A double-edge inclined-angle special-shaped frame staggered roll-bending forming process method of a carrier rocket

Abstract

The application provides a double-side inclined-angle special-shaped frame staggered distance roll bending forming process method of a carrier rocket, and comprises the following steps: S1, blanking of a profile frame part; S2, segmented staggered distance roll bending forming of the profile frame part based on a roll bending equipment; S3, cutting allowance of the profile frame part; S4, machining of the profile frame part; and S5, finishing of the profile frame part. The application has the beneficial effects that the double-side inclined-angle special-shaped frame adopts the segmented staggered distance roll bending forming method, the precision of the part after roll bending is high, the internal stress concentration is small, the end lifting amount after machining is small, the forming precision of the part is greatly improved in combination with the segmented flattening method of the displacement movement mode of a hydraulic press, the radius gap after roll bending forming is 0.4 mm, the angle gap is 0.3 mm, and the flatness gap is 0.5 mm, which is higher than the drawing and bending forming precision, the radius gap after manual finishing of the drawing and bending forming is 1.5 mm, the angle gap is 1 mm, and the flatness gap is 1.5 mm.

Description

Technical Field

[0001] This invention belongs to the field of irregular frame roll bending forming technology, and in particular relates to a roll bending forming process for a double-sided oblique irregular frame of a launch vehicle with staggered spacing. Background Technology

[0002] A double-sided beveled irregular frame, located in the conical section of a launch vehicle fairing, consists of two semi-circular frames forming a single frame. Due to its separability and high precision requirements, it is currently manufactured using a stretch bending process. This frame profile has a unique cross-section. While a normal frame profile is an angled member with one bottom edge and one vertical edge, this frame has two edges, one at the top and one at the bottom, with the vertical edge being a beveled edge at a significant angle of 64°. It is also thicker, measuring 8mm, and its cross-section resembles a "C" shape. The part's cross-section is shown below. Figure 1 As shown in (a), the part has a semi-circular outline with a large end radius of R2500mm. Figure 1 As shown in (b), the profile frame is formed in a special way. Normal profile frames can be delivered directly after being drawn and formed, but this profile frame needs to have 5 drainage slots machined at the bottom of the small end after being drawn and formed, with a width of 10mm and a height of 2mm.

[0003] The original forming process for this profile frame was a tension bending process. The forming process flow was as follows: pre-tension bending forming—quenching—replenishment tension bending forming and trimming—artificial aging—trimming—machining—trimming—inspection—packaging and delivery. This process involved many steps, and due to the special cross-section of the profile frame, multiple drainage grooves needed to be machined, resulting in several forming problems, as follows:

[0004] (1) Bending accuracy issue: Because the vertical side of the part is a slanted side with unequal lengths on the upper and lower sides, the cross-section twists after bending. The gap between the slanted side and the angle template is approximately 4mm (the technical specification requires an angle gap ≤1mm). The cross-sectional deformation is as follows: Figure 2 As shown. Subsequent manual adjustments are required. Normal profiles have only one bottom edge and one vertical edge. The angle and curvature of the vertical edge can be corrected manually. This profile has two edges, one at the top and one at the bottom, which fixes the sloping edge, causing the angle and radius of the middle sloping edge to be out of tolerance, making subsequent manual adjustments more difficult.

[0005] (2) Machining Deformation Issues: The profile frame has a unique surface with five drainage groove notches at the bottom. After bending, the drainage grooves need to be machined. Due to the poor precision of the profile after bending, the amount of manual finishing is large, and internal stress is concentrated. After machining, the internal stress of the profile is released, and the surface undergoes severe deformation. The main issue is that the bottom plane of the profile at one end gradually warps up, with a warping amount of up to 23mm (the technical specification requires a flatness gap of ≤1.5mm). Because this profile is thick and has both upper and lower double-sided profiles, the warping at the end makes manual finishing difficult, resulting in a high scrap rate for parts.

[0006] If the profile is rolled and bent, the profile frame has a special cross section. If the normal rolling and bending method is used, the rollers are all on the same plane. However, due to the asymmetrical cross section of the part and the inclined edge, the uneven force on the upper and lower sides of the rolled and bent profile cross section will cause it to twist, making it impossible to form a part with qualified dimensions.

[0007] Therefore, this invention proposes a segmented upper and lower staggered roll bending forming method to counteract uneven force on the upper and lower sides and prevent profile twisting. Combined with the end displacement mode segmented flattening method, the end warping is corrected, and high-precision parts are formed. Summary of the Invention

[0008] In view of this, the present invention aims to propose a staggered roll bending forming process for a double-sided angled irregular frame of a launch vehicle, to solve the problems of low forming accuracy, warping and deformation of the bottom plane after machining, high difficulty in manual repair, and high scrap rate of parts when using the existing stretch bending forming process for double-sided angled irregular frames. The invention employs a segmented staggered roll bending forming method for this profile frame, combined with a segmented flatness correction method, optimizing mold design, and rationally designing roll bending process parameters and flatness correction process parameters to produce parts with high dimensional accuracy.

[0009] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0010] A method for forming a double-sided oblique irregular frame of a launch vehicle by staggered roll bending includes the following steps:

[0011] S1. Cutting the profile frame parts;

[0012] S2. Segmented staggered roll bending forming of profile frame parts based on roll bending equipment;

[0013] S3. Cutting allowance for profile frame parts:

[0014] The excess material at both ends of the profile frame part is removed by cutting with a saw. The total excess material at both ends is 1000mm.

[0015] S4. Machining of profile frame parts:

[0016] The bottom of the small end of the machined profile frame part has a drainage groove with a width of 10mm and a height of 2mm.

[0017] S5. Trimming of profile frame parts:

[0018] After machining, the internal stress of the profile frame part is released, and one end is slightly raised by 10mm. The internal stress is less than the 23mm raised amount during bending.

[0019] The profile frame parts are flattened in sections using a hydraulic press displacement movement mode.

[0020] Furthermore, the bending equipment is a four-axis horizontal bending machine. The roller mold of the four-axis horizontal bending machine includes a front middle roller, a rear middle roller, a left roller, a right roller, a left pressure roller, and a right pressure roller. The front middle roller and the rear middle roller are respectively installed at the front and rear of the middle part of the profile frame part, and the left roller, the right roller, the left pressure roller, and the right pressure roller are respectively installed on the left and right sides of the profile frame part.

[0021] Furthermore, the straight edges and small rounded corner radii of the middle and rear rollers, left rollers, and right rollers are all changed to inclined edges and large rounded corner radii. The rounded corner radii are changed from R2 to R6, the straight edges are changed to inclined edges, and the inclined edge parameters are 0.5mm vertically and 20mm horizontally. In addition, a 1mm gap is left between the upper and lower sides of the profile frame parts and the roller mold to facilitate material extension.

[0022] Furthermore, in step S1, the profile frame part is cut, including:

[0023] The profile frame parts are cut into blanks with a length of 8854mm using a saw, the length including the part length of 7854mm and a allowance of 1000mm.

[0024] Furthermore, in step S2, the profile frame part is subjected to segmented staggered roll bending forming based on the roll bending equipment, including:

[0025] The arc length of the profile frame parts is divided into segments, and staggered rolling bending process parameters are set for each segment to reduce the gradual torsion of the vertical edge angle.

[0026] The precision technical indicators for profile frame parts after roll bending are three items: the part radius deviation ≤ 1.5mm, the gap between the inclined side and the angle template ≤ 0.8mm, and the gap between the bottom edge and the platform ≤ 1.5mm. If these three indicators are met, the profile frame parts are qualified.

[0027] Furthermore, the rolling bending process parameters include the number of rolling bends, the Y value, the left Zn value, and the right Zn value. The Y value is used to adjust the radius of the part, the left Zn value is the nth segment of the movement distance of the left roller, and the right Zn value is the nth segment of the movement distance of the right roller.

[0028] Furthermore, the range of the number of rolling bends is 6-20.

[0029] Furthermore, after each roll bend, the profile frame part needs to be placed on a platform to measure the angle value of the profile frame part.

[0030] Furthermore, in step S5, the profile frame parts are flattened in sections using a hydraulic press displacement movement mode, including:

[0031] The hydraulic press has two control modes: force control mode and displacement control mode. The displacement control mode is used to control the amount of downward pressure and flatten the raised parts in sections.

[0032] Since the profile frame part is quite long (7854mm), it is flattened and shaped in multiple segments. Because the end of the profile frame part has a high amount of warping, the amount of warping decreases towards the middle, and there is no warping within 1200mm of the end. Therefore, the pressing amount process parameter is set to gradually decrease in multiple segments.

[0033] Compared with existing technologies, the double-sided beveled irregular frame staggered roll bending forming process of the launch vehicle described in this invention has the following advantages:

[0034] (1) The present invention describes a method for forming a double-sided oblique irregular frame of a launch vehicle by staggered rolling. The double-sided oblique irregular frame adopts a segmented staggered rolling forming method. The part has high precision after rolling, small internal stress concentration, and small upturn at the rear end of the machined part. Combined with the segmented flattening method of hydraulic press displacement movement mode, the forming precision of the part is greatly improved. After rolling forming, the radius gap is 0.4mm, the angle gap is 0.3mm, and the flatness gap is 0.5mm, which is higher than the precision of stretch bending forming. After stretch bending forming and manual trimming, the radius gap is 1.5mm, the angle gap is 1mm, and the flatness gap is 1.5mm.

[0035] (2) The present invention describes a method for forming a double-sided oblique irregular frame of a launch vehicle by staggered rolling. The double-sided oblique irregular frame is formed by segmented staggered rolling, which does not require manual trimming, greatly reducing the labor intensity of workers and improving production efficiency.

[0036] (3) The present invention describes a double-sided oblique-shaped frame staggered roll bending forming process for launch vehicles. After machining, the double-sided oblique-shaped frame adopts a hydraulic press displacement movement mode segmented flattening method, which effectively solves the problem of the rear end of the part lifting up after machining and improves the product qualification rate by 30%.

[0037] (4) The double-sided oblique-shaped frame staggered roll bending forming process of the present invention is designed with a large rounded corner scheme for the contact surface between the double-sided oblique-shaped frame mold and the bottom edge of the profile. This can effectively solve the problem of abrasive material during profile roll bending, improve the surface quality of the parts, and leave a gap between the upper and lower sides of the parts and the mold to facilitate material extension. Attached Figure Description

[0038] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0039] Figure 1 A schematic diagram of a part in the prior art;

[0040] Figure 2 This is a schematic diagram of cross-sectional deformation in the prior art;

[0041] Figure 3 This is a top view schematic diagram of the rolling bend described in an embodiment of the present invention;

[0042] Figure 4 This is a schematic cross-sectional view of the roll bending according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the bending die before improvement according to an embodiment of the present invention;

[0044] Figure 6 This is a schematic diagram of the improved roll bending die according to an embodiment of the present invention;

[0045] Figure 7 This is a schematic diagram illustrating the lifting and flattening of the hydraulic press end as described in an embodiment of the present invention;

[0046] Figure 8 This is a schematic diagram of the method described in an embodiment of the present invention. Detailed Implementation

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] like Figures 3 to 8 As shown, a method for forming a double-sided oblique irregular frame of a launch vehicle by staggered roll bending is proposed. The cross-section of this frame is special. If the normal roll bending method is used, the rollers are all on the same plane. However, due to the asymmetry of the part cross-section and the oblique edge, the uneven force on the upper and lower sides of the roll bending profile cross-section will cause it to twist. Therefore, a segmented staggered roll bending method is proposed to counteract the uneven force on the upper and lower sides and prevent twisting.

[0052] The roll bending equipment uses a four-axis horizontal roll bending machine. The rollers are divided into a front center roller, a rear center roller, a left roller, a right roller, a left pressure roller, and a right pressure roller. The roll bending process bends straight material to the target radius while ensuring the bevel angle and bottom edge flatness meet the drawing requirements. Through multiple roll bending cycles, the forward movement distance of the left and right rollers (Y value) is adjusted each time, gradually reducing the profile radius until the target radius is reached. Simultaneously, the height difference between the left and right rollers (Z value) is adjusted each time to gradually bring the bevel angle and bottom edge flatness to the target values. A schematic diagram of the roll bending process is shown below. Figures 3 to 4 As shown.

[0053] 1. Mold optimization solution:

[0054] Normally, the roll bending die and the profile cross-section dimensions are consistent. During the roll bending process of double-sided beveled irregular frames, the part needs to undergo misalignment and twisting correction after entering the rollers. Before entering the rollers, the bottom edge of the part rubs against the rollers, causing scratches. Therefore, the contact surfaces between the middle and rear rollers, left roller, and right roller dies and the bottom edge of the profile were improved. The straight edges and small fillet radii were changed to beveled edges and large fillet radii. The fillet radius was changed from R2 to R6, and the straight edges were changed to beveled edges with vertical parameters of 0.5mm and horizontal parameters of 20mm. A 1mm gap was also left between the upper and lower sides of the part and the die to facilitate material extension. The left roller before and after the improvement is shown below. Figures 5 to 6 As shown, this innovative mold modification can effectively solve the problem of bottom edge abrasion during the bending process of parts, thereby improving the surface quality of the parts.

[0055] 2. The specific technical solution for roll forming is as follows:

[0056] (1) The blank is cut by sawing a length of 8854mm using a saw, including the length of the part of 7854mm and a allowance of 1000mm.

[0057] (2) Segmented staggered roll forming

[0058] The precision technical indicators for this part after roll bending are threefold: part radius deviation ≤ 1.5mm, gap between the inclined edge and the angle template ≤ 0.8mm, and gap between the bottom edge and the platform ≤ 1.5mm. If these three indicators are met, the part is qualified.

[0059] Due to the special cross-section of this part, which is a double-sided profile with beveled edges and a large diameter, the raw material has a long arc length of 8854mm. For this type of long cross-section part, roll bending can easily cause a slight gradual twisting of the edge angle from one end to the other. To improve the forming accuracy of the part, the arc length is divided into segments, and staggered roll bending process parameters are set for each segment to reduce the gradual twisting of the edge angle and improve the forming accuracy. The arc length of this part is divided into 3 segments, with a total length of 7854mm and a segment length of 2618mm. In each roll bending, the height difference between the left and right rollers of each segment is different. The height difference between the left and right rollers directly affects the angle and flatness values ​​of the part. If the difference is unreasonable, it will cause uneven angle and flatness of each segment. Through multiple experiments, the process parameters were solidified to make the beveled edge angle and bottom edge flatness values ​​uniform throughout the entire arc length of the profile, thus improving the accuracy. The segmented roll bending process parameter settings are shown in Table 1.

[0060] Table 1. Process Parameters for Segmented Rolling of Irregularly Shaped Frames

[0061]

[0062] The Y value in the table is used to adjust the radius of the part. As the Y value gradually increases, the radius of the part gradually decreases until it meets the technical requirements. After 8 roll bending cycles, the final radius deviation is 0.4mm, which meets the technical requirements.

[0063] Left Z1 represents the first segment's movement distance of the left roller, right Z1 represents the first segment's movement distance of the right roller, left Z2 represents the second segment's movement distance of the left roller, right Z2 represents the second segment's movement distance of the right roller, left Z3 represents the third segment's movement distance of the left roller, and right Z3 represents the third segment's movement distance of the right roller. Upward movement is positive, and downward movement is negative. As shown in Table 1, in each bend, the right roller is higher than the left roller in each arc segment. For arcs 1 and 3 (the two end arcs), the left and right roller values ​​are the same. For arc 2 (the middle arc), the difference between the left and right roller values ​​at the two end arcs is greater than that in the middle arc. In the first 5 bends, the difference between the left and right roller values ​​at the two end arcs is 4.2mm, and the difference in the middle arc is 3mm. In the last 3 bends, the difference between the left and right roller values ​​at the two end arcs is 4mm, and the difference in the middle arc is 2.8mm. The greater difference between the left and right roller values ​​at the two end arcs than in the middle arc effectively corrects the warping of the end portion. From the first to the eighth roll bending, the left and right rollers move downwards continuously. The first five roll bendings involve larger increases in value, while the last three roll bendings are a fine-tuning stage with smaller increases in value. (Specifically, the process parameters are set according to the above pattern. After multiple experiments, the fixed process parameters are obtained and saved in the four-axis roll bending machine to generate a roll bending program. Subsequent production is carried out according to the roll bending program.)

[0064] After each roll bend, place the profile on the platform and measure the angle value of the profile (the gap between the hypotenuse and the angle template). Select two points for the first arc length, one point for the second arc length, and two points for the third arc length, for a total of 5 points. The angle measurement values ​​of the irregular frame are shown in Table 2.

[0065] Table 2 Measurement Table of Angle Values ​​for Irregular Frames

[0066]

[0067] The table shows that the angle values ​​at the five points in each roll bend are relatively uniform. The angle difference between the two ends and the middle arc segment in the first five roll bends is 0.3mm, which is within a reasonable range. After fine-tuning, the angle difference between the two ends and the middle arc segment is 0 in the last three roll bends. After eight roll bends, the gap between the angle and the template is 0.3mm, meeting the technical requirements. Since angle and flatness are related, uniform angles result in uniform flatness. After the eighth roll bend, the gap between the bottom edge and the platform is 0.3mm, also meeting the technical requirements.

[0068] By employing a segmented left and right roller staggered rolling forming method, and with the difference between the left and right rollers at both ends of the arc being greater than the arc in the middle, and by fine-tuning the difference between the left and right rollers in each rolling pass from large to small, the angle and flatness of the rolled parts are uniform within the overall arc length range, resulting in high forming accuracy.

[0069] (3) Cutting allowance: The allowance at both ends of the part is removed by cutting with a saw. The total allowance at both ends is 1000mm.

[0070] (4) Machining: Machining the bottom of the small end of the part has 5 drainage grooves with a width of 10mm and a height of 2mm.

[0071] (5) Finishing: After machining, the internal stress of the part is released, and one end is slightly raised by 10mm. No manual finishing is required after rolling. The internal stress is small, less than the 23mm raised amount of the stretch bending. The small raised amount makes finishing easier.

[0072] This invention proposes using a hydraulic press with a displacement movement mode to flatten parts in sections. The hydraulic press has two control modes: force control mode and displacement control mode. The displacement control mode is used to control the downward pressure and flatten the raised areas in sections. A schematic diagram of the hydraulic press flattening process is shown below. Figure 7 As shown.

[0073] Since the profile is quite long at 7854mm, it was flattened and shaped in multiple sections. After multiple tests and adjustments to the pressing amount, it was found that the warping at the end of the part was relatively high, and the warping decreased towards the middle. There was no warping within 1200mm of the end. Therefore, the pressing amount was gradually reduced in multiple sections. The pressing amount process parameters are shown in Table 3.

[0074] Table 3. Segmented Downward Pressure Parameter Table

[0075]

[0076] The flattening process was carried out in six sections, each with an arc length of 300mm, for a total arc length of approximately 1800mm. The warping range exceeded 1200mm. The pressure applied in each stage gradually decreased from the first to the fifth stage, with the fifth and sixth stages having the same pressure parameters. The sixth stage primarily served to maintain pressure. The flattening was performed in four stages, with the pressure gradually increasing each time. The pressure in the first stage increased from 8mm to 10mm, gradually reducing the warping. By applying pressure in multiple stages with gradually decreasing pressure, the flatness of the profile frame was successfully corrected. After correction, the gap between the bottom edge and the platform was 0.5mm, meeting the technical requirements.

[0077] Advantages of this invention:

[0078] (1) The double-sided oblique irregular frame adopts the segmented staggered roll bending forming method. The part has high precision after roll bending, small internal stress concentration, and small upturn at the rear end of the machined part. Combined with the segmented flattening method of hydraulic press displacement movement mode, the forming precision of the part is greatly improved. After roll bending, the radius gap is 0.4mm, the angle gap is 0.3mm, and the flatness gap is 0.5mm, which is higher than the stretch bending forming precision. After stretch bending and manual trimming, the radius gap is 1.5mm, the angle gap is 1mm, and the flatness gap is 1.5mm.

[0079] (2) The double-sided beveled irregular frame is formed by segmented staggered rolling, which does not require manual trimming, greatly reducing the labor intensity of workers and improving production efficiency.

[0080] (3) After machining, the double-sided beveled irregular frame adopts the hydraulic press displacement mode segment flattening method, which effectively solves the problem of the rear end of the part lifting after machining and improves the product qualification rate by 30%.

[0081] (4) The contact surface between the double-sided beveled irregular frame mold and the bottom edge of the profile is designed with a beveled large round corner scheme, which can effectively solve the abrasion problem of profile rolling and improve the surface quality of the parts. There is a gap between the upper and lower sides of the parts and the mold, which can facilitate the material extension.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for forming a double-sided oblique irregular frame of a launch vehicle by staggered roll bending, characterized in that: Includes the following steps: S1. Cutting the profile frame parts; The profile frame parts are cut into blanks with a length of 8854mm using a saw, the length including 7854mm of the part length and 1000mm of allowance; S2. Segmented staggered roll bending forming of profile frame parts based on roll bending equipment; S3. Cutting allowance for profile frame parts: The excess material at both ends of the profile frame part is removed by cutting with a saw. The total excess material at both ends is 1000mm. S4. Machining of profile frame parts: The bottom of the small end of the machined profile frame part has a drainage groove with a width of 10mm and a height of 2mm. S5. Trimming of profile frame parts: After machining, the internal stress of the profile frame part is released, and one end is slightly raised by 10mm. The profile frame parts are flattened in sections using a hydraulic press displacement movement mode. In step S2, the profile frame part is subjected to segmented staggered roll bending forming based on the roll bending equipment, including: The arc length of the profile frame parts is divided into segments, and staggered rolling bending process parameters are set for each segment to reduce the gradual torsion of the vertical edge angle. The precision technical indicators for profile frame parts after roll bending are three items: the part radius deviation ≤ 1.5mm, the gap between the inclined side and the angle template ≤ 0.8mm, and the gap between the bottom edge and the platform ≤ 1.5mm. If these three indicators are met, the profile frame parts are qualified. The rolling bending process parameters include the number of rolling bends, Y value, left Zn value, and right Zn value. The Y value is used to adjust the radius of the part. As the Y value gradually increases, the radius of the profile frame part gradually decreases. The left Zn value is the distance the left roller moves in the nth segment, and the right Zn value is the distance the right roller moves in the nth segment. Moving upwards is a positive value, and moving downwards is a negative value. The arc length of the profile frame part is set to be divided into 3 segments, and the number of rolling bends for each segment is set to 8. In each rolling bend, the right roller is higher than the left roller in each arc segment. The left and right roller values ​​are the same in the arc segments at both ends. The difference between the left and right roller values ​​in the arc segments at both ends is greater than that in the middle arc segment. In the first 5 rolling bends, the difference between the left and right roller values ​​in the arc segments at both ends is 4.2mm, and the difference between the left and right roller values ​​in the middle arc segment is 3mm. In the last 3 rolling bends, the difference between the left and right roller values ​​in the arc segments at both ends is 4mm, and the difference between the left and right roller values ​​in the middle arc segment is 2.8mm. In step S5, the profile frame parts are flattened in sections using a hydraulic press displacement movement mode, including: The hydraulic press uses a displacement movement mode to control the amount of pressure and flatten the raised parts in sections. Before segmented flattening, the end of the profile frame part has a high amount of warping, and the amount of warping decreases as it moves towards the middle. There is no warping within 1200mm of the end. Therefore, the process parameters for setting the amount of pressing are adopted by gradually decreasing the amount of pressing in multiple segments. The bending equipment is a four-axis horizontal bending machine. The roller mold of the four-axis horizontal bending machine includes a front roller, a rear roller, a left roller, a right roller, a left pressure roller, and a right pressure roller. The front roller and the rear roller are respectively installed at the front and rear of the middle of the profile frame part, and the left roller, the right roller, the left pressure roller, and the right pressure roller are respectively installed on the left and right sides of the profile frame part.

2. The method for forming a double-sided oblique irregular frame of a launch vehicle by staggered roll bending according to claim 1, characterized in that: After each roll bend, the profile frame part needs to be placed on a platform to measure the angle value of the profile frame part.

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