Self-adaptive variable-diameter coal rock broaching vibration presplitting pressure relief device and method

Abstract

The invention discloses a self-adaptive variable-diameter coal rock reaming vibration presplitting pressure relief device and method. The device comprises a drill bit body and a built-in shape memory alloy assembly. The adjustable cutter tooth is composed of a telescopic rod piece and an adjustable cutter tooth body and used for adapting to hardness and fracture development degree changes of different coal rock stratums through self stretching, angle deflection or cutting parameter adjustment. The sensor cluster is used for monitoring rock stratum hardness and torque fluctuation, analyzing rock brittleness and the drill bit state and providing real-time temperature changes for a drill bit cooling system and memory alloy cutting teeth. An algorithm module is arranged in the intelligent control module; the energy recovery and cooling system consists of a micro channel, a pump body and a heat energy power generation module; the telescopic impact module is composed of a miniature high-frequency impact device and an elastic reset device. According to the device, through deep integration of real-time sensing, electric energy self-supply and intelligent adjustment, self-adaptive adjustment of the cutter teeth can be achieved, coal rock variable-diameter drilling under complex geological conditions is met, and drilling continuity and efficiency are improved.

Description

[0001] The impact mechanism, designed with a fixed frequency, struggles to dynamically match impact parameters according to the brittle characteristics of rock. In ductile coal and rock formations, this easily leads to ineffective impact losses, increasing energy consumption and equipment fatigue damage. As coal and rock mining depths increase and geological conditions become more complex, the adaptive capability, energy efficiency, and safety reliability of drilling equipment are crucial for efficient engineering implementation. Existing technologies struggle to achieve integrated coordination of advanced sensing and adaptive adjustment. Therefore, constructing a composite technical solution integrating intelligent sensing, dynamic adaptation, and energy regeneration has gradually become a focus of engineering practice and academic research. Technical Field

[0002] This invention relates to the field of coal and rock drilling engineering technology, specifically an adaptive variable diameter coal and rock borehole enlargement vibration pre-splitting and pressure relief device and method. Background Technology

[0003] In complex geological formations such as alternating layers of soft and hard rock and well-developed fractures, coal and rock drilling equipment with fixed-structure cutting teeth cannot dynamically adapt cutting parameters to geological changes. This leads to accelerated tooth wear, reduced drilling efficiency, and frequent tool replacements, increasing operating costs and increasing the risk of accidents such as stuck drill bits and drill bit burial. Adopting an adaptive variable-diameter coal and rock borehole enlargement vibration pre-splitting and pressure relief device, which proactively senses changes in rock strata and adaptively adjusts the drilling mode, provides an important basis for achieving efficient drilling and improving the efficiency and safety of operations in complex geological conditions. During drilling, the heat generated by friction is mostly dissipated through natural heat dissipation, while the vibration energy generated by the interaction between the drill bit and the rock surface is not effectively recovered and utilized. This necessitates the equipment to rely on an external power source for continuous operation, resulting in low energy efficiency. Simultaneously, traditional monitoring systems often employ single-parameter sensors, leading to data acquisition delays and limited accuracy. This makes it difficult to characterize the working status of the drill bits, the hardness of the formation rock mass, and equipment operating parameters in real time, causing drilling parameter adjustments to lag behind changes in geological conditions, further exacerbating equipment wear and efficiency losses. While existing research has explored technologies related to variable-diameter drill bits and energy recovery devices, these structures often rely on manual mechanical adjustments, resulting in slow response times and limited adjustment ranges. Furthermore, the lack of closed-loop coordinated control between the energy recovery module and the drilling system leads to low recovery efficiency, failing to meet the equipment's own energy consumption requirements. In addition, while vibration pre-splitting technology can improve rock breaking efficiency, traditional... Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides an adaptive variable diameter coal and rock borehole expansion vibration pre-splitting and pressure relief device and method, which can achieve efficient coal and rock drilling under complex geological conditions, with a compact structure and reliable operation.

[0005] To achieve the above technical objectives, this invention provides an adaptive variable-diameter coal and rock borehole enlargement vibration pre-fracturing and pressure relief device. The device includes a drill bit body, adjustable cutting teeth, a sensor cluster, an intelligent control system, an energy recovery and cooling system, and a telescopic impact module. The drill bit body is used to provide an installation foundation and structural support for the adjustable cutting teeth and energy recovery and cooling system; The adjustable cutting teeth are hinged to the drill bit body and are used to dynamically change the drilling mode according to the characteristics of the rock formation. The sensor cluster is fixed between the drill bit body and the inner wall of the adjustable cutter teeth, and is used to monitor the rock formation characteristics and drilling information in real time, forming a data sensing network. The intelligent control system is installed inside the telescopic impact module and is used to receive real-time data from the sensor cluster and send drilling parameter commands. The energy recovery and cooling system is installed in the drill bit body and adjustable cutting teeth, and is used to capture and utilize frictional heat energy during drilling. The telescopic impact module is connected to the drill bit body and is used to generate high-frequency vibration, which is transmitted to the rock surface through the drill bit body and adjustable cutting teeth to pre-crack and relieve pressure on the rock during drilling.

[0006] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the drill bit body includes a drill bit body, a drill bit connector, cutter wings, main cutting teeth, memory cutting teeth, a cleaning chamber, a drilling fluid nozzle, a threaded connector, a connecting internal thread, and a chip removal and heat dissipation groove. The drill bit body and the drill bit connector are connected by a threaded connector and a connecting internal thread. Multiple cutter wings are arranged circumferentially at equal angles around the drill bit body. Main cutting teeth and memory cutting teeth are arranged at intervals on both sides of the outer surface of each cutter wing. A cleaning chamber is provided between every two cutter wings, with a drilling fluid nozzle inside. The chip removal and heat dissipation groove is provided on both sides of the inner surface of the cutter wing.

[0007] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the adjustable cutting teeth include a roller cone drill bit, a hinge seat, a support rod, polycrystalline diamond ball teeth, shape memory alloy ball teeth, a hinge shaft, a pin shaft, a rod, a vertical sliding sleeve, a limiting post, a telescopic diamond-shaped tie rod, and a spiral screw. The rotation axis of the hinge seat is perpendicular to the axial direction of the rod. The roller cone drill bit is fixed to one end of the support rod via the hinge seat. The roller cone drill bit is embedded with annularly spaced polycrystalline diamond ball teeth and shape memory alloy ball teeth. The support rod has a hinge shaft parallel to the axial direction of the rod. The other end of the support rod is connected to the rod via a pin shaft. A vertical sliding sleeve is provided on the support rod and is fixedly connected to the support rod via a limiting post. One end of the spiral screw and the telescopic diamond-shaped tie rod are fixed to the drill bit body, and the other end of the spiral screw is hinged to the vertical sliding sleeve.

[0008] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the sensor cluster includes a hardness sensor, a torque sensor, a vibration sensor, a temperature sensor, a hardness sensor base, a torque sensor holder, a vibration sensor base, a temperature sensor base, and a drill rod. The hardness sensor is fixed on the hardness sensor base and connected to the roller cone drill bit, the main cutting tooth, and the root of the memory cutting tooth. The torque sensor is nested on the connecting shaft of the drill rod through the torque sensor holder. The vibration sensor is fixed to the bottom of the drill bit body. The temperature sensor is placed inside the roller cone drill bit and the cutter wing.

[0009] In addition to the aspects and any possible implementations described above, a further implementation is provided: the intelligent control system includes a device cavity, a core control unit, an interface module, a power management module, a heat sink, a main chip, a memory module, a storage chip, a metal box, an input interface, an output interface, a lithium battery, and a micro axial fan. The core control unit houses the main chip, the memory module, and the storage chip, and is fixed within the device cavity by the metal box. The interface module adjacent to the core control unit has four input interfaces and three output interfaces on its side, respectively connected to a memory cutting tooth, an adjustable cutting tooth, an energy recovery and cooling system, and a telescopic impact module. The power management module houses a lithium battery as a backup power source. The heat sink is attached to the main chip, and the micro axial fan is vertically positioned above the heat sink and fixed to the metal box.

[0010] In addition to the aspects described above and any possible implementations, a further implementation is provided, wherein the energy recovery and cooling system includes a thermoelectric power generation module, a coolant circulation channel, a micro-pump, a heat dissipation structure, a storage tank, a vibration power generation module, an insulation layer, a flow sensor, a temperature probe, a one-way valve, a lithium battery energy storage unit, an interface module, and a power management module. The thermoelectric power generation module is attached to the outer wall of the cutting area of ​​the drill bit body and connected to the lithium battery energy storage unit; the inlet end of the coolant circulation channel is connected to the storage tank, and the outlet end leads to the internal cooling chamber of the drill bit body and the adjustable cutting teeth, and the coolant circulation channel is wrapped with an insulation layer; the micro-pump is adjacent to the storage tank; the heat dissipation structure is set on the outer wall of the storage tank; the vibration power generation module is embedded in the drill rod connection section and connected to the lithium battery energy storage unit; a flow sensor and a temperature probe are installed in the coolant circulation channel; a one-way valve is installed on the pipeline between the storage tank and the micro-pump; and the lithium battery energy storage unit is connected to the power management module.

[0011] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the telescopic impact module includes a drive module, an impact hammer, an elastic reset device, a frequency adjustment unit, a control board, a pressure sensor, a buffer pad, a guide sleeve, a connecting flange, and a protective cover. The drive module is embedded in the axial position inside the drill bit body and is connected to the output interface of the core control unit through a cable connector. The front end of the impact hammer is rigidly connected to the root of the drill bit body, and the rear end is attached to the drive module. The elastic reset device is sleeved on the outside of the impact hammer. The frequency adjustment unit is integrated on the control board. The pressure sensor is placed between the impact hammer and the drive module. The buffer pad is placed at the contact point between the impact hammer and the guide sleeve. The guide sleeve is fixed to the inner wall of the drill bit body through the connecting flange. The protective cover covers the outside of the drive module.

[0012] The present invention also provides an adaptive variable diameter coal and rock borehole expansion vibration pre-fracturing and pressure relief method, the method is implemented by the device described above, including: S1. Installing, debugging and starting the drill bit body, adjustable cutting teeth, sensor cluster, intelligent control system, energy recovery and cooling system and telescopic impact module of the device according to the prior requirements, and performing drilling operations according to the preset process; S2. During the drilling operation, monitor and record the operating parameters of the corresponding components in the device in real time until the drilling task is completed; S3. Calculate the overall hardness of the rock mass and the cutting force of the cutting tool based on the recorded operating parameters.

[0013] As described above and in any possible implementation, a further implementation is provided, wherein the calculation process for dynamically monitoring the comprehensive hardness of rock mass includes: S311. Real-time hardness measurement values ​​are obtained from the hardness sensors of the sensor cluster; the intelligent control system calculates the temperature change rate based on the temperature sensor monitoring the temperature of the cutting teeth; the torque sensor collects torque signals in real time and records the standard deviation of torque fluctuations; the intelligent control system adaptively adjusts the weights according to the formation type; and calculates the real-time comprehensive hardness index based on the hardness measurement values, temperature change rate, and weights. S312. Based on the real-time data collected by the vibration sensor and transmitted to the intelligent control system, the system iteratively calculates the real-time crack length, the recorded impact module design parameters vibration amplitude and vibration frequency, and the rock mass density and elastic modulus at the work site, and derives the dynamic stress intensity factor at the crack tip. S313. The intelligent control system inverts the real-time comprehensive hardness index to obtain the initial fracture length of the rock mass, and calibrates the maximum fracture length when the rock mass is completely broken according to historical data, thereby obtaining the degree of fracture development. S314. The frequency adjustment unit of the device receives the degree of fracture development, and dynamically adjusts the output parameters of the drive module in combination with the rated operating parameters of the telescopic impact module and the preset frequency adjustment coefficient, so as to achieve the adaptation of the impact frequency to the current state of formation fracture development.

[0014] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the calculation of the adaptive adjustment of the cutting teeth includes the following steps: S321. Record the maximum theoretical deformation δ of the shape memory alloy used for cutting teeth. max Phase transition rate constant Phase transition initiation temperature The real-time temperature T of the shape memory alloy, obtained by monitoring and regulating the energy recovery and cooling system in conjunction with a temperature sensor, is combined with the axial stress indirectly calculated by a torque sensor. Then, the deformation δ of the memory cutting tooth, controlled by temperature and stress, is... S322. Based on the contact area S between the cutting edge and the rock mass, and the internal friction angle of the rock mass... Cohesion Rock mass compatibility coefficient Then the formula for calculating the cutting force F is: , in, This indicates the degree of fissure development.

[0015] Beneficial effects: Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art: (1) By relying on the synergistic effect of adjustable cutting teeth and shape memory alloy components, the drilling parameters such as cutting tooth angle and diameter can be dynamically adjusted to adapt to coal and rock formations with different hardness and fracture development, reduce tool wear, and improve drilling continuity and efficiency. (2) The sensor cluster and intelligent control system form a closed-loop monitoring and adjustment mechanism to perceive the geological characteristics and equipment status in real time, realize predictive parameter adjustment, avoid faults such as stuck drill and deviation, and improve the safety of operation under complex geological conditions. (3) The telescopic impact module and the rotary cutting work together to break rocks. The high-frequency vibration generates dense cracks inside the rock, reducing the rock breaking resistance and improving drilling efficiency in hard rock layers, thus enriching the technical path of coal and rock breaking. (4) The device has a high degree of integration, the various systems work together, the installation and commissioning are convenient, and it can achieve long-term continuous operation, reduce equipment maintenance costs, and provide efficient, green and safe technical solutions for coal and rock drilling projects. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the main structure of the drill bit of the present invention; Figure 3This is a schematic diagram of the adjustable cutter tooth structure of the present invention; Figure 4 This is a schematic diagram of the sensor cluster structure of the present invention; Figure 5 This is a partial structural diagram of the energy recovery and cooling system of the present invention; Figure 6 This is a partial structural diagram of the intelligent control system of the present invention; Figure 7 This is a partial structural diagram of the telescopic impact module of the present invention; Figure 8 This is a schematic diagram of the drilling state of the present invention. Detailed Implementation

[0017] An embodiment of the present invention will be further described below with reference to the accompanying drawings: like Figures 1-8 As shown, an adaptive variable diameter coal and rock borehole expansion vibration pre-splitting and pressure relief device includes a drill bit body 1, adjustable cutting teeth 2, sensor cluster 3, intelligent control system 4, energy recovery and cooling system 5, and telescopic impact module 6.

[0018] The drill bit body 1 is made of high-strength alloy steel and is used to provide an installation foundation and structural support for the adjustable cutting teeth 2 and the energy recovery and cooling system 5.

[0019] The adjustable cutting teeth 2 are hinged to the drill bit body 1 and have a built-in sensor cluster 3, which is used to dynamically change the drilling mode according to the characteristics of the rock formation, optimize the cutting contact area and force, and realize variable diameter drilling to match different hole diameter requirements.

[0020] The sensor cluster 3 components are fixed between the drill bit body 1 and the inner wall of the adjustable cutter teeth 2, and are used to monitor the rock formation characteristics and drilling information in real time, forming a data sensing network.

[0021] The intelligent control system 4 is located inside the telescopic impact module 6 and is used to receive real-time data from the sensor cluster 3 and send drilling parameter commands.

[0022] The energy recovery and cooling system 5 is located in the internal cavity of the drill bit body 1 and the adjustable cutter teeth 2, and is used to capture and utilize frictional heat energy during drilling, so as to realize self-powered operation and active cooling during drilling.

[0023] The telescopic impact module 6 is connected to the drill bit body 1 and is used to generate high-frequency vibrations, which are transmitted to the rock surface through the drill bit body 1 and the adjustable cutting teeth 2. The impact energy is used to generate dense cracks inside the rock, thereby achieving rock pre-fracture and pressure relief during drilling.

[0024] Furthermore, such as Figure 2As shown, the drill bit body 1 includes a drill bit body 1-1, a drill bit connector 1-2, cutter wings 1-3, main cutting teeth 1-4, shape memory cutting teeth 1-5, a cleaning chamber 1-6, a drilling fluid nozzle 1-7, a threaded connector 1-8, a connecting internal thread 1-9, and a chip removal and heat dissipation groove 1-10. The drill bit body 1-1 and the drill bit connector 1-2 are connected by the threaded connector 1-8 and the connecting internal thread 1-9. Multiple cutter wings 1-3 are arranged circumferentially around the drill bit body 1-1 at equal angles. During drilling, each cutter wing experiences uniform force and a balanced cutting coverage, ensuring the drill bit's rotational stability to avoid skewing, reducing localized excessive wear and equipment damage, while improving cutting efficiency and rock-breaking effect. On both sides of the outer surface of each cutter wing 1-3 are provided main cutting teeth 1-4 made of polycrystalline diamond and shape memory alloy cutting teeth 1-5 made of shape memory alloy, which are arranged alternately. The main cutting teeth 1-4 are fixed cutting teeth that bear the core cutting load of rock breaking. The shape memory cutting teeth 1-5 adaptively adjust their cutting posture through the shape memory effect of the shape memory alloy. The two work together to complete the rotary drilling operation. A cleaning chamber 1-6 is provided between each pair of blades 1-3, with a built-in drilling fluid nozzle 1-7 for cleaning rock cuttings at the bottom of the well. The chip removal and heat dissipation grooves 1-10 are located on both sides of the radial outer surface of the blades 1-3. The depth gradually increases from the cutting end near the main cutting teeth 1-4 and the shape memory cutting teeth 1-5 to the connecting end near the drill bit joint 1-2. This can quickly dissipate the heat and rock cuttings generated by cutting, preventing excessive temperature and rock cuttings accumulation from affecting drilling.

[0025] Furthermore, such as Figure 3As shown, the adjustable cutting teeth 2 include a roller cone drill bit 2-1, a hinge seat 2-2, a support rod 2-3, polycrystalline diamond ball teeth 2-4, shape memory alloy ball teeth 2-5, a hinge shaft 2-6, a pin shaft 2-7, a rod 2-8, a vertical sliding sleeve 2-9, a limiting post 2-10, a telescopic diamond-shaped tie rod 2-11, and a spiral screw 2-12. The rotation axis of the hinge seat 2-2 is perpendicular to the axis of the rod 2-8. The roller cone drill bit 2-1, as an independently movable rock-breaking actuator, is fixed to one end of the support rod 2-3 via the hinge seat 2-2. It contains polycrystalline diamond ball teeth 2-4 and shape memory alloy ball teeth 2-5, which are arranged in a ring at intervals to achieve rolling cutting, reduce friction, and maintain effective contact with the rock layer when adjusting the diameter and angle. The support rod 2-3 has a hinge shaft 2-6 parallel to the axis of the rod 2-8, which enables the roller cone to rotate. The drilling angle of drill bit 2-1 is adjusted, and its other end is connected to rod 2-8 via pin 2-7. A vertical sliding sleeve 2-9 is slidably mounted on support rod 2-3 and fixedly connected to support rod 2-3 via limiting pin 2-10. One end of telescopic diamond-shaped tie rod 2-11 and spiral screw 2-12 are fixed to drill bit body 1-1, and the other end is hinged to vertical sliding sleeve 2-9. Controlling the extension amount drives support rod 2-3 to open and close. Rod 2-8 is a hydraulic telescopic rod, with one end fixedly connected to drill bit body 1-1. By controlling its extension and retraction, the telescopic diamond-shaped tie rod 2-11 and spiral screw 2-12 can be linked, thereby pushing or pulling vertical sliding sleeve 2-9 and the connected support rod 2-3, ultimately changing the radial position of roller cone drill bit 2-1 and completing the dynamic, adaptive adjustment of the drill bit diameter.

[0026] Furthermore, such as Figure 4As shown, the sensor cluster 3 includes a hardness sensor 3-1, a torque sensor 3-2, a vibration sensor 3-3, a temperature sensor 3-4, a hardness sensor base 3-5, a torque sensor holder 3-6, a vibration sensor base 3-7, a temperature sensor base 3-8, a drill rod 3-9, a protective housing 3-10, and a coolant inlet / outlet 3-11. The hardness sensor base 3-5 is fixed to the root of the memory cutting teeth 1-5, the main cutting teeth 1-4, and the roller cone drill bit 2-1, and is threadedly connected to the hardness sensor 3-1. It has an embedded circular sealing ring for dust and water protection, ensuring stable operation of the sensor in complex drilling environments. The torque sensor 3-2 has a ring structure and is nested on the connecting shaft of the drill rod 3-9 via the torque sensor holder 3-6. The vibration sensor 3-3 is fixed to the bottom of the drill bit body 1-1 to capture the vibration frequency of the drill bit body 1 and the adjustable cutting teeth 2. The vibration sensor base 3-7 is located at the bottom of the drill bit body 1-1 and is fixedly connected to the vibration sensor (3-3). Built-in damping material filters out vibration interference from the drill rod 3-9 itself; temperature sensor 3-4 is placed inside the roller cone drill bit 2-1 and the cutter wing 1-3 to monitor the temperature of the cutting teeth in real time, providing data for the alloy control of the memory cutting teeth 1-5; coolant inlet / outlet 3-11 is connected to temperature sensor 3-4 and fixed to temperature sensor 3-8 to achieve active heat dissipation of the drill bit; the surface of temperature sensor base 3-8 is coated with graphene thermal conductive coating to ensure temperature conduction efficiency; protective shell 3-10 is placed in the cavity inside the cutter wing 1-3, is a snap-fit ​​metal shell, and its bottom is connected to temperature sensor base 3-8 to form a sealed space for sensor protection.

[0027] Furthermore, such as Figure 6As shown, the intelligent control system 4 includes a device cavity 4-1, a core control unit 4-2, an interface module 4-3, a power management module 4-4, a heat sink 4-5, a main chip 4-6, a memory module 4-7, a storage chip 4-8, a metal box 4-9, an input interface 4-10, an output interface 4-11, a lithium battery 4-12, and a micro axial flow fan 4-13. The core control unit 4-2 houses a main chip 4-6, a memory module 4-7, and a storage chip 4-8 for storing and analyzing monitoring information from the sensor cluster 3. It is fixed inside the equipment cavity 4-1 via a metal box 4-9 with ventilation holes. The metal box 4-9 contains damping pads to counteract vibrations generated during drilling. The interface module 4-3 is adjacent to the core control unit 4-2 and has four input interfaces 4-10 to receive monitoring information from the sensor cluster 3. Three output interfaces 4-11 are located on the side of the interface module adjacent to the core control unit 4-2 and are respectively connected to the memory cutting teeth 1-5, the adjustable cutting teeth 2, the energy recovery and cooling system 5, and the telescopic impact module 6. The power management module 4-4 houses a lithium battery 4-12 as a backup power source, and the core control unit 4-2 manages the power distribution. The bottom of the aluminum alloy heat sink 4-5 is coated with thermal grease and is attached to the main chip 4-6. A miniature axial fan 4-13, vertically positioned above the heat sink 4-5 and fixed to the metal box 4-9, assists in heat dissipation, ensuring stable operation of the intelligent control system 4.

[0028] Furthermore, such as Figure 5As shown, the energy recovery and cooling system 5 includes a thermoelectric power generation module 5-1, a coolant circulation channel 5-2, a micro pump body 5-3, a heat dissipation structure 5-4, a liquid storage tank 5-5, a vibration power generation module 5-6, metal pipes 5-7, an insulation layer 5-8, a flow sensor 5-9, a temperature probe 5-10, a one-way valve 5-11, a lithium battery energy storage unit 5-12, an interface module 5-13, and a power management module 5-14. Thermoelectric module 5-1 is attached to the outer wall of the cutting area of ​​drill bit body 1 and connected to lithium battery energy storage unit 5-12 via wires to convert the heat energy generated by drilling friction into electrical energy. Coolant circulation channel 5-2 is composed of spiral metal pipe 5-7 inside drill rod 3-9, with the inlet end connected to storage tank 5-5 and the outlet end leading to the internal cooling chamber of drill bit body 1 and adjustable cutting teeth 2. The heat loss along the way is reduced by the insulation layer 5-8. Micro pump body 5-3 is fixed next to storage tank and is controlled by the output signal of core control unit 4-2 to drive coolant circulation in the channel. Heat dissipation structure 5-4 is installed on the outer wall of storage tank and fits against the outlet section of circulation channel to assist in dissipating the heat absorbed by coolant. Heat; the vibration power generation module 5-6 is embedded in the connecting section of the drill rod 3-9, which generates electrical energy by capturing drilling vibration energy, and the electrical energy is fed into the lithium battery energy storage unit 5-12 through the rectifier module; the metal pipeline 5-7 is equipped with a flow sensor 5-9 and a temperature probe 5-10 along the way, which monitor the coolant flow rate and the inlet and outlet temperature difference, respectively, and the data is fed back to the core control unit 4-2 through the interface module 5-13; the one-way valve 5-11 is installed in the pipeline between the liquid storage tank 5-5 and the micro pump body 5-3 to prevent coolant backflow; the lithium battery energy storage unit 5-12 is connected to the power management module 5-14, which stores the recovered electrical energy to power the sensors and micro drive devices, realizing the coordinated operation of energy recovery and cooling functions.

[0029] like Figure 7As shown, the telescopic impact module 6 includes a drive module 6-1, an impact hammer 6-2, an elastic reset device 6-3, a frequency adjustment unit 6-4, a control board 6-5, a pressure sensor 6-6, a buffer pad 6-7, a guide sleeve 6-8, a connecting flange 6-9, and a protective cover 6-10. The drive module 6-1 is embedded inside the drill bit body 1 at its axial position and is connected to the output interface of the core control unit 4-2 via a cable connector, used to convert electrical signals into high-frequency mechanical vibration. The front end of the impact hammer 6-2 is rigidly connected to the root of the drill bit body 1, and the rear end is attached to the drive module 6-1, converting vibration energy into axial impact force. The elastic reset device 6-3 is sleeved on the outside of the impact hammer 6-2, using a high-strength spring structure to push the impact hammer 6-2 back to its original position during the impact gap. The frequency adjustment unit 6-4 is integrated on the control board 6-5 adjacent to the interface module 5-13, receiving instructions from the intelligent control system 4 forwarded by the control board 6-5. The core function of the control board 6-5 is to support the frequency adjustment unit 6-4. It includes a supporting control circuit to achieve signal interaction and adjustment command forwarding with the intelligent control system 4. The control program is a conventional adaptive adjustment program. The pressure sensor 6-6 is placed between the impact hammer 6-2 and the drive module 6-1 to monitor the impact force in real time. The data is fed back to the core control unit 4-2 through wires. The buffer pad 6-7 is made of rubber and is pasted on the contact part between the impact hammer 6-2 and the guide sleeve 6-8 to reduce lateral vibration during impact. The guide sleeve 6-8 is fixed to the inner wall of the drill bit through the connecting flange 6-9 to ensure that the impact hammer 6-2 moves axially without deviation. The protective cover 6-10 covers the outside of the drive module 6-1, has heat dissipation holes and the inner wall is pasted with sound insulation cotton to reduce vibration noise.

[0030] As a disclosed embodiment of the present invention, such as Figure 8 As shown, the present invention also provides an adaptive variable-diameter coal and rock borehole enlargement vibration pre-fracturing and pressure relief method, which is implemented using the aforementioned device. Includes: S1. The drill bit body 1, adjustable cutting teeth 2, sensor cluster 3, intelligent control system 4, energy recovery and cooling system 5, and telescopic impact module of the device are installed, integrated and started according to the pre-required requirements, and drilling operations are carried out according to the preset process; S2. During the drilling operation, monitor and record the operating parameters of the corresponding components in the device in real time until the drilling task is completed; S3. Calculate the overall hardness of the rock mass and the cutting force of the cutting tool based on the recorded operating parameters.

[0031] This invention provides an integrated technical solution for coal and rock drilling under complex geological conditions, realizing energy recovery and utilization and dynamic adaptation of cutting tools. It enriches the technical pathways for coal and rock drilling, improves the efficiency and safety of drilling in complex formations, and provides important technical support for accurately grasping changes in working conditions during the drilling process, thus optimizing the implementation of coal and rock drilling projects. Compared with existing technologies, it has the following advantages: (1) Relying on the core components of the adjustable cutter teeth 2, such as the roller cone drill bit 2-1, the hydraulic telescopic rod 2-8, the telescopic diamond tie rod 2-11, the spiral screw 2-12, the hinge shaft 2-6, the memory cutting teeth 1-5, and the shape memory alloy ball teeth 2-5, the opening and closing of the support rod 2-3 and the angle of the roller cone drill bit 2-1 are adjusted by hydraulic drive and mechanical transmission, so as to realize the dynamic adjustment of drilling parameters such as the angle and diameter of the cutter teeth; (2) The hardness sensor 3-1, torque sensor 3-2, vibration sensor 3-3, and temperature sensor 3-4 of the sensor cluster 3 form a closed-loop monitoring and adjustment mechanism with the core control unit 4-2 and interface module 4-3 of the intelligent control system 4, and collect the formation characteristics and equipment status data in real time and feed them back to the core control unit. (3) The drive module 6-1, impact hammer 6-2, frequency adjustment unit 6-4 of the telescopic impact module 6, together with the main cutting teeth 1-4, memory cutting teeth 1-5, and roller cone drill bit 2-1, rotate and cut to break the rock. The high-frequency vibration output by the drive module 6-1 is converted into axial impact force through the impact hammer 6-2. Combined with the rotational cutting action, dense cracks are generated inside the rock.

[0032] The calculation method for the adaptive adjustment of the cutting teeth in S3 is as follows: a. The real-time hardness measurement value Hs is obtained from the hardness sensor 3-1 embedded in the root of the main cutting teeth 1-4, and the temperature sensor 3-4 monitors the temperature of the cutting teeth. The temperature change rate is calculated by the intelligent control system 4. Torque sensor 3-2 is nested in the connecting shaft of drill pipe 3-9 to collect torque signals in real time and record the standard deviation of torque fluctuation. The intelligent control system 4 adaptively adjusts the weights according to the formation type to construct a real-time comprehensive hardness index based on the fusion of multi-source sensor data. : (1) Wherein, k1 is the weighting coefficient of the hardness sensor data; k2 is the weighting coefficient of the temperature change rate; and k3 is the weighting coefficient of the torque fluctuation. The weighting coefficients satisfy k1+k2+k3=1 and are adaptively adjusted by the intelligent control system 4 according to the formation type, combined with the preset parameters of geological exploration and real-time data feedback during drilling, and dynamically optimized through the built-in algorithm.

[0033] b. The stress concentration at the crack tip under vibration and impact; a larger value makes crack propagation more likely. Considering the dynamic stress generated by vibration and impact, the crack length *a* is iteratively calculated by the intelligent control system through real-time data acquisition by vibration sensor 3-3. The vibration amplitude *A* of the impact module 6 is recorded to characterize the maximum displacement of the axial vibration of the impact hammer 6-2, determining the magnitude of the impact force, and the vibration frequency *f* to characterize the number of impacts per unit time, determining the impact frequency density, which is used to calculate the short-term dynamic stress intensity factor *K* of the crack. Id The core variable is the rock mass density, provided by geological survey data. and elastic modulus Derivation of the dynamic stress intensity factor at the crack tip : (2) Dynamic stress intensity factor K Id It is a core parameter in fracture mechanics characterizing the degree of stress concentration in a fracture under dynamic loading, used to quantify the level of dynamic stress concentration per unit length at the fracture tip. Rock masses possess inherent fracture toughness K, which can be determined through geological exploration. IC Through K Id With K IC The comparison verifies the effectiveness of vibration pre-cracking and provides a quantitative basis for calculating the degree of crack development ξ.

[0034] c. Through the intelligent control system 4, H c Inversion to obtain the initial fracture length of the rock mass The maximum fracture length when the rock mass is completely broken was determined based on historical data. Calculate the degree of fracture development ξ. (3) Where, k a is the lithology correction factor, calibrated according to the stratigraphic type; n is the hardness-fracture correlation index, determined by indoor rock sample tests; b is the basic correction value, obtained by indoor tests and field calibration.

[0035] K Id <0.5K IC The cracks hardly propagate, and the physical determination indicates a weak pre-crack state, with ξ = [0.1, 0.3]. 0.5K IC ≤K Id <K IC The cracks propagate slowly, and the physical condition indicates a moderate pre-crack state, with ξ = (0.3, 0.7). K Id ≥K IC The cracks propagate rapidly, and the physical determination indicates a strong pre-crack state, with ξ being (0.7, 1.0).

[0036] d. The frequency adjustment unit 6-4 dynamically adjusts the output of the drive module 6-1 according to the rated value of the telescopic impact module 6 and the frequency adjustment coefficient. Establish the degree of fracture development With optimal impact frequency The mapping relationship forms a closed loop for sensing the rock mass condition and dynamically adjusting the pre-splitting parameters. The optimized pre-splitting effect will change the comprehensive hardness index H of the rock mass. c The degree of crack development ξ is used to drive the adaptive adjustment of the cutting teeth through the feedback intelligent control system 4.

[0037] (4) The calculation method for the adaptive adjustment of the cutting teeth in S3 is as follows: In the design, the main cutting teeth 1-4 are fixedly mounted with polycrystalline diamond, utilizing its ultra-hard properties to bear the main cutting load and maintain long-term working stability. The shape memory alloy cutting teeth 1-5 are adjustable units, adjusting the cutting contact area S in real time through phase transformation characteristics to respond to changes in the rock strata. With temperature-stress deformation as the core, the intelligent control system 4 adjusts the real-time comprehensive hardness index H... c Based on the degree of crack development ξ, the flow rate or temperature of the coolant flowing through the memory cutting teeth 1-5 is adjusted to control the temperature so that the actual strain is close to the target strain. The specific process is as follows: a. Record the inherent properties of shape memory alloys, including the maximum theoretical deformation δ. max Phase transition rate constant Phase transition initiation temperature Temperature sensor 3-4, in conjunction with energy recovery and cooling system 5, monitors and regulates the real-time temperature T of the shape memory alloy, and indirectly calculates the axial stress using torque sensor 3-2. This allows for the deformation δ of the memory cutting teeth 1-5 to be controlled by temperature and stress in a coordinated manner. (5) b. Based on existing Mohr-Coulomb strength measurements of rocks, considering the contact area S between the cutter teeth and the rock mass, and the internal friction angle of the rock mass. Cohesion Rock mass compatibility coefficient Establish the matching relationship between cutting force F and real-time comprehensive hardness index Hc and crack development degree ξ. (6) 4. A closed loop is formed by integrating hardness, acoustic pre-cracking, and cutting tooth adjustment through data feedback and parameter adaptation: a. Acoustic pre-splitting dynamically adjusts the overall rock mass hardness obtained from the intelligent control system 4, and positively drives the memory cutting teeth 1-5 to change: the higher the overall rock mass hardness, the worse the fracture development, requiring a higher acoustic impact intensity to reduce the dynamic stress intensity factor at the original fracture tip. The fracture toughness of the rock mass is greater than that of the rock mass, which promotes the rapid expansion of rock mass fissures and the initiation of new fissures, thus achieving effective pre-fracture of coal and rock. After pre-fracture, the degree of fissure development is used to provide feedback on the overall hardness, which together determines the adjustment of the cutting teeth. In intact hard rock, a large deformation is required for deep cutting at a small angle to increase the contact area between the cutting teeth and the rock mass to achieve wear resistance. In fractured rock mass, it is necessary to reduce the deformation and contact area of ​​the cutting teeth and increase the cutting angle for shallow cutting.

[0038] b. Adjust the drilling of the cutting teeth and update the comprehensive hardness in reverse to complete the closed loop of acoustic pre-splitting optimization: By updating the comprehensive hardness, the degree of rock mass fracture development calculated by the intelligent control system 4 is corrected to achieve dynamic adjustment of the optimal impact frequency.

[0039] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. An adaptive variable-diameter coal and rock borehole enlargement vibration pre-splitting and pressure relief device, characterized in that, The device includes a drill bit body (1), adjustable cutting teeth (2), a sensor cluster (3), an intelligent control system (4), an energy recovery and cooling system (5), and a telescopic impact module (6). The drill bit body (1) is used to provide an installation foundation and structural support for the adjustable cutting teeth (2) and the energy recovery and cooling system (5); The adjustable cutting teeth (2) are hinged to the drill bit body (1) and are used to dynamically change the drilling mode according to the characteristics of the rock formation; The sensor cluster (3) is fixed between the drill bit body (1) and the inner wall of the adjustable cutter teeth (2) for real-time monitoring of rock formation characteristics and drilling information, forming a data sensing network; The intelligent control system (4) is installed in the telescopic impact module (6) and is used to receive real-time data from the sensor cluster (3) and send drilling parameter instructions. The energy recovery and cooling system (5) is installed in the drill bit body (1) and the adjustable cutting teeth (2) to capture and utilize frictional heat energy during drilling. The telescopic impact module (6) is connected to the drill bit body (1) and is used to generate high-frequency vibration, which is transmitted to the rock surface through the drill bit body (1) and adjustable cutting teeth (2) to pre-crack and relieve pressure on the rock during drilling.

2. The apparatus according to claim 1, characterized in that, The drill bit body (1) includes a drill bit body (1-1), a drill bit connector (1-2), a cutter wing (1-3), main cutting teeth (1-4), memory cutting teeth (1-5), a cleaning chamber (1-6), a drilling fluid nozzle (1-7), a threaded connector (1-8), a connecting internal thread (1-9), and a chip removal and heat dissipation groove (1-10). The drill bit body (1-1) and the drill bit connector (1-2) are connected by a threaded connector (1-8) and a connecting internal thread (1-9). Multiple cutter wings (1-3) are arranged in a circumferential and equidistant manner around the drill bit body (1-1). On both sides of the outer surface of each cutter wing (1-3), there are main cutting teeth (1-4) and memory cutting teeth (1-5) arranged at intervals. A cleaning chamber (1-6) is provided between every two cutter wings (1-3), which houses the drilling fluid nozzle (1-7). The chip removal and heat dissipation groove (1-10) is located on both sides of the inner surface of the cutter wing (1-3).

3. The apparatus according to claim 2, characterized in that, The adjustable cutting teeth include a roller cone drill bit (2-1), a hinge seat (2-2), a support rod (2-3), polycrystalline diamond ball teeth (2-4), shape memory alloy ball teeth (2-5), a hinge shaft (2-6), a pin shaft (2-7), a rod (2-8), a vertical sliding sleeve (2-9), a limiting post (2-10), a telescopic diamond-shaped tie rod (2-11), and a screw rod (2-12). The rotation axis of the hinge seat (2-2) is perpendicular to the axis of the rod (2-8). The roller cone drill bit (2-1) is fixed to one end of the support rod (2-3) through the hinge seat (2-2). The roller cone drill bit (2-1) has an embedded annular spacer. The drill bit has polycrystalline diamond ball teeth (2-4) and shape memory alloy ball teeth (2-5) spaced apart; the support rod (2-3) has a hinge shaft (2-6) parallel to the axis of the rod (2-8), and the other end of the support rod (2-3) is connected to the rod (2-8) through a pin shaft (2-7); a vertical sliding sleeve (2-9) is provided on the support rod (2-3), and is fixedly connected to the support rod (2-3) through a limiting post (2-10); one end of the spiral screw (2-12) and the telescopic diamond tie rod (2-11) are fixed to the drill bit body (1-1), and the other end of the spiral screw (2-12) is hinged to the vertical sliding sleeve (2-9).

4. The apparatus according to claim 3, characterized in that, The sensor cluster includes a hardness sensor (3-1), a torque sensor (3-2), a vibration sensor (3-3), and a temperature sensor (3-4). The hardness sensor (3-1) is fixed on the hardness sensor base (3-5) and connected to the root of the roller cone drill bit (2-1), the main cutting tooth (1-4), and the memory cutting tooth (1-5). The torque sensor (3-2) is nested on the connecting shaft of the drill rod (3-9) through a torque sensor holder (3-6). The vibration sensor (3-3) is fixed to the bottom of the drill bit body (1-1). The temperature sensor (3-4) is placed inside the roller cone drill bit (2-1) and the cutter wing (1-3).

5. The apparatus according to claim 2, characterized in that, The intelligent control system includes a device cavity (4-1), a core control unit (4-2), an interface module (4-3), a power management module (4-4), a heat sink (4-5), a main chip (4-6), a memory module (4-7), a storage chip (4-8), a metal box (4-9), an input interface (4-10), an output interface (4-11), a lithium battery (4-12), and a miniature axial fan (4-13). The core control unit (4-2) integrates the main chip (4-6), the memory module (4-7), and the storage chip (4-8), and is fixed to the device cavity via the metal box (4-9). Inside 4-1); the interface module (4-3) adjacent to the core control unit (4-2) has four input interfaces (4-10) and three output interfaces (4-11) on its side. The interface module (4-3) is connected to the memory cutting tooth (1-5), the adjustable cutting tooth (2), the energy recovery and cooling system (5) and the telescopic impact module (6) respectively. The power management module (4-4) has a lithium battery (4-12) inside as a backup power source. The heat sink (4-5) is attached to the main chip (4-6), and the micro axial fan (4-13) is vertically set above the heat sink (4-5) and fixed to the metal box (4-9).

6. The apparatus according to claim 1, characterized in that, The energy recovery and cooling system (5) includes a thermoelectric power generation module (5-1), a coolant circulation channel (5-2), a micro pump (5-3), a heat dissipation structure (5-4), a storage tank (5-5), a vibration power generation module (5-6), an insulation layer (5-8), a flow sensor (5-9), a temperature probe (5-10), a one-way valve (5-11), a lithium battery energy storage unit (5-12), an interface module (5-13), and a power management module (5-14). The thermoelectric power generation module (5-1) is attached to the outer wall of the cutting area of ​​the drill bit body (1) and connected to the lithium battery energy storage unit (5-12). The inlet end of the coolant circulation channel (5-2) is connected to the storage tank (5-5), and the outlet end leads to the drill bit. The main body (1) and the adjustable cutting teeth (2) have internal cooling chambers, and the coolant circulation channel (5-2) is wrapped with an insulation layer (5-8); the micro pump body (5-3) is adjacent to the storage tank (5-5); the heat dissipation structure (5-4) is set on the outer wall of the storage tank (5-5); the vibration power generation module (5-6) is embedded in the connecting section of the drill rod (3-9) and connected to the lithium battery energy storage unit (5-12); a flow sensor (5-9) and a temperature probe (5-10) are installed in the coolant circulation channel (5-2); a one-way valve (5-11) is installed on the pipeline between the storage tank (5-5) and the micro pump body (5-3); the lithium battery energy storage unit (5-12) is connected to the power management module (5-14).

7. The apparatus according to claim 1, characterized in that, The telescopic impact module (6) includes a drive module (6-1), an impact hammer (6-2), an elastic reset device (6-3), a frequency adjustment unit (6-4), a control board (6-5), a pressure sensor (6-6), a buffer pad (6-7), a guide sleeve (6-8), a connecting flange (6-9), and a protective cover (6-10). The drive module (6-1) is embedded in the axial position inside the drill bit body (1) and is connected to the output interface of the core control unit (4-2) through a cable connector. The front end of the impact hammer (6-2) is rigidly connected to the root of the drill bit body (1). The drive module (6-1) is connected to the rear end; the elastic reset device (6-3) is sleeved on the outside of the impact hammer body (6-2); the frequency adjustment unit (6-4) is integrated on the control board (6-5); the pressure sensor (6-6) is placed between the impact hammer body (6-2) and the drive module (6-1); the buffer pad (6-7) is set at the contact part between the impact hammer body (6-2) and the guide sleeve (6-8); the guide sleeve (6-8) is fixed to the inner wall of the drill bit body through the connecting flange (6-9); the protective cover (6-10) covers the outside of the drive module (6-1).

8. An adaptive variable-diameter coal and rock borehole enlargement vibration pre-fracturing and pressure relief method, characterized in that, The method is implemented using the device described in any one of claims 1-7, comprising: S1. Installing, debugging and starting the drill bit body (1), adjustable cutting teeth (2), sensor cluster (3), intelligent control system (4), energy recovery and cooling system (5) and telescopic impact module of the device according to prior requirements, and performing drilling operations according to the preset process; S2. During the drilling operation, monitor and record the operating parameters of the corresponding components in the device in real time until the drilling task is completed; S3. Calculate the overall hardness of the rock mass and the cutting force of the cutting tool based on the recorded operating parameters.

9. The method according to claim 8, characterized in that, The calculation process for dynamic monitoring of the overall hardness of rock mass includes: S311. Based on the real-time hardness measurement value obtained by the hardness sensor (3-1) of the sensor cluster (3), the intelligent control system (4) calculates the temperature change rate by monitoring the temperature of the cutting teeth based on the temperature sensor (3-4), the torque sensor (3-2) collects the torque signal in real time and records the standard deviation of torque fluctuation, the intelligent control system (4) adaptively adjusts the weight according to the formation type, and calculates the real-time comprehensive hardness index based on the hardness measurement value, temperature change rate and weight: S312. The vibration sensor (3-3) collects data in real time and transmits it to the intelligent control system (4). The system iteratively calculates the real-time crack length, records the vibration amplitude and vibration frequency of the impact module (6) design parameters, and the rock mass density and elastic modulus at the work site. The dynamic stress intensity factor at the crack tip is then derived. S313. Intelligent control system (4) Inverts the real-time comprehensive hardness index to obtain the initial fracture length of the rock mass, and calibrates the maximum fracture length when the rock mass is completely broken according to historical data, thereby obtaining the degree of fracture development. S314. The frequency adjustment unit (6-4) of the device receives the degree of fracture development, and dynamically adjusts the output parameters of the drive module (6-1) in combination with the rated working parameters of the telescopic impact module (6) and the preset frequency adjustment coefficient, so as to achieve the adaptation of the impact frequency to the current state of formation fracture development.

10. The method according to claim 9, characterized in that, in, The calculation for adaptive adjustment of the cutting teeth includes the following steps: S321. Record the maximum theoretical deformation δ of the shape memory alloy for the shape memory cutting teeth (1-5). max Phase transition rate constant Phase transition initiation temperature The temperature sensor (3-4) works in conjunction with the energy recovery and cooling system (5) to monitor and regulate the real-time temperature T of the corresponding shape memory alloy, and the axial stress is indirectly calculated by the torque sensor (3-2). Then, the deformation δ of the memory cutting teeth (1-5) controlled by temperature and stress is... S322. Based on the contact area S between the cutting edge and the rock mass, and the internal friction angle of the rock mass... Cohesion Rock mass compatibility coefficient Then the formula for calculating the cutting force F is: ， in, Hc represents the degree of crack development, and Hc represents the real-time comprehensive hardness index.

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