 , further comprising:
a return spring disposed about an exterior peripheral surface of the piston and configured to apply a respective biasing force on the piston in the proximal direction toward the neutral position, wherein the actuated position of the piston is an equilibrium position that is based on a respective relationship between: (i) the fluid force acting on the piston in the distal direction, and (ii) the respective biasing force of the return spring and the biasing force of the first feedback spring and the second feedbacks spring acting on the piston in the proximal direction.

10. The valve of claim 1 , further comprising:
a solenoid actuator comprising a solenoid coil, a pole piece, and an armature that is mechanically coupled to the solenoid actuator sleeve, wherein when the solenoid coil is energized, the armature and the solenoid actuator sleeve coupled thereto move axially in the proximal direction toward the pole piece, thereby compressing the first feedback spring and the second feedback spring.

11. The valve of claim 10 , wherein the solenoid actuator further comprises a solenoid tube, and wherein the solenoid tube comprises: (i) a cylindrical body, (ii) a first chamber defined within the cylindrical body and configured to receive the armature of the solenoid actuator therein, and (iii) a second chamber defined within the cylindrical body, wherein the pole piece is formed as a protrusion within the cylindrical body, wherein the pole piece is disposed between the first chamber and the second chamber, and wherein the pole piece defines a channel therethrough, such that the channel of the pole piece fluidly couples the first chamber to the second chamber.

12. The valve of claim 11 , further comprising:
a manual override actuator having: (i) a manual override piston disposed, at least partially, in the second chamber of the solenoid tube, and (ii) a pin disposed through the channel of the pole piece and through the armature, wherein a proximal end of the pin contacts the manual override piston and a distal end of the pin is coupled to the piston, wherein axial motion of the manual override piston causes the pin and the piston to move axially, thereby manually moving the piston to the actuated position.

13. The valve of claim 1 , wherein the piston comprises a piston cross-hole, and wherein in the neutral position the second port is fluidly coupled to the first port via the piston cross-hole, and wherein in the actuated position, the piston

Assignees

• Sun Hydraulics Llc

Inventors

• Zähe Bernd

Classifications

• F15B2211/7054

  Having equal piston areas · CPC title

• F15B2211/30515

  Load holding valves · CPC title

• F15B13/043

  with electrically-controlled pilot valves · CPC title

• F16K31/408

  the discharge being effected through the piston and being blockable by an electrically-actuated member making contact with the piston · CPC title

• F15B13/0422

  with manually-operated pilot valves, e.g. joysticks · CPC title