Coal mine roof presplitting device and presplitting method

Abstract

The invention discloses a coal mine roof pre-splitting device and a pre-splitting method. The coal mine roof pre-splitting device comprises a plurality of blasting pipes which are sequentially arranged in the extending direction of a blasting hole. The blasting pipe comprises an outer ring wall and an inner ring wall, an outer cavity is defined by the outer ring wall and the inner ring wall, an inner cavity used for containing explosives is defined by the inner ring wall, the outer cavity comprises an energy gathering cavity and a water cavity used for containing water, and the size of the energy gathering cavity in the circumferential direction of the blasting pipe is gradually increased outwards in the radial direction of the blasting pipe so that an energy gathering opening formed outwards in the radial direction of the blasting pipe can be formed. According to the coal mine roof presplitting device, kinetic energy and potential energy of explosives can be converted into kinetic energy and potential energy of water, the water is converted into high-pressure water jet after passing through the energy gathering cavity, the high-pressure water jet is jetted outwards along the energy gathering opening of the energy gathering cavity, the energy of the high-pressure water jet is concentrated, and the explosive blasting energy utilization rate is high; and a relatively large and tidy crack can be formed in a hard rock stratum of a coal mine roof, so that a relatively good pre-splitting effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine roof blasting pre-splitting, and in particular to a coal mine roof pre-splitting device and a pre-splitting method. Background Art

[0002] The hard roof above the coal seam is one of the main factors affecting the occurrence of rock burst. During coal mining, in order to effectively reduce the strength of the hard roof in the goaf, it is necessary to pre-crack the unbroken roof above the coal seam, change the physical and mechanical properties of the roof, prevent large-area roof pressure, and thus reduce the probability of rock burst.

[0003] At present, the common means of pre-cracking coal mine roof is explosive blasting. The shock wave generated by the detonation of the explosives spreads in all directions, and the pressure acts evenly. A large part of the blasting energy is consumed in the formation of coal (rock) mass crushing, resulting in a large blasting crushing area and a small fracture area, and low energy utilization rate of explosive blasting. The pre-cracking effect on coal mine roof is poor. In addition, explosive blasting also has problems such as being able to be used only in low-gas areas, generating a large amount of dust, and a large amount of construction work. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a coal mine roof pre-splitting device, which can convert the kinetic energy and potential energy of explosives into the kinetic energy and potential energy of water. The water is converted into a high-pressure water jet after passing through an energy-gathering cavity and sprayed outward along the energy-gathering port of the energy-gathering cavity. The energy of the high-pressure water jet is relatively concentrated, and the utilization rate of the explosive blasting energy is high. It can form larger and more neat cracks in the hard rock strata of the coal mine roof, thereby achieving a better pre-splitting effect.

[0006] The coal mine roof pre-splitting device of the embodiment of the present invention comprises a plurality of blasting tubes suitable for being placed in the blasting hole, wherein the plurality of blasting tubes are arranged in sequence along the extension direction of the blasting hole; the blasting tube comprises an outer annular wall and an inner annular wall, wherein the outer annular wall and the inner annular wall form an outer cavity, wherein the inner annular wall forms an inner cavity for accommodating explosives, wherein the outer cavity comprises an energy-gathering cavity and a water cavity for accommodating water, wherein the size of the energy-gathering cavity in the circumferential direction of the blasting tube gradually increases radially outwardly along the blasting tube to form an energy-gathering port arranged radially outwardly along the blasting tube.

[0007] In some embodiments, the coal mine roof pre-splitting device also includes an energy gathering piece, which includes a first plate and a second plate arranged in a V-shape, the relatively close sides of the first plate and the second plate are connected to each other, and the relatively distant sides of the first plate and the second plate are both connected to the outer annular wall to form the energy gathering cavity between the first plate, the second plate and the outer annular wall.

[0008] In some embodiments, the first plate and the second plate form an energy focusing angle, and the energy focusing angle is 60° to 75°.

[0009] In some embodiments, there are multiple energy focusing cavities, and the multiple energy focusing cavities are arranged at intervals along the circumference of the bursting tube.

[0010] In some embodiments, the coal mine roof pre-splitting device also includes a connecting piece, and two adjacent blasting tubes arranged along the extension direction of the blasting hole are arranged at intervals. The connecting piece is arranged between the two adjacent blasting tubes, and the connecting piece is in the shape of a long strip. Both ends of the connecting piece are respectively inserted into the inner cavities of the two adjacent blasting tubes.

[0011] In some embodiments, the coal mine roof pre-splitting device also includes a detonating cord, which is passed through the inner cavity of the plurality of blasting tubes, the cavity wall of the inner cavity has a first slot, and at least a portion of the detonating cord is engaged with the first slot.

[0012] In some embodiments, the connecting member has a second slot, and at least a portion of the detonating cord is snap-fitted into the second slot.

[0013] In some embodiments, the first clamping groove has a first opening facing inward in a radial direction of the bursting tube; and / or the second clamping groove has a second opening facing outward in a radial direction of the bursting tube.

[0014] The coal mine roof pre-splitting method of the embodiment of the present invention adopts the coal mine roof pre-splitting device described in any of the above embodiments, and the coal mine roof pre-splitting method includes the following steps:

[0015] S1: determining drilling parameters for the coal mine roof, and drilling the coal mine roof to form a blasting hole;

[0016] S2: injecting water into the water cavity;

[0017] S3: installing the blasting tube into the blasting hole, and adjusting the position of the blasting tube so that the energy gathering port of the energy gathering cavity faces a preset direction;

[0018] S4: loading explosives into the inner cavity of the blasting tube;

[0019] S5: repeating the steps S2 to S4 until a preset number of the blasting tubes and the explosives are loaded into the blasting hole;

[0020] S6: Complete blasting preparations to implement blasting.

[0021] In some embodiments, the plurality of blasting tubes are sequentially formed into a plurality of tube groups along the extension direction of the blasting hole, the tube group includes 8 to 12 blasting tubes, a positioning piece is provided between two adjacent tube groups, and the positioning piece is fixedly connected to the blasting hole.

[0022] The coal mine roof pre-splitting device of the embodiment of the present invention, after blasting, the shock wave generated by the explosive blasting passes through the water body wrapped around the explosive, and the kinetic energy and potential energy of the explosive are converted into the kinetic energy and potential energy of the water body. After the water body passes through the energy focusing cavity, the kinetic energy and potential energy of the water body are converted into a high-pressure, high-speed, high-energy water jet, and is ejected outward along the energy focusing port of the energy focusing cavity. The energy of the high-pressure water jet is relatively concentrated, and the perforation ability is relatively strong, which is much greater than the dynamic load compressive strength and tensile strength of the coal mine roof rock layer. It can cut the hard coal mine roof and form a large and relatively neat crack (the width of the crack is 10mm to 20mm) in the hard rock layer of the coal mine roof. The energy utilization rate of the explosive blasting is high, and a better pre-splitting effect can be achieved. In addition, due to the neat cracks, the safety of the coal mine roof can be guaranteed in the early stage of coal mining. After the coal mining working face is advanced, the coal mine roof can be fully collapsed to achieve a better pressure relief effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view of a coal mine roof pre-splitting device according to an embodiment of the present invention.

[0024] Figure 2 It is a schematic diagram of the three-dimensional structure of a coal mine roof pre-splitting device according to an embodiment of the present invention.

[0025] Figure 3 The invention is a schematic diagram of the connection between a connecting piece of a coal mine roof pre-splitting device and two blasting tubes according to an embodiment of the present invention.

[0026] Figure 4 It is a schematic structural diagram of a connecting piece of a coal mine roof pre-splitting device according to an embodiment of the present invention.

[0027] Reference numerals:

[0028] 100. Coal mine roof pre-splitting device;

[0029] 1. blasting tube; 11. outer ring wall; 111. energy-gathering cavity; 1111. energy-gathering port; 112. water cavity; 12. inner ring wall; 121. inner cavity; 13. end wall; 131. water injection port; 14. clamping piece; 141. first clamping groove;

[0030] 2. Explosives;

[0031] 3. Energy concentrator; 31. First plate; 32. Second plate;

[0032] 4. Connecting piece; 41. Second card slot;

[0033] 5. Detonating cord. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0035] like Figures 1 to 3 As shown, the coal mine roof pre-splitting device 100 of the embodiment of the present invention includes a plurality of blasting tubes 1 suitable for being placed in a blasting hole, and the plurality of blasting tubes 1 are arranged in sequence along the extension direction of the blasting hole; the blasting tube 1 includes an outer annular wall 11 and an inner annular wall 12, the outer annular wall 11 and the inner annular wall 12 form an outer cavity, the inner annular wall 12 forms an inner cavity 121 for accommodating explosives 2, the outer cavity includes an energy-gathering cavity 111 and a water cavity 112 for accommodating water, the size of the energy-gathering cavity 111 in the circumferential direction of the blasting tube 1 gradually increases radially outwardly along the blasting tube 1 to form an energy-gathering port 1111 arranged radially outwardly of the blasting tube 1.

[0036] The coal mine roof pre-splitting device 100 of the embodiment of the present invention, when pre-splitting the coal mine roof, first determines the drilling parameters for the coal mine roof, and drills the coal mine roof to form the above-mentioned blasting hole; at the same time, water is injected into the water cavity 112 of the blasting tube 1, and after the water injection is completed, the blasting tube 1 is loaded into the blasting hole, and the position of the blasting tube 1 is adjusted so that the energy-gathering cavity 111 faces a preset direction; then, the explosive 2 is loaded into the inner cavity 121 of the blasting tube 1, and the installation of one blasting tube 1 can be realized, and multiple blasting tubes 1 are sequentially loaded into the blasting hole in the same way until a preset number of blasting tubes 1 and explosives 2 are all loaded into the blasting hole; at this point, the blasting preparation is completed, and the blasting can be implemented.

[0037] The coal mine roof pre-splitting device 100 of the embodiment of the present invention, after blasting, the shock wave generated by the blasting of the explosive 2 passes through the water body wrapped around the explosive 2, and the kinetic energy and potential energy of the explosive 2 are converted into the kinetic energy and potential energy of the water body. After the water body passes through the energy focusing cavity 111, the kinetic energy and potential energy of the water body are converted into a high-pressure, high-speed, high-energy water jet, and is ejected outward along the energy focusing port 1111 of the energy focusing cavity 111. The energy of the high-pressure water jet is relatively concentrated, and the perforation ability is relatively strong, which is much greater than the dynamic load compressive strength and tensile strength of the coal mine roof rock layer. It can cut the hard coal mine roof and form a large and relatively neat crack (the width of the crack is 10mm to 20mm) in the hard rock layer of the coal mine roof. The utilization rate of the blasting energy of the explosive 2 is high, and a better pre-splitting effect can be achieved. In addition, due to the neat cracks, the safety of the coal mine roof can be guaranteed in the early stage of coal mining. After the coal mining working face is advanced, the coal mine roof can be fully collapsed to achieve a better pressure relief effect.

[0038] At the same time, since the high-pressure water jet is ejected outward along the energy gathering port 1111, the cutting direction of the coal mine roof can be adjusted by adjusting the direction of the energy gathering port 1111, thereby achieving directional cutting of the hard coal mine roof, controlling the collapse position of the coal mine roof, and improving the safety of coal mine production.

[0039] In addition, the coal mine roof pre-splitting device 100 of the embodiment of the present invention can convert the kinetic energy and potential energy of the explosive 2 into the kinetic energy and potential energy of the water body, and cut the coal mine roof through a high-pressure water jet. It is suitable for high-gas areas and can reduce the generation of blasting dust and improve the safety of coal mine production.

[0040] When pre-cracking the coal mine roof, it is necessary to drill multiple blasting holes. Two adjacent blasting holes are facing each other. After the two blasting holes are detonated simultaneously or sequentially, the compression waves generated will superimpose on the line connecting the two blasting holes and become rarefaction waves, breaking the molecular structure of the rock on the line connecting the two blasting holes, thereby forming a larger and more thorough crack.

[0041] As an example, Figure 1 and Figure 2 As shown, the explosive 2 is installed in the form of a medicine roll, and the explosive roll 2 corresponds to the blasting tube 1 one by one, and the length of the medicine roll is less than the length of the blasting tube 1. The cross section of the inner cavity 121 is larger than the cross section of the medicine roll, that is, there is a gap between the outer side of the medicine roll and the cavity wall of the inner cavity 121, so that the medicine roll can be smoothly loaded into the inner cavity 121.

[0042] In some embodiments, Figure 1 As shown, the coal mine roof pre-splitting device 100 also includes an energy gathering member 3, which includes a first plate 31 and a second plate 32 arranged in a V shape, the relatively close sides of the first plate 31 and the second plate 32 are connected to each other, and the relatively distant sides of the first plate 31 and the second plate 32 are both connected to the outer annular wall 11 to form an energy gathering cavity 111 between the first plate 31, the second plate 32 and the outer annular wall 11.

[0043] A V-shaped energy gathering port 1111 can be formed by the first plate 31 and the second plate 32, so that the kinetic energy and potential energy of the water body can be concentrated in the energy gathering cavity 111 and ejected outward through the energy gathering port 1111, thereby achieving directional cutting of the coal mine roof.

[0044] As an example, Figures 1 to 3As shown, the outer contour of the blasting tube 1 is cylindrical. The blasting tube 1 includes an outer annular wall 11, an inner annular wall 12 and two end walls 13. The outer annular wall 11 and the inner annular wall 12 form an annular outer cavity. The two end walls 13 are respectively blocked at both ends of the outer cavity, which can ensure the airtightness of the outer cavity, and then ensure the airtightness of the water cavity 112; a water injection port 131 is provided on the blasting tube 1, and the water injection port 131 is arranged on the end wall 13 of the blasting tube 1 and is connected with the water cavity 112. Water is injected into the water cavity 112 through the water injection port 131. After the water injection is completed, the water injection port 131 is blocked to form a closed hollow annular pressure-bearing blasting tube.

[0045] The energy gathering piece 3 is arranged in the outer cavity, the energy gathering piece 3 is in the shape of an elongated strip and extends along the axial direction of the blasting tube 1, and the two ends of the energy gathering piece 3 extend to the two end walls 13 of the blasting tube 1 respectively; the cross section of the energy gathering piece 3 is V-shaped, one side of the first plate 31 and the second plate 32 are connected to each other and arranged with a gap with the inner annular wall 12, and the other sides of the first plate 31 and the second plate 32 are both connected to the outer annular wall 11 to form an energy gathering cavity 111; thereby, the continuity of the water cavity 112 along the circumference of the energy gathering tube can be ensured, so that the water body can completely wrap the explosive 2, and after the explosive 2 is exploded, the kinetic energy and potential energy of the explosive 2 are fully converted into the kinetic energy and potential energy of the water body, thereby improving the utilization rate of the blasting energy of the explosive 2.

[0046] In other embodiments, a weak area may be provided on the wall of the energy-gathering cavity 111 formed by the outer annular wall 11 , so that the high-pressure water jet can more easily pass through the wall of the energy-gathering cavity 111 .

[0047] In some embodiments, the first plate 31 and the second plate 32 form an energy focusing angle α, and the energy focusing angle α is 60° to 75°.

[0048] By setting the energy focusing angle to the above range, the energy generated by the blasting can be more concentrated, ensuring that the high-pressure water jet can be gathered in the energy focusing chamber 111 to the maximum extent and ejected along the energy focusing port 1111, thereby achieving a better energy focusing effect.

[0049] In some embodiments, there are multiple energy focusing cavities 111 , and the multiple energy focusing cavities 111 are arranged at intervals along the circumference of the bursting tube 1 .

[0050] By providing a plurality of energy-gathering chambers 111 , after the explosive 2 is exploded, high-pressure water jets can be generated along multiple directions of the blasting tube 1 , thereby achieving directional cutting of the coal mine roof in multiple directions and achieving a better pre-splitting effect.

[0051] As an example, Figure 1 As shown, there are four energy focusing cavities 111 , and the four energy focusing cavities 111 are evenly arranged along the circumference of the blasting tube 1 .

[0052] In some embodiments, Figure 3As shown, the coal mine roof pre-splitting device 100 also includes a connecting piece 4. Two blasting tubes 1 arranged adjacent to each other along the extension direction of the blasting hole are arranged at intervals. The connecting piece 4 is arranged between the two adjacent blasting tubes 1. The connecting piece 4 is in a long strip shape, and both ends of the connecting piece 4 are respectively inserted into the inner cavities 121 of the two adjacent blasting tubes 1.

[0053] It is known that when the blasting holes are arranged at an angle, the explosives 2 in the blasting tubes 1 may slip during the process of loading multiple blasting tubes 1 into the blasting holes. By providing a connector 4, the connector 4 plays a connecting role between two blasting tubes 1, and the two ends of the connector 4 are respectively inserted into the inner cavities 121 of two adjacent blasting tubes 1, the explosives 2 in the inner cavities 121 can be limited, the probability of the explosives 2 slipping during the installation process is reduced, and the convenience of installing the blasting tubes 1 is improved.

[0054] Optionally, the length of the connecting member 4 is 80-140 mm, preferably 120 mm.

[0055] In some embodiments, Figure 1 and Figure 2 As shown, the coal mine roof pre-splitting device 100 also includes a detonating cord 5, which is passed through the inner cavity 121 of the plurality of blasting tubes 1. The cavity wall of the inner cavity 121 has a first clamping groove 141, and at least a portion of the detonating cord 5 is clamped and matched with the first clamping groove 141.

[0056] Through the above arrangement, the first clamping grooves 141 on the multiple blasting tubes 1 are all engaged with the detonating cord 5, and the detonating cord 5 is arranged in a straight line along the extension direction of the blasting hole, so that the first clamping grooves 141 of the multiple blasting tubes 1 can be aligned along the extension direction of the blasting hole, and then the energy-gathering cavities 111 of the multiple blasting tubes 1 can be distributed in a straight line along the extension direction of the blasting hole. Therefore, the energy-gathering ports 1111 of the multiple energy-gathering tubes are oriented in the same direction, and the injection direction of the high-pressure water jet is consistent, which can improve the energy utilization rate of the blasting of the explosive 2, extend the range of the crack, and enable the coal mine roof to fully collapse.

[0057] In addition, by locking the detonating cord 5 into the first locking slot 141 , the detonating cord 5 can be positioned and the stability of the detonating cord 5 can be improved.

[0058] In some embodiments, Figure 4 As shown, the connecting member 4 has a second slot 41 , and at least a portion of the detonating cord 5 is engaged with the second slot 41 .

[0059] By providing the second clamping groove 41, the detonating cord 5 arranged between two adjacent blasting tubes 1 can be positioned, further improving the stability of the detonating cord 5, so that the detonating cord 5 extends in a straight line, thereby ensuring that the energy-gathering cavities 111 of the multiple blasting tubes 1 are distributed in a straight line along the extension direction of the blasting hole.

[0060] In some embodiments, Figure 1 and Figure 4 As shown, the first clamping groove 141 has a first opening facing inward along the radial direction of the bursting tube 1 ; and / or the second clamping groove 41 has a second opening facing outward along the radial direction of the bursting tube 1 .

[0061] The detonating cord 5 can be inserted into the first slot 141 along the radial direction of the blasting tube 1 through the first opening, and can be inserted into the second slot 41 along the radial direction of the blasting tube 1 through the second opening. In other words, the detonating cord 5 is more conveniently engaged with the first slot 141 and the second slot 41, thereby improving the assembly convenience of the coal mine roof pre-splitting device 100.

[0062] As an example, Figure 1 As shown, the cavity wall of the inner cavity 121 is fixedly connected with a clamping piece 14, and the clamping piece 14 has the above-mentioned first clamping groove 141, which is aligned with one of the energy-gathering cavities 111 along the radial direction of the blasting tube 1; the first clamping groove 141 is arranged to penetrate along the axial direction of the blasting tube 1, and its cross section is semicircular, thereby forming a first opening arranged radially inwardly along the blasting tube 1.

[0063] like Figure 3 and Figure 4 As shown, the outer contour of the connecting member 4 is cylindrical, and the second clamping groove 41 is provided on the outer side wall of the connecting member 4. The second clamping groove 41 penetrates the connecting member 4 axially, and its cross section is semicircular, thereby forming a second opening arranged radially outward of the bursting tube 1.

[0064] The projections of the first clamping groove 141 and the second clamping groove 41 on the cross section of the blasting tube 1 are symmetrical to each other, so that the detonating cord 5 can be positioned in two directions.

[0065] The coal mine roof pre-splitting method of the embodiment of the present invention, the coal mine roof pre-splitting device 100 of any of the above embodiments, the coal mine roof pre-splitting method comprises the following steps:

[0066] S1: determining drilling parameters for the coal mine roof, and drilling the coal mine roof to form a blasting hole;

[0067] S2: inject water into the water chamber 112;

[0068] S3: inserting the blasting tube 1 into the blasting hole, and adjusting the position of the blasting tube 1 so that the energy gathering port 1111 of the energy gathering cavity 111 faces a preset direction;

[0069] S4: Loading the explosive 2 into the inner cavity 121 of the blasting tube 1;

[0070] S5: repeating steps S2 to S4 until a preset number of blasting tubes 1 and explosives 2 are loaded into the blasting hole;

[0071] S6: Complete blasting preparations to implement blasting.

[0072] The coal mine roof pre-splitting device 100 of the embodiment of the present invention, after blasting, the shock wave generated by the blasting of the explosive 2 passes through the water body wrapped around the explosive 2, and the kinetic energy and potential energy of the explosive 2 are converted into the kinetic energy and potential energy of the water body. After the water body passes through the energy focusing cavity 111, the kinetic energy and potential energy of the water body are converted into a high-pressure, high-speed, high-energy water jet, and is ejected outward along the energy focusing port 1111 of the energy focusing cavity 111. The energy of the water jet is relatively concentrated, and the perforation ability is relatively strong, which is much greater than the dynamic load compressive strength and tensile strength of the coal mine roof rock layer. It can cut the hard coal mine roof and form a large and relatively neat crack in the hard rock layer of the coal mine roof. The energy utilization rate of the blasting of the explosive 2 is high, and a better pre-splitting effect can be achieved. In addition, due to the neat cracks, the safety of the coal mine roof can be guaranteed in the early stage of coal mining. After the coal mining working face is advanced, the coal mine roof can be fully collapsed to achieve a better pressure relief effect.

[0073] In some embodiments, multiple blasting tubes 1 are sequentially formed into multiple tube groups along the extension direction of the blasting hole. The number of blasting tubes 1 included in the tube group is 8 to 12. A positioning piece is provided between two adjacent tube groups, and the positioning piece is fixedly connected to the blasting hole.

[0074] Each time a tube group is installed, the positioning piece can prevent the blasting tube 1 from slipping out of the blasting hole under the action of its own gravity, thereby fixing the position of the installed blasting tube 1 and explosive 2.

[0075] Optionally, the positioning piece is taphole clay.

[0076] As an example, the pipe group includes ten blasting tubes 1. During the implementation of the coal mine roof pre-splitting method, every ten blasting tubes 1 are installed (correspondingly, ten explosives are also installed), and tapholes with a length of less than 50 mm are used for interval sealing to fix the position of the blasting tubes 1.

[0077] As an example, the coal mine roof pre-splitting method includes the following steps:

[0078] S1: determining drilling parameters for the coal mine roof, and drilling the coal mine roof to form a blasting hole;

[0079] S2: inject water into the water chamber 112;

[0080] S3: insert the blasting tube 1 into the blasting hole, adjust the position of the blasting tube 1 so that the energy gathering port 1111 of the energy gathering cavity 111 faces the preset direction, and at the same time, engage the detonating cord 5 with the first clamping groove 141;

[0081] S4: Load the explosive 2 into the inner cavity 121 of the blasting tube 1, then insert one end of the connecting piece 4 into the installed blasting tube 1, and engage the detonating cord 5 with the second slot 41 of the connecting piece 4;

[0082] S5: repeating steps S2 to S4 until a preset number of blasting tubes 1 and explosives 2 are loaded into the blasting hole;

[0083] S5-1: Repeat steps S2 to S4 until one set of pipes is installed, and then seal the blasting hole with taphole mud;

[0084] S5-2: repeating steps S2 to S4 to install the next set of tubes until all the preset number of blasting tubes 1 and explosives 2 are loaded into the blasting hole;

[0085] S6: inserting a detonator into the blasting tube 1 at the lowermost end to complete the blasting preparation and implement the blasting.

[0086] It can be understood that the above description of the coal mine roof pre-splitting device 100 is also applicable to the coal mine roof pre-splitting method, and will not be repeated here.

[0087] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0088] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0089] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0090] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0091] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0092] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A coal mine roof pre-splitting device (100), characterized in that: The coal mine roof is provided with a blasting hole, and the coal mine roof pre-splitting device (100) comprises a plurality of blasting tubes (1) suitable for being placed in the blasting hole, and the plurality of blasting tubes (1) are arranged in sequence along the extension direction of the blasting hole; The blasting tube (1) comprises an outer annular wall (11) and an inner annular wall (12); the outer annular wall (11) and the inner annular wall (12) enclose an outer cavity; the inner annular wall (12) encloses an inner cavity (121) for accommodating explosives (2); the outer cavity comprises an energy-gathering cavity (111) and a water cavity (112) for accommodating water; the size of the energy-gathering cavity (111) in the circumferential direction of the blasting tube (1) gradually increases radially outwardly of the blasting tube (1) to form an energy-gathering port (1111) arranged radially outwardly of the blasting tube (1).

2. The coal mine roof pre-splitting device (100) according to claim 1, characterized in that: The invention also comprises an energy concentrating member (3), wherein the energy concentrating member (3) comprises a first plate (31) and a second plate (32) arranged in a V shape, wherein the first plate (31) and the second plate (32) are connected to each other at sides that are relatively close to each other, and the first plate (31) and the second plate (32) are connected to the outer annular wall (11) at sides that are relatively far away from each other, so as to form the energy concentrating cavity (111) between the first plate (31), the second plate (32) and the outer annular wall (11).

3. The coal mine roof pre-splitting device (100) according to claim 2, characterized in that: The first plate (31) and the second plate (32) form an energy focusing angle, and the energy focusing angle is 60° to 75°.

4. The coal mine roof pre-splitting device (100) according to claim 1, characterized in that: There are a plurality of energy-gathering cavities (111), and the plurality of energy-gathering cavities (111) are arranged at intervals along the circumference of the blasting tube (1).

5. The coal mine roof pre-splitting device (100) according to claims 1-4, characterized in that: The coal mine roof pre-splitting device (100) further comprises a connecting piece (4), two adjacent blasting tubes (1) are arranged at intervals along the extension direction of the blasting hole, the connecting piece (4) is arranged between the two adjacent blasting tubes (1), the connecting piece (4) is in the shape of a long strip, and the two ends of the connecting piece (4) are respectively inserted into the inner cavities (121) of the two adjacent blasting tubes (1).

6. The coal mine roof pre-splitting device (100) according to claim 5, characterized in that: It also comprises a detonating cord (5), the detonating cord (5) being inserted into the inner cavity (121) of the plurality of blasting tubes (1), the cavity wall of the inner cavity (121) having a first clamping groove (141), and at least a portion of the detonating cord (5) being clamped and matched with the first clamping groove (141).

7. The coal mine roof pre-splitting device (100) according to claim 6, characterized in that: The connecting piece (4) has a second clamping groove (41), and at least a portion of the detonating cord (5) is clamped and matched with the second clamping groove (41).

8. The coal mine roof pre-splitting device (100) according to claim 7, characterized in that: The first clamping groove (141) has a first opening facing inwards along the radial direction of the bursting tube (1); and / or The second clamping groove (41) has a second opening facing outward in the radial direction of the bursting tube (1).

9. A method for pre-splitting a coal mine roof, characterized in that: Using the coal mine roof pre-splitting device (100) according to any one of claims 1 to 8, the coal mine roof pre-splitting method comprises the following steps: S1: determining drilling parameters for the coal mine roof, and drilling the coal mine roof to form a blasting hole; S2: injecting water into the water chamber (112); S3: inserting the blasting tube (1) into the blasting hole, and adjusting the position of the blasting tube (1) so that the energy gathering port (1111) of the energy gathering cavity (111) faces a preset direction; S4: loading explosive (2) into the inner cavity (121) of the blasting tube (1); S5: repeating the steps S2 to S4 until a preset number of the blasting tubes (1) and the explosives (2) are loaded into the blasting holes; S6: Complete blasting preparations to implement blasting.

10. The coal mine roof pre-splitting method according to claim 9, characterized in that: The plurality of blasting tubes (1) are sequentially formed into a plurality of tube groups along the extension direction of the blasting hole, wherein the number of the blasting tubes (1) included in the tube group is 8 to 12, and a positioning piece is provided between two adjacent tube groups, and the positioning piece is fixedly connected to the blasting hole.

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