A method for quickly correcting stress deformation of L-shaped profile frame parts for aerospace

Abstract

The application discloses a kind of aerospace L-shaped section frame class parts stress deformation manual quick correction method, including the correction of vertical edge radian profile accuracy, the correction of bottom plate flatness, the correction of vertical edge angle deviation.The application improves production efficiency, and the product manual correction time is improved from 2-3 hours to 15-20 minutes, the production efficiency is improved by nearly 10 times, the skill level requirement of such processing personnel is also reduced, and beginners can easily complete processing according to the method;The forming quality is improved, the technical requirements of the parts corrected by this method are easy to guarantee, and the surface hammer marks are obviously reduced;The production cost is reduced, and the production cost is reduced by improving efficiency.

Description

Technical Field

[0001] This invention relates to manual correction of L-shaped frame parts after solution heat treatment and stretch bending in the aerospace and related industries, specifically to a method for rapid manual correction of stress deformation in L-shaped frame parts for aerospace applications. Background Technology

[0002] L-shaped frame components are structural parts of launch vehicles, forming the rocket body together with stringers, skin, and other components. They are crucial radial load-bearing parts. L-shaped frame components are ring-shaped members with L-shaped cross-sections at varying angles. They are commonly made from LC9-M ultra-hard aluminum alloy profiles, with common specifications including XC119-1, XC128-6 (acute angle), XC137-6 (obtuse angle), DQ728, and DQ5621. These parts can be categorized by name as profile frames, frames, and semi-frame rings, with most having an arc length of 180 degrees. The maximum arc radius of these parts is approximately R1670mm, and their arc length can reach 6.2 meters.

[0003] The main steps in forming L-shaped frame parts are: 1. Pre-bending to a certain arc (47°) using a bending machine and a die; 2. Heat treatment and quenching; 3. Bending and forming using a bending machine and a die; 4. Manual correction to meet technical requirements. For part inspection, the industry commonly uses a method of placing the bottom of the part flat on a large circular inspection platform. The arc and angle deviations are checked using standard inspection templates and squares (feeler gauges), and the flatness is checked by checking the gap between the part and the circular inspection platform (feeler gauges). Because parts have high requirements for geometric tolerances, the surface accuracy, base plate flatness, and vertical edge angle deviation of the part will interfere with the normal assembly of the product and may even lead to deviations in the final product dimensions. Part accuracy is crucial to the final product dimensions. For a long time, parts have suffered severe deformation after solution heat treatment. After bending and forming using a bending machine and die, parts generally exhibit significant stress deformation, requiring manual correction to meet technical requirements such as surface accuracy <0.8mm, base plate flatness <1mm, and vertical edge angle deviation <0.5mm. Due to the large arc length, thick material (6-8mm), wide material (60-85mm), and high strength of the parts, manual correction is quite difficult. Generally, operators cannot accurately determine the correct correction location or apply appropriate hammering force, resulting in repeated deformation. Correction typically takes 2-3 hours, is labor-intensive, inefficient, and produces poor quality. It also demands high operator skill and has remained an unresolved issue for a long time. A schematic diagram of a typical part is shown below. Figure 1 As shown in the diagram, commonly used profile specifications are illustrated below. Figure 2 As shown. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies by providing a manual, rapid correction method for stress deformation of L-shaped profile frame parts used in aerospace applications. This method addresses problems such as low processing efficiency, high labor intensity, and difficulty in ensuring technical requirements caused by inaccurate correction methods. To achieve the above objective, this invention adopts the following technical solution:

[0005] A manual method for rapid correction of stress deformation in L-shaped profile frame parts for aerospace applications, including correction of the accuracy of the vertical edge curvature surface, correction of the flatness of the base plate, and correction of the vertical edge angle deviation;

[0006] The correction of the accuracy of the vertical edge curvature surface includes the following steps:

[0007] A1: Place the part on a circular inspection platform. If the curvature of the part's vertical edge is larger than the outer inspection template of the reverse tangent surface (gap > 0.8) and the unfitted length is greater than 500mm, use a correction method of fixing the middle and pushing both sides towards the inside of the curvature. If the curvature of the part's vertical edge is larger than the outer inspection template of the reverse tangent surface (gap > 0.8) and the unfitted length is less than 500mm, place the part vertically on the circular inspection platform to maintain stability, and use inclined shims to fix it securely under the curvature surface.

[0008] A2: Tap the end face of the base plate until the curvature meets the requirements;

[0009] A3: Place the part on a circular inspection platform. If the curvature of the part's vertical edge is smaller than that of the outer inspection template of the reverse tangent surface by more than 0.8, directly hammer the edge of the bottom plate in the area with the smaller curvature. Continue to compare the curvature template until it is qualified.

[0010] The correction of the flatness of the base plate includes the following steps:

[0011] B1: Place the part on the circular inspection platform. When the gap between the inner side of the circular ring on the lower surface of the part's base plate and the circular inspection platform is greater than 1, place a flat pad under the base plate in the area that needs to be corrected, and tap the suspended area between the pad and the circular inspection platform until the gap meets the technical requirements.

[0012] B2: Place the part on the circular inspection platform. When the gap between the outer side of the circular ring on the lower surface of the part's base plate and the circular inspection platform is greater than 1, hold the L-shaped pad and place it on the upper part of the inner side of the vertical edge where correction is needed. Tap the padding part of the L-shaped pad to correct the shape until the gap meets the technical requirements.

[0013] The correction of the deviation of the vertical side angle includes the following steps:

[0014] C1: Place the part on the circular inspection platform. When the gap between the upper end of the vertical edge of the part and the angle inspection template or right angle ruler is >0.5, hold the L-shaped pad and place the L-shaped pad on the lower part of the inner side of the vertical edge where correction is needed. Tap the padding part of the L-shaped pad to correct it until the gap meets the technical requirements.

[0015] C2: Place the part on the circular inspection platform. When the gap between the lower root of the vertical edge of the part and the angle inspection template or right angle ruler is >0.5, hold the L-shaped pad and place it on the lower part of the inner side of the vertical edge where correction is needed. Do not contact the upper inner side of the vertical edge, and maintain a distance of 10-15mm. Only contact the lower inner side to provide support. Tap the area near the upper part of the outer side of the vertical edge to correct the gap until it meets the technical requirements.

[0016] As a preferred embodiment, the striking tool used in the correction of the accuracy of the vertical edge curvature surface A2 is a long-handled bakelite hammer.

[0017] As a preferred method, when tapping the end face of the base plate in the correction of the vertical edge curvature surface accuracy A2, a larger hammering force is required to tap the suspended part between the inclined pad and the circular detection platform.

[0018] As a preferred embodiment, the hammering tool used in the correction of the accuracy of the vertical edge curvature surface A3 is a special iron hammer.

[0019] As a preferred embodiment, the striking tools used in the corrections of the flatness of the base plate, B1 and B2, are aluminum hammers.

[0020] As a preferred method, in the correction of the flatness of the base plate B1 and B2, when the part is corrected by tapping, if the area to be corrected is long, it is necessary to continuously move to the left and right ends of the area for correction.

[0021] As a preferred method, when performing the tapping correction in the base plate flatness correction B2, the L-shaped pad must be in close contact with the part.

[0022] As a preferred embodiment, the striking tool used in the corrections C1 and C2 for the deviation of the vertical edge angle is an aluminum hammer.

[0023] As a preferred method, when performing the tapping correction in the correction C1 of the vertical edge angle deviation, the L-shaped pad must be in close contact with the part.

[0024] As a preferred method, in the correction of the vertical edge angle deviation C1 and C2, when the part is tapped to correct, if the area to be corrected is long, it is necessary to continuously move to the left and right ends of the area for correction.

[0025] The present invention has the following advantages:

[0026] 1. Improved production efficiency: Reduced manual correction time from 2-3 hours to 15-20 minutes, increasing production efficiency by nearly 10 times. It also reduced the skill requirements for such processing personnel, allowing even beginners to easily complete the processing using this method.

[0027] 2. Improved forming quality: The technical requirements of the parts modified by this method are easy to guarantee, and the surface hammer marks are significantly reduced.

[0028] 3. Reduced production costs: Increased efficiency reduced production and manufacturing costs. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a typical part;

[0030] Figure 2 This is a schematic diagram of commonly used profile specifications;

[0031] Figure 3 This is a top-down view of the large bend thrust effect;

[0032] Figure 4 This is a schematic diagram illustrating the correction of a small bend into a straight section;

[0033] Figure 5 This is a top-view diagram showing the correction for a smaller curvature;

[0034] Figure 6 This is a schematic diagram showing the excessive gap between the inner side of the circular ring and the circular detection platform;

[0035] Figure 7 This is a top-view schematic diagram of the bridge arch correction;

[0036] Figure 8 This is a schematic diagram illustrating the excessive gap between the outer side of the ring and the circular detection platform, and its correction.

[0037] Figure 9 This is a top view of the ship's arched shape;

[0038] Figure 10 This is a schematic diagram showing the angle deviation at the top of the vertical edge and its correction.

[0039] Figure 11 This is a schematic diagram showing the angle deviation at the bottom of the vertical edge and its correction.

[0040] Figure 12 This is a schematic diagram of the bakelite inclined pad structure;

[0041] Figure 13 This is a schematic diagram of the flat pad block structure;

[0042] Figure 14 This is a schematic diagram of an L-shaped handheld pad.

[0043] In the diagram, 1 is a circular testing platform; 2 is a fixed pile; 3 is an inclined pad; 4 is a base plate; 5 is a vertical edge; 6 is an L-shaped pad; and 7 is a flat pad. Detailed Implementation

[0044] To make the technical means, creative features, achieved objectives, and effects of this invention readily understandable, embodiments of the invention are provided below for detailed description. It should be noted that these embodiments are only for further illustration and should not be construed as limiting the scope of protection of this invention. Those skilled in the art can make non-essential improvements and adjustments based on the content of this invention.

[0045] A manual method for rapid correction of stress deformation in L-shaped profile frame parts for aerospace applications, including correction of the accuracy of the vertical edge curvature surface, correction of the flatness of the base plate, and correction of the vertical edge angle deviation;

[0046] The correction of the accuracy of the vertical edge curvature surface includes the following steps:

[0047] A1: Place the part on the circular inspection platform 1. When the curvature of the part's vertical edge is larger than the outer inspection template of the reverse tangent surface (gap > 0.8) and the unfitted length is greater than 500mm (considered a large bend), use a correction method of fixing the middle and pushing both sides inwards towards the curvature (it can be moved to different correction positions, such as left and right). Figure 3 (As shown); The curvature of the vertical edge 5 is larger than that of the outer inspection template of the cut surface, the gap is >0.8 and the unfitted length is less than 500mm (which is a small bend, mostly found at both ends of the part, which is the part where the curvature is worse than the molded state during the stretching process). Place the part vertically on the circular inspection platform 1 to keep it stable (multiple people are required to operate). Use the inclined pad 3 to fix it securely under the curvature surface.

[0048] A2: Due to the need for greater hammering force, use a long-handled, large bakelite hammer to strike the end face of the base plate 4 (the striking point is the suspended part between the inclined pad 3 and the circular testing platform 1) until the curvature meets the requirements (e.g., Figure 3 , Figure 4 (as shown);

[0049] A3: Place the part on the circular inspection platform 1. When the arc shape of the part's vertical edge 5 is smaller than the outer inspection template of the reverse tangent surface by a gap > 0.8, directly hammer the edge of the base plate in the area with the smaller arc shape using a special iron hammer (the iron hammer is heavier and has higher shaping efficiency). Pay attention to the control of the force and the uniformity of the points. Continuously compare with the arc template until it is qualified (e.g., Figure 5 (as shown);

[0050] The correction of the flatness of the base plate includes the following steps:

[0051] B1: Place the part on the circular inspection platform 1. When the gap between the inner side of the circular ring on the lower surface of the part's base plate 4 and the circular inspection platform is greater than 1 (indicating a bridge-shaped arch), place a flat pad 7 under the base plate 4 in the area to be corrected. Use an aluminum hammer (with slight hammer marks and good surface quality) to tap the suspended area between the pad and the circular inspection platform 1 until the gap meets the technical requirements. If the area to be corrected is long, it needs to be continuously moved to the left and right ends of the area for correction. Figure 6 , Figure 7 (as shown);

[0052] B2: Place the part on the circular inspection platform 1. When the gap between the outer edge of the lower surface ring of the part's base plate 4 and the circular inspection platform is greater than 1 (indicating a boat-shaped arch), hold the L-shaped pad 6 and place it on the upper inner side of the vertical edge 5 in the area requiring correction. Use an aluminum hammer to tap and correct the shape of the L-shaped pad 6 (i.e., near the upper outer side of the vertical edge 5) until the gap meets the technical requirements. If the area requiring correction is long, it is necessary to continuously move the pad to the left and right ends of the area for correction. Note that the L-shaped pad 6 must be in close contact with the part during tapping (e.g., ...). Figure 8 , Figure 9 (as shown);

[0053] The correction of the deviation of the vertical side angle includes the following steps:

[0054] C1: Place the part on the circular inspection platform 1. When the gap between the upper end of the vertical edge 5 of the part and the angle inspection template or right-angle ruler (used when the angle is 90°) is >0.5, hold the L-shaped pad 6 and place it on the lower inner part of the vertical edge where correction is needed. Use an aluminum hammer to tap and correct the padding part of the L-shaped pad 6 (i.e., near the root of the outer side of the vertical edge 5) until the gap meets the technical requirements. If the area to be corrected is long, it is necessary to continuously move the pad to the left and right ends of the area for correction. Note that the L-shaped pad 6 must be in close contact with the part when tapping (e.g., ...). Figure 10 (as shown);

[0055] C2: Place the part on the circular inspection platform 1. When the gap between the lower root of the vertical edge 5 and the angle inspection template or right-angle ruler (used when the angle is 90°) is >0.5, hold the L-shaped pad 6 and place it on the lower inner part of the vertical edge 5 in the area that needs correction. Do not contact the upper inner part of the vertical edge 5, maintaining a distance of 10-15mm. Only contact the lower inner part to provide support. Use an aluminum hammer to tap and correct the area near the upper outer part of the vertical edge 5 until the gap meets the technical requirements. If the area to be corrected is long, it is necessary to continuously move the hammer to the left and right ends of the area for correction (e.g., Figure 11 (As shown).

[0056] The principle of this invention: When a part is bent into shape, the curvature surface has springback. If the springback is too large, it will result in a large bend, with only a small straight section at both ends. Therefore, different correction methods are needed to reduce the curvature of the part. If the springback is too small, simply making corresponding adjustments to the edge of the base plate can increase the curvature of the part.

[0057] When forming parts by stretching, uneven longitudinal stretching can cause the base plate 4 to arch in a bridge or boat shape. This manifests as a gap between the inner side of the circular ring on the lower surface of the base plate and the circular inspection platform 1, or a gap between the root of the outer edge of the circular ring on the lower surface of the base plate and the circular inspection platform 1. For a bridge-shaped arch, the arched portion in the middle of the base plate 4 needs to be corrected by tapping it downwards with an aluminum hammer. For a boat-shaped arch, the upper part of the vertical edge 5 needs to be expanded to make the material extension equal in length to the root. This corrects both types of arches.

[0058] When a part is longitudinally stretched and bent, the angle of the profile itself will change. When the angle is small, an L-shaped pad 6 is placed on the lower inner side of the vertical edge 5 and fits tightly. By hammering the corresponding part on the outer side with an aluminum hammer, the material undergoes a slight inward deformation, and the upper end flips outward, thus reducing the gap. When the angle is large, the L-shaped pad 6 is placed on the lower inner side of the vertical edge to provide support. By hammering the corresponding part on the outer side with an aluminum hammer, the larger angle is impacted and deformed, thus reducing the angle.

[0059] The special tools for shaping in this invention include bakelite hammers, aluminum hammers, iron hammers, aluminum flat pads, bakelite slanted pads, and L-shaped iron pads (one side has a suitable curvature and rounded corner radius). By using the above-mentioned cold-working sheet metal manual forming tools in combination with the special inspection template and the universal circular inspection platform 1, and by operating according to the technical solution steps, the correction work can be completed easily and quickly.

[0060] This invention effectively solves the problems of low processing efficiency, high labor intensity, and difficulty in ensuring technical requirements caused by improper shaping methods and inaccurate parts when manually correcting stress deformation after bending forming. It also increases forming efficiency by nearly 10 times while ensuring processing quality. This novel method for rapid manual correction of stress deformation in frame-type parts can quickly complete the manual stress relief and shaping of profile frame-type parts. The method is simple in principle and highly applicable.

Claims

1. A method for quickly correcting stress deformation of an L-shaped profile frame part for aerospace use by hand, characterized in that, This includes correcting the accuracy of the vertical edge curvature, the flatness of the base plate, and the deviation of the vertical edge angle; The correction of the accuracy of the vertical edge curvature surface includes the following steps: A1: Place the part on the circular inspection platform. If the curvature of the part's vertical edge is larger than the outer inspection template of the reverse tangent surface (gap > 0.8mm) and the unfitted length is greater than 500mm, use a correction method of fixing the middle and pushing both sides towards the inside of the curvature. If the curvature of the part's vertical edge is larger than the outer inspection template of the reverse tangent surface (gap > 0.8mm) and the unfitted length is less than 500mm, place the part vertically on the circular inspection platform to maintain stability, and use inclined blocks to fix it securely under the curvature surface. Tap the bottom plate end face corresponding to the suspended part between the inclined blocks and the circular inspection platform until the curvature meets the requirements. The tapping tool is a long-handled bakelite hammer. A2: Place the part on a circular inspection platform. If the curvature of the part's vertical edge is smaller than the outer inspection template of the reverse tangent surface by more than 0.8mm, directly hammer the edge of the bottom plate in the area with the smaller curvature. Continue to compare the curvature template until it is qualified. The correction of the flatness of the base plate includes the following steps: B1: Place the part on the circular inspection platform. When the gap between the inner side of the circular ring on the lower surface of the part's base plate and the circular inspection platform is >1mm, place a flat pad under the base plate in the area that needs to be corrected, and tap the suspended area between the pad and the circular inspection platform until the gap meets the technical requirements. B2: Place the part on the circular inspection platform. When the gap between the outer side of the circular ring on the lower surface of the part's base plate and the circular inspection platform is >1mm, hold the L-shaped pad and place it on the upper part of the inner side of the vertical edge where correction is needed. Tap the padding part of the L-shaped pad to correct the shape until the gap meets the technical requirements. The correction of the deviation of the vertical side angle includes the following steps: C1: Place the part on the circular inspection platform. When the gap between the upper end of the vertical edge of the part and the angle inspection template or right angle ruler is >0.5mm, hold the L-shaped pad and place it on the lower part of the inner side of the vertical edge where correction is needed. Tap the padding part of the L-shaped pad to correct it until the gap meets the technical requirements. C2: Place the part on the circular inspection platform. When the gap between the lower root of the vertical edge of the part and the angle inspection template or right angle ruler is >0.5mm, hold the L-shaped pad and place it on the lower part of the inner side of the vertical edge where correction is needed. Do not contact the upper inner side of the vertical edge, and maintain a distance of 10-15mm. Only contact the lower inner side to provide support. Tap the area near the upper part of the outer side of the vertical edge to correct the gap until it meets the technical requirements.

2. The method according to claim 1, characterized in that: In step A1 of correcting the accuracy of the vertical edge curvature surface, when striking the end face of the base plate corresponding to the suspended part between the inclined pad and the circular detection platform, a larger hammering force is used.

3. The method according to claim 1, characterized in that: In step A2 of correcting the accuracy of the vertical edge curvature surface, the hammering tool is a specially made iron hammer.

4. The method according to claim 1, characterized in that: The striking tool used in steps B1 and B2 of correcting the flatness of the base plate is an aluminum hammer.

5. The method according to claim 1, characterized in that: In steps B1 and B2 of the correction of the flatness of the base plate, when the part is corrected by tapping, if the area to be corrected is long, it is necessary to continuously move to the left and right ends of the area for correction.

6. The method according to claim 1, wherein the method is characterized in that: When performing the tapping correction in step B2 of the base plate flatness correction, the L-shaped pad must be in close contact with the part.

7. The method according to claim 1, characterized in that: The striking tool used in steps C1 and C2 for correcting the deviation of the vertical edge angle is an aluminum hammer.

8. The method according to claim 1, characterized in that: When performing the tapping correction in step C1 of the correction of the vertical edge angle deviation, the L-shaped pad must be in close contact with the part.

9. The method according to claim 1, characterized in that: In steps C1 and C2 of correcting the deviation of the vertical edge angle, when the part is tapped for correction, if the area to be corrected is long, it is necessary to continuously move to the left and right ends of the area for correction.

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