Abstract: A rotatory energy recycling control device for a hydraulic excavator, comprising: an oil line selector valve (1), a direction selector valve (2), a sequencing valve (3), a one-way valve (4) and an overflow valve (5); two oil inlets of the oil line selector valve (1) are respectively connected to an opening A and an opening B of a rotary motor; an oil outlet of the oil line selector valve (1) is connected to an inlet of the direction selector valve (2); an outlet of the direction selector valve (2) is connected to an net of the sequencing valve (3); a drainage port of the sequencing valve (3) is connected to an oil tank; an outlet of the sequencing valve (3) and an net of the one-way valve (4) communicate with the overflow valve (5): the outlet of the one-way valve (4) is connected to an energy storage and utilization device; and an outlet of the overflow valve (5) is connected to the oil tank.

Abstract: Disclosed is an apparatus for improving excavating operation characteristic and grading operation characteristic of an excavator. The apparatus includes a solenoid valve group and a hydraulically controlled selector valve. An oil controlling output A1 of the solenoid valve group is configured in series with oil controlling input a1 of the hydraulic control valve. An oil controlling output A2 of the solenoid valve group is configured in series with a pilot control end XBa2 of a multi-port valve group. An oil return port T1 of the solenoid valve group is connected to the hydraulic oil tank. An oil controlling output b1 of the hydraulically controlled selector valve is connected to a pilot control end XAb2 of the multiplexer valve group, and an oil return port T2 of the hydraulically controlled selector valve is connected with the hydraulic oil tank. The apparatus improves operational efficiency and control comfortability.

Abstract: A method for improving excavating operation characteristic and grading operation characteristic of an excavator is disclosed. A hydraulically controlled selector valve is added in a boom confluence control circuit of a hydraulic excavator, and a solenoid valve group is added in the boom confluence control circuit and the bucket/stick confluence control circuit. A controller sends a control signal to switch the solenoid valve group between a disconnected mode and a connected mode. The controller may send out a signal to disconnect the solenoid valve group, to restore a valve spool to a middle position, to restore a boom lifting confluence circuit, and to disconnect a bucket/stick swinging confluence circuit to perform a standard excavation mode. The controller may send out a signal to connect the solenoid valve group to disconnect a boom lifting confluence circuit and to increase a bucket/stick swinging confluence circuit to achieve a grading operation mode.

Abstract: An energy-saving control system of an excavator, including an engine, a main pump (1), a pilot handle, a pilot pressure pump (2), pilot control valves (4), a controller, a main control multi-way valve (3) and an execution mechanism. The main pump controls the execution mechanism via the main control multi-way valve (3). The oil paths connecting the main pump to the execution mechanism are provided with high pressure sensors (6) for transmitting signals to the controller. The main pump adjusts the flow rate thereof according to the pressure of a negative feedback oil path. The oil paths interconnecting the output end of the pilot handle with the main pump is provided with electromagnetic proportional reducing valves (7) and shuttle valves (8). A pilot oil path sequentially passes through the electromagnetic proportional reducing valves (7) and the shuttle valves (8) to control the flow rate of the main pump.

Abstract: A rotatory energy recycling control device for a hydraulic excavator, comprising: an oil line selector valve (1), a direction selector valve (2), a sequencing valve (3), a one-way valve (4) and an overflow valve (5); two oil inlets of the oil line selector valve (1) are respectively connected to an opening A and an opening B of a rotary motor; an oil outlet of the oil line selector valve (1) is connected to an inlet of the direction selector valve (2); an outlet of the direction selector valve (2) is connected to an net of the sequencing valve (3); a drainage port of the sequencing valve (3) is connected to an oil tank; an outlet of the sequencing valve (3) and an net of the one-way valve (4) communicate with the overflow valve (5): the outlet of the one-way valve (4) is connected to an energy storage and utilization device; and an outlet of the overflow valve (5) is connected to the oil tank.

Abstract: A method for improving excavating operation characteristic and grading operation characteristic of an excavator is disclosed. A hydraulically controlled selector valve is added in a boom confluence control circuit of a hydraulic excavator, and a solenoid valve group is added in the boom confluence control circuit and the bucket/stick confluence control circuit. A controller sends a control signal to switch the solenoid valve group between a disconnected mode and a connected mode. The controller may send out a signal to disconnect the solenoid valve group, to restore a valve spool to a middle position, to restore a boom lifting confluence circuit, and to disconnect a bucket/stick swinging confluence circuit to perform a standard excavation mode. The controller may send out a signal to connect the solenoid valve group to disconnect a boom lifting confluence circuit and to increase a bucket/stick swinging confluence circuit to achieve a grading operation mode.

Abstract: Disclosed is an apparatus for improving excavating operation characteristic and grading operation characteristic of an excavator. The apparatus includes a solenoid valve group and a hydraulically controlled selector valve. An oil controlling output A1 of the solenoid valve group is configured in series with oil controlling input a1 of the hydraulic control valve. An oil controlling output A2 of the solenoid valve group is configured in series with a pilot control end XBa2 of a multi-port valve group. An oil return port T1 of the solenoid valve group is connected to the hydraulic oil tank. An oil controlling output b1 of the hydraulically controlled selector valve is connected to a pilot control end XAb2 of the multiplexer valve group, and an oil return port T2 of the hydraulically controlled selector valve is connected with the hydraulic oil tank. The apparatus improves operational efficiency and control comfortability.