阅读说明：本技术 长桁过渡区喷丸成形过程中外形精度的控制方法 (Method for controlling appearance precision in shot blasting forming process of stringer transition region ) 是由 曾元松 白雪飘 王明涛 尚建勤 张尚文 于 2020-06-24 设计创作，主要内容包括：本发明公开了一种长桁过渡区喷丸成形过程中外形精度的控制方法,包括：以长桁轴线为控制线,分析长桁轴线的曲率分布；获取每一长桁轴线上的设定位置点；映射每一设定位置点至二维毛坯上；依据最小差值法,在二维毛坯上确定预弯控制线的位置；当预弯控制线确保每一长桁实现完全弯曲时,控制预弯变形量并进行喷丸成形,其中,完全弯曲为至少三点弯曲。该长桁过渡区喷丸成形过程中外形精度的控制方法目的是解决长桁与蒙皮过渡区喷丸成形时预变形施加不均导致的该区域成形精度差的问题。(The invention discloses a method for controlling the appearance precision in the shot blasting forming process of a stringer transition area, which comprises the following steps: analyzing the curvature distribution of the stringer axis by taking the stringer axis as a control line; acquiring a set position point on each stringer axis; mapping each set position point to the two-dimensional blank; determining the position of a pre-bending control line on a two-dimensional blank according to a minimum difference method; when the pre-bending control line ensures that each stringer achieves full bending, the amount of pre-bending deformation is controlled and shot-peening is performed, wherein full bending is at least three-point bending. The method for controlling the shape precision in the shot blasting forming process of the stringer transition area aims to solve the problem that the forming precision of the area is poor due to uneven pre-deformation application when the stringer and the skin transition area are subjected to shot blasting forming.)

1. A control method for shape precision in a shot blasting forming process of a stringer transition region is characterized by comprising the following steps:

analyzing the curvature distribution of the stringer axis by taking the stringer axis as a control line;

acquiring a set position point on each stringer axis;

mapping each set position point to the two-dimensional blank;

determining the position of a pre-bending control line on the two-dimensional blank according to a minimum difference method;

and when the pre-bending control line ensures that each stringer can be completely bent, controlling the pre-bending deformation amount and carrying out shot blasting forming, wherein the complete bending is at least three-point bending.

2. The method of claim 1, wherein the set points include a point with a minimum radius of curvature and a point with an abrupt change in curvature.

3. The method of claim 1, wherein a first pre-bend supplemental control line is added near the ends of the shortest stringer when the pre-bend control line fails to ensure that each stringer achieves full bend and the stringer not achieving full bend is located in the middle of the panel.

4. The method of claim 3, wherein a first pre-bend supplemental control line is added near the end of the shortest stringer, specifically: adding a first pre-bend make-up control line at a location spaced from the end set point of the shortest stringer.

5. The method of claim 4, wherein the set value is less than 200 mm.

6. The method of claim 1, wherein a second pre-bend make-up control line is added at the end of the shortest stringer when the pre-bend control line fails to ensure that each stringer is fully bent and the stringer not fully bent is on a single side of the panel.

7. The method of claim 1, wherein the number of pre-bend control lines is at least three.

8. The method of claim 3, wherein at least one additional control line is provided for pre-bending the stringer during the peen forming process.

9. The method of claim 6, wherein at least one additional pre-bend control line is provided.

Technical Field

The invention belongs to the technical field of shot blasting forming of aircraft panels, and particularly relates to a control method for shape precision in a shot blasting forming process of a stringer transition area.

Background

The wall plate is one of the most important part types on the aerospace craft, is an important component forming the aerodynamic shape, and is also a main bearing component of an airplane wing, an airplane body and the like. With the development of aerospace industry, wallboard structures have undergone a leap-type development. Complexity of the shape structure: the method is developed from initial contour curvature equal percentage line distribution, equal thickness and regular skin wall plates to variable thickness and complex contour skin wall plates with bending and twisting, and variable thickness, belt structure and complex contour ribbed integral wall plates. In order to improve the structural efficiency of the wall plate, the wall plate even has a large-deformation complex high-rib integral structure.

Shot peening is the main forming method of wall plate parts, and its basic principle is to use high speed shot flow to impact the surface of metal plate to make the impacted surface and the lower layer metal material generate plastic deformation and extend, so that the plate gradually generates bidirectional bending deformation protruding to the sprayed surface to form the required shape. Due to the increased complexity of the wall plate profile structure, the application of prestressed shot-peening is becoming more and more widespread in order to increase the wall plate forming capability.

The prestressed shot-peening is a shot-peening method in which a load is applied to a part slab in advance by a prestressing jig before shot-peening to form elastic strain, and then the part slab is formed. The method is mainly used for shot blasting forming of parts with complex shapes and structures and small curvature radius. Prestressed shot-peening has three significant features: the plastic deformation direction of the material can be controlled, and the deformation trend of the shot blasting spherical surface is changed to a certain extent; improving the shot blasting forming limit; the shot blasting manufacturability of the parts is improved, and the application range of shot blasting forming is expanded.

Disclosure of Invention

Technical problem to be solved

The invention aims to solve the technical problem that the forming precision of a transition region between a stringer and a skin is poor due to uneven pre-deformation application during shot blasting forming of the region.

(II) technical scheme

The invention provides a method for controlling the appearance precision in the shot blasting forming process of a stringer transition area, which comprises the following steps:

analyzing the curvature distribution of the stringer axis by taking the stringer axis as a control line;

acquiring a set position point on each stringer axis;

mapping each set position point to the two-dimensional blank;

determining the position of a pre-bending control line on the two-dimensional blank according to a minimum difference method;

and when the pre-bending control line ensures that each stringer can be completely bent, controlling the pre-bending deformation amount and carrying out shot blasting forming, wherein the complete bending is at least three-point bending.

Further, the set position points include a position point having a smallest radius of curvature and a position point having an abrupt change in curvature.

Further, when the pre-bend control lines fail to ensure that each of the stringers achieves full bend and the stringers that do not achieve full bend are located in the middle of the panel, a first pre-bend make-up control line is added near the end of the shortest stringer.

Further, the adding of the first pre-bending supplementary control line near the end of the shortest stringer is specifically: adding a first pre-bend make-up control line at a location spaced from the end set point of the shortest stringer.

Further, the set value is less than 200 mm.

Further, when the pre-bend control lines fail to ensure that each of the stringers achieves full bend and the stringers that do not achieve full bend are located on a single side of the panel, a second pre-bend make-up control line is added at the end of the shortest stringer.

Further, the number of the pre-bending control lines is at least three.

Further, the number of the first pre-bending supplementary control lines is at least one.

Further, the number of the second pre-bending supplementary control lines is at least one.

(III) advantageous effects

The technical scheme of the invention has the following advantages:

the invention provides a method for controlling the appearance precision in the shot blasting forming process of a stringer transition area, which comprises the following steps: analyzing the curvature distribution of the stringer axis by taking the stringer axis as a control line; acquiring a set position point on each stringer axis; mapping each set position point to the two-dimensional blank; determining the position of a pre-bending control line on a two-dimensional blank according to a minimum difference method; when the pre-bending control line ensures that each stringer achieves full bending, the amount of pre-bending deformation is controlled and shot-peening is performed, wherein full bending is at least three-point bending. The control method for the shape precision in the shot blasting forming process of the stringer transition area is designed according to the shape curvature when pre-bending is implemented, the pre-bending control line is added in the high deformation resistance area, so that smooth pre-bending is achieved when the panel is subjected to shot blasting forming, the uniformity of the shot blasting forming shape is improved, the shape precision of parts is improved, the phenomenon that the shape clearance is out of tolerance and even the parts are scrapped due to the fact that the stringer and the skin transition area are not pre-bent properly is avoided, great economic loss is avoided, and good technical and economic benefits are achieved.

Drawings

FIG. 1 is a schematic diagram illustrating a method for controlling profile accuracy during shot peening in a stringer transition region according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a method for controlling profile accuracy during shot peening of a stringer transition region according to an embodiment of the present invention;

FIG. 3 is a schematic view of the stringer deformation curvature distribution of a panel during a method of controlling profile accuracy during shot peening in a stringer transition region according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating the location of a pre-bending control line in a method for controlling profile accuracy during shot-peening formation of a stringer transition region according to an embodiment of the present invention;

fig. 5 is a schematic position diagram of a pre-bending supplementary control line in a method for controlling profile accuracy in a stringer transition region shot-peening process according to an embodiment of the present invention.

In the figure:

1. a first pre-bend control line; 2. a first pre-bend control line; 3. a second pre-bend supplementary control line; 4. a first inversion control line; 5. a second inversion control line; A. a first force application direction; B. a second force application direction; C. a curve of curvature change.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

According to an embodiment of the invention, a method for controlling the shape precision in the shot blasting forming process of a stringer transition region is provided, as shown in fig. 1, the method comprises the following steps:

s1, analyzing the curvature distribution of the stringer axial line by taking the stringer axial line as a control line;

s2, acquiring a set position point on each stringer axis;

s3, mapping each set position point to a two-dimensional blank;

s4, determining the position of a pre-bending control line on the two-dimensional blank according to a minimum difference method;

and S5, controlling the deformation amount of the preflex and performing shot-peening when the preflex control line ensures that each stringer can be completely bent, wherein the complete bending is at least three-point bending.

In the embodiment, when the pre-bending is implemented, the pre-bending control line is added in the high deformation resistance area according to the shape curvature design, so that the smooth pre-bending is realized during the shot blasting forming of the wallboard, the shot blasting forming shape uniformity is improved, the part shape precision is improved, the phenomenon that the shape clearance is out of tolerance due to the fact that the stringer and the skin transition area are not properly pre-bent is avoided, even the part is scrapped is avoided, the great economic loss is avoided, and the high-speed pre-bending control line has good technical and economic benefits.

In some alternative embodiments, the set position points include a position point having a smallest radius of curvature and a position point having an abrupt change in curvature. According to the change of the outline curvature of the wall plate, the pre-bending control line is designed at the position of the minimum curvature radius or the curvature abrupt change area.

In some alternative embodiments, when the preflex control line fails to ensure that each stringer achieves full sweep and the stringer that does not achieve full sweep is located in the middle of the panel, a first preflex make-up control line is added near the end of the shortest stringer. Specifically, whether the pre-bending control line can ensure that the stringers are bent at three points or four points is checked, and the situation of the stringers which are not completely bent at three points or four points is processed: and when the stringer is bent at two points, at least one first pre-bending supplementary control line is added, namely the application position of the upright post is added, so that uniform pre-bending of all the stringers can be ensured.

In some alternative embodiments, a first pre-bend supplemental control line is added near the end of the shortest stringer, specifically: a first pre-bend make-up control line is added at a location spaced from the end set point of the shortest stringer.

In some alternative embodiments, the set value is less than 200 mm. The first pre-bending supplement control line is deviated from the end part of the shortest stringer to be too large due to the overlarge set value, and smooth pre-bending of the wallboard during shot blasting forming is influenced.

In some alternative embodiments, when the preflex control line fails to ensure that each stringer achieves full sweep and the stringers that do not achieve full sweep are on a single side of the panel, a second preflex make-up control line is added at the end of the shortest stringer. The number of the second pre-bending supplement control lines is determined according to the length girders which are not completely bent, when the length girders are bent at one point, at least two second pre-bending supplement control lines are added, and when the length girders are bent at two points, at least one second pre-bending supplement control line, namely, the application position of the upright post is added, so that uniform pre-bending of all the length girders can be realized.

In some alternative embodiments, the pre-bend control lines are at least three.

In some alternative embodiments, the first pre-bend supplemental control lines are at least two.

In some alternative embodiments, the second pre-bending supplementary control line is at least two.

According to another method for controlling the shape precision in the shot blasting forming process of the stringer transition region, as shown in FIG. 2, the method comprises the following steps:

s201, analyzing curvature distribution of the stringer axis by taking the stringer axis as a control line;

s202, acquiring a set position point on each stringer axis;

s203, mapping each set position point to the two-dimensional blank;

s204, determining the position of a pre-bending control line on the two-dimensional blank according to a minimum difference method;

s205, judging whether a pre-bending control line ensures that each stringer is completely bent; if yes, go to step S206, otherwise go to step S207;

s206, controlling the pre-bending deformation amount and carrying out shot blasting forming;

s207, when the preflex control line cannot ensure that the stringer is completely bent and the stringer which is not completely bent is located in the middle of the wallboard, adding a first preflex supplementary control line near the end of the shortest stringer; or the like, or, alternatively,

when the pre-bend control lines fail to ensure that the stringers are fully bent and are on a single side of the panel for stringers that are not fully bent, a second pre-bend make-up control line is added at the end of the shortest stringer.

And controlling the amount of pre-bending deformation and performing shot-peening, wherein the complete bending is at least three-point bending.

After step S207 is completed, step S206 is continued to complete the shot peening of the panel.

In one embodiment, as shown in FIGS. 3-5, for a bilaterally symmetric, approximately trapezoidal panel, the stringer deformation curvature distribution is shown in FIG. 3, and the variation curve C of the stringer deformation curvature exhibits curvature at different locations on the stringer.

As shown in fig. 4, according to the curvature abrupt change situation, a first pre-bending control line 1 and a second pre-bending control line 2 are designed, and the force application direction is a and is upward; according to the bilateral symmetry of the wallboard structure, a first reverse control line 4 and a second reverse control line 5 are designed, the force application direction is B, the two lines face downwards, and the area between the first pre-bending control line 1 and the second pre-bending control line 2 is uniformly divided.

Since the stringer length is less than the panel's large deformation range and the stringer is on a single side of the panel, the first and second pre-bend control lines 1, 2 do not pass through the stringer, but the first and second reversing control lines 4, 5 pass through the stringer. Two second supplementary control lines 3 are additionally designed at positions 100mm away from the tail ends of the complete heights of the two ends of the stringer, and the control directions of the supplementary control lines are consistent with those of the first pre-bending control line 1 and the second pre-bending control line 2.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.