A hydraulic control system for lifting and lowering and a control method thereof

Abstract

The present invention relates to the technical field of hydraulic control systems, and discloses a hydraulic control system for lifting and lowering and a control method thereof. The hydraulic control system includes two oil cylinders, two displacement sensors, an oil supply module, a replenishment module, and a control module. The two displacement sensors are respectively connected to the piston rods of the two oil cylinders to collect displacement signals; the oil supply module is connected to the oil tank and can selectively supply or return oil to the rodless chamber and rod chamber of the two oil cylinders; the control module controls the replenishment module to replenish hydraulic oil to the rodless chamber or rod chamber of either of the two oil cylinders based on the difference in displacement signals collected by the two displacement sensors, so that the two oil cylinders can be raised and lowered synchronously, thereby reducing or even eliminating the problem of unbalanced loading during the lifting process.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control systems, and in particular to a hydraulic control system for lifting and lowering and a control method thereof. Background Art

[0002] With the development of the logistics industry, excavators, material grabbers, steel grabbers, and other work machines have become widely used. To improve the operator's field of view and work efficiency, these machines often require hydraulic control systems to raise and lower the control panel. However, these hydraulic control systems are susceptible to various factors and are prone to overloading, seriously affecting the smoothness and safety of the control panel's raising and lowering. Summary of the Invention

[0003] In view of this, the present invention provides a hydraulic control system for lifting and a control method thereof, so as to reduce or even eliminate the problem of unbalanced loading during the lifting process.

[0004] In a first aspect, the present invention provides a hydraulic control system for lifting, comprising: a first oil cylinder and a second oil cylinder, the first oil cylinder comprising a first piston rod, and having a first rodless cavity and a first rod cavity, the second oil cylinder comprising a second piston rod, and having a second rodless cavity and a second rod cavity; a first displacement sensor and a second displacement sensor, respectively connected to the first piston rod and the second piston rod; the first displacement sensor is used to collect the displacement signal of the first piston rod, and the second displacement sensor is used to collect the displacement signal of the second piston rod; an oil supply module, connected to the oil tank, and configured to selectively supply oil to the first rodless cavity and the second rodless cavity, and return oil to the first rod cavity and the second rod cavity, or supply oil to the first rod cavity and the second rod cavity, and return oil to the first rodless cavity and the second rodless cavity; a replenishment module , including an oil suction port, a first oil outlet, a second oil outlet, a third oil outlet and a fourth oil outlet, the oil suction port is used to communicate with the oil tank, and the oil suction port is configured to selectively communicate with the first oil outlet, or the second oil outlet, or the third oil outlet, or the fourth oil outlet; the first oil outlet is connected to the first rod cavity, the second oil outlet is connected to the second rod cavity, the third oil outlet is connected to the first rodless cavity, and the fourth oil outlet is connected to the second rodless cavity; a control module is electrically connected to the oil supply module, the replenishment module, the first displacement sensor and the second displacement sensor; the control module is configured to control the replenishment module to replenish hydraulic oil to the first rod cavity, or the second rod cavity, or the first rodless cavity, or the second rodless cavity according to the difference in displacement signals collected by the first displacement sensor and the second displacement sensor.

[0005] In an optional embodiment, the supplementary module includes: a high-pressure pump having a high-pressure pump oil suction port and a high-pressure pump oil outlet, the high-pressure pump oil suction port forming an oil suction port; a one-way valve group, the oil outlet of the one-way valve group forming a first oil outlet, a second oil outlet, a third oil outlet and a fourth oil outlet; an electro-hydraulic servo valve and a reversing valve, the electro-hydraulic servo valve and the reversing valve are connected and can be communicated between the high-pressure pump oil outlet and the oil inlet of the one-way valve group; the electro-hydraulic servo valve and the reversing valve are configured to selectively connect the high-pressure pump oil outlet with the first oil outlet, or the second oil outlet, or the third oil outlet, or the fourth oil outlet.

[0006] In an optional embodiment, the hydraulic control system also includes a buffer module, the buffer module includes an accumulator; the oil supply module includes: a proportional valve group, having a proportional valve group oil inlet, a proportional valve group oil outlet 1, a proportional valve group oil outlet 2 and a proportional valve group oil return port, the proportional valve group oil inlet is configured to be selectively connected to the proportional valve group oil outlet 1, or the proportional valve group oil outlet 2; the proportional valve group oil return port is used to connect with the oil tank, and is configured to be selectively connected to the proportional valve group oil outlet 1, or the proportional valve group oil outlet 2; the proportional valve group oil outlet 1 is connected to the first rodless cavity and the second rodless cavity, and the proportional valve group oil outlet 2 is connected to the first rod cavity and the second rod cavity; the main valve has a main valve oil outlet, the main valve oil outlet is connected to the proportional valve group oil inlet, and is connected to the accumulator.

[0007] In an optional embodiment, the buffer module also includes: a first cone valve, which can be communicatively arranged between the accumulator and the first rodless chamber, and can be communicatively arranged between the accumulator and the second rodless chamber; a second cone valve, which can be communicatively arranged between the oil tank and the first rod chamber, and can be communicatively arranged between the oil tank and the second rod chamber; a first solenoid valve, connected between the first cone valve and the second cone valve, the first solenoid valve being configured to control the on and off of the first cone valve and the second cone valve; and / or, the buffer module also includes a second solenoid valve, which can be communicatively arranged between the accumulator and the first rod chamber, and can be communicatively arranged between the accumulator and the second rod chamber.

[0008] In an optional embodiment, the oil supply module also includes two hydraulic motors, which are coaxially arranged. The oil inlets of the two hydraulic motors are connected to the oil outlet of the proportional valve group, and the oil outlets of the two hydraulic motors are respectively connected to the first rodless chamber and the second rodless chamber; the supplementary module also includes an electromagnetic clutch, which is coaxially connected between the hydraulic motor and the high-pressure pump.

[0009] In an optional embodiment, the oil supply module also includes: a first explosion-proof valve and a second explosion-proof valve, the oil inlets of the first explosion-proof valve and the second explosion-proof valve are both connected to the oil outlet 1 of the proportional valve group, the oil outlet of the first explosion-proof valve is connected to the first rodless cavity and the third oil outlet, and the oil outlet of the second explosion-proof valve is connected to the second rodless cavity and the fourth oil outlet; and / or, the oil supply module also includes: a first hydraulically controlled one-way valve and a second hydraulically controlled one-way valve, the first hydraulically controlled one-way valve is connected between the first rod cavity and the oil outlet 2 of the proportional valve group, and the second hydraulically controlled one-way valve is connected between the second rod cavity and the oil outlet 2 of the proportional valve group; the oil outlet 1 of the proportional valve group is connected to the control oil port of the first hydraulically controlled one-way valve and the control oil port of the second hydraulically controlled one-way valve.

[0010] In an optional embodiment, the proportional valve group includes a first cartridge-type proportional directional control valve, a second cartridge-type proportional directional control valve, a third cartridge-type proportional directional control valve, and a fourth cartridge-type proportional directional control valve connected in a closed loop.

[0011] In an optional embodiment, the main valve further includes a first bypass cut-off valve, the oil inlet of the first bypass cut-off valve is connected to the oil outlet of the main valve, and the oil outlet of the first bypass cut-off valve is used to communicate with the oil tank.

[0012] In the second aspect, the present invention also provides a control method for a hydraulic control system for lifting, applying the hydraulic control system as described above, the control method includes the following steps: in the ascending stage: the control unit controls the oil supply module to supply oil to the first rodless cavity and the second rodless cavity, and returns oil to the first rod cavity and the second rod cavity; in the ascending process: the control unit obtains the difference in displacement information collected by the first displacement sensor and the second displacement sensor; when the difference is 0, no action is taken; when the difference is greater than 0, the control unit controls the oil suction port to be connected to the fourth oil outlet to replenish hydraulic oil to the second rodless cavity; when the difference is less than 0, the control unit The oil suction port is controlled to be connected with the third oil outlet to replenish hydraulic oil to the first rodless chamber; in the descending stage: the control unit controls the oil supply module to supply oil to the first rod chamber and the second rod chamber, and returns oil to the first rodless chamber and the second rodless chamber; in the descending process: the control unit obtains the difference in displacement information collected by the first displacement sensor and the second displacement sensor; when the difference is 0, no action is taken; when the difference is greater than 0, the control unit controls the oil suction port to be connected with the second oil outlet to replenish hydraulic oil to the second rod chamber; when the difference is less than 0, the control unit controls the oil suction port to be connected with the first oil outlet to replenish hydraulic oil to the first rod chamber.

[0013] In an optional embodiment, the hydraulic control system further includes a buffer module, which includes: an accumulator, which is connected to the oil supply module; a first poppet valve, which can be communicatively arranged between the accumulator and the first rodless chamber, and can be communicatively arranged between the accumulator and the second rodless chamber; a second poppet valve, which can be communicatively arranged between the oil tank and the first rod chamber, and can be communicatively arranged between the oil tank and the second rod chamber; a first solenoid valve, which is connected between the first poppet valve and the second poppet valve, and is configured to control the on and off of the first poppet valve and the second poppet valve; a second solenoid valve, which can be communicatively arranged between the accumulator and the first rod chamber, and can be communicatively arranged between the accumulator and the second rod chamber;

[0014] The control method also includes the following steps: at the moment of starting the ascent and during the ascent: the control unit controls the first solenoid valve and the second solenoid valve to be disconnected, so that the oil supply module is connected to the accumulator; and / or, when the ascent stops: the control unit controls the first solenoid valve to be connected and the second solenoid valve to be disconnected, so that the first cone valve and the second cone valve are opened; the accumulator is connected to the first rodless chamber and the second rodless chamber through the first cone valve; the first rod chamber and the second rod chamber are connected to the oil tank through the second cone valve; and / or, at the moment of starting the descent: the control unit controls the first solenoid valve to be disconnected and the second solenoid valve to be connected, so that the accumulator is connected to the first rod chamber and the second rod chamber; and / or, during the descent process and when the descent stops: the control unit controls the first solenoid valve to be connected and the second solenoid valve to be disconnected, so that the first cone valve and the second cone valve are opened; the accumulator is connected to the first rodless chamber and the second rodless chamber through the first cone valve; the first rod chamber and the second rod chamber are connected to the oil tank through the second cone valve.

[0015] By utilizing the technical solution of the present invention, a hydraulic control system for lifting is provided with a supplementary module, a first displacement sensor, and a second displacement sensor. The supplementary module can selectively supplement hydraulic oil to the first rod chamber, or the second rod chamber, or the first rodless chamber, or the second rodless chamber. The first displacement sensor and the second displacement sensor can respectively collect the displacement value of the first piston rod and the displacement value of the second piston rod; the control module performs electronic control logic judgment and control on the supplementary module, the first displacement sensor, and the second displacement sensor to dynamically compensate for the flow pressure in the lifting process of the first oil cylinder and the second oil cylinder in real time, so that the first oil cylinder and the second oil cylinder are lifted and lowered synchronously, thereby reducing or even eliminating the problem of unbalanced load during the lifting process.

[0016] Furthermore, the technical solution of the present invention utilizes an accumulator, a first solenoid valve, a first cone valve, a second cone valve and a second solenoid valve, etc., in combination with the cylinder action process, to perform electronic control logic control, fully controlling the flow and pressure distribution of the accumulator, ensuring that the cylinder is at the moment of starting to rise, during the rising process, at the moment of stopping to rise, at the moment of starting to lower, during the falling process, at the moment of stopping to lower, and at each stage of construction operation after lifting to a certain position, thereby minimizing impact and pressure fluctuations to ensure comfort and safety of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a hydraulic principle diagram of a hydraulic control system for lifting according to an embodiment of the present invention;

[0019] Figure 2 This is a structural schematic diagram of a lifting module according to an embodiment of the present invention;

[0020] Figure 3 This is a structural schematic diagram of a main valve according to an embodiment of the present invention;

[0021] Figure 4 This is a structural schematic diagram of an electro-hydraulic servo valve and a reversing valve according to an embodiment of the present invention;

[0022] Figure 5 This is a structural schematic diagram of a one-way valve group according to an embodiment of the present invention;

[0023] Figure 6 This is a structural diagram of a proportional valve group according to an embodiment of the present invention;

[0024] Figure 7 This is a schematic structural diagram of a first explosion-proof valve according to an embodiment of the present invention;

[0025] Figure 8 A schematic diagram of the relationship between the current and displacement of a main pump according to an embodiment of the present invention;

[0026] Figure 9 The present invention is a flowchart of a control method of a hydraulic control system for lifting.

[0027] Explanation of the reference numerals: 1. Engine; 2. Fuel tank; 3.1. First main pump; 3.2. Second main pump; 4. Pilot pump; 5. Main valve; 5.1. Main valve oil inlet 1; 5.2. Main valve oil inlet 2; 5.3. Main valve oil outlet; 5.4. First bypass cut-off valve; 5.5. Second bypass cut-off valve; 6.1. First pilot pressure sensor; 6.2. Second pilot pressure sensor; 7. Electric pedal; 8. Controller; 9. Accumulator; 10. First solenoid valve; 11.1. First cone valve; 11.2. Second cone valve; 12. Second electric pedal Solenoid valve; 13. On-off valve; 14. Electro-hydraulic servo valve; 14.1. Electro-hydraulic servo valve oil inlet; 14.2. Electro-hydraulic servo valve oil return; 14.3. Electro-hydraulic servo valve oil outlet 1; 14.4. Electro-hydraulic servo valve oil outlet 2; 15. Directional valve; 15.1. Directional valve oil inlet 1; 15.2. Directional valve oil inlet 2; 15.3. Directional valve oil outlet 1; 15.4. Directional valve oil outlet 2; 15.5. Directional valve oil outlet 3; 15.6. Directional valve oil outlet 4; 16.1. First hydraulically controlled one-way valve; 16.2. Second hydraulically controlled one-way valve Valve; 17.1, first displacement sensor; 17.2, second displacement sensor; 18.1, first oil cylinder; 18.1.1, first piston rod; 18.1.2, first rodless cavity; 18.1.3, first rod cavity; 18.2, second oil cylinder; 18.2.1, second piston rod; 18.2.2, second rodless cavity; 18.2.3, second rod cavity; 19, lifting platform; 19.1, first pressure sensor; 19.2, second pressure sensor; 20.1, first explosion-proof valve; 20.2, second explosion-proof valve; 21, single directional valve group; 21.1, first one-way valve; 21.2, second one-way valve; 21.3, third one-way valve; 21.4, fourth one-way valve; 22, proportional valve group; 22.1, first cartridge-type proportional directional valve; 22.2, second cartridge-type proportional directional valve; 22.3, third cartridge-type proportional directional valve; 22.4, fourth cartridge-type proportional directional valve; a, proportional valve group oil inlet; b, proportional valve group oil outlet 1; c, proportional valve group oil return port; d, proportional valve group oil outlet 2; 23, hydraulic motor; 24, electromagnetic clutch; 25, high-pressure pump. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0029] Excavators hold a leading position in the field of construction machinery and are indispensable in every field. As the scope and scope of excavator applications expand, the demand for their diverse and comprehensive functions is also increasing. With the development of the logistics industry, material handling and transport are increasingly being carried out using material grabbers or steel grabbers. These grabbers are products that have been optimized and upgraded based on the excavator platform. Because they are frequently used in inland ports, harbors, and steel mills, the control console needs to be raised to improve the operator's field of view and work efficiency. This increased height of the control console poses urgent challenges in ensuring smooth and safe raising and lowering of the console, as well as reliable operation after reaching a certain height.

[0030] In the related art, it is often necessary to use a hydraulic control system to realize the lifting and lowering of the control panel. Usually, in the hydraulic control system of the related art, the control panel is installed on two hydraulic cylinders, and the lifting and lowering of the two lifting cylinders are controlled by the hydraulic oil source, the hydraulically controlled reversing valve, the pilot proportional handle, etc., so as to realize the lifting and lowering of the control panel. However, due to external interference factors (such as interference from strong winds at high altitudes), manufacturing errors of the control panel, uneven layout of various devices on the control panel, installation and manufacturing errors of the hydraulic cylinders, and inconsistent characteristics such as the stiffness and strength of the piston rods of the hydraulic cylinders, the control panel will often be overloaded. Overloading will cause the control panel to generate an overturning moment, seriously affecting the safety of the operator; at the same time, overloading will also cause the pressure flow of the rodless chambers of the two lifting cylinders to be unequal, which will lead to different movement speeds of the two lifting cylinders, causing wear and impact problems at the hinges of the lifting cylinders and the lifting mechanism. Therefore, the overloading problem seriously affects the stability and safety of the lifting.

[0031] Based on this, the present invention provides a hydraulic control system for lifting and a control method thereof, so as to reduce or even eliminate the problem of unbalanced loading during the lifting process.

[0032] The following combination Figures 1 to 9 , describing embodiments of the present invention.

[0033] According to an embodiment of the present invention, on the one hand, a hydraulic control system for lifting is provided, including a lifting module, an oil supply module, a supplement module and a control module.

[0034] Specifically, if Figure 1 and Figure 2As shown, the lifting module includes two cylinders and two displacement sensors. The two cylinders are respectively a first cylinder 18.1 and a second cylinder 18.2. The first cylinder 18.1 includes a first piston rod 18.1.1, and has a first rodless cavity 18.1.2 and a first rod cavity 18.1.3. The second cylinder 18.2 includes a second piston rod 18.2.1, and has a second rodless cavity 18.2.2 and a second rod cavity 18.2.3. The two displacement sensors are respectively a first displacement sensor 17.1 and a second displacement sensor 17.2. The first displacement sensor 17.1 and the second displacement sensor 17.2 are respectively connected to the first piston rod 18.1.1 and the second piston rod 18.2.1. The first displacement sensor 17.1 is used to collect the displacement signal of the first piston rod 18.1.1, and the second displacement sensor 17.2 is used to collect the displacement signal of the second piston rod 18.2.1.

[0035] Specifically, the oil supply module is used to communicate with the oil tank 2, and the oil supply module is configured to selectively supply oil to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2, and return oil to the first rod chamber 18.1.3 and the second rod chamber 18.2.3; or supply oil to the first rod chamber 18.1.3 and the second rod chamber 18.2.3, and return oil to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2.

[0036] Specifically, the replenishment module includes an oil intake port, a first oil outlet, a second oil outlet, a third oil outlet, and a fourth oil outlet. The oil intake port is used to communicate with the oil tank 2 and is configured to selectively communicate with the first oil outlet, the second oil outlet, the third oil outlet, or the fourth oil outlet. The first oil outlet communicates with the first rod chamber 18.1.3, the second oil outlet communicates with the second rod chamber 18.2.3, the third oil outlet communicates with the first rodless chamber 18.1.2, and the fourth oil outlet communicates with the second rodless chamber 18.2.2.

[0037] Among them, the control module is electrically connected to the oil supply module, the replenishing module, the first displacement sensor 17.1 and the second displacement sensor 17.2; the control module is configured to control the replenishing module to replenish hydraulic oil to the first rod chamber 18.1.3, or the second rod chamber 18.2.3, or the first rodless chamber 18.1.2, or the second rodless chamber 18.2.2 according to the difference between the displacement signals collected by the first displacement sensor 17.1 and the second displacement sensor 17.2.

[0038] In this embodiment, the control process of the hydraulic control system is as follows:

[0039] When the lifting module is lifted, in the ascending stage, the control unit controls the oil supply module to supply oil to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2, and returns oil to the first rod chamber 18.1.3 and the second rod chamber 18.2.3 to realize the lifting operation. In addition, during the ascending process, the control unit obtains the difference in displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2. If the difference is 0, it indicates that there is no overload, and no action is taken at this time; if the difference is greater than 0, it indicates that there is overload, and the load pressure of the first oil cylinder 18.1 is less than the load pressure of the second oil cylinder 18.2. At this time, the control unit controls the oil suction port to be connected to the fourth oil outlet to replenish hydraulic oil to the second rodless chamber 18.2.2, and perform pressure and flow compensation on the second rodless chamber 18.2.2 until the difference in displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2 is 0, so that the suction port is connected. The oil port is disconnected from the fourth oil outlet; if the difference is less than 0, it indicates that there is an unbalanced load, and the load pressure of the first oil cylinder 18.1 is greater than the load pressure of the second oil cylinder 18.2. At this time, the control unit controls the oil suction port to be connected to the third oil outlet to replenish hydraulic oil to the first rodless chamber 18.1.2, and perform pressure and flow compensation on the first rodless chamber 18.1.2 until the difference between the displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2 is 0, and the oil suction port is disconnected from the third oil outlet.

[0040] When the lifting module is lowered, during the lowering stage, the control unit controls the oil supply module to supply oil to the first rod chamber 18.1.3 and the second rod chamber 18.2.3, and returns oil to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2 to realize the lowering operation. In addition, during the lowering process, the control unit obtains the difference in displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2. If the difference is 0, it indicates that there is no overload, and no action is taken at this time; if the difference is greater than 0, it indicates that there is overload, and the load pressure of the first oil cylinder 18.1 is less than the load pressure of the second oil cylinder 18.2. At this time, the control unit controls the oil suction port to be connected with the second oil outlet port to replenish hydraulic oil to the second rod chamber 18.2.3, and perform pressure and flow compensation on the second rod chamber 18.2.3 until the difference in displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2 is 0, so that the suction port is connected. The oil port is disconnected from the second oil outlet; if the difference is less than 0, it indicates that there is an unbalanced load, and the load pressure of the first oil cylinder 18.1 is greater than the load pressure of the second oil cylinder 18.2. At this time, the control unit controls the oil suction port to be connected to the first oil outlet to replenish hydraulic oil to the first rod chamber 18.1.3, and performs pressure and flow compensation on the first rod chamber 18.1.3 until the difference between the displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2 is 0, and the oil suction port is disconnected from the second oil outlet.

[0041] Utilizing the technical solution of the present invention, first displacement sensor 17.1 and second displacement sensor 17.2 can respectively detect the displacement values ​​of first piston rod 18.1.1 and second piston rod 18.2.1. The replenishment module can selectively replenish hydraulic oil to the first rod chamber 18.1.3, the second rod chamber 18.2.3, the first rodless chamber 18.1.2, or the second rodless chamber 18.2.2. The control module electronically controls and logically determines and controls the replenishment module, first displacement sensor 17.1, and second displacement sensor 17.2 to dynamically compensate for flow and pressure during the raising and lowering of first and second cylinders 18.1, 18.2 in real time, ensuring synchronous raising and lowering of first and second cylinders 18.1, 18.2, and minimizing or even eliminating unbalanced loads during the raising and lowering process.

[0042] More specifically, in some embodiments, Figure 1 and Figure 2 As shown, the lifting module also includes a lifting platform 19 and two pressure sensors. The lifting platform 19 is connected to the first piston rod 18.1.1 and the second piston rod 18.2.1. The first oil cylinder 18.1 and the second oil cylinder 18.2 realize the lifting and lowering of the lifting platform 19 by extending and retracting the first piston rod 18.1.1 and the second piston rod 18.2.1. The two pressure sensors are the first pressure sensor 19.1 and the second pressure sensor 19.2. The first pressure sensor 19.1 is connected to the oil port of the first rodless chamber 18.1.2, and the second pressure sensor 19.2 is connected to the oil port of the second rodless chamber 18.2.2. Both the first pressure sensor 19.1 and the second pressure sensor 19.2 are electrically connected to the control module. The first pressure sensor 19.1 is used to collect pressure information of the first rodless chamber 18.1.2 and transmit this pressure information to the control module; the second pressure sensor 19.2 is used to collect pressure information of the second rodless chamber 18.2.2 and transmit this pressure information to the control module. The control module can more accurately determine the load pressure of the first rodless cavity 18.1.2 and the second rodless cavity 18.2.2 based on the pressure information, so as to perform real-time pressure and flow compensation, further reducing or even eliminating the risk of overloading.

[0043] It is understood that the hydraulic control system of the present invention can be applied to any work machine requiring lifting operations, including but not limited to excavators, steel grabbers, material grabbers, and elevators. For example, if the work machine is an excavator, the lifting platform 19 can be a control console on which the excavator cab is located. For example, if the work machine is an elevator, the lifting platform 19 can be a lifting platform used to carry materials.

[0044] In some embodiments, the supplemental module includes a high-pressure pump 25, an electro-hydraulic servo valve 14, a reversing valve 15, and a one-way valve assembly 21. Specifically, the high-pressure pump 25 has a high-pressure pump oil intake and a high-pressure pump oil outlet. The high-pressure pump oil intake is connected to the fuel tank 2 and forms the oil intake of the supplemental module. The electro-hydraulic servo valve 14 and the reversing valve 15 are connected and are arranged so as to be communicable between the high-pressure pump oil outlet and the oil inlet of the one-way valve assembly 21. The electro-hydraulic servo valve 14 and the reversing valve 15 are both electrically connected to the control module. Under the control of the control module, the electro-hydraulic servo valve 14 and the reversing valve 15 are configured to selectively connect the high-pressure pump oil outlet to the first oil outlet, the second oil outlet, the third oil outlet, or the fourth oil outlet. The oil outlet of the one-way valve assembly 21 forms the first oil outlet, the second oil outlet, the third oil outlet, and the fourth oil outlet of the supplemental module.

[0045] More specifically, if Figure 4 As shown, the electro-hydraulic servo valve 14 has an electro-hydraulic servo valve oil inlet 14.1, an electro-hydraulic servo valve oil return port 14.2, an electro-hydraulic servo valve oil outlet 1 14.3, and an electro-hydraulic servo valve oil outlet 2 14.4. The electro-hydraulic servo valve oil inlet 14.1 is connected to the high-pressure pump oil outlet and is configured to selectively connect to either electro-hydraulic servo valve oil outlet 1 14.3 or electro-hydraulic servo valve oil outlet 2 14.4. The electro-hydraulic servo valve oil return port 14.2 is connected to the oil tank 2. The electro-hydraulic servo valve 14 is electrically connected to a control module. The control module ensures that when the upper position of the electro-hydraulic servo valve 14 is energized, the lower position operates, that is, the electro-hydraulic servo valve oil inlet 14.1 is connected to the electro-hydraulic servo valve oil outlet 2 14.4. The control module ensures that when the lower position of the electro-hydraulic servo valve 14 is energized, the upper position operates, that is, the electro-hydraulic servo valve oil inlet 14.1 is connected to the electro-hydraulic servo valve oil outlet 1 14.3.

[0046] Furthermore, reversing valve 15 has reversing valve oil inlet 15.1, reversing valve oil inlet 2 15.2, reversing valve oil outlet 1 15.3, reversing valve oil outlet 2 15.4, reversing valve oil outlet 3 15.5, and reversing valve oil outlet 4 15.6. Reversing valve oil inlet 15.1 is connected to electro-hydraulic servo valve oil outlet 1 14.3 and is configured to selectively communicate with reversing valve oil outlet 1 15.3 or reversing valve oil outlet 3 15.5. Reversing valve oil inlet 2 15.2 is connected to electro-hydraulic servo valve oil outlet 2 14.4 and is configured to selectively communicate with reversing valve oil outlet 2 15.4 or reversing valve oil outlet 4 15.6. The reversing valve 15 is electrically connected to a control module, which energizes the reversing valve 15, thereby selectively connecting the reversing valve oil inlet 15.1 to the reversing valve oil outlet 1 15.3, or the reversing valve oil outlet 3 15.5; or connecting the reversing valve oil inlet 2 15.2 to the reversing valve oil outlet 2 15.4, or the reversing valve oil outlet 4 15.6.

[0047] Further, if Figure 5 As shown, the one-way valve assembly 21 includes a first one-way valve 21.1, a second one-way valve 21.2, a third one-way valve 21.3, and a fourth one-way valve 21.4. The oil inlet of the first one-way valve 21.1 is connected to the first oil outlet 15.3 of the reversing valve, and the oil outlet of the first one-way valve 21.1 forms the first oil outlet mentioned above. The oil inlet of the second one-way valve 21.2 is connected to the second oil outlet 15.4 of the reversing valve, and the oil outlet of the second one-way valve 21.2 forms the second oil outlet mentioned above. The oil inlet of the third one-way valve 21.3 is connected to the third oil outlet 15.5 of the reversing valve, and the oil outlet of the third one-way valve 21.3 forms the third oil outlet mentioned above. The oil inlet of the fourth one-way valve 21.4 is connected to the fourth oil outlet 15.6 of the reversing valve, and the oil outlet of the fourth one-way valve 21.4 forms the fourth oil outlet mentioned above. It can be understood that the first one-way valve 21.1, the second one-way valve 21.2, the third one-way valve 21.3 and the fourth one-way valve 21.4 all allow the oil to flow in one direction from the oil inlet to the oil outlet, that is, Figure 5 This arrangement controls the flow direction of the hydraulic oil to ensure the reliability of real-time pressure and flow compensation for the two cylinders.

[0048] In some embodiments, as Figure 6 As shown, the oil supply module includes a proportional valve group 22, which has a proportional valve group oil inlet a, a proportional valve group oil outlet 1b, a proportional valve group oil outlet 2d, and a proportional valve group oil return port c. The proportional valve group oil inlet a is configured to selectively communicate with either the proportional valve group oil outlet 1b or the proportional valve group oil outlet 2d. The proportional valve group oil return port c is used to communicate with the oil tank 2 and is configured to selectively communicate with either the proportional valve group oil outlet 1b or the proportional valve group oil outlet 2d. Furthermore, the proportional valve group oil outlet 1b is connected to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2, while the proportional valve group oil outlet 2d is connected to the first rod chamber 18.1.3 and the second rod chamber 18.2.3.

[0049] Among them, the proportional valve group 22 is electrically connected to the control module. When performing a lifting operation, the control module controls the proportional valve group 22 so that the proportional valve group oil inlet a is connected to the proportional valve group oil outlet 1b, thereby realizing oil supply to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2; the control module controls the proportional valve group 22 so that the proportional valve group oil return port c is connected to the proportional valve group oil outlet 2d, thereby realizing oil return from the first rod chamber 18.1.3 and the second rod chamber 18.2.3. When performing a descending operation, the control module controls the proportional valve group 22 so that the proportional valve group oil inlet a is connected to the proportional valve group oil outlet 2d, thereby realizing oil supply to the first rod chamber 18.1.3 and the second rod chamber 18.2.3; the control module controls the proportional valve group 22 so that the proportional valve group oil return port c is connected to the proportional valve group oil outlet 1b, thereby realizing oil return from the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2. The control strategy is simple and reliable.

[0050] More specifically, in some embodiments, the proportional valve assembly 22 includes four cartridge-type proportional directional valves connected in a closed loop, and the four cartridge-type proportional directional valves collectively form a bridge structure. Specifically, the four cartridge-type proportional directional valves are a first cartridge-type proportional directional valve 22.1, a second cartridge-type proportional directional valve 22.2, a third cartridge-type proportional directional valve 22.3, and a fourth cartridge-type proportional directional valve 22.4. The first cartridge-type proportional directional valve 22.1, the second cartridge-type proportional directional valve 22.2, the third cartridge-type proportional directional valve 22.3, and the fourth cartridge-type proportional directional valve 22.4 are sequentially connected to form a closed-loop bridge structure.

[0051] For example, Figure 6 As shown, each cartridge proportional directional valve has port 1 and port 2. Port 1 of the first cartridge proportional directional valve 22.1 is connected to port 1 of the fourth cartridge proportional directional valve 22.4, and the connection between the two forms an oil inlet a of the proportional valve group. Port 2 of the first cartridge proportional directional valve 22.1 is connected to port 1 of the second cartridge proportional directional valve 22.2, and the connection between the two forms an oil outlet 1 b of the proportional valve group. Port 2 of the second cartridge proportional directional valve 22.2 is connected to port 2 of the third cartridge proportional directional valve 22.3, and the connection between the two forms an oil return port c of the proportional valve group. Port 1 of the third cartridge proportional directional valve 22.3 is connected to port 2 of the fourth cartridge proportional directional valve 22.4, and the connection between the two forms an oil outlet 2 d of the proportional valve group. The control module is electrically connected to the first, second, third, and fourth proportional directional valves 22.1, 22.2, 22.3, and 22.4, independently controlling the on / off switching of each valve. By individually controlling the on / off switching of each valve, the control module regulates the flow of hydraulic oil, controlling the flow of oil into and out of the two cylinders while meeting switching requirements, minimizing circuit impact.

[0052] Furthermore, in some embodiments, Figure 1 As shown, the oil supply module also includes two hydraulic motors 23, which are coaxially arranged. The oil inlets of the two hydraulic motors 23 are both connected to the oil outlet port b of the proportional valve group, and the oil outlets of the two hydraulic motors 23 are respectively connected to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2. In this embodiment, the proportional valve group oil outlet port b of the proportional valve group 22 is supplied with oil by two hydraulic motors 23 with the same displacement and pressure. The two hydraulic motors 23 evenly distribute the input pressure oil to the rodless chambers of the two oil cylinders, namely the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2. This can initially ensure the movement consistency of the two oil cylinders during oil supply, thereby further reducing or even eliminating the problem of overloading.

[0053] In some embodiments, as Figure 1 As shown, the supplementary module also includes an electromagnetic clutch 24, which is coaxially connected between the hydraulic motor 23 and the high-pressure pump 25, that is, the two hydraulic motors 23, the electromagnetic clutch 24 and the high-pressure pump 25 are coaxially connected in sequence; and the electromagnetic clutch 24 is electrically connected to the control module, and the control module controls the on and off between the hydraulic motor 23 and the high-pressure pump 25 through the electromagnetic clutch 24, which is simple, reliable and easy to debug.

[0054] In some embodiments, the oil supply module further includes two explosion-proof valves, namely a first explosion-proof valve 20.1 and a second explosion-proof valve 20.2. The oil inlets of the first explosion-proof valve 20.1 and the second explosion-proof valve 20.2 are both connected to the oil outlet port b of the proportional valve group. The oil outlet of the first explosion-proof valve 20.1 is connected to the first rodless cavity 18.1.2 and the third oil outlet, while the oil outlet of the second explosion-proof valve 20.2 is connected to the second rodless cavity 18.2.2 and the fourth oil outlet. In this embodiment, by introducing explosion-proof valves into the rodless cavities of the two oil cylinders, the positions of the two oil cylinders can be maintained in the event of a pipeline rupture in the hydraulic control system, thereby ensuring safety.

[0055] Among them, the two explosion-proof valves can be one-way explosion-proof valves or two-way explosion-proof valves. For example, the first explosion-proof valve 20.1 and the second explosion-proof valve 20.2 are both two-way explosion-proof valves. Figure 7As shown, the two-way explosion-proof valve has an oil inlet at port A and an oil outlet at port B. A check valve is installed between ports A and B, directing flow from port A to port B. Its operating principle is as follows: During normal operation, the spring forces on both sides of the two-way explosion-proof valve are balanced, the valve core operates in a neutral position, and ports A and B are connected. If the pipeline to port B ruptures, the hydraulic pressure at port A is greater than that at port B. The resulting pressure differential overcomes the spring force, shifting the valve core to the left and disconnecting ports A and B, thus ensuring a constant load. If the pipeline to port A ruptures, the hydraulic pressure at port B is greater than that at port A. The resulting pressure differential overcomes the spring force, shifting the valve core to the right and disconnecting ports A and B, thus ensuring a constant load. This arrangement maintains the cylinder's position even if a pipeline rupture occurs at either side of the two-way explosion-proof valve, and provides flexible and convenient installation.

[0056] In some embodiments, the oil supply module also includes two hydraulically controlled one-way valves, which are a first hydraulically controlled one-way valve 16.1 and a second hydraulically controlled one-way valve 16.2. The first hydraulically controlled one-way valve 16.1 is connected between the first rod chamber 18.1.3 and the oil outlet 2d of the proportional valve group, and the second hydraulically controlled one-way valve 16.2 is connected between the second rod chamber 18.2.3 and the oil outlet 2d of the proportional valve group; and the oil outlet 1b of the proportional valve group is connected with the control oil port of the first hydraulically controlled one-way valve 16.1 and the control oil port of the second hydraulically controlled one-way valve 16.2, so as to control the opening and closing of the first hydraulically controlled one-way valve 16.1 and the second hydraulically controlled one-way valve 16.2.

[0057] It can be understood that the proportional valve group oil outlet port 1b is connected to the oil inlets of both the first explosion-proof valve 20.1 and the second explosion-proof valve 20.2. The control oil port of the first hydraulically-controlled one-way valve 16.1 can be connected to the oil outlet of the first explosion-proof valve 20.1, thereby communicating with the proportional valve group oil outlet port 1b through the first explosion-proof valve 20.1. The control oil port of the second hydraulically-controlled one-way valve 16.2 can be connected to the oil outlet of the second explosion-proof valve 20.2, thereby communicating with the proportional valve group oil outlet port 1b through the second explosion-proof valve 20.2.

[0058] It can be understood that the oil inlet of the first hydraulically controlled one-way valve 16.1 is connected to the oil outlet 2d of the proportional valve group, and the oil outlet of the first hydraulically controlled one-way valve 16.1 is connected to the first rod chamber 18.1.3. When the descending operation is performed, the hydraulic oil output from the oil outlet 2d of the proportional valve group can only flow in one direction and enter the first rod chamber 18.1.3; similarly, the oil inlet of the second hydraulically controlled one-way valve 16.2 is connected to the oil outlet 2d of the proportional valve group, and the oil outlet of the second hydraulically controlled one-way valve 16.2 is connected to the second rod chamber 18.2.3. When the descending operation is performed, the hydraulic oil output from the oil outlet 2d of the proportional valve group can only flow in one direction and enter the second rod chamber 18.2.3. During lifting operations, the hydraulic oil output from the oil outlet port 1b of the proportional valve group enters the control oil port of the first hydraulically controlled one-way valve 16.1 through the oil outlet port of the first explosion-proof valve 20.1, causing the first hydraulically controlled one-way valve 16.1 to open, and the hydraulic oil in the first rod chamber 18.1.3 can flow to the oil return port c of the proportional valve group through the first hydraulically controlled one-way valve 16.1; similarly, the hydraulic oil output from the oil outlet port 1b of the proportional valve group enters the control oil port of the second hydraulically controlled one-way valve 16.2 through the oil outlet port of the second explosion-proof valve 20.2, causing the second hydraulically controlled one-way valve 16.2 to open, and the hydraulic oil in the second rod chamber 18.2.3 can flow to the oil return port c of the proportional valve group through the second hydraulically controlled one-way valve 16.2.

[0059] Furthermore, in some embodiments, the oil supply module further includes an engine 1, two main pumps, a pilot pump 4 and a main valve 5, wherein the two main pumps are a first main pump 3.1 and a second main pump 3.2. Figure 3 As shown, the main valve 5 has a main valve oil inlet 1 5.1, a main valve oil inlet 2 5.2, a main valve oil outlet 5.3, a main valve oil return port, and multiple main valve working oil ports (not shown in the figure). Specifically, the engine 1 is coaxially connected to the first main pump 3.1, the second main pump 3.2, and the pilot pump 4. The oil suction ports of the first main pump 3.1, the second main pump 3.2, and the pilot pump 4 are all connected to the oil tank 2. The oil outlet of the first main pump 3.1 is connected to the main valve oil inlet 1 5.1, and the oil outlet of the second main pump 3.2 is connected to the main valve oil inlet 2 5.2. Each main valve working oil port is respectively connected to the hydraulic actuator oil port (not shown in the figure) of the working machine, the main valve oil return port is connected to the oil tank 2, and the main valve oil outlet 5.3 is connected to the proportional valve group oil inlet a.

[0060] Specifically, in some embodiments, Figure 3As shown, the main valve 5 also includes two bypass shut-off valves, namely a first bypass shut-off valve 5.4 and a second bypass shut-off valve 5.5. The oil inlet of the first bypass shut-off valve 5.4 communicates with the internal oil passage of the main valve and, through this internal oil passage, with the main valve oil outlet 5.3. The oil outlet of the first bypass shut-off valve 5.4 communicates with the oil tank 2. Furthermore, the oil inlet of the second bypass shut-off valve 5.5 communicates with the internal oil passage of the main valve and, through this internal oil passage, with the main valve oil outlet 5.3. The oil outlet of the second bypass shut-off valve 5.5 communicates with the oil tank 2. For example, both the first bypass shut-off valve 5.4 and the second bypass shut-off valve 5.5 can be electrically controlled two-position, two-way valves. In this embodiment, the first bypass shut-off valve 5.4 and the second bypass shut-off valve 5.5 are used to block the pressure oil in the neutral oil circuit of the main valve 5 from returning to the oil tank 2 and direct it to the required flow passage or working oil port for merging or providing working pressure.

[0061] The first bypass shut-off valve 5.4 and the second bypass shut-off valve 5.5 are both electrically connected to the control module and are controlled by the control module to be opened and closed. In this embodiment, the bypass shut-off valves are controlled by electronic control logic, and pressurized oil is drawn from the main valve 5 to provide a pressure source for the movement of the oil cylinder, which can reduce production and assembly costs and facilitate control and debugging.

[0062] It is understandable that the present invention does not impose any specific limitation on the number of bypass cut-off valves provided in the main pump and the main valve 5 , and the number of both provided depends on the operational requirements of the hydraulic control system.

[0063] It should be noted that the relationship between the control current and displacement of the main pump is as follows: Figure 8 As shown in the figure, the horizontal axis (I) represents the control current of the main pump regulator, and the vertical axis (V) represents the output displacement of the main pump. The main pump control current and output displacement are in a proportional linear relationship. When I < I1, the main pump outputs the minimum displacement. The current-displacement relationship is:

[0064]

[0065] Furthermore, in some embodiments, the control unit includes a controller 8, an electric control foot pedal 7, a first pilot pressure sensor 6.1, and a second pilot pressure sensor 6.2. Specifically, the oil suction port of the pilot pump 4 is connected to the oil tank 2, the oil outlet of the pilot pump 4 is connected to the oil inlet of the electric control foot pedal 7, and the oil return port of the electric control foot pedal 7 is connected to the oil tank 2. The electric control foot pedal 7 is installed inside the cab, and the first pilot pressure sensor 6.1 and the second pilot pressure sensor 6.2 are installed on the electric control foot pedal 7, and the first pilot pressure sensor 6.1 and the second pilot pressure sensor 6.2 are both electrically connected to the controller 8. And the controller 8 is electrically connected to the above-mentioned lifting module, oil supply module, and replenishing module, specifically, as Figure 1As shown, the controller 8 is electrically connected to the first pilot pressure sensor 6.1, the second pilot pressure sensor 6.2, the first solenoid valve 10, the second solenoid valve 12, the first switch valve 13, the electro-hydraulic servo valve 14, the reversing valve 15, the first displacement sensor 17.1, the second displacement sensor 17.2, the first pressure sensor 19.1, the second pressure sensor 19.2, the first cartridge proportional reversing valve 22.1, the second cartridge proportional reversing valve 22.2, the third cartridge proportional reversing valve 22.3, the fourth cartridge proportional reversing valve 22.4, and the electromagnetic clutch 24.

[0066] Furthermore, another problem to be solved by the present invention is the vibration and impact generated during the entire movement of the two cylinders, further improving the smoothness and safety of the lifting process. The entire movement process of the cylinders refers to the seven stages: the moment the cylinders start to rise, during the rising process, when the rising process stops, when the cylinders start to descend, during the descent process, when the cylinders stop descending, and when the cylinders are lifted to a certain position and then begin to work.

[0067] In order to solve this technical problem, in some embodiments, the hydraulic control system further includes a buffer module, which includes an accumulator 9, and the accumulator 9 is connected to the oil supply module. Specifically, the above-mentioned oil supply module includes a main valve 5, which has a main valve oil outlet 5.3. The main valve oil outlet 5.3 is connected to the proportional valve group oil inlet a and is connected to the accumulator 9. In this embodiment, at the moment of the rising start of the two oil cylinders, the proportional valve group oil inlet a and the proportional valve group oil outlet b are not yet connected, and the hydraulic oil output from the main valve oil outlet 5.3 will produce an impact. At this time, the proportional valve group oil inlet a is connected to the accumulator 9, and the accumulator 9 can absorb the generated impact. During the rising process of the two oil cylinders, the hydraulic oil output from the main valve oil outlet 5.3 can supply the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2 while also filling the accumulator 9. The accumulator 9 can absorb the part that is higher than the average flow rate, reduce the pulsation of the flow rate, and thereby reduce or even eliminate the risk of jitter during the rising process.

[0068] Furthermore, in some embodiments, Figure 1 As shown, the buffer module also includes a first cone valve 11.1, a second cone valve 11.2, and a first solenoid valve 10. The first cone valve 11.1 is communicatively disposed between the accumulator 9 and the first rodless chamber 18.1.2, and also between the accumulator 9 and the second rodless chamber 18.2.2. The second cone valve 11.2 is communicatively disposed between the oil tank 2 and the first rod chamber 18.1.3, and also between the oil tank 2 and the second rod chamber 18.2.3. The first solenoid valve 10 is connected between the first cone valve 11.1 and the second cone valve 11.2 and is configured to control the on / off operation of the first and second cone valves 11.1, 11.2.

[0069] In this embodiment, at the moment when the two oil cylinders stop rising, the oil outlet port 1 b and the oil outlet port 2 d of the proportional valve group are closed. Due to inertia, the volume of the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2 will increase and the pressure will decrease, and the volume of the first rod chamber 18.1.3 and the second rod chamber 18.2.3 will decrease and the pressure will increase. At this time, under the control of the first solenoid valve 10, the first cone valve 11.1 connects the accumulator 9 with the first rodless chamber 18.1.2, and connects the accumulator 9 with the second rodless chamber 18.2.2, so that the hydraulic oil stored in the accumulator 9 is replenished into the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2. At the same time, under the control of the first solenoid valve 10, the second cone valve 11.2 connects the oil tank 2 with the first rod chamber 18.1.3, and the oil tank 2 with the second rod chamber 18.2.3, so that the hydraulic oil in the first rod chamber 18.1.3 and the second rod chamber 18.2.3 can flow back into the oil tank 2, thereby ensuring the force balance between the two cylinders and reducing or even eliminating the risk of vibration or shaking of the lifting platform 19. After the two cylinders are lifted to a certain position and construction work begins, or when the entire machine encounters a pothole on the road, the entire machine will shake or vibrate, causing the lifting platform 19 to shake or vibrate, affecting work efficiency and operating comfort. Furthermore, during this process, the cylinder remains in a lifted position, and the hydraulic oil seals in the rod chamber and rodless chamber of the cylinder are contained within the two chambers. When the entire machine shakes or trembles, the hydraulic oil in the two chambers is compressed, causing pressure fluctuations and pressure shocks, exacerbating the shaking or trembling of the entire machine. When the hydraulic oil in the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2 is compressed and the pressure increases, under the control of the first solenoid valve 10, the first cone valve 11.1 can connect the accumulator 9 with the first rodless chamber 18.1.2, and connect the accumulator 9 with the second rodless chamber 18.2.2. The accumulator 9 can absorb the pressure shocks in the first and second rodless chambers 18.1.2, 18.2.2, thereby reducing the pressure shocks and eliminating vibrations. When the hydraulic oil in the first rod chamber 18.1.3 and the second rod chamber 18.2.3 is compressed and the pressure increases, under the control of the first solenoid valve 10, the second cone valve 11.2 connects the oil tank 2 with the first rod chamber 18.1.3, and the oil tank 2 with the second rod chamber 18.2.3, and the hydraulic oil in the first rod chamber 18.1.3 and the second rod chamber 18.2.3 can flow back to the oil tank 2 to release the pressure.

[0070] In some embodiments, the buffer module also includes a switching valve 13, which is connected between the first cone valve 11.1 and the first rodless chamber 18.1.2, and between the first cone valve 11.1 and the second rodless chamber 18.2.2. The switching valve 13 is electrically connected to the controller 8, and the controller 8 is used to control the on and off of the switching valve 13, thereby realizing the control of the on and off of the first cone valve 11.1 and the first rodless chamber 18.1.2, as well as the on and off of the first cone valve 11.1 and the second rodless chamber 18.2.2.

[0071] Specifically, first cone valve 11.1 has a first cone valve oil inlet, a first cone valve oil outlet, and a first cone valve control oil port. The first cone valve oil inlet is connected to accumulator 9, and the first cone valve oil outlet is connected to the third and fourth oil outlets, that is, the oil outlets of third check valve 21.3 and fourth check valve 21.4, and further connected to first rodless chamber 18.1.2 and second rodless chamber 18.2.2. The on-off valve 13 can be positioned between the first cone valve oil outlet and the third oil outlet, and between the first cone valve oil outlet and the fourth oil outlet. It is understood that the accumulator 9 is connected to the main valve oil outlet 5.3, and the first cone valve oil inlet is connected to the accumulator 9, that is, the first cone valve oil inlet is connected to the main valve oil outlet 5.3.

[0072] Specifically, the second cone valve 11.2 has a second cone valve oil inlet, a second cone valve oil outlet, and a second cone valve control oil port. The second cone valve oil inlet communicates with the first rod chamber 18.1.3 and the second rod chamber 18.2.3, specifically with the oil inlets of the first hydraulically controlled one-way valve 16.1 and the second hydraulically controlled one-way valve 16.2. The second cone valve oil outlet communicates with the fuel tank 2.

[0073] Specifically, the first solenoid valve 10 has a first solenoid valve oil inlet and a first solenoid valve oil outlet. The first solenoid valve oil inlet is connected to the first cone valve control oil port and the second cone valve control oil port, and the first solenoid valve oil outlet is used to connect to the oil tank 2. The first solenoid valve 10 is electrically connected to the controller 8. Under normal conditions, that is, when the first solenoid valve 10 is de-energized, the first solenoid valve oil inlet and the first solenoid valve oil outlet are disconnected; when the controller 8 energizes the first solenoid valve 10, the first solenoid valve oil inlet and the first solenoid valve oil outlet are connected, so that the hydraulic oil in the spring chambers of the first cone valve 11.1 and the second cone valve 11.2 can return to the oil tank 2 through the first cone valve control oil port and the second cone valve control oil port. At this time, the first cone valve oil inlet is connected to the first cone valve oil outlet, and the second cone valve oil inlet is connected to the second cone valve oil outlet.

[0074] In some embodiments, the buffer module further includes a second solenoid valve 12, which is communicatively disposed between the accumulator 9 and the first rod chamber 18.1.3, and is communicatively disposed between the accumulator 9 and the second rod chamber 18.2.3.

[0075] In this embodiment, at the moment the two cylinders begin to descend, the hydraulic oil output from main valve outlet 5.3 cannot enter first and second rod chambers 18.1.3, 18.2.3 in a timely manner due to gravity and the influence of the pipeline. This causes cavitation and vibration in first and second rod chambers 18.1.3, 18.2.3. At this point, second solenoid valve 12 connects accumulator 9 with first and second rod chambers 18.1.3, 18.2.3, to replenish oil in these chambers. As the two cylinders descend under their own weight, accumulator 9 connects with first and second rodless chambers 18.1.2, 18.2.2 via first cone valve 11.1 and on-off valve 13, absorbing some of the hydraulic oil above average flow, reducing flow pulsation. Accumulator 9 also provides a certain amount of back pressure to prevent the two cylinders from descending too quickly. When the two cylinders descend too quickly, draining the first and second rod chambers 18.1.3, 18.2.3, the oil tank 2 connects to them through the second cone valve 11.2 to replenish oil. When the two cylinders stop descending, the proportional valve block's oil outlets 1b and 2d close. Due to inertia, the volume of the first and second rodless chambers 18.1.2, 18.2.2 decreases, causing the pressure to rise. At this point, the accumulator 9 connects to them through the first cone valve 11.1 and the on-off valve 13, absorbing the pressure surge in the first and second rodless chambers 18.1.2, 18.2.2, and ensuring force balance between the two cylinders, reducing or even eliminating the risk of vibration or tremor in the lifting platform 19.

[0076] Specifically, the second solenoid valve 12 has a second solenoid valve oil inlet and a second solenoid valve oil outlet. The second solenoid valve oil inlet is connected to the accumulator 9, and the second solenoid valve oil outlet is connected to the first rod chamber 18.1.3 and the second rod chamber 18.2.3. The second solenoid valve 12 is electrically connected to the controller 8. Under normal conditions, that is, when the second solenoid valve 12 is de-energized, the second solenoid valve oil inlet and the second solenoid valve oil outlet are connected; when the controller 8 energizes the second solenoid valve 12, the second solenoid valve oil inlet and the second solenoid valve oil outlet are disconnected. It can be understood that the accumulator 9 is connected to the main valve oil outlet 5.3, and the second solenoid valve oil inlet is connected to the accumulator 9, that is, the second solenoid valve oil inlet is connected to the main valve oil outlet 5.3.

[0077] In some embodiments, the first hydraulically controlled one-way valve 16.1 is disposed between the first rod cavity 18.1.3 and the second solenoid valve oil outlet. The second solenoid valve oil outlet communicates with the oil inlet of the first hydraulically controlled one-way valve 16.1, and the oil outlet of the first hydraulically controlled one-way valve 16.1 communicates with the first rod cavity 18.1.3. The second hydraulically controlled one-way valve 16.2 is disposed between the second rod cavity 18.2.3 and the second solenoid valve oil outlet. The second solenoid valve oil outlet communicates with the oil inlet of the second hydraulically controlled one-way valve 16.2, and the oil outlet of the second hydraulically controlled one-way valve 16.2 communicates with the second rod cavity 18.2.3.

[0078] According to an embodiment of the present invention, on the other hand, a control method for a hydraulic control system for lifting is provided. The hydraulic control system described in the above embodiment is applied, and the control method includes the following steps:

[0079] During the ascending phase, the control unit controls the oil supply module to supply oil to the first and second rodless chambers 18.1.2, 18.2.2, and to return oil to the first and second rod chambers 18.1.3, 18.2.3. Specifically, the control unit connects the proportional valve block's oil inlet port a with the proportional valve block's oil outlet port 1b to supply oil to the first and second rodless chambers 18.1.2, 18.2.2. It also connects the proportional valve block's oil return port c with the proportional valve block's oil outlet port 2d to return oil to the first and second rod chambers 18.1.3, 18.2.3.

[0080] During the descent phase, the control unit controls the oil supply module to supply oil to the first rod chamber (18.1.3) and the second rod chamber (18.2.3), while also returning oil to the first and second rodless chambers (18.1.2, 18.2.2). Specifically, the control unit connects the proportional valve block's oil inlet port a to its oil outlet port 2 (d) to supply oil to the first and second rod chambers (18.1.3, 18.2.3). It also connects the proportional valve block's oil return port c to its oil outlet port 1 (b) to return oil to the first and second rodless chambers (18.1.2, 18.2.2).

[0081] More specifically, if Figure 9 As shown, the steps in the rising stage specifically include the following steps:

[0082] S13a: Operate the electric control foot pedal 7 to make the second pressure sensor 19.2 generate a pressure signal, and feed the pressure signal back to the controller 8, so that the controller 8 obtains the information of executing the lifting action of the lifting platform 19.

[0083] S13b: The controller 8 outputs the control current I1 so that the first main pump 3.1 is at the minimum displacement Vmin.

[0084] S13c: Controller 8 energizes first bypass shut-off valve 5.4, energizes first cartridge proportional directional valve 22.1 and third cartridge proportional directional valve 22.3, and de-energizes second cartridge proportional directional valve 22.2 and fourth cartridge proportional directional valve 22.4. At this point, first bypass shut-off valve 5.4 is in the right position, effectively opening. Hydraulic oil output by first main pump 3.1 enters main valve 5 through main valve oil inlet 1 5.1 and is delivered through main valve oil outlet 5.3 to proportional valve assembly oil inlet a. First cartridge proportional directional valve 22.1 and third cartridge proportional directional valve 22.3 are open, while second cartridge proportional directional valve 22.2 and fourth cartridge proportional directional valve 22.4 are closed. That is, the oil inlet a of the proportional valve group is connected with the oil outlet b of the proportional valve group for oil supply; the oil return port c of the proportional valve group is connected with the oil outlet d of the proportional valve group for oil return.

[0085] like Figure 9 As shown, the steps in the descending stage specifically include the following steps:

[0086] S2a: Operate the electric control pedal 7 to make the first pressure sensor 19.1 generate a pressure signal, and feed the pressure signal back to the controller 8, so that the controller 8 obtains the information for executing the lowering action of the lifting platform 19.

[0087] S2b: The controller 8 outputs the control current I1 so that the first main pump 3.1 is at the minimum displacement Vmin.

[0088] S2c: Controller 8 energizes first bypass shut-off valve 5.4, deenergizes first and third cartridge proportional directional valves 22.1 and 22.3, and energizes second and fourth cartridge proportional directional valves 22.2 and 22.4. At this point, first bypass shut-off valve 5.4 is in the right position, effectively opening. Hydraulic oil output by first main pump 3.1 enters main valve 5 through main valve inlet 1 5.1 and is delivered through main valve outlet 5.3 to proportional valve assembly inlet a. First and third cartridge proportional directional valves 22.1 and 22.3 are closed, while second and fourth cartridge proportional directional valves 22.2 and 22.4 are open. That is, the oil inlet a of the proportional valve group is connected with the oil outlet 2 d of the proportional valve group for oil supply; the oil return port c of the proportional valve group is connected with the oil outlet 1 b of the proportional valve group for oil return.

[0089] like Figure 9 As shown, when the lifting platform 19 is not in motion, the following steps are included:

[0090] S3a: The controller 8 outputs the control current I1 so that the first main pump 3.1 is at the minimum displacement Vmin.

[0091] S3b: Controller 8 de-energizes first bypass shut-off valve 5.4, de-energizing first cartridge proportional directional valve 22.1, second cartridge proportional directional valve 22.2, third cartridge proportional directional valve 22.3, and fourth cartridge proportional directional valve 22.4. At this point, first bypass shut-off valve 5.4 operates in the left position, effectively connecting the bypass to the main valve 5. The hydraulic oil output by first main pump 3.1 enters main valve 5 through main valve oil inlet 1 5.1 and enters fuel tank 2 through the oil outlet of first bypass shut-off valve 5.4.

[0092] In addition, the control method includes four stages in the ascending stage: the instant of ascending start, the process of cylinder ascending, the instant of cylinder ascending stopping, and the construction operation after lifting to a certain position; in the descending stage, it includes three stages: the instant of cylinder descending start, the process of cylinder descending, and the instant of cylinder descending stopping.

[0093] Specifically, during the oil cylinder rising and descending process, the following steps are also included:

[0094] During the ascending process: the control unit obtains the difference in displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2; when the difference is 0, no action is taken; when the difference is greater than 0, the control unit controls the oil suction port to be connected to the fourth oil outlet to replenish hydraulic oil to the second rodless chamber 18.2.2; when the difference is less than 0, the control unit controls the oil suction port to be connected to the third oil outlet to replenish hydraulic oil to the first rodless chamber 18.1.2.

[0095] During the descent process: the control unit obtains the difference in displacement information collected by the first displacement sensor 17.1 and the second displacement sensor 17.2; when the difference is 0, no action is taken; when the difference is greater than 0, the control unit controls the oil suction port to be connected to the second oil outlet to replenish hydraulic oil to the second rod chamber 18.2.3; when the difference is less than 0, the control unit controls the oil suction port to be connected to the first oil outlet to replenish hydraulic oil to the first rod chamber 18.1.3.

[0096] In this embodiment, the control module performs electronic control logic judgment and control on the supplementary module, the first displacement sensor 17.1 and the second displacement sensor 17.2 to dynamically compensate for the flow pressure in real time during the lifting and lowering process of the first cylinder 18.1 and the second cylinder 18.2, so that the first cylinder 18.1 and the second cylinder 18.2 are lifted and lowered synchronously, thereby reducing or even eliminating the problem of unbalanced loading during the lifting process.

[0097] Furthermore, another problem to be solved by the present invention is the vibration and impact problems generated during the entire movement of the two cylinders, thereby further improving the stability and safety of lifting.

[0098] In order to solve this technical problem, in some embodiments, as Figure 9As shown, the control method further includes the steps of:

[0099] At the moment of rising start: the control unit controls the first solenoid valve 10 and the second solenoid valve 12 to be disconnected. Specifically, the first solenoid valve 10 loses power, and the controller 8 energizes the second solenoid valve 12, so that the oil supply module is connected to the accumulator 9, and the accumulator 9 can absorb the impact generated at the moment of rising start. Specifically, the oil supply module includes a main valve 5, and the main valve 5 has a main valve oil outlet 5.3, and the main valve oil outlet 5.3 is connected to the accumulator 9. In this embodiment, at the moment of rising start of the two oil cylinders, the proportional valve group oil inlet a and the proportional valve group oil outlet b are not yet connected, and the hydraulic oil output from the main valve oil outlet 5.3 will generate impact. At this time, the proportional valve group oil inlet a is connected to the accumulator 9, and the accumulator 9 can absorb the impact at the main valve oil outlet 5.3, reducing or even eliminating the jitter or impact generated at the moment of rising.

[0100] In some embodiments, as Figure 9 As shown, the control method further includes the steps of:

[0101] During the ascent process: the control unit controls the first solenoid valve 10 and the second solenoid valve 12 to be disconnected. Specifically, the first solenoid valve 10 loses power, and the controller 8 energizes the second solenoid valve 12, so that the oil supply module is connected to the accumulator 9. Specifically, the oil supply module includes a main valve 5, and the main valve 5 has a main valve oil outlet 5.3, and the main valve oil outlet 5.3 is connected to the accumulator 9. In this embodiment, during the ascent process of the two oil cylinders, the hydraulic oil in the main valve oil outlet 5.3 is supplied to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2, while also filling the accumulator 9. The accumulator 9 can absorb the portion that is higher than the average flow rate, reduce the pulsation of the flow rate, and thus reduce or even eliminate the jitter or impact generated during the ascent process.

[0102] In some embodiments, as Figure 9 As shown, the control method further includes the steps of:

[0103] During the ascent, which includes two phases—the instantaneous stop and the initial operation after reaching a certain position—the control unit controls the first solenoid valve 10 to connect, the second solenoid valve 12 to disconnect, and the on-off valve 13 to connect. Specifically, the controller 8 energizes the first solenoid valve 10, the second solenoid valve 12, and the on-off valve 13. At this point, the first solenoid valve 10 connects, connecting the first and second poppet valve control oil ports to the oil tank 2 through the first solenoid valve 10. Both the first poppet valve 11.1 and the second poppet valve 11.2 open. The first poppet valve inlet of the first poppet valve 11.1 connects to the first poppet valve outlet, while the second poppet valve inlet of the second poppet valve 11.2 connects to the second poppet valve outlet. Consequently, the accumulator 9 is able to connect to the third and fourth oil outlets through the first poppet valve 11.1, and further to the first and second rodless chambers 18.1.2, supplying oil to the first and second rodless chambers 18.2.2. The oil tank 2 can be communicated with the first rod chamber 18.1.3 and the second rod chamber 18.2.3 through the second cone valve 11.2, and the first rod chamber 18.1.3 and the second rod chamber 18.2.3 return oil through the second cone valve 11.2.

[0104] In this embodiment, when the hydraulic cylinder stops ascending, power is lost to first and fourth proportional directional control valves 22.1 and 22.4, causing the valve cores to rapidly close. Due to inertia, the volumes of first and second rodless chambers 18.1.2, 18.2.2 increase, reducing pressure. Meanwhile, the volumes of first and second rodless chambers 18.1.3, 18.2.3 decrease, increasing pressure. At this point, accumulator 9 communicates with first and second rodless chambers 18.1.2, 18.2.2, via first cone valve 11.1. The hydraulic oil stored in accumulator 9 is then replenished into first and second rodless chambers 18.1.2, 18.2.2, via first cone valve 11.1. The first rod chamber 18.1.3 and the second rod chamber 18.2.3 are connected to the oil tank 2 through the second cone valve 11.2. The hydraulic oil in the first rod chamber 18.1.3 and the second rod chamber 18.2.3 returns to the oil tank 2 through the second cone valve 11.2, thereby ensuring the force balance of the two cylinders and reducing or even eliminating the risk of vibration or shaking when the ascent stops.

[0105] After the two cylinders are lifted to a certain position and construction work begins, or when the entire machine encounters a bumpy road surface, the entire machine will shake or vibrate, causing the lifting platform 19 to shake or vibrate, affecting work efficiency and operating comfort. In addition, during this process, the cylinders always maintain a lifting state, and the hydraulic oil seals of the rod chamber and the rodless chamber of the cylinder are present in the two chambers. When the entire machine shakes or shakes, the hydraulic oil in the two chambers will be compressed, thereby generating pressure fluctuations and pressure shocks, exacerbating the shaking or shaking of the entire machine. At this time, the accumulator 9 is connected to the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2 through the first cone valve 11.1. When the hydraulic oil in the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2 is compressed and the pressure increases, the accumulator 9 can absorb the pressure shock in the first rodless chamber 18.1.2 and the second rodless chamber 18.2.2 to reduce the pressure shock and eliminate vibration. The first rod chamber 18.1.3 and the second rod chamber 18.2.3 are connected to the oil tank 2 through the second cone valve 11.2. When the hydraulic oil in the first rod chamber 18.1.3 and the second rod chamber 18.2.3 is compressed and the pressure increases, the hydraulic oil in the first rod chamber 18.1.3 and the second rod chamber 18.2.3 can flow back into the oil tank 2 to release the pressure. Figure 9 As shown, the control method further includes the steps of:

[0106] At the moment of starting the descent: the control unit controls the first solenoid valve 10 to disconnect and the second solenoid valve 12 to connect, so that the first rod chamber 18.1.3 and the second rod chamber 18.2.3 are connected to the accumulator 9. Specifically, the controller 8 de-energizes the first solenoid valve 10 and the second solenoid valve 12. In this embodiment, at the moment of starting the descent of the oil cylinder, due to its own gravity and the influence of the pipeline, the hydraulic oil at the main valve oil outlet 5.3 cannot enter the first rod chamber 18.1.3 and the second rod chamber 18.2.3 in time, causing the rod chamber to be sucked empty, resulting in cavitation and vibration. At this time, the first rod chamber 18.1.3 and the second rod chamber 18.2.3 are connected to the accumulator 9, and the accumulator 9 can replenish oil to the first rod chamber 18.1.3 and the second rod chamber 18.2.3 to avoid cavitation and vibration in the first rod chamber 18.1.3 and the second rod chamber 18.2.3.

[0107] Furthermore, in some embodiments, Figure 9 As shown, the control method further includes the steps of:

[0108] During descent, the control unit connects first solenoid valve 10, disconnects second solenoid valve 12, and connects on-off valve 13. Specifically, controller 8 energizes first solenoid valve 10, second solenoid valve 12, and on-off valve 13. At this point, the first and second cone valve control oil ports connect to fuel tank 2 via first solenoid valve 10. Both first cone valve 11.1 and second cone valve 11.2 open, connecting the first cone valve inlet and the first cone valve outlet of first cone valve 11.1, and the second cone valve inlet and the second cone valve outlet of second cone valve 11.2. Accumulator 9 is connected to the third and fourth oil outlets (i.e., first and second rodless chambers 18.1.2, 18.2.2) via first cone valve 11.1 and on-off valve 13. Accumulator 9 absorbs excess flow in first and second rodless chambers 18.1.2, 18.2.2, reducing flow pulsation. It also provides a certain amount of back pressure to prevent the cylinder from descending too quickly. Reservoir 2 is connected to first and second rod chambers 18.1.3, 18.2.3, via second cone valve 11.2, replenishing hydraulic oil to prevent cavitation in first and second rod chambers 18.1.3, 18.2.3, should the cylinder descend too quickly.

[0109] In some embodiments, as Figure 9 As shown, the control method further includes the steps of:

[0110] When the descent stops, specifically in two stages: at the moment of descent stopping and at descent completion, the control unit controls the connection of the first solenoid valve 10, the disconnection of the second solenoid valve 12, and the connection of the switch valve 13. Specifically, the controller 8 energizes the first solenoid valve 10, the second solenoid valve 12, and the switch valve 13. At this time, the accumulator 9 is connected to the third and fourth oil outlets through the first cone valve 11.1 and the switch valve 13, that is, to the first and second rodless chambers 18.1.2, 18.2.2. The accumulator 9 can absorb the pressure surges within the first and second rodless chambers 18.1.2, 18.2.2. The oil tank 2 is connected to the first and second rod chambers 18.1.3, 18.2.3, through the second cone valve 11.2, replenishing hydraulic oil to the first and second rod chambers 18.1.3, 18.2.3. This prevents the first and second rod chambers 18.1.3, 18.2.3, from being sucked into the air if the cylinder descends too quickly.

[0111] Various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A hydraulic control system for lifting, characterized in that: include: A first oil cylinder (18.1) and a second oil cylinder (18.2), wherein the first oil cylinder (18.1) comprises a first piston rod (18.1.1) and has a first rodless chamber (18.1.2) and a first rod chamber (18.1.3); and the second oil cylinder (18.2) comprises a second piston rod (18.2.1) and has a second rodless chamber (18.2.2) and a second rod chamber (18.2.3); A first displacement sensor (17.1) and a second displacement sensor (17.2) are connected to the first piston rod (18.1.1) and the second piston rod (18.2.1), respectively; the first displacement sensor (17.1) is used to collect displacement information of the first piston rod (18.1.1), and the second displacement sensor (17.2) is used to collect displacement information of the second piston rod (18.2.1); an oil supply module, connected to the oil tank (2), and configured to selectively supply oil to the first rodless chamber (18.1.2) and the second rodless chamber (18.2.2) and return oil to the first rod chamber (18.1.3) and the second rod chamber (18.2.3), or to supply oil to the first rod chamber (18.1.3) and the second rod chamber (18.2.3) and return oil to the first rodless chamber (18.1.2) and the second rodless chamber (18.2.2); A supplementary module comprises an oil suction port, a high-pressure pump (25), a first oil outlet, a second oil outlet, a third oil outlet and a fourth oil outlet, wherein the high-pressure pump (25) is used to communicate with the oil tank (2) through the oil suction port, and the oil suction port is configured to selectively communicate with the first oil outlet, or the second oil outlet, or the third oil outlet, or the fourth oil outlet; the first oil outlet is communicated with the first rod cavity (18.1.3), the second oil outlet is communicated with the second rod cavity (18.2.3), the third oil outlet is communicated with the first rodless cavity (18.1.2), and the fourth oil outlet is communicated with the second rodless cavity (18.2.2); a control module electrically connected to the oil supply module, the replenishing module, the first displacement sensor (17.1) and the second displacement sensor (17.2); the control module being configured to control the replenishing module to replenish hydraulic oil to the first rod cavity (18.1.3), or the second rod cavity (18.2.3), or the first rodless cavity (18.1.2), or the second rodless cavity (18.2.2) based on a difference in displacement information collected by the first displacement sensor (17.1) and the second displacement sensor (17.2); The hydraulic control system further comprises a buffer module, wherein the buffer module comprises an accumulator (9); The oil supply module includes: A proportional valve group (22) having a proportional valve group oil inlet (a) and a proportional valve group oil outlet, wherein the proportional valve group oil outlet is connected to the first rodless cavity (18.1.2), the second rodless cavity (18.2.2), the first rod cavity (18.1.3), and the second rod cavity (18.2.3); A main valve (5), the main valve (5) having a main valve oil outlet (5.3), the main valve oil outlet (5.3) being in communication with the oil inlet (a) of the proportional valve group and also in communication with the accumulator (9); The buffer module further includes: a first cone valve (11.1) communicatively arranged between the accumulator (9) and the first rodless chamber (18.1.2), and communicatively arranged between the accumulator (9) and the second rodless chamber (18.2.2); a second cone valve (11.2) communicatively arranged between the oil tank (2) and the first rod chamber (18.1.3), and communicatively arranged between the oil tank (2) and the second rod chamber (18.2.3); a first solenoid valve (10) connected between the first cone valve (11.1) and the second cone valve (11.2), the first solenoid valve (10) being configured to control the on / off of the first cone valve (11.1) and the second cone valve (11.2); and / or The buffer module also includes a second solenoid valve (12), which can be arranged in a communicative manner between the accumulator (9) and the first rod chamber (18.1.3), and the second solenoid valve (12) can be arranged in a communicative manner between the accumulator (9) and the second rod chamber (18.2.3).

2. The hydraulic control system for lifting according to claim 1, characterized in that: The high-pressure pump (25) has a high-pressure pump oil suction port and a high-pressure pump oil discharge port, wherein the high-pressure pump oil suction port forms the oil suction port, and the replenishing module comprises: a one-way valve assembly (21), wherein the oil outlets of the one-way valve assembly (21) form the first oil outlet, the second oil outlet, the third oil outlet, and the fourth oil outlet; An electro-hydraulic servo valve (14) and a reversing valve (15) are connected and are communicatively arranged between the oil outlet of the high-pressure pump and the oil inlet of the one-way valve group (21); the electro-hydraulic servo valve (14) and the reversing valve (15) are configured to selectively connect the oil outlet of the high-pressure pump with the first oil outlet, the second oil outlet, the third oil outlet, or the fourth oil outlet.

3. The hydraulic control system for lifting according to claim 2, characterized in that: The proportional valve group (22) has a proportional valve group oil outlet port 1 (b), a proportional valve group oil outlet port 2 (d) and a proportional valve group oil return port (c); the proportional valve group oil inlet port (a) is configured to be selectively connected to the proportional valve group oil outlet port 1 (b) or the proportional valve group oil outlet port 2 (d); the proportional valve group oil return port (c) is used to be connected to the oil tank (2), and is configured to be selectively connected to the proportional valve group oil outlet port 1 (b) or the proportional valve group oil outlet port 2 (d); the proportional valve group oil outlet port 1 (b) is connected to the first rodless cavity (18.1.2) and the second rodless cavity (18.2.2), and the proportional valve group oil outlet port 2 (d) is connected to the first rod cavity (18.1.3) and the second rod cavity (18.2.3).

4. The hydraulic control system for lifting according to claim 3, characterized in that: The oil supply module further comprises two hydraulic motors (23), the two hydraulic motors (23) are coaxially arranged, the oil inlets of the two hydraulic motors (23) are both connected to the oil outlet port 1 (b) of the proportional valve group, and the oil outlets of the two hydraulic motors (23) are respectively connected to the first rodless cavity (18.1.2) and the second rodless cavity (18.2.2); The supplementary module further comprises an electromagnetic clutch (24) coaxially connected between the hydraulic motor (23) and the high-pressure pump (25).

5. The hydraulic control system for lifting according to claim 4, characterized in that: The oil supply module also includes: a first explosion-proof valve (20.1) and a second explosion-proof valve (20.2), the oil inlets of the first explosion-proof valve (20.1) and the second explosion-proof valve (20.2) are both connected to the oil outlet 1 (b) of the proportional valve group, the oil outlet of the first explosion-proof valve (20.1) is connected to the first rodless chamber (18.1.2) and the third oil outlet, and the oil outlet of the second explosion-proof valve (20.2) is connected to the second rodless chamber (18.2.2) and the fourth oil outlet; and / or, The oil supply module also includes: A first hydraulically controlled one-way valve (16.1) and a second hydraulically controlled one-way valve (16.2), wherein the first hydraulically controlled one-way valve (16.1) is connected between the first rod chamber (18.1.3) and the second oil outlet (d) of the proportional valve group, and the second hydraulically controlled one-way valve (16.2) is connected between the second rod chamber (18.2.3) and the second oil outlet (d) of the proportional valve group; the first oil outlet (b) of the proportional valve group is connected to the control oil port of the first hydraulically controlled one-way valve (16.1) and the control oil port of the second hydraulically controlled one-way valve (16.2).

6. The hydraulic control system for lifting according to any one of claims 3 to 5, characterized in that: The proportional valve group (22) comprises a first plug-in proportional directional valve (22.1), a second plug-in proportional directional valve (22.2), a third plug-in proportional directional valve (22.3) and a fourth plug-in proportional directional valve (22.4) which are connected in a closed loop.

7. The hydraulic control system for lifting according to any one of claims 3 to 5, characterized in that: The main valve (5) further comprises a first bypass cut-off valve (5.4), the oil inlet of the first bypass cut-off valve (5.4) being in communication with the main valve oil outlet (5.3), and the oil outlet of the first bypass cut-off valve (5.4) being in communication with the oil tank (2).

8. A control method for a hydraulic control system for lifting, using the hydraulic control system according to any one of claims 1 to 7, characterized in that: The control method comprises the steps of: During the ascending phase: the control unit controls the oil supply module to supply oil to the first rodless cavity (18.1.2) and the second rodless cavity (18.2.2), and to return oil to the first rod cavity (18.1.3) and the second rod cavity (18.2.3); During the ascending process: the control unit obtains the difference between the displacement information collected by the first displacement sensor (17.1) and the second displacement sensor (17.2); when the difference is 0, no action is taken; when the difference is greater than 0, the control unit controls the oil suction port to be connected to the fourth oil outlet port to replenish hydraulic oil to the second rodless chamber (18.2.2); When the difference is less than 0, the control unit controls the oil suction port to communicate with the third oil outlet port to replenish hydraulic oil to the first rodless chamber (18.1.2); During the descending phase: the control unit controls the oil supply module to supply oil to the first rod chamber (18.1.3) and the second rod chamber (18.2.3), and to return oil to the first rodless chamber (18.1.2) and the second rodless chamber (18.2.2); During the descent process: the control unit obtains the difference between the displacement information collected by the first displacement sensor (17.1) and the second displacement sensor (17.2); when the difference is 0, no action is taken; when the difference is greater than 0, the control unit controls the oil suction port to be connected to the second oil outlet to replenish hydraulic oil to the second rod chamber (18.2.3); when the difference is less than 0, the control unit controls the oil suction port to be connected to the first oil outlet to replenish hydraulic oil to the first rod chamber (18.1.3).

9. The control method of the hydraulic control system for lifting according to claim 8, characterized in that: The hydraulic control system further includes a buffer module, which includes: an accumulator (9), connected to the oil supply module; a first cone valve (11.1) communicatively arranged between the accumulator (9) and the first rodless chamber (18.1.2), and communicatively arranged between the accumulator (9) and the second rodless chamber (18.2.2); a second cone valve (11.2) communicatively arranged between the oil tank (2) and the first rod chamber (18.1.3), and communicatively arranged between the oil tank (2) and the second rod chamber (18.2.3); a first solenoid valve (10) connected between the first cone valve (11.1) and the second cone valve (11.2), the first solenoid valve (10) being configured to control the on / off of the first cone valve (11.1) and the second cone valve (11.2); a second solenoid valve (12), the second solenoid valve (12) being communicatively disposed between the accumulator (9) and the first rod chamber (18.1.3), and the second solenoid valve (12) being communicatively disposed between the accumulator (9) and the second rod chamber (18.2.3); The control method further comprises the steps of: At the moment of starting the ascent and during the ascent process: the control unit controls the first solenoid valve (10) and the second solenoid valve (12) to be disconnected, so that the oil supply module is connected to the accumulator (9); and / or, When the ascent stops: the control unit controls the first solenoid valve (10) to be connected and the second solenoid valve (12) to be disconnected, so that the first cone valve (11.1) and the second cone valve (11.2) are opened; the accumulator (9) is connected to the first rodless chamber (18.1.2) and the second rodless chamber (18.2.2) through the first cone valve (11.1); the first rod chamber (18.1.3) and the second rod chamber (18.2.3) are connected to the oil tank (2) through the second cone valve (11.2); and / or, At the moment of starting the descent: the control unit controls the first solenoid valve (10) to be disconnected and the second solenoid valve (12) to be connected, so that the accumulator (9) is connected with the first rod chamber (18.1.3) and the second rod chamber (18.2.3); and / or, During the descent process and when the descent stops: the control unit controls the first solenoid valve (10) to be connected and the second solenoid valve (12) to be disconnected, so that the first cone valve (11.1) and the second cone valve (11.2) are opened; the accumulator (9) is connected to the first rodless chamber (18.1.2) and the second rodless chamber (18.2.2) through the first cone valve (11.1); the first rod chamber (18.1.3) and the second rod chamber (18.2.3) are connected to the oil tank (2) through the second cone valve (11.2).

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