公开(公告)号：US09874232B2

公开(公告)日：2018-01-23

申请号：US14909753

申请日：2014-08-26

Applicant: KYB Corporation ,  KYB-YS CO., LTD.

Inventor： Keiichi Matsuzaki ,  Hideki Miyashita

IPC: F15B13/042 ,  F15B11/00 ,  F15B13/01 ,  F15B11/10

CPC classification number: F15B11/003 ,  F15B11/10 ,  F15B13/01 ,  F15B13/042 ,  F15B2211/30515 ,  F15B2211/329

Abstract: A fluid pressure control apparatus includes a pilot control valve configured to control a pilot pressure guided from a pilot pump to the control valve and a load retaining mechanism installed in the main passage. The load retaining mechanism includes an operated check valve configured to permit a flow of the working fluid from the load-side pressure chamber to the control valve in accordance with a back pressure and a switch valve configured to switch an action of the operated check valve. The switch valve has a discharge position configured to discharge the working fluid in a back pressure chamber when the pilot pressure has been guided from the pilot control valve. When the switch valve is set to the discharge position, the working fluid in the back pressure chamber is discharged to a tank via a drain port of the pilot control valve.

公开(公告)号：US10578132B2

公开(公告)日：2020-03-03

申请号：US15552538

申请日：2015-09-14

Applicant: KYB Corporation

Inventor： Takeshi Terao ,  Keiichi Matsuzaki ,  Hideki Miyashita

IPC: F15B13/02 ,  F15B11/028 ,  F15B11/16 ,  F15B13/06

Abstract: A fluid pressure control device includes a switching valve that has a pilot chamber to which the working oil is supplied from the supply passage through the second control valve, and a first relief valve that is provided on the downstream side of the switching valve. The second control valve allows supply of the working oil to the pilot chamber in a case where a flow of the working oil to a tilt cylinder is allowed, and blocks the supply of the working oil to the pilot chamber in a case where the flow of the working oil to the tilt cylinder is blocked. The switching valve allows a flow of the working oil to the first relief valve in a case where the working oil is supplied to the pilot chamber, and blocks the flow of the working oil to the first relief valve in a case where the supply of the working oil to the pilot chamber is blocked.