Method for rapidly measuring perimeter of large integral spinning cone bottom part for spaceflight

Abstract

The invention belongs to the technical field of spaceflight member perimeter measurement, and particularly relates to a spaceflight large-scale integral spinning cone bottom part perimeter rapid measurement method comprising the following steps: S1, downwards placing a large-scale cone bottom part with a perimeter needing to be detected on a workbench, and vertically drawing a starting line on a perimeter reference line; s2, aligning the zero line of the measuring tape with the starting line, aligning and overlapping the lower edge of the width of the measuring tape with the upper and annular reference lines of the part, and measuring the perimeter; and S3, calculating the arc length sizes of equal division and related boss circumferential angle positions according to the measurement result of the perimeter, and performing equal division lineation of four quadrants of the part and lineation of the position and the shape of each boss. The common transparent adhesive tape is adopted to replace people or calipers for fixation, the purposes of sliding control and tight attachment are achieved, long-time keeping can be achieved, the lineation requirement of a bench worker is met, the perimeter detection precision and the lineation quality of the bench worker are improved, the machining cost is reduced, and the production period is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of perimeter measurement of aerospace components, and in particular relates to a method for quickly measuring the perimeter of a large-scale integrally spun cone-bottom part for aerospace use. Background Art

[0002] The cone bottom parts of aerospace tanks are hemispherical shell components of launch vehicle bodies. In the past, they were mostly made of plates of different thicknesses that were processed in pieces and then welded together. This has the disadvantages of long production cycle, potential weld strength risks, high welding costs, and increased overall weight.

[0003] The integral spun cone bottom parts are spun by flat material, and they also need to be heat treated, strengthened, and milled. After the milling is thinned to a certain thickness, the quadrants and boss patterns need to be engraved on the integral spun cone bottom blank parts according to the drawings, so as to be used as a reference for stripping glue during subsequent milling. The accuracy of the reference line directly affects the final milling accuracy, so it is necessary to accurately measure its circumference, divide the four quadrants of the part equally according to the measurement results, and draw lines for the angular position and shape of each boss as shown in the figure. However, due to the large size of the integral spun cone bottom, the diameter after spinning is greater than 3 meters, the ball height is more than 1 meter, and the body is large. The part has an overall ellipse and slight waves on the edge. This irregular part brings great difficulty to detection.

[0004] Conventional high-precision testing instruments cannot quickly and accurately measure the circumference of large and irregularly shaped parts. Usually, they are measured by pulling a tape measure. However, tape measurement is also difficult to operate and the measuring position of the tape measure is fixed. Since the diameter of the overall spinning cone bottom is greater than 3 meters, the circumference can reach more than 10 meters, and the contact surface with the tape measure is an inclined arc surface, which makes the actual contact situation become a line of contact. When measuring the circumference of the tape measure, it must be tightly fitted to get a closer measurement result to the true value. When the measuring personnel tighten the tape measure, due to the inclined arc surface, the tape measure will slide toward the inclined surface and cannot be fixed. If a multi-person manually controlled fixing method is adopted, if one person is 1 meter, more than 10 people are needed, if 0.5 meters, more than 20 people are needed. At the same time, the control distance of 0.5 meters will produce fitting errors that cannot meet the measurement accuracy requirements, and personnel cannot synchronize and maintain an action for a long time for the fitter to complete the scribing operation. If professional calipers are used for fixing, there is a need to process convex and concave clamping feet with hyperbolic surfaces to achieve a stable fixing effect, dozens of them and the cost is high. In addition, each time the fixed caliper is fixed, it will cause different degrees of damage to the tape measure, destroying the structure of the tape measure, causing the value to deviate, and the detection tool becomes inaccurate, so it is impossible to complete accurate measurement. Therefore, the rapid and accurate measurement of the circumference of this large integral spinning cone bottom part has not been effectively solved. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for quickly measuring the circumference of a large integrally spun cone-bottom part for aerospace use; by analyzing the detection difficulties of measuring the circumference of cone-bottom parts, the type of tape measure to be selected and the placement of the tape measure and the reference line are determined, and a fixed distance is designed. Ordinary transparent tape is innovatively used to replace people or calipers for fixing, so as to achieve the purpose of controlling slippage and close fitting, and can be maintained for a long time to meet the requirements of fitter marking. The circumference detection accuracy and fitter marking quality are improved, the production efficiency is increased by nearly 40 times, the processing cost is reduced, and the production cycle is shortened.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for quickly measuring the circumference of a large integrally spun cone-bottom part for aerospace use comprises the following measuring steps:

[0008] S1. Place the large cone-bottom part to be tested with the perimeter downward on the workbench, and then vertically carve a starting line on the perimeter reference line;

[0009] S2. Align the zero line of the tape measure with the starting line, and align the lower edge of the tape measure with the circular reference line on the part to measure the circumference; align the upper edge of the tape measure with the circular reference line. Due to the inclined surface, the tape measure cannot fit tightly with the part. The upper edge of the tape measure will be suspended in the air, generating waves. The actual measurement is the circumference of the dotted line below the reference line, not the circumference of the reference line, and the correct measurement cannot be completed. When the lower edge of the tape measure is aligned and pasted with the circular reference line, due to the relationship between the lower edge and the circular reference line, the contact point can always be kept completely in contact with the surface of the part to ensure the correctness of the measurement position.

[0010] S3. Calculate the arc length of the equal division and the angle position of the relevant boss circle through the measurement results of the circumference, and divide the four quadrants of the part into equal parts, as well as the position and shape of each boss.

[0011] Furthermore, S2 also includes using a transparent adhesive tape to stick the measuring tape to the surface of the part, and sequentially performing the sticking operation along the circular reference line.

[0012] Furthermore, the lower edge of the tape measure should be aligned with the circular reference line when pasting. The lower edge of the tape measure should be aligned with the circular reference line when pasting each section. In addition, the tape measure should be placed in the center of the tape as much as possible when pasting. That is, when pasting the tape, try to ensure that it is symmetrical from top to bottom to obtain a stable fixing effect.

[0013] Furthermore, the cut length of the transparent adhesive tape is 100 mm.

[0014] Furthermore, the pasting operation is performed at intervals of 150 to 200 mm along the circular reference line. This distance can be adjusted according to the specific measured inclination, but it must be basically consistent.

[0015] The present invention has the following advantages:

[0016] (1) The present invention uses the technical solution to allow two operators to complete fixed measurement work in 5 minutes, which is much more efficient than the previous 40 minutes when more than 10 people could not accurately complete the measurement work. The number of operators is greatly reduced, and a large number of labor and professional caliper costs are eliminated, and the efficiency is improved to reduce the production cost.

[0017] (2) The present invention measures all quadrant bisectors and boss angle lines of a part under the same long-term unchanged reference, which significantly improves quality efficiency, and significantly improves detection accuracy and benchwork marking efficiency and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the integrally spun cone bottom part of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the integrally spun cone bottom part of the present invention;

[0020] Figure 3 This is a schematic diagram of perimeter measurement of the present invention;

[0021] Figure 4 This is a partial enlarged view of the baseline of the present invention;

[0022] Figure 5 This is a schematic diagram of the adhesive tape of the present invention;

[0023] In the picture, 1. parts; 2. platform; 3. measuring tape; 4. tape. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] Testing measuring tools: There are many types of tape measures and complex specifications. First of all, steel tape measures should be used. Non-metallic materials are affected by factors such as temperature and tension and cannot meet the measurement accuracy requirements. That is, precision metric unit tape measures with tape measures are used with an accuracy of 0.1mm. The measuring length is selected according to the measured size. The measuring length of the present invention is 15 meters. The contact surface of the spring tape measure is an arc, so it cannot be completely fitted when measuring the circumference, and the detection error is very large. The contact surface of the tape measure with tape measure is a plane, so it can be completely fitted with the product when measuring the circumference, and the detection error is very small.

[0027] Fixing tools: Ordinary common transparent adhesive tape can be used, but the specification width should be 40-50mm and the thickness should be 45um to achieve a firm fixing effect. The transparent material can also clearly identify the scale size of the tape measure, without affecting the reading and the fitter's scoring operation, and will not cause any damage to the tape measure.

[0028] The invention discloses a method for quickly measuring the circumference of a large integrally spun cone-bottom part for aerospace use.

[0029] S1, such as Figure 3 As shown in the figure, place the large cone-bottom part to be tested with the circumference downward on a workbench with a height of one meter, with the sphere of the part facing upward, and then vertically carve a starting line on the circumference reference line. After the spinning process of the integrally spun cone-bottom part is completed, a circle of reference lines will be engraved on the allowance along the circumference direction;

[0030] S2, such as Figure 3 , 4 As shown, align the zero line of the tape measure with the starting line, and align the lower edge of the tape measure width with the circular reference line on the part to measure the circumference; align the upper edge of the tape measure width with the circular reference line. Due to the inclined surface, the tape measure cannot fit tightly with the part. The upper edge of the tape measure width will be suspended in the air, generating waves. The actual measurement is the circumference of the dotted line below the reference line, not the circumference of the reference line, and the correct measurement cannot be completed. When the lower edge of the tape measure width is aligned and pasted with the circular reference line, due to the relationship between the lower edge and the circular reference line, the contact point can always be kept completely in contact with the surface of the part, ensuring the correctness of the measurement position.

[0031] Then take a piece of transparent adhesive tape and cut a small section of about 100mm in length. Stick the tape measure on the surface of the part, every 150~200mm. This distance can be adjusted according to the specific inclination of the measurement, but it must be basically consistent. Stick it in one place and follow the circular reference line in a few minutes to complete the fixation and circumference measurement. Figure 5 As shown, it is important to note that the lower edge of the tape measure must be aligned with the circular reference line when pasting each section. Also, try to keep the tape measure in the center of the tape when pasting. In other words, try to ensure upper and lower symmetry when pasting the tape to obtain a stable fixing effect.

[0032] S3. Keep sticking the tape, calculate the arc length of the equal division and the angle position of the related boss circle through the circumference measurement result, divide the four quadrants of the part equally, and mark the position and shape of each boss. After completion, just peel off the tape one by one, which is very efficient.

[0033] The method of the present invention solves the problem of the cost of using a large amount of manual labor or professional calipers to fix the tape measure when the tape measure slips on the inclined arc surface when measuring the circumference of a large irregular hemispherical shell component, eliminates manual errors and damage to the tape measure caused by professional calipers, and at the same time improves the circumference detection accuracy and the quality of fitter marking, so that the production efficiency increases by nearly 40 times and the production cycle is shortened. By analyzing the difficulties in detecting the circumference of parts, the type of tape measure to be selected and the placement of the tape measure and the reference line are determined, and a fixed distance is cleverly designed to use ordinary transparent tape to fix it instead of the fixing function of people or calipers, while achieving the purpose of controlling slippage and close fitting, achieving an excellent fixing effect, and can maintain for a long time to meet the needs of subsequent fitters to complete the marking operation. The method has the advantages of simple principle, low cost, and strong applicability. It has been proved through practice that this method for rapid measurement of the circumference of large integrally spun cone-bottom parts is a new measurement method that is very suitable for measuring the circumference of large irregular hemispherical shell components in aerospace and related industries.

Claims

1. A method for quickly measuring the circumference of a large integrally spun cone-bottom part for aerospace use, characterized in that: The measurement steps include: S1. Place the large cone-bottom part to be tested with the perimeter downward on the workbench, and then vertically carve a starting line on the perimeter reference line; S2. Align the zero line of the tape measure with the starting line, and align the lower edge of the tape measure width with the circular reference line on the part to measure the circumference; S3. Calculate the arc length of the equal division and the angle position of the relevant boss circle through the measurement results of the circumference, and divide the four quadrants of the part into equal parts, as well as the position and shape of each boss.

2. A method for rapid measurement of the circumference of a large integrally spun cone-bottom part for aerospace use according to claim 1, characterized in that: S2 also includes using a transparent adhesive tape to stick the measuring tape to the surface of the part, and sequentially performing the sticking operation along the circular reference line.

3. A method for rapid measurement of the circumference of a large integrally spun cone-bottom part for aerospace use according to claim 2, characterized in that: When pasting, the lower edge of the tape measure should be aligned and coincide with the circular reference line.

4. A method for rapid measurement of the circumference of a large integrally spun cone-bottom part for aerospace use according to claim 2, characterized in that: The cut length of the transparent adhesive tape is 100 mm.

5. The method for rapid measurement of the circumference of a large integrally spun cone-bottom part for aerospace use according to claim 2 is characterized in that: Carry out the pasting operation every 150 to 200 mm along the circular reference line.

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