Driving and recycling integrated movable arm hydraulic system of electric loader and control method of driving and recycling integrated movable arm hydraulic system

Abstract

The invention relates to a driving and recycling integrated movable arm hydraulic system of an electric loader and a control method of the driving and recycling integrated movable arm hydraulic system. A servo motor is coaxially connected with a two-way constant delivery pump, and a first oil outlet of the two-way constant delivery pump communicates with a rod cavity of a single-action hydraulic cylinder through a first electromagnetic valve, a first one-way valve, a second one-way valve and a third one-way valve; a second oil outlet of the two-way metering pump is communicated with a rodless cavity of the single-action hydraulic cylinder through a second electromagnetic valve, a third one-way valve and an overflow valve, and the hydraulic system is provided with a control module capable of controlling the single-action hydraulic cylinder to move accurately. The pump control system has no throttling loss of a valve and is high in energy utilization rate, meanwhile, potential energy generated in the self-weight descending stage of the movable arm is converted into electric energy to be stored to the maximum extent by the system, and the electric energy is released and used when acting outwards in the ascending stage of the movable arm, so that energy loss is effectively reduced, and the energy utilization rate is increased; in addition, driving and recycling are achieved through one set of motor-pump, and the space utilization rate is increased.

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 engineering machinery, electric loaders can effectively reduce pollution emissions. During the operation of the loader, the boom hydraulic system is one of its core components. Traditional hydraulic systems usually use valve control systems. In valve control systems, hydraulic oil will produce pressure loss and throttling loss when passing through the valve, resulting in reduced system efficiency. The energy loss problem is particularly obvious under long-term high-load operation. At the same time, the potential energy generated during the boom descent is usually lost through the throttling of the hydraulic oil, resulting in a large amount of energy waste. Summary of the invention

[0003] In view of 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 does external work during the ascending stage, effectively reducing energy loss and improving energy utilization. In addition, its drive and recovery are all achieved with a set of motor-pumps, effectively reducing costs and improving space utilization.

[0004] The technical solution adopted by the present invention is an electric loader driven recovery integrated boom hydraulic system, 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 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, and the first oil port of the second solenoid valve, the oil outlet of the third one-way valve and the oil outlet of the second one-way valve are connected to the oil tank. 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 communicatively connected to the servo motor through the converter, and the servo motor is communicatively connected to the controller through the driver, an electric control handle that can control the input signal of the servo motor is provided on 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.

[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 communicated with the oil circuits, the plurality of oil circuits include 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 communicated with the first solenoid valve, and a middle portion of the first oil circuit is communicated with a first end of the second oil circuit, a second end of the first oil circuit is communicated with a middle portion of the third oil circuit, and the third oil circuit is respectively communicated with the first ends of the fourth oil circuit, the fifth oil circuit and the sixth oil circuit, a middle portion of the fourth oil circuit is communicated with the first end of the seventh oil circuit, and the second end of the fourth oil circuit is communicated with the first one-way valve, a middle portion of the fifth oil circuit is communicated with the first end of the eighth oil circuit, and a 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 respectively connected to the first ends of the twelfth oil circuit, the thirteenth oil circuit and the fourteenth oil circuit, 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 recycling integrated boom, which comprises 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 judging 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 sucks 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 to work 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 a motor working condition, the capacitor and the external power supply jointly power the servo motor; in step S6, when the servo motor is in a generator working condition, 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 driven recovery integrated boom hydraulic system and control method thereof 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, an overflow valve is installed in the main oil circuit. When an abnormal pressure or flow in the hydraulic system is detected, rapid unloading can be completed through the overflow valve 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 stable operation of the system.

[0020] 2. The electric loader driven recovery integrated boom hydraulic system and control method provided by the present invention, based on the rated displacement of the bidirectional quantitative pump, only needs 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, and the rising and falling speed of the boom can be controlled by controlling the opening of the handle.

[0021] 3. The electric loader drive and recovery integrated boom hydraulic system and control method provided by the present invention use the same set of servo motor-pump to complete the driving and energy recovery actions. The capacitor converts the consumed potential energy generated 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 It is a schematic diagram of the hydraulic system of 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 The present 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 The present invention Figure 6 Sectional view along AA direction;

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

[0030] Fig. 9 The present invention Figure 8 Sectional view along CC direction;

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

[0032] Fig.11 The present invention Fig.10 Cross-sectional view along the DD direction;

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

[0034] Fig.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] In order to fully describe the technical content, structural features, objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

[0038] The present invention provides 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. The two hydraulic pumps are connected, and the oil outlet of the second one-way valve 4 is connected with the oil inlet of the first one-way valve 3, the oil inlet of the first one-way valve 3 is connected with 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 overflow valve 6 are all connected with 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 with the rodless chamber of the single-acting hydraulic cylinder 11, and the oil outlet of the overflow valve 6 is connected with the oil tank 17. When an abnormality is detected in the system pressure or flow, rapid unloading is completed through the overflow 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 used as a super capacitor. 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 input signal of the servo motor, and the pressure sensor 9, the flow sensor 10 and the 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, the first oil circuit 201 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 check valve 3, the middle part of the fifth oil circuit 205 is connected to the eighth oil circuit 20 The first 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 211 is connected to the second one-way valve 8. The middle part of the oil circuit 211 is connected with 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 with the pressure sensor 9, and the second end of the fourteenth oil circuit 214 is connected with the overflow valve 6, the middle part of the fourteenth oil circuit 214 is connected with the first end of the fifteenth oil circuit 215, and the second end of the eleventh oil circuit 211 is connected with the first end of the sixteenth oil circuit 216, and the middle part of the sixteenth oil circuit 216 is connected with 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 1-3 bar, and 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 problem of asymmetric flow 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] A second aspect of the present invention provides a control method for a hydraulic system of an electric loader driving and recovering integrated boom, such as Fig.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 judging 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 the controller 15 receives the opening signal of the electric control handle 16, it drives the servo motor 1 to rotate, and the servo motor 1 drives the bidirectional quantitative pump 2 to start working. At this time, the bidirectional quantitative pump 2 is used as a hydraulic pump, and the servo motor 1 is in the motor working state;

[0048] S4, the two-way quantitative pump 2 sucks 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 and then enters the oil tank 17. At this time, the boom drives the load to rise;

[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 a generator working state.

[0051] In a preferred embodiment, in step S3, when the servo motor 1 is in a motor operating 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 a generator operating 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 two-way 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 two-way metering pump 2 through the third one-way valve 5, and the oil circulates until the two-way metering pump 2 stops rotating.

[0053] like Fig.12 As shown, the controller 15 can match the corresponding motor speed signal to drive the servo motor 1 to work 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 Fig.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 during discharge 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 only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design 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 all fall within the protection scope 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 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 and the oil inlet of the overflow valve are all connected to the second oil outlet of the two-way quantitative pump, and a pressure sensor and a flow sensor are provided on the pipeline between the second oil outlet of the two-way 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. 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 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 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 communicating with the oil circuits, the plurality of oil circuits include 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 a first end of the second oil circuit, a second end of the first oil circuit is connected to a 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, a middle portion of the fourth oil circuit is connected to the first end of the seventh oil circuit, and a second end of the fourth oil circuit is connected to the first one-way valve, a middle portion of the fifth oil circuit is connected to the first end of the eighth oil circuit, and a second end of the fifth oil circuit is connected to the The second one-way valve is connected, 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 respectively connected to the first ends of the twelfth oil circuit, the thirteenth oil circuit and the fourteenth oil circuit, 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.

4. The electric loader drive 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 judging 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 sucks 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 according to the size of the electric control handle opening signal received to drive the servo motor to work. 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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