Directional control valve

Patent metadata

Field	Value
Publication number	US-10590962-B2
Application number	US-201715594772-A
Country	US
Kind code	B2
Filing date	May 15, 2017
Priority date	May 16, 2016
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

An example valve section includes: a valve body configured to be fluidly coupled to the source and the actuator; a spool movable in the valve body intermediate the source and the actuator; a pressure compensator valve disposed upstream from the spool and configured to regulate flow received from the source, where the valve body defines (i) a first passage disposed upstream from the spool and configured to fluidly couple the pressure compensator valve to the spool, and (ii) a second passage disposed downstream from the spool and configured to fluidly couple the spool to the actuator; and a counterbalance valve disposed in the second passage downstream from the spool, where the counterbalance valve is opened to permit flow therethrough from the actuator to the spool in response to a pilot pressure derived from the first passage when the spool is shifted from a neutral position.

First claim

What is claimed is:

1. A valve section comprising:
a valve body having (i) a longitudinal bore, (ii) a fluid inlet passage, and (iii) a first workport configured to be fluidly connected to an actuator, and (iv) a second workport configured to be fluidly connected to the actuator;
a spool axially movable in the longitudinal bore to shift between (i) a neutral position at which the spool is configured to block fluid flow to the first workport, and (ii) a shifted position at which the spool is configured to permit fluid flow thereacross, wherein the valve body further includes a flow path disposed downstream from the spool and configured to fluidly couple the spool to the actuator through the first workport;
a pressure compensator valve located downstream from the fluid inlet passage and upstream from the spool and configured to regulate fluid flow from the fluid inlet passage to the spool, wherein the valve body further includes a regulated-flow fluid passage disposed downstream of the pressure compensator valve and upstream of the spool and configured to communicate fluid from the pressure compensator valve to the spool; and
a counterbalance valve disposed in the flow path, wherein the counterbalance valve includes a pilot pressure port, wherein the counterbalance valve is configured to open the flow path in response to a pilot pressure signal received at the pilot pressure port, wherein the valve body further includes a pilot pressure passage configured to communicate fluid to the pilot pressure port, and wherein
when the spool is in the neutral position, the pilot pressure passage and the pilot pressure port are disconnected from the regulated-flow passage such that the counterbalance valve blocks fluid flow from the first workport, and when the spool is in the shifted position, the spool allows fluid flow from the regulated-flow passage to the second workport, and the pilot pressure passage is connected across the spool to the regulated-flow fluid passage, such that the pilot pressure signal is communicated from, and has pressure level of fluid in, the regulated-flow fluid passage to open the counterbalance valve and allow fluid flow from the first workport through the counterbalance valve.

2. The valve section of claim 1 , wherein the counterbalance valve is configured to open the flow path across the counterbalance valve based on a pressure setting,
wherein fluid pressure in the flow path achieves a portion of the pressure setting for opening the counterbalance valve, and
wherein the pilot pressure signal at the pilot pressure port generates an additional pressure, such that the fluid pressure in the flow path and the pilot pressure signal cooperate to achieve the pressure setting and open the counterbalance valve.

3. The valve section of claim 1 , further comprising:
a free-flow check valve connected in parallel with the counterbalance valve, the free-flow check valve being configured to allow free flow of fluid passing through the spool to the first workport.

4. The valve section of claim 1 , wherein the flow path is a first flow path, the shifted position of the spool is a first shifted position, the counterbalance valve is a first counterbalance valve, the pilot pressure port is a first pilot pressure port, and the pilot pressure passage is a first pilot pressure passage, wherein the second workport is configured for supplying or returning pressurized fluid to or from the actuator via a second flow path, and wherein the valve section further comprises:
a second counterbalance valve disposed in the second flow path, the second counterbalance valve being configured to open the second flow path in response to a respective pilot pressure signal received at a second pilot pressure port via a second pilot pressure passage when the spool is shifted to a second shifted position and fluid is received from the actuator via the second workport, wherein when the spool is in the second shifted position, the second pilot pressure passage is connected across the spool to the regulated-flow fluid passage, such that the respective pilot pressure signal is communicated from the regulated-flow fluid passage downstream from the pressure compensator valve.

5. The valve section of claim 1 , wherein the shifted position is a first shifted position, wherein the valve body further includes a load-sense passage that is connected to the pressure compensator valve, wherein the spool further comprises an internal channel connected to the load-sense passage, and wherein when the spool is shifted to a second shifted position, the spool defines a first fixed orifice upstream from the internal channel, and a second fixed orifice downstream from the internal channel.

6. The valve section of claim 5 , wherein when the spool is shifted to the second shifted position:
the first fixed orifice is configured to permit a trigger amount of fluid to pass therethrough to the internal channel of the spool,
the second fixed orifice is configured to restrict the trigger amount of fluid received through the internal channel of the spool and generate a load-sense pressure in the internal channel, and
the load-sense pressure is communicated through the load-sense passage to the pressure compensator valve to generate regulated flow in the regulated-flow fluid passage.

7. The valve section of claim 6 , wherein when the spool is shifted to the second shifting position, the pilot pressure passage is connected across the spool to the regulated-flow fluid passage to provide the pilot pressure signal to the counterbalance valve and open the counterbalance valve.

8. A hydraulic valve assembly comprising:
a valve body having (i) a longitudinal bore, (ii) a fluid inlet passage, (iii) a first workport configured to be fluidly connected to a first side of an actuator, (iv) a first flow path configured to communicate fluid to and from the first side of the actuator through the first workport, (v) a second workport configured to be fluidly connected to a second side of an actuator, and (vi) a second flow path configured to communicate fluid to and from the second side of the actuator through the second workport;
a spool axially movable in the longitudinal bore to shift between (i) a neutral position at which the spool blocks fluid flow to the first workport and the second workport, (ii) a first shifted position that defines a first variable area orifice configured to meter flow from the fluid inlet passage across the spool through the first flow path to the first workport, and (iii) a second shifted position that defines a second variable area orifice configured to meter flow from the fluid inlet passage across the spool through the second flow path to the second workport;
a pressure compensator valve located downstream from the fluid inlet passage and upstream from the first and second variable area orifices to regulate flow from the fluid inlet passage to the first or second variable area orifice, and wherein the valve body further includes a regulated-flow fluid passage disposed downstream of the pressure compensator valve and upstream of the first and second variable area orifices and configured to communicate fluid from the pressure compensator valve to the first or second variable area orifice;
a first counterbalance valve disposed in the first flow path, wherein the first counterbalance valve includes a first pilot pressure port, wherein the first counterbalance valve is configured to open the first flow path in response to a pilot pressure signal received at the pilot pressure port, wherein the valve body further includes a first pilot pressure passage configured to communicate fluid to the first pilot pressure port; and
a second counterbalance valve disposed in the second flow path, wherein the secon

Assignees

• Parker Hannifin Corp

Inventors

• Coolidge Gregory Thomas
• Slattery Brian
• Boey Kurt

Classifications

• F16K11/22

  with an actuating member for each valve, e.g. interconnected to form multiple-way valves · CPC title

• F15B2211/30535

  the pressure compensating valve is arranged between pressure source and directional control valve · CPC title

• F15B13/0417

  Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves · CPC title

• F15B2211/6355

  having valve means · CPC title

• F15B2211/575

  Pilot pressure control · CPC title