Large-diameter integral down-the-hole hammer combined drill bit and drill bit assembling method

Abstract

The invention relates to the field of geotechnical engineering construction, in particular to the field of down-the-hole hammer equipment, in particular to a large-diameter integral down-the-hole hammer combined drill bit and a drill bit assembling method. The down-the-hole hammer drill bit solves the problems that an existing whole down-the-hole hammer drill bit is difficult to disassemble, long in repairing time and high in construction site construction cost, can be directly operated and replaced on a construction site, does not need special equipment tools and comprises a down-the-hole hammer drill bit body and a plurality of sub drill bits, and assembling cavities with the same number as the sub drill bits are formed in the bottom of the down-the-hole hammer drill bit body; the upper portion of the sub-bit is a handle, the tail end of the sub-bit handle is provided with an annular groove limiting section, and the axis of the sub-bit is provided with a ventilation channel. A drill clamping sleeve is assembled on the outer circumferential face of the sub drill bit handle, and the sub drill bit handle and the drill clamping sleeve are assembled in the corresponding assembling cavity together. A clamping ring is assembled on the outer circumferential face of the annular groove limiting section of the sub drill bit handle, and the outer diameter of the clamping ring is larger than the inner diameter of the drill clamping sleeve. An annular snap spring groove is machined in the position, close to the bottom face, of the inner wall of the assembling cavity.

Description

Technical Field

[0001] The invention relates to the field of geotechnical engineering construction, in particular to the field of down-the-hole hammer equipment, and specifically to a large-caliber integral down-the-hole hammer combined drill bit and a drill bit assembly method. Background Art

[0002] As we all know, the most effective drilling method for drilling large-diameter rock formations is down-the-hole hammer drilling. Down-the-hole hammer drilling is an impact rock-breaking drilling method that can produce volumetric crushing and is highly efficient.

[0003] The diameter of a down-the-hole hammer is generally larger than 600mm, which is called a large-diameter down-the-hole hammer. In actual construction, the integral down-the-hole hammer drill bit is prone to wear and tear, and the alloy of the integral down-the-hole hammer drill bit wears relatively quickly. The alloy needs to be repaired and replaced after drilling into hard rock layers for 100-300 meters.

[0004] However, in addition to the easy wear of the drill bit, the large-caliber integral DTH hammer drill bit also has the following defects. The first defect is that the maintenance is limited. Due to the large diameter and weight of the integral DTH hammer drill bit, a special disassembly platform must be used to disassemble the impactor and the drill bit. Only professional manufacturers have such a large disassembly platform. Therefore, if you want to repair the drill bit, it must be done by a professional manufacturer. In actual construction, even if there is a replacement spare drill bit on the construction site, due to the large size and weight of the integral DTH hammer drill bit, and the need for professional tools, it is impossible to disassemble the impactor and the drill bit on the construction site for replacement. The second defect is the high cost. The broken and scrapped alloy on the drill bit needs to be completely removed with a special spark machine, and then the drill body is repaired by electric welding, and the drill bit body is re-drilled after heat treatment, and the alloy is embedded. Repairing a drill bit may be more expensive than embedding alloy in a new drill bit. It generally takes 7-10 days to repair a drill bit larger than 600mm. In addition, the construction site is a certain distance away from the manufacturer of the repair drill bit, and transportation and hoisting require costs. Summary of the invention

[0005] The present invention provides a large-caliber integral down-the-hole hammer combined drill bit and a drill bit assembly method, which solves the problems of difficult disassembly, long repair time and high construction cost of the previous integral down-the-hole hammer drill bit. The present invention can be directly replaced on the construction site without the need for special equipment and tools.

[0006] The present invention is achieved through the following technical solutions: A large-caliber integral down-the-hole hammer combined drill bit, comprising a down-the-hole hammer drill bit body and a plurality of sub-drill bits, wherein the bottom of the down-the-hole hammer drill bit body is provided with assembly cavities equal in number to the sub-drill bits; The upper part of the sub-drill bit is a sub-drill bit handle, the tail end of the sub-drill bit handle is provided with a ring groove limiting section, and the axis of the sub-drill bit is provided with a ventilation channel; A drill bit holder sleeve is mounted on the outer circumferential surface of the sub-drill bit handle, and the sub-drill bit handle and the drill bit holder sleeve are mounted together in the corresponding assembly cavity; a clamping ring is mounted on the outer circumferential surface of the annular groove limiting section of the sub-drill bit handle, and the outer diameter of the clamping ring is greater than the inner diameter of the drill bit holder sleeve; The inner wall of the assembly cavity is processed with an annular retaining spring groove near the bottom surface, and a retaining spring piece is installed in the retaining spring groove. The inner diameter of the retaining spring piece is smaller than the bottom outer diameter of the clamp sleeve, and the retaining spring piece is used to limit the clamp sleeve.

[0007] Furthermore, the assembly cavity is a stepped cavity, which is divided into a first stepped hole, a second stepped hole and a third stepped hole from bottom to top, and the outer side of the clamp sleeve is a stepped shaft, which is divided into a first stepped shaft, a second stepped shaft and a third stepped shaft from bottom to top; the inner wall contour of the second stepped hole and the outer wall contour of the second stepped shaft are both polygonal, and the length of the first stepped hole is greater than the length of the first stepped shaft.

[0008] Furthermore, the clamping ring is composed of two half rings joined together, and an annular groove is provided on the outer circumference of the clamping ring.

[0009] Furthermore, the outer diameter of the clamping ring is equal to the inner diameter of the third stepped hole of the assembly cavity.

[0010] Furthermore, the cross section of the clamping spring is circular, and the depth of the clamping spring groove is greater than the cross section radius of the clamping spring.

[0011] Furthermore, an annular arc groove matching with the inner side surface of the retaining spring is processed on the outer circumference of the bottom surface of the clamp sleeve.

[0012] Furthermore, the number of the sub-drill bits is N, where N is a natural number greater than 5.

[0013] A method for assembling a large-caliber integral down-the-hole hammer combined drill bit, using the large-caliber integral down-the-hole hammer combined drill bit of the present invention for assembly, comprises the following steps: S01, preparing the sub-drill bit, the clamping ring, the drill sleeve and the clamping spring to be assembled; S02, first assemble the clamping sleeve on the sub-drill bit shank, and then assemble the clamping ring on the ring groove limiting section of the sub-drill bit shank; S03, integrally assembling the drill bit shank, the clamping ring and the drill sleeve into the assembly cavity of the down-the-hole hammer drill bit body; S04, push the clamp sleeve upward to expose the clamp spring groove, assemble the clamp spring member in the clamp spring groove by using a tool, and the clamp sleeve is assembled in the assembly cavity under the limit of the clamp spring member; S05, repeating steps S01-S04, assembling all the sub-drill bits into the assembly cavities corresponding to the down-the-hole hammer drill bit body; S06. When the large-caliber integral down-the-hole hammer combined drill bit is working, the down-the-hole hammer drill bit body is vertically erected, the drill sleeve falls freely under the action of gravity, the annular arc groove at the lower end of the drill sleeve supports the clamping spring piece, the drill sleeve is supported by the clamping spring piece fixed in the clamping spring groove, and the sub-drill bit is supported by the drill sleeve under the action of the clamping ring; S07. When it is necessary to replace the drill sleeve and the retaining spring of the severely worn sub-drill bit, push the drill sleeve upward to expose the retaining spring, and remove the retaining spring from the retaining spring groove by using a tool, so that the drill sleeve and the sub-drill bit are separated from the assembly cavity; Repeat steps S01-S04 to reassemble the sub-drill bit into the assembly cavity.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The large-caliber integrated down-the-hole hammer combined drill bit of the present invention can enable the sub-drill bit to be quickly and conveniently installed in the assembly cavity of the down-the-hole hammer drill bit body through the cooperation of the drill sleeve, the retaining spring and the retaining ring, which greatly reduces the difficulty of disassembling the drill bit and the repair time. The drill bit can be replaced on the spot without relying on special equipment and tools, and the previous integral drill bit is replaced into a local sub-drill bit, which greatly reduces the cost; The large-caliber integral down-the-hole hammer combined drill bit assembly method of the present invention can quickly install and disassemble the sub-drill bit, and the whole process is quick and convenient without relying on special tools, which greatly improves the construction efficiency; 2. Compared with the whole drill bit, the processing of multiple sub-drill bits is relatively simple and low-cost. The cost of replacing a whole set of sub-drill bits is much lower than repairing a whole drill bit; 3. When the DTH drill bit body rotates, the sub-drill bit rotates due to the different linear speed friction resistance on the inner and outer circumference lines of the DTH drill bit body. The alloy wear of the sub-drill bit changes direction with the rotation, so that the alloy on the sub-drill bit is not easy to be blunted, the sub-drill bit is more wear-resistant, and the penetration speed is faster; 4. The diameter and number of sub-drill bits can be flexibly adjusted according to the diameter of the overall down-the-hole hammer drill bit, and the layout position is also reasonably configured according to the size of the overall hammer drill bit. Since the ground rock is not evenly stressed over the entire surface, multiple sub-drill bits can produce large-volume crushing more easily than the overall drill bit, and the efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the explosion of the large-caliber integral down-the-hole hammer combined drill bit of the present invention; Figure 2 This is a cross-sectional view of the large-caliber integral down-the-hole hammer combined drill bit of the present invention; Figure 3 for Figure 2 An enlarged schematic diagram of the assembly of the retaining spring at position A in the middle; Figure 4 for Figure 2An enlarged schematic diagram of removing the retaining spring at position B in the middle; Figure 5 This is a bottom view of the large-caliber integral down-the-hole hammer combined drill bit of the present invention; In the figure: 1. DTH hammer drill bit body, 2. sub-drill bit, 3. drill sleeve, 4. retaining ring, 5. retaining spring, 6. assembly cavity, 7. air supply channel, 8. sub-drill bit shank, 9. annular groove limiting section, 10. ventilation channel, 11. retaining spring groove, 12. annular arc groove. DETAILED DESCRIPTION

[0016] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0017] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or coupling. The term "and / or" used herein includes any unit and all combinations of one or more associated listed items.

[0018] like Figure 1 , Figure 2 and Figure 5 As shown, this embodiment discloses a large-caliber integral down-the-hole hammer combined drill, which includes, in addition to the down-the-hole hammer drill bit body 1, a plurality of sub-drill bits 2, a drill sleeve 3, a retaining ring 4 and a retaining spring 5. The bottom of the down-the-hole hammer drill bit body 1 is provided with assembly cavities 6 equal to the number of sub-drill bits 2. The diameter and number of sub-drill bits 2 can be flexibly adjusted according to the diameter of the integral down-the-hole hammer drill bit, and the arrangement position is also reasonably configured according to the size of the integral hammer drill bit. Since this embodiment is applied to drilling holes in large-caliber rock formations, the diameter of the integral down-the-hole hammer combined drill bit is not less than 600 mm. In this embodiment, the number of sub-drill bits 2 and assembly cavities 6 is 6.

[0019] The assembly cavity 6 is a stepped cavity, which is divided into a first stepped hole, a second stepped hole and a third stepped hole from bottom to top. The inner wall contours of the first stepped hole and the third stepped hole are cylindrical, and the inner wall contour of the second stepped hole is hexagonal. An air supply channel 7 is processed on the top of the assembly cavity 6. The sub-drill handle 8 of the sub-drill 2 is processed with an annular groove limiting section 9 at the tail end of the sub-drill handle 8, and a ventilation channel 10 is processed on the axis of the sub-drill handle 8 and the sub-drill 2.

[0020] The drill sleeve 3 is provided with an axial hole, and the drill sleeve 3 is mounted on the outer circumference of the sub-drill handle 8. The outer side of the drill sleeve 3 is a stepped shaft, and the drill sleeve 3 is divided into a first stepped shaft, a second stepped shaft and a third stepped shaft from bottom to top, wherein the outer wall profiles of the first stepped shaft and the second stepped shaft are cylindrical, and the outer wall profiles of the second stepped shaft are all hexagonal. The clamping ring 4 is composed of two half rings, and an annular groove is processed on the outer circumference of the clamping ring 4. The two half rings are respectively assembled on the annular groove limiting section 9 of the sub-drill handle 8, so that the clamping ring 4 is assembled on the annular groove limiting section 9. Assemble the sub-drill bit shank 8, the retaining ring 4 and the drill sleeve 3 together in the corresponding assembly cavity 6, the outer diameter of the retaining ring 4 is equal to the inner diameter of the third step hole of the assembly cavity 6, and the inner diameter of the retaining ring 4 is smaller than the inner diameter of the axial hole of the drill sleeve 3. With this design, when the retaining ring 4 is assembled on the annular groove limiting section, the sub-drill bit shank 8 cannot be separated from the drill sleeve 3.

[0021] like Figure 3-4 As shown, the inner wall of the first stepped hole of the assembly cavity 6 is processed with an annular retaining spring groove 11 near the bottom surface, and a retaining spring 5 is installed in the retaining spring groove 11. The cross section of the retaining spring 5 is circular, and the depth of the retaining spring groove 11 is greater than the cross-sectional radius of the retaining spring 5. The inner diameter of the retaining spring 5 is smaller than the bottom outer diameter of the clamp sleeve 3. An annular arc groove 12 matching the inner side of the retaining spring 5 is processed on the outer circumference of the bottom surface of the clamp sleeve 3, so that the clamp sleeve 3 is limited by the retaining spring 5. In the design process, the length of the first stepped hole is greater than the length of the first stepped shaft. When the clamp sleeve 3 is pushed upward, the annular arc groove 12 of the clamp sleeve 3 can be separated from the retaining spring, which is convenient for removing the retaining spring.

[0022] Based on the above-mentioned large-caliber integral down-the-hole hammer combined drill, this embodiment also discloses a large-caliber integral down-the-hole hammer combined drill bit assembly method, including the following steps: S01, preparing the sub-drill bit 2, the clamping ring 4, the drill sleeve 3 and the clamping spring 5 to be assembled; S02, first assemble the drill sleeve 3 on the drill bit shank 8 from top to bottom, and then assemble the clamping ring 4 on the annular groove limiting section 9 of the drill bit shank 8. In order to prevent the two half rings of the clamping ring 4 from separating, an elastic rubber ring can be temporarily fixed in the annular groove; S03, integrally assembling the drill bit shank 8, the clamping ring 4 and the drill sleeve 3 into the assembly cavity 6 of the down-the-hole hammer drill bit body 1; S04, push the clamp sleeve 3 upward to expose the clamp spring groove 11, assemble the clamp spring member 5 into the clamp spring groove 11 by means of a tool, and under the limit of the clamp spring member 5, the clamp sleeve 3 is assembled into the assembly cavity 6; S05, repeating steps S01-S04, assembling all the sub-drill bits 2 into the assembly cavity 6 corresponding to the down-the-hole hammer drill bit body 1; S06. When the large-caliber integral down-the-hole hammer combined drill bit is working, the down-the-hole hammer drill bit body 1 is vertically erected, and the drill sleeve 3 falls freely under the action of gravity. The annular arc groove 12 at the lower end of the drill sleeve 3 supports the clamping spring member 5, and the drill sleeve 3 is supported by the clamping spring member 5 fixed in the clamping spring groove 11. The sub-drill bit 2 is supported by the drill sleeve 3 under the action of the clamping ring 4; because the clamping ring 4 is always located in the third step hole of the assembly cavity 6, and the inner diameter of the clamping ring 4 is slightly larger than the outer diameter of the sub-drill bit shank 8, the outer diameter of the clamping ring 4 is equal to the inner diameter of the third step hole of the assembly cavity 6, so the clamping ring 4 will not be opened in the third step hole of the assembly cavity; S07, when it is necessary to replace the drill sleeve 3 and the retaining spring of the severely worn sub-drill bit 2, push the drill sleeve 3 upward to expose the retaining spring 5, and remove the retaining spring 5 from the retaining spring groove 11 by a tool, so that the drill sleeve 3 and the sub-drill bit 2 are separated from the assembly cavity 6; Repeat steps S01 - S04 to reassemble the sub-drill bit 2 into the assembly cavity 6 .

[0023] The large-caliber integral down-the-hole hammer combined drill bit and drill bit assembly method described in the present invention can enable the sub-drill bit 2 to be quickly and conveniently installed in the assembly cavity 6 of the down-the-hole hammer drill bit body 1 through the cooperation of the drill sleeve 3, the retaining spring, and the retaining ring 4, which greatly reduces the difficulty of disassembling the drill bit and reduces the repair time. It can be replaced on the spot without relying on special equipment and tools, and the previous overall replacement is converted into a partial replacement of the sub-drill bit 2, which greatly reduces the cost and overcomes the problem of difficult maintenance of the previous integral down-the-hole hammer drill bit. Although there are attempts in the prior art to install the sub-drill bit 2 on the bottom surface of the down-the-hole hammer drill bit body 1 by threaded connection, during the rotation impact process, due to the rotation of the sub-drill bit 2, the threaded connection is easy to loosen, causing the sub-drill bit 2 to fall off during the construction process, and under the action of the impact force, the threaded connection is easy to lock, which is not easy to disassemble later, and the large-caliber integral down-the-hole hammer combined drill bit of this embodiment does not have this problem.

Claims

1. A large-caliber integrated down-the-hole hammer combined drill bit, characterized in that: It comprises a down-the-hole hammer drill bit body and a plurality of sub-drill bits, wherein the bottom of the down-the-hole hammer drill bit body is provided with assembly cavities equal to the number of the sub-drill bits; The upper part of the sub-drill bit is a sub-drill bit handle, the tail end of the sub-drill bit handle is provided with a ring groove limiting section, and the axis of the sub-drill bit is provided with a ventilation channel; A drill bit holder sleeve is mounted on the outer circumferential surface of the sub-drill bit handle, and the sub-drill bit handle and the drill bit holder sleeve are mounted together in the corresponding assembly cavity; a clamping ring is mounted on the outer circumferential surface of the annular groove limiting section of the sub-drill bit handle, and the outer diameter of the clamping ring is greater than the inner diameter of the drill bit holder sleeve; The inner wall of the assembly cavity is processed with an annular retaining spring groove near the bottom surface, and a retaining spring piece is installed in the retaining spring groove. The inner diameter of the retaining spring piece is smaller than the bottom outer diameter of the clamp sleeve, and the retaining spring piece is used to limit the clamp sleeve.

2. The large-caliber integral down-the-hole hammer combined drill bit according to claim 1, characterized in that: The assembly cavity is a stepped cavity, which is divided into a first stepped hole, a second stepped hole and a third stepped hole from bottom to top; the outer side of the clamp sleeve is a stepped shaft, which is divided into a first stepped shaft, a second stepped shaft and a third stepped shaft from bottom to top; the inner wall contour of the second stepped hole and the outer wall contour of the second stepped shaft are both polygonal, and the length of the first stepped hole is greater than the length of the first stepped shaft.

3. The large-caliber integral down-the-hole hammer combined drill bit according to claim 2, characterized in that: The clamping ring is composed of two half rings joined together, and an annular groove is arranged on the outer circumference of the clamping ring.

4. The large-caliber integral down-the-hole hammer combined drill bit according to claim 2, characterized in that: The outer diameter of the clamping ring is equal to the inner diameter of the third stepped hole of the assembly cavity.

5. The large-caliber integral down-the-hole hammer combined drill bit according to claim 3, characterized in that: The cross section of the clamping spring is circular, and the depth of the clamping spring groove is greater than the cross section radius of the clamping spring.

6. The large-caliber integral down-the-hole hammer combined drill bit according to claim 3, characterized in that: The outer circumference of the bottom surface of the clamp sleeve is processed with an annular arc groove that matches the inner side surface of the clamp spring.

7. The large-caliber integral down-the-hole hammer combined drill bit according to any one of claims 1 to 6, characterized in that: The number of the sub-drill bits is N, where N is a natural number greater than 5.

8. A method for assembling a large-caliber integral down-the-hole hammer combined drill bit, using the large-caliber integral down-the-hole hammer combined drill bit according to claim 6 for assembly, comprising the following steps: S01, preparing the sub-drill bit, the clamping ring, the drill sleeve and the clamping spring to be assembled; S02, first assemble the clamping sleeve on the sub-drill bit shank, and then assemble the clamping ring on the ring groove limiting section of the sub-drill bit shank; S03, integrally assembling the drill bit shank, the clamping ring and the drill sleeve into the assembly cavity of the down-the-hole hammer drill bit body; S04, push the clamp sleeve upward to expose the clamp spring groove, assemble the clamp spring member in the clamp spring groove by using a tool, and the clamp sleeve is assembled in the assembly cavity under the limit of the clamp spring member; S05, repeating steps S01-S04, assembling all the sub-drill bits into the assembly cavities corresponding to the down-the-hole hammer drill bit body; S06. When the large-caliber integral down-the-hole hammer combined drill bit is working, the down-the-hole hammer drill bit body is vertically erected, the drill sleeve falls freely under the action of gravity, the annular arc groove at the lower end of the drill sleeve supports the clamping spring piece, the drill sleeve is supported by the clamping spring piece fixed in the clamping spring groove, and the sub-drill bit is supported by the drill sleeve under the action of the clamping ring; S07. When it is necessary to replace the drill sleeve and the retaining spring of the severely worn sub-drill bit, push the drill sleeve upward to expose the retaining spring, and remove the retaining spring from the retaining spring groove by using a tool, so that the drill sleeve and the sub-drill bit are separated from the assembly cavity; Repeat steps S01-S04 to reassemble the sub-drill bit into the assembly cavity.

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