公开(公告)号：US20230131384A1

公开(公告)日：2023-04-27

申请号：US17973789

申请日：2022-10-26

申请人： Caterpillar SARL

发明人： Isao Konishi ,  Genta Mine ,  Yuya Kanenawa ,  Shinya Ohmura ,  Sei Shimahara ,  Kazuya Miyamori

IPC分类号： E02F9/22 ,  E02F9/20 ,  F15B15/00 ,  F15B13/02

摘要： Problem to be solved: To provide a hydraulic circuit for the construction machine which enables to use the relief valve of low capacity in the work tool circuit. Solution: The hydraulic circuit 2 for a construction machine has: a hydraulic pump 4 of variable capacity, a work tool 6 operated by hydraulic oil delivered by the hydraulic pump 4, a work tool operating device 10 to output a signal for operating the work tool 6, a control valve 14 allowing the hydraulic pump 4 to supply the hydraulic oil to the work tool 6 based on the signal output from the work tool operating device 10, a tool's relief valve 44 to release the hydraulic oil flowing between the control valve 14 and the work tool 6, a pressure sensor 46 to detect a pressure of hydraulic oil flowing into the work tool 6, and a controller 48 to reduce a delivery rate from the hydraulic pump 4 when the pressure detected by the pressure sensor 46 exceeds a predetermined value.