A high-frequency brazing process for angular pipe end threaded joints

Abstract

A high-frequency brazing process method for angular pipe end threaded joints belongs to the field of aero-engine technology. The high-frequency brazing process method for angular pipe end threaded joints includes: pre-assembly of the angular pipe end threaded joint and the high-frequency brazing tooling, installing the angular pipe end threaded joint on the top of the adjustment block, installing a protective cover on the top of the adjustment seat, adjusting the position of the adjustment block so that the side wall of the angular pipe end threaded joint fits with the protective cover; adjusting the height of the adjustment seat so that the area to be welded of the angular pipe end threaded joint is located on the upper part of the protective cover; installing a protective block on the top of the adjustment seat, and fitting the protective block and the protective cover to form a circular structure; inserting a catheter into the top hole of the angular pipe end threaded joint for high-frequency induction brazing. The high-frequency brazing process method for angular pipe end threaded joints can achieve high-frequency brazing of angular pipe end threaded joints, thereby improving the quality and processing efficiency of aero-engine pipeline products.

Description

Technical Field

[0001] The invention relates to the technical field of aviation engines, and in particular to a high-frequency brazing process method for angular pipe end threaded joints. Background Art

[0002] Many external pipelines of aircraft engines are brazed. Flame brazing is a traditional brazing process that has been maturely applied to various types of structural pipelines, with minimal constraints on joints and pipe types. However, due to process limitations, the flame brazing process is subject to significant human influence, resulting in large and irregular welding deformation, which is difficult to control. Post-weld problems include elliptical conical surfaces and large form and position tolerances on the pipe joints. After flame brazing, the pipelines must undergo flux removal and corrosion in the hot-dip galvanizing workshop, resulting in a long processing cycle, low production efficiency, and quality risks such as excessive weld corrosion. Human control of the welding process leads to poor welding quality stability, and special structural pipelines also face quality issues such as cracks caused by the welding process.

[0003] As engine technology advances, the factory continues to improve high-frequency welding technology and has mastered high-frequency brazing applications. High-frequency brazing offers significant advantages over flame brazing in controlling weld deformation, reducing part processing cycles, and enabling automated process parameter control. However, a large number of special-shaped joints, including angled pipe-end threaded joints, remain impractical for high-frequency brazing due to structural limitations. Angled pipe-end threaded joints are asymmetrical structures, and when heated by induction, the induced magnetic field cannot be accurately concentrated on the weld area, resulting in uneven heating temperatures across the weld area and impacting the weld quality. Therefore, improved process methods are urgently needed to achieve high-frequency brazing of angled pipe-end threaded joints. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a high-frequency brazing process method for angular pipe end threaded joints, which can realize high-frequency brazing of angular pipe end threaded joints, thereby improving the quality and processing efficiency of aircraft engine pipeline products.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A high-frequency brazing process for angular pipe end threaded joints comprises the following steps:

[0007] S1. Pre-assembly of angular pipe end threaded joints and high-frequency brazing tooling

[0008] The high-frequency brazing tool comprises a copper base, an adjustment block disposed inside the copper base, and an adjustment seat that can be raised and lowered outside the copper base. The angled pipe end threaded joint is mounted on top of the adjustment block, and a protective cover is mounted on top of the adjustment seat. The position of the adjustment block is adjusted so that the side wall of the angled pipe end threaded joint fits with the protective cover.

[0009] S2. Complete the assembly of high-frequency brazing tooling

[0010] Adjust the height of the adjustment seat so that the area to be welded of the angled pipe end threaded joint is located above the protective cover; install the protective block on the top of the adjustment seat so that the protective block and the protective cover fit together to form a circular structure;

[0011] S3. Welding

[0012] Insert the conduit into the top hole of the angle-type pipe end threaded joint and perform high-frequency induction brazing.

[0013] Furthermore, the copper base is a cylindrical structure with an open top, and a cylindrical blind hole is provided at the center of the bottom of the copper base, and the cylindrical blind hole is connected to the outside of the copper base through a vent.

[0014] Furthermore, the adjustment seat is a cylindrical structure with openings at both ends, which is sleeved on the outside of the copper base and threadedly connected to the copper base.

[0015] Furthermore, the adjustment block includes an inverted T-shaped cylindrical structure and a conical structure arranged on the top of the T-shaped cylindrical structure. A longitudinal hole is provided in the middle of the adjustment block, and the longitudinal hole is connected to the side wall of the inverted T-shaped cylindrical structure through several through holes.

[0016] Furthermore, the protective cover is a semicircular structure, and a groove is provided at a position where it fits with the angular pipe end threaded joint. The protective cover is coaxial with the longitudinal hole of the adjustment block.

[0017] Furthermore, the protection block is a semicircular structure.

[0018] Furthermore, the copper base, adjustment seat, adjustment block, protection cover and protection block are all made of copper.

[0019] Beneficial effects of the present invention:

[0020] (1) The process method of the present invention is used for brazing processing. Compared with the traditional flame brazing method using "oxy-acetylene" flame heating and using flux protection, it can not only eliminate the surface treatment processes such as flux removal and corrosion after flame brazing, but also save more than one day of part processing cycle. The protection effect of using argon gas is better than that of flux.

[0021] (2) The process method of the present invention can achieve high-frequency brazing of angular pipe end threaded joints, replacing the original flame brazing method, and improving the quality and processing efficiency of aircraft engine pipeline products;

[0022] (3) The process method of the present invention adopts high-frequency brazing tooling for processing, which has low dependence on the operator's skill level, stable quality, and is not prone to defects. It meets the high quality, high efficiency, and low cost requirements of aircraft engines and has great quality and economic benefits.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is a schematic structural diagram of a high-frequency brazing tool provided by an embodiment of the present invention;

[0025] Figure 2 The diagram is a schematic diagram of an angular pipe-end threaded joint provided by an embodiment of the present invention connected to a branch pipe and a conduit to form a pipeline.

[0026] The reference numerals in the drawings of the specification include:

[0027] 1-Copper base, 2-Adjustment seat, 3-Adjustment block, 4-Protective cover, 5-Protective block, 6-Angle pipe end threaded joint, 7-Conduit, 8-Branch pipe, 9-Vent hole, 10-Longitudinal hole, 11-Through hole. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0029] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "vertical", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0030] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0031] In order to solve the problems existing in the prior art, such as Figure 1 and Figure 2 As shown, the present invention provides a high-frequency brazing process method for angular pipe end threaded joints, comprising the following steps:

[0032] S1. Pre-assembly of angular pipe end threaded joint 6 and high-frequency brazing tooling

[0033] The high-frequency brazing tooling includes a copper base 1, an adjustment block 3 disposed inside the copper base 1, and an adjustment seat 2 that can be raised and lowered and disposed outside the copper base 1. An angular pipe-end threaded joint 6 is mounted on top of the adjustment block 3, and a protective cover 4 is mounted on top of the adjustment seat 2. The position of the adjustment block 3 is adjusted so that the side wall of the angular pipe-end threaded joint 6 fits in contact with the protective cover 4.

[0034] The copper base 1 is a cylindrical structure with an open top. A cylindrical blind hole is provided at the center of the bottom of the copper base 1. The cylindrical blind hole is connected to the outside of the copper base 1 through a vent 9 for filling with argon gas.

[0035] The adjustment seat 2 is a cylindrical structure with openings at both ends. It is sleeved on the outside of the copper base 1 and threadedly connected to the copper base 1. The copper base 1 cooperates with the adjustment seat 2. The height of the adjustment seat 2 is adjusted by threading so that the area to be welded of the angular pipe-end threaded joint 6 is completely exposed on the upper surface of the protective cover 4. The top of the adjustment seat 2 is provided with an end face for cooperating with the periphery and bottom of the protective cover 4 and the protective block 5, so that the upper part of the high-frequency brazing tooling forms a symmetrical circular structure.

[0036] The adjustment block 3 includes an inverted T-shaped cylindrical structure and a conical structure arranged on top of the T-shaped cylindrical structure. A longitudinal hole 10 is provided in the middle of the adjustment block 3. The longitudinal hole 10 is connected to the side wall of the inverted T-shaped cylindrical structure through a plurality of through holes 11. The argon gas entering the vent hole 9 at the bottom of the copper base 1 enters the angular pipe end threaded joint 6 and the conduit 7 through the longitudinal hole 10 of the adjustment block 3, achieving internal argon protection. Part of the argon gas enters the inner cavity of the high-frequency brazing tool through the longitudinal hole 10 and the through hole 11, so that the angular pipe end threaded joint 6 is protected by argon gas, preventing the non-welded part of the angular pipe end threaded joint 6 from oxidation and deformation under high temperature. In actual use, the adjustment block 3 can be set at different heights to meet the welding requirements of angular pipe end threaded joints 6 of different heights.

[0037] The protective cover 4 is a semicircular structure, and a groove is provided at the position where it fits with the angular pipe-end threaded joint 6. The protective cover 4 is coaxial with the longitudinal hole 10 of the adjustment block 3. During the specific assembly, the adjustment block 3 is first placed in the copper base 1, and the inner hole of the angular pipe-end threaded joint 6 is put on the cone structure of the adjustment block 3. The adjustment block 3 is moved to the middle part of the copper base 1, and the protective cover 4 is installed. The adjustment block 3 is moved to make the angular pipe-end threaded joint 6 fit with the groove of the protective cover 4, and the longitudinal hole 10 of the adjustment block 3 is coaxial with the protective cover 4 to ensure uniform heating of the annular welding position and further ensure welding accuracy.

[0038] S2. Complete the assembly of high-frequency brazing tooling

[0039] Adjust the height of the adjustment seat 2 so that the area to be welded of the angled pipe end threaded joint 6 is located above the protective cover 4; install the protective block 5 on the top of the adjustment seat 2, and the protective block 5 and the protective cover 4 fit together to form a circular structure;

[0040] The protective block 5 is a semicircular structure. In actual use, the outer bottom of the protective block 5 is placed on the adjustment seat 2. The inner wall of the protective block 5 is provided with a reserved groove that cooperates with the connection between the angular pipe end threaded joint 6 and the branch pipe 8. The connection between the angular pipe end threaded joint 6 and the branch pipe 8 is located in the reserved groove, and the branch pipe 8 can extend from the side of the reserved groove. When the protective block 5 is attached to the outer wall of the angular pipe end threaded joint 6 and the protective cover 4 to form a circular structure, the protective block 5 does not interfere with the angular pipe end threaded joint 6 and the branch pipe 8. Wrapping the angular pipe end threaded joint 6 in a circular tooling for high-frequency induction brazing can adjust the induced magnetic field and eliminate the influence of the asymmetric structure. In this embodiment, the protective block 5 and the protective cover 4 are attached to form a circular structure so that the non-welded part of the angular pipe end threaded joint 6 is in a relatively sealed environment.

[0041] S3. Welding

[0042] Insert the conduit 7 into the top hole of the angle-shaped pipe-end threaded joint 6 and perform high-frequency induction brazing. Specifically, place a brazing ring at the weld to be welded, connect a high-frequency brazing inductor, and power on to perform high-frequency induction brazing under appropriate parameters. After cooling after welding, remove the part and prepare for welding the next part.

[0043] In this embodiment, before the angular pipe end threaded joint 6 is welded to the conduit 7, the angular pipe end threaded joint 6 is usually already connected to the branch pipe 8. The angular pipe end threaded joint 6 is installed on the conical structure of the adjustment block 3, and then the circular cover formed by the protective cover 4 and the protective block 5 is placed on the top of the adjustment seat 2. The protective block 5 is arranged on the outside of the connection between the angular pipe end threaded joint 6 and the branch pipe 8 and is fitted with the protective cover 4 to form a circular cover, which can realize the angular pipe end threaded joint 6 being wrapped in a circular tooling for high-frequency induction brazing, adjusting the induced magnetic field, and eliminating the influence of the asymmetric structure.

[0044] The copper base 1, adjustment seat 2, adjustment block 3, protective cover 4 and protection block 5 are all made of copper, which can quickly conduct heat away from non-welding parts, protect non-welding parts, and prevent threaded joints from deforming due to high temperature.

[0045] The working principle of the high-frequency brazing process of the angular pipe end threaded joint of the present invention is as follows:

[0046] Since the angular pipe end threaded joint 6 is an asymmetric structure, when an inductor is used for heating, the induced magnetic field cannot be accurately concentrated on the welding part, resulting in uneven heating temperature in the welding area, affecting the welding effect. The high-frequency brazing tool of the present invention wraps the entire angular pipe end threaded joint 6 in the tool, and the circular tool structure adjusts the induced magnetic field, eliminates the influence of the asymmetric structure, and concentrates the heating part in the center position, playing the role of magnetic field blocking. The copper base 1, adjustment seat 2, adjustment block 3, protective cover 4 and protective block 5 of the high-frequency brazing tool are all made of copper material, which can quickly conduct heat away from the non-welding part, protect the non-welding part, prevent the angular pipe end threaded joint 6 from high temperature deformation, and play the role of heat conduction and cooling. Argon is filled into the inner cavity of the high-frequency brazing tool and the inside of the angular pipe end threaded joint 6 and the conduit 7 for argon protection, which can achieve protection of the welding part and the non-welding part, and provide all-round protection for the angular pipe end threaded joint 6. In summary, the present invention places the angular pipe end threaded joint 6 in a high-frequency brazing tool, and performs welding on the angular pipe end threaded joint 6 in a synchronous "protection + thermal cooling + magnetic field blocking" mode, so that the heating temperature in the heating area is as uniform as possible, and the power output of the high-frequency induction brazing equipment is reduced from the existing 15-2010KW to less than 10KW, thereby protecting the equipment and saving energy.

[0047] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A high-frequency brazing process for angular pipe end threaded joints, characterized in that: The steps include: S1. Pre-assembly of angular pipe end threaded joints and high-frequency brazing tooling The high-frequency brazing tool comprises a copper base, an adjustment block disposed inside the copper base, and an adjustment seat that can be raised and lowered outside the copper base. The angled pipe end threaded joint is mounted on top of the adjustment block, and a protective cover is mounted on top of the adjustment seat. The position of the adjustment block is adjusted so that the side wall of the angled pipe end threaded joint fits with the protective cover. The copper base is a cylindrical structure with an open top, and a cylindrical blind hole is provided at the center of the bottom of the copper base, and the cylindrical blind hole is connected to the outside of the copper base through a vent hole; The adjustment seat is a cylindrical structure with two ends open, which is sleeved on the outside of the copper base and connected to the copper base with threads; The adjustment block includes an inverted T-shaped cylindrical structure and a cone structure arranged on the top of the T-shaped cylindrical structure. A longitudinal hole is provided in the middle of the adjustment block, and the longitudinal hole is connected to the side wall of the inverted T-shaped cylindrical structure through a plurality of through holes. The protective cover is a semicircular structure, and a groove is provided at the position where it fits with the angular pipe end threaded joint. The protective cover is coaxial with the longitudinal hole of the adjustment block; S2. Complete the assembly of high-frequency brazing tooling Adjust the height of the adjustment seat so that the area to be welded of the angled pipe end threaded joint is located above the protective cover; install the protective block on the top of the adjustment seat so that the protective block and the protective cover fit together to form a circular structure; The protective block is a semicircular structure; the outer bottom of the protective block is placed on the adjustment seat, and the inner wall of the protective block is provided with a reserved groove that matches the angle-type pipe end threaded joint and the branch pipe connection. The angle-type pipe end threaded joint and the branch pipe connection are located in the reserved groove, and the branch pipe can extend from the side of the reserved groove. S3. Welding Insert the conduit into the top hole of the angle-type pipe end threaded joint and perform high-frequency induction brazing.

2. The high-frequency brazing process for angular pipe end threaded joints according to claim 1 is characterized in that: The copper base, adjustment seat, adjustment block, protection cover and protection block are all made of copper.

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