US 6,186,172 B1 · Directional control valve apparatus

Abstract

A directional control valve system is provided in conjunction with a hydraulic actuator, using a meter-in flow control valve that is simple in structure to permit pressure fluid to be fed into a first and a second chamber of the hydraulic actuator. The directional control valve system includes a meter-in flow control valve 1 for establishing and blocking fluid communication of a pump port with an outlet port 12, a first and a second load checking valve 2 and 3 that is in fluid communication with the outlet port 12, and a meter-out flow control valve 4 for establishing fluid communication of one of a first and a second actuator port 72 and 74 at an output side of the first and second load checking valves 2 and 3 with a tank port 71, and has an arrangement that permits the first and second load checking valves 2 and 3 to be held in a closed state with pressure fluid. The system provides feeding a first and a second chamber 99a and 99b with pressure fluid from the first or second actuator port 72 or 74 notwithstanding a simple configuration of the meter-in flow control valve 1 to establish and block fluid communication between the outlet port 12 and the pump port.

Claims12

Dependent claims

A directional control valve system, characterized in that it comprises:

a meter-in flow control valve 1 for establishing and blocking fluid communication of a pump port with a single outlet port 12;
a first load checking valve 2 disposed between said outlet port 12 and a first actuator port 72 and adapted to be held in a closed state in response to an external signal;
a second load checking valve 3 disposed between said outlet port 12 and a second actuator port 74 and adapted to be held in a closed state in response to an external signal;
and
a meter-out flow control valve 4 for establishing fluid communication of one of said first actuator port 72 and said second actuator port 74 with a tank port 71, in which:
coaxially with said first checking valve 2 there is disposed a relief for a check valve 63 for permitting fluid flow from the first actuator port 72 into a relief port 59, and
coaxially with said second load checking valve 3 there is disposed a relief for a check valve 63 for permitting fluid flow from the second actuator port 74 into a relief port 59,
said relief ports 59 being connected to a single relief valve 130.

5 more elements

A directional control valve system, characterized in that it comprises:

a meter-in flow control valve 1 constructed:
to include an outlet port 12, a first pump port 13, a second pump port 16 and a meter-in spool 19 and
to be operable to block fluid communication between the ports when the meter-in spool 19 is located at a neutral position thereof and
to be operable to establish fluid communication for each of the ports when the meter-in spool 19 is located at a first position that is on one side of the neutral position as well as when the meter-in spool 19 is located at a second position that is on the other side of the neutral position,
a first load checking valve 2 disposed between said outlet port 12 and a first actuator port 72 and adapted to be held in a closed state in response to an external signal;
a second load checking valve 3 disposed between said outlet port 12 and a second actuator port 74 and adapted to be held in a closed state in response to an external signal;
and
a meter-out flow control valve 4 for establishing fluid communication of one of said first actuator port 72 and said second actuator port 74 with a tank port 71, in which:
coaxially with said first checking valve 2 there is disposed the relief for the check valve 63 for permitting fluid flow from the first actuator port 72 into a relief port 59, and
coaxially with said second load checking valve 3 there is disposed the relief for the check valve 63 for permitting fluid flow from the second actuator port 74 into a relief port 59,
said relief ports 59 being connected to a single relief valve 130.

8 more elements

A directional control valve system, comprising:

a meter-in flow control valve 1 constructed:
to include an outlet port 12, a first pump port 13, a second pump port 16 and a meter-in spool 19 and
to be operable to block fluid communication between the ports when the meter-in spool 19 is located at a neutral position thereof and
to be operable to establish fluid communication between the ports when the meter-in spool 19 is located at a first position that is on one side of the neutral position as well as when the meter-in spool 19 is located at a second position that is on the other side of the neutral position,
a first load checking valve 2 disposed between said outlet port 12 and a first actuator port 72 and adapted to be held in a closed state in response to an external signal;
a second load checking valve 3 disposed between said outlet port 12 and a second actuator port 74 and adapted to be held in a closed state in response to an external signal;
and
a meter-out flow control valve 4 for establishing fluid communication of one of said first actuator port 72 and said second actuator port 74 with a tank port 71, in which:
each of said first and second load checking valves 2 and 3 is adapted to be held in a closed state in the presence of pressure fluid acting on a pressure receiving area thereof and is adapted to operate in an open state with pressure fluid in the outlet port 12 in the absence of pressure fluid so acting on the pressure receiving area, so that
locating said meter-in spool 19 at its first position establishes fluid communication of the first pump port with the pressure receiving area 46 of the first load checking valve 2 to feed pressure fluid and
locating said meter-in spool 19 at its second position establishes fluid communication of the second pump port with the pressure receiving area 46 of the second load checking valve 3 to feed pressure fluid.

8 more elements

A directional control valve system comprising:

a meter-in flow control valve 1 constructed:
to include an outlet port 12, a first pump port 13, a second pump port 16 and a meter-in spool 19 and
to be operable to block fluid communication between the ports when the meter-in spool 19 is located at a neutral position thereof and
to be operable to establish fluid communication between the ports when the meter-in spool 19 is located at a first position that is on one side of the neutral position as well as when the meter-in spool 19 is located at a second position that is on the other side of the neutral position,
a first load checking valve 2 disposed between said outlet port 12 and a first actuator port 72 and adapted to be held in a closed state in response to an external signal;
a second load checking valve 3 disposed between said outlet port 12 and a second actuator port 74 and adapted to be held in a closed state in response to an external signal;
and
a meter-out flow control valve 4 for establishing fluid communication of one of said first actuator port 72 and said second actuator port 74 with a tank port 71, in which:
each of said first and second load checking valves 2 and 3 is adapted to be held in a closed state in the presence of pressure fluid acting on a pressure receiving area thereof and is adapted to operate in an open state with pressure fluid in the outlet port 12 in the absence of pressure fluid so acting on the pressure receiving area, there being formed:
a fluid feed passage for establishing fluid communication of the first pump port 13 with the pressure receiving area of the first load checking valve 2 and fluid communication of the second pump port 16 with the pressure receiving area of the second load checking valve 3 when said meter-in spool 19 lies at its neutral position,
a fluid feed passage for establishing fluid communication of the first pump port 13 with the pressure receiving area of the first load checking valve 2 and fluid communication of the pressure receiving area of the second load checking valve 3 with the tank port when the meter-in spool 19 lies at its first position, and
a fluid feed passage for establishing fluid communication of the second pump port 16 with the pressure receiving area of the second load checking valve 3 and fluid communication of the pressure receiving area of the first load checking valve 2 with the tank port when the meter-in spool 19 lies at its second position.

9 more elements

A directional control valve system, comprising:

a meter-in flow valve 1 constructed:
to include an outlet port 12, a first pump port 13, a second pump port 16 and a meter-in spool 19 and
to be operable to block fluid communication between the ports when the meter-in spool 19 is located at a neutral position thereof and
to be operable to establish fluid communication between the ports when the meter-in spool 19 is located at a first position that is on one side of the neutral position as well as when the meter-in spool 19 is located at a second position that is on the other side of the neutral position,
a first load checking valve 2 disposed between said outlet port 12 and a first actuator port 72 and adapted to be held in a closed state by a pump discharge pressure;
a second load checking valve 3 disposed between said outlet port 12 and a second actuator port 74 and adapted to be held in a closed state by a pump discharge pressure;
and
a meter-out flow control valve 4 for establishing fluid communication of one said first actuator port 72 and said second actuator port 74 with a tank port 71, in which:
one of said first and second load checking valves 2 and 3 and said meter-out flow control valve 4 are adapted to be switched over depending on the position of the meter-in spool of the meter-in flow control valve 1 and thereby each to be held in a closed state as well as to be operatively switched.

6 more elements

A directional control valve system, comprising:

a meter-in flow control valve 1 for establishing and blocking fluid communication of a pump port with a single outlet port 12;
a first load checking valve 2 disposed between said outlet port 12 and a first actuator port 72 and adapted to be held in a closed state in response to an external signal;
a second load checking valve 3 disposed between said outlet port 12 and a second actuator port 74 and adapted to be held in a closed state in response to an external signal;
and
a meter-out flow control valve 4 for establishing fluid communication of one of said first actuator port 72 and said second actuator port 74 with a tank port 71, in which:
said meter-in flow control valve 1 is constructed to include an outlet port 12, a first pump port 13, a second pump port 16 and a meter-in spool 19 and
to be operable to block fluid communication between the ports when the meter-in spool 19 is located at a neutral position thereof and
to be operable to establish fluid communication between the ports when the meter-in spool 19 is located at a first position that is on one side of the neutral position as well as when the meter-in spool 19 is located at a second position that is on the other side of the neutral position,
each of said first and second load checking valves 2 and 3 is adapted to be held in a closed state in the presence of pressure fluid acting on a pressure receiving area thereof and is adapted to operate in an open state with pressure fluid in the outlet port 12 in the absence of pressure fluid so acting on the pressure receiving area, so that
locating said meter-in spool 19 at its first position establishes fluid communication of the first pump port with the pressure receiving area 46 of the first load checking valve 2 to feed pressure fluid and
locating said meter-in spool 19 at its second position establishes fluid communication of the second pump port with the pressure receiving area 46 of the first load checking valve 3 to feed pressure fluid, further comprising:
a first meter-in electromagnetic proportional control valve 23 for causing the meter-in spool 19 to assume its first position,
a second meter-in electromagnetic proportional control valve 29 for causing the meter-in spool 19 to assume its second position,
a meter-out electromagnetic proportional pressure control valve 81,
a first pilot switching valve 87-1 for controllably applying an output pressure of said electromagnetic proportional pressure control valve 81 into a first pressure receiving chamber 79 to establish a first state of the meter-out flow control valve 4 in which a first actuator port 72 communicates with a drain port 71, and
a second pilot switching valve 87-2 for controllably applying an output pressure of said electromagnetic proportional pressure control valve 81 into a second pressure receiving chamber 80 to establish a second state of the meter-out flow control valve 4 In which a second actuator port 74 communicates with a drain port 71, so that
pressure fluid in the pressure receiving area of said first load checking valve 2 causes the first pilot switching valve 87-1 to assume a position of fluid communication, and
pressure fluid in the pressure receiving area of said second load checking valve 3 causes the second pilot switching valve 87-2 to assume a position of communication.

15 more elements

Dependencies are inferred from the claim text.

Directional control valve apparatus

Life of this patent

Directional control valve apparatus

Life of this patent

Abstract

Claims12