Abrasive water jet drilling and slotting integrated device

Abstract

The utility model relates to the technical field of mineral engineering construction, in particular to an abrasive water jet drilling and slotting integrated device based on pressure control. The device comprises a nozzle cap, a combined spray head, a mandrel, a bearing cover, a first roller pin thrust combined ball bearing, a first bearing jackscrew, a second bearing jackscrew, a second roller pin thrust combined ball bearing, a movable ring set, a turbine blade, a flow guide blade, a static ring set, a spring, a drilling shell, a connector, a slotting shell, a high-low pressure conversion valve, a slotting nozzle, a first sealing ring, a disc spring and a second sealing ring. A third sealing ring, a fourth sealing ring and a liquid inlet. The device is simple and compact in design structure, few in related equipment devices, low in failure rate and easy to maintain, free conversion between drilling and slotting can be achieved through water pressure control, the construction technology is simplified, and therefore construction efficiency and construction operation safety are improved, and construction cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of mining engineering construction technology, and in particular to an integrated device for pressure-controlled abrasive waterjet drilling and slotting. Background Technology

[0002] Although my country currently possesses abundant proven coal resources, the coal seams have complex geological conditions. Approximately one-third of these seams have hard, difficult-to-collapse roofs, and these are widely distributed in my country's main coal-producing areas. With the widespread adoption of fully mechanized mining technology, over 40% of fully mechanized mining faces now have roofs that are subject to intense pressure and are difficult to collapse.

[0003] The most commonly used method for roof cutting and pressure relief is blasting roof cutting. This method can effectively reduce the length of the lateral overhang of the roof of the working face. However, the controllability of blasting drilling roof cutting is poor, the safety risk is high, and it is very easy to cause over-blasting or under-blasting, which often damages the roof coal and rock mass that is still in use.

[0004] Another method is to use high-pressure hydraulic slit cutting to relieve pressure at the top, but this technology has many shortcomings in its implementation. Drilling is performed first, followed by slit cutting, and these two operations need to be carried out separately. This requires the use of various construction equipment and facilities, and each step requires specialized equipment and personnel. Consequently, this method results in long construction time, low efficiency, complex processes, and high costs.

[0005] To address the numerous shortcomings of existing high-pressure hydraulic slitting and roof-cutting depressurization methods, this invention provides an integrated abrasive waterjet drilling and slitting device based on pressure control. This device combines drilling and slitting functions, allowing for seamless switching between these modes by controlling the water pressure. Under low-pressure conditions, the device utilizes a self-rotating nozzle for abrasive waterjet drilling. When the water pressure rises to a certain value, the self-rotating nozzle automatically switches to a lateral abrasive waterjet spray, thus slitting the borehole wall. Using this device, forward drilling and slitting of the borehole wall can be achieved in a single drilling cycle, significantly saving construction time, improving work efficiency, and reducing costs. This provides a more efficient, safe, and economical solution for roof pre-fracture in coal mining. Summary of the Invention

[0006] This invention proposes an integrated device for abrasive waterjet drilling and slitting based on pressure control, in order to solve the problems existing in the prior art.

[0007] A pressure-controlled abrasive waterjet drilling and slitting integrated device, comprising:

[0008] Nozzle cap, combined nozzle, mandrel, bearing cover, first needle roller thrust combined ball bearing, first bearing set screw, second bearing set screw, second needle roller thrust combined ball bearing, moving ring assembly, turbine blade, guide vane, stationary ring assembly, spring, drilling housing, joint, slotting housing, high and low pressure switching valve, slotting nozzle, first sealing ring, disc spring, second sealing ring, third sealing ring, fourth sealing ring and liquid inlet.

[0009] Preferably, the guide vane and the inner cavity of the stationary ring assembly are in an interference fit. The guide vane and the stationary ring assembly remain stationary during operation.

[0010] Preferably, the stationary ring assembly is connected to the connector via a threaded connection.

[0011] Preferably, the stationary ring assembly and the drilling housing are sealed by the third sealing ring 22.

[0012] Preferably, the stationary ring assembly and the rotating ring assembly achieve a mechanical seal through the end faces of the two shafts.

[0013] Preferably, the fit between the turbine blade and the inner cavity of the moving ring assembly is an interference fit.

[0014] Preferably, the moving ring assembly and the mandrel are connected by a threaded connection.

[0015] Preferably, the moving ring assembly and the drilling housing are sealed by a fourth sealing ring 23.

[0016] Preferably, the mandrel and the nozzle cap 1 are connected by a threaded connection.

[0017] Preferably, the high-low pressure switching valve and the slotted housing are sealed by the first sealing ring and the second sealing ring.

[0018] The dynamic ring assembly and the drilling casing are sealed by the fourth sealing ring.

[0019] The working principle of this utility model device is as follows:

[0020] In some embodiments, the inlet of the device is connected and fixed to an abrasive water jet pump. The pump pressure of the abrasive water jet pump is adjusted to within 30 MPa. The device is then advanced forward at the coal seam mining face to perform drilling operations. After drilling is completed, the pump pressure is increased to above 30 MPa. At this point, the drilling operation is terminated, and the slotting operation begins. The device is gradually pulled out of the borehole. When the device is completely pulled out of the borehole, the slotting operation is completed simultaneously.

[0021] Specifically, when the pump pressure of the abrasive water jet pump is below 30 MPa, the abrasive flow enters from the inlet. At this time, the thrust of the abrasive flow is less than the counter-thrust generated by the spring disc. The high-low pressure switching valve moves along its axis towards the stationary ring assembly, but it cannot block the inlet of the stationary ring assembly. At the same time, the slit nozzle is still blocked by the high-low pressure switching valve. Therefore, the abrasive flow flows out through the inner cavity of the high-low pressure switching valve and into the inner cavity of the stationary ring assembly, instead of flowing out from the slit nozzle, and cannot generate a lateral cutting jet at the slit nozzle. After the abrasive flow enters the inner cavity of the stationary ring assembly, it flows through the turbine blade under the guidance of the guide vanes and then enters the inner cavity of the moving ring assembly. The torque generated by the abrasive flow flowing through the turbine blade can drive the moving ring assembly, the mandrel, the inner ring of the first needle roller thrust combined ball bearing, the inner ring of the second needle roller thrust combined ball bearing, the combined nozzle, and the nozzle cap to rotate. Finally, the abrasive flow rushes out from the combined nozzle to form multiple jets to impact the coal and rock, realizing the drilling operation.

[0022] Furthermore, when an abrasive flow with a pressure greater than 30 MPa enters through inlet 24, the thrust of the abrasive flow exceeds the counter-thrust generated by the spring disc. At this point, the high-low pressure switching valve moves along its axis towards the stationary ring assembly, completely blocking the inlet of the stationary ring assembly. This causes the rotating ring assembly, mandrel, inner rings of the first and second needle roller thrust ball bearings, combined nozzle, and nozzle cap to stop rotating. No jet is ejected from the combined nozzle, and drilling terminates. Simultaneously, the high-low pressure switching valve moves, connecting the slit nozzle to the inlet. The abrasive flow then exits from the slit nozzle, forming multiple lateral jets to cut the coal and rock, thus achieving the slit-cutting operation.

[0023] The pressure parameters mentioned above are just examples. Depending on different construction requirements, the design can be adapted by adjusting the size parameters and material selection of the high-low pressure switching valve, disc spring, and other components.

[0024] The present invention has the following advantages over the prior art:

[0025] 1. Using this utility model device, drilling and cutting can be freely switched through water pressure control. During construction, there is no need to manually change the gear to switch between drilling and cutting operations. Therefore, the construction process is simpler and the equipment operation is simpler, thereby saving construction time, improving construction efficiency and safety, and reducing construction costs.

[0026] 2. The design of this utility model device is simple and compact, involving fewer components, resulting in a low failure rate and easy maintenance. This significantly reduces maintenance costs and operational complexity, extending the device's service life. It allows for miniaturization of the device's size, enabling operation in confined spaces, particularly suitable for limited working environments such as underground coal mines, thus enhancing its applicability. Furthermore, this utility model employs abrasive waterjet technology, achieving high rock-breaking efficiency, capable of handling rocks of varying hardness, and improving cutting quality and depth. Attached Figure Description

[0027] Figure 1 This is a cross-sectional structural schematic diagram of an integrated abrasive waterjet drilling and slitting device based on pressure control according to this utility model.

[0028] Figure 2 This is a three-dimensional schematic diagram of an integrated abrasive waterjet drilling and kerfing device based on pressure control according to this utility model.

[0029] Figure label:

[0030] Nozzle cap 1, combined nozzle 2, mandrel 3, bearing cover 4, first needle roller thrust combined ball bearing 5, first bearing set screw 6, second bearing set screw 7, second needle roller thrust combined ball bearing 8, moving ring assembly 9, turbine blade 10, guide vane 11, stationary ring assembly 12, spring 13, drilling housing 14, connector 15, slit housing 16, high and low pressure conversion valve 17, slit nozzle 18, first sealing ring 19, disc spring 20, second sealing ring 21, third sealing ring 22, fourth sealing ring 23, liquid inlet 24. Detailed Implementation

[0031] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments.

[0032] In this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0035] according to Figure 1 As shown, a pressure-controlled abrasive waterjet drilling and slit-cutting integrated device includes:

[0036] Nozzle cap 1, combined nozzle 2, mandrel 3, bearing cover 4, first needle roller thrust combined ball bearing 5, first bearing set screw 6, second bearing set screw 7, second needle roller thrust combined ball bearing 8, moving ring assembly 9, turbine blade 10, guide vane 11, stationary ring assembly 12, spring 13, drilling housing 14, connector 15, slit housing 16, high and low pressure conversion valve 17, slit nozzle 18, first sealing ring 19, disc spring 20, second sealing ring 21, third sealing ring 22, fourth sealing ring 23, and liquid inlet 24.

[0037] Furthermore, the fit between the guide vane 11 and the inner cavity of the stationary ring assembly 12 is an interference fit. The guide vane 11 and the stationary ring assembly 12 remain stationary during operation.

[0038] Furthermore, the stationary ring assembly 12 is connected to the connector 15 via a threaded connection.

[0039] Furthermore, the stationary ring assembly 12 and the drilling housing 14 are sealed by the third sealing ring 22.

[0040] Furthermore, the stationary ring assembly 12 and the moving ring assembly 9 are mechanically sealed through the end faces of the two shafts.

[0041] Furthermore, the fit between the turbine blade 10 and the inner cavity of the moving ring assembly 9 is an interference fit.

[0042] Furthermore, the moving ring assembly 9 and the mandrel 3 are connected by a threaded connection.

[0043] Furthermore, the dynamic ring assembly 9 and the drilling housing 14 are sealed by a fourth sealing ring 23.

[0044] Furthermore, the mandrel 3 and the nozzle cap 1 are connected by a threaded connection.

[0045] Furthermore, the high-low pressure switching valve 17 and the slotted housing 16 are sealed together by the first sealing ring 19 and the second sealing ring 21.

[0046] Furthermore, the dynamic ring assembly 9 and the drilling housing 14 are sealed by a fourth sealing ring 23.

[0047] The working principle of the above device is as follows:

[0048] Connect and fix the inlet 24 of this utility model device to the abrasive water jet pump, adjust the pump pressure of the abrasive water jet pump to within 30MPa, push this utility model device forward at the coal seam mining face to perform drilling operation, after drilling is completed, increase the pump pressure to above 30MPa, at which point the drilling operation is terminated and the slotting operation begins, gradually pull this utility model device out of the borehole, and when the device is completely pulled out of the borehole, the slotting operation is completed at the same time.

[0049] Specifically, when the pump pressure of the abrasive water jet pump is lower than 30 MPa, the abrasive flow enters from the inlet 24. At this time, the thrust of the abrasive flow is less than the counter-thrust generated by the spring disc 20. The high-low pressure switching valve 17 moves along its axis toward the stationary ring assembly 12, but cannot block the inlet of the stationary ring assembly 12. At the same time, the slit nozzle 18 is still blocked by the high-low pressure switching valve 17. Therefore, the abrasive flow flows out through the inner cavity of the high-low pressure switching valve 17 and into the inner cavity of the stationary ring assembly 12, instead of flowing out from the slit nozzle 18, and no lateral cutting jet is generated at the slit nozzle 18. After the abrasive flow enters the inner cavity of the stationary ring assembly 12, it flows through the turbine blade 10 under the guidance of the guide vane 11, and then enters the inner cavity of the moving ring assembly 9. The torque generated by the abrasive flow passing through the turbine blade 10 can drive the rotating ring assembly 9, the spindle 3, the inner ring of the first needle roller thrust ball bearing 5, the inner ring of the second needle roller thrust ball bearing 8, the combined nozzle 2, and the nozzle cap 1 to rotate. Finally, the abrasive flow is ejected from the combined nozzle 2 to form multiple jets to impact the coal and rock, thereby realizing the drilling operation.

[0050] Specifically, when an abrasive flow with a pressure greater than 30 MPa enters through the inlet 24, the thrust of the abrasive flow is greater than the counter-thrust generated by the spring disc 20. At this time, the high-low pressure switching valve 17 moves along its axis toward the stationary ring assembly 12 and completely blocks the inlet of the stationary ring assembly 12. This causes the rotating ring assembly 9, the spindle 3, the inner ring of the first needle roller thrust combined ball bearing 5, the inner ring of the second needle roller thrust combined ball bearing 8, the combined nozzle 2, and the nozzle cap 1 to stop rotating. The combined nozzle 2 then emits no jet, and the drilling terminates. At the same time, the high-low pressure switching valve 17 moves, and the slit nozzle 18 connects with the inlet 24. The abrasive flow is ejected from the slit nozzle 18, forming multiple lateral jets to cut the coal and rock, thus realizing the slit cutting operation.

Claims

1. An integrated device for abrasive waterjet drilling and slit cutting, characterized in that, include: Nozzle cap (1), combined nozzle (2), mandrel (3), bearing cover (4), first needle roller thrust combined ball bearing (5), first bearing set screw (6), second bearing set screw (7), second needle roller thrust combined ball bearing (8), moving ring assembly (9), turbine blade (10), guide vane (11), stationary ring assembly (12), spring (13), drilling housing (14), joint (15), slotting housing (16), high and low pressure switching valve (17), slotting nozzle (18), first sealing ring (19), disc spring (20), second sealing ring (21), third sealing ring (22), fourth sealing ring (23), and liquid inlet (24); The fit between the guide vane (11) and the inner cavity of the stationary ring assembly (12) is an interference fit; The stationary ring assembly (12) is connected to the connector (15) via a threaded connection; The stationary ring assembly (12) and the drilling housing (14) are sealed together by the third sealing ring (22); The stationary ring assembly (12) and the moving ring assembly (9) achieve a mechanical seal through the end faces of the two shafts; The fit between the turbine blade (10) and the inner cavity of the moving ring assembly (9) is an interference fit; The moving ring assembly (9) and the mandrel (3) are connected by a threaded connection; The dynamic ring assembly (9) and the drilling housing (14) are sealed by a fourth sealing ring (23); The mandrel (3) and the nozzle cap (1) are connected by a threaded connection; The high-low pressure switching valve (17) and the slotted housing (16) are sealed by the first sealing ring (19) and the second sealing ring (21).

2. The integrated abrasive waterjet drilling and slit-cutting device according to claim 1, characterized in that, The guide vane (11) and the stationary ring assembly (12) remain stationary during operation.

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