Emergency descending system and method for rice counting arm frame type overhead working truck

Abstract

The invention provides an emergency descending system and method for a rice counting arm frame type overhead working truck, the system comprises a telescopic balance valve and a variable amplitude balance valve, and further comprises an emergency control valve group, the emergency control valve group comprises a two-position two-way electromagnetic reversing valve, a hand pump and a two-position three-way hand-operated reversing valve which are sequentially communicated through a hydraulic pipeline, and the two-position two-way electromagnetic reversing valve, the hand pump and the two-position three-way hand-operated reversing valve are communicated through a hydraulic pipeline. Two oil outlets of the hand-operated direction valve are respectively communicated with a pilot oil port of the balance valve and an oil inlet pipeline of the two-position two-way electromagnetic directional valve, and the hand pump is arranged on an oil way between the two-position two-way electromagnetic directional valve and the hand-operated direction valve. According to the method, a normal power-on mode and an insufficient power mode are divided according to whether the whole machine is normally powered on; the electromagnetic reversing valve is activated, and the balance valve in the variable-amplitude balance valve is activated through the hand pump. By arranging the emergency control valve set, when the main arm variable-amplitude oil cylinder breaks down and cannot be controlled to descend through self weight or hydraulic pressure, the balance valve in the variable-amplitude balance valve is activated through the hand pump, and emergency descending is achieved.

Description

Technical Field

[0001] The present invention relates to an emergency descent system and method for a multi-section boom aerial work platform, belonging to the technical field of aerial work platforms. Background Art

[0002] As the working height of boom aerial work platforms gets higher and higher, when the whole machine fails, it becomes increasingly difficult to bring personnel back to the ground from high altitude or to perform maintenance.

[0003] For boom aerial work platforms on the domestic market, the original balance valve was used to control the luffing cylinder. By supplying oil to the rod chamber of the luffing cylinder, the luffing cylinder retracts to complete the descent action. The self-weight descent is achieved by connecting the rodless chamber of the luffing cylinder to the hydraulic oil tank and using the self-weight of the load on the luffing cylinder to complete the descent action. Although the self-weight descent technology has many advantages, there are also the following problems.

[0004] Firstly, the self-weight descent controls the descent speed of the boom by adjusting the opening size of the electro-hydraulic proportional valve. As the angle of the boom changes, the load acting on the luffing cylinder also changes. To ensure the boom descends at a constant speed and avoid the boom descent speed from changing with the load, a compensating valve is usually used in conjunction with the electro-hydraulic proportional valve to control the descent speed. For safety reasons, multi-section boom aerial work platforms often add a switch redundant valve on the basis of the electro-hydraulic proportional valve and the compensating valve to ensure that it will not accidentally fall.

[0005] However, during the operation of boom aerial work platforms, the control wire harness often rubs against the boom structure, resulting in damage or breakage of the wire harness. After long-term use, when the hydraulic oil is contaminated and the spool inside the luffing self-weight descent valve gets stuck and cannot commutate normally, the boom will be lifted in the air and cannot fall. In this case, it is often necessary to arrange another device to pick up people from high altitude, and then let the boom fall by flying wires or adjusting the relief valve on the self-weight descent valve. However, it is often difficult to find a vehicle of the appropriate height in a short time at the construction site, and the operation is difficult and dangerous.

[0006] In the emergency descent method disclosed in an emergency descent system and control method for an aerial work platform with the publication number CN115289102A, the emergency descent is achieved by applying a control pressure to its hydraulic control port to open the balance valve, allowing the oil in the large chamber of the luffing cylinder to flow back to the oil tank under the action of the load.

[0007] However, in the actual use process, there are facilities such as crossbeams or roofs under the boom of the articulated boom aerial work platform. Emergency lowering can not only lower the boom at any time, but also make it stop at any position at any time. Secondly, in the existing emergency plans, an emergency pump is generally configured as the power oil source in case of emergency, and the emergency pump needs to be driven by an electric motor. Once the whole vehicle cannot be powered on, the emergency function will fail, so there are still potential hazards. Finally, in the operating conditions of the large-meterage boom aerial work platform, the operating curve has amplitude limitations, and conventional emergency lowering may cause the operator to start under the condition of exceeding the amplitude, which may lead to the overturning of the whole vehicle and cause serious accidents. Summary of the Invention

[0008] Object of the Invention: Aiming at the deficiencies in the prior art, the present invention provides an emergency lowering system and method for a large-meterage boom aerial work platform to solve the problems mentioned in the above background technology.

[0009] Technical Solution: An emergency lowering system for a large-meterage boom aerial work platform includes a telescopic balance valve for controlling the telescopic oil cylinder of the main boom and a luffing balance valve for controlling the luffing oil cylinder of the main boom. Both the telescopic balance valve and the luffing balance valve are connected to the hydraulic oil tank through a main control valve. The main control valve extracts hydraulic oil from the hydraulic oil tank through a pump motor assembly. The luffing balance valve includes a balance valve and a luffing control valve group; It further includes an emergency control valve group. One end of the emergency control valve group is connected to the hydraulic oil tank through a hydraulic pipeline, and the other end is connected to the balance valve through a hydraulic pipeline; The emergency control valve group includes a two-position two-way electromagnetic directional valve, a hand-operated pump, and a two-position three-way manual directional valve that are connected in sequence through a hydraulic pipeline. The two-position two-way electromagnetic directional valve is connected to the hydraulic oil tank. The two oil outlets of the manual directional valve are respectively connected to the pilot oil port of the balance valve and the oil inlet pipeline of the two-position two-way electromagnetic directional valve, The hand-operated pump is arranged on the oil pipeline between the two-position two-way electromagnetic directional valve and the manual directional valve, and check valves are arranged on the oil pipelines between the hand-operated pump and the two-position two-way electromagnetic directional valve and between the hand-operated pump and the manual directional valve, so that the hydraulic oil can only flow in the direction of the manual directional valve.

[0010] By setting the emergency control valve group, when the luffing oil cylinder of the main boom fails and cannot be lowered by its own weight or hydraulic control, the hand-operated pump supplies the hydraulic oil in the hydraulic oil tank to the pilot oil port of the balance valve to establish an activation pressure, activate the balance valve in the luffing balance valve, and the hydraulic oil in the luffing oil cylinder of the main boom slowly flows back to the hydraulic oil tank by its own weight to achieve emergency lowering and ensure the safety of construction workers.

[0011] It further includes a relief valve, and the relief valve is arranged between the hydraulic pipeline between the hand-operated pump and the manual directional valve and the oil inlet pipeline of the manual directional valve and the two-way electromagnetic directional valve.

[0012] After the pressure at the pilot oil port of the balance valve is established, to avoid excessive pressure in the oil circuit of the emergency control valve group and damage to hydraulic components, the excess hydraulic oil pumped out from the hand pump flows back to the hydraulic oil tank through the relief valve.

[0013] A manual switching knob is provided on the two-position two-way solenoid valve. In the power-off state, the two-position two-way solenoid directional valve is controlled to connect the oil circuit through the manual switching knob.

[0014] When the whole machine is completely powered off, the two-position two-way solenoid valve cannot switch the oil circuit through the electromagnet. By setting a manual switching knob, in the absence of power supply, the oil circuit of the two-position two-way solenoid valve can be switched to the connected position through the manual switching knob, and then the manual directional valve is rotated to connect the oil circuit between the balance valve and the hand pump, realizing the emergency descent in the power-off state.

[0015] A length and angle sensor is provided at the end of the boom. The length and angle sensor is used to measure the extension distance of the main boom and the luffing angle of the main boom. A travel switch is provided at the end of the boom, and the travel switch is used to detect whether the boom is fully retracted; a weighing device and a wind speed sensor are provided on the operation platform, which are used to detect the load of the operation platform and the wind load.

[0016] By setting the length and angle sensor, the extension distance of the main boom and the luffing angle of the main boom can be monitored, which is convenient for the staff to understand whether the current state of the main boom exceeds the limit. The travel switch can monitor whether the main boom is fully retracted. After the emergency mode is started, the main boom is fully retracted. When the travel switch is triggered, it is in the fully retracted state. The weighing and wind speed sensors are convenient for monitoring the load and wind load of the work platform. By combining the extension distance, luffing angle, load and wind load, it can be determined whether the current state exceeds the limit.

[0017] It also includes a calendar clock module set in the whole machine controller. When the whole machine starts to execute the emergency descent mode, the timing is started. After reaching the preset start time, the emergency descent mode is closed and the two-position two-way solenoid directional valve loses power.

[0018] After the emergency mode is started by the calendar clock module, the timing starts according to the preset time. When the time arrives, the emergency descent mode is stopped, avoiding unnecessary safety accidents caused by forgetting.

[0019] The control method of the emergency descent system of the large-tonnage boom-type aerial work platform is divided into a normal power-on mode and a power-deficient mode according to whether the whole machine is normally powered on; The control strategy of the normal power-on mode is as follows: Step 1: Turn on the emergency lowering mode through the machine control panel. First, perform boom retraction detection and outrigger status detection. When it is detected that the boom is not fully retracted or in an outrigger state, the machine control panel prompts the operator to retract the boom. The operator controls the boom to retract to the fully retracted or non-outrigger state. The machine control panel prompts that the emergency lowering mode has been turned on, and the two-position two-way solenoid directional valve is energized, connecting the hand pump to the hydraulic oil tank; Step 2: Rotate the manual directional valve clockwise to connect the hand pump to the oil circuit of the balance valve through the manual directional valve. Operate the hand pump to draw the hydraulic oil in the hydraulic oil tank to the pilot oil port of the balance valve to establish an opening pressure for the balance valve to activate the balance valve. The hydraulic oil of the main boom luffing cylinder slowly returns to the hydraulic oil tank through the balance valve, realizing the emergency lowering of the main boom; The control strategy for the power failure mode is as follows: When the whole machine's power system fails and cannot be powered on, rotate the switching knob set on the two-position two-way solenoid directional valve to control the oil circuit switching of the two-position two-way solenoid directional valve to connect the oil circuit between the hydraulic oil tank and the hand pump; rotate the manual directional valve to switch the oil circuit to connect the oil circuit between the hand pump and the balance valve. Operate the hand pump to deliver the hydraulic oil in the hydraulic oil tank to the pilot oil port of the balance valve to establish an activation pressure to activate the balance valve, causing the hydraulic oil of the main boom luffing cylinder to return to the hydraulic oil tank to realize emergency lowering.

[0020] During the emergency lowering process, when there are obstacles in the lowering path and it cannot be lowered smoothly, rotate the manual directional valve counterclockwise, and the hydraulic oil at the pilot oil port in the balance valve returns to the hydraulic oil tank, and the boom stops falling. When the obstacle is removed, rotate the manual directional valve clockwise to continue the emergency lowering operation.

[0021] Beneficial effects: By setting up an emergency control valve group, when the main boom luffing cylinder fails and cannot be lowered by its own weight or hydraulic control, the hydraulic oil in the hydraulic oil tank is supplied to the pilot oil port of the balance valve through the hand pump to establish an activation pressure to activate the balance valve in the luffing balance valve. The hydraulic oil in the main boom luffing cylinder slowly returns to the hydraulic oil tank by its own weight to realize emergency lowering, ensuring the safety of construction personnel.

[0022] When the whole machine is completely powered off, the two-position two-way solenoid valve cannot switch the oil circuit through the electromagnet. By setting a manual switching knob, in the case of no power supply, the oil circuit of the two-position two-way solenoid valve is switched to the connected position through the manual switching knob, and then the manual directional valve is rotated to connect the oil circuit between the balance valve and the hand pump to realize emergency lowering in the power-off state.

[0023] The present invention sets up multiple levels of emergency unlocking measures to avoid accidental start-up of the program caused by misoperation, resulting in unnecessary losses. On the premise of combining electric control and manual control, the standardization of the operation process is ensured to the greatest extent, reducing equipment and personnel injuries. Brief Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0025] Figure 1 This is the hydraulic schematic diagram of the present invention. Detailed Embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0028] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0029] As Figure 1 shown, an emergency descent system for a multi-boom aerial work platform for rice includes a telescopic balance valve 2 for controlling the telescopic movement of the main boom telescopic cylinder 1 and a luffing balance valve 4 for controlling the luffing movement of the main boom luffing cylinder 3. Both the telescopic balance valve 2 and the luffing balance valve 4 are connected to the hydraulic oil tank 6 through a main control valve 5. The main control valve 5 draws hydraulic oil from the hydraulic oil tank 6 through a pump motor assembly 8. The luffing balance valve 4 includes a balance valve 41 and a luffing control valve group 42; It further includes an emergency control valve group 7. One end of the emergency control valve group 7 is communicated with a hydraulic oil tank 6 through a hydraulic pipeline, and the other end is communicated with a balance valve 41 through a hydraulic pipeline. The emergency control valve group 7 includes a two-position two-way electromagnetic directional valve 71, a hand pump 72, and a two-position three-way manual directional valve 73 that are sequentially communicated through a hydraulic pipeline. The two-position two-way electromagnetic directional valve 71 is communicated with the hydraulic oil tank 6. Two oil outlets of the manual directional valve 73 are respectively communicated with a pilot oil port of the balance valve 41 and an oil inlet pipeline of the two-position two-way electromagnetic directional valve 71. The hand pump 72 is arranged on the oil path between the two-position two-way electromagnetic directional valve 71 and the manual directional valve 73. Check valves are arranged on the oil paths between the hand pump 72 and the two-position two-way electromagnetic directional valve 71 and between the hand pump 72 and the manual directional valve 73, so that the hydraulic oil can only flow in the direction of the manual directional valve 73.

[0030] By setting the emergency control valve group 7, when the main boom luffing cylinder 3 fails and cannot descend by its own weight or hydraulic control, the hand pump 72 supplies the hydraulic oil in the hydraulic oil tank 6 to the pilot oil port of the balance valve 41 to establish an activation pressure, so that the balance valve 41 in the luffing balance valve 4 is activated, and the hydraulic oil in the main boom luffing cylinder 3 slowly flows back to the hydraulic oil tank 6 by its own weight, realizing emergency descent and ensuring the safety of construction personnel.

[0031] In this embodiment, the area ratio of the pilot oil port of the balance valve to the spring chamber of the luffing balance valve is 1:4. In the emergency descent procedure, the activation pressure of the pilot oil port is only 1 / 4 of the system pressure, which can be activated in a short time, reducing the time for personnel to be trapped at high altitude and reducing the risk of injury caused by accidents.

[0032] It further includes an overflow valve 74. The overflow valve 74 is arranged between the hydraulic pipeline between the hand pump 72 and the manual directional valve 73 and the oil inlet pipeline between the manual directional valve 73 and the two-way electromagnetic directional valve.

[0033] After the pressure of the pilot oil port of the balance valve 41 is established, in order to avoid excessive pressure in the oil path of the emergency control valve group 7 and damage the hydraulic components, the excess hydraulic oil pumped out from the hand pump 72 flows back to the hydraulic oil tank 6 through the overflow valve 74.

[0034] A manual switching knob 75 is arranged on the two-position two-way electromagnetic directional valve 71. The two-position two-way electromagnetic directional valve 71 is controlled to communicate the oil path through the manual switching knob 75 in the power-off state.

[0035] When the entire machine loses power completely, the two-position two-way electromagnetic directional valve 71 cannot switch the oil circuit through the electromagnet. By setting a manual switching knob 75, in the absence of power supply, the oil circuit of the two-position two-way electromagnetic directional valve 71 is switched to the connected position through the manual switching knob 75, and then the manual directional valve 73 is rotated to connect the oil circuit between the balance valve 41 and the hand pump 72, realizing the emergency descent in the power-off state.

[0036] A length and angle sensor is provided at the end of the boom. The length and angle sensor is used to measure the extension distance of the main boom and the luffing angle of the main boom. A travel switch is provided at the end of the boom, and the travel switch is used to detect whether the boom is fully retracted; a weighing device and a wind speed sensor are provided on the operation platform for detecting the load on the operation platform and the wind load.

[0037] By setting the length and angle sensor, the extension distance of the main boom and the luffing angle of the main boom can be monitored, which is convenient for the staff to understand whether the current state of the main boom exceeds the limit. The travel switch can monitor whether the main boom is fully retracted. After the emergency mode is started, the main boom is fully retracted. When the travel switch is triggered, it is in the fully retracted state. The weighing and wind speed sensors are convenient for monitoring the load on the work platform and the wind load. By combining the extension distance, luffing angle, load and wind load, it can be determined whether the current state exceeds the limit.

[0038] It also includes a calendar clock module set in the whole machine controller. When the whole machine starts to execute the emergency descent mode, the timing is started. After reaching the preset start time, the emergency descent mode is closed and the two-position two-way electromagnetic directional valve 71 loses power.

[0039] After the emergency mode is turned on by the calendar clock module, timing starts according to the preset time, and the emergency descent mode stops when the time arrives, avoiding unnecessary safety accidents caused by forgetting.

[0040] The control method of the emergency descent system of the rice-number boom type aerial work platform is divided into a normal power-on mode and a power-deficient mode according to whether the whole machine is normally powered on; The control strategy of the normal power-on mode is as follows: Step 1: Turn on the emergency descent mode through the whole machine control panel. First, perform boom retraction detection and over-limit state detection. When it is detected that the boom is not fully retracted or in an over-limit state, the whole machine control panel prompts to retract the boom. The operator controls the boom to retract to the fully retracted or non-over-limit state. The whole machine control panel prompts that the emergency descent mode has been turned on. The two-position two-way electromagnetic directional valve 71 is powered on, and the hand pump 72 is connected to the hydraulic oil tank 6; Step 2: Rotate the manual reversing valve 73 clockwise to connect the hand-operated pump 72 to the oil circuit of the balance valve 41 through the manual reversing valve 73. Operate the hand-operated pump 72 to extract the hydraulic oil in the hydraulic oil tank 6 to the pilot oil port of the balance valve 41, establish the opening pressure for the balance valve 41, activate the balance valve 41, and the hydraulic oil of the main boom luffing cylinder 3 slowly returns to the hydraulic oil tank 6 through the balance valve 41 to achieve the emergency lowering of the main boom. The control strategy for the power shortage mode is as follows: When the entire machine's power system fails and cannot be powered on, rotate the switching knob provided on the two-position two-way electromagnetic reversing valve 71 to control the oil circuit switching of the two-position two-way electromagnetic reversing valve 71, so that the oil circuit between the hydraulic oil tank 6 and the hand-operated pump 72 is connected; rotate the manual reversing valve 73 to switch the oil circuit to be connected between the hand-operated pump 72 and the balance valve 41, operate the hand-operated pump 72 to transport the hydraulic oil in the hydraulic oil tank 6 to the pilot oil port of the balance valve 41, establish the activation pressure, activate the balance valve 41, and make the hydraulic oil of the main boom luffing cylinder 3 return to the hydraulic oil tank 6 to achieve emergency lowering.

[0041] During the actual operation process, the emergency lowering operation is evaluated by professionals on-site to determine whether it meets the emergency lowering conditions. If it meets the conditions, the emergency lowering operation can be executed. If it does not meet the conditions, such as in an overamplitude state and abnormal power supply for the entire machine, fault repair needs to be carried out first before the emergency lowering operation can be executed, to ensure personnel safety to the greatest extent.

[0042] When there are obstacles in the lowering path during the emergency lowering process and it is impossible to lower smoothly, rotate the manual reversing valve 73 counterclockwise, and the hydraulic oil at the pilot oil port in the balance valve 41 returns to the hydraulic oil tank 6, and the boom stops falling. When the obstacle is removed, rotate the manual reversing valve 73 clockwise to continue the emergency lowering operation.

[0043] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description in the method part.

[0044] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An emergency descent system for a rice multi-boom aerial work platform, comprising a telescopic balance valve (2) for controlling the telescopic main boom cylinder (1) and a luffing balance valve (4) for controlling the luffing main boom cylinder (3). The telescopic balance valve (2) and the luffing balance valve (4) are both connected to a hydraulic oil tank (6) through a main control valve (5). The main control valve (5) draws hydraulic oil from the hydraulic oil tank (6) through a pump motor assembly (8). It is characterized in that: The luffing balance valve (4) includes a balance valve (41) and a luffing control valve group (42); It further includes an emergency control valve group (7). One end of the emergency control valve group (7) is connected to the hydraulic oil tank (6) through a hydraulic pipeline, and the other end is connected to the balance valve (41) through a hydraulic pipeline; The emergency control valve group (7) includes a two-position two-way electromagnetic directional valve (71), a hand pump (72), and a two-position three-way manual directional valve (73) that are connected in sequence through hydraulic pipelines. The two-position two-way electromagnetic directional valve (71) is connected to the hydraulic oil tank (6). Two oil outlets of the manual directional valve (73) are respectively connected to the pilot oil port of the balance valve (41) and the oil inlet pipeline of the two-position two-way electromagnetic directional valve (71), The hand pump (72) is arranged on the oil pipeline between the two-position two-way electromagnetic directional valve (71) and the manual directional valve (73). Check valves are arranged on the oil pipelines between the hand pump (72) and the two-position two-way electromagnetic directional valve (71) and between the hand pump (72) and the manual directional valve (73), so that the hydraulic oil can only flow in the direction of the manual directional valve (73).

2. The emergency descent system for the rice boom aerial work platform according to claim 1, characterized in that: It further includes a relief valve (74). The relief valve (74) is arranged between the hydraulic pipeline between the hand pump (72) and the manual directional valve (73) and the oil inlet pipeline of the two-way electromagnetic directional valve between the manual directional valve (73).

3. The emergency descent system for the rice boom aerial work platform according to claim 1, characterized in that: A manual switching knob (75) is arranged on the two-position two-way electromagnetic directional valve (71). In the power-off state, the two-position two-way electromagnetic directional valve (71) is controlled to connect the oil circuit through the manual switching knob (75).

4. The emergency descent system for a rice boom type aerial work platform according to claim 1, characterized in that: A length and angle sensor is arranged at the end of the boom. The length and angle sensor is used to measure the extended distance of the main boom and the luffing angle of the main boom. A travel switch is arranged at the end of the boom. The travel switch is used to detect whether the boom is fully retracted; A weighing device and a wind speed sensor are arranged on the work platform to detect the load of the work platform and the wind load.

5. The emergency descent system of the rice boom aerial work platform according to claim 1, characterized in that: It further includes a calendar clock module arranged in the whole machine controller. When the whole machine starts to execute the emergency descent mode, timing is started. After reaching the preset start time, the emergency descent mode is closed, and the two-position two-way electromagnetic directional valve (71) loses power.

6. The control method of the emergency descent system for a rice multi-boom aerial work platform according to any one of claims 1 to 5, characterized in that: It is divided into a normal power-on mode and a power-deficient mode according to whether the whole machine is normally powered on; Among them, the control strategy of the normal power-on mode is as follows: Step 1: Turn on the emergency lowering mode through the machine's control panel. First, perform the boom retraction detection and the outreach status detection. When it is detected that the boom is not fully retracted or in the outreach state, the machine's control panel prompts to retract the boom. The operator controls the boom to retract to the fully retracted or non-outreach state. The machine's control panel prompts that the emergency lowering mode has been turned on, and the two-position two-way solenoid directional valve (71) is energized, and the hand pump (72) is connected to the hydraulic oil tank (6). Step 2: Rotate the manual directional valve (73) clockwise to connect the hand pump (72) to the oil circuit of the balance valve (41) through the manual directional valve (73). Operate the hand pump (72) to draw the hydraulic oil in the hydraulic oil tank (6) to the pilot oil port of the balance valve (41) to establish an opening pressure for the balance valve (41) to activate the balance valve (41). The hydraulic oil of the main boom luffing cylinder (3) slowly returns to the hydraulic oil tank (6) through the balance valve (41) to achieve the emergency lowering of the main boom. The control strategy for the power failure mode is as follows: When the entire machine's power system fails and cannot be powered on, rotate the switching knob set on the two-position two-way solenoid directional valve (71) to control the oil circuit switching of the two-position two-way solenoid directional valve (71) to connect the oil circuit between the hydraulic oil tank (6) and the hand pump (72). Rotate the manual directional valve (73) to switch the oil circuit to connect the hand pump (72) and the balance valve (41). Operate the hand pump (72) to transport the hydraulic oil in the hydraulic oil tank (6) to the pilot oil port of the balance valve (41) to establish an activation pressure to activate the balance valve (41), so that the hydraulic oil of the main boom luffing cylinder (3) returns to the hydraulic oil tank (6) to achieve emergency lowering.

7. The control method of the emergency descent system of the rice boom aerial work vehicle according to claim 6, characterized in that: During the emergency lowering process, when there are obstacles in the lowering path and the boom cannot be lowered smoothly, rotate the manual directional valve (73) counterclockwise, and the hydraulic oil at the pilot oil port in the balance valve (41) returns to the hydraulic oil tank (6), and the boom stops falling. When the obstacle is removed, rotate the manual directional valve (73) clockwise to continue the emergency lowering operation.

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