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CN-116324186-B - Direction, flow control valve and hydraulic system

CN116324186BCN 116324186 BCN116324186 BCN 116324186BCN-116324186-B

Abstract

The directional and flow control valve (1) comprises a housing (2) having a pump port (11), a first supply/discharge port (12), a second supply/discharge port (13), and a tank port (14), and having a first pilot chamber (41), a second pilot chamber (45), and a third pilot chamber (25) formed therein, and a first valve element (5) and a second valve element (6) that are independent of each other. The first valve body (5) has a first end surface (5 a) facing the first pilot chamber (41) and a second end surface (5 b) facing the third pilot chamber (25), and the second valve body (6) has a first end surface (6 a) facing the second pilot chamber (45) and a second end surface (6 b) facing the third pilot chamber (25). The first valve element (5) and the second valve element (6) respectively communicate the first supply/discharge port (12) and the second supply/discharge port (13) with one of the pump port (11) and the tank port (14) and the other.

Inventors

  • CHIKATI TEHIRO
  • Muraoka Etae
  • TOUDE YOSHIYUKI

Assignees

  • 川崎重工业株式会社

Dates

Publication Date
20260505
Application Date
20211011
Priority Date
20201013

Claims (12)

  1. 1. A directional and flow control valve is provided with: a housing having a pump port, a first supply/discharge port, a second supply/discharge port, and a tank port, and forming a first pilot chamber, a second pilot chamber, and a third pilot chamber therein; A first valve body having a first end surface facing the first pilot chamber and a second end surface facing the third pilot chamber, and blocking the first supply/discharge port from both the pump port and the tank port or allowing the first supply/discharge port to communicate with either one of the pump port and the tank port, and A second valve element independent of the first valve element, the second valve element having a first end surface facing the second pilot chamber and a second end surface facing the third pilot chamber, the second valve element blocking the second supply/discharge port from both the pump port and the tank port or communicating the second supply/discharge port with the other of the pump port and the tank port, The first supply and discharge port and the second supply and discharge port are used for being connected with a head side chamber and a rod side chamber of the same hydraulic cylinder, The housing includes a housing body having a through hole in which the first valve element and the second valve element are slidably inserted, The third pilot chamber is a portion between the first spool and the second spool in the through hole, A first inflow annular groove and a second inflow annular groove recessed radially outward from the through hole are formed in the housing main body on both sides of the third pilot chamber, the first inflow annular groove and the second inflow annular groove being connected to the pump port, The first valve core includes a land portion constituting the second end face, The second valve core includes a land portion constituting the second end face, The casing body is provided with a first leakage annular groove recessed radially outward from the through hole between the first inflow annular groove and the third pilot chamber, and the first leakage annular groove is connected to the tank port or the discharge passage.
  2. 2. The directional, flow control valve of claim 1 wherein, The casing body is provided with a second leakage annular groove recessed radially outward from the through hole between the second inflow annular groove and the third pilot chamber, and the second leakage annular groove is connected to the tank port or the discharge passage.
  3. 3. The directional, flow control valve of claim 1 or 2, characterized in that, The case body is formed with a second outflow annular groove or a second discharge annular groove recessed radially outward from the through hole on the opposite side of the second inflow annular groove from the first inflow annular groove, the second outflow annular groove being connected to the tank port, The second valve body is provided with a leakage path extending from a position on the outer peripheral surface of the land between the second inflow annular groove and the second end surface to the second outflow annular groove or the second discharge annular groove.
  4. 4. The directional, flow control valve of claim 1 or 2, characterized in that, A first outflow annular groove and a second outflow annular groove or a first discharge annular groove and a second discharge annular groove recessed radially outward from the through hole are formed in the housing main body outside the first inflow annular groove and the second inflow annular groove, the first outflow annular groove and the second outflow annular groove being connected to the tank port, The first valve body is provided with a leakage path extending from a position on the outer peripheral surface of the land between the first inflow annular groove and the second end surface to the first outflow annular groove or the first discharge annular groove, The second valve body is provided with a leakage path extending from a position on the outer peripheral surface of the land between the second inflow annular groove and the second end surface to the second outflow annular groove or the second discharge annular groove.
  5. 5. The directional, flow control valve of claim 1 or 2, characterized in that, And a central annular groove recessed radially outward from the through hole is formed in the housing main body between the first valve element and the second valve element, and a guide passage is formed so as to open to the central annular groove.
  6. 6. The directional, flow control valve of claim 1 or 2, characterized in that, A pilot passage opening to the through hole is formed between the first valve element and the second valve element in the housing main body, At least one of a portion adjacent to the second end surface in the land of the first valve element and a portion adjacent to the second end surface in the land of the second valve element is reduced in diameter.
  7. 7. The directional, flow control valve of claim 1 or 2, characterized in that, The first pilot chamber is provided with a first spring for applying a force to the first valve body to maintain the first valve body at a neutral position where the first supply/discharge port is blocked from both the pump port and the tank port, The second pilot chamber is provided with a second spring for applying a force to maintain the second spool in a neutral position, which is a position to isolate the second supply and discharge port from both the pump port and the tank port, to the second spool.
  8. 8. A hydraulic system is provided with: A directional, flow control valve as claimed in any one of claims 1 to 7; A hydraulic pump connected to the pump port of the directional, flow control valve; The hydraulic actuator is connected with the first supply and discharge port and the second supply and discharge port of the direction and flow control valve and works in a first direction and a second direction; A first electromagnetic proportional valve that adjusts the direction and the pressure of the first pilot chamber of the flow control valve; a second electromagnetic proportional valve that adjusts the direction and the pressure of the second pilot chamber of the flow control valve; A third electromagnetic proportional valve for regulating the pressure of the third pilot chamber of the flow control valve, and And a control device for controlling the first electromagnetic proportional valve, the second electromagnetic proportional valve and the third electromagnetic proportional valve.
  9. 9. The hydraulic system of claim 8, wherein the hydraulic system is configured to, The control device communicates a secondary pressure port of the third electromagnetic proportional valve with a tank port when the hydraulic actuator is operated in the first direction, causes the first electromagnetic proportional valve to output a first secondary pressure, causes the second electromagnetic proportional valve to output a second secondary pressure, and causes the third electromagnetic proportional valve to output a third secondary pressure when the hydraulic actuator is operated in the second direction.
  10. 10. The hydraulic system of claim 9, wherein the hydraulic system is configured to, The control device causes the first secondary pressure and the second secondary pressure to be different when the hydraulic actuator is operated in the first direction.
  11. 11. The hydraulic system of claim 9 or 10, wherein the hydraulic system is configured to, When the hydraulic actuator is operated in the second direction, the control device communicates the secondary pressure port of the first electromagnetic proportional valve with the tank port, and communicates the secondary pressure port of the second electromagnetic proportional valve with the tank port.
  12. 12. The hydraulic system of claim 9 or 10, wherein the hydraulic system is configured to, The control device may be configured to, when the hydraulic actuator is operated in the second direction, cause a secondary pressure port of one of the first electromagnetic proportional valve and the second electromagnetic proportional valve to communicate with a tank port, and when the other of the first electromagnetic proportional valve and the second electromagnetic proportional valve is the first electromagnetic proportional valve, cause the first electromagnetic proportional valve to output a first secondary pressure smaller than the third secondary pressure, and when the other of the first electromagnetic proportional valve and the second electromagnetic proportional valve is the second electromagnetic proportional valve, cause the second electromagnetic proportional valve to output a second secondary pressure smaller than the third secondary pressure.

Description

Direction, flow control valve and hydraulic system Technical Field The present disclosure relates to a directional, flow control valve for a bi-directional working hydraulic actuator and a hydraulic system including the directional, flow control valve. Background Among hydraulic actuators that operate bi-directionally, directional, flow control valves that include multiple spools are used. Each valve body opens and closes between specific ports, and the opening area between the ports (i.e., the flow rate of the working fluid) changes according to the amount of movement of the valve body. For example, as shown in fig. 11, patent document 1 discloses a directional flow control valve 100 (referred to as "independent metering valve (METERING VALVE)" in patent document 1) disposed between a hydraulic cylinder 120 and a hydraulic pump 110. As shown in fig. 11, the directional, flow control valve 100 has a pump port 101, a pair of supply and discharge ports 102, 103, and a tank port 104. The directional flow control valve 100 includes a first valve body 130 that opens and closes between the pump port 101 and the supply/discharge port 102, a second valve body 140 that opens and closes between the supply/discharge port 102 and the tank port 104, a third valve body 150 that opens and closes between the pump port 101 and the supply/discharge port 103, and a fourth valve body 160 that opens and closes between the supply/discharge port 103 and the tank port 104. With this configuration, independent metering (metering) control can be performed on the metering (meter-in) side or the metering (meter-out) side, regardless of the direction in which the hydraulic cylinder 120 is operated. Prior art literature: Patent literature: patent document 1 Japanese patent laid-open No. 11-241702. Disclosure of Invention Problems to be solved by the invention: In patent document 1, "electric hydraulic displacement control" is described with respect to the first to fourth spools 130 to 160. It is presumed that this means converting the electric signal into the pilot pressure, and the spool is displaced by the pilot pressure. In such a configuration, an electromagnetic proportional valve is generally used. That is, the direction of patent document 1 and the flow control valve 100 require four electromagnetic proportional valves. The electromagnetic proportional valve may be incorporated into the direction/flow control valve 100, or may be connected to the direction/flow control valve 100 via a pipe. In the direction of patent document 1, since four spools are used in the flow control valve 100, it is desirable to reduce the number of spools. This point contemplates integrating the first spool 130 and the second spool 140, and integrating the third spool 150 and the fourth spool 160. Even with such a configuration, independent metering control is possible. But the number of electromagnetic proportional valves required is still four. It is therefore an object of the present disclosure to provide a directional, flow control valve that can be independently metering controlled with fewer electromagnetic proportional valves and a hydraulic system including the directional, flow control valve. Means for solving the problems: In order to solve the above problems, the direction and flow control valve of the present disclosure is characterized by comprising a housing having a pump port, a first supply/discharge port, a second supply/discharge port, and a tank port, wherein a first pilot chamber, a second pilot chamber, and a third pilot chamber are formed therein, a first valve element having a first end surface facing the first pilot chamber and a second end surface facing the third pilot chamber, wherein the first supply/discharge port is blocked from both the pump port and the tank port, or wherein the first supply/discharge port is communicated with either one of the pump port and the tank port, and a second valve element independent of the first valve element, wherein the second valve element has a first end surface facing the second pilot chamber and a second end surface facing the third pilot chamber, and wherein the second supply/discharge port is blocked from both the pump port and the tank port, or wherein the second supply/discharge port is communicated with the other of the pump port and the tank port. According to the above configuration, the hydraulic actuator connected to the first supply and discharge port and the second supply and discharge port can be operated in both directions by using the two valve elements, i.e., the first valve element and the second valve element. Further, since the first valve element and the second valve element are independent of each other, the first valve element can be moved according to the pressure difference between the first pilot chamber and the third pilot chamber, and the second valve element can be moved according to the pressure difference between the second pilot chamber and the third pilot c