Sawtooth expansion bolt

Abstract

The invention relates to the technical field of building fasteners, and provides a sawtooth expansion bolt which comprises an expansion pipe, the periphery of the expansion pipe is provided with a head expansion structure and a middle expansion structure which can be opened in two directions, sawteeth bent outwards are distributed on the two sides of the head expansion structure, the top of the head expansion structure is provided with a guide face bent outwards, and the middle expansion structure is connected with the middle expansion structure. The head expansion structure is fixedly connected with the upper round pipe through a first bend with the expansion face sinking downwards, the upper round pipe is fixedly connected with the middle expansion structure through a second bend with the expansion face sinking upwards, and the lower round pipe is arranged on the lower side of the middle expansion structure. And the middle expansion structure is fixedly connected with the lower circular pipe through an inward V-shaped bend. And through the action of the composite expansion mechanism, the anti-drawing strength can be improved, and the displacement in the vibration test can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of building fasteners, and particularly to an expansion bolt with a sawtooth structure, which is applicable to the anchoring of brittle materials such as concrete, red bricks, perforated bricks, aerated blocks, and stones. Background Art

[0002] Deficiencies of traditional expansion bolts: There are many voids in ordinary red bricks, hollow bricks, perforated bricks, and aerated block walls. Traditional expansion bolts cannot effectively provide tensile force in holes with voids. They rely on frictional expansion and are prone to loosening in a vibrating environment. The smooth bolt body has insufficient bite force with the base material, and the anti-pulling performance is limited by the strength of the expansion piece.

[0003] Defects of existing improvement solutions: Holes with voids cannot provide effective tensile force, the strength of the aerated block base material is insufficient, threaded expansion bolts are prone to cause stress concentration and cracking of the base material, and chemical anchor bolts are complex in construction and have a long curing time. Summary of the Invention

[0004] The purpose of the present invention is to provide an expansion bolt with a sawtooth structure to overcome the problems existing in the prior art.

[0005] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a sawtooth expansion bolt, which includes an expansion tube. The periphery of the expansion tube is provided with a head expansion structure and a middle expansion structure that can expand bidirectionally. Sawteeth that bend outward are distributed on both sides of the head expansion structure. The top of the head expansion structure is provided with a guiding surface that bends outward. The head expansion structure is fixedly connected to the upper round tube through a first bend where the expansion surface sinks downward. The upper round tube is fixedly connected to the middle expansion structure through a second bend where the expansion surface rises upward. A lower round tube is provided on the lower side of the middle expansion structure. The middle expansion structure and the lower round tube are fixedly connected through an inward third bend.

[0007] Further, a tapered screw column penetrates through the center of the expansion tube. A gasket is provided on the lower side of the expansion tube, a spring washer is provided on the lower side of the gasket, and a nut is provided on the lower side of the spring washer. The expansion tube, the gasket, and the spring washer are sequentially sleeved on the outer wall of the tapered screw column, and a nut is installed at the rear end of the tapered screw column.

[0008] Further, sawteeth are symmetrically distributed on both sides of the head expansion structure, and the bending angle between the sawteeth and the head expansion structure is 45°.

[0009] Further, the angle at which the guiding surface bends outward is 45°.

[0010] Further, the third bend is in a V shape.

[0011] Advantages of the present invention:

[0012] A serrated expansion bolt provided by the present invention, in which the head of the expansion tube is bent at 45° to provide a condition for expansion. An axial serrated structure is arranged on the surface of the expansion tube. The serrated head expansion structure and the middle expansion structure sink inward through bending to adapt to the diameter of the hole. The angle between the serrations and the tube section is 45°, the serration angle is 90°, and the tooth height is 0.8 mm. Through the action of the composite expansion mechanism, the tapered bolt drives the upper part to open towards the head, and the bolt pressure is transmitted to the middle bending part to make the middle expansion structure open towards the tail, forming an anchoring effect in the front and back. Compared with ordinary expansion bolts of the same specification, the tensile strength is increased by more than 40%, and the displacement amount is reduced by 60% in the vibration test. Description of the drawings

[0013] Figure 1 is a schematic diagram of the overall structure of the serrated expansion bolt of the present invention;

[0014] Figure 2 is a schematic diagram of the overall structure of the serrated expansion bolt of the present invention.

[0015] In the figure: 1 - expansion tube, 2 - serrations, 3 - first bend, 4 - second bend, 5 - middle expansion structure, 6 - third bend, 7 - head expansion structure, 8 - guiding surface, 9 - lower round tube, 10 - upper round tube, 11 - gasket, 12 - spring washer, 13 - nut, 14 - tapered screw column. Detailed implementation manners

[0016] The present invention provides a serrated expansion bolt, including an expansion tube 1. The periphery of the expansion tube 1 is provided with a head expansion structure 7 and a middle expansion structure 5 that can be opened bidirectionally. The two sides of the head expansion structure 7 are distributed with serrations 2 that are bent outward. The top of the head expansion structure 7 is provided with a guiding surface 8 that is bent outward. The head expansion structure 7 is fixedly connected to the upper round tube 10 through a first bend 3 where the expansion surface sinks downward. The upper round tube 10 is fixedly connected to the middle expansion structure 5 through a second bend 4 where the expansion surface sinks upward. The lower round tube 9 is provided below the middle expansion structure 5. The middle expansion structure 5 and the lower round tube 9 are fixedly connected through an inward third bend 6.

[0017] The expansion tube includes serrations including the first bend 3, the second bend 4, the middle expansion structure 5, the V-shaped bend 6, the head expansion structure 7, the guiding surface 8, the lower round tube 9, the upper round tube 10, and the expansion tube 1 is an integral structure.

[0018] The expansion tube 1 is centrally penetrated by a conical screw column 14. A gasket 11 is provided on the lower side of the expansion tube 1, a spring washer 12 is provided on the lower side of the gasket 11, and a nut 13 is provided on the lower side of the spring washer 12. The expansion tube 1, the gasket 11, and the spring washer 12 are sequentially sleeved on the outer wall of the conical screw column 14, and the nut 13 is installed at the rear end of the conical screw column 14.

[0019] Sawteeth 2 are symmetrically distributed on both sides of the head expansion structure 7, and the bending angle between the sawteeth 2 and the head expansion structure 7 is 45°.

[0020] The guiding surface 8 is bent outward at an angle of 45°.

[0021] The third bend 6 is V-shaped.

[0022] Prefabricated sawtooth process: Continuous sawteeth with a spacing of 2 mm are formed on the expanded surface of the bolt body by stamping. Grooving of the expansion sleeve: A 7 mm * 2 mm rectangular groove is made at the bending part. Bending: The expanded surface with sawteeth is pressed inward and bent outward.

[0023] Working principle and usage method: When the serrated expansion bolt of this embodiment is used, first, a hole with a diameter of 14.5 mm and a depth of 60 mm is drilled, and the expansion bolt is inserted. Then, a torque of 30 Nm is applied to fully expand the expansion sleeve 1. The sawteeth 2 adopt a wavy continuous curved surface to form a mechanical interlock with the base material. The head expansion structure 7 and the middle expansion structure 5 with sawteeth sink inward by bending to adapt to the diameter of the hole. The angle between the sawteeth 2 and the tube section plane is 45°, the sawtooth angle is 90°, and the tooth height is 0.8 mm. Through the action of the composite expansion mechanism, the conical bolt drives the upper part to open towards the head, and the bolt pressure is transmitted to the middle bending part to make the middle expansion structure open towards the tail, forming an anchoring effect in the front and back. The present invention is applicable to the anchoring of brittle materials such as concrete, red bricks, perforated bricks, aerated blocks, and stones.

[0024] As can be seen from the above embodiments, the present invention provides a serrated expansion bolt. The 45° bending of the head of the expansion tube provides the expansion condition. An axial sawtooth structure is arranged on the surface of the expansion tube. The head expansion structure and the middle expansion structure with sawteeth sink inward by bending to adapt to the diameter of the hole. The angle between the sawteeth and the tube section plane is 45°, the sawtooth angle is 90°, and the tooth height is 0.8 mm. Through the action of the composite expansion mechanism, the conical bolt drives the upper part to open towards the head, and the bolt pressure is transmitted to the middle bending part to make the middle expansion structure open towards the tail, forming an anchoring effect in the front and back. Compared with the ordinary expansion bolts of the same specification, the tensile strength is increased by more than 40%, and the displacement in the vibration test is reduced by 60%.

[0025] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A serrated expansion bolt, characterized in that, It includes an expansion tube (1), around which there are provided a head expansion structure (7) and a middle expansion structure (5) that can expand bidirectionally. On both sides of the head expansion structure (7), there are distributed sawteeth (2) bent outward. At the top of the head expansion structure (7), there is a guiding surface (8) bent outward. The head expansion structure (7) is fixedly connected to an upper circular tube (10) through a first bend (3) where the expansion surface sinks downward. The upper circular tube (10) is fixedly connected to the middle expansion structure (5) through a second bend (4) where the expansion surface sinks upward. Below the middle expansion structure (5), there is a lower circular tube (9), and the middle expansion structure (5) is fixedly connected to the lower circular tube (9) through an inward third bend (6).

2. The serrated expansion bolt according to claim 1, characterized in that, A conical screw column body (14) penetrates through the center of the expansion tube (1). Below the expansion tube (1), there is a gasket (11). Below the gasket (11), there is a spring washer (12). Below the spring washer (12), there is a nut (13). The expansion tube (1), the gasket (11), and the spring washer (12) are sequentially sleeved on the outer wall of the conical screw column body (14), and the nut (13) is installed at the rear end of the conical screw column body (14).

3. The serrated expansion bolt according to claim 2, wherein On both sides of the head expansion structure (7), the sawteeth (2) are symmetrically distributed, and the bending angle between the sawteeth (2) and the head expansion structure (7) is 45°.

4. The serrated expansion bolt according to claim 1, wherein, The angle at which the guiding surface (8) bends outward is 45°.

5. The serrated expansion bolt according to claim 2 or 4, characterized in that, The third bend (6) is in a V shape.

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