Cold extrusion lug-free supporting plate self-locking nut

Abstract

The utility model relates to the technical field of fasteners, and discloses a cold extrusion lug-free supporting plate self-locking nut. The cold extrusion lug-free supporting plate self-locking nut is in the shape of a hollow cylinder with a round head, and internal threads are arranged at the tail of the cylinder. The cylindrical surface of the outer wall of the internal thread adopts three-point closing to form a self-locking characteristic, and the inner hole, close to the head, of the self-locking nut is smaller and is a cold extrusion strengthening area; the inner diameter of the middle groove is larger, and the middle groove is a riveting deformation area; an inner hole between the rivet pulling deformation area and the threaded section is small and is a rivet pulling deformation transition area, and it is guaranteed that threads do not deform after rivet pulling. A round head is arranged on the outer wall of the cold extrusion round-head lug-free supporting plate self-locking nut, a cold extrusion strengthening area is arranged on the inner wall of the cold extrusion round-head lug-free supporting plate self-locking nut, a rivet pulling deformation area is arranged on the inner wall of the cold extrusion round-head lug-free supporting plate self-locking nut, an internal thread is arranged at the tail of the cold extrusion round-head lug-free supporting plate self-locking nut, and a rivet pulling deformation area is arranged at the tail of the cold extrusion round-head lug-free supporting plate self-locking nut. The inner wall between the internal thread and the riveting deformation area is a riveting deformation transition area, and the cylindrical surface of the outer wall of the internal thread adopts three-point closing to form a self-locking characteristic.

Description

Technical Field

[0001] The utility model relates to the technical field of fasteners, in particular to a cold-extruded earless support plate self-locking nut. Background Art

[0002] Self-locking nuts are a type of nut that can self-lock by friction. The main functions of self-locking nuts are to prevent loosening and vibration.

[0003] Currently, in some aircraft structures, it is necessary to fasten multiple layers of thin-walled sheet metal structures, and oval-head, earless, self-locking nuts are used. Their disadvantages are as follows: 1. The head is an oval structure. The oval head 1 has two angles β and γ in the perpendicular cross-section, the former being 16° larger than the latter. The transition zone between the two angles together constitutes the oval head, which requires special process equipment to form. The angle and shape are difficult to guarantee, and the nut does not fit tightly with the countersink structure of the thin-walled sheet metal. 2. Countersinking is required on the thin-walled sheet metal, and the shape and angle of the countersink are also strictly required. 3. After the nut is riveted to the thin-walled sheet metal structure, a gap exists between the outer cylindrical surface of the nut and the wall of the hole in the thin-walled sheet metal structure. Due to the "breathing" effect, salt spray or acidic foreign matter can easily enter the gap, causing chemical or electrochemical corrosion. 4. After the nut is riveted to the thin-walled sheet metal structure, a gap exists between the outer cylindrical surface and the wall of the hole in the thin-walled sheet metal structure, making the nut itself have no contribution to the fatigue gain of the thin-walled sheet metal. Utility Model Content

[0004] In response to the shortcomings of the existing technology, the utility model provides a cold-extruded earless support plate self-locking nut, which has strong practicality and high installation efficiency. The cold extrusion technology is used to increase the fatigue life of the structure by more than 2 times, solving the problems raised by the above-mentioned background technology.

[0005] The utility model provides the following technical solutions: a cold-extruded earless support plate self-locking nut, comprising a cold-extruded round head earless support plate self-locking nut, the outer wall of the cold-extruded earless support plate self-locking nut is provided with a round head, the inner wall of the cold-extruded round head earless support plate self-locking nut is provided with a cold extrusion strengthening area, the inner wall of the cold-extruded earless support plate self-locking nut is provided with a rivet deformation area, the inner wall of the cold-extruded round head earless support plate self-locking nut is provided with a rivet deformation transition area, the tail of the cold-extruded round head earless support plate self-locking nut is provided with an internal thread, the outer wall of the internal thread of the cold-extruded round head earless support plate self-locking nut is provided with a threaded closing area, and the outer wall of the cold-extruded round head earless support plate self-locking nut is provided with a tail sealed closed type or a tail non-sealed type.

[0006] As an optimal technical solution of the present invention, the head height of the cold-extruded round-head earless support plate self-locking nut is h>0.5mm, and the cone angle of the extruded round-head earless support plate self-locking nut head is 90°>α>100°.

[0007] As an optimal technical solution of the present invention, the cold extrusion strengthening zone is arranged on the inner wall of the cold extruded round head earless support plate self-locking nut near the head, and the aperture of the cold extrusion strengthening zone is smaller than the aperture of the rivet deformation zone.

[0008] As an optimal technical solution of the present utility model, the rivet deformation zone is arranged in the middle section of the inner wall of the cold-extruded round head earless support plate self-locking nut, and the rivet deformation transition zone is arranged between the middle section of the inner wall and the threaded section of the cold-extruded round head earless support plate self-locking nut.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] 1. The cold-extruded earless support plate self-locking nut is a round-headed, hollow cylinder with an internal thread at the tail of the cylinder. The internal thread adopts three-point closing to form a self-locking characteristic. The inner hole near the head of the self-locking nut is smaller, which is the cold extrusion strengthening area; the inner diameter of the middle groove is larger, which is the rivet deformation area; the inner hole between the middle section and the threaded section is smaller, which is the rivet deformation transition area, ensuring that the thread is not deformed after riveting.

[0011] 2. This cold-extruded, earless self-locking nut has a total structural plate thickness of 4.1mm. The thickness of the thin-walled sheet metal on the left side ranges from (1.8 to 2.3) mm, and the thickness of the thin-walled sheet metal on the right side ranges from (1.8 to 2.3) mm. The thin-walled sheet metal on the right side has a chamfer C0.5 that matches the round head h of the nut, and the cold extrusion interference is 5%. The aperture of the thin-walled sheet metal structure ranges from φ6 to φ7 mm, and the thread specification is MJ6×1. In this patent, two layers of structural plates are preferably stacked. The unscrewing torque is not less than 6.5 Nm, the push-out force is not less than 5 kN, and the axial tensile load is not less than 8 kN. The fatigue resistance of the thin-walled sheet metal structure is increased by more than 2 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the three-dimensional structure of the utility model (including the self-locking nut and installation tool of the present invention);

[0013] Figure 2 This is a half-section diagram of the structure of the old technology oval head earless support plate self-locking nut;

[0014] Figure 3 This is a schematic diagram of the semi-sectional structure of the cold-extruded round head earless support plate self-locking nut of the utility model (the left picture is the non-sealed type, and the right picture is the sealed type);

[0015] Figure 4 This is a schematic diagram of the three-dimensional cross-sectional structure of the utility model;

[0016] Figure 5 For this utility model Figure 4 Schematic diagram of the local cross-section structure;

[0017] Figure 6 This is a schematic diagram of the structure of the limit ring of the utility model;

[0018] Figure 7 This is a schematic diagram of the structure of the rivet screw of the utility model;

[0019] Figure 8 This is a schematic diagram of the thin-walled sheet metal structure on the left side of the utility model;

[0020] Figure 9 This is a schematic diagram of the British and metric thread tables of the present invention.

[0021] In the figure: 3. Round head; 4. Cold extrusion strengthening zone; 5. Rivet deformation zone; 6. Rivet deformation transition zone; 7. Threaded end zone; 8. Tail sealed closed type or tail non-sealed type; 9. Cold extruded round head earless support plate self-locking nut; 10. Thin-walled sheet metal on the left; 11. Thin-walled sheet metal on the right; 12. Limiting head; 13. Bushing fixing seat; 14. Connecting head; 15. Pull gun piston rod; 16. Pull gun housing; 17. Cold extrusion mandrel; 18. Open bushing; 19. Limiting ring; 20. Rivet screw. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] See also Figure 1-9 , a cold-extruded earless support plate self-locking nut includes a cold-extruded earless support plate self-locking nut 9, the outer wall of the cold-extruded earless support plate self-locking nut 9 is provided with a round head 3, the inner wall of the cold-extruded round head earless support plate self-locking nut 9 is provided with a cold extrusion strengthening zone 4, the inner wall of the cold-extruded earless support plate self-locking nut 9 is provided with a rivet deformation zone 5, the inner wall of the cold-extruded round head earless support plate self-locking nut 9 is provided with a rivet deformation transition zone 6, the outer wall of the internal thread of the cold-extruded round head earless support plate self-locking nut 9 is provided with a threaded closing area 7 for forming a self-locking characteristic, and the outer wall of the cold-extruded round head earless support plate self-locking nut 9 is provided with a tail sealed closed type 8 or a tail non-sealed type.

[0024] In a preferred embodiment, the cold-extruded earless support plate self-locking nuts 9 are divided into two categories according to the thread type: British cold-extruded earless support plate self-locking nuts 9 and male cold-extruded earless support plate self-locking nuts 9.

[0025] British cold extrusion strengthened earless support plate self-locking nuts are divided into two categories according to the tail structure: British non-sealed cold extrusion strengthened earless support plate self-locking nuts and British sealed cold extrusion strengthened earless support plate self-locking nuts;

[0026] Metric cold extruded and strengthened earless pallet self-locking nuts are divided into two categories according to the tail structure: metric non-sealed cold extruded and strengthened earless pallet self-locking nuts and metric sealed cold extruded and strengthened earless pallet self-locking nuts.

[0027] In a preferred embodiment, the head height of the cold-extruded earless support plate self-locking nut 9 is h>0.5mm, and the head cone angle of the cold-extruded earless support plate self-locking nut 9 is 90°>α>100°. The smaller head size of the nut means that the cold-extruded earless support plate self-locking nut 9 only needs to make holes and chamfers on the thin-walled sheet metal structure before assembly, which can be completed in one step, and then the nut can be installed.

[0028] In a preferred embodiment, the cold extrusion strengthening zone 4 is arranged on the inner wall of the cold extruded earless support plate self-locking nut 9 near the head, and the aperture of the cold extrusion strengthening zone 4 is smaller than the aperture of the rivet deformation zone 5.

[0029] In a preferred embodiment, the rivet deformation zone 5 is arranged in the middle section of the inner wall of the cold-extruded round head earless support plate self-locking nut 9, and the rivet deformation transition zone 6 is arranged between the middle section of the inner wall and the thread section of the cold-extruded round head earless support plate self-locking nut 9. After the cold extrusion strengthening is completed by the cold extrusion strengthening zone 4 on the device, the device reuses the rivet deformation zone 5 for deformation operation, and utilizes the subsequent rivet deformation transition zone 6 for deformation transition effect, so as to ensure that the thread is not deformed after riveting.

[0030] In a preferred embodiment, the cold-extruded earless support plate self-locking nut 9 inches includes a cold extrusion interference range of 4% to 10% for sealing and non-sealing and thin-walled sheet metal structure apertures, and the thread specifications are 0.1900-32UNJF-3B, 0.2500-28UNJF-3B, 0.3125-24UNJF-3B, 0.3750-21UNJF-3B, etc. The thickness range of the single-layer thin-walled sheet metal structure is (1.8 to 2.3) mm, and the cumulative stacked total thickness of the multi-layer thin-walled sheet metal structure is up to 45 mm. The aperture D of the cold-extruded thin-walled sheet metal structure ranges from φ6 mm to φ12 mm, the cold-extruded hole margin is not less than 1.7D, the hole spacing is not less than 3D, and the fatigue life gain of the thin-walled sheet metal structure is at least increased by 2 times.

[0031] In a preferred embodiment, the cold-extruded earless support plate self-locking nut 9 metric includes sealed and unsealed cold extrusion interference with the aperture of the thin-walled sheet metal structure in the range of 4% to 10%, and the thread specifications are M5×0.80-4H6H, M6×1.00-4H5H, M7×1.00-4H5H, M8×1.25-4H5H, M10×1.50-4H5H, etc. The thickness range of the single-layer thin-walled sheet metal structure is (1.8~2.3) mm, and the cumulative total thickness of the multi-layer thin-walled sheet metal structure is up to 45 mm. The aperture D of the cold-extruded thin-walled sheet metal structure ranges from φ6.20 mm to φ13.0 mm, the cold-extruded hole margin is not less than 1.7D, the hole spacing is not less than 3D, and the fatigue life gain of the thin-walled sheet metal structure is at least increased by 2 times.

[0032] In a preferred embodiment, the material of the cold-extruded earless support plate self-locking nut 9 is 17-4PH, GH2123 and 304L. In order to adapt to the material structure of the left thin-walled sheet metal 10 and the right thin-walled sheet metal 11, the cold-extruded earless support plate self-locking nut 9 on the device is suitable for structures with thin-walled sheet metal materials such as 7050-T7451 and TC4.

[0033] The installation of cold-extruded earless support plate self-locking nuts is divided into two steps: cold extrusion and riveting. Both must be completed in sequence and neither can be missing.

[0034] Step 1: Cold extrusion process. ① The connector 14 is connected to the gun housing 16 through threads; ② The bushing fixing seat 13 is connected to the connector 14 through threads; ③ The outer circle of the tail of the open bushing 18 is inserted into the hole of the bushing fixing seat 13; ④ The limit head 12 is connected to the connector 14 through threads; ⑤ The cold extrusion core rod 17 is connected to the gun piston rod 15 through threads; ⑥ The cold extrusion earless support plate self-locking nut is inserted into the cold extrusion core rod 17, with the round head of the nut facing the limit head 12; ⑦ After completing steps ① to ⑥, insert the assembly with the nut into the holes of the two layers of thin-walled sheet metal 10 and 11, so that the end face of the limit head 12 is tightly attached to the end face of the structure 10 and remains stationary, start the gun, and the gun piston rod 15 drives the cold extrusion core rod to move to the right, completing the cold extrusion process, and remove the gun.

[0035] Step 2: Riveting process. ⑧ Insert the external thread of the left end of the rivet screw 20 of the rivet gun from the nut head into the inner hole on the right side of the nut, and push it forward slightly so that its external thread hits the edge of the internal thread hole of the self-locking nut 9. At this time, the external thread of the rivet gun screw 20 automatically screws into the internal thread of the self-locking nut 9. When the limit ring 19 fits the end face of the thin-walled sheet metal 10, release the external force; ⑨ Press and hold the rivet gun button to start the rivet gun. The rivet screw 20 moves to the right and starts to rivet, forming a bulge; ⑩ After the riveting is completed, press and hold the rivet gun button. The rivet screw 20 of the rivet gun reverses and withdraws from the nut.

[0036] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cold-extruded earless support plate self-locking nut, comprising a cold-extruded round head earless support plate self-locking nut (9), characterized in that: The outer wall of the cold-extruded round-head self-locking nut (9) without ear support plate is provided with a round head (3), the inner wall of the cold-extruded round-head self-locking nut (9) without ear support plate is provided with a cold-extruded strengthening zone (4), the inner wall of the cold-extruded round-head self-locking nut (9) without ear support plate is provided with a rivet deformation zone (5), the inner wall of the cold-extruded round-head self-locking nut (9) without ear support plate is provided with a rivet deformation transition zone (6), the outer wall of the cold-extruded round-head self-locking nut (9) without ear support plate is provided with a threaded closing zone (7), and the outer wall of the cold-extruded round-head self-locking nut (9) without ear support plate is provided with a tail sealed closed type (8) or a tail non-sealed type.

2. The cold-extruded earless support plate self-locking nut according to claim 1, characterized in that: The head height of the cold-extruded round-headed earless support plate self-locking nut (9) is h>0.5mm, and the head cone angle of the extruded round-headed earless support plate self-locking nut (9) is 90°>α>100°.

3. The cold-extruded earless support plate self-locking nut according to claim 1, characterized in that: The cold extrusion strengthening zone (4) is arranged on the inner wall of the cold extruded round head earless support plate self-locking nut (9) close to the head, and the aperture of the cold extrusion strengthening zone (4) is smaller than the aperture of the rivet deformation zone (5).

4. The cold-extruded earless support plate self-locking nut according to claim 1, characterized in that: The pull rivet deformation zone (5) is arranged in the middle section of the inner wall of the cold-extruded round head earless support plate self-locking nut (9), and the pull rivet deformation transition zone (6) is arranged between the middle section of the inner wall and the thread section of the cold-extruded round head earless support plate self-locking nut (9).

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