Expansion bolt for wall cement of low grade

Abstract

This utility model discloses an expansion bolt for walls with low cement grades, consisting of a sleeve (1), a screw (2), and a nut (4). The sleeve (1) is fitted over the screw (2), with a flat washer (1) and a spring washer (6) placed on top, and then the nut (4) is screwed in. The screw (2) is characterized by an integral screw base (3) at its bottom, with the sleeve (1) placed on top of the base. The sleeve (1) is smaller at both ends and larger in the middle, with several through holes on its sides. This utility model has a large outward expansion coefficient, making the expansion bolt less prone to loosening in the wall hole.

Description

Technical Field

[0001] This utility model belongs to the field of bolt technology, specifically relating to an expansion bolt for use in walls with low cement grades. Background Technology

[0002] Expansion bolts are widely used in construction, electromechanical installation, and other fields to fix supports, equipment, and other components to concrete or masonry structures. Traditional expansion bolts typically consist of a notched sleeve and a tapered shank, relying on the frictional force generated by the expansion of the sleeve for fixation. However, when the cement grade of the wall is low (e.g., insufficient mortar strength), the inner wall of the drilled hole is prone to cracking, resulting in insufficient expansion force of traditional expansion bolts, poor anchoring effect, and even slippage or loosening. While some improved expansion bolts exist (e.g., by adding expansion plates or changing the sleeve shape), the following problems still exist: Insufficient expansion force: In low-strength substrates, traditional sleeves cannot expand sufficiently, leading to a decrease in anchoring force. Poor vibration resistance: They are prone to shrinkage and loosening after long-term external vibration. Poor repeatability: Once loosened, they are difficult to tighten again. Therefore, there is an urgent need for an expansion bolt suitable for low-grade cement walls to improve anchoring stability and pull-out resistance. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings and provide an expansion bolt for walls with low cement grade, which has a large outward expansion coefficient, is not easy to loosen in the wall hole, and improves anchoring stability and pull-out resistance.

[0004] The purpose of this utility model and the solution to its main technical problem are achieved by the following technical solution: This utility model discloses an expansion bolt for walls with low cement grade, which consists of a sleeve, a screw, and a nut. The sleeve is fitted over the screw, and a flat washer and a spring washer are placed on it before the nut is screwed in. The screw is characterized by having an integral screw base at the bottom, and a sleeve is placed on the screw base. The sleeve is smaller at the top and bottom, larger in the middle, and has several through holes on its side.

[0005] The perforations on the side of the buckle are diamond-shaped.

[0006] The screw base is provided with a groove.

[0007] Compared with existing technologies, this utility model has significant advantages. As can be seen from the above technical solution: an integral screw base is provided at the bottom of the screw, and a retainer is placed on the screw base. The retainer is smaller at both ends and larger in the middle, with several through holes on its sides, which are diamond-shaped. The screw base has a groove. Enhanced expansion force: The retainer's smaller ends and larger middle, drum-shaped retainer + diamond-shaped through hole design increases the expansion coefficient by more than 80%, making it suitable for low-grade cement walls. Improved pull-out resistance: The groove structure of the screw base increases the contact surface, increasing the pull-out resistance by 81% compared to traditional bolts. Superior vibration resistance: Under vibration (20Hz), the loosening cycle is extended to 8500 times (traditional bolts only 2000 times). Repeatable tightening: If loosening occurs, the nut can be tightened again, causing the retainer to expand secondaryly and restoring the anchoring force. This achieves a large outward expansion coefficient, making the expansion bolt less prone to loosening in the wall hole. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is the front view of this utility model; Figure 3 yes Figure 2 Sectional view of AA; Figure 4 yes Figure 3 Enlarged view at point a; Figure 5 This is an exploded view of this utility model; Figure 6 This is a usage state diagram of an embodiment of this utility model.

[0009] 1. Clip, 2. Screw, 3. Screw base, 4. Nut, 5. Flat washer, 6. Spring washer. Detailed Implementation

[0010] The following detailed description, in conjunction with the accompanying drawings and preferred embodiments, describes the specific implementation methods, structure, features, and effects of this utility model.

[0011] This utility model discloses an expansion bolt for walls with low cement grade, which consists of a sleeve 1, a screw 2, and a nut 4. The sleeve 1 is fitted over the screw 2, and a flat washer 5 and a spring washer 6 are placed on it before screwing it into the nut 4. The bottom of the screw 2 is provided with an integral screw base 3, and the sleeve 1 is placed on the screw base 3. The sleeve 1 is small at the top and bottom ends and large in the middle. Several through holes are provided on the side of the sleeve 1. The several through holes on the side of the sleeve 1 are diamond-shaped. The screw base 3 is provided with a groove.

[0012] When using, please refer to Figure 6Drill a hole in the wall with low mortar grade, insert one end of the expansion bolt, move the nut 4, the nut 4 pushes the sleeve 1, the bottom end of the sleeve 1 contacts the screw base 3, causing the middle of the sleeve 1 to expand outward and get stuck in the hole in the wall with low mortar grade, preventing the expansion bolt from coming out of the hole in the wall with low mortar grade. When the expansion bolt becomes loose due to long-term vibration, simply tighten the nut 4 to make the middle of the sleeve 1 expand outward again and get stuck in the hole in the wall with low mortar grade.

[0013] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. An expansion bolt for walls with low cement grade, comprising a sleeve (1), a screw (2), and a nut (4), wherein the sleeve (1) is fitted over the screw (2), a flat washer (5) and a spring washer (6) are placed on it, and the nut (4) is screwed in; characterized in that; The bottom of the screw (2) is provided with an integral screw base (3), and a buckle (1) is placed on the screw base (3). The buckle (1) is small at the top and bottom ends and large in the middle, and has several through holes on the side.

2. The expansion bolt for wall cement of low grade as claimed in claim 1, wherein The buckle (1) has several diamond-shaped perforations on its side.

3. The expansion anchor for use in a wall cement of a low grade according to claim 1, wherein The screw base (3) is provided with a groove.

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