Stepless variable-diameter drill bit for engineering pile foundation hole forming and adjusting method of stepless variable-diameter drill bit

Abstract

The invention discloses a stepless variable-diameter drill bit for engineering pile foundation pore forming and an adjusting method thereof.The variable-diameter drill bit comprises a main shaft, a trepanning drill bit, a connecting piece, four sets of variable-diameter reaming assemblies, a positioning assembly and a wall protecting ring, the trepanning drill bit is arranged at the bottom of the main shaft and used for trepanning drilling, and the connecting piece is arranged at the bottom of the main shaft; the four sets of variable-diameter reaming assemblies are evenly arranged on the main shaft through the connecting pieces and used for stepless reducing of formed holes, the positioning assembly is arranged on the main shaft and used for positioning the variable-diameter reaming assemblies, and the wall protecting rings are arranged on the variable-diameter reaming assemblies and used for protecting hole walls. In engineering pile foundation hole-forming drilling construction, through mutual cooperation of the connecting piece, the variable-diameter reaming assembly, the positioning assembly and the wall protecting ring, drilling of formed holes with different pile diameters by the same drill bit is achieved.

Description

Technical Field

[0001] The invention relates to a stepless diameter-variable drill bit for drilling holes in engineering pile foundations and an adjustment method thereof. Background Art

[0002] In the current pile foundation hole construction, the construction party often configures different diameter hole drill bits for construction according to different design pile diameter requirements. However, due to the different bearing capacity requirements of buildings, the corresponding pile diameter range is also relatively wide. This puts high demands on the construction party, and it must pre-configure drill bits of many diameter models. The drill bits used for drilling holes are not only bulky in structure and have a long production cycle, but also require welding of a large number of expensive carbide blades. This will greatly increase the construction party's inventory costs and reduce its operating efficiency. There are very few related technical countermeasures available. Similar technologies include pile bottom expansion drilling technology. This method uses an ordinary drill bit to drill into the bearing layer, then replaces the bottom expansion drill bit, and then uses a hydraulic cylinder to support the expansion blade of the drill bit, so that it rotates and cuts the stratum to expand the bottom diameter of the hole. After reaching the bottom expansion diameter required by the design, concrete is poured into the pile to form a concrete expansion head and improve the bearing capacity of the pile end. The main defects of this method are:

[0003] 1. This method only changes the diameter of part of the bottom of the original hole. If the technology is applied to the entire hole, it is very easy to cause the hole wall to collapse, which will cause a high risk of construction accidents.

[0004] 2. This method requires the assistance of a hydraulic transmission system to complete the hole expansion process, which is relatively costly. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] The technical problem to be solved by the present invention is how to achieve the problem of drilling holes with different pile diameters with the same drill bit in the construction of pile foundation holes.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a stepless variable diameter drill bit for drilling holes in engineering pile foundations, which includes a main shaft, a hole-opening drill bit, a connecting piece, four groups of variable diameter hole-expanding components, a positioning component and a wall protection ring. The hole-opening drill bit is arranged at the bottom of the main shaft for drilling holes, the four groups of variable diameter hole-expanding components are evenly arranged on the main shaft through the connecting piece for stepless diameter change in hole-forming, the positioning component is arranged on the main shaft for positioning the variable diameter hole-expanding component, and the wall protection ring is arranged on the variable diameter hole-expanding component for protecting the hole wall.

[0008] As a preferred solution of the stepless variable diameter drill bit for drilling engineering pile foundations described in the present invention, the connecting part includes a first fixed block, a second fixed block and a moving block, the first fixed block is arranged at the bottom of the main shaft, the second fixed block is arranged at the middle of the main shaft, and the moving block is arranged at the upper part of the main shaft, which plays the role of connecting the main shaft and the variable diameter hole expansion assembly.

[0009] As a preferred solution of the stepless variable diameter drill bit for drilling engineering pile foundations described in the present invention, the variable diameter reaming assembly includes a reaming tool holder, a first blade, a wall guard frame, a second blade, a rocker and a connecting rod, the reaming tool holder is arranged on the first fixed block, the first blade is arranged on the reaming tool holder, the wall guard frame is arranged on the reaming tool holder, the second blade is arranged at the bottom of the wall guard frame, the wall guard frame is connected to the second fixed block through the rocker, the main shaft, the first fixed block, the second fixed block, the reaming tool holder, the wall guard frame and the rocker constitute a parallelogram mechanism, one end of the connecting rod is arranged on the moving block, and the other end of the connecting rod is connected to the connecting end between the reaming tool holder and the wall guard frame to achieve adjustment of the outer diameter of the drill bit.

[0010] As a preferred solution of the stepless variable diameter drill bit for drilling engineering pile foundations described in the present invention, the positioning assembly includes a long sleeve, a short sleeve and an adjustment ring, the long sleeve is arranged between the first fixed block and the second fixed block, the short sleeve is arranged between the second fixed block and the moving block, and the adjustment ring is arranged between the short sleeve and the moving block, so as to position the first fixed block, the second fixed block and the moving block during installation.

[0011] As a preferred solution of the stepless variable diameter drill bit for drilling holes in engineering pile foundations described in the present invention, a screw sleeve is provided between the main shaft and the moving block to fix the moving block.

[0012] As a preferred solution of the stepless variable diameter drill bit for drilling holes in engineering pile foundations described in the present invention, a top nut is provided on the top of the threaded sleeve to prevent it from falling off.

[0013] As a preferred solution of the stepless variable diameter drill bit for drilling engineering pile foundations described in the present invention, a shock absorbing sleeve is provided between the main shaft and the first fixed block and the second fixed block to weaken the vibration and impact from the end of the drill bit.

[0014] As a preferred solution of the stepless variable diameter drill bit for drilling engineering pile foundations described in the present invention, the wall protection ring is evenly provided with wall protection ribs corresponding to the wall protection frame to stir and dilute the sediment returned from the bottom of the hole to prevent the upper drilled hole wall from being damaged and collapsed, the wall protection ribs are provided with countersunk holes, and the wall protection frame is provided with threaded holes matching the countersunk holes, so that the screw heads are retracted into the countersunk holes to prevent the screws from scratching the hole walls.

[0015] A method for adjusting a stepless diameter drill bit, comprising the stepless diameter drill bit for drilling holes in engineering pile foundations, comprises the following specific steps:

[0016] Step 1: Install the hole drill bit on the lower end of the spindle;

[0017] Step 2: Install the first fixed block and the second fixed block at the bottom and the middle of the main shaft in sequence, and position the first fixed block and the second fixed block with a long sleeve;

[0018] Step 3: Install the parallelogram mechanism in any set of the variable diameter hole expansion components, then install the combination of the moving block and the connecting rod, and connect the connecting rod to the parallelogram mechanism. Use a tape measure to measure and calculate the axial distance between the wall guard and the main shaft, and adjust the position of the wall guard until the distance is the drilling radius required by this construction design;

[0019] Step 4: After determining the position of the lower wall guard, install the combination of the moving block and the connecting rod, and record the axial position of the moving block on the spindle at this time, and measure the distance between the upper side of the second fixed block and the lower side of the moving block. This distance is the sum of the heights of the short sleeve and the required adjustment ring;

[0020] Step 5: Remove the moving block from the connecting rod and take it out from the main shaft, configure the short sleeve and the adjusting ring according to the calculation results, and then install the short sleeve and the adjusting ring in sequence;

[0021] Step 6: Put the moving block onto the spindle again and combine it with the connecting rod. At this time, the rotary diameter of the drill bit has been limited to the design value;

[0022] Step 7: Complete the installation of the remaining three sets of reducing and expanding components;

[0023] Step 8: Configure the wall protection ring according to the rotation diameter of the wall protection frame, and fix it to the wall protection frame with screws;

[0024] Step 9: Install the top nuts to complete the overall installation;

[0025] Step 10: Connect the main shaft to the drill rod and start drilling.

[0026] The beneficial effects of the present invention are:

[0027] 1. In the construction of pile foundation drilling, the connector, diameter-changing hole-expanding assembly, positioning assembly and wall protection ring cooperate with each other to achieve the same drill bit drilling holes of different pile diameters;

[0028] 2. The present invention realizes the multi-purpose use of one drill. Drilling construction can be carried out according to the requirements of different hole diameters. There is no need to replace the drill bit, but only to adjust the drill bit, which greatly reduces the inventory cost;

[0029] 3. Compared with conventional reaming drills, the present invention avoids the collapse of the hole wall and does not require additional reaming drill bits and hydraulic auxiliary devices, further reducing the construction cost;

[0030] 4. The overall structure of the present invention is simple and easy to manufacture. The main shaft and the original drilling rod are connected by threads, which is easy to assemble and disassemble. When used for drilling construction of different pile diameters, only different wall protection rings and adjustment rings need to be configured, and the applicability is wide. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0032] Figure 1 It is a schematic diagram of the overall structure of a stepless variable diameter drill bit used for drilling holes in engineering pile foundations.

[0033] Figure 2 The present invention is a schematic diagram of the position structure of the main shaft, connecting parts, diameter-changing hole-expanding components and positioning components of a stepless variable diameter drill bit used for drilling holes in engineering pile foundations.

[0034] Figure 3 It is a partial cross-sectional view of a steplessly variable diameter drill bit used for drilling holes in engineering pile foundations.

[0035] Figure 4 The schematic diagram is a structural diagram of a parallelogram mechanism in a variable diameter hole expansion assembly of a stepless variable diameter drill bit used for drilling holes in engineering pile foundations.

[0036] Figure 5 It is a stepless diameter drill bit used for drilling holes in engineering pile foundations. Figure 3 Enlarged view of point A in the middle.

[0037] In the figure: 1. spindle; 2. hole-opening drill bit; 3. connecting piece; 31. first fixed block; 32. second fixed block; 33. moving block; 4. variable diameter reaming assembly; 41. reaming tool holder; 42. first blade; 43. wall guard; 44. second blade; 45. rocker; 46. connecting rod; 5. positioning assembly; 51. long sleeve; 52. short sleeve; 53. adjusting ring; 6. wall guard ring; 7. screw sleeve; 8. top nut; 9. shock absorbing sleeve; 10. wall guard rib; 11. countersunk hole; 12. threaded hole. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0041] Example 1

[0042] Reference Figures 1 to 5 , is the first embodiment of the present invention, which provides a stepless variable diameter drill bit for drilling engineering pile foundations, which includes a main shaft 1, a hole-opening drill bit 2, a connecting piece 3, four sets of variable diameter hole-expanding components 4, a positioning component 5 and a wall protection ring 6. The hole-opening drill bit 2 is arranged at the bottom of the main shaft 1 for drilling holes, the four sets of variable diameter hole-expanding components 4 are evenly arranged on the main shaft 1 through the connecting piece 3, and are used for stepless diameter change in hole-forming, the positioning component 5 is arranged on the main shaft 1, and is used for positioning the variable diameter hole-expanding component 4, and the wall protection ring 6 is arranged on the variable diameter hole-expanding component 4 for protecting the hole wall.

[0043] The main shaft 1 is made of seamless steel pipe and is stepped. It not only serves as the installation base of the variable diameter drill bit, but also serves as the power input end of the variable diameter drill bit. An internal thread matching the thread of the drill rod to be drilled is arranged at the top of the upper end of the main shaft 1, so as to connect the main shaft 1 and the drill rod together to transmit power. An ordinary external thread is processed at the shaft body position of the upper section of the main shaft 1 for the purpose of assembling and positioning the parts on the shaft. A hole-opening drill bit 2 is welded at the bottom of the main shaft 1, and the weld is on the inner side of the hole-opening drill bit 2. Hole drilling can be performed through the hole-opening drill bit 2. A boss is formed between the hole-opening drill bit 2 and the main shaft 1 to facilitate the installation of the variable diameter hole expansion component 4. A connecting piece 3 is installed on the main shaft 1, and four groups of variable diameter hole expansion components 4 are evenly arranged on the connecting piece 3. In this embodiment, the variable diameter is changed by these four groups of variable diameter hole expansion components 4. The diameter of the drill bit can be changed steplessly, and the adjustment range of the variable diameter drill bit can be improved. A positioning component 5 is also installed on the main shaft 1. The positioning component 5 can be used to position the variable diameter expansion component 4 when installing and adjusting it. A wall protection ring 6 is installed on the periphery of the variable diameter expansion component 4. As the hole-making end of the variable diameter drill bit, the wall protection ring 6 is a hollow cylindrical shape as a whole, and is made of plate winding and welding, so as to play a certain protective role on the hole wall during the drilling process and avoid the collapse of the hole wall during the drilling process. It should be noted that based on the cumulative error factor, the wall protection ring 6 should be made on-site as much as possible. In the construction of engineering pile foundation drilling, the connector 3, the variable diameter expansion component 4, the positioning component 5 and the wall protection ring 6 cooperate with each other to realize the drilling of holes of different pile diameters by the same drill bit.

[0044] Specifically, the connecting member 3 includes a first fixed block 31 , a second fixed block 32 and a moving block 33 . The first fixed block 31 is arranged at the bottom of the main shaft 1 , the second fixed block 32 is arranged at the middle of the main shaft 1 , and the moving block 33 is arranged at the upper part of the main shaft 1 .

[0045] The connecting member 3 in this embodiment is mainly composed of a first fixed block 31, a second fixed block 32 and a moving block 33. The first fixed block 31 is installed at the bottom of the main shaft 1. When installing, the first fixed block 31 can be inserted from the top of the main shaft 1 and moved to the bottom of the main shaft 1. The first fixed block 31 is positioned by the boss formed between the hole drill 2 and the main shaft 1. The second fixed block 32 is installed in the middle of the main shaft 1. The second fixed block 32 cooperates with the first fixed block 31 to play a fixed support role. A moving block 33 is installed on the part to form a moving pair. It should be noted that the first fixed block 31, the second fixed block 32 and the moving block 33 in this embodiment are all rectangular structures as a whole, and four hinge supports are evenly arranged on the first fixed block 31, the second fixed block 32 and the moving block 33 at 90° intervals, so that the main shaft 1 and the variable diameter reaming assembly 4 can be connected through the first fixed block 31, the second fixed block 32 and the moving block 33, so that the variable diameter reaming assembly 4 can better adjust the outer diameter of the variable diameter drill bit.

[0046] Specifically, the variable diameter reaming assembly 4 includes a reaming tool holder 41, a first blade 42, a wall guard frame 43, a second blade 44, a rocker 45 and a connecting rod 46. The reaming tool holder 41 is arranged on the first fixed block 31, the first blade 42 is arranged on the reaming tool holder 41, the wall guard frame 43 is arranged on the reaming tool holder 41, the second blade 44 is arranged at the bottom of the wall guard frame 43, the wall guard frame 43 is connected to the second fixed block 32 through the rocker 45, the spindle 1, the first fixed block 31, the second fixed block 32, the reaming tool holder 41, the wall guard frame 43 and the rocker 45 constitute a parallelogram mechanism, one end of the connecting rod 46 is arranged on the moving block 33, and the other end of the connecting rod 46 is connected to the connecting end between the reaming tool holder 41 and the wall guard frame 43.

[0047] The variable diameter reaming assembly 4 in this embodiment is mainly composed of a reaming tool holder 41, a first blade 42, a wall guard frame 43, a second blade 44, a rocker 45 and a connecting rod 46. The reaming tool holder 41 is hinged on a hinge support of the first fixed block 31, and the first blade 42 is welded on the reaming tool holder 41. The wall guard frame 43 is hinged on the end of the reaming tool holder 41 away from the first fixed block 31. The second blade 44 is welded on the bottom of the wall guard frame 43. The second blade 44 cooperates with the first blade 42 to realize drilling holes of different pile diameters. The first blade 42 and the second blade 44 are both carbide blades. The wall guard frame 43 is hinged on the end away from the reaming tool holder 41. The other end of the rocker 45 is hinged to the corresponding hinge support on the second fixed block 32, so that the spindle 1, the first fixed block 31, the second fixed block 32, the reaming tool holder 41 are hinged. , the wall guard frame 43 and the rocker 45 form a parallelogram mechanism, so that the wall guard frame 43 can be telescopically adjusted left and right, thereby realizing the adjustment of the outer diameter of the drill bit, and the wall guard frame 43 is parallel to the main shaft 1, and both are in a vertical state, and the parallelogram mechanism can also ensure that the wall guard frame 43 always remains in a vertical state during the drilling process, and a connecting rod 46 is hinged on the hinge support on the moving block 33, and the end of the connecting rod 46 away from the moving block 33 is hinged to the connecting end between the reaming tool holder 41 and the wall guard frame 43, that is, a composite hinge connection is formed, so that the parallelogram mechanism can be locked after the outer diameter adjustment of the variable diameter drill bit is completed. It should be noted that in other embodiments, the parallelogram mechanism (wall guard frame 43, reaming tool holder 41, rocker 45, main shaft 1) and the length of the connecting rod 46 can also be changed to obtain aperture adjustment ranges of different magnitudes.

[0048] Specifically, the positioning assembly 5 includes a long sleeve 51, a short sleeve 52 and an adjusting ring 53. The long sleeve 51 is arranged between the first fixed block 31 and the second fixed block 32, the short sleeve 52 is arranged between the second fixed block 32 and the moving block 33, and the adjusting ring 53 is arranged between the short sleeve 52 and the moving block 33.

[0049] The positioning assembly 5 in this embodiment is mainly composed of a long sleeve 51, a short sleeve 52 and an adjusting ring 53. The long sleeve 51 is sleeved between the first fixed block 31 and the second fixed block 32. After the positioning and installation of the first fixed block 31 is completed, the long sleeve 51 is inserted into the main shaft 1, and then the second fixed block 32 is inserted into the main shaft 1 to achieve the positioning of the second fixed block 32. After the positioning is completed, the first fixed block 31, the second fixed block 32 and the long sleeve 51 can be welded together by welding, and the weld is on the outside of the long sleeve 51 to achieve the installation and fixation of the first fixed block 31 and the second fixed block 32. After the diameter change is completed, After the reaming assembly 4 is adjusted, a short sleeve 52 is inserted between the second fixed block 32 and the movable block 33 to facilitate axial positioning of the second fixed block 32 and the movable block 33, and an adjusting ring 53 is then inserted between the short sleeve 52 and the movable block 33, which can not only cooperate with the short sleeve 52 to achieve coordinated positioning, but also facilitate adjustment of the diameter of the variable diameter drill bit. It should be noted that in order to improve the adjustment accuracy of the variable diameter drill bit, in other embodiments, the adjusting ring 53 can also be composed of a plurality of adjusting rings 53 of different heights, and based on the cumulative error factor, the adjusting ring 53 should be assembled on site as much as possible.

[0050] Furthermore, a threaded sleeve 7 is provided between the main shaft 1 and the moving block 33 .

[0051] After completing the adjustment of the variable diameter reaming assembly 4 and re-installing the moving block 33 on the main shaft 1, there is a certain gap between the moving block 33 and the main shaft 1. In this embodiment, a screw sleeve 7 is installed on the main shaft 1, and the screw sleeve 7 contains internal and external threads. The internal thread on the screw sleeve 7 can form a threaded connection with the external thread on the main shaft 1, and a threaded hole 12 matching the external thread of the screw sleeve 7 is provided on the inner side of the moving block 33, so that the screw sleeve 7 can be nested in the internal threaded hole 12 of the moving block 33. During installation, the screw sleeve 7 is screwed between the main shaft 1 and the moving block 33, and ensures that the end face of the screw sleeve 7 fits with the end face of the moving block 33, thereby fixing the moving block 33.

[0052] Furthermore, a top nut 8 is provided on the top of the threaded sleeve 7 .

[0053] After the installation of the screw sleeve 7 is completed, in this embodiment, a top nut 8 is installed on the top of the screw sleeve 7 to prevent the screw sleeve 7 from loosening during the operation of the variable diameter drill bit, thereby playing a certain role in preventing it from falling off.

[0054] Furthermore, a shock-absorbing sleeve 9 is provided between the main shaft 1 and the first fixed block 31 and the second fixed block 32 .

[0055] During operation, since the first fixed block 31 and the second fixed block 32 are subjected to vibration and impact of the drill head, this embodiment has a certain buffering and shock-absorbing effect by installing a shock-absorbing sleeve 9 made of rubber material between the main shaft 1 and the first fixed block 31 and between the main shaft 1 and the second fixed block 32, thereby weakening the vibration and impact from the end of the drill bit.

[0056] Furthermore, the wall protection ring 6 is evenly provided with wall protection ribs 10 corresponding to the wall protection frame 43 , the wall protection ribs 10 are provided with countersunk holes 11 , and the wall protection frame 43 is provided with threaded holes 12 matching with the countersunk holes 11 .

[0057] In this embodiment, four wall protection ribs 10 corresponding to the wall protection frame 43 are evenly welded on the wall protection ring 6 at 90° intervals. When the variable diameter drill bit is working, the wall protection ribs 10 on the wall protection ring 6 can stir and dilute the sediment returning from the bottom of the hole to prevent the upper hole wall drilled from being damaged and collapsed. Furthermore, in this embodiment, two countersunk holes 11 are provided on the wall protection ribs 10, and threaded holes 12 matching the countersunk holes 11 are provided on the wall protection frame 43. When installing the wall protection ring 6, the screws are inserted into the countersunk holes 11 and screwed into the corresponding threaded holes 12 on the wall protection frame 43 to achieve a fixed connection between the wall protection ring 6 and the wall protection frame 43. The countersunk holes 11 are used to allow the screw heads to retract into the countersunk holes, thereby preventing the screws from scratching the hole walls, further avoiding damage to the upper hole walls drilled, and ensuring the smooth completion of drilling.

[0058] Example 2

[0059] Reference Figures 1 to 5 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0060] A method for adjusting a stepless diameter drill bit, including a stepless diameter drill bit for drilling holes in engineering pile foundations, comprises the following specific steps:

[0061] Step 1: Prepare the spindle 1, process the required internal and external threads, the length of the external thread should be greater than the estimated limit value, insert the inner hole of the hole drill bit 2 into the lower end of the spindle 1 for a certain distance, and weld the inner side of the hole drill bit 2 to complete the connection between the hole drill bit 2 and the spindle 1;

[0062] Step 2: Install the combination of the first fixed block 31 and the shock-absorbing sleeve 9 from the upper end of the main shaft 1 until it reaches the shoulder of the hole drill bit 2, and then install the long sleeve 51 and the combination of the second fixed block 32 and the shock-absorbing sleeve 9 in sequence, and complete the welding between the upper and lower ends of the long sleeve 51 and the first fixed block 31 and the second fixed block 32, and the weld is arranged on the outside of the long sleeve 51;

[0063] Step 3: Install the parallelogram mechanism (wall guard 43, reaming tool holder 41, rocker 45 and spindle 1) in any group of the variable diameter reaming components 4, then install the combination of the moving block 33 and the connecting rod 46, and connect the connecting rod 46 to the parallelogram mechanism, rotate the parallelogram mechanism to the estimated position, use a tape measure to measure and calculate the axial distance between the second blade 44 on the wall guard 43 and the spindle 1, and at the same time fine-tune the position of the wall guard 43 (the position of the parallelogram mechanism) until the distance is the drilling radius required by the current construction design, so as to complete the stepless adjustment of the aperture;

[0064] Step 4: After determining the position of the lower wall guard 43, that is, after confirming the hole diameter, record the axial position of the moving block 33 on the spindle 1 at this time, and measure the distance between the upper side of the second fixed block 32 and the lower side of the moving block 33. This distance is the sum of the heights of the short sleeve 52 and the adjusting ring 53 required for the hole diameter requirement;

[0065] Step 5: Remove the moving block 33 from the connecting rod 46 and take it out from the main shaft 1, configure the short sleeve 52 and the adjusting ring 53 according to the calculation result of step 4, and then install the short sleeve 52 and the adjusting ring 53 in sequence;

[0066] Step 6: Put the moving block 33 onto the main shaft 1 again, then screw the screw sleeve 7 between the main shaft 1 and the moving block 33, and hinge the moving block 33 with the connecting rod 46. At this time, the rotary diameter of the drill bit has been limited to the design value;

[0067] Step 7: Complete the installation between the remaining three sets of variable diameter hole expansion components 4 and the first fixed block 31, the second fixed block 32 and the moving block 33;

[0068] Step 8: According to the structural dimensions and the turning radius of the wall protection frame 43, the steel plate is cut and wound into a cylindrical wall protection ring 6, four wall protection ribs 10 spaced 90 degrees apart are welded on the wall protection ring 6, corresponding countersunk holes 11 are processed on the wall protection ribs 10, and the wall protection ring 6 is fixedly installed on the wall protection frame 43 with eight screws;

[0069] Step 9: Install the top nut 8 to complete the overall installation;

[0070] Step 10: Connect the spindle 1 to the drill rod and start drilling.

[0071] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A stepless diameter drill bit for drilling holes in engineering pile foundations, characterized in that: The invention comprises a main shaft (1), a hole-opening drill bit (2), a connecting piece (3), four groups of variable diameter hole-expanding components (4), a positioning component (5) and a wall protection ring (6); the hole-opening drill bit (2) is arranged at the bottom of the main shaft (1) for drilling holes; the four groups of variable diameter hole-expanding components (4) are evenly arranged on the main shaft (1) through the connecting piece (3) for stepless diameter change of holes; the positioning component (5) is arranged on the main shaft (1) for positioning the variable diameter hole-expanding components; the wall protection ring (6) is arranged on the variable diameter hole-expanding components (4) for protecting the hole wall.

2. The stepless diameter-variable drill bit for drilling holes in engineering pile foundations according to claim 1, characterized in that: The connecting member (3) comprises a first fixed block (31), a second fixed block (32) and a moving block (33); the first fixed block (31) is arranged at the bottom of the main shaft (1); the second fixed block (32) is arranged at the middle of the main shaft (1); and the moving block (33) is arranged at the upper part of the main shaft (1).

3. The stepless variable diameter drill bit for drilling holes in engineering pile foundations according to claim 2, characterized in that: The variable diameter reaming assembly (4) comprises a reaming tool holder (41), a first blade (42), a wall protection frame (43), a second blade (44), a rocker (45) and a connecting rod (46); the reaming tool holder (41) is arranged on the first fixed block (31); the first blade (42) is arranged on the reaming tool holder (41); the wall protection frame (43) is arranged on the reaming tool holder (41); the second blade (44) is arranged on the bottom of the wall protection frame (43); The wall protection frame (43) is connected to the second fixed block (32) through the rocker (45); the main shaft (1), the first fixed block (31), the second fixed block (32), the reaming tool holder (41), the wall protection frame (43) and the rocker (45) constitute a parallelogram mechanism; one end of the connecting rod (46) is arranged on the moving block (33), and the other end of the connecting rod (46) is connected to the connecting end between the reaming tool holder (41) and the wall protection frame (43).

4. The stepless diameter-variable drill bit for drilling holes in engineering pile foundations according to claim 2, characterized in that: The positioning assembly (5) comprises a long sleeve (51), a short sleeve (52) and an adjusting ring (53); the long sleeve (51) is arranged between the first fixed block (31) and the second fixed block (32); the short sleeve (52) is arranged between the second fixed block (32) and the moving block (33); and the adjusting ring (53) is arranged between the short sleeve (52) and the moving block (33).

5. The stepless diameter-variable drill bit for drilling holes in engineering pile foundations according to claim 2, characterized in that: A screw sleeve (7) is arranged between the main shaft (1) and the moving block (33).

6. The stepless diameter-variable drill bit for drilling holes in engineering pile foundations as claimed in claim 5, characterized in that: A counter nut (8) is arranged on the top of the threaded sleeve (7).

7. The stepless diameter-variable drill bit for drilling holes in engineering pile foundations according to claim 2, characterized in that: A shock absorbing sleeve (9) is provided between the main shaft (1) and the first fixed block (31) and the second fixed block (32).

8. The stepless diameter-variable drill bit for drilling holes in engineering pile foundations as claimed in claim 3, characterized in that: The wall protection ring (6) is evenly provided with wall protection ribs (10) corresponding to the wall protection frame (43), the wall protection ribs (10) are provided with countersunk holes (11), and the wall protection frame (43) is provided with threaded holes (12) matching the countersunk holes (11).

9. A method for adjusting a stepless diameter drill bit, comprising the stepless diameter drill bit for drilling a hole in an engineering pile foundation as claimed in any one of claims 1 to 8, characterized in that: The steps include: Step 1: Install a hole drill bit (2) on the lower end of the spindle (1); Step 2: Install the first fixed block (31) and the second fixed block (32) at the bottom and the middle of the main shaft (1) in sequence, and position the first fixed block (31) and the second fixed block (32) with a long sleeve (51); Step 3: First install the parallelogram mechanism in any one of the sets of variable diameter hole expansion components (4), then install the combination of the moving block (33) and the connecting rod (46), and connect the connecting rod (46) to the parallelogram mechanism, use a tape measure to measure and calculate the axial distance between the wall guard (43) and the main shaft (1), and adjust the position of the wall guard (43) until the distance is the drilling radius required by the current construction design; Step 4: After determining the position of the lower wall guard (43), record the axial position of the moving block (33) on the main shaft (1) at this time, and measure the distance between the upper side of the second fixed block (32) and the lower side of the moving block (33). This distance is the sum of the heights of the short sleeve (52) and the required adjustment ring (53); Step 5: Remove the moving block (33) from the connecting rod (46) and take it out from the main shaft (1), configure the short sleeve (52) and the adjusting ring (53) according to the calculation results, and then install the short sleeve (52) and the adjusting ring (53) in sequence; Step 6: The moving block (33) is again mounted on the main shaft (1) and combined with the connecting rod (46). At this time, the rotary diameter of the drill bit has been limited to the design value; Step 7: Complete the installation of the remaining three sets of reducing diameter and expanding hole components (4); Step 8: According to the rotation diameter of the wall protection frame (43), a wall protection ring (6) is configured and fixedly connected to the wall protection frame (43) by screws; Step 9: Install the top nut (8) to complete the overall installation; Step 10: Connect the main shaft (1) to the drill rod and start drilling.

Images