Twist-off type anti-theft bolt

Abstract

The invention belongs to the technical field of bolts, and particularly relates to a twist-off type anti-theft bolt which comprises a bolt rod with external threads and a bolt head connected to one axial end of the bolt rod. The bolt head comprises a fixed part and a movable part which can rotate relatively, the movable part is provided with a wrenching surface, and the fixed part and the movable part are connected through a connecting rod and provided with a limiting structure for limiting rotation; when the bolt is screwed, rotation limitation is relieved, so that the fixed part and the movable part can rotate relatively, and after locking, the connecting rod is broken to enable the movable part to be separated so as to achieve theft prevention; and when the bolt is loosened, rotation of the connecting rod and the bolt is limited, metal fatigue on the connecting rod when dismounting is needed due to installation errors is avoided, and the fracture threshold value is prevented from being influenced by re-dismounting, so that installation fault tolerance is improved, and scrap loss is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of bolts, and in particular relates to a twist-off anti-theft bolt. Background Art

[0002] Anti-theft bolts are a type of fastener that significantly increases the difficulty of disassembly through a special structural design, thereby preventing unauthorized disassembly and playing an anti-theft role. They are widely used in outdoor installations where anti-theft measures are required.

[0003] Traditional anti-theft bolts often use a twist-off method, which divides the bolt head into two parts and provides a weak neck between the two parts. Continuing to apply force after the bolt is tightened will cause the weak neck to break, thereby separating from the bolt head part with the wrench surface, thereby achieving an anti-theft effect. However, in actual construction, installation errors (such as position deviation and angle error) are difficult to completely avoid. If the weak neck is not twisted off, disassembly and reassembly due to installation errors will also cause the fracture threshold of the weak part to decrease. In other words, reassembly will cause metal fatigue to the weak neck, and it is easy to break prematurely before the specified tightening degree is reached after reinstallation. Even if there is no abnormality from the outside, it will not be reused for safety reasons. Therefore, in order to achieve the anti-theft effect, traditional anti-theft bolts have a low fault tolerance in bolt installation, which increases the scrapping of bolts due to installation errors in actual construction. Summary of the Invention

[0004] The purpose of the present invention is to provide a twist-off anti-theft bolt to address the above-mentioned technical problems, which allows the bolt to be disassembled and assembled multiple times in complex scenarios, thereby improving the fault tolerance of the anti-theft bolt when in use.

[0005] In view of this, the present invention provides a twist-off anti-theft bolt, comprising: The bolt shank has an external thread on its radial surface; The bolt head is connected to one axial end of the bolt rod and includes a fixed portion and a movable portion that can rotate relative to each other; A connecting rod is provided between the fixed portion and the movable portion and is used to connect the fixed portion and the movable portion; The limiting structure is installed between the fixed part and the movable part, and is used to release the restriction on the relative rotation of the two in the direction of tightening the bolt and to limit the relative rotation in the direction of loosening the bolt; The connecting rod can be broken after relative rotation occurs between the fixed portion and the movable portion, so that the movable portion is separated from the fixed portion, and a wrench surface is provided on the movable portion.

[0006] In the above technical solution, further: A plurality of anti-slip teeth arranged at equal intervals around the circumference are provided on one side of the fixing portion close to the bolt rod; Among them, the anti-slip teeth are used to prevent the bolt from slipping along the direction of loosening.

[0007] In the above technical solution, further, the limiting structure includes: A plurality of first one-way teeth are arranged at equal intervals along the circumference of a side of the fixed portion close to the movable portion; A plurality of second one-way teeth are provided at equal intervals along a circumference of a side of the movable portion close to the fixed portion and mesh with the first one-way teeth; The second one-way teeth can slide and frictionally move with the first one-way teeth in the direction of tightening the bolt, and lock with the first one-way teeth in the direction of loosening the bolt.

[0008] In the above technical solution, further: When the second one-way teeth generate frictional sliding with the first one-way teeth in the direction of tightening the bolt, the movable portion and the fixed portion can be relatively offset in the axial direction.

[0009] In the above technical solution, further: The cross-sections of the first one-way tooth and the second one-way tooth are both right triangles; Among them, along the direction of tightening the bolt, the first one-way tooth is a locking straight surface, and the second one-way tooth is a guiding inclined surface. Along the direction of loosening the bolt, the first one-way tooth is a guiding inclined surface, and the second one-way tooth is a locking straight surface.

[0010] In the above technical solution, further comprising: A connecting piece is installed between the movable part and the connecting rod and is used to connect the two; The fixing portion is provided with a first countersunk hole for embedding one end of the connecting rod; The movable portion is provided with a second countersunk hole for inserting the other end of the connecting rod, and is capable of axially sliding with the connecting rod; The connecting member allows axial offset and deflection around the axis between the movable portion and the fixed portion, and limits the offset.

[0011] In the above technical solution, further, the connecting piece includes: A limiting rod is provided radially passing through the movable portion and the connecting rod; Among them, the movable part is provided with a fixing hole fixedly connected to the limiting rod, and the connecting rod is provided with a through slot, and the two ends of the through slot are on the radial surface of the connecting rod, and the size gradually increases away from the axis direction to form a fan-shaped cross-section.

[0012] In the above technical solution, further: An annular twist-off groove is provided on the connecting rod.

[0013] In the above technical solution, further: A chamfer is formed on one side of the fixing portion away from the axis.

[0014] In the above technical solution, further: The wrench surface is formed with an external hexagonal groove, an internal hexagonal groove, a cross groove or a slotted groove for matching a wrench.

[0015] The beneficial effects of the present invention are: 1. The limiting structure is used to limit the rotation between the fixed part and the movable part in the bolt head in one direction and to release the limit in the reverse direction. That is, in the direction of tightening the bolt, the limit is released so that the movable part and the fixed part can rotate relative to each other, so that after the bolt is tightened, the connecting rod breaks and the movable part is separated, thereby achieving an anti-theft effect. In the direction of loosening the bolt, the limit is imposed so that the movable part and the fixed part cannot rotate relative to each other, thereby avoiding metal fatigue of the connecting rod during disassembly due to installation errors, and avoiding affecting the fracture threshold of the connecting rod due to re-disassembly, thereby improving the installation fault tolerance of the anti-theft bolt and reducing the effect of scrap loss.

[0016] 2. By providing anti-slip teeth on the fixing part, the resistance of the bolt in the loosening direction after it is installed in place can be further increased, thereby improving the installation stability of the bolt and further improving the anti-theft effect.

[0017] 3. By adopting the first one-way teeth and the second one-way teeth, the abutment locking strength between the fixed part and the movable part in the opposite direction of the bolt loosening is improved, on the one hand, the fault tolerance is improved, and in the case of installation error, the anti-theft bolt can be disassembled without affecting the fracture threshold of the connecting rod. On the other hand, even if the connecting rod is broken after the bolt is installed in place, the bolt can be disassembled by the axial force of the wrench and the cooperation of the first one-way teeth and the second one-way teeth, avoiding the use of unconventional disassembly due to incorrect installation due to the breakage of the connecting rod, preventing the possibility of damage to the outdoor device, or directly making a mistake and affecting the installation stability of the outdoor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 is an exploded view of the present invention; Figure 3 It is a front view of the present invention; Figure 4 This invention Figure 3 Cross-sectional view at AA in the middle; Figure 5 This invention Figure 4 Cross-sectional view at the middle BB; The markings in the figure are: 1. Bolt rod; 2. External thread; 3. Bolt head; 30. Fixed part; 31. Movable part; 4. Connecting rod; 5. Limiting structure; 50. First one-way tooth; 51. Second one-way tooth; 6. Tightening surface; 7. Anti-slip tooth; 8. Connecting piece; 80. Limiting rod; 81. Fixed hole; 82. Through slot; 9. First countersunk hole; 10. Second countersunk hole; 11. Twist-off groove; 12. Chamfer. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0020] Example 1: This embodiment provides a twist-off anti-theft bolt, comprising: The bolt shank 1 has an external thread 2 on its radial surface; The bolt head 3 is connected to one axial end of the bolt rod 1 and includes a fixed portion 30 and a movable portion 31 that can rotate relative to each other; The connecting rod 4 is provided between the fixed portion 30 and the movable portion 31 and is used to connect the fixed portion 30 and the movable portion 31; The limiting structure 5 is installed between the fixed part 30 and the movable part 31 and is used to release the restriction of the relative rotation of the two in the direction of tightening the bolt and to restrict the relative rotation in the direction of loosening the bolt; The connecting rod 4 can break after relative rotation occurs between the fixed portion 30 and the movable portion 31, and the movable portion 31 is separated from the fixed portion 30, and a wrench surface 6 is provided on the movable portion 31; At the same time, the external thread 2 on the screw rod can be a full thread or a half thread, and the fixing portion 30 and the bolt rod 1 adopt an integrated structure. Furthermore, the anti-theft bolts of the present application preferably adopt specifications of M12-M24.

[0021] The locking mechanism 5 is used to lock the locking nut 30 so that the locking nut 30 is unlocked and the locking nut 30 is unlocked, so that the user can unlock the nut 30 and the user can unlock the nut 30. The user can then unlock the nut 30 and the user can unlock the nut 30. The wrench surface 6 facilitates the cooperation between the anti-theft bolt and the wrench to apply force.

[0022] Example 2: This embodiment provides a twist-off anti-theft bolt, which, in addition to the technical solutions of the above embodiments, also has the following technical features: A surface of the fixing portion 30 close to the bolt rod 1 is provided with a plurality of anti-slip teeth 7 arranged at equal intervals around the circumference; Among them, the anti-slip teeth 7 are used to prevent the bolt from slipping along the direction of loosening; At the same time, the anti-slip teeth 7 and the fixing portion 30 adopt an integrated structure.

[0023] It can be seen from this embodiment that by providing the anti-slip teeth 7 on the fixing portion 30 , the resistance of the bolt in the loosening direction after being installed in place can be further increased, thereby improving the installation stability of the bolt and further improving the anti-theft effect.

[0024] Example 3: This embodiment provides a twist-off anti-theft bolt. In addition to the technical solutions of the above embodiments, it also has the following technical features: the limiting structure 5 includes: A plurality of first one-way teeth 50 are provided at equal intervals along a circumference of a surface of the fixed portion 30 close to the movable portion 31; A plurality of second one-way teeth 51 are provided at equal intervals along the circumference of a surface of the movable portion 31 close to the fixed portion 30 and mesh with the first one-way teeth 50; The second one-way teeth 51 can slide and rub against the first one-way teeth 50 in the direction of tightening the bolt, and lock with the first one-way teeth 50 in the direction of loosening the bolt; At the same time, the first one-way teeth 50 and the fixed portion 30 adopt an integrated structure, while the second one-way teeth 51 and the movable portion 31 adopt an integrated structure, and the number of the first one-way teeth 50 and the second one-way teeth 51 is set to be the same.

[0025] As can be seen from this embodiment, by adopting the first one-way teeth 50 and the second one-way teeth 51, the abutment and locking strength between the fixed portion 30 and the movable portion 31 is improved in the opposite direction of the bolt loosening. Therefore, on the one hand, the fault tolerance can be improved. In the case of installation errors, the anti-theft bolt can be disassembled without affecting the fracture threshold of the connecting rod 4, thus avoiding the anti-theft bolt from being scrapped; On the other hand, even if the connecting rod 4 breaks after the bolt is installed in place, the bolt can be removed by applying axial force of the wrench and cooperating with the first one-way teeth 50 and the second one-way teeth 51, thereby avoiding the possibility of being forced to use unconventional methods to remove the connecting rod 4 in the event of an incorrect installation due to a break, which may easily cause damage to the outdoor device; or directly making the mistake, which may easily cause installation errors to affect the installation stability of the outdoor device; Furthermore, after the anti-theft bolt of the present application is installed, the movable portion 31 needs to be recovered and taken away to avoid being left at the scene and being used by thieves.

[0026] Example 4: This embodiment provides a twist-off anti-theft bolt, which, in addition to the technical solutions of the above embodiments, also has the following technical features: When the second one-way teeth 51 frictionally slide with the first one-way teeth 50 along the direction in which the bolt is tightened, the movable portion 31 and the fixed portion 30 can be relatively offset in the axial direction.

[0027] As can be seen from this embodiment, when the first one-way teeth 50 and the second one-way teeth 51 undergo frictional sliding, they are relatively offset in the axial direction, which facilitates the second one-way teeth 51 to disengage from the first one-way teeth 50, thereby enabling the movable portion 31 and the fixed portion 30 to rotate relative to each other at a large angle, thereby facilitating torsional fracture of the connecting rod 4. At the same time, when the second one-way tooth 51 and the first one-way tooth 50 are relatively offset in the axial direction, the force applied to the connecting rod 4 to achieve torsional fracture can be appropriately reduced. Specifically, when the bolt is axially in place and the connecting rod 4 is about to enter torsional fracture, the position of the fixed portion 30 and the end of the connecting rod 4 close to the fixed portion 30 is fixed. When the second one-way tooth 51 is axially offset, the movable portion 31 will be moved away from the fixed portion 30, thereby increasing the force arm applied to the end of the connecting rod 4 close to the movable portion 31, thereby reducing the torsional force accordingly, thereby having a certain effort-saving effect on the torsional fracture of the connecting rod 4.

[0028] Example 5: This embodiment provides a twist-off anti-theft bolt, which, in addition to the technical solutions of the above embodiments, also has the following technical features: The cross-sections of the first one-way tooth 50 and the second one-way tooth 51 are both right triangles; Among them, along the direction of tightening the bolt, the first one-way tooth 50 is a locking straight surface, and the second one-way tooth 51 is a guiding inclined surface. Along the direction of loosening the bolt, the first one-way tooth 50 is a guiding inclined surface, and the second one-way tooth 51 is a locking straight surface.

[0029] It can be seen from this embodiment that by making the cross-sections of the first one-way teeth 50 and the second one-way teeth 51 both right-angled triangles, it is ensured that when the bolt is rotated in the loosening direction while being driven by rotation under axial force, the locking straight surface of the second one-way teeth 51 can abut against the locking straight surface of the first one-way teeth 50, thereby ensuring the rotational drive of the first one-way teeth 50, the fixing portion 30 and the bolt rod 1, facilitating disassembly, and preventing slippage, thereby improving stability during rotation. When the bolt is rotated in the tightening direction, the guiding inclined surface of the second one-way tooth 51 can abut against the guiding inclined surface of the first one-way tooth 50, and there is a certain friction force under the action of the axial force. In the initial stage of bolt installation, no torsional force is caused to the connecting rod 4. When the bolt is installed in place and there is a large friction between the fixing portion 30 and the installation surface, the axial force is not enough to maintain the guiding inclined surface of the second one-way tooth 51 and the first one-way tooth 50 abutting against each other, thereby causing friction slip, pushing the second one-way tooth 51 and the movable portion 31 to axially deviate, and causing the movable portion 31 to rotate relative to the fixed portion, thereby breaking the connecting rod 4 and completing the installation of the anti-theft bolt. Therefore, the axial force can be used to ensure that the torsional force is applied to the connecting rod 4 only when the friction resistance between the fixing portion 30 and the installation surface can overcome the friction resistance generated by the axial force between the two guiding inclined surfaces, thereby avoiding affecting the fracture threshold due to premature application of torsional force to the connecting rod 4, thereby ensuring installation accuracy; In addition, the cooperation between multiple second one-way teeth 51 and the first one-way teeth 50 can make it unnecessary to maintain the force on the twisting surface 6 on the movable part 31 all the time. After a single rotation, the second one-way teeth 51 and the locking straight surface of the first one-way teeth 50 can perform reverse locking, converting the continuous force into a fractional force plus locking to maintain position, which not only avoids the force loss caused by rebound, but also reduces the operating intensity, thereby achieving torsional fracture of the connecting rod 4 more effortlessly.

[0030] Example 6: This embodiment provides a twist-off anti-theft bolt. In addition to the technical solutions of the above embodiments, it also has the following technical features: The connecting member 8 is installed between the movable portion 31 and the connecting rod 4 and is used to connect the two; The fixing portion 30 is provided with a first countersunk hole 9 for embedding one end of the connecting rod 4; The movable portion 31 is provided with a second countersunk hole 10 for inserting the other end of the connecting rod 4 and is capable of axially sliding with the connecting rod 4; The connecting member 8 allows axial offset and deflection around the axis between the movable portion 31 and the fixed portion 30, and limits the offset. The offset includes an axial offset distance and an axial deflection angle. The axial offset distance is equal to the axial height of the first one-way tooth 50, and the axial deflection angle is equal to 360° / N, where N is the number of first one-way teeth 50 provided. In actual situations, the axial offset distance is allowed to be slightly greater than the axial height of the first one-way tooth 50 , and the deflection angle around the axial direction is slightly greater than 360° / N, thereby reducing the machining accuracy requirements. At the same time, the fit between the connecting rod 4 and the first countersunk hole 9 is an interference fit.

[0031] It can be seen from this embodiment that the opening of the first countersunk hole 9 and the embedding of one end of the connecting rod 4 can improve the stability and accuracy of the installation of the connecting rod 4, while the second countersunk hole 10 facilitates the insertion of the connecting rod 4 into the movable portion 31, thereby facilitating the installation of the connecting member 8. In addition, the connecting member 8 allows axial offset and axial deflection to occur between the movable part 31 and the fixed part 30. On the one hand, the axial offset can facilitate the separation of the second one-way tooth 51 from the first one-way tooth 50 after axial movement, thereby facilitating the rotation of the movable part 31. On the other hand, the axial deflection can facilitate the connecting member 8 to not hinder the cooperation between the first one-way tooth 50 and the second one-way tooth 51, thereby facilitating the frictional sliding of the first one-way tooth 50 and the second one-way tooth 51 in the direction of tightening the bolt and locking in the direction of loosening the bolt.

[0032] Example 7: This embodiment provides a twist-off anti-theft bolt. In addition to the technical solutions of the above embodiments, it also has the following technical features. The connecting member 8 includes: The limiting rod 80 is provided to radially penetrate the movable portion 31 and the connecting rod 4; The movable portion 31 is provided with a fixing hole 81 fixedly connected to the limiting rod 80, and the connecting rod 4 is provided with a through slot 82. The through slot 82 has two ends on the radial surface of the connecting rod 4, and the size thereof gradually increases away from the axis to form a sector-shaped cross-section. At the same time, interference fit is adopted between the ends of the limiting rod 80 and the fixing holes 81 on the movable part 31; Furthermore, in order to ensure that the connecting rod 4 is twisted and broken, the material and size of the limit rod 80 can be selected and set as required. For example, the material can be a metal material with high hardness and good bending resistance to prevent the limit rod 80 from bending, deforming and breaking before the connecting rod 4 breaks. The selection of specific material and size is made by technicians in the relevant technical field according to the actual bolt size. It is a routine operation and will not be elaborated in this application.

[0033] It can be seen from this embodiment that by adopting the formation of the fixing hole 81, the limiting rod 80 can be connected and fixed to the movable part 31, and at the same time, the movable part 31 is limited in the axial direction by the through-slot hole 82, thereby connecting the movable part 31 to the fixed part 30, ensuring the integrity of the bolt and improving the convenience of transportation and use of the anti-theft bolt; The two ends of the slot hole 82 on the radial surface of the connecting rod 4 gradually increase in size away from the axial direction to form a fan-shaped cross-section, which makes it easier for the movable part 31 to deflect around the axial direction of the connecting rod 4 based on the limiting rod 80, thereby facilitating the cooperation between the first one-way tooth 50 and the second one-way tooth 51.

[0034] Example 8: This embodiment provides a twist-off anti-theft bolt, which, in addition to the technical solutions of the above embodiments, also has the following technical features: The connecting rod 4 is provided with an annular twist-off groove 11 .

[0035] It can be seen from this embodiment that the provision of the twist-off groove 11 facilitates the control of the position of the breaking point of the connecting rod 4, thereby preventing the protruding portion from being too long when the connecting rod 4 breaks, thereby improving the aesthetics and safety of the anti-theft bolt installation.

[0036] Example 9: This embodiment provides a twist-off anti-theft bolt, which, in addition to the technical solutions of the above embodiments, also has the following technical features: A chamfer 12 is formed on a side of the fixing portion 30 away from the axis.

[0037] It can be seen from this embodiment that the anti-theft effect of the anti-theft bolt can be further improved by setting the chamfer 12 on the fixing part 30. Specifically, the setting of the chamfer 12 increases the difficulty of lifting or damaging the fixing part 30 by using tools to bend the edge of the fixing part 30.

[0038] Example 10: This embodiment provides a twist-off anti-theft bolt, which, in addition to the technical solutions of the above embodiments, also has the following technical features: The wrench surface 6 is formed with an external hexagonal groove, an internal hexagonal groove, a cross groove or a slotted groove for matching a wrench.

[0039] It can be seen from this embodiment that by adopting the common shape and structure of the wrench surface 6 to match the wrench tool, the anti-theft bolt of the present application can be installed and disassembled in the event of installation errors using a conventional wrench tool, thereby improving applicability.

[0040] The embodiments of the present application are described above in conjunction with the accompanying drawings. Unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A twist-off anti-theft bolt, characterized in that: include: The bolt shank (1) has an external thread (2) on its radial surface; A bolt head (3) is connected to one axial end of the bolt rod (1) and comprises a fixed portion (30) and a movable portion (31) capable of relative rotation; A connecting rod (4) is provided between the fixed portion (30) and the movable portion (31) and is used for connecting the fixed portion (30) and the movable portion (31); A limiting structure (5) is installed between the fixed portion (30) and the movable portion (31) and is used to release the restriction on the relative rotation of the two in the direction of tightening the bolt and to restrict the relative rotation in the direction of loosening the bolt; The connecting rod (4) can break after relative rotation occurs between the fixed portion (30) and the movable portion (31), causing the movable portion (31) to separate from the fixed portion (30), and a wrench surface (6) is provided on the movable portion (31).

2. The twist-off anti-theft bolt according to claim 1, characterized in that: A plurality of anti-slip teeth (7) are provided on a surface of the fixing portion (30) close to the bolt rod (1) and arranged at equal intervals around the circumference; The anti-slip teeth (7) are used to prevent the bolt from slipping along the direction of loosening.

3. The twist-off anti-theft bolt according to claim 1, characterized in that: The limiting structure (5) includes: A plurality of first one-way teeth (50) are arranged at equal intervals along a circumference of a surface of the fixed portion (30) close to the movable portion (31); A plurality of second one-way teeth (51) are arranged at equal intervals along a circumference of a surface of the movable portion (31) close to the fixed portion (30), and mesh with the first one-way teeth (50); The second one-way tooth (51) can slide frictionally with the first one-way tooth (50) in the direction of tightening the bolt, and lock with the first one-way tooth (50) in the direction of loosening the bolt.

4. The twist-off anti-theft bolt according to claim 3, characterized in that: When the second one-way tooth (51) and the first one-way tooth (50) undergo frictional sliding along the direction of bolt tightening, the movable portion (31) and the fixed portion (30) can be relatively offset in the axial direction.

5. The twist-off anti-theft bolt according to claim 4, characterized in that: The cross-sections of the first one-way tooth (50) and the second one-way tooth (51) are both right triangles; In the direction of tightening the bolt, the first one-way tooth (50) is a locking straight surface, and the second one-way tooth (51) is a guiding inclined surface; in the direction of loosening the bolt, the first one-way tooth (50) is a guiding inclined surface, and the second one-way tooth (51) is a locking straight surface.

6. The twist-off anti-theft bolt according to claim 4, characterized in that: Also includes: A connecting member (8) is installed between the movable portion (31) and the connecting rod (4) and is used to connect the two; The fixing portion (30) is provided with a first countersunk hole (9) for embedding one end of the connecting rod (4); The movable portion (31) is provided with a second countersunk hole (10) for inserting the other end of the connecting rod (4), and is capable of axially sliding with the connecting rod (4); The connecting member (8) allows axial displacement and deflection about the axis between the movable portion (31) and the fixed portion (30), and limits the displacement.

7. The twist-off anti-theft bolt according to claim 6, characterized in that: The connecting member (8) comprises: A limiting rod (80) is provided radially penetrating the movable portion (31) and the connecting rod (4); The movable portion (31) is provided with a fixing hole (81) fixedly connected to the limiting rod (80), and the connecting rod (4) is provided with a through slot (82), and the two ends of the through slot (82) are on the radial surface of the connecting rod (4), and the size thereof gradually increases in a direction away from the axis to form a fan-shaped cross-section.

8. The twist-off anti-theft bolt according to claim 1, characterized in that: The connecting rod (4) is provided with an annular twist-off groove (11).

9. The twist-off anti-theft bolt according to claim 1, characterized in that: A chamfer (12) is provided on a side of the fixing portion (30) away from the axis.

10. The twist-off anti-theft bolt according to claim 1, characterized in that: The wrench surface (6) is formed with an external hexagonal slot, an internal hexagonal slot, a cross slot or a slotted slot for matching a wrench.

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