Numerical control roll bending method for aircraft variable-curvature skin part

Abstract

The application discloses a kind of aircraft variable curvature skin part numerical control roll bending method, comprising: first, the trial production of skin part, the rolling of preforming blank and each time during the rolling process, record the depth of each time of the down-regulation of upper roll, and the distance between the rolling mark line of left and right sides of part and the center line of part;For subsequent skin part blank processing: the blank of part is cut to be completely identical with the size and shape of blank used in the first step, and the center line of each blank is determined;According to the same method as the first time, without the aid of section sample during numerical control processing, in preforming blank and each time during the rolling process, the data recorded in the first step are used to program the rolling equipment, so that the rolling equipment adjusts the depth of down-regulation of upper roll and rolling arc length according to the program, i.e. without taking down blank, equipment completes the processing of entire part finally in the order of preforming, first rolling, second rolling…

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft variable curvature skin part roll forming, in particular to a numerical control roll forming method for aircraft variable curvature skin part. BACKGROUND

[0002] The aircraft wing leading edge skin part is generally formed by the traditional roll forming method. The part is mainly formed by multiple roll forming with the curvature gradually increasing. Generally, the large leading edge part needs 9-13 times of roll forming. When the large leading edge part is roll formed, at least three people are needed to operate together, one person operates the machine tool, and two people stabilize the part to align with the roll forming center line. Otherwise, the reference line of the raw material will deviate, and the center axis of the upper roll will not coincide, resulting in unqualified parts and wasting manpower. Since the roll forming is performed according to the roll forming mark line, the reaction speed of each person is different when observing the reference line position, and the time for notifying the machine tool operator to stop the machine tool will be different. The communication with the machine tool operator will produce errors, affecting the stability of product quality. In order to ensure the quality of the part, high skill level and a large amount of work experience are often needed. SUMMARY

[0003] The purpose of the present application is to provide a numerical control roll forming method for aircraft variable curvature skin part, which overcomes the problems of large error, difficult operation and low efficiency in the prior art.

[0004] In order to achieve the above task, the present application adopts the following technical scheme:

[0005] A numerical control roll forming method for aircraft variable curvature skin part, comprising:

[0006] Step 1: Collecting numerical control roll forming technical parameters

[0007] Firstly, the raw material of the skin part is placed on the roll forming equipment, the center line of the skin part is adjusted so that the center line passes through the centers of the two lower roll axes, and then the position of the upper roll axis is adjusted so that the lower part of the upper roll axis is higher than the highest point of the lower roll axis by a first preset distance. The roll forming equipment is started to make the raw material roll to the left and right to a second preset distance from the edge, so as to obtain a pre-formed raw material with a certain arc;

[0008] Secondly, the pre-formed raw material is taken down, the section template is placed on the pre-formed raw material so that the center lines of the two are aligned, and then the section template is rolled to the left and right. The position of the circular arc at the bottom of the section template and the tangent line of the pre-formed raw material is recorded as the roll forming mark line.

[0009] Again, after the rolling bending mark line is recorded, the preformed material is placed on the rolling bending equipment again for the first rolling bending; the first rolling bending needs the material to roll for multiple rounds, and each time the material is rolled, the upper rolling shaft is first adjusted downward by a depth, and then the rolling bending equipment is started to make the preformed material roll left and right for N times; then the upper rolling shaft is continuously adjusted downward, and the rolling bending equipment is started again to roll the preformed material; the same method is adopted to continuously adjust the downward depth of the upper rolling shaft, and the preformed material is rolled left and right after each adjustment;

[0010] Second rolling bending is performed: the preformed material after the first rolling bending is taken down, a section template is used to roll on the material to determine the rolling bending mark line of this time, and then the material is placed on the equipment, and the same method as the first rolling bending is adopted to process the material;

[0011] The above steps are repeated to roll the material for a preset number of times to obtain the processed part;

[0012] For the rolling of the preformed material and the rolling process each time, the downward depth of the upper rolling shaft each time and the distance between the rolling bending mark line of the left and right sides of the part and the center line of the part are recorded;

[0013] Second step, numerical control processing

[0014] For subsequent skin part material processing:

[0015] The part material is cut into a size and shape completely consistent with the material used in the first step, and the center line of each material is determined;

[0016] In the preformed material and each rolling process, the data recorded in the first step is used to program the rolling bending equipment, so that the rolling bending equipment adjusts the downward depth of the upper rolling shaft and the rolling arc length according to the program, that is, the material does not need to be taken down, and the equipment completes the processing of the entire part in the order of preformed material, first rolling bending, second rolling bending, and so on.

[0017] Further, for LY12-CZ-δ0.8 material, the downward adjustment range of the upper rolling shaft during the preformed material processing process should be 10 mm.

[0018] Further, the first preset distance is 4-10 mm.

[0019] Further, the second preset distance is 5-10 mm.

[0020] Further, the section template is a tool for manufacturing or inspecting the inner surface of the part, and the bottom of the section template is a circular arc surface.

[0021] Further, the value of N is 2-5 times.

[0022] Further, the preset number of times is 9-12 times.

[0023] A numerical control machining device, wherein a computer program for realizing the numerical control roll bending method of the aircraft variable curvature skin part is stored.

[0024] Compared with the prior art, the present application has the following technical features:

[0025] Through the method of the present application, the skin plate material is rolled to fit the part section template gradually when rolling, and the rolling distance L and the distance H between the upper and lower rollers are controlled by the machine tool, so that the problem of low efficiency and high labor intensity in the rolling of the variable curvature skin part is solved; the repeated alignment of the rolling center line and the visual inspection of the raw material rolling mark are no longer needed, so that the problem of large error caused by human factors and poor part quality in the rolling of the variable curvature skin part is solved. When the method of the present application is used, only the data recorded in the trial production need to be input into the machine tool, and the part can be rolled and formed gradually. The application of this method can improve the processing efficiency of the variable curvature skin part by about 80% compared with the existing method, and greatly improve the part quality. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The first step is a schematic diagram of the machining process for collecting numerical control roll bending technical parameters;

[0027] Figure 2 The second step is a schematic diagram of the numerical control machining process;

[0028] Wherein: t-material thickness;

[0029] R0-curvature radius of the part during rolling;

[0030] d1, d2-respectively the radius of the upper and lower rollers;

[0031] a-half pitch between the two lower rollers;

[0032] H-distance between the upper and lower rollers;

[0033] Figure 3 The third step is a schematic diagram of the raw material on the rolling equipment;

[0034] Figure 4 The fourth step is a schematic diagram of the data recorded in each rolling process in the embodiment of the present application. DETAILED DESCRIPTION

[0035] In view of the above problems of the prior art, the present application aims to provide a method for numerical control roll bending of an aircraft variable curvature skin part, to solve the problems of low efficiency, high labor intensity and poor part surface quality in the rolling of the existing variable curvature skin part, and to improve the processing efficiency.

[0036] The method for numerical control roll bending of an aircraft variable curvature skin part comprises the following steps: roll bending a variable curvature skin part, measuring the distance between a mark line and a base line of a blank after each roll bending, and recording the relative distance H between upper and lower rollers.

[0037] Referring to the drawings Figures 1-4 The present application provides a method for numerical control roll bending of an aircraft variable curvature skin part, comprising the following steps:

[0038] Firstly, collect technical parameters for numerical control roll bending

[0039] Firstly, place a blank of a skin part on a roll bending device, adjust the center line of the skin part so that the center line passes through the centers of two lower rollers, then adjust the position of an upper roller so that the lower part of the upper roller is 4-10 mm higher than the highest point of the lower roller, turn on the roll bending device to make the blank roll left and right to a position 5-10 mm away from the edge, thereby obtaining a preformed blank with a certain curvature; wherein the adjustment range of the lower part of the upper roller should be determined according to the specific thickness and material of the blank; generally, for a blank of LY12-CZ-δ0.8 material, the adjustment range should be 10 mm;

[0040] Secondly, take the preformed blank, place a section template on the preformed blank so that the center lines of the two are aligned, then roll the section template left and right, and record the position of the circular arc at the bottom of the section template and the tangent line of the preformed blank, which is recorded as a roll bending mark line; wherein the section template is a tool for manufacturing or inspecting the inner surface of a part, and the bottom of the section template is a circular arc surface;

[0041] Thirdly, after the roll bending mark line is recorded, place the preformed blank on the roll bending device again to perform the first roll bending; the first roll bending requires multiple rounds of rolling of the blank; each time, first lower the upper roller by a certain depth, then turn on the roll bending device to make the preformed blank roll left and right for 3 times; then continue to lower the upper roller, turn on the roll bending device again to roll the preformed blank; use the same method to continuously adjust the lowering depth of the upper roller;

[0042] Perform the second roll bending: take the preformed blank after the first roll bending, roll the blank using the section template to determine the roll bending mark line for this time, then place the blank on the device, and use the same method as the first roll bending to process the blank;

[0043] Repeat the above steps to roll the blank for 9-12 times to obtain the processed part;

[0044] In the first step, record the lowering depth of the upper roller each time and the distance between the roll bending mark line on the left and right sides of the part and the center line of the part during the rolling of the preformed blank and each roll bending process.

[0045] Second step, numerical control processing

[0046] For the subsequent skin parts raw material processing:

[0047] The part raw material is cut into the same size and shape as the raw material used in the first step, and the center line of each raw material is determined;

[0048] According to the same method as the first time, without the help of the section template, in the preforming raw material and each rolling bending process, use the data recorded in the first step to program the rolling bending equipment, so that the rolling bending equipment adjusts the upper rolling shaft downward depth and rolling arc length according to the program, that is, without taking out the raw material, the equipment stops rolling after reaching the preset number of preforming, first rolling, second rolling… or the part has been formed, completing the entire part processing.

[0049] Embodiment:

[0050] Step one, trial variable curvature skin parts, after each rolling, measure and record the arc length L between the rolling mark line and the raw material center line, and the relative distance H between the upper and lower rolling shafts, such as Figure 2 .

[0051] Step two, processing subsequent parts, align the reference line of the raw material with the axis of the upper rolling shaft, determine the curvature radius R of the first rolling, adjust the distance H between the upper and lower rolling shafts, first roll forward L1 distance, then roll backward L1+L2 distance, and finally roll forward L2 distance, so that the reference line of the raw material and the axis of the upper rolling shaft coincide again;

[0052] Step three, adjust the distance H between the upper and lower rolling shafts successively, roll the corresponding distance L, until the part is finally shaped.

[0053] This method fills the gap of digital processing of variable curvature skin parts of aircraft, making the part processing process accurate; This method overcomes the shortcomings of low efficiency and high labor intensity of existing aircraft skin rolling forming, reduces labor intensity and improves part processing efficiency; This method overcomes the shortcomings of discontinuous curvature and poor surface quality of existing aircraft skin rolling forming, realizes smooth transition of each area of the part, and improves the surface quality of the part. This method overcomes the shortcomings of part defects caused by lack of personal experience in existing aircraft skin rolling forming, so that inexperienced and apprentice workers can also manufacture qualified parts.

Claims

1. A method for numerical control roll bending of an aircraft variable curvature skin part, characterized in that, The application relates to a numerical control rolling bending method for an aircraft variable-curvature skin part. Firstly, the raw material of the skin part is placed on a rolling bending device, the center line of the skin part is adjusted so that the center line passes through the centers of two lower rolling shafts, then the position of an upper rolling shaft is adjusted so that the lower part of the upper rolling shaft is higher than the highest point of the lower rolling shaft by a first preset distance, the rolling bending device is started to make the raw material roll to the left and right to a second preset distance from the edge, so that a preformed raw material with a certain arc is obtained; secondly, the preformed raw material is taken down, a cutting surface template is placed on the preformed raw material so that the center lines of the preformed raw material and the cutting surface template are aligned, then the cutting surface template is rolled to the left and right, and the position of the tangent line of the bottom arc of the cutting surface template and the preformed raw material is recorded as a rolling bending mark line; thirdly, after the rolling bending mark line is recorded, the preformed raw material is placed on the rolling bending device again to perform first rolling bending; the preformed raw material needs to be rolled for multiple rounds in the first rolling bending, and each time, the upper rolling shaft is first adjusted to a certain depth, then the rolling bending device is started to make the preformed raw material roll to the left and right for N times; then the upper rolling shaft is continuously adjusted to a certain depth, and the rolling bending device is started again to roll the preformed raw material; the same method is adopted to continuously adjust the depth of the upper rolling shaft, and the preformed raw material is rolled to the left and right after each adjustment; second rolling bending is performed: the preformed raw material after the first rolling bending is taken down, the cutting surface template is rolled on the raw material to determine the rolling bending mark line of this time, then the raw material is placed on the rolling bending device, and the same method as the first rolling bending is adopted to process the raw material; the above steps are repeated to roll the raw material for a preset number of times to obtain a processed part; the depth of the upper rolling shaft is recorded each time, and the distance between the rolling bending mark lines on the left and right sides of the part and the center line of the part is recorded during the rolling of the preformed raw material and each rolling process; numerical control processing is performed: when the raw material of the subsequent skin part is processed, the raw material of the part is cut into the same size and shape as the raw material used in the first step, and the center line of each raw material is determined; during the preforming of the raw material and each rolling process, the data recorded in the first step is used to program the rolling bending device, so that the rolling bending device adjusts the depth of the upper rolling shaft and the rolling arc length according to the program, that is, the raw material does not need to be taken down, and the device finally completes the processing of the whole part in the order of preforming, first rolling bending, second rolling bending and the like. For the raw material of LY12-CZ-0.8, the adjusting range of the depth of the upper rolling shaft during the preforming of the raw material should be 10 mm. The first preset distance is 4-10 mm. The second preset distance is 5-10 mm. The cutting surface template is a tool for manufacturing or testing the inner surface of a part, and the bottom of the cutting surface template is a circular arc surface. The value of N is 2-5 times. The preset number of times is 9-12 times.

8. A numerical control processing device, wherein a computer program for realizing the numerical control rolling bending method for an aircraft variable-curvature skin part according to any one of claims 1-7 is stored in the numerical control processing device. ​ ​ ​ 2. The method of claim 1, wherein, ​ 3. The method of claim 1, wherein, ​ 4. The method of claim 1, wherein, ​ 5. The method of claim 1, wherein, ​ 6. The method of claim 1, wherein, ​ 7. The method of claim 1, wherein, ​ ​

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