Self-tapping stainless steel threaded bolt

Abstract

The invention relates to the technical field of self-tapping bolts, in particular to a self-tapping stainless steel threaded bolt which comprises a nut head, a bolt rod is fixedly connected to the bottom end of the nut head, self-tapping threads are arranged on the outer side wall face of the bolt rod, a compensation device is arranged in the bolt rod, an ejector rod is arranged in the compensation device, and when the bolt rod is completely inserted into a base material, the ejector rod is inserted into the base material. The self-tapping thread and the tightening latch abut against the base material through the ejector rod. The compensation device comprises a placement hole formed in the bottom end of the tightening latch, a plurality of partition grooves are evenly formed in the inner side wall face of the placement hole, and the partition grooves communicate with the exterior of the tightening latch; an ejector rod is movably installed in the containing hole and is in a circular truncated cone shape, the side wall face of the containing hole is a conical face, and the conical face abuts against the side wall face of the ejector rod; the top end of the ejector rod does not make contact with the bottom end of the containing hole. The problem that the anti-drawing performance of the self-tapping bolt is reduced due to the fact that the connecting tightness degree between the self-tapping thread and the base material is insufficient is solved.

Description

Technical Field

[0001] This invention relates to the field of self-tapping bolt technology, specifically a self-tapping stainless steel threaded bolt. Background Technology

[0002] Self-tapping bolts, also known as self-tapping anchors, are threaded fasteners commonly used in the construction industry. To use a self-tapping bolt, a hole must first be drilled in the substrate. The bolt is then placed in the hole and screwed in. During this process, the threads on the bolt break down the inner wall of the hole, allowing them to embed and significantly increase the length of the threads that grip the substrate. This results in a much stronger bond between the bolt and the substrate, leading to excellent pull-out resistance. Furthermore, self-tapping bolts require only two steps to complete the connection, greatly improving work efficiency. Therefore, they are widely used.

[0003] Existing self-tapping bolts generally take the form shown in patent number CN103452992B, entitled "An Anchor Bolt." This type of self-tapping bolt relies on the compressive and shear forces exerted by the threads on the substrate to penetrate it. When the substrate is a brittle material such as concrete, the substrate's brittleness makes it prone to fracture when the threads break, causing surrounding material to crumble. This means the actual damage caused by the threads is greater than intended. This crumbling material is pushed and falls to the bottom of the hole as the threads continue to penetrate, rather than remaining in its original position. This creates a localized cavity at the fracture site, limiting the actual gripping length of the threads on the substrate. Consequently, the tightness of the connection between the threads and the substrate is reduced, ultimately negatively impacting the pull-out resistance of the self-tapping bolt.

[0004] Therefore, a self-tapping stainless steel threaded bolt is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a self-tapping stainless steel threaded bolt to solve the problem of reduced pull-out resistance of the self-tapping bolt due to insufficient tightness of connection between the self-tapping thread and the substrate.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A self-tapping stainless steel threaded bolt includes a nut head, a bolt rod fixedly connected to the bottom end of the nut head, a self-tapping thread on the outer wall of the bolt rod, a compensation device inside the bolt rod, and a push rod inside the compensation device. When the bolt rod is fully inserted into the substrate, the push rod presses the self-tapping thread and the bolt rod against the substrate.

[0007] Based on this setup, when using this invention, a hole is first drilled in the substrate where the bolt needs to be embedded using an electric drill. Then, the bottom end of the bolt rod of this invention is placed at the opening of the drilled hole. An electric wrench is then used to screw the invention into the substrate. During this process, the self-tapping thread cuts the hole wall, and simultaneously, the bolt rod and the self-tapping thread adhere to the hole wall, thus allowing the bolt to grip the substrate. When the bolt has penetrated to a predetermined depth, the push rod abuts against the bottom of the drilled hole, causing the push rod to be pushed upwards. This drives the compensation device, which pushes the bolt rod and the self-tapping thread towards the hole wall, allowing the sidewall of the bolt rod and the self-tapping thread to adhere more tightly to the substrate, resulting in a better grip and compensating for the reduced pull-out resistance of the self-tapping bolt caused by insufficient tightness in the connection between the self-tapping thread and the substrate.

[0008] Preferably, the compensation device includes a placement hole at the bottom of the bolt, and a plurality of dividing grooves are evenly formed on the inner side wall of the placement hole, the dividing grooves communicating with the outside of the bolt; a push rod is movably installed in the placement hole, the push rod is frustoconical, the side wall of the placement hole is conical, and the conical surface abuts against the side wall of the push rod; the top end of the push rod does not contact the bottom end of the placement hole.

[0009] With this setup, when the bolt penetrates the substrate to a predetermined depth, the push rod will abut against the bottom of the drilled hole, causing it to be pushed upwards. The sidewall of the push rod will then press against the sidewall of the placement hole. Furthermore, the presence of the dividing groove divides the bolt into multiple independent plate-like structures. These plate-like structures will open outwards due to the pressure of the frustum-shaped push rod, and under the pressure of the push rod, they will fit more tightly against the substrate. This allows the sidewall of the bolt and the self-tapping threads to fit more closely against the substrate, achieving a better grip and compensating for the reduced pull-out resistance of the self-tapping bolt caused by insufficient tightness in the connection between the self-tapping threads and the substrate.

[0010] Preferably, the bottom end of the push rod has an extension that protrudes beyond the bottom end of the bolt rod. The bottom end of the extension has a gathering groove, which is a spherical groove, and the center of the gathering groove is on the same straight line as the axis of the push rod.

[0011] When the bolt is driven down into the substrate, the material cut off from the hole wall will be pushed into the bottom of the hole by the self-tapping thread and gravity, and will eventually accumulate at the bottom of the hole. As a result, when the push rod receives the extrusion force from the bottom of the hole, it will inevitably be squeezed by these fragments.

[0012] However, the accumulation of these debris materials is complex and varied. If the amount of debris accumulation on one side of the bottom of the borehole is greater than that on the opposite side, the push rod may be subjected to unnecessary bending moment and overturn when it tries to receive the extrusion force from the bottom of the borehole on its bottom end face. This results in the extrusion force exerted by the push rod on a specific local side wall of the placement hole being greater than the extrusion force exerted by the push rod on other parts of the side wall of the placement hole. Consequently, the friction force on the push rod is increased, making it more difficult to push it upward in the placement hole. Furthermore, when the push rod moves in the placement hole with excessive extrusion force, it may also damage the bolt rod, thereby reducing the pull-out resistance of the bolt.

[0013] By incorporating the extension and the gathering groove, the scrap material can be directly compressed against the gathering groove when it comes into contact with the bottom of the push rod. Utilizing the spherical shape of the gathering groove, the reaction force from the groove on the scrap material will have a horizontal component along the axis of the push rod. This causes the scrap material to tend to move towards the center of the gathering groove. Finally, at the center of the gathering groove, the resultant force of all the extrusion forces exerted by the scrap material on the push rod will be entirely along the axis of the push rod. This avoids the push rod bearing unnecessary bending moments, thereby protecting the push rod and the bolt rod from damage and improving the reliability of the invention.

[0014] Furthermore, due to the extension portion, when the top rod moves upward within the placement hole, the extension portion can take over the portion that abuts the lower end of the bolt rod. This allows the bolt rod to always grip the substrate at its full length, preventing loss of the bolt's gripping length and improving the gripping performance of the invention, thereby enhancing the bolt's pull-out resistance.

[0015] Preferably, a plurality of filling parts are fixedly installed on the side wall of the top rod, and the plurality of filling parts extend into each of the dividing grooves respectively.

[0016] By incorporating a filling section that can be positioned within the dividing groove, debris remaining on the inner wall of the drilled hole after being cut by the self-tapping thread is blocked by the filling section and prevented from entering the gap between the placement hole and the ejector rod through the dividing groove. This helps avoid increased friction between the ejector rod and the placement hole due to debris intrusion into the gap, ensuring smooth movement of the ejector rod within the placement hole and improving the stability of the movement of the invention. Simultaneously, it also helps prevent the bolt rod from experiencing concentrated high stress locally after debris intrudes into the gap, thus avoiding damage to the bolt rod due to excessive local stress and ensuring the bolt's pull-out resistance.

[0017] Based on this, a plastic cover can be fitted on the outside of the filling part, so that the side wall of the plastic cover away from the top rod is flush with the outer side of the bolt rod, and a transition fit is adopted between the plastic cover and the dividing groove.

[0018] By using a plastic cover with a transition fit and flush sides, the design effectively conceals the dividing groove, preventing residual material from the borehole wall from entering it. This prevents material from intruding into the gap between the placement hole and the push rod. Simultaneously, the low coefficient of friction between the plastic and steel materials helps reduce resistance to the push rod's movement.

[0019] Furthermore, the plastic material of the plastic cover is more flexible than the substrate. Therefore, even if the outer surface of the plastic cover rubs against the substrate during the bolt insertion process, the plastic cover will not cause additional cutting to the substrate, thus preventing unnecessary damage to the substrate. At the same time, the plastic cover can also undergo plastic deformation when it rubs against the substrate, causing the material on the outside of the plastic cover to shift in the circumferential direction of the bolt, thereby better shielding the separation groove.

[0020] Preferably, a limiting rod is fixedly installed at the bottom of the placement hole, a limiting block is provided at the lower end of the limiting rod, a limiting groove is opened at the top of the top rod, the limiting rod extends into the limiting groove, a limiting part is provided in the limiting groove, and the limiting part is used to abut against the limiting block.

[0021] During the bolt insertion into the substrate, the sidewall of the drilled hole exerts a reaction force on the bolt rod, causing the bolt rod to press inward against the push rod inside the placement hole. At this point, due to the shape fit between the push rod and the placement hole, the push rod will experience a force towards its bottom end, causing it to tend to detach from the placement hole. This design, through the abutting engagement of the limiting block and the limiting part, restricts the movement of the push rod towards its bottom end, thereby preventing the push rod from detaching during bolt insertion into the substrate and improving the reliability of the invention.

[0022] Preferably, the top of the nut head has a mounting hole extending downwards into the limiting rod. The mounting hole is a blind hole. The lower end of the limiting rod has two storage slots that communicate with the mounting hole. The limiting block is movably installed in the storage slots. A push rod is provided in the mounting hole. A V-shaped spring piece is fixedly installed at the bottom of the push rod. Both ends of the V-shape of the spring piece are fixedly connected to the limiting block. The push rod is fixedly connected to the bottom end of the V-shape of the spring piece.

[0023] With this setup, during the installation of the push rod into the placement hole, the push rod is first pushed, which then presses against the first spring, causing it to deform and retract both ends towards the installation hole. Consequently, the corresponding limiting block also retracts into the receiving groove, ultimately being completely housed within it. When the push rod is then inserted into the placement hole, the limiting block will not engage with the limiting part, allowing the limiting rod to insert into the limiting groove. When the opening height of the receiving groove is lower than the height of the limiting part, the push rod can be released. At this point, under the action of the first spring, the push rod is pushed upwards to reset, and the limiting block will also be pushed back out of the receiving groove by the elastic force of the first spring. Thus, the limiting block can now engage with the limiting part to restrict the movement of the push rod towards the bottom of the bolt.

[0024] Therefore, when the present invention needs to be disassembled and reused, the limiting block can be made not to cooperate with the limiting part by pushing the push rod, so that the top rod can be easily and smoothly disassembled, making it convenient to replace vulnerable components such as plastic covers. This allows the present invention to be conveniently restored to a brand-new state that can be reused, improving the reusability and maintainability of the present invention, and helping to save materials and reduce costs.

[0025] Preferably, the top of the nut head has a countersunk groove, the top of the push rod extends into the countersunk groove, and the height of the top of the push rod is not higher than the top height of the nut head; a U-shaped spring piece 2 is fixedly installed on the top of the push rod, and the two ends of the spring piece 2 abut against the bottom end of the countersunk groove.

[0026] This design increases the force application area when pushing the push rod using the second spring, making it easier to push and preventing the push rod tip from injuring the operator's hand. Furthermore, the countersunk groove ensures that the push rod tip is always lower than the nut head tip, reducing the risk of accidental activation by an electric wrench or other external force, thus improving the reliability of the invention. Additionally, the elasticity of the second spring also helps resist accidental activation of the push rod by external forces, further reducing the risk of accidental activation.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By setting a compensation device, when the bolt is driven downward to a predetermined depth, the push rod abuts against the bottom of the drilled hole, causing the push rod to be pushed upward. The push rod then drives the compensation device to operate, causing the compensation device to push the bolt and self-tapping thread towards the hole wall. This allows the side wall of the bolt and the self-tapping thread to fit more tightly with the substrate, thereby achieving a better gripping effect and compensating for the problem of reduced pull-out resistance of the self-tapping bolt caused by insufficient tightness of the connection between the self-tapping thread and the substrate.

[0028] 2. By setting the extension and the gathering groove, the scrap material can be directly squeezed into the gathering groove when it comes into contact with the bottom end of the push rod. Utilizing the spherical shape of the gathering groove, the reaction force from the gathering groove on the scrap material will have a horizontal component in the direction of the push rod axis. This causes the scrap material to tend to move towards the center of the gathering groove. Finally, at the center of the gathering groove, the resultant force of all the extrusion forces of the scrap material on the push rod will be entirely along the axis of the push rod. This avoids the push rod bearing unnecessary bending moments, thereby protecting the push rod and the bolt rod from damage and improving the reliability of the invention.

[0029] 3. By setting up a spring, a limiting block, and a limiting part, when the present invention needs to be disassembled and reused, the limiting block can be made not to cooperate with the limiting part by pushing the push rod, so that the top rod can be easily and smoothly disassembled, which facilitates the replacement of easily damaged components such as plastic covers. This allows the present invention to be conveniently restored to a brand-new state that can be reused, improves the reusability and maintainability of the present invention, and helps to save materials and reduce costs. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the fit between the nut head and the bolt after the top rod is removed in this invention. Figure 3 for Figure 1 Schematic diagram of the cross-section of section SS; Figure 4 for Figure 1 A magnified view of part A in the middle; Figure 5 for Figure 3 A magnified view of part B in the middle section; Figure 6 for Figure 3 A magnified view of part C in the middle; Figure 7 for Figure 5 A magnified view of part D in the middle; Figure 8 for Figure 5 A schematic diagram of the working state after the push rod is pushed down.

[0031] In the diagram: 1. Nut head; 2. Bolt rod; 3. Self-tapping thread; 4. Push rod; 5. Spring piece 2; 6. Countersunk groove; 11. Placement hole; 12. Dividing groove; 13. Mounting hole; 14. Limiting rod; 41. Filling part; 42. Plastic cover; 43. Limiting groove; 44. Limiting part; 45. Gathering groove; 46. Extension part; 51. Push rod; 52. Spring piece 1; 53. Limiting block; 54. Storage groove. Detailed Implementation

[0032] The following description, with the aid of the accompanying drawings listed in the foregoing "Description of Drawings", will clearly illustrate the specific embodiments of the present invention, in order to enable readers to have a more complete and objective understanding of the working principle and corresponding technical effects of the present invention.

[0033] like Figures 1 to 8 The image shows a specific embodiment of the present invention.

[0034] When the present invention is installed, the bolt body is composed of the nut head 1 and the bolt rod 2. The outer wall surface of the bolt rod 2 is provided with a self-tapping thread 3. A compensation device is provided inside the bolt rod 2. A push rod 4 is provided inside the compensation device. When the bolt rod 2 is fully inserted into the substrate, the push rod 4 presses the self-tapping thread 3 and the bolt rod 2 against the substrate.

[0035] The compensation device includes a placement hole 11 at the bottom of the bolt 2. Multiple dividing grooves 12 are evenly distributed on the inner side wall of the placement hole 11, and the dividing grooves 12 are connected to the outside of the bolt 2. A push rod 4 is movably installed in the placement hole 11. The push rod 4 is frustoconical, and the side wall of the placement hole 11 is conical, and the conical surface abuts against the side wall of the push rod 4. The top end of the push rod 4 does not contact the bottom end of the placement hole 11.

[0036] The bottom end of the push rod 4 has an extension 46 that protrudes beyond the bottom end of the bolt rod 2. A gathering groove 45, which is a spherical groove, is formed at the bottom end of the extension 46, and its center is aligned with the axis of the push rod 4. Multiple filling parts 41 are fixedly installed on the side wall of the push rod 4, extending into each of the dividing grooves 12. A plastic cover 42 is fitted over the outer side of each filling part 41, with the side wall of the plastic cover 42 furthest from the push rod 4 flush with the outer surface of the bolt rod 2; the plastic cover 42 fits seamlessly with the dividing groove 12.

[0037] Additionally, a limiting rod 14 is fixedly installed at the bottom of the placement hole 11, and a limiting block 53 is provided at the lower end of the limiting rod 14. A limiting groove 43 is opened at the top of the top rod 4, and the limiting rod 14 extends into the limiting groove 43. A limiting part 44 is provided in the limiting groove 43, and the limiting part 44 is used to abut against the limiting block 53. The top of the nut head 1 is provided with a mounting hole 13, which extends downward into the limiting rod 14. The mounting hole 13 is a blind hole. Two receiving grooves 54 are opened at the lower end of the limiting rod 14, and the receiving grooves 54 are connected to the mounting hole 13. The limiting block 53 is movably installed in the receiving grooves 54. A push rod 51 is provided in the mounting hole 13, and a V-shaped spring piece 52 is fixedly installed at the bottom of the push rod 51. Both ends of the V-shape of the spring piece 52 are fixedly connected to the limiting block 53, and the push rod 51 is fixedly connected to the bottom end of the V-shape of the spring piece 52. Meanwhile, a countersunk groove 6 is provided at the top of the nut head 1, and the top of the push rod 51 extends into the countersunk groove 6, and the height of the top of the push rod 51 is not higher than the top height of the nut head 1; a U-shaped spring piece 2 5 is fixedly installed at the top of the push rod 51, and the two ends of the spring piece 2 5 abut against the bottom end of the countersunk groove 6.

[0038] When this invention is in operation, a hole is first drilled in the substrate where the bolt needs to be embedded using an electric drill. Then, the bottom end of the bolt rod 2 is placed at the opening of the drilled hole. An electric wrench is then used to screw the invention into the substrate. During this process, the self-tapping thread 3 cuts the hole wall, and simultaneously, the bolt rod 2 and the self-tapping thread 3 fit against the hole wall, thus allowing the bolt to grip the substrate. When the bolt has penetrated to a predetermined depth, the push rod 4 abuts against the bottom of the drilled hole, causing the push rod 4 to be pushed upwards. The push rod 4 then drives the compensation device to actuate, causing the compensation device to push the bolt rod 2 and the self-tapping thread 3 towards the hole wall. This allows the sidewall of the bolt rod 2 and the self-tapping thread 3 to fit more tightly against the substrate, achieving a better grip and compensating for the reduced pull-out resistance of the self-tapping bolt caused by insufficient tightness in the connection between the self-tapping thread 3 and the substrate.

[0039] The compensation device works as follows: when the bolt penetrates the substrate to a predetermined depth, the push rod 4 abuts against the bottom of the drilled hole, causing it to be lifted upwards. This push rod 4's sidewall then presses against the sidewall of the placement hole 11. Furthermore, the presence of the dividing groove 12 divides the bolt 2 into multiple independent plate-like structures. These plate-like structures are then forced outwards by the pressure of the frustum-shaped push rod 4, and under the pressure of the push rod 4, they adhere more tightly to the substrate. This allows the sidewall of the bolt 2 and the self-tapping thread 3 to adhere more closely to the substrate, achieving a better grip and compensating for the reduced pull-out resistance of the self-tapping bolt caused by insufficient tightness in the connection between the self-tapping thread 3 and the substrate.

[0040] It is worth adding that when the bolt is driven downward into the substrate, the material cut off from the hole wall will be pushed into the bottom of the hole under the action of the self-tapping thread 3 and gravity, and will eventually accumulate at the bottom of the hole. Therefore, when the push rod 4 receives the extrusion force from the bottom of the hole, it will inevitably be squeezed by these fragments.

[0041] However, the accumulation of these debris materials is complex and varied. If the amount of debris accumulation on one side of the bottom of the borehole is greater than that on the opposite side, the push rod 4 may be subjected to unnecessary bending moment and overturn when it attempts to receive the extrusion force from the bottom of the borehole on its bottom end face. This results in the extrusion force exerted by the push rod 4 on a specific local side wall of the placement hole 11 being greater than the extrusion force exerted by the push rod 4 on other parts of the side wall of the placement hole 11. Consequently, the friction force on the push rod 4 is increased, making it more difficult to push it upward in the placement hole 11. Furthermore, when the push rod 4 moves in the placement hole 11 with excessive extrusion force, it may also damage the bolt rod 2, thereby reducing the pull-out resistance of the bolt.

[0042] By providing the extension 46 and the gathering groove 45, the scrap material can be directly squeezed into the gathering groove 45 when it comes into contact with the bottom end of the push rod 4. Utilizing the spherical shape of the gathering groove 45, the reaction force from the gathering groove 45 on the scrap material will have a horizontal component in the direction of the axis of the push rod 4, causing the scrap material to tend to move towards the center of the gathering groove 45. Finally, at the center of the gathering groove 45, the resultant force of all the extrusion forces of the scrap material on the push rod 4 will be entirely along the axis of the push rod 4, thereby avoiding unnecessary bending moments on the push rod 4, which helps to protect the push rod 4 and the bolt rod 2 from damage and improves the reliability of the invention.

[0043] Furthermore, due to the provision of the extension portion 46, when the top rod 4 is displaced upward within the placement hole 11, the extension portion 46 can take over the portion that abuts against the lower end of the bolt rod 2, thereby ensuring that the bolt rod 2 can always grip the substrate at its full length in the portion where it performs the function of gripping the substrate, thus preventing the loss of the bolt's gripping length, which helps to improve the gripping performance of the present invention, and further improves the bolt's pull-out resistance.

[0044] Furthermore, by setting up a spring plate 52, a push rod 51, a limiting block 53, and a limiting part 44, during the process of installing the top rod 4 into the placement hole 11, the push rod 51 is first pushed, which then compresses the spring plate 52, causing the spring plate 52 to deform and retract both ends of the spring plate 52 towards the installation hole 13. Consequently, the corresponding limiting block 53 also retracts into the receiving groove 54, ultimately being completely received within the receiving groove 54. At this point, the top rod 4 is inserted into the placement hole 11, so the limiting block 53 will not engage with the limiting part 44, allowing the limiting rod 14 to be inserted into the limiting groove 43. When the height of the opening of the receiving groove 54 is lower than the height of the limiting part 44, the push rod 51 can be released. At this time, under the action of the spring plate 52, the push rod 51 is pushed upwards to reset, and the limiting block 53 is also pushed out of the receiving groove 54 again under the elastic force of the spring plate 52. Therefore, the limiting block 53 can engage with the limiting part 44 to restrict the movement of the push rod 4 toward the bottom of the bolt 2.

[0045] Therefore, when the present invention needs to be disassembled and reused, the limiting block 53 can be made not to cooperate with the limiting part 44 by pushing the push rod 51, so that the top rod 4 can be easily and smoothly disassembled, making it convenient to replace easily damaged components such as the plastic cover 42. This allows the present invention to be conveniently restored to a brand-new state that can be reused, improving the reusability and maintainability of the present invention, and helping to save materials and reduce costs.

[0046] It should be emphasized that, based on the content described above, although the beneficial effects of the present invention have been explained in detail and corresponding specific embodiments have been provided, those skilled in the art can still achieve the same technical effects by making conventional substitutions, modifications, or other alterations to the given technical solutions without creative effort, provided they fully understand the working principle of the present invention. However, such modifications should not be considered as exceeding the scope of the present invention. Specifically, the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-tapping stainless steel threaded bolt, comprising a nut head (1), a bolt shank (2) fixedly connected to the bottom end of the nut head (1), a self-tapping thread (3) provided on the outer lateral wall surface of the bolt shank (2), characterized in that, The compensation device is provided in the bolt rod (2), and a jacking rod (4) is provided in the compensation device, and the jacking rod (4) abuts the self-tapping thread (3) and the bolt rod (2) on the base material when the bolt rod (2) is completely inserted into the base material.

2. A self-tapping stainless steel threaded bolt as claimed in claim 1, wherein, The compensation device comprises a placing hole (11) formed at the bottom end of the bolt rod (2), a plurality of split grooves (12) are uniformly formed on the inner side wall surface of the placing hole (11), and the split grooves (12) are in communication with the outside of the bolt rod (2); the jacking rod (4) is movably mounted in the placing hole (11), the jacking rod (4) is a circular truncated cone, the side wall surface of the placing hole (11) is a tapered surface, and the tapered surface is in abutment with the side wall surface of the jacking rod (4); and the top end of the jacking rod (4) is not in contact with the bottom end of the placing hole (11).

3. A self-tapping stainless steel threaded bolt as claimed in claim 2, wherein, The jacking rod (4) has an extension (46) at the bottom end, the extension (46) protrudes outward from the bottom end of the bolt rod (2), a converging groove (45) is formed at the bottom end of the extension (46), the converging groove (45) is a spherical groove, and the center of the converging groove (45) is on the same straight line as the axis of the jacking rod (4).

4. A self-tapping stainless steel threaded bolt as claimed in claim 2, wherein, A plurality of filling portions (41) are fixedly mounted on the side wall surface of the jacking rod (4), and the filling portions (41) respectively extend into the split grooves (12).

5. A self-tapping stainless steel threaded bolt as claimed in claim 4, wherein, A plastic cover (42) is sleeved outside the filling portions (41), the side wall surface of the plastic cover (42) away from the jacking rod (4) is flush with the outer side surface of the bolt rod (2); and the plastic cover (42) is in transition cooperation with the split grooves (12).

6. A self-tapping stainless steel threaded bolt as claimed in claim 2, wherein, A limiting rod (14) is fixedly mounted at the bottom end of the placing hole (11), a limiting block (53) is arranged at the lower end of the limiting rod (14), a limiting groove (43) is formed at the top end of the jacking rod (4), the limiting rod (14) extends into the limiting groove (43), a limiting portion (44) is arranged in the limiting groove (43), and the limiting portion (44) is used for abutting cooperation with the limiting block (53).

7. A self-tapping stainless steel threaded bolt as claimed in claim 6, wherein, An installation hole (13) is formed at the top end of the nut head (1), the installation hole (13) extends downward into the limiting rod (14), the installation hole (13) is a blind hole, two receiving grooves (54) are formed at the lower end of the limiting rod (14), the receiving grooves (54) are in communication with the installation hole (13), the limiting block (53) is movably mounted in the receiving groove (54), a push rod (51) is arranged in the installation hole (13), a V-shaped elastic sheet one (52) is fixedly mounted at the bottom end of the push rod (51), the two ends of the V-shaped elastic sheet one (52) are fixedly connected with the limiting block (53), and the push rod (51) is fixedly connected with the bottom end of the V-shaped elastic sheet one (52).

8. A self-tapping stainless steel threaded bolt as claimed in claim 7, wherein, A countersunk groove (6) is formed at the top end of the nut head (1), the top end of the push rod (51) extends into the countersunk groove (6), and the height of the top end of the push rod (51) is not higher than the height of the top end of the nut head (1); a U-shaped elastic sheet two (5) is fixedly mounted at the top end of the push rod (51), and the two ends of the U-shaped elastic sheet two (5) abut against the bottom end of the countersunk groove (6).

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