Patent Publication Number: US-2022219200-A1

Title: Sorting system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present disclosure a 35 U.S.C. 371 national phase application of PCT International Application No. PCT/CN2020/079122 filed on Mar. 13, 2020, which claims the priority of a Chinese patent application with an application number of 201910352473.0 and a name of “sorting system” filed on Apr. 29, 2019, the entire contents of both are incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the technical field of logistics devices, and in particular to a sorting system. 
     BACKGROUND 
     In the logistics industry, when sorting packages, cross-belt sorters are usually used. Currently, the most commonly used sorters are circular cross-belt sorters and vertical cross-belt sorters. The cross-belt sorter is a closed conveying and sorting system composed of a group of trolleys, generally in a ring shape. Each trolley moves along a rail, and the surface belt of the trolley can rotate in the horizontal and vertical direction with respect to the movement of the trolley, so as to put the package into the respective grid. However, the circular cross-belt sorter and the vertical cross-belt sorter as currently used have a long turning radius and a long trolley pitch (where a trolley pitch refers to the distance between the central axis of two adjacent trolleys), which is usually 600 mm. In this case, a small package also needs to occupy a trolley, resulting in a waste of transportation resources. In addition, when packages are transported on a trolley, they may be skewed thus causing throwing troubles. If the trolley pitch is large, a trolley only carries one package, which renders it difficult to achieve automatic package correction, and the correction will be not accurate. 
     SUMMARY 
     According to one aspect of the present disclosure, there is provided a sorting system for conveying a package. The sorting system includes a conveying mechanism and a control system. The conveying mechanism comprises a rack, two rollers, a chain and a plurality of trolleys. Two rollers are arranged on the rack at intervals along a first horizontal direction. The chain is wound around the two rollers. The plurality of trolleys are respectively connected to the chain and arranged in sequence along the first horizontal direction. Each of the trolleys includes a trolley body and a sorting and conveying mechanism provided on the trolley body. The bottom part of the trolley body is connected to the chain. The sorting and conveying mechanism is configured to carry and convey the package in a second horizontal direction perpendicular to the first horizontal direction. The control system includes a controller connected to the conveying mechanism. The controller is configured to control the conveying mechanism to transport the package in the first horizontal direction, and is configured to independently control the sorting and conveying mechanism of each trolley to convey the package along the second horizontal direction. 
     According to an embodiment of the present disclosure, the sorting and conveying mechanism includes a driving roller, a tension roller, and a conveying belt. The driving roller is provided on the trolley body. The tension roller is arranged on the trolley body and is spaced apart from the driving roller. The conveying belt is wound around the driving roller and the tension roller. The controller is configured to control the driving roller, such that the forward or reverse movement of the conveying belt in the second horizontal direction is controlled to adjust the position of the package. 
     According to an embodiment of the present disclosure, each trolley further includes wheels arranged on respective sides of the trolley body, and the rack includes an upper rail arranged on the inner side of the upper part of the rack. The wheels are slidingly fitted with the upper rail. 
     According to an embodiment of the present disclosure, each trolley further includes wheels arranged on respective sides of the trolley body, the rack includes a lower rail, and the lower rail is arranged on the inner side of the lower part of the rack. The wheels are slidingly fitted with the lower rail. 
     According to an embodiment of the present disclosure, each wheel includes a wheel body and a wheel shaft. The wheel shaft is penetrated through the wheel body, and the gap between the end of the wheel shaft close to the rack and the inner side of the rack is 1 to 5 mm. 
     According to an embodiment of the present disclosure, the end surface of the wheel shaft at an end close to the rack is a curved surface. 
     According to an embodiment of the present disclosure, the rack further includes an upper cover and a wear-resistant strip. One side of the upper cover is arranged on the rack, and the other side of the upper cover extends above the upper rail to cover the wheels on the upper rail. The wear-resistant strip is made of wear-resistant material. The wear-resistant strip is arranged inside the rack along the first horizontal direction and is located between the upper cover and the upper rail. The wear-resistant strip is configured to prevent the wheel shaft and the inner side of the rack from wearing. 
     According to an embodiment of the present disclosure, the wear-resistant material is ultra-high molecular weight polyethylene. 
     According to an embodiment of the present disclosure, the rack further includes shock-absorbing feet arranged on respective sides of the rack to support the rack. 
     According to an embodiment of the present disclosure, the conveying mechanism further includes a connecting piece, and the chain is connected to the bottom part of each trolley through the connecting piece. 
     According to an embodiment of the present disclosure, one of the two rollers is an active roller, and the other of the two rollers is a passive roller. The active roller includes a driving sprocket, a bearing seat, a driving shaft, and a driving motor. The driving sprocket meshes with the chain. The bearing seat is arranged on the rack. The driving shaft is penetrated through the center part of the driving sprocket, and has both ends penetrated into the bearing seat. The driving motor is in a transmission connection with the driving shaft and is configured to drive the driving shaft to rotate and drive the driving sprocket to rotate. 
     According to an embodiment of the present disclosure, one of the two rollers is an active roller, and the other of the two rollers is a passive roller. The passive roller includes a tension sprocket, a tension shaft, and a tension assembly. The tension sprocket meshes with the chain. The tension shaft passes through the center part of the tension sprocket. The tension assembly is connected to an end of the tension shaft, and is configured to adjust the tension degree of the chain by adjusting the displacement of the tension shaft in the first horizontal direction. 
     According to an embodiment of the present disclosure, the tension assembly includes a sliding rail, a tension spring, a tension rod, and an elasticity adjustment component. The sliding rail is arranged on the rack along the first horizontal direction, and the sliding rail is provided with a sliding groove. The tension spring is connected to one end of the sliding rail along the first horizontal direction. The tension rod passes through the sliding rail and the tension spring in sequence along the first horizontal direction. The elasticity adjustment component is arranged at an end of the tension spring away from the sliding rail, connects the tension rod and the tension spring, and compresses or stretches the tension spring. An end of the tension rod is connected with the tension shaft, and the end of the tension shaft is slidably arranged in the sliding groove. 
     According to an embodiment of the present disclosure, the conveying mechanism further includes a first shock-absorbing rail, which is arranged inside the rack and extends along the end of the lower rail. The upper surface of the first shock-absorbing rail is gradually reduced to a wedge-shaped surface from the upper surface of the lower rail, so that the wheels of each trolley are transitioned to the lower rail for sliding. 
     According to an embodiment of the present disclosure, the conveying mechanism further includes a second shock-absorbing rail, which is arranged inside the rack and extends along the end of the upper rail. The upper surface of the second shock-absorbing rail is gradually reduced to a wedge-shaped surface from the upper surface of the upper rail, so that the wheels of each trolley are transitioned to the upper rail for sliding. 
     According to an embodiment of the present disclosure, the control system further includes a data acquisition module. The data acquisition module includes a code scanner, which is electrically connected to the controller. The data acquisition module is configured to collect the sorting information of the package and transmit it to the controller. The controller is configured to control the rollers and the sorting and conveying mechanism of the trolley according to the sorting information, so that the package is thrown to a designated throwing grid. 
     According to an embodiment of the present disclosure, the data acquisition module further includes a position sensor, electrically connected to the controller, and configured to detect the first position information of the package at the initial position. The controller is configured to respectively control the sorting and conveying mechanism of each trolley according to the first position information to adjust the position of the package. 
     According to an embodiment of the present disclosure, the data acquisition module further includes a detection sensor, electrically connected to the controller, and configured to detect the second position information of the package in the adjustment position. The controller is configured to control the sorting and conveying mechanism of each trolley according to the second position information of the package, so as to assist in adjusting the position of the package. 
     According to an embodiment of the present disclosure, one of the two rollers is an active roller, and the other of the two rollers is a passive roller. The passive roller includes a tension shaft and a tension assembly. The tension assembly is connected to the end of the tension shaft and configured to adjust the tension degree of the chain by adjusting the displacement of the tension shaft in the first horizontal direction. The data acquisition module further includes a tension sensor, connected to the controller, arranged on the rack, being opposite to the tension assembly in the first horizontal direction, and configured to detect the distance between tension sensor and the tension assembly. 
     According to an embodiment of the present disclosure, the tension assembly includes a tension rod, arranged along the first horizontal direction, and having two ends, i.e., a first end and a second end respectively. The first end is connected to the end of the tension shaft, so that the end of the tension shaft slides along the first horizontal direction. The data acquisition module further includes a sensing piece arranged at the second end of the tension rod. The tension sensor is opposite to the sensing piece in the first horizontal direction and is configured to detect the distance between the tension sensor and the sensing sheet. 
     According to an embodiment of the present disclosure, the sorting system further includes a package supply mechanism. The package supply mechanism includes a package supply rack and a package supply belt. The package supply belt is arranged on the package supply rack and is configured to convey the package to the trolleys. 
     In the present disclosure, through the following description of preferred embodiments with reference to the accompanying drawings, the above and other objectives, features and advantages of the present disclosure will be more apparent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       By considering the following detailed description of the preferred embodiments of the present disclosure in conjunction with the accompanying drawings, various objectives, features, and advantages of the present disclosure will become more apparent. The drawings are merely exemplary illustrations of the present disclosure, and are not necessarily drawn to scale. In the drawings, the same reference numerals always refer to the same or similar parts. In the drawings: 
         FIG. 1  is a three-dimensional schematic diagram of a sorting system in an embodiment of the present disclosure; 
         FIG. 2  is a schematic diagram of a side structure of a rack and a trolley in an embodiment of the present disclosure; 
         FIG. 3  is a partial structural diagram of the rack and the trolley in  FIG. 2 ; 
         FIG. 4  is a three-dimensional structural schematic diagram of a trolley in an embodiment of the present disclosure; 
         FIG. 5  is an exploded structural schematic diagram of the trolley in  FIG. 4 ; 
         FIG. 6  is a schematic diagram showing the bottom structure of the trolley in  FIG. 4 ; 
         FIG. 7  is a schematic structural diagram of an active roller of a sorting system in an embodiment of the present disclosure; 
         FIG. 8  is a schematic structural view of the other side of the active roller in  FIG. 7 ; 
         FIG. 9  is a schematic structural diagram of a passive roller of a sorting system in an embodiment of the present disclosure; 
         FIG. 10  is a schematic structural diagram of the passive roller in  FIG. 9  as seen from another angle; 
         FIG. 11  is an exploded structural schematic diagram of the passive roller in  FIG. 9 ; 
         FIG. 12  is a cross-sectional view of the tension assembly of the passive roller in  FIG. 9 ; 
         FIG. 13  is a schematic diagram of the connection structure between the shock-absorbing rail and the passive roller in an embodiment of the present disclosure; 
         FIG. 14  is a schematic structural diagram of a package supply mechanism in an embodiment of the present disclosure; 
         FIG. 15  is a schematic structural diagram of the electric pickup set provided on the trolley in an embodiment of the present disclosure; 
         FIG. 16  is a schematic structural diagram of the signal transceiver installed on the trolley in an embodiment of the present disclosure; 
         FIG. 17  is a schematic structural diagram of the actuator installed on the trolley in an embodiment of the present disclosure; 
         FIG. 18  is a structural diagram of a control system in an embodiment of the present disclosure. 
         FIG. 19  is a schematic diagram of the position adjustment process of the package by the trolley in an embodiment of the present disclosure. 
     
    
    
     In the drawings, the reference signs are explained as follows: 
       1 , conveying mechanism;  11 , rack;  111 , upper rail;  112 , lower rail;  113 , shock-absorbing feet;  114 , upper cover;  115 , wear-resistant strip;  12 , chain;  13 , trolley;  131 , trolley body;  132 , sorting and conveying mechanism;  1321 , driving roller;  1322 , tension roller;  1323 , conveying belt;  133 , wheel;  1331 , wheel body;  1332 , wheel shaft;  14 , guide table;  15 ,  16 , roller;  151 , active roller;  1511 , driving sprocket;  1512 , driving shaft;  1513 , bearing seat;  1514 , driving motor;  161 , passive roller;  1611 , tension sprocket;  1612 , tension shaft;  1613 , tension assembly;  16131 , sliding rail;  16132 , sliding groove;  16133 , opening;  16134 , tension spring;  16135 , cavity;  16136 , tension rod;  16137 , elasticity adjustment component;  16138 , baffle;  17 , connecting piece;  18 , first shock-adsorbing rail;  19 , second shock-adsorbing rail; 
       2 , control system;  21 , controller;  22 , data acquisition module;  221 , code scanner;  222 , position sensor;  224 , tension sensor;  225 , sensing piece;  226 , sliding contact wire;  227 , electric pickup set;  228 , external antenna;  229 , signal transceiver;  230 , actuator;  231 , first-trolley sensing piece;  232 , first-trolley detection sensor;  233 , driving encoder; 
       3 , package supply mechanism;  31 , package supply rack;  32 , package supply belt; 
       4 , package; 
     F 1 , first horizontal direction; 
     F 2 , second horizontal direction. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Typical embodiments embodying the features and advantages of the present disclosure will be described in detail in the following description. It should be understood that the present disclosure can have various changes in different embodiments, which do not depart from the scope of the present disclosure. The description and drawings therein are essentially for illustrative purposes, rather than limiting the present disclosure. 
     In the following description of the different exemplary embodiments of the present disclosure, it is made with reference to the accompanying drawings, which form a part of the present disclosure, and in which different exemplary structures, systems and steps that can implement various aspects of the present disclosure are shown by way of example. It should be understood that other specific solutions of components, structures, exemplary devices, systems, and steps may be used, and structural and functional modifications may be made without departing from the scope of the present disclosure. Moreover, although the terms “upper end”, “lower end”, “between”, “side”, etc. may be used in the present specification to describe different exemplary features and elements of the present disclosure, these terms are used herein only for convenience, for example, based on the example directions described in the drawings. Nothing in the present specification should be understood as requiring a specific three-dimensional direction of any structure to fall within the scope of the present disclosure. 
     References are made to  FIGS. 1 to 19  of the present specification.  FIG. 1  representatively shows a three-dimensional schematic diagram of the sorting system in the present disclosure.  FIGS. 2 to 3  show schematic structural diagrams of the trolley and the rack.  FIGS. 4 to 6  show the specific structural diagram of the trolley.  FIGS. 7-8  show the structural schematic diagrams of the active roller.  FIGS. 9-13  show the structural schematic diagrams of the passive roller.  FIG. 14  shows the structural schematic diagram of the package supply mechanism.  FIGS. 15-18  show a schematic structural diagram of the control system. It is easy for those skilled in the art to understand that, various modifications, additions, substitutions, deletions or other changes can be made to the following specific embodiments, in order to apply the relevant design of the present disclosure to other application scenarios, and these changes are still falling within the scope of the principle of the sorting system proposed in the present disclosure. 
     Implementation of the Sorting System 
     As shown in  FIG. 1  and  FIG. 19 , in an embodiment, the sorting system proposed in the present disclosure can be used to transport packages  4 . As shown in  FIG. 1 , the sorting system proposed in the present disclosure includes a conveying mechanism  1  and a control system  2 . The conveying mechanism  1  includes a rack  11 , two rollers  15  and  16 , a chain  12  and a plurality of trolleys  13 . The two rollers  15  and  16  are arranged on the rack  11  at intervals along the first horizontal direction F. The chain  12  is wound between the two rollers  15  and  16 . As shown in  FIGS. 1, 5 and 6 , the plurality of trolleys  13  are respectively connected to the chain  12  and arranged in sequence along the first horizontal direction F 1 . Each trolley  13  includes a trolley body  131  and a sorting and conveying mechanism  132  provided on the trolley body  131 . The bottom part of the trolley body  131  is connected to the chain  12 . The sorting and conveying mechanism  132  is configured to carry and convey packages along a second horizontal direction F 2  perpendicular to the first horizontal direction F 1 . The control system  2  includes a controller  21  connected to the conveying mechanism  1 . The controller  21  is configured to control the conveying mechanism  1  to transport the package  4  along the first horizontal direction F 1 , and is configured to independently control the sorting and conveying mechanism  132  of each trolley  13  to convey the package  4  along the second horizontal direction F 2 . 
     With the above design, in the sorting system proposed by the present disclosure, the trolley  13  is transporting in the first horizontal direction F 1 , transporting above the rack  11 , and sorting the package  4  and returning it below the rack  11 . Thus, pitch of the trolley  13  can be reduced. For the transportation of smaller packages  4 , the transportation resources are saved, and at the same time, the utilization rate of the occupied space is improved. The control system  2  controls the conveying mechanism  1  of the trolley  13  and can independently control the sorting and conveying mechanism  132  of each trolley  13 . This helps to realize the automated transportation by the sorting system, saves labor, and can automatically control each trolley  13  to convey packages in the second horizontal direction F 2 , thereby realizing the more accurate throwing and correction of the package. 
     The rack  11  extends along the first horizontal direction F 1  to provide support for the entire conveying mechanism. The conveying mechanism  1  is a symmetrical structure. The following content in the present disclosure is a description of the structure from one side, and the structure from the other side is symmetrical to it. 
     The first horizontal direction F 1  is the transportation direction of the trolley  13 , and the second horizontal direction F 2  is the throwing direction of the package. Therefore, the second horizontal direction F 2  is perpendicular to the first horizontal direction F 1 . In addition, the controller  21  in the present disclosure is electrically connected to the conveying mechanism  1 . It can be a wired connection, such as through a USB interface, or a wireless connection, such as through Bluetooth or near field communication (NFC), infrared, etc., as long as the signal transmission between the controller  21  and the conveying mechanism  1  can be achieved, which is not limited here. 
     Furthermore, as shown in  FIGS. 2 to 4 , in an embodiment, the rack  11  includes a rail for guiding the trolley  13  to slide. The trolley  13  also includes wheels  133 , which are arranged on respective sides of the trolley body  131  thereof. In an embodiment, two wheels  133  are provided on one side and one wheel  133  is provided on the other side. Alternatively, two wheels  133  are provided on each side, which is not limited here. The rail may only have an upper rail  111 , which is arranged on the inner side of the upper part of the rack  11  and extends along the first horizontal direction F 1 . The wheels  133  of the trolley  13  are in sliding engagement with the upper rail  111 , and the upper rail  111  serves as a support and guide part. Since the bottom part of the trolley  13  is fixedly connected to the chain  12 , the trolley  13  can move in the first horizontal direction F 1  along with the chain  12 . Therefore, the rail can also only have a lower rail  112 , which is arranged along the inner side of the lower part of the rack  11 , and extends along the first horizontal direction F 1 . The wheels  133  are slidably fitted with the lower rail  112 , and slide along the first horizontal direction F 1 . Apparently, the rail can also have the above-mentioned upper rail  111  and the lower rail  112  at the same time, so as to provide support and guidance for the wheels  133  of the trolley  13 . It should be noted that the wording “inside” of the rack  11  refers to the side of the rack  11  close to its center line along the first horizontal direction F 1 . In the present disclosure, the trolley  13  is arranged inside the rack  11 . 
     Furthermore, as shown in  FIGS. 2 to 3 , in an embodiment, the rack  11  further includes an upper cover  114 , one side of which is arranged on the rack  11 , and the other side of which extends above the upper rail  111  to cover the wheels  133  on the upper rail  111 , to prevent foreign objects from falling therein. Specifically, one side of the upper cover  114  may be arranged on the top end of the rack  11  or on the inner side of the rack  11 , and the other side of the upper cover  114  may extend along the second horizontal direction F 2  to cover the wheels  133 . 
     Furthermore, as shown in  FIGS. 4 to 6 , in an embodiment, each wheel  133  further includes a wheel body  1331  and a wheel shaft  1332 . The wheel shaft  1332  penetrates through the wheel body  1331 , and a gap exists between the end of the wheel shaft  1332  close to the rack  11  and the inner side of the rack  11 , which gap is set to be 1 to 5 mm. This gap has a small value, so that the rack  11  limits the position of the trolley  13 . When the trolley  13  throws a package, the end surface of the wheel shaft can contact the inner side of the rack  11  to prevent the trolley  13  from shaking significantly along the second horizontal direction F 2 . 
     Furthermore, as shown in  FIG. 3 , in an embodiment, the end surface of the wheel shaft  1332  at one end close to the rack  11  is a curved surface, so as to reduce the wearing when the wheel shaft  1332  contacts the inner side of the rack  11 . 
     Furthermore, as shown in  FIGS. 2 to 3 , in an embodiment, the rack  11  further includes a wear-resistant strip  115 . The wear-resistant strip  115  is made of wear-resistant material. The wear-resistant strip  115  is arranged on the inner side of the rack  11  along the first horizontal direction F 1  and is located between the upper cover  114  and the upper rail  111 , so as to prevent the abrasion caused by the long-term contact between the inner side of the rack  11  and the wheel shaft  1332 . 
     Further, in an embodiment, the wear resistant material of the wear-resistant strip  115  is ultra-high molecular weight polyethylene. Of course, it can also be other wear-resistant materials, which is not limited here. 
     Further, as shown in  FIGS. 1 and 7 , the rack  11  in an embodiment further includes shock-absorbing feet  113 , which are arranged on respective sides of the rack  11  to support the rack  11 . It can be seen from the figures that there are multiple shock-absorbing feet  113 , which are arranged on respective sides of the rack  11  and arranged at intervals. This helps to reduce the vibration of each section of the rack  11  and prevent the ground and the equipment platform from being penetrated by the vibration. 
     Further, as shown in  FIGS. 1, 7 to 8 , in an embodiment, one of the two rollers  15 ,  16 , for example the roller  15 , of the conveying mechanism  1  is an active roller  151 , and the other roller is a passive roller  161 . The driving roller  151  includes a driving sprocket  1511 , a driving shaft  1512 , a bearing seat  1513 , and a driving motor  1514 . The driving sprocket  1511  meshes with the chain  12 . The bearing seat  1513  is arranged on the rack  11 . The driving shaft  1512  passes through the center part of the driving sprocket  1511 , and has two ends passing through the bearing seat  1513 . The driving motor  1514  is in a transmission connection with the driving shaft  1512 , and is configured to drive the driving shaft  1512  to rotate and drive the driving sprocket  1511  to rotate. That is, the active roller  151  is used to provide power for the entire conveying mechanism  1  and to make the chain  12  rotate. 
     Specifically, as shown in  FIG. 8 , in an embodiment, a connecting plate is provided on one side of the rack  11  corresponding to the driving shaft  1512 , and a plurality of elongated holes are opened on the connecting plate. The bearing seat  1513  is fixed onto the connecting plate by bolts, and the bolts pass through the elongated holes. In addition, the upper and lower ends of the connecting plate have flanges protruding in the second horizontal direction F 2 . A threaded hole is opened in the lower flange at a position facing the bearing seat  1513 , and at least one height adjustment bolt is pressed against the bottom part of the bearing seat  1513  through the threaded hole. On the one hand, the height adjustment bolt provides support for the bearing seat  1513 . On the other hand, according to actual needs, when installing the driving shaft  1512  and the bearing seat  1513 , the height of the bearing seat  1513  can be adjusted along the elongated hole and then tightened. The height adjustment bolt realizes the fine adjustment of the height of the driving shaft  1512 , so that a good running effect is achieved by the sprocket. 
     Further, as shown in  FIG. 6 , the conveying mechanism  1  further includes a connecting piece  17  through which the chain  12  is connected to the bottom part of the trolley  13 . Specifically, the connecting piece  17  may be a right-angle connecting plate, and the chain  12  is connected to the bottom part of the trolley  13  by bolts. 
     It should be noted that the chain  12  is connected to the bottom part of the trolley  13  through the connecting piece  17 . The “bottom part” in the present disclosure refers to the part near the chain  12  when the trolley  13  runs along the first horizontal direction F 1  on the upper rail  111 . When the trolley  13  runs along the first horizontal direction F 1  on the lower rail  112 , the “bottom part” of the trolley  13  is still the side close to the chain  12 , not the side close to the bottom surface. 
     Further, as shown in  FIGS. 9 to 12 , in an embodiment, one of the two rollers  15  and  16  of the conveying mechanism  1  is an active roller  151 , and the other is a passive roller  161 . The passive roller  161  includes a tension sprocket  1611 , a tension shaft  1612  and a tension assembly  1613 . The tension sprocket  1611  meshes with the chain  12 . The tension shaft  1612  passes through the center part of the tension sprocket  1611 . The tension assembly  1613  is connected to the end of the tension shaft  1612 , and is configured to adjust the tension degree of the chain  12  by adjusting the displacement of the tension shaft  1612  in the first horizontal direction F 1 . 
     Further, as shown in  FIGS. 9 to 12 , in an embodiment, the tension assembly  1613  includes a sliding rail  16131 , a tension spring  16134 , a tension rod  16136 , and an elasticity adjustment component  16137 . 
     The sliding rail  16131  is fixedly arranged on the rack  11  along the first horizontal direction F 1 , as shown in  FIG. 12 . In one embodiment, the sliding rail  16131  is connected to the rack  11  by bolts. The sliding rail  16131  is provided with a sliding groove  16132  penetrating along the second horizontal direction F 2 , and the end of the tension shaft  1612  penetrates through the sliding groove  16132  along the second horizontal direction F 2 . The sliding rail  16131  is further provided with an opening  16133  at one end away from the active roller  151 , and the opening  16133  is in a communication connection with the sliding groove  16132 . 
     Further, as shown in  FIGS. 10 and 11 , the tension assembly  1613  further includes a baffle  16138  connected to the end surface of the tension shaft  1612 . The baffle  16138  is provided on the side of the sliding rail  16131  away from the tension sprocket  1611 , and the size of the baffle  16138  in the vertical direction is larger than the width of the sliding groove  16132 . The purpose of setting the baffle  16138  here is to prevent the tension shaft  1612  from sliding out from the side of the sliding groove  16132 , and the baffle  16138  plays a guiding role. Specifically, as shown in  FIGS. 10 and 11 , the cross-sectional shape of the baffle  16138  is C-shaped, and two guide grooves are provided on both the upper and lower sides of the sliding groove  16132  of the slide rail  16131 , which are used to mate with the two sides of the baffle  16138 . It should be noted that, in an embodiment, the vertical direction refers to a direction perpendicular to and away from the ground. 
     The tension spring  16134  is connected to one end of the sliding rail  16131  with the opening  16133  along the first horizontal direction F 1 . The tension spring  16134  has a cavity  16135  extending along the first horizontal direction F 1 , and the cavity  16135  is in communication with the opening  16133 . 
     The tension rod  16136  passes through the cavity  16135  of the tension spring  16134  and the sliding groove  16132  of the sliding rail  16131  in sequence along the first horizontal direction F 1 . The end of the tension rod  16136  located in the sliding groove  16132  of the sliding rail  16131  is defined as the first end, and the other end of the tension rod  16136  located in the sliding groove  16132  is defined as the second end. The first end of the tension rod  16136  is connected to the end of the tension shaft  1612 . When the tension rod  16136  moves along the first horizontal direction F 1 , the end of the tension shaft  1612  can be driven to slide along the first horizontal direction F 1  in the sliding groove  16132 . The second end of the tension rod  16136  extends out of the tension spring  16134 . Reference is made to  FIG. 12 . In an embodiment, the cross section of the sliding groove  16132  is T-shaped. Specifically, it is a shape obtained after the T-shaped cross section is rotated 90° clockwise. The sliding groove  16132  can be divided into a first through groove and a second through groove. The first through groove is a rectangle shape extending in the first horizontal direction F 1 , and the second through groove is a rectangle shape extending in the vertical direction (a direction perpendicular to the ground). The first through groove and the second through groove are in communication with each other. The width of the rectangle-shaped first through groove matches the size of the tension shaft  1612 , so that the tension shaft  1612  can slide along the upper and lower sides of the rectangle-shaped first through groove to limit the tension shaft  1612  in position and prevent the tension shaft  1612  from swaying up and down in the vertical direction. The second through groove extends in the vertical direction. The purpose is to facilitate the assembly of the tension rod  16136  and the tension shaft in the second through groove, completing the connection, and then moving into the first through groove. 
     The surface of the tension rod  16136  has threads. For example, the tension rod  16136  is a screw, and one end of the screw is fixedly connected to the tension shaft  1612 . The tension rod  16136  may also be a threaded rod. Of course, in one embodiment, the tension rod  16136  may be a rod without threads, as long as one end of the tension rod can be fixedly connected to the shaft  9 , which is not limited here. 
     The elasticity adjustment component  16137  is arranged at one end of the tension spring  16134  away from the sliding rail  15231 , connects the tension rod  16136  and the tension spring  16134 , and compresses or stretches the tension spring  16134 . The elasticity adjustment component  16137  may be a nut. As shown in  FIG. 12 , in an embodiment, the tension spring  16134  is initially in a compressed state to provide pre-tension force for the tension rod  16136 . The elasticity adjustment component  16137  can adjust the compression length of the spring, thereby adjusting the magnitude of the pre-tension force. When the chain  12  becomes loose, the tension spring  16134  will elongate, driving the tension rod  16136  to move away from the active roller  151 , and then driving the tension shaft  1612  to slide along the sliding groove  15232  to tension the chain  12 . In another embodiment, when the tension assembly  1613  is installed in a direction opposite to the first horizontal direction F 1  in  FIGS. 11 and 12 , it can be set to stretch the tension spring  16134  to provide pre-tension force in the same direction. Therefore, the tension assembly  1613  of the present disclosure can automatically perform tension compensation after the chain  12  is stretched due to long-term operation, so as to avoid undesirable phenomena caused by the chain  12  being slack, out of gear or jumping gear and the like. 
     Further, as shown in  FIGS. 11 and 13 , in an embodiment, the conveying mechanism  1  further includes a first shock-adsorbing rail  18  and/or a second shock-adsorbing rail  19 . The first shock-adsorbing rail  18  is arranged inside the rack  11  and extends along the end of the lower rail  112 . The upper surface of the first shock-adsorbing rail  18  is gradually reduced from the upper surface of the lower rail  112  to a wedge-shaped surface, so that the wheels of the trolley  13   133  are transitioned to the lower rail  112  for sliding. The second shock-absorbing rail  19  is arranged inside the rack  11  and extends along the end of the upper rail  111 . The upper surface of the second shock-absorbing rail  19  is gradually reduced from the upper surface of the upper rail  111  to a wedge-shaped surface, so that the wheels of the trolley  13  are transitioned to the upper rail  111  for sliding. As shown in  FIG. 13 , when the trolley  13  rotates back from the driving sprocket  1511  or the tension sprocket  1611 , and the line connecting the wheels  133  of the trolley  13  and the axle center of the driving sprocket  1511  or the tension sprocket  1611  is perpendicular to the ground, the wheels  133  of the trolley  13  are at the lowest position, and the distance below the lowest position of the wheels  133  in the horizontal section is c. The height of the connection part between the first shock-adsorbing rail  18  and the second shock-adsorbing rail  19  and the upper rail  111  or the lower rail  112  is a, and the height of the ends thereof is b, wherein a&gt;b. The wheels  133  of the trolley  13  are transitioned to the upper rail  111  or the lower rail  112  through the first shock-adsorbing rail  18  and the second shock-adsorbing rail  19 , so as to prevent the wheels  133  from directly colliding with the upper rail  111  or the lower rail  112 , thereby reducing noise and protecting the trolley  13 . Reference is made to  FIG. 1 . When the transport direction of the trolley  13  is from the passive roller  161  to the active roller  151 , in one embodiment, the first anti-vibration rail is arranged on the lower rail  112  corresponding to the active roller  151 , and the second anti-vibration rail is arranged on the upper rail  111  corresponding to the passive roller  161 . Of course, the first anti-vibration rail and the second anti-vibration rail can also be arranged at the lower rail  112  and the upper rail  111  corresponding to the active roller  151  and the lower rail  112  and the upper rail  111  corresponding to the passive roller  161 . When adjustment is made to the transport direction of the trolley  13 , the shock absorption effect can be achieved. In an embodiment, only the first shock-adsorbing rail  18  may be provided, or only the second shock-adsorbing rail  19  may be provided, which is not limited here according to actual needs. 
     Further, in an embodiment, materials of the first shock-adsorbing rail  18  and the second shock-adsorbing rail  19  are both ultra-high molecular weight polyethylene with high wear resistance. 
     Further, as shown in  FIG. 14 , in an embodiment, the sorting system further includes a package supply mechanism  3 , and the package supply mechanism  3  includes a package supply rack  31  and a package supply belt  32 . The package supply belt  32  is arranged on the package supply rack  31  and is configured to transport the package  4  to the trolley  13 . 
     Furthermore, as shown in  FIG. 2 , the conveying mechanism  1  of the sorting system further includes a guide table  14 , corresponding to each throwing grid and arranged on respective sides of the rack  11 , wherein the package has been led out of the conveying mechanism through the throwing opening. 
     Further, as shown in  FIGS. 15 to 19 , in an embodiment, the control system  2  further includes a data acquisition module  22 . The data acquisition module  22  includes a code scanner  221 . The code scanner  221  is configured to collect the sorting information of the package  4 . The controller  21  is connected to the code scanner  221 . Based on the sorting information collected by the code scanner  221 , the controller  21  can determine the throwing grid of the package  4  to be delivered, and control the movement of the conveying mechanism  1  along the first horizontal direction F 1  and the movement of the sorting and conveying mechanism  132  of each trolley  13  along the second horizontal direction F 2 , causing the package  4  to be thrown to the designated throwing grid. Reference is made to  FIG. 2 , where a guide table  14  is also provided for exporting the package  4  to the conveying mechanism. The throwing grid designated in the present disclosure refers to the grid corresponding to the guide table, which is used to transfer the package  4  from the trolley to the guide table  14 . 
     Specifically, in an embodiment, the code scanner  221  can be set on the package supply rack  31  or on the rack  11  of the conveying mechanism, as long as the sorting information of the package  4  can be read before transportation. It is not limited here. The code scanner  221  reads the label on the package and sends the sorting information on the label to the controller  21 . The controller  21  obtains the destination grid of the package  4  from its internal database according to the sorting information, and then controls the conveying mechanism  1  to transport the package  4  to the destination grid. After that, the sorting and conveying mechanism  132  on the trolley  13  carrying the package is separately controlled to move along the second horizontal direction F 2  to throw the package. 
     Reference is made to  FIG. 5 . In an embodiment, the sorting and conveying mechanism  132  on the trolley  13  includes two rollers and a conveying belt  1323  wound on the two rollers. One of the two rollers is a driving roller  1321  and the other is a tension roller  1322 . The driving roller  1321  and the tension roller  1322  are both arranged on the trolley body  131  and they are arranged at intervals. The controller  21  is electrically connected to the driving roller  1321 , and controls start, stop, and adjustment of the rotation speed and rotation direction of the driving roller  1321 , so as to control the forward or reverse movement of the conveying belt  1323  in the second horizontal direction F 2 , thereby adjusting the position of the package  4  and putting the package  4  in a proper orientation (as shown in  FIG. 19 ). Regarding how the controller  21  is electrically connected to the driving roller  1321  and how to realize the control of the driving roller  1321 , those skilled in the art can implement according to related technologies. For example, an encoder can be provided on each driving roller  1321 , and a control signal can be received from the controller  21 , or other means can be used, which will not be repeated here. Therefore, the controller  21  can control start, rotation speed and rotation direction of the driving roller  1321  on the trolley  13  according to the sorting information collected by the code scanner  221 , and make sure the package  4  is thrown to the correct grid. 
     Further, as shown in  FIGS. 15 to 19 , in an embodiment, the data acquisition module  22  further includes a position sensor  222 , which is configured to detect the first position information of the package  4  at the initial position. The controller  21  is connected to the position sensor  222  and independently controls the sorting and conveying mechanism  132  of each trolley  13  according to the first position information of the package  4  so as to adjust the position of the package  4 . 
     Specifically, in an embodiment, the position sensor  222  can be arranged on the package supply rack  31  or on the rack  11  of the conveying mechanism, as long as the first position information of the package  4  can be read, and it is not limited here. The first position information may include the size of the package  4 , the size offset from the center line of the trolley  13  along the first horizontal direction F 1  (that is, when the package is in a skewed state), and the like. The position sensor  222  sends such position parameter to the controller  21 , and the controller  21  independently controls the movement of the sorting and conveying mechanism  132  of the trolley  13  carrying the package  4  in the second horizontal direction F 2  according to the first position information. As shown in  FIG. 19 , the controller  21  controls the activation of the driving roller of the respective trolley  13  according to the first position information, and adjusts the rotation speed, rotation direction of the driving roller of each trolley  13  and also the displacement of the conveying belt along the second horizontal direction F 2 , so as to move the package  4  to the middle position of the trolley  13 . That is, the center line of the package  4  and the center line of the trolley  13  coincide in the first horizontal direction F 1 . 
     Further, in an embodiment, the data acquisition module  22  further includes a detection sensor (not shown in the figures), which is configured to detect the second position information of the package  4  at the adjustment position. It may be that after the initial position of the package  4  is adjusted, it is transported to the adjustment position, and the position is adjusted for a second time. The controller  21  is electrically connected to the detection sensor, and independently controls the sorting and conveying mechanism  132  of each trolley  13  according to the second position information of the package  4  to assist in adjusting the position of the package  4 . The function of the detection sensor is to collect for a second time the position parameters of the package that has been adjusted, and send the position parameter information to the controller  21 . If the controller  21  determines that the package  4  is still in a skewed state, it will further adjust the driving roller of the respective trolley  13 , so as to adjust the package  4  to the middle position of the trolley  13 . If the package  4  is still in a skewed state after re-adjustment, it can be manually adjusted or dropped in advance or later. 
     The initial position refers to a position where the package  4  is placed on the sorting trolley and has not yet been transported, or placed on another mechanism capable of transporting the package to the sorting trolley  13 , such as the package supply rack  31 . The adjustment position refers to a position where the package  4  is located after being transported for a certain period of time from the initial position. Such period of time is not a specific value, and it can be adjusted according to actual conditions. 
     For example, in an embodiment, the position sensor  222  may be arranged on the package supply rack  31  of the sorter, and the package  4  is first placed on the package supply belt  32  (at the initial position). The position sensor  222  collects the position parameter (or the first position information) of the package  4  and sends it to the controller  21 . The multiple sorting trolleys  13  located on the sorter rack can be divided into an adjustment area and a transportation area along the first horizontal direction F 1 . The package  4  is transported to the adjustment area (or the adjustment position) via the package supply belt  32 . The controller  21  controls the electric roller of the corresponding sorting trolley  13  to adjust the position of the package  4  in the adjustment area. After that, the detection sensor detects the adjusted position parameter (or the second position information) of the package. If the adjusted position parameter meets the requirements for putting the package in a proper orientation, the controller  21  controls the conveying mechanism  1  to transport the package  4  to the transportation area. If the adjusted position parameter does not meet the requirements for putting the package in a proper orientation, the controller  21  will re-control the electric roller to adjust the position of the package  4  according to the adjusted position parameter (or the second position information). In an embodiment, the detection sensor may be a detection camera, which is arranged directly above the adjustment area, takes a picture of the package, and sends the image information to the controller  21 . Alternatively, the detection sensor may also be an encoder, which is arranged on each sorting trolley  13  to detect the position parameter of the package on the sorting trolley  13  and send the position parameter to the controller  21 . Therefore, the sorting trolley  13  in the present disclosure can realize the automatic position adjustment of the package, so that the throwing and dropping is more accurate, and at the same time, the amount of manual labor is saved. 
     Further, as shown in  FIG. 10 , in an embodiment, the data acquisition module  22  further includes a tension sensor  224 . The tension sensor  224  is arranged on the rack  11 , electrically connected to the controller  21 , opposite to the tension assembly  1613  in the first horizontal direction F 1 , and configured to detect the distance between the tension sensor  224  and the tension assembly  1613 . The distance is sent to the controller  21  in the form of an electric signal. At the same time, the tension sensor  224  can also detect the distance X moved by the tension sprocket  1611  due to the looseness of the chain  12 . If it is detected that the difference in the distance X between the two sides of the tension sprocket  1611  is large, it means that the chains  12  are inconsistent in stretching on both sides, and the chain  12  of the device needs to be adjusted to prevent further damage to the device. 
     Further, continuing referring to  FIG. 10 , in an embodiment, the data acquisition module  22  further includes a sensing piece  225 . The sensing piece  225  is disposed at the second end of the tension rod  16136 . The tension sensor  224  is opposite to the sensing piece  225  in the first horizontal direction F 1 , and is configured to detect the distance between the tension sensor and the sensing piece  225 . The controller  21  determines the amount of deformation of the tension spring  16134  according to the distance. When the tension spring  16134  stretches too long and the elastic force decreases, it will issue a prompt and notify the staff to make adjustments accordingly. 
     Furthermore, as shown in  FIG. 3 , the data acquisition module  22  further includes a first-trolley sensing piece  231  and a first-trolley detection sensor  232 . The first-trolley sensing piece  231  and the first-trolley detection sensor  232  are installed on any trolley  13 , and the first-trolley sensing piece  232  is connected to the controller  21 . When the conveying mechanism  1  starts to operate, the first-trolley sensing piece  232  will trigger the first-trolley sensor  231  at regular intervals. By providing the first-trolley detection sensor  232 , the position of the first trolley at the trigger time can be known, and the controller  21  can calculate the accurate position of any other trolley  13  at the trigger time. The calculation method is as follows, where it is supposed that the pitch of the chain  12  is P, and every N links of the chain  12  are connected to the bottom part of the trolley  13  through the connecting piece  17 . Thus, the initial pitch of the trolley  13  can be obtained as P 0 =N*P, where N is a positive integer, and 1≤N≤20. In an embodiment, P=50.8 and N=6. In addition, the tension sensor  224  needs to sense the distance X moved by the tension sprocket  1611  and send it to the controller  21 . Assuming that the number of trolleys  13  is N 1 , the pitch P 1  of two adjacent trolleys  13  is 2X/N 1 +P 0 , and the distance from the first one to the last one among N adjacent trolleys  13  is N*P 1 . 
     Further, referring to  FIG. 7 , in an embodiment, a driving encoder  233  is also provided on the driving motor  1514 , and the driving encoder  233  is connected to the controller  21  for detecting and controlling the rotation speed of the driving sprocket  1511 . 
     The specific structure and connection relationship between the control system  2  and the conveying mechanism  1  in an embodiment will be described in detail below. Referring to  FIG. 18 , where two sides of the rack  11  are respectively provided with a sliding contact wire  226  and an external antenna  228 . The sliding contact wire  226  is connected to a power source to provide power for the sorting system. The external antenna  228  is connected to the controller  21  and used for transmitting the command signal of the controller  21 . Reference is made to  FIG. 15 , where at least one of the trolleys  13  is provided with an electric pickup set  227  at the bottom part of the trolley  13 . The electric pickup set  227  is in contact with the sliding contact wire  226 , so as to obtain power from the sliding contact wire  226  and supply it to other trolleys  13 . A power line can be set between the trolleys  13 , and one trolley  13  can supply power to multiple trolleys  13 . Reference is made to  FIG. 16 , where a signal transceiver  229  is provided at the bottom part of at least one of the trolleys  13 . The signal transceiver  229  may be an encoder, and the signal transceiver  229  may cooperate with the external antenna  228  for receiving and sending instruction signals from the controller  21 , so as to realize the communication between the trolley  13  and the controller  21 . Reference is made to  FIG. 17 , where an actuator  230  is provided at the bottom part of at least one of the trolleys  13 . The actuator  230  can receive an instruction signal from the controller  21  to control the start and stop of the driving rollers of the plurality of trolleys  13 . One actuator  230  can be connected with the driving rollers of multiple trolleys  13 . 
     Apparently, the above-mentioned signal transceiver  229  and actuator  230  may not be provided separately, and the controller  21  may have modules integrating the functions of the two devices, so that the controller  21  can perform direct control. Those skilled in the art can easily ascertain how to realize the signal transmission between the controller  21 , the actuator  230 , and the signal transceiver  229 . For example, the controller  21  can be a microprocessor, and its functions can be realized according to the internal program thereof. This will not be repeated here. 
     In the sorting system of the present disclosure, the trolley  13  is transported in the first horizontal direction F 1 , and the packages are sorted above the rack  11 , and returned below the rack  11 . This can reduce the pitch of the trolley  13 , and save the transportation resources for smaller packages. At the same time, the utilization rate of occupied space is improved. The control system  2  controls the conveying mechanism  1  of the trolley  13  to transport the packages in the first horizontal direction F 1 , and can independently control the sorting and conveying mechanism  132  of each trolley  13  to transport the packages in the second horizontal direction F 2 . This helps to realize the automated transportation of the sorting system, saves labor, and can automatically control the transportation of each trolley  13  in the second horizontal direction F 2 . Thus, the more accurate throwing and correction of the package is realized. 
     Exemplary embodiments of the sorting system proposed by the present disclosure are described and/or illustrated above in detail. However, the embodiments of the present disclosure are not limited to the specific embodiments described herein. On the contrary, the components and/or steps of each embodiment can be used independently and separately from other components and/or steps described herein. Each component and/or step of one embodiment can also be used in combination with other components and/or steps of other embodiments. When introducing the elements/components/etc. described and/or illustrated herein, the terms “a”, “an”, and “above” are used to indicate that there are one or more elements/components/etc. The terms “comprising”, “including” and “having” are used to mean open-ended inclusion, which means that there may be additional elements/components/etc. in addition to the listed elements/components/etc. In addition, the terms “first” and “second” in the claims and specification are used only as marks, and are not numerical limitations on their objects. 
     Although the sorting system proposed in the present disclosure has been described according to different specific embodiments, those skilled in the art will recognize that the implementation of the present disclosure can be modified within the spirit and scope of the claims.