A welding fixture for processing an aircraft gas duct

Abstract

This invention provides a welding fixture for aircraft gas pipe processing, relating to the field of aircraft gas pipe processing technology. It includes: a fixture body for fixing a tee pipe; a clamping mechanism for elastically clamping a sealing plate to the port flange to deliver protective gas into the tee pipe; a sealing plug located at the exhaust port of the tee pipe, with a conical hole in its center containing a metal ball; and an elastic component connected to the metal ball for driving the metal ball to move and seal the conical hole. The thicker the wall of the tee pipe, the greater the displacement of the sealing plate due to thermal expansion, and the greater the displacement of the elastic component towards the conical hole. This invention utilizes the difference in thermal elongation caused by different wall thicknesses to automatically adjust the preload of the metal ball, achieving adaptive matching of back pressure under thick-walled and thin-walled welding conditions. For thick-walled pipes, it provides high back pressure to prevent root depression, while for thin-walled pipes, it maintains low back pressure to prevent molten pool blow-through. This improves the forming quality of the weld back of pipes with different wall thicknesses without manual intervention.

Description

Technical Field

[0001] This invention relates to the field of aircraft gas pipe processing technology, and in particular to a welding fixture for aircraft gas pipe processing. Background Technology

[0002] In the welding of aircraft gas pipes, the tee pipe, as a key component for pipe connection, directly affects the airtightness and structural strength of the pipeline due to the quality of its weld back formation. During welding, shielding gas must be introduced into the pipe to maintain a certain back pressure to support the molten pool and prevent root depression or burn-through. Thick-walled pipes, due to the large welding current and deep molten pool, require higher back pressure to counteract the downward sag of the molten metal; thin-walled pipes require lower back pressure to prevent the molten pool from being blown through.

[0003] However, the exhaust section of existing welding fixtures is usually fixed or requires manual pre-adjustment, making it difficult to automatically match the back pressure with the thermal expansion state of the tee pipe during the welding process. Fixed back pressure cannot take into account both thick-walled and thin-walled working conditions. Furthermore, when the back pressure is too high, the molten pool of thin-walled pipes is easily blown through, and when the back pressure is too low, the root of thick-walled pipes is easily sunken, resulting in unstable back weld formation quality and requiring frequent manual intervention. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by proposing a welding fixture for processing aircraft gas pipes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A welding fixture for processing aircraft gas pipes includes: a fixture body for supporting and fixing a tee pipe; a clamping mechanism located at the port flange of the tee pipe for using an elastic force to press a sealing plate against the port flange, thereby delivering protective gas to the tee pipe at constant pressure through the sealing plate; a sealing plug installed in the exhaust port of the tee pipe, having a conical hole in its center, with a metal ball inside the conical hole; and an elastic component connected to the metal ball for driving the metal ball to move along an axis to seal the conical hole. The thicker the wall of the tee pipe, the greater the upward displacement of the sealing plate due to thermal expansion, the greater the displacement of the elastic component towards the conical hole, and the greater the pre-tightening force, thus requiring greater pressure for the metal ball to open the conical hole. Higher gas pressure inside the tee pipe results in a larger flow cross-section for the conical hole.

[0006] Preferably, the clamp body includes a main clamping base and multiple sets of radial clamping assemblies. The multiple sets of radial clamping assemblies are mounted on the main clamping base. The radial clamping assemblies are located on the periphery of the main pipe section or bend section of the tee pipe. The radial clamping assemblies include multiple opposing positioning seats and a horizontal drive mechanism. The surface of the positioning seat facing the pipe is provided with a V-groove that matches the shape of the outer wall of the pipe. The horizontal drive mechanism includes a cylinder, which is connected to the positioning seat.

[0007] Preferably, the clamping mechanism includes a hydraulic cylinder, a first sleeve, a piston plate, a first spring, and a telescopic rod. The hydraulic cylinder is fixedly installed on the upper end of the main clamping base, and its output end extends downward and is fixedly connected to the upper end of the first sleeve. The piston plate is slidably connected to the inner surface of the first sleeve. The first spring is fastened between the inner top surface of the first sleeve and the upper end of the piston plate. The telescopic rod is fastened between the bottom end of the piston plate and the upper end of the sealing pressure plate. The bottom end of the first sleeve is an open end.

[0008] Preferably, an air inlet pipe is fixedly installed inside the sealing pressure plate, the air inlet end of the air inlet pipe is connected to the air outlet end of an external air pump, and a copper sealing gasket is fixedly provided at the bottom end of the sealing pressure plate.

[0009] Preferably, the elastic component includes a support plate, a movable rod, and a third spring. The end of the movable rod is fixed to the outside of the metal ball, and the movable rod is slidably connected to the middle of the support plate. The third spring covers the outside of the movable rod and is fastened between the side of the support plate and the outside of the metal ball. When the pipe expands thermally, the greater the upward displacement of the sealing pressure plate, the more the support plate is driven to move towards the conical hole.

[0010] Preferably, a second sleeve is fixedly provided in the middle of the side of the sealing plug, and a sleeve is fixedly provided in the middle of the second sleeve. The space formed between the inner wall of the second sleeve and the outer wall of the sleeve is an annular cavity. A piston ring is slidably connected to the inner wall of the annular cavity. Two mutually symmetrical connecting rods are fastened between the piston ring and the support plate. A second spring is sleeved on the outer side of the sleeve. The second spring is fastened between the bottom surface of the annular cavity and the side of the piston ring away from the connecting rod.

[0011] Preferably, the space formed by the upper end of the piston plate and the inner wall of the first sleeve is the first chamber, and the space formed by the inner wall of the annular cavity and the side of the piston ring is the second chamber. A retractable hose is fastened between the first chamber and the second chamber, and both the first chamber and the second chamber are filled with hydraulic oil.

[0012] Preferably, the metal ball coincides with the axis of the conical hole, and the metal ball seals the conical hole when the support plate contacts the sleeve.

[0013] Preferably, the sealing plate is made of high-temperature resistant heat-insulating material, and the sealing plug is made of the same material as the tee pipe.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The sealing plate fits the port flange with elastic force. When the tee pipe is heated and undergoes axial extension displacement, this elastic force provides continuous compression compensation, ensuring that the sealing surface remains in a gapless fit during the thermal expansion of the pipeline, and ensuring the continuous and sealed delivery of protective gas. 2. The thermal expansion displacement of the sealing pressure plate synchronously drives the elastic component to change the preload of the metal ball. By utilizing the difference in thermal elongation caused by different pipe wall thicknesses, the pressure threshold required for opening the tapered hole is automatically adjusted to achieve adaptive matching of back pressure under thin-walled and thick-walled welding conditions. 3. For different wall thicknesses, the self-adjusting structure provides a large back pressure under high heat input thick-walled conditions to prevent root sagging and indentation, and maintains a low back pressure under thin-walled conditions to prevent the molten pool from being blown through, thereby improving the forming quality of the back of the weld of pipe fittings with different wall thicknesses without the need for manual intervention. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the welding fixture for processing aircraft gas pipes according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the side structure of the main clamping base in the welding fixture for processing aircraft air pipes according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the hydraulic cylinder output end structure in the welding fixture for processing aircraft air pipes according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the internal structure of the first sleeve in the welding fixture for processing aircraft gas pipes according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the internal structure of the second sleeve in the welding fixture for processing aircraft gas pipes according to an embodiment of the present invention; Figure 6 This is a three-dimensional structural diagram of the internal structure of the annular cavity in the welding fixture for processing aircraft gas pipes according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the internal structure of the annular cavity during the welding of thin-walled pipes in the welding fixture for processing aircraft gas pipes according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the internal structure of the annular cavity during the welding of thick-walled pipes in the welding fixture for processing aircraft air pipes, according to an embodiment of the present invention.

[0016] In the diagram: 100, main clamping base; 200, hydraulic cylinder; 300, first sleeve; 301, piston plate; 302, first spring; 303, telescopic rod; 304, sealing pressure plate; 305, air inlet pipe; 400, sealing plug; 401, tapered hole; 402, second sleeve; 403, sleeve; 404, annular cavity; 405, piston ring; 406, second spring; 407, connecting rod; 408, support plate; 409, movable rod; 410, third spring; 411, metal ball; 500, first chamber; 501, telescopic hose; 502, second chamber. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] The terms used in this invention, such as "upper," "lower," "left," "right," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0019] like Figures 1-8 As shown, this embodiment of the invention provides a welding fixture for processing aircraft gas pipes, comprising: a fixture body for supporting and fixing a tee pipe; a clamping mechanism disposed at the port flange of the tee pipe for using an elastic force to fit a sealing pressure plate 304 to cover the port flange, thereby delivering protective gas to the tee pipe at constant pressure through the sealing pressure plate 304; a sealing plug 400 installed in the exhaust port of the tee pipe, wherein a conical hole 401 is provided in the middle, and a metal ball 411 is disposed in the conical hole 401; and an elastic component connected to the metal ball 411 for driving the metal ball 411 to move along the axis to seal the conical hole 401; wherein, the thicker the wall of the tee pipe, the greater the displacement of the sealing pressure plate 304 pushed upward by the thermal expansion of the pipe, the greater the displacement of the elastic component towards the conical hole 401, and the greater the pre-tightening force, so that the pressure required for the metal ball 411 to open the conical hole 401 is greater; the higher the gas pressure inside the tee pipe, the larger the flow cross section of the conical hole 401.

[0020] In this embodiment, before welding, the tee pipe is fixed to the fixture body, aligning the port flange of the tee pipe with the clamping mechanism. The sealing plug 400 is installed inside the exhaust port of the tee pipe. The clamping mechanism is activated, causing the sealing plate 304 to be elastically pressed against and cover the port flange of the tee pipe. Protective gas is then delivered to the tee pipe at constant pressure through the sealing plate 304. At this time, since welding has not yet commenced, the tee pipe has not undergone thermal expansion, the sealing plate 304 is in its initial position, the elastic component is in its initial state, and the preload force of the metal ball 411 driven by the elastic component on the tapered hole 401 is at a low value. The back pressure inside the tee pipe is at a low level to accommodate low-current welding of thin-walled pipes. In applications where high back pressure is not required, as welding begins, the current load heats the tee pipe, causing the gas inside to expand and increase in pressure. This pressure pushes the metal ball 411 outward along the tapered hole 401, automatically enlarging the flow cross-section of the tapered hole 401 to release pressure and prevent instantaneous high pressure from impacting the molten pool. During the continuous welding phase, the tee pipe undergoes thermal extension, causing the end face of the tee pipe to push the sealing plate 304 upward, resulting in displacement in the same direction. Since the sealing plate 304 and the clamping mechanism are kept in contact by elastic force, the elastic force maintains a constant clamping force on the port flange during this displacement process, ensuring that no pressure is generated between the sealing plate 304 and the port flange during the thermal expansion of the pipeline. During the gap, the protective gas remains in a closed-loop supply state, continuously maintaining the airtightness of the protective gas environment. Simultaneously, the displacement of the sealing plate 304 synchronously drives the elastic component to move along the axis towards the conical hole 401, increasing the pre-tightening force on the metal ball 411. Under this structure, the thicker the wall of the tee pipe, the greater the heat input generated by welding, and the greater the thermal extension of the pipe, the greater the displacement of the sealing plate 304, resulting in a higher pre-tightening force of the conical hole 401. Consequently, the valve opening pressure is significantly increased. This increased high back pressure after the valve is matched with the welding of thick-walled pipes: because the weld pool depth is large and the amount of molten metal is large before the arc ends in the welding of thick-walled pipes, this high back pressure can match the high current conditions of thick-walled pipes. The back support force required for the lower molten pool counteracts the downward tendency of the molten metal under gravity. For thin-walled pipes, due to the small thermal elongation, the elastic component is not significantly compressed, the valve opening pressure remains low, and the back pressure is maintained at a low value to avoid high back pressure causing blow-through of the thin-walled molten pool. This structure utilizes the difference in thermal elongation of the pipe to achieve adaptive adjustment of back pressure under thick-walled and thin-walled welding conditions. After welding, the tee pipe gradually cools and shrinks, and the sealing plate 304 returns to its original position as the pipe retracts. At this time, the thrust of the elastic component and the flow cross-sectional area of ​​the tapered hole 401 also return to their initial state synchronously as the displacement decreases, completing the adaptive back pressure control process throughout the entire welding cycle.

[0021] like Figure 1 and Figure 2As shown, optionally, the clamp body includes a main clamping base 100 and multiple sets of radial clamping assemblies. The multiple sets of radial clamping assemblies are installed on the main clamping base 100. The radial clamping assemblies are located on the periphery of the main pipe section or bend section of the tee pipe. The radial clamping assemblies include multiple opposing positioning seats and a horizontal drive mechanism. The surface of the positioning seat facing the pipe is provided with a V-groove that matches the shape of the outer wall of the pipe. The horizontal drive mechanism includes a cylinder, which is connected to the positioning seat.

[0022] In this embodiment, the main clamping base 100 cooperates with multiple sets of radial clamping components to center and clamp the main pipe section or bend section of the tee pipe through the V-groove, so that the tee pipe remains stable during welding and avoids positional displacement caused by welding heat input. The radial clamping components are set on the periphery of the main pipe section or bend section, which can independently clamp different pipe sections of the tee pipe, adapt to the multi-directional structure of the tee pipe, and ensure the correspondence accuracy between the port flange of the tee pipe and the clamping mechanism. The cylinder is connected to the positioning seat and is used to push the positioning seat to move in the horizontal direction, so that the positioning seats on both sides move closer to each other, and finally clamp and fix the pipe wall of the tee pipe in the V-groove. Since it is existing technology, its specific structure and working principle will not be described here.

[0023] like Figure 1 , Figure 3 and Figure 4 As shown, optionally, the clamping mechanism includes a hydraulic cylinder 200, a first sleeve 300, a piston plate 301, a first spring 302, and a telescopic rod 303. The hydraulic cylinder 200 is fixedly installed on the upper end of the main clamping base 100, and its output end extends downward and is fixedly connected to the upper end of the first sleeve 300. The piston plate 301 is slidably connected to the inner surface of the first sleeve 300. The first spring 302 is fastened between the inner top surface of the first sleeve 300 and the upper end of the piston plate 301. The telescopic rod 303 is fastened between the bottom end of the piston plate 301 and the upper end of the sealing pressure plate 304. The bottom end of the first sleeve 300 is an open end.

[0024] Specifically, before welding, the hydraulic cylinder 200 is activated. The output end of the hydraulic cylinder 200 pushes the first sleeve 300 downward, causing the first sleeve 300 to drive the piston plate 301, the telescopic rod 303, and the sealing plate 304 to move downward as a whole towards the port flange of the tee pipe. When the sealing plate 304 contacts the port flange, the hydraulic cylinder 200 continues to advance, and the first spring 302 is compressed. The elastic force of the first spring 302 is transmitted to the sealing plate 304 through the piston plate 301 and the telescopic rod 303, causing the sealing plate 304 to fit and cover the port flange through elastic force.

[0025] In this optional embodiment, the hydraulic cylinder 200 provides the clamping power, and the first spring 302 provides elastic clamping force between the sealing plate 304 and the port flange. When the tee pipe is heated and expands upward to push the sealing plate 304, the compression of the first spring 302 changes accordingly, so that the sealing plate 304 always stays in contact with the port flange during the thermal expansion of the pipeline without gaps, ensuring that the protective gas is continuously delivered in a constant pressure and sealed manner. The piston plate 301 slides in the first sleeve 300, so that the displacement of the sealing plate 304 can be converted into the deformation of the first spring 302, realizing the adaptive maintenance of the clamping force.

[0026] like Figure 3 and Figure 4 As shown, optionally, an air inlet pipe 305 is fixedly installed inside the sealing plate 304, the air inlet end of the air inlet pipe 305 is connected to the air outlet end of an external air pump, and a copper sealing gasket is fixedly provided at the bottom end of the sealing plate 304.

[0027] Specifically, before welding, the air inlet end of the air inlet pipe 305 is connected to the air outlet end of an external air pump. The air pump is started, and protective gas is delivered into the tee pipe through the air inlet pipe 305. The copper sealing gasket is located between the bottom end of the sealing pressure plate 304 and the port flange of the tee pipe. It is pressed under the elastic force of the pressing mechanism to form a seal at the port flange.

[0028] In this optional embodiment, the protective gas enters the interior of the tee pipe directly through the inlet pipe 305. The external pipeline does not interfere with the movement of the clamping mechanism. The copper sealing gasket fits tightly with the port flange under the action of elastic force. The ductility of the copper material fills the microscopic unevenness on the surface of the port flange, improving the airtightness at the port flange. Combined with the elastic clamping force of the first spring 302, no gap is generated between the sealing pressure plate 304 and the port flange during the thermal expansion displacement of the pipeline.

[0029] like Figures 5-8 As shown, optionally, the elastic component includes a support plate 408, a movable rod 409, and a third spring 410. The end of the movable rod 409 is fixed to the outside of the metal ball 411. The movable rod 409 and the middle of the support plate 408 are slidably connected to each other. The third spring 410 covers the outside of the movable rod 409 and is fastened between the side of the support plate 408 and the outside of the metal ball 411. When the pipe expands thermally, the greater the upward displacement of the sealing pressure plate 304, the greater the displacement of the support plate 408 towards the conical hole 401.

[0030] Specifically, when the pipe expands thermally, the greater the upward displacement of the sealing pressure plate 304, the more the drive support plate 408 moves towards the conical hole 401. When the support plate 408 moves towards the conical hole 401, the third spring 410 is compressed, and the elastic force of the third spring 410 is transmitted to the metal ball 411, increasing the preload of the metal ball 411 on the conical hole 401. When the gas pressure in the tee increases, the gas pushes the metal ball 411 to drive the movable rod 409 to slide relative to the support plate 408, and the metal ball 411 leaves the conical hole 401, increasing the flow cross section of the conical hole 401.

[0031] In this optional embodiment, the thicker the pipe wall, the greater the thermal expansion, the greater the compression of the third spring 410, the greater the preload of the metal ball 411, and the higher the opening pressure of the tapered hole 401. This provides a higher back pressure to support the molten pool during thick-walled high-current welding. The movable rod 409 is slidably connected to the support plate 408, allowing the metal ball 411 to move relative to the support plate 408 under gas pressure, thereby achieving automatic adjustment of the flow section of the tapered hole 401. At the same time, the elastic force of the third spring 410 provides a restoring force for the metal ball 411.

[0032] like Figures 5-8 As shown, optionally, a second sleeve 402 is fixedly provided in the middle of the side of the sealing plug 400, and a sleeve 403 is fixedly provided in the middle of the second sleeve 402. The space formed between the inner wall of the second sleeve 402 and the outer wall of the sleeve 403 is an annular cavity 404. A piston ring 405 is slidably connected to the inner wall of the annular cavity 404. Two mutually symmetrical connecting rods 407 are fastened between the piston ring 405 and the support plate 408. A second spring 406 is sleeved on the outer side of the sleeve 403. The second spring 406 is fastened between the bottom surface of the annular cavity 404 and the side of the piston ring 405 away from the connecting rod 407.

[0033] Specifically, when the sealing plate 304 is displaced upward, the piston ring 405 slides in the annular cavity 404, and the second spring 406 is stretched. When the sealing plate 304 retracts and resets, the elastic force of the second spring 406 pulls the piston ring 405 to move in the opposite direction, and the piston ring 405 drives the support plate 408 to reset through the connecting rod 407.

[0034] In this optional embodiment, the piston ring 405 drives the support plate 408 to move synchronously through the connection of the connecting rod 407, the second spring 406 provides a restoring force for the piston ring 405 and the support plate 408, and the third spring 410 provides a sealing pre-tightening force for the metal ball 411 on the tapered hole 401.

[0035] like Figures 1-8As shown, optionally, the space formed by the upper end of the piston plate 301 and the inner wall of the first sleeve 300 is the first chamber 500, and the space formed by the inner wall of the annular cavity 404 and the side of the piston ring 405 is the second chamber 502. A retractable hose 501 is fastened between the first chamber 500 and the second chamber 502, and both the first chamber 500 and the second chamber 502 are filled with hydraulic oil.

[0036] Specifically, when the sealing pressure plate 304 is heated and extended, pushing it to move upward, the piston plate 301 moves relative to the first sleeve 300, and the volume of the first chamber 500 changes. The hydraulic oil in the first chamber 500 enters the second chamber 502 through the retractable hose 501. The hydraulic oil in the second chamber 502 pushes the piston ring 405 to move in the annular cavity 404. The piston ring 405 drives the support plate 408 to move towards the tapered hole 401 through the connecting rod 407.

[0037] In this optional embodiment, the first chamber 500 and the second chamber 502 are connected by a retractable hose 501 to form a hydraulic passage. The displacement of the sealing plate 304 is converted into a volume change of the first chamber 500 by the piston plate 301, and then transmitted to the second chamber 502 through the retractable hose 501, driving the piston ring 405 to move, thereby realizing long-distance transmission of displacement. The retractable hose 501 can extend and retract with the change of the relative position between the first sleeve 300 and the sealing plug 400.

[0038] like Figure 7 As shown, optionally, the metal ball 411 coincides with the axis of the tapered hole 401, and the metal ball 411 seals the tapered hole 401 when the support plate 408 contacts the sleeve 403.

[0039] In this optional embodiment, the metal ball 411 coincides with the axis of the tapered hole 401, allowing the metal ball 411 to uniformly press against the inner wall of the tapered hole 401 under the push of the third spring 410. During thin-walled tube welding, to ensure that the metal ball 411 seals the tapered hole 401 before welding, the compression of the third spring 410 is small, and the preload is low. The metal ball 411 can open the tapered hole 401 under low gas pressure, maintaining a low back pressure to meet the process requirements of thin-walled, low-current welding. The preload is increased by moving the support plate 408.

[0040] like Figure 1 As shown, optionally, the sealing plate 304 is made of high-temperature resistant heat insulation material, and the sealing plug 400 is made of the same material as the tee pipe.

[0041] Specifically, during welding, the sealing plate 304 is located at the port flange of the tee pipe, directly bearing the heat conducted by the tee pipe. The high-temperature resistant insulation material isolates the temperature transfer, ensuring the normal operation of the internal structure of the first sleeve 300. The sealing plug 400 is installed in the exhaust port of the tee pipe and is heated synchronously with the tee pipe during the welding process. The sealing plug 400 and the tee pipe are made of the same material, and both have the same coefficient of thermal expansion.

[0042] In this optional embodiment, the sealing plate 304 is made of high-temperature resistant heat-insulating material, maintaining dimensional stability under high-temperature welding conditions. This prevents gaps between the sealing plate 304 and the port flange due to thermal deformation, ensuring a continuous and sealed supply of protective gas. The sealing plug 400 is made of the same material as the tee pipe. During welding heating, the sealing plug 400 and the exhaust port of the tee pipe expand synchronously, preventing gaps or jamming between the sealing plug 400 and the exhaust port due to differences in thermal expansion coefficients, thus ensuring the reliability of the seal at the exhaust port.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A welding fixture for machining aircraft gas pipes, characterized in that, include: The clamp body is used to support and fix the tee pipe; A clamping mechanism is provided at the port flange of the tee pipe, which is used to press the sealing plate (304) against the port flange by elastic force, so as to deliver protective gas into the tee pipe at constant pressure through the sealing plate (304); A sealing plug (400) is installed in the exhaust port of the three-way pipe, and a tapered hole (401) is provided in the middle of the tapered hole (401), and a metal ball (411) is provided in the tapered hole (401); An elastic component, connected to the metal ball (411), is used to drive the metal ball (411) to move along the axis to seal the conical hole (401); The thicker the wall of the three-way pipe, the greater the displacement of the sealing pressure plate (304) pushed upward by the thermal expansion of the pipe, the greater the displacement of the elastic component towards the conical hole (401), the greater the pre-tightening force, and the greater the pressure required for the metal ball (411) to open the conical hole (401); the higher the gas pressure inside the three-way pipe, the larger the flow cross section of the conical hole (401).

2. The welding fixture for processing aircraft air pipes according to claim 1, characterized in that, The clamp body includes a main clamping base (100) and multiple sets of radial clamping assemblies. The multiple sets of radial clamping assemblies are mounted on the main clamping base (100). The radial clamping assemblies are located on the periphery of the main pipe section or bend section of the tee pipe. The radial clamping assemblies include multiple opposing positioning seats and a horizontal drive mechanism. The surface of the positioning seat facing the pipe is provided with a V-groove that matches the shape of the outer wall of the pipe. The horizontal drive mechanism includes a cylinder, which is connected to the positioning seat.

3. The welding fixture for processing aircraft air pipes according to claim 2, characterized in that, The clamping mechanism includes a hydraulic cylinder (200), a first sleeve (300), a piston plate (301), a first spring (302), and a telescopic rod (303). The hydraulic cylinder (200) is fixedly installed on the upper end of the main clamping base (100), and its output end extends downward and is fixedly connected to the upper end of the first sleeve (300). The piston plate (301) is slidably connected to the inner surface of the first sleeve (300). The first spring (302) is fastened between the inner top surface of the first sleeve (300) and the upper end of the piston plate (301). The telescopic rod (303) is fastened between the bottom end of the piston plate (301) and the upper end of the sealing pressure plate (304). The bottom end of the first sleeve (300) is an open end.

4. The welding fixture for processing aircraft air pipes according to claim 3, characterized in that, An air inlet pipe (305) is fixedly installed inside the sealing pressure plate (304). The air inlet end of the air inlet pipe (305) is connected to the air outlet end of an external air pump. A copper sealing gasket is fixedly provided at the bottom end of the sealing pressure plate (304).

5. The welding fixture for processing aircraft air pipes according to claim 3, characterized in that, The elastic component includes a support plate (408), a movable rod (409), and a third spring (410). The end of the movable rod (409) is fixed to the outside of the metal ball (411). The movable rod (409) and the middle of the support plate (408) are slidably connected to each other. The third spring (410) covers the outside of the movable rod (409) and is fastened between the side of the support plate (408) and the outside of the metal ball (411). When the pipe expands thermally, the greater the upward displacement of the sealing pressure plate (304), the greater the displacement of the support plate (408) towards the conical hole (401).

6. The welding fixture for processing aircraft air pipes according to claim 5, characterized in that, A second sleeve (402) is fixedly provided in the middle of the side of the sealing plug (400), and a sleeve (403) is fixedly provided in the middle of the second sleeve (402). The space formed between the inner wall of the second sleeve (402) and the outer wall of the sleeve (403) is an annular cavity (404). A piston ring (405) is slidably connected to the inner wall of the annular cavity (404). Two mutually symmetrical connecting rods (407) are fastened between the piston ring (405) and the support plate (408). A second spring (406) is sleeved on the outside of the sleeve (403). The second spring (406) is fastened between the bottom surface of the annular cavity (404) and the side of the piston ring (405) away from the connecting rod (407).

7. The welding fixture for processing aircraft air pipes according to claim 6, characterized in that, The space formed by the upper end of the piston plate (301) and the inner wall of the first sleeve (300) is the first chamber (500), and the space formed by the inner wall of the annular cavity (404) and the side of the piston ring (405) is the second chamber (502). A retractable hose (501) is fastened between the first chamber (500) and the second chamber (502), and both the first chamber (500) and the second chamber (502) are filled with hydraulic oil.

8. The welding fixture for processing aircraft air pipes according to claim 7, characterized in that, The metal ball (411) coincides with the axis of the conical hole (401), and the metal ball (411) seals the conical hole (401) when the support plate (408) contacts the sleeve (403).

9. The welding fixture for processing aircraft air pipes according to claim 1, characterized in that, The sealing plate (304) is made of high-temperature resistant heat insulation material, and the sealing plug (400) is made of the same material as the tee pipe.

Images