Drive system for construction machinery and method of controlling hydraulic circuit means thereof
US4369625A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1980 |
| Grant date | Jan 25, 1983 |
| Priority date | — |
| Expiry date | Feb 20, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02F9/2292
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drive system for construction machinery in which hydraulic circuit is provided with a plurality of variable-displacement hydraulic pumps and a plurality of hydraulic actuators, each pump being connected in closed circuit to one or a plurality of the actuators via a solenoid-operated valve or valves to drive a movable member or members connected to the actuator or respective actuators when pressurized fluid is supplied to the actuator or actuators from the pump. At least one of the selected hydraulic actuators is further connected in closed circuit through a solenoid-operated valve to at least one of the hydraulic pumps other than the hydraulic pump which is connected in closed circuit to the hydraulic actuator. The hydraulic circuit means is controlled such that timing for switching the solenoid-operated valves is controlled in conjunction with the operation of the pump so as to absorb the shock which would otherwise be produced when each actuator is rendered operative and inoperative. The hydraulic circuit means is further controlled such that, when the operation speed of each hydraulic actuator is increased or reduced including the time at which the actuator is rendered operati…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.