Expansion bolt

Abstract

The utility model relates to an expansion bolt, and belongs to the technical field of fasteners. The expansion screw comprises a screw rod, a nut and an expansion pipe, the screw rod comprises a rod body and a screw head arranged at one end of the rod body, the end, away from the screw head, of the rod body is in threaded fit with the nut, the rod body is sleeved with the expansion pipe, the expansion pipe is clamped between the screw head and the nut, the screw head is in the shape of a circular truncated cone, and the expansion pipe is in threaded fit with the screw head. The screw head is arranged on the rod body, the diameter of the screw head is gradually increased in the radial direction away from the rod body, the larger diameter of the screw head is larger than the inner diameter of the expansion pipe, a plurality of deformation open grooves are formed in the end, close to the screw head, of the expansion pipe, and the deformation open grooves are formed in the circumferential direction of the expansion pipe at equal-angle intervals. The end of the expansion pipe is divided into a plurality of deformation parts, and abutting protrusions are arranged on the inner walls of the deformation parts in the direction of the rod body in a protruding mode. The expansion pipe has the effect that the side face of the expansion pipe is not prone to deformation when stressed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fasteners, in particular to an expansion bolt. BACKGROUND

[0002] Fasteners are also known as standard parts in the market, which are a kind of mechanical parts used when two or more parts (or components) are fastened and connected to form a whole. Expansion bolts are one of the common fasteners, which are composed of a screw rod and an expansion tube. The expansion bolt is fixed by using the wedge slope to promote the expansion to generate frictional gripping force, thereby achieving the fixing effect.

[0003] The common expansion bolt includes a screw rod, a nut and an expansion tube. The screw rod and the nut are threadedly connected, the expansion tube is sleeved on the screw rod, and the expansion tube is clamped between the screw head of the screw rod and the nut. The screw head of the screw rod is in the shape of a circular truncated cone. The diameter of the screw head towards the expansion tube is smaller than the inner diameter of the expansion tube. The diameter of the screw head is larger than the inner diameter of the expansion tube. In use, the screw head enters a hole for installing the expansion bolt until the expansion tube also enters the hole. When the nut is tightened, the screw rod moves outward, the screw head part moves through the axial movement of the screw rod, and then extrudes the expansion tube to expand outward, thereby forming a large positive pressure on the outer periphery of the expansion tube, so that the wall body, the expansion tube and the screw head form a frictional self-locking, thereby achieving the fixing effect. In order to make the expansion tube expand and deform more smoothly, a plurality of deformation slots are formed on the end of the expansion tube close to the screw head, so as to divide the end of the expansion tube into several parts that can expand and deform outward.

[0004] The expansion tube of the above-mentioned expansion bolt has a space to fluctuate relative to the screw rod due to the diameter difference between the expansion tube and the screw rod. The end of the expansion tube is prone to deformation under stress due to the existence of the deformation slots, so that the side of the expansion bolt is prone to deformation under a large external force, which affects the normal use, especially the driving of the expansion tube. Content of the utility model

[0005] In order to prevent the side of the expansion tube from being deformed under stress and affecting the use, the present application provides an expansion bolt.

[0006] The expansion bolt provided by the present application adopts the following technical scheme:

[0007] An expansion bolt comprises a screw rod, a nut and an expansion tube, the screw rod comprises a rod body and a screw head arranged at one end of the rod body, the end of the rod body away from the screw head is threadedly connected with the nut, the expansion tube is sleeved on the rod body, and the expansion tube is clamped between the screw head and the nut, the screw head is in the shape of a circular truncated cone, the diameter of the screw head gradually increases in the direction away from the rod body, the larger diameter of the screw head is larger than the inner diameter of the expansion tube, the end of the expansion tube close to the screw head is provided with deformation grooves, the deformation grooves are arranged at equal angles around the expansion tube, and the expansion tube is divided into a plurality of deformation portions, and the inner wall of the deformation portion is provided with an abutting protrusion protruding towards the rod body.

[0008] By adopting the above technical scheme, when the expansion tube is installed on the rod body, the inner wall of the deformation portion of the expansion tube is provided with the abutting protrusion, so that when the expansion tube is subjected to a lateral external force, the deformation portion of the expansion tube is in contact with the rod body through the abutting protrusion, thereby supporting the deformation portion by the rod body, reducing the deformation of the deformation portion, keeping the overall structure of the expansion bolt stable when the expansion bolt is not used, not affecting the use of the expansion bolt, and at the same time, the abutting protrusion is arranged, so that when the expansion bolt is used, the screw head moves outward to extrude the deformation portion of the expansion tube, so that the abutting protrusion further increases the degree of expansion of the deformation portion when the deformation portion expands, so that the diameter of the end portion of the expansion bolt is larger after the expansion tube expands, and the expansion bolt can be fixed in a larger hole, and in the same size hole, the expansion bolt provided with the abutting protrusion can be installed more firmly and is not easy to loosen and fall out.

[0009] Optionally, the abutting protrusion comprises an abutting portion and a guide portion, the abutting portion is located on the side of the guide portion away from the screw head, the inner wall of the guide portion is part of a circular truncated cone, and the inner wall of the guide portion gradually moves away from the axis of the expansion tube in the direction away from the abutting portion.

[0010] By adopting the above technical scheme, the abutting protrusion is provided with the abutting portion and the guide portion, the abutting portion ensures that the deformation portion of the expansion tube is not easy to deform, and the guide portion guides the deformation portion of the expansion tube to smoothly expand and deform under the pushing of the screw head when the expansion bolt is used.

[0011] Optionally, the abutting protrusion is formed by folding the deformation portion inward.

[0012] By adopting the above technical scheme, the abutting protrusion is folded out by the deformation portion, and production is more convenient.

[0013] Optionally, the abutting protrusion is formed by first folding the deformation portion inward and then partially folding the deformation portion inward, and the part of the abutting protrusion close to the screw head has only one layer of the deformation portion folded inward.

[0014] By adopting the technical scheme, the abutting protrusion inside the deformation part is more stable in strength and is not easy to deform, only one layer of the abutting protrusion near the screw head part is inwardly folded first, the deformation part is gradually expanded outward under the abutting of the screw head, and the screw head drives the deformation part to be stressed and expanded outward more labor-saving.

[0015] Optionally, the abutting protrusion is formed by inwardly folding and then outwardly turning the deformation part, the part of the deformation part outwardly turned after being inwardly folded is clamped between the inwardly folded part and the inner wall of the deformation part and forms the abutting part, and the part of the deformation part inwardly folded and then outwardly turned lifts the inwardly folded part of the deformation part and forms the guide part.

[0016] By adopting the technical scheme, the abutting protrusion of the inner wall of the deformation part is formed in a folded manner, the integrity of the abutting protrusion and the deformation part is guaranteed, the processing and production are facilitated, and the abutting part and the deformation part of the abutting protrusion are better formed.

[0017] Optionally, the inner wall of the deformation part is integrally provided with a protruding block, the abutting protrusion is formed by inwardly folding part of the deformation part and abutting the protruding block, and the protruding block and the end face of the expansion pipe are spaced apart to form the guide part.

[0018] By adopting the technical scheme, the abutting part and the deformation part are naturally formed after part of the deformation part is inwardly folded and abuts the protruding block, the state of the abutting part is more stable, the thickness of the abutting part is more controllable during production, and the thickness precision of the abutting part is ensured.

[0019] Optionally, the inner wall of the deformation part is integrally provided with a protruding block, the abutting protrusion is formed by inwardly folding part of the deformation part and abutting the protruding block.

[0020] By adopting the technical scheme, the thickness precision of the abutting protrusion is ensured, the part of the end of the deformation part directly contacted with the screw head is smoother, the end of the deformation part is a smooth arc surface, and the screw head can better push the deformation part to expand and deform.

[0021] Optionally, the abutting protrusion is formed by inwardly folding part of the deformation part, and the inwardly folded part of the deformation part is integrally provided with a protruding block towards the inner wall of the expansion pipe, and the protruding block abuts the inner wall of the expansion pipe.

[0022] By adopting the technical scheme, the thickness precision of the abutting protrusion is ensured, the part of the end of the deformation part directly contacted with the screw head is smoother, the end of the deformation part is a smooth arc surface, and the screw head can better push the deformation part to expand and deform.

[0023] Optionally, the abutting protrusion is formed by inwardly folding part of the deformation part, and the inwardly folded part of the deformation part is provided with a protruding block protruding towards the inner wall of the expansion pipe, the protruding block abuts the inner wall of the expansion pipe, and the protruding block and the end of the expansion pipe are spaced apart to form the guide part.

[0024] By adopting the technical scheme, the thickness precision of the abutting protrusion is ensured, meanwhile, the part of the end of the deformed part directly contacted with the screw head is smoother, and the corresponding guide part can be formed, the end of the deformed part is a smooth arc surface, cooperating with the inclination of the guide part, the screw head can better push the deformed part to expand and deform

[0025] Optionally, the deformed part is folded twice to form the abutting protrusion, and the end of the part folded secondly is removed to form the guide part.

[0026] By adopting the technical scheme, the strength of the guide part is also high enough, and there is no gap in the guide part, so that the guide part is not easily extruded and deformed when the deformed part is expanded by the screw head.

[0027] In summary, when the expansion pipe is installed on the rod body, the inner wall of the deformed part of the expansion pipe is provided with the abutting protrusion, so that when the expansion pipe is subjected to lateral external force, the deformed part of the expansion pipe is contacted with the rod body through the abutting protrusion, thereby the deformed part is supported by the rod body to reduce the deformation of the deformed part, so that the overall structure of the expansion bolt is stable when the expansion bolt is not used, and the use of the expansion bolt is not affected. Meanwhile, the abutting protrusion is arranged, so that when the expansion bolt is used, the screw head moves outward to extrude the deformed part of the expansion pipe, so that when the deformed part expands, the abutting protrusion further increases the expansion degree of the deformed part, so that after the expansion pipe expands, the diameter of the end of the expansion bolt is larger, and the expansion bolt can be fixed in a larger hole. In the same size hole, the expansion bolt provided with the abutting protrusion can be installed more firmly and is not easy to loosen and fall out. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic view of the expansion bolt in the embodiment of the present application;

[0029] Figure 2 is a structural schematic view of the screw rod in the embodiment of the present application;

[0030] Figure 3 is a structural schematic view of the expansion pipe in the embodiment of the present application;

[0031] Figure 4 is a sectional view of the expansion bolt in the embodiment of the present application;

[0032] Figure 5 is a partial sectional view of the expansion bolt in the embodiment of the present application Figure 1 ;

[0033] Figure 6 is a partial sectional view of the expansion bolt in the embodiment of the present application Figure 2 ;

[0034] Figure 7 is a partial cross-section of an expansion bolt in an embodiment of the present application Figure 3 ;

[0035] Figure 8 is a partial cross-section of an expansion bolt in an embodiment of the present application Figure 4 ;

[0036] Figure 9 is a structural schematic diagram of an expansion tube before bending in an embodiment of the present application;

[0037] Figure 10 is a structural schematic diagram of an expansion tube after expansion in an embodiment of the present application.

[0038] Reference signs: 1, screw rod; 11, screw head; 12, rod body; 2, nut; 3, expansion tube; 31, deformation part; 32, deformation slot; 4, spring washer; 5, flat washer; 6, abutting protrusion; 61, abutting part; 62, guide part; 63, protruding block. DETAILED DESCRIPTION

[0039] The following will be described in detail in combination with the accompanying Figures 1-10 The present application is further described in detail.

[0040] An embodiment of the present application discloses an expansion bolt.

[0041] With reference to Figure 1 and Figure 2 , an expansion bolt comprises a screw rod 1, a nut 2, an expansion tube 3, a flat washer 5 and a spring washer 4, the screw rod 1 comprises a rod body 12 and a screw head 11 coaxially arranged at one end of the rod body 12, the screw head 11 is in the shape of a circular truncated cone, the outer diameter of the screw head 11 gradually decreases along the axial direction towards the rod body 12 until the diameter of the screw head 11 is consistent with that of the rod body 12, an outer thread is formed at the end of the rod body 12 away from the screw head 11 and threadedly matched with the nut 2, the expansion tube 3, the flat washer 5 and the spring washer 4 are sequentially sleeved on the rod body 12 and located between the screw head 11 and the nut 2, the nut 2 limits the expansion tube 3, the flat washer 5 and the spring washer 4 from being separated from the rod body 12, wherein the outer diameter of the flat washer 5 is greater than the diameter of the screw head 11, the outer diameter of the spring washer 4 is smaller than that of the flat washer 5, and the nut 2 completely covers the spring washer 4, the flat washer 5 and the spring washer 4 are both standard parts, the spring washer 4 has staggered openings and elasticity, the sharp corners of the staggered openings of the spring washer 4 are used to pierce into the nut 2 and the flat washer, thereby preventing the nut 2 from loosening.

[0042] With reference to Figure 1 and Figure 3The expansion pipe 3 is a circular pipe, and the diameter of the larger screw head 11 is greater than the inner diameter of the expansion pipe 3, and the diameter of the larger screw head 11 is greater than or equal to the outer diameter of the expansion pipe 3, so that the expansion bolt is convenient to be placed in the hole for the expansion bolt installation. When the expansion pipe 3 is in the form of being punched, the diameter of the screw head 11 is preferably slightly smaller than the outer diameter of the expansion pipe 3, so as to conveniently drive the screw head 11 to move axially and extrude the expansion pipe 3.

[0043] The expansion pipe 3 is a circular pipe, and the diameter of the larger screw head 11 is greater than the inner diameter of the expansion pipe 3, and the diameter of the larger screw head 11 is greater than or equal to the outer diameter of the expansion pipe 3, so that the expansion bolt is convenient to be placed in the hole for the expansion bolt installation. When the expansion pipe 3 is in the form of being punched, the diameter of the screw head 11 is preferably slightly smaller than the outer diameter of the expansion pipe 3, so as to conveniently drive the screw head 11 to move axially and extrude the expansion pipe 3.

[0044] Referring to Figure 3 and Figure 4 The inner wall of each deformation part 31 is provided with an abutting protrusion 6 protruding towards the shaft 12, and the abutting protrusion 6 has multiple setting modes and multiple forming modes.

[0045] In one setting mode, the abutting protrusion 6 includes an abutting part 61 and a guide part 62, the abutting part 61 is located on the side of the guide part 62 away from the screw head 11, the inner wall of the abutting part 61 is part of a cylindrical surface, the inner wall of the guide part 62 is part of a circular truncated cone surface, and the inner wall of the guide part 62 gradually moves away from the axis of the expansion pipe 3 in the direction away from the abutting part 61.

[0046] The above setting mode corresponds to multiple forming modes, one forming mode is that the abutting protrusion 6 is integrally protruded on the inner wall of the deformation part 31, and another forming mode is that the deformation part 31 is partially folded to form the above abutting protrusion 6.

[0047] The folding mode of the deformation part 31 also has multiple modes:

[0048] Referring to Figure 5 One mode is that the deformation part 31 can be first folded inward and then partially folded inward to form the abutting protrusion 6, and the part of the abutting protrusion 6 close to the screw head 11 only has one layer of the first inward folding, thereby forming the corresponding abutting part 61 and guide part 62; referring to Figure 6 The part of the deformation part 31 folded inward again can have the same length as the part folded inward first, but the part of the deformation part 31 folded inward again is cut to form the corresponding guide part 62.

[0049] Referring to Figure 3 and Figure 4, another way is that the deformed part 31 is folded inward and then outward to form the abutting protrusion 6, the part of the deformed part 31 folded inward and then outward is clamped between the folded inward part and the inner wall of the deformed part 31 and forms the abutting part 61, and the part of the deformed part 31 folded inward and then outward is spaced apart from the end of the deformed part 31 by a certain distance, so that the part of the deformed part 31 folded inward and then outward lifts the folded inward part of the deformed part 31 and forms the guide part 62.

[0050] With reference to Figure 7 and Figure 8 The integral protruding manner and the deformed part 31 folding manner can also be organically combined to form the abutting protrusion 6. Specifically, the inner wall of the deformed part 31 integrally protrudes to be provided with a protrusion 63, the deformed part 31 is partially folded inward and abuts against the protrusion 63 to form the abutting protrusion 6, and the protrusion 63 is spaced apart from the end face of the expansion pipe 3 to form the guide part 62. In addition, the protrusion 63 can also be arranged on the folded inward part of the deformed part 31, that is, the deformed part 31 is partially folded inward to form the abutting protrusion 6, and the folded inward part of the deformed part 31 integrally protrudes towards the inner wall of the expansion pipe 3 and is provided with a protrusion 63, and the protrusion 63 abuts against the inner wall of the expansion pipe 3. At this time, the protrusion 63 is also spaced apart from the end face of the expansion pipe 3.

[0051] Further, in order to make the folded part of the deformed part 31 more stable, the inner wall of the expansion pipe 3 is provided with a clamping groove for clamping the protrusion 63, and the clamping groove is correspondingly arranged according to the position of the protrusion 63.

[0052] In another arrangement, the inner wall of the abutting protrusion 6 is part of a cylindrical surface, and there are also a plurality of forming modes, including the integral protruding mode and the deformed part 31 folding mode, and the partial integral protruding and partial deformed part 31 folding mode.

[0053] With reference to Figure 9 In order to facilitate production, the expansion pipe 3 is bent from a metal sheet to form a circular pipe, so that the deformed slot 32 is easy to process, and the deformed part 31 is also easy to bend. The abutting protrusion 6 is preferably formed by folding the deformed part 31 and has the guide part 62. The joint gap of the expansion pipe 3 after bending and forming can be welded to form a whole. In some use modes, the joint gap of the expansion pipe 3 can also be reserved to increase the deformation capacity.

[0054] With reference to Figure 1 and Figure 10The implementation principle of the expansion bolt is as follows: when the nut 2 is tightened, the screw rod 1 moves outward, the axial movement of the screw rod 1 causes the screw head 11 to move, and then the expansion pipe 3 is extruded to expand, the screw head 11 first extrudes the guide part 62, and then extrudes the abutting part 61, the expansion pipe 3 enters the thickness between the screw head 11 and the hole wall of the hole where the expansion bolt is installed, a large positive pressure is formed on the outer peripheral surface of the expansion pipe 3, so that the friction self-locking is formed among the wall body, the expansion pipe 3 and the screw head 11, and then the fixing effect is achieved, and since the thickness of the part of the expansion pipe 3 under pressure can be increased, the stability of the expansion bolt installation is ensured.

[0055] The above are preferred embodiments of the application, and do not limit the protection scope of the application, so: any equivalent changes made on the basis of the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. An expansion bolt, characterized by: The screw (1) comprises a shank (12) and a screw head (11) arranged at one end of the shank (12), the end of the shank (12) away from the screw head (11) is threadedly connected with a nut (2), and an expansion tube (3) is sleeved on the shank (12) and clamped between the screw head (11) and the nut (2), the screw head (11) is in the shape of a circular truncated cone, the diameter of the screw head (11) gradually increases in the direction away from the shank (12), the larger diameter of the screw head (11) is larger than the inner diameter of the expansion tube (3), the end of the expansion tube (3) close to the screw head (11) is provided with deformation slots (32), the deformation slots (32) are arranged at equal angles around the expansion tube (3), and the expansion tube (3) is divided into a plurality of deformation portions (31) at the end thereof, and the inner wall of the deformation portion (31) is provided with an abutting protrusion (6) protruding towards the shank (12).

2. An expansion bolt according to claim 1 wherein: The abutting protrusion (6) comprises an abutting portion (61) and a guide portion (62), the abutting portion (61) is located on the side of the guide portion (62) away from the screw head (11), the inner wall of the guide portion (62) is part of a circular truncated cone, and the inner wall of the guide portion (62) gradually moves away from the axis of the expansion tube (3) in the direction away from the abutting portion (61).

3. An expansion bolt according to claim 1 wherein: The deformation portion (31) is inwardly folded to form the abutting protrusion (6).

4. An expansion bolt according to claim 3 wherein: The deformation portion (31) is inwardly folded and then partially outwardly folded to form the abutting protrusion (6), and only the inwardly folded layer of the portion of the abutting protrusion (6) close to the screw head (11) is provided.

5. An expansion bolt according to claim 2 wherein: The deformation portion (31) is inwardly folded and then partially outwardly folded to form the abutting protrusion (6), and the outwardly folded portion of the deformation portion (31) after being inwardly folded is clamped between the inwardly folded portion and the inner wall of the deformation portion (31) and forms the abutting portion (61), and the portion of the deformation portion (31) that is inwardly folded and then outwardly folded again lifts the inwardly folded portion of the deformation portion (31) and forms the guide portion (62).

6. An expansion bolt according to claim 2 wherein: The inner wall of the deformation portion (31) is integrally provided with a protrusion (63), the deformation portion (31) is partially inwardly folded and abuts against the protrusion (63) to form the abutting protrusion (6), and the protrusion (63) and the end face of the expansion tube (3) are spaced apart to form the guide portion (62).

7. An expansion bolt according to claim 1 wherein: The inner wall of the deformation portion (31) is integrally provided with a protrusion (63), the deformation portion (31) is partially inwardly folded and abuts against the protrusion (63) to form the abutting protrusion (6).

8. An expansion bolt according to claim 1 wherein: The deformation portion (31) is partially inwardly folded to form the abutting protrusion (6), and the inwardly folded portion of the deformation portion (31) is integrally provided with a protrusion (63) protruding towards the inner wall of the expansion tube (3), and the protrusion (63) abuts against the inner wall of the expansion tube (3).

9. An expansion bolt according to claim 2 wherein: The deformed part (31) is partially inwardly folded to form the abutting protrusion (6), and the inwardly folded part of the deformed part (31) is provided with a protrusion (63) protruding towards the inner wall of the expansion pipe (3), the protrusion (63) abuts the inner wall of the expansion pipe (3), and the protrusion (63) and the end of the expansion pipe (3) are spaced apart to form the guide part (62).

10. An expansion bolt according to claim 2 wherein: The deformed part (31) is partially inwardly folded to form the abutting protrusion (6), and the inwardly folded part of the deformed part (31) is provided with a protrusion (63) protruding towards the inner wall of the expansion pipe (3), the protrusion (63) abuts the inner wall of the expansion pipe (3), and the protrusion (63) and the end of the expansion pipe (3) are spaced apart to form the guide part (62).

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