A bolted connection assembly and its processing technology

Abstract

This application relates to the field of mechanical fasteners, and in particular to a bolt connection assembly and its processing technology. The bolt connection assembly includes a screw and a bushing fitted around the screw. The bushing includes an inner sleeve and an outer sleeve, with the inner sleeve inside the outer sleeve. A first flange is provided around the opening of the outer sleeve, and a locking flange is provided on the inner side of the upper part of the outer sleeve. A wedge-shaped opening is provided at the upper end of the inner sleeve below the locking flange. A groove for accommodating the locking flange is provided on the upper peripheral wall of the screw, and a second flange is provided around the lower opening of the inner sleeve. This application divides the bushing into inner and outer sleeves. When the screw is tightened, the distance between the inner and outer sleeves and the object to be connected is utilized. After the screw is fully tightened, the locking flange of the inner sleeve fits precisely into the groove of the screw. Under further compression, the deflected locking flange is locked in the groove, preventing the screw from rotating out of the outer sleeve.

Description

Technical Field

[0001] This application relates to the field of mechanical fasteners, and more particularly to a bolted connection assembly and its processing technology. Background Technology

[0002] Bolts are common fasteners used to connect two parts together. To prevent the bolt head from exerting excessive pressure on the connected parts and damaging them, a bushing is usually fitted over the bolt to form a combined bolt. The flange of the bushing increases the contact area and reduces pressure, thus protecting the connected parts. In use, the bushing needs to be pre-welded or fixed to the first part to be connected. Then, the bolt is passed through the bushing, and the threaded end of the bolt is screwed into the second part to achieve a locking connection. Because the bolt portion in the second part lacks a nut for reinforcement, it is prone to loosening due to vibration over prolonged use, leading to bolt connection failure, safety hazards, and failure to meet usage requirements. Summary of the Invention

[0003] To improve the anti-loosening performance of bolted connection assemblies, this application provides a bolted connection assembly and its processing technology, adopting the following technical solution.

[0004] A bolted connection assembly includes a screw and a bushing sleeved outside the screw. The screw has a nut at its top and external threads on its lower peripheral wall. The bushing includes an inner sleeve and an outer sleeve. The inner sleeve is connected inside the outer sleeve. A first flange is provided around the opening of the outer sleeve. A locking flange is provided on the inner side of the upper part of the outer sleeve. The locking flange is bent downwards. A wedge-shaped opening is provided at the upper end of the inner sleeve below the locking flange. A curved groove that mates with the wedge-shaped opening is provided at the lower part of the locking flange. A groove for accommodating the locking flange is provided on the upper peripheral wall of the screw. A second flange is provided around the opening of the inner sleeve.

[0005] By adopting the above technical solution, the bushing is fixed to the first object to be received. Then, the knob nut drives the external thread section of the screw inside the bushing to screw into the second object to be received. During the screwing process, the distance between the first and second objects to be received will be gradually compressed, causing the inner sleeve of the bushing to gradually slide towards the upper opening of the outer sleeve. This causes the wedge-shaped opening of the inner sleeve to continuously approach the locking edge of the outer sleeve, thereby gradually squeezing the locking edge of the outer sleeve. The groove of the locking edge begins to deform under the pressure of the wedge-shaped opening, causing the locking edge on one side of the groove to bend towards the central axis of the outer sleeve. Then, as the screw rotates, the bent locking edge fits into the groove of the screw. Under further pressure, the bent locking edge is stuck in the groove, locking the rotation of the screw and the outer sleeve, thus preventing the screw from rotating out.

[0006] Optionally, the distance from the outer edge of the second flange to the central axis of the inner sleeve is less than the outer diameter of the outer sleeve.

[0007] By adopting the above technical solution, the outer contour of the second flange is located inside the outer diameter of the outer sleeve, which allows the inner sleeve to be directly inserted into the mounting hole of the object to be received, thus avoiding the problem that the inner sleeve does not need to be installed because the space on the other side of the object to be received is too small.

[0008] Optionally, the periphery of the first flange is provided with a downwardly bent elastic pressing edge.

[0009] By adopting the above technical solution, the elastic pressing edge deforms under the pressure of the nut, making the first flange fit more tightly with the lower side of the nut, increasing the frictional resistance between the nut and the first flange, hindering the rotation of the nut, and improving the bolt's anti-loosening performance.

[0010] Optionally, the bottom surface of the groove is provided with a slope and a stop surface on the left and right sides respectively, and the opening area of ​​the groove gradually decreases along the slope towards the bottom surface of the groove.

[0011] By adopting the above technical solution, during extrusion, the wedge-shaped opening first contacts the bottom of the curved groove and gradually expands the curved groove, causing the locking edge to bend outward. The end of the locking edge first enters the groove. At this time, because the part of the locking edge end entering the groove is small and there is still a gap between the locking edge end and the wedge-shaped opening of the inner tube sleeve, the blocking strength of the screw is low. Therefore, the slope can guide the tip of the locking edge end to more easily disengage from the groove when the screw is tightened in the forward direction, so that the screw can be further tightened and locked. That is, when a larger part of the locking edge enters the groove and the locking edge end is more closely fitted with the wedge-shaped opening of the inner tube sleeve, the screw reaches the tightened state. At this time, the blocking and anti-rotation strength of the locking edge of the stop surface is greater, and the bolt anti-loosening performance is stronger.

[0012] Optionally, the groove depth gradually increases as it approaches the top of the screw.

[0013] By adopting the above technical solution, the groove depth gradually increases as it approaches the top of the screw, which can reduce the resistance of the groove and locking edge to the screw in the forward tightening before reaching the locking position, reduce the construction difficulty, and improve the locking strength through the wedge structure.

[0014] Optionally, the inner tube sleeve includes a first sub-tube sleeve and a second sub-tube sleeve. One end of the first sub-tube sleeve is provided with a wedge-shaped opening, and the other end of the first sub-tube sleeve is provided with a first splicing groove and a second splicing groove of different depths. One end of the second sub-tube sleeve is provided with a second flange, and the other end of the second sub-tube sleeve is provided with a splicing rod that fits into the first splicing groove or the second splicing groove.

[0015] By adopting the above technical solution, the splicing structure of the inner sleeve makes the length of the inner sleeve adjustable, which makes the bushing suitable for objects of different thicknesses and improves the applicability of the product.

[0016] Optionally, the outer sleeve is provided with an anti-detachment strip on its outer peripheral wall, and an anti-detachment rubber sleeve is provided on the screw on the lower side of the inner sleeve.

[0017] By adopting the above technical solutions, the anti-detachment strip can improve the connection and tightness between the outer tube sleeve and the object to be connected, and the anti-detachment rubber sleeve can lock the outer tube sleeve, inner tube sleeve and screw, so that the bolt assembly will not come apart during transportation and is convenient to use.

[0018] Optionally, the inner sleeve includes a wedge-shaped tube and a flange tube, and an elastic mechanism is provided in the wall thickness space between the wedge-shaped tube and the flange tube.

[0019] By adopting the above technical solution, the elastic mechanism gives the bolt assembly a certain degree of shock absorption, enhances the bolt assembly's impact resistance during use, and improves the service life of the bolt assembly.

[0020] Optionally, the elastic mechanism includes an elastic element and a damping pad. The elastic element includes a first connector and a second connector. A spring is connected between the first connector and the second connector. Both the first connector and the second connector have protrusions on their outer sides. The ends of the wedge tube and the flange tube are provided with slots for the protrusions to be inserted. Damping pads are provided between the first connector and the wedge tube and between the second connector and the flange tube on one side of the slot.

[0021] By adopting the above technical solution, the damping pad contains a large amount of fibrous material in the horizontal direction. During vibration, the crisscrossing arrangement of the fibers absorbs kinetic energy through internal friction. The damping pad, in conjunction with the elastic mechanism, enhances the seismic energy dissipation capacity of the bolt assembly, making it more durable.

[0022] A processing method for a bolted connection assembly as described above includes the following steps: extruding a cylindrical workpiece to form a head and a shank with a first flange; extruding the head to form an upper half-hole and a deep hole in the shank, extruding the upper half-hole and the deep hole to form a disc, punching the disc to connect the upper half-hole and the deep hole to form a through hole, and leaving several protrusions on the inner wall of the through hole; extruding the protrusions to bend them downwards to form a locking flange, thus obtaining an outer bushing; forming a prefabricated sleeve with a second flange and a through hole by extruding the cylindrical workpiece, and extruding the port of the prefabricated sleeve using a conical pressure head to form a wedge-shaped opening at one end of the prefabricated sleeve away from the second flange, thus obtaining an inner sleeve.

[0023] By adopting the above technical solution, cold heading of bolt bushings avoids complex forming processes such as drilling and milling, reduces the requirements for production equipment, lowers production costs, and improves processing efficiency.

[0024] In summary, this application includes at least one of the following beneficial technical effects: By dividing the bushing into two components, inner and outer sleeves, when the screw is tightened, the distance relationship between the inner and outer sleeves and the object to be received is utilized to ensure that after the screw is fully tightened, the locking edge of the inner sleeve fits into the groove of the screw. Under further compression, the deflected locking edge is stuck in the groove, locking the rotation of the screw and the outer sleeve, thus preventing the screw from rotating out. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this application.

[0026] Figure 2 This is a front view structural diagram of Embodiment 1 of this application.

[0027] Figure 3 This is a cross-sectional structural diagram of Embodiment 1 of this application.

[0028] Figure 4 yes Figure 3 Enlarged view of part A in the image.

[0029] Figure 5 This is a schematic diagram of the screw structure in Embodiment 1 of this application.

[0030] Figure 6 This is a schematic diagram of the top cross section of the screw in Embodiment 1 of this application.

[0031] Figure 7 This is a schematic diagram of the screw groove structure in Embodiment 1 of this application.

[0032] Figure 8 This is a schematic diagram of the outer sleeve structure of Embodiment 1 of this application.

[0033] Figure 9 This is a schematic diagram of the inner sleeve structure of Embodiment 1 of this application.

[0034] Figure 10 This is a schematic diagram of the structure of Embodiment 2 of this application.

[0035] Figure 11 This is a schematic diagram of the inner sleeve structure in Embodiment 2 of this application.

[0036] Explanation of reference numerals in the attached drawings: 1. Screw; 11. Nut; 12. Groove; 121. Sloping surface; 122. Stop surface; 13. Anti-detachment sleeve; 14. External thread; 2. Bushing; 21. Outer sleeve; 211. First flange; 212. Elastic pressing edge; 213. Locking flange; 214. Bend; 215. Anti-detachment strip; 22. Inner sleeve; 221. Wedge-shaped opening; 222. Second flange; 223. First sub-sleeve; 224. First splicing groove; 225. Second sub-sleeve; 226. Second splicing groove; 227. Splicing rod; 23. Wedge-shaped tube; 24. Flange tube; 25. Elastic mechanism; 251. Elastic element; 252. First connector; 253. Second connector; 254. Protruding post; 255. Slot; 256. Spring; 26. Damping pad. Detailed Implementation

[0037] The following is in conjunction with the appendix Figure 1-11 This application will be described in further detail.

[0038] Example 1

[0039] This application discloses a bolted connection assembly and its processing technology.

[0040] Reference Figure 1-8 The bolt connection assembly includes a screw 1 and a bushing 2 sleeved on the outside of the screw 1. The top of the screw 1 is provided with a nut 11 and an integrally formed washer is provided on the lower side of the nut 11. The lower peripheral wall of the screw 1 is provided with an external thread 14. The bushing 2 includes an inner sleeve 22 and an outer sleeve 21. The inner sleeve 22 is connected inside the outer sleeve 21. The outer peripheral wall of the outer sleeve 21 is provided with an anti-disengagement strip 215. The upper opening of the outer sleeve 21 is provided with a first flange 211. The periphery of the first flange 211 is provided with a downwardly bent elastic pressing edge 212. The upper inner side of the outer sleeve 21 is provided with a locking flange 213, which is bent downwards. The upper end of the inner sleeve 22 below the locking flange 213 is provided with a wedge-shaped opening 221. The lower part of the locking flange 213 is provided with a curved groove 214 that mates with the wedge-shaped opening 221. The upper peripheral wall of the screw 1 is provided with a groove 12 for accommodating the locking flange 213. The left and right sides of the bottom surface of the groove 12 are respectively provided with a slope 121 and a stop surface 122. The opening area of ​​the groove 12 gradually decreases along the slope 121 towards the bottom surface of the groove 12, and the depth of the groove 12 gradually increases as it approaches the top of the screw 1. A second flange 222 is provided around the lower opening of the inner sleeve 22. The distance from the outer edge of the second flange 222 to the central axis of the inner sleeve 22 is less than the outer diameter of the outer sleeve 21. When leaving the factory, an anti-detachment sleeve 13 is fitted on the screw 1 under the inner sleeve 22 to prevent the screw 1 from easily coming off the bushing 2 during transportation, and to prevent the inner sleeve 22 from easily separating from the outer sleeve 21, thereby improving the construction efficiency during use.

[0041] Reference Figure 9The inner sleeve 22 includes a first sub-sleeve 223 and a second sub-sleeve 225. A wedge-shaped opening 221 is provided at one end of the first sub-sleeve 223. The other end of the first sub-sleeve 223 is provided with a first splicing groove 224 and a second splicing groove 226 of different depths. A second flange 222 is provided at one end of the second sub-sleeve 225. The other end of the second sub-sleeve 225 is provided with a splicing rod 227 that fits into the first splicing groove 224 or the second splicing groove 226. In this embodiment, the depth of the first splicing groove 224 is less than the length of the splicing rod 227, and the depth of the second splicing groove 226 is the same as the length of the splicing rod 227. When the splicing rod 227 is connected to different splicing grooves, the length of the inner sleeve 22 changes, making it easier for the bushing 2 to be used with objects of different thicknesses, thus improving the applicability of the product.

[0042] A processing technology for a bolted connection assembly includes the following steps: extruding a cylindrical workpiece to form a head and a shank with a first flange 211; extruding the head to form an upper half-hole and a deep hole in the shank, extruding the upper half-hole and the deep hole to form a disc, punching the disc to connect the upper half-hole and the deep hole to form a through hole, and cutting several protrusions on the inner wall of the through hole; extruding the protrusions to bend them downwards to form a locking flange 213, thus obtaining an outer sleeve 21 of a bushing 2; forming a prefabricated sleeve with a second flange 222 and a through hole by extruding the cylindrical workpiece, extruding the port of the prefabricated sleeve with a conical pressure head, and forming a wedge-shaped opening 221 at one end of the prefabricated sleeve away from the second flange 222, thus obtaining an inner sleeve 22. In use, the bushing 2 is fixed to the object to be received. Then, the knob nut 11 is turned to drive the external thread 14 of the screw 1 inside the bushing 2 into the approaching object to be received. During the screwing process, the distance between the object to be received and the object to be received will be gradually compressed, causing the inner sleeve 22 of the bushing 2 to gradually slide towards the upper opening of the outer sleeve 21. This causes the wedge-shaped opening 221 of the inner sleeve 22 to continuously approach the locking edge 213 of the outer sleeve 21, thereby gradually squeezing the outer sleeve 21 to lock. The groove 214 of the locking edge 213 is deformed by the pressure of the wedge-shaped opening 221, causing the locking edge 213 on one side of the groove 214 to bend towards the central axis of the outer sleeve 21. Then, as the screw 1 rotates, the bent locking edge 213 fits into the groove 12 of the screw 1. Under further pressure, the bent locking edge 213 is stuck in the groove 12, locking the rotation of the screw 1 and the outer sleeve 21, thus preventing the screw 1 from rotating out.

[0043] Example 2

[0044] Reference Figure 10-11The difference between this embodiment 2 and embodiment 1 lies in the structure of the inner sleeve 22. Specifically, the inner sleeve 22 used in this embodiment 2 includes a wedge-shaped tube 23 and a flange tube 24. An elastic mechanism 25 is provided in the wall thickness space between the wedge-shaped tube 23 and the flange tube 24. The elastic mechanism 25 includes an elastic element 251 and a damping pad 26. The elastic element 251 includes a first connector 252 and a second connector 253. A spring 256 is connected between the first connector 252 and the second connector 253. Both the first connector 252 and the second connector 253 have protrusions 254 on their outer sides. Both the wedge-shaped tube 23 and the flange tube 24 have slots 255 at their ends for the protrusions 254 to be inserted. Damping pads 26 are provided between the first connector 252 and the wedge-shaped tube 23 and between the second connector 253 and the flange tube 24 on one side of the slot 255.

[0045] The implementation principle of a bolt connection assembly according to an embodiment of this application is as follows: The wedge tube 23, damping pad 26, elastic mechanism 25, and flange tube 24 are sequentially assembled and then installed into the outer sleeve 21. Due to the interference fit between the wedge tube 23, flange tube 24, and the inner wall of the outer sleeve 21, they are not easily dislodged after installation. When vibration occurs during use, the elastic mechanism 25 reduces the impact force, and the damping pad 26 further dissipates energy, improving the seismic performance of the bolt assembly.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A bolted connection assembly, characterized in that: The device includes a screw (1) and a bushing (2) fitted around the screw (1). The screw (1) has a nut (11) at the top and an external thread (14) on the lower circumferential wall. The bushing (2) includes an inner sleeve (22) and an outer sleeve (21). The inner sleeve (22) is connected inside the outer sleeve (21). The outer sleeve (21) has a first flange (211) around the upper opening and a locking flange on the upper inner side of the outer sleeve (21). 213), the locking edge (213) is bent downwards, the upper end of the inner tube sleeve (22) on the lower side of the locking edge (213) is provided with a wedge-shaped opening (221), the lower part of the locking edge (213) is provided with a curved groove (214) that matches the wedge-shaped opening (221), the upper peripheral wall of the screw (1) is provided with a groove (12) for accommodating the locking edge (213), and a second flange (222) is provided around the lower tube opening of the inner tube sleeve (22); the inner tube sleeve (213) 2) Includes a wedge tube (23) and a flange tube (24). An elastic mechanism (25) is provided in the wall thickness space between the wedge tube (23) and the flange tube (24). The elastic mechanism (25) includes an elastic element (251) and a damping pad (26). The elastic element (251) includes a first connector (252) and a second connector (253). A spring (256) is connected between the first connector (252) and the second connector (253). A protrusion (254) is provided on the outer side of both the first connector (252) and the second connector (253). A slot (255) for the protrusion (254) is provided at the end of both the wedge tube (23) and the flange tube (24). A damping pad (26) is provided between the first connector (252) and the wedge tube (23) and between the second connector (253) and the flange tube (24) on one side of the slot (255).

2. The bolt connection assembly according to claim 1, characterized in that: The distance from the outer edge of the second flange (222) to the central axis of the inner sleeve (22) is less than the outer diameter of the outer sleeve (21).

3. A bolted connection assembly according to claim 1, characterized in that: The first flange (211) has a downwardly bent elastic pressing edge (212) around its periphery.

4. A bolted connection assembly according to claim 1, characterized in that: The bottom surface of the groove (12) is provided with a slope (121) and a stop surface (122) on the left and right sides respectively. The opening area of ​​the groove (12) gradually decreases along the slope (121) towards the bottom surface of the groove (12).

5. A bolted connection assembly according to claim 4, characterized in that: The depth of the groove (12) gradually increases as it approaches the top of the screw (1).

6. A bolted connection assembly according to claim 1, characterized in that: The outer sleeve (21) has an anti-detachment strip (215) on its outer peripheral wall, and the inner sleeve (22) has an anti-detachment rubber sleeve (13) on the screw (1) on its lower side.

7. A processing method for a bolted connection assembly as described in claim 1, characterized in that, Includes the following steps: The cylindrical workpiece is extruded to form a head and a rod with a first flange (211); the head is extruded to form an upper half hole and a deep hole in the rod; a disc is formed between the upper half hole and the deep hole; the disc is punched to connect the upper half hole and the deep hole to form a through hole; several protrusions are cut out on the inner wall of the through hole; the protrusions are extruded to bend the protrusions downward to form a locking flange (213), thus obtaining the outer sleeve (21) of the bushing (2); a prefabricated sleeve with a second flange (222) and a through hole is formed by extruding the cylindrical workpiece; the port of the prefabricated sleeve is extruded by using a conical press head; a wedge-shaped opening (221) is formed at one end of the prefabricated sleeve away from the second flange (222), thus obtaining the inner sleeve (22).

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