Welding fixture for repairing air conduit of aero-engine

Abstract

The utility model provides a welding fixture for repairing an air conduit of an aero-engine, which belongs to the technical field of aero-engine repair and comprises a mandrel, a copper sleeve and a positioning bush. The mandrel is provided with a main channel and branch channels, and the branch channels are communicated with the main channel; the mandrel comprises a threaded section, a working section and a positioning section which are sequentially connected from the first end to the second end. The working section is sleeved with the copper sleeve, a plurality of gas film holes communicated with the branch channels are formed in the side wall of the copper sleeve, and argon forms a flowing argon film between the inner wall of the air guide pipe and the copper sleeve; and the positioning bushing is sleeved outside the threaded section. The welding fixture designed by the utility model can ensure the coaxiality during welding and solve the problem that the weld joint on the inner wall of the air conduit is too high in the welding process, and can accelerate the cooling and solidification speed of the weld joint through the designed argon passage, thereby not only avoiding the problem that the weld joint on the inner wall of the air conduit is difficult to polish and repair manually after welding, but also improving the welding efficiency. And the welding seam quality of the air conduit is improved, and the working efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of aircraft engine repair technology, specifically relating to a welding fixture for repairing air ducts of aircraft engines. Background Technology

[0002] An air duct for an aircraft engine is welded from three sections. Common repair issues include weld cracking and pipe wall fissures, requiring argon arc welding. The welding requirements during repair are: after welding, the duct should allow unobstructed passage of a diameter [missing information]. The measuring rod. This requires controlling the coaxiality between different parts and the weld height during conduit welding.

[0003] Currently, the traditional clamp is a two-section butt joint installed in the air duct. After welding, it is pulled out from both ends of the air duct. Although this clamp can ensure the coaxiality of the air duct, it has obvious disadvantages: the height of the weld seam on the inner wall of the air duct cannot be controlled, and post-grinding is required. The grinding time is long and the work efficiency is low. Moreover, due to the limitations of the air duct structure, manual grinding is easy to damage the pipe wall substrate. Utility Model Content

[0004] The purpose of this invention is to solve the problem that the weld height of the inner wall of the air duct cannot be controlled when repairing air ducts using existing fixtures, requiring manual grinding. Therefore, this invention provides a welding fixture for repairing air ducts of aircraft engines.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] A welding fixture for repairing air ducts in aircraft engines is provided, comprising a mandrel, a copper sleeve, and a positioning bushing. The mandrel has a main channel for argon gas to enter the mandrel along its axial direction and multiple branch channels for argon gas to exit the mandrel along its radial direction, the branch channels communicating with the main channel. The mandrel includes a threaded section, a working section, and a positioning section connected sequentially from a first end to a second end. The outer diameter of the threaded section and the working section is smaller than the inner diameter of the air duct. The air duct is sleeved on the outer wall of the working section. The positioning section has a positioning surface with a gradually increasing diameter from the working section to the positioning section at one end. The inner wall of the air duct near the positioning section has a chamfered surface that matches the positioning surface. The copper sleeve is sleeved on the outside of the working section, and its side wall has multiple gas film holes for argon gas to pass through, the branch channels communicating with the gas film holes. The positioning bushing, sleeved on the outside of the threaded section, includes a positioning cylinder and a limiting flange extending radially outward from the end of the positioning cylinder away from the positioning section. The positioning bushing is installed on the mandrel by a nut that mates with the threaded section, the outer diameter of the positioning cylinder matching the inner diameter of the air duct.

[0007] Furthermore, the main channel is an open channel at both ends. One end of the positioning section is equipped with a screw for preventing blockage, and the other end of the threaded section is open for connecting an argon gas source.

[0008] Furthermore, the outer wall of the positioning section near the working section is provided with multiple first exhaust grooves along the axial direction, and the outer wall of the copper sleeve in contact with the positioning section is provided with multiple second exhaust grooves, with each second exhaust groove corresponding to a first exhaust groove.

[0009] Furthermore, the positioning section has a first pin hole, and the end of the copper sleeve near the positioning section has a second pin hole; the welding fixture also includes a positioning pin for connecting the copper sleeve to the mandrel.

[0010] Furthermore, multiple sub-channels are respectively set on multiple cross sections at equal intervals in the working section, and each cross section has four sub-channels, which are evenly distributed along the circumference of the mandrel.

[0011] Furthermore, a gap of 0.5-0.7mm is left between the outer wall of the copper sleeve and the inner wall of the air duct.

[0012] Furthermore, the inner diameter of the copper sleeve is smaller than the diameter of the end face of the positioning section and the outer diameter of the positioning cylinder, respectively.

[0013] The advantages of this utility model are:

[0014] This utility model designs a welding fixture for repairing air ducts of aircraft engines. By cooperating between the positioning surface on the mandrel and the positioning cylinder on the positioning bushing, it can solve the problem of low coaxiality of different sections of the air duct during welding. The copper sleeve on the mandrel can solve the problem of excessive weld height on the inner wall of the air duct. The main channel and branch channel designed on the mandrel for argon gas flow can accelerate the cooling and solidification speed of the weld and effectively prevent the welding fixture from sticking to the weld. This not only avoids the problem of difficulty in manually grinding and repairing the weld on the inner wall of the air duct after welding, but also improves the welding quality and efficiency of the air duct. Attached Figure Description

[0015] The features and advantages of this invention will become more readily understood from the following description with reference to the accompanying drawings, which are not drawn to scale and some features are enlarged or reduced to show details of specific parts.

[0016] Figure 1 This is an assembly drawing of the fixture of this utility model;

[0017] Figure 2 This is a cross-sectional view of the fixture of this utility model;

[0018] Figure 3 This is a schematic diagram illustrating the clamping effect of the fixture and the air duct of this utility model.

[0019] In the diagram: 1-Mandrel; 11-Positioning surface; 12-Main channel; 13-Sub-channel; 2-Copper sleeve; 21-Argon film; 3-Positioning bushing; 31-Positioning cylinder; 32-Limiting flange; 4-Nut; 5-Screw; 6-Positioning pin. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and exemplary embodiments thereof. It should be noted that the following detailed description of the present invention is for illustrative purposes only and is not intended to limit the scope of the invention.

[0021] Air ducts for aero engines are welded from three sections, with two weld seams. After a period of use, air ducts for aero engines are prone to weld cracking and pipe wall cracking, requiring argon arc welding repair. To ensure the coaxiality of the air duct during the repair welding process and to solve the problem of excessive weld height on the inner wall of the air duct requiring subsequent grinding, a welding fixture for repairing air ducts for aero engines is proposed.

[0022] like Figure 1 As shown, a welding fixture for repairing air ducts of aircraft engines includes a mandrel 1, a copper sleeve 2, and a positioning bushing 3.

[0023] like Figure 1 , 2 As shown, the mandrel 1 includes a threaded section, a working section and a positioning section connected sequentially from the first end to the second end. The outer diameter of the threaded section and the working section is smaller than the inner diameter of the air duct. The air duct is sleeved on the outer wall of the working section. The positioning section has a positioning surface 11 with a diameter that gradually increases from the working section to the positioning section at one end near the working section. The inner wall of the air duct near the positioning section has a chamfered surface that matches the positioning surface 11.

[0024] like Figure 1 , 2 As shown, the copper sleeve 2 is installed outside the working section, and its side wall is provided with multiple gas film holes for argon gas to pass through. The branch channel 13 is connected to the gas film holes, and the argon gas forms a flowing argon gas film 21 between the inner wall of the air duct and the copper sleeve 2.

[0025] like Figure 1 , 2 As shown in Figure 3, a positioning bushing 3 is fitted outside the threaded section. The positioning bushing 3 includes a positioning cylinder 31 and a limiting flange 32 extending radially outward from the end of the positioning cylinder 31 away from the positioning section. The positioning bushing 3 is mounted on the spindle 1 by a nut 4 that mates with the threaded section. The outer diameter of the positioning cylinder 31 matches the inner diameter of the air duct.

[0026] During fixture assembly, first heat the copper sleeve 2 and install it onto the working section of the mandrel 1; during welding, if... Figure 3 As shown, one end of the mandrel 1 with a threaded section passes through the inner wall of the air duct, and the air duct is fitted onto the working section of the mandrel 1. Then, after the threaded section of the mandrel 1 extends out of the air duct at the right end, the positioning bushing 3 is installed on the threaded section and fixed by the nut 4. One end of the air duct at the left end is positioned by the positioning surface 11 provided on the positioning section, and the inner wall of the air duct at the right end is tightly attached to the limiting flange 32 on the positioning bushing 3 and positioned by the positioning cylinder 31.

[0027] The welding fixture designed in this embodiment can fix the air conduit on the welding fixture through the cooperation of the mandrel 1 and the positioning bushing 3. On the one hand, the positioning cylinder 31 is inserted into the air conduit to realize the positioning of the air conduit, so that the air conduit and the copper sleeve 2 can maintain a uniform gap and improve multiple coaxiality. The limiting flange 32 stops at the end of the air conduit, and the air conduit can be clamped by tightening the nut 4. On the other hand, a preset gap is left between the copper sleeve 2 and the air duct. Even if the solder fills the preset gap, the height of the solder on the inner wall of the air duct still meets the inspection requirements, solving the problem of excessively high weld seams on the inner wall of the air duct. During the welding process, the main channel 12 and the sub-channel 13 designed on the mandrel 1 for the argon gas flow path, and the copper sleeve 2 are machined with oil-dense gas film holes in the circumferential direction. At the same time as forming an argon gas pressure holding chamber with the mandrel, argon gas is introduced into the flowing argon gas film 21 formed between the copper sleeve 2 and the inner wall of the air duct. With a certain gas pressure and flow rate, the weld seam cooling and solidification speed can be accelerated, effectively preventing the fixture from sticking to the weld seam, and forming a smooth and defect-free weld seam quality, solving the problem of excessively high weld seams on the inner wall of the air duct. This not only avoids the problem of the difficulty in manually grinding and repairing the weld seam on the inner wall of the air duct after welding, but also improves the welding quality of the air duct and increases the welding efficiency.

[0028] In one embodiment, the main channel 12 is an open channel at both ends. One end of the positioning section is provided with a screw 5 for preventing blockage, and the other end of the threaded section is open for argon gas to enter. The main channel 12 is an open channel at both ends for ease of processing. The screw 5 can seal the argon gas, allowing the argon gas to flow from the branch channel 13 to the space between the copper sleeve 2 and the air duct.

[0029] In another embodiment, the main channel 12 is a channel with one end open. The main channel 12 is provided in the threaded section and the working section. The opening at one end of the threaded section is connected to an argon gas source.

[0030] like Figure 2 As shown, the outer wall of the positioning section near the working section has multiple first exhaust grooves along the axial direction, and the outer wall of the copper sleeve 2 in contact with the positioning section has multiple second exhaust grooves, with each second exhaust groove corresponding to a first exhaust groove. The first and second exhaust grooves are connected to the cavity of the argon membrane 21 for the discharge of argon gas.

[0031] like Figure 1 , 2 As shown, the positioning section has a first pin hole, and the end of the copper sleeve 2 near the positioning section has a second pin hole; the welding fixture also includes a positioning pin 6, which is used to connect the copper sleeve 2 to the mandrel 1. The second pin hole on the copper sleeve 2 is aligned with the first pin hole on the positioning section, and the first vent groove and the second vent groove are also aligned simultaneously. The positioning pin 6 is pressed into the pin hole to install and secure the copper sleeve 2, and the end face of the positioning pin 6 does not protrude above the outer surface of the copper sleeve 2.

[0032] like Figure 2 Multiple sub-channels 13 are respectively set on multiple cross sections at equal intervals in the working section, and each cross section is provided with four sub-channels 13, which are evenly distributed along the circumference of the mandrel.

[0033] A gap of 0.5-0.7mm is maintained between the outer wall of the copper sleeve 2 and the inner wall of the air duct. A preferred gap is 0.6mm. During butt welding at both ends, the coaxiality of the middle duct wall needs to be adjusted to no more than 0.1mm. During welding, when the gap between the copper sleeve 2 and the inner wall of the air duct is 0.7mm, the solder fills the gap completely, and the solder height on the inner wall of the air duct meets inspection requirements.

[0034] like Figure 1 As shown, the inner diameter of the copper sleeve 2 is smaller than the diameter of the end face of the positioning section and the outer diameter of the positioning cylinder 31.

[0035] When repairing cracks in the wall of an air duct using a fixture, one end of the mandrel 1 with the copper sleeve 2 installed is passed through the air duct, and the positioning bushing 3 is installed at the other end. The nut 4 is then tightened to secure it. When butt welding of the duct using the fixture, one end of the mandrel 1 with the copper sleeve 2 installed is passed through the duct. After verifying that the gap at the weld meets the specifications, the positioning bushing 3 is installed at the other end. The nut 4 is rotated to make the limiting flange 32 of the positioning bushing 3 fit against the end face of the duct. During welding, an argon gas pipe is connected to one end of the welding fixture, and argon gas at a certain pressure and flow rate is introduced into the main channel 12.

[0036] Finally, it should be noted that the features mentioned and / or shown in the above description of exemplary embodiments of the present invention can be combined in the same or similar manner with one or more other embodiments, combined with features in other embodiments, or substituted for corresponding features in other embodiments. These combined or substituted technical solutions should also be considered as included within the protection scope of the present invention.

Claims

1. A welding fixture for repairing air ducts of aircraft engines, characterized in that, include: A mandrel (1) is provided with a main channel (12) for argon gas to enter the mandrel (1) along its axial direction and a plurality of branch channels (13) for argon gas to exit the mandrel (1) along its radial direction. The branch channels (13) are connected to the main channel (12). The mandrel (1) includes a threaded section, a working section and a positioning section connected sequentially from a first end to a second end. The outer diameter of the threaded section and the working section is smaller than the inner diameter of the air duct. The air duct is sleeved on the outer wall of the working section. The positioning section is provided with a positioning surface (11) with a diameter that gradually increases from the working section to the positioning section at one end. The inner wall of the air duct near the positioning section is provided with a chamfered surface that matches the positioning surface (11). A copper sleeve (2) is fitted outside the working section, and its side wall is provided with a plurality of gas film holes for argon gas to pass through. The sub-channel (13) is connected to the gas film holes. And a positioning bushing (3) sleeved outside the threaded section, the positioning bushing (3) including a positioning cylinder (31) and a limiting flange (32) extending radially outward from the end of the positioning cylinder (31) away from the positioning section, the positioning bushing (3) being mounted on the spindle (1) by a nut (4) that mates with the threaded section, the outer diameter of the positioning cylinder (31) matching the inner diameter of the air duct.

2. The welding fixture for repairing air ducts of aircraft engines according to claim 1, characterized in that, The main channel (12) is a channel with openings at both ends. One end of the positioning section is provided with a screw (5) for preventing blockage, and one end of the threaded section is open for connecting an argon gas source.

3. A welding fixture for repairing air ducts of aircraft engines according to claim 2, characterized in that, The outer wall of the positioning section near the working section is provided with a plurality of first exhaust grooves along the axial direction, and the outer wall of the copper sleeve (2) in contact with the positioning section is provided with a plurality of second exhaust grooves, and the second exhaust grooves correspond one-to-one with the first exhaust grooves.

4. The welding fixture for repairing air ducts of aircraft engines according to claim 1, characterized in that, The positioning section has a first pin hole, and the copper sleeve (2) has a second pin hole near the end of the positioning section; The welding fixture also includes a positioning pin (6), which is used to connect the copper sleeve (2) to the mandrel (1).

5. A welding fixture for repairing air ducts of aircraft engines according to claim 1, characterized in that, Multiple sub-channels (13) are respectively arranged on multiple cross sections at equal intervals on the working section, and each cross section is provided with four sub-channels (13), and the four sub-channels (13) are evenly distributed along the circumference of the mandrel.

6. A welding fixture for repairing air ducts of aircraft engines according to claim 1, characterized in that, A gap of 0.5-0.7 mm is left between the outer wall of the copper sleeve (2) and the inner wall of the air duct.

7. A welding fixture for repairing air ducts of aircraft engines according to claim 1, characterized in that, The inner diameter of the copper sleeve (2) is smaller than the diameter of the end face of the positioning section and the outer diameter of the positioning cylinder (31).

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