Explosion-proof cover opening and closing structure of coal mine air return vertical shaft

Abstract

The utility model relates to the technical field of anti-explosion covers of air return vertical shafts, in particular to an opening and closing structure of an anti-explosion cover of a coal mine air return vertical shaft. In order to solve the problem that an explosion-proof cover body in an existing air return vertical shaft explosion-proof cover structure cannot be automatically opened along with shock waves generated by explosion, the novel coal mine air return vertical shaft explosion-proof cover opening and closing structure is provided. Comprising an explosion-proof cover main body, a plurality of groups of air reversing mechanisms and a plurality of groups of opening and closing mechanisms, wherein each group of opening and closing mechanism comprises a first driving oil cylinder and a pulley counterweight assembly, and a pressing block is fixed at the telescopic end of each first driving oil cylinder; each opening and closing mechanism comprises a second driving oil cylinder, a pin shaft, a rotating seat and a lifting seat, the telescopic end of each second driving oil cylinder is connected with the corresponding rotating seat through the corresponding vertically-arranged pin shaft, the end, close to the anti-explosion cover body, of each rotating seat is hinged to the middle of the corresponding lifting seat, and the bottom face of each lifting seat is provided with an inclined face matched with the surface of the anti-explosion cover body. The structure can guarantee normal underground ventilation, and is simple in structure, convenient to operate and high in working efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of air return vertical shaft explosion -proof cover, concretely is a coal mine air return vertical shaft explosion -proof cover opening and closing structure. BACKGROUND

[0002] The air return vertical shaft explosion -proof cover is a special sealing well lid installed on the air exhaust shaft mouth with the main ventilator.

[0003] According to the provisions of the first hundred and sixty -first of " coal mine safety regulations " : " during the main ventilator stop running, must open the explosion -proof door and the relevant air door of shaft mouth, utilize natural wind pressure ventilation. " The one hundred and fifty -ninth of " coal mine safety regulations " provides that " should check the anti -wind facility at least once every quarter, should carry out anti -wind drill once every year, should carry out anti -wind drill once when the mine ventilation system has bigger change. " In order to meet the coal mine safety regulations, the existing air return vertical shaft explosion -proof cover structure includes the explosion -proof cover main part, the drive cylinder that the telescopic end can be up and down telescopic, the telescopic end of drive cylinder is driven to telescopic upwards, and the explosion -proof cover main part opens when the ventilator stops running, and the downhole utilizes natural wind ventilation, when needing to carry out anti -wind drill, the telescopic end of drive cylinder is driven to extend downwards, and the explosion -proof cover main part is pressed tightly, but when the downhole explosion accident occurs, since the explosion -proof cover main part is connected and fixed with drive cylinder by pin shaft, the explosion -proof cover main part cannot open automatically with the shock wave produced by explosion, leading to the main ventilator damage, finally causing the accident to be unable to effectively control, and simultaneously, when needing to check the drive cylinder, the explosion -proof cover main part cannot open at this time, and the telescopic end of drive cylinder is connected with the explosion -proof cover main part through pin shaft, needs to remove the connection of explosion -proof cover main part and pin shaft to check the drive cylinder, and the check test efficiency is low. SUMMARY

[0004] The utility model discloses to solve the problem that the explosion -proof cover main part in the existing air return vertical shaft explosion -proof cover structure cannot open automatically with the shock wave produced by explosion, and provides a new coal mine air return vertical shaft explosion -proof cover opening and closing structure.

[0005] The utility model discloses the following technical scheme is realized:

[0006] A coal mine air return vertical shaft explosion -proof cover structure, including explosion -proof cover main part, multiple groups of anti -wind mechanism, multiple groups of opening and closing mechanism:

[0007] The explosion-proof cover body is uniformly provided with a plurality of anti-wind grooves and a plurality of opening and closing grooves, the plurality of anti-wind grooves and the plurality of opening and closing grooves are arranged in a circumferential direction, each of the plurality of anti-wind grooves is provided with a slot and is arranged away from the center of the explosion-proof cover body, and each of the plurality of opening and closing grooves is provided with a first slot and is arranged away from the center of the explosion-proof cover body;

[0008] The plurality of anti-wind mechanisms are arranged on the outer periphery of the explosion-proof cover body and correspond to the positions of the plurality of anti-wind grooves, each of the plurality of opening and closing mechanisms includes a first drive oil cylinder fixed to the ground and arranged in a radial direction of the explosion-proof cover body, a pulley counterweight assembly, the pulley counterweight assembly includes a pulley, a counterweight block, a steel wire rope, and a fixed support, the pulley is installed on the fixed support, one end of the steel wire rope is fixed to the counterweight block, the other end of the steel wire rope is fixed outside the corresponding anti-wind groove, and the extension end of the first drive oil cylinder is fixed with a pressing block that can be inserted into the corresponding anti-wind groove and can be pressed against the corresponding part of the bottom end of the outer circumferential surface of the explosion-proof cover body.

[0009] The plurality of opening and closing mechanisms are arranged on the outer periphery of the explosion-proof cover body and correspond to the positions of the plurality of opening and closing grooves, each of the plurality of opening and closing mechanisms includes a 7-shaped support fixed to the ground, a second drive oil cylinder arranged vertically, a pin shaft, a rotating seat, and a lifting seat, the fixed end of the second drive oil cylinder is fixed to the top end of the 7-shaped support, the extension end of the second drive oil cylinder is connected to the rotating seat through the vertically arranged pin shaft, the lifting seat is arranged below the rotating seat, one end of the rotating seat close to the explosion-proof cover body is hinged to the middle part of the lifting seat, and the hinge shaft is arranged in a radial direction perpendicular to the corresponding part of the explosion-proof cover body, and one end of the lifting seat close to the explosion-proof cover body is matched with the opening and closing groove, and the bottom surface of the lifting seat is provided with a slope matched with the surface of the explosion-proof cover body.

[0010] Working process: in normal use, the end of the lifting seat close to the explosion-proof cover body is inserted into the corresponding opening and closing groove; when the anti-wind drill needs to be carried out regularly, the extension end of the first drive oil cylinder is driven to extend, the pressing block is extended into the corresponding anti-wind groove and is pressed on the corresponding part of the bottom end of the outer circumferential surface of the explosion-proof cover body, so as to lock the explosion-proof cover body, avoid the failure of anti-wind drill caused by the blowing of the explosion-proof cover body, after the completion of the anti-wind drill, the extension end of the first drive oil cylinder is retracted, and the pressing block is separated from the anti-wind groove; when the main ventilator is powered off, the extension end of the second drive oil cylinder is extended upward, the explosion-proof cover body is lifted, and the explosion-proof cover body is in an open state, ensuring the natural ventilation of the underground and the safety of the personnel, when the main ventilator is powered on, the explosion-proof cover body is closed by the second drive oil cylinder; when the explosion occurs underground and the shock wave is generated, the explosion-proof cover body is lifted by the shock wave, and since the middle part of the lifting seat is hinged to one end of the rotating seat, the lifting seat is lifted together with the explosion-proof cover body, and is separated from the opening and closing groove, after the release of the shock wave, the explosion-proof cover body falls, the lifting seat is rotated into the opening and closing groove, and the explosion-proof cover body returns to the normal state, avoiding the damage of the shock wave to the main ventilator, ensuring the normal work of the main ventilator and the normal ventilation; in addition, the function of the pulley counterweight assembly is to offset the weight of the explosion-proof cover body by the counterweight, so that the lifting of the explosion-proof cover body by the shock wave is more sensitive, and the pulley counterweight assembly can also ensure the explosion-proof cover body to return to the original position when falling.

[0011] Further, each of the opening and closing grooves is also provided with a second slot, each second slot is arranged adjacent to the first slot, and the pin shaft is rotatably connected to the rotating seat. When the second drive oil cylinder needs to be checked and tested, the rotating seat is rotated to make the rotating seat and the lifting seat rotate, the lifting seat is separated from the opening and closing groove through the second slot, and the opening and closing mechanism is separated from the explosion-proof cover body. At this time, the explosion-proof cover body is not opened, and the checking and testing of the second drive oil cylinder can be carried out under the condition of normal ventilation underground, which is convenient to operate and effectively improves the checking and testing efficiency. In addition, the first drive oil cylinder can be checked and tested at any time under the condition that the explosion-proof cover body is not opened and the underground is normally ventilated.

[0012] Further, the fixed support is a T-shaped support, and the pulleys in the counterweight block assembly are two, which are installed at the two ends of the horizontal rod at the top of the T-shaped support, improving the stability of the structure.

[0013] Further, the upper end of the vertical rod of the T-shaped support is fixed perpendicularly to a limiting baffle near one side of the explosion-proof cover body, the limiting baffle does not interfere with the steel wire rope, the end of the limiting baffle coincides with the end of the explosion-proof cover body, and a limiting spring is arranged between the limiting baffle and the end of the horizontal rod near the explosion-proof cover body. When an explosion occurs underground and an impact wave is generated, the explosion-proof cover body rises to release the impact wave, and when the impact wave is too large, the explosion-proof cover body may fly out to injure people and cause impact damage to the pulley, and the limiting baffle and the limiting spring can effectively reduce the risk of the explosion-proof cover body flying out to injure people and the phenomenon of impact damage to the pulley.

[0014] Further, the middle top surface of the lifting seat is fixed with two hinge blocks, the end surface of the rotating seat near the explosion-proof cover body is provided with two hinge through grooves arranged in an up-down manner, the two hinge through grooves are fixed with hinge shafts, and the ends of the two hinge blocks, which are not fixed to the lifting seat, are rotatably connected to the corresponding hinge shafts. The hinge structure at the lifting seat and the rotating seat is specific and standardized.

[0015] Further, the two hinge shafts on the two hinge through grooves are integrally fixed as a total hinge shaft, and the two ends of the total hinge shaft are fixed to the two ends of the end surface of the rotating seat near the explosion-proof cover body. The structure is specific and standardized.

[0016] Further, the bottom end of the pin shaft integrally extends a circular boss, the rotating seat is provided with a reverse T-shaped groove in clearance fit with the bottom end of the pin shaft and the circular boss, and the rotating seat is facilitated to rotate relative to the pin shaft.

[0017] Further, the second driving oil cylinder is linked with the main ventilator for control, namely, when the main ventilator stops, the telescopic end of the second driving oil cylinder is retracted upward to lift the explosion-proof cover body, so that natural ventilation can be ensured when the main ventilator stops, and when the main ventilator resumes ventilation, the telescopic end of the second driving oil cylinder is extended downward to restore the explosion-proof cover body, so that automatic and unmanned control of the explosion-proof cover body is realized.

[0018] Further, the four groups of air reversing mechanisms and the four groups of opening and closing mechanisms are specific and standardized.

[0019] The explosion-proof cover opening and closing structure of the backflow vertical shaft can ensure normal ventilation of the shaft when the main ventilator stops, air reversing is performed, an explosion occurs underground, and the driving oil cylinder is checked and tested, the structure is simple, the operation is convenient, and the working efficiency is high. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings incorporated into the specification and forming a part thereof, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0021] In order to more clearly illustrate the above and other purposes, features and advantages of the present application, the following will further describe the present application. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0022] Figure 1 The overall structure diagram of the opening and closing structure of the explosion-proof cover is shown in the figure.

[0023] Figure 2 The top view of the explosion-proof cover body is shown in the figure.

[0024] Figure 3 The assembly structure front view of the rotating seat, the lifting seat and the pin shaft is shown in the figure.

[0025] Figure 4 The side view of Figure 3 is shown in the figure.

[0026] Figure 5 The top view of Figure 3 is shown in the figure.

[0027] In the figure: 1-explosion-proof cover body, 2-opening and closing groove, 3-anti-wind groove, 4-first drive oil cylinder, 5-pulley, 6-counterweight, 7-steel wire rope, 8-fixed support, 9-pressing block, 10-7-shaped support, 11-second drive oil cylinder, 12-pin shaft, 13-rotating seat, 14-lifting seat, 15-limiting baffle, 16-limiting spring, 17-hinge block, 18-hinge through groove, 19-hinge shaft, 20-circular boss. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the above and other purposes, features and advantages of the present application, the following will further describe the present application. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0029] In the description, it should be noted that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. It should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] Many specific details are set forth in the following description in order to provide a thorough understanding of the present application. However, the present application can be practiced according to other embodiments that can not be described in detail herein; obviously, the embodiments described in the specification are only a part of all possible embodiments of the present application, and are not all the embodiments.

[0031] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0032] As shown in Figure 1 and 2 , a coal mine return air shaft explosion-proof cover structure, comprising an explosion-proof cover body 1, a plurality of anti-wind mechanisms, a plurality of opening and closing mechanisms:

[0033] The explosion-proof cover body 1 is uniformly distributed with a plurality of anti-wind grooves 3 and a plurality of opening and closing grooves 2, the plurality of anti-wind grooves 3 and the plurality of opening and closing grooves 2 are circumferentially spaced, the plurality of anti-wind grooves 3 are each provided with a slot and are arranged towards the direction away from the center of the explosion-proof cover body 1, and the plurality of opening and closing grooves 2 are each provided with a first slot and are arranged towards the direction away from the center of the explosion-proof cover body 1;

[0034] The plurality of anti-wind mechanisms are arranged around the outer periphery of the explosion-proof cover body 1 and correspond to the positions of the plurality of anti-wind grooves 3, each opening and closing mechanism comprises a first drive oil cylinder 4 fixed to the ground and arranged radially along the explosion-proof cover body 1, a pulley 5 counterweight assembly, the pulley 5 counterweight assembly comprises a pulley 5, a counterweight block 6, a steel wire rope 7, and a fixed support 8, the pulley 5 is installed on the fixed support 8, one end of the steel wire rope 7 is fixed to the counterweight block 6, the other end of the steel wire rope 7 is fixed outside the corresponding anti-wind groove 3, and the extension end of the first drive oil cylinder 4 is fixed with a pressing block 9 that can be inserted into the corresponding anti-wind groove 3 and can be pressed against the corresponding part of the bottom end of the outer circumferential surface of the explosion-proof cover body 1;

[0035] The plurality of opening and closing mechanisms are arranged around the outer periphery of the explosion-proof cover body 1 and correspond to the positions of the plurality of opening and closing grooves 2, each opening and closing mechanism comprises a 7-shaped support 10 fixed to the ground, a second drive oil cylinder 11 arranged vertically, a pin shaft 12, a rotating seat 13, and a lifting seat 14, the fixed end of the second drive oil cylinder 11 is fixed to the top end of the 7-shaped support 10, the extension end of the second drive oil cylinder 11 is connected to the rotating seat 13 through the vertically arranged pin shaft 12, the lifting seat 14 is arranged below the rotating seat 13, one end of the rotating seat 13 close to the explosion-proof cover body 1 is hinged to the middle part of the lifting seat 14, and the hinge shaft 19 is arranged perpendicular to the radial direction of the corresponding part of the explosion-proof cover body 1, one end of the lifting seat 14 close to the explosion-proof cover body 1 is matched with the opening and closing groove 2, and the bottom surface thereof is provided with a slope matched with the surface of the explosion-proof cover body 1.

[0036] Working process: in normal use, the end of the lifting seat close to the explosion-proof cover body 1 is inserted into the corresponding opening and closing groove 2; when the regular anti-wind drill is needed, the extension end of the first drive oil cylinder 4 is driven to extend, the pressing block 9 extends into the corresponding anti-wind groove 3 and is pressed on the corresponding part of the bottom end of the outer circumferential surface of the explosion-proof cover body 1, so as to lock the explosion-proof cover body 1, avoid the failure of anti-wind drill caused by the blowing of the explosion-proof cover body 1, and after the completion of the anti-wind drill, the extension end of the first drive oil cylinder 4 is retracted, and the pressing block 9 is separated from the anti-wind groove 3; when the main ventilator is powered off, the extension end of the second drive oil cylinder 11 is upwardly retracted, the explosion-proof cover body 1 is lifted, and the explosion-proof cover body 1 is in an open state, ensuring the natural ventilation of the underground mine and ensuring the safety of the personnel, and when the main ventilator is powered on, the explosion-proof cover body 1 is closed by the second drive oil cylinder 11; when the explosion occurs in the underground mine and the shock wave is generated, the explosion-proof cover body 1 is lifted by the shock wave, and since the middle part of the lifting seat is hinged to one end of the rotating seat 13, the lifting seat is lifted together with the explosion-proof cover body 1, and is separated from the opening and closing groove 2, after the release of the shock wave, the explosion-proof cover body 1 falls, the lifting seat is rotated into the opening and closing groove 2, and the explosion-proof cover body 1 returns to the normal state, avoiding the damage of the shock wave to the main ventilator, ensuring the normal work of the main ventilator, and ensuring the normal ventilation; in addition, the function of the pulley 5 counterweight assembly is to offset the weight of the explosion-proof cover body 1 by the counterweight, so that the lifting of the explosion-proof cover body 1 by the shock wave is more sensitive, and the pulley 5 counterweight assembly can also ensure the explosion-proof cover body 1 to return to the original position when falling.

[0037] In specific implementation, each opening and closing groove 2 is also provided with a second slot, each second slot is arranged adjacent to the first slot, and the pin shaft 12 is rotationally connected to the rotating seat 13. When the second drive oil cylinder 11 needs to be checked and tested, the rotating seat 13 is rotated to make the rotating seat 13 rotate with the lifting seat, and the lifting seat is separated from the opening and closing groove 2, and the opening and closing mechanism is separated from the explosion-proof cover body 1, at this time, the explosion-proof cover body 1 is not opened and the checking and testing of the second drive oil cylinder 11 can be carried out under the condition of normal ventilation in the underground mine, which is convenient to operate and effectively improves the checking and testing efficiency. In addition, the first drive oil cylinder 4 can be checked and tested at any time under the condition that the explosion-proof cover body 1 is not opened and the underground mine is normally ventilated.

[0038] In specific implementation, the fixed support 8 is a T-shaped support, and the pulley 5 in the counterweight sliding block assembly is two, and the two pulleys 5 are installed on the two ends of the horizontal rod of the top of the T-shaped support, improving the stability of the structure.

[0039] In specific implementation, the upper end of the vertical rod of the T-shaped support is fixed vertically near one side of the explosion-proof cover body 1 with a limiting baffle 15, the limiting baffle 15 does not interfere with the steel wire rope 7, the end of the limiting baffle 15 coincides with the end of the explosion-proof cover body 1, and a limiting spring 16 is arranged between the limiting baffle 15 and the end of the horizontal rod near the explosion-proof cover body 1. When an explosion occurs underground and an impact wave is generated, the explosion-proof cover body 1 rises to release the impact wave. When the impact wave is too large, the explosion-proof cover body 1 may fly out to injure people and cause impact damage to the pulley 5. The limiting baffle 15 and the limiting spring 16 can effectively reduce the risk of the explosion-proof cover body 1 flying out to injure people and the phenomenon of impact damage to the pulley 5.

[0040] In specific implementation, as shown in FIG. 5, the middle top surface of the lifting seat is fixed with two hinge blocks 17, the end surface of the rotating seat 13 near the explosion-proof cover body 1 is provided with two hinge through grooves 18 arranged in an up-down manner, the two hinge through grooves 18 are each fixed with a hinge shaft 19, and the end of each of the two hinge blocks 17, which is not fixed with the lifting seat, is rotationally connected to the corresponding hinge shaft 19. The hinge structure at the lifting seat and the rotating seat 13 is specified and standardized. Figure 3 、 4

[0041] In specific implementation, the two hinge shafts 19 on the two hinge through grooves 18 are integrally fixed as one total hinge shaft 19, and the two ends of the total hinge shaft 19 are fixed to the two ends of the end surface of the rotating seat 13 near the explosion-proof cover body 1. The structure is specified and standardized.

[0042] In specific implementation, the bottom end of the pin shaft 12 integrally extends with a circular boss 20, and the rotating seat 13 is provided with a reverse T-shaped groove in clearance fit with the bottom end of the pin shaft 12 and the circular boss 20, so as to facilitate the rotation of the rotating seat 13 relative to the pin shaft 12.

[0043] In specific implementation, the second driving oil cylinder 11 is linked with the main ventilator for control, that is, when the main ventilator stops, the telescopic end of the second driving oil cylinder 11 is retracted upward to lift the explosion-proof cover body 1, so as to ensure that the underground can be naturally ventilated when the main ventilator stops. When the main ventilator resumes ventilation, the telescopic end of the second driving oil cylinder 11 is elongated downward to restore the explosion-proof cover body 1, so as to realize the automatic and unmanned control of the explosion-proof cover body 1.

[0044] In specific implementation, the four groups of anti-wind mechanisms and the four groups of opening and closing mechanisms are provided, and the structure is specified and standardized.

[0045] ​The above merely describes specific implementation manners of the present application, and enables those skilled in the art to understand or implement the present application. Although the foregoing embodiments are described in detail, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and should be covered in the protection scope of the claims.

Claims

1. A structure for opening and closing an explosion-proof cover in a coal mine return air shaft, characterized in that, Includes the explosion-proof cover body (1), multiple sets of anti-wind mechanisms, and multiple sets of opening and closing mechanisms; The explosion-proof cover body (1) is evenly distributed with multiple reverse air grooves (3) and multiple opening and closing grooves (2). The multiple reverse air grooves (3) and multiple opening and closing grooves (2) are arranged circumferentially at intervals. Each of the multiple reverse air grooves (3) has a groove opening and is arranged in a direction away from the center of the explosion-proof cover body (1). Each of the multiple opening and closing grooves (2) has a first groove opening and the first groove opening is arranged in a direction away from the center of the explosion-proof cover body (1). Multiple sets of anti-ventilation mechanisms are arranged around the outside of the explosion-proof cover body (1) and correspond to the positions of multiple anti-ventilation slots (3). Each set of opening and closing mechanisms includes a first drive cylinder (4) fixed to the ground and its extension direction is arranged radially along the explosion-proof cover body (1), a pulley (5) counterweight assembly. The pulley (5) counterweight assembly includes a pulley (5), a counterweight block (6), a wire rope (7), and a fixed bracket (8). The pulley (5) is installed on the fixed bracket (8). One end of the wire rope (7) is fixed to the counterweight block (6), and the other end of the wire rope (7) is fixed to the outside of the corresponding anti-ventilation slot (3). The extension end of the first drive cylinder (4) is fixed with a pressing block (9) that can be inserted into the corresponding anti-ventilation slot (3) and can be pressed against the corresponding part of the bottom end of the outer circumference of the explosion-proof cover body (1). Multiple opening and closing mechanisms are arranged around the outer perimeter of the explosion-proof cover body (1) and correspond to the positions of multiple opening and closing slots (2). Each opening and closing mechanism includes a 7-shaped bracket (10) fixed to the ground, a vertically arranged second drive cylinder (11), a pin (12), a rotating seat (13), and a lifting seat (14). The fixed end of the second drive cylinder (11) is fixed to the top of the 7-shaped bracket (10), and the telescopic end of the second drive cylinder (11) is connected by a vertically arranged pin. (12) Connected to the rotating seat (13), the lifting seat (14) is arranged below the rotating seat (13). The end of the rotating seat (13) near the explosion-proof cover body (1) is hinged to the middle of the lifting seat (14) and the hinge shaft (19) is arranged in the radial direction perpendicular to the corresponding part of the explosion-proof cover body (1). The end of the lifting seat (14) near the explosion-proof cover body (1) is adapted to the opening and closing groove (2) and its bottom surface is provided with an inclined surface adapted to the surface of the explosion-proof cover body (1).

2. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 1, characterized in that, Each of the multiple opening and closing slots (2) is also provided with a second slot, and each second slot is arranged adjacent to the first slot. The pin (12) is rotatably connected to the rotating seat (13).

3. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 2, characterized in that, The fixed bracket (8) is a T-shaped bracket. There are two pulleys (5) in the counterweight slider assembly. The two pulleys (5) are installed at both ends of the top horizontal bar of the T-shaped bracket.

4. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 3, characterized in that, A limit baffle (15) is vertically fixed at the upper end of the vertical rod of the T-shaped bracket near the side of the explosion-proof cover body (1). The limit baffle (15) does not interfere with the wire rope (7) and its end coincides with the end of the explosion-proof cover body (1). A limit spring (16) is provided between the limit baffle (15) and the end of the horizontal rod near the explosion-proof cover body (1).

5. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 4, characterized in that, Two hinge blocks (17) are fixed on the top surface of the middle part of the lifting seat. Two hinge slots (18) are arranged vertically on one end face of the rotating seat (13) near the explosion-proof cover body (1). A hinge shaft (19) is fixed on each of the two hinge slots (18). The ends of the two hinge blocks (17) that are not fixed to the lifting seat are rotatably connected to the corresponding hinge shafts (19).

6. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 5, characterized in that, The two hinge shafts (19) on the two hinge slots (18) are fixed as a whole as a total hinge shaft (19), and the two ends of the total hinge shaft (19) are fixed to the two ends of the rotating seat (13) near the end face of the explosion-proof cover body (1).

7. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 6, characterized in that, The bottom end of the pin (12) is integrally extended with a circular boss (20), and the rotating seat (13) is provided with an inverted T-shaped groove that is clearance-fitted with the bottom end of the pin (12) and the circular boss (20).

8. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 7, characterized in that, The second drive cylinder (11) is linked to the main ventilation fan for control.

9. The explosion-proof cover opening and closing structure for a coal mine return air shaft according to claim 8, characterized in that, There are four sets of reversing mechanisms and four sets of opening and closing mechanisms.

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