Floating control system and high-altitude operation equipment

Abstract

The utility model belongs to the field of hydraulic control, and particularly relates to a floating control system and high-altitude operation equipment, an unloading valve is matched with a flow valve to realize automatic pressurizing and releasing, so that a pump is in a low-pressure standby working condition in most time of a walking working condition, the relative output energy consumption is lower, the generated contrast is smaller, and the influence on components is smaller; and the control is simpler.

Description

Technical Field

[0001] This application relates to the field of hydraulic control technology, and in particular to a floating control system and an aerial work platform. Background Technology

[0002] In the existing field of aerial work platforms, such as aerial work platforms or high-reach telescopic boom trucks, chassis floating functions are usually incorporated to improve the vehicle's off-road performance. Active floating is often the preferred floating solution due to its superior safety and reliability, as well as its better dynamic response and wider applicability. In an active floating system, the floating mechanism adjusts autonomously according to its structural limits. However, the prerequisite for effective floating is that the hydraulic system must provide a stable pressure oil source to the floating mechanism, and this oil source must be sustainable and have higher responsiveness.

[0003] In existing floating control hydraulic systems, the system oil source is typically provided by a load-sensitive variable pump. The floating oil source control valve is usually connected in parallel with other mechanism control valves. When other mechanisms in the system output actions, their pressurized oil can simultaneously serve as the oil source for the floating mechanism. When the equipment is in a pure walking state without outputting actions to other mechanisms, the pump will be in a low-pressure standby state. Because the pressure of the load-sensitive variable pump in the low-pressure standby state is very low, generally only 20-25 bar, it is far from reaching the pressure required by the floating system (specifically, only the floating system needs pressure to work during walking, but it is not continuous operation; this pressure is only needed to meet the floating requirements when the floating condition is encountered). Therefore, the load-sensitive pump is usually switched to a constant-pressure control mode to provide a stable oil source for the floating mechanism. Since there are inherent leaks in the system, the energy consumption is relatively higher when in constant-pressure standby mode. For electrified products, this can cause more than 30% energy loss in pure walking conditions, resulting in a decrease in the overall vehicle's range. At the same time, since the system components are often in high-voltage standby conditions, it will also have a certain impact on the lifespan of the components. Utility Model Content

[0004] This application provides a floating control system and a high-altitude work equipment, which aims to reduce standby power consumption and improve the service life of components.

[0005] Therefore, according to one aspect of this application, a floating control system is provided, including a hydraulic tank, a variable pump, a floating control valve, an accumulator, and a boom function valve. The inlet of the variable pump is connected to the hydraulic tank, the inlet of the floating control valve and the inlet of the boom function valve are connected in parallel to the outlet of the variable pump, and the feedback port of the floating control valve and the feedback port of the boom function valve are connected in parallel to the feedback port of the variable pump through a feedback oil circuit.

[0006] The floating control valve includes a first check valve, a second check valve, a first constant flow valve, a pressure reducing valve, and a pilot-operated unloading valve. The inlet of the first check valve serves as the inlet of the floating control valve. The outlet of the first check valve is connected to the connecting pipeline between the accumulator, the inlet of the pressure reducing valve, and the pilot port of the pilot-operated unloading valve. The outlet of the pressure reducing valve is used to connect to the floating mechanism. The inlet of the pilot-operated unloading valve is connected to the pipeline between the inlet of the second check valve and the outlet of the first constant flow valve. The outlet of the second check valve serves as the feedback port of the floating control valve. The inlet of the first constant flow valve is connected to the inlet of the first check valve. The connecting pipeline between the outlet of the pilot-operated unloading valve and the pressure reducing valve is connected to the hydraulic oil tank.

[0007] The boom function valve includes a steering proportioning valve, a third check valve, a relief valve, and a second constant flow valve. The inlet of the relief valve serves as the inlet of the boom function valve. The inlet of the steering proportioning valve is connected to the inlet of the relief valve. The outlet of the steering proportioning valve is used to connect to an external load. The inlet of the third check valve is connected to the outlet of the steering proportioning valve. The outlet of the third check valve is connected to the inlet of the second constant flow valve. The inlet of the second constant flow valve serves as the feedback port of the boom function valve. The outlets of the second constant flow valve and the relief valve are connected in parallel to the hydraulic oil tank.

[0008] Optionally, the floating control valve further includes an adjustable flow valve, which is connected in series in the pipeline between the oil outlet of the pressure reducing valve and the floating mechanism.

[0009] Optionally, the boom function valve includes multiple steering proportional valves and multiple third check valves. The oil inlets of the multiple steering proportional valves are connected in parallel to the oil inlet of the relief valve. The oil outlets of the multiple steering proportional valves are respectively used to connect to different loads. The oil inlets of the multiple third check valves are respectively connected one-to-one to the oil outlets of the multiple steering proportional valves. The oil outlets of the multiple third check valves are connected in parallel to the oil inlet of the second constant flow valve.

[0010] According to one aspect of this application, a floating control system is provided, including a hydraulic tank, a fixed displacement pump, a floating control valve, an accumulator, and a boom function valve. The inlet of the fixed displacement pump is connected to the hydraulic tank, the inlet of the floating control valve and the inlet of the boom function valve are connected in parallel to the outlet of the fixed displacement pump, and the feedback port of the floating control valve and the feedback port of the boom function valve are connected through a feedback oil circuit.

[0011] The floating control valve includes a first check valve, a second check valve, a first constant flow valve, a pressure reducing valve, and a pilot-operated unloading valve. The inlet of the first check valve serves as the inlet of the floating control valve. The outlet of the first check valve is connected to the connecting pipeline between the accumulator, the inlet of the pressure reducing valve, and the pilot port of the pilot-operated unloading valve. The outlet of the pressure reducing valve is used to connect to the floating mechanism. The inlet of the pilot-operated unloading valve is connected to the pipeline between the inlet of the second check valve and the outlet of the first constant flow valve. The outlet of the second check valve serves as the feedback port of the floating control valve. The inlet of the first constant flow valve is connected to the inlet of the first check valve. The connecting pipeline between the outlet of the pilot-operated unloading valve and the pressure reducing valve is connected to the hydraulic oil tank.

[0012] The boom function valve includes a steering proportional valve, a third check valve, a relief valve, a hydraulic control logic valve, and a second constant flow valve. The inlet of the relief valve serves as the inlet of the boom function valve. The inlets of the steering proportional valve and the hydraulic control logic valve are connected in parallel to the inlet of the relief valve. The outlet of the steering proportional valve is used to connect to an external load. The inlet of the third check valve is connected to the outlet of the steering proportional valve. The outlet of the third check valve and the control port of the hydraulic control logic valve are connected in parallel to the inlet of the second constant flow valve. The inlet of the second constant flow valve serves as the feedback port of the boom function valve. The outlets of the second constant flow valve, the relief valve, and the hydraulic control logic valve are connected in parallel to the hydraulic oil tank.

[0013] Optionally, the floating control valve further includes an adjustable flow valve, which is connected in series in the pipeline between the oil outlet of the pressure reducing valve and the floating mechanism.

[0014] Optionally, the boom function valve includes multiple steering proportional valves and multiple third check valves. The oil inlets of the multiple steering proportional valves are connected in parallel to the oil inlet of the relief valve. The oil outlets of the multiple steering proportional valves are respectively used to connect to different loads. The oil inlets of the multiple third check valves are respectively connected one-to-one to the oil outlets of the multiple steering proportional valves. The oil outlets of the multiple third check valves are connected in parallel to the oil inlet of the second constant flow valve.

[0015] According to another aspect of this application, an aerial work platform is provided, including a floating control system as described above.

[0016] The floating control system and aerial work equipment provided in this application have at least the following beneficial effects:

[0017] 1. Reduce standby power consumption. Since the variable pump / displacement pump is in a low-pressure standby state after the pressure reaches the set value, it is more energy-efficient for the equipment as a whole.

[0018] 2. Simplified control: In the prior art, the variable pump outlet pressure oil needs to be connected to the variable pump feedback port through a solenoid valve to make the variable pump reach the constant pressure standby condition. In this application, no other complicated control is required. The pilot-operated unloading valve itself senses the pressure and performs real-time autonomous control.

[0019] 3. Longer component lifespan: Since the pressure is only briefly increased for oil replenishment, the variable pump / fixed displacement pump is in low-pressure standby condition most of the time during pure walking output, so the component lifespan is relatively longer.

[0020] 4. Lower noise: When the pump is in high-pressure standby mode, the increased pressure will increase the noise generated by the hydraulic system. In this application, the pressure will only increase for a short period of time. Most of the time, the variable pump / displacement pump is in low-pressure standby mode, so the noise generated is relatively lower and more environmentally friendly.

[0021] 5. Better versatility: The same floating control valve can be used in both fixed displacement pump systems and variable displacement pump systems, basically covering all models. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] in:

[0024] Figure 1 This is a control principle diagram of a floating control system shown in one embodiment of this application;

[0025] Figure 2 This is another embodiment of the present application showing the control principle diagram of the floating control system.

[0026] Description of main component symbols:

[0027] 10. Hydraulic oil tank;

[0028] 20. Variable displacement pump;

[0029] 30. Dispensing pump;

[0030] 40. Floating control valve;

[0031] 41. First check valve; 42. Second check valve; 43. First constant flow valve; 44. Pressure reducing valve;

[0032] 45. Pilot-operated unloading valve; 46. Adjustable flow valve;

[0033] 50. Accumulator;

[0034] 60. Boom function valve;

[0035] 61. Steering proportional valve; 62. Third check valve; 63. Relief valve; 64. Second constant flow valve;

[0036] 65. Hydraulic control logic valve. Detailed Implementation

[0037] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many other different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0038] It should be noted that when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to it. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0040] It should also be noted that in the embodiments of this application, the same reference numerals are used to represent the same component or part. For the same part in the embodiments of this application, the reference numerals may only be used to mark one part or component as an example. It should be understood that the reference numerals are also applicable to other identical parts or components.

[0041] As described in the background section, in related technologies, the energy consumption of floating control hydraulic systems is relatively higher when in constant pressure standby mode. For electrified products, this can result in energy loss of more than 30% in pure driving conditions, leading to a decrease in the vehicle's range. Furthermore, since system components are frequently in high-pressure standby conditions, this also has a certain impact on their lifespan.

[0042] The embodiments of this application achieve automatic pressurization and release through the combination of an unloading valve and a flow valve, so that the pump is in a low-pressure standby condition most of the time during the walking operation, resulting in relatively lower output energy consumption, smaller imaging, less impact on components, and simpler control.

[0043] In one embodiment, such as Figure 1 As shown, the floating control system includes a hydraulic oil tank 10, a variable pump 20, a floating control valve 40, an accumulator 50, and a boom function valve 60. The oil inlet of the variable pump 20 is connected to the hydraulic oil tank 10. The oil inlets of the floating control valve 40 and the boom function valve 60 are connected in parallel to the oil outlet of the variable pump 20. The feedback oil ports of the floating control valve 40 and the boom function valve 60 are connected in parallel to the feedback oil port of the variable pump 20 through a feedback oil circuit.

[0044] The floating control valve 40 includes a first check valve 41, a second check valve 42, a first constant flow valve 43, a pressure reducing valve 44, and a pilot-operated unloading valve 45. The inlet of the first check valve 41 serves as the inlet of the floating control valve 40. The outlet of the first check valve 41 is connected to the accumulator 50, the inlet of the pressure reducing valve 44, and the pilot port of the pilot-operated unloading valve 45. The outlet of the pressure reducing valve 44 is used to connect to the floating mechanism. The inlet of the pilot-operated unloading valve 45 is connected to the pipeline between the inlet of the second check valve 42 and the outlet of the first constant flow valve 43. The outlet of the second check valve 42 serves as the feedback port of the floating control valve 40. The inlet of the first constant flow valve 43 is connected to the inlet of the first check valve 41. The pipeline between the outlet of the pilot-operated unloading valve 45 and the pressure reducing valve 44 is connected to the hydraulic oil tank 10.

[0045] The boom function valve 60 includes a steering proportioning valve 61, a third check valve 62, a relief valve 63, and a second constant flow valve 64. The inlet of the relief valve 63 serves as the inlet of the boom function valve 60. The inlet of the steering proportioning valve 61 is connected to the inlet of the relief valve 63. The outlet of the steering proportioning valve 61 is used to connect to the external load. The inlet of the third check valve 62 is connected to the outlet of the steering proportioning valve 61. The outlet of the third check valve 62 is connected to the inlet of the second constant flow valve 64. The inlet of the second constant flow valve 64 serves as the feedback port of the boom function valve 60. The outlet of the second constant flow valve 64 and the outlet of the relief valve 63 are connected in parallel to the hydraulic oil tank 10.

[0046] In this embodiment, the floating control valve 40 and the load are connected in parallel at the outlet of the variable pump 20. When the load generates pressure, its pressure oil enters the floating control valve 40 synchronously, is stored by the accumulator 50, and is provided to the floating mechanism as a stable oil source after being reduced by the pressure reducing valve 44. At this time, the feedback pressure of the feedback port (LS port) of the variable pump 20 depends on the load size.

[0047] When the load pressure causes the outlet pressure of the variable pump 20 to exceed the pilot set pressure of the pilot unloading valve 45, the pilot unloading valve 45 opens, and the maximum load pressure is fed back to the LS port of the variable pump 20. When the outlet pressure of the variable pump 20 after the load pressure is applied is lower than the pilot set pressure of the pilot unloading valve 45, the pilot unloading valve 45 will close under the action of the spring force. Since there is a difference between the first constant flow valve 43 and the second constant flow valve 64, the pressure at the LS port of the variable pump 20 will continue to rise until the pressure at the accumulator 50 rises to the value of the pilot set pressure of the pilot unloading valve 45. At this time, the pilot unloading valve 45 opens, and the pressure after the first constant flow valve 43 is unloaded through the pilot unloading valve 45. At this time, the LS port of the variable pump 20 will feed back the load pressure, and the variable pump 20 will output a certain flow rate to maintain the load pressure. When the floating mechanism consumes the pressure inside the accumulator 50, causing the pilot pressure of the pilot unloading valve 45 to continuously decrease to the pilot opening pressure, the pilot unloading valve 45 continues to close, repeating the above process.

[0048] When the equipment is in pure walking operation, the variable pump 20 needs to be in standby mode. When the pressure at the accumulator 50 is still higher than the pilot opening pressure of the pilot unloading valve 45, the pilot unloading valve 45 is in the open state. The oil at the outlet of the variable pump 20 is unloaded through the first constant flow valve 43, then through the pilot unloading valve 45 and the second constant flow valve 64. At this time, there is no feedback pressure at the LS port of the variable pump 20, so the variable pump 20 will not change direction and will remain in a low-pressure standby state. When the pressure consumption of the accumulator 50 becomes lower than the pilot set pressure of the pilot unloading valve 45, the pilot unloading valve 45 closes. Similarly, due to the difference between the first constant flow valve 43 and the second constant flow valve 64, the pressure at the LS port of the variable pump 20 increases, and the pressure at the outlet of the variable pump 20 increases until it reaches the pilot set pressure of the pilot unloading valve 45. Then, the pilot unloading valve 45 opens, and after unloading, the outlet pressure of the variable pump 20 returns to the low-pressure standby condition.

[0049] The floating control valve 40 also includes an adjustable flow valve 46, which is connected in series in the pipeline between the oil outlet of the pressure reducing valve 44 and the floating mechanism.

[0050] The boom function valve 60 includes multiple steering proportion valves 61 and multiple third check valves 62. The oil inlets of the multiple steering proportion valves 61 are connected in parallel to the oil inlet of the relief valve 63. The oil outlets of the multiple steering proportion valves 61 are used to connect to different loads. The oil inlets of the multiple third check valves 62 are connected one-to-one to the oil outlets of the multiple steering proportion valves 61. The oil outlets of the multiple third check valves 62 are connected in parallel to the oil inlet of the second constant flow valve 64.

[0051] In another embodiment, such as Figure 2 As shown, the floating control system includes a hydraulic oil tank 10, a fixed displacement pump 30, a floating control valve 40, an accumulator 50, and a boom function valve 60. The oil inlet of the fixed displacement pump 30 is connected to the hydraulic oil tank 10. The oil inlets of the floating control valve 40 and the boom function valve 60 are connected in parallel to the oil outlet of the fixed displacement pump 30. The feedback oil port of the floating control valve 40 and the feedback oil port of the boom function valve 60 are connected through a feedback oil circuit.

[0052] The floating control valve 40 includes a first check valve 41, a second check valve 42, a first constant flow valve 43, a pressure reducing valve 44, and a pilot-operated unloading valve 45. The inlet of the first check valve 41 serves as the inlet of the floating control valve 40. The outlet of the first check valve 41 is connected to the accumulator 50, the inlet of the pressure reducing valve 44, and the pilot port of the pilot-operated unloading valve 45. The outlet of the pressure reducing valve 44 is used to connect to the floating mechanism. The inlet of the pilot-operated unloading valve 45 is connected to the pipeline between the inlet of the second check valve 42 and the outlet of the first constant flow valve 43. The outlet of the second check valve 42 serves as the feedback port of the floating control valve 40. The inlet of the first constant flow valve 43 is connected to the inlet of the first check valve 41. The pipeline between the outlet of the pilot-operated unloading valve 45 and the pressure reducing valve 44 is connected to the hydraulic oil tank 10.

[0053] The boom function valve 60 includes a steering proportioning valve 61, a third check valve 62, a relief valve 63, a hydraulic control logic valve 65, and a second constant flow valve 64. The inlet of the relief valve 63 serves as the inlet of the boom function valve 60. The inlets of the steering proportioning valve 61 and the hydraulic control logic valve 65 are connected in parallel to the inlet of the relief valve 63. The outlet of the steering proportioning valve 61 is used to connect to the external load. The inlet of the third check valve 62 is connected to the outlet of the steering proportioning valve 61. The outlet of the third check valve 62 and the control port of the hydraulic control logic valve 65 are connected in parallel to the inlet of the second constant flow valve 64. The inlet of the second constant flow valve 64 serves as the feedback port of the boom function valve 60. The outlets of the second constant flow valve 64, the relief valve 63, and the hydraulic control logic valve 65 are connected in parallel to the hydraulic oil tank 10.

[0054] In this embodiment, the floating control valve 40 operates on the same principle as in the previous embodiments, and is connected in parallel to the outlet of the pump (in this embodiment, the pump is a fixed displacement pump 30). When there is other output action, the load pressure is fed back to the hydraulic control logic valve 65. At this time, the outlet pressure of the fixed displacement pump 30 rises to a level higher than the load pressure. Similarly, the outlet pressure of the fixed displacement pump 30 acts on the floating control valve 40 to pressurize the accumulator 50. After the accumulator 50 is fully pressurized, it is unloaded through the floating feedback oil circuit. Similarly, when the load pressure is lower than the pilot set pressure of the pilot unloading valve 45, the outlet pressure of the fixed displacement pump 30 will continue to rise until the pilot unloading valve 45 opens to unload, and the feedback pressure returns to the pressure of the system's maximum load. When there is no load output, all the oil in the fixed displacement pump 30 is unloaded from the hydraulic control logic valve 65, and the outlet of the fixed displacement pump 30 is in a low-pressure standby state. There are two states for the feedback pressure. When the floating mechanism consumes the oil in the accumulator 50, causing the pressure at the accumulator 50 to be lower than the pilot set pressure of the pilot unloading valve 45, the feedback pressure will increase. At this time, the oil outlet pressure of the fixed displacement pump 30 will increase synchronously, pressurizing the accumulator 50 and the floating mechanism. When the pilot set pressure of the pilot unloading valve 45 is reached, the floating feedback oil circuit will be unloaded, and the oil outlet pressure of the fixed displacement pump 30 will return to the low-pressure standby state. The other state is when the pressure at the accumulator 50 is sufficient to open the pilot unloading valve 45. At this time, the oil outlet pressure of the fixed displacement pump 30 will not increase. Only when the pressure at the accumulator 50 decreases will pressure oil be fed back to the hydraulic control logic valve 65.

[0055] The floating control valve 40 also includes an adjustable flow valve 46, which is connected in series in the pipeline between the oil outlet of the pressure reducing valve 44 and the floating mechanism.

[0056] The boom function valve 60 includes multiple steering proportioning valves 61 and multiple third check valves 62. The oil inlets of the multiple steering proportioning valves 61 are connected in parallel to the oil inlet of the relief valve 63. The oil outlets of the multiple steering proportioning valves 61 are respectively used to connect to different loads. The oil inlets of the multiple third check valves 62 are respectively connected to the oil outlets of the multiple steering proportioning valves 61. The oil outlets of the multiple third check valves 62 are connected in parallel to the oil inlet of the second constant flow valve 64.

[0057] This application also provides an aerial work platform, such as an aerial work platform or a high-reach telescopic boom truck, which includes the floating control system described in the above embodiments.

[0058] In summary, implementing the floating control system and high-altitude work equipment in the embodiments of this application has at least the following beneficial effects:

[0059] 1. Reduced standby power consumption: Since the variable pump 20 / fixed displacement pump 30 is in a low-pressure standby state after the pressure reaches the set value, it is more energy-efficient for the equipment as a whole.

[0060] 2. Simplified control: In the prior art, the outlet pressure oil of the variable pump 20 needs to be connected to the feedback port of the variable pump 20 through a solenoid valve to make the variable pump 20 reach the constant pressure standby condition. In this application, no other complicated control is required. The pilot unloading valve 45 itself senses the pressure and performs real-time autonomous control.

[0061] 3. Longer component lifespan: Since the pressure is only briefly increased for oil replenishment, the variable pump 20 / fixed displacement pump 30 is in low-pressure standby condition most of the time during pure walking output, so the component lifespan is relatively longer.

[0062] 4. Lower noise: When the pump is in high-pressure standby mode, the increased pressure will increase the noise generated by the hydraulic system. In this application, the pressure will only increase for a short period of time. Most of the time, the variable pump 20 / fixed displacement pump 30 is in low-pressure standby mode, so the noise generated is relatively lower and more environmentally friendly.

[0063] 5. Better versatility: The same floating control valve can be used in both fixed displacement pump systems and variable displacement pump systems, basically covering all models.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A floating control system, characterized in that, It includes a hydraulic oil tank, a variable pump, a floating control valve, an accumulator, and a boom function valve. The oil inlet of the variable pump is connected to the hydraulic oil tank. The oil inlets of the floating control valve and the boom function valve are connected in parallel to the oil outlet of the variable pump. The feedback oil ports of the floating control valve and the boom function valve are connected in parallel to the feedback oil port of the variable pump through a feedback oil circuit. The floating control valve includes a first check valve, a second check valve, a first constant flow valve, a pressure reducing valve, and a pilot-operated unloading valve. The inlet of the first check valve serves as the inlet of the floating control valve. The outlet of the first check valve is connected to the connecting pipeline between the accumulator, the inlet of the pressure reducing valve, and the pilot port of the pilot-operated unloading valve. The outlet of the pressure reducing valve is used to connect to the floating mechanism. The inlet of the pilot-operated unloading valve is connected to the pipeline between the inlet of the second check valve and the outlet of the first constant flow valve. The outlet of the second check valve serves as the feedback port of the floating control valve. The inlet of the first constant flow valve is connected to the inlet of the first check valve. The connecting pipeline between the outlet of the pilot-operated unloading valve and the pressure reducing valve is connected to the hydraulic oil tank. The boom function valve includes a steering proportioning valve, a third check valve, a relief valve, and a second constant flow valve. The inlet of the relief valve serves as the inlet of the boom function valve. The inlet of the steering proportioning valve is connected to the inlet of the relief valve. The outlet of the steering proportioning valve is used to connect to an external load. The inlet of the third check valve is connected to the outlet of the steering proportioning valve. The outlet of the third check valve is connected to the inlet of the second constant flow valve. The inlet of the second constant flow valve serves as the feedback port of the boom function valve. The outlets of the second constant flow valve and the relief valve are connected in parallel to the hydraulic oil tank.

2. The floating control system according to claim 1, characterized in that, The floating control valve also includes an adjustable flow valve, which is connected in series in the pipeline between the oil outlet of the pressure reducing valve and the floating mechanism.

3. The floating control system according to claim 1 or 2, characterized in that, The boom function valve includes multiple steering proportional valves and multiple third check valves. The oil inlets of the multiple steering proportional valves are connected in parallel to the oil inlet of the relief valve. The oil outlets of the multiple steering proportional valves are respectively used to connect to different loads. The oil inlets of the multiple third check valves are respectively connected one-to-one to the oil outlets of the multiple steering proportional valves. The oil outlets of the multiple third check valves are connected in parallel to the oil inlet of the second constant flow valve.

4. A floating control system, characterized in that, It includes a hydraulic oil tank, a fixed displacement pump, a floating control valve, an accumulator, and a boom function valve. The oil inlet of the fixed displacement pump is connected to the hydraulic oil tank. The oil inlets of the floating control valve and the boom function valve are connected in parallel to the oil outlet of the fixed displacement pump. The feedback oil port of the floating control valve and the feedback oil port of the boom function valve are connected through a feedback oil circuit. The floating control valve includes a first check valve, a second check valve, a first constant flow valve, a pressure reducing valve, and a pilot-operated unloading valve. The inlet of the first check valve serves as the inlet of the floating control valve. The outlet of the first check valve is connected to the connecting pipeline between the accumulator, the inlet of the pressure reducing valve, and the pilot port of the pilot-operated unloading valve. The outlet of the pressure reducing valve is used to connect to the floating mechanism. The inlet of the pilot-operated unloading valve is connected to the pipeline between the inlet of the second check valve and the outlet of the first constant flow valve. The outlet of the second check valve serves as the feedback port of the floating control valve. The inlet of the first constant flow valve is connected to the inlet of the first check valve. The connecting pipeline between the outlet of the pilot-operated unloading valve and the pressure reducing valve is connected to the hydraulic oil tank. The boom function valve includes a steering proportional valve, a third check valve, a relief valve, a hydraulic control logic valve, and a second constant flow valve. The inlet of the relief valve serves as the inlet of the boom function valve. The inlets of the steering proportional valve and the hydraulic control logic valve are connected in parallel to the inlet of the relief valve. The outlet of the steering proportional valve is used to connect to an external load. The inlet of the third check valve is connected to the outlet of the steering proportional valve. The outlet of the third check valve and the control port of the hydraulic control logic valve are connected in parallel to the inlet of the second constant flow valve. The inlet of the second constant flow valve serves as the feedback port of the boom function valve. The outlets of the second constant flow valve, the relief valve, and the hydraulic control logic valve are connected in parallel to the hydraulic oil tank.

5. The floating control system according to claim 4, characterized in that, The floating control valve also includes an adjustable flow valve, which is connected in series in the pipeline between the oil outlet of the pressure reducing valve and the floating mechanism.

6. The floating control system according to claim 4 or 5, characterized in that, The boom function valve includes multiple steering proportional valves and multiple third check valves. The oil inlets of the multiple steering proportional valves are connected in parallel to the oil inlet of the relief valve. The oil outlets of the multiple steering proportional valves are respectively used to connect to different loads. The oil inlets of the multiple third check valves are respectively connected one-to-one to the oil outlets of the multiple steering proportional valves. The oil outlets of the multiple third check valves are connected in parallel to the oil inlet of the second constant flow valve.

7. An aerial work platform, characterized in that, Including the floating control system as described in any one of claims 1-6.

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