Self tapping expansion bolts

Abstract

The present invention relates to the technical field of fasteners, and provides a self-drilling expansion bolt, comprising: an expansion tube, with openings at both ends and a strip-shaped notch extending in the axial direction at one end; a bolt body, with one end in the axial direction being the first end and the other end being the second end; the first end is used to connect a drilling rig, a terminal head is formed on the second end, the size of the terminal head is larger than the inner diameter of the expansion tube, the expansion tube is slidably sleeved outside the bolt body, and one end of the expansion tube provided with the strip-shaped notch abuts against the terminal head; a locking nut is threadedly connected to the bolt body and acts on the end of the expansion tube away from the terminal head, and is used to drive the expansion tube to slide toward the terminal head; a drill bit is detachably connected to the second end. Compared with the related art, the drill bit can be disassembled and recycled after drilling a hole in the self-drilling expansion bolt, so as to realize the recycling of the drill bit and save costs. In addition, the disassembly and assembly of the drill bit can be flexibly selected according to different construction scenarios, and the drill bit can be quickly disassembled when self-drilling is not required, which improves the flexibility of construction.

Description

Technical Field

[0001] The invention relates to the technical field of fasteners, and in particular to a self-tapping expansion bolt. Background Art

[0002] In the process of fixing and installing construction, decoration and various mechanical equipment, expansion bolts are widely used as an important fastener. It achieves the fixing effect by inserting the bolts into pre-prepared holes and then using the expansion effect of the expansion tube in the hole. Self-tapping expansion bolts are a special fastener that combines the self-tapping function and the expansion fastening mechanism. Because it omits the drill tool and the drilling, hole entry and installation processes, it can improve the overall installation efficiency.

[0003] In the related art, self-drilling expansion bolts are generally drilled by a drill at the end of the bolt body. During the drilling process, the expansion tube enters the drill hole. After the drilling is completed, the expansion tube is driven to move by screwing the nut at the tail of the bolt body to expand the expansion tube, thereby realizing the installation of the self-drilling expansion bolt.

[0004] Regarding the above-mentioned related technologies, although self-drilling expansion bolts can improve installation efficiency to a certain extent, the high production cost is still one of the main factors limiting their promotion and use. Summary of the invention

[0005] The invention provides a self-drilling expansion bolt, which is used to solve the defect of high cost of the self-drilling expansion bolt in the prior art, and can effectively avoid the waste of drill bits and reduce costs.

[0006] The present invention provides a self-tapping expansion bolt, comprising: The expansion tube has two openings at both ends and one end is provided with a strip-shaped notch extending along the axial direction; The bolt body has one end in the axial direction as the first end and the other end as the second end; the first end is used to connect to the drilling rig, and the second end is formed with a head, the size of the head is larger than the inner diameter of the expansion tube, the expansion tube is slidably sleeved on the bolt body, and one end of the expansion tube provided with a strip notch is in contact with the head; A locking nut, threadedly connected to the bolt body and acting on an end of the expansion tube away from the end head, for driving the expansion tube to slide toward the end head; A drill bit is detachably connected to the second end.

[0007] According to a self-drilling expansion bolt provided by the present invention, the drill bit comprises a main body and a drill cutter; one end of the main body is detachably connected to the second end of the bolt body, and the drill cutter is fixedly connected to the other end of the main body.

[0008] According to a self-tapping expansion bolt provided by the present invention, a groove is provided at the other end of the main body relative to the second end, and the drill is embedded in the groove.

[0009] According to a self-drilling expansion bolt provided by the present invention, the drill bit and the second end are detachably connected via a connecting structure; the connecting structure comprises: a fitting portion protruding from one of the drill bit and the second end; An engaging groove is provided on the other of the drill bit and the second end, and the engaging portion engages with the engaging groove to limit the relative rotation of the drill bit and the bolt body along the circumferential direction.

[0010] According to a self-tapping expansion bolt provided by the present invention, the engaging portion comprises an insert body along the axial direction and a boss protruding from the periphery of the insert body along the radial direction; The engaging groove includes a first groove along the axial direction and a second groove extending in the radial direction and penetrating the first groove. The shapes of the first groove and the second groove are matched with the shape of the engaging portion.

[0011] According to a self-tapping expansion bolt provided by the present invention, the engaging groove further comprises a third groove, which is fan-shaped with the center of the first groove as the center and one side of the third groove is connected to the second groove for the boss to be embedded.

[0012] According to a self-tapping expansion bolt provided by the present invention, the bolt body comprises a first section and a second section which are coaxially connected; The first end is an end of the first section away from the second section, the second end is an end of the second section away from the first section, a thread is arranged on the outer circumference of the first section, and a spiral guide groove is arranged on the outer circumference of the second section.

[0013] According to a self-tapping expansion bolt provided by the present invention, the outer diameter of the end head gradually expands to a cone shape from the first end to the second end.

[0014] According to a self-tapping expansion bolt provided by the present invention, the end portion of the first end is provided with an embedding groove with a polygonal cross-section, and the embedding groove is coaxially arranged with the bolt body.

[0015] A self-tapping expansion bolt provided according to the present invention further includes a washer, which is sleeved outside the bolt body and located between the locking nut and the expansion tube.

[0016] According to a self-tapping expansion bolt provided by the present invention, a plurality of strip-shaped notches are evenly distributed around the axis of the expansion tube.

[0017] The self-tapping expansion bolt provided by the present invention is used in actual applications. The bolt body is inserted into the expansion tube. One end of the expansion tube provided with a strip notch is abutted against the end head. The drill bit is threadedly connected to the second end of the bolt body. The locking nut is threadedly connected to the bolt body and abutted against the end of the expansion tube away from the end head, so as to realize the assembly of the self-tapping expansion bolt. During construction, the drill bit is abutted against the wall, the drilling machine is started, the bolt body drives the drill bit to rotate to drill a hole, and the expansion tube enters the drill hole naturally. After the drilling is completed, the self-tapping expansion bolt is taken out from the drill hole and then the drill bit is disassembled and recycled. Then the self-tapping expansion bolt without the drill bit is inserted into the drill hole. The locking nut is screwed with a wrench or other tools. The locking nut drives the expansion tube to move toward the end head. Under the joint extrusion of the locking nut and the end head, the expansion tube expands from the strip notch to realize fixation. Compared with related technologies, the drill bit can be disassembled and recycled after drilling holes for self-drilling expansion bolts, which can achieve the recycling of the drill bit and save costs. In addition, the disassembly and assembly of the drill bit can be flexibly selected according to different construction scenarios. When self-drilling is not required, the drill bit can be quickly disassembled, which improves the flexibility of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a schematic structural diagram of a self-tapping expansion bolt provided in an embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure of a drill bit provided by an embodiment of the present invention.

[0021] Figure 3 It is a structural schematic diagram of a bolt body provided by an embodiment of the present invention.

[0022] Figure 4 It is a schematic diagram of the structure of the interlocking groove provided in an embodiment of the present invention.

[0023] Figure 5 It is a cross-sectional view of the fitting groove along the CC direction provided by an embodiment of the present invention.

[0024] Figure 6 It is a cross-sectional view of the fitting groove along the DD direction provided by an embodiment of the present invention.

[0025] Reference numerals: 10. expansion tube; 11. strip notch; 20. bolt body; 200. first section; 201. second section; 21. end; 22. embedding groove; 30. locking nut; 40. drill bit; 41. main body; 42. drill bit; 50. connection structure; 51. embedding part; 510. insert; 511. boss; 52. embedding groove; 520. first groove; 521. second groove; 522. third groove; 60. washer. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In order to better understand the self-tapping expansion bolts provided in the embodiments of the present invention, the application background thereof is first introduced. In the process of construction, decoration and fixing and installation of various mechanical equipment, expansion bolts are widely used as an important fastener, and the self-tapping expansion bolts combine the self-tapping function and the expansion fastening mechanism. Since the processes of cleaning the hole and installing the hole are omitted during the installation process, the overall installation efficiency can be improved.

[0028] In the related art, self-drilling expansion bolts are generally drilled by a drill at the end of the bolt body. During the drilling process, the expansion tube enters the drill hole. After the drilling is completed, the expansion tube is driven to move by screwing the nut at the tail of the bolt body to expand the expansion tube, thereby realizing the installation of the self-drilling expansion bolt.

[0029] Regarding the above-mentioned related technologies, although self-drilling expansion bolts can improve installation efficiency to a certain extent, the high manufacturing cost caused by the waste of drill bits is still one of the main factors restricting their promotion and use.

[0030] In view of the above problems, an embodiment of the present invention provides a self-drilling expansion bolt, which can avoid the waste of drill bits and reduce costs.

[0031] Combine the following Figure 1-Figure 6 The self-drilling expansion bolt of the present invention is described.

[0032] Reference Figure 1A self-tapping expansion bolt comprises an expansion tube 10, a bolt body 20, a locking nut 30 and a drill bit 40; wherein, the expansion tube 10 has openings at both ends and one end is provided with a strip-shaped notch 11 extending in the axial direction; one end of the bolt body 20 in the axial direction is a first end, and the other end is a second end, the first end is used to connect a drilling rig, and a terminal head 21 is formed on the second end, the size of the terminal head 21 is larger than the inner diameter of the expansion tube 10, the expansion tube 10 can be slidably sleeved outside the bolt body 20, and one end of the expansion tube 10 provided with the strip-shaped notch 11 abuts against the terminal head 21; the locking nut 30 is threadedly connected to the bolt body 20 and acts on one end of the expansion tube 10 away from the terminal head 21, and is used to drive the expansion tube 10 to slide toward the terminal head 21; the drill bit 40 is detachably connected to the second end.

[0033] The drill bit 40 is threadedly connected to the second end of the bolt body 20, and the locking nut 30 is threadedly connected to the bolt body 20 and abuts against the end of the expansion tube 10 away from the end 21, so as to realize the assembly of the self-tapping expansion bolt. During construction, the drill bit 40 is abutted against the wall, and the drilling machine is started. The bolt body 20 drives the drill bit 40 to rotate for drilling, and the expansion tube 10 enters the drill hole. After the drilling is completed, the self-tapping expansion bolt is taken out from the drill hole and the drill bit 40 is disassembled and recycled, and then the self-tapping expansion bolt without the drill bit 40 is inserted into the drill hole, and the locking nut 30 is screwed with a wrench or other tools. The locking nut 30 drives the expansion tube 10 to move toward the end 21. Under the joint extrusion of the locking nut 30 and the end 21, the expansion tube 10 expands from the strip notch 11 to achieve fixation.

[0034] Compared with the related art, the drill bit 40 can be disassembled and recycled after drilling the self-drilling expansion bolt, so that the drill bit 40 can be recycled and the cost can be saved. In addition, the disassembly and assembly of the drill bit 40 can be flexibly selected according to different construction scenarios. When self-drilling is not required, the drill bit 40 can be quickly disassembled, which improves the flexibility of construction.

[0035] In one embodiment of the present invention, referring to Figure 2 The drill bit 40 includes a main body 41 and a drill bit 42 ; one end of the main body 41 is detachably connected to the second end of the bolt body 20 , and the drill bit 42 is connected to the other end of the main body 41 .

[0036] Specifically, the drill bit 42 and the main body 41 can be integrally formed with the same material, or they can be made of different materials and assembled. In practical applications, in order to ensure the strength and durability of the drill bit 42 and optimize the cost and performance of the overall tool, the drill bit 42 is usually made of a high-hardness material to ensure its cutting ability, while the main body 41, as the part connecting the drill bit 42 and the bolt body 20, requires better toughness and torsional strength. Therefore, in this embodiment, the drill bit 42 and the main body 41 are made of different materials, and the two are assembled to form a whole.

[0037] In one embodiment of the present invention, a slot is provided at one end of the main body 41 away from the bolt body 20. The slot can be set to an "I" shape or a "X" shape according to actual needs. The shape of the drill 42 matches the shape of the slot and is embedded in the slot, thereby realizing the assembly of the drill 42 and the main body 41.

[0038] In one embodiment of the present invention, referring to Figures 2 to 4 , the drill bit 40 and the second end of the bolt body 20 are detachably connected through a connecting structure 50; the connecting structure 50 includes a fitting portion 51 and a fitting groove 52; wherein the fitting portion 51 is convexly provided on one of the drill bit 40 and the second end, and the fitting groove 52 is provided on the other of the drill bit 40 and the second end, and the fitting portion 51 and the fitting groove 52 are fitted to limit the relative rotation of the drill bit 40 and the bolt body 20 along the circumferential direction. In this way, when the drill bit 40 is connected, the fitting portion 51 and the fitting groove 52 are fitted to limit the relative rotation of the drill bit 40 and the bolt body 20 along the circumferential direction, so that the bolt body 20 can drive the drill bit 40 to rotate to drill a hole, and after the drilling is completed, the drill bit 40 is pulled axially to realize the disassembly of the drill bit 40 and the bolt body 20.

[0039] Specifically, the engaging portion 51 is connected to the drill bit 40 , and the engaging groove 52 is opened at the second end of the bolt body 20 .

[0040] In one embodiment of the present invention, referring to Figures 2 to 6 The interlocking portion 51 includes an insert body 510 along the axial direction and a boss 511 radially protruding from the outer periphery of the insert body 510; the interlocking groove 52 includes a first groove 520 extending along the axial direction and a second groove 521 extending along the radial direction and penetrating the first groove 520, and the shapes of the first groove 520 and the second groove 521 are arranged to match the shape of the interlocking portion 51.

[0041] When actually connecting the drill bit 40, the insertion body 510 of the engaging portion 51 is made to correspond to the first groove 520, and the boss 511 of the engaging groove 52 is made to correspond to the second groove 521, and then the engaging portion 51 is axially inserted into the engaging groove 52 to realize the connection of the drill bit 40 on the bolt body 20. Under the restriction of the engaging boss 511 and the second groove 521, the circumferential relative rotation of the drill bit 40 and the bolt body 20 can be avoided, so that the bolt body 20 can drive the drill bit 40 to rotate to drill holes; when the drill bit 40 needs to be removed, the drill bit 40 and the bolt body 20 only need to be pulled axially to realize the separation of the engaging portion 51 and the engaging groove 52, thereby realizing the removal of the drill bit 40.

[0042] Although the above solution can facilitate the disassembly of the drill bit 40 and the bolt body 20, the drill bit 40 may fall off and remain in the drill hole during the process of pulling the self-drilling expansion bolt out of the drill hole to recover the drill bit 40.

[0043] To solve the above problems, in one embodiment of the present invention, the engaging groove 52 further includes a third groove 522 . The third groove 522 is fan-shaped with the center of the first groove 520 as the center and one side is connected to the second groove 521 for the boss 511 to be embedded.

[0044] When the drill bit 40 is actually connected, the insertion body 510 of the engaging portion 51 is made to correspond to the first groove 520, and the boss 511 of the engaging groove 52 is made to correspond to the second groove 521. Then, the engaging portion 51 is inserted into the engaging groove 52 along the axial direction, and the drill bit 40 is rotated circumferentially. The boss 511 of the engaging portion 51 is embedded in the third groove 522. The engaging boss 511 and the third groove 522 can limit the drill bit 40 and the bolt body 20 axially and circumferentially, which can prevent the drill bit 40 and the bolt body 20 from generating circumferential relative rotation, so that the bolt body 20 can drive the drill bit 40 to rotate to drill a hole, and can also prevent the drill bit 40 from directly detaching from the bolt body 20 along the axial direction, thereby avoiding the problem of the drill bit 40 being left in the drill hole when the drill bit 40 is recovered.

[0045] When the drill bit 40 needs to be removed, rotate the drill bit 40 circumferentially so that the insert body 510 corresponds to the first groove 520, and the boss 511 of the engaging groove 52 corresponds to the second groove 521. Then, the drill bit 40 and the bolt body 20 are pulled axially to separate the engaging portion 51 and the engaging groove 52, thereby realizing the removal of the drill bit 40.

[0046] The specific structure of other components of the self-drilling expansion bolt will be described in detail below with reference to the accompanying drawings.

[0047] Reference Figure 1In one embodiment of the present invention, a strip-shaped notch 11 axially penetrates the end of the expansion tube 10 and is evenly distributed around the axis of the expansion tube 10. With this arrangement, when the locking nut 30 pushes the expansion tube 10 to slide toward the end head 21, the expansion tube 10 can be evenly expanded from the strip-shaped notch 11, thereby improving the efficiency of the expansion tube 10 deforming outward.

[0048] Reference Figure 1 In one embodiment of the present invention, the bolt body 20 includes a first section 200 and a second section 201 that are coaxially connected; the end of the first section 200 away from the second section 201 is the above-mentioned first end, and the end of the second section 201 away from the first section 200 is the above-mentioned second end. The outer periphery of the first section 200 is provided with a thread, and the outer periphery of the second section 201 is provided with a spiral guide groove.

[0049] With such a configuration, during the drilling process of the self-drilling expansion bolt, a portion of the wall debris will be discharged through the strip opening on the expansion tube 10, while the remaining wall debris will be filled in the gap between the bolt body 20 and the expansion tube 10. This design not only helps to maintain the smoothness of the drilling process and prevent the wall debris from hindering the construction, thereby improving the drilling efficiency. In addition, the wall debris filled in can also play a supporting role, preventing the expansion tube 10 from unnecessary shrinkage during tightening, ensuring that the expansion tube 10 can expand outward more effectively, and the locking nut 30 only needs a small displacement to achieve full expansion of the expansion tube 10, reducing the length of the bolt body 20 exposed to the wall.

[0050] In one embodiment of the present invention, in order to ensure structural strength, the first section 200 and the second section 201 are integrally formed.

[0051] In some optional embodiments, the outer diameters of the first section 200 and the second section 201 may be the same or different. When the outer diameter of the first section 200 is smaller than the outer diameter of the second section 201, the gap between the first section 200 and the expansion tube 10 increases, and part of the wall debris can be discharged from the gap between the first section 200 and the expansion tube 10.

[0052] It can be understood that when the locking nut 30 and the expansion tube 10 are in an unfastened state, the normal discharge of the wall debris during the drilling process will not be hindered. When the locking nut 30 is tightened with a wrench, the locking nut 30 can apply sufficient axial pre-tightening force to the expansion tube 10, so that the expansion tube 10 overcomes any possible wall debris resistance and slides smoothly. During the locking process, the locking nut 30 will push the expansion tube 10 and the wall debris to move toward the bolt end 21. The wall debris will gather at the end 21 and help to push the expansion tube 10 outward, thereby improving the expansion efficiency of the expansion tube 10.

[0053] In order to improve the expansion efficiency of the expansion tube 10, in one embodiment of the present invention, the outer diameter of the end 21 gradually expands from the first end to the second end to form a cone.

[0054] In order to facilitate the connection between the self-drilling expansion bolt and the drilling rig, in one embodiment of the present invention, the end of the first end is provided with a embedding groove 22 with a polygonal cross section, and the embedding groove 22 is coaxially arranged with the bolt body 20. In this way, the polygonal embedding groove 22 located at the first end of the bolt body 20 can be embedded with the polygonal clamping column at the power output end of the drilling rig, so that the drilling rig can drive the bolt body 20 to rotate and drill a hole. In addition, the embedding groove 22 can further reduce the length of the self-drilling expansion bolt exposed in the wall.

[0055] It can be understood that the shape of the embedding groove 22 will be different depending on the specific form of the power output end of the drilling rig. For example, when the cross-section of the power output end of the drilling rig is a quadrilateral, the embedding groove 22 is a quadrilateral groove, and when the cross-section of the power output end of the drilling rig is a hexagon, the embedding groove 22 is a hexagonal groove. In other words, the specific shape of the embedding groove 22 can be set according to actual needs, and the specific shape of the embedding groove 22 is not limited in the embodiment of the present invention.

[0056] In one embodiment of the present invention, the self-drilling expansion bolt further includes a washer 60, which is sleeved outside the bolt body 20 and located between the locking nut 30 and the expansion tube 10. In this arrangement, when the locking nut 30 is screwed, the locking nut 30 acts on the washer 60, and the expansion tube 10 moves toward the end 21 of the bolt body 20 and expands under the push of the washer 60. The washer 60 can disperse the pressure of the locking nut 30 on the expansion tube 10, reduce local stress concentration, and avoid damage to the expansion tube 10 or the locking nut 30 due to excessive local force.

[0057] The locking nut 30 can be selected as a square nut, a hexagonal nut, etc. according to actual needs, and there is no specific limitation in the embodiment of the present invention.

[0058] It is to be understood that, without mutual contradiction, those skilled in the art may combine and combine the different embodiments or examples and the features of the different embodiments or examples described in this specification.

[0059] Through the self-drilling expansion bolt provided in the embodiment of the present invention, the drill bit 40 can be disassembled and recycled after drilling the hole of the self-drilling expansion bolt, so as to realize the recycling of the drill bit 40 and save costs. In addition, the disassembly and assembly of the drill bit 40 can be flexibly selected according to different construction scenarios. When self-drilling is not required, the drill bit 40 can be quickly disassembled, thereby improving the flexibility of construction.

[0060] Finally, 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-tapping expansion bolt, characterized in that: include: An expansion tube (10) with openings at both ends and a strip-shaped notch (11) extending in the axial direction at one end; The bolt body (20) has one end in the axial direction as a first end and the other end as a second end; the first end is used to connect to a drilling machine, and the second end is formed with an end head (21), the size of the end head (21) is larger than the inner diameter of the expansion tube (10), the expansion tube (10) is slidably sleeved outside the bolt body (20), and one end of the expansion tube (10) provided with a strip notch (11) is in contact with the end head (21); A locking nut (30) is threadedly connected to the bolt body (20) and acts on an end of the expansion tube (10) away from the end head (21) to drive the expansion tube (10) to slide toward the end head (21); A drill bit (40) is detachably connected to the second end.

2. The self-tapping expansion bolt according to claim 1, characterized in that: The drill bit (40) and the second end are detachably connected via a connecting structure (50); the connecting structure (50) comprises: An engaging portion (51) protrudingly disposed on one of the drill bit (40) and the second end; An engaging groove (52) is provided on the other of the drill bit (40) and the second end, and the engaging portion (51) engages with the engaging groove (52) to limit the relative rotation of the drill bit (40) and the bolt body (20) along the circumferential direction.

3. The self-tapping expansion bolt according to claim 2, characterized in that: The fitting portion (51) comprises an insert body (510) along the axial direction and a boss (511) protruding from the outer periphery of the insert body (510) along the radial direction; The engaging groove (52) comprises a first groove (520) along the axial direction and a second groove (521) extending in the radial direction and penetrating the first groove (520), and the shape of the arrangement of the first groove (520) and the second groove (521) is adapted to the shape of the engaging portion (51).

4. The self-tapping expansion bolt according to claim 3, characterized in that: The embedding groove (52) further comprises a third groove (522), which is fan-shaped with the center of the first groove (520) as the center and one side of which is connected to the second groove (521) for embedding the boss (511).

5. The self-tapping expansion bolt according to any one of claims 1 to 4, characterized in that: The bolt body (20) comprises a first section (200) and a second section (201) which are coaxially connected; The end of the first section (200) away from the second section (201) is the first end, and the end of the second section (201) away from the first section (200) is the second end. The outer circumference of the first section (200) is provided with a thread, and the outer circumference of the second section (201) is provided with a spiral guide groove.

6. The self-tapping expansion bolt according to claim 1, characterized in that: The outer diameter of the end head (21) gradually expands in a tapered shape from the first end to the second end.

7. The self-tapping expansion bolt according to claim 1, characterized in that: The end of the first end is provided with an embedding groove (22) with a polygonal cross section, and the embedding groove (22) is coaxially arranged with the bolt body (20).

8. The self-tapping expansion bolt according to claim 1, characterized in that: It also includes a washer (60), which is sleeved outside the bolt body (20) and located between the locking nut (30) and the expansion tube (10).

9. The self-tapping expansion bolt according to claim 1, characterized in that: A plurality of strip-shaped notches (11) are evenly distributed around the axis of the expansion tube (10).

10. The self-tapping expansion bolt according to claim 1, characterized in that: The drill bit (40) comprises a main body (41) and a drill bit (42); one end of the main body (41) is detachably connected to the second end of the bolt body (20), and the drill bit (42) is fixedly connected to the other end of the main body (41); a slot is provided at the other end of the main body (41) relative to the second end, and the drill bit (42) is embedded in the slot.

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