Anti-falling expansion bolt

Abstract

The utility model relates to the technical field of expansion bolts, in particular to an anti-falling expansion bolt. The device comprises a screw, an expansion sleeve, a gasket, a spring washer and a nut, external threads are arranged at the end, close to the nut, of the screw, a conical expansion head is arranged at the other end of the screw, a plurality of expansion grooves are formed in the end, close to the expansion head, of the expansion sleeve, and a plurality of pulling assisting holes are symmetrically formed in the periphery of the end, close to the nut, of the expansion sleeve. Marking grooves used for marking the positions of the pulling assisting holes are correspondingly formed in the positions, close to the pulling assisting holes, of the edge of the outer end of the expansion sleeve, a plurality of barbs are evenly distributed on the peripheral face of the end, close to the nut, of the expansion sleeve, and a plurality of limiting clamping grooves are formed in the end face of the end, close to the expansion head, of the expansion sleeve. A limiting protrusion capable of being clamped into the limiting clamping groove is arranged on the side, close to the limiting clamping groove, of the expansion head. After the prior art is improved, the screw rod and the expansion sleeve do not rotate along with each other in the installation process, so that the installation is relatively easy, and the overall structural stability is good after the installation is completed.

Description

Technical Field

[0001] The utility model relates to the technical field of expansion bolts, in particular to an anti-dropping expansion bolt. Background Art

[0002] As an important mechanical fastener, expansion bolts are widely used in many fields such as construction, machinery, electric power, automotive and aviation industries. Due to its unique expansion fixing mechanism, expansion bolts can achieve firm connection and fixation in various solid materials (such as concrete, stone, bricks, etc.). However, precisely because of its deep fastening position and reliable fixation, conversely, when people need to pull it out, it is very difficult. Usually, it is really difficult to pull it out unless the carrier is damaged.

[0003] In view of this, a Chinese patent document with the authorization number CN206785812U discloses a super-value expansion bolt, which includes a screw rod, a gasket, a spring washer, a nut and an expansion sleeve. A plurality of extraction holes are opened in the area near the outer end of the tube wall of the expansion sleeve, and corresponding extraction hole marks are set at the positions near the extraction holes on the outer edge of the outer end of the expansion sleeve. When it is necessary to pull out the expansion sleeve, it can be easily pulled out by the cooperation of the expansion bolt extraction pliers and the extraction holes on the expansion sleeve; however, during the tightening process of the screw rod and the nut during the installation of the above expansion bolt, the expansion sleeve will rotate with the screw rod, the overall stability is poor, and the installation is relatively time-consuming and laborious.

[0004] Therefore, it is necessary to improve the deficiencies of the above prior art. Summary of the Invention

[0005] The technical problem to be solved by the utility model is to provide an anti-dropping expansion bolt aiming at the deficiencies of the above prior art, and solve the problems that the expansion sleeve will rotate with the screw rod during the tightening process of the screw rod and the nut during the installation of the expansion bolt in the prior art, the overall stability is poor, and the installation is relatively time-consuming and laborious.

[0006] To achieve the above object, the utility model provides the following technical solution: An anti-dropping expansion bolt, which includes a screw rod, an expansion sleeve, a gasket, a spring washer and a nut. One end of the screw rod close to the nut is provided with an external thread, and the other end is provided with a tapered expansion head. A plurality of expansion grooves are provided at one end of the expansion sleeve close to the expansion head. The gasket and the spring washer are sequentially arranged between the expansion sleeve and the nut. A plurality of extraction holes are symmetrically arranged on the outer periphery of one end of the expansion sleeve close to the nut. A marking groove for marking the position of the extraction hole is correspondingly provided at the position on the outer edge of the outer end of the expansion sleeve close to the extraction hole. A plurality of barbs are evenly arranged on the outer peripheral surface of one end of the expansion sleeve close to the nut, and a plurality of limiting grooves are provided on the end surface of one end of the expansion sleeve close to the expansion head. A limiting protrusion capable of being clamped into the limiting groove is provided on one side of the expansion head close to the limiting groove.

[0007] With the above technical solution, when installing the expansion bolt, the screw rod and the expansion sleeve can be first inserted into the installation hole and then the screw rod is pulled outwards. The expansion head of the screw rod abuts against the expansion sleeve and drives the expansion sleeve to move in the opposite direction out of the installation hole, so that the barbs on the expansion sleeve can be inserted into the inner wall of the installation hole to limit the expansion sleeve and make it not easy to rotate. During the process of screwing the nut, the limiting protrusion on the expansion head can be stuck into the limiting groove, so that neither the screw rod nor the expansion sleeve rotates, making the installation relatively easy. After installation, the overall structure has good stability; when the expansion bolt needs to be removed, first remove the nut, spring washer and gasket, and then with the help of the expansion bolt extraction pliers and the extraction hole on the expansion sleeve, the expansion sleeve can be easily pulled out, and then the screw rod can be taken out.

[0008] A further setting of the above technical solution is that: the barb is a triangular sheet structure and the oblique angle is less than 45°.

[0009] With the above technical solution, the barb is set as a triangular sheet structure and the oblique angle is less than 45°, so that the barb can be more easily and firmly inserted into the inner wall of the installation hole.

[0010] A further setting of the above technical solution is that: the limiting groove is set as a semi-circular arc shape, and the two sides of the limiting protrusion are provided with arc-shaped transition arc surfaces.

[0011] With the above technical solution, the transition arc surfaces on both sides of the limiting protrusion cooperate with the semi-circular arc-shaped limiting groove, so that the limiting protrusion can be smoothly stuck into the limiting groove.

[0012] A further setting of the above technical solution is that: one end of the expansion groove far from the expansion head is communicated with an expansion round hole.

[0013] With the above technical solution, the expansion round hole can prevent the expansion groove from being torn when it expands.

[0014] A further setting of the above technical solution is that: several spiral chip guiding grooves are also provided on the middle side surface of the expansion sleeve.

[0015] With the above technical solution, the setting of the chip guiding grooves can accommodate powders and debris, which is convenient for the expansion sleeve to extend into the installation hole.

[0016] The beneficial effects achieved by the present utility model are: during the installation process, neither the screw rod nor the expansion sleeve rotates, making the installation relatively easy. After installation, the overall structure has good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0018] Figure 2 is an exploded structural diagram of an embodiment of the present utility model;

[0019] Figure 3 It is a schematic structural diagram of an expansion casing in an embodiment of the present utility model. Specific embodiments

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0021] As Figures 1-3 shown in, an anti-dropping expansion bolt includes a screw rod 1, an expansion casing 2, a gasket 3, a spring washer 4 and a nut 5. The screw rod 1 is provided with an external thread 11 at one end close to the nut 5 and a tapered expansion head 12 at the other end. The expansion casing 2 is provided with a plurality of expansion grooves 21 at one end close to the expansion head 12. The gasket 3 and the spring washer 4 are sequentially arranged between the expansion casing 2 and the nut 5. The outer circumference of the expansion casing 2 at one end close to the nut 5 is symmetrically provided with a plurality of extraction-assisting holes 22. A marking groove 23 for marking the position of the extraction-assisting holes 22 is correspondingly provided at a position on the outer edge of the outer end of the expansion casing 2 close to the extraction-assisting holes 22. A plurality of barbs 24 are uniformly arranged on the outer circumferential surface of the expansion casing 2 at one end close to the nut 5, and a plurality of limiting card slots 25 are provided on the end surface at one end close to the expansion head 12. A limiting protrusion 121 capable of being inserted into the limiting card slot 25 is provided on one side of the expansion head 12 close to the limiting card slot 25. The barb 24 is a triangular sheet structure with an oblique angle less than 45°. The limiting card slot 25 is set to be semi-circular arc-shaped, and the two sides of the limiting protrusion 121 are provided with arc-shaped transition arc surfaces. The expansion groove 21 communicates with an expansion round hole 26 at one end far from the expansion head 12. A plurality of spiral chip guide grooves 27 are further provided on the side surface of the middle part of the expansion casing 2.

[0022] In the above embodiment, when installing the expansion bolt, the screw rod 1 and the expansion casing 2 can be first inserted into the installation hole and then the screw rod 1 is pulled outwards. The expansion head 12 of the screw rod 1 abuts against the expansion casing 2 and drives the expansion casing 2 to move in the opposite direction out of the installation hole, so that the barbs 24 on the expansion casing 2 can be inserted into the inner wall of the installation hole to limit the expansion casing 2 and make it not easy to rotate. During the process of screwing the nut 5, the limiting protrusion 121 on the expansion head 12 can be inserted into the limiting card slot 25, so that neither the screw rod 1 nor the expansion casing 2 rotates, making the installation relatively easy. After installation, the overall structure has good stability. When it is necessary to remove the expansion bolt, first remove the nut 5, the spring washer 4 and the gasket 3, and then it is very easy to pull out the expansion casing 2 by means of the cooperation of an expansion bolt extraction pliers and the extraction-assisting holes 22 on the expansion casing 2, and then take out the screw rod 1.

Claims

1. An anti-drop expansion bolt, comprising a screw, an expansion sleeve, a gasket, a spring washer and a nut, wherein the screw is provided with an external thread at one end close to the nut and a conical expansion head at the other end, the expansion sleeve is provided with a plurality of expansion grooves at one end close to the expansion head, the gasket and the spring washer are sequentially arranged between the expansion sleeve and the nut, the expansion sleeve is symmetrically provided with a plurality of extraction holes at the outer periphery of one end close to the nut, and a marking groove for marking the position of the extraction holes is provided on the outer edge of the expansion sleeve at a position close to the extraction holes, characterized in that: The expansion sleeve has a plurality of barbs evenly distributed on its outer peripheral surface near the nut, a plurality of limit slots are arranged on its end surface near the expansion head, and a limit protrusion that can be inserted into the limit slot is arranged on one side of the expansion head near the limit slot.

2. The anti-drop expansion bolt according to claim 1, characterized in that: The barbs are triangular sheet-like structures with an oblique angle less than 45°.

3. The anti-drop expansion bolt according to claim 2, characterized in that: The limiting slot is configured as a semicircular arc, and both sides of the limiting protrusion are configured as arc-shaped transition surfaces.

4. The anti-drop expansion bolt according to claim 3, characterized in that: The expansion groove is connected with an expansion circular hole at one end away from the expansion head.

5. An anti-drop expansion bolt according to any one of claims 1 to 4, characterized in that: A plurality of spiral chip guide grooves are also arranged on the side surface of the middle part of the expansion sleeve.

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