A coal rock roadway drilling hole bottom reaming device

Abstract

The application discloses a coal and rock roadway drilling hole bottom reaming device, which comprises an internal pipe pusher, a fixing pin, a fan-shaped rotary rock breaker, a pusher, a flat spring and a spring push thread device. The front end of the internal pipe pusher is provided with the fan-shaped rotary rock breaker which can rotate freely at 0-90 degrees, and high-strength pick heads are arranged on the upper and lower sides of the fan-shaped rotary rock breaker. The pusher is located behind the fan-shaped rotary rock breaker, and the pusher is pushed to move forward by the flat spring, so that the fan-shaped rotary rock breaker is unfolded. When rotating in the drilling hole, the fan-shaped rotary rock breaker is gradually opened by the combined action of centrifugal force and spring pushing force, the surrounding rock of the drilling hole bottom and side wall is cut, and an enlarged area is formed. The application increases the contact area of the anchoring body and the surrounding rock, significantly improves the anchoring effect and the overall stability of the roadway, and is simple in structure, close in component cooperation and convenient and fast in construction, and is especially suitable for soft rock stratum, soft and broken coal body and roadway support under complex geological conditions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coal mine roadway support, and relates to a coal and rock roadway drilling hole bottom reaming device. BACKGROUND

[0002] In the construction process of coal mine roadway and underground engineering, the stability of the surrounding rock directly relates to the safety and efficiency of the construction. The traditional supporting methods mainly include anchor rods, anchor cables, shotcreting and steel arches, etc. Among them, the anchor rod support is widely adopted due to its simple construction and low cost. However, the traditional drilling and supporting method has many deficiencies under complex geological conditions:

[0003] (1) Uniform hole diameter, limited anchoring range: The hole diameter of traditional drilling is basically consistent from the entrance to the hole bottom, usually 30-50 mm. Such design leads to limited contact area between the anchoring agent and the surrounding rock, and cannot form a large range of anchoring body. The uneven distribution of the anchoring agent in the hole easily forms accumulation at the hole bottom and weak areas on the hole wall. This uniform structure limits the anchoring agent or resin to form effective mechanical locking in the hole, especially in soft surrounding rock, which is more likely to cause the overall slippage of the anchor rod (cable), affecting the supporting effect.

[0004] (2) Insufficient initial anchoring force under complex geological conditions: Under the conditions of soft and broken coal or water, the anchoring agent is difficult to fully penetrate and solidify. Water will dilute the anchoring agent, reducing its bonding strength; soft and broken coal is difficult to provide stable support points for the anchor rod (cable). The insufficient initial anchoring force of the anchor rod (cable) cannot meet the supporting requirements, leading to deformation, collapse and other accidents of the surrounding rock of the roadway, seriously affecting the production safety.

[0005] (3) Anchoring body easily pulled out, unstable supporting effect: Due to the small mechanical interlocking force between the anchoring body and the surrounding rock, the anchoring body may be pulled out under stress, especially when the roadway is subjected to vibration, stress change or long-term load. This not only reduces the supporting effect of a single anchor rod (cable), but also may trigger a chain reaction, leading to the failure of the overall supporting system, increasing the safety risk and maintenance cost.

[0006] (4) Limitations of existing reaming methods: Although some reaming technologies have been applied to roadway support, such as anchor rod head expander, chemical expanding agent, etc., these methods usually have problems such as complex equipment, cumbersome construction, high cost, etc. It is difficult to operate in narrow underground space, and the transportation and installation of equipment are limited. In addition, these methods are often difficult to flexibly adjust the size and shape of the anchoring area according to different geological conditions, leading to insufficient adaptability in complex and variable mine environment.

[0007] (5) Lack of targeted solutions: there is currently a lack of specialized hole expanding devices for coal rock roadway soft surrounding rock conditions in the market, which cannot meet the needs of actual production. Most equipment and technology is mainly applied to hard rock or medium-hard rock strata, and has poor applicability to soft rock and soft and broken coal bodies.

[0008] In summary, the coal mine roadway support field urgently needs a device with simple structure, convenient construction and the ability to form an enlarged area at the bottom of the drill hole to improve anchoring effect and meet the needs of roadway support under complex geological conditions. This not only helps to improve the safety production level of the mine, but also has important economic and social benefits. SUMMARY

[0009] In view of the deficiencies in the prior art, the purpose of the present application is to provide a coal rock roadway drill hole bottom hole expanding device to solve the problems of limited anchoring range, insufficient anchoring force, complex construction, high cost and other problems in the existing coal mine roadway support technology. Through innovative mechanical structure design and scientific construction method, the present application realizes the formation of an enlarged area at the bottom of the drill hole, significantly increases the contact area between the anchoring body and the surrounding rock, thereby improving the anchoring effect and enhancing the overall stability of the roadway, and meets the needs of roadway support under complex geological conditions.

[0010] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0011] A coal rock roadway drill hole bottom hole expanding device, comprising an internal pipe pusher, a fixed pin, a fan-shaped rotary rock breaker, a pusher, a flat spring and a spring push thread device;

[0012] The internal pipe pusher is in tubular structure and is made of high-strength alloy steel, with an outer diameter matched with the drill hole diameter to enable it to enter the drill hole and remain stable. The internal pipe pusher has two internal holes of different diameters, namely a rear end internal hole diameter N and a front internal hole diameter M, and an internal thread located between the two and at the rear end position;

[0013] The fixed pin is provided at the front end of the internal pipe pusher and is made of high-strength alloy steel material, with a through hole at the top for mounting the fan-shaped rotary rock breaker. The structure of the fixed pin matches the groove of the fan-shaped rotary rock breaker, so that the fan-shaped rotary rock breaker can rotate freely within a range of 0°-90°;

[0014] The pusher can be placed inside the internal pipe pusher and is located behind the fan-shaped rotary rock breaker. It is made of high-strength steel material, with the front end face of the pusher in close contact with the bottom surface of the fan-shaped rotary rock breaker. The flat spring behind the pusher can push the pusher forward to expand the fan-shaped rotary rock breaker;

[0015] The spring pushing threaded device is installed at the rear end of the built-in pipe pusher, is made of alloy steel, is matched with the internal thread, and can accurately adjust the compression state of the flat spring by tightening or loosening the spring pushing threaded device, so as to adapt to different construction requirements.

[0016] The application also comprises the following technical features:

[0017] Specifically, the diameter difference between the built-in pipe pusher and the drill hole wall is 2-4 mm, so as to ensure that the device can smoothly enter the drill hole, maintain good stability during rotation and reaming, avoid device shaking or deviation caused by too large gap, and improve the accuracy and safety of construction.

[0018] Specifically, the diameter difference between the pusher and the built-in pipe pusher is 0-5 mm, so that the pusher can smoothly move in the built-in pipe pusher, reduce friction resistance, avoid jamming caused by too small gap or shaking caused by too large gap, and thus ensure the stability and efficiency of the reaming process.

[0019] Specifically, the inner diameter N of the built-in pipe pusher is slightly larger than the inner diameter M, and the diameter difference between the two is 1-4 mm, facilitating the installation and disassembly of the assembly, ensuring the smooth installation of the pusher, flat spring and spring pushing threaded device in the built-in pipe pusher, and also helping to maintain the overall structural strength and stability of the device.

[0020] Specifically, the outer thread length of the spring pushing threaded device is slightly larger than the effective length of the internal thread of the built-in pipe pusher, so as to ensure that the flat spring can be completely compressed during tightening, ensure the firmness of installation, avoid the risk of loosening or falling of the spring pushing threaded device during construction, and improve the reliability and safety of the device.

[0021] Specifically, the groove of the fan-shaped rotary rock breaker is matched with the fixed pin, so that the maximum opening angle of the fan-shaped rotary rock breaker is 90°, and through accurate mechanical cooperation, the fan-shaped rotary rock breaker can be smoothly expanded to the designed angle under the action of rotation and centrifugal force, so as to expand the cutting range, improve the cutting efficiency of the surrounding rock, form a larger expansion area, and enhance the anchoring effect.

[0022] Specifically, the distance between the thread starting section of the spring pushing threaded device and the exposed surface is less than or equal to the length of the inner diameter N of the built-in pipe pusher, so that the spring pushing threaded device can be completely embedded inside the built-in pipe pusher during tightening, avoid the external interference or damage of the overlong exposed part, and ensure the safety and stability of the device during construction.

[0023] Specifically, the upper side and the lower side of the fan-shaped rotary rock breaker are both installed with a plurality of pick heads made of hard alloy material, which has high hardness and wear resistance, so that the fan-shaped rotary rock breaker can simultaneously cut the surrounding rock at the bottom and the sidewall of the drill hole after being unfolded, thereby accelerating the reaming speed, improving the reaming effect, and improving the construction efficiency.

[0024] Specifically, the flat spring material is selected from spring steel with high elasticity and high fatigue strength, which has good durability and stability, can adapt to multiple cycles, and prolong the service life of the device.

[0025] The construction method of the coal and rock roadway drill hole bottom reaming device comprises the following steps:

[0026] Step 1. Device assembly:

[0027] Step 1.1, installation of the fixed pin and the fan-shaped rotary rock breaker: install the fixed pin at the front end of the built-in push tube, then align the groove of the fan-shaped rotary rock breaker with the fixed pin, and install it in place to ensure that it can rotate freely;

[0028] Step 1.2, installation of the pusher and the flat spring: place the pusher in the built-in push tube so that it is in contact with the bottom surface of the fan-shaped rotary rock breaker; then place the flat spring behind the pusher;

[0029] Step 1.3, installation of the spring push thread device: screw the spring push thread device into the internal thread of the built-in push tube to compress the flat spring to a fully compressed state;

[0030] Step 2. Device installation:

[0031] Slowly push the assembled reaming device into the pre-drilled drill hole, the outer diameter of the built-in push tube matches the diameter of the drill hole to ensure that the device stably reaches the bottom of the drill hole;

[0032] Step 3. Rotation unfolding:

[0033] Step 3.1, start rotating: connect the built-in push tube with the drill rig, start the drill rig, and make the device start rotating;

[0034] Step 3.2, unfolding of the fan-shaped rotary rock breaker: under the joint action of centrifugal force and spring thrust, the fan-shaped rotary rock breaker starts to open outward;

[0035] Step 3.3, action of the flat spring: the flat spring gradually relaxes from the fully compressed state, pushing the pusher to move forward and accelerating the unfolding of the fan-shaped rotary rock breaker;

[0036] Step 4. Cutting and reaming:

[0037] Step 4.1, cutting process: the cutting tooth head on the fan-shaped rotary rock breaker starts to cut the surrounding rock at the bottom and sidewall of the borehole;

[0038] Step 4.2, formation of the enlarged area: as the fan-shaped rotary rock breaker gradually expands to the maximum opening angle of 90°, an enlarged area with a larger diameter is formed;

[0039] Step 5. Completion of reaming:

[0040] Step 5.1, reaching the design requirement: when the flat spring reaches the preset partially relaxed state, the enlarged area reaches the designed size;

[0041] Step 5.2, stop rotating: stop the rotation of the drilling machine, and the reaming process is completed;

[0042] Step 6. Device recovery:

[0043] Step 6.1, loosen the spring push thread device: use the cross-shaped rotator to loosen the spring push thread device;

[0044] Step 6.2, remove the assembly: remove the flat spring and the pusher in sequence; due to the loss of centrifugal force and spring pushing force of the fan-shaped rotary rock breaker, it will automatically fold;

[0045] Step 6.3, remove the device: remove the built-in pipe pusher and the fan-shaped rotary rock breaker together from the borehole.

[0046] Compared with the prior art, the present application has the following technical effects:

[0047] (1) Significantly improve the anchoring force: by forming an enlarged area at the bottom of the borehole, the contact area between the anchoring agent or resin anchoring body and the surrounding rock is increased. Experiments and practical applications show that the anchoring force can be improved by 30%-50%. The enlarged area forms a reliable mechanical locking effect, enhances the bonding and biting force between the anchoring body and the surrounding rock, greatly reduces the risk of anchor rod or anchor cable slipping, and improves the overall stability of the support system.

[0048] (2) Strong adaptability: the device structure is simple, the cooperation between the components is precise, and the reaming diameter and depth can be flexibly adjusted according to different geological conditions. It is especially suitable for roadway support in complex geological conditions such as soft rock, soft and broken coal body, etc., effectively solving the problem of insufficient anchoring force of traditional support methods in these conditions, and filling the market gap.

[0049] (3) Convenient construction: The device design fully considers the restrictions of underground construction environment, with small size and light weight, easy to carry and install. The device can be used with existing drilling machines, without the need for large-scale equipment replacement, reducing equipment investment and maintenance costs. The construction steps are standardized, easy to operate, easy for site workers to master, reducing the requirement for the skill level of operators and the possibility of construction errors.

[0050] (4) High cost-effectiveness: By improving the support effect of individual anchor rods or anchor cables, the number of support units can be reduced by 20%-30%, thereby reducing the overall support cost. It improves construction efficiency, reduces labor costs and equipment usage time. Due to the durability and reusability of the device, long-term use can further reduce unit costs, bringing significant economic benefits.

[0051] (5) Safe and reliable: The device has high stability during operation, and the connection between components is firm, reducing the risk of failure during construction. The materials and structural design of the device have undergone strict testing and verification, capable of withstanding high-strength construction pressure and complex underground environmental conditions. It reduces the construction risk, ensures the safety of construction personnel, and improves the safety production level of the mine.

[0052] (6) Facilitates grouting: The enlarged area provides more space for grouting, improving the distribution of grouting materials in the hole. Grouting materials can more fully penetrate into the cracks of surrounding rock, filling voids and enhancing the overall performance of the anchoring body, improving the shock resistance and durability of the support system.

[0053] (7) Prolonged support life: Enhanced anchoring effect helps to extend the service life of the support system, reducing the frequency of later maintenance and reinforcement. It reduces long-term operating costs, improves the efficiency and safety of the roadway. For deep mining and long-distance roadways, extending the support life has important economic and safety significance.

[0054] (8) Technological innovation: The invention has innovation in mechanical design and construction technology, providing a new solution for coal mine roadway support. The promotion and application of the device will promote the progress of the industry, with important demonstration effect.

[0055] (9) High promotion value: Due to its wide range of applications, significant economic benefits and high safety performance, it has a wide range of promotion and application value. It can be widely used in domestic and foreign coal mines, tunnels and underground engineering, promoting the development of related industries. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 Schematic diagram of the position of the drilling machine and the borehole in the roadway.

[0057] Figure 2This is a schematic diagram of the built-in pipe jacking device being pushed into the borehole.

[0058] Figure 3 A schematic diagram showing the preparation of the jacking device for installation inside the built-in jacking device.

[0059] Figure 4 A schematic diagram of the assembly of a flat spring, a spring-pushing threaded device, and a cross-shaped rotator in the relaxed state.

[0060] Figure 5 This is a schematic diagram of the hole reaming device starting its hole reaming operation.

[0061] Figure 6 A schematic diagram of a hole enlarging device used to enlarge a borehole.

[0062] The meanings of the labels in the diagram are as follows:

[0063] 1. Drilling rig; 2. Drilling hole; 8. Inner diameter N; 9. Internal thread; 10. Built-in pipe jacking device; 11. Fixing pin; 12. Through hole; 13. Fan-shaped rotary rock breaker; 14. Cutting tooth head; 16. Outer surface; 18. Jacking device; 20. Cross-shaped rotator; 21. Embedded cross lock; 22. External thread; 23. Front head; 24. Flat spring; 24-2. Gradually relaxed state of the flat spring; 24-4. Maximum relaxed state of the flat spring; 29. ​​Inner diameter M; 34. Embedded threaded hole; 35. Spring jacking thread device. Detailed Implementation

[0064] This invention provides a bottom hole enlargement device for drilling in coal and rock roadways, such as... Figures 1 to 6 As shown, the device includes key components such as a built-in pipe jacking device 10, a fixing pin 11, a fan-shaped rotary rock breaker 13, a pusher 18, a flat spring 24, and a spring-driven threaded device 35. The front end of the built-in pipe jacking device is equipped with a fan-shaped rotary rock breaker that can rotate freely within a range of 0°-90°. High-strength cutting teeth are installed on both the upper and lower sides of the fan-shaped rotary rock breaker to enhance cutting ability. The pusher is located behind the fan-shaped rotary rock breaker and is pushed forward by the force of the flat spring, thus unfolding the fan-shaped rotary rock breaker. While rotating within the borehole, the device utilizes the combined action of centrifugal force and spring thrust to gradually open the fan-shaped rotary rock breaker, cutting the surrounding rock at the bottom and sidewalls of the borehole to form an enlarged area. This enlarged area increases the contact area between the anchor body and the surrounding rock, significantly improving the anchoring effect and the overall stability of the tunnel. The device has a simple structure, tightly fitted components, and is convenient and quick to construct. It can be used with existing drilling rigs without requiring additional large equipment investment. It is particularly suitable for roadway support in soft rock strata, loose and fractured coal seams, and complex geological conditions, solving the problem of insufficient anchoring force of traditional support methods under these conditions. It has broad application prospects and promotional value. Specifically:

[0065] (1) Inner push pipe device 10:

[0066] Structural features: tubular structure, made of high-strength alloy steel, with good wear resistance and impact resistance. The outer diameter is matched with the hole diameter, the gap between the outer surface 16 and the hole wall is 0-10mm, preferably 2-4mm, to ensure that the device can smoothly enter the hole and remain stable.

[0067] Internal design: the inner hole of the inner push pipe device 10 is divided into two sections with different diameters, the rear end inner hole diameter N8 and the front inner hole diameter M29, and the internal thread 9 located between the two and at the rear end position, used to install the spring push thread device 35.

[0068] Function: as the main structure of the device, it contains and supports other components and transmits rotary power.

[0069] (2) Fixed pin 11:

[0070] Material selection: fixed pin 11 is located at the front end of the inner push pipe device 10, made of high-strength alloy steel, with sufficient strength and toughness.

[0071] Structural features: the top is provided with a through hole 12 for installing the fan-shaped rotary rock breaker 13; the structure of the fixed pin 11 matches the groove of the fan-shaped rotary rock breaker 13.

[0072] Function: allows the fan-shaped rotary rock breaker 13 to rotate freely within 0°-90°, with a maximum opening angle of 90°, thereby improving the cutting range and efficiency.

[0073] (3) Fan-shaped rotary rock breaker 13:

[0074] Material selection: the fan-shaped rotary rock breaker 13 is installed at the front end of the inner push pipe device 10 through the fixed pin 11, made of wear-resistant alloy steel, with special heat treatment and hardening treatment on the surface, enhancing its wear resistance and service life.

[0075] Structural design: the groove is 90° in structure, allowing free rotation within 0°-90°. The upper and lower sides are evenly installed with multiple pick heads 14.

[0076] Pick heads 14 are made of hard alloy material, with high hardness and wear resistance, excellent cutting performance and wear resistance, used for cutting the side wall and bottom of the surrounding rock, achieving efficient reaming of the hole bottom and side wall.

[0077] Function: used for cutting the side wall and bottom of the surrounding rock, achieving efficient reaming of the hole bottom and side wall.

[0078] (4) Pusher 18:

[0079] Material selection: The pusher 18 can be placed inside the built-in push pipe 10 behind the fan-shaped rotary rock breaker 13, made of high-strength steel, with good mechanical strength and durability.

[0080] Structural features: The front end of the pusher 18 is in close contact with the bottom surface of the fan-shaped rotary rock breaker 13, and the rear end is provided with an embedded threaded hole 34 for easy disassembly after construction is completed.

[0081] Size design: The diameter difference between the pusher 18 and the built-in push pipe 10 is 0-5mm, preferably 2mm, to ensure smooth movement of the pusher in the built-in push pipe without jamming.

[0082] Function: The flat spring 24 behind the pusher 18 can push the pusher 18 forward to expand the fan-shaped rotary rock breaker 13.

[0083] (5) Flat spring 24:

[0084] Material selection: The flat spring 24 is installed behind the pusher 18, made of spring steel with high elasticity and high fatigue strength, and has excellent elastic properties and durability after special heat treatment.

[0085] The flat spring provides a continuous and stable pushing force between the fully compressed state (A1) and the partially relaxed state (A3), with an elastic force that meets the formula: F=k×(A3-A1), where F is the elastic force and k is the spring constant. By accurately designing the parameters of the spring, sufficient pushing force is provided during operation to smoothly expand the fan-shaped rotary rock breaker 13.

[0086] Parameter design:

[0087] ① Spring constant (k): accurately calculated according to actual needs to ensure sufficient pushing force during operation.

[0088] ② Fully compressed length (A1) and partially relaxed length (A3): Adjust these two parameters to control the spring's pushing force range.

[0089] Function: Provides a continuous and stable pushing force between the fully compressed state and the partially relaxed state to smoothly expand the fan-shaped rotary rock breaker 13.

[0090] (6) Spring push thread device 35:

[0091] Material selection: The spring push thread device 35 is installed at the rear end of the built-in push pipe 10, made of alloy steel, with good mechanical strength and wear resistance.

[0092] Structural features: the length L2 of the external thread 22 is slightly larger than the effective length (L1) of the internal thread 9 of the built-in pipe pusher 10, which ensures the firmness of the installation and the complete compression of the spring.

[0093] Design details: the distance (L4) between the thread starting segment of the spring push thread device and the exposed surface is designed to be less than or equal to the length (L5) of the internal hole diameter N8 of the built-in pipe pusher 10, avoiding damage to the spring push thread device during tightening.

[0094] Functional role: by tightening or loosening the spring push thread device 35, the compression state of the flat spring 24 can be accurately adjusted to meet different construction requirements.

[0095] More specifically, the diameter difference between the built-in pipe pusher 10 and the borehole wall is 2-4mm, which ensures that the device can smoothly enter the borehole and maintain good stability during rotation and reaming, avoiding device shaking or deviation due to excessive clearance, improving the accuracy and safety of construction.

[0096] The diameter difference between the pusher 18 and the built-in pipe pusher 10 is 0-5mm, preferably 2mm. Such design allows the pusher 18 to move smoothly within the built-in pipe pusher 10, reducing friction resistance, avoiding jamming due to too small clearance or shaking due to too large clearance, thereby ensuring the stability and efficiency of the reaming process.

[0097] The internal hole diameter N8 of the built-in pipe pusher 10 is slightly larger than the internal hole diameter M29, with a diameter difference of 1-4mm, preferably 2mm. Such design facilitates the installation and disassembly of the assembly, ensuring the smooth installation of the pusher 18, flat spring 24 and spring push thread device 35 within the built-in pipe pusher 10, while also helping to maintain the overall structural strength and stability of the device.

[0098] The length (L2) of the external thread 22 of the spring push thread device 35 is slightly larger than the effective length (L1) of the internal thread 9 of the built-in pipe pusher 10, ensuring that the flat spring 24 can be completely compressed during tightening and ensuring the firmness of the installation. Such design avoids the risk of the spring push thread device 35 loosening or falling off during construction, improving the reliability and safety of the device.

[0099] The groove of the fan-shaped rotary rock breaker 13 matches the fixed pin 11, with a maximum opening angle of 90°. Through precise mechanical cooperation, the fan-shaped rotary rock breaker 13 can be smoothly expanded to the designed angle under the action of rotation and centrifugal force, thereby expanding the cutting range, improving the cutting efficiency of the surrounding rock, forming a larger expansion area and enhancing the anchoring effect.

[0100] The distance (L4) between the thread starting section of the spring pushing thread device 35 and the exposed surface is designed to be less than or equal to the length (L5) of the inner hole diameter N8 of the built-in jacking pipe 10, so that the spring pushing thread device 35 can be completely embedded in the built-in jacking pipe 10 during the screwing process, avoiding the exposed part from being too long to be disturbed or damaged externally, and ensuring the safety and stability of the device during the construction process.

[0101] The upper side and the lower side of the fan-shaped rotary rock breaker 13 are both installed with a plurality of pick heads 14, which are made of hard alloy material and have high hardness and wear resistance, so that the fan-shaped rotary rock breaker 13 can simultaneously cut the surrounding rock at the bottom and the sidewall of the drill hole after being unfolded, speed up the reaming speed, improve the reaming effect, and improve the construction efficiency.

[0102] The spring force and size of the flat spring 24 are accurately calculated and designed to provide a continuous and stable pushing force during the construction process, ensuring that the fan-shaped rotary rock breaker 13 maintains a good unfolded state during the reaming process. The material of the spring is selected to be spring steel with high elasticity and high fatigue strength, which has good durability and stability after special heat treatment process, can adapt to multiple cycles, and prolong the service life of the device.

[0103] The components of the device are precisely mechanically matched and assembled, and the connection parts between the components are strictly processed and inspected, so that the device has good overall stability and reliability in the construction environment of high strength and high speed. The materials and surface treatment of the device are optimally designed to have wear resistance, corrosion resistance and impact resistance, and are suitable for complex and variable geological conditions and environment of coal mine roadway.

[0104] Specifically, Figure 1 The figure is a schematic diagram of a roadway drill hole of the coal rock roadway drill hole reaming device, which shows the position of the drill and the drill hole in the roadway, and the overall application environment of the device. Figure 2 The figure is a schematic diagram of the process of pushing the built-in jacking pipe into the drill hole, which shows the process of the built-in jacking pipe entering the drill hole, and ensures that the device reaches the predetermined position smoothly. Figure 3 The figure is a schematic diagram of the built-in jacking pipe ready to install the pusher inside, which shows the relative position of the pusher and the built-in jacking pipe, and the preparation work before installation. Figure 4 The figure is a schematic diagram of the assembly of the flat spring, the spring pushing thread device and the cross-shaped rotator in the relaxed state, which shows the structural details and assembly relationship of these components, and provides guidance for subsequent installation. Figure 5 The figure is a schematic diagram of the drill hole reaming device starting reaming work, which shows the working state of the device in the drill hole, and the fan-shaped rotary rock breaker starts to unfold under the action of rotation and centrifugal force to perform reaming work. Figure 6The schematic diagram of the device completing the reaming of the borehole bottom shows the state after the reaming is completed, and the fan-shaped rotary rock breaker is fully expanded to form the expected enlarged area.

[0105] Details of the components in the drawings: Drilling machine: used to drive the device to rotate, realize the drilling and reaming operation. Borehole: a hole drilled in advance in the surrounding rock of the tunnel, used to install the device for reaming the bottom of the hole. The first section of the built-in push tube has an inner diameter, which is used to accommodate the pusher, flat spring and spring push thread device. The internal thread at the rear end of the built-in push tube cooperates with the external thread of the spring push thread device. The built-in push tube is the main structure of the device, which is tubular and accommodates and supports other components. The fixed pin is installed at the front end of the built-in push tube, which is used to fix the fan-shaped rotary rock breaker and allows it to rotate freely within the range of 0°-90°. The through hole at the top of the fixed pin is used to install the fan-shaped rotary rock breaker, which can rotate around the fixed pin. The fan-shaped rotary rock breaker is installed on the fixed pin and has a groove structure that can expand under the action of rotation and centrifugal force to cut the surrounding rock. The pick head embedded on the fan-shaped rotary rock breaker is installed on the hard alloy pick of the fan-shaped rotary rock breaker, which is used to efficiently cut the sidewall and bottom of the surrounding rock. The outer surface of the built-in push tube contacts the borehole wall, which is precisely machined to reduce frictional resistance and ensure that the device can smoothly enter the borehole. The pusher is located inside the built-in push tube and is pushed by the flat spring to expand the fan-shaped rotary rock breaker. The cross-shaped rotator is used to tighten or loosen the spring push thread device to adjust the compression state of the flat spring. The embedded cross-shaped lock of the spring push thread device is arranged in the cross-shaped groove at the rear end of the spring push thread device, which is used to insert the cross-shaped rotator to realize the tightening or loosening operation. The external thread of the spring push thread device cooperates with the internal thread of the built-in push tube to adjust the compression degree of the flat spring. The front head of the spring push thread device is located at the front end of the spring push thread device, which is used to compress the flat spring and the front end surface contacts the spring. The flat spring provides a pushing force to move the pusher forward to expand the fan-shaped rotary rock breaker. The fully compressed state of the flat spring is after the installation is completed, the flat spring is fully compressed and ready to provide a pushing force. The gradually relaxed state of the flat spring is during the reaming process, the flat spring gradually relaxes to push the pusher forward. The further relaxed state of the flat spring is the flat spring continues to relax, the pusher continues to advance, and the fan-shaped rotary rock breaker gradually expands. The maximum relaxed state of the flat spring is the flat spring reaches the designed working length, the pushing force reaches the expected value, and the fan-shaped rotary rock breaker is fully expanded. The top surface of the pusher contacts the bottom surface of the fan-shaped rotary rock breaker to transfer the pushing force of the flat spring. The inner diameter M of the built-in push tube is the second section of the built-in push tube, which is used to accurately position the pusher and the fan-shaped rotary rock breaker. The embedded threaded hole is arranged at the rear end of the pusher, which is used to insert a tool when disassembled to remove the pusher. The spring push thread device is installed at the rear end of the built-in push tube and is tightened or loosened to adjust the compression state of the flat spring.

[0106] L1 - Effective length of internal thread: The length that cooperates with the external thread of the spring push thread device, ensuring firm installation. L2 - Thread length of the spring push thread device external thread: Slightly larger than the effective length of the internal thread, ensuring complete compression of the spring. L3 - Effective length of the fixing pin: The depth of the fixing pin inserted into the built-in jacking pipe and the fan-shaped rotary rock breaker, ensuring firm connection. L4 - Distance from the exposed surface of the spring push thread device thread starting section: Designed to be less than or equal to the length of the built-in jacking pipe inner diameter N, to avoid damaging the device. L5 - Length of the built-in jacking pipe inner diameter N: The length of the part that contains the flat spring and the pusher. φa - Outer diameter size of the pusher: Slightly smaller than the inner diameter M, ensuring smooth movement of the pusher in the built-in jacking pipe.

[0107] The construction method of the coal rock roadway borehole bottom reaming device comprises the following steps:

[0108] Step 1. Device assembly:

[0109] Step 1.1, installation of fixing pin and fan-shaped rotary rock breaker: Install the fixing pin at the front end of the built-in jacking pipe, then align the groove of the fan-shaped rotary rock breaker with the fixing pin and install it in place, ensuring that it can rotate freely;

[0110] Step 1.2, installation of pusher and flat spring: Place the pusher into the built-in jacking pipe so that it is in contact with the bottom surface of the fan-shaped rotary rock breaker; then place the flat spring behind the pusher;

[0111] Step 1.3, installation of spring push thread device: Screw the spring push thread device into the internal thread of the built-in jacking pipe, compressing the flat spring to a fully compressed state (A1);

[0112] Step 2. Device installation:

[0113] Slowly push the assembled reaming device into the pre-drilled borehole, with the outer diameter of the built-in jacking pipe matching the borehole diameter, ensuring that the device reaches the bottom of the borehole stably;

[0114] Step 3. Rotation and expansion:

[0115] Step 3.1, start rotation: Connect the built-in jacking pipe to the drilling machine and start the drilling machine to make the device start rotating;

[0116] Step 3.2, expansion of fan-shaped rotary rock breaker: Under the combined action of centrifugal force and spring thrust, the fan-shaped rotary rock breaker begins to expand outward;

[0117] Step 3.3, action of flat spring: The flat spring gradually relaxes from the fully compressed state, pushing the pusher forward to accelerate the expansion of the fan-shaped rotary rock breaker;

[0118] Step 4. Cutting and reaming:

[0119] Step 4.1, cutting process: the cutting tooth heads on the fan-shaped rotary rock breaker begin to cut the surrounding rock at the bottom and sidewall of the borehole;

[0120] Step 4.2, formation of enlarged area: as the fan-shaped rotary rock breaker gradually expands to the maximum opening angle of 90°, an enlarged area with a larger diameter is formed;

[0121] Step 5, completion of reaming:

[0122] Step 5.1, reaching design requirements: when the flat spring reaches the preset partially relaxed state, the enlarged area reaches the designed size;

[0123] Step 5.2, stop rotating: stop the rotation of the drilling machine, and the reaming process is completed;

[0124] Step 6, device recovery:

[0125] Step 6.1, loosen the spring push thread device: use the cross-shaped rotator to loosen the spring push thread device;

[0126] Step 6.2, remove the assembly: remove the flat spring and the pusher in sequence; due to the loss of centrifugal force and spring thrust of the fan-shaped rotary rock breaker, it will automatically fold;

[0127] Step 6.3, remove the device: remove the built-in pipe pusher and the fan-shaped rotary rock breaker from the borehole together.

[0128] The present application includes the following detailed design:

[0129] 1. Innovative design of fan-shaped rotary rock breaker:

[0130] (1) Free rotation structure: through the special cooperation of the fixed pin and the fan-shaped rotary rock breaker, automatic unfolding and folding under the action of rotation and centrifugal force are realized.

[0131] (2) Multi-surface cutting: the upper and lower sides of the fan-shaped rotary rock breaker are equipped with cutting tooth heads, which can simultaneously cut the bottom and sidewall of the borehole, improving the reaming efficiency.

[0132] 2. Ingenious application of flat spring:

[0133] (1) Continuous and stable thrust: by accurately calculating the spring constant and compression amount, the flat spring provides continuous and stable thrust during the reaming process, ensuring the smooth unfolding of the fan-shaped rotary rock breaker.

[0134] (2) Simple and reliable: compared with complex hydraulic or mechanical drive systems, the application of flat spring simplifies the structure, reduces the failure rate, and improves the reliability.

[0135] 3. Modular and standardized design of the device:

[0136] (1) Component standardization: standardized dimensions and interfaces for each component, facilitating production, assembly, and maintenance.

[0137] (2) Adaptability: the device's size and parameters can be adjusted according to different drilling diameters and geological conditions, ensuring good versatility.

[0138] 4. Optimization of materials and processes:

[0139] (1) High-performance materials: high-strength alloy steel, spring steel, and hard alloy are used to ensure the device's wear resistance and service life.

[0140] (2) Advanced processing techniques: heat treatment and surface hardening are used to improve the mechanical properties and corrosion resistance of the components.

[0141] The invention includes the following application effects:

[0142] 1. Significantly improved anchoring force

[0143] (1) By forming an enlarged area at the bottom of the borehole, the contact area between the anchoring agent and the surrounding rock is increased, and the anchoring force is improved by up to 30%-50%.

[0144] (2) The mechanical interlocking force between the anchor rod (cable) and the surrounding rock is enhanced, reducing the risk of slipping.

[0145] 2. Improved roadway stability

[0146] (1) The enhanced anchoring effect significantly improves the overall stability of the roadway, reducing the likelihood of deformation and collapse.

[0147] (2) The effect is particularly evident for soft rock layers and soft and broken coal bodies.

[0148] 3. High construction efficiency

[0149] (1) The device has a simple structure and is easy to operate, and can be used with existing drilling machines without the need for large-scale equipment replacement.

[0150] (2) The construction steps are standardized, reducing construction time and labor costs.

[0151] 4. Significant economic benefits

[0152] (1) The support effect of individual anchor rods (cables) is improved, reducing the number of support units and overall support costs.

[0153] (2) The service life of the support system is extended, reducing the frequency of later maintenance and reinforcement.

[0154] 5. Safe and reliable

[0155] (1) The device runs stably, the components are connected firmly, the construction risk is reduced, and the safety of construction personnel is ensured.

[0156] (2) It is suitable for various complex geological conditions, and improves the safety of construction.

[0157] Compared with the prior art, the present application has the following advantages:

[0158] 1. Disadvantages of traditional methods

[0159] (1) Complex equipment, high cost: The existing reaming equipment usually has complex structure and high cost, which is not conducive to popularization and application.

[0160] (2) Complicated construction, low efficiency: multiple operation steps, long construction time, and increased labor cost.

[0161] 2. Advantages of the present application

[0162] (1) Simple structure, low cost: the device is designed simply, the manufacturing cost is low, and it is easy to popularize.

[0163] (2) Convenient construction, high efficiency: simple operation, fast construction speed, and improved work efficiency.

[0164] (3) Strong adaptability, high universality: can be adjusted according to different needs, wide application range.

[0165] The present application includes the following industrialization prospects:

[0166] 1. Market demand

[0167] (1) With the increase of coal mining depth and the complication of geological conditions, the demand for efficient and safe roadway support technology is urgent.

[0168] (2) The device of the present application has strong adaptability and meets the actual needs of the market.

[0169] 2. Economic benefits

[0170] (1) The safety production level of the mine is improved, and the occurrence of safety accidents is reduced.

[0171] (2) The construction and maintenance cost is reduced, and good economic benefits are obtained.

[0172] 3. Social benefits

[0173] (1) The technical level of the coal mining industry is improved, and the progress of the industry is promoted.

[0174] (2) The safety of construction personnel is ensured, and it has positive social significance.

[0175] The coal rock roadway drilling hole bottom reaming device provided by the application has the advantages of simple structure, convenient construction, strong adaptability, significant improvement of anchoring effect, and enhancement of the overall stability of the roadway, and has obvious advantages compared with the traditional technology, and has broad application prospect and promotion value.

[0176] The following specific embodiments of the application are given, and it should be noted that the application is not limited to the following specific embodiments, and any equivalent variations made on the basis of the technical solutions of the application fall within the protection scope of the application.

[0177] Embodiment:

[0178] The coal rock roadway drilling hole bottom reaming device provided by the application has the advantages of simple structure, convenient construction, strong adaptability, significant improvement of anchoring effect, and enhancement of the overall stability of the roadway, and has obvious advantages compared with the traditional technology, and has broad application prospect and promotion value.

[0179] I. Specific structure and parameters of the device

[0180] 1. Built-in pipe pusher 10

[0181] (1) Material selection:

[0182] ① High-strength alloy steel is used, such as 42CrMo or 35CrMo, which is quenched and tempered, has excellent mechanical properties and wear resistance. The yield strength of the material is not less than 800 MPa, the tensile strength is not less than 1000 MPa, and the elongation is more than 12%.

[0183] ② In order to adapt to the complex working environment of the coal mine roadway, the surface can be carburized or nitrided to improve the surface hardness to HRC58-62, and enhance the wear resistance and corrosion resistance.

[0184] (2) Size parameters:

[0185] ① Outer diameter (D1): Φ42mm, matched with the conventional drilling diameter (Φ45mm), to ensure that the device can smoothly enter the drilling hole, and the gap between the outer diameter and the drilling hole diameter is 1.5mm.

[0186] ② Length (L0): 1500mm, meeting the depth requirements of general roadway anchor rod support, which can be adjusted within the range of 1000mm to 3000mm according to actual needs.

[0187] (3) Internal structure:

[0188] ① Inner hole diameter N8:

[0189] Inner diameter (d1): Φ32mm, length (L5): 1400mm.

[0190] For accommodating the pusher 18, flat spring 24 and spring push thread device 35.

[0191] Wall thickness (δ1): calculated according to the outer diameter and inner diameter, δ1 = (D1-d1) / 2 = (42mm-32mm) / 2 = 5mm, to ensure the strength and stiffness of the built-in push tube.

[0192] ②Inner hole diameter M29:

[0193] Inner diameter (d2): Φ30mm, located in the front end part, length (L6) is 100mm.

[0194] For accurate positioning of the pusher 18 and fan-shaped rotary rock breaker 13, to ensure that it does not deviate during operation.

[0195] ③Internal thread 9:

[0196] Thread type: M30x1.5, precision grade 6g, to ensure the firmness and reliability of the threaded connection.

[0197] Effective length (L1): 80mm, to meet the requirements of spring push thread device 35 installation.

[0198] (4) Outer surface 16:

[0199] ①The surface is precisely turned, with a roughness Ra ≤1.6μm, keeping smooth to reduce frictional resistance in the borehole.

[0200] ②Can be galvanized or sprayed with anti-corrosion paint, to enhance corrosion resistance and prolong service life.

[0201] 2. Fixed pin 11

[0202] (1) Material selection:

[0203] ① Alloy steel such as 40Cr or 45 steel is used, which is quenched and tempered, with a surface hardness of HRC40-45, having high strength and wear resistance.

[0204] (2) Size parameters:

[0205] ① Diameter (d3): Φ10mm, to ensure sufficient strength to fix the fan-shaped rotary rock breaker 13, to withstand the torque and shear force generated during cutting.

[0206] ② Effective length (L3): 20mm, to ensure that the fixed pin can be firmly embedded in the front end of the built-in push tube 10 and the groove of the fan-shaped rotary rock breaker 13.

[0207] ③ Through hole 12: diameter Φ6mm, located at the top of the fixed pin, used for installing the fan-shaped rotary rock breaker 13 and allowing it to rotate freely within the range of 0°-90°.

[0208] 3. Fan-shaped rotary rock breaker 13

[0209] (1) Material selection:

[0210] ① High-strength wear-resistant alloy steel such as T8 or T10 steel is used, which is quenched and tempered, with a surface hardness of HRC55-60.

[0211] ② The surface can be carburized or nitrided to further improve wear resistance and impact resistance.

[0212] (2) Structure design:

[0213] ① Size:

[0214] Length (L7): 100mm, adjustable within the range of 80mm to 150mm according to the drilling diameter and reaming requirements.

[0215] Width (W1): 30mm, ensuring effective cutting of the drilling sidewall after unfolding.

[0216] Thickness (T1): 15mm, ensuring the strength and rigidity of the fan-shaped rotary rock breaker.

[0217] ② Groove structure:

[0218] Matching with the fixed pin 11, the groove angle is 90° and the depth h1 is 10mm, ensuring that the fan-shaped rotary rock breaker can rotate freely within the range of 0°-90° under the restriction of the fixed pin.

[0219] ③ Range of motion:

[0220] Through the cooperation of the fixed pin 11 and the groove, under the action of rotation and centrifugal force, it gradually unfolds from the retracted state (0°) to the maximum open state (90°).

[0221] The unfolding angle (θ) of the fan-shaped rotary rock breaker is related to the rotation speed (n) and centrifugal force (F_c), which can be calculated by the formula:

[0222] F_c = m·r·ω^2

[0223] Where:

[0224] m - mass of the fan-shaped rotary rock breaker;

[0225] r - rotation radius;

[0226] ω - angular velocity, ω = 2πn / 60.

[0227] ④Pick head 14:

[0228] Three hard alloy picks are installed on each of the upper and lower sides.

[0229] Pick diameter (d4): Φ8mm, made of YG11C hard alloy, hardness above HRA89, bending strength not less than 2200MPa.

[0230] The picks are arranged at equal intervals with a spacing (s) of 25mm, ensuring uniform distribution of cutting force and improving reaming efficiency.

[0231] ⑤Surface treatment:

[0232] The surface of the fan-shaped rotary rock breaker is shot blasted to eliminate stress concentration and improve fatigue life.

[0233] A wear-resistant coating such as TiN or Al2O3 can be applied to improve surface hardness and wear resistance.

[0234] 4. Pusher 18

[0235] (1) Material selection:

[0236] ① High-strength steel such as 42CrMo is used after quenching and tempering treatment, with a hardness of HRC28-32, capable of bearing the thrust of the flat spring 24 and the pressure generated during construction.

[0237] ② The surface is precisely machined with a roughness Ra≤0.8μm to reduce frictional resistance.

[0238] (2) Structure design:

[0239] ① Outer diameter : Φ29.5mm, 0.5mm smaller than the inner hole diameter M29, ensuring smooth movement in the built-in pusher 10 without jamming.

[0240] ② Length (L8): 200mm, meeting the travel requirements for fully deploying the fan-shaped rotary rock breaker 13.

[0241] ③ Top surface:

[0242] The front end surface is in close contact with the bottom surface of the fan-shaped rotary rock breaker 13, designed as a flat or spherical surface to reduce contact stress.

[0243] The rear end surface is in contact with the flat spring 24, designed as a flat surface to ensure uniform stress.

[0244] ④ Inlaid threaded hole 34:

[0245] The thread size is M12×1.75 with a depth of 30mm, used to remove the pusher 18 after construction is completed through a lead screw or special tool for easy reuse.

[0246] ⑤ Surface treatment:

[0247] Surface chromium or nickel plating can be performed with a thickness of 0.02-0.05mm to improve wear resistance and corrosion resistance.

[0248] 5. Flat spring 24

[0249] (1) Material selection:

[0250] ① High-quality spring steel such as 60Si2Mn or 50CrVA is used, which is oil quenched and tempered, with an elastic modulus of 196GPa and an ultimate strength of not less than 1500MPa.

[0251] (2) Parameter design:

[0252] ① Spring constant (k):

[0253] Set to 500N / mm to ensure sufficient thrust during compression and relaxation.

[0254] Spring constant calculation formula:

[0255] k = Gd^4 / (8nD^3)

[0256] Where:

[0257] G is the shear modulus, about 79.3GPa;

[0258] d is the spring wire diameter;

[0259] n is the effective number of turns;

[0260] D is the spring mean diameter.

[0261] ② Size parameters:

[0262] Spring wire diameter (d5): calculated according to spring constant, d5 = 8mm.

[0263] Spring mean diameter (D2): D2 = 28mm, ensuring matching with the inner hole diameter N8 of the built-in top pipe device 10, with a clearance of 2mm.

[0264] Effective number of turns (n): calculated, n = 5 turns.

[0265] ③ Length design:

[0266] Fully relaxed length (A2): 200mm, i.e. the free length of the spring when not under stress.

[0267] Fully compressed length (A1): 50mm, i.e. the length of the spring when under maximum compression force.

[0268] Working length (A3): 100mm, which is the actual working length of the spring during construction.

[0269] ④Spring force calculation:

[0270] Spring force calculation formula:

[0271] F = k × (A2 - A3)

[0272] Substitute numerical values:

[0273] F = 500 N / mm × (200 mm - 100 mm) = 50,000 N

[0274] Ensure that the spring force meets the requirements of pushing the pusher 18.

[0275] ⑤Fatigue life:

[0276] After special heat treatment and surface strengthening treatment, the fatigue life of the spring can reach more than 10^6 cycles, meeting the long-term use requirements.

[0277] 6. Spring push thread device 35

[0278] (1) Material selection:

[0279] ① Use alloy steel such as 40Cr, after quenching and tempering treatment, surface hardness HRC40-45, with high strength and wear resistance.

[0280] (2) Structure design:

[0281] ① External thread 22:

[0282] Thread specification M30 × 1.5, thread length (L2) 85mm, slightly larger than the effective length (L1) 80mm of the internal thread 9 of the built-in push tube device 10, to ensure the firmness of installation.

[0283] ② Front head 23:

[0284] Length (L9) 20mm, diameter (D3) Φ28mm, used for compressing flat spring 24.

[0285] The front end surface is finely ground, with roughness Ra ≤0.8μm, and uniform pressure is applied.

[0286] ③ Embedded cross lock 21:

[0287] Depth (h2) 10mm, width (b1) 10mm, used for inserting cross-shaped rotator 20, realizing the tightening and loosening of the spring push thread device.

[0288] ④ Surface treatment:

[0289] The threaded part is precision machined with a thread accuracy grade of 6g and a smooth surface to reduce frictional resistance.

[0290] It can be nitrided to improve surface hardness and corrosion resistance.

[0291] 7. Cross-shaped rotator 20

[0292] (1) Material selection:

[0293] ① Made of high-strength steel, such as 45 steel, the handle features an anti-slip design with a rubber or anti-slip textured surface to increase grip comfort and ensure safe operation.

[0294] (2) Size design:

[0295] ① Compatibility: It perfectly matches the embedded cross lock 21 of the spring push thread device 35, with an insertion depth (h2) of 10mm and a width (b1) of 10mm.

[0296] ② Handle length (L10): 300mm, handle diameter (D4): 20mm, which facilitates the application of sufficient torque to tighten and loosen the threads.

[0297] ③ Structure: The handle adopts a "T" or "+" shaped design to increase the operating lever arm and reduce the burden on the operator.

[0298] II. Working Principle of the Device

[0299] 1. Initial state

[0300] (1) The fan-shaped rotating rock breaker 13 is in a retracted state and is fixed at the front end of the built-in pipe jacking device 10 with an opening angle θ = 0°.

[0301] (2) The flat spring 24 is fully compressed to length A1 = 50mm by the spring push thread device 35, and the elastic force reaches the maximum value.

[0302] (3) The pusher 18 is located at the rearmost position of the built-in pusher 10, and its rear end face is in contact with the flat spring.

[0303] 2. Rotation process

[0304] (1) Connect the built-in pipe jacking tool 10 to the drilling rig 1 via the connector and start rotating.

[0305] (2) The rotational speed is set to n = 60 rpm and the angular velocity is ω = 2πn / 60 = 6.28 rad / s.

[0306] (3) During the rotation process, the fan-shaped rotating rock breaker 13 begins to open outward under the action of centrifugal force.

[0307] 3. Spring release

[0308] (1) As rotation proceeds, flat spring 24 gradually relaxes from fully compressed length A1 = 50 mm to working length A3 = 100 mm under the restriction of spring pusher screw device 35.

[0309] (2) Pusher 18 moves forward by distance ΔL = A3 - A1 = 50 mm under the thrust of flat spring.

[0310] (3) The advance of pusher pushes the bottom of fan-shaped rotary rock breaker 13, further promoting its outward expansion.

[0311] 4. Cutting surrounding rock

[0312] (1) Pick head 14 on fan-shaped rotary rock breaker 13 starts to cut the surrounding rock at the bottom and sidewall of the borehole under the combined action of centrifugal force and spring thrust.

[0313] (2) The reaming diameter D = D1 + 2W1 sin θ, when θ = 90°, the reaming diameter D = 42 mm + 230 mm = 102 mm.

[0314] (3) The cutting force F_s can be estimated by the formula:

[0315]

[0316] Where: F_c is the centrifugal force; is the rake angle of the pick head, generally taken as 15°.

[0317] 5. Complete reaming

[0318] (1) When flat spring 24 reaches working length A3 = 100 mm, fan-shaped rotary rock breaker 13 is fully expanded to maximum opening angle θ = 90°.

[0319] (2) The reaming process is completed, forming the expected enlarged hole, with the hole bottom diameter reaching 102 mm, meeting the design requirements.

[0320] 6. Stop rotation

[0321] (1) Gradually reduce the rotation speed of drill rig 1 to avoid sudden stop causing equipment damage or unstable hole wall.

[0322] (2) Finally stop rotation, ready for subsequent operations.

[0323] 7. Disassemble the device

[0324] (1) Use cross-shaped rotator 20 to rotate counterclockwise, loosen spring pusher screw device 35, release the residual elastic force of flat spring.

[0325] (2) Take out the spring pushing thread device 35, flat spring 24 and pusher 18 in turn.

[0326] (3) The fan-shaped rotary rock breaker 13 is automatically folded to the original position (θ = 0°) without the action of centrifugal force and spring thrust.

[0327] (4) Slowly pull out the built-in push pipe device 10 together with the fan-shaped rotary rock breaker 13 from the borehole.

[0328] III. Installation and use method of the device

[0329] 1. Preparation

[0330] (1) Equipment inspection: check the integrity of all parts, especially threads, pick head, spring, etc., and lubricate and replace if necessary.

[0331] (2) Personnel training: ensure that the operator is familiar with the structure, working principle and operation steps of the device, and has the necessary safety knowledge.

[0332] 2. Install the fan-shaped rotary rock breaker 13

[0333] (1) Fixing pin 11 installation: insert the fixing pin into the hole at the front end of the built-in push pipe device 10, and ensure that it is fixed firmly.

[0334] (2) Fan-shaped rotary rock breaker installation: align the groove of the fan-shaped rotary rock breaker with the fixing pin 11, insert it into place, and check that it rotates freely within the range of 0°-90° without jamming.

[0335] 3. Push the built-in push pipe device 10

[0336] (1) Lubrication treatment: evenly apply an appropriate amount of lubricating oil or graphite powder to the outer surface of the built-in push pipe device 10 to reduce the pushing resistance.

[0337] (2) Pushing process: two workers hold the rear end of the built-in push pipe device and slowly and evenly push it into the borehole 2 until the fan-shaped rotary rock breaker 13 reaches the bottom of the borehole.

[0338] (3) Position confirmation: ensure that the built-in push pipe device reaches the predetermined position by measurement or marking, with an error of not more than ±10 mm.

[0339] 4. Install the pusher 18 and flat spring 24

[0340] (1) Pusher inspection: ensure that the surface of the pusher is smooth, without burrs, and the size meets the requirements.

[0341] (2) Push the pusher: slowly push the pusher from the rear end of the built-in push pipe device until the front end surface contacts the bottom surface of the fan-shaped rotary rock breaker.

[0342] (3) Place the flat spring into the built-in push tube, behind the pusher, ensuring that the spring axis coincides with the built-in push tube axis to prevent skewing.

[0343] 5. Install the spring push thread device 35

[0344] (1) Initial screwing in: Align the external threads of the spring push thread device with the internal threads of the built-in push tube, and manually screw in 2-3 turns.

[0345] (2) Use the cross-shaped rotator 20: Insert the built-in cross lock and rotate clockwise, gradually compressing the flat spring until it reaches the fully compressed state (A1 = 50 mm).

[0346] (3) Fix the built-in push tube: During the tightening process, use pipe wrenches or special tools to fix the exposed part of the built-in push tube to prevent it from following the rotation.

[0347] 6. Connect the drilling machine 1

[0348] (1) Connection method: Use special joints or connecting rods to connect the built-in push tube with the drilling machine, ensuring firm and reliable connection.

[0349] (2) Safety inspection: Check all connection parts to confirm that there is no looseness or damage, and that the power supply and hydraulic system are working properly.

[0350] 7. Start reaming

[0351] (1) Rotation parameter setting: According to geological conditions and design requirements, set appropriate rotation speed n and advance speed v.

[0352] (2) Start the drilling machine: Start slowly and gradually reach the set rotation speed and advance speed to avoid sudden acceleration causing equipment damage or safety accidents.

[0353] (3) Monitor the process: The operator should closely monitor the running state of the equipment, pay attention to sound, vibration and torque signals, and timely discover and handle abnormal situations.

[0354] 8. Complete reaming

[0355] (1) Stop rotation: When the fan-shaped rotary rock breaker is fully deployed and the reaming reaches the expected effect, gradually reduce the rotation speed of the drilling machine until it stops.

[0356] (2) Reaming effect inspection: Use measuring tools such as calipers or probes to confirm that the diameter and depth of the enlarged and shaped hole meet the design requirements.

[0357] (3) Clean the hole debris: Clean the debris and rock powder in the hole through compressed air or suction equipment to ensure the hole is clean and prepare for subsequent anchoring operations.

[0358] 9. Disassembly device

[0359] (1) Loosen the spring push thread device: Use the cross-shaped rotator to rotate counterclockwise, gradually loosen the spring push thread device, and release the tension of the flat spring.

[0360] (2) Take out the assembly: Take out the spring push thread device, flat spring and pusher in order, pay attention to prevent falling and damage.

[0361] (3) Exit the built-in push pipe and fan-shaped rotary rock breaker: Slowly pull out the built-in push pipe together with the fan-shaped rotary rock breaker from the borehole, check whether the fan-shaped rotary rock breaker is restored to the folded state.

[0362] 1. Safe operation

[0363] (1) Personal protection: Construction personnel must wear protective equipment such as safety helmets, safety belts, protective gloves, protective glasses and dust masks.

[0364] (2) Operation procedures: Strictly follow the equipment operation procedures, do not modify the equipment parameters or perform illegal operations.

[0365] (3) Environmental monitoring: In the roadway with high gas concentration, gas detector should be equipped to ensure construction within the safe range.

[0366] 2. Equipment maintenance

[0367] (1) Regular inspection: Before and after daily construction, check all parts of the equipment, especially the vulnerable parts such as pick heads, springs, threaded components, etc., and replace or repair them in time.

[0368] (2) Lubrication and maintenance: Threaded and movable parts should be regularly coated with lubricating oil to reduce wear and tear and prolong the service life of the equipment.

[0369] (3) Storage and maintenance: When the equipment is not in use, it should be properly stored in a dry and ventilated place to prevent moisture, rust or damage.

[0370] 3. Construction environment

[0371] (1) Roof support: During construction, ensure the stability of the surrounding roof, and temporary support measures such as support net, shed frame or temporary support can be used.

[0372] (2) Temperature conditions: In low temperature environment (below 0℃), attention should be paid to the performance change of the equipment and the applicability of the lubricating oil, and insulation measures should be taken if necessary.

[0373] (3) Geological conditions: According to different geological conditions, adjust the construction parameters such as rotation speed, pushing speed and reaming depth, etc.

[0374] 4. Quality Control

[0375] (1) Construction Record: Detailed records of construction parameters (such as rotation speed, pushing speed), time, personnel, geological conditions, and other information are recorded to facilitate later tracing and analysis.

[0376] (2) Effectiveness of Reaming Detection: After construction is completed, the hole diameter and depth are measured to ensure that the reaming effect meets the design requirements.

[0377] (3) Anchoring Effectiveness Detection: After subsequent anchoring construction is completed, a pull-out test is conducted to detect whether the anchoring force meets the design requirements.

[0378] Application Effects of This Embodiment:

[0379] 1. Improved Anchoring Force

[0380] (1) Experimental Results: Through the pull-out test, the anchoring force is improved by about 50%, from the original 150 kN to more than 225 kN.

[0381] (2) Analysis: The enlarged area increases the contact area between the anchoring agent and the surrounding rock, forming a mechanical locking effect and significantly enhancing the bonding force between the anchor (cable) and the surrounding rock.

[0382] 2. High Construction Efficiency

[0383] (1) Time Saving: The reaming time for a single hole is about 5 minutes, which is 30% less than the traditional method.

[0384] (2) Personnel Requirements: The operation is simple and standardized, reducing the dependence on high-skilled operators and lowering labor costs.

[0385] 3. Strong Applicability

[0386] (1) Geological Conditions: Suitable for various geological conditions, especially in soft rock, soft and broken coal body, aquifer, and other complex conditions, good support effect can be achieved.

[0387] (2) Applicable Range: Can be applied to coal mine tunnels, tunnels, underground engineering, and other places where anchoring force needs to be improved.

[0388] 4. Significant Economic Benefits

[0389] (1) Material Savings: By improving the support effect of individual anchor (cable), the number of support units can be reduced by 20%-30%, reducing overall support costs.

[0390] (2) Prolonged Life: Enhanced anchoring effect prolongs the service life of the support system, reduces the frequency of later maintenance and reinforcement, and reduces long-term operating costs.

[0391] 5. Safety level is improved

[0392] (1) Risk is reduced: the risk of surrounding rock collapse and anchor failure is reduced, and the safety of construction personnel is ensured.

[0393] (2) Stability is enhanced: the deformation of the roadway is significantly reduced, the stability of the surrounding rock is effectively controlled, and the safety production level of the mine is improved.

[0394] In summary, the coal and rock roadway drilling hole bottom reaming device of the present application significantly improves the anchoring effect and enhances the overall stability of the roadway through innovative mechanical structure design and scientific construction methods. The device has a simple structure, is convenient to construct, and has strong adaptability, and has a wide application prospect and promotional value.

[0395] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0396] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again by the present application.

[0397] Furthermore, various different embodiments of the present application can also be combined in any manner, as long as they do not deviate from the idea of the present application, and they should also be considered as disclosed by the present application.

Claims

1. A coal rock roadway drilling hole bottom reaming device, characterized in that, It comprises a built-in jacking pipe (10), a fixed pin (11), a fan-shaped rotary rock breaker (13), a pusher (18), a flat spring (24) and a spring push thread device (35); The built-in jacking pipe (10) is in a tubular structure and made of high-strength alloy steel, with an outer diameter matched with the diameter of the drill hole to enter the drill hole and remain stable; the inside of the built-in jacking pipe (10) is a two-section inner hole with different diameters, namely a rear end inner hole diameter N (8) and a front end inner hole diameter M (29) and an inner thread (9) located between the two and at the rear end position; The fixed pin (11) is arranged at the front end of the built-in jacking pipe (10) and made of high-strength alloy steel, with a through hole (12) at the top for installing the fan-shaped rotary rock breaker (13); the structure of the fixed pin (11) is matched with the groove of the fan-shaped rotary rock breaker (13) to enable the fan-shaped rotary rock breaker (13) to rotate freely within a range of 0°-90°; The pusher (18) can be arranged inside the built-in jacking pipe (10) and located behind the fan-shaped rotary rock breaker (13) and made of high-strength steel; the front end surface of the pusher (18) is in close contact with the bottom surface of the fan-shaped rotary rock breaker (13); the flat spring (24) behind the pusher (18) can push the pusher (18) to move forward to expand the fan-shaped rotary rock breaker (13); The spring push thread device (35) is installed at the rear end of the built-in jacking pipe (10) and made of alloy steel, matched with the inner thread (9); by tightening or loosening the spring push thread device (35), the compression state of the flat spring (24) can be accurately adjusted to meet different construction requirements.

2. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The diameter difference between the built-in jacking pipe (10) and the drill hole wall is 2-4 mm to ensure that the device can smoothly enter the drill hole and maintain good stability during rotation and reaming, avoiding device shaking or deviation due to excessive gap, improving the accuracy and safety of construction.

3. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The diameter difference between the pusher (18) and the built-in jacking pipe (10) is 0-5 mm, enabling the pusher (18) to move smoothly inside the built-in jacking pipe (10), reducing friction resistance, avoiding jamming due to excessive gap or shaking due to excessive gap, thereby ensuring the stability and efficiency of the reaming process.

4. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The inner hole diameter N (8) of the built-in jacking pipe (10) is slightly larger than the inner hole diameter M (29), with a diameter difference of 1-4 mm, facilitating the installation and disassembly of the components, ensuring the smooth installation of the pusher (18), the flat spring (24) and the spring push thread device (35) inside the built-in jacking pipe (10), and also helping to maintain the structural strength and stability of the device as a whole.

5. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The length of the outer thread (22) of the spring push thread device (35) is slightly larger than the effective length of the inner thread (9) of the built-in jacking pipe (10), ensuring that the flat spring (24) can be completely compressed during tightening and ensuring the firmness of the installation, avoiding the risk of loosening or falling off of the spring push thread device (35) during construction, improving the reliability and safety of the device.

6. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The groove of the fan-shaped rotary rock breaker (13) matches the fixed pin (11), and the maximum opening angle thereof is 90°. Through precise mechanical cooperation, the fan-shaped rotary rock breaker (13) can be smoothly unfolded to the designed angle under the action of rotation and centrifugal force, so as to expand the cutting range, improve the cutting efficiency on the surrounding rock, form a larger enlarged area, and enhance the anchoring effect.

7. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The distance between the thread starting section of the spring pushing thread device (35) and the exposed surface is less than or equal to the length of the inner hole diameter N (8) of the built-in push pipe device (10). During the tightening process, the spring pushing thread device (35) can be completely embedded inside the built-in push pipe device (10), avoiding the exposed part being too long and being disturbed or damaged by the outside, and ensuring the safety and stability of the device during the construction process.

8. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The upper side and the lower side of the fan-shaped rotary rock breaker (13) are both installed with a plurality of pick heads (14) made of hard alloy material, which has high hardness and wear resistance. After unfolding, the fan-shaped rotary rock breaker (13) can simultaneously cut the surrounding rock at the bottom and the sidewall of the drill hole, speed up the reaming speed, improve the reaming effect, and improve the construction efficiency.

9. The coal rock roadway drilling hole bottom reaming device according to claim 1, characterized in that, The flat spring (24) is made of spring steel with high elasticity and high fatigue strength, which has good durability and stability, can adapt to multiple cycles, and prolong the service life of the device.

10. The method for constructing the coal rock roadway drilling hole bottom reaming device according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: Step 1. Device assembly: Step 1.1, installation of fixed pin and fan-shaped rotary rock breaker: install the fixed pin at the front end of the built-in push pipe device, and then align the groove of the fan-shaped rotary rock breaker with the fixed pin and install it in place to ensure that it can rotate freely; Step 1.2, installation of pusher and flat spring: place the pusher inside the built-in push pipe device so that it is in contact with the bottom surface of the fan-shaped rotary rock breaker; then place the flat spring behind the pusher; Step 1.3, installation of spring pushing thread device: screw the spring pushing thread device into the internal thread of the built-in push pipe device, and compress the flat spring to a fully compressed state; Step 2. Device installation: Slowly push the assembled reaming device into the pre-drilled drill hole, and the outer diameter of the built-in push pipe device matches the diameter of the drill hole to ensure that the device stably reaches the bottom of the drill hole; Step 3. Rotation and unfolding: Step 3.1, start rotating: connect the built-in push pipe device with the drilling machine, start the drilling machine, and make the device start rotating; Step 3.2, unfolding of the fan-shaped rotary rock breaker: under the joint action of centrifugal force and spring force, the fan-shaped rotary rock breaker starts to open outward; Step 3.3, action of flat spring: the flat spring gradually relaxes from the fully compressed state, pushing the pusher to move forward and accelerating the unfolding of the fan-shaped rotary rock breaker; Step 4. Cutting and reaming: Step 4.1, cutting process: the pick heads on the fan-shaped rotary rock breaker start to cut the surrounding rock at the bottom and sidewall of the drill hole; Step 4.2, formation of enlarged area: as the fan-shaped rotary rock breaker gradually unfolds to the maximum opening angle of 90°, an enlarged area with a larger diameter is formed; Step 5. Complete reaming: Step 5.1, reach the design requirements: when the flat spring reaches the pre-set partially relaxed state, the enlarged area reaches the designed size; Step 5.2, stop rotation: stop the rotation of the drilling machine, the reaming process is completed; Step 6. Device recovery: Step 6.1, loosen the spring push thread device: use the cross-shaped rotator to loosen the spring push thread device; Step 6.2, take out the assembly: take out the flat spring and the pusher in turn; due to the loss of centrifugal force and spring thrust of the fan-shaped rotary rock breaker, it will automatically fold; Step 6.3, take out the device: take out the built-in pipe pusher and the fan-shaped rotary rock breaker together from the borehole.

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