Coal mine roof fall early warning device

Abstract

The utility model provides a coal mine roof fall early warning device, which belongs to the field of laneway engineering and comprises a base, two ends of the base are respectively and rotatably connected with a first support frame, the two first support frames are movably connected through a contact opening mechanism, and each first support frame is fixedly connected with a second support frame through a reinforcing frame. The second supporting frame is fixedly connected with the third supporting frame, the third supporting frame is fixedly connected with the first supporting frame through the reinforcing plate, the top of the third supporting frame is connected with the alarm body through the sensing falling-off assembly, the alarm body is located above the reinforcing plate, the contact opening mechanism is located below the reinforcing plate, and a through hole is formed in the position, directly facing the alarm body, of the reinforcing plate. When roof collapse occurs, the alarm body works, when the collapse critical point is reached, the alarm body falls downwards, penetrates through the through hole in the reinforcing plate, touches and falls into the contact opening mechanism, the contact opening mechanism is separated from the first supporting frame to form a safety area, and the alarm body is located in the safety area and is prevented from being damaged.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of well and roadway engineering, especially relates to a coal mine roof fall early warning device. BACKGROUND

[0002] The coal mine roof fall mainly refers to the phenomenon that the coal mine roof rock collapses naturally due to the change of the original mine pressure balance caused by the influence of the mining in the actual mining process. When the coal mine roof falls, the staff needs to be timely reminded to move to a safe area, so as to avoid causing serious casualties. The existing alarm device will issue an alarm when sensing the change of the roof pressure. However, when the roof fall event occurs, the alarm device may be damaged due to the sudden strong extrusion force and cannot continue to issue the alarm. Moreover, the alarm device cannot send the rescue signal externally due to the damage, which brings great difficulty to the rescue work. SUMMARY

[0003] The utility model is used for solving the problem that the alarm body is easily damaged due to the sudden extrusion force when the roof fall occurs.

[0004] The utility model solves the above technical problem through the following technical scheme: a coal mine roof fall early warning device, the device comprises a base, one first support frame is rotationally connected to each end of the base, two first support frames are movably connected through a contact opening mechanism, each first support frame is fixedly connected to a second support frame through a reinforcing frame, the second support frame is fixedly connected to a third support frame, the third support frame is fixedly connected to the first support frame through a reinforcing plate, the top of the third support frame is connected to an alarm body through an induction falling component, the alarm body is located above the reinforcing plate, the contact opening mechanism is located below the reinforcing plate, and the reinforcing plate has a through hole at the position opposite to the alarm body.

[0005] In the coal mine roof fall early warning device, the base, the first support frame, the second support frame and the third support frame form an integral support structure, the reinforcing frame stably connects the first support frame and the second support frame, and the reinforcing plate stably connects the first support frame and the third support frame. When there is no roof fall, the device can play a good supporting role. When the roof fall occurs, the induction falling component can detect the strong extrusion to make the alarm body work. When reaching the critical point of collapse, the alarm body is separated from the third support frame and falls downward, passes through the through hole on the reinforcing plate, touches and falls into the contact opening mechanism, and the contact opening structure can form a safe area after being separated from the first support frame. The alarm body is located in the safe area and can avoid being damaged due to the sudden extrusion force.

[0006] Preferably, the through hole on the reinforcing plate is located at the center position of the reinforcing plate and has a diameter greater than that of the alarm body.

[0007] Preferably, the contact opening mechanism comprises a connecting frame, a receiving bag and a second induction sheet, one end of the connecting frame is rotatably connected to the end of a first support frame, the other end of the connecting frame has a folding groove, the folding groove has a first clamping block, the end of the other first support frame has a first clamping groove, the first clamping block is clamped in the first clamping groove and is connected with a first electric telescopic rod, the second induction sheet is located on the upper surface of the connecting frame, and the receiving bag is located on the lower surface of the connecting frame.

[0008] Preferably, the end of the first support frame where the first clamping groove is located has a buffer cavity, and the edge of the first support frame where the buffer cavity is located is arc-shaped.

[0009] Preferably, the connecting frame has a through hole at the center position, the second induction sheet is located at the through hole on the connecting frame and directly below the through hole on the reinforcing plate, and the opening of the receiving bag is directly below the second induction sheet.

[0010] Preferably, the induction falling assembly comprises a first induction sheet and a second clamping block, the first induction sheet is located on the upper surface of a third support frame, the second clamping block is located on the top of an alarm body, the bottom of the third support frame has a second clamping groove, the second clamping block is clamped in the second clamping groove and is connected with a second electric telescopic rod.

[0011] Preferably, the second clamping groove is arc-shaped in cross section, and the second clamping block is C-shaped in cross section.

[0012] Preferably, one end of the first support frame is rotatably connected to the end of a base, the other end of the first support frame has two irregularly shaped clamping blocks, the ends of the reinforcing frame and the reinforcing plate each have an irregularly shaped clamping groove, and the irregularly shaped clamping blocks are clamped with the irregularly shaped clamping grooves.

[0013] Preferably, the third support frame comprises an outer support sheet and an inner support sheet, one end of the outer support sheet is fixedly connected to one end of the inner support sheet, the other end of the outer support sheet is fixedly connected to the end of a second support frame, and the other end of the inner support sheet is fixedly connected to a reinforcing plate.

[0014] Preferably, the first support frame is arc-shaped in cross section, the second support frame and the third support frame jointly form an arch surface shape, the first support frame, the reinforcing frame and the third support frame are non-hollow, and the second support frame, the reinforcing plate and the connecting frame are hollow.

[0015] The advantage of the utility model lies in:

[0016] (1) The utility model discloses a coal mine roof fall early warning device, base, first support frame, second support frame and third support frame form integral support structure, and the first support frame and the second support frame are stably connected by the reinforcing frame, and the first support frame and the third support frame are stably connected by the reinforcing plate, when there is no roof fall, the device can play a good supporting role, when the roof fall appears, the inductive falling component can detect the strong extrusion and make the alarm body work, when reaching the critical point of collapse, the alarm body separates from the third support frame and falls down, passes through the through -hole on the reinforcing plate, touches and falls into the contact opening mechanism, the contact opening mechanism can form a safety area after separating from the first support frame, and the alarm body is located in the safety area, which can avoid damage caused by the sudden extrusion force, so that the alarm body can continue to work and continuously send out the alarm to the outside, so that the staff has more survival possibility when the uncontrollable accident occurs.

[0017] (2) When the roof fall appears, the first support frame in the utility model discloses a coal mine roof fall early warning device loses the support of the connecting frame and generates the inward folding force, and the second support frame and the third support frame generate the extrusion deformation along with the beginning of the collapse, continuously push the first support frame to fold inward, and then the first support frame is completed and the first support frame and the base form a triangular safety space, and the area is enough for two people to squat in it, which can temporarily protect the trapped personnel during the rescue process and reduce the possibility of injury.

[0018] (3) The utility model discloses a first clamping groove is arranged at the end of the first support frame, a first clamping block is arranged at the end of the connecting frame, the first clamping block can be quickly clamped in the first clamping groove, the connecting frame is connected with the first support frame and becomes an integral whole, so that the top of the first support frame is fixed, the first support frame and the connecting frame play a good supporting effect on the second support frame and the third support frame, the stability of the tunnel of coal mining is better, and the possibility of roof fall is reduced.

[0019] (4) The utility model discloses a second clamping groove is arranged at the bottom of the third support frame, and a second clamping block is arranged at the top of the alarm body, so that the alarm body can be quickly clamped and fixed in the second clamping groove. When the roof fall occurs, the first sensing sheet can receive the induction in time and transmit the signal to the alarm body, the alarm body sends out the alarm, reminds the staff in the tunnel to evacuate quickly, when the signal reaches a certain intensity, the second electric telescopic rod receives the signal and starts, the second clamping block separates from the second clamping groove, the alarm body separates from the second support frame, and the alarm body falls down to the receiving bag under the action of gravity, so that the alarm body is prevented from being damaged under the oppression of the strong pressure.

[0020] (5) The utility model discloses the cross section of first support frame 2 is arranged as arc, make the first support frame in the use process has the force of the inwards extrusion to the connecting frame, make the stability of connecting frame better. The arch surface shape that second support frame and third support frame form together makes the stress of whole device in the use process be more even, increase the stability of device and the cooperation degree between structure, second support frame, reinforcing plate, connecting frame are all arranged as the hollow, can reduce the use of material, reduce production cost, first support frame, reinforcing frame and third support frame are all arranged as non-hollow, can strengthen the strength of device, protection is more comprehensive, and prevent dust or ballast from entering from the gap of device. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The utility model provides a coal mine roof fall early warning device three -dimensional structure schematic diagram for embodiment of the utility model;

[0022] Figure 2 For Figure 1 The utility model provides a coal mine roof fall early warning device first use state structure schematic diagram for embodiment of the utility model;

[0023] Figure 3 The utility model provides a coal mine roof fall early warning device second use state structure schematic diagram for embodiment of the utility model;

[0024] Figure 4 The utility model provides a coal mine roof fall early warning device second use state structure schematic diagram for embodiment of the utility model;

[0025] Figure 5 The utility model provides a coal mine roof fall early warning device second use state structure schematic diagram for embodiment of the utility model;

[0026] Figure 6 The utility model provides a coal mine roof fall early warning device second use state structure schematic diagram for embodiment of the utility model;

[0027] In the drawing: 1 base, 2 first support frame, 3 reinforcing frame, 4 second support frame, 5 reinforcing plate, 6 third support frame, 61 outer support piece, 62 inner support piece, 7 connecting frame, 8 receiving bag, 9 alarm body, 10 first induction sheet, 11 first clamping groove, 12 buffer cavity, 13 first clamping block, 14 first electric telescopic rod, 15 second clamping groove, 16 second clamping block, 17 second electric telescopic rod, 18 second induction sheet. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the utility model clearer and more apparent, the technical scheme of the utility model is described clearly and completely below in combination with specific embodiments and with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0029] As shown in Figure 1 The embodiment provides a coal mine roof fall early warning device which comprises a base 1, one first support frame 2 is rotationally connected to each end of the base 1, the end of the base 1 is connected with one end of the first support frame 2 through a pin shaft, the one end of the first support frame 2 is provided with a pin shaft, a through hole matched with the pin shaft is formed in the upper surface of the base 1, the pin shaft is inserted into the through hole in the base 1, and the two first support frames 2 are movably connected through a contact opening mechanism; the contact opening mechanism comprises a connecting frame 7, a receiving bag 8 and a second induction sheet 18; one end of the connecting frame 7 is rotationally connected to the end of one of the first support frames 2, for example, the one end of the connecting frame 7 is provided with a pin shaft, a through hole matched with the pin shaft is formed in the end of the first support frame 2, and the pin shaft is inserted into the through hole in the end of the first support frame 2 to realize that the one end of the connecting frame 7 is fixedly connected to the end of the first support frame 2 and can rotate around the end of the first support frame 2.

[0030] As shown in Figure 2 The other end of the connecting frame 7 is provided with a folding groove, the folding groove is provided with a first clamping block 13, the end of the other first support frame 2 is provided with a first clamping groove 11, the first clamping block 13 is clamped in the first clamping groove 11 and is connected with a first electric telescopic rod 14, the first electric telescopic rod 14 is a one-way telescopic rod, the power source used by the first electric telescopic rod 14 is a battery mounted in the connecting frame 7, the first electric telescopic rod 14 drives the first clamping block 13 to move, and the first clamping block 13 can be clamped or separated from the first clamping groove 11. By arranging the first clamping groove 11 in the end of the first support frame 2 and arranging the first clamping block 13 in the end of the connecting frame 7, when the device is installed, the first clamping block 13 can be quickly clamped in the first clamping groove 11 under the control of the first electric telescopic rod 14, so that the connecting frame 7 is connected with the first support frame 2 as a whole, the top of the first support frame 2 is fixed, the first support frame 2 cooperates with the connecting frame 7 to well support the second support frame 4 and the third support frame 6, the stability of the tunnel for coal mining is better, and the possibility of roof fall is reduced. When an accident occurs, the first clamping block 13 can be quickly separated from the first clamping groove 11, so that the connecting frame 7 is folded downward under the action of gravity, and a safe triangular protection space is formed.

[0031] As shown in Figure 1The second induction sheet 18 is located on the upper surface of the connecting frame 7, and the receiving bag 8 is located on the lower surface of the connecting frame 7. Specifically, the connecting frame 7 has a through hole at the center position, the second induction sheet 18 is located on the through hole of the connecting frame 7 and directly below the through hole of the reinforcing plate 5, the opening of the receiving bag 8 is located directly below the second induction sheet 18, the receiving bag 8 is wide at the top and narrow at the bottom, and the material of the receiving bag 8 is cotton and linen.

[0032] The other end of each first support frame 2 is fixedly connected to the second support frame 4 through the reinforcing frame 3, the second support frame 4 is fixedly connected to the third support frame 6, and the third support frame 6 is fixedly connected to the other end of the first support frame 2 through the reinforcing plate 5, as shown in Figure 3 The third support frame 6 includes an outer support sheet 61 and an inner support sheet 62, one end of the outer support sheet 61 is fixedly connected to one end of the inner support sheet 62, the other end of the outer support sheet 61 is fixedly connected to the end of the second support frame 4, and the other end of the inner support sheet 62 is fixedly connected to the reinforcing plate 5.

[0033] Referring to Figure 4 The other end of the first support frame 2 has two irregular-shaped clamping blocks, one end of the reinforcing frame 3 and the reinforcing plate 5 has an irregular-shaped clamping groove, and the irregular-shaped clamping block is clamped with the irregular-shaped clamping groove. The other end of the reinforcing frame 3 can be fixedly connected to the second support frame 4 through a threaded connection, for example, the other end of the reinforcing frame 3 is provided with a threaded hole, and the side surface of the second support frame 4 is provided with a screw matched with the threaded hole. The first support frame 2 and the second support frame 4 are connected together through the reinforcing frame 3 as a medium, so as to realize the tightness and stability of the connection between the first support frame 2 and the second support frame 4.

[0034] The bottom of the third support frame 6 is connected to the second support frame 4 through a threaded connection, for example, the bottom of the outer support sheet 61 is provided with a threaded hole, and the top of the second support frame 4 is provided with a screw matched with the threaded hole. The two ends of the reinforcing plate 5 are fixedly connected to the third support frame 6 through a threaded connection, and the two ends of the reinforcing plate 5 are also fixedly welded to the top of the second support frame 4. For example, one end of the outer support sheet 61 is fixedly welded to one end of the inner support sheet 62, the other end of the outer support sheet 61 is provided with a threaded groove, the two ends of the reinforcing plate 5 are provided with screws matched with the threaded groove, the other end of the inner support sheet 62 is fixedly welded to the top of the reinforcing plate 5, and the reinforcing plate 5 and the inner support sheet 62 form a triangle. By arranging the reinforcing plate 5 between the first support frame 2 and the third support frame 6, a good supporting effect can be achieved on the overall supporting structure, so as to ensure the stable connection between the first support frame 2 and the third support frame 6. By arranging the inner support sheet 62, and the two inner support sheets 62 and the reinforcing plate 5 forming a triangle, the strength of the device can be further enhanced.

[0035] As shown in Figure 5 and Figure 6As shown, the top of the third support frame 6 is connected with the alarm body 9 through an induction falling assembly, which comprises a first induction sheet 10 and a second clamping block 16. The first induction sheet 10 is located on the upper surface of the third support frame 6, and the second clamping block 16 is located on the top of the alarm body 9. The bottom of the third support frame 6 has a second clamping groove 15, and the second clamping block 16 is clamped in the second clamping groove 15 and is connected with a second electric telescopic rod 17. The cross section of the second clamping groove 15 is arc-shaped, and the cross section of the second clamping block 16 is C-shaped. The second electric telescopic rod 17 is a bidirectional telescopic rod, and the power supply used by the alarm body 9 and the second electric telescopic rod 17 is supplied together by a battery installed in the alarm body 9. The second electric telescopic rod 17 drives two second clamping blocks 16 to move towards or away from each other, thereby realizing the quick and stable installation of the alarm body 9 on the bottom of the third support frame 6 or the quick disengagement of the alarm body 9 from the bottom of the third support frame 6.

[0036] By arranging the second clamping groove 15 on the bottom of the third support frame 6 and the second clamping block 16 on the top of the alarm body 9, the alarm body 9 can be quickly clamped and fixed in the second clamping groove 15 under the control of the second electric telescopic rod 17. When a roof fall event occurs, the first induction sheet 10 can timely receive induction and transmit signals to the alarm body 9, and the alarm body 9 can issue an alarm to remind the staff in the tunnel to evacuate quickly. When the signal reaches a certain intensity, the second electric telescopic rod 17 receives the signal and starts, the second clamping block 16 is disengaged from the second clamping groove 15, the alarm body is separated from the second support frame 6, and the alarm body 9 falls downward under the action of gravity and falls into the receiving bag 8, thereby preventing the alarm body 8 from being damaged under the oppression of the strong pressure suddenly generated.

[0037] The alarm body 9 is located above the reinforcing plate 5, the contact opening mechanism is located below the reinforcing plate 5, and the reinforcing plate 5 has a through hole opposite the position of the alarm body 9. The through hole on the reinforcing plate 5 is located at the center of the reinforcing plate 5 and has a diameter larger than that of the alarm body 9. When the alarm body 9 falls downward from the bottom of the third support frame 6, the alarm body 9 will pass through the through hole on the reinforcing plate 5 and fall into the receiving bag 8. In this process, the alarm body 9 will touch the second sensing sheet 18 on the upper surface of the connecting frame 7, thereby triggering the first electric telescopic rod 14 to move the first clamping block 13 away from the first clamping groove 11 and into the folding groove of the connecting frame 7. The end of the connecting frame 7 where the first clamping block 13 is installed is separated from the end of the first support frame 2 and rotates downward around the other end of the connecting frame 7. The top of the two first support frames 2 moves towards each other due to the extrusion from the upper layer until the two ends of the first support frames 2 abut together. At this time, the two first support frames 2 and the base 1 form a safe triangular area, and the alarm body 9 is located in this triangular area, which can avoid being damaged by the sudden strong extrusion force and continue to issue an alarm to remind the staff to evacuate in time. The alarm body 9 can also normally send a rescue signal to help the smooth development of rescue work and increase the survival probability of trapped staff.

[0038] The end of the first support frame 2 where the first clamping groove 11 is located has a buffer cavity 12, which can enhance the extrusion and deformation tendency. The edge of the first support frame 2 where the buffer cavity 12 is located is arc-shaped.

[0039] The cross section of the first support frame 2 is arc-shaped. The arc-shaped design makes the first support frame 2 have a force that extrudes the connecting frame 7 inward during use, making the stability of the connecting frame 7 better. The second support frame 4 and the third support frame 6 jointly form an arch surface shape. The arch surface shape design makes the stress of the entire device more uniform during use, increases the stability of the device and the cooperation degree between structures, and makes the use effect and safety of the device better. The first support frame 2, the reinforcing frame 3, and the third support frame 6 are non-hollow, and the second support frame 4, the reinforcing plate 5, and the connecting frame 7 are hollow. The hollow design can reduce the use of materials and reduce production costs. The first support frame 2, the reinforcing frame 3, and the third support frame 6 are set to be non-hollow, which can enhance the strength of the device, provide more comprehensive protection, and prevent dust or slag from entering from the gaps of the device.

[0040] Working principle: In use, first install and fix the base 1, then rotate and install the first support frame 2 on top of the base 1, then make the connecting frame 7 parallel to the base 1, then activate the first electric telescopic rod 14, so that the first locking block 13 is locked and fixed in the first slot 11, connecting the two sets of first support frames 2 and connecting frame 7 into one unit. Then install the reinforcing frame 3 on top of the first support frame 2, then install the second support frame 4, and connect and fix it to the first support frame 2 through the reinforcing frame 3. Then install the third support frame 6 on top of the second support frame 4, and install the reinforcing plate 5 on the bottom of the third support frame 6. Lock the second locking block 16 on the top of the alarm body 9 into the second slot 15 to quickly install and fix the alarm body 9. During use, if Figure 3 As shown, the first sensor 10 is in contact with the inner wall of the mining tunnel, providing real-time detection and early warning. The coordinated use of the frame provides good support for the underground tunnel. This is the first usage state, meaning there is no roof collapse and all components are in a naturally extended state.

[0041] When a roof collapse occurs, the first sensor 10 detects strong compressive force, causing the alarm body 9 to sound. At this point, there is still some time to escape, and workers quickly evacuate. When it is detected that the tunnel is about to collapse, workers keep their bodies low and run outwards, escaping along the top of the base 1. When the critical point of collapse is reached, the second electric telescopic rod 17 on the top of the alarm body 9 receives a signal, causing the second locking block 16 to separate from the second locking slot 15, separating the alarm body 9 from the third support frame 6. This causes the alarm body 9 to fall downwards under the force of gravity, passing through the reinforcing plate 5. Inside the receiving bag 8, the inclined surface of the receiving bag 8 acts as a buffer guide for the alarm body 9, preventing damage to the alarm body 9 upon fall. Simultaneously, the second sensor 18 receives a contact pressure signal, causing the first electric telescopic rod 14 to receive a signal, resulting in the separation of the first locking block 13 and the first locking slot 11. This causes the connecting frame 7 to retract downwards under the force of gravity. The first support frame 2, losing the support of the connecting frame 7, generates an inward retraction force. As the collapse begins, the second support frame 4 and the third support frame 6 undergo compression deformation, continuously pushing the first support frame 2 to retract further inwards. Subsequently, the first support frame 2 completes its retraction. Figure 4For the second use state, all components are deformed by extrusion, the first support frame 2 and the base 1 form a triangular safety space, the transverse space is enough for two people to squat in it, and the alarm body 9 is received in it and is not damaged by strong extrusion force, so that the alarm body 9 can continue to send signals to the outside, facilitating the rescue work, then the second support frame 4 and the third support frame 6 continue to deform until the tunnel collapses completely, the small space formed by the base 1 and the first support frame 2 reduces the possibility of injury of the escapee, and the possibility of survival while waiting for rescue in the space is greater, and the alarm body 9 can also be used to indicate the position of the person to the outside, further increasing the possibility of survival, and the device has simple structure and better safety in use.

[0042] The coal mine roof falling early warning device can not only quickly send an alarm when a roof falling event occurs, but also drop the alarm body 9 when the mining tunnel is about to collapse, so as to prevent the alarm body 9 from being damaged by the strong extrusion suddenly generated, the alarm body falls into the receiving bag 8, the second induction sheet 18 receives induction, the contact opening mechanism opens the connecting frame 7, and the two groups of first support frames 2 are inwards folded to form a narrow and stable triangular space with the base 1, at this time, the staff who fail to escape in time can hide in the space, the alarm body 9 is collected in the space, so that it can continue to work and continuously send an alarm to the outside, so that the staff has more possibility of survival when an uncontrollable accident occurs, and the safety of the device is higher in cooperation between structures.

[0043] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A coal mine roof collapse early warning device, characterized in that: The device comprises a base (1), the two ends of the base (1) are rotatably connected with a first support frame (2), the two first support frames (2) are movably connected through a contact opening mechanism, each first support frame (2) is fixedly connected with a second support frame (4) through a reinforcing frame (3), the second support frame (4) is fixedly connected with a third support frame (6), the third support frame (6) is fixedly connected with the first support frame (2) through a reinforcing plate (5), the top of the third support frame (6) is connected with an alarm body (9) through an induction falling assembly, the alarm body (9) is located above the reinforcing plate (5), the contact opening mechanism is located below the reinforcing plate (5), the reinforcing plate (5) has a through hole at the position opposite to the alarm body (9).

2. The coal mine roof fall early warning device according to claim 1, characterized in that: The through hole on the reinforcing plate (5) is located at the center of the reinforcing plate (5) and the diameter of the through hole is larger than the diameter of the alarm body (9).

3. The coal mine roof fall early warning device according to claim 1, characterized in that: The contact opening mechanism comprises a connecting frame (7), a receiving bag (8) and a second induction sheet (18), one end of the connecting frame (7) is rotatably connected with the end of the first support frame (2), the other end of the connecting frame (7) has a folding groove, the folding groove has a first clamping block (13) therein, the end of the other first support frame (2) has a first clamping groove (11), the first clamping block (13) is clamped in the first clamping groove (11) and is connected with a first electric telescopic rod (14), the second induction sheet (18) is located on the upper surface of the connecting frame (7), and the receiving bag (8) is located on the lower surface of the connecting frame (7).

4. The coal mine roof fall early warning device according to claim 3, characterized in that: The end of the first support frame (2) where the first clamping groove (11) is located has a buffer cavity (12), and the edge of the first support frame (2) where the buffer cavity (12) is located is in arc shape.

5. The coal mine roof fall early warning device according to claim 3, characterized in that: The connecting frame (7) has a through hole at the center thereof, the second induction sheet (18) is located at the through hole on the connecting frame (7) and directly below the through hole on the reinforcing plate (5), and the opening of the receiving bag (8) is directly below the second induction sheet (18).

6. The coal mine roof fall early warning device according to claim 1, characterized in that: The induction falling assembly comprises a first induction sheet (10) and a second clamping block (16), the first induction sheet (10) is located on the upper surface of the third support frame (6), the second clamping block (16) is located on the top of the alarm body (9), the bottom of the third support frame (6) has a second clamping groove (15), the second clamping block (16) is clamped in the second clamping groove (15) and is connected with a second electric telescopic rod (17).

7. The coal mine roof fall early warning device according to claim 6, characterized in that: The second clamping groove (15) is in arc shape in cross section, and the second clamping block (16) is in C shape in cross section.

8. The coal mine roof fall early warning device according to claim 1, characterized in that: One end of the first support frame (2) is rotatably connected with the end of the base (1), the other end of the first support frame (2) has two irregular clamping blocks, the ends of the reinforcing frame (3) and the reinforcing plate (5) have irregular clamping grooves, and the irregular clamping blocks are clamped in the irregular clamping grooves.

9. The coal mine roof falling early warning device according to claim 1, characterized in that: The third support frame (6) comprises an outer support sheet (61) and an inner support sheet (62), one end of the outer support sheet (61) is fixedly connected with one end of the inner support sheet (62), the other end of the outer support sheet (61) is fixedly connected with the end of the second support frame (4), and the other end of the inner support sheet (62) is fixedly connected with the reinforcing plate (5).

10. The coal mine roof fall early warning device according to claim 1, characterized in that: The cross section of the first support frame (2) is arc-shaped, the second support frame (4) and the third support frame (6) jointly form an arch surface shape, the first support frame (2), the reinforcing frame (3) and the third support frame (6) are non-hollow, and the second support frame (4), the reinforcing plate (5) and the connecting frame (7) are hollow.

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