Unfolding type bolt capable of achieving one-way work and fastening method

Abstract

The invention provides an unfolding type bolt capable of achieving one-way work and a fastening method, and belongs to the technical field of mechanical assembly. The unfolding type bolt capable of achieving one-way work comprises a screw body, a rotating shaft and a limiting sliding block. An internal thread counter bore is formed in one end of the screw body, a sliding groove communicating with the outer side wall of the screw body is formed in the side wall of the closed end of the internal thread counter bore, the limiting sliding block is installed in the sliding groove in a sliding mode and connected with the interior of the screw body through an elastic piece, and a wedge-shaped face is arranged on the side, facing the interior of the screw body, of the limiting sliding block. The rotating shaft penetrates through the internal thread counter bore and is in threaded connection with the internal thread counter bore, and the end, facing the bottom of the internal thread counter bore, of the rotating shaft abuts against the wedge-shaped face. The unfolding type bolt can be matched with a closed-section workpiece and a large-scale working condition to achieve one-way fastening and dismounting, no component is damaged in the construction and recovery process, the structural integrity and strength are guaranteed, and meanwhile the construction difficulty and cost are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical assembly, and particularly to an expandable bolt and a fastening method for realizing one-way operation. Background Art

[0002] A bolt is a type of fastener composed of two parts: a head and a cylindrical screw rod with external threads, which needs to cooperate with a nut for firmly connecting two parts with through holes. Bolt connection has become the core connection technology in the engineering field due to its flexibility, reliability, and economy.

[0003] In the related art, for ordinary bolts, they are not applicable when facing operations in restricted spaces, closed-section members, and installations of large structures. The traditional construction method is to open hand holes on the components, and construction workers fix the bolts at the other end through these temporary holes. After construction, the temporary holes are filled again. This is not only cumbersome and time-consuming, but also easily damages the integrity of the components and ultimately reduces the bearing capacity of the structure.

[0004] Using the construction method in the related art, although traditional bolts can achieve the fastening function, they often have the defects of being unable to be disassembled unidirectionally or not being reusable after disassembly. This not only increases the use cost but also causes an unnecessary burden on the environment. In addition, using conventional one-way bolts on the market for the aforementioned fixed connection can achieve one-way disassembly, but it often needs to be achieved by damaging the components, which not only affects the integrity of the workpiece but also limits its application range. Summary of the Invention

[0005] The embodiments of the present invention provide an expandable bolt and a fastening method for realizing one-way operation, which can adapt to closed-section workpieces and large working conditions to achieve one-way fastening and disassembly, without damaging any components during construction and recycling, ensuring the integrity and strength of the structure while reducing the construction difficulty and cost. The technical solution is as follows:

[0006] In a first aspect, the embodiments of the present invention provide an expandable bolt for realizing one-way operation, including:

[0007] A screw rod body, a rotating shaft, and a limiting slider,

[0008] One end of the screw body is provided with an internal thread counterbore. On the side wall of the closed end of the internal thread counterbore, there is a sliding groove arranged along the radial direction of the screw body and communicating with the outer side wall of the screw body. The limit slider is slidably installed in the sliding groove and is connected to the inside of the screw body through an elastic member. The length of the limit slider is greater than the length of the sliding groove. On the side of the limit slider facing the inside of the screw body, there is a wedge surface. In the direction towards the opening side of the internal thread counterbore, the distance between the wedge surface and the axis of the screw body gradually increases. The rotating shaft is inserted into the internal thread counterbore and is threadedly connected to the internal thread counterbore. One end of the rotating shaft facing the bottom of the internal thread counterbore abuts against the wedge surface.

[0009] Optionally, there are multiple sliding grooves, and the multiple sliding grooves are arranged at equal angular intervals around the circumferential direction of the screw body. Each sliding groove is correspondingly provided with the limit slider.

[0010] Optionally, there are two sliding grooves, and they are symmetrically arranged with respect to the internal thread counterbore. The limit sliders in the two sliding grooves are connected through the elastic member.

[0011] Optionally, on at least one side of the sliding groove, an installation groove penetrating the screw body is opened in the same direction. The elastic member is a spring. The limit slider is provided with a hook matching the installation groove. Two ends of the elastic member are respectively hung on the hooks on the two limit sliders.

[0012] Optionally, on the end face of one end of the rotating shaft close to the opening side of the internal thread counterbore, an internal hexagonal counterbore is opened.

[0013] Optionally, one end of the rotating shaft close to the opening side of the internal thread counterbore is provided with a reduced-diameter section with a relatively smaller diameter. At the opening side of the internal thread counterbore, there is a limit ring with an inner diameter matching the diameter of the reduced-diameter section, and the reduced-diameter section is inserted through the limit ring.

[0014] Optionally, the length of the reduced-diameter section is equal to the thickness of the limit slider in the axial direction of the screw body.

[0015] Optionally, the length of the limit slider in the radial direction of the screw body is equal to the radius of the screw body. The end face of the side of the limit slider close to the outer side wall of the screw body is co-arc with the outer side wall of the screw body.

[0016] Optionally, an anti-loosening rubber ring is arranged at the end of the threaded connection between the internal thread counterbore and the rotating shaft.

[0017] Second aspect, an embodiment of the present invention further provides a fastening method for constructing an expandable bolt that realizes one-way operation as described in the first aspect above, including:

[0018] First, screw the nut onto the external thread of the screw body, then place the entire expandable bolt at the working position, and use an external tool to rotate the rotating shaft, causing it to displace inward into the internal thread counterbore and contact the wedge surface on the limit slider, so as to extend the limit slider radially outward from the sliding groove along the screw body. After that, tighten the nut to complete the fastening;

[0019] Use the external tool to reverse-rotate the rotating shaft, causing it to displace outward from the internal thread counterbore and separate from the wedge surface on the limit slider, so as to use the elastic force of the elastic member to retract the limit slider into the sliding groove. After that, remove the entire expandable bolt from the working position from the side where the nut is located.

[0020] The beneficial effects brought by the technical solution provided by the embodiment of the present invention at least include:

[0021] By adopting the expandable bolt that realizes one-way operation provided by the embodiment of the present invention, through a special design of the structure of the screw body, a rotating shaft that is single-sidedly screwed into the internal thread counterbore is set as an adjustment component. By screwing the rotating shaft to perform axial telescopic displacement relative to the screw body, the limit slider at the other end of the screw body can be controlled to slide in the sliding groove, so as to realize radial extension and retraction relative to the screw body, replacing the bolt head structure in the traditional bolt structure. Through extension and retraction adjustment, it can cooperate with the nut to achieve one-way fastening and disassembly from the working position of the component to be fixed. The operation is simple, suitable for large-scale working conditions and closed-section workpieces, and does not damage any components during construction and recovery, ensuring the integrity and strength of the structure while reducing the construction difficulty and cost. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is a front view structural schematic diagram of the expandable bolt that realizes one-way operation provided by the embodiment of the present invention;

[0024] Figure 2 is Figure 1 the sectional view taken along line A-A in

[0025] Figure 3 It is an exploded view of the structure of the expandable bolt that realizes one-way operation provided by an embodiment of the present invention;

[0026] Figure 4 It is a front view of the structure of the expandable bolt that realizes one-way operation provided by an embodiment of the present invention in cooperation with a workpiece to be fixed;

[0027] Figure 5 It is a schematic three-dimensional structure diagram of the expandable bolt that realizes one-way operation provided by an embodiment of the present invention in cooperation with a workpiece to be fixed;

[0028] Figure 6 It is a flowchart of the fastening method provided by an embodiment of the present invention.

[0029] In the figure: 1 - screw body; 2 - rotating shaft; 3 - limiting slider; 4 - elastic member; 5 - nut; 11 - internal thread counterbore; 12 - sliding groove; 13 - mounting groove; 21 - internal hexagonal counterbore; 22 - variable reduction section; 31 - wedge surface; 32 - hook; 111 - limiting ring; 112 - anti-loosening rubber ring; m - workpiece to be fixed. Detailed implementation manners

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0031] Figure 1 It is a front view structure diagram of the expandable bolt that realizes one-way operation provided by an embodiment of the present invention;

[0032] Figure 2 is Figure 1 the sectional view at A - A in

[0033] Figure 3 It is an exploded view of the structure of the expandable bolt that realizes one-way operation provided by an embodiment of the present invention;

[0034] Figure 4 It is a front view of the structure of the expandable bolt that realizes one-way operation provided by an embodiment of the present invention in cooperation with a workpiece to be fixed; Figure 5 It is a schematic three-dimensional structure diagram of the expandable bolt that realizes one-way operation provided by an embodiment of the present invention in cooperation with a workpiece to be fixed. As Figures 1 to 5 shown, an embodiment of the present invention provides an expandable bolt that realizes one-way operation, including a screw body 1, a rotating shaft 2, and a limiting slider 3.

[0035] Wherein, one end of the screw body 1 is provided with an internal thread counterbore 11, and a sliding groove 12 is arranged on the side wall of the closed end of the internal thread counterbore 11, which is arranged along the radial direction of the screw body 1 and communicates with the outer side wall of the screw body 1. The limit slider 3 is slidably installed in the sliding groove 12 and is connected to the inside of the screw body 1 through an elastic member 4. The length of the limit slider 3 is greater than the length of the sliding groove 12. A wedge surface 31 is arranged on one side of the limit slider 3 facing the inside of the screw body 1, and the distance between the wedge surface 31 and the axis of the screw body 1 gradually increases in the direction towards the opening side of the internal thread counterbore 11. The rotating shaft 2 is inserted into the internal thread counterbore 11 and is threadedly connected to the internal thread counterbore 11. One end of the rotating shaft 2 facing the bottom of the internal thread counterbore 11 abuts against the wedge surface 31.

[0036] In an embodiment of the present invention, the expandable bolt that realizes one-way operation adopts a screw body 1 with the same outer shape as that of a conventional bolt as the main structure mainly inserted into a component m to be fixed. By transforming the internal structure of the screw body 1, an internal threaded counterbore 11 is coaxially formed inside the screw body 1, and sliding grooves 12 arranged radially along the screw body 1 are formed at the closed end of the internal threaded counterbore 11 according to actual requirements. One end of the sliding groove 12 far from the internal threaded counterbore 11 communicates with the outer side wall of the screw body 1 to form a channel for the limit slider 3 to extend and retract. By additionally configuring a rotating shaft 2 with a standard external thread in the middle section, which is coaxially screwed into the internal threaded counterbore 11 and can be screwed by an external tool to realize outward extension and inward retraction relative to the screw body 1 in the axial direction. The limit slider 3 is connected to the inside of the screw body 1 through an elastic member 4. When one end of the rotating shaft 2 facing the bottom of the internal threaded counterbore 11 does not contact the limit slider 3, the limit slider 3 is integrally retracted into the sliding groove 12 under the pulling force of the elastic member 4, and the expandable bolt as a whole presents a circular rod-shaped structure, and a part of the rotating shaft 2 extends from the opening of the internal threaded counterbore 11. When it is necessary to use the expandable bolt for one-way fastening construction, the closed end of the screw body 1, that is, the end provided with the sliding groove 12 and the limit slider 3, faces the installation hole position of the component m to be fixed. First, the nut 5 is screwed onto the external thread of the screw body 1, and then the closed end of the screw body 1 is inserted into the installation hole position, and the nut 5 is used to contact the component m to realize the function of limiting and preventing falling on the operable side. Then, the rotating shaft 2 is rotated by an external tool so that it displaces into the internal threaded counterbore 11 and contacts the wedge surface 31 on the limit slider 3. Since the distance between the wedge surface 31 and the axis of the screw body 1 gradually increases in the direction towards the opening side of the internal threaded counterbore 11, during the process of the rotating shaft 2 extending inward and approaching the bottom of the internal threaded counterbore 11, the limit slider 3 will be pushed outward along the radial direction of the screw body 1, so that the limit slider 3 extends outward along the radial direction of the screw body 1 from the sliding groove 12. The outward-extended limit slider 3 can replace the bolt head structure of a conventional bolt to make a limit contact with the component m from the other side, and then the nut 5 is tightened to complete the fastening with the limit slider 3 on both sides of the component m to be fixed. When it is necessary to remove the expandable bolt from the working position, the rotating shaft 2 is rotated in the reverse direction by an external tool so that it displaces outside the internal threaded counterbore 11 and separates from the wedge surface 31 on the limit slider 3. After the abutting and outward pushing of the rotating shaft 2 are released, the limit slider 3 will move towards the direction close to the internal threaded counterbore 11 under the elastic force of the elastic member 4, and finally retract into the sliding groove 12, and then the entire expandable bolt is taken out from the working position from the side where the nut 5 is located, realizing one-way fastening and disassembly.

[0037] Using the expandable bolt for unidirectional operation provided by the embodiments of the present invention, through the special design of the structure of the screw body 1, a rotating shaft 2 screwed on one side in the internal thread counterbore 11 is set as an adjusting component. By screwing the rotating shaft 2 to perform an axial telescopic displacement relative to the screw body 1, the limit slider 3 at the other end of the screw body 1 can be controlled to slide in the sliding groove 12, so as to realize the radial extension and retraction relative to the screw body 1, so as to replace the bolt head structure in the traditional bolt structure. Through the adjustment of extension and retraction, it can cooperate with the nut 5 to realize unidirectional fastening and disassembly from the working point of the component m to be fixed. The operation is simple, suitable for large working conditions and closed-section workpieces, and does not damage any components during the construction and recovery processes. While ensuring the integrity and strength of the structure, the construction difficulty and cost are reduced.

[0038] Optionally, a plurality of sliding grooves 12 are provided, and the plurality of sliding grooves 12 are arranged at equal angular intervals around the circumference of the screw body 1, and each sliding groove 12 is correspondingly provided with a limit slider 3. By providing a plurality of sliding grooves 12 and cooperating with the limit slider 3, the contact support area between the expandable bolt and the component m to be fixed can be increased, and the force can be evenly distributed, avoiding excessive concentration of the load on a single limit slider 3 after fastening, and improving the fastening stability and service life. Further, in the embodiments of the present invention, two sliding grooves 12 are provided and are symmetrically arranged relative to the internal thread counterbore 11, and the limit sliders 3 in the two sliding grooves 12 are connected by an elastic member 4. After being pushed by the rotating shaft 2, the two limit sliders 3 will extend from the opposite sides of the screw body 1 to realize the abutting contact with the component m to be fixed. The two limit sliders 3 moving in the reverse direction can be directly interconnected through the elastic member 4 passing through the inside of the screw body 1 and passing through the internal thread counterbore 11. During the process of the rotating shaft 2 being screwed out of the internal thread counterbore 11, the two limit sliders 3 will approach each other and synchronously retract into their respective sliding grooves 12 under the pulling force of the elastic member 4, without the need to separately provide an elastic member 4 and connect it to the inside of the screw body 1 respectively, further reducing the processing difficulty.

[0039] Optionally, an installation groove 13 penetrating the screw body 1 is provided on at least one side of the same direction of the sliding groove 12, the elastic member 4 is a spring, and a hook 32 matching the installation groove 13 is provided on the limit slider 3, and the two ends of the elastic member 4 are respectively hung on the hooks 32 on the two limit sliders 3. Exemplarily, in the embodiments of the present invention, one elastic member 4-matching installation groove 13 for the elastic member 4 to penetrate the screw body 1 is provided on each side of the limit slider 3, so as to realize the limit and guidance of the spring. The elastic member 4 can pass through the screw body 1 through the installation groove 13, and the two ends are respectively hung on the hook 32 structures on the corresponding sides of the two limit sliders 3. The structure is simple and the installation is convenient. When the limit slider 3 retracts into the sliding groove 12, the installation groove 13 can also be used as a space for the hook 32 to retract, avoiding interference.

[0040] Optionally, the rotation axis 2 is close to Internal thread counterbore 11 is opened A hexagonal countersunk hole 21 is provided on one end surface of the mouth side. For example, in the embodiment of the present invention, the rotating shaft 2 can be screwed and adjusted by the hexagonal handle from the open side of the internal threaded countersunk hole 11. Compared with the traditional adjustment by a wrench, the operation mode of the hexagonal connection requires less construction space, which further improves the working adaptability of the expansion bolt.

[0041] Optionally, a relatively small diameter shrinking section 22 is provided at one end of the rotating shaft 2 near the opening side of the internal thread counterbore 11, and a limiting ring 111 whose inner diameter matches the diameter of the shrinking section 22 is provided at the opening side of the internal thread counterbore 11, and the shrinking section 22 is inserted through the limiting ring 111. Exemplarily, in the embodiment of the present invention, by providing the limiting ring 111 at the opening of the internal thread counterbore 11, and by providing the shrinking section 22 matching the inner diameter at the extended end of the rotating shaft 2 to perform expansion and contraction, the length of the shrinking section 22 is controlled to be equal to the thickness of the limiting slider 3 in the axial direction of the screw body 1. The distance from the end of the rotating shaft 2 that is farthest from the axis of the screw body 1 at the contact wedge surface 31 to the end that is closest to the axis of the screw body 1 at the contact wedge surface 31 is exactly equal to the length of the shrinking section 22. That is, by screwing in and out the entire shrinking section 22, the maximum stroke of extending and retracting the limiting slider 3 can be achieved. By abutting the limiting ring 111 and the reducing section 22 with the reducing end face of the middle section of the rotating shaft 2 provided with threads, the maximum screwing stroke of the rotating shaft 2 can be limited to prevent the rotating shaft 2 from being screwed out excessively while ensuring the adjustment accuracy.

[0042] Exemplarily, in an embodiment of the present invention, when the limit slider 3 is at the maximum extension stroke, the length of the limit slider 3 extending outside the screw body 1: the length of the wedge surface 31: the length of the limit slider 3 from the top of the wedge surface 31 to the opening of the sliding groove 12 = 3:3:4.

[0043] Optionally, the length of the limiting slider 3 in the radial direction of the screw body 1 is equal to the radius of the screw body 1, and the end face of the limiting slider 3 close to the outer wall of the screw body 1 is in the same arc as the outer wall of the screw body 1. Exemplarily, when the limiting slider 3 is retracted into the sliding groove 12 and reaches the maximum stroke, the end face of the limiting slider 3 close to the outer wall of the screw body 1 will be completely flush with the outer wall of the screw body 1, and has as large a coverage area in the length direction as possible to ensure the strength of the formed bolt head, while ensuring the structural integrity of the outer surface of the screw body 1 after retraction.

[0044] Optionally, an anti-loosening rubber ring 112 is provided at the end of the threaded connection between the internal-thread counterbore 11 and the rotating shaft 2. Exemplarily, in the embodiment of the present invention, by adding an anti-loosening rubber ring 112 at the top of the threaded portion between the screw body 1 and the rotating shaft 2, it is possible to prevent the thread from losing its self-locking ability under vibration conditions, resulting in bolt failure, and further improve the fastening stability.

[0045] Figure 6 is a flowchart of a fastening method provided by an embodiment of the present invention. As Figure 6 shown, an embodiment of the present invention also provides a fastening method for constructing an expandable bolt that realizes one-way operation as Figures 1 to 5 shown, and the method includes the following steps:

[0046] S1. First, screw the nut 5 onto the external thread of the screw body 1, then place the entire expandable bolt at the working position, and use an external tool to rotate the rotating shaft 2 so that it displaces inward into the internal-thread counterbore 11 and contacts the wedge surface 31 on the limit slider 3, so as to extend the limit slider 3 radially outward from the sliding groove 12 along the screw body 1, and then tighten the nut 5 to complete the fastening;

[0047] S2. Use an external tool to reversely rotate the rotating shaft 2 so that it displaces outward from the internal-thread counterbore 11 and separates from the wedge surface 31 on the limit slider 3, so as to use the elastic force of the elastic member 4 to retract the limit slider 3 into the sliding groove 12, and then take out the entire expandable bolt from the working position from the side where the nut 5 is located.

[0048] When using the expandable bolt that realizes one-way operation provided by the embodiment of the present invention and using the above-mentioned fastening method for fastening construction at the working position, through a special design of the structure of the screw body 1, a rotating shaft 2 that is single-sidedly screwed into the internal-thread counterbore 11 is set as an adjusting component. By screwing the rotating shaft 2 to perform axial telescopic displacement relative to the screw body 1, the limit slider 3 at the other end of the screw body 1 can be controlled to slide in the sliding groove 12, so as to realize radial extension and retraction relative to the screw body 1, so as to replace the bolt head structure in the traditional bolt structure. Through extension and retraction adjustment, it is possible to cooperate with the nut 5 to realize one-way fastening and disassembly from the working position of the component m to be fixed. The operation is simple, suitable for large-scale working conditions and closed-section workpieces, and does not damage any components during construction and recovery, ensuring the structural integrity and strength while reducing the construction difficulty and cost.

[0049] Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which this invention pertains. The terms "first", "second" and similar terms used in the specification and claims of this patent application for invention do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but mean that there is at least one. The terms "comprising" or "including" and similar terms mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. The terms "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0050] The above are only optional embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An expansion bolt that realizes one-way operation, characterized in that: include: The screw body (1), the rotating shaft (2) and the limit slider (3) are An internal threaded countersunk hole (11) is provided at one end of the screw body (1), and a sliding groove (12) is provided on the closed end side wall of the internal threaded countersunk hole (11) and is arranged along the radial direction of the screw body (1) and is connected to the outer side wall of the screw body (1). The limiting slider (3) is slidably installed in the sliding groove (12) and is connected to the inside of the screw body (1) through an elastic member (4). The length of the limiting slider (3) is greater than the length of the sliding groove (12). A wedge-shaped surface (31) is provided on one side of the limiting slider (3) facing the inside of the screw body (1); in the direction toward the opening side of the internal threaded countersunk hole (11), the distance between the wedge-shaped surface (31) and the axis of the screw body (1) gradually increases; the rotating shaft (2) is inserted into the internal threaded countersunk hole (11) and is threadedly connected to the internal threaded countersunk hole (11); and one end of the rotating shaft (2) facing the bottom of the internal threaded countersunk hole (11) abuts against the wedge-shaped surface (31).

2. The expandable bolt capable of achieving one-way operation according to claim 1, characterized in that: A plurality of the sliding grooves (12) are provided, and the plurality of the sliding grooves (12) are arranged at equal angles around the circumference of the screw body (1), and each of the sliding grooves (12) is correspondingly provided with the limiting sliding block (3).

3. The one-way expansion bolt according to claim 2, characterized in that: Two sliding grooves (12) are provided and are symmetrically arranged relative to the internal thread countersunk hole (11), and the limiting sliding blocks (3) in the two sliding grooves (12) are connected via the elastic member (4).

4. The expandable bolt capable of achieving one-way operation according to claim 3, characterized in that: At least one side of the sliding groove (12) is provided with a mounting groove (13) penetrating the screw body (1) in the same direction, the elastic member (4) is a spring, the limit slider (3) is provided with a hook (32) matching the mounting groove (13), and the two ends of the elastic member (4) are respectively mounted on the hooks (32) on the two limit sliders (3).

5. The expandable bolt capable of achieving one-way operation according to claim 1, characterized in that: A hexagonal countersunk hole (21) is formed on an end surface of the rotating shaft (2) close to the opening side of the internal thread countersunk hole (11).

6. An expandable bolt capable of achieving one-way operation according to any one of claims 1 to 5, characterized in that: A reducing section (22) with a relatively small diameter is arranged at one end of the rotating shaft (2) close to the opening side of the internal thread countersunk hole (11), and a limiting ring (111) with an inner diameter matching the diameter of the reducing section (22) is arranged on the opening side of the internal thread countersunk hole (11), and the reducing section (22) is inserted into the limiting ring (111).

7. The one-way expansion bolt according to claim 6, characterized in that: The length of the shrinking section (22) is equal to the thickness of the limiting sliding block (3) in the axial direction of the screw body (1).

8. The one-way expansion bolt according to claim 7, characterized in that: The length of the limiting slider (3) in the radial direction of the screw body (1) is equal to the radius of the screw body (1), and the end surface of one side of the limiting slider (3) close to the outer wall of the screw body (1) is in the same arc as the outer wall of the screw body (1).

9. An expandable bolt capable of achieving one-way operation according to any one of claims 1 to 5, characterized in that: An anti-loosening rubber ring (112) is provided at the end of the threaded connection between the internal thread countersunk hole (11) and the rotating shaft (2).

10. A fastening method, based on the one-way working expandable bolt according to any one of claims 1 to 9, characterized in that: include: First, the nut (5) is put onto the external thread of the screw body (1), and then the entire expansion bolt is placed at the working point. The rotating shaft (2) is rotated by using an external tool so that it moves toward the inside of the internal thread counterbore (11) and contacts the wedge surface (31) on the limiting slider (3), so that the limiting slider (3) is extended outward from the sliding groove (12) along the radial direction of the screw body (1), and then the nut (5) is tightened to complete the tightening; The rotating shaft (2) is rotated in the reverse direction by using the external tool, so that it is displaced toward the outside of the internal threaded countersunk hole (11) and separated from the wedge surface (31) on the limiting slider (3), so that the elastic force of the elastic member (4) is used to retract the limiting slider (3) into the sliding groove (12), and then the entire expanded bolt is removed from the working point from the side where the nut (5) is located.

Images