Construction machine
US10767674B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 2017 |
| Grant date | Sep 8, 2020 |
| Priority date | — |
| Expiry date | Nov 7, 2037 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/785
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A construction machine includes a bidirectionally tiltable type hydraulic pump 2, a hydraulic cylinder 1 having a cap chamber 1e and a rod chamber 1f, a first flow path 11 connecting the hydraulic pump 2 and the cap chamber 1e, a second flow path 12 connecting the hydraulic pump 2 and the rod chamber 1f, a discharge flow path 16 branched from the first flow path 11, a discharge valve 32 that is disposed in the discharge flow path 16 and controls a discharge rate of hydraulic working oil from the cap chamber 1e to the discharge flow path 16, an operation device 54 that instructs an action of the hydraulic cylinder 1, and a controller 56. The controller 56 controls the hydraulic pump 2 and the discharge valve 32 such that at least a part of hydraulic working oil discharged from the cap chamber 1e is discharged to the discharge flow path 16 when an operation amount of the operation device 54 lies within a fine operation region during a pulling action of the hydraulic cylinder 1 in a state that a load is applied in a contraction direction. Accordingly, operability improves during fine operation of the pulling action of the hydraulic cylinder in the state that the load is applied in the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.