A support fixture and welding method for controlling the excess height of butt welds inside conduits.

Abstract

This invention discloses a support fixture and welding method for controlling the excess height of butt welds inside conduits. In the support fixture, a fork-shaped screw is placed in the central shaft hole of a mandrel. The mandrel is nested within the stepped shaft hole of a positioning sleeve via a stepped shaft structure. The screw is positioned and installed within the central shaft hole of the mandrel by a positioning seat, and the screw extends into the inner end of the mandrel and is screwed and fixed to one end of the fork-shaped screw. Each set of tapered sleeve and expansion block assemblies includes: a tapered sleeve and an expansion block configured as circumferentially separate structures; the tapered sleeve is fitted onto the outside of the mandrel and has an outer conical surface, and the expansion block is fitted onto the tapered sleeve. The outer side has an inner conical surface that compensates for the structure of the outer conical surface of the conical sleeve; at least one end of the fork-shaped screw has a mounting hole, through which a connecting pin perpendicular to the axis of the spindle is installed, and the connecting pin is fixedly connected to the end face of the conical sleeve by a nut; the guide tube to be welded is sleeved on the outside of the expansion block, and is sleeved on the outside of one end of the positioning sleeve 2 through the annular groove of the flange at the end of its guide tube connector; by turning the screw, the fork-shaped screw is driven to move axially, and the conical sleeve is driven to move axially through the connecting pin, thereby realizing the contraction or expansion of the expansion block.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of catheter welding technology, and particularly to a support fixture and welding method for controlling the excess height of butt welds inside catheters. Background Technology

[0002] Aircraft ducts play a crucial role in aircraft structures, responsible for transporting hydraulic fluid, fuel, air, and other supplies, and are essential for the normal operation of the aircraft. Aircraft ducts are not only numerous but also require precise arrangement and connection to ensure their effective operation within the aircraft systems. Welded ducts constitute a significant portion of aircraft manufacturing, especially in components with unique duct structures.

[0003] For welded conduits, weld reinforcement refers to the height of the metal protruding from the line connecting the two weld toes on the weld surface. Weld reinforcement refers to the portion of the deposited metal that protrudes from the base metal surface or the portion above the connection line at the end of the fillet weld. The presence of weld reinforcement disrupts the continuity of the weld surface geometry, and will generate additional bending moments due to abrupt changes in shape, resulting in higher local stress. These crack initiations caused by weld defects will accelerate their propagation under the action of local stress until fracture.

[0004] Controlling the weld reinforcement height of the weld seam in duct welding has become a major challenge affecting the weld quality of welded ducts. For circumferential welds and local lug welding of small-diameter ducts, the spatial structure limits the use of many mechanisms that support the inner wall of the duct, making it difficult to control the weld reinforcement height of aircraft welded ducts. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems. This invention provides a support fixture and welding method for controlling the weld reinforcement height of the butt weld inside the conduit, in order to solve the problem that for the circumferential weld and local lug welding of small-diameter conduits, many mechanisms supporting the inner wall of the conduit cannot be used due to spatial constraints, which makes it difficult to control the weld reinforcement height of aircraft welded conduits.

[0006] The technical solution of the present invention: In a first aspect, the present invention provides a support clamp for controlling the excess height of the butt weld in the conduit, comprising: a mandrel 1, a positioning sleeve 2, a positioning seat 3, a locking seat 4, a screw 5, a locking nut 6, a fork-type screw 16, a connecting pin 10, and at least one set of tapered sleeve and expansion block assembly;

[0007] The positioning sleeve 2 has a stepped hole on its axis, and the mandrel 1 has a central shaft hole along its axis. A fork-shaped screw 16 is placed in the central shaft hole. The central shaft hole at one end of the mandrel 1 is set as a stepped shaft hole, and the outer side of the stepped shaft hole at this end is set as a stepped shaft structure. The mandrel 1 is nested in the stepped shaft hole of the positioning sleeve 2 through its stepped shaft structure, so as to restrict the axial movement of the mandrel 1 through the positioning sleeve 2. The screw 5 with a flange in the middle passes through the middle through hole of the positioning seat 3 and is positioned and installed on the outer end face of the positioning seat 3 through its flange, so that the screw 5 is positioned and installed in the central shaft hole of the mandrel 1 through the positioning seat 3, so as to restrict the axial position of the positioning seat 3 and the screw 5 through the stepped hole of the mandrel 1. The screw 5 extends into the inner end of the mandrel 1 and is screwed and fixed to the fork-shaped part at one end of the fork-shaped screw 16. The locking seat 4 is sleeved on the screw 5 and abuts against the outer end face of its flange. The locking nut 6 screwed to the outer end of the screw 5 is used to press the screw 5 onto the positioning seat 3.

[0008] Each set of the conical sleeve and expansion block assembly includes: a conical sleeve and an expansion block configured as circumferentially separate structures; the conical sleeve is fitted on the outside of the mandrel 1 and has an outer conical surface, and the expansion block is fitted on the outside of the conical sleeve and has an inner conical surface that compensates for the structure of the outer conical surface of the conical sleeve; at least one end of the fork-shaped screw 16 has a mounting hole for mounting a connecting pin 10 that is radially perpendicular to the axis of the mandrel 1, and the connecting pin 10 is fixedly connected to the end face of the conical sleeve by a nut;

[0009] The entire conduit to be welded is fitted over the expansion block, and is fitted over one end of the positioning sleeve 2 through the annular groove of the flange at the end of the conduit connector 12 to restrict the axial position of the conduit; by turning the screw 5, the fork screw 16 is driven to move axially along the mandrel 1, and the conical sleeve is driven to move axially along the mandrel 1 through the connecting pin 10, thereby realizing the contraction or expansion of the expansion block.

[0010] Optionally, the support fixture for controlling the excess height of the butt weld inside the conduit, as described above, specifically includes two sets of tapered sleeves and expansion block assemblies, respectively including: a first tapered sleeve 17 and a first expansion block 7, and a second tapered sleeve 14 and a second expansion block 15; the first tapered sleeve 17 is sleeved on the outside of the mandrel 1 and has an outer tapered surface, the first expansion block 7 is sleeved on the outside of the first tapered sleeve 17 and has an inner tapered surface that compensates for the structure of the outer tapered surface of the first tapered sleeve 17; the second tapered sleeve 14 is sleeved on the outside of the mandrel 1 and has an outer tapered surface, the second expansion block 15 is sleeved on the outside of the second tapered sleeve 14 and has an inner tapered surface that compensates for the structure of the outer tapered surface of the second tapered sleeve 14;

[0011] The fork-shaped screw 16 has mounting holes on its two fork-shaped portions, which are used to install connecting pins 10 that are radially perpendicular to the axis of the spindle 1. The two connecting pins 10 are respectively connected to the end faces of the first tapered sleeve 17 and the second tapered sleeve 14 by nuts.

[0012] The fork-shaped screw 16 moves axially along the spindle 1, and through the two connecting pins 10, drives the first tapered sleeve 17 and the second tapered sleeve 14 to move axially, thereby realizing the contraction or expansion of the first expansion block 7 and the second expansion block 15.

[0013] Optionally, the support fixture for controlling the excess height of the butt weld inside the conduit as described above further includes: a hexagonal thin nut 18 and a limiting plate 19 disposed between the two sets of tapered sleeves and expansion block assemblies;

[0014] The spindle 1 has an external thread on the outer periphery of the middle part of the shaft body. A hexagonal thin nut 18 is screwed onto the spindle 1 shaft body to form an annular shoulder. The limiting plate 19 is positioned and installed on the side end face of the first expansion block 7 near the second tapered sleeve 14 by the nut, and the axial position of the limiting plate 19 and the first expansion block 7 is limited by the hexagonal thin nut 18.

[0015] The mandrel 1 has axially oriented oblong holes at both ends of its shaft body, through which the connecting pins 10 at both ends of the fork screw 16 pass.

[0016] Optionally, in the support fixture described above for controlling the excess height of the butt weld inside the conduit,

[0017] In each set of the conical sleeve and expansion block assembly, one set of conical sleeves includes at least two annular conical sleeves arranged in segments along the circumference, which are spliced ​​together along the mandrel to form a conical structure. One set of expansion blocks includes at least two annular expansion blocks arranged in segments along the circumference, which are spliced ​​together along the circumference of the conical sleeve to form a conical wedge-shaped hole inside, which is used to cooperate with the conical structure of the conical sleeve.

[0018] Optionally, in the support fixture described above for controlling the excess height of the butt weld inside the conduit,

[0019] In each set of the conical sleeve and expansion block assembly, the multiple annular expansion blocks used to form a set of expansion blocks are provided with at least one annular groove along the circumferential direction for placing a tightening mechanism in the annular groove so that when the fork screw 16 moves toward the side for shrinking the expansion block, the multiple annular expansion blocks are tightened radially by the tightening mechanism so as to facilitate the removal of the support clamp from the welded conduit.

[0020] Optionally, in the support clamp for controlling the excess height of the butt weld inside the conduit as described above, the tightening mechanism includes: a tension spring 8, or a tension spring 8 and a tension spring rod 9;

[0021] In each annular groove of the plurality of annular expansion blocks, a tension spring 8 is installed around the perimeter to apply radial pressure to the plurality of annular expansion blocks around the perimeter; or,

[0022] On the outer cylindrical surface of the annular expansion block, multiple tension spring rods 9 parallel to the axial direction are pressed into each annular groove. A tension spring 8 is connected between adjacent tension spring rods 9 to apply radial pressure to the multiple annular expansion blocks around the circumference.

[0023] Optionally, in the support fixture described above for controlling the excess height of the butt weld inside the conduit,

[0024] In each set of cone sleeve and expansion block assembly, each cone sleeve has multiple vent nozzles 11a that are circumferentially parallel to the axial direction on its end face, and each expansion block has a guide hole on its inner cone surface that connects the vent nozzles 11a to the weld position.

[0025] The positioning sleeve 2, located outside the stepped hole, has a multi-level annular shoulder structure for connecting with a three-jaw chuck for welding. The outer surface of the other end of the positioning sleeve 2 has a vent 11b and two symmetrically arranged lifting rings 11c. The vent 11b is used to connect the cavity between the vent nozzle 11a, the vent 11b, and the guide hole after the guide tube is fitted on the support fixture, so as to deliver protective gas between each expansion block and the guide tube, thereby providing gas protection during welding. The symmetrically arranged lifting rings 11c are used for lifting and transporting the support fixture and the guide tube.

[0026] Optionally, in the support fixture described above for controlling the excess height of the butt weld inside the conduit,

[0027] The fork-shaped screw 16 includes a small-diameter rod in the middle and a large-diameter cylindrical rod fixedly connected to both ends of the small-diameter rod. A threaded hole is opened on the end face of the large-diameter cylindrical rod at one end for screwing with the external thread at the inner end of the screw 5. The fork-shaped screw 16 can be moved axially by rotating the screw 5.

[0028] Secondly, embodiments of the present invention also provide a welding method for controlling the excess height of butt welds inside a duct, wherein a support fixture for controlling the excess height of butt welds inside a duct, as described in any of the preceding claims, is used to support the aircraft duct to facilitate the welding operation; wherein the two sets of tapered sleeves and expansion block assemblies in the support fixture respectively include: a first tapered sleeve 17 and a first expansion block 7 used in conjunction, and a second tapered sleeve 14 and a second expansion block 15 used in conjunction; the welding method includes:

[0029] Step 1: Rotate the screw 5 clockwise or counterclockwise to drive the fork screw 16 to move axially toward one end of the screw 5, thereby driving the connecting pin 10 to move toward the same end, and driving the first cone sleeve 17 and the second cone sleeve 14 to move toward the same end, so that the first expansion block 7 and the second expansion block 15 contract simultaneously.

[0030] Step 2: Insert the entire shaft of the mandrel 1 of the support clamp into the conduit, and fit the conduit connector 12 at one end of the conduit onto the end of the positioning sleeve 2 to fix the relative position of the conduit and the mandrel 1. Place the first expansion block 7 and the second expansion block 15 in the conduit at the position to be supported for welding.

[0031] Step 3: Rotate screw 5 counterclockwise or clockwise to drive fork screw 16 to move axially away from screw 5, drive connecting pin 10 to the same end, and drive first cone sleeve 17 and second cone sleeve 14 to the same end, so that first expansion block 7 and second expansion block 15 expand simultaneously, supporting first expansion block 7 and second expansion block 15 on the inner wall of the position to be welded on conduit 12;

[0032] Step 4: The support fixture and the guide tube assembled through it are installed as a whole on the three-jaw chuck of the welding equipment turntable through the positioning sleeve 2. After clamping, the welding robot is used to perform welding operation on the part to be welded.

[0033] Step 5: After the welding operation is completed, remove the support clamp and the conduit together. Rotate the screw 5 of the support clamp clockwise or counterclockwise to shrink the expansion block in the support clamp, and then remove the entire support clamp from the conduit.

[0034] Optionally, in the welding method described above for controlling the excess height of the butt weld inside the conduit,

[0035] In step 4, the circumferential welding position of the conduit or the local lug of the conduit, which is supported and fixedly installed on the welding equipment by a support clamp, is welded. During the welding process, protective gas is introduced through the vent connector 11b and the vent nozzle 11a to provide gas protection during the welding operation.

[0036] The beneficial effects of this invention are as follows: For the circumferential welding of small-diameter ducts and the welding of local lugs in aircraft structures, this invention provides a support fixture for controlling the excess height of the butt weld inside the duct. It employs a mandrel 1 with a central shaft hole and a forked screw 16 disposed inside the mandrel 1. A connecting pin 10 connected to the forked screw 16 extends radially out of the mandrel 1 and is fixedly connected to a tapered sleeve sleeved outside the mandrel 1. An expansion block is fitted onto the outside of the tapered sleeve. The rotation of the screw 5 screwed to the forked screw 16 drives the forked screw 16 to move axially along the mandrel 1, thereby driving the tapered sleeve to move axially, achieving the contraction or expansion of the expansion block. Using this support fixture, the duct can be fitted with the expansion block in a contracted state. After fitting the duct, the expansion block is expanded by the axial movement of the forked screw 16, and the welding process is performed while the expansion block is expanded. This satisfies the requirement of supporting the inner wall of the duct during the duct welding process. After welding, the expansion block is expanded by the axial movement of the forked screw 16, and the duct is removed while the expansion block is contracted. The support fixture provided in this embodiment of the invention supports the inner wall of the conduit during welding by expanding the block, and in conjunction with filling the conduit with protective gas, controls the weld reinforcement during the welding process, thereby improving the welding quality and fatigue life of the conduit. Attached Figure Description

[0037] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0038] Figure 1 A schematic diagram of the external structure of a support fixture for controlling the excess height of butt welds inside a conduit, provided in an embodiment of the present invention;

[0039] Figure 2 for Figure 1 A cross-sectional view of a support fixture for controlling the excess height of butt welds inside a conduit, provided in the illustrated embodiment;

[0040] Figure 3 for Figure 1 The illustrated embodiment provides a schematic diagram of the mandrel structure in the support fixture for controlling the excess height of the butt weld inside the conduit.

[0041] Figure 4 for Figure 1 The illustrated embodiment provides a schematic diagram of the fork-shaped screw in the support fixture for controlling the excess height of the butt weld inside the conduit.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1-Mandrel, 2-Positioning sleeve, 3-Positioning seat, 4-Locking seat, 5-Screw, 6-Locking nut, 7-First expansion block, 8-Tension spring, 9-Tension spring rod, 10-Connecting pin, 11a-Ventilation nozzle, 11b-Ventilation interface, 11c-Mounting eye, 12-Conduit connector, 13-Ear, 14-Second cone sleeve, 15-Second expansion block, 16-Fork-shaped screw, 17-First cone sleeve, 18-Hexagonal thin nut, 19-Limiting plate. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0045] As explained in the background section, aircraft ducts play a crucial role, and welded ducts constitute a significant portion of aircraft manufacturing. Specifically, aircraft ducts account for a substantial proportion of aircraft manufacturing, playing an indispensable role in the structural integrity, functional realization, and safety of the aircraft. Welding accounts for approximately 25% to 35% of aircraft duct manufacturing, especially in components with unique duct structures. This high welding percentage reflects the vital role of welding technology in aircraft manufacturing, particularly in the widespread application of welding techniques in aircraft duct manufacturing.

[0046] For widely used welded conduits, the weld reinforcement height must be controlled during the welding process to avoid the weld reinforcement height from disrupting the continuity of the weld surface geometry and causing additional bending moments due to abrupt changes in shape, resulting in high local stress and other problems.

[0047] To address the aforementioned problems and the need for controlling weld reinforcement height, this invention provides a support fixture and welding method for controlling the reinforcement height of butt welds inside a conduit. The support fixture is installed into the conduit to be welded before welding, expanding the conduit to support the inner wall of the conduit during welding, thereby controlling the weld reinforcement height.

[0048] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0049] Figure 1 This is a schematic diagram of the external structure of a support fixture for controlling the excess height of butt welds inside a conduit, provided by an embodiment of the present invention. Figure 2 for Figure 1 A cross-sectional view of a support fixture for controlling the excess height of butt welds inside a conduit, provided in the illustrated embodiment. (Refer to...) Figure 1 and Figure 2As shown, the support fixture for controlling the excess height of the butt weld inside the conduit provided in this embodiment of the invention may include: a mandrel 1, a positioning sleeve 2, a positioning seat 3, a locking seat 4, a screw 5, a locking nut 6, a fork-shaped screw 16, a connecting pin 10, and at least one set of tapered sleeve and expansion block assembly.

[0050] like Figure 1 and Figure 2 In the structure of the support clamp shown, a stepped hole is provided on the axis of the positioning sleeve 2, and the mandrel 1 has a central shaft hole along its axis. A fork-shaped screw 16 is placed in the central shaft hole. The central shaft hole at one end of the mandrel 1 is set as a stepped shaft hole, and the outer side of the stepped shaft hole at this end is set as a stepped shaft structure. The mandrel 1 is nested in the stepped shaft hole of the positioning sleeve 2 through its stepped shaft structure, so as to restrict the axial movement of the mandrel 1 by the positioning sleeve 2. The screw 5 with a flange in the middle passes through the middle through hole of the positioning seat 3 and is positioned and installed in the positioning seat through its flange. On the outer end face of the seat 3, the screw 5 is positioned and installed in the central shaft hole of the mandrel 1 through the positioning seat 3, so that the axial position of the positioning seat 3 and the screw 5 is restricted by the stepped hole of the mandrel 1. The screw 5 extends into the inner end of the mandrel 1 and is screwed and fixed to the fork-shaped part of one end of the fork-shaped screw 16. The locking seat 4 is sleeved on the screw 5 and abuts against the outer end face of its flange. The locking nut 6 screwed to the outer end of the screw 5 is used to press the screw 5 onto the positioning seat 3, that is, the locking seat 4 and the locking nut 6 lock the screw 5 in the working state.

[0051] In this embodiment of the invention, each set of tapered sleeve and expansion block assembly includes: a tapered sleeve and an expansion block configured as circumferentially split structures; the tapered sleeve is fitted on the outside of the mandrel 1 and has an outer tapered surface, and the expansion block is fitted on the outside of the tapered sleeve and has an inner tapered surface that compensates for the structure of the outer tapered surface of the tapered sleeve; at least one end of the fork-shaped screw 16 has a mounting hole for mounting a connecting pin 10 that is radially perpendicular to the axis of the mandrel 1, and the connecting pin 10 is fixedly connected to the end face of the tapered sleeve by a nut.

[0052] Using the support clamp provided in this embodiment of the invention, the entire conduit to be welded is sleeved on the outside of the expansion block, and the conduit connector 12 is sleeved on the outside of one end of the positioning sleeve 2 through the annular groove of the flange at the end of the conduit connector 12 to restrict the axial position of the conduit; by turning the screw 5, the fork screw 16 is driven to move axially along the mandrel 1, and the conical sleeve is driven to move axially along the mandrel 1 through the connecting pin 10, thereby realizing the contraction or expansion of the expansion block.

[0053] It should be noted that the support clamp provided in the embodiment of the present invention can fit the conduit in the state of the expansion block contraction. After the conduit is fitted, the expansion block is expanded by the axial movement of the fork screw 16, and the welding process is carried out in the state of the expansion block contraction. This can meet the requirements of supporting the inner wall of the conduit in the conduit welding process. After the welding is completed, the expansion block is expanded by the axial movement of the fork screw 16, and the conduit is taken out in the state of the expansion block contraction.

[0054] In one implementation of this invention, a set of conical sleeves and expansion block assemblies may be used, for example including... Figure 2 The first conical sleeve 17 and the first expansion block 7 shown are provided, wherein the first conical sleeve 17 is sleeved on the outside of the mandrel 1 and has an outer conical surface, and the first expansion block 7 is sleeved on the outside of the first conical sleeve 17 and has an inner conical surface that compensates for the structure of the outer conical surface of the first conical sleeve 17.

[0055] In one implementation of this invention, the support clamp preferably includes two sets of conical sleeves and expansion block assemblies, comprising: a first conical sleeve 17 and a first expansion block 7, and a second conical sleeve 14 and a second expansion block 15. Figure 2 As shown, in one set of components, the first conical sleeve 17 is fitted on the outside of the mandrel 1 and has an outer conical surface, and the first expansion block 7 is fitted on the outside of the first conical sleeve 17 and has an inner conical surface that compensates for the structure of the outer conical surface of the first conical sleeve 17; in another set of components, the second conical sleeve 14 is fitted on the outside of the mandrel 1 and has an outer conical surface, and the second expansion block 15 is fitted on the outside of the second conical sleeve 14 and has an inner conical surface that compensates for the structure of the outer conical surface of the second conical sleeve 14.

[0056] It should be noted that in this implementation, the cone surfaces of the first cone sleeve 17 and the second cone sleeve 14 have the same direction, such as... Figure 2 In this embodiment, the large ends of the cones in the first conical sleeve 17 and the second conical sleeve 14 are both located near the end of the positioning sleeve 2. Thus, when the first conical sleeve 17 and the second conical sleeve 14, which have the same conical surface direction, move axially in one direction, they synchronously contract or expand the first expansion block 7 and the second expansion block 15. Furthermore, it should be noted that in this embodiment, the conical surface direction of the cones in each set of conical sleeves and expansion block assemblies is not limited, but all conical sleeves must have the same conical surface direction. When the conical surface directions of the sleeves are opposite, it only affects the rotational direction of the contraction or expansion of the expansion blocks.

[0057] In this implementation, mounting holes are respectively provided on the fork-shaped portions at both ends of the fork-shaped screw 16, for mounting connecting pins 10 that are radially perpendicular to the axis of the mandrel 1 through the two mounting holes. The two connecting pins 10 are respectively connected to the end faces of the first tapered sleeve 17 and the second tapered sleeve 14 by nuts. For example, Figure 2 The connecting pin 10 installed on the mounting hole at the left end of the fork-type screw 16 is fixedly connected to the end face of the first tapered sleeve 17. Figure 2 The connecting pin 10 installed on the mounting hole at the right end of the fork-type screw 16 is fixedly connected to the end face of the second tapered sleeve 14.

[0058] In this implementation, the fork-shaped screw 16 moves axially along the mandrel 1, driving the first tapered sleeve 17 and the second tapered sleeve 14 to move axially via two connecting pins 10. This axial movement of the first tapered sleeve 17 and the second tapered sleeve 14 achieves the contraction or expansion of the first expansion block 7 and the second expansion block 15. It should be noted that this implementation uses two sets of expansion blocks with a longer axial length, and the two sets of tapered sleeves and expansion block assemblies provide better support for the inner wall of the conduit.

[0059] Furthermore, for a support clamp employing two sets of tapered sleeves and expansion block assemblies, it also includes: a hexagonal thin nut 18 and a limiting plate 19 disposed between the two sets of tapered sleeves and expansion block assemblies.

[0060] like Figure 3 As shown, Figure 1 The illustrated embodiment provides a schematic diagram of the mandrel in a support fixture for controlling the excess height of butt welds inside conduits. (Refer to...) Figure 2 and Figure 3 As shown, the outer circumference of the middle part of the mandrel 1 is provided with an external thread. A hexagonal thin nut 18 is screwed onto the mandrel 1 to form an annular shoulder. The limiting plate 19 is positioned and installed on the end face of the first expansion block 7 near the second tapered sleeve 14 by the nut, and the axial position of the limiting plate 19 and the first expansion block 7 is limited by the hexagonal thin nut 18. It should be noted that in this embodiment of the invention, the limiting plate 19 is already limited to the extreme position of the first tapered sleeve 17 by the hexagonal thin nut 18, and since the second tapered sleeve 14 and the first tapered sleeve 17 are linked by the fork-type screw 16, it is not necessary to set an axial limiting structure for the second tapered sleeve 14 separately.

[0061] In a specific implementation, the two ends of the spindle 1 are respectively provided with axially oriented waist-shaped holes, which are used for the connecting pins 10 at both ends of the fork-shaped screw 16 to pass through the corresponding waist-shaped holes, and serve as guide space for the axial movement of the connecting pins 10.

[0062] In one implementation of the present invention, a conical sleeve and expansion block assembly is provided. In each set of conical sleeve and expansion block assemblies, one set of conical sleeves includes at least two annular conical sleeves arranged in segments along the circumferential direction, which are spliced ​​together along the mandrel to form a conical structure. One set of expansion blocks includes at least two annular expansion blocks arranged in segments along the circumferential direction, which are spliced ​​together along the circumferential direction of the conical sleeve to form a conical wedge-shaped hole inside, which is used to cooperate with the conical structure of the conical sleeve.

[0063] In specific implementations, for example, it includes a 3-lobed annular cone sleeve with a 120-degree ring segment and a 3-lobed annular expansion block with a 120-degree ring segment.

[0064] In one embodiment of the present invention, in each set of cone sleeve and expansion block assembly, the plurality of annular expansion blocks used to form a set of expansion blocks are provided with at least one annular groove along the circumferential direction for placing a tightening mechanism in the annular groove so that when the fork screw 16 moves toward the side for shrinking the expansion block, the plurality of annular expansion blocks are tightened radially by the tightening mechanism so as to facilitate the removal of the support clamp from the welded conduit.

[0065] Furthermore, each set of cone sleeve and expansion block assembly also includes: tension spring 8, or tension spring 8 and tension spring rod 9.

[0066] In one embodiment, a tension spring 8 is installed in each annular groove of the plurality of annular expansion blocks to apply radial pressure to the plurality of annular expansion blocks around the perimeter.

[0067] In another embodiment, a plurality of tension spring rods 9 parallel to the axial direction are pressed into the outer cylindrical surface of the annular expansion block along the circumference of each annular groove, and a tension spring 8 is connected between adjacent tension spring rods 9 to apply radial pressure to the plurality of annular expansion blocks around the circumference.

[0068] In the above embodiment, when the expansion block contracts, the tension spring 8 contracts along the axis to cause the three-lobed annular expansion block to contract, making it easier to remove from the inner wall of the catheter.

[0069] In one implementation of this invention, in each set of conical sleeve and expansion block assemblies, each conical sleeve has multiple vent nozzles 11a arranged circumferentially and parallel to the axial direction on its end face, and each expansion block has a guide hole on its inner conical surface that connects the vent nozzles 11a to the weld position. Correspondingly, the column of the positioning sleeve 2 located outside the stepped hole is configured as a multi-level annular shoulder structure for connection with the three-jaw chuck for welding operations. The outer surface of the column at the other end of the positioning sleeve 2 is provided with a venting interface 11b and two symmetrically arranged mounting rings 11c.

[0070] In this implementation, the venting port 11b is used to connect the cavity between the venting nozzle 11a, the venting port 11b and the guide hole after the conduit is fitted on the support fixture, so as to deliver protective gas to each expansion block and the conduit, thereby providing gas protection during welding; the symmetrically arranged installation lifting rings 11c are used to lift and transport the support fixture and the conduit.

[0071] In one implementation of this invention, such as Figure 4 As shown, Figure 1 The illustrated embodiment provides a schematic diagram of the fork-shaped screw in a support fixture for controlling the excess height of butt welds inside conduits. (Refer to...) Figure 2 and Figure 4As shown, the fork-shaped screw 16 in this implementation includes a small-diameter rod in the middle and a large-diameter cylindrical rod fixedly connected to both ends of the small-diameter rod. A threaded hole is opened on the end face of the large-diameter cylindrical rod at one end for screwing with the external thread at the inner end of the screw 5. The fork-shaped screw 16 can be moved axially by rotating the screw 5.

[0072] For the circumferential welding and partial lug welding of small-diameter ducts in aircraft structures, this invention provides a support fixture for controlling the excess height of the butt weld inside the duct. It employs a mandrel 1 with a central shaft hole and a forked screw 16 disposed inside the mandrel 1. A connecting pin 10 connected to the forked screw 16 extends radially out of the mandrel 1 and is fixedly connected to a tapered sleeve sleeved outside the mandrel 1. An expansion block is fitted onto the outside of the tapered sleeve. Rotation of the screw 5 screwed to the forked screw 16 drives the forked screw 16 to move axially along the mandrel 1, thereby driving the tapered sleeve to move axially, achieving the contraction or expansion of the expansion block. Using this support fixture, the duct can be fitted with the expansion block in a contracted state. After fitting the duct, the expansion block is expanded by the axial movement of the forked screw 16, and the welding process is performed while the expansion block is expanded. This satisfies the requirement of supporting the inner wall of the duct during the duct welding process. After welding, the expansion block is expanded by the axial movement of the forked screw 16, and the duct is removed while the expansion block is contracted. The support fixture provided in this embodiment of the invention supports the inner wall of the conduit during welding by expanding the block, and in conjunction with filling the conduit with protective gas, controls the weld reinforcement during the welding process, thereby improving the welding quality and fatigue life of the conduit.

[0073] Based on the support fixture for controlling the excess height of butt welds inside the duct provided in the above embodiments of the present invention, the present invention also provides a welding method for controlling the excess height of butt welds inside the duct. The support fixture for controlling the excess height of butt welds inside the duct provided in any of the above embodiments can be used to support the aircraft duct to facilitate welding operations. For example, in the embodiments of the present invention, the following method is used: Figure 2 The support clamp shown includes two sets of conical sleeve and expansion block assemblies, each comprising: a first conical sleeve 17 and a first expansion block 7 for mating use, and a second conical sleeve 14 and a second expansion block 15 for mating use. The welding method provided in this embodiment of the invention includes the following implementation steps:

[0074] Step 1: Rotate the screw 5 clockwise or counterclockwise to drive the fork screw 16 to move axially toward one end of the screw 5, thereby driving the connecting pin 10 to move toward the same end, and driving the first cone sleeve 17 and the second cone sleeve 14 to move toward the same end, so that the first expansion block 7 and the second expansion block 15 contract simultaneously.

[0075] Step 2: Insert the entire shaft of the mandrel 1 of the support clamp into the conduit, and fit the conduit connector 12 at one end of the conduit onto the end of the positioning sleeve 2 to fix the relative position of the conduit and the mandrel 1. Place the first expansion block 7 and the second expansion block 15 in the conduit at the position to be supported for welding.

[0076] Step 3: Rotate screw 5 counterclockwise or clockwise to drive fork screw 16 to move axially away from screw 5, drive connecting pin 10 to the same end, and drive first cone sleeve 17 and second cone sleeve 14 to the same end, so that first expansion block 7 and second expansion block 15 expand simultaneously, supporting first expansion block 7 and second expansion block 15 on the inner wall of the position to be welded on conduit 12;

[0077] Step 4: The support fixture and the guide tube assembled through it are installed as a whole on the three-jaw chuck of the welding equipment turntable through the positioning sleeve 2. After clamping, the welding robot is used to perform welding operation on the part to be welded.

[0078] Step 5: After the welding operation is completed, remove the support clamp and the conduit together. Rotate the screw 5 of the support clamp clockwise or counterclockwise to shrink the expansion block in the support clamp, and then remove the entire support clamp from the conduit.

[0079] In one implementation of this invention, the placement positions of the first expansion block 7 and the second expansion block 15 in step 2 are, for example, the circumferential welding positions of the two conduits, or the portion 13 of a local ear piece of a single conduit.

[0080] Accordingly, in step 4, the circumferential welding position of the conduit or the local lug of the conduit is welded using a support clamp and fixedly installed on the welding equipment. During the welding process, protective gas is introduced through the vent connector 11b and the vent nozzle 11a to provide gas protection during the welding operation.

[0081] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A support clamp for controlling the excess height of butt welds inside conduits, characterized in that, include: The mandrel (1), positioning sleeve (2), positioning seat (3), locking seat (4), screw (5), locking nut (6), fork screw (16), connecting pin (10), and at least one set of tapered sleeve and expansion block assembly; The positioning sleeve (2) has a stepped hole on its axis, and the mandrel (1) has a central shaft hole along its axis. A fork-shaped screw (16) is placed in the central shaft hole. The central shaft hole at one end of the mandrel (1) is set as a stepped shaft hole, and the outer side of the stepped shaft hole at this end is set as a stepped shaft structure. The mandrel (1) is nested in the stepped shaft hole of the positioning sleeve (2) through its stepped shaft structure, so as to restrict the axial movement of the mandrel (1) through the positioning sleeve (2). The screw (5) with a flange in the middle passes through the middle through hole of the positioning seat (3) and is positioned by its flange. Installed on the outer end face of the positioning seat (3), so that the screw (5) is positioned and installed in the central shaft hole of the mandrel (1) through the positioning seat (3), so as to restrict the axial position of the positioning seat (3) and the screw (5) through the stepped hole of the mandrel (1). The screw (5) extends into the inner end of the mandrel (1) and is screwed and fixed to the fork-shaped part of one end of the fork-shaped screw (16). The locking seat (4) is sleeved on the screw (5) and abuts against the outer end face of its flange. The locking nut (6) screwed on the outer end of the screw (5) presses the screw (5) onto the positioning seat (3). Each set of the conical sleeve and expansion block assembly includes: a conical sleeve and an expansion block configured as circumferentially split structures; the conical sleeve is fitted on the outside of the mandrel (1) and has an outer conical surface, and the expansion block is fitted on the outside of the conical sleeve and has an inner conical surface that compensates for the structure of the outer conical surface of the conical sleeve; at least one end of the fork-shaped screw (16) has a mounting hole for installing a connecting pin (10) that is radially perpendicular to the axis of the mandrel (1), and the connecting pin (10) is fixedly connected to the end face of the conical sleeve by a nut; The entire conduit to be welded is fitted over the expansion block, and is fitted over one end of the positioning sleeve (2) through the annular groove of the flange at the end of the conduit connector (12) to restrict the axial position of the conduit; by turning the screw (5) to drive the fork screw (16) to move axially along the mandrel (1), and by connecting pin (10) to drive the tapered sleeve to move axially along the mandrel (1), thereby realizing the contraction or expansion of the expansion block.

2. The support clamp for controlling the excess height of butt welds inside a conduit according to claim 1, characterized in that, Specifically, it includes two sets of conical sleeves and expansion block assemblies, including: a first conical sleeve (17) and a first expansion block (7), as well as a second conical sleeve (14) and a second expansion block (15); the first conical sleeve (17) is sleeved on the outside of the mandrel (1) and has an outer conical surface, the first expansion block (7) is sleeved on the outside of the first conical sleeve (17) and has an inner conical surface that compensates for the structure of the outer conical surface of the first conical sleeve (17); the second conical sleeve (14) is sleeved on the outside of the mandrel (1) and has an outer conical surface, the second expansion block (15) is sleeved on the outside of the second conical sleeve (14) and has an inner conical surface that compensates for the structure of the outer conical surface of the second conical sleeve (14); The fork-shaped screw (16) has mounting holes on its fork-shaped portions at both ends, which are used to install connecting pins (10) that are radially perpendicular to the axis of the spindle (1) through the two mounting holes. The two connecting pins (10) are respectively connected to the end faces of the first tapered sleeve (17) and the second tapered sleeve (14) by nuts. The fork-shaped screw (16) moves axially along the spindle (1), and through two connecting pins (10), it drives the first cone sleeve (17) and the second cone sleeve (14) to move axially, thereby realizing the contraction or expansion of the first expansion block (7) and the second expansion block (15).

3. The support clamp for controlling the excess height of the butt weld inside the conduit according to claim 2, characterized in that, Also includes: Hexagonal thin nuts (18) and limiting plates (19) are provided between the two sets of tapered sleeves and expansion block assemblies; The spindle (1) has an external thread on the outer periphery of the middle part of the shaft body. A hexagonal thin nut (18) on the spindle (1) shaft body is screwed to form an annular shoulder. The limiting plate (19) is positioned and installed on the side end face of the first expansion block (7) near the second tapered sleeve (14) by the nut, and the axial position of the limiting plate (19) and the first expansion block (7) is limited by the hexagonal thin nut (18). The mandrel (1) has axially oriented oblong holes at both ends of its shaft body, which are used for the connecting pins (10) at both ends of the fork screw (16) to pass through the oblong holes at the corresponding positions.

4. The support clamp for controlling the excess height of butt welds inside a conduit according to any one of claims 1 to 3, characterized in that, In each set of the conical sleeve and expansion block assembly, one set of conical sleeves includes at least two annular conical sleeves arranged in circumferential segments, which are spliced ​​together in the circumferential direction along the mandrel (1) to form a conical structure. One set of expansion blocks includes at least two annular expansion blocks arranged in circumferential segments, which are spliced ​​together in the circumferential direction along the conical sleeve to form a conical wedge-shaped hole inside, which is used to cooperate with the conical structure of the conical sleeve.

5. The support clamp for controlling the excess height of the butt weld inside the conduit according to claim 4, characterized in that, In each set of the conical sleeve and expansion block assembly, the multiple annular expansion blocks used to form a set of expansion blocks are provided with at least one annular groove along the circumferential direction for placing a tightening mechanism in the annular groove so as to tighten the multiple annular expansion blocks radially by the tightening mechanism when the fork screw (16) moves toward the side for shrinking the expansion block, so as to facilitate the removal of the support clamp from the welded conduit.

6. The support clamp for controlling the excess height of the butt weld inside the conduit according to claim 5, characterized in that, The tightening mechanism includes: a tension spring (8), or a tension spring (8) and a tension spring rod (9); In each annular groove of the plurality of annular expansion blocks, a tension spring (8) is installed around the perimeter to apply radial pressure to the plurality of annular expansion blocks around the perimeter; or, On the outer cylindrical surface of the annular expansion block, multiple tension spring rods (9) parallel to the axial direction are pressed into each annular groove. A tension spring (8) is connected between adjacent tension spring rods (9) to apply radial pressure to the multiple annular expansion blocks around the circumference.

7. The support clamp for controlling the excess height of butt welds inside a conduit according to any one of claims 1 to 3, characterized in that, In each set of cone sleeve and expansion block assembly, each cone sleeve has multiple vent nozzles (11a) circumferentially parallel to the axial direction on its end face, and each expansion block has a guide hole on its inner cone surface that connects the vent nozzles (11a) to the weld position. The positioning sleeve (2) has a multi-level annular shoulder structure on the column outside the stepped hole, which is used to connect with the three-jaw chuck for welding. The outer surface of the column at the other end of the positioning sleeve (2) is provided with a venting port (11b) and two symmetrically arranged mounting rings (11c). The venting port (11b) is used to connect the cavity between the venting nozzle (11a), the venting port (11b) and the guide hole after the guide tube is fitted on the support fixture, so as to deliver protective gas to each expansion block and the guide tube, thereby providing gas protection during welding. The symmetrically arranged mounting rings (11c) are used to lift and transport the support fixture and the guide tube.

8. The support clamp for controlling the excess height of butt welds inside a conduit according to any one of claims 1 to 3, characterized in that, The fork-shaped screw (16) includes a small-diameter rod in the middle and a large-diameter cylindrical rod fixedly connected to both ends of the small-diameter rod. A threaded hole is opened on the end face of the large-diameter cylindrical rod at one end for screwing with the external thread of the inner end of the screw (5). The fork-shaped screw (16) can move axially by rotating the screw (5).

9. A welding method for controlling the reinforcement height of butt welds inside conduits, characterized in that, The aircraft duct is supported by a support fixture as described in any one of claims 1 to 8 for controlling the excess height of the butt weld inside the duct, in order to facilitate the welding operation; The support fixture comprises two sets of tapered sleeves and expansion blocks, each including a first tapered sleeve (17) and a first expansion block (7) for use, and a second tapered sleeve (14) and a second expansion block (15) for use; the welding method includes: Step 1: Rotate the screw (5) clockwise or counterclockwise to drive the fork screw (16) to move axially toward one end of the screw (5), thereby driving the connecting pin (10) to move toward the same end, and driving the first cone sleeve (17) and the second cone sleeve (14) to move toward the same end, so that the first expansion block (7) and the second expansion block (15) contract simultaneously. Step 2: Insert the entire shaft of the mandrel (1) of the support fixture into the conduit, and put the conduit connector (12) at one end of the conduit onto the end of the positioning sleeve (2) to fix the relative position of the conduit and the mandrel (1). Place the first expansion block (7) and the second expansion block (15) in the conduit at the position to be supported and welded. Step 3: Rotate the screw (5) counterclockwise or clockwise to drive the fork screw (16) to move axially away from the end of the screw (5), drive the connecting pin (10) to move to the same end, and drive the first cone sleeve (17) and the second cone sleeve (14) to move to the same end, so that the first expansion block (7) and the second expansion block (15) expand simultaneously, and support the first expansion block (7) and the second expansion block (15) on the inner wall of the conduit to be welded; Step 4: The support fixture and the guide tube assembled through it are installed as a whole structure on the three-jaw chuck of the welding equipment turntable through the positioning sleeve (2). After clamping, the welding robot is used to perform welding operation on the part to be welded. Step 5: After the welding operation is completed, remove the support clamp and the conduit together. Rotate the screw (5) of the support clamp clockwise or counterclockwise to shrink the expansion block in the support clamp and then remove the entire support clamp from the conduit.

10. The welding method for controlling the reinforcement height of butt welds inside a conduit according to claim 9, characterized in that, The support clamp supporting the aircraft duct is the support clamp for controlling the excess height of the butt weld inside the duct as described in claim 7; In step 4, the circumferential welding position of the conduit or the local lug of the conduit, which is supported and fixedly installed on the welding equipment by a support clamp, is welded. During the welding process, protective gas is introduced through the venting port (11b) and the venting nozzle (11a) to provide gas protection during the welding operation.

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