A drill bit exchange-free rotary drilling rig

Abstract

The application discloses a drill bit replacement-free rotary drilling rig, which comprises a rotary drilling rig body and an expansion assembly, wherein the expansion assembly comprises a connecting arm, a cutter block and an elastic member; the cutter block is hinged to one end of the connecting arm away from the rotary drilling rig body; two limiting portions are formed on the connecting arm and used to limit the maximum position of the rotation of the cutter block around the hinged end; and the elastic member promotes the cutter block to keep in the position abutting against the first limiting portion. The technical scheme can effectively avoid the damage of the cutter block due to the direct rigid impact on pebbles, effectively reduce the torque pressure of the joint position of the connecting arm and the rotary drilling rig body, effectively prolong the service life of the expansion assembly, and does not need to replace the drill bit additionally. The expansion assembly is suitable for the existing rotary drilling rig body, does not need to redesign the rotary drilling rig body, can greatly improve the operation efficiency and reduce the operation cost, and has a simple overall structure and is easy to realize, so that the problems of the breakage in the operation process or the replacement due to the rigid impact damage can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rotary drilling, in particular to a rotary drilling without changing drill bit. BACKGROUND

[0002] During the deep hole digging operation of the rotary drilling machine, a rotary drill bit with a larger diameter is usually used to dig a foundation pit for installing a steel casing, and then a rotary drill bit with a relatively smaller diameter is used to dig a hole after the steel casing is installed. This makes it necessary to prepare a rotary drill bit with a size matching the steel casing and to change the drill bit during construction, which makes it difficult to optimize the construction cost and construction period, and puts a lot of pressure on the operators. Therefore, the technical personnel in this field have gradually begun to develop a rotary drilling without changing drill bit.

[0003] Referring to the patent application with the application number "201910840658": "An expanded bottom rotary drill bit capable of accommodating a casing", which comprises a cylinder, a connecting square is arranged on the top surface, an automatic slag removal structure is arranged inside, and a detachable cutting disc is arranged at the bottom; the automatic slag removal structure is arranged along the axial direction of the cylinder, the upper end is fixedly connected with the top surface of the cylinder, and the lower end is provided with a plurality of telescopic structures; the telescopic structure extends along the radial direction of the cylinder, one end is fixedly connected with the automatic slag removal structure, and the other end is provided with a support structure for expanding the bottom, a slot corresponding to the position of the support structure and matching in size is formed in the side wall of the cylinder, and the support structure is driven by the telescopic structure to protrude out of or retract into the cylinder; a drill bottom opening and closing structure for detaching the cutting disc is further arranged on the telescopic structure, and the drill bottom opening and closing structure is detachably connected with the cutting disc.

[0004] Obviously, by arranging the expandable bottom structure outwardly in the rotary drill, the problem of digging a foundation pit for installing a steel casing without changing the drill bit can be solved, but in actual application, the steel casing is usually 2 to 4 meters deep into the ground and 30 centimeters above the ground, 2 to 4 meters is a shallow soil layer, compared with the case where there are many large rocks in the deep soil layer, the soil in the shallow soil layer is relatively loose, but there are a large number of pebbles, the hardness is not high, but the resistance in the soil layer is large, if the cutting head continuously impacts the pebbles, the cutting head may be broken or damaged. And the design of the expandable bottom structure requires the entire rotary drill to be redesigned, which cannot be used with the existing rotary drill, and it is difficult to maintain and repair after the cutting head is broken, at the same time, since the expandable bottom structure is different from the entire cylindrical rotary drill body, it is a single rod structure, and the torque is large when it is resisted by the soil layer, especially when it is resisted by the pebbles, there is a risk of rod breakage, so there is still room for improvement to solve the above technical problems. SUMMARY

[0005] In view of the above problems existing in the prior art, the present application provides a rotary drilling without changing drill bit, which can overcome at least one of the above technical defects.

[0006] The specific technical solutions are as follows:

[0007] The drill bit replacement-free rotary drilling rig comprises a rotary drilling rig body, at least one detachable extension assembly mounted on the outer edge of the upper end of the rotary drilling rig body, and the extension assembly is used for synchronously excavating a foundation pit for installing a steel casing in the working state of the rotary drilling rig body; the extension assembly comprises:

[0008] A connecting arm is provided with an assembly structure at one end, and is detachably radially assembled on the outer edge of the upper end of the rotary drilling rig body; the front and back sides of the connecting arm are respectively protruded to form a first limiting part and a second limiting part;

[0009] A cutter block is hingedly connected to the other end of the connecting arm, and the front end of the cutter block is provided with a cutter head; the first limiting part and the second limiting part limit the maximum positions of the cutter block rotating in two directions around the hinged end;

[0010] An elastic member is connected to the rear part of the cutter block and the assembly structure or the connecting arm at both ends, and is used for providing a pushing force to the cutter block when rotating to abut against the first limiting part;

[0011] In the working state, when the cutter head of the front end of the cutter block is blocked by touching pebbles in the soil layer, the cutter block can rotate to the direction of the second limiting part, and the working state of the cutter block on the pebbles is changed from cutting to pushing, and the cutter block is pushed back to the position abutting against the first limiting part by the elastic member after the pebbles are loosened.

[0012] Preferably, a mounting groove is transversely formed in the middle part of the cutter block, the end of the connecting arm away from the rotary drilling rig body extends into the mounting groove and is hingedly connected to the cutter block; the first limiting part and the second limiting part are both semicircular protrusions formed on the front and back sides of the connecting arm, and the cutter block is limited to rotate around the hinged end to the maximum position by abutting against the first limiting part and the second limiting part on the inward side of the cutter block.

[0013] Preferably, a screw hole passing through the mounting groove is formed in the cutter block, and a longitudinal through hole is formed in the connecting arm in a corresponding manner; the cutter block is hingedly connected to the connecting arm by a screw rod passing through the screw hole and the longitudinal through hole at the same time.

[0014] Preferably, the included angle between the cutter block and the connecting arm is limited to 120 degrees to 150 degrees by the first limiting part and the second limiting part.

[0015] Preferably, the elastic member is a compression spring, and the compression spring is always in a compressed state.

[0016] Preferably, the assembly structure comprises two oppositely arranged first arc-shaped plates and second arc-shaped plates, and the radii of the first arc-shaped plates and the second arc-shaped plates are consistent with the radius of the outer wall of the rotary drilling rig body.

[0017] One end of the connecting arm and one end of the compression spring are connected to the side of the second arc-shaped plate away from the first arc-shaped plate, and the side of the first arc-shaped plate facing the second arc-shaped plate has a first connecting block, the first connecting block has a receiving groove formed in it, and the side of the second arc-shaped plate facing the first arc-shaped plate has a second connecting block matching the shape of the receiving groove;

[0018] The upper edge of the outer wall of the rotary drilling body has a slot matching the shape of the first connecting block, and the bottom surface of the slot, the first connecting block, and the second connecting block each have a threaded hole, and the first connecting block and the second connecting block are assembled in the slot by a stud, and the first arc-shaped plate and the second arc-shaped plate jointly clamp the outer wall of the rotary drilling body.

[0019] Preferably, one end of the connecting arm is welded to the second arc-shaped plate.

[0020] Preferably, the two ends of the compression spring are welded to the sides of the second arc-shaped plate and the cutter block facing each other.

[0021] Preferably, the two ends of the compression spring are welded to the cutter block and the connecting arm, the connecting arm has at least two mounting through holes formed longitudinally to form an assembly structure, and the upper edge of the outer wall of the rotary drilling body has an equal number of mounting screw holes corresponding to the positions of the mounting through holes, so that the connecting arm can be screwed to the rotary drilling body by fasteners.

[0022] The technical scheme has the advantages that:

[0023] The drill-bit-free rotary drilling machine includes a rotary drilling body and an expansion assembly, and the expansion assembly includes a connecting arm, a cutter block, and an elastic member, the cutter block is hingedly connected to one end of the connecting arm away from the rotary drilling body, the connecting arm has two limiting portions for limiting the maximum position of the rotation of the cutter block about the hinged end, and the elastic member keeps the cutter block in the position abutting against the first limiting portion. This can effectively prevent the cutter block from being damaged by directly and rigidly impacting pebbles, effectively reduce the torque pressure at the position where the connecting arm connects with the rotary drilling body, effectively improve the service life of the expansion assembly, and enable the expansion assembly to dig a foundation pit for placing a steel casing during the entire working state of the rotary drilling machine without the need to replace the drill bit. The expansion assembly is suitable for existing rotary drilling bodies without the need to redesign the rotary drilling body, and can achieve the technical purpose of drill-bit-free by simply mounting the expansion assembly on the rotary drilling body, greatly improving the work efficiency and reducing the work cost. The overall structure of the expansion assembly is simple and easy to implement, has a long service life, and can avoid the problems of breakage or damage due to rigid impact during work, thereby eliminating the need for rework and replacement. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FIG. 1 is a perspective view of the drill-bit-free rotary drilling machine of the present application;

[0025] Figure 2A plan view of the drill bit replacement-free rotary drilling rig of the present application;

[0026] Figure 3 A partial exploded view of the drill bit replacement-free rotary drilling rig of the present application;

[0027] Figure 4 An exploded view of the extension assembly in the drill bit replacement-free rotary drilling rig of the present application;

[0028] Figure 5 An exploded view of the extension assembly in the drill bit replacement-free rotary drilling rig of the present application from another perspective;

[0029] Figure 6 A perspective view of the extension assembly in another embodiment of the drill bit replacement-free rotary drilling rig of the present application. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the following embodiments are described in detail in combination with the drawings. And the following terms are defined as Figure 2 In the embodiment, the front end direction of the extension assembly is the clockwise direction along the rotary drilling rig body, the rear end direction of the extension assembly is the counterclockwise direction along the rotary drilling rig body, and the outer-to-inner direction of the extension assembly is the radial direction from the outside to the inside of the rotary drilling rig body.

[0031] Embodiment one,

[0032] Referring to FIG. 1, the drill bit replacement-free rotary drilling rig provided by the embodiment includes a rotary drilling rig body 1 and at least one extension assembly 2 detachably mounted on the outer edge of the upper end of the rotary drilling rig body 1, and the extension assembly 2 is used to simultaneously excavate a foundation pit for installing a steel casing in the working state of the rotary drilling rig body 1; wherein the extension assembly 2 includes: Figures 1 to 5 A connecting arm 3 having one end provided with a mounting structure for detachable radial mounting on the outer edge of the upper end of the rotary drilling rig body 1, and the front and rear sides of the connecting arm 3 are respectively protruded to form a first limiting portion 8 and a second limiting portion 9;

[0033] A cutter block 4 hingedly connected to the other end of the connecting arm 3, and the front end of the cutter block 4 is provided with a cutter head 6, and the first limiting portion 8 and the second limiting portion 9 limit the maximum positions of the cutter block 4 rotating in two directions around the hinged end;

[0034] A resilient member 5 having two ends respectively connected to the rear part of the cutter block 4 and the connecting arm 3 or the mounting structure, for providing a pushing force to the cutter block 4 rotating to abut against the first limiting portion 8;

[0035]

[0036] ​And, in the working state, the cutter head 6 of the blade block 4 is blocked by the pebbles in the soil layer and can rotate to the direction of the second limiting portion 9, and the working state of the blade block 4 on the pebbles is changed from cutting to pushing, and the blade block 4 is pushed to the position abutting against the first limiting portion 8 by the elastic member 5 after the pebbles are loosened.

[0037] Based on the above technical scheme, the drill bit-free rotary drilling rig comprises a rotary drilling rig body 1 and an expansion assembly 2, and the expansion assembly 2 comprises a connecting arm 3, a blade block 4 and an elastic member 5. The blade block 4 is hinged to one end of the connecting arm 3 away from the rotary drilling rig body 1. Two limiting portions are formed on the connecting arm 3 to limit the maximum position of the blade block 4 rotating around the hinged end. The elastic member 5 urges the blade block 4 to remain in the position abutting against the first limiting portion 8.

[0038] In a specific application, the blade block 4 is detachably assembled to the outer edge of the rotary drilling rig body 1 through the connecting arm 3. In the initial state of the expansion assembly 2 (the position of the blade block 4 abutting against the first limiting portion 8 on the inward side), the radial length from the shaft center of the rotary drilling rig body 1 to the outermost side of the expansion assembly 2 is the maximum radius of the preset steel casing. During the process of rotating and digging the hole downwardly with respect to the center of the pile position, the expansion assembly 2 rotates and is used to dig the foundation pit for placing the steel casing. After digging to the preset depth, the rotary drilling rig body 1 and the expansion assembly 2 are extracted upwardly, the expansion assembly 2 is detached, then the steel casing is placed into the foundation pit, and the soil is backfilled to the position outside the outer edge of the steel casing if necessary, and then the rotary drilling rig body 1 continues to operate downwardly to dig the hole.

[0039] In the whole working state, when the cutter head 6 of the blade block 4 is blocked by the pebbles in the soil layer, and the pebbles are too hard to be directly cut and damaged, the blade block 4 can rotate around the hinged end to the direction of the second limiting portion 9 under the resistance provided by the pebbles, and the treatment of the pebbles is changed from cutting to pushing. During the whole process, the rotary drilling rig body 1 continues to rotate, and the blade block 4 is reset under the action of the elastic member 5 after the pebbles are loosened. The blade block 4 can be effectively prevented from being damaged by directly rigidly impacting the pebbles, and the torque pressure at the position where the connecting arm 3 is connected to the rotary drilling rig body 1 can be effectively reduced, thereby effectively improving the service life of the expansion assembly 2. Meanwhile, the rotary drilling rig can dig the foundation pit for placing the steel casing through the expansion assembly 2 in the whole working state without the need of replacing the drill bit. The expansion assembly 2 is suitable for the existing rotary drilling rig body 1, and the rotary drilling rig body 1 does not need to be redesigned. The expansion assembly 2 is only needed to be fixed to the rotary drilling rig body 1 to achieve the technical purpose of drill bit-free, thereby greatly improving the work efficiency and reducing the work cost. The overall structure of the expansion assembly 2 is simple and easy to realize, and the service life is long, thereby avoiding the problems of rework and replacement due to breakage or damage caused by rigid impact during the work process.

[0040] In a preferred embodiment, specifically asFigure 4 and Figure 5 As shown in Figure 2 , the middle of the blade 4 is transversely provided with a mounting slot 7, the end of the connecting arm 3 away from the rotary drilling body 1 extends into the mounting slot 7 and is hinged with the blade 4, and the first limiting part 8 and the second limiting part 9 are both semicircular protrusions formed on the front and rear sides of the connecting arm 3, and the inner side of the blade 4 abuts against the first limiting part 8 and the second limiting part 9 to limit the maximum position of the rotation of the blade 4 around the hinged end. Further, the blade 4 is longitudinally provided with a threaded hole passing through the mounting slot 7, and the connecting arm 3 is oppositely provided with a longitudinal through hole, and the blade 4 is hinged with the connecting arm 3 by a threaded rod 10 passing through the threaded hole and the longitudinal through hole. Further, as shown in Figure 2 , in the clockwise direction, the first limiting part 8 and the second limiting part 9 limit the included angle between the blade 4 and the connecting arm 3 to 120 degrees to 150 degrees, so that the cutting head 6 of the blade 4 has a rotation space of 30 degrees when it collides with pebbles, avoiding direct impact and damage. Further, the elastic member 5 is a compression spring, and the compression spring is always in a compressed state, that is, whether the cutting head 6 rotates to the position abutting against the first limiting part 8 or the position abutting against the second limiting part 9, the compression spring always provides a pushing force to the blade 4 in the direction of the first limiting part 8, and when the cutting head 6 rotates in the direction of the second limiting part 9 due to the resistance of the pebbles, the compression spring is further compressed. In this process, only when the resistance of the pebbles to the cutting head 6 is greater than the elastic pushing force provided by the compression spring, the state of the elastic force being greater than the resistance will not further rotate the cutting head 6 because it will not cause breakage or damage to the cutting head 6.

[0041] In a preferred embodiment, as shown in Figures 3 to 5 , the assembly structure includes two oppositely arranged first arc-shaped plates 11 and second arc-shaped plates 12, the radii of the first arc-shaped plates 11 and the second arc-shaped plates 12 are consistent with the radius of the outer wall of the rotary drilling body 1, and one end of the connecting arm 3 and one end of the compression spring are both connected to the side of the second arc-shaped plate 12 away from the first arc-shaped plate 11, and the side of the first arc-shaped plate 11 facing the second arc-shaped plate 12 has a first connecting block 13, the first connecting block 13 is recessed to form a receiving groove, the side of the second arc-shaped plate 12 facing the first arc-shaped plate 11 has a second connecting block 14 matching the shape of the receiving groove, and the upper edge of the outer wall of the rotary drilling body 1 is provided with a slot 15 matching the shape of the first connecting block 13, and threaded holes are formed on the bottom surface of the slot 15, the first connecting block 13 and the second connecting block 14, and a threaded rod is used to assemble the first connecting block 13 and the second connecting block 14 in the slot 15, and the first arc-shaped plate 11 and the second arc-shaped plate 12 jointly clamp the outer wall of the rotary drilling body 1, so that the overall connecting structure is stable and reliable and easy to disassemble and assemble, and is not easy to separate and break due to the radial torque.

[0042] As a further preferred embodiment, one end of the connecting arm 3 is welded to the second arc-shaped plate 12, so that the connecting structure is more stable, but it is obvious that the connection can also be achieved by fasteners. Further, both ends of the compression spring are welded to the second arc-shaped plate 12 and the side of the cutter block 4 facing each other. But it is obvious that the installation can also be achieved by hooking or additional hole setting, and is not limited thereto.

[0043] Embodiment two,

[0044] Referring to the embodiment shown in Figure 6 , the technical features of the rotary drilling rig provided by the embodiment are basically the same as those of the above-mentioned embodiment one, and the difference is only that both ends of the compression spring are welded to the cutter block 4 and the connecting arm 3, the connecting arm 3 is longitudinally provided with at least two mounting through holes 16 to form an assembly structure, and the outer wall of the rotary drilling rig body 1 is provided with an equal number of mounting screw holes corresponding to the positions of the mounting through holes 16, so as to detachably screw the connecting arm 3 to the rotary drilling rig body 1 by fasteners.

[0045] In addition, as an example, the outer diameter of the rotary drilling rig body 1 is 1.2 m, and the outer diameter of the steel casing used is 1.4 m, that is, the radial length of the expansion assembly 2 is within 10 cm, and the steel casing is usually 2-4 m deep into the ground and 30 cm exposed to the ground. 2-4 m is a shallow soil layer, and compared with the case where there are more large rocks in the deep soil layer, the soil in the shallow soil layer is relatively loose, but there are a large number of pebbles mixed therein, which has low hardness itself but has large resistance in the soil layer. If the cutter head 6 continuously impacts the pebbles directly, it may be broken or damaged, and the movable cutter block 4 in the embodiment has a rotation space of about 30 degrees (the cutter block 4 rotates clockwise, and the back is already excavated and does not exist hard soil, and as Figure 1 known from the above, the soil in the foundation pit will move inward to the upper end of the rotary drilling rig body 1 and fall into the accommodating cavity in the rotary drilling rig body 1 from the two side passages after being excavated by the expansion assembly 2), so that the cutter head 6 is not easy to be damaged by directly impacting the pebbles, or the connecting arm 3 and the rotary drilling rig body 1 are broken due to excessive torque at the joint.

[0046] The above is only a preferred embodiment of the present application, which is only illustrative but not limiting. It is understood by those skilled in the art that many changes, modifications and even equivalents can be made within the spirit and scope of the present application as defined in the claims, and all of them will fall within the protection scope of the present application.

Claims

1. A drill bit exchange-free rotary drilling rig comprising a rotary drilling rig body (1), at least one detachable extension assembly (2) mounted on the outer edge of the upper end of the rotary drilling rig body (1), and the extension assembly (2) is used to simultaneously excavate a foundation pit for installing a steel casing in the working state of the rotary drilling rig body (1); characterized in that, The extension assembly (2) comprises: a connecting arm (3) provided with an assembling structure at one end for detachable radial assembling to the outer edge of the upper end of the rotary drilling body (1), and first and second limiting portions (8, 9) are respectively formed on the front and back of the connecting arm (3); a cutter block (4) hingedly connected to the other end of the connecting arm (3), and the front end of the cutter block (4) is provided with a cutter head (6), and the first and second limiting portions (8, 9) limit the maximum position of the cutter block (4) rotating in two directions around the hinged end; a resilient member (5) connected to the rear of the cutter block (4) and the connecting arm (3) or the assembling structure at both ends, for providing a pushing force to the cutter block (4) when rotating to abut against the first limiting portion (8); and in the working state, the cutter head (6) of the front end of the cutter block (4) can rotate to the direction of the second limiting portion (9) when blocked by pebbles in the soil layer, and the working state of the cutter block (4) on the pebbles changes from cutting to pushing, and the cutter block (4) is pushed back to the position abutting against the first limiting portion (8) by the resilient member (5) after the pebbles are loosened; the first and second limiting portions (8, 9) limit the included angle between the cutter block (4) and the connecting arm (3) to 120-150 degrees, so that the cutter head (6) has a rotation space of 30 degrees when abutting against the pebbles.

2. The drill bit exchangeable rotary drill according to claim 1, wherein, the middle part of the cutter block (4) is transversely provided with a mounting groove (7), one end of the connecting arm (3) away from the rotary drilling body (1) extends into the mounting groove (7) and is hingedly connected to the cutter block (4), and the first and second limiting portions (8, 9) are both semicircular protrusions formed on the front and back of the connecting arm (3), and the cutter block (4) abuts against the first and second limiting portions (8, 9) on the inner side to limit the maximum position of the cutter block (4) rotating around the hinged end.

3. The drill bit exchangeable rotary drill according to claim 2, wherein, a screw hole passing through the mounting groove (7) is longitudinally formed on the cutter block (4), a longitudinal through hole is oppositely formed on the connecting arm (3), and the cutter block (4) is hingedly connected to the connecting arm (3) by a screw rod (10) simultaneously passing through the screw hole and the longitudinal through hole.

4. The drill bit exchangeable rotary drill according to claim 1, wherein the resilient member (5) is a compression spring, and the compression spring is always in a compressed state.

5. The drill bit exchangeable rotary drill according to claim 4, wherein the assembling structure comprises two oppositely arranged first and second arc-shaped plates (11, 12), and the radii of the first and second arc-shaped plates (11, 12) are consistent with the radius of the outer wall of the rotary drilling body (1); one end of the connecting arm (3) and one end of the compression spring are both connected to the side of the second arc-shaped plate (12) away from the first arc-shaped plate (11), and the side of the first arc-shaped plate (11) facing the second arc-shaped plate (12) is provided with a first connecting block (13) with an accommodation groove formed therein, and the side of the second arc-shaped plate (12) facing the first arc-shaped plate (11) is provided with a second connecting block (14) matching the shape of the accommodation groove; The outer wall of the rotary drilling body (1) is provided with a notch (15) matching the shape of the first connecting block (13), and the bottom surface of the notch (15), the first connecting block (13) and the second connecting block (14) are all provided with threaded holes, and the first connecting block (13) and the second connecting block (14) are assembled in the notch (15) by a stud, and the first arc-shaped plate (11) and the second arc-shaped plate (12) jointly clamp the outer wall of the rotary drilling body (1).

6. The drill bit exchangeable rotary drill according to claim 5, wherein, One end of the connecting arm (3) is welded to the second arc-shaped plate (12).

7. The drill bit exchangeable rotary drill according to claim 6, wherein The two ends of the compression spring are respectively welded to the second arc-shaped plate (12) and the side of the cutter block (4) facing each other.

8. The drill bit exchangeable rotary drill according to claim 4, wherein, The two ends of the compression spring are respectively welded to the cutter block (4) and the connecting arm (3), the connecting arm (3) is longitudinally provided with at least two mounting through holes (16) to form the assembly structure, and the outer wall of the rotary drilling body (1) is provided with mounting screw holes in the same number and position as the mounting through holes (16) to detachably screw the connecting arm (3) to the rotary drilling body (1) through fasteners.

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