A low-clearance pile driver drill bit suitable for use under hard rock formations

Abstract

The present invention discloses a low-headroom pile driver drill bit suitable for use under hard rock formations, belonging to the technical field of cast-in-place pile construction. The present invention comprises: a main shaft detachably mounted on a drill rod of a drilling rig, a drill bit mounted on the main shaft away from the end of the drill rod, an annular support plate mounted on the main shaft and arranged around the main shaft, a plurality of inclined rods mounted on the support plate rotatably around the main shaft axis, a plurality of drill teeth mounted side by side on the inclined rods, a threaded section provided on the main shaft, a threaded sleeve threadedly connected to the threaded section, a support sleeve rotatably mounted on one side of the threaded sleeve, a limiting slide groove provided on the threaded section, the support sleeve limitedly slidingly mounted in the limiting slide groove, a peripheral wall of the support sleeve circumferentially provided with a plurality of mounting grooves around the support sleeve axis, a mounting block rotatably mounted in the mounting groove, the inclined rod extending into the mounting groove and limitedly slidingly connected to the mounting block. The present invention can adjust the angle between the inclined rod and the horizontal plane so that the drill teeth on the inclined rod can drill holes at different inclination angles to adapt to hard rock formations of different hardness.

Description

Technical Field

[0001] The invention belongs to the technical field of cast-in-place pile construction, and particularly relates to a low-clearance pile driver drill bit suitable for use under hard rock strata. Background Art

[0002] During the construction of deep foundation pits for super high-rise buildings, due to factors such as design and construction conditions, many bored piles are constructed under low clearance conditions. Most pile foundation working spaces are 6m or less, and the complex geological conditions add many difficulties to the construction.

[0003] Due to low-headroom restrictions, the rotary drilling rigs currently available on the market do not meet operational requirements. Low-headroom drilling rigs have a minimum height of 8m, leaving significant room for modification to achieve a 6m operating height, making modification difficult. Current rotary drilling rigs on the market have a body height of 6.8m. By comparison, these rigs can be modified to meet low-headroom requirements and are currently used in some construction projects. However, these modifications have resulted in the reduction of some components that affect the rig's height, resulting in low drilling efficiency, especially in hard rock formations.

[0004] An existing Chinese patent with authorization publication number CN 217632270 U discloses a drilling tool that enables simultaneous cutting, drilling, and mixing of piles by the front drill bit and the alloy cutter head on the inclined rod, ensuring a secure connection between the drill rod and the drill bit. This allows for rapid drilling and mixing operations in low-headroom drilling rig areas with height restrictions and restricted surrounding environments, thereby improving the efficiency of cast-in-place pile construction and foundation reinforcement in low-headroom areas. However, the above technology cannot adjust the angle between the inclined rod and the horizontal plane, resulting in a limited scope of application.

[0005] Therefore, it is necessary to propose a low clearance pile driver drill bit suitable for use under hard rock formations to solve the above problems. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a low-clearance pile driver drill bit suitable for use under hard rock formations, so as to solve the problem in the prior art that the angle between the inclined rod and the horizontal plane cannot be adjusted, resulting in a low range of applicability.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a low-headroom pile driver drill bit suitable for use in hard rock formations, comprising: a main shaft detachably mounted on a drill rod of the drilling rig, the main shaft being equipped with a drill bit away from an end of the drill rod, an annular support plate arranged around the main shaft being mounted on the support plate, a plurality of inclined rods being rotatably mounted around the main shaft axis, a plurality of drill teeth being mounted side by side on the inclined rods, a threaded section being provided on the main shaft, a threaded sleeve being threadedly connected to the threaded section, a support sleeve being rotatably mounted on one side of the threaded sleeve, a limiting slide being provided on the threaded section, the support sleeve being limitedly slidably mounted in the limiting slide groove, a peripheral wall of the support sleeve being circumferentially equipped with a plurality of mounting grooves around the support sleeve axis, a mounting block being rotatably mounted in the mounting groove, and the inclined rod extending into the mounting groove and being limitedly slidably connected to the mounting block.

[0009] Furthermore, a plurality of sliding grooves are provided on the outer peripheral wall of the support plate with the axis of the support plate as the center, and a slider is slidably installed in the sliding groove, and the slider is rotatably connected to the oblique rod. An annular groove located between the plurality of sliding grooves is provided on the support plate, and a screw is threadedly connected to the slider, and the screw is rotatably installed on the support plate. Rotating the screw can make the slider slide along the sliding groove, and the screw extends away from the slider end to the annular groove where a gear is fixedly installed, and a ring gear meshing with the gear is rotatably installed in the annular groove, and rotating the ring gear can drive the gear to rotate to rotate the screw.

[0010] Furthermore, the annular groove is provided with a smooth portion and a threaded portion, the annular gear is rotatably installed in the smooth portion, an annular plate is threadedly connected to the threaded portion, a gap is provided between the annular plate and the annular gear, a plurality of through holes are circumferentially provided on the annular plate with the axis of the annular plate as the center, a plurality of insertion rods corresponding to the through holes are fixedly installed on the annular gear, the insertion rods extend into the through holes and are slidably connected, and rotating the annular plate can drive the annular gear to rotate through the insertion rods.

[0011] Furthermore, an arc-shaped plate is detachably mounted on one end of the sliding block extending out of the sliding groove.

[0012] Furthermore, the slider is provided with a threaded hole that cooperates with the screw rod, and the slider is provided with a limiting cavity that is connected to the threaded hole. The diameter of the limiting cavity is larger than the diameter of the threaded hole, and a limiting block is installed at the end of the screw rod extending to the limiting cavity.

[0013] Furthermore, the number of the diagonal bars is at least 4.

[0014] The beneficial effects of the present invention are:

[0015] The present invention can adjust the angle between the inclined rod and the horizontal plane so that the drill teeth on the inclined rod can drill holes at different inclination angles, and the inclined rod can extend into the installation groove, thereby ensuring the integrity of the inclined rod. When the angle between the inclined rod and the horizontal plane is small, the contact surface between the inclined rod and the rock formation in the hole is small, which is suitable for hard rock formations with relatively high hardness. When the angle between the inclined rod and the horizontal plane is large, the contact surface between the inclined rod and the rock formation in the hole is large, which is suitable for hard rock formations with relatively low hardness. At the same time, the support plate supports the inner wall of the hole during the drilling process. By arranging the threaded sleeve, it is convenient to adjust the angle of the inclined rod. By arranging the support sleeve, the rotating threaded sleeve can adjust the inclination angles of multiple inclined rods at the same time.

[0016] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration:

[0018] Figure 1 Schematic diagram of the overall structure of an embodiment of the present invention;

[0019] Figure 2 For the embodiment of the present invention Figure 1 A magnified view of the middle section A;

[0020] Figure 3 is a cross-sectional view of an embodiment of the present invention;

[0021] Figure 4 For the embodiment of the present invention Figure 3 Enlarged view of part B in the middle.

[0022] The markings in the accompanying drawings are as follows: main shaft 1, threaded section 101, limiting slide groove 102, drill rod 2, drill bit 3, support plate 4, slide groove 401, slider 402, annular groove 403, screw 404, gear 405, ring gear 406, smooth part 407, threaded part 408, annular plate 409, through hole 410, insertion rod 411, threaded hole 412, limiting cavity 413, limiting block 414, inclined rod 5, drill tooth 501, threaded sleeve 6, support sleeve 7, mounting groove 701, mounting block 8, arc plate 9. DETAILED DESCRIPTION

[0023] like Figures 1 to 4As shown, the present invention provides a low-headroom pile driver drill bit suitable for hard rock formations, comprising: a main shaft 1, the main shaft 1 being detachably mounted on a drill rod 2 of a drilling rig, a drill bit 3 being mounted on the main shaft 1 away from the end of the drill rod 2, an annular support plate 4 arranged around the main shaft 1 is mounted on the main shaft 1, a plurality of inclined rods 5 are rotatably mounted on the support plate 4 with the axis of the main shaft 1 as the center, a plurality of drill teeth 501 are mounted side by side on the inclined rods 5, a threaded section 101 is provided on the main shaft 1, a threaded sleeve 6 is threadedly connected to the threaded section 101, a support sleeve 7 is rotatably mounted on one end of the threaded sleeve 6, a limiting slide groove 102 is provided on the threaded section 101, the support sleeve 7 is limitedly slidably mounted in the limiting slide groove 102, a plurality of mounting grooves 701 are circumferentially provided on the peripheral wall of the support sleeve 7 with the axis of the support sleeve 7 as the center, a mounting block 8 is rotatably mounted in the mounting groove 701, and the inclined rod 5 extends into the mounting groove 701 and is limitedly slidably connected to the mounting block 8.

[0024] In this program, if Figure 1 In order to adapt to the hardness of the hard rock formation, the threaded sleeve 6 is rotated to drive the support sleeve 7 to slide along the extension direction of the limiting slide groove 102. When the support sleeve 7 slides in the direction away from the drill bit 3, the inclined rod 5 is driven to rotate in the direction away from the drill bit 3 and can slide on the mounting block 8 in the direction extending into the mounting groove 701. Figure 2 , to reduce the angle between the inclined rod 5 and the horizontal plane; when the support sleeve 7 slides in the direction close to the drill bit 3, it drives the inclined rod 5 to rotate in the direction close to the drill bit 3 and can slide on the mounting block 8 in the direction extending outside the mounting groove 701 to increase the angle between the inclined rod 5 and the horizontal plane.

[0025] Through the design of the above structure, the angle between the inclined rod 5 and the horizontal plane can be adjusted so that the drill teeth 501 on the inclined rod 5 can drill holes at different inclination angles, and the inclined rod 5 can extend into the mounting groove 701, thereby ensuring the integrity of the inclined rod 5. When the angle between the inclined rod 5 and the horizontal plane is small, the contact surface between the inclined rod 5 and the rock formation in the hole is small, which is suitable for hard rock formations with relatively high hardness. When the angle between the inclined rod 5 and the horizontal plane is large, the contact surface between the inclined rod 5 and the rock formation in the hole is large, which is suitable for hard rock formations with relatively low hardness. At the same time, the support plate 4 supports the inner wall of the hole during the drilling process. By arranging the threaded sleeve 6, it is convenient to adjust the angle of the inclined rod 5. By arranging the support sleeve 7, the rotating threaded sleeve 6 can adjust the inclination angles of multiple inclined rods 5 at the same time.

[0026] In one embodiment of the present invention, a plurality of sliding grooves 401 are circumferentially provided on the outer peripheral wall of the support plate 4 with the axis of the support plate 4 as the center, a slider 402 is slidably installed in the sliding groove 401, and the slider 402 is rotatably connected to the inclined rod 5, and the support plate 4 is provided with an annular groove 403 connected to the sliding groove 401, and a screw 404 is threadedly connected to the slider 402, and the screw 404 extends away from the end of the slider 402 to the annular groove 403 where a gear 405 is fixedly installed, and the screw 404 is rotatably installed on the support plate 4, and a ring gear 406 meshing with the gear 405 is rotatably installed in the annular groove 403. Rotating the ring gear 406 can drive the gear 405 to rotate so that the slider 402 slides along the sliding groove 401.

[0027] In this program, if Figure 3 By setting a sliding block 402 and an inclined rod 5 in rotational connection, when the sliding block 402 slides along the slide groove 401, it can drive the inclined rod 5 to rotate, so that the inclined rod 5 and the end of the sliding block 402 move away from the axis of the main shaft 1, thereby expanding the drilling range of multiple inclined rods 5 to adapt to drilling holes of different sizes.

[0028] This solution increases the scope of application by setting the movement of the slider 402 to drive the movement of the inclined rod 5 to adapt to drilling holes of different sizes, and the slider 402 slides by rotating the screw 404, ensuring the stability of the sliding of the slider 402; by setting the gear 405 to engage with the ring gear 406, the ring gear 406 can drive multiple gears 405 to rotate synchronously, so that multiple sliders 402 slide synchronously, ensuring the synchronization of the extension of multiple inclined rods 5, that is, ensuring the roundness of the drilled holes, and saving manpower.

[0029] In one embodiment of the present invention, the annular groove 403 is provided with a smooth portion 407 and a threaded portion 408, the ring gear 406 is rotatably installed in the smooth portion 407, the threaded portion 408 is threadedly connected to an annular plate 409, a gap is provided between the annular plate 409 and the ring gear 406, a plurality of through holes 410 are circumferentially provided on the annular plate 409 with the axis of the annular plate 409 as the center, a plurality of insertion rods 411 corresponding to the through holes 410 are fixedly installed on the ring gear 406, the insertion rods 411 extend into the through holes 410 for sliding connection, and rotating the annular plate 409 can drive the ring gear 406 to rotate through the insertion rods 411.

[0030] In this program, if Figure 4When the annular plate 409 is rotated, the annular gear 406 is driven to rotate through the insertion rod 411, and the annular plate 409 moves along the axial direction of the threaded portion 408 to approach or move away from the annular gear 406 when rotating. By setting the threaded portion 408, the annular plate 409 is easy to lock after rotation, so that after the slider 402 slides to the preset position, the slider 402 is more stable through the locking of the annular plate 409.

[0031] In one embodiment of the present invention, an arc-shaped plate 9 is installed at one end of the slider 402 extending out of the slide groove 401 .

[0032] In this solution, after drilling, multiple curved plates 9 support the hole wall. The curved plates 9 increase the contact area with the hole wall and ensure the stability of the support of the hole wall by the curved plates 9.

[0033] In one embodiment of the present invention, a threaded hole 412 cooperating with the screw rod 404 is provided on the slider 402, and a limiting cavity 413 connected to the threaded hole 412 is provided in the slider 402. The diameter of the limiting cavity 413 is larger than the diameter of the threaded hole 412, and the screw rod 404 extends to the end of the limiting cavity 413 to install a limiting block 414.

[0034] In this solution, by providing a limit block 414 , when the screw rod 404 rotates to drive the slider 402 to slide, the limit block 414 is used to limit the slider 402 to prevent the slider 402 from sliding off the screw rod 404 .

[0035] In one embodiment of the present invention, the number of the inclined rods 5 is at least four.

[0036] In this solution, four inclined rods 5 are provided, which saves costs while ensuring drilling efficiency.

[0037] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A low clearance pile driver drill bit suitable for use under hard rock formations, characterized in that: include: The cam is provided with a plurality of guide wheels, and the guide wheels are connected with a plurality of guide wheels respectively. On the plate, rotating the screw can make the slider slide along the slide groove, and the screw extends away from the slider end to the annular groove where a gear is fixedly installed, and a ring gear meshing with the gear is rotatably installed in the annular groove, and rotating the ring gear can drive the gear to rotate so that the screw rotates; the annular groove is provided with a smooth portion and a threaded portion, and the ring gear is rotatably installed in the smooth portion, and an annular plate is threadedly connected in the threaded portion, and a gap is provided between the annular plate and the annular gear, and the annular plate is circumferentially provided with a plurality of through holes centered on the axis of the annular plate, and a plurality of plug rods corresponding to the through holes are fixedly installed on the ring gear, and the plug rods extend into the through holes for sliding connection, and rotating the annular plate can drive the ring gear to rotate through the plug rods; an arc plate is detachably installed on one end of the slider extending out of the slide groove; a threaded hole cooperating with the screw is provided on the slider, and a limiting cavity connected to the threaded hole is provided in the slider, and the diameter of the limiting cavity is larger than the diameter of the threaded hole, and a limiting block is installed at the end of the screw extending to the limiting cavity 2. The low clearance pile driver drill bit suitable for use under hard rock formations according to claim 1, characterized in that: The number of the diagonal bars is at least 4.

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