A reusable expansion bolt structure

Abstract

The application provides a reusable expansion bolt structure, which comprises a bolt and an expansion sleeve which is arranged outside the bolt and detachably connected with the bolt, wherein the expansion sleeve comprises a first expansion sleeve, a second expansion sleeve, a third expansion sleeve and a fourth expansion sleeve which are sequentially arranged from top to bottom, the bottom of the first expansion sleeve is coupled with the top of the second expansion sleeve, the bottom of the second expansion sleeve is coupled with the top of the third expansion sleeve, and the bottom of the third expansion sleeve is coupled with the top of the fourth expansion sleeve. In operation, the bolt is first pre-tightened with the expansion sleeve, then the expansion bolt is placed into a through hole, and the lower end of the second expansion sleeve and the upper end of the third expansion sleeve are simultaneously expanded outward and contacted with the hole wall under the action of force in the process of re-tightening the bolt, so that the bolt and the expansion sleeve can tightly fix different hole diameters of various parts.

Description

Technical Field

[0001] This invention belongs to the field of expansion bolts, and specifically relates to a reusable expansion bolt structure. Background Technology

[0002] The development of modern industry relies heavily on the use of standard parts. In automobiles, standard parts constitute a significant portion of the weight, including bolts of various specifications. The automotive industry represents a nation's industrial level, involving numerous components, most of which are connected and assembled using bolts. However, during vehicle prototyping, various production line stoppages inevitably occur due to incompatibility between standard parts and finished components. Therefore, this application proposes a reusable expansion bolt structure, solving the bolt mismatch problem during assembly and significantly improving prototyping efficiency. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a reusable expansion bolt structure, comprising a bolt and an expansion sleeve disposed outside the bolt and detachably connected to the bolt. The expansion sleeve comprises a first expansion sleeve, a second expansion sleeve, a third expansion sleeve, and a fourth expansion sleeve arranged sequentially from top to bottom. The bottom of the first expansion sleeve is coupled to the top of the second expansion sleeve, the bottom of the second expansion sleeve is coupled to the top of the third expansion sleeve, and the bottom of the third expansion sleeve is coupled to the top of the fourth expansion sleeve.

[0004] Furthermore, the bottom of the first expansion sleeve is provided with several grooves at intervals around its perimeter, and the second expansion sleeve is composed of several first expansion bands with raised upper ends at intervals, and the raised upper ends of the several first expansion bands are coupled one by one with the several grooves at the bottom of the first expansion sleeve.

[0005] Furthermore, a first coupling end is provided at the top of several grooves on the first expansion sleeve, and a second coupling end is provided at the top of the upper protrusions of several first expansion bands. The second coupling end can slide towards the inner diameter of the expansion sleeve under the action of the first coupling end.

[0006] Furthermore, a first wedge is provided on the outer side of the lower end of several first expansion bands, and the third expansion sleeve is composed of several second expansion bands spaced apart. A second wedge is provided on the inner side of the upper end of the second expansion bands, and the upper end second wedges of several second expansion bands are coupled one-to-one with the lower end first wedges of several first expansion bands.

[0007] Furthermore, a third wedge is provided on the outer side of the lower end of several second expansion bands, and a number of raised fourth wedges are provided at intervals around the inner side of the upper end of the fourth expansion sleeve. The third wedges on several second expansion bands are coupled one-to-one with the number of fourth wedges on the fourth expansion sleeve.

[0008] Furthermore, the top of several third wedges is provided with an upward slope, and the top of several fourth wedges is provided with a downward slope. Under the action of force, the upward slope of the third wedge slides towards the inner diameter of the expansion sleeve on the downward slope of the fourth wedge.

[0009] Furthermore, the lower end of the fourth expansion sleeve is provided with a threaded connection end, and the bolt is screwed into the threaded connection end of the lower end of the fourth expansion sleeve.

[0010] Furthermore, the first expansion sleeve, the second expansion sleeve, the third expansion sleeve, and the fourth expansion sleeve are all connected by spring rods.

[0011] Furthermore, the expansion sleeve is made of steel.

[0012] Furthermore, a gasket is provided between the nut of the bolt and the large end face of the first expansion sleeve.

[0013] Compared with the prior art, the beneficial effects of this application are as follows:

[0014] 1. The expansion bolt structure of this application consists of a bolt and an expansion sleeve. The expansion sleeve is composed of a first expansion sleeve, a second expansion sleeve, a third expansion sleeve, and a fourth expansion sleeve. During operation, the bolt and the expansion sleeve are pre-tightened first, and then the expansion bolt is inserted into the through hole. During the process of tightening the bolt again, the lower end of the second expansion sleeve and the upper end of the third expansion sleeve expand outward simultaneously under the action of force and contact the hole wall, so as to achieve the effect of fastening the bolt and the expansion sleeve to various parts with different hole diameters.

[0015] 2. The expansion bolt structure of this application adopts a detachable connection between the bolt and the expansion sleeve. When using it, the user can choose the appropriate bolt and expansion sleeve to use, which reduces the cost of using expansion bolts.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the expansion bolt structure in an embodiment of the present invention is shown;

[0019] Figure 2 A cross-sectional view of the expansion bolt structure in an embodiment of the present invention is shown;

[0020] Figure 3 A schematic diagram of the expansion sleeve in an embodiment of the present invention is shown;

[0021] Figure 4 A partially enlarged view of the expansion bolt structure A in an embodiment of the present invention is shown;

[0022] Figure 5 A partially enlarged view of the expansion bolt structure B in an embodiment of the present invention is shown;

[0023] Figure 6 A partially enlarged view of the expansion bolt structure C in an embodiment of the present invention is shown.

[0024] In the figure, 1-bolt, 2-expansion sleeve, 21-first expansion sleeve, 211-first coupling end, 22-second expansion sleeve, 221-second coupling end, 222-first wedge, 23-third expansion sleeve, 231-second wedge, 232-third wedge, 24-fourth expansion sleeve, 241-fourth wedge, 242-threaded connection end. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] like Figure 1 As shown, this application provides a reusable expansion bolt structure, including a bolt 1, and an expansion sleeve 2 disposed outside the bolt 1 and detachably connected to the bolt 1. The expansion sleeve 2 includes a first expansion sleeve 21, a second expansion sleeve 22, a third expansion sleeve 23, and a fourth expansion sleeve 24 arranged sequentially from top to bottom. The bottom of the first expansion sleeve 21 is coupled to the top of the second expansion sleeve 22, the bottom of the second expansion sleeve 22 is coupled to the top of the third expansion sleeve 23, and the bottom of the third expansion sleeve 23 is coupled to the top of the fourth expansion sleeve 24.

[0027] like Figure 2As shown, bolt 1 consists of a stud and a nut. The expansion sleeve 2, composed of a first expansion sleeve 21, a second expansion sleeve 22, a third expansion sleeve 23, and a fourth expansion sleeve 24, has a hollow cylindrical interior. The top of the first expansion sleeve 21 has a large end face, which acts as a limit to the nut during tightening. The fourth expansion sleeve 24 is thicker at the lower end and thinner in the middle and upper ends. The inner diameter of the lower end is equal to the outer diameter of bolt 1, while the inner diameters of the middle and upper ends are larger than the outer diameter of bolt 1. Bolt 1 is spaced apart from the inner walls of the first expansion sleeve 21, the second expansion sleeve 22, the third expansion sleeve 23, and the fourth expansion sleeve 24 at their middle and upper ends. The outer side of the lower end of bolt 1 contacts the inner side of the lower end of the fourth expansion sleeve 24 and is detachably connected.

[0028] like Figure 3 As shown, the bottom of the first expansion sleeve 21 is provided with several grooves at intervals around its perimeter, and the second expansion sleeve 22 is composed of several first expansion bands with protruding upper ends at intervals. The protruding upper ends of the several first expansion bands are coupled one by one to the several grooves at the bottom of the first expansion sleeve 21.

[0029] The expansion sleeve 2 is hollow. The height of the lugs on both sides of the groove of the first expansion sleeve 21 is the same as the height of the protrusion on the first expansion band. The lugs on both sides of the groove of the first expansion sleeve 21 and the protrusion on the first expansion band are connected by a spring rod.

[0030] like Figure 4 As shown, a first coupling end 211 is provided on the top of several grooves on the first expansion sleeve 21, and a second coupling end 221 is provided on the top of several upper protrusions of the first expansion band. The second coupling end 221 can slide towards the inner diameter of the expansion sleeve 2 under the action of the first coupling end 211.

[0031] The first coupling end 211 has a downward slope, and the top inner side of the second coupling end 221 consists of a flat section and a downward slope, with the two downward slopes being parallel. When the bolt is tightened further to the required torque, the slope of the first coupling end 211 of the first expansion sleeve 21 slides relative to the slope of the second coupling end 221 of the second expansion sleeve 22. Since there is a certain space between the inner wall of the second expansion sleeve 22 and the outer side of the bolt 1, the upper end of the second expansion sleeve 22 slides inward toward the bolt 1.

[0032] like Figure 5 As shown, a first wedge 222 is provided on the outer side of the lower end of a plurality of first expansion bands, and the third expansion sleeve 23 is composed of a plurality of second expansion bands arranged at intervals. A second wedge 231 is provided on the inner side of the upper end of the second expansion bands, and the upper end second wedge 231 of a plurality of second expansion bands is coupled to the lower end first wedge 222 of a plurality of first expansion bands one by one.

[0033] The bottom of the first wedge 222 and the bottom step of the second wedge 231 form a limit. When the bolt is tightened further to the required torque, the upper end of the second expansion sleeve 22 slides towards the bolt 1. Since the bottom of the first wedge 222 and the bottom step of the second wedge 231 form a limit, the second expansion sleeve 22 does not simply move downward. At this time, the second expansion sleeve 22 bends downward, and the bottom of the first wedge 222 exerts a force on the wedge surface of the second wedge 231, causing the lower end of the second expansion sleeve 22 and the upper end of the third expansion sleeve 23 to expand outward as a whole.

[0034] A number of third wedges 232 are provided on the outer side of the lower end of the second expansion bands, and a number of protruding fourth wedges 241 are provided at intervals around the inner side of the upper end of the fourth expansion sleeve 24. The third wedges 232 on the second expansion bands are coupled one by one with the fourth wedges 241 on the fourth expansion sleeve 24.

[0035] The top of several third wedges 232 is provided with an upward slope, and the top of several fourth wedges 241 is provided with a downward slope. Under the action of force, the upward slope of the third wedges 232 slides on the downward slope of the fourth wedges 241 toward the inner diameter of the expansion sleeve 2.

[0036] When the upper end of the third expansion sleeve 23 expands outward, the upward-sloping surface of the top of the third wedge 232 slides against the downward-sloping surface of the top of the fourth wedge 241, and the lower end of the third expansion sleeve 23 slides inward toward the bolt 1, so that the lower end of the second expansion sleeve 22 and the upper end of the third expansion sleeve 23 expand outward together to adapt to the fastening requirements of different hole diameters.

[0037] At this point, as the bolts are tightened to the required torque, the inclined surface of the first coupling end 211 of the first expansion sleeve 21 slides relative to the inclined surface of the second coupling end 221 of the second expansion sleeve 22, causing the upper end of the second expansion sleeve 22 to slide inward toward the bolt 1. Since the bottom of the first wedge 222 and the bottom step of the second wedge 231 form a limit, the second expansion sleeve 22 bends downward as a whole. The bottom of the first wedge 222 exerts a force on the wedge surface of the second wedge 231, causing the lower end of the second expansion sleeve 22 and the upper end of the third expansion sleeve 23 to expand outward as a whole. When the upper end of the third expansion sleeve 23 expands outward, the upward-sloping surface of the top of the third wedge 232 slides against the downward-sloping surface of the top of the fourth wedge 241, and the lower end of the third expansion sleeve 23 slides inward toward the bolt 1, so that the lower end of the second expansion sleeve 22 and the upper end of the third expansion sleeve 23 expand outward together to adapt to the fastening requirements of different hole diameters.

[0038] like Figure 6As shown, the lower end of the fourth expansion sleeve 24 is provided with a threaded connection end 242, and the bolt 1 is screwed to the threaded connection end 242 at the lower end of the fourth expansion sleeve 24.

[0039] The first expansion sleeve 21, the second expansion sleeve 22, the third expansion sleeve 23, and the fourth expansion sleeve 24 are all connected by spring rods. This allows for unrestricted expansion and allows for elastic deformation to meet the required degree of expansion.

[0040] The expansion sleeve 2 is made of steel.

[0041] A gasket is provided between the nut of the bolt 1 and the large end face of the first expansion sleeve 21.

[0042] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reusable expansion bolt structure, comprising a bolt (1), characterized in that: The expansion sleeve (2) is provided outside the bolt (1) and detachably connected to the bolt (1). The expansion sleeve (2) includes a first expansion sleeve (21), a second expansion sleeve (22), a third expansion sleeve (23) and a fourth expansion sleeve (24) arranged sequentially from top to bottom. The bottom of the first expansion sleeve (21) is coupled to the top of the second expansion sleeve (22), the bottom of the second expansion sleeve (22) is coupled to the top of the third expansion sleeve (23), and the bottom of the third expansion sleeve (23) is coupled to the top of the fourth expansion sleeve (24). The bottom of the first expansion sleeve (21) is provided with a plurality of grooves at intervals around its perimeter. The second expansion sleeve (22) is composed of a plurality of first expansion bands with protruding upper ends at intervals. The protruding upper ends of the plurality of first expansion bands are coupled one by one to the plurality of grooves at the bottom of the first expansion sleeve (21). The top of the plurality of grooves on the first expansion sleeve (21) is provided with a first coupling end (211), and the top of the protruding upper ends of the plurality of first expansion bands is provided with a second coupling end (221). The second coupling end (221) can slide towards the inner diameter of the expansion sleeve (2) under the action of the first coupling end (211); A first wedge (222) is provided on the outer side of the lower end of a plurality of first expansion bands. The third expansion sleeve (23) is composed of a plurality of second expansion bands spaced apart. A second wedge (231) is provided on the inner side of the upper end of the second expansion bands. The upper end second wedge (231) of a plurality of second expansion bands is coupled to the lower end first wedge (222) of a plurality of first expansion bands one by one. A number of third wedges (232) are provided on the outer side of the lower end of the second expansion bands, and a number of raised fourth wedges (241) are provided at intervals around the inner side of the upper end of the fourth expansion sleeve (24). The third wedges (232) on the second expansion bands are coupled one by one with the fourth wedges (241) on the fourth expansion sleeve (24).

2. The reusable expansion bolt structure according to claim 1, characterized in that: The top of several third wedges (232) is provided with an upward slope, and the top of several fourth wedges (241) is provided with a downward slope. Under the action of force, the upward slope of the third wedges (232) slides towards the inner diameter of the expansion sleeve (2) on the downward slope of the fourth wedges (241).

3. The reusable expansion bolt structure according to claim 1, characterized in that: The lower end of the fourth expansion sleeve (24) is provided with a threaded connection end (242), and the bolt (1) is screwed to the threaded connection end (242) at the lower end of the fourth expansion sleeve (24).

4. The reusable expansion bolt structure according to claim 1, characterized in that: The first expansion sleeve (21), the second expansion sleeve (22), the third expansion sleeve (23) and the fourth expansion sleeve (24) are all connected by spring rods.

5. The reusable expansion bolt structure according to claim 1, characterized in that: The expansion sleeve (2) is made of steel.

6. The reusable expansion bolt structure according to claim 1, characterized in that: A gasket is provided between the nut of the bolt (1) and the large end face of the first expansion sleeve (21).

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