Combined sleeper replacement machine unit and working method

Abstract

The embodiment of the application provides a combined sleeper replacement machine set and a working method, which comprises a sleeper conveying vehicle, a plurality of sleeper replacement vehicles and a power vehicle connected in sequence; the power vehicle is used for providing a machine set traction power, a brake air source, a machine set power supply and a machine set working control system; the sleeper conveying vehicle is used for conveying new and old sleepers before and after working; the sleeper replacement vehicle is used for replacing old sleepers and laying new sleepers, and the sleeper conveying trolley of the connected whole replacement vehicle is aligned with upper and lower conveying belts respectively, so that the sleeper conveying trolley can convey sleepers on the upper and lower conveying belts of the whole vehicle. The machine set can self-traction walking, can meet the working requirements by combining a plurality of sleeper replacement vehicles, a plurality of points can independently work, the working is flexible, and the machine sets do not affect each other, the efficiency of the combined machine set is high, the sleeper replacement working can be completed without damaging the old sleepers, and the lifting or shunting action is not needed, and the machine set is suitable for the technical field of railway line maintenance.

Description

TECHNICAL FIELD

[0001] The application relates to a combined sleeper replacement machine set and a working method, and belongs to the technical field of railway line maintenance. BACKGROUND

[0002] Currently, the continuous sleeper replacement operation of old foreign lines is mainly performed by using large-scale track and sleeper replacement equipment. These equipment has long operation lines, large volume, low work efficiency, difficult construction organization, long operation time and difficult parking.

[0003] In addition to such large equipment, small excavators with multifunctional sleeper grabbing devices are used for railway sleeper replacement machine construction in China. The single operation efficiency is not high, and multiple machines can be used for simultaneous operation to flexibly meet the requirement of operation efficiency. This mode cannot transport sleepers at one time, and at least three times of special construction are required to completely replace sleepers, which is difficult to organize, requires a large number of personnel and has great safety hazards.

[0004] At present, whether it is large-scale track and sleeper replacement equipment or small excavators transformed into sleeper replacement machines, the following defects exist: during construction, it is inevitable to perform track lifting or track shifting, which will damage the bed and the rail; only a short distance of sleeper replacement can be realized at one time, and new sleepers and old sleepers need to be frequently transported to meet the construction requirements, which is low in construction efficiency; two sets of equipment need to be respectively arranged for new sleeper laying and old sleeper recovery, which increases the cost and the length of the whole sleeper replacement equipment; since the existing sleeper replacement equipment is a complete working line, once a link fails, the construction must be stopped, and the construction progress is delayed until the failed link is repaired. SUMMARY

[0005] In order to solve one of the above technical defects, a combined sleeper replacement machine set and a working method are provided in the embodiments of the application.

[0006] The first aspect of the application provides a combined sleeper replacement machine set, which comprises a sleeper transfer car, a plurality of sleeper replacement cars and a power car connected in sequence.

[0007] The sleeper transfer car comprises a special flat car, a transfer conveyor belt is arranged on the special flat car, one end of the transfer conveyor belt can slide horizontally on the special flat car, the other end of the transfer conveyor belt can be vertically lifted, and a hoisting transport car is further arranged on the special flat car.

[0008] The sleeper replacement vehicle comprises a replacement vehicle frame and a sleeper conveying trolley, the replacement vehicle frame is provided with an upper conveying belt and a lower conveying belt above, and the sleeper conveying trolley moves horizontally and / or vertically lifts on the replacement vehicle frame; a horizontally movable mobile sleeper replacement trolley is arranged below the replacement vehicle frame, and the mobile sleeper replacement trolley is provided with a lifting flat conveying belt at the end of the frame.

[0009] According to another aspect of the embodiment of the present application, a working method of the combined sleeper replacement machine set is provided, comprising the following steps:

[0010] S1, sleeper loading: the sleepers in the sleeper conveying special vehicle are hoisted to the transfer conveying belt by the hoisting conveying vehicle;

[0011] S2, sleeper conveying: the right end of the transfer conveying belt is lifted or lowered to be flush with the upper conveying belt or the lower conveying belt by operating the lifting guide column, the transfer conveying belt and the upper conveying belt or the lower conveying belt are synchronously operated, the sleepers on the transfer conveying belt are conveyed to the upper conveying belt or the lower conveying belt, and the number of sleepers on the upper conveying belt or the lower conveying belt meets the working requirement;

[0012] S3, new sleeper replacement: the sleeper replacement vehicle moves to the to-be-constructed section under the traction of the power vehicle, the lower conveying belt conveys the new sleepers to the sleeper conveying trolley, the sleeper conveying trolley vertically lowers through the lifting mechanism and then horizontally moves to the end of the frame of the mobile sleeper replacement trolley, the sleeper conveying trolley conveys the new sleepers to the lifting flat conveying belt, the lifting flat conveying belt vertically lowers by a proper height, the mobile sleeper replacement trolley takes out the old sleepers from the working section and places them on the lifting flat conveying belt, the mobile sleeper replacement trolley continues to grab the new sleepers and completes the installation of the new sleepers, and the mobile sleeper replacement trolley is driven to the next sleeper replacement position;

[0013] S4, old sleeper storage: while the new sleepers are installed, the lifting flat conveying belt vertically rises and conveys the old sleepers to the sleeper conveying trolley, the sleeper conveying trolley horizontally moves to the lifting mechanism and then vertically rises to the upper conveying belt, the sleeper conveying trolley conveys the old sleepers to the upper conveying belt and then vertically lowers to the lower conveying belt; meanwhile, the folding lifting conveying belt vertically rises to the upper conveying belt and catches the new sleepers pushed out from the upper conveying belt, the folding lifting conveying belt vertically lowers to the lower conveying belt and conveys the new sleepers to the lower conveying belt;

[0014] S5, the steps S3-S4 are repeated, if the replacement of sleepers on the section is completed, step S6 is executed, and if the lower conveying belt is full of old sleepers, step S7 is executed.

[0015] S6, send a command to the tractor, and the tractor advances the distance of the group of sleepers, and the step S5 is continuously executed until the whole construction section of sleeper replacement is completed;

[0016] S7, the old sleepers on the sleeper replacement vehicle are transported to the sleeper conveying vehicle for unified recycling, and after the old sleepers are unloaded by the hoisting and transporting vehicle, the steps S1, S2 and S5 are executed again.

[0017] The combined sleeper replacement machine set and the operation method provided in the embodiments of the present application have the following beneficial effects:

[0018] 1, the sleeper replacement vehicle in the present application has an upper conveying belt and a lower conveying belt, which can not only carry more new sleepers for sleeper replacement operation, but also cooperate with the lifting mechanism, the sleeper conveying trolley and the lifting flat belt conveyor to realize the circulation of new and old sleepers in the sleeper replacement vehicle, without the need to separately set two sets of equipment for new sleeper laying and old sleeper recycling, thereby saving the cost and reducing the length / volume of the overall equipment; and without the need to frequently transport new sleepers and output old sleepers, the transportation cost is greatly saved, and the construction efficiency is increased.

[0019] 2, in the present application, the sleeper replacement vehicles are used to synchronously perform the sleeper replacement operation, and through the combination of the sleeper replacement vehicles, the operation mileage requirement of different lengths in the same time can be realized, the sleeper replacement vehicles work independently and do not affect each other, and each sleeper replacement vehicle completes the new sleeper laying and old sleeper recycling work in the region, a long distance sleeper replacement can be realized at one time, and the damage of a single sleeper replacement vehicle will not affect other sleeper replacement vehicles, thereby the influence of equipment failure on the construction efficiency of the machine set is minimized.

[0020] 3, in the present application, when the mobile sleeper replacement trolley on the sleeper replacement vehicle performs the sleeper replacement operation, through the cooperation of the pneumatic wrench, the scraper, the gripper and the hydraulic device, the old sleeper can be taken out without damaging the old sleeper, and the new sleeper can be installed, without the need for track lifting or track shifting action, the influence on the deformation or stress of the steel rail is small, the safety risk is small during the construction operation, the line shape is well maintained, the line in front of and behind the operation section can be used for the operation vehicle to run, and the time for the vehicle to be collected and released is short.

[0021] 4, in the present application, in order to cooperate with the double-layer conveying belt structure of the sleeper replacement vehicle, one end of the transfer conveying belt on the sleeper conveying vehicle can be lifted or lowered under the action of the lifting guide column, and the other end of the transfer conveying belt can slide horizontally in the sliding platform, and by adopting this structure, the sleeper conveying vehicle can transport the sleepers to the upper conveying belt and the lower conveying belt of the sleeper replacement vehicle.

[0022] 5、The sleeper transport trolley and the folding lifting conveyor belt in the application can be lifted / descended to the corresponding position when it is needed to replace the multi-section sleeper on the vehicle transporting new sleepers, and serve as a transport bridge between the upper conveyor belts or the lower conveyor belts, so that a complete sleeper transport line is formed between the upper conveyor belts or the lower conveyor belts, and the sleeper conveying vehicle can complete the transport of the new sleepers on the upper / lower conveyor belts of the multi-section sleeper replacement vehicle at one time, or the upper / lower conveyor belts of the multi-section sleeper replacement vehicle can complete the transport of the old sleepers to the sleeper conveying vehicle, further saving the additional transport cost caused by the frequent transport of new and old sleepers, and increasing the construction efficiency.

[0023] 6、After the sleeper transport vehicle and the sleeper conveying vehicle are connected, the running tracks of the two vehicles are connected, the hoisting transport vehicle moves on the running track and hoists the sleepers on the sleeper transport vehicle to the conveying conveyor belt, so that the sleeper conveying vehicle does not need to frequently transport the sleepers between the sleeper storage yard and the construction site, and further saves the transport cost of the new and old sleepers.

[0024] 7、The loading and unloading of the sleepers only needs to be performed at the sleeper transport vehicle and the sleeper conveying vehicle, and the vehicle group at the construction site does not need to be moved, so that the power loss, the delay of construction and the error caused by the replacement of the site are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings described herein are used to provide further understanding of the application, and form a part of the application. The schematic embodiments of the application and the description thereof are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0026] Figure 1 A combined sleeper replacement machine structure schematic diagram is provided for the embodiments of the application;

[0027] Figure 2 A sleeper conveying vehicle structure schematic diagram is provided for the embodiments of the application;

[0028] Figure 3 A sleeper replacement vehicle structure schematic diagram is provided for the embodiments of the application;

[0029] Figure 4 A power vehicle structure schematic diagram is provided for the embodiments of the application;

[0030] In the figure: 1 is a sleeper transfer car, 2 is a sleeper replacement car, 3 is a power car, 11 is a transfer conveyor belt, 12 is a special flat car, 14 is a hoisting transport car, 15 is a lifting guide column, 16 is a sliding platform, 21 is a replacement car frame, 13 and 23 are both lap hubs, 24 is an upper conveyor belt, 25 is a lower conveyor belt, 26 is a sleeper transfer trolley, 27 is a folding lifting conveyor belt, 28 is a moving sleeper replacement trolley, 41 is an operating room, 42 is a grabbing arm, 43 is a pneumatic wrench, 44 is a lifting support plate, 31 is a traction beam, 32 is a rest room, 33 is a power room, 34 is a running driver's room, 35 is a frame, and 22 and 36 are both bogies. DETAILED DESCRIPTION

[0031] In order to make the technical solutions and advantages in the embodiments of the present application clearer and more apparent, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0032] In the present embodiment, the direction extending along the steel rail is defined as the longitudinal direction, the direction perpendicular to the steel rail is defined as the transverse direction, and the direction perpendicular to the transverse direction and the longitudinal direction is defined as the vertical direction. The advancing direction during mechanical operation is defined as the front direction.

[0033] In the process of implementing the present application, the inventors found that the existing sleeper replacement equipment on the market, whether it is a large-scale sleeper replacement equipment or a small-scale excavator converted sleeper replacement machine, has the following defects: during construction, it is inevitable to perform track lifting or track shifting, which will damage the track bed and the steel rail; only a short distance of sleeper replacement can be achieved at a time, and new sleepers and old sleepers need to be frequently transported to meet the construction requirements, resulting in low construction efficiency; two sets of equipment need to be provided for new sleeper laying and old sleeper recovery, which increases the cost and the length of the whole sleeper replacement equipment; since the existing sleeper replacement equipment is mostly a complete working line, once a link fails, the construction has to be stopped, and the construction progress is delayed until the failed link is repaired.

[0034] In view of the above problems, the present embodiment provides a combined sleeper replacement machine, as shown in Figures 1-4 which comprises a sleeper transfer car 1, a plurality of sleeper replacement cars 2 connected in sequence, and a power car 3 providing traction.

[0035] The track tie conveying vehicle 1 comprises a special flat car 12, a sliding platform 16 is arranged at the front end of the special flat car 12, a lifting guide column 15 is arranged at the rear end of the special flat car 12, a transfer conveying belt 11 is arranged on the sliding platform 16 and the lifting guide column 15, one end of the transfer conveying belt 11 can slide horizontally on the sliding platform 16, the other end of the transfer conveying belt 11 can be vertically lifted through the lifting guide column 15, and a hoisting transport vehicle 14 is further arranged on the special flat car 12.

[0036] The track tie replacement vehicle 2 comprises a replacement vehicle frame 21, a bogie 22, a front-rear overlapping center plate 23, and a track tie conveying trolley 26, an upper conveying belt 24 and a lower conveying belt 25 are arranged above the replacement vehicle frame 21, a lifting mechanism is arranged at the front end above the replacement vehicle frame 21, a folding lifting conveying belt 27 is arranged at the rear end above the replacement vehicle frame 21, the track tie conveying trolley 26 can be vertically lifted in the lifting mechanism, the track tie conveying trolley 26 can move horizontally on the replacement vehicle frame 21, a mobile tie replacement trolley 28 which can move horizontally along the inside of the I-beam of the replacement vehicle frame 21 is arranged below the replacement vehicle frame 21, and a lifting flat belt conveyor 44 is arranged at the frame end of the mobile tie replacement trolley 28. The rear end of the transfer conveying belt 11 is connected with the upper conveying belt 24 of the track tie replacement vehicle 2, and after being lowered, the transfer conveying belt 11 can be connected with the lower conveying belt 25 of the track tie replacement vehicle. Before operation, new ties are placed horizontally and neatly on the transfer conveying belt 11, the conveying belt is started to convey the ties backward, and the ties can be pushed to the upper conveying belt or the lower conveying belt of the whole train through the lifting guide column 15.

[0037] Further, the upper conveying belt 24 and the lower conveying belt 25 are chain supporting plate structures on both sides, and the ties can be pushed forward or backward through the forward and reverse rotation of the chains.

[0038] Further, the combined track tie replacement machine set further comprises a track tie transport vehicle, a running track is arranged on the track tie transport vehicle, a running track is also arranged on the special flat car 12, the track tie transport vehicle is connected with the track tie conveying vehicle 1, and the running tracks of the two vehicles are connected, a running driving wheel is arranged below the hoisting transport vehicle 14, and the hoisting transport vehicle 14 moves horizontally on the running tracks of the track tie transport vehicle and the track tie conveying vehicle 1 through the running driving wheel. The hoisting transport vehicle 14 hoists and carries the track ties on the track tie transport vehicle and places the track ties on the transfer conveying belt 11. Alternatively, the track ties on the track tie transport vehicle can be self-arranged to a freight yard where the track ties are stacked, and the track ties are placed on the transfer conveying belt 11 through a crane of the freight yard.

[0039] Further, the mobile sleeper changing trolley 28 comprises an operating room 41, a grabbing arm 42, and a pneumatic wrench 43. The grabbing arm 42 has two output ends, on which a scraper and a grabber are respectively installed, the scraper is used to scrape off parts such as rubber pads on the sleepers, and the grabber is used to grab the sleepers. The grabbing arm 42 further comprises an arm support and a hydraulic device, and the sleepers are grabbed by hydraulic power. When the sleepers are stacked by the grabber, the old sleepers 45 are stacked in front, and the new sleepers 46 are placed in the rear, so as to facilitate the grabber to take the sleepers. When the rail changing operation is performed, the pneumatic wrench 43 loosens the sleeper fasteners, so as to remove the restraint on the sleepers, and facilitate the grabber to grab the sleepers.

[0040] Further, the power car 3 comprises a traction shaft 31, a rest room 32, a power room 33, an operation driver room 34, a car frame 35, and a bogie 36.

[0041] Further, the power car 3 is used to provide traction power of the unit, a gas source for braking, a power source of the whole machine, and a whole machine operation control system.

[0042] Further, the lap center plate 13 of the sleeper conveying trolley 1 is connected with the front lap center plate 23 of the sleeper changing trolley 2 to complete the lap of the two trolleys, and the sleeper conveying trolley 1 and the sleeper changing trolley 2 share one bogie 22; between the sleeper changing trolleys 2, the front lap center plate 23 of the rear trolley is connected with the rear lap center plate of the front trolley to complete the lap of the two trolleys, and each trolley shares the front bogie 22 with the front trolley; between the sleeper changing trolley 2 and the power car 3, the rear lap center plate 23 of the sleeper changing trolley 2 is connected with the traction shaft 31 of the power car 3, and the power car 3 is separately provided with two sets of bogies 36.

[0043] The embodiment also provides a working method of the combined sleeper changing unit.

[0044] S1, sleeper loading: the sleepers in the sleeper transporting special vehicle are hoisted to the transfer conveying belt 11 by the hoisting and transporting trolley 14;

[0045] S2, sleeper transporting: the right end of the transfer conveying belt 11 is lifted or lowered to be flush with the upper conveying belt 24 or the lower conveying belt 25 by operating the lifting guide column 15, the transfer conveying belt 11 and the upper conveying belt 24 or the lower conveying belt 25 are synchronously operated, the sleepers on the transfer conveying belt 11 are conveyed to the upper conveying belt 24 or the lower conveying belt 25, and the number of sleepers on the upper conveying belt 24 or the lower conveying belt 25 is increased until the number of sleepers meets the requirement of the operation;

[0046] S3, new sleeper replacement: the track sleeper replacement vehicle 2 moves to the section to be constructed under the traction of the power vehicle 3, the lower conveying belt 25 conveys the new track sleeper 46 to the track sleeper conveying trolley 26, the track sleeper conveying trolley 26 vertically descends through the lifting mechanism to the rear of the replacement vehicle frame 21 and then horizontally moves to the end of the structure of the moving sleeper replacement trolley 28, the track sleeper conveying trolley 26 conveys the new track sleeper 46 to the lifting flat conveying belt 44, the lifting flat conveying belt 44 vertically descends by a proper height, the moving sleeper replacement trolley 28 takes out the old track sleeper 45 from the working section and places it on the lifting flat conveying belt 44, the moving sleeper replacement trolley 28 continues to grab the new track sleeper 46 and completes the installation of the new track sleeper 46, and the moving sleeper replacement trolley 28 is driven to the next track sleeper replacement position;

[0047] S4, old sleeper storage: while the new track sleeper 46 is being installed, the lifting flat conveying belt 44 vertically rises and conveys the old track sleeper 45 to the track sleeper conveying trolley 26, the track sleeper conveying trolley 26 horizontally moves to the rear of the lifting mechanism and vertically rises to the upper conveying belt 24, the track sleeper conveying trolley 26 conveys the old track sleeper 45 to the upper conveying belt 24 and then vertically descends to the lower conveying belt 25; at the same time, the folding lifting conveying belt 27 vertically rises to the upper conveying belt 24 and catches the new track sleeper pushed out from the upper conveying belt 24, the folding lifting conveying belt 27 vertically descends to the lower conveying belt 25 and conveys the new track sleeper to the lower conveying belt 25;

[0048] S5, repeat the steps S3-S4, if the replacement of the track sleeper in the section is completed, execute the step S6; if the lower conveying belt 25 is full of old track sleepers, execute the step S7;

[0049] S6, send a command to the traction vehicle 3, the traction vehicle 3 advances by the distance of the group of track sleepers, and continue to execute the step S5 until the replacement of the track sleepers in the entire section is completed;

[0050] S7, the old track sleepers on the track sleeper replacement vehicle are transported in the reverse direction to the track sleeper conveying vehicle 1 for unified recycling, the track sleeper conveying vehicle 1 unloads the old sleepers through the hoisting and transporting vehicle 14, and then executes the steps S1, S2 and S5.

[0051] Further, the S3 step of moving the sleeper changing trolley 28 to remove the old sleeper 45 and install the new sleeper 46, specifically: the worker in the operating room 41 controls the completion of the sleeper changing operation, controls the pneumatic wrench 43 to loosen the sleeper fastener, controls the grab arm 42 to adjust to a certain angle, so that the scraper of the grab arm 42 contacts the ballast, and the scraper of the grab arm 42 is used to scrape and gather the ballast in the sleeper box to the rear until a deep pit is formed for removing the sleeper, the grab arm 42 is rotated to a certain angle to make the center line of the grab arm 42 opposite to the center line of the old sleeper 45, the vertical movement of the grab arm 42 is adjusted by the hydraulic device, the grab hand of the grab arm 42 clamps the old sleeper 45 to be replaced, the swing angle of the grab hand of the grab arm 42 is controlled to move the old sleeper 45 left and right and rotate, so that the old sleeper 45 is vertically not interfered with the steel rail, the old sleeper 45 is lifted and placed at the front end of the lifting flat belt conveyor 44; the grab hand of the grab arm 42 is adjusted to clamp the new sleeper 46 on the lifting flat belt conveyor 44, the grab hand is rotated to adjust to a certain angle, so that the new sleeper 46 does not vertically interfere with the steel rail, and the new sleeper 46 is placed in the deep pit scraped by the grab arm scraper, and then the new sleeper 46 is rotated to be normal.

[0052] Further, in the S2 step, when the new sleeper 46 is transported from the sleeper conveying vehicle 1 to the sleeper changing vehicle 2, the sleeper conveying trolley 26 moves to the upper conveying belt 24 or the lower conveying belt 25 through the lifting platform inside the lifting mechanism, and serves as a transition connection section between the upper conveying belt 24 or the lower conveying belt 25 and the transfer conveying belt 11, and the sleeper conveying trolley 26 stops at the lower conveying belt 25 after the new sleeper 46 is transported by the lower conveying belt 25 to wait for the next instruction.

[0053] Further, in the S2 step, when the new sleeper 46 is transported from the sleeper conveying vehicle 1 to the sleeper changing vehicle 2, the sleeper conveying trolley 26 moves to the upper conveying belt 24 or the lower conveying belt 25 through the lifting platform inside the lifting mechanism, and serves as a transition connection section between the upper conveying belt 24 or the lower conveying belt 25 and the transfer conveying belt 11, and the sleeper conveying trolley 26 stops at the lower conveying belt 25 after the new sleeper 46 is transported by the lower conveying belt 25 to wait for the next instruction.

[0054] Further, in the S1 step, the sleeper conveying vehicle 1 can also be opened to the freight yard where the sleepers are stacked, and the sleepers in the freight yard are lifted to the transfer conveying belt 11 by the lifting and transporting vehicle 14.

[0055] Further, the folding lifting conveying belt 27 needs to be folded back when the vehicle is running, so as to avoid interference caused by the rotation of the conveying belt when turning.

[0056] In the specific implementation, when receiving the sleeper replacement operation plan, the sleeper conveying vehicle 1 is opened to the sleeper stacking yard, the sleepers in the yard are hoisted to the transfer conveying belt 11 by the hoisting vehicle 14, or a sleeper transport special vehicle is connected behind the machine set, and the sleepers in the sleeper transport special vehicle are hoisted to the transfer conveying belt 11 by the hoisting vehicle 14.

[0057] In the application, the running tracks of the two vehicles are connected after the sleeper transport vehicle is connected with the sleeper conveying vehicle, the hoisting vehicle moves on the running track and hoists the sleepers on the sleeper transport vehicle to the transfer conveying belt, so that the sleeper conveying vehicle does not need to frequently transport sleepers between the sleeper stacking yard and the construction site, and the transportation cost of new and old sleepers is further saved.

[0058] The lifting guide column 15 is lifted, one end of the transfer conveying belt 11 is lifted to the same height as the upper conveying belt 24 under the action of the lifting guide column 15, the other end of the transfer conveying belt 11 horizontally slides in the sliding platform 16, the transfer conveying belt 11 and the upper conveying belt 24 rotate synchronously in the clockwise direction, the new sleepers 46 are conveyed to the upper conveying belt 24, until the number of the new sleepers 46 loaded on the upper conveying belt 24 meets the operation requirement, the lifting guide column 15 is lowered, one end of the transfer conveying belt 11 is lowered to the same height as the lower conveying belt 25 under the action of the lifting guide column 15, the other end of the transfer conveying belt 11 horizontally slides in the sliding platform 16, the transfer conveying belt 11 and the lower conveying belt 25 rotate synchronously in the clockwise direction, the new sleepers 46 are conveyed to the lower conveying belt 25, until the number of the new sleepers 46 loaded on the lower conveying belt 25 meets the operation requirement.

[0059] In order to match the double-layer conveying belt structure of the sleeper replacement vehicle, one end of the transfer conveying belt on the sleeper conveying vehicle can be lifted or lowered under the action of the lifting guide column, and the other end of the transfer conveying belt horizontally slides in the sliding platform. With this structure, the sleeper conveying vehicle can transport sleepers to the upper conveying belt and the lower conveying belt of the sleeper replacement vehicle, respectively.

[0060] Specifically, the sleeper conveying trolley 26 should have a space to load new and old sleepers during operation, so that there are no sleepers during the transfer, and after loading is completed, a special pressing device is used to press and lock the sleepers on the conveying belt. The whole process is program-controlled and does not need or only needs a small amount of manual intervention.

[0061] Specifically, when transporting the new sleeper 46 from the sleeper conveying vehicle 1 to the sleeper replacement vehicle 2, the sleeper conveying trolley 26 moves to the upper conveying belt 24 or the lower conveying belt 25 through the lifting platform inside the lifting mechanism, serving as the transition connection section between the upper conveying belt 24 or the lower conveying belt 25 and the transfer conveying belt 11, and the sleeper conveying trolley 26 stays at the lower conveying belt 25 after the lower conveying belt 25 completes the transportation of the new sleeper 46, waiting for the next instruction;

[0062] Before operation, the sleeper transport vehicle 1, several sleeper replacement vehicles 2 and the power vehicle 3 are coupled. The sleeper replacement vehicle 2 moves to the section to be constructed under the traction of the power vehicle 3, the lower conveyor belt 25 rotates counterclockwise to move the new sleeper 46 to the sleeper transport trolley 26 which is stopped, the lifting platform inside the lifting mechanism lowers the sleeper transport trolley 26 to the plane of the replacement vehicle frame 21, the driving wheels under the sleeper transport trolley 26 are operated to move the sleeper transport trolley 26 longitudinally to the end of the frame of the mobile sleeper replacement trolley 28, and the sleeper transport trolley 26 is connected with the raised lifting flat conveyor belt 44 to push the new sleeper 46 to the rear end of the lifting flat conveyor belt 44. The lifting flat conveyor belt 44 vertically lowers by a proper height, the mobile sleeper replacement trolley 28 starts the sleeper replacement operation, takes out the old sleeper 45 from the operation section and places it on the front end of the lifting flat conveyor belt 44, the mobile sleeper replacement trolley 28 grabs the new sleeper 46 and completes the installation of the new sleeper 46, while the mobile sleeper replacement trolley 28 installs the new sleeper 46, the lifting flat conveyor belt 44 with the old sleeper 45 vertically moves upward and is connected with the sleeper transport trolley 26 which is stopped at the end of the frame of the mobile sleeper replacement trolley 28 to stack the old sleeper 45 on the sleeper transport trolley 26, the driving wheels under the sleeper transport trolley 26 are operated to move the sleeper transport trolley 26 to the lifting platform inside the lifting mechanism, the sleeper transport trolley 26 is lifted to the same height as the upper conveyor belt 24 by the lifting platform inside the lifting mechanism, the conveyor belt on the sleeper transport trolley 26 and the upper conveyor belt 24 are synchronously rotated clockwise to convey the old sleeper 45 to the upper conveyor belt 24; at the same time, the folding lifting conveyor belt 27 is unfolded and lifted to the same height as the upper conveyor belt 24, the new sleeper pushed out of the upper conveyor belt 24 is caught by the folding lifting conveyor belt 27, the folding lifting conveyor belt 27 is lowered to the same height as the lower conveyor belt 25, and the folding lifting conveyor belt 27 and the lower conveyor belt 25 are counterclockwise rotated to push the new sleeper on the folding lifting conveyor belt 27 into the lower conveyor belt 25 to supplement the number of new sleepers on the lower conveyor belt 25; the mobile sleeper replacement trolley 28 moves forward to the next sleeper replacement position, the sleeper transport trolley 26 is moved to the lower conveyor belt 25 to prepare for the next cycle. Thus, the replacement cycle of the new and old sleepers is completed, the above steps are repeated until the replacement operation of the section to be constructed is completed or the lower conveyor belt 25 is stacked with the old sleepers, the operation is stopped, the old sleepers are recycled and the new sleepers are supplemented on the sleeper replacement vehicle 2.

[0063] The sleeper replacement vehicle in the application has an upper conveying belt and a lower conveying belt, which can not only carry more new sleepers for sleeper replacement operation, but also cooperate with the lifting mechanism, sleeper conveying trolley and lifting flat belt conveyor to realize the circulation of new and old sleepers in the sleeper replacement vehicle, without the need to separately set two sets of equipment for new sleeper laying and old sleeper recycling, thereby saving the cost and reducing the length / volume of the overall equipment; and without the need to frequently transport new sleepers and output old sleepers, the transportation cost is greatly saved, and the construction efficiency is increased.

[0064] Specifically, when the mobile sleeper replacement trolley 28 is in operation, the staff in the operation room 41 manipulates to complete the sleeper replacement operation: the pneumatic wrench 43 is manipulated to loosen the sleeper fastener, the grab arm 42 is manipulated to adjust a certain angle, so that the scraper plate contacts the ballast, and the ballast in the sleeper box is scraped and gathered to the rear by the scraper plate of the grab arm 42 until a deep pit for taking out the sleeper is formed; the grab arm 42 is rotated by a certain angle to make the center line of the grab arm 42 opposite to the center line of the old sleeper 45, the vertical movement of the grab arm 42 is adjusted by the hydraulic device, the grab hand of the grab arm 42 clamps the old sleeper 45 to be replaced, the swing angle of the grab hand of the grab arm 42 is manipulated to move and rotate the old sleeper 45 left and right, so that the old sleeper 45 does not interfere with the vertical direction of the rail, the old sleeper 45 is lifted and placed at the front end of the lifting flat belt conveyor 44, and when the grab hand piles up the sleepers, the old sleeper 45 is piled up in front and the new sleeper 46 is placed behind, so as to facilitate the grab hand to take the sleeper; the grab hand of the grab arm 42 is adjusted to clamp the new sleeper 46 on the lifting flat belt conveyor 44, the grab hand is rotated to adjust a certain angle, so that the new sleeper 46 does not interfere with the vertical direction of the rail, and the new sleeper 46 is placed in the deep pit scraped by the grab arm scraper plate, then the new sleeper 46 is rotated to the right, and the pneumatic wrench 43 is manually operated to install the fastener for the new sleeper 46. After completing the replacement of a group of new and old sleepers, the mobile sleeper replacement trolley 28 is moved forward to the next sleeper replacement position, and the above steps are repeated.

[0065] When the mobile sleeper replacement trolley on the sleeper replacement vehicle in the application is in operation, the old sleeper can be taken out and the new sleeper can be installed without damaging the old sleeper through the cooperation of the pneumatic wrench, scraper plate, grab hand and hydraulic device, without the need for track lifting or track shifting, the deformation or stress of the rail is small, the safety risk during construction operation is small, the line shape is well maintained, the front and rear lines of the operation section can be used for operation of the vehicle, and the time for collecting and releasing the vehicle is short.

[0066] Specifically, the whole machine operation control system is programmed to work. At least the functions of loading new sleepers and unloading old sleepers by the sleeper conveying vehicle, the internal sleeper circulation and selection function of the single machine, and the clockwise or counterclockwise rotation and replacement function of the new and old sleepers can be realized.

[0067] Specifically, each several sleepers is a group, after replacing a group of sleepers, the staff sends a command to the tractor 3, the tractor 3 advances the distance of the group of sleepers, so that the sleeper replacement vehicle 2 carries out the replacement of the next group of old sleepers. As a preferred solution, two groups of sleepers are replaced in the design state to cover the length of the sleeper replacement vehicle 2. After completing the replacement of the sleepers in the whole vehicle range, the power vehicle 3 is advanced to the next vehicle length range for operation. A work site can carry out operation in multiple vehicle length ranges. According to the operation amount required by the owner, the number of sleeper replacement vehicles 2 to be used can be predicted in advance to meet the demand for operation efficiency on the same day.

[0068] When each sleeper replacement vehicle 2 completes the replacement of 5 sleepers, the main machine is informed one by one through the whole machine operation control system, and after collecting all the completed operations, the whole machine is advanced by 5 sleepers to cross the completed operation area, and the moving sleeper changing car 28 of the sleeper replacement vehicle 2 is retreated to the starting point of the track to continue the replacement of the 5 sleepers that have not been completed. The whole machine can complete the operation range of one vehicle length by one step. The length of one-time operation can be increased or decreased according to the number of sleeper replacement vehicles 2 to meet the needs. The whole machine can complete multiple vehicle length operation distances within one operation window.

[0069] In the present application, multiple sleeper replacement vehicles are used to carry out the replacement of sleepers synchronously, and through the combination of multiple sleeper replacement vehicles, the operation distance of different lengths within the same time can be realized, the sleeper replacement vehicles work independently and do not affect each other, and each sleeper replacement vehicle completes the placement of new sleepers and the recovery of old sleepers in the region, and a long distance of sleeper replacement can be realized at one time, and the damage of a single sleeper replacement vehicle will not affect other sleeper replacement vehicles, thereby minimizing the influence of equipment failure on the construction efficiency of the unit.

[0070] Specifically, the power vehicle 3 includes a traction shaft 31, a rest room 32, a power room 33, an operation driver's room 34, a vehicle frame 35, and a bogie 36. Before operation, the power vehicle 3 is connected with the sleeper replacement vehicle 2 and the sleeper conveying vehicle 1 through the traction shaft 31 to form a vehicle unit. During operation, the vehicle unit is pulled to the operation area by the power vehicle 3. The sleeper replacement vehicle 2 carries out operation on the old sleepers. After replacing a group of sleepers, the moving sleeper changing car 28 sends a command to the power vehicle 3. The power vehicle 3 pushes the whole vehicle to advance by the distance of a group of sleepers. After replacing the whole vehicle range, the power vehicle 3 is pushed to advance by the distance of the whole vehicle.

[0071] Specifically, when the multiple sleeper replacement vehicles 2 are connected in the train, the new sleepers are transported to all the sleeper replacement vehicles 2, and only the front sleeper conveying trolleys 26 and the rear folding lifting conveyors 27 of all the sleeper replacement vehicles 2 need to be adjusted to be aligned with the upper conveyors 24 or the lower conveyors 25, respectively, to form a complete sleeper conveyor from the connecting sleeper conveying vehicle 1 to the last sleeper replacement vehicle 2. After all the upper conveyors 24 are aligned, the conveyors are started to push the new sleepers backward one by one. After the last sleeper replacement vehicle 2 is filled, the upper conveyor 24 of the last sleeper replacement vehicle 2 is stopped. The conveyors are stopped after each sleeper replacement vehicle 2 is filled, until the first sleeper replacement vehicle 2 is filled. Similarly, when the old sleepers need to be unloaded and recycled from the multiple sleeper replacement vehicles 2, the above method is reversed.

[0072] The sleeper conveying trolleys and the folding lifting conveyors in the present application can be raised / lowered to the corresponding positions when the new sleepers need to be transported to the multiple sleeper replacement vehicles, and serve as the transportation bridge between the multiple upper conveyors or the multiple lower conveyors, so that a complete sleeper transportation line is formed between the multiple upper conveyors or the multiple lower conveyors. The sleeper conveying vehicle can complete the transportation of the new sleepers on the upper and lower conveyors of the multiple sleeper replacement vehicles at one time, or complete the transportation of the old sleepers from the sleeper conveying vehicle to the upper and lower conveyors of the multiple sleeper replacement vehicles at one time. The additional transportation cost caused by the frequent transportation of the new and old sleepers is further saved, and the construction efficiency is increased. Meanwhile, the loading and unloading of the sleepers only need to be performed at the sleeper transportation vehicle and the sleeper conveying vehicle, and the train does not need to be moved, so that the power loss, the delay of the construction, and the error caused by the change of the location are avoided.

[0073] Specifically, the folding lifting conveyors 27 need to be folded back when the vehicle is running, so as to avoid the interference caused by the rotation of the conveyors when the vehicle turns.

[0074] Specifically, different sleepers can be selected in a cycle according to the needs, so as to meet the replacement operation of various sleepers.

[0075] It should be noted that the components in the present embodiment are only examples, and any components that can achieve the functions of the components are acceptable, such as: the driving types of the conveyors, the trolleys, and the lifting mechanisms can be motors, hydraulic motors, or pneumatic motors; the execution devices of the lifting mechanisms can be chain drives, oil cylinders, or air cylinders; the types of the guide rails can be rails, guide grooves, dovetails, guide columns, etc.; the connection between the vehicles can be achieved by using a center plate or a center pin; the power source of the sleeper replacement vehicle can be provided by the vehicle itself or an external power vehicle; the sleeper replacement vehicle can share the bogies with the front vehicle, or can have two bogies and be connected to the front vehicle by using a coupler or a connecting rod, etc.

[0076] The combined sleeper replacement machine set and operation method provided by the embodiment can realize self-traction, can meet the requirement of operation efficiency by combining several sleeper replacement vehicles, each sleeper replacement vehicle is an operation point, multiple points are independently operated, operation is flexible, and mutual influence is avoided, and the combined machine has high efficiency. The sleeper replacement vehicle can deliver and store new and old sleepers, realizes one-time completion of all sleeper replacement operations, and has high practicability.

[0077] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0078] In addition, the terms "first", "second" are only for description purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0079] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or can be integrated; can be mechanical connection, or can be electrical connection or can communicate with each other; can be directly connected, or indirectly connected through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0080] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic creative concept. Therefore, the appended claims are intended to include the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0081] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A combined sleeper replacement unit, characterized in that: It includes a sleeper transfer vehicle (1), a plurality of sleeper replacement vehicles (2), and a power vehicle (3) for providing traction force, which are connected in sequence. The sleeper transfer vehicle (1) comprises a dedicated flat car (12), a transfer conveyor belt (11) is provided on the dedicated flat car (12), one end of the transfer conveyor belt (11) can slide horizontally on the dedicated flat car (12), and the other end of the transfer conveyor belt (11) can be lifted vertically, and a hoisting transport vehicle (14) is also provided on the dedicated flat car (12); The sleeper replacement vehicle (2) comprises a replacement vehicle frame (21) and a sleeper transport trolley (26); an upper conveyor belt (24) and a lower conveyor belt (25) are provided above the replacement vehicle frame (21); the sleeper transport trolley (26) moves horizontally and / or lifts vertically on the replacement vehicle frame (21); a horizontally movable mobile sleeper replacement trolley (28) is provided below the replacement vehicle frame (21); a lifting flat conveyor belt (44) is provided at the end of the structure of the mobile sleeper replacement trolley (28); The front end of the special flat car (12) is provided with a sliding platform (16), the rear end of the special flat car (12) is provided with a lifting guide column (15), and a transfer conveyor belt (11) is provided on the sliding platform (16) and the lifting guide column (15); one end of the transfer conveyor belt (11) can slide horizontally on the sliding platform (16), and the other end of the transfer conveyor belt (11) can be vertically lifted and lowered by the lifting guide column (15); It also includes a sleeper transport vehicle, the sleeper transport vehicle is provided with a running track, the special flat car (12) is also provided with a running track, the sleeper transport vehicle is connected to the sleeper transfer vehicle (1) and the running tracks of the two vehicles are connected; the hoisting transport vehicle (14) is provided with a running drive wheel, and the hoisting transport vehicle (14) moves horizontally on the running tracks of the sleeper transport vehicle and the sleeper transfer vehicle (1) through the running drive wheel.

2. The combined sleeper replacement unit according to claim 1, characterized in that: The mobile pillow-changing trolley (28) comprises an operating room (41), a grab arm (42), and a pneumatic wrench (43). The grab arm (42) has two output ends, on which a scraper and a grab hand are respectively mounted. The grab arm (42) also comprises an arm frame and a hydraulic device.

3. The combined sleeper replacement unit according to claim 2, characterized in that: The power car includes a traction shaft (31), a rest room (32), a power room (33), a driving cab (34), a vehicle frame (35) and a bogie (36).

4. The combined sleeper replacement unit according to claim 1, characterized in that: A lifting mechanism is provided at the front end above the replacement vehicle frame (21), and a folding lifting conveyor belt (27) is provided at the rear end above the replacement vehicle frame (21). The sleeper transport trolley (26) can be vertically lifted and lowered in the lifting mechanism, and the sleeper transport trolley (26) can be horizontally moved on the replacement vehicle frame (21).

5. An operating method of a combined sleeper replacement unit, wherein the combined sleeper replacement unit is the combined sleeper replacement unit according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, sleeper installation: hoisting the sleepers onto the transfer conveyor belt (11) via a hoisting transport vehicle (14); S2, sleeper transport: operate the lifting guide column (15) to lift or lower one end of the transfer conveyor belt (11) to be flush with the upper conveyor belt (24) or the lower conveyor belt (25), and synchronously operate the transfer conveyor belt (11) and the upper conveyor belt (24) or the lower conveyor belt (25) to transport the sleepers on the transfer conveyor belt (11) to the upper conveyor belt (24) or the lower conveyor belt (25) until the number of sleepers carried on the upper conveyor belt (24) or the lower conveyor belt (25) meets the operation requirements; S3, replacement of new sleepers: the sleeper replacement vehicle (2) is moved to the road section to be constructed under the traction of the power vehicle (3), the lower conveyor belt (25) transfers the new sleeper (46) to the sleeper transport trolley (26), the sleeper transport trolley (26) is vertically lowered to the replacement vehicle frame (21) by the lifting mechanism and then horizontally moved to the frame end of the mobile sleeper replacement trolley (28), the sleeper transport trolley (26) transfers the new sleeper (46) to the lifting flat conveyor belt (44), the lifting flat conveyor belt (44) is vertically lowered to an appropriate height, the mobile sleeper replacement trolley (28) takes the old sleeper (45) out of the working section and places it on the lifting flat conveyor belt (44), the mobile sleeper replacement trolley (28) continues to grab the new sleeper (46) and completes the installation of the new sleeper (46), and drives the mobile sleeper replacement trolley (28) to the next sleeper replacement position; S4, storage of old sleepers: while the new sleepers (46) are being installed, the lifting flat conveyor belt (44) rises vertically and transfers the old sleepers (45) to the sleeper transfer trolley (26), the sleeper transfer trolley (26) moves horizontally to the lifting mechanism and then rises vertically to the upper conveyor belt (24), the sleeper transfer trolley (26) transfers the old sleepers (45) to the upper conveyor belt (24) and then descends vertically to the lower conveyor belt (25); at the same time, the folding lifting conveyor belt (27) rises vertically to the upper conveyor belt (24) and catches the new sleepers pushed out from the upper conveyor belt (24), the folding lifting conveyor belt (27) descends vertically to the lower conveyor belt (25) and transfers the new sleepers to the lower conveyor belt (25); S5, repeating steps S3-S4, if the sleeper replacement operation is completed in this construction section, executing step S6; if the lower conveyor belt (25) is full of old sleepers, executing S7; S6, issuing a command to the power car (3), the power car (3) moves forward the distance of the sleeper group, and continues to execute step S5 until the sleeper replacement operation of the entire construction section is completed; S7, transporting the old sleepers on the sleeper replacement vehicle in reverse to the sleeper transfer vehicle (1) for unified recycling. After the sleeper transfer vehicle (1) unloads the old sleepers via the hoisting transport vehicle (14), steps S1, S2 and S5 are then executed.

6. The operating method of the combined sleeper replacement unit according to claim 5, characterized in that: In the step S3, the sleeper replacement trolley (28) is moved to remove the old sleeper (45) and install the new sleeper (46), specifically: the staff is located in the operating room (41) and operates to complete the sleeper replacement operation, operates the pneumatic wrench (43) to loosen the sleeper fastener, operates the grab arm (42), adjusts a certain angle so that its scraper contacts the ballast, and uses the scraper of the grab arm (42) to scrape and gather the ballast in the sleeper box backward until a deep pit for removing the sleeper is formed, operates the grab arm (42) to rotate a certain angle so that the center line of the grab arm (42) is aligned with the center line of the old sleeper (45), and adjusts the vertical movement of the grab arm (42) by the hydraulic device so that the grab arm (42) Clamp the old sleeper (45) to be replaced, manipulate the swing angle of the grab arm (42) grabber to move the old sleeper (45) left and right and rotate it so that the old sleeper (45) does not interfere with the rail vertically, lift the old sleeper (45) and place it on the front end of the lifting flat conveyor belt (44); adjust the grab arm (42) grabber so that the grabber grabs the new sleeper (46) on the lifting flat conveyor belt (44), rotate the grabber to a certain angle so that the new sleeper (46) does not interfere with the rail vertically, and place the new sleeper (46) into the deep pit scraped out by the grab arm scraper, then straighten the new sleeper (46), and manually operate the pneumatic wrench (43) to install fasteners for the new sleeper (46).

7. The operating method of the combined sleeper replacement unit according to claim 5, characterized in that: In the step S2, when the new sleeper (46) is transported from the sleeper transfer vehicle (1) to the sleeper replacement vehicle (2), the sleeper transport trolley (26) is moved to between the upper conveyor belt (24) or the lower conveyor belt (25) and the transfer conveyor belt (11) through the lifting platform inside the lifting mechanism, and serves as a transition connection section between the upper conveyor belt (24) or the lower conveyor belt (25) and the transfer conveyor belt (11). After the lower conveyor belt (25) completes the transportation of the new sleeper (46), the sleeper transport trolley (26) stays at the lower conveyor belt (25) and waits for the next instruction.

8. The operating method of the combined sleeper replacement unit according to claim 5, characterized in that: In the step S2, when it is necessary to transport new sleepers on the multi-section sleeper replacement vehicle (2), it is only necessary to adjust the front end sleeper transport trolley (26) and the rear end folding lifting conveyor belt (27) of all sleeper replacement vehicles (2) to be aligned with the upper conveyor belt (24) or the lower conveyor belt (25) respectively, so as to form a complete sleeper conveyor belt connecting the sleeper transfer vehicle (1) to the last section sleeper replacement vehicle (2). After all are aligned with the upper conveyor belt (24) or the lower conveyor belt (25), the conveyor belt is opened to push the new sleepers backward one by one. After the last section sleeper replacement vehicle (2) is filled, the upper conveyor belt (24) of the last section sleeper replacement vehicle (2) is stopped. After each section is filled, the conveyor belt is stopped until the first section sleeper replacement vehicle (2) is filled.

9. The operating method of the combined sleeper replacement unit according to claim 5, characterized in that: In the step S1, the sleeper transfer vehicle (1) is driven to the freight yard where the sleepers are stacked, and the sleepers in the freight yard are hoisted onto the transfer conveyor belt (11) by the hoisting transport vehicle (14).

10. The operating method of the combined sleeper replacement unit according to claim 5, characterized in that: When the vehicle is running, the folding lifting conveyor belt (27) is folded and retracted.

Images