A method for rolling and bending a hollow unequal-sided profile frame

Abstract

The present invention provides a method for rolling and bending a hollow unequal-sided profile frame, comprising the following steps: S1, cutting a raw material to be rolled and bent from a parent material according to requirements; S2, performing filler treatment on the gaps in the raw material to be rolled and bent; S3, performing pre-rolling and bending on the raw material after filler treatment to obtain a pre-finished product; S4, removing the filler in the pre-finished product and performing quenching treatment to obtain a semi-finished product; S5, performing filler treatment on the gaps in the raw material of the semi-finished product; S6, performing supplementary rolling and bending on the semi-finished product; S7, removing the filler from the product obtained in step 6, and cutting the remaining material to obtain a finished product. The method for rolling and bending a hollow unequal-sided profile frame described in the present invention reasonably designs a rolling and heating treatment forming process according to the structural characteristics of the hollow profile frame parts, and combines the mold design with different springback amounts on the two vertical sides. Through process improvement and process innovation, hollow profile frame parts with qualified sizes are produced to meet the production requirements of launch vehicles.

Description

Technical Field

[0001] The invention belongs to the field of rocket profile frames, and in particular relates to a rolling and bending forming method for a hollow unequal-sided profile frame. Background Art

[0002] The launch vehicle profile frame is a large sheet metal part, a launch vehicle fairing frame profile frame, with a hollow cross-section, and the heights of the two sides are inconsistent, one side is high and the other side is low, the shape is semicircular, and the diameter is Φ4197mm. The profile specification of this profile frame is DQ981, the raw material is 2A12 aluminum alloy, in an arc state, the raw material is straight material, and the original forming process uses stretch bending to be bent into a semicircle.

[0003] This profile bending and forming equipment adopts a profile bending machine. Since the hollow part of the hollow profile needs to be filled before bending and forming, the two ends of the straight profile after filling are clamped by the bending machine, and a certain bending force is applied to rotate the profile around the bending die. The bending die is semicircular, so that the profile fits the die and bends into a semicircle.

[0004] like Figure 5-6 As shown, this profile has a special structure. It is a hollow profile with two vertical edges, and the heights of the two sides are not equal. The wall thickness is only 2mm. It adopts the stretch-bending forming process. The arc rebound after stretch-bending is very large. Figure 5 As shown, the springback of the ordinary profile frame is only about 5mm. Combined with the theoretical arc 8 and the arc 9 after rebound, the springback of the finished product 1 reaches 30mm, and there is a gap between the vertical edge angle torsion and the square ruler 11 and the platform 10, the gap is 2mm, as shown in FIG. Figure 6 As shown. After the supplementary stretching and bending, a lot of manual trimming is required. The angle size and arc size of the profile frame are contradictory. After trimming the angle size of the part, the angle gap is smaller, but the arc gap is larger, from 30mm to 40mm. The arc size needs to be trimmed again. The two sizes need to be trimmed repeatedly. The trimming intensity is very large and the scrap rate is very high. Summary of the invention

[0005] In view of this, the present invention aims to propose a method for rolling and bending a hollow unequal-sided profile frame to solve the problem that the existing technology requires high strength of post-processing and high scrap rate when forming the hollow unequal-sided profile into an arc shape.

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

[0007] A method for rolling and bending a hollow unequal-sided profile frame comprises the following steps: S1, cutting a raw material to be rolled and bent from a parent material according to requirements; S2, performing a filler treatment on the gaps in the raw material to be rolled and bent; S3, performing a pre-rolling and bending process on the raw material after the filler treatment to obtain a pre-finished product; S4, removing the filler in the pre-finished product and performing a quenching process to obtain a semi-finished product; S5, performing a filler treatment on the gaps in the raw material of the semi-finished product;

[0008] S6, performing additional rolling and bending on the semi-finished product; S7, removing the filler from the product obtained in step 6, and cutting the remaining material to obtain the finished product.

[0009] Furthermore, the cross-section of the mother material is a U-shaped structure, the length dimension of the first side of the mother material is smaller than the length dimension of the second side, and the filler in step 2 is filled into the U-shaped structure.

[0010] Furthermore, the rolling device is a four-axis rolling machine, and the pre-rolling forming method is to roll the raw material multiple times through the four-axis rolling machine, the radius after rolling is larger than the actual radius of the part, and the pre-rolling radius leaves a rebound amount.

[0011] Furthermore, the quenching treatment method for the pre-finished product is: the quenching temperature is 500±3°C, the holding time is 30 to 35 minutes, and water cooling is performed after the quenching is completed.

[0012] Furthermore, the filler is made of polyester.

[0013] Furthermore, the four-axis rolling bending machine includes a left roller, a right roller, an upper roller and a lower roller installed on a main frame, and the upper roller is located above the lower roller, the left roller and the right roller are respectively located on both sides of the upper roller, the left roller and the right roller are both driven rollers, and the lower roller and the upper roller are both power rollers. The periphery of the raw material is successively located above the left roller, between the upper roller and the lower roller, and above the right roller, and the periphery of the raw material is successively abutted against the periphery of the left roller, the periphery of the upper roller, the periphery of the lower roller and the periphery of the right roller.

[0014] Furthermore, a first annular mold groove is provided on the periphery of the upper roller, and the first annular mold groove is used to position the second side and the first side of the mother material, and the cross-section of the first annular mold groove is the same as the cross-section of the mother material, the left roller and the right roller respectively push the raw material upward to reduce the radius of the raw material, the left roller and the right roller respectively push the raw material sideways, and the side push is to move in the axial direction, and the side push can prevent the raw material from twisting as a whole, the left roller and the right roller are respectively provided with a rotation value, and the rotation direction is left and right swing, and the rotation value can correct the angle of the first side and the second side, the left roller and the right roller have the same rotation value, the upper roller can slide vertically, and the upper roller presses the raw material profile downward.

[0015] Furthermore, the rolling forming method is to fill the U-shaped structure with fillers, and then roll the structure back and forth for multiple times through a four-axis rolling machine. During each rolling forming, the left roller side push value is greater than the right roller side push value, the left roller side push value gradually increases with each rolling, the right roller side push value gradually increases with each rolling, and the upper push value is the same for each rolling or decreases with each rolling.

[0016] Compared with the prior art, the method for rolling and bending a hollow unequal-sided profile frame described in the present invention has the following beneficial effects: according to the characteristics of the hollow profile frame part structure, the rolling and heating treatment forming process is reasonably designed, the mold structure is optimized and improved, and molds with different springback amounts on the two vertical sides are designed. Through process improvements and technological innovations, hollow profile frame parts with qualified sizes are produced to meet the production requirements of launch vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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:

[0018] Figure 1 This is a schematic diagram of the hollow unequal-sided profile frame structure according to an embodiment of the present invention;

[0019] Figure 2 This is a cross-sectional schematic diagram of a hollow unequal-sided profile frame according to an embodiment of the present invention;

[0020] Figure 3 It is a cross-sectional schematic diagram of a profile frame formed by a four-axis rolling bending machine according to an embodiment of the present invention;

[0021] Figure 4 It is a front view schematic diagram of a profile frame formed by a four-axis rolling bending machine according to an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of the radius springback of a profile frame formed by the prior art according to an embodiment of the present invention;

[0023] Figure 6 It is a schematic diagram of the deformation of the profile frame section formed by the prior art according to the embodiment of the present invention;

[0024] Figure 7 It is a cross-sectional schematic diagram of the first annular die groove bending raw material described in an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1-finished product; 2-raw material; 21-first side; 22-second side; 3-upper roller; 4-lower roller; 5-left roller; 6-right roller; 7-first annular mold groove; 8-theoretical arc; 9-arc after rebound; 10-platform; 11-square ruler. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0031] A launch vehicle fairing frame profile frame, the cross section is a hollow profile, and the heights of the two sides are inconsistent, one side is high and the other side is low, the shape is semicircular, and the diameter is Φ4197mm. The profile specification of this profile frame is DQ981, the raw material is 2A12 aluminum alloy, the arc structure, and quenching treatment is required. Therefore, it is necessary to reasonably design the rolling and heating treatment forming process, select appropriate rolling forming process parameters, and roll-bending to form parts with qualified dimensions.

[0032] In addition, since the profile frame has two vertical edges with different heights and radii, the two vertical edges are subjected to different forces during roll bending, and the angles of the two vertical edges are easily twisted after rolling, and the twisting amount is also inconsistent, that is, the gaps between the two vertical edges and the square are different. In this case, the angles of the two vertical edges cannot be qualified by adjusting the process parameters alone. Therefore, the mold structure needs to be optimized. In a normal mold design, the cross-section of the roller mold is consistent with the cross-section of the profile, and the vertical edge of the roller mold is 90°. This profile adopts the design of the roller mold with two vertical edges that are slightly tilted, and the inclination gaps between the high vertical edge and the short vertical edge are inconsistent. The inclination gap of the high edge is 0.5mm, and the inclination gap of the short edge is 1mm. At the same time, there is a gap of 1mm between the top of the short vertical edge and the mold. The use of this mold can effectively prevent the angle of the part from twisting, giving the part better ductility, and the angle and flatness dimensional accuracy of the part after forming is high.

[0033] like Figure 1-7 As shown, a method for rolling and bending a hollow unequal-sided profile frame comprises the following steps: S1, cutting a raw material 2 to be rolled and bent from a parent material according to requirements;

[0034] The cross-section of the mother material is a U-shaped structure, and the length of the first side 21 of the mother material is smaller than the length of the second side 22. Specifically, the profile frame drawing requires that the radius deviation is less than 1.5mm, the gap between the bottom plane flatness and the platform is less than 1.5mm, the gap between the high vertical edge angle and the square is less than 1mm, and the gap between the short vertical edge angle and the square is less than 0.5mm. If all four indicators are met, the part is qualified. The sawing machine is used to saw the rough material 2 with a length of 7100mm.

[0035] S2, filling the gap in the raw material 2 to be rolled;

[0036] Fill the hollow part of the profile 2 with polyurethane filler material, which is 400 mm long and divided into sections, with a total of 17 sections;

[0037] S3, pre-rolling and bending the filler-treated raw material 2 to obtain a pre-finished product 1;

[0038] The rolling equipment uses a four-axis rolling machine, pre-rolling and forming, rolling three times, the radius after rolling is greater than the actual radius of the part, R2800mm, and the pre-rolling radius has a springback to prevent the radius from becoming smaller after heat treatment. Due to the asymmetry of the profile, the rolling parameters with different side push values ​​of the left and right rollers 6 are used.

[0039] The pre-bending process parameters and the part values ​​after bending are shown in Table 1:

[0040]

[0041] Table 1 Pre-bending process parameters and part values ​​after bending

[0042] S4, removing the filler in the pre-finished product 1 and performing quenching treatment to obtain a semi-finished product 1;

[0043] The quenching treatment method for the pre-finished product 1 is: the quenching temperature is 500±3℃, the holding time is 30-35min, and water cooling is performed after the quenching is completed.

[0044] S5, performing filling treatment on the gaps in the semi-finished product 1;

[0045] Fill the hollow part of the semi-finished product 1 with a filler made of polyester, which is a section of 400 mm in length, and a total of 17 sections;

[0046] S6, performing additional rolling bending on the semi-finished product 1;

[0047] The four-axis rolling bending machine includes a left roller 5, a right roller 6, an upper roller 3 and a lower roller 4 installed on a main frame, and the upper roller 3 is located above the lower roller 4, and the left roller 5 and the right roller 6 are respectively located on both sides of the upper roller 3. The left roller 5 and the right roller 6 are both driven rollers, and the lower roller 4 and the upper roller 3 are both active rollers. The left roller and the right roller can move relative to each other in the axial direction. The outer periphery of the raw material 2 is located above the left roller 5, between the upper roller 3 and the lower roller 4, and above the right roller 6 in sequence, and the outer periphery of the raw material 2 abuts against the outer periphery of the left roller 5, the outer periphery of the upper roller 3, the outer periphery of the lower roller 4 and the outer periphery of the right roller 6 in sequence.

[0048] The outer periphery of the lower roller 4 is used to locate the second side 22 of the base material, and the outer periphery of the upper roller 3 is provided with a first annular mold groove 7, and the first annular mold groove 7 is used to locate the second side 22 and the first side 21 of the base material, and the cross section of the first annular mold groove 7 is a matching size with the cross section of the base material, such as Figure 7 As shown, the first annular mold groove 7 has a matching gap with the first edge 21 and the second edge 22, the left roller 5 and the right roller 6 push the raw material 2 upward to reduce the radius of the raw material 2, the left roller 5 and the right roller 6 push the raw material 2 sideways respectively, and the side push is to move in the axial direction, which can prevent the raw material 2 from twisting as a whole. The left roller 5 and the right roller 6 are respectively provided with a rotation value, and the rotation direction is left and right swinging. The rotation value can correct the angle of the first edge 21 and the second edge 22. The left roller 5 and the right roller 6 have the same rotation value, the upper roller 3 can slide vertically, and the upper roller 4 presses the raw material 2 profile downward.

[0049] The method of supplementary rolling and bending is to fill the U-shaped structure with fillers, and then roll the structure back and forth for multiple times through a four-axis rolling machine. Each time the rolling and bending is performed, the side push value of the left roller 5 is greater than the side push value of the right roller 6. The side push value of the left roller 5 gradually increases with each rolling and bending, and the side push value of the right roller 6 gradually increases with each rolling and bending. The downward pressure value is the same for each rolling or decreases with each rolling and bending. Here, the side push is the sliding of the left roller 5 and the right roller 6 along the axial direction, and the side push value is the sliding displacement value of the left roller 5 and the right roller 6 along the axial direction. The outer periphery of the left roller 5 and the right roller 6 is provided with an annular groove, and the outer periphery of the raw material 2 is located in the annular groove. When rolling and bending, the above two annular grooves are not on the same linear surface.

[0050] Due to the large radius springback of the part, multiple rolling bending methods were adopted, with a total of 6 rolling bendings to accurately achieve the qualified radius size. The rolling parameters with different side push values ​​of the left and right rollers 6 were adopted. In order to prevent angular torsion, the rotation value was increased by 1.5mm. The rotation was that arc rollers were set at the lower ends of the left stick 5 and the right roller 6, and both the left stick 5 and the right roller 6 could slide along the arc rollers. The rotation value was the sliding arc of the left and right rollers 5 and 6 relative to the upper and lower rollers. After multiple rolling bending, parts with qualified dimensions were formed, and the qualified flatness and angle dimensions were accurately achieved. The radius value of the part after the 6th rolling was 2098.5mm, the gap between the flatness and the platform was 0.4mm, the gap between the high vertical edge and the square ruler was 0.4mm, and the gap between the short vertical edge and the square ruler was 0.2mm, all of which met the tolerance requirements of the drawing.

[0051] The process parameters of the supplementary rolling bending and the values ​​of the parts after rolling bending are shown in Table 2:

[0052]

[0053] Table 2 Bending process parameters and part values ​​after bending

[0054] S7, removing the filler from the product obtained in step 6, and cutting the remaining material to obtain the finished product 1.

[0055] Mark the two ends of the part according to the template cutting line, and cut the excess at both ends of the part according to the line. At this time, the part is rolled into a semicircle with a diameter of Φ4197mm.

[0056] 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 rolling and bending a hollow unequal-sided profile frame, characterized in that: The steps include: S1. Cut the raw material to be rolled and bent from the parent material according to the demand; S2, fill the gaps in the raw material to be rolled; S3, pre-rolling and bending the raw material after the filler treatment to obtain a pre-finished product; S4, removing the filler in the pre-finished product and performing quenching treatment to obtain a semi-finished product; S5. Filling the gaps in the raw material of the semi-finished product; S6, performing additional rolling and bending on the semi-finished product; S7, removing the filler from the product obtained in step 6, and cutting the remaining material to obtain a finished product; The cross section of the raw material to be rolled is a U-shaped structure, the length of the first side of the raw material to be rolled is smaller than the length of the second side, and the filler in step 2 is filled into the U-shaped structure; The rolling equipment is a four-axis rolling machine. The pre-rolling forming method is to roll the raw material multiple times through the four-axis rolling machine. The radius after rolling is larger than the actual radius of the part, and the pre-rolling radius has a springback amount. The four-axis rolling bending machine comprises a left roller, a right roller, an upper roller and a lower roller installed on a main frame, and the upper roller is located above the lower roller, the left roller and the right roller are located on both sides of the upper roller respectively, the left roller and the right roller are both driven rollers, the lower roller and the upper roller are both active rollers, the left roller and the right roller are both able to move relative to each other along the axial direction, the outer periphery of the raw material is located above the left roller, between the upper roller and the lower roller, and above the right roller in sequence, and the outer periphery of the raw material abuts against the outer periphery of the left roller, the outer periphery of the upper roller, the outer periphery of the lower roller and the outer periphery of the right roller in sequence; The outer periphery of the lower roller is used to position the second side of the rough material, and the outer periphery of the upper roller is provided with a first annular mold groove, and the first annular mold groove is used to position the first side and the second side of the rough material, and the cross-section of the first annular mold groove is the same as the cross-section of the rough material, the left roller and the right roller respectively push the rough material upward to reduce the radius of the rough material, and the left roller and the right roller respectively push the rough material sideways, and the side push is to move in the axial direction, and the side push can prevent the rough material from twisting as a whole, and the left roller and the right roller are respectively provided with a rotation value, and the rotation direction is left and right swing, and the rotation value can correct the angle of the first side and the second side, and the left roller and the right roller have the same rotation value, and the upper roller can slide vertically, and the upper roller presses the rough material profile downward.

2. A method for rolling and bending a hollow unequal-sided profile frame according to claim 1, characterized in that: The quenching treatment method for the pre-finished product is: quenching temperature 500±3℃, holding time 30~35min, water cooling after quenching.

3. A method for rolling and bending a hollow unequal-sided profile frame according to claim 1, characterized in that: The material of the filler is polyester.

4. A method for rolling and bending a hollow unequal-sided profile frame according to claim 1, characterized in that: The method of supplementary rolling and bending is to perform rolling and bending reciprocatingly for multiple times by a four-axis rolling bending machine, and each time the rolling and bending is performed, the side push value of the left roller is greater than the side push value of the right roller, the side push value of the left roller gradually increases with successive rolling and the side push value of the right roller gradually increases with successive rolling, wherein the side push value is the sliding displacement value of the left roller and the right roller along the axial direction; the left and right roller push values ​​are the same for each rolling or decrease with successive rolling.

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