CN115847354A - Device for replacing trolley body of circular cooler and replacing method - Google Patents

Abstract

A device for replacing a trolley body of a ring cooling machine is positioned between the trolley body and a trolley track and comprises a transverse moving mechanism and a jacking mechanism, wherein the transverse moving mechanism comprises a guide rail and a moving part, the guide rail is erected on the trolley track, the moving part is arranged on the guide rail, and the moving part can move along the guide rail; the jacking mechanism is arranged on the moving part and is positioned between the moving part and the trolley body. The trolley replacing device can work in a narrow space, and the trolley to be replaced can stably drive away from or into the circular cooler along the guide rail under the action of the transverse moving mechanism and the jacking mechanism, so that the trolley to be replaced can be replaced. Meanwhile, the upper casing and the lower slide carriage of the annular cooler are prevented from being disassembled, the rapid replacement of the trolley body of the annular cooler is realized, and the trolley replacement efficiency is improved.

Description

Device for replacing trolley body of circular cooler and replacing method

Technical Field

The invention relates to the field of steel smelting, in particular to a device and a method for replacing a trolley body of a circular cooler.

Background

The circular cooler is mainly used for cooling sintered ore produced by a sintering machine in steel production. The whole ring cooling machine is arranged in a ring shape and is divided into a cooling area and a non-cooling area along the circumferential direction. The trolley is one of the important parts of the circular cooler and is used for bearing hot sintering ores. The traditional circular cooler has a plurality of trolleys with different quantities and consistent shapes according to different scales. Wherein, the platform truck includes platform truck body and wheel, the wheel set up in on the platform truck body. The trolleys are hinged on the revolving frame of the circular cooler and are sequentially arranged along the circumferential direction of the circular cooler to form a structure similar to a circular ring, and the trolleys can rotate around the revolving center of the circular cooler along the trolley track. The rotary frame is formed by connecting a plurality of trolley radial supporting beams and inner and outer frames at two ends of the trolley radial supporting beams. It should be noted that, the side of the trolley provided with the hinged seat is the front end, and the side provided with the wheels is the rear end. The front end of the trolley can be hinged on a front trolley supporting beam through a hinge seat, the rear end of the trolley is supported on inner and outer side rails of the trolley respectively through inner side wheels and outer side wheels, the trolley rails are fixedly arranged on a pad beam, and the pad beam is fixedly arranged on a plane beam of the circular cooler. In the operation process, mineral aggregate to be cooled is injected into each trolley from a charging station of a non-cooling area, the trolley cools the mineral aggregate through pressure air after entering the cooling area, and then the trolley enters an unloading station of the non-cooling area to finish cooling and unloading.

Generally, when the circular cooling machine trolley is replaced, the trolley to be replaced needs to be operated to the discharging area, the dust cover and the dust removal pipe of the trolley are removed, the trolley is turned over by using hoisting equipment to adjust the direction, then the trolley is hoisted out from the upper side of the track, and the installation process is reverse operation of the steps. Or, the trolley body dismounting method of the circular cooler disclosed as patent application number 201110396184.4 is adopted: and (3) stopping the trolley to be replaced above the detachable section trolley track and the pad beam, and removing the pressing relation between the rear side supporting beam of the trolley body and the plane beam of the circular cooler framework. After the trolley body to be replaced is lifted upwards to be in a suspended supporting shape, the horizontal rail of the detachable section, the pad beam and the front end spherical hinge of the trolley can be detached in sequence, and then the trolley body to be replaced is placed to finish the detaching process. When the trolley is replaced by adopting the mode, the upper encloser and the lower slide carriage of the circular cooler need to be disassembled, so that the workload is large.

Furthermore, the stress balance of the trolley body is in a three-point supporting mode and comprises a hinged seat, an inner side wheel and an outer side wheel. When the trolley is released from hinging, the gravity center of the trolley body is easy to shift to the rear end of the trolley, so that the gravity center or the balance point is difficult to position when the trolley is hoisted, the time consumption is long, and the production efficiency of equipment is low. In addition, the upper casing and the lower chute of the ring cooler need to be disassembled, so that the trolley replacement efficiency is influenced. The trolley body is respectively provided with a frame with the same height, a friction plate and other parts for blocking, so that the replacement space of the trolley is narrow.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the object of the present invention is to provide a device for changing the body of a ring cooler trolley.

The invention provides a device for replacing a trolley body of a ring cooling machine, which is positioned between a trolley body and a trolley track, and comprises a transverse moving mechanism and a jacking mechanism, wherein the transverse moving mechanism comprises a guide rail and a moving part, the guide rail is erected on the trolley track, the moving part is arranged on the guide rail, and the moving part can move along the guide rail; the jacking mechanism is arranged on the moving part and is positioned between the moving part and the trolley body.

Preferably, the device further comprises a guide mechanism, the guide mechanism comprises a guide sleeve and a guide shaft inserted into the guide sleeve, and the guide shaft is arranged on the bottom surface of the trolley body and is positioned on one side far away from the trolley wheels; the guide sleeve is fixedly arranged on the moving part; the guide shaft slides up and down along the guide sleeve under the condition that the guide sleeve is sleeved.

Preferably, the jacking mechanism comprises a plurality of synchronous jacks, the synchronous jacks are uniformly distributed on the moving part, and the synchronous jacks are positioned between the moving part and the trolley body.

Preferably, the bottom of the moving part is provided with a plurality of rollers, and the rollers are matched with the guide rails.

Preferably, the device further comprises a driving mechanism, the driving mechanism comprises a winch and a steel wire rope, two ends of the steel wire rope are respectively connected with the moving part and the winch, and the winch is used for driving the steel wire rope to drive the moving part to move along the guide rail.

Preferably, a method for disassembling a body of a ring cooling machine trolley, which adopts the device for replacing the body of the ring cooling machine trolley in claim 1, comprises the following steps:

s1, erecting the guide rail on the trolley track, wherein the jacking mechanism is in contact with the bottom surface of the trolley body;

s2, disassembling a trolley body to be replaced hinged to a revolving frame of the annular cooler;

s3, lifting the trolley body through the jacking mechanism to lift the lowest point of the outer edge of the wheel on the trolley body to be replaced to a position higher than the upper surface of the trolley track;

and S4, drawing the moving part to move along the guide rail, and removing the trolley body to be replaced from the circular cooler.

Preferably, the device still includes guiding mechanism, guiding mechanism includes the uide bushing and inserts the guiding axle of uide bushing, the guiding axle is in the uide bushing cover is established down to follow the uide bushing slides from top to bottom, before step S2, will the guiding axle set up in platform truck automobile body bottom surface just is located keeps away from platform truck wheel one side, with the guiding axle complex the uide bushing is fixed in on the removal portion.

As described above, the apparatus for replacing a body of a loop cooler pallet and the replacing method according to the present invention have the following features

Has the advantages that:

(1) When the trolley is detached, the trolley to be replaced is lifted by the jacking mechanism in a narrow space, so that the outer edge of the trolley wheel is higher than the upper surface of the trolley track, and the trolley wheel is prevented from interfering with the trolley track. Utilize the cooperation between guiding mechanism and the climbing mechanism, realize that the platform truck keeps balanced at the lifting with remove the in-process, prevent to lead to unbalance because of the focus skew. The trolley is moved out of the circular cooler along the guide rail through the transverse moving mechanism, and then the trolley is disassembled. Meanwhile, the annular cooler housing and the lower chute are prevented from being disassembled, and the disassembling efficiency is improved.

(2) When the trolley is reloaded, the trolley is lifted through the jacking mechanism in a narrow space, the interference of trolley wheels and trolley tracks is avoided, and the balance of the trolley in the transferring and descending process is realized by the cooperation of the guide mechanism and the jacking mechanism. The trolley is transferred to the trolley rail along the rail through the transverse moving mechanism and the pulley, and the trolley is fixed on the rotary frame of the circular cooler, so that the trolley is installed, and the production efficiency of equipment is improved.

In conclusion, the trolley replacing device can work in a narrow space, and the trolley to be replaced can stably drive away from or into the circular cooler along the guide rail under the action of the transverse moving mechanism and the jacking mechanism, so that the trolley to be replaced can be replaced. Meanwhile, the disassembly of the upper housing and the lower slide carriage of the circular cooler is avoided, the quick replacement of the trolley body of the circular cooler is realized, and the trolley replacement efficiency is improved.

Drawings

Fig. 1 is a schematic front view of an apparatus for changing the body of a loop cooler truck according to the present invention.

Fig. 2 is a schematic side view of an apparatus for changing the body of a ring cooler pallet according to the present invention.

Fig. 3 is a schematic diagram of a top view of an apparatus for changing the body of a ring cooler pallet according to the present invention.

Fig. 4 is a schematic view of a disassembly trolley of an apparatus for replacing the body of a loop cooler trolley according to the present invention.

Fig. 5 is a schematic view of a retrieval truck of an apparatus for replacing the body of a loop cooler truck of the present invention.

FIG. 6 is a schematic view of the device for replacing the body of the trolley of the circular cooler for completing the reloading of the trolley.

Description of the reference numerals:

100. a trolley; 110. a trolley body; 120. a wheel; 130. a trolley rail; 140. a hinged seat; 200. a traversing mechanism; 210. a guide rail; 220. a moving part; 230. a roller; 300. a jacking mechanism; 310. a synchronous jack; 400. a drive mechanism; 410. a winch; 420. a wire rope; 430. a pulley; 500. a guide mechanism; 510. a guide shaft; 520. and a guide sleeve.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, ratios, sizes, etc. shown in the drawings and attached to the description are only for understanding and reading the disclosure of the present invention, and are not intended to limit the practical conditions of the present invention, so that the present invention has no technical significance, and any modifications of the structures, changes of the ratio relationships, or adjustments of the sizes, should still fall within the scope of the technical contents of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms such as "upper", "lower", "left", "right", "middle", etc. used in the present specification are used for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms may be changed or adjusted without substantial technical change.

As shown in fig. 1, the present invention provides an apparatus for replacing a trolley body of a ring cooler, wherein a trolley 100 comprises a trolley body 110 and wheels 120, the wheels 120 are arranged on the trolley body 110, the trolley body 110 is hinged on a revolving frame of the ring cooler and can move along a trolley track 130, wherein the apparatus is located between the trolley body 110 and the trolley track 130, the apparatus comprises a traversing mechanism 200 and a jacking mechanism 300, the traversing mechanism 200 comprises a guide rail 210 and a moving part 220, the guide rail 210 is arranged on the trolley track 130, the moving part 220 is arranged on the guide rail 210, the moving part 220 can move along the guide rail 210, and the moving part 220 is located at the bottom of the trolley body 110; the jacking mechanism 300 is arranged on the moving part 220; the jacking mechanism 300 is located between the moving part 220 and the trolley body 110.

Specifically, when the guide rail 210 is erected on the trolley track 130, the guide rail 210 is erected along the direction from the inner track to the outer track of the trolley track 130, and is fixed on the upper surfaces of the inner track and the outer track of the trolley track 130, so as to ensure that the trolley body 110 drives away from or into the circular cooler along the guide rail 210, thereby realizing the replacement of the trolley and preventing the guide rail 210 from deviating in the using process. Further, the guide rail 210 is made of 16# channel steel, has a length of 6m and a width of 1m, and is located between the moving part 220 and the carriage rail 130. The moving part 220 matched with the guide rail is formed by welding 10# channel steel, the moving part 220 is integrally of a frame type structure, and a welding rib plate is additionally arranged on the moving part 220 to enhance the integral bearing strength of the moving part 220. The jacking mechanism 300 is in contact with the bottom of the trolley body 110, and when the trolley is used, the jacking mechanism 300 ascends to lift the trolley body 110 away from the trolley track 130 until the lowest end of the outer edge of the trolley wheels 120 is higher than the upper surface of the trolley track 130, so that the trolley wheels 120 are prevented from interfering with the trolley track 130 when the trolley body 110 moves. The moving portion 220 drives the trolley body 110 lifted to a predetermined height to move along the guide rail 210 under the action of traction force, thereby implementing replacement of the trolley 100.

As shown in fig. 2, the device further comprises a guiding mechanism 500, wherein the guiding mechanism 500 comprises a guiding sleeve 520 and a guiding shaft 510 inserted into the guiding sleeve 520, and the guiding shaft 510 is arranged on the bottom surface of the trolley body 110 and is positioned on the side far away from the trolley wheels 120; the guide sleeve 520 is fixedly disposed on the moving portion 220, and the guide shaft 510 slides up and down along the guide sleeve 520 under the sleeving of the guide sleeve 520.

It should be noted that the side of the trolley 100 where the hinge base 140 is provided is the front end, and the side where the wheels 120 are provided is the rear end, so that the weight of the rear end of the trolley 100 is greater than that of the front end, and the center of gravity is biased to the rear end. After the trolley 100 is released from the hinge joint, the trolley 100 is easily lifted by the jacking mechanism 300, and the weight of the front end and the rear end of the trolley 100 is uneven, so that the gravity center of the trolley 100 is easily deviated to one side of the trolley wheels 120, and further the trolley 100 is unbalanced. Based on this, when assembling, the guide shaft 510 is welded to the bottom surface of the carriage body 110 on the side away from the carriage wheel 120, the guide sleeve 520 is welded to the moving portion 220 at a position corresponding to the guide shaft 510, the guide shaft 510 and the guide sleeve 520 are fitted to each other, and the guide shaft 510 can slide up and down along the guide sleeve 520. The trolley 100 is stably supported through the guide mechanism 500 and the jacking mechanism 300, and when the trolley 100 is lifted or lowered, the guide shaft 510 can be stably lifted and lowered along with the jacking mechanism 300, so that the gravity center offset phenomenon can be effectively prevented.

As shown in fig. 2 to 3, the jacking mechanism 300 includes a plurality of synchronization jacks 310, the synchronization jacks 310 are uniformly arranged on the moving part 220, and the synchronization jacks 310 are located between the moving part 220 and the trolley body 110.

Further, the synchronous jacks 300 comprise jacks, single-operation synchronous valves, matched oil pipes and pressure gauges, the jacks are connected with the synchronous valves, the pressure gauges and the matched oil pipes, the synchronous jacks 300 are all connected with the electric hydraulic pump, and the jacks are 4 single-action jacks of 15 t. During assembly, the 4 synchronous jacks 310 are uniformly distributed at four corners of the moving part 220 and are in contact with the trolley body 110, so that the 4 synchronous jacks 310 can be ensured to be synchronously lifted to the same height when the trolley 100 is lifted.

As shown in fig. 1-2, the bottom of the moving part 220 is provided with a plurality of rollers 230, and the rollers 230 are adapted to the guide rail 210.

As shown in fig. 3 to 6, the apparatus further includes a driving mechanism 400, the driving mechanism 400 includes a winding machine 410 and a steel wire rope 420, two ends of the steel wire rope 420 are respectively connected to the moving portion 220 and the winding machine 410, and the winding machine 410 is used for driving the steel wire rope 420 to drive the moving portion 220 to move along the guide rail 210.

The trolley body 110 is trapezoidal, wherein one side of the trolley body 110 close to the inner track of the trolley is a narrow side, and one side close to the outer track of the trolley is a wide side. The winch 410 is arranged outside the trolley outer rail 130, when the trolley 100 is detached in use, the steel wire rope 420 is fixed to the moving part 220 on the same side with the wide side of the trolley body 110, and when the trolley 100 is moved out, the moving part 220 is driven to move the trolley 100 out of the circular cooler along the guide rail 210 through manual switch control. In the process of reloading the trolley 100, a pulley 430 is required to be disposed on one side of the guide rail 210 close to the trolley inner rail 130, and the steel wire rope 420 is fixed to the moving portion 220 on the same side with the narrow side of the trolley body 110 and bypasses the pulley 430 to change the force direction of the moving portion 220. When the cart 100 is returned, the moving unit 220 is driven by a manual switch to move the cart 100 along the guide rail 210 into the circular cooler.

As shown in fig. 1-4, a method for replacing a car body of a trolley of a circular cooler, which adopts the method of claim 1 for specific operation, comprises the following steps:

step S1, erecting a guide rail 210 on a trolley track 130, and enabling a jacking mechanism 300 to be in contact with the bottom surface of a trolley body 110;

s2, disassembling the trolley body 110 to be replaced hinged on the revolving frame of the annular cooler;

step S3, lifting the trolley body 110 through the jacking mechanism 300, so that the lowest point of the outer edge of the wheel 120 on the trolley body 110 to be replaced is lifted to be higher than the upper surface of the trolley track 130;

and S4, the traction moving part 220 moves along the guide rail 210, and the trolley body 110 to be replaced is moved out of the circular cooler.

When the above method is adopted to disassemble the trolley 100, specifically, when the step S1 is performed, since the trolley body 110 is provided with the fence, it is easy to hinder the replacement of the trolley 100. Therefore, before the cart 100 is disassembled, the balustrade of the cart body 110 needs to be disassembled. The guide rail 210 is erected on the upper surface of the trolley rail 130, wherein the guide rail 210 is fixed to the upper surface of the trolley rail 130 to prevent the guide rail from being deviated when transferring the trolley 100. The jacking mechanism 300 is slightly abutted against the bottom surface of the trolley body 110 so that the jacking mechanism can support the trolley body 110 in preparation for next step of disassembling the trolley body 110. The trolley body 110 is fixedly provided with a hinge base 140 at one side far away from the trolley wheels 120, and the hinge base 140 is hinged with the circular cooler re-installation frame through a pin shaft. When the step S2 is performed, the pin shaft engaged with the hinge base 140 is removed, and the jacking mechanism 300 in contact with the bottom surface of the trolley body 110 stably supports the trolley body 110, so that the trolley body 110 can be ensured to be stably separated from the circular cooler, and the trolley body 110 removed at this time forms an integral body with the jacking mechanism 300 and the traversing mechanism 200. When step S3 is performed, the height of the trolley body 110 is adjusted by the jacking mechanism 300, and the trolley body 110 is synchronously lifted to a predetermined height, so that the lowest point of the outer edge of the wheel 120 on the trolley body 110 to be replaced is lifted to be higher than the upper surface of the trolley track 130, thereby preventing the wheel 120 from interfering with the trolley track 130 when the trolley body 110 is transferred. It should be noted that, when the height of the trolley body 110 is raised, the height of the end of the trolley body 110 not provided with the wheels 120 needs to be slightly lower than the end provided with the wheels 120, so as to ensure that the trolley 100 can be kept stable during the process of transferring the trolley 100. When the step S4 is performed, the wire rope 420 is connected to the winding machine 410 and the moving part 220, respectively, the winding machine 410 drives the wire rope 420 to further pull the moving part 220 to move along the guide rail 210, and the ring cooling machine is driven away until the central point of the trolley body 110 is located outside the outer track of the trolley. Finally, the trolley 100 to be replaced is directly lifted away by the lifting device, and a new trolley is replaced.

When the trolley is reloaded, the newly replaced trolley is stably arranged on the jacking mechanism 300 through the hoisting equipment, a pulley 430 is arranged on one side of the guide rail 210 close to the inner track of the trolley, one end of the steel wire rope 420 is connected with the winch 430, and the steel wire rope 420 bypasses the pulley 430 to be connected with the moving part 220. Under the driving of the winch 430, the wire rope 420 drives the moving part 220 to move along the direction of the trolley inner rail until the trolley wheels 120 are positioned right above the trolley rail 130. Then, the height is synchronously adjusted by the jacking mechanism 300, and the trolley is lowered until the trolley wheels 120 are engaged with the trolley rails 130. Finally, the newly replaced trolley 100 is fixed to the ring cooler slewing frame in an articulated manner, the detached sideboard is mounted on the trolley body 110, the mobile part 220 is moved out, and the guide rail 210 is detached.

As shown in fig. 2, the apparatus further includes a guide mechanism 500, the guide mechanism 500 includes a guide sleeve 520 and a guide shaft 510 inserted into the guide sleeve 520, the guide shaft 510 slides up and down along the guide sleeve 520 under the guide sleeve 520, before step S2, the guide shaft 510 is disposed on the bottom surface of the trolley body 110 and located on the side away from the trolley wheel 120, and the guide sleeve 520 engaged with the guide shaft 510 is fixed to the moving portion 220.

In the process of detaching the trolley, when step S1 is implemented, the jacking mechanism 300 contacts the bottom surface of the trolley body 110, so that the jacking mechanism 300 can support the trolley body 110, the guide shaft 510 is welded to the bottom surface of the trolley body 110 and is located on one side away from the trolley wheels 120, the guide sleeve 520 matched with the guide shaft 510 is welded on the corresponding moving part 220, and therefore the trolley 100 can be guaranteed to be stably kept in the lifting and transferring processes.

In the process of reloading the trolley, it should be noted that the newly replaced trolley 100 is hoisted to the jacking mechanism 300 by the hoisting device, so that the jacking mechanism 300, the trolley 100 and the moving portion 220 are integrated, and the moving portion 220 is provided with the guide sleeve 520 matched with the previous trolley, so that the guide shaft 510 needs to be welded at the position corresponding to the guide sleeve 520 under the supporting action of the jacking mechanism 330, so as to ensure that the trolley 100 is kept stable in the transferring and descending processes.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims (7)

1. The device for replacing the trolley body of the ring cooler is characterized by being located between a trolley body (110) and a trolley track (130), and comprising a transverse moving mechanism (200) and a jacking mechanism (300), wherein the transverse moving mechanism (200) comprises a guide rail (210) and a moving part (220), the guide rail (210) is erected on the trolley track (130), the moving part (220) is arranged on the guide rail (210), and the moving part (220) can move along the guide rail (210); the jacking mechanism (300) is arranged on the moving part (220); the jacking mechanism (300) is located between the moving part (220) and the trolley body (110).

2. The device for replacing the trolley body of the ring cooler according to claim 1, characterized in that the device further comprises a guide mechanism (500), the guide mechanism (500) comprises a guide sleeve (520) and a guide shaft (510) inserted into the guide sleeve (520), and the guide shaft (510) is arranged on the bottom surface of the trolley body (110) and is positioned on the side far away from the trolley wheels (120); the guide sleeve (520) is fixedly arranged on the moving part (220); the guide shaft (510) slides up and down along the guide sleeve (520) under the sleeving of the guide sleeve (520).

3. The apparatus for replacing the body of a ring cooler trolley according to claim 2, characterized in that the jacking mechanism (300) comprises a plurality of synchronized jacks (310), the synchronized jacks (310) are uniformly arranged on the moving part (220), and the synchronized jacks (310) are located between the moving part (220) and the trolley body (110).

4. The device for replacing the body of the ring cooler trolley according to the claim 1, characterized in that a plurality of rollers (230) are arranged at the bottom of the moving part (220), and the rollers (230) are matched with the guide rail (210).

5. The apparatus for replacing the body of the ring cooling machine trolley according to claim 1, further comprising a driving mechanism (400), wherein the driving mechanism (400) comprises a winch (410) and a steel wire rope (420), two ends of the steel wire rope (420) are respectively connected with the moving part (220) and the winch (410), and the winch (410) is used for driving the steel wire rope (420) to drive the moving part (220) to move along the guide rail (210).

6. The method for replacing the body of the ring cooling machine trolley is characterized in that the device for replacing the body of the ring cooling machine trolley, which is disclosed by claim 1, is adopted, and the specific operation comprises the following steps:

s1, erecting the guide rail (210) on the trolley track (130), wherein the jacking mechanism (300) is in contact with the bottom surface of the trolley body (110);

s2, disassembling a trolley body (110) to be replaced, which is hinged on the revolving frame of the annular cooler;

s3, lifting the trolley body (110) through the jacking mechanism (300) to enable the lowest point of the outer edge of the wheel (120) on the trolley body (110) to be replaced to be lifted to be higher than the upper surface of the trolley track (130);

and S4, drawing the moving part (220) to move along the guide rail (210) and moving the trolley body (110) to be replaced out of the circular cooler.

7. The replacement method of the trolley body of the ring cooling machine according to claim 6, wherein the device further comprises a guide mechanism (500), the guide mechanism (500) comprises a guide sleeve (520) and a guide shaft (510) inserted into the guide sleeve (520), the guide shaft (510) slides up and down along the guide sleeve (520) under the condition that the guide sleeve (520) is sleeved, before the step S2, the guide shaft (510) is arranged on the bottom surface of the trolley body (110) and positioned on the side far away from the trolley wheels (120), and the guide sleeve (520) matched with the guide shaft (510) is fixed on the moving part (220).

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