CN110102603B - Cold sizing method for deformation of aluminum alloy longitudinal beam part - Google Patents

Abstract

The invention belongs to the technical field of machining, and relates to a cold sizing method for deformation of an aluminum alloy longitudinal beam part. Designing and manufacturing an appearance rapid detection tool in an assembling mode, placing a part on the appearance rapid detection tool, and determining a part deformation mode; spraying the web surfaces of the longitudinal beam parts from two sides, and correcting the deformation of the parts in the length direction; the two sides of the surface of the spraying edge strip are oppositely aligned, and the shape correcting part deforms in the width direction; and finally, evaluating whether the part after shape correction meets the design requirements. The invention has no damage to the surface of the part and no adverse effect on the performance of the part; the application range is wide, and the limitation of the structure (such as the symmetry of the cross section and the length direction, the structural distribution of reinforcing ribs, edge strips and the like) and the overall dimension of the part is avoided; the method is not limited by the deformation mode of the part, and complex deformation such as single bending and distortion can be corrected; the shape correction capability is high, and the shape correction cost is low; the sizing methods and parameters may be set and specified on a process file for guiding different operators.

Description

Cold sizing method for deformation of aluminum alloy longitudinal beam part

Technical Field

The invention belongs to the technical field of machining, and relates to a cold sizing method for deformation of an aluminum alloy longitudinal beam part.

Background

The aluminum alloy longitudinal beam machining part of the civil aircraft is an important connecting structural member and consists of a flange strip, a web surface, a reinforcing rib and other structures, the outer dimension is large, the thickness is small, the structure is complex, the form and position tolerance is tight, and the outer shape is easy to deform and exceeds the specification of a drawing after numerical control machining. Common shape correction methods include manual shape correction, hydraulic shape correction and the like. However, such methods are limited by the structure of the longitudinal beam parts and the complexity of the distortion deformation, and cannot be used for correcting the longitudinal beam parts.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a cold-sizing method for deformation of an aluminum alloy longitudinal beam part, which is a universal cold-sizing method free from the limitation of the structure (such as the structural distribution of the part structure, the structural distribution of reinforcing ribs, flanges and the like), the external dimension and the deformation mode of the longitudinal beam part. In order to realize the shape correction purpose, a pre-stressed module and a shape rapid detection tool are designed and used simultaneously.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a cold-sizing method for deformation of aluminum alloy longitudinal beam parts comprises the following steps:

first, determining the deformation mode of the part

Designing and manufacturing a rapid appearance detection tool in an assembling mode, wherein the rapid appearance detection tool comprises an inspector 7, a limiting block a8, a limiting block b9 and a reference surface 11;

placing the part on a rapid appearance detection tool, and limiting the part by a limiting block a8 and a limiting block b 9;

firstly, determining the deformation in the length direction, measuring the gap between an edge strip surface 10 of a part and a reference surface 11 of a detection tool by using a feeler gauge, and if the gaps on two sides of the edge strip at the same cross section are consistent, indicating that the part is simple single-curve deformation; if the gaps on the two sides are not consistent, the web surface or the edge strip of the part is distorted and deformed;

then determining the deformation in the width direction, wherein the deformation determination reference in the width direction is an inspector 7 designed according to the structure of the part, and a wedge block or a clearance gauge is used for measuring the clearance between the surface of the part and the inspection surface of the inspector 7;

second, the shape correcting part is deformed in the length direction

When the length direction correction is carried out, a prestress structure is used and comprises a screw rod 1, a rigid gasket 2, a pressing plate 3, a cushion block 4, a nut 5 and a platform 6;

(1) applying deformation displacement by using an Abaqus software static simulation algorithm to determine the maximum elastic deformation of the part;

(2) placing the part on a platform 6, and adding cushion blocks 4 at corresponding parts of the part according to the boundary condition of the simulated loading;

(3) positioning the screw rod 1 by utilizing a nut 5 for a lightening hole or a sand leakage hole at a corresponding position on the platform 6;

(4) placing a cushion block 4 on the outer side of the screw rod 1, pressing one end of a pressing plate 3 on the cushion block 4, and pressing the other end of the pressing plate on a part surface stress part;

(5) the rigid washer 2 is sleeved on the screw rod 1, and the rotary nut 5 applies prestress to the part through the pressing plate 3, so that the part is elastically deformed in advance. When the part is simply bent, prestress needs to be symmetrically applied to the edge strips on two sides of the web plate surface, when the part is distorted and deformed, the prestress cannot be symmetrically applied, and larger prestress needs to be applied to the edge strip on one side with large warpage;

(6) and a plurality of prestress applying points are arranged to gradually deform the part, so that the middle part of the part is prevented from arching after shape correction. The distance between every two prestress application points is ensured to ensure that the difference of the deformation amount between the two points is not more than 1.0mm or the distance between the prestress application points is not more than 500mm (taking the minimum distance), and the accumulated maximum prestress amount is the theoretical maximum elastic deformation amount of the part multiplied by the safety factor of 0.8;

(7) bilateral opposite-spraying longitudinal beam part web surface and web surface shot blasting area h_lH is the thickness of the web surface; the maximum strength of the shot blasting is not more than 10% of the thickness of the web surface;

thirdly, deforming the shape correcting part in the width direction

The width direction is free state, the shot blasting part is the two side surfaces of the edge strip, the shot blasting region is shown in figure 3, when the width dimension H of the edge strip at one side is arched₁Is greater than the width dimension H of the other side edge strip₂At the shot blasting part h_w1Maximum range of

H₀Is the part width; when arching a side edge strip width dimension H₃Is less than the width dimension H of the other side edge strip₄At the shot blasting part h_w2Maximum range of

When the shot blasting parts on the two sides of the edge strip are the same, H₁＝H₂Or H₃＝H₄At the time of shot blasting

And fourthly, evaluating whether the shape-corrected part meets the design requirement.

The invention has the beneficial effects that:

① has no damage to the surface of the part and no adverse effect on the performance of the part;

② has wide application range, and is not limited by the structure (such as symmetry of cross section and length direction, structural distribution of reinforcing ribs and flanges) and the external dimension of the parts;

③ is not limited by the deformation mode of the parts, and can correct complex deformation such as single curve and distortion;

④, the shape correction capability is high, and the shape correction cost is low;

⑤ calibration methods and parameters may be set and specified on a process file for guiding various operators.

The invention can also be popularized and applied to stringer type or box type ribbed parts with other structural forms, such as T-shaped, L-shaped, U-shaped, H-shaped and the like.

Drawings

FIG. 1 is a schematic structural diagram of a prestressing module;

FIG. 2(a) is a schematic view showing the direction of application of the prestressing force and the shot blasting region on the web surface;

FIG. 2(b) is a schematic view showing the direction of application of the prestressing force and the shot blasting region on the web surface;

FIG. 3(a) is a schematic view of a bead peening region;

FIG. 3(b) is a schematic view of the bead peening region;

FIG. 4 is a schematic structural view of the shape detection tool;

FIG. 5 is a schematic view of a deformation mode of a part;

FIG. 6 is a schematic view of a pre-stress application position;

FIG. 7 is a schematic view of a calibration part;

in the figure: 1, a screw rod; 2 a rigid gasket; 3, pressing a plate; 4, cushion blocks; 5, a nut; 6, a platform; 7, a checker; 8, a limiting block; 9 a limiting block; 10 parts rafter surface; 11 reference plane.

Detailed Description

The invention is further illustrated below with reference to specific embodiments and the accompanying drawings.

As shown in fig. 5, the component is a key component for connecting the butt joint of the wall plate of the fuselage, the floor beam and the barrel section of different fuselages. The length and width direction structures of the part are asymmetrical, the appearance of the machined part is distorted and deformed, the out-of-tolerance rate exceeds 80%, and the manufacturing cost and the project period are seriously influenced. The part shape correction cannot be finished by adopting the traditional cold shape correction mode.

A cold-sizing method for deformation of aluminum alloy longitudinal beam parts comprises the following steps:

firstly, designing and manufacturing an appearance inspection tool in an assembling mode, wherein the structure of the tool is shown in figure 4. The tool is composed of an inspector 7, a limit block a8, a limit block b9 and a reference surface 11. The assembly part can be designed by standard metal blocks or special design.

And (3) placing the edge strip surface 10 of the part on a reference surface 11 of the detection tool, and detecting the deformation of the part. The clearance distribution between the edge strip surface 10 and the reference surface 11 is checked by a feeler gauge, and the clearance between the surface of the part and the checker 1 is checked by a wedge-shaped quick check. The part is distorted and the distortion of the part is shown in figure 5.

Second, the shape correcting part is deformed in the length direction

Prestress is applied according to asymmetrical sections of the deformation condition of the part, and the maximum elastic predeformation of two ends is 12 mm. The prestress application position is shown in fig. 6. Under the condition of prestress, the upper half part of the web surface of the part is oppositely sprayed on two sides, the shot blasting pressure is 40-50PSI, the coverage rate is 60%, and the distortion in the length direction of the part is corrected.

Thirdly, deforming the shape correcting part in the width direction

In a free state, the upper half parts of the edge strips of the parts are oppositely sprayed on two sides, the shot blasting pressure is 20-30PSI, the coverage rate is 80%, and the deformation of the parts in the width direction is corrected. The calibration part is shown in figure 7.

Fourth step, Effect and evaluation

Before shape correction, the maximum clearance between the lower edge strips of different parts and the reference surface is between 1.9 and 2.7mm (the design requirement is 0.25mm), and the clearance between the abutting ends of the parts and the detection surface is between 0 and 3mm or 8 and 9mm (the design requirement is 6 +/-1 mm). After the shape correction, the maximum gap between the lower edge strip and the reference surface is 0.25mm, the gap between the butt joint end detection surface is 5.8-6.2mm, and the surface roughness of the part is Ra3.2, which all meet the design requirements.

The method has stable shape correction result, and corrects all out-of-tolerance parts to meet the design requirement.

Claims (1)

1. A cold-straightening method for deformation of aluminum alloy longitudinal beam parts is characterized by comprising the following steps:

first, determining the deformation mode of the part

Designing and manufacturing an appearance rapid detection tool in an assembling mode, wherein the appearance rapid detection tool comprises an inspector (7), a limiting block a (8), a limiting block b (9) and a reference surface (11);

placing the part on a rapid appearance detection tool, and limiting the part through a limiting block a (8) and a limiting block b (9);

firstly, determining the deformation of a part in the length direction, measuring the gap between an edge strip surface (10) of the part and a detection tool reference surface (11) by using a feeler gauge, and if the gaps on two sides of the edge strip at the same cross section are consistent, indicating that the part is simple single-curve deformation; if the gaps on the two sides are not consistent, the web surface or the edge strip of the part is distorted and deformed;

then determining the deformation of the part in the width direction, wherein the deformation determination reference in the width direction is an inspector (7) designed according to the structure of the part, and a wedge block or a clearance gauge is used for measuring the clearance between the surface of the part and the inspection surface of the inspector (7);

second, the shape correcting part is deformed in the length direction

When the shape is corrected in the length direction, a prestress structure is adopted, and the prestress structure comprises a screw rod (1), a rigid gasket (2), a pressing plate (3), a cushion block (4), a nut (5) and a platform (6);

(1) applying deformation displacement by using an Abaqus software static simulation algorithm to determine the maximum elastic deformation of the part;

(2) placing the part on a platform (6), and adding cushion blocks (4) at corresponding parts of the part according to the boundary condition of simulated loading;

(3) positioning the screw rod (1) by utilizing a nut (5) for lightening holes or sand leakage holes at corresponding positions on the platform (6);

(4) placing a cushion block (4) on the outer side of the screw rod (1), pressing one end of a pressing plate (3) on the cushion block (4), and pressing the other end of the pressing plate on a part surface stress position;

(5) sleeving a rigid gasket (2) on the screw rod (1), and applying prestress to the part by rotating a nut (5) through a pressing plate (3) to enable the part to generate elastic predeformation; when the part is simply bent, prestress needs to be symmetrically applied to the edge strips on two sides of the web plate surface, when the part is distorted and deformed, the prestress cannot be symmetrically applied, and larger prestress needs to be applied to the edge strip on one side with large warpage;

(6) a plurality of prestress application points are arranged to enable the part to deform gradually, and the middle part of the part is prevented from arching after shape correction; the distance between every two prestress application points is ensured to ensure that the difference of the deformation amount between the two points is not more than 1.0mm or the distance between the prestress application points is not more than 500mm, and the accumulated maximum prestress amount is the theoretical maximum elastic deformation amount of the part multiplied by the safety factor of 0.8;

(7) bilateral opposite-spraying longitudinal beam part web surface and web surface shot blasting area

H is the thickness of the web surface; the maximum strength of the shot blasting is not more than 10% of the thickness of the web surface;

thirdly, deforming the shape correcting part in the width direction

The width direction is free state, the shot blasting part is the two side surfaces of the edge strip, when the width dimension H of the edge strip at one side is arched₁Is greater than the width dimension H of the other side edge strip₂At the shot blasting part h_w1Maximum range of

H₀Is the part width; when arching a side edge strip width dimension H₃Is less than the width dimension H of the other side edge strip₄At the shot blasting part h_w2Maximum range of

When the shot blasting parts on the two sides of the edge strip are the same, H₁＝H₂Or H₃＝H₄At the time of shot blasting

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