CN107521718B

CN107521718B - Method for measuring shrinkage of sealant between aircraft skins

Info

Publication number: CN107521718B
Application number: CN201710537362.8A
Authority: CN
Inventors: 田利平
Original assignee: Xian Aircraft Industry Group Co Ltd
Current assignee: Xian Aircraft Industry Group Co Ltd
Priority date: 2017-07-04
Filing date: 2017-07-04
Publication date: 2020-12-29
Anticipated expiration: 2037-07-04
Also published as: CN107521718A

Abstract

The application provides a method for measuring shrinkage of a sealant between aircraft skins. The measuring gauge is made in a plate shape or a sheet shape, so that the number of the measuring gauges is reduced, the storage is convenient, and the measuring gauges can be designed to be polygonal. There is a projecting measuring head on each edge outside edge, the projecting width of the measuring head corresponding to the typical butt seam width. The invention has the advantages of simple structure, strong applicability, simple operation, quick measurement, reduced rework rate, quicker and better improvement of the coating quality of the product and effective improvement of the delivery rate of the product. The method provides a unified inspection basis relative to visual and manual touch inspection.

Description

Method for measuring shrinkage of sealant between aircraft skins

Technical Field

The application relates to the technical field of aircraft manufacturing, in particular to a method for measuring sealant shrinkage between aircraft skins.

Background

The function of the flap is to improve the lift force of the airplane during takeoff by changing the camber of the wing profile and increasing the wing area, and the outer surface of the flap has good aerodynamic shape. Aerodynamic profile refers to the profile of an aircraft designed according to aerodynamic principles. The good aerodynamic appearance of an airplane can improve the flying speed of the airplane and reduce the fuel quantity, and also represents the production technical level of the modern airplane.

The outer skins of certain inner flap wings of the boeing are in butt joint. Gap width of butt joint: 2.54 ± 1.27mm, butt seam depth: 2.6-4.3 mm, and the maximum length of the butt seam is 8.2 meters. And filling the butt seam gap with a sealant, wherein after the butt seam sealant is cured, the step difference between the sealant and an adjacent skin is required to be 0-0.25 mm in a drawing, namely the shrinkage depression value of the sealant is allowed to be 0-0.25 mm, so as to ensure a good pneumatic appearance.

The measurement of shrinkage must be gone on after the sealed glue solidification reaches hardness number Shore A30, because 0.25mm is very little, 1/4 of 1mm, can't see 0.25 mm's recess from naked eye, also can't feel with the hand touch, because rubber-like sealed glue hardness is little after the solidification, ordinary measuring tool's measuring head is telescopic and need press the measurement hard, the measuring head is mostly the metal head, the hardness of measuring head is far greater than sealed glue hardness, the measuring head is impressed and is led to the measured data inaccurate in the elasticity sealed glue during the measurement. Due to the lack of good measuring methods and tools and the lack of uniform standards, a large amount of unnecessary rework is caused, the workload of workers is increased, the time and material costs are also increased, and the delivery schedule of the product is affected. In order to solve the above problem, a measurement method is required to determine whether the shrinkage is acceptable.

Disclosure of Invention

The method for measuring the gap of the sealant by using the gauge is adopted to judge whether the shrinkage is qualified. A method for measuring the shrinkage of a sealant between aircraft skins comprises a plate-shaped polygonal gauge, wherein a convex measuring head is arranged on the outer side of each edge of a polygon, the head width of the convex measuring head corresponds to the butt seam width between the skins, the side edge of a shoulder part is a finish-machined measuring reference surface, and the measuring method comprises the following steps:

1 coating a sealant in a butt seam of a skin and a butt joint skin;

2, strickling the butt joint sealant and smoothing the outer surface of the sealant;

3, selecting a measuring head which is adaptive to the actual butt seam width on the gauge;

4, vertically placing the measuring head at the butt seam corresponding to the width of the measuring head;

5, irradiating a measuring head of the gauge by using a flashlight to vertically measure the gauge and to be parallel to the skin butt seam;

6 if the measuring reference surface is contacted with the product and the measuring head of the gauge is not contacted with the sealant, light can be transmitted out under the contact head, and the product is judged to be unqualified; if the measuring reference surface is not contacted with the product, light is transmitted out from the lower part of the reference surface, the measuring head of the gauge is contacted with the sealant, and no light is transmitted out from the lower part of the contact point, so that the product is judged to be qualified;

7, selecting measuring heads with other sizes on the gauge, repeating the operations of the steps 4 to 6 on the shrinkage of the butt joint sealant with different widths, and carrying out measurement and inspection;

8, picking out the sealant coating with unqualified measurement, marking, and enabling an operator to rework to complete the measurement.

The invention has the advantages of simple structure, strong applicability, simple operation, quick measurement, reduced rework rate, quicker and better improvement of the coating quality of the product and effective improvement of the delivery rate of the product. The method provides a unified inspection basis relative to visual and manual touch inspection.

The application is described in further detail below with reference to the accompanying drawings of embodiments.

Drawings

FIG. 1 is a schematic view of a filling structure of a butt-joint sealant

FIG. 2 schematic view of a gauge

FIG. 3 is a schematic diagram of the measurement of a measuring gauge failing to work

FIG. 4 is a schematic diagram of the measurement of a measuring gauge

The reference numbers in the figures illustrate: 1 covering, 2 butt joint covering, 3 structural material, 4 sealant, 5 sealant shrinkage, 6 butt joint depth, 7 butt joint width, 8 measuring heads, 9 measuring datum plane, 10 step difference and 11 measuring head width

Detailed Description

As shown in fig. 1-4, a method for measuring the shrinkage of a sealant between skins of an aircraft comprises a plate-shaped polygonal gauge, wherein a convex measuring head 8 is arranged on the outer side of each side of the polygon, the head width of the convex measuring head corresponds to the butt seam width 7 between the skins, and the shoulder side is a finish-machined measuring reference surface 9, and the measuring method comprises the following steps:

1 coating a sealant in a butt seam of a skin 1 and a butt joint skin 2;

2, scraping off the sealant 4 between the butt seams and smoothing the outer surface of the sealant 4;

3, selecting a measuring head 8 which is adaptive to the actual butt seam width 7 on the gauge;

4, vertically placing the measuring head 8 at a butt seam corresponding to the width of the measuring head 8;

5, irradiating a measuring head 8 of the gauge by using a flashlight to vertically measure the gauge and parallel to the skin butt joint;

6, if the measuring reference surface 9 is contacted with the product and the gauge measuring head 8 is not contacted with the sealant 4, light can be transmitted under the contact head, and the product is judged to be unqualified; if the measuring reference surface 9 is not contacted with the product, light is transmitted out from the lower part of the reference surface, the gauge measuring head 8 is contacted with the sealant 4, and no light is transmitted out from the lower part of the contact point, so that the product is judged to be qualified;

7, selecting measuring heads 8 with other sizes on the gauge, repeating the operations of the steps 4 to 6 on the shrinkage 5 of the butt joint sealant with different widths, and carrying out measurement and inspection;

8, picking out the sealant 4 with unqualified measurement, coating, marking, and allowing an operator to rework to complete the measurement.

In particular to the workpiece shown in the figure, in the example of the invention, the sealant shrinkage measurement gauge comprises six measuring heads 8, the height of the protrusion of each measuring head 8 is 0.25mm, and the widths of the measuring heads 8 are respectively 1.0mm, 2.0mm, 2.5mm, 3.0mm and 3.5mm so as to adapt to different butt seam widths 7. After the sealant 4 is filled into the butt seam, a sealant scraping plate is used for scraping, smoothing and rectifying along the butt seam, when the sealant is cured and measured, a gauge measuring head 8 with proper width is correspondingly selected to be vertically placed at the butt seam for measurement, when the butt seam is measured and sunken, a flashlight is used for vertically measuring the gap and is parallel to the butt seam for irradiation, if the gauge measuring head 8 is contacted with the sealant 4, a measuring reference surface 9 is not contacted with a product and light is transmitted from two sides, the step difference 10 is not more than 0.25mm, and the coating is proved to be qualified; if the measuring datum plane 9 is in contact with the product and the measuring head 8 is not in contact with the sealant 4, light can be transmitted out, which indicates that the shrinkage depression is greater than 0.25mm, and the product is not qualified. And (4) refilling and rectifying the large shrinkage depression amount and the large shrinkage depression amount to be qualified.

By the application on site, the method fundamentally and effectively solves the problem that the shrinkage of the sealant cannot be measured, provides a uniform measurement basis and reduces errors and reworking of manual measurement. The pneumatic outer surface gluing quality is effectively improved, the production cost is reduced, the assembly period is shortened, and meanwhile, the good pneumatic appearance of the product is ensured.

Claims

1. The method for measuring the shrinkage of the sealant between the skins of the airplane is characterized by comprising a plate-shaped polygonal gauge, wherein a convex measuring head is arranged on the outer side of each edge of the polygon, the head width of the convex measuring head corresponds to the butt seam width between the skins, and the side edge of a shoulder is a finish-machined measuring reference surface, and the measuring method comprises the following steps:

1-1 coating a sealant in a butt seam of a skin and a butt joint skin;

1-2, scraping off the sealant between the butt seams and smoothing the outer surface of the sealant;

1-3, selecting a measuring head which is adaptive to the actual butt seam width on a gauge;

1-4, vertically placing the measuring head at a butt seam corresponding to the width of the measuring head;

1-5, irradiating a measuring head of a gauge by using a flashlight to vertically measure the gauge and to be parallel to a skin butt seam;

1-6, if the measuring reference surface is contacted with the product and the measuring head of the gauge is not contacted with the sealant, the light can be transmitted out under the contact head, and the product is judged to be unqualified; if the measuring reference surface is not contacted with the product, light is transmitted out from the lower part of the reference surface, the measuring head of the gauge is contacted with the sealant, and no light is transmitted out from the lower part of the contact point, so that the product is judged to be qualified;

1-7, selecting measuring heads with other sizes on the gauge, repeating the operations from the step 1-4 to the step 1-6 on the shrinkage of the butt seam sealant with different widths, and carrying out measurement and inspection;

1-8, picking out the sealant coating with unqualified measurement, marking, and allowing an operator to rework to complete the measurement.