Correcting tool and method for welding deformation of high-temperature oxidizable rib skin structure

Abstract

The present application relates to the technical field of welding, in particular to a kind of correction tool and method for high-temperature easy oxidizable rib skin structure welding deformation.The tool includes pull rod, crossbeam frame, pressing plate and support seat, the two ends of pull rod are respectively fixedly connected with the end face of the crossbeam of crossbeam frame, the end face of pressing plate away from rib skin welding piece, the gap part formed between pressing plate and support seat is used to place rib skin welding piece;Pull rod includes rod body and pull rod seat connected to the two ends of rod body respectively, and the surface of rod body is provided with heat insulation layer.The purpose of the correction tool and method for high-temperature easy oxidizable rib skin structure welding deformation is to solve the problem that the laser welding deformation of rib skin structure composed of titanium alloy is difficult to eliminate.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and specifically to a tooling and method for correcting welding deformation of high-temperature, easily oxidized rib skin structures. Background Technology

[0002] To increase structural stiffness, thin-walled skins are typically welded with longitudinally and transversely distributed stiffeners, such as... Figure 1 As shown. For ease of description, the longitudinally distributed stiffeners in this specification are referred to as stringers, and the transversely distributed stiffeners as bulges. The stringers and bulges are perpendicular to each other and form a T-joint with the skin. This T-joint will produce angular deformation during welding, and even laser welding cannot completely avoid this deformation. The angular deformation of the T-joint is shown below. Figure 2 As shown, after welding, the skin on both sides of the stiffener bends upward, making the angle between the stiffener and the skin smaller than the initial angle before welding. Once this deformation occurs, it is difficult to eliminate in subsequent stages. Even with prolonged post-weld heat treatment, it cannot be completely eliminated effectively. This deformation significantly damages the appearance and performance of the product. Therefore, measures need to be taken to avoid angular deformation.

[0003] The correction of welding deformation must be carried out at the plastic temperature of the material; otherwise, there is a significant risk of cracking and rendering the part unusable. The same applies to the correction of ribbed skin structures. If the material is composed of easily oxidized materials (such as titanium alloys), the heat treatment of the part must be carried out under vacuum conditions, i.e., in a vacuum furnace, to avoid oxidation. In this case, it is impossible to apply external force to the part for correction, mainly because the condition that correction can only be performed after the part has reached its plastic temperature cannot be met.

[0004] Therefore, the inventors have provided a tooling and method for correcting welding deformation of high-temperature, easily oxidized rib skin structures. Summary of the Invention

[0005] (1) Technical problems to be solved

[0006] This invention provides a tooling and method for correcting welding deformation of high-temperature, easily oxidized rib skin structures, solving the technical problem that laser welding deformation of rib skin structures made of titanium alloy is difficult to eliminate.

[0007] (2) Technical solution

[0008] A first aspect of the present invention provides a straightening fixture for welding deformation of a high-temperature, easily oxidized rib skin structure, comprising a tie rod, a crossbeam frame, a pressure plate, and a support base. The two ends of the tie rod are respectively fixedly connected to the crossbeam of the crossbeam frame and the end face of the pressure plate away from the rib skin weldment. The gap formed between the pressure plate and the support base is used to place the rib skin weldment; wherein...

[0009] The pull rod includes a rod body and pull rod seats respectively connected to both ends of the rod body, and the surface of the rod body is provided with a heat insulation layer.

[0010] Furthermore, the cross-sectional area of ​​the rod is inversely correlated with the yield strength of the rod material and the number of rods, and positively correlated with the weight of the pressure plate.

[0011] Furthermore, the formula for calculating the cross-section of the rod is as follows:

[0012]

[0013] In the formula, ψ is the index, and σ is the index. sT Let n be the yield strength of the tie rod material, n be the number of tie rods, S be the cross-sectional area of ​​each tie rod, and G be the weight of the pressure plate.

[0014] Furthermore, all the pull rod seats are made of ceramic.

[0015] Furthermore, the pressure plate includes a flat plate and vertical plates, and multiple vertical plate groups are sequentially and spaced apart on the end face of the flat plate facing the rib skin weldment. Each vertical plate group includes two vertical plates with a set gap, and the ribs of the rib skin weldment are located between two adjacent vertical plates.

[0016] Furthermore, the support base has a plurality of support plates on its first end face facing the rib skin weldment, which correspond one-to-one with the ribs of the rib skin weldment. A positioning block for positioning the rib skin weldment is provided at the corner of the first end face. The support plates and the positioning blocks are at the same height.

[0017] Furthermore, the axis of each of the support plates coincides with the axis of the corresponding rib.

[0018] Furthermore, the vertical portion of the crossbeam frame is fixed to both sides of the support base.

[0019] A second aspect of the present invention provides a correction method using the above-described correction fixture for welding deformation of a high-temperature, easily oxidized rib skin structure, comprising the following steps:

[0020] After the high-temperature and easily oxidized rib skin weldment is installed in the straightening fixture, it is placed in a vacuum furnace for heat treatment.

[0021] When the high-temperature easily oxidized rib skin weldment is heated to the plastic temperature, the tie rod undergoes tensile deformation, and the pressure plate descends to exert downward pressure on the skin of the high-temperature easily oxidized rib skin weldment to complete the deformation correction.

[0022] Furthermore, the initial distance between the pressure plate and the high-temperature easily oxidized rib skin weldment is a preset value.

[0023] (3) Beneficial effects

[0024] In summary, this invention, through a specially designed tie rod structure, allows the straightening force to be applied after the temperature of the welded joint of the part reaches the heat treatment temperature, thus ensuring safe and reliable straightening. After the temperature of the welded part reaches the heat treatment temperature, the straightening action automatically begins, solving the problem that vacuum heat treatment cannot intervene in straightening. Straightening and post-weld heat treatment are completed simultaneously without adding any extra steps. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a high-temperature, easily oxidized rib skin structure;

[0027] Figure 2 This is a schematic diagram of the deformation of the T-shaped joint angle;

[0028] Figure 3 This is a schematic diagram of a correction fixture for welding deformation of a high-temperature, easily oxidized rib skin structure provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of a support seat in a straightening fixture provided in an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the structure of a straightening fixture and a weldment being installed together, according to an embodiment of the present invention.

[0031] Figure 6 This is a schematic diagram of the structure of a pressure plate in a straightening fixture provided in an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the support seat in another straightening fixture provided in an embodiment of the present invention;

[0033] Figure 8 This is an assembly diagram of the pressure plate and rib skin structure in another straightening fixture provided in this embodiment of the invention;

[0034] Figure 9 This is a schematic diagram of the structure of the support seat in another type of straightening fixture provided in an embodiment of the present invention;

[0035] Figure 10 This is a first-view structural schematic diagram of the pressure plate in another type of straightening fixture provided in this embodiment of the invention;

[0036] Figure 11 This is a second-view structural schematic diagram of the pressure plate in another type of straightening fixture provided in this embodiment of the invention;

[0037] Figure 12 This is a flowchart illustrating a method for correcting welding deformation of a high-temperature, easily oxidized rib skin structure, provided by an embodiment of the present invention.

[0038] In the picture:

[0039] 1-Tie rod; 101-Rib body; 102-Tie rod seat; 2-Crossbeam frame; 3-Pressure plate; 301-Flat plate; 302-Upright plate; 4-Support seat; 401-Support plate; 402-Positioning block; 100-Rib skin weldment. Detailed Implementation

[0040] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments, and any modifications, substitutions and improvements to the parts, components and connection methods are covered without departing from the spirit of the present invention.

[0041] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0042] Figure 3 This is a schematic diagram of a correction fixture for welding deformation of a high-temperature, easily oxidized rib skin structure provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the straightening fixture may include a tie rod 1, a crossbeam frame 2, a pressure plate 3, and a support base 4. The two ends of the tie rod 1 are fixedly connected to the crossbeam frame 2 and the end face of the pressure plate 3 away from the rib skin weldment 100, respectively. The gap formed between the pressure plate 3 and the support base 4 is used to place the rib skin weldment 100. The tie rod 1 includes a rod body 101 and tie rod seats 102 connected to both ends of the rod body 101. The surface of the rod body 101 is provided with a heat insulation layer.

[0043] In the above embodiment, the weldment is installed before heat treatment, and the tie rod 1 pulls the pressure plate 3 to prevent it from exerting force on the part. Since the yield strength of metallic materials decreases with increasing temperature, the yield strength of the tie rod 1 will decrease as the temperature rises after the weldment is placed in the vacuum heat treatment furnace. To ensure that the straightening effect is performed when the temperature of the weldment reaches above the plastic temperature, i.e., to delay the temperature rise of the tie rod 1, heat insulation material is wrapped around the tie rod 1 beforehand.

[0044] Tie rod 1 is a replaceable part, made of heat-resistant stainless steel. Under the condition that the heat insulation material and thickness are determined, its cross-sectional dimensions are set according to formula (1):

[0045]

[0046] In the formula, ψ is the index, and σ is the index. sT denoted as , where is the yield strength of the tie rod material at the heat treatment temperature, n is the number of tie rods, S is the cross-sectional area of ​​each tie rod, and G is the weight of the pressure plate.

[0047] As can be seen from formula (1), when the yield strength σ of the tie rod material is... sT After determining the number of tie rods n, the weight of the pressure plate G, etc., the ψ index changes with the cross-sectional area S of the tie rod. Different ψ values ​​are obtained by formula (1) using different cross-sectional areas S. Then, the pull-down delay time corresponding to the ψ value is obtained by thermo-elastic-plastic finite element calculation, which is listed in Table 1. Since the ψ value is a function of the cross-sectional area S of the tie rod, the delay time is also a function of the cross-sectional area S of the tie rod.

[0048] Table 1 shows the relationship between ψ and pull-down delay time.

[0049] Serial Number ψ Delay time (s) Effect 1 0.658 >6000 Too long 2 0.365 5000s longer 3 0.292 4000s Moderate 4 0.219 3000s Moderate 5 0.146 2000s shorter 6 0.0731 1000s too short

[0050] As shown in Table 1, based on the required delay time, the corresponding range of ψ values ​​is first found, and the ψ value is obtained through appropriate interpolation. Then, the cross-sectional area of ​​the tie rod is calculated according to formula (1). For example, if the required delay time is 1 hour, i.e. 3600s, the ψ value is found to be between 0.292 and 0.219 from Table 1. Through linear interpolation, the ψ value corresponding to 3600s is 0.2628. Substituting this value into formula (1) yields the cross-sectional area of ​​the tie rod, and the radius is then calculated from the cross-sectional area.

[0051] After the stringer is straightened, the partition frame is welded. Following this, another heat treatment and straightening process is performed. At this point, the part consists of the skin, stringer, and partition frame. During the heat treatment and straightening process, the following method is used: Figure 7 The support base 4 shown and Figure 8 The pressure plate 2 shown is similar to the stringer straightening in other aspects. It also achieves straightening by controlling the deformation of the pressure plate 2 by its own weight and the tie rod 1.

[0052] If no heat treatment is performed between the stringer and the diaphragm, and the diaphragm is welded after the stringer is welded, then heat treatment and straightening are performed after both the stringer and the diaphragm are completely welded. Figure 9 The support base 4 shown and Figure 10 The pressure plate 3 shown is similar in structure to the one described above.

[0053] As an optional implementation, the tie rod seat is made of ceramic. The ceramic material prevents the beam frame 2 and pressure plate 3 from transferring heat to the rod body through the tie rod seat after they are heated, thus slowing down the heating rate of the rod body and ensuring that the weldment reaches the heat treatment temperature first.

[0054] As an optional implementation method, such as Figure 6 As shown, the pressure plate 3 includes a flat plate 301 and a vertical plate 302. Multiple vertical plate groups are arranged sequentially at intervals on the end face of the flat plate 301 facing the rib skin weldment 100. Each vertical plate group includes two vertical plates 302 with a set gap. The ribs of the rib skin weldment 100 are located between two adjacent vertical plates 302.

[0055] The specific structure of pressure plate 3 is not limited, such as... Figure 8 , 10 As shown in Figure 11, the structure should be compatible with the upper surface of the rib skin weldment 100, as long as it can provide sufficient pressure for applying pressure to the rib skin weldment 100. To prevent lateral misalignment due to different coefficients of thermal expansion, the plate 301 is made of a material (or titanium alloy) with a coefficient of thermal expansion similar to that of titanium alloy. Unless otherwise specified, other structures are made of heat-resistant stainless steel.

[0056] As an optional implementation method, such as Figure 4 As shown, the support base 4 has a plurality of support plates 401 on the first end face facing the rib skin weldment 100, which correspond one-to-one with the ribs of the rib skin weldment 100. The corner of the first end face is provided with a positioning block 402 for positioning the rib skin weldment 100. The support plates 401 and the positioning blocks 402 are at the same height.

[0057] The specific structure of support base 4 is not limited, such as Figure 4 , 7 As shown in Figure 9, as long as it can satisfy the support and positioning of the rib skin weldment 100, its structure should be adapted to the lower surface of the rib skin weldment 100.

[0058] As an optional implementation method, such as Figure 5 As shown, the axis of each support plate 401 coincides with the axis of the corresponding rib. This design ensures a one-to-one correspondence between the support plate 401 and the rib of the rib skin weldment 100, thereby achieving a compressive effect.

[0059] As an optional implementation method, such as Figure 3 As shown, the vertical parts of the crossbeam frame 2 are fixed to both sides of the support base 4. Specifically, the specific installation method of the crossbeam frame 2 is not limited, as long as the crossbeam frame 2 can be fixed to the support base 4 while the tie rod 1 is suspended, so as to realize the pulling of the tie rod 1 on the pressure plate 3.

[0060] Figure 12 This is a flowchart illustrating a correction method provided in an embodiment of the present invention, as shown below. Figure 12 As shown, the method may include the following steps:

[0061] S100. After installing the high-temperature easily oxidized rib skin weldment into the straightening fixture, place the whole assembly in a vacuum furnace for heat treatment.

[0062] S200. When the high-temperature easily oxidized rib skin weldment is heated to the plastic temperature, the tie rod undergoes tensile deformation, and the pressure plate descends to exert downward pressure on the skin of the high-temperature easily oxidized rib skin weldment to complete the deformation correction.

[0063] In the above embodiment, while the part is placed in a vacuum furnace for heat treatment, after a time delay, the rib skin weldment 100 is heated to the plastic temperature, and an appropriate amount of straightening force is automatically applied to the rib skin weldment 100 to complete the correction of welding deformation, and at the same time, the post-weld heat treatment is completed to eliminate residual stress.

[0064] As an optional implementation, the initial distance between the pressure plate and the high-temperature, easily oxidized rib skin weldment is a preset value. Specifically, considering the thermal expansion and deformation of the material, a allowance is preset in the initial distance between the pressure plate 3 and the rib skin weldment 100 during heat treatment loading to prevent the pressure plate from applying pressure to the weldment due to thermal expansion during the heating process. When the required delay time is reached, the weldment as a whole has reached the heat treatment temperature, the tie rod 1 begins to stretch and deform, and the pressure plate 3 begins to exert downward pressure on the rib skin weldment 100, producing an appropriate downward pressure effect that eliminates existing deformation without causing new deformation.

[0065] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0066] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A straightening fixture for welding deformation of a high-temperature, easily oxidized rib skin structure, characterized in that, The assembly includes a tie rod (1), a crossbeam frame (2), a pressure plate (3), and a support base (4). The two ends of the tie rod (1) are fixedly connected to the crossbeam of the crossbeam frame (2) and the end face of the pressure plate (3) away from the rib skin weldment (100), respectively. The gap formed between the pressure plate (3) and the support base (4) is used to place the rib skin weldment (100). The pull rod (1) includes a rod body (101) and pull rod seats (102) respectively connected to both ends of the rod body (101). The surface of the rod body (101) is provided with a heat insulation layer, and the pull rod seat (102) is made of ceramic material. The formula for calculating the cross-section of the rod (101) is as follows: ； In the formula, ψ is an index. σ sT The yield strength of the tie rod material. n Number of levers S The cross-sectional area of ​​each tie rod. G This is the weight of the pressure plate.

2. The straightening fixture for welding deformation of high-temperature easily oxidized rib skin structures according to claim 1, characterized in that, The pressure plate (3) includes a flat plate (301) and a vertical plate (302). Multiple vertical plate groups are arranged sequentially at intervals on the end face of the flat plate (301) facing the rib skin weldment (100). Each vertical plate group includes two vertical plates (302) with a set gap. The ribs of the rib skin weldment (100) are located between two adjacent vertical plates (302).

3. The straightening fixture for welding deformation of high-temperature easily oxidized rib skin structures according to claim 1, characterized in that, The support base (4) has a plurality of support plates (401) on the first end face facing the rib skin weldment (100) that correspond one-to-one with the ribs of the rib skin weldment (100). The corner of the first end face is provided with a positioning block (402) for positioning the rib skin weldment (100). The support plate (401) and the positioning block (402) are at the same height.

4. The straightening fixture for welding deformation of high-temperature easily oxidized rib skin structures according to claim 3, characterized in that, The axis of each of the support plates (401) coincides with the axis of the corresponding rib.

5. The straightening fixture for welding deformation of high-temperature easily oxidized rib skin structures according to claim 1, characterized in that, The vertical part of the crossbeam frame (2) is fixed to both sides of the support base (4).

6. A method for correcting welding deformation of a high-temperature, easily oxidized rib skin structure using a correcting fixture as described in any one of claims 1-5, characterized in that, The method includes the following steps: After the high-temperature and easily oxidized rib skin weldment is installed in the straightening fixture, it is placed in a vacuum furnace for heat treatment. When the high-temperature easily oxidized rib skin weldment is heated to the plastic temperature, the tie rod undergoes tensile deformation, and the pressure plate descends to exert downward pressure on the skin of the high-temperature easily oxidized rib skin weldment to complete the deformation correction.

7. The correction method according to claim 6, characterized in that, The initial distance between the pressure plate and the high-temperature, easily oxidized rib skin weldment is a preset value.

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