A correction method for large cones with unequal extreme negative angles

Abstract

The present invention provides a correction method for a large-scale cone with an unevenly inclined extreme negative angle, comprising the following steps: oblique shape surveying and fitting; multi-pass progressive leveling; surveying and fitting; large end lifting and multi-pass progressive leveling; secondary surveying and fitting; multi-pass overall approximate synchronous trajectory design; tertiary surveying and fitting; overall trajectory design. The present invention has the following beneficial effects: a correction method for the bottom of an extremely oblique cone is established, a new forming path is explored, the process window is increased for product forming implementation, and high-precision control of the product is achieved; a correction method for a large-scale cone with an unevenly inclined extreme negative angle is adopted to successfully avoid high-cost product scrapping, laying a practical engineering experience and data foundation for subsequent similar product development.

Description

Technical Field

[0001] The invention belongs to the field of rocket box bottom forming, and in particular relates to a correction method for a large cone with an oblique unequal extreme negative angle. Background Art

[0002] The new launch vehicle adopts a large cone bottom structure design. The cone bottom ring is designed to be 2219 aluminum alloy, with a cone angle of 90°, a thickness of 20mm, a large end diameter of Ф5000mm, a small end diameter of about Ф2000mm, and a busbar length of about 2100mm. The difference in the curvature radius of the upper and lower ends of the product is large. In order to ensure the force transmission effect, the roundness and straightness of the product need to be controlled to 2mm. The large cone bottom is an equal cone angle structure, which needs to be processed from a flat plate state to a half cone angle of 45°. The deformation is large. At the same time, the forming process is affected by multiple factors such as temperature, temperature range, and sheet diameter-thickness ratio. It is very easy to be unstable and deformed. In severe cases, the sheet flips up and the spinning wheel wraps the edge, making it difficult to continue the spinning process, resulting in product scrapping, causing great economic losses and cycle impact.

[0003] For the integral spinning formed cone bottom structure, affected by the product size structure and process, the process parameters are required to be high. If the control is not done properly, the product quality is likely to be out of control, as follows:

[0004] (1) Length of busbar: Due to the long busbar, under the dual effects of compressive stress and tensile stress during the forming process, the large end of the cone bottom gradually accumulates deformation, and there are many superimposed factors, which causes great trouble to the product precision control;

[0005] (2) Large diameter-to-thickness ratio: The semi-cone angle of the cone bottom is 45°. According to the sine rate of spinning, the thickness is reduced by about 30% after forming. The size profile reaches 5 meters, the diameter-to-thickness ratio reaches more than 100:1, and the product has an obvious tendency to become unstable.

[0006] (3) Amount of pressure reduction: The spinning process usually adopts a single-pass shear spinning. Due to the yield of the spinning equipment and the material rebound characteristics, negative deviation is required for downward pressure. The rationality of the downward pressure has an important influence on the overall spinning instability of the cone bottom.

[0007] (4) Temperature field: The product has a large size and contour, and the overall blank temperature needs to be controlled in an open environment. The uniformity directly affects the material plasticity and forming resistance, and the lagging spinning continuity affects the forming accuracy. Summary of the invention

[0008] In view of this, the present invention aims to propose a correction method for large cones with uneven oblique extreme negative angles, so as to address the engineering problem of deformation with uneven oblique extreme negative angles caused by unstable wrinkling at the bottom of super-large cones, control the non-uniform contact deformation and the trimming trajectory during the trimming process, solve the unstable factors in the actual production process of the project, increase the product processing technology range, and improve the product qualification rate.

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

[0010] A correction method for a large cone with an unequally inclined limit negative angle comprises the following steps:

[0011] S1, oblique topography mapping and fitting;

[0012] S2, multi-pass progressive leveling;

[0013] S3, surveying and fitting;

[0014] S4, lift the big end and level it gradually over multiple passes;

[0015] S5, secondary mapping fitting;

[0016] S6, multi-pass overall approximate synchronous trajectory design;

[0017] S7, three-dimensional mapping fitting;

[0018] S8. Overall trajectory design.

[0019] Furthermore, in step S1, the oblique topography surveying and fitting includes:

[0020] Select the highest and lowest points of the inclined cone bottom sheet through circumferential runout;

[0021] Record the outer surface coordinate points at equal intervals of 100-150mm along the busbar direction;

[0022] Set the feeler gauge gap to 1-3mm, measure the profile thickness with a thickness gauge, and perform coordinate linear fitting.

[0023] Furthermore, in step S2, multi-pass progressive leveling includes:

[0024] The angle between the cone bottom and the horizontal plane is 15-20 degrees after being tilted. The unspun area of ​​the super-long generatrix of the cone bottom is 1500mm, and a multi-pass progressive flattening process is adopted from the middle area of ​​the unspun area to the small end;

[0025] The multi-pass progressive leveling trajectory is designed for variable gap equal height control, using a 9-pass design:

[0026] Passes 1-4 use L1 equal gap, where L1 is 150-180mm;

[0027] The gap is gradually reduced in passes 5-9, and gradually changes to 40-50mm in the 9th pass. The deformation height of the rotation section in each pass is 50-80mm.

[0028] The whole spinning process is heated, the temperature is controlled at 220-250℃, and contact temperature measurement is adopted.

[0029] Furthermore, in step S3, the secondary surveying and fitting includes:

[0030] After the product has been leveled in multiple passes, the rotating area has been leveled, and for the raised part at the large end, the highest and lowest points of the product after multiple passes of leveling are selected through circumferential runout;

[0031] The outer surface coordinate points are recorded at equal intervals of 100-150mm along the generatrix direction, and the feeler gauge gap is set to 1-3mm. At the same time, the profile thickness is measured by a thickness gauge to perform coordinate linear fitting.

[0032] Further, in step S4, the large end is raised and leveled in multiple passes, including:

[0033] The end of the raised position of the cone bottom is subjected to a multi-pass gradual leveling process from the small end to the center area;

[0034] The multi-pass progressive leveling trajectory is designed to be controlled with equal gap and equal height, using an 8-pass design:

[0035] Set L2n to 70-85mm, and the deformation height of each unscrewing section to 40-60mm;

[0036] The whole spinning process is heated, the temperature is controlled at 220-250℃, and contact temperature measurement is adopted.

[0037] Furthermore, in step S5, three surveying and mapping fittings are performed, including:

[0038] After the product is leveled by multiple passes of progressive leveling, the lifting position is leveled, and the highest and lowest points of the product after multiple passes of progressive leveling are selected through circumferential runout;

[0039] The outer surface coordinate points are recorded at equal intervals of 100-150mm along the generatrix direction, and the feeler gauge gap is set to 1-3mm. At the same time, the profile thickness is measured by a thickness gauge, and the coordinate linear fitting is performed again to achieve synchronization of the highest and lowest points.

[0040] Furthermore, in step S6, the multi-pass overall approximate synchronous trajectory design includes:

[0041] Adjust the highest point and the lowest point of the cone-bottom blank to approximately the same latitude to achieve equal deformation;

[0042] The trajectory design uses a multi-pass overall approximate synchronous trajectory design for the transition from the small end bonding area to the large end, and the trajectory deformation is lower than the lowest point on the outer surface of the blank;

[0043] The track design is equal gap and equal height control, using 6-pass design:

[0044] Set L3n to 150-180mm, the deformation height of each spinning section to 40-50mm, and the first pass overlaps the previous spinning area by 20-50mm;

[0045] The whole spinning process is heated, the temperature is controlled at 220-250℃, and contact temperature measurement is adopted.

[0046] Further, in step S7, three surveying and mapping fittings are performed, including:

[0047] The discrete coordinates of the highest and lowest points of the product are marked by circumferential runout, and the outer surface coordinate points are recorded at equal intervals of 100-150mm along the direction of the generatrix. The feeler gauge gap is set to 1-3mm. At the same time, the surface thickness is measured by a thickness gauge, and the coordinate linear fitting is performed again.

[0048] Furthermore, in step S8, the overall trajectory design includes:

[0049] After three overall trajectory adjustments, the trajectory design was performed using a single shear spinning process based on the measured morphology and thickness, and the theoretical tire-attaching trajectory was set according to the spinning sine law.

[0050] The negative deviation depression is established as the trajectory translation Δ = measured thickness × (6-8)%.

[0051] Compared with the prior art, the correction method for a large cone with an unequally inclined limit negative angle described in the present invention has the following advantages:

[0052] The method for correcting large cones with uneven inclined extreme negative angles described in the present invention establishes a method for correcting the bottom of cones with extreme inclined sizes, explores a new forming approach, increases the process window for product forming implementation, and achieves high-precision control of products. The method for correcting large cones with uneven inclined extreme negative angles successfully avoids the scrapping of high-cost products, laying a practical engineering experience and data foundation for the subsequent development of similar products. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0054] Figure 1 This is a schematic diagram of the process flow of an embodiment of the present invention;

[0055] Figure 2 A schematic diagram of the morphology of a large-scale cone with an oblique unequal extreme negative angle according to an embodiment of the present invention;

[0056] Figure 3A schematic diagram of a multi-pass progressive leveling trajectory according to an embodiment of the present invention;

[0057] Figure 4 for Figure 3 A partial enlarged schematic diagram of

[0058] Figure 5 It is a schematic diagram of the multi-pass progressive leveling trajectory of the big end lifting according to an embodiment of the present invention;

[0059] Figure 6 for Figure 5 A partial enlarged schematic diagram of

[0060] Figure 7 A schematic diagram of a multi-pass overall approximate synchronous trajectory design according to an embodiment of the present invention;

[0061] Figure 8 for Figure 7 A partial enlarged schematic diagram of

[0062] Fig. 9 This is a schematic diagram of the overall trajectory design of a single shear spinning process according to an embodiment of the present invention;

[0063] Fig.10 for Fig. 9 A partial enlarged schematic diagram of . DETAILED DESCRIPTION

[0064] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0065] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0066] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0067] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0068] like Figures 1 to 10 As shown, a correction method for a large cone with an unequally inclined limit negative angle comprises the following steps:

[0069] S1, oblique topography mapping and fitting;

[0070] S2, multi-pass progressive leveling;

[0071] S3, surveying and fitting;

[0072] S4, lift the big end and level it gradually over multiple passes;

[0073] S5, secondary mapping fitting;

[0074] S6, multi-pass overall approximate synchronous trajectory design;

[0075] S7, three-dimensional mapping fitting;

[0076] S8. Overall trajectory design.

[0077] The advantages of the present invention are: a correction method for the bottom of an extremely inclined cone is established, a new forming method is explored, the process window for product forming is increased, and high-precision control of the product is achieved; a correction method for large cones with uneven inclined extreme negative angles is adopted to successfully avoid the scrapping of high-cost products, laying a practical engineering experience and data foundation for the subsequent development of similar products.

[0078] In a preferred embodiment of the present invention, according to the product structure and material characteristics, the cone bottom ring is a typical rotating body part, which is processed by an integral spinning process. According to the inclined uneven limit negative angle structure of the large cone bottom, a multi-pass progressive trajectory forming is designed to gradually and progressively trim the product.

[0079] In a preferred embodiment of the present invention, the oblique topography mapping and fitting comprises:

[0080] The highest and lowest points of the inclined cone bottom sheet are selected through circumferential runout, and the outer surface coordinate points are recorded at equal intervals of 100-150mm along the generatrix direction. The feeler gauge gap is set to 1-3mm. At the same time, the surface thickness is measured by a thickness gauge to perform coordinate linear fitting.

[0081] In a preferred embodiment of the present invention, multi-pass progressive leveling includes:

[0082] After the cone bottom is tilted, the angle with the horizontal plane is 15-20°. Considering that the unspun area of ​​the super-long busbar of the cone bottom is about 1500mm, a multi-pass progressive flattening process is adopted from the middle area of ​​the unspun area to the small end to prevent the re-wrapping angle and the rebound failure of the large end. The trajectory design is variable gap equal height control, and a 9-pass design is adopted, that is, 1-4 passes use L1 equal gap, L1 is 150-180mm; 5-9 passes use a step-by-step decreasing variable gap design, the 9th pass gradually changes to 40-50mm, and the deformation height of each pass spinning section is 50-80mm. Heating is used throughout the spinning process, and the temperature is controlled at 220-250℃. Contact temperature measurement is used to ensure temperature accuracy.

[0083] In a preferred embodiment of the present invention, the secondary surveying and mapping fitting comprises:

[0084] After multiple passes of progressive leveling, the product has been leveled in the rotation area, but there is still some lifting at the large end. The highest and lowest point generatrix of the product after multiple passes of progressive leveling are selected through circumferential runout, and the outer surface coordinate points are recorded at equal intervals of 100-150mm along the generatrix direction. The feeler gauge gap is set to 1-3mm, and the surface thickness is measured by a thickness gauge to perform coordinate linear fitting.

[0085] In a preferred embodiment of the present invention, the large end is raised and leveled in multiple passes, including:

[0086] The end of the raised position of the cone bottom is gradually leveled from the small end to the center area to prevent the large end from rising again. The trajectory design is equal gap and equal height control, and an 8-pass design is adopted, that is, L2n is 70-85mm, and the deformation height of each pass is 40-60mm. Heating is used throughout the spinning process, and the temperature is controlled at 220-250℃. Contact temperature measurement is used to ensure temperature accuracy.

[0087] In a preferred embodiment of the present invention, surveying and mapping fitting includes:

[0088] After the product is leveled by multiple passes of progressive leveling, the lifting position is leveled, and the highest and lowest point generatrixes of the product after multiple passes of progressive leveling are selected through circumferential runout. The outer surface coordinate points are recorded at equal intervals of 100-150mm along the generatrix direction, and the feeler gauge gap is set to 1-3mm. At the same time, the surface thickness is measured by a thickness gauge, and the coordinate linear fitting is performed again to achieve synchronization of the highest and lowest points.

[0089] In a preferred embodiment of the present invention, the multi-pass overall approximate synchronous trajectory design includes:

[0090] In order to achieve the overall forming effect of the cone bottom, the highest and lowest points of the cone bottom blank are adjusted to approximately the same latitude to achieve equal deformation. The trajectory design uses a multi-pass overall approximate synchronous trajectory design to transition from the small end fitting area to the large end, and the trajectory deformation is greater than the lowest point on the outer surface of the blank. The trajectory design is equal gap and height control, using a 6-pass design, that is, L3n is 150-180mm, and the deformation height of each pass of the spinning section is 40-50mm. The first pass overlaps with the previous spinning area by 20-50mm to ensure the plastic deformation connection. Heating is used throughout the spinning process, and the temperature is controlled at 220-250℃. Contact temperature measurement is used to ensure temperature accuracy.

[0091] In a preferred embodiment of the present invention, three-time surveying and mapping fitting includes:

[0092] The discrete coordinates of the highest and lowest points of the product are marked by circumferential runout, and the outer surface coordinate points are recorded at equal intervals of 100-150mm along the direction of the generatrix. The feeler gauge gap is set to 1-3mm. At the same time, the surface thickness is measured by a thickness gauge, and the coordinate linear fitting is performed again.

[0093] In a preferred embodiment of the present invention, the overall trajectory design includes:

[0094] After three overall adjustments to the trajectory, the trajectory was designed using a single shear spinning process based on the measured morphology and thickness. The theoretical tire-attaching trajectory was set according to the spinning sine law. Taking into account the equipment's yield and rebound, the negative deviation reduction was established as the trajectory translation Δ = measured thickness × (6-8)%.

[0095] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for correcting large cones with unequal extreme negative angles, characterized in that: The following steps are involved: S1, oblique topography mapping and fitting; S2, multi-pass progressive leveling; S3, surveying and fitting; S4, lift the big end and level it gradually over multiple passes; S5, secondary mapping fitting; S6, multi-pass overall approximate synchronous trajectory design; S7, three-dimensional mapping fitting; S8, overall trajectory design; Oblique topography mapping and fitting, including: Select the highest and lowest points of the inclined cone bottom sheet through circumferential runout; Record the outer surface coordinate points at equal intervals of 100-150mm along the busbar direction; Set the feeler gauge gap to 1-3mm, measure the profile thickness with a thickness gauge, and perform coordinate linear fitting; Multi-pass progressive leveling, including: The angle between the cone bottom and the horizontal plane is 15-20 degrees after the cone bottom is tilted. The unspun area of ​​the super-long busbar of the cone bottom is 1500mm, and it is processed by multi-pass progressive flattening from the middle area of ​​the unspun area to the small end. The multi-pass progressive leveling trajectory is designed for variable gap equal height control, using a 9-pass design: Passes 1-4 use L1 equal gap, where L1 is 150-180mm; The gap is gradually reduced in passes 5-9, and gradually changes to 40-50mm in the 9th pass. The deformation height of the rotation section in each pass is 50-80mm. The whole spinning process is heated, the temperature is controlled at 220-250℃, and contact temperature measurement is adopted; Secondary mapping fitting, including: After the product has been leveled in multiple passes, the rotating area has been leveled, and for the raised part at the large end, the highest and lowest points of the product after multiple passes of leveling are selected through circumferential runout; Record the outer surface coordinate points at equal intervals of 100-150mm along the generatrix direction, set the feeler gauge gap to 1-3mm, and measure the profile thickness with a thickness gauge to perform coordinate linear fitting; The big end is raised and leveled gradually in multiple passes, including: The end of the raised position of the cone bottom is subjected to a multi-pass gradual leveling process from the small end to the center area; The multi-pass progressive leveling trajectory is designed to be controlled with equal gap and equal height, using an 8-pass design: Set L2n to 70-85mm, and the deformation height of each unscrewing section to 40-60mm; The whole spinning process is heated, the temperature is controlled at 220-250℃, and contact temperature measurement is adopted; Three-dimensional mapping fitting, including: After the product is leveled by multiple passes of progressive leveling, the lifting position is leveled, and the highest and lowest points of the product after multiple passes of progressive leveling are selected through circumferential runout; Record the outer surface coordinate points at equal intervals of 100-150mm along the generatrix direction, set the feeler gauge gap to 1-3mm, measure the profile thickness with a thickness gauge, and perform linear coordinate fitting again to achieve synchronization of the highest and lowest points; Multi-pass overall approximate synchronous trajectory design, including: Adjust the highest point and the lowest point of the cone-bottom blank to approximately the same latitude to achieve equal deformation; The trajectory design uses multi-pass overall approximate synchronous trajectory design for the transition from the small end bonding area to the large end, and the trajectory deformation is lower than the lowest point on the outer surface of the blank; The track design is equal gap and equal height control, using 6-pass design: Set L3n to 150-180mm, the deformation height of each spinning section to 40-50mm, and the first pass overlaps the previous spinning area by 20-50mm; The whole spinning process is heated, the temperature is controlled at 220-250℃, and contact temperature measurement is adopted; Three-dimensional mapping fitting, including: Through circumferential runout, the discrete coordinates of the highest and lowest points of the product are marked, and the outer surface coordinate points are recorded at equal intervals of 100-150mm along the direction of the generatrix. The feeler gauge gap is set to 1-3mm. At the same time, the thickness of the profile is measured by a thickness gauge, and the coordinate linear fitting is performed again; Overall trajectory design, including: After three overall trajectory adjustments, the trajectory design was performed using a single shear spinning process based on the measured morphology and thickness, and the theoretical tire-attaching trajectory was set according to the spinning sine law. The negative deviation pressure is established as the trajectory translation Δ = measured thickness × (6-8)%.

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