Stepped hole-reaming mechanism and crawler-type hole-reaming and hoisting integrated device

Abstract

This invention relates to the field of pile foundation reaming technology, and discloses a stepped reaming mechanism and a crawler-type integrated reaming and hoisting device. The stepped reaming mechanism includes a supporting column, a rotating part, a cutting part, and an abutting part. There are two rotating parts, which are connected to the supporting column in an upper and lower distributed manner. The cutting part includes a tool holder, a telescopic component, a tool seat, and a cutting edge. The tool holder is connected to the rotating part located on the lower side. The telescopic component has a fixed end connected to the tool holder and a telescopic end. One end of the tool seat is connected to the telescopic end of the telescopic component, and the other end of the tool seat is stepped. There are multiple cutting edges, which are fixed to the sidewalls of the protruding parts of the stepped end face of the tool seat. The abutting part includes a lifting component and an abutting seat. The lifting component is connected to the rotating part located on the upper side. The abutting seat is connected to the lifting component, and a stepped groove is opened on the lower end face of the abutting seat. This invention can realize continuous cutting construction of the stepped enlarged structure in one go, reducing damage to the upper formed stepped structure.

Description

Technical Field

[0001] This invention relates to the field of pile foundation hole enlargement technology, specifically a stepped hole enlargement mechanism and a crawler-type hole enlargement hoisting integrated device. Background Technology

[0002] In the foundation construction of power transmission and transformation lines, to improve the bearing capacity of the tower foundation, traditional pile foundation wells are typically designed with features such as... Figure 1 The truncated cone-shaped enlarged structure shown uses the conical surface of the truncated cone-shaped enlarged structure to increase the contact area with the soil and increase the tensile bearing capacity, thereby improving the bearing capacity of the tower foundation.

[0003] With technological advancements and increasing demands on foundation bearing capacity, the enlarged structure within pile foundation wells has evolved from a frustum-shaped enlarged structure to a stepped enlarged structure, such as... Figure 2 As shown, the stepped enlarged structure, through its multi-step design, can form multiple independent shear surfaces. When each step comes into contact with the soil, it can trigger an independent shear failure mechanism, thereby superimposing and increasing the pull-out resistance. Furthermore, the stepped enlarged structure, by dispersing the load through multiple steps, can also reduce stress concentration at the pile end and lower the risk of long-term settlement.

[0004] Although stepped enlarged structures have stronger load-bearing capacity, there is currently a lack of dedicated hole-reaming devices for such structures. Traditional hole-reaming mechanisms typically combine a horizontally extendable cutter bar with a vertical drilling drive mechanism to perform cutting and reaming operations while rotating downwards and extending horizontally. This often results in frustum-shaped enlarged structures. For example, our company's previous patent publication number CN115012827B, entitled "An Invention Patent for a Hole-Reaming Device for Pile Foundation Wells," uses a variable-diameter cutting mechanism consisting of an electric push rod and a cutter bar to perform hole-reaming operations. To achieve stepped enlarged structures, the cutting path needs to be adjusted, cutting in layers from top to bottom in a progressively larger manner. After each layer is cut, the cutter bar needs to be retracted into the pile foundation well, and then a lifting mechanism adjusts the vertical position of the cutter bar to move it to the next layer, before extending the cutter bar again for further cutting. This method requires frequent positioning checks and adjustments to the position of the cutter bar. The upper stepped structure, which has already been formed, will develop cracks or even partially collapse due to the vibration caused by the back-and-forth extension and retraction of the cutter bar, affecting its pull-out bearing capacity. At the same time, as the electric push rod drives the cutter bar to extend further, the resistance generated by the cutting of the extended part of the electric push rod will gradually increase, causing the extension rod part of the electric push rod to be subjected to excessive force and deform, resulting in a decrease in positioning accuracy and making it difficult to meet construction requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a stepped hole-expanding mechanism and a tracked hole-expanding hoisting integrated device to solve the problems of existing hole-expanding mechanisms easily damaging the upper formed stepped structure and causing deformation of the telescopic components due to excessive stress as the telescopic length increases during the cutting operation of stepped enlargement structures.

[0006] The technical solution of this invention is:

[0007] A stepped hole-reaming mechanism includes a support column, a rotating part, a cutting part, and an abutting part. The rotating part is a pair, distributed vertically on the support column. The cutting part includes a tool holder, a telescopic component, a tool base, and cutting edges. The tool holder is connected to the rotating part located on the lower side, and rotates around the support column under the drive of the rotating part. The telescopic component has a fixed end connected to the tool holder and a telescopic end with an adjustable telescopic distance. One end of the tool base is connected to the telescopic end of the telescopic component, and the other end of the tool base is stepped, with its length increasing from top to bottom. Multiple cutting edges are present, their number corresponding to the number of edges protruding from the stepped end face of the tool base. The number of parts is the same, and each of the cutting edges corresponds one-to-one with the side wall of the stepped end face protrusion of the tool holder; the abutment part includes a lifting assembly and an abutment seat. The lifting assembly is connected to the rotating part set on the upper side and rotates synchronously with the tool holder; the abutment seat is connected to the lifting assembly and is located above the tool holder. The width of the abutment seat is greater than the width of the tool holder. The lower end face of the abutment seat has a stepped groove that matches the stepped end face of the tool holder. When the hole enlargement is started, the stepped end face of the tool holder retracts into the stepped groove, and the side wall of the tool holder facing away from the cutting edge abuts against the inner wall of the stepped groove.

[0008] Preferably, as a further improvement of the present invention, the rotating part includes a rotary support base and a rotary drive disk. The rotary support base is connected to the bearing column, and the rotary drive disk is rotatably connected to the rotary support base. The rotary drive disks in the upper and lower rotating parts are fixedly connected by a connecting column. The lower end of the connecting column passes through the rotary drive disk located on the lower side and is fixedly connected to the tool holder. An annular support platform is fixedly connected to the upper end face of the rotary drive disk located on the upper side, and the lifting assembly is connected to the annular support platform.

[0009] Preferably, as a further improvement of the present invention, there are multiple connecting columns, which are evenly distributed around the supporting column.

[0010] Preferably, as a further improvement of the present invention, the abutment seat is slidably connected to the plurality of connecting posts via a sliding connector, the sliding connector comprising a plurality of connecting plates, the plurality of connecting plates being stacked vertically and slidably passing through the plurality of connecting posts, and the sidewall of the abutment seat being fixed to the plurality of connecting plates.

[0011] Preferably, as a further improvement of the present invention, there are at least two sets of the tool holder and the telescopic member, arranged longitudinally along the supporting column, each tool holder is fixed to the connecting column, and the telescopic end of each telescopic member is fixed to the tool holder.

[0012] Preferably, as a further improvement of the present invention, the abutting part further includes a plurality of abutting support components, which are arranged one by one along the stepped surface of the stepped groove. The abutting support component includes an abutting rod and a linear moving member. The abutting rod is slidably connected in the strip-shaped mounting groove, which is vertically opened on the stepped surface of the stepped groove. The bottom of the abutting rod is provided with a slot for holding the telescopic end of the telescopic member. The linear moving member is disposed in the strip-shaped mounting groove, and the output end of the linear moving member is connected to the abutting rod for driving the abutting rod to slide longitudinally along the strip-shaped mounting groove.

[0013] Preferably, as a further improvement of the present invention, the linear moving member includes an electromagnet and a limiting structure; the electromagnet is fixed on the inner top surface of the strip mounting groove, and the abutment rod is made of ferromagnetic material; the limiting structure includes a limiting rod and a limiting slide groove, the limiting slide groove is vertically opened on the side wall of the abutment rod, the limiting rod is horizontally arranged, and one end of the limiting rod is fixed to the inner wall at the opening of the strip mounting groove, and the other end of the limiting rod is slidably connected in the limiting slide groove.

[0014] Preferably, as a further improvement of the present invention, a buffer protective layer is provided on the top groove surface of the card slot.

[0015] The present invention also discloses a tracked hole-expanding hoisting integrated device, including a boom mounted on a tracked mobile body, and the aforementioned stepped hole-expanding mechanism, wherein the top of the supporting column in the stepped hole-expanding mechanism is connected to the end of the boom.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. By setting the end face of the tool holder with the cutting edge in a stepped shape, a stepped cutting process can be formed. Each cutting edge can be adjusted with the extension of the telescopic component to achieve one-time cutting of the stepped enlarged structure. There is no need to adjust the positioning back and forth in the vertical direction or control the extension and retraction of the tool holder in the horizontal direction. While realizing continuous operation of hole enlargement construction, it reduces the damage to the upper stepped structure.

[0018] 2. The abutment part can provide abutment support to the rotating tool holder during the cutting process, and distribute the reaction force generated by cutting, so as to avoid excessive force on the telescopic end of the single telescopic part, which would cause deformation and damage and affect the construction accuracy. Attached Figure Description

[0019] Figure 1 A schematic diagram of a frustum-shaped enlarged structure installed inside a pile foundation well.

[0020] Figure 2 A schematic diagram of a stepped enlarged structure installed inside a pile foundation well.

[0021] Figure 3 This is a three-dimensional structural diagram of a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0022] Figure 4 This is a three-dimensional structural diagram of the cutting part in a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of the front view of a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram showing the initial positions of multiple abutment support components in a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0025] Figure 7 This is a schematic diagram showing the positions of multiple abutment support components in the first movement stage of a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0026] Figure 8 This is a schematic diagram showing the positions of multiple abutment support components in the second movement stage of a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0027] Figure 9 This is a schematic diagram showing the positions of multiple abutment support components in the third movement stage of a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0028] Figure 10 This is a three-dimensional structural diagram of the abutment rod in a stepped hole-expanding mechanism according to an embodiment of the present invention.

[0029] Figure 11 This is a schematic front view of a tracked hole-expanding hoisting device according to an embodiment of the present invention.

[0030] Figure 12 This is a comparison diagram of the upward load displacement curves of the frustum-shaped enlarged structure and the stepped enlarged structure.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Support column; 2. Rotating part; 31. Tool holder; 32. Telescopic component; 33. Tool holder; 34. Cutting edge; 35. Scraper; 41. Lifting assembly; 411. Drive motor; 412. Lead screw; 413. Internal threaded sleeve; 42. Abutment seat; 421. Stepped groove; 5. Annular support platform; 6. Sliding connector; 71. Abutment rod; 711. Slot; 72. Strip mounting groove; 73. Electromagnet; 74. Limiting rod; 75. Limiting slide; 76. Buffer protective layer; 8. Lifting lug; 91. Centering support structure; 92. Slag removal cylinder. Detailed Implementation

[0033] The following is combined with Figures 3-12 The specific embodiments of the present invention will be described in detail below. In the description of the invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0035] Example 1

[0036] like Figures 3-5 As shown, an embodiment of the present invention provides a stepped hole-expanding mechanism, including a bearing column 1, a rotating part 2, a cutting part, and an abutting part.

[0037] Among them, there is a pair of rotating parts 2, which are connected to the support column 1 in an upper and lower distributed manner. The rotating part 2 located on the lower side serves as the power source of the cutting part to drive the cutting part to rotate and realize the circumferential cutting process.

[0038] The cutting section comprises a tool holder 31, a telescopic member 32, a tool base 33, and a cutting edge 34. The tool holder 31 serves as the support base for the cutting section and is connected to the rotating part 2 located on the lower side. The tool holder 31 rotates around the supporting column 1 under the drive of the rotating part 2. The telescopic member 32 serves as the power source for driving the tool base 33 and the cutting edge 34 to move radially along the hole wall for hole enlargement cutting. The telescopic member 32 has a fixed end connected to the tool holder 31 and a telescopic end with an adjustable telescopic distance. In specific implementation, the telescopic member 32 can be driven by any one of a hydraulic cylinder, an electric cylinder, or an electric push rod to move the tool base 33 telescopically, depending on the geological conditions. The tool base 33 serves as the carrier of the cutting edge 34 and is also an improvement of this invention. Compared with the traditional straight rod-shaped tool base, this invention sets the end face of the tool base 33 with the cutting edge 34 in a stepped shape, which facilitates one-time hole enlargement to form a stepped enlargement structure. The back end of the tool base 33 is fixedly connected to the telescopic end of the telescopic member 32. The cutting edge 34 serves as the hole-reaming cutting edge, and there are multiple cutting edges, the number of which is the same as the number of the stepped end face protrusions of the tool holder 33. Each cutting edge 34 is fixedly connected to the side wall of the stepped end face protrusion of the tool holder 33, thus forming a stepped cutting process. Each cutting edge 34 can be adjusted with the extension feed of the telescopic member 32 to achieve one-time cutting of the stepped enlarged structure. There is no need to adjust the positioning back and forth in the vertical direction or control the extension and retraction of the tool holder in the horizontal direction. This increases the continuous operation of construction while reducing the damage to the upper stepped structure.

[0039] In this process of hole reaming, considering that the tool holder 31 rotates around the support column 1 under the drive of the rotating part 2, and that the tool holder 31 drives the tool seat 33 and cutting edge 34 to move radially along the hole wall for stepped reaming cutting via the telescopic member 32, the resistance encountered is relatively large, which can easily cause reaction force to the telescopic end of the telescopic member 32, causing it to deform. Therefore, during the cutting process, the tool seat 33 is abutted and supported to bear part of the reaction force for the telescopic member 32, preventing damage to the telescopic member 32 due to excessive force. Specifically, the abutting part includes a lifting assembly 41 and an abutting seat 42. The lifting assembly 41 is connected to the rotating part 2 located on the upper side. The two rotating parts 2 rotate synchronously during operation, thereby driving the lifting assembly 41 to rotate synchronously with the tool holder 31. The abutment seat 42 serves as the contact part with the tool holder 33 and plays a supporting role during the cutting process. The abutment seat 42 is connected to the lifting assembly 41 and is located above the tool holder 33. The width of the abutment seat 42 is greater than the width of the tool holder 33. The lower end face of the abutment seat 42 is provided with a stepped groove 421 that matches the stepped end face of the tool holder 33. When the hole reaming is started, the stepped end face of the tool holder 33 retracts into the stepped groove 421, and the side wall of the tool holder 33 facing away from the cutting edge 34 abuts against the inner wall of the stepped groove 421.

[0040] During the reaming operation, the abutment seat 42 provides support for the tool holder 33, distributing the reaction force generated by cutting and preventing excessive stress on the telescopic end of the single telescopic component 32, which could cause deformation and damage. In the stepped reaming process, the lifting assembly 41 first raises the abutment seat 42 by one step height, and then the telescopic component 32 moves the tool holder 33 and cutting edge 34 horizontally by one step width. This process is repeated to achieve a stepped feed cutting process. During the rising process, the abutment seat 42 remains in contact with the tool holder 33, distributing the reaction force.

[0041] Specifically, as an optional embodiment of the rotating part 2, the rotating part 2 in this embodiment includes a rotary support base and a rotary drive disk 21. The rotary support base is connected to the bearing column 1, and the rotary drive disk 21 is rotatably connected to the rotary support base. The rotary drive disk 21 can rotate around the rotary support base. The rotary drive disks 21 in the upper and lower rotating parts 2 are fixedly connected by a connecting column 22 to maintain synchronous rotation. The lower end of the connecting column 22 passes through the rotary drive disk 21 located on the lower side and is fixedly connected to the tool holder 31. The upper end face of the rotary drive disk 21 located on the upper side is fixedly connected to an annular support platform 5, and the lifting assembly 41 is connected to the annular support platform 5.

[0042] Furthermore, as an optimization scheme of the above-mentioned rotating part 2 specific embodiment, in order to improve the connection strength and torsional strength, multiple connecting columns 22 are provided and evenly distributed around the bearing column 1. The rotating drive disk 21 and the tool holder 31 are fixed together as a whole by multiple connecting columns 22. The evenly distributed connecting columns 22 make the force more uniform when the rotating drive disk 21 drives the tool holder 31 to rotate.

[0043] Specifically, such as Figure 3 As shown, in order to improve the connection strength of the abutment seat 42 and the knife holder 31 during the synchronous rotation of the abutment seat 42 and the knife holder 31 through the rotation of the lifting assembly 41 following the rotation of the rotary drive disk 21, so that the abutment seat 42 can withstand the abutment reaction force, the abutment seat 42 is slidably connected to multiple connecting columns 22 through the sliding connector 6. The sliding connector 6 includes several connecting plates, which are stacked on top of each other and slidably pass through the multiple connecting columns 22. The side wall of the abutment seat 42 is fixed to the several connecting plates. The presence of the several connecting plates can not only drive the abutment seat 42 to rotate synchronously during the rotation of the multiple connecting columns 22, but also move along the longitudinal direction of the multiple connecting columns 22 under the drive of the lifting assembly 41.

[0044] Specifically, as an optional implementation of the lifting component 41, such as Figure 3As shown, the lifting assembly 41 in this embodiment includes a drive motor 411, a lead screw 412, and an internally threaded sleeve 413. The drive motor 411 is mounted and fixed on the top of the annular support platform 5. The internally threaded sleeve 413 is fixed to the side walls of several connecting plates. One end of the lead screw 412 is connected to the drive motor 411, and the other end of the lead screw 412 passes through the annular support platform 5 and is threadedly connected to the internally threaded sleeve 413. When the lifting assembly 41 drives the abutment seat 42 to rise and fall, the drive motor 411 drives the lead screw 412 to rotate. During the rotation of the lead screw 412, the rotational motion is converted into linear motion through cooperation with the internally threaded sleeve 413, thereby driving several connecting plates to move longitudinally along several connecting columns 22. During the movement of several connecting plates, the abutment seat 42 is simultaneously driven to rise and fall.

[0045] Furthermore, in other embodiments of the present invention, such as Figure 3 and Figure 4 As shown, there are at least two sets of tool holders 31 and telescopic members 32, arranged along the longitudinal direction of the bearing column 1. Each tool holder 31 is fixed to the connecting column 22, and the telescopic end of each telescopic member 32 is fixed to the tool holder 33. By increasing the number of tool holders 31 and telescopic members 32, the connection strength with the tool holder 33 can be improved, and the deformation of the telescopic end of the telescopic member 32 due to force concentration can be reduced.

[0046] Considering that as the horizontal distance of the tool holder 33 extends, the abutment force provided by the abutment seat 42 to the tool holder 33 gradually decreases due to its gradual rise, the abutment part has been improved and optimized in order to achieve compensatory support. In this embodiment, the abutment part also includes multiple abutment support components, which are set one by one along the stepped surface of the stepped groove 421.

[0047] Among them, such as Figure 6 and Figure 10 As shown, the abutment support assembly includes an abutment rod 71 and a linear moving member. The abutment rod 71 is slidably connected in the strip mounting groove 72, which is vertically opened on the stepped surface of the stepped groove 421. The bottom of the abutment rod 71 is provided with a slot 711 for holding the telescopic end of the telescopic member 32. The linear moving member is disposed in the strip mounting groove 72, and the output end of the linear moving member is connected to the abutment rod 71 to drive the abutment rod 71 to slide longitudinally along the strip mounting groove 72.

[0048] Reference Figure 6 and Figure 7As shown, whenever the lifting assembly 41 raises the abutment seat 42 by one step height, the telescopic component 32 correspondingly moves the tool holder 33 and the cutting edge 34 horizontally to the left by one step width. During the rising process, the linear moving component moves the abutment rod 71 to retract into the strip mounting groove 72. When the tool holder 33 moves to the left by one step width, the abutment rod 71 located on the far right is no longer obstructed by the top of the tool holder 33. At this time, the linear moving component moves the abutment rod 71 out of the strip mounting groove 72 and inserts it into the telescopic end of the telescopic component 32 using the slot 711. This provides abutment support to the telescopic end of the telescopic component 32, preventing it from extending too much and lacking support when it drives the tool holder 33 to extend for rotary cutting, thus preventing excessive stress and deformation. The opening shape of the slot 711 is adapted to the telescopic end of the telescopic component 32. For example, when the telescopic component 32 uses a hydraulic cylinder, refer to... Figure 10 As shown, the shape of the top groove surface of the slot 711 matches the shape of the piston rod of the hydraulic cylinder, adopting a U-shape; as Figure 8 As shown, as the telescopic member 32 drives the tool holder 33 and the cutting edge 34 to move continuously to the left, more of the strip mounting groove 72 on the right side, which is not folded by the tool holder 33, is exposed. Therefore, the abutment rods 71 ​​in the multiple abutment support assemblies extend under the drive of the linear moving member to abut and support the telescopic end of the telescopic member 32, dispersing the reaction force transmitted by cutting. As the extension distance of the telescopic end of the telescopic member 32 increases, the number of abutment rods 71 ​​also increases, thereby ensuring the abutment strength and reducing the deformation of the telescopic end of the telescopic member 32.

[0049] Specifically, such as Figures 6-9 As shown, as an optional embodiment of the linear motion component, the linear motion component in this embodiment includes an electromagnet 73 and a limiting structure. The electromagnet 73 is fixed to the inner top surface of the strip mounting groove 72. The abutment rod 71 is made of ferromagnetic material. The limiting structure includes a limiting rod 74 and a limiting groove 75. The limiting groove 75 is vertically opened on the side wall of the abutment rod 71. The limiting rod 74 is horizontally set, and one end of the limiting rod 74 is fixed to the inner wall at the opening of the strip mounting groove 72. The other end of the limiting rod 74 is slidably connected in the limiting groove 75.

[0050] In this embodiment, the lifting assembly 41 serves as the power source for the linear moving component. When the lifting assembly 41 raises the abutment seat 42 by one step height, the telescopic component 32 correspondingly moves the tool holder 33 and the cutting edge 34 horizontally to the left by one step width. During the ascent, the electromagnet 73 attracts the abutment rod 71, which is made of ferromagnetic material, to avoid interfering with the movement. Each time the telescopic component 32 moves the tool holder 33 and the cutting edge 34 horizontally to the left by a preset step width, the electromagnets 73 are de-energized sequentially from right to left. The de-energization signal of the electromagnets 73 is controlled according to the telescopic step distance of the telescopic component 32, and they no longer attract the abutment rod 71. This ensures that after the tool holder 33 moves to the left by one step width, an area is created below the abutment rods 71 ​​arranged sequentially from right to left, preventing them from being obstructed by the top of the tool holder 33. Under the influence of gravity and guided by the strip mounting groove 72, the abutment rod 71 inserts into the telescopic end of the telescopic component 32 for abutment support. Figures 6-8 As shown, the number of abutment rods 71 ​​increases with the extension distance of the telescopic end of the telescopic member 32. When the cutting is completed and the tool holder 33 needs to retract, refer to... Figure 9 As shown, the lifting assembly 41 drives the tool holder 33 to move upward. Due to the presence of the limiting rod 74, the abutment rod 71 will be lifted through the limiting slide groove 75, so that each abutment rod 71 will disengage from the telescopic end of the telescopic member 32, thereby facilitating the telescopic member 32 to retract the tool holder 33.

[0051] Furthermore, in order to reduce the impact force generated when the abutment rod 71 falls onto the telescopic end of the telescopic member 32 under the action of gravity, a buffer protective layer 76 is provided on the top groove surface of the slot 711. The buffer protective layer 76 is made of silicone or rubber to achieve flexible buffering.

[0052] Below, taking a 100mm pull-out condition as an example, the pull-out bearing capacity of the stepped enlarged structure implemented in this invention and the traditional frustum-shaped enlarged structure are simulated and compared. The simulation process uses the characteristics of a single soil layer, considering the effects of soil elasticity and plasticity, large deformation, and initial ground stress, and employs the Mohr-Coulomb model for simulation. The simulation results are shown in Table 1 and... Figure 12 As shown.

[0053] Table 1 Comparison of Uplift Bearing Capacity between Frustum-shaped Enlarged Structure and Stepped Enlarged Structure

[0054]

[0055] As can be seen from the above, under the condition of upward pull of 100mm, compared with the traditional frustum-shaped enlargement structure, the stepped enlargement head realized by the present invention can improve the pull-out bearing capacity by 6.76%~10.18%, effectively improving the bearing capacity of the tower foundation.

[0056] Example 2

[0057] Based on Embodiment 1, the present invention, as follows: Figure 11 As shown, a tracked hole-reaming and hoisting integrated device is disclosed, including a boom mounted on a tracked mobile body, and the aforementioned stepped hole-reaming mechanism, which is located at the end of the boom.

[0058] Specifically, a lifting lug 8 is fixed to the top of the supporting column 1, and the lifting lug 8 is connected to the hook at the end of the boom.

[0059] The interior of the bearing column 1 is equipped with a cavity and a height adjustment mechanism as required. The height adjustment mechanism can be a screw lifting mechanism. The screw lifting mechanism is connected to the rotary support seats in the two rotating parts 2 through a moving seat. The overall position of the stepped hole-expanding mechanism can be adjusted through the screw lifting mechanism to move it to the required hole-expanding position.

[0060] The bearing column 1 is equipped with a centering support structure 91, which includes three sets of telescopic support arms arranged at a 120° angle to each other. During the hole enlargement operation, the bearing column 1 is placed into the drilled pile hole by means of the boom. By controlling the synchronous extension and retraction of the three sets of telescopic support arms to abut against the pile hole wall, the bearing column 1 is fixed in the pile hole, which facilitates the hole enlargement operation using the stepped hole enlargement mechanism.

[0061] In order to collect the soil and debris generated during the borehole enlargement process, a slag collection cylinder 92 is fixed at the bottom of the bearing column 1, and a scraper 35 is fixed at the bottom of the side wall of the cutter holder 33 on the side where the cutting edge 34 is located. Before enlarging the borehole, a reserved collection space is extended below the borehole enlargement position of the pile foundation well by drilling equipment. During the borehole enlargement, the slag collection cylinder 92 can be moved below the borehole enlargement position, and then the borehole is enlarged by cutting. The scraper 35 rotates with the cutting, and the soil and debris generated during the borehole enlargement is pushed into the slag collection cylinder 92 for collection through the guide surface on the scraper 35. After the borehole enlargement is completed, the bearing column 1 and the slag collection cylinder 92 are pulled out of the pile foundation well, and then the reserved collection space is filled and leveled.

[0062] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A stepped hole-expanding mechanism, characterized in that, include: Load-bearing columns; The rotating part has a pair, which are connected to the supporting column in an up-down distributed manner; The cutting part includes: a tool holder connected to the rotating part disposed on the lower side, the tool holder rotating around the supporting column under the drive of the rotating part; a telescopic member having a fixed end connected to the tool holder and a telescopic end with an adjustable telescopic distance; a tool holder having one end connected to the telescopic end of the telescopic member, the other end of the tool holder being stepped, with the length increasing sequentially from top to bottom; and multiple cutting edges, the number of which is the same as the number of the stepped end face protrusions of the tool holder, each cutting edge being fixedly connected to the side wall of the stepped end face protrusion of the tool holder. The abutment part includes: a lifting assembly connected to the rotating part disposed on the upper side, which rotates synchronously with the tool holder; and an abutment seat connected to the lifting assembly and located above the tool holder. The width of the abutment seat is greater than the width of the tool holder. The lower end face of the abutment seat is provided with a stepped groove that matches the stepped end face of the tool holder. When the hole enlargement is started, the stepped end face of the tool holder retracts into the stepped groove, and the side wall of the tool holder facing away from the cutting edge abuts against the inner wall of the stepped groove.

2. The stepped hole-expanding mechanism according to claim 1, characterized in that, The rotating part includes a rotary support base and a rotary drive disk. The rotary support base is connected to the bearing column, and the rotary drive disk is rotatably connected to the rotary support base. The rotary drive disks in the upper and lower rotating parts are fixedly connected by a connecting column. The lower end of the connecting column passes through the rotary drive disk located on the lower side and is fixedly connected to the tool holder. An annular support platform is fixedly connected to the upper end face of the rotary drive disk located on the upper side, and the lifting assembly is connected to the annular support platform.

3. The stepped hole-expanding mechanism according to claim 2, characterized in that, There are multiple connecting columns, which are evenly distributed around the supporting column.

4. The stepped hole-expanding mechanism according to claim 3, characterized in that, The abutment seat is slidably connected to multiple connecting posts via a sliding connector. The sliding connector includes several connecting plates, which are stacked vertically and slidably pass through the multiple connecting posts. The sidewall of the abutment seat is fixed to the several connecting plates.

5. The stepped hole-expanding mechanism according to claim 2, characterized in that, There are at least two sets of the tool holder and telescopic component, arranged longitudinally along the supporting column. Each tool holder is fixed to the connecting column, and the telescopic end of each telescopic component is fixed to the tool holder.

6. The stepped hole-expanding mechanism according to claim 1, characterized in that, The abutting portion further includes multiple abutting support components, which are arranged sequentially along the stepped surface of the stepped groove. Each abutting support component includes: The abutment rod is slidably connected in the strip-shaped mounting groove, which is vertically opened on the stepped surface of the stepped groove. The bottom of the abutment rod is provided with a slot for holding the telescopic end of the telescopic component. A linear moving component is disposed in a strip-shaped mounting groove. The output end of the linear moving component is connected to the abutment rod and is used to drive the abutment rod to slide longitudinally along the strip-shaped mounting groove.

7. The stepped hole-reaming mechanism according to claim 6, characterized in that, The linear motion component includes: An electromagnet is fixed on the inner top surface of the strip mounting groove, and the abutment rod is made of ferromagnetic material; The limiting structure includes a limiting rod and a limiting groove. The limiting groove is vertically opened on the side wall of the abutment rod. The limiting rod is horizontally set, and one end of the limiting rod is fixed to the inner wall of the slot of the strip mounting groove. The other end of the limiting rod is slidably connected in the limiting groove.

8. The stepped hole-expanding mechanism according to claim 7, characterized in that, A buffer protective layer is provided on the top groove surface of the card slot.

9. A tracked hoisting and lifting integrated device for expanding boreholes, comprising a boom mounted on a tracked mobile body, characterized in that, It also includes a stepped hole-expanding mechanism as described in any one of claims 1 to 8, wherein the top of the supporting column in the stepped hole-expanding mechanism is connected to the end of the boom.

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