Expansion bolt with bayonet

Abstract

The utility model discloses a kind of expansion bolts with bayonet, including sleeve assembly and fastening assembly, it is characterized in that, the sleeve assembly includes straight cylinder part and the expansion part connected in straight cylinder part one end, the fastening assembly includes the screw rod through sleeve assembly and the conical locking piece for supporting open expansion part with screw rod thread cooperation is used.Formation sawtooth structure by the bayonet of metal expansion petal side wall, with the bayonet point of conical locking piece surface multi-stage occlusion, cooperate the accurate guidance of truncated pyramid type cavity, realize the progressive locking of overall controllable expansion and anti-retraction, overall give consideration to installation convenience, anchoring stability, significantly improve service life.

Description

Technical Field

[0001] This utility model relates to the field of expansion bolt manufacturing technology, and in particular to an expansion bolt with a locking jaw. Background Technology

[0002] Expansion bolts, as a common fastener, are widely used in construction, machinery installation, bridge reinforcement, and other fields, especially on harder substrates such as concrete and masonry, where they have strong fixing capabilities. However, traditional expansion bolts still have many problems in use, particularly in terms of fixing stability, ease of disassembly, and reusability, where significant technical bottlenecks exist.

[0003] Although expansion bolts are widely used, existing expansion bolts have many unreasonable structural designs, leading to the following problems during installation and disassembly: In the design of traditional expansion bolts, there is no relatively fixed relationship between the expansion component and the sleeve. When the user tightens the bolt, the expansion component will rotate and cannot expand effectively. This not only affects the fixing strength of the expansion bolts but may also lead to installation failure and reduce safety. During disassembly, because the expansion component and the sleeve are not effectively fixed, the expansion component may rotate with the bolt when the user tries to loosen it, causing free spin and making it impossible to unscrew the bolt smoothly. Users often need to use external force or violence to disassemble it, which is time-consuming and may damage the mounting substrate. Because the expansion component and the sleeve are not effectively fixed, gaps may form between the various parts of the expansion bolt during repeated installation and disassembly, causing the connection structure to gradually loosen and making stable reuse impossible. After traditional expansion bolts are removed, usually only the nut can be removed, while the bolt body and expansion sleeve remain in the wall or equipment structure, forming a protruding part. In demanding installation environments, this protruding bolt residue not only affects aesthetics but may also affect construction efficiency.

[0004] To address the shortcomings of existing technologies, this invention provides an expansion bolt with a bayonet. By optimizing the structural design, it ensures locking reliability, improves disassembly convenience, and enhances reusability, thereby overcoming the technical defects of traditional expansion bolts. This makes it more suitable for modern construction, equipment installation, and other applications with high requirements for fastener performance, providing the industry with a more efficient, safe, and economical expansion bolt solution. Utility Model Content

[0005] The purpose of this invention is to provide an expansion bolt with a bayonet.

[0006] The innovation of this utility model lies in the collaborative design of the split sleeve assembly and the fastening assembly. The sawtooth structure formed by the snap-fit ​​of the metal expansion flap sidewall engages with the multi-level snap-fit ​​of the snap-fit ​​points on the surface of the conical locking part. Combined with the precise guidance of the truncated pyramidal cavity, it achieves controllable expansion and anti-retraction progressive locking. The overall design takes into account the ease of installation and anchoring stability, and significantly improves the service life.

[0007] To achieve the aforementioned objectives, the technical solution of this utility model is as follows: an expansion bolt with a bayonet, comprising a sleeve assembly and a fastening assembly, characterized in that the sleeve assembly includes a straight cylindrical portion and an expansion portion connected to one end of the straight cylindrical portion, and the fastening assembly includes a threaded rod penetrating the sleeve assembly and a tapered locking member threadedly engaged with the threaded rod to open the expansion portion. Controllable expansion is achieved through the engagement of the tapered locking member and the threaded rod, simplifying the installation process; the split design reduces processing difficulty, the straight cylindrical portion provides stable support, and the expansion portion provides anchoring functionality.

[0008] Furthermore, the expansion section includes several metal expansion flaps that are equally spaced and connected to the circumference of one end of the straight cylinder section. The equal-spaced distribution of the metal expansion flaps ensures that the expansion bolts are subjected to uniform force during expansion, avoiding local stress concentration; the multi-metal expansion flap design ensures both passage in the contracted state and the formation of a stable support surface during expansion.

[0009] Furthermore, when the metal expansion petals are not deployed, all the metal expansion petals enclose a truncated pyramidal cavity structure, and the outer wall of the metal expansion petals has a fan-shaped structure. The truncated pyramidal cavity formed by the metal expansion petals provides precise guidance for the conical locking component; after expansion, the outer wall of the fan-shaped structure forms a continuous curved surface contact with the hole wall, significantly improving the frictional anchoring force.

[0010] Furthermore, the two side walls of the fan-shaped structure are each provided with several equally spaced slots extending along the axial direction, and the slots of adjacent fan-shaped structures intersect to form a sawtooth structure. The interlocking design of the slots of adjacent fan-shaped structures forms a mechanical interlock, effectively preventing expansion and contraction; the sawtooth structure increases the roughness of the contact surface, improving the overall seismic resistance.

[0011] Furthermore, the outer surface of the tapered locking member is provided with several locking points that cooperate with the serrated structure. The locking points and the serrated structure form a multi-stage engagement, achieving progressive locking, enhancing axial load-bearing capacity, and preventing accidental loosening.

[0012] Furthermore, the metal expansion flap is made of cold-rolled spring steel plate, and a galvanized layer is provided on the surface of the metal expansion flap. The cold rolling process ensures the elastic memory performance of the metal expansion flap; the galvanized layer provides corrosion protection and extends its outdoor service life.

[0013] Furthermore, the straight cylindrical portion of the sleeve assembly is made of Q235 carbon structural steel. The plastic deformation capacity of Q235 steel can absorb impact loads and prevent brittle fracture.

[0014] Furthermore, the end of the straight cylindrical section that joins the expansion section is provided with several buffer grooves that communicate with the serrated structure. These buffer grooves serve as stress-relieving sections, dispersing the radial stress generated by expansion, reducing the risk of metal fatigue, and simultaneously improving the controllability of expansion deformation.

[0015] Furthermore, the conical locking component is made of 40Cr alloy structural steel, and a wear-resistant layer is provided on the surface of the conical locking component. Using a conical locking component made of 40Cr alloy structural steel ensures its compressive strength; the added wear-resistant layer on the surface of the conical locking component reduces the coefficient of friction and extends the number of times it can be reused.

[0016] The beneficial effects of this utility model are:

[0017] 1. In this utility model, controllable expansion is achieved through the cooperation of a conical locking component and a screw, simplifying the installation process; the split design reduces processing difficulty, the straight cylindrical part provides stable support, and the expansion part achieves anchoring function; the equidistant distribution of the added metal expansion petals ensures uniform force on the expansion bolts during expansion, avoiding local stress concentration; the multi-metal expansion petal design ensures both the passage in the contracted state and the formation of a stable support surface during expansion; the fan-shaped outer wall forms a continuous curved surface contact with the hole wall after expansion, significantly improving the frictional anchoring force.

[0018] 2. In this utility model, the interlocking design of adjacent fan-shaped structures forms a mechanical interlock, effectively preventing expansion and contraction; the sawtooth structure increases the roughness of the contact surface, improving the overall shock resistance; the interlocking points and sawtooth structure form a multi-level engagement, achieving progressive locking, enhancing the axial load bearing capacity, and preventing accidental loosening; a buffer groove is added as a stress release section to disperse the radial stress generated by expansion, reduce the risk of metal fatigue, and improve the controllability of expansion deformation.

[0019] 3. In this utility model, the elastic memory performance of the metal expansion valve is ensured by the cold rolling process; the galvanized layer provides anti-corrosion protection and extends the service life outdoors; the plastic deformation capacity of Q235 steel can absorb impact loads and avoid brittle fracture; the conical locking part made of 40Cr alloy structural steel ensures the compressive strength of the conical locking part; and the surface wear-resistant layer of the conical locking part is added to reduce the coefficient of friction and extend the number of times it can be reused. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of the overall structure of this utility model.

[0022] In the diagram: 1. Sleeve assembly; 2. Fastening assembly; 3. Straight section; 4. Expansion section; 5. Screw; 6. Conical locking element; 7. Metal expansion flap; 8. Bayonet; 9. Locking point; 10. Buffer groove; Detailed Implementation

[0023] The technical solutions in the embodiments of this utility model will now be clearly and completely described with reference to the accompanying drawings.

[0024] Example 1: As Figure 1 , 2 The diagram illustrates an expansion bolt with bayonet slots, comprising a sleeve assembly 1 and a fastening assembly 2. The sleeve assembly 1 includes a straight cylindrical portion 3 and an expansion portion 4 connected to one end of the straight cylindrical portion 3. The fastening assembly 2 includes a threaded rod 5 penetrating the sleeve assembly 1 and a conical locking member 6 threadedly engaged with the threaded rod 5 to open the expansion portion 4. The expansion portion 4 includes several metal expansion flaps 7 evenly spaced on the circumference of one end of the straight cylindrical portion 3. When not deployed, all the metal expansion flaps 7 enclose a truncated pyramidal cavity structure, with the outer wall of the metal expansion flaps 7 having a fan-shaped structure. Each of the two side walls of the fan-shaped structure has several equally spaced bayonet slots 8 extending axially, with the slots 8 of adjacent fan-shaped structures intersecting to form a serrated structure. The outer surface of the conical locking member 6 has several locking points 9 that engage with the serrated structure. The metal expansion flaps 7 are made of cold-rolled spring steel plate, and the surface of the metal expansion flaps 7 has a galvanized layer. The straight cylindrical portion of the sleeve assembly 1 is made of Q235 carbon structural steel. The straight cylindrical part 3 has several buffer grooves 10 that communicate with the serrated structure at the joint end with the expansion part 4. The conical locking part 6 is made of 40Cr alloy structural steel and has a wear-resistant layer on its surface.

[0025] The working principle of this utility model is as follows: During operation, a mounting hole is first drilled on the user's fixed wall surface, with the hole diameter approximately 2mm larger than the expansion bolt diameter. The straight cylindrical part 3 of the sleeve assembly 1 is inserted into the hole with its outer side facing outwards. A hammer is used to strike the end of the screw rod 5, causing the outer end of the screw rod 5 to fit tightly against the fixed wall surface. The screw rod 5 is tightened with a wrench, and the conical locking member 6 generates axial displacement through the threaded engagement. At this time, the sleeve assembly 1 and the screw rod 5 remain relatively stationary. As the conical locking member 6 moves axially, it gradually embeds into the truncated pyramidal cavity structure composed of several metal expansion petals 7. The locking point 9 on the outer periphery of the conical locking member 6 engages with the serrated structure on the sidewall of the metal expansion petal 7. Under the action of the conical surface, the metal expansion petal 7 undergoes elastic deformation, and the outer wall of the fan-shaped structure expands outwards to form multi-point contact. The buffer groove 10 at the end of the straight cylindrical part 3 effectively alleviates stress concentration and prevents deformation at the root of the metal expansion petal 7. When the predetermined torque is reached, the locking point 9 is fully embedded in the locking slot 8, forming a mechanical self-locking mechanism. During disassembly, rotate screw 5 in the opposite direction to achieve non-destructive disassembly.

[0026] In summary, the described embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. An expansion bolt with a bayonet, comprising a sleeve assembly and a fastening assembly, characterized in that, The sleeve assembly includes a straight cylindrical section and an expansion section connected to one end of the straight cylindrical section. The fastening assembly includes a screw penetrating the sleeve assembly and a conical locking member threadedly engaged with the screw to open the expansion section. The expansion section includes several metal expansion petals connected at equal intervals to the circumference of one end of the straight cylindrical section. When not unfolded, all the metal expansion petals enclose a truncated pyramidal cavity structure. The outer wall of the metal expansion petals is a fan-shaped structure. The two side walls of the fan-shaped structure are respectively provided with several equally spaced slots extending axially. The slots of adjacent fan-shaped structures intersect to form a sawtooth structure. The outer surface of the conical locking member is provided with several locking points that cooperate with the sawtooth structure.

2. The expansion bolt with a bayonet as described in claim 1, characterized in that, The metal expansion flap is made of cold-rolled spring steel plate, and the surface of the metal expansion flap is provided with a galvanized layer.

3. The expansion bolt with a bayonet as described in claim 1, characterized in that, The upper straight section of the sleeve assembly is made of Q235 carbon structural steel.

4. The expansion bolt with a bayonet according to claim 1, characterized in that, The straight section is provided with several buffer grooves at the joint end with the expansion section, which are connected to the sawtooth structure.

5. The expansion bolt with a bayonet according to claim 1, characterized in that, The conical locking component is made of 40Cr alloy structural steel, and the surface of the conical locking component is provided with a wear-resistant layer.

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