A hydraulic system for controlling loading and unloading platforms

Abstract

The present application relates to a hydraulic system for controlling a loading and unloading platform. The hydraulic system includes an execution module for driving the loading and unloading platform, an oil supply module for providing power to the execution module, and a control module disposed between the oil supply module and the execution module. The execution module includes a lifting cylinder connected to the loading and unloading platform for driving the loading and unloading platform to move up and down, and an adjustment cylinder for adjusting the angle of the loading and unloading platform. The control module includes an oil supply line and an oil return line connected to the oil supply module, a first connecting line connected to the lifting cylinder, and a second connecting line connected to the adjustment cylinder, wherein both the first connecting line and the second connecting line are connected to the oil supply line and the oil return line. The hydraulic system also includes a switch assembly and a controller for controlling the operation of the switch assembly, which is used to adjust the opening and closing of the return oil line, the first connecting line, and the second connecting line. The present application has the effect of reducing inconvenience caused to the use of the loading and unloading platform and improving applicability.

Description

Technical Field

[0001] The present application relates to the field of hydraulic control, and in particular to a hydraulic system for controlling a loading and unloading platform. Background Art

[0002] The rear of a vehicle used to transport goods is generally equipped with a loading and unloading platform to assist in loading and unloading goods, thereby reducing the labor intensity of employees and improving the efficiency of loading and unloading goods.

[0003] Reference Figure 1 , is a schematic diagram of a loading and unloading platform on a vehicle in the related art, wherein the loading and unloading platform is a plate-shaped structure connected to the rear of the vehicle via a lifting arm, and the two ends of the lifting arm are rotatably connected to the rear of the vehicle and the loading and unloading platform respectively; a hydraulic system for adjusting the position and angle of the loading and unloading platform is also provided between the loading and unloading platform and the vehicle. The control module 3 realizes the automatic lowering of the loading and unloading platform when it touches the ground and the automatic raising of the loading and unloading platform before leaving the ground, so that the loading and unloading platform maintains a normal lifting process.

[0004] Reference Figure 2 The hydraulic system includes an execution module 1, an oil supply module 2 for providing power to the actuator, and a control module 3 arranged between the oil supply module 2 and the execution module 1; wherein, the execution module 1 includes a lifting cylinder 11 for driving the loading and unloading platform to rise and fall and an adjusting cylinder 12 for adjusting the angle of the loading and unloading platform, and the control module 3 includes a first pipeline 31 and a second pipeline 32 connected to the oil supply module 2, and the ends of the first pipeline 31 and the second pipeline 32 are respectively connected to the two oil ports of a booster cylinder 33, and at the same time, the lifting cylinder 11 and the adjusting cylinder 12 are respectively connected to the booster cylinder 33. The two oil ports are connected; among them, the second pipeline 32 is connected to the oil outlet end of the oil supply module 2; the first pipeline 31 is provided with a first oil return valve 311 and a first throttle valve 312 which are connected in series, and the first oil return valve 311 is located on the side of the first throttle valve 312 facing the oil supply module 2; the second pipeline 32 is provided with a second throttle valve 321; a transfer pipeline 34 is connected between the first pipeline 31 and the second pipeline 32, one end of the transfer pipeline 34 is located between the first throttle valve 312 and the first oil return valve 311, and the other end is located on the side of the second throttle valve 321 facing the oil supply module 2.

[0005] When the loading and unloading platform is adjusted, the lifting cylinder 11 drives the loading and unloading platform down to a state where it contacts the ground. At this time, due to the limitation of the ground, the lifting cylinder 11 stops moving, and the regulating cylinder 12 continues to retract under the action of gravity. The pressure at one end of the boosting cylinder 33 connected to the first pipeline 31 is less than the pressure at the other end connected to the second pipeline 32, so that the boosting cylinder 33 is retracted under the action of pressure, driving the loading and unloading platform to lower its head; before the loading and unloading platform is lifted and raised, the pressure difference at both ends of the boosting cylinder 33 drives the boosting cylinder 33 to be pushed out, driving the loading and unloading platform to raise its head.

[0006] With respect to the above-mentioned related technologies, the inventors found that: in actual use, the boost cylinder 33 will occupy a large space, and the weight of the boost cylinder 33 is extremely large, which will increase the overall weight, making the overall use of the loading and unloading platform subject to great restrictions, and it is relatively inconvenient to apply the loading and unloading platform to existing vehicles. Summary of the Invention

[0007] In order to reduce the inconvenience caused to the use of the loading and unloading platform and improve its applicability, the present application provides a hydraulic system for controlling the loading and unloading platform.

[0008] The hydraulic system for controlling a loading and unloading platform provided in this application adopts the following technical solution:

[0009] A hydraulic system for controlling a loading and unloading platform, the hydraulic system comprising an execution module for driving the loading and unloading platform to move, an oil supply module for providing power to the execution module, and a control module disposed between the oil supply module and the execution module;

[0010] The execution module includes a lifting cylinder connected to the loading and unloading platform for driving the loading and unloading platform to rise and fall, and an adjusting cylinder for adjusting the angle of the loading and unloading platform;

[0011] The control module includes an oil supply pipeline and an oil return pipeline, both of which are connected to the oil supply module, and the ends of the oil supply pipeline and the oil return pipeline away from the oil supply module are connected by a pipeline, the pipeline is connected to the oil supply pipeline at point A, and the pipeline is connected to the oil return pipeline at point B;

[0012] The lifting cylinder is connected to a first connecting pipeline, and the adjusting cylinder is connected to a second connecting pipeline. The first connecting pipeline and the second connecting pipeline are respectively connected to one of point A and point B;

[0013] The control module also includes a switch component and a controller for controlling the operation of the switch component, and is used to adjust the opening and closing of the oil return pipeline, the first connecting pipeline and the second connecting pipeline.

[0014] By adopting the above technical solution, multiple valve bodies are used instead of booster cylinders to realize the control of raising and lowering the loading and unloading platform, which saves a lot of space. When the loading and unloading platform and the hydraulic system are applied to existing vehicles, it is not easy to be restricted by space problems, thereby improving applicability. Compared with the solution of using booster cylinders, the hydraulic system reduces its own weight and has higher work efficiency during cargo loading and unloading. Compared with the solution of adjusting the loading and unloading platform by booster cylinders in related technologies, the hydraulic system disclosed in the present application can realize the regulation of the lifting cylinder and the adjustment cylinder separately and independently, thereby improving the convenience of control.

[0015] Optionally, a regulating valve is provided on the second connecting pipeline, and the oil flow in the second connecting pipeline is regulated by the regulating valve.

[0016] By adopting the above technical solution, the flow rate of the oil in the second connecting pipeline can be adjusted, which can directly adjust the movement speed of the adjusting cylinder and realize the adjustment of the raising and lowering speed of the loading and unloading platform, which is more convenient to operate.

[0017] Optionally, the second connecting pipeline includes a first pressure-regulating pipeline and a second pressure-regulating pipeline arranged in parallel; a first one-way valve is connected in series to the first pressure-regulating pipeline, the liquid flow direction of the first one-way valve is toward the regulating cylinder, and the first pressure-regulating pipeline is further connected to a first regulating valve connected in parallel with the first one-way valve; a second one-way valve is connected in series to the second pressure-regulating pipeline, the liquid flow direction of the second one-way valve is away from the regulating cylinder, and the second pressure-regulating pipeline is further connected to a second regulating valve connected in parallel with the second one-way valve;

[0018] When the oil supply module passes oil to the regulating cylinder, the first pipeline and the oil return pipeline are closed, and one of the first pressure regulating pipeline and the second pressure regulating pipeline is opened;

[0019] When the regulating cylinder returns oil to the oil supply module, the first pipeline and the oil supply pipeline are closed, and one of the first pressure regulating pipeline and the second pressure regulating pipeline is opened.

[0020] When the loading and unloading platform is stationary or only the lifting cylinder is in motion, the first pressure regulating pipeline and the second pressure regulating pipeline are closed at the same time.

[0021] By adopting the above technical solution, in the process of supplying oil to the regulating cylinder, the first solenoid valve is controlled to be closed and the second solenoid valve is connected, so that the oil passes into the regulating cylinder through the second regulating valve. In the process of the oil in the regulating cylinder flowing back, the first solenoid valve is controlled to be connected and the second solenoid valve is controlled to be closed, and the oil in the regulating cylinder flows back through the first regulating valve. In this way, in the process of the regulating cylinder driving the loading and unloading platform to realize the raising and lowering actions, the oil flow rate can be regulated by the second regulating valve and the first regulating valve respectively, that is, the speed of raising and lowering the loading and unloading platform can be controlled, and the speed can be regulated according to the actual needs during use, thereby improving applicability.

[0022] Optionally, the switch assembly includes a first solenoid valve connected in series to the first pressure regulating pipeline and a second solenoid valve connected in series to the second pressure regulating pipeline;

[0023] When the oil supply module passes oil to the regulating cylinder, the first pipeline and the oil return pipeline are closed, and one of the first solenoid valve and the second solenoid valve is opened;

[0024] When the regulating cylinder returns oil to the oil supply module, the first pipeline and the oil supply pipeline are closed, and one of the first solenoid valve and the second solenoid valve is opened.

[0025] Optionally, the switch assembly includes a three-position four-way valve, the first pressure regulating pipeline is disconnected from the middle of the second pressure regulating pipeline, and its four power-off points are respectively connected to the four contacts of the three-position four-way valve. The three-position four-way valve is used to control the first pressure regulating pipeline and the second pressure regulating pipeline to respectively handle the connected state, or the first pressure regulating pipeline and the second pressure regulating pipeline are in the closed state at the same time.

[0026] By adopting the above technical solution, during operation, when regulating the first pressure regulating pipeline and the second pressure regulating pipeline, only one signal is needed to control the action of the three-position four-way valve, which simplifies the control method and makes it more convenient. At the same time, it can further improve the integration of the hydraulic system and reduce space occupancy.

[0027] Optionally, the first regulating valve is a throttle valve or a speed regulating valve, and the second regulating valve is a throttle valve or a speed regulating valve.

[0028] Optionally, a lifting regulating valve is connected in series on the first connecting pipeline to regulate the flow rate of oil in the first connecting pipeline.

[0029] By adopting the above technical solution, the liquid flow in the first connecting pipeline can be adjusted more conveniently, thereby realizing the adjustment of the movement speed of the lifting cylinder. During actual construction and use, the moving speed of the loading and unloading platform can be controlled more conveniently.

[0030] Optionally, an overflow valve is connected between the oil supply pipeline and the oil return pipeline, and the liquid flow direction of the overflow valve is toward the side of the oil return pipeline.

[0031] By adopting the above technical solution, during the process of supplying oil to the lifting cylinder or the regulating cylinder, the lifting cylinder or the regulating cylinder stops moving, but the power parts continue to supply oil, which increases the pressure of the oil in the oil supply pipeline. After the pressure difference between the oil supply pipeline and the oil return pipeline reaches a certain value, the oil in the oil supply pipeline flows back to the liquid storage tank through the overflow valve and the oil return pipeline, thereby reducing the occurrence of problems such as damage to pipelines and components.

[0032] Optionally, the oil supply module includes a liquid storage tank and a power component connected to the liquid storage tank, and the oil supply pipeline is connected to the power component; a liquid level gauge and an air filter are also installed in the liquid storage tank, and the air filter is used to connect the inside and outside of the liquid storage tank.

[0033] By adopting the above technical solution, the oil level in the liquid storage tank can be monitored more conveniently. When the oil level is too low, it is necessary to detect and determine whether there is a leakage problem or it is normal loss, and then repair and replenish the oil to reduce the interference with the normal operation of the lifting cylinder and the adjusting cylinder due to the low oil level.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. This hydraulic system replaces the existing booster cylinder system. During the operation of the lifting and adjusting cylinders, the controller controls the switch assembly to control the opening and closing of multiple pipelines. This allows for regulation of the lifting and adjusting cylinders. Compared to the existing booster cylinder system, this hydraulic system is lighter and occupies less space. Therefore, in actual use, it is less likely to affect the operation of the loading and unloading platform. Furthermore, by reducing the overall weight of the loading and unloading platform, the loading and unloading capacity of the loading and unloading platform can be increased.

[0036] 2. In the process of supplying oil to the regulating cylinder, the first solenoid valve is controlled to be closed and the second solenoid valve is connected, so that the oil passes into the regulating cylinder through the second regulating valve. In the process of the oil in the regulating cylinder flowing back, the first solenoid valve is controlled to be connected and the second solenoid valve is controlled to be closed, and the oil in the regulating cylinder flows back through the first regulating valve. In this way, in the process of the regulating cylinder driving the loading and unloading platform to realize the raising and lowering actions, the oil flow rate can be regulated by the second regulating valve and the first regulating valve respectively, that is, the speed of raising and lowering the loading and unloading platform can be controlled, and the speed can be regulated according to the actual needs during use, thereby improving applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the installation structure of a loading and unloading platform in the related art;

[0038] Figure 2 It is a schematic diagram of a hydraulic control system of a loading and unloading platform in the related art;

[0039] Figure 3 is a schematic diagram of a hydraulic system according to an embodiment of the present application;

[0040] Figure 4 This is a schematic diagram of the oil flow path when controlling the loading and unloading platform's head-down speed;

[0041] Figure 5This is a schematic diagram of the oil flow path when controlling the lifting speed of the loading and unloading platform;

[0042] Figure 6 This is a schematic diagram of the oil flow path when the loading and unloading platform is in a rapid lifting state;

[0043] Figure 7 This is a schematic diagram of the oil flow path when the loading and unloading platform is in a rapid lowering state;

[0044] Figure 8 It is a schematic diagram of the oil flow path when the lifting platform is driven to rise;

[0045] Figure 9 It is a schematic diagram of the oil flow path when the loading and unloading platform is driven to descend;

[0046] Figure 10 This is a schematic diagram of the hydraulic system for controlling the lowering speed of the loading and unloading platform;

[0047] Figure 11 This is a schematic diagram of a hydraulic system in which a three-position four-way valve is used to replace the first solenoid valve and the second solenoid valve.

[0048] Explanation of the accompanying symbols: 1. Execution module; 11. Lifting cylinder; 12. Adjustment cylinder; 2. Oil supply module; 21. Liquid storage tank; 22. Power component; 23. Filter; 24. Liquid level gauge; 25. Air filter; 3. Control module; 31. First pipeline; 311. First oil return valve; 312. First throttle valve; 32. Second pipeline; 321. Second throttle valve; 33. Boost cylinder; 34. Transfer pipeline; 35. Oil supply pipeline; 351. Oil supply check valve; 36. Oil return Pipeline; 361, flow control valve; 4, first connecting pipeline; 41, lifting check valve; 42, lifting control valve; 5, second connecting pipeline; 51, first pressure regulating pipeline; 511, first check valve; 512, first control valve; 52, second pressure regulating pipeline; 521, second check valve; 522, second control valve; 6, switch assembly; 61, lifting solenoid valve; 62, first solenoid valve; 63, second solenoid valve; 64, return oil solenoid valve; 65, three-position four-way valve; 7, overflow valve. DETAILED DESCRIPTION

[0049] The following is combined with Figure 3-11 This application is described in further detail.

[0050] The embodiment of the present application discloses a hydraulic system for controlling a loading and unloading platform, which is used to adjust the height and angle of the loading and unloading platform. Figure 3The hydraulic system includes an actuator 1 for driving the loading and unloading platform to move, an oil supply assembly 2 for providing power to the actuator 1, and a regulating assembly 3 arranged between the oil supply assembly 2 and the actuator 1, and the movement of the actuator 1 is controlled by the regulating assembly 3; wherein, the actuator 1 includes a lifting cylinder 11 for driving the loading and unloading platform to lift and lower, and an adjusting cylinder 12 for adjusting the angle of the loading and unloading platform. The lifting cylinder 11 and the adjusting cylinder 12 in this application are both based on the use of hydraulic cylinders as an example; the oil supply assembly 2 includes a liquid storage tank 21 and a power member 22. The power member 22 is connected to the inside of the liquid storage tank 21 to discharge the stored liquid therein. Specifically, the power member 22 can choose to use an oil pump, and a filter 23 is provided between the oil pump and the liquid storage tank 21 for filtering the oil discharged from the liquid storage tank 21 to reduce the problem of blockage of the oil pipeline or the hydraulic cylinder.

[0051] Reference Figure 3 The regulating assembly 3 includes an oil supply line 35 and an oil return line 36, wherein the oil supply line 35 is connected to the oil pump, and the oil return line 36 is directly connected to the interior of the liquid storage tank 21. The ends of the oil supply line 35 and the oil return line 36 away from the liquid storage tank 21 are connected by a pipeline, and the pipeline is connected to the oil supply line 35 at point A, and the pipeline is connected to the oil return line 36 at point B; the lifting cylinder 11 is connected to a first connecting line 4, and the first connecting line 4 is connected to point A; the regulating cylinder 12 is connected to a second connecting line 5, and the second connecting line 5 is connected to point B; The second connecting pipeline 5 includes a first pressure regulating pipeline 51 and a second pressure regulating pipeline 52 arranged in parallel with each other; the regulating component 3 also includes a switch component 6 and a controller that controls the operation of the switch component 6. The switch component 6 includes a lifting solenoid valve 61 installed on the first connecting pipeline 4, a first solenoid valve 62 installed on the first pressure regulating pipeline 51, a second solenoid valve 63 installed on the second pressure regulating pipeline 52 and an oil return solenoid valve 64 installed on the return oil pipeline 36. The opening and closing of multiple solenoid valves are controlled by the controller to realize the opening and closing of each pipeline.

[0052] Reference Figure 3 A first one-way valve 511 is provided on the first pressure-regulating pipeline 51, and its liquid flow direction is toward the regulating cylinder body 12, and it is connected in series with the first solenoid valve 62. A first regulating valve 512 is also installed on the first pressure-regulating pipeline 51, and the first regulating valve 512 is connected in parallel with the first one-way valve 511; a second one-way valve 521 is provided on the second pressure-regulating pipeline 52, and its liquid flow direction is toward the direction away from the regulating cylinder body 12, and it is connected in series with the second solenoid valve 63. A second regulating valve 522 is also installed on the second pressure-regulating pipeline 52, and the second regulating valve 522 is connected in parallel with the second one-way valve 521; in actual implementation, the first regulating valve 512 can be selected as a throttle valve or a speed regulating valve, and the second regulating valve 522 can also be selected as a throttle valve or a speed regulating valve, as long as it can achieve the regulation of the flow rate of oil in the pipeline.

[0053] Reference Figure 4 , showing the flow path of the oil when the loading and unloading platform is under load and lowering its head, the oil in the regulating cylinder 12 is discharged under the action of the load. At the same time, under the control of the signal sent by the controller, the first solenoid valve 62 and the return oil solenoid valve 64 are energized and actuated, and both are in a connected state. At this time, the first pressure regulating pipeline 51 and the return oil pipeline 36 are in a connected state. In this state, the other solenoid valves are in a power-off closed state. In addition, because the flow direction of the first regulating valve 512 is toward the regulating cylinder 12, the oil in the regulating cylinder 12 When the liquid flows back to the liquid storage tank 21 through the first pressure regulating pipeline 51, the first one-way valve 511 is in the cut-off state, and the oil can only flow through the path where the first regulating valve 512 is located, that is, the oil in the regulating cylinder 12 flows through the first regulating valve 512, the first solenoid valve 62 and the return oil solenoid valve 64 and flows back to the liquid storage tank 21, thereby realizing the lowering action; in the process of the loading and unloading platform completing the lowering action, by adjusting the throttle opening of the first regulating valve 512, the flow rate of the oil flowing in the first pressure regulating pipeline 51 can be controlled, thereby realizing the control of the lowering speed.

[0054] Reference Figure 5 , shows the flow path of the oil when the loading and unloading platform is in the state of lifting up under load, the oil pump pumps out the oil in the liquid storage tank 21, and the controller controls the second solenoid valve 63 to energize, so that the second connecting pipeline 5 where it is located is connected, and the other solenoid valves are in the power-off closed state. In addition, the liquid flow direction of the second regulating valve 522 is toward the side away from the regulating cylinder 12. When oil is passed to the regulating cylinder 12 through the second pressure regulating pipeline 52, the second one-way valve 521 is in the cut-off state, and the oil can only flow from the path where the second regulating valve 522 is located, that is, the oil is passed into the regulating cylinder 12 through the second regulating valve 522 to realize the lifting action; in the process of the loading and unloading platform completing the lifting action, by adjusting the throttle opening of the second regulating valve 522, the flow rate of the oil flowing in the second pressure regulating pipeline 52 can be controlled, and the lifting speed can be controlled.

[0055] By setting up this hydraulic system and using multiple valve bodies instead of booster cylinders, the lifting and lowering control of the loading and unloading platform can be achieved, which saves a lot of space. When the loading and unloading platform and this hydraulic system are applied to existing vehicles, it is not easy to be restricted by space problems, thereby improving applicability. Compared with the solution of using booster cylinders, this hydraulic system reduces its own weight and has higher work efficiency during cargo loading and unloading. Compared with the solution of using booster cylinders to adjust the loading and unloading platform in the related art, the hydraulic system disclosed in the present application can realize the regulation of the lifting cylinder 11 and the adjustment cylinder 12 separately and independently, thereby improving the convenience of control.

[0056] At the same time, during the process of lowering and raising the head, the oil passes through the first regulating valve 512 and the second regulating valve 522 respectively. By adjusting the throttle opening of the first regulating valve 512 and the second regulating valve 522, the speed and flow of the oil passing through the two can be adjusted, that is, the extension and contraction speed of the regulating cylinder 12 can be adjusted, and the lowering and raising speed of the loading and unloading platform can be adjusted to a suitable speed or a required speed value, thereby improving the accuracy of the hydraulic system in adjusting the loading and unloading platform. In the process of the oil passing through the first regulating valve 512 or the second regulating valve 522, only the corresponding passage is in a connected state, and the other passages are in a closed state, so the extension and contraction speed of the regulating cylinder 12 can be adjusted more accurately and more conveniently.

[0057] By adjusting the cylinder 12, while driving the loading and unloading platform to achieve the lowering and raising movements, it is also necessary to drive the loading and unloading platform to achieve the closing and opening movements. The so-called closing means that the loading and unloading platform is retracted so that it can be used as the rear baffle of the vehicle or attached to the rear side of the compartment. Correspondingly, opening the door means adjusting the loading and unloading platform to a flat state to assist in loading and unloading goods. Figure 6 , showing the flow path of the oil in the process of controlling the closing of the loading and unloading platform. The first solenoid valve 62 is energized and opened by the controller, and the second solenoid valve 63 is closed. At this time, the first one-way valve 511 is in a flow state. Driven by the oil pump, the oil passes through the opened first solenoid valve 62 and the first one-way valve 511 in sequence into the regulating cylinder 12, so that the regulating cylinder 12 is quickly extended, driving the loading and unloading platform to close. In this process, the oil flows through the first one-way valve 511, and the path is in a completely open state, which can pass the oil into the regulating cylinder 12 at the fastest speed, realizing the rapid movement of the regulating cylinder 12 and the loading and unloading platform.

[0058] Reference Figure 7 , showing the oil flow path in the process of controlling the opening of the loading and unloading platform. First, the controller controls the return oil solenoid valve 64 and the second solenoid valve 63 to be energized, so that the two are in the open state, and the first solenoid valve 62 is in the closed state. At this time, the second one-way valve 522 is in the flow state, and the oil in the regulating cylinder 12 flows through the second one-way valve 521, the second solenoid valve 63 and the return oil solenoid valve 64 in turn, and finally flows back to the liquid storage tank 21, so that the regulating cylinder 12 is quickly recovered, driving the loading and unloading platform to open.

[0059] When the hydraulic system is used to control the loading and unloading platform to close and open the door, the controller controls the opening and closing of the solenoid valve so that the oil is transmitted through the corresponding one-way valve, which can realize the rapid opening and closing of the loading and unloading platform. Compared with the form of the first regulating valve 512 and the second regulating valve 522, the loading and unloading platform can complete the opening and closing action in a shorter time, thereby improving the operation efficiency.

[0060] Reference Figure 8 , showing the flow path of oil when the lifting cylinder 11 drives the loading and unloading platform to rise. The controller controls the lifting solenoid valve 61 to energize, so that the lifting solenoid valve 61 is in an open state, and the first solenoid valve 62, the second solenoid valve 63 and the oil return solenoid valve 64 are all in a power-off closed state. The oil at the oil pump flows through the lifting solenoid valve 61 into the lifting cylinder 11, so that the lifting cylinder 11 extends to drive the loading and unloading platform to rise. At this time, the passage where the lifting solenoid valve 61 is located is in a fully open state, which can realize rapid oil injection into the lifting cylinder 11, that is, rapid lifting of the lifting platform.

[0061] Reference Figure 9 , showing the flow path of the oil when the lifting cylinder 11 drives the loading and unloading platform to descend. The controller controls the lifting solenoid valve 61 and the oil return solenoid valve 64 to energize, and both are in an open state. The first solenoid valve 62 and the second solenoid valve 63 are both in a power-off closed state. The lifting cylinder 11 is retracted under the action of the external load, and the oil in the lifting cylinder 11 flows through the lifting solenoid valve 61 and the oil return solenoid valve 64, and then flows back to the liquid storage tank 21, so that the lifting cylinder 11 contracts and drives the loading and unloading platform to descend; in this process, the passage where the lifting solenoid valve 61 is located is in a fully open state, which can realize the rapid movement of the lifting cylinder 11, that is, the rapid descent of the loading and unloading platform.

[0062] In addition, refer to Figure 10 In another embodiment, a lifting adjustment member is installed on the first connecting pipeline 4, which is connected in series with the lifting solenoid valve 61, and the lifting adjustment member is located between the lifting solenoid valve 61 and the lifting cylinder body 11. The lifting adjustment member includes a lifting check valve 41 and a lifting regulating valve 42 arranged in parallel with each other. The liquid flow direction of the lifting check valve 41 is set away from the lifting cylinder body 11. When oil is passed to the lifting cylinder body 11, the lifting solenoid valve 61 is energized and is in an open state. The first solenoid valve 62, the second solenoid valve 63 and the oil return solenoid valve 64 are all in a power-off closed state. When liquid is passed to the lifting cylinder body 11 through the oil pump, the lifting check valve 41 is in a cut-off state, so that the oil flows through the lifting regulating valve 42. By adjusting the throttle opening of the lifting regulating valve 42, the oil flow rate can be regulated, and the lifting speed of the loading and unloading platform can be adjusted by adjusting the action speed of the lifting cylinder body 11.

[0063] At the same time, referring to the figure, a flow regulating valve 361 is also installed on the return oil pipeline 36, and the flow regulating valve 361 is located on the side of the return oil solenoid valve 64 facing the oil tank; when the lifting cylinder 11 returns oil, the lifting solenoid valve 61 and the return oil solenoid valve 64 are energized and are in an open circuit state, and the first solenoid valve 62 and the second solenoid valve 63 are both in a power-off closed circuit state. At this time, the lifting check valve 41 is in a circulation state, and the oil in the lifting cylinder 11 passes through the lifting check valve 41, the lifting solenoid valve 61, the return oil solenoid valve 64 and the flow regulating valve 361. By adjusting the throttle opening of the flow regulating valve 361, the return oil flow rate is regulated, that is, the lowering speed of the loading and unloading platform can be regulated by adjusting the movement speed of the lifting cylinder 11.

[0064] Through this solution, the speed of lifting and lowering the loading and unloading platform can be achieved. During actual use, it is convenient to adjust according to actual needs, which can reduce the problem of unstable goods caused by the loading and unloading platform lifting speed being too fast, and at the same time improve the convenience of use; and in the actual design and use process, in order to achieve the adjustment of the lifting and lowering speed of the loading and unloading platform, the movement speed of the lifting cylinder 11 can also be controlled in the same way as the adjustment speed of the adjustment cylinder 12.

[0065] Reference Figure 3 , an oil supply check valve 351 is installed on the oil supply pipeline 35. When the oil in the lifting cylinder 11 and the regulating cylinder 12 flows back to the liquid storage tank 21, it is not easy for some oil to flow to the oil pump and cause backflow; an overflow valve 7 is connected between the oil supply pipeline 35 and the oil return pipeline 36. The overflow valve 7 is connected to the oil supply pipeline 35 between the oil pump and the oil supply check valve 351, and is connected to the return oil pipeline 36 at a position where the flow regulating valve 361 flows toward the liquid storage tank. The overflow valve 7 is on one side of the tank 21, and the flow direction of the overflow valve 7 is toward the side of the return oil pipeline 36. When the amount of oil pumped out by the oil pump is greater than the required amount, the excess oil flows into the return oil pipeline 36 through the overflow valve 7 and flows back to the liquid storage tank 21, which can reduce the problem of damage to the oil pump. In addition, when the subsequent oil delivery pipeline is blocked, the pumped oil can also be diverted through the overflow valve 7 to reduce the problem of damage to the pipeline caused by excessive pressure of the oil in the pipeline.

[0066] Reference Figure 3A liquid level gauge 24 is fixed in the liquid storage tank 21 for detecting the amount of oil in the liquid storage tank 21. In the event of oil leakage or loss during long-term use, the oil can be replenished in time to reduce the impact on the normal operation of the hydraulic system. At the same time, an air filter 25 is also installed in the liquid storage tank 21. The air filter 25 is used to connect the inside and outside of the liquid storage tank 21. During the oil circulation process, the pressure inside and outside the liquid storage tank 21 is kept balanced. At the same time, it is not easy for foreign matter such as dust from the outside to enter the liquid outlet tank, and it is not easy to cause pipeline blockage.

[0067] Reference Figure 11 In another embodiment, a three-position four-way valve 65 is selected to replace the first solenoid valve 62 and the second solenoid valve 63, and the first pressure regulating pipeline 51 and the second pressure regulating pipeline 52 are disconnected therefrom, and the four power-off points of the two pipelines are respectively connected to the four contacts of the three-position four-way valve 65; when not working, the three-position four-way valve 65 is in the middle static position; during operation, the three-position four-way valve 65 is energized and actuated. When the three-position four-way valve 65 is in the first working position, the first pressure regulating pipeline 51 is connected, and when the three-position four-way valve 65 is in the second working position, the second pressure regulating pipeline 52 is connected; during operation, when the first pressure regulating pipeline 51 and the second pressure regulating pipeline 52 are regulated, only one signal is needed to control the action of the three-position four-way valve 65, which simplifies the control method and is more convenient. At the same time, it can further improve the integration of the hydraulic system and reduce space occupation.

[0068] The implementation principle of a hydraulic system for controlling a loading and unloading platform in an embodiment of the present application is as follows: in the process of controlling the movement of the loading and unloading platform, a controller is used to control the power on and power off of multiple solenoid valves, so that different pipelines are connected, thereby realizing the control of the lifting cylinder 11 and the adjusting cylinder 12, replacing the existing booster cylinder. First, when controlling the raising and lowering movements of the loading and unloading platform, there is no need to compare the pressures at both ends of the booster cylinder as in the related art. The corresponding oil circuit can be directly controlled by the controller, and the lifting and angle of the loading and unloading platform can be regulated separately to reduce the influence between the two, simplify the control method and procedure, and make the operation of the hole more convenient. A large amount of space is saved, and when the loading and unloading platform and the hydraulic system are installed on a vehicle, space restrictions are reduced, thereby improving the convenience of use. Secondly, the weight of the hydraulic system is reduced. The hydraulic system is applied to the loading and unloading platform to reduce its own weight and improve the efficiency of loading and unloading.

[0069] In the process of controlling the lifting and lowering of the loading and unloading platform and realizing the raising and lowering movements, the speed of the loading and unloading platform movement can be adjusted, so that the movement of the loading and unloading platform is more suitable for the specific working environment, the process of loading and unloading goods is more stable, and it is not easy to have problems such as goods tipping over.

[0070] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A hydraulic system for controlling a loading and unloading platform, characterized by: The hydraulic system comprises an execution module (1) for driving the loading and unloading platform to move, an oil supply module (2) for providing power to the execution module (1), and a control module (3) arranged between the oil supply module (2) and the execution module (1); The execution module (1) comprises a lifting cylinder (11) connected to the loading and unloading platform and used to drive the loading and unloading platform to rise and fall, and an adjusting cylinder (12) used to adjust the angle of the loading and unloading platform; The control module (3) comprises an oil supply pipeline (35) and an oil return pipeline (36), the oil supply pipeline (35) and the oil return pipeline (36) are both connected to the oil supply module (2), and the ends of the oil supply pipeline (35) and the oil return pipeline (36) away from the oil supply module (2) are connected through a pipeline, the pipeline is connected to the oil supply pipeline (35) at point A, and the pipeline is connected to the oil return pipeline (36) at point B; The lifting cylinder (11) is connected to a first connecting pipeline (4), and the regulating cylinder (12) is connected to a second connecting pipeline (5). The first connecting pipeline (4) and the second connecting pipeline (5) are respectively connected to one of point A and point B. The control module (3) further comprises a switch assembly (6) and a controller for controlling the operation of the switch assembly (6), and is used to adjust the opening and closing of the oil return pipeline (36), the first connecting pipeline (4) and the second connecting pipeline (5); The second connecting pipeline (5) is provided with a regulating valve, and the oil flow in the second connecting pipeline (5) is regulated by the regulating valve; The second connecting pipeline (5) comprises a first pressure regulating pipeline (51) and a second pressure regulating pipeline (52) arranged in parallel; a first one-way valve (511) is connected in series to the first pressure regulating pipeline (51), the liquid flow direction of the first one-way valve (511) is toward the regulating cylinder (12), and the first pressure regulating pipeline (51) is further connected to a first regulating valve (512) connected in parallel with the first one-way valve (511); a second one-way valve (521) is connected in series to the second pressure regulating pipeline (52), the liquid flow direction of the second one-way valve (521) is away from the regulating cylinder (12), and the second pressure regulating pipeline (52) is further connected to a second regulating valve (522) connected in parallel with the second one-way valve (521); When the oil supply module (2) passes oil to the regulating cylinder (12), the first pipeline (31) and the oil return pipeline (36) are closed, and one of the first pressure regulating pipeline (51) and the second pressure regulating pipeline (52) is opened; When the regulating cylinder (12) returns oil to the oil supply module (2), the first pipeline (31) and the oil supply pipeline (35) are closed, and one of the first pressure regulating pipeline (51) and the second pressure regulating pipeline (52) is opened; When the loading and unloading platform is stationary or only the lifting cylinder (11) is in motion, the first pressure regulating pipeline (51) and the second pressure regulating pipeline (52) are closed simultaneously.

2. The hydraulic system for controlling a loading and unloading platform according to claim 1, characterized in that: The switch assembly (6) comprises a first solenoid valve (62) connected in series to a first pressure regulating pipeline (51) and a second solenoid valve (63) connected in series to a second pressure regulating pipeline (52); When the oil supply module (2) passes oil to the regulating cylinder (12), the first pipeline (31) and the oil return pipeline (36) are closed, and one of the first solenoid valve (62) and the second solenoid valve (63) is opened; When the regulating cylinder (12) returns oil to the oil supply module (2), the first pipeline (31) and the oil supply pipeline (35) are closed, and one of the first electromagnetic valve (62) and the second electromagnetic valve (63) is opened.

3. The hydraulic system for controlling a loading and unloading platform according to claim 1, characterized in that: The switch assembly (6) includes a three-position four-way valve (65), wherein the first pressure regulating pipeline (51) and the second pressure regulating pipeline (52) are disconnected in the middle, and the four power-off switches are respectively connected to the four contacts of the three-position four-way valve (65). The three-position four-way valve (65) controls the first pressure regulating pipeline (51) and the second pressure regulating pipeline (52) to be in a connected state respectively, or the first pressure regulating pipeline (51) and the second pressure regulating pipeline (52) are simultaneously in a closed state.

4. The hydraulic system for controlling a loading and unloading platform according to claim 1, characterized in that: The first regulating valve (512) is a throttle valve or a speed regulating valve, and the second regulating valve (522) is a throttle valve or a speed regulating valve.

5. The hydraulic system for controlling a loading and unloading platform according to claim 1, characterized in that: A lifting regulating valve (42) is connected in series to the first connecting pipeline (4) for regulating the flow of oil in the first connecting pipeline (4).

6. The hydraulic system for controlling a loading and unloading platform according to claim 1, characterized in that: An overflow valve (7) is connected between the oil supply pipeline (35) and the oil return pipeline (36), and the liquid flow direction of the overflow valve (7) is toward the oil return pipeline (36).

7. The hydraulic system for controlling a loading and unloading platform according to claim 1, characterized in that: The oil supply module (2) comprises a liquid storage tank (21) and a power component (22) connected to the liquid storage tank (21), and the oil supply pipeline (35) is connected to the power component (22); a liquid level meter (24) and an air filter (25) are also installed in the liquid storage tank (21), and the air filter (25) is used to communicate with the inside and outside of the liquid storage tank (21).

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