Passive shock wave retarding structure for coal mine tunnel

Abstract

The invention provides a passive shock wave retarding structure for a coal mine tunnel, and belongs to the technical field of coal mine safety protection. The passive shock wave retarding structure is composed of a folding structure, a center chassis and a lattice truss structure, the folding structure is formed by folding a plane regular hexagon thin plate according to designed frontal lines and valley lines, and the longest valley line of the folding structure radiates supporting rods towards the center; the central base plate is cylindrical, a sliding groove is formed in the outer side of the central base plate, and the supporting rod can slide in the sliding groove of the central base plate. The lattice truss is of a plane frame structure and is composed of long-strip-shaped components which intersect with one another, the intersection positions of the long-strip-shaped components form connecting nodes of the center base plate, and one end of the center base plate is fixed to the nodes of the lattice truss structure. The passive shock wave retarding structure for the coal mine tunnel has the advantages of being small in occupied space, light in weight, simple in opening and closing structure and reliable in work, and can be installed and arranged according to the actual situation of the coal mine tunnel.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine safety protection, and specifically relates to a passive shock wave blocking structure for coal mine tunnels, which is applied to block and protect shock waves of gas explosions in underground tunnels, thereby reducing the consequences of multiple or continuous gas explosions. Background Art

[0002] Coal mine gas explosions are a major hazard in coal mine safety production. When a gas explosion occurs underground, the resulting shock wave propagates at supersonic speeds through the tunnels. This high-speed airflow sweeps up coal dust deposited within the tunnels, forming an explosive dust cloud that can easily trigger secondary or even multiple explosions. Statistics show that over 70% of casualties in major coal mine explosions are caused by consecutive explosions. Therefore, effectively blocking the propagation of shock waves is a key technical challenge in preventing the spread of these disasters.

[0003] At present, the industry mainly adopts technical means that combine passive protection and active isolation: (1) Explosion-proof doors and explosion relief devices release explosion pressure through preset weak structures, but there are problems of triggering lag and high maintenance cost, and they are prone to failure due to structural deformation in coal dust-rich areas. The above structures do not have ventilation functions and cannot be used in tunnels; (2) Tunnel water curtain and rock powder shed barrier technology relies on manual or electrical control systems to start the isolation layer. In actual applications, it exposes defects such as insufficient response time (usually >500ms) and limited coverage, making it difficult to cope with the instantaneous effect of explosion shock waves; (3) Rapid sealing airbag technology, although it can achieve tunnel sealing, requires an independent air source and control system, and has technical bottlenecks such as bulky equipment, slow response, and large daily ventilation resistance.

[0004] In recent years, research institutions both domestically and internationally have proposed several novel solutions to address the need for dynamic shock wave suppression. For example, patent CN110374678A discloses a flexible shock wave protection device for blasting tunnels and its use method. While this patent utilizes a baffle to block shock waves, its structure relies on complex mechanical structures to achieve its function and fails to meet the requirement for shock wave front peak suppression. Another example is the active explosion suppression system recently published in the Journal of Mining and Safety Engineering and Coal Technology. This system uses array sensors to monitor and trigger the injection of explosion suppressants in real time, but its reliability is limited by electromagnetic interference in the harsh underground environment. Existing technologies generally suffer from the contradiction between "active system response hysteresis" and "passive structure irreversible damage," and a lightweight solution that balances daily ventilation needs with instantaneous explosion response has yet to be developed. Summary of the Invention

[0005] To address the prevalent issue of "active system response hysteresis" and "irreversible damage to passive structures" in existing technologies, the inventors have proposed a passive shock wave arrester for coal mine tunnels. When not in operation, the shock wave arrester is folded, occupying a small space and meeting tunnel ventilation requirements. When the shock wave from an explosion strikes, the protective structure passively deploys, blocking the shock wave's propagation and preventing the risk of subsequent explosions. The shock wave arrester is lightweight and can be easily moved and deployed within the tunnel.

[0006] The design concept and technical solution of the shock wave blocking structure proposed by the present invention are as follows:

[0007] A passive shock wave blocking structure for coal mine tunnels is designed using an origami design concept and is arranged in a matrix on a tunnel cross section. The passive shock wave blocking structure is in a folded and tightened state when not in operation. After being impacted by a shock wave, the structure unfolds along a folding front line and a valley line to shield the shock wave. The passive shock wave blocking structure comprises: a folding structure (1), a central chassis (2), and a lattice truss (3); the folding structure (1) is fixed at a node of the lattice truss (3) through the central chassis (2), and the central chassis (2) is connected to the node of the lattice truss (3).

[0008] The folding structure (1) is umbrella-shaped and is formed by folding a flat regular hexagonal thin plate according to its designed front lines and valley lines. The front lines and valley lines include main front lines and main valley lines and secondary front lines and secondary valley lines. The main front lines and main valley lines are set from each vertex and the midpoint of each side of the flat regular hexagon to the center of the flat regular hexagon. The secondary front lines and secondary valley lines are symmetrically set on both sides of the main front lines and main valley lines, extending from the main front lines and main valley lines to the edge of the flat regular hexagon. The material at each front line and valley line is grooved and thinned. The central chassis (2) is cylindrical, and a slide groove is opened on the outside of the cylinder. The longest radial valley line of the folding structure (1) is connected to the support rod and the central position chassis (2) structure, and the support rod can slide in the slide groove of the central chassis (2).

[0009] The lattice truss (3) is a planar frame structure, which is composed of mutually intersecting long strip-shaped members. The intersection of the long strip-shaped members constitutes a connection node with the central chassis (2). The central chassis (2) is fixed at the connection node, thereby realizing the positioning and fixation of the folding structure (1).

[0010] The number of nodes of the array truss (3) and the number of folding structures (1) are adjusted according to the size of the tunnel cross-sectional area, and multiple node fixed folding structures (1) are arranged in the tunnel direction to ensure effective blocking of the explosion shock wave.

[0011] The lattice truss (3) structure supports the folding structure (1) after it is unfolded, thereby preventing reverse folding under the action of shock waves.

[0012] The expansion and contraction of each folding structure (1) does not rely on any mechanical structure movement. The passive expansion of the structure is achieved by notching the front line and valley line of the design. The force required for the expansion of the folding structure (1) can be adjusted according to the depth of the notch, ensuring that the folding structure (1) is expanded only when impacted by a shock wave, thereby avoiding malfunction during ventilation.

[0013] Beneficial effects:

[0014] The passive shock wave blocking structure for coal mine tunnels of the present invention has the following three advantages: first, the structure is in a folded state when not in operation, occupies a small space, and can meet the ventilation needs of the tunnel; second, the structure adopts a passive working principle, the opening and closing structure is simple, the operation is reliable, and it can respond quickly and reliably when the shock wave comes; third, the structure is lightweight, and it is easy to install and arrange. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 : Planar unfolding and folding diagrams of a single folding structure. The folding diagram shows the states when the folding degree is 20%, 40%, 60% and 80%;

[0016] Figure 2 : Schematic diagram of the connection between a single folding structure and the central chassis;

[0017] Figure 3 : Schematic diagram of the connection between the nodes of the lattice truss and the central chassis and folding structure. DETAILED DESCRIPTION

[0018] See the instructions attached Figure 1 、 2 3. The present invention relates to a passive shock wave blocking structure for coal mine tunnels. A folding structure (1) is designed using a thin aluminum plate or a thin steel plate with a thickness of 1.0 mm. The plate is grooved according to the positions of the front and valley lines drawn in advance to facilitate the folding and unfolding of the structure. The groove depth is adjusted according to the shock wave pressure response requirements. The unfolded outer contour of the folding structure (1) is a regular hexagon with a side length of 100 mm. Six supporting rods are radiated from the six valley lines toward the center of the structure. The ends of the rods penetrate into the chute of the central chassis (2) and can slide in the chute.

[0019] In the non-working state, the folding structure (1) is in a folded and converged state, meeting the ventilation requirements of the tunnel. When a shock wave hits, the folding structure (1) will be passively unfolded by the pressure of the shock wave. When unfolded into a flat state, it is supported by the point-to-point truss structure to prevent the structure from folding in reverse, thereby achieving a blocking effect on the shock wave.

[0020] The present invention has been described in detail above through the examples. It should be noted that the above examples are only preferred embodiments of the present invention, not all embodiments of the present invention, and do not constitute any limitation to the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims of this application document. Under the premise of not departing from the spirit of the present invention, those skilled in the art who make equivalent substitutions or other various transformations of the technical features of the present invention shall all fall within the scope of protection of the present invention.

Claims

1. A passive shock wave blocking structure for coal mine tunnels, characterized by: The passive shock wave blocking structure is composed of a folding structure (1), a central chassis (2) and a lattice truss structure (3). The folding structure (1) is formed by folding a flat regular hexagonal thin plate according to designed front lines and valley lines, and its longest valley line radiates support rods toward the center; the central chassis (2) is cylindrical and has a sliding groove on the outside; the longest radial valley line support rod of the folding structure (1) is connected to the central chassis (2), and the support rod can slide in the sliding groove of the central chassis (2); the central chassis (2) is fixed at the node of the lattice truss structure (3).

2. A passive shock wave blocking structure for coal mine tunnels according to claim 1, characterized in that: The folding structure (1) is umbrella-shaped, and its front lines and valley lines include main front lines and valley lines and secondary front lines and valley lines. The main front lines and valley lines are arranged from each vertex and the midpoint of each side of the plane regular hexagon to the center of the plane regular hexagon. The secondary front lines and valley lines are symmetrically arranged on both sides of the main front lines and valley lines, extending from the main front lines and valley lines to the edge of the plane regular hexagon, and the material at each front line and valley line is grooved and thinned.

3. A passive shock wave blocking structure for coal mine tunnels according to claim 2, characterized in that: The lattice truss (3) is a planar frame structure, which is composed of mutually intersecting long strip-shaped components, and the intersection of the long strip-shaped components constitutes a connection node with the central chassis (2).

4. A passive shock wave blocking structure for coal mine tunnels according to claim 3, characterized in that: The number of nodes of the lattice truss structure (3) and the folding structure (1) can be adjusted according to the size of the tunnel cross-sectional area, and multiple node-fixed folding structures (1) are arranged along the tunnel direction according to specific circumstances to ensure effective blocking of shock waves.

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