Rock breaking and easy returning type reaming drill bit

Abstract

The utility model provides a broken rock formation easy to return type reamer, which comprises a guide head, a drill bit body and a connecting cylinder, which are coaxially arranged. The guide head and the drill bit body are provided with multi-stage cutting tooth devices, wherein the guide cutting teeth at the front end of the guide head can be accurately positioned and preliminarily break rocks, the front cutting teeth at the upper end of the drill bit body are densely distributed to efficiently break rock layers, the rear cutting teeth at the lower end cut the rock fragments in the hole and the deformed hole wall during back drilling to break the jam. The drill bit body and the guide head are provided with annular slag discharge grooves on the outer sides, which form a spiral slag discharge channel in cooperation with the flushing holes on the body to improve the slag discharge efficiency. The cutting teeth are detachably connected with the tooth holes through threads, which facilitates replacement and maintenance. The coaxial integrated structure and the high-strength material design reduce the eccentric wear and prolong the service life. The utility model realizes efficient drilling and smooth back drilling in the broken rock formation, significantly improves the operation efficiency, reduces the equipment loss and has good engineering application value.

Description

Technical Field

[0001] This utility model relates to the field of mining drill bit technology, and in particular to an easy-return reaming drill bit for fractured rock strata. Background Technology

[0002] In mining, tunneling, and underground engineering construction, rock drilling is a core process. However, fractured rock formations, due to their complex structure (containing fissures, weak interlayers, cavities, or loose deposits), pose a significant challenge to the reliability and drilling efficiency of rock drilling equipment. When operating in intact rock formations, traditional rock drill bits can achieve smooth withdrawal of the drill bit after drilling thanks to the breaking capacity of the front-end cutting teeth and conventional slag removal design. However, in fractured rock formations, existing drill bits have significant shortcomings.

[0003] First, the heterogeneity of fractured rock formations makes the borehole wall prone to collapse and fracturing during drilling, resulting in a large accumulation of rock fragments in the gap between the drill bit and the borehole wall. This is especially problematic when drilling downwards at an angle, where the gravity of the rock fragments exacerbates the risk of blockage. Second, traditional drill bits only have cutting teeth at the front end, lacking the ability to break rocks behind the drill bit. When the drill bit needs to return after drilling, fallen rocks or slight borehole wall deformation caused by ground pressure can jam the drill bit, preventing it from rotating or exiting, resulting in a "stuck drill bit" phenomenon. Furthermore, the design of existing drill bits' slag discharge channels and flushing holes fails to adequately consider the high slag discharge requirements of fractured rock formations, and the flushing fluid's slag-carrying capacity is insufficient, further increasing the risk of stuck drill bits. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an easy-return reaming drill bit for breaking rock strata. Through structural optimization, it can efficiently break rocks during drilling and reliably remove obstacles in the hole during return, thereby solving the problem of stuck drill bit and extending the service life of the equipment.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A reversible reaming drill bit for breaking rock formations includes a guide head, a drill bit body, and a connecting sleeve. The guide head is connected to the upper end face of the drill bit body, and the connecting sleeve is connected to the lower end face of the drill bit body. The guide head, drill bit body, and connecting sleeve are coaxially arranged. The guide head and drill bit body are provided with cutting tooth devices.

[0007] In a preferred embodiment, the cutting tooth device includes a guide cutting tooth, a front cutting tooth, and a rear cutting tooth. The guide cutting tooth is detachably connected to the guide head, the front cutting tooth is detachably connected to the upper end face of the drill bit body, and the rear cutting tooth is detachably connected to the lower end face of the drill bit body.

[0008] In a preferred embodiment, the guide head is provided with guide tooth holes, and three guide tooth holes are provided and arranged symmetrically in a ring around the axis of the guide head. The end of the guide cutting tooth is provided with an external thread and is threadedly connected to the guide tooth hole.

[0009] In a preferred embodiment, the upper end face of the drill bit body is provided with a front cutting tooth hole. There are twelve front cutting tooth holes arranged symmetrically in a ring around the axis of the drill bit body. The end of the front cutting tooth is provided with an external thread and is threadedly connected to the front cutting tooth hole.

[0010] In a preferred embodiment, the lower end face of the drill bit body is provided with a rear cutting tooth hole. There are eight rear cutting tooth holes arranged symmetrically in a ring around the axis of the drill bit body. The end of the rear cutting tooth is provided with an external thread and is threadedly connected to the rear cutting tooth hole.

[0011] In a preferred embodiment, the drill bit body has flushing holes, which are arranged symmetrically in a ring around the axis of the drill bit body.

[0012] In a preferred embodiment, a slag discharge groove is provided on the outer side of the drill bit body and the guide head, and the slag discharge groove is arranged symmetrically in a ring around the axis of the drill bit body and the guide head.

[0013] In a preferred embodiment, the end of the connecting cylinder is provided with a connecting hole, and the connecting hole is provided with an internal thread and is threadedly connected to an external transmission shaft.

[0014] A reversible reaming drill bit for fractured rock formations, the device having the following advantages:

[0015] 1. The three guide cutting teeth distributed in a triangle at the front end of the guide head can accurately position the drilling path, reduce drilling deviation and shaking, pre-break the loose surface rock, and provide a stable support point for the front cutting teeth; the 12 annularly distributed front cutting teeth on the upper end face of the drill bit body break the rock through high-frequency impact with a large contact area, which increases the drilling speed by 20%-30% compared with the traditional single-stage cutting design, effectively dealing with heterogeneous rock formations with fractures;

[0016] 2. The eight ring-shaped back cutting teeth on the lower end face are driven by the rotation of the rock drill during re-drilling, which can efficiently cut the broken rock or slightly deformed hole wall in the hole and remove the jamming obstacles. According to engineering tests, the re-drilling success rate under inclined downward drilling conditions has increased from 60% to more than 95%, completely solving the "jammed drill bit" problem.

[0017] 3. The annular symmetrical slag discharge grooves on the outside of the guide head and drill bit body, in conjunction with the flushing holes on the drill bit body, form a spiral slag discharge channel. High-speed flushing fluid rapidly carries away the broken rock cuttings, increasing slag discharge efficiency by 40% compared to traditional straight slag discharge grooves, effectively preventing rock debris from accumulating and jamming the drill. The guide cutting teeth and front / rear cutting teeth are detachably connected to the tooth holes via external threads. Individual cutting teeth can be replaced independently after wear, reducing replacement costs by 70% and shortening downtime for maintenance.

[0018] 4. The device as a whole systematically solves the problem of stuck drill bit in rock drilling operations in fractured rock formations through a three-level functional design of "front-end crushing - mid-end guiding - rear-end obstacle clearing". It achieves a comprehensive improvement in drilling efficiency, return drilling reliability and equipment life, and has significant engineering application value and economic benefits. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a schematic diagram showing the installation position of the cutting gear device of this utility model;

[0022] Figure 3 This is a schematic diagram of the connecting cylinder and slag discharge trough of this utility model;

[0023] Figure 4 This is a schematic diagram of the connection method of the tooth-cutting device of this utility model.

[0024] In the diagram: 1. Guide head; 2. Drill bit body; 3. Connecting cylinder; 4. Guide tooth hole; 5. Guide cutting tooth; 6. Front cutting tooth hole; 7. Front cutting tooth; 8. Rear cutting tooth hole; 9. Rear cutting tooth; 10. Connecting hole; 11. Internal thread; 12. External thread; 13. Slag discharge groove; 14. Flushing hole. Detailed Implementation

[0025] like Figure 1 As shown, a reversible reaming drill bit for fractured rock formations mainly consists of a guide head 1, a drill bit body 2, and a connecting sleeve 3. The guide head 1 is mounted on the upper end face of the drill bit body 2, and its function is to provide accurate guidance for the drill bit during drilling, making the drilling direction more precise and preventing drill bit deviation. The connecting sleeve 3 is connected to the lower end face of the drill bit body 2, serving to connect the drill bit to the drive shaft of external rock drilling equipment, realizing power transmission. It is worth emphasizing that the guide head 1, drill bit body 2, and connecting sleeve 3 are strictly coaxially arranged. This design ensures that the drill bit is subjected to uniform force during drilling and reversing, effectively reducing drill bit wear and damage caused by uneven force distribution, and extending the service life of the drill bit. Simultaneously, to achieve efficient cutting of fractured rock formations, cutting tooth devices are installed on the guide head 1 and the drill bit body 2.

[0026] Preferred solutions include Figure 2 As shown, the cutting tooth device includes a guide cutting tooth 5, a front cutting tooth 7, and a rear cutting tooth 9. The guide cutting tooth 5 is detachably connected to the guide head 1. This connection method facilitates individual replacement of the guide cutting tooth 5 when it is worn or damaged, reducing operating costs. During drilling, the guide cutting tooth 5 first contacts the rock, performing preliminary crushing and guiding, laying the foundation for subsequent cutting work. The front cutting tooth 7 is also detachably connected to the upper end face of the drill bit body 2. During drilling, the front cutting tooth 7 is responsible for the main cutting work on the rock. Because it is located at the front end of the drill bit body 2, it can directly act on the rock to be crushed, improving drilling efficiency. The rear cutting tooth 9 is also detachably connected to the lower end face of the drill bit body 2. When the drill bit completes drilling and needs to return, the rear cutting tooth 9 plays an important role. It can crush rock fragments that may appear behind the borehole or obstacles caused by borehole wall deformation, ensuring that the drill bit can return smoothly, effectively solving the problem of stuck drill bit that easily occurs during the return drilling process of traditional drill bits.

[0027] Preferred solutions include Figure 2 and Figure 4 As shown, the guide head 1 has guide tooth holes 4, and three guide tooth holes 4 are arranged symmetrically in a ring around the axis of the guide head 1. This symmetrical design allows the guide cutting teeth 5 to be evenly distributed on the guide head 1 after installation, enabling uniform crushing and guiding of the rock during drilling, thus improving the accuracy and stability of the guidance. The end of the guide cutting tooth 5 is provided with an external thread 12, which is threadedly connected to the guide tooth hole 4. The threaded connection has the advantages of strong connection and easy disassembly, ensuring that the guide cutting tooth 5 will not loosen during operation, and also facilitating the replacement of the guide cutting tooth 5.

[0028] Preferred solutions include Figure 2 and Figure 4 As shown, the upper end face of the drill bit body 2 is provided with front cutting tooth holes 6. Twelve front cutting tooth holes 6 are arranged symmetrically in a ring around the axis of the drill bit body 2. The larger number of front cutting tooth holes 6 allows for the installation of more front cutting teeth 7, increasing the contact area between the drill bit and the rock, thereby improving drilling efficiency. Furthermore, the symmetrical arrangement ensures that each front cutting tooth 7 is subjected to uniform force during operation, avoiding damage caused by excessive localized force. The ends of the front cutting teeth 7 are provided with external threads 12, which are threaded into the front cutting tooth holes 6, ensuring that the front cutting teeth 7 can be firmly installed on the drill bit body 2, guaranteeing its stability when cutting rock.

[0029] Preferred solutions include Figure 2 and Figure 4As shown, the lower end face of the drill bit body 2 is provided with rear cutting tooth holes 8, and eight rear cutting tooth holes 8 are arranged symmetrically in a ring around the axis of the drill bit body 2. This arrangement allows the rear cutting teeth 9 to comprehensively break the rock behind the borehole during re-drilling, effectively removing obstacles. The end of the rear cutting teeth 9 is provided with external threads 12, which are threadedly connected to the rear cutting tooth holes 8, ensuring the stability and reliability of the rear cutting teeth 9 during operation.

[0030] Preferred solutions include Figure 2 As shown, the drill bit body 2 has flushing holes 14, which are symmetrically arranged in a ring around the axis of the drill bit body 2. During drilling, high-pressure flushing fluid (such as water or compressed air) is introduced into the flushing holes 14. The flushing fluid carries away the cuttings generated by the drill bit cutting the rock out of the borehole, thus cooling the drill bit and removing cuttings. The symmetrical arrangement allows the flushing fluid to be evenly distributed around the drill bit, improving the cuttings removal effect and preventing cuttings from accumulating in the borehole, which would affect drilling efficiency.

[0031] Preferred solutions include Figure 3 As shown, a slag discharge groove 13 is provided on the outer side of the drill bit body 2 and the guide head 1. The slag discharge groove 13 is symmetrically arranged in a ring around the axis of the drill bit body 2 and the guide head 1. The slag discharge groove 13 cooperates with the flushing hole 14. After the flushing fluid carries the debris out from the bottom of the borehole, the debris can be discharged from the borehole along the slag discharge groove 13. The symmetrical design of the slag discharge groove 13 ensures the smooth discharge of debris, further improves the slag discharge efficiency, ensures the cleanliness of the borehole, and provides a good environment for the normal operation of the drill bit.

[0032] Preferred solutions include Figure 3 As shown, the end of the connecting cylinder 3 has a connecting hole 10, and the connecting hole 10 has an internal thread 11 that is threadedly connected to the external drive shaft. This threaded connection method enables a reliable connection between the connecting cylinder 3 and the external drive shaft, ensuring that the power of the rock drilling equipment can be stably transmitted to the drill bit, allowing the drill bit to work normally. At the same time, the threaded connection facilitates disassembly and installation, making it convenient to replace and maintain the drill bit.

Claims

1. A reversible reaming drill bit for fractured rock formations, comprising a guide head (1), a drill bit body (2), and a connecting sleeve (3), characterized in that: A guide head (1) is connected to the upper end face of the drill bit body (2), and a connecting cylinder (3) is connected to the lower end face of the drill bit body (2). The guide head (1), the drill bit body (2) and the connecting cylinder (3) are coaxially arranged. Cutting tooth devices are provided on the guide head (1) and the drill bit body (2). The cutting tooth device includes a guide cutting tooth (5), a front cutting tooth (7) and a rear cutting tooth (9). The guide cutting tooth (5) is detachably connected to the guide head (1), the front cutting tooth (7) is detachably connected to the upper end face of the drill body (2), and the rear cutting tooth (9) is detachably connected to the lower end face of the drill body (2). The guide head (1) is provided with guide tooth holes (4), and three guide tooth holes (4) are provided and arranged symmetrically in a ring around the axis of the guide head (1). The end of the guide cutting tooth (5) is provided with an external thread (12) and is threadedly connected to the guide tooth hole (4). The upper end face of the drill bit body (2) is provided with a front cutting tooth hole (6). There are twelve front cutting tooth holes (6) arranged symmetrically in a ring around the axis of the drill bit body (2). The end of the front cutting tooth (7) is provided with an external thread (12) and is threadedly connected to the front cutting tooth hole (6). The lower end face of the drill bit body (2) is provided with a rear cutting tooth hole (8). There are eight rear cutting tooth holes (8) arranged symmetrically in a ring around the axis of the drill bit body (2). The end of the rear cutting tooth (9) is provided with an external thread (12) and is threadedly connected to the rear cutting tooth hole (8). The drill bit body (2) and the guide head (1) are provided with a slag discharge groove (13) on their outer sides. The slag discharge groove (13) is arranged symmetrically around the axis of the drill bit body (2) and the guide head (1).

2. The easily returnable reaming drill bit for fractured rock formations according to claim 1, characterized in that: The drill bit body (2) is provided with a flushing hole (14), which is arranged symmetrically around the axis of the drill bit body (2).

3. The easily returnable reaming drill bit for fractured rock formations according to claim 1, characterized in that: The end of the connecting cylinder (3) is provided with a connecting hole (10), and the connecting hole (10) is provided with an internal thread (11) and is threadedly connected to the external transmission shaft.

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