A blasting protection device for a tunnel portal

Abstract

The utility model belongs to the security protection technical field of blasting construction, especially to the automation and security of security protection device are strengthened design, a kind of blasting protection device for tunnel portal, including support and flexible protective curtain, further include lifting transmission assembly and towrope;The support is installed above tunnel portal, the top of flexible protective curtain is fixed on the support, and its bottom is connected with lifting transmission assembly by towrope;Lifting transmission assembly is assembled on support, for driving towrope reciprocating motion along the height direction of support, make flexible protective curtain switch between deployment protection state and stowed state.

Description

Technical Field

[0001] This utility model belongs to the field of safety protection technology for blasting construction, and in particular focuses on enhancing the automation and safety of safety protection devices. Background Technology

[0002] Tunnel blasting is a highly dangerous operation, and the resulting flyrock is a critical factor that must be strictly controlled during construction. The potential hazards of flyrock during blasting operations should not be underestimated; they can range from minor damage to surrounding buildings to serious injuries or even fatalities.

[0003] In existing tunnel blasting protection technologies, the traditional approach is to hang protective curtains at the tunnel entrance. However, the assembly process is highly dependent on excavators, resulting in complex operations, low efficiency, and insufficient curtain stability. Chinese patent CN107782211A proposes a coal mine blasting protection shelter solution. This solution employs a foldable support frame and a nylon mesh composite structure, with built-in rubber partitions and sound-absorbing cotton for dual protection. The curtain has ventilation holes to ensure air circulation. A rotating connecting rod mechanism enables rapid deployment, and combined with a bottom sand-filled fixing seat and a ring anchor point stabilization device, it balances portability, impact resistance, noise reduction, and rapid deployment requirements.

[0004] However, the aforementioned patented technology still has significant technical shortcomings in practical applications. On the one hand, the sand-filled fixing base at the bottom of the device has high requirements for sand ratio and ground flatness, and is prone to settlement and displacement in soft soil foundations or sloping terrain, weakening the overall stability. On the other hand, the device occupies ground space after being retracted, affecting the passage of construction equipment inside the tunnel. Utility Model Content

[0005] In order to overcome the shortcomings of the prior art, a blast protection device for tunnel entrances is provided.

[0006] This utility model is achieved through the following technical solution: a blasting protection device for tunnel entrances, comprising a support and a flexible protective curtain, and further comprising a lifting transmission assembly and a traction rope; the support is installed above the tunnel entrance, the top end of the flexible protective curtain is fixed to the support, and its bottom end is connected to the lifting transmission assembly through the traction rope; the lifting transmission assembly is mounted on the support and is used to drive the traction rope to reciprocate along the height direction of the support, so that the flexible protective curtain switches between an unfolded protective state and a retracted state.

[0007] Preferably, the bottom of the flexible protective curtain is provided with a first reinforcing tube, and the middle and bottom of the flexible protective curtain are provided with a second reinforcing tube, both the first and second reinforcing tubes being laid along the width direction of the flexible protective curtain.

[0008] Preferably, the end of the traction rope is provided with a fixing clamp for connecting to the second reinforcing tube.

[0009] Preferably, a rigid connector is welded to the top of the flexible protective curtain, and the rigid connector is connected to the bracket.

[0010] Preferably, the flexible protective curtain includes multiple longitudinally arranged rubber belts that are arranged horizontally.

[0011] Preferably, the lifting transmission assembly includes a winch and a directional pulley block; the winch is installed on the central support platform of the bracket, and the directional pulley block is installed on the top crossbeam of the bracket; one end of the traction rope is wound around the winch, and the other end passes around the directional pulley block and is connected to the second reinforcing pipe.

[0012] Preferably, the directional pulley assembly is installed on the upper end face of the top crossbeam; the directional pulley assembly includes two pulleys arranged side by side, and the pulleys are provided with positioning grooves for the traction rope to pass through.

[0013] Preferably, multiple winches and directional pulley blocks are provided, which are evenly distributed on the central support platform and the top crossbeam.

[0014] Preferably, a limiter is provided on the lower end face of the top crossbeam, and the limiter is electrically connected to the motor controller of the winch.

[0015] Preferably, a remote control module is also included, which is electrically connected to the lifting transmission assembly.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The tunnel entrance blasting protection device uses a support frame as the top support structure, with the flexible protective curtain suspended above the tunnel entrance via the support frame. The support frame adopts a non-ground-fixed design, which can adapt to various tunnel road surface conditions, avoid ground undulations and obstacle interference, and ensure the overall stability of the protective curtain.

[0018] Furthermore, the top of the flexible protective curtain is rigidly connected to the bracket, and the bottom is connected to the lifting transmission component through a traction rope to realize automated lifting and lowering along the height direction of the bracket.

[0019] Furthermore, the flexible protective curtain enhances the environmental compatibility of off-ground installation supports, and the automated deployment and retraction simplifies the operation process. When deployed, it forms a full-section protective barrier to block flying stones, and when retracted, it fits tightly against the top of the support to free up ground space and ensure the smooth passage of construction equipment.

[0020] Furthermore, the flexible protective curtain is equipped with first and second reinforcing pipes at the bottom and middle, using rigid steel pipes to enhance bending stiffness, disperse blasting impact loads, improve impact resistance, prevent curtain deformation and tearing, and extend service life; the continuous layout ensures uniform stress distribution and avoids local stress concentration.

[0021] Furthermore, the end of the traction rope is connected to the second reinforcing tube through a fixing clamp, which is reliably fixed by mechanical biting force, facilitating assembly and improving efficiency.

[0022] Furthermore, a rigid connector is welded to the top of the flexible protective curtain. It is rigidly connected to the bracket through detachable parts such as bolts, buckles, and pins to form a fixed support point, which simplifies the installation process, facilitates disassembly and maintenance, ensures reliable fixation at the top, and prevents the curtain from falling off.

[0023] Furthermore, the flexible protective curtain is composed of multiple longitudinally and horizontally arranged rubber belts, which utilize their high elasticity and interlayer friction to dissipate blast impact energy, enhance energy absorption capacity, and buffer the impact of flying stones.

[0024] Furthermore, the winch winds the traction rope to provide lifting power, while the directional pulley block changes direction and reduces frictional resistance. Together, they achieve smooth lifting and lowering of the curtain, reduce the intensity of manual operation, ensure controllable traction path, and prevent rope deviation and jamming.

[0025] Furthermore, the directional pulley is assembled on the upper surface of the top crossbeam, with two pulleys arranged side by side. The positioning groove constrains the trajectory of the traction rope, distributes the force, extends the life of the pulley, prevents the rope from slipping, and improves the reliability of the transmission.

[0026] Furthermore, multiple sets of winches and pulley blocks are evenly distributed, and multi-point traction balances the force on the curtain, disperses the explosive impact load, avoids single-point overload, improves the synchronization of lifting and lowering, and prevents the curtain from tilting and getting stuck.

[0027] Furthermore, a limit switch is installed on the top crossbeam below the pulley to detect the distance between the second reinforcing tube and the top crossbeam, preventing the curtain from over-rolling. After receiving the signal, the motor controller stops the winch, automatically limiting the equipment to ensure safety, eliminating errors from manual monitoring, and improving operational accuracy.

[0028] Furthermore, the remote control module controls the start and stop of the lifting transmission components via wireless signals, enabling remote operation. This keeps operators away from dangerous areas, improves operational safety, allows for rapid response to emergencies, and shortens deployment time.

[0029] Other features and advantages of this utility model will be disclosed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings:

[0031] Figure 1 This is a side view schematic diagram of the structure of a blasting protection device for tunnel entrance according to the present invention;

[0032] Figure 2 This is a front view schematic diagram of the structure of the bracket and lifting transmission assembly of this utility model;

[0033] Figure 3 This is a schematic diagram of the pulley structure of this utility model;

[0034] Figure 4 This is a schematic diagram of the structure of the flexible protective curtain of this utility model;

[0035] The annotations in the attached figures are explained as follows:

[0036] 1. Support frame, 11. Top beam, 12. Middle support platform, 2. Flexible protective curtain, 3. Lifting transmission assembly, 4. Traction rope, 41. Fixing clamp, 5. Limiter, 21. Rigid connector, 22. Rubber belt, 23. First reinforcing pipe, 24. Second reinforcing pipe, 31. Winch, 311. Motor controller, 32. Directional pulley block, 321. Positioning groove, 3211. Detailed Implementation

[0037] The technical solutions of the present utility model will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present utility model.

[0038] In the following description, terms such as “inner,” “outer,” “upper,” “lower,” “left,” and “right” are used only to facilitate the description of the embodiments and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0039] like Figures 1 to 4 As shown, a blasting protection device for a tunnel entrance includes a support 1, a flexible protective curtain 2, a lifting transmission assembly 3, and a traction rope 4. The support 1 is mounted above the tunnel entrance, and the top end of the flexible protective curtain 2 is fixed to the support 1, while its bottom end is connected to the lifting transmission assembly 3 via the traction rope 4. The lifting transmission assembly 3 is mounted on the support 1 and is used to drive the traction rope 4 to reciprocate along the height direction of the support 1, so that the flexible protective curtain 2 switches between an unfolded protective state and a retracted state.

[0040] The support frame 1 is a steel frame structure, including a top crossbeam 11 and a middle support platform 12. The top crossbeam 11 is horizontally fixed to the top of the support frame 1 and is used to install the directional pulley block 32 and the limiter 5; the middle support platform 12 is located in the middle of the support frame 1 and is used to fix the winch 31. With the help of this support frame 1, the flexible protective curtain 2 can be precisely assembled at the tunnel entrance. This support frame 1 does not rely on ground installation, so the flexible protective curtain 2 can be used on tunnel surfaces with different conditions, unaffected by ground road conditions, effectively avoiding interference and obstruction caused by ground conditions under different geological and topographical conditions at the tunnel entrance to the installation of the blasting protection device, and enhancing the stability of the flexible protective curtain 2. Specifically, the support frame 1 is firmly anchored to the top of the tunnel entrance with anchor bolts, thus ensuring that the entire protection device maintains high stability during operation, which is sufficient to cope with various complex ground conditions such as soft soil foundations and sloping terrain.

[0041] Furthermore, the dimensions of support frame 1 are precisely set to be 3.5m high, 16m long, and 1.5m wide, with the intermediate rectangular frames spaced 4m apart to optimize the support effect. Horizontal bracing is installed between the intermediate rectangular frames to further enhance the overall structure's resistance to wind pressure and earthquakes.

[0042] The flexible protective curtain 2 is mounted above the tunnel entrance via a bracket 1. A first reinforcing pipe 23 and a second reinforcing pipe 24 are respectively installed at the bottom and middle of the flexible protective curtain 2. These rigid steel pipes enhance the bending stiffness of the flexible protective curtain 2 and disperse the blasting impact load. This improves the impact resistance of the flexible protective curtain 2, prevents deformation or tearing of the curtain body due to blasting vibration, and extends its service life. The first reinforcing pipe 23 and the second reinforcing pipe 24 are installed along their entire length to ensure uniform stress distribution and avoid localized stress concentration. The flexible protective curtain 2 includes multiple longitudinally arranged rubber belts 22 arranged horizontally. The high elasticity and interlayer friction of the rubber belts 22 dissipate the blasting impact energy. The multiple longitudinally arranged rubber belts 22 enhance the energy absorption capacity of the flexible protective curtain 2, effectively buffering the impact of flying rocks.

[0043] The flexible protective curtain 2 has a rigid connector 21 welded to its top, which is rigidly connected to the bracket 1 via detachable connectors such as bolts, clips, and pins to form a fixed support point. This simplifies the installation process of the flexible protective curtain 2 and facilitates quick disassembly and maintenance; the rigid connection ensures that the top of the curtain is reliably fixed, preventing the curtain from falling off under explosive impact. The bottom of the flexible protective curtain 2 is provided with a first reinforcing tube 23, and a second reinforcing tube 24 is provided between the middle and the bottom, both of which are laid out along the width of the curtain. The first reinforcing tube 23 is close to the ground to enhance the impact resistance of the bottom of the curtain; the second reinforcing tube 24 is connected to the traction rope 4 via a fixing clamp 41, and the mechanical biting force of the clamp is used to achieve reliable fixation, which facilitates the fixing of the traction rope 4 to the second reinforcing tube 24 and improves the assembly efficiency of the device.

[0044] Specifically, a 16.8m long φ108mm first reinforcing pipe 23 is used to reinforce the bottom edge of the flexible protective curtain 2 at a distance of 0.5m above the bottom edge to enhance its impact resistance. Simultaneously, a 16.8m long φ108mm second reinforcing pipe 24 is used as a suspension point for the steel wire rope at a distance of 3m from the bottom to secure the curtain. The top of the flexible protective curtain 2 is also fixedly connected using a 16.8m long φ108mm rigid connector 21 to ensure stable suspension and raising / lowering of the flexible protective curtain 2.

[0045] In this embodiment, the flexible protective curtain 2 is made of 14 rubber belts vertically spliced ​​together, each belt having a thickness of 15mm, a length of 9m, and a width of 1.2m.

[0046] The traction rope 4 and the lifting transmission component 3 work together to automate the deployment and retraction of the flexible protective curtain 2, improving operational convenience. When deployed, the flexible protective curtain 2 is in a protective state, forming a closed protective surface that effectively blocks flying rocks from blasting. The flexible protective curtain 2 is retracted to the top of the support frame via the lifting transmission component 3 and the traction rope 4. After being retracted, it reduces the space occupied on the ground at the tunnel entrance, facilitating the passage of construction equipment inside the tunnel.

[0047] The lifting transmission assembly 3 includes a winch 31 and a directional pulley block 32. The winch 31 is mounted on the central support platform 12, and its motor controller 311 is electrically connected to the limit switch 5. The directional pulley block 32 is mounted on the upper surface of the top beam 11 and includes two pulleys 321 arranged side by side. The pulleys 321 have positioning grooves 3211 for restraining the traction rope 4. The winch 31 provides lifting power by winding the traction rope 4, and the directional pulley block 32 changes the direction of the traction rope 4 and reduces frictional resistance. The winch 31 and the directional pulley block 32 work together to achieve smooth lifting and lowering of the flexible protective curtain 2, reducing the intensity of manual operation; the directional pulley block 32 ensures that the traction path is controllable and avoids rope deviation and jamming. The double pulleys are arranged side by side on the upper surface of the top beam 11, and the positioning grooves 3211 restrain the movement trajectory of the traction rope 4. The double pulley design distributes the force on the rope and extends the life of the pulleys.

[0048] The positioning groove 3211 prevents the rope from slipping and improves transmission reliability. Multiple sets of winches 31 and pulley blocks are evenly distributed, balancing the force on the curtain through multi-point traction, dispersing the explosive impact load, and avoiding single-point overload; improving the synchronization of lifting and lowering, and preventing the flexible protective curtain 2 from tilting or getting stuck. One end of the traction rope 4 is wound around the winch 31, and the other end passes through the positioning groove 3211 of the pulley 321 and is connected to the second reinforcing pipe 24 through the fixing clamp 41.

[0049] When the winch 31 starts, the traction rope 4 changes direction via the pulley 321, causing the second reinforcing pipe 24 and the flexible protective curtain 2 to rise and fall along the height of the support 1. A limiter 5 is installed on the lower end face of the top crossbeam 11. The limiter 5 is a non-contact photoelectric sensor used to detect the distance between the second reinforcing pipe 24 and the crossbeam, preventing the flexible protective curtain 2 from being raised too high, which could cause the second reinforcing pipe 24 to collide with the top crossbeam 11. After receiving the signal from the limiter 5, the motor controller 311 stops the winch 31. The limiter 5 automatically limits the movement to prevent the flexible protective curtain 2 from over-rolling or colliding with the support, protecting equipment safety; eliminating errors from manual monitoring and improving operational accuracy.

[0050] This device is also equipped with a remote control module, which connects to the motor controller 311 of the winch 31 via wireless signal. Operators can remotely control the raising and lowering of the flexible protective curtain 2 via remote control, enabling rapid deployment or retraction of the protective device in a safe area, keeping operators away from blasting hazard areas and improving operational safety; it also allows for rapid response to emergencies and shortens the deployment time of the flexible protective curtain 2.

[0051] On-site installation steps:

[0052] Installation of Support 1: Support 1 was fixed on both sides of the tunnel entrance, and the verticality of the columns was adjusted. During the arch support pouring process, two 400×200×20mm steel plates were pre-embedded as the connecting foundation for Support 1, with a center-to-center distance of 1.5m between the two steel plates. Simultaneously, the formwork reinforcement bars (φ22mm) used during arch support pouring were used as the connecting reinforcement bars for Support 1. The steel support was precisely installed onto the arch support using a crane frame and welded to the pre-reserved steel plates and reinforcement bars. To further enhance stability, 16# I-beam vertical supports were added to both sides of the arch and welded to the pre-reserved reinforcement bars.

[0053] The rigid connector 21 of the flexible protective curtain 2 is connected to the bracket by bolts, and the traction rope 4 is fastened to the second reinforcing tube 24 by the fixing clamp 41. The traction rope 4 is connected to the lifting transmission assembly 3 to realize the lifting function of the curtain.

[0054] Adjust the stroke parameters of the winch 31 and set the trigger threshold of the limit switch 5.

[0055] The flexible protective curtain 2 is deployed as follows: the winch 31 releases the traction rope 4, and the flexible protective curtain 2 hangs down naturally under the action of gravity. The first reinforcing pipe 23 contacts the ground to form a closed protective surface, blocking the flying rocks from the blast.

[0056] The flexible protective curtain 2 is retracted as follows: the winch 31 winds up the traction rope 4, which pulls the second reinforcing pipe 24 to raise the curtain of the flexible protective curtain 2 to below the top crossbeam 11. The limiter 5 is triggered to stop, and the curtain of the flexible protective curtain 2 is suspended and retracted to avoid obstructing the passage of construction equipment.

[0057] The blast protection device used at the tunnel entrance utilizes a remote control module to remotely control the lifting and transmission assembly 3 and the flexible protective curtain 2 to raise for protection. This innovative approach solves the complex process of traditional mechanical installation and manual fastening, greatly improving the stability and ease of operation of the curtain. This technology not only significantly shortens the preparation time for blast protection at the tunnel entrance but also effectively avoids potential damage caused by repeated handling, thus extending the service life of the flexible protective curtain 2. More importantly, it constructs a reliable safety barrier, effectively blocking the potential threats of flying rocks to surrounding buildings, machinery, and personnel, greatly reducing safety hazards and providing strong protection for tunnel construction safety.

[0058] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Those skilled in the art should understand that this utility model includes, but is not limited to, the content described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of this utility model will be included within the scope of the claims.

Claims

1. A blasting protection device for tunnel entrances, comprising a support (1) and a flexible protective curtain (2), characterized in that: It also includes a lifting transmission assembly (3) and a traction rope (4); the bracket (1) is installed above the tunnel entrance, the top of the flexible protective curtain (2) is fixed on the bracket (1), and its bottom end is connected to the lifting transmission assembly (3) through the traction rope (4); the lifting transmission assembly (3) is mounted on the bracket (1) and is used to drive the traction rope (4) to reciprocate along the height direction of the bracket (1), so that the flexible protective curtain (2) switches between the unfolded protective state and the retracted state; the bottom of the flexible protective curtain (2) is provided with a first reinforcing tube (23), and the middle and bottom of the flexible protective curtain (2) are provided with a second reinforcing tube (24), and the first reinforcing tube (23) and the second reinforcing tube (24) are both laid out along the width direction of the flexible protective curtain (2).

2. The blasting protection device for tunnel entrances according to claim 1, characterized in that: The end of the traction rope (4) is provided with a fixing clamp (41) for connecting with the second reinforcing tube (24).

3. The blasting protection device for tunnel entrances according to claim 1, characterized in that: The top of the flexible protective curtain (2) is welded with a rigid connector (21), which is connected to the bracket (1).

4. A blasting protection device for tunnel entrances according to claim 1, characterized in that: The flexible protective curtain (2) includes multiple longitudinally arranged rubber belts (22) arranged in the horizontal direction.

5. A blasting protection device for tunnel entrances according to claim 1, characterized in that: The lifting transmission assembly (3) includes a winch (31) and a directional pulley block (32); the winch (31) is installed on the central support platform (12) of the bracket (1), and the directional pulley block (32) is installed on the top crossbeam (11) of the bracket (1); one end of the traction rope (4) is wound around the winch (31), and the other end passes around the directional pulley block (32) and is connected to the second reinforcing pipe (24).

6. A blasting protection device for tunnel entrances according to claim 5, characterized in that: The directional pulley assembly (32) is installed on the upper end face of the top beam (11); the directional pulley assembly (32) includes two pulleys (321) arranged side by side, and the pulleys are provided with positioning grooves (3211) for the traction rope (4) to pass through.

7. A blasting protection device for tunnel entrances according to claim 6, characterized in that: Multiple winches (31) and directional pulley blocks (32) are provided and are evenly distributed on the central support platform (12) and the top crossbeam (11).

8. A blasting protection device for tunnel entrances according to claim 6, characterized in that: The lower end face of the top beam (11) is provided with a limiter (5), and the limiter (5) is electrically connected to the motor controller (311) of the winch (31).

9. A blasting protection device for tunnel entrances according to claim 1, characterized in that: It also includes a remote control module, which is electrically connected to the lifting transmission assembly (3).

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