Buffering pressure relief device for preventing impact of underground mine roadway well wall

Abstract

The invention discloses an anti-impact buffer pressure relief device for an underground mine roadway well wall. The anti-impact buffer pressure relief device aims at effectively absorbing and relieving damage of impact force to the well wall. The device comprises an energy absorption matrix, an energy absorption layer, a top plate and a bottom plate, wherein the energy absorption matrix consists of a plurality of energy absorption elements. The energy absorption element is used for absorbing impact or vibration energy transmitted downwards by the top plate, and impact on the well wall is reduced. The energy absorption element comprises a bearing plate, a transmission shaft, a connecting rod, a limiting plate, a rubber damper, a recovery device and a base. The rubber damper converts external impact force into heat energy or internal energy consumption through elastic deformation, and therefore transmission of the impact force is reduced. And the recovery device is used for recovering the initial state of each component after external force is removed. An energy absorption layer is arranged on the contact face of the energy absorption matrix and the bottom plate. Through optimized design and material selection, impact energy can be effectively absorbed and dissipated in an underground mine roadway, the stability of a well wall is improved, and damage of impact to a mine structure is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical engineering energy absorption and shock absorption, and in particular to a buffer pressure relief device for preventing impact on the shaft wall of an underground mine tunnel. Background Art

[0002] In the process of ore transportation in underground mines, the ore is transported to the top of the production chute by a trackless rubber-wheeled vehicle, unloaded into the chute, and finally released by a vibrating ore-discharging machine. During this process, the contact between the ore and the shaft wall and the vibrating ore-discharging machine inevitably produces static load friction and dynamic load impact. Especially under the action of dynamic load impact, the ore and the equipment collide violently, which may cause wear and damage to the shaft wall and equipment, and even cause failures, thereby affecting the efficiency of the ore transportation system. Therefore, there is an urgent need for a device that can effectively absorb and alleviate the impact load of ore. Summary of the invention

[0003] In view of the defects of the prior art, the present invention provides a buffer pressure relief device for preventing impact on the shaft wall of an underground mine tunnel.

[0004] In order to achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0005] A buffer pressure relief device for preventing impact on the shaft wall of an underground mine tunnel, comprising: an energy absorption matrix 1, a top plate 3 and a bottom plate 4;

[0006] The energy absorption matrix 1 is covered with a top plate 3 on the top and fixed on a bottom plate 4 on the bottom;

[0007] The energy absorption matrix 1 is composed of a plurality of energy absorption elements 5; the energy absorption elements 5 are used to absorb and dissipate the downward impact or vibration energy of the top plate 3;

[0008] Further, the energy absorbing element 5 includes: a bearing plate 6, a transmission shaft 7, a connecting rod 8, a limit plate 9, a rubber damper 10, a recovery device 11 and a base 12;

[0009] The bearing plate 6 is used to hold up the top plate 3;

[0010] The transmission shaft 7 is connected to the rubber damper 10 through a connecting rod 8; the rubber damper 10 converts the external impact force into heat energy or internal energy consumption through the elastic deformation of the internal rubber material to reduce the transmission of the impact force.

[0011] The limit plate 9 is fixed on the base 12 as a stable support for the rubber damper 10;

[0012] The recovery device 11 is installed on the base 12 and supports the entire bearing plate 6 through the internal spring; it is used to restore the initial state of all components of the energy absorbing element after the external force is removed.

[0013] Furthermore, the rubber damper 10 adopts a high damping rubber constitutive model, which is a Burgers model. The Burgers model includes a Kelvin model element and a Maxwell model element connected in series. The total strain of the Burgers model is provided by the spring strain and the viscosity pot strain, and the strain of the model is expressed as the following formula:

[0014]

[0015] Among them, E1 and E2 are the elastic moduli of the two springs of the Burgers model, η1 and η2 are the viscosities of the two viscous pots of the Burgers model, σ0 represents the stress applied to the material externally, and t is the time variable.

[0016] The creep and recovery process of the Burgers model is expressed as follows:

[0017]

[0018] Among them, t cp It is a specific point in time that marks the transition from the creep phase to the creep recovery phase.

[0019] Preferably, an energy absorbing layer 2 is provided on the contact surface between the energy absorbing matrix 1 and the bottom plate 4;

[0020] Preferably, the energy absorbing layer 2 has orthotropic anisotropy, and its stress-strain relationship is:

[0021]

[0022] Among them, σ1 to σ6 are stress components, ε1 to ε6 are strain components, and C ij is the stiffness matrix coefficient of the material.

[0023] Preferably, the elastic constitutive relation of the energy absorbing layer 2 is represented by engineering constants and calculated using the Gibson formula and its modified formula. The stress-strain relation of the material is:

[0024]

[0025] Among them, v 12 , v 13 , v 23 , v 31 , v 21 , v 32 is Poisson's ratio, E1, E2, E3 are elastic moduli, G 12 , G 13 , G 22 , is the shear modulus, and Δ is a constant.

[0026] Preferably, the energy absorbing layer 2 is two layers of aramid fiber material.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] 1. By designing energy-absorbing elements and their matrix structures with high-efficiency energy absorption and buffering capabilities, the present invention can effectively absorb and mitigate mechanical impact and vibration energy, thereby significantly improving the energy absorption efficiency of the system and reducing damage to equipment and structures.

[0029] 2. The present invention adopts a buffer device with high damping characteristics, which can maintain a good shock absorption effect under a wide range of working conditions, reduce the impact of mechanical shock and vibration on the equipment, and extend the service life of the equipment.

[0030] 3. The present invention is designed with the operation requirements under various working conditions in mind, and can automatically adjust its energy absorption performance according to different external shock and vibration inputs. Whether it is under low-frequency and high-amplitude or high-frequency and low-amplitude working conditions, the system can effectively reduce vibration.

[0031] 4. The application of the present invention enables the structure to effectively reduce vibration propagation when encountering external impact, thereby improving the stability and safety of the structure, especially when facing earthquakes, impacts or other extreme working conditions, and can significantly reduce the risk of damage.

[0032] 5. The present invention has a simple structure, is easy to integrate into existing equipment and systems, and has low maintenance requirements. The device shows excellent durability and stability in practical applications, reducing maintenance costs.

[0033] 6. The energy absorption matrix of the present invention can flexibly adjust the energy absorption area according to actual needs, realize efficient energy distribution and management, and ensure that the system maintains balance and efficient operation when facing different loads.

[0034] 7. Through the shock absorption and energy absorption functions, the present invention not only improves the working environment of the equipment, but also reduces the impact of vibration and noise on the surrounding environment, meeting environmental protection requirements.

[0035] 8. Through optimized design, the present invention can adapt to changes in different external vibration and impact sources, thereby improving the adaptability and intelligence level of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the structure of an energy absorbing element according to an embodiment of the present invention;

[0037] Figure 2 is a top view of the energy absorption matrix structure of an embodiment of the present invention;

[0038] Figure 3is a Burgers model diagram of the high damping rubber according to an embodiment of the present invention;

[0039] Figure 4 It is a schematic structural diagram of a buffer pressure relief device according to an embodiment of the present invention;

[0040] Figure 5 is a finite element mesh diagram of an energy absorbing element according to an embodiment of the present invention;

[0041] Figure 6 This is a disassembly diagram of a buffer pressure relief device according to an embodiment of the present invention;

[0042] Figure 7 is the energy absorption matrix finite element mesh of an embodiment of the present invention;

[0043] Figure 8 It is a coupling constraint and binding definition diagram of the energy absorption matrix model of an embodiment of the present invention;

[0044] Fig. 9 It is a contact definition diagram of the energy absorption matrix model of an embodiment of the present invention;

[0045] Fig.10 It is the constraint and load diagram of the energy absorption matrix model of the embodiment of the present invention;

[0046] Fig.11 is a stress cloud diagram of a buffer vibration reduction sequence according to an embodiment of the present invention;

[0047] Fig.12 is a strain cloud diagram of a buffer vibration reduction sequence according to an embodiment of the present invention;

[0048] Fig.13 is a time variation curve diagram of kinetic energy of a buffer vibration reduction sequence according to an embodiment of the present invention;

[0049] Fig.14 is a stress cloud diagram of the aramid fiber energy absorbing board model according to an embodiment of the present invention;

[0050] Fig.15 This is a strain cloud diagram of the aramid fiber energy absorbing board model according to an embodiment of the present invention;

[0051] Fig.16 is a curve diagram of impact energy absorption of the buffer and vibration reduction material according to an embodiment of the present invention;

[0052] Fig.17 is a stress cloud diagram of a buffer pressure relief device according to an embodiment of the present invention;

[0053] Fig.18 is a displacement cloud diagram of the buffer pressure relief device according to an embodiment of the present invention;

[0054] Fig.19 It is a curve diagram of impact energy absorption by the buffer pressure relief device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0056] A buffer pressure relief device for preventing impact on the shaft wall of an underground mine tunnel, comprising: an energy absorption matrix 1, an energy absorption layer 2, a top plate 3 and a bottom plate 4;

[0057] 1. Energy Absorption Matrix 1 Structure

[0058] Due to the limitation of space and the need of practical engineering application, the shock absorber needs to have simple structure, convenient maintenance, high load-bearing capacity and good durability, and good vibration reduction effect. Therefore, an energy-absorbing element 5 is designed to meet the impact force during ore transportation. The energy-absorbing element 5 mainly includes five mechanical components: a bearing plate 6, a transmission shaft 7, a limit plate 9, a rubber damper 10 and a recovery device 11.

[0059] The working principle of the energy absorbing element 5 is that the bearing plate 6 receives the impact force of the ore, converts the vertical impact load into the horizontal direction through the transmission shaft 7, and then dissipates the energy through the rubber damper 10, and finally restores the entire vibration reduction device to the state before the load through the recovery device 11. The high damping rubber can effectively absorb and dissipate the mechanical energy brought by the impact of the ore.

[0060] When designing the energy absorbing element 5, attention should be paid to the coordination between the various components to ensure that a better vibration reduction effect can be exerted during operation. The overall size of the energy absorbing element 5 proposed by the present invention is 300mm×90mm×120mm. Figure 1 shown.

[0061] The energy absorption matrix 1 is composed of nine energy absorption elements 5 ( Figure 1 ) is formed through reasonable arrangement and combination. The specific layout diagram is as follows Figure 2 shown.

[0062] 2. Buffering and vibration reduction materials

[0063] (1) High damping model components

[0064] The high damping model component can effectively isolate vibration and absorb impact energy because it has good mechanical properties, hysteresis, reversible large deformation damping, anti-seismic properties, etc. The present invention describes the constitutive model of the high damping material used in the shock absorber. The high damping rubber constitutive model used in the rubber damper 10 is a Burgers model constructed by connecting Kelvin model elements and Maxwell model elements in series, such as Figure 3 shown.

[0065] The Burgers model consists of two springs and two viscometers. The total strain of the model is the sum of the strains of the Kelvin model elements and the Maxwell model elements, which is provided by the spring strain and the viscometer strain:

[0066]

[0067] In the formula, E1 and E2 are the elastic moduli of the two springs in the Burgers model, and η1 and η2 are the viscosities of the two viscous pots in the Burgers model. cp When the stress that causes creep is relieved, the deformation behavior enters the creep recovery stage.

[0068] The creep recovery motion equation of this model can be written as:

[0069]

[0070] Therefore, the creep and recovery process of the Burgers model can be expressed as:

[0071]

[0072] The high damping model parameters used in the present invention are shown in the following table:

[0073] Table 1 High damping model parameters

[0074]

[0075] (2) Energy-absorbing and vibration-reducing materials

[0076] According to the research results of homogenization theory, the Gibson formula and its modified formula can be used to describe the energy absorbing layer 2. The energy absorbing and vibration damping material has obvious orthogonal anisotropy. The material has three planes of symmetric performance. The change of its strain component satisfies the principle of constant strain energy density. Its stiffness matrix coefficient is reduced to nine, and its stress-strain relationship is:

[0077]

[0078] In the material principal direction coordinate system, normal stress only causes linear strain but not shear strain, and shear stress only causes shear strain but not linear strain. There is no relationship between shear strain and shear stress in different planes, that is, there is no coupling effect.

[0079] By using engineering constants such as elastic modulus, Poisson's ratio, and shear modulus to represent the constitutive relationship of the material, the elastic constitutive relationship of the honeycomb material represented by the engineering constants is:

[0080]

[0081] Establishing an accurate constitutive model is one of the key steps in modeling energy absorbing and vibration damping materials. Since the temperature of energy absorbing and vibration damping materials does not change significantly during the impact energy process, they have a high strain rate change effect. Therefore, the plastic constitutive equation of energy absorbing and vibration damping materials can be simplified to a functional relationship between stress and strain rate.

[0082] The elastic modulus E of the energy absorbing and vibration reducing material selected in the present invention is s 4000Mpa, shear modulus G s is 1420M pa. Based on the elastic constitutive equation established by formula (5), the Gibson and its modified formula are used to calculate the relevant parameters, and the equivalent elastic engineering constants are shown in Table 2. The material density is set to 4.8E-11t / mm 3 The fracture strain was set to 0.007, the shear stress ratio to 0.01, and the strain ratio to 0.

[0083] Table 2 Equivalent elastic engineering constants of energy absorbing and vibration reducing materials

[0084]

[0085] (3) Restoration spring

[0086] Energy-absorbing and vibration-damping materials will undergo structural deformation and consume energy after being loaded, but the impact load of the ore is large. Under complex working conditions, the device cannot completely absorb the impact energy of the ore. A recovery device 11 is required to temporarily store part of the impact energy, and when the energy-absorbing element 5 reaches its upper limit of energy absorption, the stored energy is released in the form of mechanical kinetic energy to prevent the buffer device from being damaged due to excessive energy absorption.

[0087] 3. Buffer pressure relief device

[0088] The overall size of the buffer pressure relief device is 1000mm×1000mm×240mm, and the structure is divided into three layers ( Figure 4 ). The first layer is a steel plate with a size of 1000mm×1000mm×100mm, the second layer is nine energy absorbing elements 5, and the third layer is a buffering and vibration-damping material with a size of 1000mm×1000mm×20mm.

[0089] The working principle of the energy absorption matrix 1 is that the impact load of the ore is first directly contacted by the steel plate with greater rigidity, and the impact load is evenly transferred to the nine energy absorption elements 5. The high damping device of the energy absorption element 5 absorbs the impact energy, converts part of the impact energy that cannot be absorbed into the elastic potential energy of the spring, and transfers part of the excess energy to the buffer vibration reduction material. The new buffer vibration reduction material further absorbs energy through plastic deformation. After that, the impact energy formed by the impact of the ore is absorbed.

[0090] 4. Test and analysis of energy absorption effect of buffer pressure relief device

[0091] 4.1 Numerical model of energy absorption matrix 1

[0092] When the three-dimensional model of the energy absorbing element 5 is imported into ABAQUS for assembly, in order to accurately determine the relative positions of the various components, the center point of the lower surface of the base is set as the origin of the coordinate axis, the center line of the axis is the z-axis, and the directions perpendicular and parallel to the front end surface of the carrier plate 6 are the x-axis and y-axis to establish a coordinate system. In addition, this study only focuses on the movement of the shock absorber and the slider in its working direction, so coaxial constraints are imposed on each component to ensure that it does not move axially.

[0093] In order to ensure the accuracy of the calculation of key features and prevent the calculation from being unable to proceed due to abnormal singular units, the shock absorber components should be segmented before meshing. Comprehensive analysis of the characteristics of the shock absorber components and the topological relationship can be used to generate a hexahedral mesh in ABAQUS, but the control method is relatively complicated. This time, hypermesh is used for meshing to generate a mesh of appropriate thickness. The mesh effect is as follows: Figure 5 shown.

[0094] Figure 5 Except for the dark yellow high damping rubber, all parts are steel. The gray connecting rod and the orange base and the green block are in rotational relationship. The blue steel plate and the yellow high damping rubber are vulcanized together, and the high damping rubber and the orange base are also vulcanized together. The blue steel plate and the orange base can slide relative to each other, but are damped by the rubber. The green part and the orange base are connected by a conceptual spring, which needs to be established in A BAQUS and is equipped with a guide mechanism.

[0095] High damping rubber is used as the main energy absorption device, and the spring is only used for rebound. The relative movement between the blue steel plate and the orange base is used to shear the rubber, and the rubber absorbs energy to prevent the device from falling. The gray connecting rod and the orange base and the green block are all in rotational relationship, so the rotation pair, that is, the hinge unit, is set in the software. The blue steel plate and the yellow high damping rubber are vulcanized together, and the high damping rubber and the orange base are also vulcanized together, so they should be processed into one body in HM using a common node, but the materials in different areas are different. The green part is connected to the orange base in the middle by a conceptual spring. The guide mechanism is realized by friction contact, and the tangential behavior is set to smooth.

[0096] 4.2 Numerical model of buffer pressure relief device

[0097] (1) Numerical model establishment

[0098] The geometric dimensions of the solid model of the energy absorption matrix 1 are first established in the three-dimensional modeling software SW. The energy absorption matrix 1 model consists of four parts: the top plate 3, the energy absorption element 5, the aramid fiber board and the bottom plate 4. Figure 6 This is the simplified entity model of the energy absorption matrix 1. When the energy absorption matrix 1 absorbs the impact energy of the ore, some features that have little effect on the model analysis results can be ignored. The simplification of the finite element analysis model of the energy absorption matrix 1 is consistent with the simplified processing of the energy absorption element 5.

[0099] When the built three-dimensional model of the energy absorption matrix 1 is imported into ABAQUS for assembly, in order to accurately determine the relative positions of the various components, the center point of the lower surface of the bottom plate is taken as the origin of the coordinate axis, the center line of the axis is taken as the z-axis, and the directions perpendicular and parallel to the front end surface of the top plate 3 are taken as the x-axis and y-axis to establish a coordinate system.

[0100] In addition, this study only focuses on the movement of the energy absorption matrix 1 in its working direction, so coaxial constraints are imposed on each component to ensure that it only moves axially.

[0101] (2) Material properties

[0102] After the assembly geometry model is built, the next step is to define the material properties of each component. When defining the material of the energy absorption matrix 1, the top plate 3, the energy absorption element 5 and the aramid fiber board are mainly defined.

[0103] (3) Contact definition and mesh division

[0104] In order to ensure the accuracy of the calculation of key features and to prevent the calculation from being unable to proceed due to abnormal singular units, the shock absorber components should be segmented before meshing. The characteristics of the shock absorber components are comprehensively analyzed, and the topological relationship is generated by segmenting the hexahedral mesh in ABAQUS, but the control method is relatively complicated.

[0105] The energy absorption matrix 1 model is imported using the hypermesh geometry model, assembled in abaqus, and then meshed. After segmentation, the mesh type is set to hexahedron. The mesh of the assembly is as follows Figure 7 As shown in the figure. In the energy absorption matrix 1 model of this study, 128 surfaces are created from top to bottom, forming 72 contact pairs. In addition to the surfaces and contact pairs defined in the energy absorption element 5, the "surface-to-surface binding" attribute is also used to simulate the connection relationship between the top plate 3 and the energy absorption element 5 to ensure that the axial motion state of the energy absorption matrix 1 is consistent.

[0106] There are three types of link relationships in the energy absorption matrix 1 model: contact, coupling and binding. The aramid fiberboard and the bottom plate are bound, and the base and the aramid fiberboard are bound; the guide mechanism between the bearing plate 6 and the top plate 3, and between the bearing plate 6 and the base is frictionless contact; the upper surface of the top plate 3 is coupled with the reference point at its center point, the cylindrical surface at the hinge of the kinematic pair is coupled with the reference point, and the two reference points connected to the spring are coupled with the bearing plate 6 and the surface of the base that bears the force.

[0107] Coupling and binding constraints such as Figure 8 As shown, contact Fig. 9 To ensure the calculation quality, the surface of the component with large stiffness is selected as the main surface, that is, the contact surface of the mesh block is the secondary surface when in contact.

[0108] When numerically simulating a structure based on ABAQUS, the unit type and size have a decisive influence on the precision and accuracy of the fitting results. The three-dimensional units available are hexahedrons, tetrahedrons and wedges, and the two-dimensional units available are triangles and quadrilaterals; for three-dimensional problems, hexahedral units are selected as much as possible in the simulation, which has low computational cost and better results.

[0109] 4.3 Energy absorption effect test analysis

[0110] In order to compare the performance of the energy absorption matrix 1 structure and the new buffer vibration reduction material in absorbing impact energy, the following three combined models of the energy absorption matrix 1 model, the buffer vibration reduction material, and the buffer pressure relief device are analyzed respectively:

[0111] (1) Energy absorption matrix 1 model

[0112] The energy absorption matrix 1 model is a buffer vibration reduction sequence composed of 9 energy absorption elements 5 and a top plate 3 and a bottom plate 4. The model studies the energy absorption effect of the model after an impact load of 500 kN is applied for 0.1 s without an aramid fiber board layer.

[0113] The load condition for the analysis model is an impact load of 500 kN. The load is applied to the reference point of the top plate 3, the bottom plate is fixed, and the degrees of freedom of the reference point of the top plate 3 are constrained in directions other than the impact direction. The surface at the bottom of the slider is constrained in the impact direction, which makes the shear effect of the rubber more obvious. The material properties are consistent with the single device model. The effects of constraints and loads are shown in Figure 1. Fig.10 shown.

[0114] The energy absorbing element 5 in the model uses a spring stiffness coefficient of 5000N / mm. The stress and strain cloud diagrams of the model are as follows: Fig.11 and Fig.12 shown.

[0115] From the stress cloud diagram, we can see that the maximum stress of the analysis model is 289.1MPa at the final moment, which appears on the load-bearing plate 6 of the buffer device. From the strain cloud diagram, we can see that the maximum displacement is 16.7mm, but the displacement of 16.7mm does not appear at 0.1s, but at the moment of downward rush. Therefore, from the perspective of deformation storage (absorption) energy, the buffer vibration reduction sequence has a certain energy absorption capacity.

[0116] At the same time, this study analyzes the energy absorption capacity of the model under impact load. The curve relationship between the absorbed energy and time of the model is as follows: Fig.13 As shown in the figure, according to the kinetic energy curve, the maximum peak kinetic energy is 1.82341E+06J, and the minimum peak kinetic energy is 9.05508E+05J, with a difference of 723167J. The energy absorption effect of this model is average, but the rebound speed is very fast.

[0117] (2) Buffering and vibration-damping materials

[0118] The comparative analysis model is an aramid fiber energy absorption plate. While ensuring that the size and material of the top plate 3 and bottom plate of the buffer vibration reduction sequence model remain unchanged, the 9 energy absorption elements 5 are replaced with a 20mm thick aramid fiber plate. The top plate 3 is used to impact the aramid fiber plate and the bottom steel plate. The impact load applied to the upper top plate 3 is still 500KN. The energy absorption of the model after 0.1s is analyzed. Fig.14 and Fig.15 They are respectively the stress cloud diagram and strain cloud diagram of the model under the working load.

[0119] Under the impact load of 500kN, the buffer vibration reduction model has a maximum strain of 16.7mm, and a strain of 289.1MPa is generated at the load plate 6. According to the kinetic energy curve in the finite element, the model absorbs 723167J of impact load energy within 0.1s ( Fig.16 ). After absorbing the impact load energy, the energy absorption matrix 1 model is still in a plastic state, and it takes a certain amount of time to return to the initial state.

[0120] (3) Buffer pressure relief device

[0121] The comparative analysis model is an energy absorption matrix 1 model. The model is composed of 9 energy absorption elements 5, a 20 mm aramid fiber board, a top plate 3 and a bottom plate 4. The energy absorption element 5 in the model adopts a spring stiffness coefficient of 5000 N / mm. After an impact load of 500 kN acts for 0.1 s, the energy absorption effect of the model is analyzed.

[0122] The load condition for the analysis model is an impact load of 500kN, which is consistent with the setting of the buffer vibration reduction sequence model. The load is applied to the reference point of the top plate 3, the bottom plate is fixed, and the degrees of freedom of the reference point of the top plate 3 in directions other than the impact direction are constrained. At the same time, the surface at the bottom of the slider constrains the degrees of freedom in the impact direction, which makes the shear effect of the rubber more obvious. The effects of the constraints and loads are shown in the figure. Figure 17-18 shown.

[0123] according to Fig.19 The impact energy absorption curve of the buffer pressure relief device shows that the energy absorption is completed at 0.912s, indicating that the device has the ability to fully absorb the impact energy. The rapid rebound of the energy absorption matrix 1 provides time guarantee for the recovery of the buffer pressure relief device.

[0124] V. Conclusion

[0125] The present invention develops a buffer pressure relief device, which better solves the impact problem in the ore transportation process. The buffer pressure relief device is studied by controlling variables. The device is composed of an energy absorption matrix 1 structure and a new type of buffer vibration reduction material. The following conclusions are drawn.

[0126] (1) The energy absorption matrix 1 structure is composed of a number of energy absorption elements 5 arranged in a certain manner. Test analysis shows that the device has a certain ability to absorb impact load energy and has a fast recovery speed.

[0127] (2) The cushioning and vibration reduction material is composed of multiple layers of high damping material. Test analysis shows that the material has a very strong impact load energy capacity, but the recovery speed is slow.

[0128] (3) The buffer pressure relief device is composed of an energy absorption matrix 1 structure and a buffer vibration reduction material. It has both the fast recovery rate of the energy absorption matrix 1 structure and the strong ability of the buffer vibration reduction material to absorb impact load energy.

[0129] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the implementation methods of the present invention, and should be understood that the protection scope of the present invention is not limited to such special statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A buffer pressure relief device for preventing impact on the shaft wall of an underground mine tunnel, characterized in that: include: An energy absorbing matrix (1), a top plate (3) and a bottom plate (4); The energy absorption matrix (1) is covered with a top plate (3) on the top and fixed on a bottom plate (4) on the bottom; The energy absorption matrix (1) is composed of a plurality of energy absorption elements (5); the energy absorption elements (5) are used to absorb and dissipate the downward impact or vibration energy of the top plate (3).

2. The buffer pressure relief device according to claim 1, characterized in that: The energy absorbing element (5) comprises: a bearing plate (6), a transmission shaft (7), a connecting rod (8), a limiting plate (9), a rubber damper (10), a restoring device (11) and a base (12); The bearing plate (6) is used to support the top plate (3); The transmission shaft (7) is connected to the rubber damper (10) through a connecting rod (8); the rubber damper (10) converts external impact force into heat energy or internal energy consumption through elastic deformation of internal rubber material, so as to reduce the transmission of impact force; The limit plate (9) is fixed on the base (12) to serve as a stable support for the rubber damper (10); The recovery device (11) is installed on the base (12) and supports the entire bearing plate (6) through an internal spring; it is used to restore the initial state of all components of the energy absorbing element after the external force is removed.

3. The buffer pressure relief device according to claim 1, characterized in that: The rubber damper (10) adopts a high damping rubber constitutive model, which is a Burgers model. The Burgers model includes a Kelvin model element and a Maxwell model element connected in series. The total strain of the Burgers model is provided by the spring strain and the viscosity pot strain, and the strain of the model is expressed as the following formula: Among them, E1 and E2 are the elastic moduli of the two springs of the Burgers model, η1 and η2 are the viscosities of the two viscosity pots of the Burgers model, σ0 represents the stress applied to the material externally, and t is the time variable; The creep and recovery process of the Burgers model is expressed as follows: Among them, t cp It is a specific point in time that marks the transition from the creep phase to the creep recovery phase.

4. The buffer pressure relief device according to claim 1, characterized in that: An energy absorbing layer (2) is provided on the contact surface between the energy absorbing matrix (1) and the bottom plate (4).

5. The buffer pressure relief device according to claim 4, characterized in that: The energy absorbing layer (2) has orthotropic anisotropy, and its stress-strain relationship is: Among them, σ1 to σ6 are stress components, ε1 to ε6 are strain components, and C ij is the stiffness matrix coefficient of the material.

6. The buffer pressure relief device according to claim 5, characterized in that: The elastic constitutive relation of the energy absorbing layer (2) is expressed by engineering constants and calculated using the Gibson formula and its modified formula. The stress-strain relation of the material is: Among them, v 12 , v 13 , v 23 , v 31 , v 21 , v 32 is Poisson's ratio, E1, E2, E3 are elastic moduli, G 12 , G 13 , G 22 , is the shear modulus, and Δ is a constant.

7. The buffer pressure relief device according to claim 4, characterized in that: The energy absorbing layer (2) is two layers of aramid fiber material.

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