Shovel
AssigneeSumitomo Construction Machinery Co., Ltd.
InventorYouji Misaki
Life of this patent
Estimating the term…
Abstract
A shovel includes a lower traveling body, an upper turning body turnably mounted on the lower traveling body, an engine provided in the upper turning body, a hydraulic pump and a hydraulic oil tank provided in the upper turning body, a plurality of hydraulic actuators driven by the hydraulic pump, and a hydraulic circuit connected to the hydraulic pump, wherein the hydraulic circuit includes a plurality of control valves configured to control flows of hydraulic oil between the hydraulic pump and the plurality of hydraulic actuators, and a unified bleed-off valve configured to collectively control bleed-off flowrates of the plurality of control valves, wherein the hydraulic circuit is configured so that a discharge pressure of the hydraulic pump becomes equal to or less than a predetermined pressure during start-up of the engine.
Claims9
A shovel comprising:
- a lower traveling body;
- an upper turning body mounted on the lower traveling body in a turnable manner;
- a power source provided in the upper turning body;
- a hydraulic pump and a hydraulic oil tank provided in the upper turning body;
- a plurality of hydraulic actuators driven by the hydraulic pump;
- a hydraulic circuit connected to the hydraulic pump,
- wherein the hydraulic circuit includes:
- a plurality of control valves configured to control flows of hydraulic oil between the hydraulic pump and the plurality of hydraulic actuators;
- and
- a unified bleed-off valve configured to collectively control bleed-off flowrates of the plurality of control valves, and
- the hydraulic circuit is configured to set an opening area of the unified bleed-off valve to a predetermined value so that a discharge pressure of the hydraulic pump becomes equal to or less than a predetermined pressure during start-up of the power source;
- and
- a processor configured to adjust the opening area of the unified bleed-off valve according to an operating state of the plurality of hydraulic actuators such that the opening area of the unified bleed-off valve is less than the predetermined value to generate a bleed pressure, when the power source is running and the plurality of hydraulic actuators are enabled.
A shovel comprising:
- a lower traveling body;
- an upper turning body mounted on the lower traveling body in a turnable manner;
- a power source provided in the upper turning body;
- a hydraulic pump and a hydraulic oil tank provided in the upper turning body;
- a plurality of hydraulic actuators driven by the hydraulic pump;
- a hydraulic circuit connected to the hydraulic pump,
- wherein the hydraulic circuit includes:
- a plurality of control valves configured to control flows of hydraulic oil between the hydraulic pump and the plurality of hydraulic actuators;
- and
- a unified bleed-off valve configured to collectively control bleed-off flowrates of the plurality of control valves, and
- the hydraulic circuit is configured so that a discharge pressure of the hydraulic pump becomes equal to or less than a predetermined pressure during start-up of the power source;
- a processor configured to change an opening area of the unified bleed-off valve, based on an amount of manipulation of a manipulating apparatus for operating at least one of the plurality of hydraulic actuators;
- and
- a start circuit configured to control, separately from the processor, an opening of the unified bleed-off valve during the start-up of the power source.
Dependencies are inferred from the claim text.