Electric control refueling vehicle reel driving system, transformation and installation method and testing method

Abstract

The invention relates to the technical field of aviation special equipment, discloses an electric control refueling truck reel driving system, a transformation and installation method and a testing method, and aims to solve the problems that a hydraulic follow-up reel of an existing aviation pipeline refueling truck is prone to oil leakage, high in failure rate and free of system-level anti-explosion verification after transformation. The explosion-proof electromagnetic hydraulic valve bank is arranged nearby an original reel reserved position, an original follow-up hose and an original reel are replaced by a fixed metal hard pipe, and a redundant electric control loop only depends on an original vehicle explosion-proof standby power source in a matched mode; and meanwhile, a standardized reconstruction installation process and a field explosion-proof test method covering full dimensions are matched. The leakage fault hidden danger is eliminated from the source, the safety redundancy of the system is improved, and the anti-explosion requirement of the aviation apron and the supervision specification of special civil aviation equipment can be met.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic control technology, specifically relating to an electronically controlled refueling truck reel drive system, its modification and installation method, and testing method. Background Technology

[0002] Aviation pipeline refueling trucks are core specialized equipment providing aviation fuel refueling services to aircraft on airport aprons. Low-altitude pipeline refueling trucks are equipped with a liftable operating platform to adapt to the refueling port height requirements of different aircraft models. In existing technology, the hydraulic drive system of the lifting platform typically has its hydraulic control valve assembly fixedly mounted on the refueling truck chassis, while the hydraulic cylinders that perform the actions are mounted on the liftable platform body. The two are connected by a flexible hydraulic hose. To accommodate the dynamic changes in pipeline length during platform lifting, a hydraulically driven follow-up reel is installed to synchronously extend and retract the hydraulic hose as the platform rises and falls, ensuring pipeline integrity and continuous fuel supply.

[0003] During long-term use, the aforementioned follow-up reel structure is prone to oil leakage due to high-frequency rotation and unwinding, and the complex environment of the apron. The hydraulic hose is also prone to aging and cracking after repeated bending. This not only leads to a high overall failure rate and long maintenance cycle, but the leaking hydraulic oil can also pose a safety hazard in the explosive gas environment of the apron. At the same time, the existing manual hydraulic control valve lacks operational flexibility and has low safety redundancy in the emergency descent function. It is easy for the platform to jam due to the failure of a single component, which will affect the normal operation of the apron. The existing modification schemes for this type of equipment lack the design of a dedicated electrical control system adapted to the scenario, and there is no corresponding system-level on-site explosion-proof compliance testing method. Relying solely on the laboratory explosion-proof certification of a single component cannot guarantee the overall explosion-proof safety of the modified system under apron conditions, and it is difficult to meet the regulatory requirements for special equipment in civil aviation. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides an electronically controlled refueling truck reel drive system, a modification and installation method, and a testing method. The aim is to replace the original hydraulic follow-up reel with a nearby explosion-proof electromagnetic hydraulic valve group and a fixed metal rigid pipe structure, thereby eliminating the potential faults of hose bending and dynamic seal leakage.

[0005] The technical solution adopted in this invention is as follows: In a first aspect, the present invention provides an electronically controlled refueling truck reel drive system for controlling the lifting platform of an aviation pipeline refueling truck, replacing the original vehicle-mounted hydraulic follow-up reel system, including a hydraulic actuator and an electronically controlled control unit; The hydraulic actuator includes an explosion-proof electromagnetic hydraulic valve group installed in a reserved installation position after the original vehicle hydraulic follow-up reel is removed, a fixed metal hydraulic hard pipe connecting the original vehicle hydraulic station and the explosion-proof electromagnetic hydraulic valve group, and a fixed metal hydraulic hard pipe connecting the explosion-proof electromagnetic hydraulic valve group and the lifting platform hydraulic cylinder. The electronic control unit includes a power input module electrically connected to the backup power supply of the explosion-proof junction box of the original vehicle platform, a main lifting control circuit electrically connected to the explosion-proof electromagnetic hydraulic valve group, a multi-level redundant emergency descent control circuit physically isolated from the main lifting control circuit, and a fault monitoring and light display feedback module. The input terminal of the power input module is only electrically connected to the 12V DC backup power supply of the original vehicle platform explosion-proof junction box, and the output terminals supply power to the main lifting control circuit, the multi-level redundant emergency descent control circuit, and the fault monitoring and light display feedback module.

[0006] In conjunction with the first aspect, the present invention provides a first embodiment of the first aspect, wherein the main lifting control circuit includes two sets of explosion-proof double-coil electromagnetic directional valves corresponding to the lifting and lowering actions of the lifting platform, respectively. The two coils of each electromagnetic directional valve are independently wired and protected by independent fuses. The main lifting control circuit is also provided with an electrical interlock and a mechanical interlock structure for the lifting and lowering actions, as well as explosion-proof limit switches for the upper and lower limits of the platform connected in series in the main lifting control circuit.

[0007] In conjunction with the first aspect, the present invention provides a second embodiment of the first aspect, wherein the multi-level redundant emergency descent control circuit has a power supply and wiring structure completely independent of the main lifting control circuit, including three levels of redundant circuits arranged in parallel: The first stage is an emergency descent circuit with a knob unlocking mechanism located at the operating position of the lifting platform; The second level is a ground-level emergency descent circuit with a knob unlocking mechanism, located at the ground operating position of the vehicle chassis. The third stage is a bypass of the explosion-proof manual shut-off valve connected in parallel to the emergency descent hydraulic circuit.

[0008] In conjunction with the first aspect, the present invention provides a third embodiment of the first aspect, wherein the fault monitoring and indicator feedback module is a pure hardware circuit structure, including explosion-proof indicator lights corresponding to normal power supply, action execution, and fault warning respectively, as well as a current sampling unit and a fault judgment comparator for collecting the current of the solenoid valve circuit, which can realize fault triggering and indicator warning for coil open circuit and circuit overcurrent / short circuit, and cut off the corresponding main circuit in the event of a fault, while retaining the power supply to the emergency descent control circuit.

[0009] Secondly, the present invention also provides a method for modifying and installing an electronically controlled refueling truck reel drive system, used to modify the original vehicle's hydraulically driven lifting system into an electronically controlled refueling truck reel drive system as described in any one of the above-mentioned methods, comprising the following steps: S1. First, park the refueling truck to be modified in the designated safe area and secure it, complete the risk identification and personnel safety training, and disconnect the main power supply of the original vehicle's hydraulic system and electrical system; S2. Then remove the original vehicle's hydraulic follow-up reel assembly, follow-up hydraulic hose, original vehicle manual hydraulic reversing valve and corresponding connecting pipes; S3. Fix the explosion-proof electromagnetic hydraulic valve group in the reserved installation position of the original vehicle hydraulic follow-up reel, and use fixed metal hydraulic hard pipes to connect the original vehicle hydraulic station to the explosion-proof electromagnetic hydraulic valve group and the explosion-proof electromagnetic hydraulic valve group to the lifting platform hydraulic cylinder to complete the sealing and pressure test of the hydraulic pipeline. S5. Installation of electrical control unit: Lay out explosion-proof cables and wiring pipes, and complete the installation and wiring of explosion-proof junction boxes, operation buttons and indicator lights for power input module, main lifting control circuit, multi-level redundant emergency descent control circuit, fault monitoring and light display feedback module. All wiring is sealed through explosion-proof sealing joints. S4. Restore the original vehicle power and hydraulic system, and sequentially complete the no-load and load debugging of the main lifting action, multi-stage emergency lowering action, and fault warning function to confirm that the system operates normally, without leakage, and without malfunction.

[0010] In conjunction with the second aspect, the present invention provides a first embodiment of the second aspect, in step S4, all metal housings, hydraulic lines and mounting brackets of the electronic control units are grounded at two points with equipotentiality with the original vehicle chassis, the grounding resistance is ≤4Ω, all cables are laid through flame-retardant corrugated pipes throughout, and drag chains are added for protection at bends.

[0011] Thirdly, the present invention also provides a test method for an electronically controlled reel drive system for a fuel truck, used for on-site explosion-proof compliance testing of an electronically controlled reel drive system for a fuel truck after installation, comprising the following steps: T1. Verify the explosion-proof certificates and nameplate information of all live components in the system, and confirm that the explosion-proof level of all components is not lower than ExdⅡBT4, the protection level is not lower than IP65, and the rated parameters match the design values; T2. Conduct a waterproof spray test on all explosion-proof wiring cavities and sealed joints to confirm that no moisture intrusion occurs; test the grounding resistance of all metal parts and the original vehicle chassis to confirm that the grounding resistance at all test points is not greater than 4Ω; T3. The insulation resistance between the energized circuit and the grounding terminal of the test system shall not be less than 20MΩ. When simulating a short circuit fault, the maximum discharge spark energy under the short circuit condition shall not be greater than 0.28mJ. T4. Simulates extreme working conditions of vehicle vibration and apron electromagnetic interference. The test system showed no solenoid valve malfunction, no abnormal discharge, and no degradation of explosion-proof performance. T5. Simulates main circuit power failure, short circuit, and coil burnout faults, triggering multi-level emergency descent control circuits to confirm that there are no sparks, no abnormal discharges, and uninterrupted grounding continuity during the emergency action.

[0012] Step T4 further includes a redundant circuit explosion-proof effectiveness test, specifically: The power supply branches of the single-group solenoid valve coils and the single-path emergency descent control circuit in the main lifting control circuit are disconnected step by step. The operational reliability of the remaining redundant circuits is tested separately. At the same time, it is checked that there are no abnormal discharge sparks during the circuit switching process, and it is confirmed that the insulation resistance and grounding resistance of the remaining circuits still meet the explosion-proof requirements under the single-path fault condition. The test is completed only by switching operation, multimeter and portable spark detector, without disassembling the core explosion-proof components.

[0013] This also includes a system-wide electrostatic explosion-proof test, specifically: First, the surface resistivity of the fixed metal hydraulic hard pipe, solenoid valve mounting bracket, and lifting platform hinge was tested to confirm that they meet the requirements for anti-static metal materials. The normal operating condition of continuous lifting and lowering of the platform throughout its full stroke was simulated again, and the surface electrostatic potential of the pipeline and valve group during the flow of hydraulic oil was tested to confirm that its maximum electrostatic potential does not exceed 100V. Finally, the continuity of the electrostatic discharge path of the entire system was tested to confirm that the equipotential bonding resistance between the platform hinge, valve group and vehicle chassis is ≤0.5Ω, and that the static electricity generated during operation can be completely discharged to the vehicle chassis through the grounding circuit.

[0014] In conjunction with the third aspect, the present invention provides a second embodiment of the third aspect, wherein step T5 further includes an explosion-proof linkage test of the fault early warning circuit, specifically: The fault conditions of solenoid valve coil open circuit and circuit overcurrent / short circuit were simulated respectively. The early warning triggering of the fault monitoring and light display feedback module and the corresponding main circuit cut-off action were tested to confirm that there was no arcing spark during the circuit cut-off process. Under the fault condition, the emergency descent control circuit still maintained independent power supply and explosion-proof performance. Simultaneously, simulating the pollution conditions of aviation kerosene leakage, aviation kerosene spray tests were conducted on the sealed interfaces of all electrical components to confirm that the insulation resistance of the components did not decrease and there was no risk of short circuit discharge after spraying.

[0015] The beneficial effects of this invention are as follows: (1) The present invention arranges an explosion-proof electromagnetic hydraulic valve group near the reserved installation position after the original hydraulic follow-up reel is removed, and uses a fixed metal hard pipe to connect the hydraulic station and the valve group, and the valve group and the platform hydraulic cylinder. It does not require modification of the original structure of the vehicle lifting platform and the hydraulic cylinder, eliminates the fault hazards of repeated bending and aging of hydraulic hoses and oil leakage of the dynamic seal during reel rotation, and reduces the failure rate and daily maintenance cost of the equipment. (2) The electronic control system of the present invention only uses the backup DC power supply of the explosion-proof junction box of the original vehicle platform, without the need to add an independent energy storage device, and will not cause additional operating burden to the original vehicle electrical system. It is suitable for the transformation needs of old refueling trucks. At the same time, through the design of dual coil redundant solenoid valve, electrical and mechanical double interlock, and stroke limit protection, the reliability of the main lifting control circuit is improved, and the circuit failure and equipment damage caused by single component failure can be avoided. (3) This invention realizes independent emergency control of the platform position and the ground position through a three-level redundant emergency descent control circuit that is physically isolated from the main lifting control circuit. At the same time, it is equipped with a mechanical emergency bypass, which can avoid the failure of emergency function caused by power failure, short circuit and other faults in the main circuit. It meets the safety specifications of aviation refueling equipment and improves the safety of operation under extreme fault conditions. (4) The modification and installation method of this invention has formulated a standardized full-process installation specification for the structure after the original vehicle reel is removed and the apron operation scenario, which can ensure the safety of the modification process and the adaptability of the system after installation. At the same time, the safety risk of static electricity accumulation during equipment operation is reduced by the dual-point equipotential grounding design of the whole system. (5) The explosion-proof compliance test method of this invention covers all dimensions of testing, including component pre-verification, electrical circuit safety, electrostatic explosion protection, redundancy circuit effectiveness, and fault condition linkage, for the exclusive structure of the modified system and the use scenario of the apron. It can be implemented on the apron site without the need for complicated laboratory equipment. It can effectively verify the overall explosion-proof compliance of the modified system and meet the regulatory and technical file traceability requirements of civil aviation special equipment. Attached Figure Description

[0016] Figure 1 This is a simplified diagram of a modified hydraulic circuit in an embodiment of the present invention; Figure 2 This is a modified descent control circuit diagram in an embodiment of the present invention. Detailed Implementation

[0017] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this application, it should be noted that the use of terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the use of terms such as "first" and "second" in the description of this application is only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Example

[0024] This exemplary embodiment provides an electronically controlled refueling truck reel drive system, a modification and installation method, and an explosion-proof compliance testing method. The system is applied to the modification of the lifting platform of an aviation pipeline refueling truck to replace the original hydraulic follow-up reel system.

[0025] In one possible implementation, refer to Figure 1The electronically controlled refueling truck reel drive system comprises two core components: a hydraulic actuator and an electronic control unit.

[0026] The hydraulic actuator is used to construct the oil supply and return circuits of the hydraulic cylinder of the lifting platform, so as to realize the action execution of the lifting platform.

[0027] In one possible implementation, the hydraulic actuator includes an explosion-proof solenoid hydraulic valve assembly and a fixed metal hydraulic hose.

[0028] For example, the explosion-proof electromagnetic hydraulic valve group is fixedly installed in the reserved installation position after the original vehicle hydraulic follow-up reel is removed. This installation position is the hinge root connecting the lifting platform and the vehicle chassis. No matter where the lifting platform is in any stroke position of lifting or lowering, the relative position between this installation position and the hydraulic cylinder of the lifting platform remains fixed and there is no relative displacement.

[0029] In one possible implementation, the fixed metal hydraulic rigid pipe includes a first hydraulic rigid pipe and a second hydraulic rigid pipe. The first hydraulic rigid pipe connects the outlet and return ports of the original vehicle hydraulic station to the corresponding ports of the explosion-proof solenoid hydraulic valve group. Both ends of the first hydraulic rigid pipe are fixed to the fixed structure of the vehicle chassis, with no relative displacement throughout its entire length, and no need to adapt to dynamic length changes. The second hydraulic rigid pipe connects the working port of the explosion-proof solenoid hydraulic valve group to the corresponding port of the hydraulic cylinder of the lifting platform. Both ends of the second hydraulic rigid pipe are fixed to the valve group mounting seat at the hinge root and the cylinder barrel fixed end of the hydraulic cylinder, respectively. The relative positions of the two do not change with the lifting and lowering of the platform, and no need to adapt to dynamic length changes.

[0030] Optionally, the fixed metal hydraulic hard pipe is made of galvanized seamless steel pipe. For example, the outer diameter of the steel pipe is 12mm and the wall thickness is not less than 1mm, which is compatible with the rated working pressure of the original vehicle hydraulic system.

[0031] In some embodiments, the hydraulic actuator further includes hydraulic auxiliary components, including hydraulic straight-through transition joints, hydraulic pipe tees, hydraulic manifold blocks, hydraulic pipe ferrule nuts, and hydraulic plugs.

[0032] For example, the hydraulic straight-through transition fittings come in two sizes, 1CB-18-06WD and 1CB-18-08WD, for sealing connections between rigid pipes of different diameters; the hydraulic tee uses the Yonghua Eaton AC-18 size for branch connections in the hydraulic circuit; the hydraulic manifold block uses the Jieyuan 02-2W size for integrated installation of multiple sets of solenoid directional valves, simplifying the hydraulic circuit layout; the hydraulic pipe ferrule nut uses the Parker KDL-12L size for ferrule sealing between the rigid pipe and the fitting; and the hydraulic plugs come in two sizes, 3 / 8 inch and 1 / 2 inch, for sealing spare ports.

[0033] The electronic control unit is used to realize the action control, status feedback and emergency safety protection of the hydraulic actuator. It relies solely on the backup power supply of the original vehicle platform explosion-proof junction box and has no independent energy storage module.

[0034] In one possible implementation, refer to Figure 2 The electronic control unit includes a power input module, a main lifting control circuit, a multi-level redundant emergency descent control circuit, and a fault monitoring and indicator feedback module.

[0035] The power input module's input terminal is electrically connected to the 12V DC backup power supply of the original vehicle platform's explosion-proof junction box, while its output terminal provides stable operating power to the main lifting control circuit, the multi-level redundant emergency descent control circuit, and the fault monitoring and lighting feedback module.

[0036] In one possible implementation, the power input module includes an explosion-proof circuit breaker, reverse connection protection components, and EMI filtering components.

[0037] For example, the explosion-proof circuit breaker has a rated current of 10A and is connected in series in the main power input circuit to cut off the circuit under overload and short circuit faults; the reverse connection protection element uses a 15A Schottky diode, connected in series in the main circuit to prevent the positive and negative terminals of the power supply from being reversed, which would cause the element to burn out; the EMI filter element uses a π-type filter circuit, connected in parallel across the main circuit to filter out voltage fluctuations and electromagnetic interference generated by the original vehicle alternator and ignition system, and output a stable 12V DC working voltage.

[0038] Optionally, the static standby current of the power input module is no more than 40mA and the static standby power consumption is no more than 0.5W, so that the original vehicle battery will not be depleted when left idle.

[0039] The main lifting control circuit is electrically connected to the main directional valve in the explosion-proof electromagnetic hydraulic valve group, and is used to control the lifting platform's raising, lowering and stopping actions.

[0040] In one possible implementation, the main lifting control circuit includes two sets of explosion-proof dual-coil electromagnetic directional valves, with the two sets of valves corresponding to the lifting platform's rising and lowering actions, respectively.

[0041] For example, the explosion-proof dual-coil solenoid directional valve uses a 12V DC coil with a single coil rated power of no more than 10W, which is compatible with the load capacity of the original vehicle power supply. The two coils of each solenoid directional valve are independently wired and protected by independent fuses. When a single coil burns out or the circuit is broken, the other coil can still drive the valve group to complete the corresponding action normally.

[0042] In one possible implementation, the main lifting control circuit is equipped with a double interlocking structure, which includes electrical interlocking and mechanical interlocking, to prevent valve group oil leakage damage caused by simultaneous triggering of lifting and lowering actions.

[0043] For example, the electrical interlock is achieved by cross-connecting the normally closed contacts of two AC contactors, while the mechanical interlock is achieved by the mechanical interlocking structure of the explosion-proof button, so that the up button and the down button cannot be pressed at the same time to conduct.

[0044] In some embodiments, the main lifting control circuit is also connected in series with an upper limit explosion-proof limit switch and a lower limit explosion-proof limit switch. The two limit switches are respectively installed at the mounting points corresponding to the highest lifting position and the lowest lowering position of the lifting platform. When the platform runs to the corresponding limit position, the limit switch automatically cuts off the control circuit of the corresponding action to prevent the hydraulic cylinder from being damaged due to overtravel.

[0045] For example, the explosion-proof button adopts the Huarong BA8060-ⅡA2 and Huarong BA8060-ⅡB specifications. The explosion-proof limit switch is adapted to the explosion-proof environment requirements of the apron, and the protection level is not lower than IP65.

[0046] The multi-level redundant emergency descent control circuit is physically isolated from the main lifting control circuit, and uses an independent power supply branch, independent wiring, and independent protection components. Any failure of the main lifting control circuit will not affect the normal operation of this circuit, which is used to realize the emergency descent of the lifting platform under extreme failure conditions.

[0047] In one possible implementation, the multi-level redundant emergency descent control circuit includes three levels of redundant circuits connected in parallel. The first level of redundant circuit is the platform position emergency descent circuit, which is located in the explosion-proof switch box on the operating side of the lifting platform and is used by personnel on the platform to trigger emergency operations.

[0048] For example, the platform position emergency descent circuit adopts a structure of explosion-proof rotary unlocking switch and explosion-proof self-resetting trigger button connected in series. The unlocking knob must be rotated first to unlock the circuit, and the trigger button must be pressed to activate the circuit and drive the corresponding explosion-proof emergency descent solenoid valve, preventing accidental triggering. The second-level redundant circuit is the ground position emergency descent circuit, which is located in the explosion-proof switch box on the ground operating side of the chassis. It is used by ground monitoring personnel to trigger emergency operations and is completely connected in parallel with the first-level redundant circuit, without interference.

[0049] For example, the ground-level emergency descent circuit adopts the same series structure of knob unlocking + button triggering as the first-level circuit, driving another parallel explosion-proof emergency descent solenoid valve to achieve independent emergency control at two points. A failure of a single switch box will not affect the emergency operation at the other point. The third-level redundant circuit is a mechanical emergency bypass, connected in parallel to the emergency descent hydraulic circuit. It uses an explosion-proof manual shut-off valve for use in extreme conditions where the electrical circuit completely fails. The shut-off valve is manually operated to open the return oil passage of the hydraulic cylinder, and the descent action is completed by the platform's own weight.

[0050] For example, the explosion-proof emergency descent solenoid valve adopts the Parker D1VW020BNKW91 specification and is equipped with a waterproof universal 10A250V three-terminal explosion-proof plug without light; the explosion-proof switch box adopts the Shanghai Tianyi TYX4 specification 4-hole button box, and the waterproof junction box adopts the Deenlai 1-in-2-out specification and is equipped with black waterproof connectors of PG9 and PG13.5 specifications.

[0051] The fault monitoring and indicator feedback module is a pure hardware circuit structure without a programmable control unit. It is used to realize real-time monitoring of the system's operating status and intuitive indicator feedback, while also realizing loop protection under fault conditions.

[0052] In one possible implementation, the fault monitoring and indicator feedback module includes an explosion-proof indicator light group, a current sampling unit, a fault judgment comparator, and a protection execution relay. The explosion-proof indicator light group includes a green power status indicator light, a yellow operation status indicator light, and a red fault warning indicator light. All indicator lights are 12V explosion-proof indicator lights of the Chint ND16-22DS specification and are installed in a visible position on the operation panel.

[0053] For example, the green power status indicator light is connected in parallel to the output terminal of the power input module. It is always on when the power supply is normal and turns off when the power is cut off or the circuit breaker trips. There are two sets of yellow action status indicator lights, which correspond to the rising and falling actions respectively. They are lit when the corresponding action circuit is connected and turn off when the action stops. The red fault warning indicator light is used for early warning of fault conditions.

[0054] The current sampling unit uses milliohm-level sampling resistors connected in series in the control loops of each solenoid valve to collect the operating current of the loop in real time. The fault diagnosis comparator uses a voltage comparator chip to convert the collected loop current signal into a corresponding voltage signal, compare it with a preset threshold voltage, and determine the operating status of the loop.

[0055] The protection relay is connected in series in the power supply branch of the main lifting control circuit. It receives the output signal of the fault judgment comparator and realizes the main circuit disconnection under fault conditions.

[0056] In one possible implementation, the fault monitoring and indicator feedback module can monitor and protect against three fault conditions.

[0057] The first operating condition is a coil open circuit fault. When the corresponding action button is triggered, there is no working current in the circuit. The fault judgment comparator outputs a trigger signal, the red fault warning light flashes, and the protection execution relay cuts off the corresponding fault circuit.

[0058] The second operating condition is an overcurrent or short-circuit fault. When the circuit current exceeds 1.5 times the rated value, the fault judgment comparator outputs a trigger signal, the red fault warning indicator light stays on, and the protection execution relay cuts off the entire main lifting control circuit, retaining power only for the multi-level redundant emergency descent control circuit. The third operating condition is an emergency trigger condition. When any level of emergency descent circuit is activated, the red fault warning indicator light stays on, indicating that the system is in emergency operation mode.

[0059] Optionally, the wiring of the electrical control unit uses a TRVV3*1.0 drag chain cable from Zongkai. The cable is laid through an AD10 PP flame-retardant corrugated pipe throughout, and drag chain protection is added at bends to prevent cable wear and damage.

[0060] This exemplary embodiment also provides a method for modifying and installing an electronically controlled refueling truck reel drive system, which is used to modify the original vehicle's lifting system with a hydraulic follow-up reel into the aforementioned electronically controlled refueling truck reel drive system.

[0061] In one possible implementation, the modification and installation method includes the following core steps: S1. Pre-construction preparation S2, Original vehicle parts removal S3, Hydraulic actuator installation S4, Installation of Electronic Control Unit S5, System Debugging In one possible implementation, step S1, pre-construction preparation, specifically includes: parking the aviation pipeline refueling truck to be modified in a designated isolated maintenance area at the airport, an area free from aviation kerosene leakage risks, open flame operations, and where unauthorized personnel are prohibited from entering; fully engaging the vehicle's parking brake; and securing the wheels with wheel chocks on both sides. For example, the aviation pipeline refueling truck to be modified is a CF5061GXJYNKR low-altitude pipeline refueling truck manufactured in 2015 by Shanghai Chengfei Aviation Special Equipment Co., Ltd.

[0062] Complete the risk identification for this operation, provide safety education and technical briefings to all personnel involved, clarify the operation procedures, safety regulations and emergency response plans, and retain corresponding training and briefing records. Disconnect the main shut-off valve of the original vehicle's hydraulic system, disconnect the main power supply of the original vehicle's electrical system, and disconnect the negative terminal of the battery to ensure that there is no hydraulic oil leakage and no risk of working with electricity during the operation.

[0063] Optionally, prepare the corresponding tools and installation materials before the operation, and check the specifications, explosion-proof certificates and quality certificates of all materials to ensure that they meet the design requirements.

[0064] In one possible implementation, step S2 involves removing the original vehicle components, specifically including: first, draining the residual hydraulic oil from the original vehicle's follow-up reel and corresponding hydraulic hose, and then using a special oil receiving container to collect the oil to prevent it from spilling onto the apron floor.

[0065] Remove the fixing bolts of the original vehicle's hydraulic follow-up reel assembly, remove the reel body, and remove the corresponding rotary joint, hydraulic motor, and other supporting components.

[0066] Remove the connectors at both ends of the original vehicle's hydraulic hose, pull out the entire hose, and clean the residual oil and impurities from the original vehicle's pipe interfaces.

[0067] Remove the original manual hydraulic directional valve installed in the chassis control box, as well as the corresponding connecting pipes and control components of the valve group. Clean the corresponding interfaces of the original hydraulic station and seal them to prevent impurities from entering the oil circuit.

[0068] Optionally, after removal, the original vehicle's pre-reserved installation positions, hydraulic interfaces, and electrical wiring terminals should be cleaned and rust-removed to prepare for subsequent installation.

[0069] In one possible implementation, step S3, the installation of the hydraulic actuator, specifically includes: fixing the hydraulic oil circuit block and the explosion-proof electromagnetic hydraulic valve group in the reserved installation position after the original hydraulic follow-up reel has been removed, using internal hexagonal stainless steel screws for fixing. For example, the screws are of 850 and 550 specifications, and are matched with stainless steel self-locking nuts of the corresponding specifications to ensure that the valve group is installed firmly and without loosening.

[0070] Fixed metal hydraulic hard pipes are used to lay the first oil circuit hard pipe, connecting the oil outlet and return port of the original vehicle hydraulic station with the corresponding oil ports of the explosion-proof solenoid hydraulic valve group. The bends of the hard pipes are formed in one step using a pipe bender to avoid welding joints. The pipes are fixed to the reserved installation holes on the chassis using pipe clamps, without the need for additional drilling and welding.

[0071] A fixed metal hydraulic hard pipe is used, and a second oil circuit hard pipe is laid to connect the working oil port of the explosion-proof electromagnetic hydraulic valve group with the corresponding oil port of the hydraulic cylinder of the lifting platform. The two ends of the hard pipe are sealed and connected by hydraulic straight-through crossover joints and compression fitting nuts to ensure that the pipeline is free of bends and stress concentration.

[0072] After completing the installation of all hydraulic lines, a sealing pressure test is performed on the entire hydraulic system. The test pressure is 1.5 times the rated working pressure of the original vehicle hydraulic system, and the pressure holding time is not less than 30 minutes. Check that all joints and lines are free from leakage and deformation.

[0073] Optionally, after the pressure test is completed, replace the hydraulic oil and filter elements of the original vehicle's hydraulic system, and clean the hydraulic oil circuit to ensure that there are no impurities remaining in the oil circuit.

[0074] In one possible implementation, step S4, the installation of the electrical control unit, specifically includes: laying explosion-proof cables according to the design path, with the cables running through PP flame-retardant corrugated pipes throughout, adding drag chains for protection at bends, reserving sufficient wiring slack at both ends of the cables, and sealing all wiring locations with waterproof and explosion-proof connectors.

[0075] Explosion-proof operating buttons, indicator lights, and explosion-proof circuit breakers are installed in the corresponding positions on the original vehicle control panel. Emergency descent explosion-proof switch boxes are installed on the platform control position and the ground control position respectively. All operating components are firmly fixed with stainless steel bolts.

[0076] All circuits are wired in the original explosion-proof junction box. The wiring is tinned and the terminals are tightened securely. All cover plates of the wiring chambers are sealed with gaskets to ensure that the protection level meets the requirements.

[0077] All metal casings, hydraulic lines, and mounting brackets of the electronic control units are grounded at two points with the original vehicle chassis. The grounding wires are made of multi-strand copper core flexible wires, and each grounding point is fixed with two stainless steel bolts to ensure continuous and reliable grounding.

[0078] For example, the grounding resistance test value of all grounding points is not greater than 4Ω, and the equipotential bonding resistance between the platform hinge, valve group and vehicle chassis is not greater than 0.5Ω.

[0079] In one possible implementation, step S5, system debugging, specifically includes: Reconnect the original vehicle battery wiring and hydraulic system master shut-off valve, start the vehicle engine, and bring the hydraulic system to its rated working pressure and temperature. First, perform a no-load test by triggering the up and down buttons to test whether the lifting platform moves smoothly, without jamming or abnormal noises, whether the limit switches can be triggered to cut off the circuit normally, and whether the operation status indicator lights are displayed normally.

[0080] After the no-load test is completed, a load test is performed. The rated load is applied to the lifting platform, and the full-stroke lifting action is repeated no less than 10 times. The test shows that the platform's lifting speed is stable, without shaking or creeping, the hydraulic system has no leakage, and the solenoid valves operate reliably. The emergency descent circuits at the platform position and the ground position are triggered separately to test the reliability of the emergency action. The descent speed is smooth and meets the safety specifications.

[0081] Next, the mechanical emergency bypass of the manual shut-off valve was tested to confirm that the platform could still descend smoothly even when the electrical circuit was completely disconnected. Simulating fault conditions such as coil open circuit and circuit overcurrent, the fault monitoring and indicator feedback module was tested to ensure it could trigger warnings normally, that the corresponding circuit could be disconnected normally, and that the emergency descent circuit maintained normal power supply.

[0082] After all debugging items are completed, confirm that the system operates normally, without leakage, malfunctions, or fault warnings, and retain complete debugging records.

[0083] This exemplary embodiment also provides a method for testing the explosion-proof compliance of an electronically controlled refueling truck reel drive system. This method is used to conduct on-site explosion-proof compliance tests on the electronically controlled refueling truck reel drive system after installation. All test items can be carried out on-site at the airport apron without the need for complex laboratory equipment. This method can comprehensively verify the overall explosion-proof compliance of the system in the explosive gas environment of the airport apron.

[0084] In one possible implementation, the explosion-proof compliance testing method includes the following core steps: T1, Pre-verification T2, Sealing and Grounding Test T3, Circuit Safety Test T4, Operating Condition Stability Test T5, Fault Condition Test In one possible implementation, step T1 pre-verification specifically includes: verifying the explosion-proof certificates, inspection reports, and nameplate information of all live components in the system, including explosion-proof buttons, explosion-proof junction boxes, explosion-proof indicator lights, explosion-proof coils of solenoid valves, explosion-proof limit switches, and waterproof connectors; confirming that the explosion-proof rating of all components is not lower than ExdⅡBT4, the protection rating is not lower than IP65, and the rated voltage, rated current, and other parameters are fully matched with the design values ​​and are within the scope of the accessories catalog approved by civil aviation special equipment.

[0085] Verify the material certificates for all hydraulic components, pipelines, and grounding components to confirm they meet the requirements for anti-static and corrosion-resistant use on the apron. For example, all components have valid explosion-proof certificates, and the nameplate information is completely consistent with the certificate information, without any alteration or damage.

[0086] Optionally, the pre-verification also includes checking the modification and installation records to confirm that the installation process meets the design requirements and safety specifications, and that all installation records are complete and traceable.

[0087] In one possible implementation, step T2, sealing and grounding test, specifically includes: explosion-proof sealing performance test, using a pressure spray device to conduct an IP65-level waterproof spray test on all explosion-proof wiring cavities, solenoid valve coil wiring cavities, sealed joints, and waterproof junction boxes, with a spray pressure of not less than 100 kPa and a spray time of not less than 30 minutes.

[0088] After spraying is completed, all wiring cavities and connectors are disassembled to check for water ingress and moisture intrusion, and to ensure that the sealing gaskets are not deformed or damaged. A system-wide grounding continuity test is performed using a calibrated equipotential bonding tester to test the grounding resistance of all metal components. Test points include solenoid valve bodies, junction box housings, operating button boxes, hydraulic pipeline connectors, valve assembly mounting brackets, and lifting platform hinges. There are no fewer than 20 test points, and each test point is tested three times consecutively, with the average value taken.

[0089] For example, the grounding resistance test value of all test points is no greater than 4Ω. For the dual-point grounding of the core safety components, even if one grounding wire is disconnected, the grounding resistance of the other grounding wire is still no greater than 4Ω.

[0090] Optionally, the grounding test may also include a mechanical strength check of the grounding wire to confirm that the grounding wire is undamaged, loose, and corroded, and is securely fixed.

[0091] In one possible implementation, the safety test of the T3 circuit specifically includes: insulation resistance test. With the system completely powered off, a 500V insulation resistance tester is used to test the insulation resistance between all energized circuits and the grounding terminal of the vehicle body. Each circuit is tested separately, including the rising branch and the falling branch of the main lifting control circuit, the two-stage emergency falling control circuit, and the power input circuit.

[0092] For example, the insulation resistance test value of all circuits is not less than 20MΩ, with no insulation damage or leakage potential. Circuit spark energy testing simulates fault conditions such as circuit short circuits and line insulation damage to ground. A portable circuit spark energy tester is used to test the maximum discharge spark energy of the circuit under fault conditions, separately testing the short-circuit spark energy of the main circuit and emergency circuit. For example, the maximum discharge spark energy under all conditions is not greater than 0.28mJ, which is half the minimum ignition energy of aviation kerosene, meeting the intrinsic safety requirements of Zone 1 explosive gas atmospheres.

[0093] Wide voltage adaptability test, simulating the working conditions of original vehicle battery aging and alternator output fluctuation, uses an adjustable DC power supply to power the system within a wide voltage range of 9V~16V. The system operates normally at each voltage node, with no abnormal discharge, no sparks, and no malfunctioning solenoid valves.

[0094] In one possible implementation, step T4, the stability test under operating condition, specifically includes: For the vibration environment explosion-proof stability test, a vibration tester is used to apply random vibration of 5Hz~50Hz and acceleration of 1g to the valve group mounting base, junction box and operation button box of the system for a duration of not less than 4 hours to simulate the working conditions of long-term vehicle driving and tarmac vibration. After the vibration test is completed, the insulation resistance, grounding resistance and sealing performance of the system are retested to confirm that there is no attenuation, no loosening and no abnormal discharge.

[0095] Electromagnetic interference explosion-proof stability test: A radio frequency electromagnetic interference simulator is used to apply radio frequency interference of 80MHz~1000MHz and field strength of 10V / m to the system for a duration of not less than 30 minutes to simulate the electromagnetic environment of the apron of aircraft radar, tower signals and vehicle ignition system. During the test, the system has no solenoid valve malfunction, no abnormal discharge and no circuit false trigger.

[0096] The comprehensive electrostatic explosion-proof test for the entire system includes three testing stages: The first step is to test the surface resistivity of the materials. A surface resistivity tester is used to test the surface resistivity of the fixed metal hydraulic hard pipes, solenoid valve mounting brackets, and lifting platform hinges to confirm that they meet the requirements for anti-static metal materials and that there is no risk of static electricity accumulation caused by insulating coatings.

[0097] The second step is the electrostatic potential test under operating conditions. This involves simulating the normal operating conditions of continuous lifting and lowering of the platform throughout its full stroke. The platform completes no less than 20 full-stroke lifting and lowering actions. A non-contact electrostatic potential tester is used to test the surface electrostatic potential of the pipeline and valve group during the hydraulic oil flow process, confirming that the maximum electrostatic potential does not exceed 100V.

[0098] The third step is the electrostatic discharge path continuity test. The test involves the equipotential bonding resistance between the platform hinge, the valve group and the vehicle chassis. The test confirms that the bonding resistance is no greater than 0.5Ω, and that the static electricity generated during operation can be completely discharged to the vehicle chassis through the grounding circuit, with no potential for static electricity accumulation.

[0099] The explosion-proof effectiveness test of redundant circuits involved disconnecting the power supply branches of the corresponding single-group solenoid valve coils in the main lifting control circuit and the single-path emergency descent control circuit in stages, and testing the operational reliability of the remaining redundant circuits. At the same time, a spark detector was used to check for abnormal discharge sparks during the circuit switching process, confirming that the insulation resistance and grounding resistance of the remaining circuits still met the explosion-proof requirements under single-path fault conditions.

[0100] For example, during the redundant circuit test, there is no need to disassemble the core explosion-proof components. The test can be completed simply by switching on and off, using a multimeter and a portable spark detector. The test cost is low and the test is highly feasible on site.

[0101] In one possible implementation, step T5, the fault condition test, specifically includes: emergency function explosion-proof safety test, simulating extreme fault conditions such as main circuit power failure, short circuit, and solenoid valve coil burnout, triggering the emergency descent circuits of the platform position and the ground position, as well as the mechanical emergency bypass, to confirm that the emergency action is reliable, there are no sparks or abnormal discharges during the action, the grounding continuity is uninterrupted, and there is no risk of explosion-proof failure.

[0102] The explosion-proof linkage test of the fault warning circuit simulated fault conditions such as open circuit of the solenoid valve coil and overcurrent / short circuit of the circuit. The test tested the warning triggering of the fault monitoring and light display feedback module and the corresponding main circuit cut-off action. It was confirmed that there was no arcing spark during the circuit cut-off process. Under fault conditions, the emergency descent control circuit still maintained independent power supply and explosion-proof performance.

[0103] The aviation kerosene pollution condition explosion-proof test simulates the pollution condition of aviation kerosene leakage. All electrical component sealing interfaces and wiring cavity covers are subjected to aviation kerosene spray test. After spraying, the components are left to stand for 24 hours, and the insulation resistance of the components is retested to confirm that the insulation resistance has not decreased, there is no risk of short circuit discharge, and the sealing performance has not deteriorated.

[0104] Optionally, the fault condition test also includes a live-opening interlock test, which checks all explosion-proof junction boxes and solenoid valve wiring cavities. Before opening the cover, the power supply to the corresponding circuit must be cut off, so there is no possibility of opening the cover while it is energized, and the risk of sparks igniting fuel gas is eliminated during the opening process.

[0105] In some embodiments, after all test items are completed, a complete explosion-proof compliance test report is issued. The report includes the test conditions, test data, judgment results, test photos, test personnel signatures, test dates, all test data, copies of component explosion-proof certificates, and modification and installation records for each test item. All of these are archived in the vehicle's special equipment technical file to meet the full life cycle traceability requirements of the civil aviation regulatory authorities.

[0106] This invention is not limited to the optional embodiments described above, and anyone can derive other various forms of products based on the inspiration of this invention. The specific embodiments described above should not be construed as limiting the scope of protection of this invention; the scope of protection of this invention should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. An electronically controlled refueling truck reel drive system for controlling the lifting platform of an aviation pipeline refueling truck, replacing the original hydraulic follow-up reel system, characterized in that, Includes hydraulic actuators and electronic control units; The hydraulic actuator includes an explosion-proof electromagnetic hydraulic valve group installed in a reserved installation position after the original vehicle hydraulic follow-up reel is removed, a fixed metal hydraulic hard pipe connecting the original vehicle hydraulic station and the explosion-proof electromagnetic hydraulic valve group, and a fixed metal hydraulic hard pipe connecting the explosion-proof electromagnetic hydraulic valve group and the lifting platform hydraulic cylinder. The electronic control unit includes a power input module electrically connected to the backup power supply of the explosion-proof junction box of the original vehicle platform, a main lifting control circuit electrically connected to the explosion-proof electromagnetic hydraulic valve group, a multi-level redundant emergency descent control circuit physically isolated from the main lifting control circuit, and a fault monitoring and light display feedback module. The input terminal of the power input module is electrically connected to the 12V DC backup power supply of the explosion-proof junction box of the original vehicle platform, and the output terminals supply power to the main lifting control circuit, the multi-level redundant emergency descent control circuit, and the fault monitoring and light display feedback module.

2. The electronically controlled refueling truck reel drive system according to claim 1, characterized in that, The main lifting control circuit includes two sets of explosion-proof double-coil solenoid directional valves corresponding to the lifting and lowering actions of the lifting platform, respectively. The two coils of each set of solenoid directional valves are independently wired and protected by independent fuses. The main lifting control circuit is also equipped with an electrical interlock and a mechanical interlock structure for the lifting and lowering actions, as well as explosion-proof limit switches for the upper and lower limits of the platform connected in series in the main lifting control circuit.

3. The electronically controlled refueling truck reel drive system according to claim 1, characterized in that, The multi-level redundant emergency descent control circuit has a power supply and wiring structure that is completely independent of the main lifting control circuit, including three levels of redundant circuits connected in parallel: The first stage is an emergency descent circuit with a knob unlocking mechanism located at the operating position of the lifting platform; The second level is a ground-level emergency descent circuit with a knob unlocking mechanism, located at the ground operating position of the vehicle chassis. The third stage is a bypass of the explosion-proof manual shut-off valve connected in parallel to the emergency descent hydraulic circuit.

4. The electronically controlled refueling truck reel drive system according to claim 1, characterized in that, The fault monitoring and indicator feedback module is a pure hardware circuit structure, including explosion-proof indicator lights corresponding to normal power supply, action execution, and fault warning, as well as a current sampling unit and fault judgment comparator for collecting the current of the solenoid valve circuit. It can realize fault triggering and indicator warning for coil open circuit and circuit overcurrent / short circuit, and cut off the corresponding main circuit in case of fault, while maintaining the power supply to the emergency descent control circuit.

5. A method for modifying and installing an electronically controlled refueling truck reel drive system, used to modify the original vehicle's lifting system with a hydraulic follow-up reel into an electronically controlled refueling truck reel drive system as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. First, park the refueling truck to be modified in the designated safe area and secure it, complete the risk identification and personnel safety training, and disconnect the main power supply of the original vehicle's hydraulic system and electrical system; S2. Then remove the original vehicle's hydraulic follow-up reel assembly, follow-up hydraulic hose, original vehicle manual hydraulic reversing valve and corresponding connecting pipes; S3. Fix the explosion-proof electromagnetic hydraulic valve group in the reserved installation position of the original vehicle hydraulic follow-up reel, and use fixed metal hydraulic hard pipes to connect the original vehicle hydraulic station to the explosion-proof electromagnetic hydraulic valve group and the explosion-proof electromagnetic hydraulic valve group to the lifting platform hydraulic cylinder to complete the sealing and pressure test of the hydraulic pipeline. S4. Installation of electrical control unit: Lay out explosion-proof cables and wiring pipes, and complete the installation and wiring of explosion-proof junction boxes, operation buttons and indicator lights for power input module, main lifting control circuit, multi-level redundant emergency descent control circuit, fault monitoring and light display feedback module. All wiring is sealed through explosion-proof sealing joints. S5. Restore the original vehicle power and hydraulic system, and sequentially complete the no-load and load debugging of the main lifting action, multi-stage emergency lowering action, and fault warning function to confirm that the system operates normally, without leakage, and without malfunction.

6. The method for modifying and installing an electronically controlled refueling truck reel drive system according to claim 5, characterized in that, In step S4, all metal casings, hydraulic lines, and mounting brackets of the electronic control units are grounded at two points with equipotential bonding to the original vehicle chassis, with a grounding resistance of ≤4Ω. All cables are laid through flame-retardant corrugated pipes throughout, and drag chains are added for protection at bends.

7. A test method for an electronically controlled refueling truck reel drive system, characterized in that, The method for conducting on-site explosion-proof compliance testing of the electronically controlled fuel truck reel drive system according to any one of claims 1-4 after installation includes the following steps: T1. Verify the explosion-proof certificates and nameplate information of all live components in the system, and confirm that the explosion-proof level of all components is not lower than ExdⅡBT4, the protection level is not lower than IP65, and the rated parameters match the design values; T2. Conduct a waterproof spray test on all explosion-proof wiring cavities and sealed joints to confirm that no moisture intrusion occurs; test the grounding resistance of all metal parts and the original vehicle chassis to confirm that the grounding resistance at all test points is not greater than 4Ω; T3. The insulation resistance between the live circuit and the grounding terminal of the test system shall not be less than 20MΩ. When simulating a short circuit fault, the maximum discharge spark energy under the short circuit condition shall not be greater than 0.28mJ. T4. Simulates extreme working conditions of vehicle vibration and apron electromagnetic interference. The test system showed no solenoid valve malfunction, no abnormal discharge, and no degradation of explosion-proof performance. T5. Simulates main circuit power failure, short circuit, and coil burnout faults, triggering multi-level emergency descent control circuits to confirm that there are no sparks, no abnormal discharges, and uninterrupted grounding continuity during the emergency action.

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