Underground coal mine monorail crane shortening device and monorail crane shortening method

Abstract

The invention discloses an underground coal mine monorail crane shortening device which comprises a monorail crane body, a separable partition structure is arranged in the middle of the monorail crane body, two shortening mechanisms are connected to the partition structure in the middle of the monorail crane body, and the two shortening mechanisms are connected through a connecting device. The invention further discloses an underground coal mine monorail crane shortening method. The coal mine underground monorail crane shortening device solves the problems that an existing coal mine underground monorail crane is long and difficult to install and transport in some roadways with limited space.

Description

Technical Field

[0001] This invention belongs to the technical field of underground coal mine transportation equipment, specifically relating to a shortening device for underground monorail cranes in coal mines, and also to a method for shortening the aforementioned shortening device for underground monorail cranes in coal mines. Background Technology

[0002] In underground coal mine transportation, monorails serve as an important transport device, offering advantages such as flexible operation and strong adaptability. However, in practical applications, existing underground monorails in coal mines suffer from excessive length, which can lead to installation and transportation difficulties in some space-constrained roadways, affecting transportation efficiency and increasing maintenance costs.

[0003] Therefore, it is necessary to improve the monorail system in coal mines to shorten its length and improve its adaptability and transportation efficiency. Summary of the Invention

[0004] The first objective of this invention is to provide a shortening device for underground monorail cranes in coal mines, which solves the problem that existing underground monorail cranes are too long and difficult to install and transport in some roadways with limited space.

[0005] A second objective of this invention is to provide a method for shortening the aforementioned shortening device for a monorail crane in a coal mine.

[0006] The first technical solution adopted in this invention is: a shortening device for a monorail crane in a coal mine, comprising a monorail crane body, a separable partition structure in the middle of the monorail crane body, and two shortening mechanisms connected at the partition structure in the middle of the monorail crane body, which are connected by a connecting device.

[0007] The invention is further characterized by: The main body of the monorail includes a rail and a crane. The crane is equipped with wheels, and the crane and wheels are configured in conjunction. It also includes two connecting plates that connect to the crane, and each connecting plate is connected to a corresponding shortening mechanism.

[0008] Each shortening mechanism includes a telescopic component and a fixing component; The telescopic assembly includes a telescopic plate, one end of which is slidably mounted on a corresponding connecting plate on the main body of the monorail crane, and the other end of which is connected to a connecting device. A hydraulic cylinder is provided on the bottom end face of the telescopic plate in the same direction as the telescopic plate, and the working end of the hydraulic cylinder points to the connecting plate connected to the corresponding telescopic plate. The fixing component includes several locking holes on the telescopic plate and several slotted grooves on the connecting plate. The slotted grooves are configured to cooperate with the locking holes. The component also includes a fixing bolt and a nut that are configured to cooperate. The fixing bolt passes through the slotted groove and the locking hole, and the nut fixes the fixing bolt.

[0009] The bottom of the connecting plate is provided with a slide rail that cooperates with the telescopic plate, and the end of the telescopic plate away from the connecting device is slidably set in the slide rail.

[0010] The telescopic plate has a slider at the end away from the connecting device. The slider is slidably set in the slide rail. A limit groove is opened in the middle of the slider. The working end of the hydraulic cylinder is fixedly set in the limit groove. A rotating shaft perpendicular to the hydraulic cylinder is rotatably passed through the slider. Pressure rollers are connected to both ends of the rotating shaft. Both pressure rollers are in rotatable contact with the bottom end of the connecting plate.

[0011] The locking hole is a threaded hole. The upper end of the fixing bolt is set in the waist-shaped groove, and the lower end of the fixing bolt is threaded into the locking hole.

[0012] The connecting device includes a connecting joint, which is connected to two telescopic plates respectively. The connecting joint is disc-shaped and has an annular groove at the bottom. The telescopic plates are provided with an insert rod that mates with the annular groove. The insert rod is movably set in the corresponding annular groove. It also includes two fasteners, both of which are semi-circular and mate with the connecting joint. Both fasteners are located on the outer periphery of the connecting joint and are fixedly connected to the telescopic plate by fastening bolts. Two spring grooves are provided at the center of the two fastener ports, and damping springs are provided in the spring grooves of two adjacent fastener ports. The two fasteners are connected by damping springs.

[0013] The second technical solution adopted in this invention is: a method for shortening a monorail crane in an underground coal mine, utilizing the aforementioned monorail crane shortening device in an underground coal mine, the specific method of which is as follows: S1. Determine the length that the monorail needs to be shortened based on the size of the tunnel space; S2. Operate the shortening mechanism to retract the telescopic components, thereby shortening the length of the monorail crane body; S3. Use fixing components to secure the shortened monorail body to ensure its stability; S4. Connect the shortened monorail body to other components using the connecting device to complete the shortening and installation of the monorail.

[0014] The beneficial effects of this invention are: (1) The coal mine underground monorail shortening device of the present invention, by setting a shortening mechanism and a connecting device, when the monorail needs to be shortened, the length is adjusted by the shortening mechanism. When the appropriate length is reached, it is fixed by the connecting device. It can effectively shorten the length of the coal mine underground monorail, making it more suitable for roadways with limited space and improving transportation efficiency. (2) The coal mine underground monorail shortening device of the present invention has a reasonable shortening mechanism design, which can realize the rapid shortening of the monorail in 15-20 minutes. It has high connection strength, low vibration amplitude, and extended maintenance cycle to 3 months. It is suitable for underground roadways with limited space, improves transportation efficiency and reduces maintenance costs. The connection device is reliable, ensuring the stability and safety of the monorail after shortening. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall connection structure of the coal mine underground monorail shortening device of the present invention; Figure 2 This is a front view of the coal mine underground monorail shortening device of the present invention; Figure 3 This is a schematic diagram of the bottom structure of the coal mine underground monorail shortening device of the present invention; Figure 4 This is a schematic diagram of the bottom structure of the shortening mechanism in the shortening device for a monorail crane in a coal mine of the present invention; Figure 5 This is a schematic diagram of the fixed component structure in the coal mine underground monorail shortening device of the present invention; Figure 6 This is a schematic diagram of the connecting device structure in the coal mine underground monorail shortening device of the present invention.

[0016] In the diagram: 1. Main body of the monorail crane; 101. Suspension rail; 102. Suspension wheel; 103. Crane; 11. Slide rail; 2. Shortening mechanism; 21. Telescopic assembly; 211. Telescopic plate; 212. Hydraulic cylinder; 213. Pressure roller; 214. Embedded rod; 22. Fixing assembly; 221. Waist-shaped groove; 222. Fixing bolt; 223. Locking hole; 224. Nut; 3. Connecting device; 31. Connecting joint; 311. Ring groove; 32. Fastener; 321. Fastening bolt; 322. Spring groove; 323. Vibration damping spring. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] The present invention relates to a shortening device for a monorail crane in an underground coal mine, such as... Figure 1 , 2 As shown, it includes a monorail crane body 1, with a separable partition structure in the middle of the monorail crane body 1. Two shortening mechanisms 2 are connected to the partition structure in the middle of the monorail crane body 1, and the two shortening mechanisms 2 are connected to each other by a connecting device 3.

[0019] Furthermore, the main body 1 of the monorail crane includes a rail 101 and a crane 103. The crane 103 is equipped with a wheel 102, and the crane 103 and the wheel 102 are configured in cooperation. In use, a small cantilever crane is used to lift the monorail body onto the preset rail 101 to ensure that the monorail body is placed horizontally without tilting deviation. The lifting wheel 102 is responsible for providing the travel power and suspension capacity for the monorail body, and the crane 103 is used to lift goods.

[0020] It also includes two connecting plates that are connected to the crane 103, and the two connecting plates are respectively connected to the corresponding shortening mechanism 2.

[0021] The shortening mechanism 2 is installed at the partition structure and is used to drive the monorail main body 1 to move relative to the partition to shorten the overall length. The connecting device 3 is used to fix the two parts of the monorail main body 1 after shortening.

[0022] Furthermore, each shortening mechanism 2 includes a telescopic component 21 and a fixing component 22; the telescopic component 21 is used to drive the relative movement of the monorail body 1; the fixing component 22 is used to fix the position of the shortened monorail body 1.

[0023] like Figure 3 As shown, the telescopic assembly 21 includes a telescopic plate 211. One end of the telescopic plate 211 is slidably mounted on a corresponding connecting plate on the monorail crane body 1. Specifically, the bottom end of the connecting plate is provided with a slide rail 11 that cooperates with the telescopic plate 211, and the end of the telescopic plate 211 away from the connecting device 3 is slidably mounted in the slide rail 11. The other end of the telescopic plate 211 is connected to the connecting device 3. A hydraulic cylinder 212 is provided on the bottom end face of the telescopic plate 211, which is arranged in the same direction as the telescopic plate 211. The working end of the hydraulic cylinder 212 points to the connecting plate connected to the corresponding telescopic plate 211. like Figure 4 As shown, the telescopic plate 211 has a slider at the end away from the connecting device 3. The slider is slidably set in the slide rail 11. A limit groove is opened in the middle part of the slider. The working end of the hydraulic cylinder 212 is fixedly set in the limit groove. A rotating shaft perpendicular to the hydraulic cylinder 212 is rotatably passed through the slider. Pressure rollers 213 are connected to both ends of the rotating shaft. Both pressure rollers 213 are in rotatable contact with the bottom end of the connecting plate.

[0024] During operation, the piston rod of the hydraulic cylinder 212 extends smoothly and drives the telescopic plate 211 to move along the slide rail 11 towards the rear section of the main body. At this time, the pressure wheel 213 at the end of the telescopic plate 211 is in close contact with the inner wall of the bottom of the monorail main body 1 and rolls, which effectively reduces the frictional resistance between the telescopic plate 211 and the slide rail 11, making the telescopic process smoother.

[0025] like Figure 5As shown, the fixing component 22 includes a plurality of locking holes 223 formed on the telescopic plate 211, and a plurality of waist-shaped grooves 221 formed on the connecting plate. The waist-shaped grooves 221 are configured to cooperate with the locking holes 223. It also includes a fixing bolt 222 and a nut 224 configured to cooperate. The fixing bolt 222 passes through the waist-shaped groove 221 and the locking hole 223, and the nut 224 fixes the fixing bolt 222.

[0026] Alternatively, the locking hole 223 is a threaded hole, with the upper end of the fixing bolt 222 set in the waist-shaped groove 221, and the lower end of the fixing bolt 222 threadedly connected to the locking hole 223.

[0027] When the shortening mechanism 2 shortens the main body 1 of the monorail to a suitable position, the fixing bolt 222 is passed through the waist-shaped groove 221 and the locking hole 223, and then the nut 224 is tightened to complete the fixing of the shortening mechanism 2; or the fixing bolt 222 is passed through the waist-shaped groove 221, and then the lower end is screwed into the locking hole 223 to complete the fixing of the shortening mechanism 2.

[0028] Furthermore, such as Figure 6 As shown, the connecting device 3 includes a connecting joint 31, which is connected to two telescopic plates 211 respectively. The connecting joint 31 is disc-shaped and has an annular groove 311 at the bottom. The telescopic plate 211 is provided with an embedded rod 214 that cooperates with the annular groove 311. The embedded rod 214 is slidably disposed in the corresponding annular groove 311. It also includes two fasteners 32, which are used to fasten the connecting joint 31. Both fasteners 32 are semi-circular and mate with the connecting joint 31. Both fasteners 32 are located on the outer periphery of the connecting joint 31 and are fixedly connected to the telescopic plate 211 by fastening bolts 321. Two spring grooves 322 are provided at the center of the port of the two fasteners 32. Vibration damping springs 323 are respectively provided in the spring grooves 322 of the ports of two adjacent fasteners 32. The two fasteners 32 are connected by vibration damping springs 323.

[0029] When fixing the connecting joint 31 and the telescopic plate 211, firstly, the embedding rod 214 at the end of the telescopic plate 211 is naturally inserted into the annular groove 311 of the rear main connecting joint 31 to achieve initial positioning. Then, the inner walls of the two semi-annular fasteners 32 are fitted against the outer circumference of the connecting joint 31, and then the two ends of the two fasteners 32 are tightened to the telescopic plate 211 with the fastening bolts 321. At this time, the vibration damping spring 323 in the annular spring groove 322 in the middle of the fastener 32 is compressed and enters the working state. The vibration damping spring 323 can stably absorb the vibration energy during the operation of the monorail, improve the connection stability at each position, and meet the transportation needs of the underground return airway.

[0030] The present invention relates to a method for shortening a monorail crane in an underground coal mine, the specific method of which is as follows: S1. Determine the required shortening length of the monorail based on the size of the tunnel space. This can be done by measuring the width, height, and other dimensions of the tunnel, as well as the installation location and transportation route of the monorail.

[0031] S2. Operate the shortening mechanism 2 to retract the telescopic component 21, thereby shortening the length of the monorail crane body 1. During operation, attention should be paid to controlling the retraction speed and force of the telescopic component 21 to avoid damage to the monorail crane body 1.

[0032] S3. Use the fixing component 22 to fix the shortened monorail body 1 to ensure its stability. During the fixing process, check whether the connection of the fixing component 22 is firm to ensure that the monorail body 1 will not loosen or fall off during transportation.

[0033] S4. Connect the shortened monorail body 1 to other components using the connecting device 3 to complete the shortening and installation of the monorail. During the connection process, pay attention to checking whether the connection joint 31 and fastener 32 are tight to ensure the stability and safety of the monorail.

[0034] Example 1 This embodiment is based on a shortening device driven by a hydraulic cylinder, and is applied to a monorail hoisting renovation project in a 3m wide return airway in a coal mine.

[0035] During actual underground operations, the width and height of the target return airway are first comprehensively measured using a laser rangefinder to determine the effective passage width of the roadway as 3m. Considering the requirement to reserve a 0.5m safety clearance during monorail transport, it is calculated that the monorail needs to be shortened from its original length of 6m to 4m, a reduction of 2m. Subsequently, the assembled monorail main body 1, shortening mechanism 2, and connecting device 3 are transported to the work site using an underground explosion-proof transport vehicle. A small cantilever crane is used to hoist the monorail main body 1 onto the pre-set rail 101, ensuring that the monorail main body 1 is placed horizontally without tilting deviation. The lifting wheel 102 is responsible for providing the travel power and suspension capacity for the monorail main body 1, and the crane 103 is used for lifting goods.

[0036] See Figures 3-5As shown, the downhole hydraulic station is started, and the pressure is adjusted to 16MPa to provide power to the hydraulic cylinder 212 of the shortening mechanism 2. Since the cylinder body of the hydraulic cylinder 212 is fixed on the inner wall support of the telescopic plate 211, the piston rod will extend smoothly and drive the telescopic plate 211 to move along the slide rail 11 towards the rear section of the main body. At this time, the pressure wheel 213 at the end of the telescopic plate 211 is in close contact with the bottom inner wall of the monorail main body 1 and rolls, which effectively reduces the frictional resistance between the telescopic plate 211 and the slide rail 11, making the extension process smoother. At the same time, the operator can observe the extension length of the piston rod in real time through the stroke display screen of the hydraulic cylinder 212. When the stroke reaches 1m, the telescopic plate retracts by 1m, the total retraction on both sides is 2m, and the total length of the monorail is shortened to 4m. The hydraulic station is immediately shut down and the hydraulic cylinder 212 is stopped.

[0037] See Figures 4-6 As shown, the next step is to fix the bolt. After fitting the 8.8 grade M16 fixing bolt 222 with a 65Mn spring washer, pass it through the waist-shaped groove 221 on the side of the front main body and align it with the corresponding M16 locking hole 223 on the telescopic plate 211. Use a torque wrench to apply 80-100N. Slowly tighten the bolts with torque m until the spring washer is completely flattened. The elastic preload of the spring washer will firmly lock the telescopic plate 211 to the front body to prevent relative slippage during subsequent operation, thus completing the installation and commissioning of the entire shortening device.

[0038] See Figures 5-6 As shown, the connection and reinforcement are finally completed. At this time, the embedded rod 214 at the end of the telescopic plate 211 has naturally been inserted into the annular groove 311 of the rear main body connecting joint 31, achieving initial positioning. The inner walls of the two semi-annular fasteners 32 are in contact with the outer periphery of the connecting joint 31. Then, the two ends of the two fasteners 32 are tightened to the telescopic plate 211 with the fastening bolts 321. At this time, the damping spring 323 in the annular spring groove 322 in the middle of the fastener 32 is compressed to 15mm and enters the working state.

[0039] During the subsequent trial operation, the monorail was started and run unloaded for 30 minutes. The temperature of components such as hydraulic cylinder 212 and pressure roller 213 was monitored by an infrared thermometer to ensure that there was no overheating. At the same time, no obvious abnormal noise was observed at the three connection devices. Then, a 20t simulated weight was loaded for load operation, and the vibration amplitude of the connection parts was measured by an acceleration sensor. After running continuously for 72 hours, the torque of fixing bolt 222 and fastening bolt 321 was checked. There were no signs of loosening, and the connection joint 31 could flexibly drive the front and rear sections of the main body to deflect at the roadway bend without any jamming. The vibration damping spring 323 can stably absorb the vibration energy during the monorail operation, improve the connection stability at each position, and meet the transportation needs of the 3m wide return airway underground.

[0040] After three months of operation, maintenance and inspection of the device revealed that the polytetrafluoroethylene coating on the inner wall of the slide rail 11 showed no obvious wear marks, and the wear of the nitrile rubber layer of the pressure roller 213 was low, which significantly reduced the frequency and cost of maintenance and verified the practicality and reliability of the invention in complex downhole environments.

[0041] Example 2 This embodiment describes a shortening device for a monorail crane in an underground coal mine, such as... Figure 1 , 2 As shown, it includes a monorail crane body 1, with a separable partition structure in the middle of the monorail crane body 1. Two shortening mechanisms 2 are connected to the partition structure in the middle of the monorail crane body 1, and the two shortening mechanisms 2 are connected to each other by a connecting device 3.

[0042] Furthermore, the main body 1 of the monorail crane includes a rail 101 and a crane 103. The crane 103 is equipped with a wheel 102, and the crane 103 and the wheel 102 are configured in cooperation. In use, a small cantilever crane is used to lift the monorail body onto the preset rail 101 to ensure that the monorail body is placed horizontally without tilting deviation. The lifting wheel 102 is responsible for providing the travel power and suspension capacity for the monorail body, and the crane 103 is used to lift goods.

[0043] It also includes two connecting plates that are connected to the crane 103, and the two connecting plates are respectively connected to the corresponding shortening mechanism 2.

[0044] The shortening mechanism 2 is installed at the partition structure and is used to drive the monorail main body 1 to move relative to the partition to shorten the overall length. The connecting device 3 is used to fix the two parts of the monorail main body 1 after shortening.

[0045] Example 3 In this embodiment of the coal mine underground monorail shortening device, based on embodiment 2, each shortening mechanism 2 further includes a telescopic component 21 and a fixing component 22; the telescopic component 21 is used to drive the relative movement of the monorail body 1; the fixing component 22 is used to fix the position of the shortened monorail body 1.

[0046] like Figure 3 As shown, the telescopic assembly 21 includes a telescopic plate 211. One end of the telescopic plate 211 is slidably mounted on a corresponding connecting plate on the monorail crane body 1. Specifically, the bottom end of the connecting plate is provided with a slide rail 11 that cooperates with the telescopic plate 211, and the end of the telescopic plate 211 away from the connecting device 3 is slidably mounted in the slide rail 11. The other end of the telescopic plate 211 is connected to the connecting device 3. A hydraulic cylinder 212 is provided on the bottom end face of the telescopic plate 211, which is arranged in the same direction as the telescopic plate 211. The working end of the hydraulic cylinder 212 points to the connecting plate connected to the corresponding telescopic plate 211. like Figure 4As shown, the telescopic plate 211 has a slider at the end away from the connecting device 3. The slider is slidably set in the slide rail 11. A limit groove is opened in the middle part of the slider. The working end of the hydraulic cylinder 212 is fixedly set in the limit groove. A rotating shaft perpendicular to the hydraulic cylinder 212 is rotatably passed through the slider. Pressure rollers 213 are connected to both ends of the rotating shaft. Both pressure rollers 213 are in rotatable contact with the bottom end of the connecting plate.

[0047] During operation, the piston rod of the hydraulic cylinder 212 extends smoothly and drives the telescopic plate 211 to move along the slide rail 11 towards the rear section of the main body. At this time, the pressure wheel 213 at the end of the telescopic plate 211 is in close contact with the inner wall of the bottom of the monorail main body 1 and rolls, which effectively reduces the frictional resistance between the telescopic plate 211 and the slide rail 11, making the telescopic process smoother.

[0048] like Figure 5 As shown, the fixing component 22 includes a plurality of locking holes 223 formed on the telescopic plate 211, and a plurality of waist-shaped grooves 221 formed on the connecting plate. The waist-shaped grooves 221 are configured to cooperate with the locking holes 223. It also includes a fixing bolt 222 and a nut 224 configured to cooperate. The fixing bolt 222 passes through the waist-shaped groove 221 and the locking hole 223, and the nut 224 fixes the fixing bolt 222.

[0049] Example 4 In this embodiment of the coal mine underground monorail shortening device, based on embodiment 3, the locking hole 223 is further designed to be a threaded hole. The upper end of the fixing bolt 222 is positioned within the slot 221, and the lower end of the fixing bolt 222 is threaded into the locking hole 223. The fixing bolt 222 is passed through the slot 221 and then its lower end is screwed into the locking hole 223, thus securing the shortening mechanism 2.

[0050] Example 5 In this embodiment of the coal mine underground monorail shortening device, based on embodiment 4, the connecting device 3 further includes a connecting joint 31, which is connected to two telescopic plates 211 respectively. The connecting joint 31 is disc-shaped and has an annular groove 311 at the bottom. The telescopic plate 211 is provided with an embedded rod 214 that cooperates with the annular groove 311. The embedded rod 214 is slidably disposed in the corresponding annular groove 311. It also includes two fasteners 32, which are used to fasten the connecting joint 31. Both fasteners 32 are semi-circular and mate with the connecting joint 31. Both fasteners 32 are located on the outer periphery of the connecting joint 31 and are fixedly connected to the telescopic plate 211 by fastening bolts 321. Two spring grooves 322 are provided at the center of the port of the two fasteners 32. Vibration damping springs 323 are respectively provided in the spring grooves 322 of the ports of two adjacent fasteners 32. The two fasteners 32 are connected by vibration damping springs 323.

[0051] When fixing the connecting joint 31 and the telescopic plate 211, firstly, the embedding rod 214 at the end of the telescopic plate 211 is naturally inserted into the annular groove 311 of the connecting joint 31 of the rear main body to achieve initial positioning. Then, the inner walls of the two semi-annular fasteners 32 are fitted against the outer periphery of the connecting joint 31, and then the two ends of the two fasteners 32 are tightened to the telescopic plate 211 with the fastening bolts 321. At this time, the vibration damping spring 323 in the annular spring groove 322 in the middle of the fastener 32 is compressed and enters the working state. The vibration damping spring 323 can stably absorb the vibration energy during the operation of the monorail, improve the connection stability at each position, and meet the transportation needs of the underground return airway.

[0052] Example 6 The present invention relates to a method for shortening a monorail crane in an underground coal mine, the specific method of which is as follows: S1. Determine the required shortening length of the monorail based on the size of the tunnel space. This can be done by measuring the width, height, and other dimensions of the tunnel, as well as the installation location and transportation route of the monorail.

[0053] S2. Operate the shortening mechanism 2 to retract the telescopic component 21, thereby shortening the length of the monorail crane body 1. During operation, attention should be paid to controlling the retraction speed and force of the telescopic component 21 to avoid damage to the monorail crane body 1.

[0054] S3. Use the fixing component 22 to fix the shortened monorail body 1 to ensure its stability. During the fixing process, check whether the connection of the fixing component 22 is firm to ensure that the monorail body 1 will not loosen or fall off during transportation.

[0055] S4. Connect the shortened monorail body 1 to other components using the connecting device 3 to complete the shortening and installation of the monorail. During the connection process, pay attention to checking whether the connection joint 31 and fastener 32 are tight to ensure the stability and safety of the monorail.

Claims

1. A shortening device for a monorail crane in a coal mine, characterized in that, The system includes a monorail main body (1), which has a separable partition structure in the middle. Two shortening mechanisms (2) are connected to the partition structure in the middle of the monorail main body (1), and the two shortening mechanisms (2) are connected by a connecting device (3).

2. The shortening device for a monorail crane in a coal mine according to claim 1, characterized in that, The main body (1) of the monorail crane includes a rail (101) and a crane (103). The crane (103) is provided with a wheel (102), and the crane (103) and the wheel (102) are configured to cooperate with each other. It also includes two connecting plates connected to the crane (103), and the two connecting plates are respectively connected to the corresponding shortening mechanism (2).

3. The shortening device for a monorail crane in a coal mine according to claim 2, characterized in that, Each of the shortening mechanisms (2) includes a telescopic component (21) and a fixing component (22); The telescopic assembly (21) includes a telescopic plate (211), one end of which is slidably mounted on a corresponding connecting plate on the main body (1) of the monorail crane, and the other end of which is connected to a connecting device (3). A hydraulic cylinder (212) is provided on the bottom end face of the telescopic plate (211) in the same direction as it, and the working end of the hydraulic cylinder (212) points to the connecting plate connected to the corresponding telescopic plate (211). The fixing component (22) includes a plurality of locking holes (223) opened on the telescopic plate (211) and a plurality of waist-shaped grooves (221) opened on the connecting plate. The waist-shaped grooves (221) are configured to cooperate with the locking holes (223). It also includes a fixing bolt (222) and a nut (224) configured to cooperate. The fixing bolt (222) passes through the waist-shaped groove (221) and the locking hole (223), and the nut (224) fixes the fixing bolt (222).

4. The shortening device for a monorail crane in a coal mine according to claim 3, characterized in that, The bottom end of the connecting plate is provided with a slide rail (11) that cooperates with the telescopic plate (211), and the end of the telescopic plate (211) away from the connecting device (3) is slidably disposed in the slide rail (11).

5. The shortening device for a monorail crane in a coal mine according to claim 4, characterized in that, The telescopic plate (211) has a slider at one end away from the connecting device (3). The slider is slidably disposed in the slide rail (11). A limit groove is provided in the middle part of the slider. The working end of the hydraulic cylinder (212) is fixedly disposed in the limit groove. A rotating shaft perpendicular to the hydraulic cylinder (212) is rotatably disposed inside the slider. Pressure wheels (213) are respectively connected to both ends of the rotating shaft. Both pressure wheels (213) are in rotatable contact with the bottom end of the connecting plate.

6. The shortening device for a monorail crane in a coal mine according to claim 3, characterized in that, The locking hole (223) is a threaded hole, the upper end of the fixing bolt (222) is set in the waist-shaped groove (221), and the lower end of the fixing bolt (222) is threadedly connected to the locking hole (223).

7. The shortening device for a monorail crane in a coal mine according to claim 3, characterized in that, The connecting device (3) includes a connecting joint (31), which is connected to two telescopic plates (211) respectively. The connecting joint (31) is disc-shaped and has an annular groove (311) at the bottom. The telescopic plate (211) is provided with an embedded rod (214) that cooperates with the annular groove (311). The embedded rod (214) is movably disposed in the corresponding annular groove (311). It also includes two fasteners (32), both of which are semi-circular and cooperate with the connecting joint (31). Both fasteners (32) are located on the outer periphery of the connecting joint (31). Both fasteners (32) are fixedly connected to the telescopic plate (211) by fastening bolts (321). Two spring grooves (322) are provided at the center of the port of the two fasteners (32). A damping spring (323) is provided in the spring groove (322) of the port of two adjacent fasteners (32). The two fasteners (32) are connected by the damping springs (323).

8. A method for shortening a monorail crane in a coal mine, characterized in that, The specific method using the coal mine underground monorail shortening device as described in any one of claims 1 to 7 is as follows: S1. Determine the length that the monorail needs to be shortened based on the size of the tunnel space; S2. Operate the shortening mechanism (2) to retract the telescopic component (21), thereby shortening the length of the monorail crane body (1); S3. Use fixing components (22) to fix the shortened monorail body (1) to ensure its stability; S4. Connect the shortened monorail body (1) to other components through the connecting device (3) to complete the shortening and installation of the monorail.

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