Construction machine
US12104349B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 2020 |
| Grant date | Oct 1, 2024 |
| Priority date | — |
| Expiry date | Dec 5, 2041 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/85
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Provided is a construction machine configured such that a hydraulic actuator is driven by a hydraulic pump for a closed circuit, by which oil film breakage of the hydraulic pump for a closed circuit is prevented to improve the reliability and a high operation rate can be obtained. The construction machine includes a switching valve that is provided in a branch hydraulic line connecting one of suction/delivery ports of a closed circuit pump and a charge line to each other and is opened and closed according to a control signal from a controller. The controller is configured to, in a case where a state in which a delivery volume of the closed circuit pump is kept to zero continues for a predetermined time period or more, open the switching valve and keep the delivery volume of the closed circuit pump to a predetermined delivery volume or more, the predetermined delivery volume being greater than zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.