A bending attachment with a small bending radius
By using internal high-pressure forming technology and threaded laser welding to manufacture bent sleeves, the problems of inner surface roughness and mechanical properties of bent accessories with small bending radii have been solved, and high-quality manufacturing of bent accessories has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 江苏纳光通信科技有限公司
- Filing Date
- 2025-08-25
- Publication Date
- 2026-07-31
AI Technical Summary
Existing technologies for curved attachments with small bending radii have problems such as insufficient internal surface roughness, high cost of metal 3D printing, and alteration of material mechanical properties during manufacturing.
The tube is bent using internal high-pressure forming technology, and the sleeve is manufactured by threaded connection and laser welding to ensure that the tube surface is smooth and the mechanical properties remain unchanged.
It achieves a small bending radius, smooth inner surface and high reliability of the bending attachment, meeting the needs of environmentally restricted use and avoiding the shortcomings of existing technologies.
Smart Images
Figure CN224582796U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of electrical connector technology, and in particular relates to a bent accessory with a small bending radius. Background Technology
[0002] As the aviation industry continues to develop, the types of aircraft are also increasing. Due to limited space during wiring for some aircraft models, conventional curved accessories are too bulky to meet the requirements of the application scenario. In this case, curved accessories with a small bending radius must be used.
[0003] Small-radius curved tailpieces cannot be directly obtained through machining. Currently, small-radius curved tailpieces can be manufactured by obtaining blanks through metal 3D printing or precision casting molds, and then machining to the required dimensions.
[0004] The methods of metal 3D printing or precision casting mold making have the following problems:
[0005] a) The surface roughness of parts made by metal 3D printing or precision casting molds cannot meet the requirements;
[0006] b) Metal 3D printing uses adhesives, which require aerospace verification, and the testing costs are high.
[0007] c) During the manufacturing process of precision casting molds, heat treatment will change the mechanical properties of the original materials.
[0008] To address the above problems, a bending attachment with a small bending radius is designed. Utility Model Content
[0009] This utility model addresses the problems in the prior art by proposing the following technical solution:
[0010] A bent accessory with a small bending radius includes a bent sleeve, the bent sleeve comprising a straight sleeve and a bent tube formed by bending using an internal high-pressure forming technology, the bent portion of the bent tube having a smooth surface, and the minimum bending radius of the bent portion of the bent tube being 5.5 mm.
[0011] One end of the bent pipe is inserted into the inside of the straight sleeve and threadedly connected thereto. The straight sleeve covers the end of the bent pipe and is welded and fixed to the bent pipe in the circumferential direction.
[0012] As a preferred embodiment of the above technical solution, it also includes a hexagonal nut fitted onto the straight sleeve, and the bent accessory is fixed to the external mounting panel by the hexagonal nut.
[0013] As a preferred embodiment of the above technical solution, an O-ring is also included;
[0014] The straight sleeve covers the end of the bent pipe and extends radially outward to form a positioning plate. The O-ring is fitted on the straight sleeve and is located between the external mounting panel and the positioning plate.
[0015] As a preferred embodiment of the above technical solution, the positioning plate is provided with an O-ring groove, and the O-ring is assembled in the O-ring groove.
[0016] As a preferred embodiment of the above technical solution, the inner ring of the straight sleeve is provided with thread one, and the outer ring of the bent pipe is provided with thread two, with thread one and thread two matching.
[0017] As a preferred embodiment of the above technical solution, the straight sleeve is provided with a milled flat surface.
[0018] As a preferred embodiment of the above technical solution, the positioning plate of the straight sleeve is provided with a hexagonal shape.
[0019] The beneficial effects of this utility model are as follows:
[0020] 1. This technical solution provides a small bending radius bent accessory that can accommodate several cables or optical fibers, primarily used in the aerospace field. It employs internal high-pressure forming technology to bend the accessory into a bent tube, inserts the bent tube into the inside of a straight sleeve and threads it, and then welds the straight sleeve and the bent tube together to obtain the bent sleeve. This effectively meets the needs of using bent accessories under environmentally restricted conditions. Furthermore, this method avoids the problems associated with existing methods using metal 3D printing or precision casting molds, such as the inability to meet the required surface roughness of the inner tube.
[0021] 2. The small bending radius of the bending accessory in this technical solution has a small bending radius and volume. The minimum bending radius of the bending part of the pipe is 5.5mm. The internal transition is smooth and there are no sharp edges. The internal roughness of the pipe is of high quality and can meet the customer's requirements. The bending process does not change the mechanical properties of the original material. The bending sleeve is obtained by threaded connection and laser welding, which makes it more reliable. Attached Figure Description
[0022] Figure 1 The diagram shown is a structural schematic of a bent attachment with a small bending radius in Embodiment 1;
[0023] Figure 2 The diagram shown is a cross-sectional view of a bent attachment with a small bending radius in Embodiment 1.
[0024] Figure 3 The diagram shown is a side view of a bent attachment with a small bending radius according to Embodiment 1;
[0025] Figure 4 The diagram shown is a structural schematic of the straight sleeve in Embodiment 1;
[0026] Figure 5 The diagram shown is a structural schematic of the bend in Example 1;
[0027] Figure 6 The diagram shown illustrates the state of the sleeve first being processed into a straight sleeve during the bending process in Example 1.
[0028] Figure 7 The diagram shown is a schematic of the straight sleeve being directly bent using a bending machine in Example 1.
[0029] Figure 8 The diagram shown is a schematic of the straight sleeve in Embodiment 1 with tooling installed at both ends and filled with high-pressure liquid.
[0030] Figure 9 The diagram shown is a schematic of the state in Example 1 where the straight bushing is bent using a bending machine to maintain high pressure inside.
[0031] Figure 10 The diagram shown is a structural schematic of the mold for the final forming of the bent pipe in Example 1;
[0032] Figure 11 The diagram shown illustrates the state of the straight sleeve after bending in the mold in Example 1;
[0033] Figure 12 The diagram shown is a schematic representation of the bent tube after molding in Example 1.
[0034] Figure 13 The diagram shown is an assembly diagram of the straight sleeve and the bent pipe in Example 1.
[0035] Figure reference numerals: O-ring 1; hexagonal nut 2; bent sleeve 3; straight sleeve 31; O-ring groove 311; thread one 312; milled flat 313; hexagonal 314; bent pipe 32; thread two 321. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.
[0037] Example 1
[0038] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, a bent accessory with a small bending radius includes a bent sleeve 3, which includes a straight sleeve 31 and a bent tube 32 formed by bending using an internal high-pressure forming technology. The bent portion of the bent tube 32 has a smooth surface, and the minimum bending radius of the bent portion of the bent tube 32 is 5.5 mm.
[0039] One end of the bent pipe 32 is inserted into the inside of the straight sleeve 31 and threadedly connected thereto. The straight sleeve 31 covers the end of the bent pipe 32 and is welded and fixed to the bent pipe 32 in the circumferential direction.
[0040] This technical solution presents a small-bending-radius bent accessory that can accommodate several cables or optical fibers, primarily used in the aerospace field. It employs internal high-pressure forming technology to bend the accessory into a bent tube 32, which is then inserted into a straight sleeve 31 and threaded together. The straight sleeve 31 and the bent tube 32 are then welded together to obtain the bent sleeve 3, effectively meeting the needs of using bent accessories under environmentally constrained conditions. Furthermore, this method avoids the problems associated with existing methods using metal 3D printing or precision casting molds, such as the inability to meet the required surface roughness of the inner tube.
[0041] This technical solution presents a small bending radius bend accessory with a small bending radius and volume. The minimum bending radius of the bent section of the bend 32 is 5.5mm. The internal transition is smooth, without any sharp edges or corners. The internal roughness of the tube is of high quality, which can meet the customer's requirements. The bending process of the bend 32 does not change the mechanical properties of the original material. The bend sleeve 3 is obtained through threaded connection and laser welding, which makes it more reliable.
[0042] like Figure 1 , Figure 2 As shown, a bent accessory with a small bending radius also includes a hexagonal nut 2 and an O-ring 1 sleeved on a straight sleeve 31. The bent accessory is fixed to the external mounting panel by the hexagonal nut 2.
[0043] The straight sleeve 31 covers the end of the bent pipe 32 and extends radially outward to form a positioning plate. The O-ring 1 is sleeved on the straight sleeve 31 and located between the external mounting panel and the positioning plate to achieve a seal between the bent accessory and the mounting panel.
[0044] like Figure 1 , Figure 2 , Figure 4 As shown, an O-ring groove 311 is provided on the positioning plate, and the O-ring 1 is assembled in the O-ring groove 311 to ensure the positional stability of the O-ring 1 and further ensure the sealing function between the bent accessory and the mounting panel.
[0045] To achieve the configuration where one end of the bent pipe 32 is inserted into the interior of the straight sleeve 31 and threadedly connected thereto, further specific settings are made for the bent pipe 32 and the straight sleeve 31, such as... Figure 4 , Figure 5 As shown, the inner ring of the straight sleeve 31 is provided with thread 312, and the outer ring of the bent pipe 32 is provided with thread 321. Thread 312 and thread 321 are matched.
[0046] like Figure 1 , Figure 3 As shown, the straight sleeve 31 is provided with a milled flat 313, and the positioning plate of the straight sleeve 31 is provided with a hexagonal 314; when the bent accessory is installed on the panel, the milled flat 313 plays a role in preventing rotation, and the hexagonal 314 plays a role in facilitating installation.
[0047] The small bending radius bending accessory in this technical solution includes the following steps when the bent pipe 32 is formed by bending using internal high-pressure forming technology:
[0048] 1. For example Figure 6 As shown, the bent pipe 32 is first processed into a straight sleeve, with its inner and outer diameters being consistent with the dimensions after bending. During machining, the surface roughness of the inner surface of the straight sleeve can be controlled through finishing.
[0049] 2. For example Figure 7 As shown, when a straight sleeve is bent directly on a bending machine, wrinkles are likely to occur. These wrinkles are plastic deformations and are basically impossible to repair later.
[0050] In this regard, such as Figure 8 As shown, fixtures 1 and 2 are installed at both ends of the straight sleeve, and high-pressure liquid is applied to its interior through the fixtures to form an internal high pressure (approximately 200 MPa) to support the inner wall. When bending on a bending machine, this can eliminate wrinkles; however, the resulting bent part has a larger dimension L, and the bent portion is not in an ideal state, such as... Figure 9 As shown, EE is a cross-sectional view of the bent portion.
[0051] 3. For example Figure 11 As shown, the bent straight sleeve, along with tooling 1 and tooling 2, is placed into the forming mold. At this point, there is a gap between the bent part and the mold. (Reference) Figure 10 The mold for the final forming of the bent pipe 32 is divided into two types: an upper mold and a lower mold. The mold is machined with a groove of the same size as the bent pipe 32 for placing the bent pipe 32 after bending.
[0052] High-pressure liquid (300MPa~400MPa) is applied to the inside of the bend through tooling 1 and tooling 2 to create internal high pressure. Due to the internal high pressure, the bent portion of the bend extends outward to the dimension formed on the mold. Simultaneously with the application of internal high pressure, a thrust is applied from both ends of the bend to... Figure 11 Once the gap shown is eliminated, dimension L will meet the requirements.
[0053] 4. For example Figure 12 As shown, Figure a shows the bent tube 32 after mold forming, and Figure b shows the front thread 321 and other features obtained through additional processing.
[0054] 5. For example Figure 13As shown, after the thread 312 inside the straight sleeve 31 mates with the thread 321 on the bent pipe 32, it is fixed by circumferential welding on its outside, as shown. Figure 3 As shown, milled flat 313 and hexagonal 314 are obtained by supplementary machining.
[0055] The above embodiments are only used to illustrate the technical solution of this utility model, and are not intended to limit it.
Claims
1. A small bend radius elbow fitting comprising a bend sleeve (3) characterised in that, The bent sleeve (3) includes a straight sleeve (31) and a bent tube (32) formed by bending using internal high-pressure forming technology. The bent part of the bent tube (32) has a smooth surface and the minimum bending radius of the bent part of the bent tube (32) is 5.5 mm. One end of the bent pipe (32) is inserted into the inside of the straight sleeve (31) and threadedly connected thereto. The straight sleeve (31) covers the end of the bent pipe (32) and is welded and fixed to the bent pipe (32) in the circumferential direction.
2. A small bend radius elbow fitting according to claim 1, wherein, It also includes a hexagonal nut (2) fitted on the straight sleeve (31), and the bent accessory is fixed to the external mounting panel by the hexagonal nut (2).
3. A small bend radius elbow fitting according to claim 2, wherein, It also includes O-rings (1); The straight sleeve (31) covers the end of the bent pipe (32) and extends radially outward to form a positioning plate. The O-ring (1) is sleeved on the straight sleeve (31) and located between the external mounting panel and the positioning plate.
4. A small bend radius elbow fitting according to claim 3, wherein, The positioning plate has an O-ring groove (311), and the O-ring (1) is assembled in the O-ring groove (311).
5. A small bend radius elbow fitting according to claim 1 wherein, The inner ring of the straight sleeve (31) is provided with thread one (312), and the outer ring of the bent pipe (32) is provided with thread two (321). Thread one (312) and thread two (321) are matched.
6. A bendover according to claim 1, wherein, The straight sleeve (31) is provided with a milled flat (313).
7. A small bend radius elbow fitting according to claim 3 wherein, The positioning plate of the straight sleeve (31) is provided with a hexagon (314).