High-strength expansion bolt

Abstract

The application relates to the technical field of expansion bolts, and particularly provides a high-strength expansion bolt which comprises a screw rod, an expansion sleeve, a gasket pipe, a flat washer and a nut, the expansion end of the screw rod is provided with a 2-stage or more than 2-stage circular truncated cone body, the other end of the screw rod is provided with a thread, the expansion sleeve, the gasket pipe, the flat washer and the nut are sequentially arranged on the screw rod, the expansion sleeve is provided with a 2-stage or more than 2-stage circular truncated cone cavity, the circular truncated cone cavity of the expansion sleeve corresponds to the circular truncated cone body of the expansion end of the screw rod, and the inclined surface of the circular truncated cone cavity of the expansion sleeve corresponds to the inclined surface of the circular truncated cone body of the screw rod; the expansion sleeve is an axial split structure and is composed of two or more than two expansion pieces. The stress span between the high-strength expansion bolt and the wall of a drill hole of a base body is large, the stress contact area is large, stress is dispersed, the wall of the drill hole of the base body is not easily damaged, the anti-seismic performance is good, the bearing capacity is strong, and the high-strength expansion bolt can be normally installed and anchored even when the base body is relatively soft.

Description

Technical fields:

[0001] This invention relates to the field of expansion bolt technology, and in particular to a high-strength expansion bolt. Background technology:

[0002] Expansion bolts are threaded fasteners used to install and fix equipment or objects to buildings. They are commonly used hardware fasteners in engineering installations and residential installations.

[0003] In existing technology, expansion bolts include a screw, an expansion sleeve, a flat washer, and a nut. The expansion end of the screw has a frustum, and the other end has threads. The expansion sleeve is fitted onto the screw, and the expansion sleeve has several openings near the tail of the frustum. During installation, the expansion bolt is placed into a drilled hole of the corresponding size in the building foundation. A wedge-shaped gap is formed between the inclined surface of the screw frustum and the wall of the drilled hole. When the nut is tightened, the screw frustum and the nut move towards each other. The inclined surface of the screw frustum compresses the expansion sleeve, and the tail of the expansion sleeve with slits expands and further compresses against the wall of the drilled hole, generating a frictional gripping force, thereby achieving the purpose of anchoring.

[0004] However, since the expansion sleeve of the existing expansion bolt is made of flat material and rolled into a circle, the inner side of the expansion sleeve cannot be tightly fitted with the inclined surface of the screw's truncated cone. The force contact between the expansion sleeve and the borehole wall of the base is a circular force contact, with a small force contact area and stress concentration. The borehole wall of the base is easily damaged, thus greatly limiting the load-bearing capacity of the expansion bolt. When the strength of the borehole base is insufficient, or when the fastened object is frequently vibrating, the expansion bolt is prone to loosening and falling off. Summary of the Invention:

[0005] In order to overcome the problems and shortcomings of existing expansion bolts, such as low load-bearing capacity, easy loosening and falling off due to small contact area between the expansion sleeve and the borehole wall of the base material and stress concentration, the purpose of this invention is to provide a high-strength expansion bolt that has a wide range of adaptability to the borehole base material, good seismic performance, strong load-bearing capacity, convenient and quick installation, practicality and reliability, and is easy to implement.

[0006] To achieve the above objectives, the technical solution adopted is as follows:

[0007] 1. A high-strength expansion bolt, comprising a screw, an expansion sleeve, a washer tube, a flat washer, and a nut, wherein the expansion end of the screw is provided with a frustum, and the other end of the screw is provided with a thread, and the expansion sleeve, washer tube, flat washer, and nut are sequentially arranged on the screw; the expansion sleeve is provided with a frustum-shaped cavity, the frustum-shaped cavity of the expansion sleeve corresponding to the frustum-shaped cavity of the expansion end of the screw; the expansion sleeve is a split structure, composed of two or more expansion plates; one end of the washer tube contacts the expansion sleeve, and the other end contacts the flat washer.

[0008] 2. A high-strength expansion bolt as described in technical solution 1, wherein the expansion end of the screw is provided with a frustum of two or more levels; and the expansion sleeve is provided with a frustum-shaped cavity of two or more levels.

[0009] 3. A high-strength expansion bolt as described in technical solution 2, wherein a first cylinder is provided between two adjacent frustum-shaped bodies at the expansion end of the screw; and a first cylindrical cavity is provided between two adjacent frustum-shaped cavities of the expansion sleeve.

[0010] 4. A high-strength expansion bolt as described in technical solutions 1, 2 or 3, wherein the expansion end of the screw is provided with a second cylinder, and the expansion sleeve is provided with a second cylindrical cavity.

[0011] 5. A high-strength expansion bolt as described in technical solutions 1, 2, 3 or 4, wherein the expansion end of the screw is provided with a limiting stop, the limiting stop abuts against the expansion sleeve to prevent the expansion sleeve from moving towards the nut; one end of the washer tube is sleeved on the limiting stop and contacts the expansion sleeve, and the other end contacts the flat washer.

[0012] 6. A high-strength expansion bolt as described in technical solution 1, wherein the expansion sleeve is composed of axially separated expansion plates connected by elastic rings.

[0013] 7. A high-strength expansion bolt as described in technical solution 6, wherein the outer side of the expansion sleeve is provided with a groove, and the elastic ring is mounted on the groove.

[0014] 8. A high-strength expansion bolt as described in technical solution 6 or 7, wherein the outer diameter of the elastic ring is larger than the diameter of the corresponding specification of the base hole, and when the expansion bolt is inserted into the base hole, the elastic ring disengages from the expansion sleeve, and the expansion plates that make up the expansion sleeve separate in the base hole.

[0015] 9. A high-strength expansion bolt as described in technical solution 1, wherein the outer surface of the expansion sleeve is provided with anti-slip patterns.

[0016] The beneficial effects of this invention are that the force span and force contact area are large, the stress is dispersed, the hole wall of the base is not easily damaged, the range of drilling base materials is wide, the seismic performance is good, and the bearing capacity is strong. Even when encountering a relatively soft base or when the fastened object is frequently vibrating, the expansion bolts will not easily loosen or fall off. The installation and construction are convenient, practical and reliable, and easy to implement. Attached image description:

[0017] Figure 1 This is a schematic diagram of the external structure of the present invention;

[0018] Figure 2This is a partial cross-sectional view of the overall structure of the present invention;

[0019] Figure 3 This is a schematic diagram showing the state when the present invention is inserted into the substrate through drilling.

[0020] Figure 4 This is a schematic diagram of the anchoring state installed in the drilled hole of the substrate according to the present invention;

[0021] Figure 5 For the present invention Figure 3 Schematic diagram of the cross section of line AA.

[0022] Explanation of the reference numerals: 1-Screw; 2-Nut; 3-Flat washer; 4-Washer tube; 5-Expansion sleeve; 6-Frustum; 7-Elastic ring; 8-Groove; 9-Limiting stop; 10-Second cylinder; 11-First cylinder; 12-Base hole. Detailed implementation method:

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through an embodiment. It should be understood that the drawings and embodiments described herein are merely for explaining the technical solution of the present invention and are not intended to limit the scope of the invention.

[0024] One embodiment of the present invention is as follows, referring to... Figures 1 to 5 As shown, a high-strength expansion bolt includes a screw 1, an expansion sleeve 5, a washer 4, a flat washer 3, and a nut 2. The expansion end of the screw 1 is provided with a frustum 6, and the other end of the screw 1 is provided with a thread. The expansion sleeve 5, the washer 4, the flat washer 3, and the nut 2 are sequentially arranged on the screw 1. The expansion sleeve 5 is provided with a frustum-shaped cavity. The expansion sleeve 5 is sleeved on the expansion end of the screw 1. The frustum-shaped cavity of the expansion sleeve 5 corresponds to the frustum 6 at the expansion end of the screw 1, and the inclined surface of the frustum-shaped cavity of the expansion sleeve 5 corresponds to the inclined surface of the frustum 6 at the expansion end of the screw 1. To increase the length and outer surface area of ​​the expansion sleeve 5, thereby increasing the force span and contact area between the expansion sleeve 5 and the borehole wall 12 of the base, the expansion sleeve 5 has two or more frustum-shaped cavities, with a first cylindrical cavity connecting adjacent frustum-shaped cavities. One end of the expansion sleeve 5 has a second cylindrical cavity connected to the frustum-shaped cavity. Correspondingly, the screw 1 has two or more frustum-shaped bodies 6 at its expansion end, with a first cylinder 11 connecting adjacent frustum-shaped bodies 6. The screw 1 also has a second cylinder 10 at its expansion end, connected to the frustum-shaped bodies 6. The expansion sleeve 5 is an axially split structure, composed of two or more relatively independent single expansion plates connected by elastic rings 7.

[0025] A limiting stop 9 is provided at the expansion end of the screw 1. The limiting stop 9 abuts against the expansion sleeve 5. When the expansion bolt is inserted into the drilled hole in the base, the limiting stop 9 can prevent the expansion sleeve 5 from moving towards the nut 2 and avoid damage to the washer tube 4 caused by the movement of the expansion sleeve 5 towards the nut 2. One end of the washer tube 4 is sleeved on the limiting stop 9 and contacts the expansion sleeve 5, which can maintain a good concentricity between the washer tube 4 and the screw 1, and thus maintain a relatively uniform contact between the washer tube 4 and each individual expansion piece that makes up the expansion sleeve 5. The other end of the washer tube 4 contacts the flat washer 3. When the nut 2 is tightened, the thrust generated by the opposing movement of the nut 2 and the frustum 6 of the screw 1 can be relatively evenly transmitted to each individual expansion piece that makes up the expansion sleeve 5 through the washer tube 4.

[0026] The outer surface of the expansion sleeve 5 is provided with a groove 8 for mounting the elastic ring 7. The elastic ring 7 is mounted on the groove 8 to prevent it from easily and accidentally detaching from the expansion sleeve 5 without human intervention. The outer diameter of the elastic ring 7 is larger than the diameter of the corresponding specification of the base drill hole 12. During installation, the expansion bolt is inserted into the base drill hole 12. Because the outer diameter of the elastic ring 7 is larger than the diameter of the corresponding specification of the base drill hole 12, the elastic ring 7 is blocked outside the opening of the base drill hole 12 and cannot enter the base drill hole 12. The elastic ring 7 retracts towards the pad tube 4 and detaches from the expansion sleeve 5. The relatively independent axially split expansion pieces that make up the expansion sleeve 5 are separated in the base drill hole 12.

[0027] Since the frustum-shaped cavity of the expansion sleeve 5 corresponds to the frustum-shaped body 6 of the screw 1, and the inclined surface of the frustum-shaped cavity of the expansion sleeve 5 corresponds to the inclined surface of the frustum-shaped body 6 of the screw 1, the expansion sleeve 5 can fit well into the wedge-shaped gap between the inclined surface of the frustum-shaped body 6 at the expansion end of the screw 1 and the wall of the borehole 12 in the base, thus making the force contact between the expansion sleeve 5 and the screw 1 an annular contact state, with a long force span and a large contact area. Tightening nut 2 causes the thrust generated by the opposing movement of nut 2 and the truncated cone 6 of screw 1 to be transmitted to expansion sleeve 5 through washer tube 4. With the mutual support and interaction of the inclined surfaces of the truncated cone cavity of expansion sleeve 5 and the inclined surfaces of the truncated cone 6 of screw 1 at two or more corresponding levels, there are two or more supporting contact surfaces between expansion sleeve 5 and truncated cone 6 of screw 1. Therefore, the entire outer surface of the single expansion piece, which is not restrained and separated in the base hole 12, including both the front and rear ends, simultaneously exerts pressure on the hole wall of the base hole 12. Thus, the force span and force contact area between expansion sleeve 5 and screw 1, as well as between expansion sleeve 5 and the hole wall of the base hole, are relatively large, which is incomparable to that of traditional expansion bolts with a circular force contact state.

[0028] Since the frustum-shaped cavity of the expansion sleeve 5 corresponds to the frustum-shaped body 6 of the screw 1, and the inclined surface of the frustum-shaped cavity of the expansion sleeve 5 corresponds to the inclined surface of the frustum-shaped body 6 of the screw 1, tightening the nut 2 pulls the screw 1 outward toward the drilled hole 12 in the base. Under the mutual guiding action of the inclined surfaces of the expansion sleeve 5 and the frustum-shaped body 6, the outward pulling force of the frustum-shaped body 6 of the screw 1 is transformed into a compressive force acting on the wall of the drilled hole 12 in the base of the expansion sleeve 5. According to the principle of inclined surfaces, the greater the outward pulling force of the screw 1, the greater the expansion... The greater the extrusion force of the sleeve 5 on the wall of the drilled hole 12 in the base, the greater the pressure. Since the diameter of the drilled hole 12 in the base is fixed, after the gap between the outer side of the expansion sleeve 5 and the wall of the drilled hole 12 in the base is filled, the expansion sleeve 5 cannot continue to move towards the wall of the drilled hole 12 in the base. Therefore, the greater the pull-out force of the screw 1, the greater the frictional gripping force generated between the expansion sleeve 5 and the drilled hole 12 in the base, and the tighter the screw 1 is locked, thus forming a greater pull-out force and achieving a better anchoring purpose.

[0029] To enhance the interlocking friction between the outer surface of the expansion sleeve 5 and the hole wall of the base drilled hole 12, the outer surface of the expansion sleeve 5 is provided with anti-slip patterns.

[0030] Because the expansion sleeve 5 has a large force span and a large contact area with the base hole 12, the stress is dispersed, and the base hole 12 is not easily damaged. Even when encountering a relatively soft base, brick joints, gaps, or objects that are frequently vibrated by fasteners, it can be installed and used normally without easily loosening or falling off. This invention has wide applicability and can be well applied to concrete, solid red bricks, hollow bricks, porous bricks, honeycomb bricks, lightweight bricks, aerated bricks, and other material bases.

Claims

1. A high-strength expansion bolt, characterized in that: The device includes a screw, an expansion sleeve, a washer tube, a flat washer, and a nut. The expansion end of the screw has a frustum-shaped body, and the other end of the screw has a thread. The expansion sleeve, washer tube, flat washer, and nut are sequentially arranged on the screw. The expansion sleeve has a frustum-shaped cavity, which corresponds to the frustum-shaped body at the expansion end of the screw. The expansion sleeve is a split structure, consisting of two or more expansion plates. One end of the washer tube contacts the expansion sleeve, and the other end contacts the flat washer.

2. The high-strength expansion bolt according to claim 1, characterized in that: The screw expansion end is provided with two or more frustums; the expansion sleeve is provided with two or more frustum-shaped cavities.

3. A high-strength expansion bolt according to claim 2, characterized in that: The screw expansion end has a first cylinder connecting two adjacent frustum-shaped bodies; the expansion sleeve has a first cylindrical cavity connecting two adjacent frustum-shaped cavities.

4. A high-strength expansion bolt according to claim 1, 2 or 3, characterized in that: The screw expansion end is provided with a second cylinder, and the expansion sleeve is provided with a second cylindrical cavity.

5. A high-strength expansion bolt according to claim 1, 2, 3 or 4, characterized in that: The screw expansion end is provided with a limit stop, which abuts against the expansion sleeve to prevent the expansion sleeve from moving towards the nut; one end of the gasket is sleeved on the limit stop and in contact with the expansion sleeve, and the other end is in contact with the flat washer.

6. A high-strength expansion bolt according to claim 1, characterized in that: The expansion sleeve is composed of axially separate expansion plates connected by elastic rings.

7. A high-strength expansion bolt according to claim 6, characterized in that: The outer side of the expansion sleeve is provided with a groove, and the elastic ring is installed on the groove.

8. A high-strength expansion bolt according to claim 6 or 7, characterized in that: The outer diameter of the elastic ring is larger than the diameter of the corresponding specification of the base hole. When the expansion bolt is inserted into the base hole, the elastic ring is separated from the expansion sleeve, and the expansion plates that make up the expansion sleeve separate in the base hole.

9. A high-strength expansion bolt according to claim 1, characterized in that: The outer surface of the expansion sleeve is provided with anti-slip patterns.

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