An electro-hydraulic drive cylinder system for a construction machine and a method of using the same

Abstract

The application discloses an engineering machine electro-hydraulic driving oil cylinder system and a use method thereof. The oil cylinder system comprises: a driving oil way, wherein the driving oil way comprises a high-speed motor, a high-speed pump, a first electromagnetic reversing valve, a second electromagnetic reversing valve, a first electric proportional reversing valve and a second electric proportional reversing valve; and a supplementary oil way, wherein the supplementary oil way comprises an oil tank, a motor, a supplementary oil pump, a third check valve and a hydraulic control check valve. The application can improve electro-hydraulic modular integration, shorten pipelines, save space, reduce energy loss, improve power density, eliminate system coupling and improve composite action control performance.

Description

Technical Field

[0001] This invention belongs to the technical field of hydraulic systems for engineering machinery, and relates to an electro-hydraulic drive cylinder system for engineering machinery and its usage method. Background Technology

[0002] Hydraulic excavators are widely used in earthwork construction and mining industries, including housing construction, road engineering, water conservancy construction, farmland development, port construction, and national defense projects. Due to increasingly stringent regulations on road traffic pollutant emissions and exhaust gas treatment, the electrification of mobile machinery will become a widely discussed topic in the future. However, hydraulic drive technology remains a crucial component for achieving operational movement, placing high demands on the power, power density, and impact resistance of the drive systems in mobile machinery such as excavators.

[0003] Most existing hydraulic excavators use a main pump to output pressurized oil, which is then controlled by an integrated multi-way valve that controls the machine's hydraulic circuit. The multi-way valve is mounted on the turntable and connected to the actuator via pipelines, ultimately driving the working device. The speed of the actuator is controlled by a pilot valve that controls the opening of the main valve and the displacement of the main pump, thereby regulating the flow of hydraulic oil into the actuator.

[0004] However, the hydraulic pump and actuator are located far apart, with long pipelines in between, and the control components are centrally located, which is limited by space and the system occupies a large space, resulting in serious energy loss. Currently used hydraulic pumps are mostly variable pumps, and flow control is achieved by adjusting the pump displacement and valve opening. The engine or motor speed is not adjusted, the oil inlet speed regulation is large and it is easy to cause energy waste. Moreover, the response of adjusting the main pump displacement by controlling the pump is slow. Furthermore, using a single main pump to supply oil to each actuator results in poor controllability of the compound actions of the working device. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an electro-hydraulic drive cylinder system for engineering machinery and its usage method, which can improve the modular integration of electro-hydraulic systems, shorten pipelines, save space, reduce energy loss, increase power density, eliminate system coupling, and improve the controllability of compound actions.

[0006] To achieve the above objectives, the present invention is implemented using the following technical solution: An electro-hydraulic drive cylinder system for engineering machinery, comprising: An active oil circuit, comprising a high-speed motor, a high-speed pump, a first solenoid directional valve, a second solenoid directional valve, a first electro-proportional directional valve, and a second electro-proportional directional valve; The supplementary oil circuit includes an oil tank, a motor, a supplementary oil pump, a third check valve, and a hydraulically controlled check valve; The high-speed motor is connected to the high-speed pump. The oil outlet of the high-speed pump is connected to the first ports of the first electromagnetic directional valve and the second electromagnetic directional valve, respectively. The oil inlet of the high-speed pump is connected to the first port of the hydraulically controlled check valve, and the oil outlet of the high-speed pump is connected to the oil tank. The second port of the first electromagnetic directional valve is connected to the second port of the hydraulic cylinder and the first port of the second electro-proportional directional valve, respectively. The second port of the second electromagnetic directional valve is connected to the first port of the hydraulic cylinder and the first port of the first electro-proportional directional valve, respectively. The second port of the hydraulically controlled check valve is connected to the second port of the first electro-proportional directional valve, the second electro-proportional directional valve, and the second port of the third check valve, respectively. The hydraulically controlled oil port of the hydraulically controlled check valve is connected to the first port of the third check valve and the replenishing pump, respectively. The replenishing pump is connected to the motor and the oil tank, respectively.

[0007] Optionally, the active oil circuit further includes an accumulator, which is connected to the second port of the hydraulic check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively.

[0008] Optionally, the supplementary oil circuit further includes a radiator, the first port of which is connected to the supplementary oil pump, and the second port of which is connected to the hydraulic control port of the hydraulic control check valve and the first port of the third check valve, respectively.

[0009] Optionally, the supplemental oil circuit further includes a filter, the first port of which is connected to the supplemental oil pump, and the second port of which is connected to the first port of the radiator.

[0010] Optionally, the active oil circuit further includes an electro-proportional relief valve, the first port of which is connected to the oil outlet of the high-speed pump, the first port of the first solenoid directional valve, and the second port of the second solenoid directional valve, respectively. The second port of which is connected to the second port of the hydraulic control check valve, the second port of the first solenoid directional valve, the second port of the second solenoid directional valve, and the second port of the third check valve, respectively.

[0011] Optionally, the active oil circuit further includes a first relief valve, the first end of which is connected to the second port of the second solenoid directional valve, the first port of the hydraulic cylinder, and the first port of the first electro-proportional directional valve, respectively. The second port of the first relief valve is connected to the second port of the hydraulic control check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively.

[0012] Optionally, the active oil circuit further includes a second relief valve, the first end of which is connected to the second port of the first solenoid directional valve, the second port of the hydraulic cylinder, and the first port of the second electro-proportional directional valve, respectively. The second port of the second relief valve is connected to the second port of the hydraulic control check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively.

[0013] Optionally, the active oil circuit further includes a first check valve, the first end of which is connected to the second port of the second solenoid directional valve, the first port of the hydraulic cylinder, and the first port of the first electro-proportional directional valve, respectively, and the second port of the first check valve is connected to the second port of the hydraulically controlled check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively.

[0014] Optionally, the active oil circuit further includes a second check valve, the first end of which is connected to the second port of the first solenoid directional valve, the second port of the hydraulic cylinder, and the first port of the second electro-proportional directional valve, respectively. The second port of the second check valve is connected to the second port of the hydraulically controlled check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively.

[0015] A method of using an electro-hydraulic drive cylinder system for engineering machinery includes: The hydraulic cylinder lifts the object, the high-speed motor operates, driving the high-speed pump to rotate, the motor operates, driving the replenishing pump to rotate, the third check valve establishes pressure in the replenishing oil circuit, thereby opening the hydraulic control check valve, the second solenoid directional valve is energized and opened, the hydraulic oil is output by the high-speed pump and enters the large chamber connected to the first port of the hydraulic cylinder, the second electro-proportional directional valve is energized and opened, the hydraulic oil in the small chamber connected to the second port of the hydraulic cylinder flows into the suction port of the high-speed pump, and the extension action of the hydraulic cylinder is completed; The object that has been lifted retracts the hydraulic cylinder by its own weight. The first solenoid directional valve is energized and opened. The first electro-proportional directional valve controls the flow rate of the hydraulic oil in the hydraulic cylinder. The hydraulic oil in the large chamber connected to the first port of the hydraulic cylinder flows to the small chamber connected to the second port and the accumulator. The retraction action of the hydraulic cylinder is completed. The hydraulic cylinder lifts the object, the high-speed motor operates, driving the high-speed pump to rotate, the motor operates, driving the replenishing pump to rotate, the third check valve establishes pressure in the replenishing oil circuit, thereby opening the hydraulic control check valve, the first solenoid directional valve is energized and opened, the hydraulic oil is output by the high-speed pump and enters the small chamber connected to the second port of the hydraulic cylinder, the first electro-proportional directional valve is energized and opened, the hydraulic oil in the large chamber connected to the first port of the hydraulic cylinder flows into the suction port of the high-speed pump, and the hydraulic cylinder retraction action is completed; The lifted object extends the hydraulic cylinder by its own weight. The second solenoid directional valve is energized and opened. The second electro-proportional directional valve controls the flow rate of hydraulic oil in the hydraulic cylinder. The hydraulic oil in the small chamber connected to the second port and the accumulator flows to the large chamber connected to the first port, and the extension action of the hydraulic cylinder is completed.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This invention provides an electro-hydraulic drive cylinder system for engineering machinery and its usage method. The active oil circuit and the supplementary oil circuit are connected to the hydraulic cylinder to reduce pipeline losses. Furthermore, each actuator in the active oil circuit and the supplementary oil circuit is supplied with oil by an independent main pump, which reduces system coupling and improves the controllability of compound actions. By directly driving the high-speed motor and the high-speed pump, the power density is increased, and the system flow rate is adjusted by directly controlling the motor speed, thereby improving the system response speed. By installing a first solenoid directional valve and a second solenoid directional valve in the hydraulic cylinder inlet circuit, and a first electro-proportional directional valve and a second electro-proportional directional valve in the hydraulic cylinder return circuit, energy loss caused by throttling speed regulation in the inlet circuit is avoided, and return speed regulation also ensures smooth operation under heavy load conditions. Detailed Implementation

[0017] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. Example

[0020] An electro-hydraulic drive cylinder system for engineering machinery, comprising: The active oil circuit includes a high-speed motor, a high-speed pump, a first solenoid directional valve, a second solenoid directional valve, an accumulator, an electro-proportional relief valve, a first relief valve, a second relief valve, a first check valve, a second check valve, a first electro-proportional directional valve, and a second electro-proportional directional valve. The replenishment oil circuit includes an oil tank, motor, replenishment pump, radiator, filter, third check valve, and hydraulic control check valve.

[0021] A high-speed motor is connected to a high-speed pump. The outlet of the high-speed pump is connected to the first port of the electro-proportional relief valve, the first port of the first solenoid directional valve, and the first port of the second solenoid directional valve. The inlet of the high-speed pump is connected to the first port of the hydraulic check valve. The outlet of the high-speed pump is connected to the oil tank. The second port of the first solenoid directional valve is connected to the second port (B) of the hydraulic cylinder, the first port of the second relief valve, the first port of the second check valve, and the first port of the second electro-proportional directional valve. The second port of the second solenoid directional valve is connected to the first port (A) of the hydraulic cylinder, the first port of the first relief valve, the first port of the first check valve, and the first electro-proportional directional valve. The first port of the directional valve is connected to the second port of the hydraulically controlled check valve, which is connected to the second port of the electro-proportional relief valve, the second port of the first relief valve, the second port of the first check valve, the second port of the second relief valve, the second port of the second check valve, the accumulator, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve. The hydraulic control port of the hydraulically controlled check valve is connected to the first port of the third check valve and the second port of the radiator. The motor is directly connected to the oil replenishment pump, which is connected to the oil tank. The oil replenishment pump is connected to the first port of the filter, and the second port of the filter is connected to the first port of the radiator. Example

[0022] Unlike Embodiment 1, this embodiment provides a method for using an electro-hydraulic drive cylinder system for engineering machinery, including: The hydraulic cylinder lifts the object, the high-speed motor operates, driving the high-speed pump to rotate, the motor operates, driving the replenishing pump to rotate, the third check valve establishes pressure in the replenishing oil circuit, thereby opening the hydraulic control check valve, the second solenoid directional valve is energized and opened, the hydraulic oil is output by the high-speed pump and enters the large chamber connected to the first port of the hydraulic cylinder, the second electro-proportional directional valve is energized and opened, the hydraulic oil in the small chamber connected to the second port of the hydraulic cylinder flows into the suction port of the high-speed pump, and the extension action of the hydraulic cylinder is completed; The object that has been lifted retracts the hydraulic cylinder by its own weight. The first solenoid directional valve is energized, and the first electro-proportional directional valve controls the flow rate of the hydraulic oil in the hydraulic cylinder. The hydraulic oil in the large chamber connected to the first port of the hydraulic cylinder flows to the small chamber connected to the second port and the accumulator, and the retraction action of the hydraulic cylinder is completed. The hydraulic cylinder lifts the object, the high-speed motor operates, driving the high-speed pump to rotate, the motor operates, driving the replenishing pump to rotate, the third check valve establishes pressure in the replenishing oil circuit, thereby opening the hydraulic control check valve, the first solenoid directional valve is energized and opened, the hydraulic oil is output by the high-speed pump and enters the small chamber connected to the second port of the hydraulic cylinder, the first electro-proportional directional valve is energized and opened, the hydraulic oil in the large chamber connected to the first port of the hydraulic cylinder flows into the suction port of the high-speed pump, and the hydraulic cylinder retraction action is completed; The lifted object extends the hydraulic cylinder by its own weight. The second solenoid directional valve is energized and opened. The second electro-proportional directional valve controls the flow rate of hydraulic oil in the hydraulic cylinder. The hydraulic oil in the small chamber connected to the second port and the accumulator flows to the large chamber connected to the first port, and the extension action of the hydraulic cylinder is completed.

[0023] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electro-hydraulic drive cylinder system for engineering machinery, characterized in that, include: An active oil circuit, comprising a high-speed motor, a high-speed pump, a first solenoid directional valve, a second solenoid directional valve, a first electro-proportional directional valve, and a second electro-proportional directional valve; The supplementary oil circuit includes an oil tank, a motor, a supplementary oil pump, a third check valve, and a hydraulically controlled check valve; The high-speed motor is connected to the high-speed pump. The oil outlet of the high-speed pump is connected to the first ports of the first electromagnetic directional valve and the second electromagnetic directional valve, respectively. The oil inlet of the high-speed pump is connected to the first port of the hydraulically controlled check valve, and the oil outlet of the high-speed pump is connected to the oil tank. The second port of the first electromagnetic directional valve is connected to the second port of the hydraulic cylinder and the first port of the second electro-proportional directional valve, respectively. The second port of the second electromagnetic directional valve is connected to the first port of the hydraulic cylinder and the first port of the first electro-proportional directional valve, respectively. The second port of the hydraulically controlled check valve is connected to the second port of the first electro-proportional directional valve, the second electro-proportional directional valve, and the second port of the third check valve, respectively. The hydraulically controlled oil port of the hydraulically controlled check valve is connected to the first port of the third check valve and the replenishing pump, respectively. The replenishing pump is connected to the motor and the oil tank. The active oil circuit also includes an accumulator, which is connected to the second port of the hydraulic check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively. The supplementary oil circuit also includes a radiator, the first port of which is connected to the supplementary oil pump, and the second port of which is connected to the hydraulic control port of the hydraulic control check valve and the first port of the third check valve, respectively. The supplemental oil circuit also includes a filter, the first port of which is connected to the supplemental oil pump, and the second port of which is connected to the first port of the radiator.

2. The electro-hydraulic drive cylinder system for engineering machinery according to claim 1, characterized in that: The active oil circuit also includes an electro-proportional relief valve. The first port of the electro-proportional relief valve is connected to the oil outlet of the high-speed pump, the first port of the first electromagnetic directional valve, and the second port of the second electromagnetic directional valve. The second port of the electro-proportional relief valve is connected to the second port of the hydraulic control check valve, the second port of the first electromagnetic directional valve, the second port of the second electromagnetic directional valve, and the second port of the third check valve.

3. The electro-hydraulic drive cylinder system for engineering machinery according to claim 1, characterized in that: The active oil circuit also includes a first relief valve, the first end of which is connected to the second port of the second solenoid directional valve, the first port of the hydraulic cylinder, and the first port of the first electro-proportional directional valve, respectively. The second port of the first relief valve is connected to the second port of the hydraulic control check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively.

4. The electro-hydraulic drive cylinder system for engineering machinery according to claim 1, characterized in that: The active oil circuit also includes a second relief valve. The first end of the second relief valve is connected to the second port of the first solenoid directional valve, the second port of the hydraulic cylinder, and the first port of the second electro-proportional directional valve. The second port of the second relief valve is connected to the second port of the hydraulic control check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve.

5. The electro-hydraulic drive cylinder system for engineering machinery according to claim 1, characterized in that: The active oil circuit also includes a first check valve, the first end of which is connected to the second port of the second solenoid directional valve, the first port of the hydraulic cylinder, and the first port of the first electro-proportional directional valve, respectively. The second port of the first check valve is connected to the second port of the hydraulically controlled check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve, respectively.

6. The electro-hydraulic drive cylinder system for engineering machinery according to claim 1, characterized in that: The active oil circuit also includes a second check valve. The first end of the second check valve is connected to the second port of the first solenoid directional valve, the second port of the hydraulic cylinder, and the first port of the second electro-proportional directional valve. The second port of the second check valve is connected to the second port of the hydraulically controlled check valve, the second port of the first electro-proportional directional valve, the second port of the second electro-proportional directional valve, and the second port of the third check valve.

7. A method of using an electro-hydraulic drive cylinder system for engineering machinery according to any one of claims 1-6, characterized in that, include: The hydraulic cylinder lifts the object, the high-speed motor operates, driving the high-speed pump to rotate, the motor operates, driving the replenishing pump to rotate, the third check valve establishes pressure in the replenishing oil circuit, thereby opening the hydraulic control check valve, the second solenoid directional valve is energized and opened, the hydraulic oil is output by the high-speed pump and enters the large chamber connected to the first port of the hydraulic cylinder, the second electro-proportional directional valve is energized and opened, the hydraulic oil in the small chamber connected to the second port of the hydraulic cylinder flows into the suction port of the high-speed pump, and the extension action of the hydraulic cylinder is completed; The object that has been lifted retracts the hydraulic cylinder by its own weight. The first solenoid directional valve is energized and opened. The first electro-proportional directional valve controls the flow rate of the hydraulic oil in the hydraulic cylinder. The hydraulic oil in the large chamber connected to the first port of the hydraulic cylinder flows to the small chamber connected to the second port and the accumulator. The retraction action of the hydraulic cylinder is completed. The hydraulic cylinder lifts the object, the high-speed motor operates, driving the high-speed pump to rotate, the motor operates, driving the replenishing pump to rotate, the third check valve establishes pressure in the replenishing oil circuit, thereby opening the hydraulic control check valve, the first solenoid directional valve is energized and opened, the hydraulic oil is output by the high-speed pump and enters the small chamber connected to the second port of the hydraulic cylinder, the first electro-proportional directional valve is energized and opened, the hydraulic oil in the large chamber connected to the first port of the hydraulic cylinder flows into the suction port of the high-speed pump, and the hydraulic cylinder retraction action is completed; The lifted object extends the hydraulic cylinder by its own weight. The second solenoid directional valve is energized and opened. The second electro-proportional directional valve controls the flow rate of hydraulic oil in the hydraulic cylinder. The hydraulic oil in the small chamber connected to the second port and the accumulator flows to the large chamber connected to the first port, and the extension action of the hydraulic cylinder is completed.