Electric loader drive recovery integrated boom hydraulic system and control method thereof

Abstract

The present invention relates to an electric loader drive recovery integrated boom hydraulic system and a control method thereof, wherein a servo motor is coaxially connected to a two-way fixed-displacement pump, and a first oil outlet of the two-way fixed-displacement pump is connected to a rod chamber of a single-acting hydraulic cylinder via a first solenoid valve, a first non-return valve, a second non-return valve, and a third non-return valve, and a second oil outlet of the two-way fixed-displacement pump is connected to a rodless chamber of a single-acting hydraulic cylinder via a second solenoid valve, a third non-return valve, and a relief valve, and the hydraulic system is provided with a control module capable of controlling the precise movement of the single-acting hydraulic cylinder. The pump control system of the present invention has no throttling loss of a valve and has a high energy utilization rate. At the same time, the system converts the potential energy generated by the boom's own weight during the descent phase into electrical energy to the greatest extent and stores it, and releases and uses it when the boom performs external work during the ascent phase, effectively reducing energy loss and improving energy utilization. In addition, its drive recovery is achieved using a set of motor-pumps, thereby improving space utilization.

Description

Technical Field

[0001] The present invention relates to the technical field of electric loaders, and in particular to an electric loader driving and recovery integrated boom hydraulic system and a control method thereof. Background Art

[0002] As a clean energy-powered construction machine, electric loaders can effectively reduce pollution emissions. During loader operation, the boom hydraulic system is one of its core components. Traditional hydraulic systems typically utilize valve-controlled systems. In valve-controlled systems, hydraulic oil experiences pressure and throttling losses as it passes through the valves, reducing system efficiency. Energy loss is particularly noticeable during prolonged, high-load operation. Furthermore, the potential energy generated during boom lowering is typically dissipated through throttling of the hydraulic oil, resulting in significant energy waste. Summary of the Invention

[0003] In response to the problems existing in the prior art, the present invention provides an electric loader drive and recovery integrated boom hydraulic system and a control method thereof. The pump control system has no valve throttling loss and has high energy utilization. At the same time, the system converts the potential energy generated by the boom's own weight descending stage into electrical energy to the greatest extent and stores it, and releases and uses it when the boom performs external work during the ascending stage, effectively reducing energy loss and improving energy utilization. In addition, its drive and recovery are all achieved by a set of motor-pumps, effectively reducing costs and improving space utilization.

[0004] The technical solution adopted by the present invention is a hydraulic system for an electric loader driven recovery integrated boom, which includes a servo motor, a two-way quantitative pump, a first one-way valve, a second one-way valve, a third one-way valve, a relief valve, a first solenoid valve, a second solenoid valve, a single-acting hydraulic cylinder and a control module. The output end of the servo motor is connected to the driving end of the two-way quantitative pump through a coupling, and the first oil outlet of the two-way quantitative pump is connected to the oil tank; the first solenoid valve and the second solenoid valve are both two-position two-way solenoid valves, and the first oil port of the first solenoid valve, the oil outlet of the first one-way valve, the oil inlet of the second one-way valve and the oil inlet of the third one-way valve are all connected to the first oil outlet of the two-way quantitative pump, the second oil port of the first solenoid valve is connected to the rod chamber of the single-acting hydraulic cylinder, and the oil outlet of the second one-way valve is connected to the oil inlet of the first one-way valve, the oil inlet of the first one-way valve is connected to the oil tank, the first oil port of the second solenoid valve, the oil outlet of the third one-way valve are connected to the oil tank, and the first oil port of the second solenoid valve, the oil outlet of the third one-way valve and the oil inlet of the third one-way valve are connected to the first oil outlet of the two-way quantitative pump. and the oil inlet of the overflow valve is connected to the second oil outlet of the bidirectional quantitative pump, and a pressure sensor and a flow sensor are provided on the pipeline between the second oil outlet of the bidirectional quantitative pump and the first oil port of the second solenoid valve, the second oil port of the second solenoid valve is connected to the rodless chamber of the single-acting hydraulic cylinder, and the oil outlet of the overflow valve is connected to the oil tank; the control module can control the precise movement of the single-acting hydraulic cylinder, and the control module includes a capacitor, a converter, a driver and a controller, a driver is provided in the servo motor, the capacitor is communicated with the servo motor through the converter, and the servo motor is communicated with the controller through the driver, the servo motor is provided with an electric control handle that can control the input signal of the servo motor, and the pressure sensor, flow sensor and electric control handle are all communicated with the controller, a speed sensor that can detect the speed of the single-acting hydraulic cylinder is provided at the end of the single-acting hydraulic cylinder, and the speed sensor is connected to the controller.

[0005] Furthermore, the first one-way valve, the second one-way valve, the third one-way valve, the overflow valve, the first solenoid valve, the second solenoid valve and the pressure sensor are arranged on the hydraulic valve block.

[0006] Preferably, the hydraulic valve block is provided with a plurality of oil circuits and a plurality of oil ports communicating with the oil circuits, the plurality of oil circuits including a first oil circuit, a second oil circuit, a third oil circuit, a fourth oil circuit, a fifth oil circuit, a sixth oil circuit, a seventh oil circuit, an eighth oil circuit, a ninth oil circuit, a tenth oil circuit, an eleventh oil circuit, a twelfth oil circuit, a thirteenth oil circuit, a fourteenth oil circuit, a fifteenth oil circuit and a sixteenth oil circuit, a first end of the first oil circuit is connected to the first solenoid valve, and a middle portion of the first oil circuit is connected to the first end of the second oil circuit, a second end of the first oil circuit is connected to the middle portion of the third oil circuit, and the third oil circuit is respectively connected to the first ends of the fourth oil circuit, the fifth oil circuit and the sixth oil circuit, the middle portion of the fourth oil circuit is connected to the first end of the seventh oil circuit, and the second end of the fourth oil circuit is connected to the first one-way valve, the middle portion of the fifth oil circuit is connected to the first end of the eighth oil circuit, and the second end of the fifth oil circuit The first oil circuit is connected to the second one-way valve, the middle part of the seventh oil circuit is connected to the second end of the eighth oil circuit through the ninth oil circuit, and the first end of the ninth oil circuit is provided with a plug, the middle part of the sixth oil circuit is connected to the first end of the tenth oil circuit, the second end of the tenth oil circuit is provided with a plug, and the second end of the sixth oil circuit is connected to the third one-way valve, the first end of the eleventh oil circuit is connected to the second solenoid valve, and the middle part of the eleventh oil circuit is connected to the first ends of the twelfth oil circuit, the thirteenth oil circuit and the fourteenth oil circuit respectively, the second end of the thirteenth oil circuit is connected to the pressure sensor, and the second end of the fourteenth oil circuit is connected to the overflow valve, the middle part of the fourteenth oil circuit is connected to the first end of the fifteenth oil circuit, and the second end of the eleventh oil circuit is connected to the first end of the sixteenth oil circuit, and the middle part of the sixteenth oil circuit is connected to the middle part of the tenth oil circuit.

[0007] Preferably, the opening pressure of the second one-way valve is 1-3 bar, and when the single-acting hydraulic cylinder retracts, the oil in the rodless chamber of the single-acting hydraulic cylinder can first flow back to the rod chamber of the single-acting hydraulic cylinder.

[0008] Another aspect of the present invention provides a control method for the hydraulic system of the aforementioned electric loader driving and recovering integrated boom, comprising the following steps:

[0009] S1. Start the hydraulic system and identify the working condition of the hydraulic system;

[0010] S2. Detecting the opening signal of the electric control handle through the controller and determining whether the opening signal of the electric control handle is greater than zero. If the opening signal of the electric control handle is greater than zero, the hydraulic system is in an external working condition, and then executing steps S3 and S4; if the opening signal of the electric control handle is less than or equal to zero, the hydraulic system is in an energy recovery condition, and then directly executing steps S5 and S6;

[0011] S3, after receiving the opening signal of the electric control handle, the controller drives the servo motor to rotate, and the servo motor drives the bidirectional quantitative pump to start working. At this time, the bidirectional quantitative pump is used as a hydraulic pump, and the servo motor is in the motor working state;

[0012] S4, the bidirectional quantitative pump draws oil from the oil tank and flows through the second solenoid valve into the rodless chamber of the single-acting hydraulic cylinder. At the same time, the oil in the rod chamber of the single-acting hydraulic cylinder flows through the first solenoid valve and the second one-way valve into the oil tank. At this time, the boom drives the load to rise;

[0013] S5, the boom automatically falls under the deadweight of the load, and the single-acting hydraulic cylinder retracts;

[0014] S6. The oil in the rodless chamber of the single-acting hydraulic cylinder flows through the second solenoid valve and then enters the bidirectional quantitative pump. At this time, the bidirectional quantitative pump is used as a hydraulic motor, and the servo motor is in a generator working state.

[0015] Preferably, the controller can match the corresponding motor speed signal to drive the servo motor according to the size of the electric control handle opening signal received. When the boom rises, the opening range of the electric control handle is 0<α≤α max , the corresponding speed range of the servo motor is 0<n≤n max When the boom is lowered, the opening range of the electric control handle is α min ≤α<0, the corresponding speed range of the servo motor is n min ≤n<0.

[0016] Preferably, in step S3, when the servo motor is in the motor working state, the capacitor and the external power supply jointly power the servo motor; in step S6, when the servo motor is in the generator working state, the servo motor rotates to generate electricity, and then stores the generated electrical energy in the capacitor.

[0017] Preferably, when the speed of the single-acting hydraulic cylinder is zero, the first solenoid valve and the second solenoid valve are both in a closed state, and the single-acting hydraulic cylinder is locked; when the speed of the single-acting hydraulic cylinder is not zero, the first solenoid valve and the second solenoid valve are both in an open state, and the main oil circuit of the hydraulic system is connected.

[0018] The characteristics and beneficial effects of the present invention are:

[0019] 1. The electric loader drive recovery integrated boom hydraulic system and its control method provided by the present invention use a servo motor to drive a quantitative pump as a power source to supply oil to the hydraulic system. At the same time, a relief valve is installed in the main oil circuit. When an abnormal pressure or flow in the hydraulic system is detected, the relief valve can quickly unload the load to protect the stable operation of the system. In addition, the hydraulic system is connected to an external oil tank to replenish oil for the system, solve the problem of asymmetric flow of single-acting hydraulic cylinders, and ensure the stable operation of the system.

[0020] 2. The electric loader driven recovery integrated boom hydraulic system and its control method provided by the present invention are based on the rated displacement of the bidirectional quantitative pump. It is only necessary to control the speed of the servo motor to control the output flow rate, and then control the speed of the hydraulic cylinder. At the same time, the opening size of the electric control handle is matched with the motor speed. By controlling the opening of the handle, the rising and falling speed of the boom can be controlled.

[0021] 3. The electric loader drive and recovery integrated boom hydraulic system and control method provided by the present invention use the same servo motor-pump set to complete the drive and energy recovery actions. The capacitor converts the potential energy consumed when the boom descends into electrical energy and stores it, and releases and uses it when the boom rises, which can maximize energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the hydraulic system for the electric loader driving and recovering integrated boom of the present invention;

[0023] Figure 2 It is a control principle diagram of the hydraulic module of the present invention;

[0024] Figure 3 It is a structural schematic diagram of the hydraulic valve block of the present invention;

[0025] Figure 4 It is a right side view of the hydraulic valve block of the present invention;

[0026] Figure 5 This invention Figure 4 Cross-sectional view along the BB direction;

[0027] Figure 6 is a top view of the hydraulic valve block of the present invention;

[0028] Figure 7 This invention Figure 6 Cross-sectional view along the AA axis;

[0029] Figure 8 This is a front view of the hydraulic valve block of the present invention;

[0030] Figure 9 This invention Figure 8 Cross-sectional view in CC direction;

[0031] Figure 10 It is a left side view of the hydraulic valve block of the present invention;

[0032] Figure 11 This invention Figure 10 Cross-sectional view in the middle DD direction;

[0033] Figure 12 is a flow chart of a control method of a hydraulic system of the present invention;

[0034] Figure 13 It is a flow chart of the capacitor charging and discharging control method of the hydraulic system of the present invention.

[0035] Main reference numerals:

[0036] Servo motor 1; bidirectional quantitative pump 2; first one-way valve 3; second one-way valve 4; third one-way valve 5; overflow valve 6; first solenoid valve 7; second solenoid valve 8; pressure sensor 9; flow sensor 10; single-acting hydraulic cylinder 11; capacitor 12; converter 13; driver 14; controller 15; electric control handle 16; oil tank 17; speed sensor 18; hydraulic valve block 20; first oil circuit 201; second oil circuit 202; third oil circuit 203; fourth oil circuit 204; fifth oil circuit 205; sixth oil circuit 206; seventh oil circuit 207; eighth oil circuit 208; ninth oil circuit 209; tenth oil circuit 210; eleventh oil circuit 211; twelfth oil circuit 212; thirteenth oil circuit 213; fourteenth oil circuit 214; fifteenth oil circuit 215; sixteenth oil circuit 216. DETAILED DESCRIPTION

[0037] To fully describe the technical content, structural features, objectives and effects of the present invention, the following is a detailed description with reference to the accompanying drawings.

[0038] The present invention is an electric loader driving and recycling integrated boom hydraulic system, such as Figure 1As shown, it includes a servo motor 1, a bidirectional quantitative pump 2, a first one-way valve 3, a second one-way valve 4, a third one-way valve 5, a relief valve 6, a first solenoid valve 7, a second solenoid valve 8, a single-acting hydraulic cylinder 11 and a control module. The output end of the servo motor 1 is connected to the driving end of the bidirectional quantitative pump 2 through a coupling, and the first oil outlet P1 of the bidirectional quantitative pump 2 is connected to the oil tank 17; the first solenoid valve 7 and the second solenoid valve 8 are both two-position two-way solenoid valves, and the first oil port B1 of the first solenoid valve 7, the oil outlet of the first one-way valve 3, the oil inlet of the second one-way valve 4 and the oil inlet of the third one-way valve 5 are all connected to the first oil outlet P1 of the bidirectional quantitative pump 2, and the second oil port A1 of the first solenoid valve 7 is connected to the rod chamber of the single-acting hydraulic cylinder 11. They are connected, and the oil outlet of the second one-way valve 4 is connected to the oil inlet of the first one-way valve 3, the oil inlet of the first one-way valve 3 is connected to the oil tank 17, the first oil port B2 of the second solenoid valve 8, the oil outlet of the third one-way valve 5 and the oil inlet of the relief valve 6 are all connected to the second oil outlet P2 of the two-way metering pump 2, and a pressure sensor 9 and a flow sensor 10 are provided on the pipeline between the second oil outlet P2 of the two-way metering pump 2 and the first oil port B2 of the second solenoid valve 8, the second oil port A2 of the second solenoid valve 8 is connected to the rodless chamber of the single-acting hydraulic cylinder 11, and the oil outlet of the relief valve 6 is connected to the oil tank 17. When an abnormality in the system pressure or flow is detected, rapid unloading is completed through the relief valve 6 to protect the stable operation of the system.

[0039] like Figure 2 As shown, the control module can control the precise movement of the single-acting hydraulic cylinder 11, and the control module includes a capacitor 12, a converter 13, a driver 14, and a controller 15. The servo motor 1 is provided with a driver 14, and the capacitor 12 can be a supercapacitor. The capacitor 12 is connected to the servo motor 1 through the converter 13, and the servo motor 1 is connected to the controller 15 through the driver 14. The servo motor 1 is provided with an electric control handle 16 that can control the servo motor input signal, and the pressure sensor 9, flow sensor 10, and electric control handle 16 are all connected to the controller 15. The end of the single-acting hydraulic cylinder 11 is provided with a speed sensor 18 that can detect the speed of the single-acting hydraulic cylinder 11, and the speed sensor 18 is connected to the controller 15.

[0040] like Figure 3 As shown, the first one-way valve 3 , the second one-way valve 4 , the third one-way valve 5 , the overflow valve 6 , the first solenoid valve 7 , the second solenoid valve 8 and the pressure sensor 9 are arranged on the hydraulic valve block 20 .

[0041] like Figures 4 to 11As shown, the hydraulic valve block 20 is provided with a plurality of oil circuits and a plurality of oil ports communicating with the oil circuits, the plurality of oil circuits including a first oil circuit 201, a second oil circuit 202, a third oil circuit 203, a fourth oil circuit 204, a fifth oil circuit 205, a sixth oil circuit 206, a seventh oil circuit 207, an eighth oil circuit 208, a ninth oil circuit 209, a tenth oil circuit 210, an eleventh oil circuit 211, a twelfth oil circuit 212, a thirteenth oil circuit 213, a fourteenth oil circuit 214, a fifteenth oil circuit 215 and a sixteenth oil circuit 216. One end is connected to the first solenoid valve 7, and the middle part of the first oil circuit 201 is connected to the first end of the second oil circuit 202, the second end of the first oil circuit 201 is connected to the middle part of the third oil circuit 203, and the third oil circuit 203 is respectively connected to the first ends of the fourth oil circuit 204, the fifth oil circuit 205 and the sixth oil circuit 206, the middle part of the fourth oil circuit 204 is connected to the first end of the seventh oil circuit 207, and the second end of the fourth oil circuit 204 is connected to the first one-way valve 3, the middle part of the fifth oil circuit 205 is connected to the eighth oil circuit 20 8, and the second end of the fifth oil circuit 205 is connected to the second one-way valve 4, the middle part of the seventh oil circuit 207 is connected to the second end of the eighth oil circuit 208 through the ninth oil circuit 209, and the first end of the ninth oil circuit 209 is provided with a plug, the middle part of the sixth oil circuit 206 is connected to the first end of the tenth oil circuit 210, the second end of the tenth oil circuit 210 is provided with a plug, and the second end of the sixth oil circuit 206 is connected to the third one-way valve 5, the first end of the eleventh oil circuit 211 is connected to the second solenoid valve 8, and the eleventh oil circuit The middle part of the oil circuit 211 is connected to the first ends of the twelfth oil circuit 212, the thirteenth oil circuit 213 and the fourteenth oil circuit 214 respectively, the second end of the thirteenth oil circuit 213 is connected to the pressure sensor 9, and the second end of the fourteenth oil circuit 214 is connected to the overflow valve 6, the middle part of the fourteenth oil circuit 214 is connected to the first end of the fifteenth oil circuit 215, and the second end of the eleventh oil circuit 211 is connected to the first end of the sixteenth oil circuit 216, and the middle part of the sixteenth oil circuit 216 is connected to the middle part of the tenth oil circuit 210.

[0042] In a preferred embodiment, the opening pressure of the second one-way valve 4 is 1 to 3 bar. When the single-acting hydraulic cylinder 11 retracts, the oil in the rodless chamber of the single-acting hydraulic cylinder 11 can first flow back to the rod chamber of the single-acting hydraulic cylinder 11.

[0043] Specifically, the oil tank 17 is used to solve the flow asymmetry problem of the single-acting hydraulic cylinder 11. When the single-acting hydraulic cylinder 11 is extended, the flow missing from the rodless chamber is provided by the oil tank 17; when the single-acting hydraulic cylinder 11 is retracted, the excess flow in the rodless chamber flows back to the oil tank 17.

[0044] The second aspect of the present invention provides a control method for the hydraulic system of the electric loader driving and recovering integrated boom, such as Figure 12As shown, it includes the following steps:

[0045] S1. Start the hydraulic system and identify the working condition of the hydraulic system;

[0046] S2. Detecting the opening signal of the electric control handle 16 through the controller 15 and determining whether the opening signal of the electric control handle 16 is greater than zero. If the opening signal of the electric control handle 16 is greater than zero, the hydraulic system is in an external working condition, and then executing steps S3 and S4; if the opening signal of the electric control handle 16 is not greater than zero, that is, less than or equal to zero, the hydraulic system is in an energy recovery condition, and then directly executing steps S5 and S6;

[0047] S3. After receiving the opening signal of the electric control handle 16, the controller 15 drives the servo motor 1 to rotate, and the servo motor 1 drives the bidirectional fixed-displacement pump 2 to start working. At this time, the bidirectional fixed-displacement pump 2 is used as a hydraulic pump, and the servo motor 1 is in the motor working state;

[0048] S4, the bidirectional quantitative pump 2 draws oil from the oil tank 17 and flows through the second solenoid valve 8 into the rodless chamber of the single-acting hydraulic cylinder 11. At the same time, the oil in the rod chamber of the single-acting hydraulic cylinder 11 flows through the first solenoid valve 7 and the second one-way valve 4 into the oil tank 17. At this time, the boom drives the load up;

[0049] S5, the boom automatically falls under the deadweight of the load, and the single-acting hydraulic cylinder 11 retracts;

[0050] S6. The oil in the rodless chamber of the single-acting hydraulic cylinder 11 flows through the second solenoid valve 8 and enters the bidirectional quantitative pump 2. At this time, the bidirectional quantitative pump 2 is used as a hydraulic motor, and the servo motor 1 is in generator mode.

[0051] In a preferred embodiment, in step S3, when the servo motor 1 is in the motor working state, the capacitor 12 and the external power supply jointly power the servo motor 1; in step S6, when the servo motor 1 is in the generator working state, the servo motor 1 rotates to generate electricity, and then stores the generated electrical energy in the capacitor 12.

[0052] Specifically, when the hydraulic system is in the energy recovery condition, the boom is lowered to the bottom and the single-acting hydraulic cylinder 11 is fully retracted, due to inertia, the bidirectional metering pump 2 will continue to rotate to drive the oil flow. At this time, the oil flows back to the oil inlet of the bidirectional metering pump 2 through the third one-way valve 5, and the oil circulates until the bidirectional metering pump 2 stops rotating.

[0053] like Figure 12 As shown, the controller 15 can match the corresponding motor speed signal to drive the servo motor 1 according to the size of the opening signal of the electric control handle 16 received. When the boom rises, the opening range of the electric control handle 16 is 0<α≤α max, the corresponding speed range of servo motor 1 is 0<n≤n max When the boom is lowered, the opening range of the electric control handle 16 is α min ≤α<0, the corresponding speed range of servo motor 1 is n min ≤n<0.

[0054] In a preferred embodiment, when the speed of the single-acting hydraulic cylinder 11 is zero, the first solenoid valve 7 and the second solenoid valve 8 are both in a closed state, and the single-acting hydraulic cylinder 11 is locked; when the speed of the single-acting hydraulic cylinder 11 is not zero, the first solenoid valve 7 and the second solenoid valve 8 are both in an open state, and the main oil circuit of the hydraulic system is connected.

[0055] like Figure 13 As shown, the capacitor 12 energy storage system detects the current. If the current value I<0, it means that the hydraulic system is in the energy recovery state, the capacitor 12 is charged, and the low voltage terminal voltage U of the converter 13 is adjusted during charging. L If the current value I>0, it means that the hydraulic system is in the external working condition. According to the discharge control strategy of the capacitor 12, the high-voltage terminal voltage U of the converter 13 is adjusted when discharging and charging. H The system is operated by adjusting the low voltage terminal voltage U L And high voltage terminal voltage U H By controlling the charging and discharging power of the capacitor string energy storage unit, the input and output power of the boom pump control system can be matched.

[0056] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. An electric loader drive recovery integrated boom hydraulic system, characterized in that: It includes a servo motor, a bidirectional quantitative pump, a first one-way valve, a second one-way valve, a third one-way valve, a relief valve, a first solenoid valve, a second solenoid valve, a single-acting hydraulic cylinder and a control module. The output end of the servo motor is connected to the driving end of the bidirectional quantitative pump through a coupling, and the first oil outlet of the bidirectional quantitative pump is connected to the oil tank; The first solenoid valve and the second solenoid valve are both two-position two-way solenoid valves, and the first oil port of the first solenoid valve, the oil outlet of the first one-way valve, the oil inlet of the second one-way valve and the oil inlet of the third one-way valve are all connected to the first oil outlet of the bidirectional quantitative pump, the second oil port of the first solenoid valve is connected to the rod chamber of the single-acting hydraulic cylinder, and the oil outlet of the second one-way valve is connected to the oil inlet of the first one-way valve, the oil inlet of the first one-way valve is connected to the oil tank, the first oil port of the second solenoid valve, the oil outlet of the third one-way valve and the oil inlet of the relief valve are all connected to the second oil outlet of the bidirectional quantitative pump, and a pressure sensor and a flow sensor are provided on the pipeline between the second oil outlet of the bidirectional quantitative pump and the first oil port of the second solenoid valve, the second oil port of the second solenoid valve is connected to the rodless chamber of the single-acting hydraulic cylinder, and the oil outlet of the relief valve is connected to the oil tank; The control module can control the precise movement of the single-acting hydraulic cylinder, and the control module includes a capacitor, a converter, a driver and a controller. The servo motor is provided with a driver, the capacitor is communicatively connected to the servo motor through the converter, and the servo motor is communicatively connected to the controller through the driver. The servo motor is provided with an electric control handle that can control the input signal of the servo motor, and the pressure sensor, flow sensor and electric control handle are all communicatively connected to the controller. A speed sensor that can detect the speed of the single-acting hydraulic cylinder is provided at the end of the single-acting hydraulic cylinder, and the speed sensor is connected to the controller.

2. The electric loader drive and recovery integrated boom hydraulic system according to claim 1, characterized in that: The first one-way valve, the second one-way valve, the third one-way valve, the overflow valve, the first solenoid valve, the second solenoid valve and the pressure sensor are arranged on the hydraulic valve block.

3. The electric loader drive and recovery integrated boom hydraulic system according to claim 2, characterized in that: The hydraulic valve block is provided with a plurality of oil circuits and a plurality of oil ports connected to the oil circuits, the plurality of oil circuits including a first oil circuit, a second oil circuit, a third oil circuit, a fourth oil circuit, a fifth oil circuit, a sixth oil circuit, a seventh oil circuit, an eighth oil circuit, a ninth oil circuit, a tenth oil circuit, an eleventh oil circuit, a twelfth oil circuit, a thirteenth oil circuit, a fourteenth oil circuit, a fifteenth oil circuit and a sixteenth oil circuit, a first end of the first oil circuit is connected to the first solenoid valve, and a middle portion of the first oil circuit is connected to the first end of the second oil circuit, a second end of the first oil circuit is connected to the middle portion of the third oil circuit, and the third oil circuit is respectively connected to the first ends of the fourth oil circuit, the middle portion of the fourth oil circuit is connected to the first end of the seventh oil circuit, and the second end of the fourth oil circuit is connected to the first one-way valve, the middle portion of the fifth oil circuit is connected to the first end of the eighth oil circuit, and the second end of the fifth oil circuit is connected to the The second one-way valve is connected, the middle portion of the seventh oil circuit is connected to the second end of the eighth oil circuit through the ninth oil circuit, and the first end of the ninth oil circuit is provided with a plug, the middle portion of the sixth oil circuit is connected to the first end of the tenth oil circuit, the second end of the tenth oil circuit is provided with a plug, and the second end of the sixth oil circuit is connected to the third one-way valve, the first end of the eleventh oil circuit is connected to the second solenoid valve, and the middle portion of the eleventh oil circuit is connected to the first ends of the twelfth oil circuit, the thirteenth oil circuit and the fourteenth oil circuit respectively, the second end of the thirteenth oil circuit is connected to the pressure sensor, and the second end of the fourteenth oil circuit is connected to the relief valve, the middle portion of the fourteenth oil circuit is connected to the first end of the fifteenth oil circuit, and the second end of the eleventh oil circuit is connected to the first end of the sixteenth oil circuit, and the middle portion of the sixteenth oil circuit is connected to the middle portion of the tenth oil circuit.

4. The electric loader drive and recovery integrated boom hydraulic system according to claim 1, characterized in that: The opening pressure of the second one-way valve is 1-3 bar. When the single-acting hydraulic cylinder retracts, the oil in the rodless chamber of the single-acting hydraulic cylinder can first flow back to the rod chamber of the single-acting hydraulic cylinder.

5. A control method for the hydraulic system of the electric loader driving and recovering integrated boom according to any one of claims 1 to 4, characterized in that: It includes the following steps: S1. Start the hydraulic system and identify the working condition of the hydraulic system; S2. Detecting the opening signal of the electric control handle through the controller and determining whether the opening signal of the electric control handle is greater than zero. If the opening signal of the electric control handle is greater than zero, the hydraulic system is in an external working condition, and then executing steps S3 and S4; if the opening signal of the electric control handle is less than or equal to zero, the hydraulic system is in an energy recovery condition, and then directly executing steps S5 and S6; S3, after receiving the opening signal of the electric control handle, the controller drives the servo motor to rotate, and the servo motor drives the bidirectional quantitative pump to start working. At this time, the bidirectional quantitative pump is used as a hydraulic pump, and the servo motor is in the motor working state; S4, the bidirectional quantitative pump draws oil from the oil tank and flows through the second solenoid valve into the rodless chamber of the single-acting hydraulic cylinder. At the same time, the oil in the rod chamber of the single-acting hydraulic cylinder flows through the first solenoid valve and the second one-way valve into the oil tank. At this time, the boom drives the load to rise; S5, the boom automatically falls under the deadweight of the load, and the single-acting hydraulic cylinder retracts; S6. The oil in the rodless chamber of the single-acting hydraulic cylinder flows through the second solenoid valve and then enters the bidirectional quantitative pump. At this time, the bidirectional quantitative pump is used as a hydraulic motor, and the servo motor is in a generator working state.

6. The control method of the hydraulic system of the electric loader driving and recovering integrated boom according to claim 5, characterized in that: The controller matches the corresponding motor speed signal to drive the servo motor according to the size of the electric control handle opening signal received. When the boom rises, the opening range of the electric control handle is 0<α≤α max , the corresponding speed range of the servo motor is 0<n≤n max When the boom is lowered, the opening range of the electric control handle is α min ≤α<0, the corresponding speed range of the servo motor is n min ≤n<0.

7. The control method of the hydraulic system of the electric loader driving and recovering integrated boom according to claim 5, characterized in that: In step S3, when the servo motor is in the motor working state, the capacitor and the external power supply jointly power the servo motor; in step S6, when the servo motor is in the generator working state, the servo motor rotates to generate electricity, and then stores the generated electrical energy in the capacitor.

8. The control method of the hydraulic system of the electric loader driving and recovering integrated boom according to claim 5, characterized in that: When the speed of the single-acting hydraulic cylinder is zero, the first solenoid valve and the second solenoid valve are both in a closed state, and the single-acting hydraulic cylinder is locked; when the speed of the single-acting hydraulic cylinder is not zero, the first solenoid valve and the second solenoid valve are both in an open state, and the main oil circuit of the hydraulic system is connected.

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