Impact drill bit

Abstract

The utility model belongs to the technical field of drilling tools, and relates to a percussion bit, which comprises an outer-layer percussion head, an inner-layer percussion head, an inner-layer percussion head and an outer-layer percussion head, the inner-layer impact head is coaxially nested in the outer-layer impact head, and a second hard alloy tooth group is arranged on the front end surface of the inner-layer impact head; the slag discharging structure comprises a slag discharging notch formed in the surface of the outer-layer impact head and a slag discharging hole formed in the slag discharging notch so as to discharge broken stones generated in the impact process; each of the first hard alloy tooth group and the second hard alloy tooth group comprises a plurality of hard alloy teeth which are annularly distributed; the first hard alloy tooth set and the second hard alloy tooth set each comprise a plurality of hard alloy teeth in the axis direction of the percussion bit, and the tooth tip of the second hard alloy tooth set does not exceed the slag discharging hole. Through cooperative guiding of the inner-layer impact head and the outer-layer impact head and real-time deslagging design, coring-free accurate hole forming is achieved, the high-altitude rock core falling risk is effectively eliminated, and the construction efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of drilling tools, and relates to an impact drill bit. BACKGROUND

[0002] In the technical field of non-explosive rock excavation engineering, the water mill drill annular occlusion hole construction method is widely used in urban subway shafts, deep foundation pit support and other construction scenes sensitive to the surrounding environment due to its low vibration characteristics. The process densely drills annularly arranged core holes along the designed contour line through a water mill drill with a diameter of 150-300 mm, forms a continuous free surface by using the rock wall retained between adjacent holes, and then implements split hole drilling and hydraulic splitter expansion cracking operations. However, the mature process has two defects in actual engineering applications: firstly, due to the friction adsorption effect and vacuum negative pressure effect between the core and the inner wall of the coring tube, about 30%-40% of the core remains in the hole when the drilling tool is lifted, forcing the construction personnel to use a pneumatic pick for secondary crushing or a steel wire rope for retrieval, which increases the time consumption of single-hole disposal by 45-60 minutes, and in the case where the hole depth exceeds 5 m, the self-weight of a single granite core can reach 80-120 kg, which poses serious safety hazards such as high-altitude falling and core sliding; secondly, the direct hole-forming process of the impact drill developed to avoid the coring problem, although it replaces the whole core removal with high-frequency impact crushing, shortens the single-hole operation time to 60% of the original process, but the transverse resonance phenomenon of the drill rod system under the impact frequency of 200-500 times per minute causes the drilling axis to deviate by 3°-5°, the actual measured hole position deviation rate reaches 18.2%, which causes the spacing error between adjacent holes to exceed 2-3 times the design allowable value, and the free surface fragmentation rate drops to below 60%, directly causing the subsequent split hole positioning to be inaccurate, the rock splitting surface to be uneven, and other chain problems.

[0003] In view of the above technical bottlenecks, existing improvement schemes focus on local optimization of a single process: in the water mill drilling technical route, although the adhesion-reducing coating of polytetrafluoroethylene is used to reduce the core retention probability, it cannot solve the problem of safe removal caused by the self-weight of the core; in the impact drilling technical route, although the system stiffness is improved by increasing the wall thickness of the drill rod and setting damping weights, the total weight of the drill increases by more than 35%, which leads to a 40%-50% decrease in equipment transplanting efficiency and significantly reduces the applicability in narrow shafts and other restricted spaces.

[0004] Therefore, the existing technology has not achieved the coordinated improvement of hole forming accuracy and construction efficiency, which seriously restricts the promotion and application of non-explosive excavation technology in high-precision scenarios. Therefore, how to maintain the construction efficiency while ensuring the accuracy and safety of the drilling when using the impact drill bit for non-explosive excavation has become a technical problem to be solved. UTILITY MODEL CONTENTS

[0005] Therefore, the impact coring drill capable of drilling occlusal holes is provided to improve the accuracy, safety and work efficiency of drilling operation.

[0006] To achieve the above object, the utility model provides an impact drill bit, including:

[0007] The outer impact head is in a cylindrical structure, and a first hard alloy tooth group is arranged on the front end face of the outer impact head;

[0008] The inner impact head is coaxially nested in the outer impact head, and a second hard alloy tooth group is arranged on the front end face of the inner impact head;

[0009] The slag discharge structure includes a slag discharge groove on the surface of the outer impact head and a slag discharge hole in the slag discharge groove to discharge the broken stones generated in the impact process.

[0010] The first hard alloy tooth group and the second hard alloy tooth group each include a plurality of annularly distributed hard alloy teeth.

[0011] Optionally, the outer impact head and the inner impact head are detachably connected.

[0012] Optionally, the hard alloy teeth of the second hard alloy tooth group impact a complementary area to the hollow area of the outer impact head.

[0013] Optionally, the number of the slag discharge grooves is multiple, and the multiple slag discharge grooves are uniformly distributed along the circumference of the outer impact head.

[0014] Optionally, the number of the slag discharge holes is multiple, and the multiple slag discharge holes are uniformly distributed along the circumference of the outer impact head, and the axes of the multiple slag discharge holes coincide with the center lines of the multiple slag discharge grooves.

[0015] Optionally, the impact drill bit further includes a mounting portion for connecting a drill rod, the mounting portion is assembled to the rear end face of the inner impact head, and the mounting portion is integrally formed with the inner impact head or detachably connected with the inner impact head; the impact drill bit is mounted to the output end of an impactor through the mounting portion.

[0016] Optionally, an air inlet channel for introducing compressed air is arranged in the mounting portion along the axis of the impact drill bit, and a flushing channel is arranged in the inner impact head; the inlet of the flushing channel is communicated with the air inlet channel, and the outlet of the flushing channel extends to the front end face of the inner impact head to form an air outlet hole.

[0017] Optionally, the number of the flushing channels is multiple, and each flushing channel is communicated with the air inlet channel; the outlets of the multiple flushing channels are uniformly distributed in the front end face of the inner impact head in the form of an annular array.

[0018] Optionally, the flushing channels are arranged in the inner impact head in a manner of being inclined from the center of the inner impact head to the edge.

[0019] The utility model discloses beneficial effect lies in:

[0020] The utility model discloses a coaxial nesting structure design of outer layer impact head and inner layer impact head makes the annular guide groove of outer layer impact head in the drilling process first formation, effectively suppresses the lateral resonance of drill rod system, ensures the drilling axis precision. The inner layer impact head is accurate under the constraint of guide groove and breaks the central rock mass, realizes the accurate forming of the occlusal hole. The complementary layout of inner and outer layer impact head hard alloy tooth group, cooperate the linkage discharge path of slag slot and slag hole, make the broken rock chip can be discharged in real time along the impact operation, completely eliminate the rock core taking process needed by traditional water mill drilling process, fundamentally eliminate the safety hidden trouble of high altitude coring operation.

[0021] Meanwhile, the detachable connecting structure design facilitates the quick replacement of hard alloy tooth group, and significantly improves the adaptability and maintenance efficiency of the drill bit to different rock layers. The integrated design of the inner layer impact head flushing channel and the air inlet channel further assists the discharge of rock debris through fluid power, forms a synergistic working mechanism of impact crushing and fluid discharge, and effectively improves the continuity of drilling operation and the overall construction efficiency.

[0022] Finally, the drill bit of the utility model can also be widely applied to devices such as downhole drills and hydraulic rock drills, and has strong versatility and adaptability. The unique structure design and excellent working performance enable construction personnel to easily cope with different types of rocks and operating environments, thereby improving construction quality and operating efficiency.

[0023] Other advantages, objects and features of the utility model will be described in the subsequent specification to some extent, and to some extent, will be obvious to those skilled in the art based on the study of the following text or can be taught from the practice of the utility model. The objects and other advantages of the utility model can be realized and obtained through the following specification. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to make the purpose, technical scheme and advantages of the utility model more clear, the preferred detailed description of the utility model will be described below in combination with the drawings, in which:

[0025] Fig. 1 It is a structure schematic view of the impact drill bit provided by the utility model;

[0026] Fig. 2 It is a structure schematic view of the impact drill bit provided by the utility model;

[0027] Fig. 3 It is a sectional view of the impact drill bit provided by the utility model;

[0028] Fig. 4The utility model provides a working schematic diagram of impact drill bit.

[0029] Reference signs:

[0030] 100-impact drill bit;110-outer impact head;111-first hard alloy tooth group;112-slagging notch;113-slagging hole;120-inner impact head;121-second hard alloy tooth group;130-mounting part;131-air inlet channel;132-flushing channel;133-air outlet hole. DETAILED DESCRIPTION

[0031] The other advantages and effects of the utility model can be easily understood by the person skilled in the art from the content disclosed in the specification. The utility model can also be implemented or applied by different specific embodiments, and various modifications or changes can be made to the details in the specification based on different viewpoints and applications without departing from the spirit of the utility model. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the utility model in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0032] Wherein, the drawings are only used for example description, and the representation is only a schematic diagram, not a real object drawing, and cannot be understood as a limitation of the utility model; in order to better illustrate the embodiments of the utility model, some components in the drawings can be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it can be understood that some known structures and their descriptions in the drawings can be omitted.

[0033] The same or similar reference signs in the drawings of the embodiments of the utility model correspond to the same or similar components; in the description of the utility model, it should be understood that if the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "front", "back" and the like is based on the orientation or position relationship shown in the drawings, only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, therefore the terms describing the position relationship in the drawings are only used for example description, and cannot be understood as a limitation of the utility model, and for those skilled in the art, the specific meaning of the above terms can be understood according to the specific situation.

[0034] Please refer to Figs. 1-4 The utility model provides an impact drill bit 100, aims at solving the problem that the hole forming precision and construction efficiency are difficult to be improved simultaneously in the existing non-blasting excavation technology.

[0035] The percussion drill bit 100 comprises an outer percussion head 110, an inner percussion head 120, a slagging structure and a mounting portion 130.

[0036] The outer percussion head 110 is in a cylindrical structure and is made of high-strength wear-resistant alloy steel to ensure sufficient strength and wear resistance during rock impact. The front end face of the outer percussion head 110 is provided with a first hard alloy tooth group 111. In this embodiment, the first hard alloy tooth group 111 comprises a plurality of hard alloy teeth arranged in two circles, each hard alloy tooth being independent and inclined. The tooth tips of one circle of hard alloy teeth are inclined towards the center of the drill bit, and the tooth tips of the other circle of hard alloy teeth are inclined towards the edge of the drill bit. This unique arrangement allows the outer percussion head 110 to simultaneously perform annular cutting and internal trimming of the rock during drilling, effectively improving drilling efficiency and stability.

[0037] The inner percussion head 120 is coaxially nested inside the outer percussion head 110. The front end face of the inner percussion head 120 is provided with a second hard alloy tooth group 121. The second hard alloy tooth group 121 also comprises a plurality of annularly distributed hard alloy teeth. The distribution of the plurality of hard alloy teeth of the second hard alloy tooth group 121 needs to meet the following rule: the hard alloy tooth impact coverage area of the second hard alloy tooth group 121 and the hollow uncovered area of the outer percussion head 110 form a complement. In this way, the rock can be fully broken during drilling, leaving no dead angle, thereby achieving precise hole forming. Along the axial direction of the percussion drill bit 100, the tooth tips of the second hard alloy tooth group 121 do not exceed the slagging hole 113. Such a layout facilitates the smooth discharge of broken rock through the slagging structure when breaking the rock, avoiding blockage.

[0038] The slagging structure comprises a slagging groove 112 formed on the surface of the outer percussion head 110 and a slagging hole 113 formed in the slagging groove 112. The number of slagging grooves 112 is multiple, and the multiple slagging grooves 112 are uniformly distributed along the circumference of the outer percussion head 110. The number of slagging holes 113 is also multiple, and the multiple slagging holes 113 are also uniformly distributed along the circumference of the outer percussion head 110, and their axes coincide with the center lines of the slagging grooves 112. This design ensures that the broken rock produced during impact can be timely and effectively discharged from the drill hole, ensuring smooth drilling operation. In this embodiment, the number of slagging grooves 112 is 3, and the 3 slagging grooves 112 are spaced 120° apart. Correspondingly, the number of slagging holes 113 is also 3.

[0039] The mounting portion 130 is assembled to the rear end face of the inner impact head 120. It can be understood that the end face of the inner impact head 120 close to the rock is the front end face, and the rear end face is opposite to the front end face. The mounting portion 130 is integrally formed with the inner impact head 120 or detachably connected. The impact drill bit is mounted to the output end of the impactor through the mounting portion 130 to provide impact power for the drill bit. The air inlet channel 131 for passing in compressed air is arranged in the mounting portion 130 along the axis of the impact drill bit 100, and the flushing channel 132 is arranged in the inner impact head 120. The inlet of the flushing channel 132 is communicated to the air inlet channel 131, and the outlet extends to the front end face of the inner impact head 120 to form the air outlet hole 133. The number of the flushing channels 132 is multiple, and the number of the air outlet holes 133 corresponds to the number of the flushing channels 132. Each flushing channel 132 is communicated to the air inlet channel 131, and the outlets of the multiple flushing channels 132 are uniformly distributed in the form of a ring array on the front end face of the inner impact head 120. In the embodiment, the number of the flushing channels 132 is three, and the three flushing channels 132 are arranged around the center of the inner impact head 120 in the form of a ring array with an interval of 120°.

[0040] The flushing channels 132 are arranged in the inner impact head 120 in a manner that is inclined from the center to the edge of the inner impact head 120. By passing high-pressure liquid or gas into the air inlet channel 131, the fluid can be sprayed to the bottom of the drill hole through the flushing channels 132, further assisting the rock to be discharged, and improving the efficiency of the rock discharge.

[0041] The outer impact head 110 and the inner impact head 120 are detachably connected, for example, a threaded connection can be used. An external thread is arranged on the outer periphery of the inner impact head 120, and an internal thread matched with the external thread is arranged on the inner wall of the outer impact head 110. The two can be detached and installed by rotating, which is convenient for replacing the hard alloy tooth group when it is worn or damaged. Of course, other detachable connection modes such as buckle connection can also be used.

[0042] In some optional embodiments, the second hard alloy tooth group 121 also includes two circles of hard alloy teeth independent of each other. Preferably, the hard alloy tooth group of the outer circle is distributed on the front end face of the inner impact head 120 and close to the edge, and the hard alloy tooth group of the inner circle surrounds the opening of the flushing channel 132 on the inner impact head 120, so as to obtain a better flushing and discharging effect.

[0043] In the actual working process, when the percussion drill bit 100 is connected with the drill rod and starts to work, the outer impact head 110 first contacts the rock, and the first hard alloy tooth group 111 on the front end face thereof cuts the rock to form an annular guide groove. Due to the inclined arrangement of the two circles of hard alloy teeth, the transverse resonance generated by the drill rod system during the impact process can be effectively inhibited, the drilling axis accuracy can be ensured, and the occurrence of drilling deviation can be reduced. With the drilling of the outer impact head 110, the inner impact head 120 is constrained in the guide groove, and the second hard alloy tooth group 121 on the front end face thereof breaks the rock in the annular groove. Due to the complementary arrangement of the second hard alloy tooth group 121 and the hollow uncovered area of the outer impact head 110, the rock can be fully broken.

[0044] In the process of impact breaking of the rock, the broken rock enters the discharge hole 113 through the discharge slot 112 to realize real-time discharge. At the same time, the fluid introduced through the air inlet channel 131 and the flushing channel 132 can flush and push the broken rock at the bottom of the drill hole, so that the broken rock can pass through the discharge structure more smoothly and be discharged outside the hole. The synergistic working mechanism of impact breaking and fluid discharge effectively improves the continuity of the drilling operation and the overall construction efficiency.

[0045] In addition, the percussion drill bit of the utility model can be used as an impact drill bit of a down-the-hole drill, and when applied to a down-the-hole drill device, the mounting portion 130 is adaptively connected with the drill rod of the down-the-hole drill, the impact power provided by the down-the-hole drill is utilized, the outer impact head 110 and the inner impact head 120 work cooperatively, and the drilling operation is completed. It can also be used as the front end impact drill bit after the drill rod is connected with the hydraulic rock drill, and when applied to the hydraulic rock drill, the mounting portion 130 is adaptively connected with the output end of the drill rod connected with the hydraulic rock drill, and the drilling operation on the rock is realized by means of the power of the hydraulic rock drill.

[0046] The percussion drill bit 100 of the utility model effectively solves the problems in the prior art through the above structural design and cooperative working mode. In actual application, not only can the core-free operation be realized and the safety hazard of high-altitude core taking operation be eliminated, but also the accuracy and safety of drilling can be ensured, the construction efficiency is improved, and the utility model has strong universality and adaptability, thereby providing strong support for popularization and application of the non-explosive excavation technology in high-precision requirement scenes.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model and not to limit the utility model. Although the utility model has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the utility model can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions, and all should be covered in the scope of the claims of the utility model.

Claims

1. An impact drill bit, characterized by: The impact drill bit (100) comprises: an outer impact head (110) in a cylindrical structure, the front end surface of which is provided with a first hard alloy tooth group (111); an inner impact head (120) coaxially nested inside the outer impact head (110), and the front end surface of which is provided with a second hard alloy tooth group (121); a slag discharge structure comprising a slag discharge notch (112) formed on the surface of the outer impact head (110), and a slag discharge hole (113) formed in the slag discharge notch (112) to discharge the broken stones generated during the impact process; wherein the first hard alloy tooth group (111) and the second hard alloy tooth group (121) each comprise a plurality of annularly distributed hard alloy teeth.

2. The impact bit of claim 1, wherein: The outer impact head (110) and the inner impact head (120) are detachably connected.

3. The impact bit of claim 1, wherein: The hard alloy tooth impact coverage area of the second hard alloy tooth group (121) and the hollow uncovered area of the outer impact head (110) form a complement.

4. The impact bit of claim 1, wherein: The number of the slag discharge notches (112) is multiple, and the multiple slag discharge notches (112) are uniformly distributed along the circumference of the outer impact head (110).

5. The impact bit of claim 4, wherein: The number of the slag discharge holes (113) is multiple, and the multiple slag discharge holes (113) are uniformly distributed along the circumference of the outer impact head (110), and the axis thereof coincides with the center line of the slag discharge notch (112).

6. The impact bit of claim 1, wherein: The impact drill bit (100) further comprises a mounting portion (130) assembled to the rear end surface of the inner impact head (120), which is integrally formed with the inner impact head (120) or detachably connected in a separate manner; the impact drill bit (100) is mounted to the output end of the impactor through the mounting portion (130).

7. The impact bit of claim 6, wherein: An air inlet channel (131) for passing in compressed air is arranged along the axis of the impact drill bit (100) in the mounting portion (130), and a flushing channel (132) is formed in the inner impact head (120); the inlet of the flushing channel (132) is communicated to the air inlet channel (131), and the outlet extends to the front end surface of the inner impact head (120) to form an air outlet hole (133).

8. The impact bit of claim 7, wherein: The number of the flushing channels (132) is multiple, and each of the flushing channels (132) is communicated to the air inlet channel (131); the outlets of the multiple flushing channels (132) are uniformly distributed in an annular array manner on the front end surface of the inner impact head (120).

9. A percussion drill bit according to claim 7 or 8, characterized in that: The flushing channels (132) are arranged in the inner impact head (120) in a manner inclined from the center to the edge of the inner impact head (120).

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