A wall-adaptive drill bit for smooth tunnel blasting

Abstract

This invention relates to the field of drill bits and discloses a wall-adhering guide drill bit for smooth tunnel blasting, comprising: a guide drill bit; a guide fitting structure; the guide drill bit is connected to the guide fitting structure via a drill bit connecting end, the guide fitting structure comprising a drill bit connecting sleeve, a drill rod connecting end, a drive shaft, a first ball bearing, a conical drive gear, a conical meshing gear, a driven shaft, a rear ring, a second ball bearing, and a drill bit connecting head. In this invention, through the guide fitting structure, the drive shaft inside the drill bit connecting sleeve is rotatably supported by the first ball bearing, and the rotational power input from the external drill rod along the axis is transmitted to the drill bit connecting head via the driven shaft and the second ball bearing through the meshing transmission of the conical drive gear and the conical meshing gear. Since the axes of the driven shaft and the drive shaft are arranged perpendicular to each other, the vertical rotation transmission of the drill rod power direction is realized, enabling the guide drill bit to adhere to the tunnel sidewall for rotary drilling.

Description

Technical Field

[0001] This invention relates to the field of drill bits, and more particularly to a wall-guided drill bit for smooth tunnel blasting. Background Technology

[0002] Smooth blasting technology is a key technology in modern underground engineering construction to control the quality of tunnel excavation, reduce over-excavation and under-excavation, and protect the stability of surrounding rock. In smooth blasting construction, the drilling accuracy and quality of the peripheral holes directly determine the smoothness of the perimeter profile after blasting. In order to obtain a smooth excavation profile, the external insertion angle of the peripheral holes should be as small as possible (usually controlled within 1°~3°), and all peripheral holes should be located on the same designed excavation profile surface as much as possible.

[0003] In existing tunnel smooth blasting construction technology, traditional drill bits usually adopt a direct-drive structure, and the power of the drill rod can only be transmitted along a single axis. It is difficult to achieve vertical turning and power conversion in the direction of drilling close to the wall. As a result, when the drill bit is drilling close to the tunnel sidewall or contour surface, it cannot maintain a stable rotational cutting posture, and the drilling trajectory is very easy to deviate from the design contour. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a wall-guided drill bit for smooth tunnel blasting, thus solving the above problems.

[0005] To achieve the above objectives, the present invention provides a wall-hugging guide drill bit for smooth tunnel blasting, comprising: a guide drill bit; a guide fitting structure; the guide drill bit is connected to the guide fitting structure via a drill bit connecting end, the guide fitting structure comprising a drill bit connecting sleeve, a drill rod connecting end, a drive shaft, a first ball bearing, a conical drive gear, a conical meshing gear, a driven shaft, a rear ring, a second ball bearing, and a drill bit connecting head; the drill rod connecting end is disposed inside one end of the drill bit connecting sleeve; the drive shaft is rotatably connected to the drill bit connecting sleeve via the first ball bearing; the end of the drive shaft near the drill rod connecting end is connected to an external drill rod; the conical drive gear is fixedly mounted on the drive shaft; the driven shaft is rotatably connected to the rear ring via the second ball bearing; the conical meshing gear is fixedly mounted on the driven shaft and engages with the conical drive gear. The drive gear transmission utilizes a transmission shaft inside the drill bit connecting sleeve, supported by a ball bearing, and transmits the rotational power input from the external drill rod along its axis to the drill bit connecting head via a driven shaft and ball bearings. Because the driven shaft and the transmission shaft are arranged perpendicularly, the power transmission of the drill rod is vertically redirected, allowing the guide drill bit to rotate and drill close to the tunnel sidewall. Simultaneously, the detachable connection between the drill bit connecting head and the drill bit shaft, along with the engaging connection between the drill bit connecting end and the drill bit connecting head, not only ensures reliable power transmission but also facilitates quick disassembly and replacement of the guide drill bit, significantly improving construction efficiency. Furthermore, the fixed connection between the rear ring and the drill bit connecting sleeve effectively enhances the rigidity and stability of the overall structure, ensuring that the guide drill bit maintains an accurate drilling trajectory during wall-hugging drilling, meeting the stringent requirements for drilling accuracy in smooth tunnel blasting.

[0006] According to one embodiment of the present invention, the drill bit connector is installed at the end of the driven shaft away from the bevel meshing gear, and the drill bit connector is detachably connected to the drill bit shaft.

[0007] According to one embodiment of the present invention, the rear ring is fixedly connected to one end of the drill bit connecting sleeve away from the drill rod connecting end, and the axis of the driven shaft is arranged perpendicular to the axis of the transmission shaft.

[0008] According to one embodiment of the present invention, the tail end of the guide drill bit is provided with a drill bit connecting end, and the drill bit connecting end is engaged with the drill bit connecting head.

[0009] According to one embodiment of the present invention, the front end of the guide drill bit is provided with a plurality of drill bit side edges, the plurality of drill bit side edges are evenly distributed along the circumference of the guide drill bit, and the cutting edge orientation of the drill bit side edges is consistent with the drilling direction of the guide drill bit.

[0010] According to one embodiment of the present invention, the front end of the guide drill bit is further provided with a side cutting groove, which is disposed between two adjacent drill bit side cutting edges.

[0011] According to one embodiment of the present invention, the guide drill bit and the drill bit connection end are provided with a drill bit shaft.

[0012] According to one embodiment of the present invention, the head of the guide drill bit is a tapered guide structure, and the drill bit shaft is arranged along the axis of the guide drill bit and fixedly connected to the guide drill bit.

[0013] According to one embodiment of the present invention, the guide fitting structure is connected to the external drill rod through the drill rod connecting end, and the rotational power of the external drill rod is transmitted to the driven shaft through the transmission shaft, the bevel transmission gear and the bevel meshing gear to drive the guide drill bit to rotate and drill along the wall.

[0014] According to one embodiment of the present invention, the drill bit side cutting edge protrudes from the outer surface of the guide drill bit. Beneficial effects

[0015] This invention provides a wall-following guide drill bit for smooth tunnel blasting. Compared with the prior art, it has the following advantages: 1. In this invention, through the designed guide fitting structure, the transmission shaft inside the drill bit connecting sleeve is rotated and supported by a ball bearing, and the rotational power input from the external drill rod along the axis is transmitted to the drill bit connecting head via the driven shaft and the second ball bearing through the meshing of the conical transmission gear and the conical meshing gear. Since the axes of the driven shaft and the transmission shaft are arranged perpendicular to each other, the vertical direction of the drill rod power transmission is realized, enabling the guide drill bit to fit against the tunnel sidewall for rotary drilling. At the same time, the detachable connection between the drill bit connecting head and the drill bit shaft and the snap-fit ​​connection between the drill bit connecting end and the drill bit connecting head not only ensures the reliability of power transmission, but also facilitates the quick disassembly and replacement of the guide drill bit, significantly improving construction efficiency. Furthermore, the fixed connection between the rear ring and the drill bit connecting sleeve effectively enhances the rigidity and stability of the overall structure, ensuring that the guide drill bit always maintains an accurate drilling trajectory during the wall-hugging drilling process, meeting the strict requirements for drilling accuracy in tunnel smooth blasting. 2. In this invention, the guide drill bit and its multiple drill bit side edges at its front end are evenly distributed around the circumference of the guide drill bit and protrude from its outer surface. This allows the cutting edges of the drill bit side edges to closely adhere to the tunnel wall and cut along the drilling direction during drilling. This forms a regular guide groove on the hole wall while drilling, effectively guiding the drilling direction and preventing drill bit deviation, significantly improving the straightness and positioning accuracy of wall-hugging drilling. At the same time, by setting side edge grooves between adjacent drill bit side edges, drill cuttings can be discharged in time, reducing drilling resistance and heat accumulation, avoiding drill jamming. The conical guide structure adopted by the guide drill bit head, together with the drill bit shaft arranged along the axis and fixedly connected to the guide drill bit, further enhances the guiding performance and structural strength of the drill bit, allowing the drill bit to smoothly enter the rock surface and withstand greater drilling pressure. Ultimately, this ensures the flatness of the hole wall and the accuracy of contour control in smooth tunnel blasting, reduces over-excavation and under-excavation, and improves blasting quality. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the front three-dimensional structure of a wall-guided drill bit for smooth tunnel blasting proposed in this invention. Figure 2 This is a schematic diagram of the rear three-dimensional structure of a wall-guided drill bit for smooth tunnel blasting proposed in this invention. Figure 3 This is a schematic diagram of the guide drill bit in a wall-mounted guide drill bit for smooth tunnel blasting proposed in this invention. Figure 4 This is a schematic diagram of the guiding and bonding structure in a wall-mounted guide drill bit for smooth tunnel blasting proposed in this invention. Figure 5 This is a cross-sectional schematic diagram of the guiding and bonding structure in a wall-mounted guide drill bit for smooth tunnel blasting proposed in this invention. Figure 6 This is a cross-sectional schematic diagram of the other side of the guiding and bonding structure in a wall-mounted guide drill bit for smooth tunnel blasting proposed in this invention.

[0017] Legend: 1. Guide drill bit; 2. Drill bit side cutting edge; 3. Guide fitting structure; 301. Drill bit connecting sleeve; 302. Drill rod connecting end; 303. Drive shaft; 304. Ball bearing one; 305. Bevel drive gear; 306. Bevel meshing gear; 307. Driven shaft; 308. Rear ring; 309. Ball bearing two; 310. Drill bit connector; 4. Drill bit connecting end; 5. Side cutting edge groove; 6. Drill bit shaft. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1-6 The present invention provides two technical solutions, specifically including the following embodiments: Example 1:

[0020] A wall-hugging guide drill bit for smooth tunnel blasting includes: a guide drill bit 1; a guide fitting structure 3; the guide drill bit 1 is connected to the guide fitting structure 3 via a drill bit connecting end 4, and the guide fitting structure 3 includes a drill bit connecting sleeve 301, a drill rod connecting end 302, a drive shaft 303, a first ball bearing 304, a bevel drive gear 305, a bevel meshing gear 306, a driven shaft 307, a rear ring 308, a second ball bearing 309, and a drill bit connecting head 310. The drill bit connecting sleeve 301... One end of the drive shaft is provided with a drill rod connection end 302. The drive shaft 303 is rotatably connected to the drill bit connection sleeve 301 through a ball bearing 304. The end of the drive shaft 303 near the drill rod connection end 302 is connected to the external drill rod. The conical drive gear 305 is fixedly installed on the drive shaft 303. The driven shaft 307 is rotatably connected to the rear ring 308 through a ball bearing 309. The conical meshing gear 306 is fixedly installed on the driven shaft 307 and meshes with the conical drive gear 305 for transmission.

[0021] During operation, the drive shaft 303 inside the drill bit connecting sleeve 301 is rotated and supported by the ball bearing 304. Through the meshing of the bevel transmission gear 305 and the bevel meshing gear 306, the rotational power input from the external drill rod along the axis is transmitted to the drill bit connecting head 310 via the driven shaft 307 and the ball bearing 309. Since the axes of the driven shaft 307 and the drive shaft 303 are arranged perpendicular to each other, the vertical direction of the drill rod power is transmitted, enabling the guide drill bit 1 to fit against the tunnel sidewall for rotary drilling. Meanwhile, the detachable connection between the drill bit connector 310 and the drill bit shaft 6, and the engaging connection between the drill bit connector end 4 and the drill bit connector 310, not only is the reliability of power transmission guaranteed, but also the quick disassembly and replacement of the guide drill bit 1 is facilitated, which significantly improves construction efficiency. Furthermore, the fixed connection between the rear ring 308 and the drill bit connector sleeve 301 effectively enhances the rigidity and stability of the overall structure, ensuring that the guide drill bit 1 always maintains an accurate drilling trajectory during wall-hugging drilling, meeting the strict requirements of tunnel smooth blasting for drilling accuracy. Example 2:

[0022] Based on Embodiment 1, the drill bit connector 310 is installed at the end of the driven shaft 307 away from the bevel meshing gear 306. The drill bit connector 310 is detachably connected to the drill shaft 6. The rear ring 308 is fixedly connected to the end of the drill bit connecting sleeve 301 away from the drill rod connecting end 302. The axis of the driven shaft 307 is arranged perpendicular to the axis of the transmission shaft 303. The tail of the guide drill bit 1 is provided with a drill bit connecting end 4, which engages with the drill bit connector 310. The front end of the guide drill bit 1 is provided with multiple drill bit side edges 2. The drill bit side cutting edges 2 are evenly distributed around the circumference of the guide drill bit 1. The cutting edge of the drill bit side cutting edge 2 faces the same direction as the drilling direction of the guide drill bit 1. The front end of the guide drill bit 1 is also provided with a side cutting edge groove 5, which is located between two adjacent drill bit side cutting edges 2. The guide drill bit 1 and the drill bit connection end 4 are provided with a drill bit shaft 6. The head of the guide drill bit 1 is a tapered guide structure. The drill bit shaft 6 is arranged along the axis of the guide drill bit 1 and is fixedly connected to the guide drill bit 1. The guide fitting structure 3 is connected to the external drill rod through the drill rod connection end 302. The rotational power of the external drill rod is transmitted through the transmission... The drive shaft 303, bevel transmission gear 305, and bevel meshing gear 306 transmit power to the driven shaft 307 to drive the guide drill bit 1 to rotate and drill along the tunnel wall. The drill bit side cutting edge 2 protrudes from the outer surface of the guide drill bit 1. Multiple drill bit side cutting edges 2 are evenly distributed circumferentially along the guide drill bit 1 and protrude from its outer surface, allowing the cutting edges of the drill bit side cutting edges 2 to closely adhere to the tunnel wall and cut along the drilling direction during drilling. This forms regular guide grooves on the hole wall while drilling, effectively guiding the drilling direction and preventing drill bit deviation, significantly improving the wall-hugging drilling performance. The straightness and positioning accuracy are ensured. Meanwhile, by setting side cutting grooves 5 between adjacent drill bit side cutting edges 2, drill cuttings can be discharged in time, drilling resistance can be reduced, heat accumulation can be reduced, and stuck drill can be avoided. The conical guiding structure adopted by the head of the guide drill bit 1, together with the drill bit shaft 6 arranged along the axis and fixedly connected to the guide drill bit 1, further enhances the guiding performance and structural strength of the drill bit, enabling the drill bit to smoothly enter the rock surface and withstand greater drilling pressure. Ultimately, this ensures the flatness of the hole wall and the contour control accuracy of the tunnel smooth blasting, reduces over-excavation and under-excavation, and improves the blasting quality.

[0023] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A wall-following guide drill bit for smooth tunnel blasting, characterized in that: include: Guide drill bit (1); Guide fitting structure (3); the guide drill bit (1) is connected to the guide fitting structure (3) through the drill bit connecting end (4). The guide fitting structure (3) includes a drill bit connecting sleeve (301), a drill rod connecting end (302), a transmission shaft (303), a ball bearing one (304), a bevel transmission gear (305), a bevel meshing gear (306), a driven shaft (307), a rear ring (308), a ball bearing two (309), and a drill bit connecting head (310). The drill rod connecting end (302) is provided inside one end of the drill bit connecting sleeve (301). The drive shaft (303) is rotatably connected to the drill bit connecting sleeve (301) via the first ball bearing (304). The end of the drive shaft (303) near the drill rod connecting end (302) is connected to the external drill rod. The conical drive gear (305) is fixedly installed on the drive shaft (303). The driven shaft (307) is rotatably connected to the rear ring (308) via the second ball bearing (309). The conical meshing gear (306) is fixedly installed on the driven shaft (307) and meshes with the conical drive gear (305) for transmission.

2. The wall-adhering guide drill bit for smooth tunnel blasting according to claim 1, characterized in that: The drill bit connector (310) is installed at one end of the driven shaft (307) away from the bevel meshing gear (306), and the drill bit connector (310) is detachably connected to the drill bit shaft (6).

3. A wall-adhering guide drill bit for smooth tunnel blasting according to claim 1, characterized in that: The rear ring (308) is fixedly connected to the end of the drill bit connecting sleeve (301) away from the drill rod connecting end (302), and the axis of the driven shaft (307) is arranged perpendicular to the axis of the transmission shaft (303).

4. A wall-adhering guide drill bit for smooth tunnel blasting according to claim 1, characterized in that: The tail of the guide drill bit (1) is provided with a drill bit connection end (4), which is engaged with the drill bit connector (310).

5. A wall-adhering guide drill bit for smooth tunnel blasting according to claim 1, characterized in that: The front end of the guide drill bit (1) is provided with a plurality of drill bit side cutting edges (2), which are evenly distributed along the circumference of the guide drill bit (1), and the cutting edge of the drill bit side cutting edge (2) is aligned with the drilling direction of the guide drill bit (1).

6. A wall-adhering guide drill bit for smooth tunnel blasting according to claim 5, characterized in that: The front end of the guide drill bit (1) is also provided with a side cutting groove (5), which is located between two adjacent drill bit side cutting edges (2).

7. A wall-adhering guide drill bit for smooth tunnel blasting according to claim 1, characterized in that: The guide drill bit (1) and the drill bit connection end (4) are provided with a drill bit shaft (6).

8. A wall-following guide drill bit for smooth tunnel blasting according to claim 7, characterized in that: The head of the guide drill bit (1) is a tapered guide structure, and the drill bit shaft (6) is arranged along the axis of the guide drill bit (1) and fixedly connected to the guide drill bit (1).

9. A wall-adhering guide drill bit for smooth tunnel blasting according to claim 1, characterized in that: The guide fitting structure (3) is connected to the external drill rod through the drill rod connection end (302). The rotational power of the external drill rod is transmitted to the driven shaft (307) through the transmission shaft (303), the conical transmission gear (305) and the conical meshing gear (306) to drive the guide drill bit (1) to rotate and drill along the wall.

10. A wall-adhering guide drill bit for smooth tunnel blasting according to claim 5, characterized in that: The drill bit side cutting edge (2) protrudes from the outer surface of the guide drill bit (1).

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