Large-stroke heavy-load obstacle-crossing electrically-driven trolley and using method

Abstract

The invention provides a large-stroke heavy-load obstacle-crossing electrically-driven trolley and a using method, the large-stroke heavy-load obstacle-crossing electrically-driven trolley comprises a walking system used for driving the whole trolley to walk automatically, a lifting system is installed on a walking chassis of the walking system, and horizontal expansion systems are symmetrically installed on the two sides of a lifting tabletop of the lifting system; a rear lifting wheel system capable of ascending and descending is installed at one end of the tail of the horizontal expansion system, and a front lifting wheel system capable of ascending and descending is installed at one end of the head of the horizontal expansion system. The top of the lifting tabletop is used for carrying heavy objects needing to be transferred. According to the trolley, heavy objects can be transferred, obstacle crossing carrying operation can be achieved, the traditional manual carrying process is replaced, then the carrying efficiency is effectively improved, and the carrying operation difficulty is reduced.

Description

Technical Field

[0001] This invention relates to the field of hydropower equipment maintenance technology, specifically to a long-stroke, heavy-duty obstacle-crossing electric handcart and its usage method. Background Technology

[0002] The electric brake switch, arc-extinguishing chamber, and circuit breaker are located in the brake switch room in the corridor of the auxiliary plant on the upstream side of the plant hall. According to the brake switch overhaul strategy, the electric brake switch, the three-phase arc-extinguishing chamber, and the operating mechanism need to be disassembled, hoisted out, and transported to the GIS room or clean room for disassembly and maintenance. There are no lifting facilities in the switch room, and there is a high and wide cement threshold at the entrance and exit of the brake switch room.

[0003] The current transfer method involves using a lifting platform both inside and outside the entrance / exit. When transferring out, the transfer trolley moves to the inner lifting platform, and both platforms rise until they are flush with the top surface of the threshold. At this point, the transfer trolley is pushed to the outer lifting platform, which then lowers, allowing the transfer trolley to leave. The process for entering the building is the same. This method effectively completes the transfer work, but it has several drawbacks: 1) The trolley is quite heavy when carrying heavy objects. In order to ensure safety, the internal and external lifting platforms are quite heavy and need to be moved by personnel, which makes the layout extremely inconvenient. 2) The system is cumbersome, with a small car and two lifting platforms, plus the lifting power required for the lifting platforms. Storage is inconvenient and takes up a lot of space. Summary of the Invention

[0004] To address the existing technical problems, the main objective of this invention is to provide a long-stroke, heavy-duty obstacle-crossing electric trolley and its usage method. This trolley can transfer heavy objects and perform obstacle-crossing operations, replacing the traditional manual handling process, thereby effectively improving handling efficiency and reducing the difficulty of handling operations.

[0005] To achieve the above-mentioned technical features, the present invention aims to provide a long-stroke, heavy-duty obstacle-crossing electric handcart, comprising a walking system for automatically driving the entire cart, a lifting system mounted on the walking chassis of the walking system, horizontal extension systems symmetrically mounted on both sides of the lifting platform of the lifting system, a rear lifting wheel system capable of being raised and lowered mounted at one end of the rear of the horizontal extension system, and a front lifting wheel system capable of being raised and lowered mounted at one end of the front of the horizontal extension system; the top of the lifting platform is used to carry heavy objects that need to be transferred.

[0006] Preferably, the walking system includes a walking chassis, a main universal wheel is installed on the head side of the bottom of the walking chassis, a drive wheel is installed on the tail side of the bottom of the walking chassis, a battery for providing power is fixedly installed at the bottom of the walking chassis, a handrail is fixedly installed at one end of the top of the walking chassis, a lifting cylinder support is provided at the bottom of the walking chassis, and a level is provided at the top of the walking chassis.

[0007] Preferably, the drive wheel is connected to a hub motor for driving its rotation.

[0008] Preferably, a controller mounting plate is fixedly installed on the upper part of the handrail, and a control box is fixedly installed on the outer wall of the controller mounting plate; The control box is connected to the walking system, lifting system, horizontal extension system, rear lifting wheel system, and front lifting wheel system.

[0009] Preferably, the lifting system includes a scissor arm rail, which is fixed to the top of the chassis. Scissor arms are mounted on the scissor arm rail, with the middle part of the scissor arms hinged via a pivot. A lifting platform is mounted on the top of the scissor arms, and limit baffles are symmetrically mounted on both sides of the top of the lifting platform. A weight fixing handle is fixed to the top of the limit baffles. The scissor arms are hinged to the piston rod end of the lifting cylinder via a pin. The cylinder body of the lifting cylinder is hinged between the base and the base is located inside the lifting cylinder support. Outer sleeves for installing the horizontal extension system are provided on both sides of the lifting platform.

[0010] Preferably, the horizontal expansion system includes a rear expansion inner sleeve and a front expansion inner sleeve respectively fitted inside the outer sleeve at both ends, and a first electric telescopic screw is installed between the rear expansion inner sleeve and the front expansion inner sleeve through a screw drive; a rear lifting wheel system is fixed at the end of the rear expansion inner sleeve, and a front lifting wheel system is fixed at the end of the front expansion inner sleeve.

[0011] Preferably, the outer sleeve, the rear extension inner sleeve, and the front extension inner sleeve are all made of square tubing.

[0012] Preferably, the rear lifting wheel system and the front lifting wheel system adopt the same structural form. The rear lifting wheel system includes a rear lifting wheel system main pipe. A telescopic support is installed inside the rear lifting wheel system main pipe in cooperation with an electric lifting telescopic screw. A secondary universal wheel is installed at the bottom end of the telescopic support. A support beam is fixed between the rear lifting wheel system main pipes on both sides of the displacement. A limiting pin is provided between the rear lifting wheel system main pipe and the telescopic support for locking both.

[0013] Both the main pipe and the telescopic support of the rear lifting wheel system are made of round tubes. Preferably, the control box includes walking control, lifting control, front and rear lifting wheel system telescopic lifting control, and an alarm system, which includes a horizontal alarm, an overload alarm, and a battery alarm light.

[0014] Another aspect of the present invention provides a method for using a long-stroke, heavy-duty obstacle-crossing electric handcart, comprising the following steps: Step 1: Move the trolley carrying the heavy object to the obstacle. Step 2: The lifting system drives the lifting platform to rise; Step 3: Control the horizontal extension system to extend, thereby extending the rear lifting wheel system and the front lifting wheel system, and allowing the front lifting wheel system to pass over the obstacle; Step 4: Control the rear lifting wheel system and the front lifting wheel system to extend, so that the bottom casters of the rear lifting wheel system and the front lifting wheel system contact the ground, and fix the limit pins to make the extension length consistent; Step 5: The lifting system reacts to raise the walking system; Step 6: Manually push the trolley to move the walking system, lifting system, and load over the obstacle as a whole; Step 7: The lifting system is activated, lowering the walking system and then lowering the walking chassis again; Step 8: Release the fixing pins of the rear lifting wheel system and the front lifting wheel system, and control the extended ends of the rear lifting wheel system and the front lifting wheel system to retract. Step 9: Control the horizontal extension system to retract, thereby closing the rear lifting wheel system and the front lifting wheel system, and allowing the rear lifting wheel system to pass over the obstacle; Step 10: The lifting system controls the lifting platform to descend, the system returns to its original position, and begins normal operation.

[0015] The present invention has the following beneficial effects: 1. The trolley provided by this invention has the advantages of being easy to use, occupying little space, and being able to smoothly pass through obstacles such as thresholds. It supports walking on normal roads through its walking system. When crossing obstacles, the lifting system first rises, a horizontal extension system is set up to cross the obstacle, and the rear and front lifting wheel systems push the trolley body over the obstacle before lowering it, thus achieving obstacle-crossing transport.

[0016] 2. The present invention employs the above-described walking system. Attached Figure Description The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a structural diagram of the trolley of the present invention during normal transportation.

[0018] Figure 2 This is an overall structural diagram of the lifting platform of the present invention when it is lifted up.

[0019] Figure 3 This is an overall structural diagram of the lifting system of the present invention.

[0020] Figure 4 This is an overall structural diagram of the rear lifting wheel system and the front lifting wheel system of the present invention.

[0021] Figure 5This is an overall structural diagram of the walking system of the present invention.

[0022] Figure 6 This is a state diagram for step 1 of the present invention.

[0023] Figure 7 This is a state diagram for step 2 of the present invention.

[0024] Figure 8 This is a state diagram for step 3 of the present invention.

[0025] Figure 9 This is a state diagram for step 4 of the present invention.

[0026] Figure 10 This is a state diagram for step 5 of the present invention.

[0027] Figure 11 This is a state diagram for step 6 of the present invention.

[0028] Figure 12 This is a state diagram for step 7 of the present invention.

[0029] Figure 13 This is a state diagram for step 8 of the present invention.

[0030] Figure 14 This is a state diagram for step 9 of the present invention.

[0031] Figure 15 This is a state diagram for step 10 of the present invention.

[0032] In the diagram: 1-Walking system; 1.1-Walking chassis; 1.2-Way casters; 1.3-Drive wheels including motor; 1.4-Battery; 1.5-Lifting cylinder support; 1.6-Handrail; 1.7-Controller mounting plate; 1.8-Level indicator; 1.9-Wheel hub motor; 2-Lifting system; 2.1-Lifting cylinder; 2.2-Base; 2.3-Scissor arm rail; 2.4-Scissor arm; 2.5-Rotating shaft; 2.6-Lifting platform; 2.7-Fixed point for load; 2.8-Pin; 2.9-Outer sleeve; 2.10-Roller; 3-Rear extension wheel system; 3.1-Rear extension wheel system frame; 3.2-Support beam; 3.3-Telescopic strut; 3.4-Limit pin; 3.5-Electric lifting telescopic screw; 3.6-Secondary swivel casters; 4-Front lifting wheel system; 5-Control box; 6-Heavy object; 7-Horizontal extension system; 7.1-First electric telescopic screw; 7.2-Front extension inner sleeve; 7.3-Rear extension inner sleeve; 8-Obstacles. Detailed Implementation

[0033] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Currently, the most common method for transporting heavy objects across obstacles using trolleys involves using lifting platforms both inside and outside entrances / exits. When exiting, the trolley travels to the inner lifting platform, which then rises to be level with the top surface of the threshold. At this point, the trolley is pushed to the outer lifting platform, which descends, allowing the trolley to leave. The process is the same when entering an indoor area. While this method effectively completes the transport, it has several drawbacks: the trolley is quite heavy when carrying heavy objects, requiring the inner and outer lifting platforms to be heavy for safety, necessitating manual handling and making setup extremely inconvenient; the system is cumbersome, requiring the trolley, two lifting platforms, and the lifting power needed for each platform, making storage inconvenient and space-consuming.

[0036] like Figure 1-5 As shown, this embodiment provides a long-stroke heavy-duty obstacle-crossing electric trolley to solve the problems existing in traditional obstacle-crossing heavy object transfer trolleys. It includes a walking system 1 for driving the entire trolley to move automatically. A lifting system 2 is installed on the walking chassis 1.1 of the walking system 1. Horizontal extension systems 7 are symmetrically installed on both sides of the lifting platform 2.6 of the lifting system 2. A rear lifting wheel system 3 that can be raised and lowered is installed at one end of the rear of the horizontal extension system 7, and a front lifting wheel system 4 that can be raised and lowered is installed at one end of the front of the horizontal extension system 7. The top of the lifting platform 2.6 is used to carry the heavy object 6 that needs to be transferred. By adopting the aforementioned trolley, a lifting system 2 is integrated, serving as the chassis of the trolley. A rear lifting wheel system 3 and a front lifting wheel system 4, capable of retracting forward and backward, are used. These systems have a long-stroke lifting structure, allowing the trolley to be lifted entirely when raised. The wheelbase of the rear and front lifting wheel systems 3 and 4 is adjustable. When raised, the wheelbase of the rear and front lifting wheel systems 3 and 4 is adjusted to cross obstacles. The wheelbase is the sum of the trolley's length and the lengths of the two obstacles. In the high chassis state, the trolley is manually pushed over obstacles. After crossing the obstacles, the trolley is lowered, and the rear and front lifting wheel systems 3 and 4 are stored. A double-acting hydraulic cylinder is used, with a forward lifting mechanism of 2.6 liters for the lifting platform and a reverse lifting mechanism for the walking chassis.

[0037] Furthermore, the walking system 1 includes a walking chassis 1.1. A main caster wheel 1.2 is mounted on the head side of the bottom of the walking chassis 1.1, a drive wheel 1.3 is mounted on the tail side of the bottom of the walking chassis 1.1, a battery 1.4 for providing power is fixedly mounted on the bottom of the walking chassis 1.1, a handrail 1.6 is fixedly mounted on one end of the top of the walking chassis 1.1, a lifting cylinder support 1.5 is provided at the bottom of the walking chassis 1.1, and a level 1.8 is provided at the top of the walking chassis 1.1. The walking system 1, under normal operating conditions, facilitates the automatic movement of the entire trolley, thereby enabling the transfer of heavy objects on top. During operation, power is provided by the battery 1.4, which in turn drives the entire walking chassis 1.1 to move via the drive wheel 1.3. The handrail 1.6 facilitates control of the direction of movement.

[0038] Furthermore, the drive wheel 1.3 is connected to a hub motor 1.9 for driving its rotation. The hub motor 1.9 provides the driving power for the drive wheel 1.3.

[0039] Furthermore, a controller mounting plate 1.7 is fixedly installed on the upper part of the handle 1.6, and a control box 5 is fixedly installed on the outer wall of the controller mounting plate 1.7; the control box 5 facilitates the corresponding control of the normal operation process of the entire trolley.

[0040] Furthermore, the control box 5 is simultaneously connected to the walking system 1, the lifting system 2, the horizontal extension system 7, the rear lifting wheel system 3, and the front lifting wheel system 4. Through the aforementioned control methods, automated control of the entire trolley's operation can be provided.

[0041] Furthermore, the lifting system 2 includes a scissor arm rail 2.3, which is fixed to the top of the walking chassis 1.1. A scissor arm 2.4 is mounted on the scissor arm rail 2.3. The middle part of the scissor arm 2.4 is hinged by a pivot 2.5. A lifting platform 2.6 is mounted on the top of the scissor arm 2.6. Limiting baffles 2.11 are symmetrically mounted on both sides of the top of the lifting platform 2.6. A weight fixing handle 2.7 is fixed on the top of the limiting baffles 2.11. The scissor arm 2.4 is hinged to the piston rod end of the lifting cylinder 2.1 by a pin 2.8. The cylinder body of the lifting cylinder 2.1 is hinged between the bases 2.2. The bases 2.2 are located inside the lifting cylinder support 1.5. Outer sleeves 2.9 for installing the horizontal extension system 7 are provided on both sides of the lifting platform 2.6. The aforementioned lifting system 2 can be used to lift the lifting platform 2.6, thereby achieving the fixed-lift position of the rear lifting wheel system 3 and the front lifting wheel system 4. It also facilitates the lifting of the chassis 1.1 during obstacle crossing, thus enabling the chassis 1.1 to perform obstacle crossing. The lifting cylinder 2.1 is a double-acting cylinder.

[0042] During operation, when lifting is required, the lifting cylinder 2.1 is activated, which pushes the scissor arm 2.4. The scissor arm 2.4 and the roller 2.10 slide inside the scissor arm track 2.3, thereby raising and lowering the scissor arm 2.4. The scissor arm 2.4 then drives the lifting platform 2.6 to rise.

[0043] When obstacle crossing is required, the piston rod of the lifting cylinder 2.1 retracts, which in turn drives the walking chassis 1.1 at its bottom to rise synchronously, so that the walking chassis 1.1 can cross the obstacle and ultimately achieve the obstacle crossing effect.

[0044] Furthermore, the horizontal extension system 7 includes a rear extension inner sleeve 7.3 and a front extension inner sleeve 7.2 respectively fitted inside both ends of the outer sleeve 2.9. A first electric telescopic screw 7.1 is installed between the rear extension inner sleeve 7.3 and the front extension inner sleeve 7.2 via a screw drive. The rear lifting wheel system 3 is fixed to the end of the rear extension inner sleeve 7.3, and the front lifting wheel system 4 is fixed to the end of the front extension inner sleeve 7.2. The horizontal extension system 7 facilitates the extension of the rear lifting wheel system 3 and the front lifting wheel system 4, thereby facilitating subsequent support for the lifting system 2 and the walking system 1 during obstacle crossing. During obstacle crossing, the rotation of the first electric telescopic screw 7.1 drives the threaded rear lifting wheel system 3 and the front lifting wheel system 4 to extend, thereby changing their wheelbase and enabling them to cross corresponding obstacles.

[0045] Furthermore, the outer sleeve 2.9, the rear extension inner sleeve 7.3, and the front extension inner sleeve 7.2 are all made of square tubing. The use of square tubing effectively ensures structural strength and smooth extension or retraction.

[0046] Furthermore, the rear lifting wheel system 3 and the front lifting wheel system 4 adopt the same structural form. The rear lifting wheel system 3 includes a rear lifting wheel system main pipe 3.1. A telescopic support column 3.3 is installed inside the rear lifting wheel system main pipe 3.1 via an electric lifting telescopic screw 3.5. A secondary universal wheel 3.6 is installed at the bottom end of the telescopic support column 3.3. A support beam 3.2 is fixed between the rear lifting wheel system main pipe 3.1 on both sides of the displacement. A limiting pin 3.4 is provided between the rear lifting wheel system main pipe 3.1 and the telescopic support column 3.3 for locking both. Through the aforementioned rear lifting wheel system 3 and front lifting wheel system 4, the telescopic support column 3.3 can be extended and retracted, thereby facilitating reliable support for the walking system 1 and the lifting system 2 during subsequent obstacle crossing operations, thus assisting in the obstacle crossing process.

[0047] During obstacle crossing, when support is needed for the walking system 1 and the lifting system 2, the electric lifting telescopic screw 3.5 is activated, which drives the telescopic support column 3.3 to extend, thereby allowing the auxiliary universal wheel 3.6 to be supported on the ground.

[0048] Furthermore, both the main pipe 3.1 and the telescopic support 3.3 of the rear lifting wheel system are round tubes; the use of round tubes ensures smooth extension or retraction between the main pipe 3.1 and the telescopic support 3.3.

[0049] Furthermore, control box 5 includes walking control, lifting control, front and rear lifting wheel system telescopic lifting control, and an alarm system. The alarm system includes a level alarm, an overload alarm, and a battery alarm light. Through the above control functions, the entire trolley can be operated automatically.

[0050] Example 2: See Figure 6-15 Another aspect of the present invention provides a method for using a long-stroke, heavy-duty obstacle-crossing electric handcart, comprising the following steps: Step 1: The trolley carrying the heavy object 6 is moved to the obstacle 8. Step 2: The lifting system 2 drives the lifting platform 2.6 to rise; Step 3: Control the horizontal extension system 7 to extend, thereby extending the rear lifting wheel system 3 and the front lifting wheel system 4, and allowing the front lifting wheel system 4 to pass over the obstacle 8; Step 4: Control the rear lifting wheel system 3 and the front lifting wheel system 4 to extend, so that the bottom universal wheels of the rear lifting wheel system 3 and the front lifting wheel system 4 contact the ground, and fix the limit pins to make the extension length consistent. Step 5: The lifting system 2 reacts to raise the walking system 1; Step 6: Manually push the trolley to allow the walking system 1, lifting system 2, and weight 6 to pass over obstacle 8 as a whole; Step 7: The lifting system 2 is activated, lowering the walking system 1, and then lowering the walking chassis 1.1 again; Step 8: Release the fixing pins of the rear lifting wheel system 3 and the front lifting wheel system 4, and control the extended ends of the rear lifting wheel system 3 and the front lifting wheel system 4 to retract. Step 9: Control the horizontal extension system 7 to retract, thereby closing the rear lifting wheel system 3 and the front lifting wheel system 4, and allowing the rear lifting wheel system 3 to pass over the obstacle 8; Step 10: The lifting system 2 controls the lifting platform 2.6 to fall, the system returns to its original position, and begins normal operation.

[0051] The present invention and its embodiments have been described above. This description is not restrictive. The accompanying drawings are only one embodiment of the present invention. The actual structure is not limited to this. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the present invention, such design should fall within the protection scope of the present invention.

Claims

1. A long-stroke, heavy-duty obstacle-crossing electric-driven handcart, characterized in that, The system includes a walking system (1) for driving the entire trolley to move automatically. A lifting system (2) is installed on the walking chassis (1.1) of the walking system (1). A horizontal extension system (7) is symmetrically installed on both sides of the lifting platform (2.6) of the lifting system (2). A rear lifting wheel system (3) capable of lifting is installed at one end of the rear of the horizontal extension system (7). A front lifting wheel system (4) capable of lifting is installed at one end of the head of the horizontal extension system (7). The top of the lifting platform (2.6) is used to carry heavy objects (6) that need to be transferred.

2. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 1, characterized in that: The walking system (1) includes a walking chassis (1.1), a main universal wheel (1.2) is installed on the head side of the bottom end of the walking chassis (1.1), a drive wheel (1.3) is installed on the tail side of the bottom end of the walking chassis (1.1), a battery (1.4) for providing power is fixedly installed at the bottom end of the walking chassis (1.1), a handrail (1.6) is fixedly installed at one end of the top of the walking chassis (1.1), a lifting cylinder support (1.5) is provided at the bottom of the walking chassis (1.1), and a level (1.8) is provided at the top of the walking chassis (1.1).

3. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 2, characterized in that: The drive wheel (1.3) is connected to a hub motor (1.9) for driving its rotation.

4. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 2, characterized in that: A controller mounting plate (1.7) is fixedly installed on the upper part of the handrail (1.6), and a control box (5) is fixedly installed on the outer wall of the controller mounting plate (1.7). The control box (5) is connected to the walking system (1), the lifting system (2), the horizontal extension system (7), the rear lifting wheel system (3), and the front lifting wheel system (4).

5. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 2, characterized in that: The lifting system (2) includes a scissor arm rail (2.3), which is fixed on the top of the walking chassis (1.1). Scissor arms (2.4) are installed on the scissor arm rail (2.3). The middle part of the scissor arms (2.4) is hinged by a pivot (2.5). A lifting platform (2.6) is installed on the top of the scissor arms (2.4). Limiting baffles (2.11) are symmetrically installed on both sides of the top of the lifting platform (2.6). A weight fixing handle (2.7) is fixed on the top of the limiting baffles (2.11). The scissor arms (2.4) are hinged to the piston rod end of the lifting cylinder (2.1) by a pin (2.8). The cylinder body of the lifting cylinder (2.1) is hinged between the bases (2.2). The bases (2.2) are located inside the lifting cylinder support (1.5). Outer sleeves (2.9) for installing the horizontal extension system (7) are provided on both sides of the lifting platform (2.6).

6. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 5, characterized in that: The horizontal expansion system (7) includes a rear expansion inner sleeve (7.3) and a front expansion inner sleeve (7.2) respectively fitted inside both ends of the outer sleeve (2.9). A first electric telescopic screw (7.1) is installed between the rear expansion inner sleeve (7.3) and the front expansion inner sleeve (7.2) through a screw drive. The rear expansion inner sleeve (7.3) is fixed with a rear lifting wheel system (3), and the front expansion inner sleeve (7.2) is fixed with a front lifting wheel system (4).

7. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 6, characterized in that: The outer sleeve (2.9), the rear extension inner sleeve (7.3), and the front extension inner sleeve (7.2) are all made of square tubes.

8. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 6, characterized in that: The rear lifting wheel system (3) and the front lifting wheel system (4) adopt the same structural form. The rear lifting wheel system (3) includes a rear lifting wheel system main pipe (3.1). The interior of the rear lifting wheel system main pipe (3.1) is equipped with a telescopic support (3.3) through an electric lifting telescopic screw (3.5). The bottom end of the telescopic support (3.3) is equipped with a secondary universal wheel (3.6). A support beam (3.2) is fixed between the rear lifting wheel system main pipe (3.1) on both sides of the displacement. A limiting pin (3.4) for locking the rear lifting wheel system main pipe (3.1) and the telescopic support (3.3) is provided.

9. The long-stroke heavy-duty obstacle-crossing electric handcart according to claim 8, characterized in that: The main pipe (3.1) and telescopic support (3.3) of the rear lifting wheel system are both made of round tubes; The control box (5) includes walking control, lifting control, front and rear lifting wheel system telescopic lifting control and alarm system. The alarm system includes horizontal alarm, overload alarm and battery alarm light.

10. The method of using a long-stroke heavy-duty obstacle-crossing electric handcart as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: The trolley carrying the heavy object (6) is moved to the obstacle (8); Step 2, the lifting system (2) drives the lifting platform (2.6) to rise; Step 3: Control the horizontal extension system (7) to extend, thereby extending the rear lifting wheel system (3) and the front lifting wheel system (4), and allowing the front lifting wheel system (4) to pass over the obstacle (8). Step 4: Control the rear lifting wheel system (3) and the front lifting wheel system (4) to extend, so that the bottom universal wheels of the rear lifting wheel system (3) and the front lifting wheel system (4) contact the ground, and fix the limit pins to make the extension length consistent; Step 5, the lifting system (2) reacts to raise the walking system (1); Step 6: Manually push the trolley to allow the walking system (1), lifting system (2) and heavy object (6) to pass over the obstacle (8) as a whole. Step 7: The lifting system (2) is activated, lowering the walking system (1), and then lowering the walking chassis (1.1) again; Step 8: Release the fixing pins of the rear lifting wheel system (3) and the front lifting wheel system (4) and control the extended ends of the rear lifting wheel system (3) and the front lifting wheel system (4) to retract. Step 9: Control the horizontal extension system (7) to retract, thereby closing the rear lifting wheel system (3) and the front lifting wheel system (4), and allowing the rear lifting wheel system (3) to pass over the obstacle (8). Step 10: The lifting system (2) controls the lifting platform (2.6) to fall, the system returns to its original position, and begins to move normally.

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