Patent ID: 9115728
Filing Date: 2015-08-25
Classification: F15B,Y10T

Abstract:
1. A directional control valve device comprising: a first directional control valve configured to be switched between a first supply position and a first discharge position, wherein in said first supply position a pressure port is arranged to communicate with a first supply/discharge port and in said first discharge position a return port is arranged to communicate with the first supply/discharge port; a second directional control valve configured to be switched between a second discharge position and a second supply position, wherein in said second discharge position the return port is arranged to communicate with a second supply/discharge port and in said second supply position the pressure port is arranged to communicate with the second supply/discharge port; a first switching mechanism configured to switch the first directional control valve; a second switching mechanism configured to switch the second directional control valve; and a communication passage configured to cause a second valve chamber of the second directional control valve to communicate with a pressure chamber of the first switching mechanism, wherein the first switching mechanism is configured to permit the first directional control valve to be switched to the first supply position in a state where the second switching mechanism has switched the second directional control valve to the second discharge position, a check valve configured to permit a flow from the pressure port to the first supply/discharge port and blocks a reverse flow by being arranged at least either in the first directional control valve at the first supply position or between the pressure port and the first directional control valve, and said check valve being configured so that a pressure fluid supplied from the second valve chamber of the second directional control valve at the second supply position to the pressure chamber of the first switching mechanism via the communication passage switches the first directional control valve to the first discharge position via the first switching mechanism, in a state where the second switching mechanism has switched the second directional control valve to the second supply position, wherein the check valve is arranged inside of the first directional control valve at the first supply position, said check valve comprising a check member and a check spring, wherein the first directional control valve includes a first valve chamber, a first valve member which is arranged in the first valve chamber so as to be movable in an axial direction, a first supply valve seat which is provided in an end wall on the pressure port side among both end walls of the first valve chamber, and a first discharge valve seat which is provided in an end wall on the return port side among both said end walls, wherein the first valve member comprises a closing member arranged to face the first discharge valve seat, the check member arranged to face the first supply valve seat, and the check spring configured to urge the check member to the first supply valve seat, wherein the first switching mechanism includes a first hole arranged linearly with respect to the first valve chamber and the first discharge valve seat so as to cause an inside of the first discharge valve seat to communicate with the return port, a piston arranged in the first hole and moved between a state where the closing member is permitted to contact and close the first discharge valve seat and a state where the piston causes the check member to contact and close the first supply valve seat via the closing member, and the pressure chamber configured to facilitate pressing the piston toward the first valve chamber, wherein the second directional control valve includes the second valve chamber, a second valve member arranged in the second valve chamber so as to be movable in the axial direction, a second supply valve seat which is provided in an end wall on the pressure port side among both end walls of the second valve chamber, and a second discharge valve seat which is provided in an end wall on the return port side among said both end walls of the second valve chamber, and wherein the second switching mechanism includes a second hole arranged linearly with respect to the second valve chamber and the second discharge valve seat so as to cause an inside of the second discharge valve seat to communicate with the return port, an operating member which is inserted in the second hole and moved between a position where the second valve member is caused to contact and close the second supply valve seat and is separated from the second discharge valve seat and a position where the second valve member is separated from the second supply valve seat and is permitted to contact and close the second discharge valve seat, a driving mechanism configured to switch the position of the operating member, and the communication passage configured to cause the second valve chamber to communicate with the pressure chamber of the first switching mechanism.