A method for fine spinning of segmented film laminating on a cone bottom after heat treatment deformation

Abstract

The present invention provides a method for fine spinning of segmented film-applying on a cone bottom after heat treatment deformation, comprising the following steps: assembly before fine spinning; mapping and fitting; first fine spinning trajectory; second fine spinning trajectory; and shape evaluation. Beneficial effects of the present invention: the method can effectively avoid the problem of scrapping of products due to quenching deformation; provides a control method for solving the heat treatment deformation of large-scale spun cone bottoms; adopts quenching, quenching, fine spinning and aging to achieve coordinated improvement of shape and ensure product quality.

Description

Technical Field

[0001] The invention belongs to the field of rocket cone bottom processing, and in particular relates to a segmented film-sticking fine-spinning method for the cone bottom after heat treatment deformation. Background Art

[0002] The cone bottom ring of the new launch vehicle 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, a busbar length of about 2100mm, and the material is heat treated and strengthened. The forming curvature radius of the upper and lower ends of the cone bottom ring is very different. During the solution treatment process, the cone bottom needs to be heated to nearly 540°C, and it needs to be quickly cooled and quenched in a very short time to facilitate the precipitation of the dispersion strengthening phase in the subsequent aging process. Due to extreme hot and cold working conditions, the large box bottom is very prone to shrinkage and elliptical, which seriously restricts subsequent machining and is difficult to meet product processing requirements. According to the surface deviation, the surface is trimmed by fine spinning after quenching to ensure the processing margin and performance improvement after deformation, and realize the integrated manufacturing of the product.

[0003] At present, there are few studies on the heat treatment deformation of 5m-class ultra-long large cone bottoms, and there are few means to deal with shrinkage deformation during quenching. Usually, mechanical three-point bending, local rolling cone shaping or flanging machine rounding are used. In the mechanical external force three-point bending shaping, the forces are mutually restricted, and the forming accuracy is difficult to control; in the local rolling cone shaping, the inclination angle and process parameters need to be adjusted in real time with the deformation of the product, and the precise control of the profile is difficult to achieve; in the flanging machine rounding, it is affected by the depth of the cone bottom box, and only the large end part can be rounded, the internal stress is large, and it is difficult to achieve the overall busbar shaping. At the same time, the operator's skill level is required to be high during rounding, and the stability is insufficient.

[0004] In summary, after the large cone bottom becomes oval and shrinks during heat treatment, it is difficult to achieve precise control of the product, which can easily lead to product scrapping. Summary of the invention

[0005] In view of this, the present invention aims to propose a method for segmented film-sticking and precision rotation of the cone bottom after heat treatment deformation, so as to address the processing bottleneck problem caused by shrinkage and elliptical deformation during the heat treatment of large aluminum alloy cone bottoms. By establishing an assembly relationship before rotation, sequential control of the film-sticking strategy is achieved, and the product processing redundancy is improved, thus solving the practical engineering problem that the deformation of large cone bottoms during heat treatment is difficult to control and the product cannot be processed.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A method for fine spinning of a segmented film-sticking on a cone bottom after heat treatment deformation, comprising the following steps:

[0008] S1, fine pronation assembly;

[0009] S2, surveying and fitting;

[0010] S3, one fine rotation trajectory;

[0011] S4, secondary fine rotation trajectory;

[0012] S5. Form evaluation.

[0013] Furthermore, in step S1, the fine pronation assembly includes:

[0014] Place the quenched cone bottom on the spinning tire, and use a number of positioning pins to ensure centering and alignment. The pin holes are designed as blind holes.

[0015] After the position is aligned, use a steel ruler to measure the thickness of the aluminum lining, that is, H = total height - sheet thickness;

[0016] 4-6 blocks are arranged in a circle at the center hole, and 8-10 blocks are arranged in a circle at the tail top boundary;

[0017] Apply pressure by pressing down with the top of the tail.

[0018] Furthermore, in step S2, surveying and fitting includes:

[0019] Select the generatrix of the highest and lowest points of the cone bottom after quenching through circumferential runout;

[0020] 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.

[0021] Furthermore, in step S3, a fine rotation trajectory includes:

[0022] The first fine rotation trajectory is carried out by the overall correction method from the small end to the large end;

[0023] The distance d between the inner profile and the outer surface of the spinning tire is fitted according to the thickness of the cone bottom and the coordinates of the outer surface;

[0024] The trajectory of a fine rotation is that the deformation of the initial section is large, and the deformation of the waist area is small in the film-adhering state;

[0025] The large end area is the key position for shape correction. Applying a larger downward pressure will cause plastic deformation of the large end of the cone bottom. Therefore, d downward pressure = d spacing * (1.1~1.2), and the larger downward pressure value is taken at the large end.

[0026] Furthermore, in step S4, the secondary fine rotation trajectory includes:

[0027] The overall local shape correction from the small end to the large end is adopted to fit the product shape according to the product thickness and outer surface coordinates;

[0028] The secondary fine rotation trajectory is that the deformation amount of the initial section is large, and it gradually transitions to the equal thickness section, that is, d down pressure = d spacing * (1 ~ 1.2);

[0029] The small end area adopts a spacing of 1.2d at the initial position of the rotation, and the cross-section equal thickness area is selected as the last demoulding section.

[0030] Furthermore, in the first fine spinning trajectory and the second fine spinning trajectory, the cone bottom busbar adopts overall uniform heating, and a contact thermocouple is used to monitor the sheet temperature, and the temperature range is 140℃-170℃.

[0031] Compared with the prior art, the method for fine spinning of the segmented film-attaching of the cone bottom after heat treatment deformation described in the present invention has the following advantages:

[0032] The present invention discloses a method for fine spinning of segmented film on the bottom of a cone after heat treatment deformation. This method can effectively avoid the problem of product scrapping due to quenching deformation. It provides a control method for solving the heat treatment deformation of large spun cone bottoms. It adopts quenching, fine spinning and aging to achieve coordinated improvement of shape and ensure product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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:

[0034] Figure 1 This is a schematic diagram of the bonding area between the large end of the product and the mold according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the precision pronation assembly according to an embodiment of the present invention;

[0036] Figure 3 for Figure 2 A partial enlarged schematic diagram;

[0037] Figure 4 This is a schematic diagram of the precision pronation assembly according to an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of a single fine rotation trajectory according to an embodiment of the present invention;

[0039] Figure 6 for Figure 5 A partial enlarged schematic diagram;

[0040] Figure 7 A schematic diagram of a secondary fine rotation trajectory according to an embodiment of the present invention;

[0041] Figure 8 for Figure 7 A partial enlarged schematic diagram is shown in the figure. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0046] like Figures 1 to 8 As shown, a method for fine spinning of segmented film laminating of a cone bottom after heat treatment deformation comprises the following steps:

[0047] S1, fine pronation assembly;

[0048] S2, surveying and fitting;

[0049] S3, one fine rotation trajectory;

[0050] S4, secondary fine rotation trajectory;

[0051] S5. Form evaluation.

[0052] In a preferred embodiment of the present invention, due to the overall shrinkage of the product, it is difficult to completely sit on the cone bottom spinning tooling by heating and expansion. At present, a spacer of equal thickness is added in the middle to achieve this; there are uneven areas such as fitting and hanging at the lower end, and the mechanism of the influence of trajectory design on product unevenness is clarified, such as Figure 1 shown.

[0053] In a preferred embodiment of the present invention, the precision pronation assembly comprises:

[0054] The quenched cone bottom is placed on the spinning tire, and the centering and alignment are determined by 6 positioning pins. The pin holes are designed as blind holes, and the size is = cone bottom thickness - (5-8) mm, which is convenient for the tail top force support in the subsequent spinning process. After the position is centered and aligned, the thickness of the aluminum plate to be padded is measured with a steel ruler, that is, H = total height - sheet thickness. In order to ensure a good overall stress state, 4-6 pieces are arranged in a ring at the center hole, and 8-10 pieces are arranged in a ring at the tail top boundary.

[0055] Example: The spinning tire is attached with 6 positioning pins, the height from the upper surface of the spinning tire is 50-5=45mm (the raw material is 50mm), and the pins are used to align and position with the hole area of ​​the sheet material. Through the positioning pins and the sheet material positioning holes, the distance from the upper surface of the quenched cone bottom to the upper surface of the spinning tire is measured with a steel ruler, such as 65mm, which determines that the thickness of the cushion aluminum plate is 15mm (65-50mm). The two-circle mode is adopted, with 6 blocks arranged in a circle in the center area and 10 blocks arranged in a circle at the tail top boundary, to achieve nearly full contact, expand the force-bearing area, and ensure that the tail top area is subjected to overall force during the spinning process.

[0056] After laying the inner and outer ring aluminum linings, pressure is applied by pressing down on the tail top with a load of 60T.

[0057] In a preferred embodiment of the present invention, surveying and mapping fitting includes:

[0058] The highest and lowest points of the product after quenching are selected through 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 to perform coordinate linear fitting.

[0059] Example: The spinning wheel of the spinning equipment is used to measure the circumferential runout of the quenched cone bottom driven by the main shaft to ensure that the highest point and the lowest point of the product correspond to the generatrix. The outer surface coordinate points are recorded at equal intervals of 120mm along the generatrix direction. The feeler gauge gap is selected as 2mm. The coordinate points at each position are determined by adjusting the feeler gauge gap. At the same time, the coordinate points are calibrated, the thickness at the location is measured, the coordinate linear fitting is performed, and the inner surface profile is calculated.

[0060] In a preferred embodiment of the present invention, a fine rotation trajectory includes:

[0061] The first fine spinning trajectory is carried out in an overall shape correction method from the small end to the large end to control the overall downward pressure. The distance d between the inner profile and the outer surface of the spinning tire is fitted according to the product thickness and the outer surface coordinates. The deformation of the first fine spinning trajectory is large in the initial section, and the deformation of the waist area is small in the film-sticking state; the large end area is the key position for shape correction, and a large downward pressure is required to cause plastic deformation of the large end of the box bottom, so d downward pressure = d spacing * (1.1 ~ 1.2), and the large end takes a larger downward pressure value to achieve negative deviation of product downward pressure and increase the plastic deformation ratio.

[0062] Example: According to the product thickness and outer surface coordinate fitting, the distance d between the inner profile and the outer surface of the spinning tire is 5mm. In order to ensure the product deformation, the pressing amount is 5.5mm. By pressing the product thickness, the plastic deformation is increased to ensure better product film adhesion.

[0063] The busbar at the bottom of the box is evenly heated as a whole, and contact thermocouples are used to monitor the temperature of the sheet to ensure that it is maintained at 140℃-170℃ (about 160℃) to avoid product aging due to excessive heating temperature, element burnout, and affected performance.

[0064] In a preferred embodiment of the present invention, the secondary fine rotation trajectory includes:

[0065] Based on the overall deformation result achieved by the first fine spinning trajectory, the overall local correction from the small end to the large end is adopted, and the product morphology is also fitted according to the product thickness and outer surface coordinates. The second fine spinning trajectory has a large deformation in the initial section and gradually transitions to the equal thickness section, that is, d down pressure = d spacing * (1~1.2). The small end is restricted by the top cover area and has a large tensile stress constraint, so a 1.2d spacing is used at the initial position of the spin, and the equal thickness area of ​​the cross section is selected as the last demolding section to ensure the overall accuracy of the product.

[0066] Example: For the area with large deformation at the small end, the distance d between the inner profile and the outer surface of the spinning tire is 8mm based on the product thickness and the outer surface coordinate fitting. A large downward pressure of 9.6mm is used at the initial position. The plastic deformation is increased by pressing down the product thickness to ensure better film adhesion of the product.

[0067] The busbar at the bottom of the box is evenly heated as a whole, and contact thermocouples are used to monitor the temperature of the sheet to ensure that it is maintained at 140℃-170℃, avoiding product aging due to excessive heating temperature, element burnout, and affecting performance.

[0068] In a preferred embodiment of the present invention, the morphological evaluation includes:

[0069] By adopting the method of quenching fine spinning + aging, the performance of aluminum alloy can be significantly improved by the deformation after quenching and the surface processing margin envelope can be achieved, achieving improvements in both form and properties, providing a new way for stable product production.

[0070] Advantages of the present invention:

[0071] This method can effectively avoid the problem of product scrapping due to quenching deformation; it provides a control method for solving the heat treatment deformation of large spun cone bottoms; it adopts quenching, fine spinning and aging to achieve coordinated improvement of shape and ensure product quality.

[0072] 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 fine spinning of segmented film laminating of a cone bottom after heat treatment deformation, characterized in that: The following steps are involved: S1, fine pronation assembly; S2, surveying and fitting; S3, one fine rotation trajectory; S4, secondary fine rotation trajectory; S5, morphological assessment; In step S2, mapping and fitting are performed, including: Select the generatrix of the highest and lowest points of the cone bottom after quenching 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; In step S3, a fine rotation trajectory is performed, including: The first fine rotation trajectory is carried out by the overall correction method from the small end to the large end; According to the thickness of the cone bottom and the coordinates of the outer surface, the distance between the inner profile and the outer surface of the spinning tire is d distance; The trajectory of a fine rotation is that the deformation of the initial section is large, and the deformation of the waist area is small in the film-adhering state; The large end area is the key position for shape correction. Applying a larger downward pressure will cause plastic deformation of the large end of the cone bottom. Therefore, d downward pressure = d spacing * (1.1~1.2), and the large end takes the larger downward pressure value; In step S4, the secondary fine rotation trajectory includes: The overall local shape correction from the small end to the large end is adopted to fit the product shape according to the product thickness and outer surface coordinates; The secondary fine rotation trajectory is that the deformation amount of the initial section is large, and it gradually transitions to the equal thickness section, that is, d down pressure = d spacing * (1~1.2); The small end area adopts a spacing of 1.2 d at the initial position of the rotation, and the cross-section equal thickness area is selected as the last demoulding section.

2. According to claim 1, a method for fine spinning of a segmented film-sticking on a cone bottom after heat treatment deformation, characterized in that: In step S1, the fine pronation assembly includes: Place the quenched cone bottom on the spinning tire, and use several positioning pins to ensure centering and alignment. The pin holes are designed as blind holes. After the position is aligned, use a steel ruler to measure the thickness of the aluminum lining, that is, H = total height - sheet thickness; 4-6 blocks are arranged in a circle at the center hole, and 8-10 blocks are arranged in a circle at the tail top boundary; Apply pressure by pressing down with the top of the tail.

3. The method for fine spinning of a segmented film-sticking cone bottom after heat treatment deformation according to claim 1, characterized in that: In the first and second fine spinning trajectories, the cone bottom busbar is heated uniformly as a whole, and a contact thermocouple is used to monitor the sheet temperature, with a temperature range of 140℃-170℃.

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