High-quality accurate forming method for fixed-curvature bending component

Abstract

The invention discloses a high-quality accurate forming method for a fixed-curvature bent component, and relates to the technical field of advanced manufacturing of metal components, the method comprises the following steps: firstly, carrying out axis extraction on a target component and obtaining a corresponding program through theoretical analysis, and secondly, carrying out high-quality accurate forming on the target component by using free bending forming equipment on the premise of ensuring the forming quality through an experiment. The arc length l and the forming time t of the transition section program are reduced as much as possible to improve the forming quality and the forming precision, then the transition section program is used for replacing part of the straight line sections to compensate errors of the transition sections in advance, meanwhile, the error accumulation situation caused by multiple transition sections is avoided, and finally an experimental component model is obtained through laser scanning equipment after an experiment. According to the high-quality precise forming method for the fixed-curvature bent component, the urgent requirements for high-precision components in the fields of aerospace, the automobile industry, energy equipment and the like are met, and the bottlenecks of a traditional forming technology on precision control, quality stability and production efficiency are effectively broken through.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal construction manufacturing, in particular to a high-quality precise forming method for a curved member with a specified curvature. BACKGROUND

[0002] In the modern industrial field, especially in key industries such as aerospace, automobile industry and energy equipment, the high-quality precise forming technology of curved members with a specified curvature occupies a decisive position.

[0003] With the continuous rapid development of science and technology, these industries have put forward increasingly stringent requirements for the performance and quality of equipment. Taking aerospace as an example, the lightweight design and high performance pursuit of aircraft require that key components such as engines and fuel systems must have higher precision and reliability; in the automobile industry, in order to meet the increasingly stringent energy-saving and emission-reducing standards, engines and fuel systems need to be continuously optimized and efficiency improved; in the field of energy equipment, whether it is the transportation pipeline of petroleum and chemical industry or the key components of new energy equipment, there are high expectations for the forming quality of the components.

[0004] In the engine and fuel pipeline system, high-precision and high-quality curved members with a specified curvature play a decisive role. They not only directly relate to the overall performance of the system, ensuring smooth transmission of fluids and efficient conversion of energy, but also significantly improve the space utilization rate within the system, achieving more compact and reasonable layout design. However, existing forming technologies have certain limitations in precision, quality stability, etc., and are difficult to fully meet these increasingly upgraded needs. Therefore, there is an urgent need for an innovative high-quality precise forming method for curved members with a specified curvature to break through technical bottlenecks and promote the high-quality development of related industries. SUMMARY

[0005] The purpose of the present application is to provide a high-quality precise forming method for curved members with a specified curvature, which solves the problem of inconvenience in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A high-quality precise forming method for curved members with a specified curvature, first extracts the axis of the target member and obtains the corresponding program through theoretical analysis, then uses a free bending forming device to reduce the arc length l and forming time t of the transition section program as much as possible under the premise of ensuring forming quality, to improve forming quality and forming precision, then replaces part of the straight line segment with the transition section program to compensate for the error of the transition section in advance, while avoiding error accumulation caused by multiple transition sections, and finally measures and calculates the forming angle difference θ between the experimental member model and the target member model through a laser scanning device after the experiment, and calculates the arc length through the arc length calculation formula The length of the stable forming section that needs to be compensated or reduced is calculated, and the forming program is finally determined.

[0008] Based on the technical scheme, the application further provides the following optional technical schemes.

[0009] In an optional scheme, the axis of the target component is extracted by digital-analog software first, and each stable arc bending section of the curved component needs to have a certain straight section on both sides, that is, the corresponding program of each stable arc bending section obtained by theoretical analysis includes: straight section 1 program, transition section 1 program, stable forming section program, transition section 2 program, and straight section 2 program.

[0010] In an optional scheme, the smaller the arc length l of the transition section program is, the shorter the time t is, the larger the Vu (bending die eccentric speed) is, the higher the axis accuracy is, and the smaller the error is. In the experiment using the free bending forming equipment, the arc length of the transition section 1 is taken as the stable arc bending section program at the beginning of the experiment The eccentric distance of the stable arc bending section, that is, the distance from the center of the bending die to the origin, and the Vz (pipe material pushing speed) = 20 mm / s, and the time t = l / 20 s. First, the time t is fixed, and the arc length l is gradually reduced by 0.1U each time. As long as the forming surface is not scratched and wrinkled, the process continues, and the minimum arc length lmin of the transition section 1 is finally determined. Second, based on the determination of lmin, the time t is gradually reduced, that is, Vu = U / t is gradually increased. As long as the forming surface is not scratched and wrinkled, the process continues, and the minimum time tmin of the transition section 1 is finally determined, and then the transition section 1 program is determined. The transition section 2 is the same.

[0011] In an optional scheme, the determined transition section 1 program is executed at the tail of the straight section 1 program, the arc length replaced by the straight section 1 program accounts for k (0≤k≤1) in the transition section 1 arc length, the arc length replaced by the straight section 1 program is supplemented into the stable forming section program. First, take k = 0, and perform the experiment. The experimental component model obtained by the laser scanning device is compared with the target component model. If the maximum error is less than 1%, k can be determined. The transition section 2 program is processed in the same way.

[0012] The experimental component model of the determined program is obtained by the laser scanning device, and the experimental component model is measured and calculated with the target component model forming angle difference θ. The arc length calculation formula is The length of the stable forming section that needs to be compensated or reduced is calculated, and the forming program is finally determined.

[0013] Compared with the prior art, the application has the following beneficial effects:

[0014] The application provides a high-quality precise forming method for a constant-curvature curved component, and effectively breaks through the bottleneck of traditional forming technology in precision control, quality stability and production efficiency in the fields of aerospace, automobile industry, energy equipment and the like. Through fine optimization of transition section parameters, intelligent replacement of straight sections and transition sections and error compensation mechanism based on laser scanning, the method significantly improves the forming precision and surface quality of the constant-curvature curved component, and through shortening the arc length and time of the transition section, the forming efficiency of a single component is improved, and the material utilization rate is improved.

[0015] In the field of aerospace, the method can help the engine fuel pipeline to realize a bending angle precision of ±0.1°, and guarantee the reliability and space utilization rate of the fuel system. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 . It is a flow chart of the high-quality precise forming method for a constant-curvature curved component;

[0017] Figure 2 . It is a schematic view of an axis of a target component;

[0018] Figure 3 . It is a schematic view of an axis comparison between a target component and an experimental component;

[0019] Figure 4 . It is a schematic view of a transition section axis comparison between a target component and an experimental component;

[0020] Figure 5 . It is a schematic view of a stable forming section axis comparison between a target component and an experimental component;

[0021] Figure 6 . It is a schematic view of an experimental component. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0023] The application provides a high-quality precise forming method for a constant-curvature curved component, and the specific process is as follows Figure 1As shown, characterized in that: first, the corresponding program of the target component is obtained by theoretical analysis of the target component; second, under the premise of ensuring the forming quality, the arc length l and the forming time t of the transition section program are reduced as much as possible to improve the forming quality and forming precision, then the error of the transition section is compensated in advance by replacing part of the straight line section with the transition section program, while avoiding the error accumulation caused by multiple transition sections, finally the experimental component model is obtained by laser scanning equipment after the experiment, the experimental component model and the target component model are measured and calculated at the forming angle difference θ, and the arc length calculation formula The length to be compensated or reduced in the stable forming section is calculated, and the forming program is finally determined.

[0024] The high-quality and precise forming method of the constant-curvature curved component is characterized in that: first, the axis of the target component is extracted by numerical modeling software, and second, each stable arc bending section of the constant-curvature curved component needs to have a certain straight line section on both sides, that is, the corresponding program obtained by theoretical analysis includes: straight line section 1 program, transition section 1 program, stable forming section program, transition section 2 program, and straight line section 2 program.

[0025] The high-quality and precise forming method of the constant-curvature curved component is characterized in that: the smaller the transition section arc length l is, the shorter the time t is, the larger the Vu (bending die eccentric speed) is, the higher the axis precision is, and the smaller the error is. The transition section 1 arc length is taken as the stable arc bending section program at the beginning of the experiment The stable arc bending section eccentricity, that is, the distance from the bending die center to the origin, and the Vz (pipe material pushing speed) = 20 mm / s, the time t = l / 20 s, first, fix the time t and gradually reduce the arc length l by 0.1U each time, as long as the forming surface is not scratched and wrinkled, continue, finally determine the transition section 1 arc length lmin, second, gradually reduce the time t based on the determination of lmin, increase Vu = U / t by 0.2s each time, as long as the forming surface is not scratched and wrinkled, continue, finally determine the transition section 1 time tmin, and then determine the transition section 1 program, and the transition section 2 is the same.

[0026] The high-quality and precise forming method of the constant-curvature curved component is characterized in that: the determined transition section 1 program is executed at the tail of the straight line section 1 program, the replaced arc length of the straight line section 1 program accounts for k (0≤k≤1) in the transition section 1 arc length, the replaced arc length of the straight line section 1 program is supplemented into the stable forming section program, first, take k = 0, perform the experiment, compare the experimental component model and the target component model by laser scanning equipment, if the maximum error is less than 1%, k is determined, if not, k = k + 0.1 continue the experiment. The transition section 2 program is processed in the same way.

[0027] The experimental component model determined in the previous step is obtained by a laser scanning device, the experimental component model and the target component model are measured and calculated at a forming angle difference θ, and the length to be compensated or reduced in the stable forming section is calculated by an arc length calculation formula The length to be compensated or reduced in the stable forming section is calculated, and the forming program is finally determined.

[0028] Embodiment

[0029] First, the axis of the target component is extracted by a digital model software, as shown in FIG. 1, and then the corresponding program of the target component is obtained by theoretical analysis. Each stable arc bending section program includes: straight line section 1 program, transition section 1 program, stable forming section program, transition section 2 program, and straight line section 2 program. Figure 2

[0030] Straight line section 1 program: x1=0, y1=0, z1=60, t1=3;

[0031] Transition section 1 program: x2=0, y2=6, z2=24, t2=1.2;

[0032] Stable forming section program: x3=0, y3=6, z3=150, t3=7.5

[0033] Transition section 2 program: x4=0, y4=0, z4=24, t4=1.2;

[0034] Straight line section 2 program: x5=0, y5=0, z5=60, t5=3.

[0035] Second, the arc length of the transition section 1 is taken as the stable arc bending section program at the beginning of the experiment The eccentricity of the stable arc bending section is the distance from the bending die center to the origin, and the tube pushing speed Vz is 20 mm / s, the time t is 1 / 20 s. First, fix the time t and gradually reduce the arc length l by 0.1U each time. As long as the forming surface is not scratched and wrinkled, continue to proceed, and finally determine the transition section 1 arc length lmin=18=z2. Secondly, gradually reduce the time t based on the determination of lmin, that is, Vu=U / t gradually increases each time. As long as the forming surface is not scratched and wrinkled, continue to proceed, and finally determine the transition section 1 time tmin=0.2. Further determine the transition section 1 program, and the transition section 2 is the same.

[0036] Transition section 1 program: x2=0, y2=6, z2=18, t2=0.2;

[0037] Transition section 2 program: x4=0, y4=0, z4=18, t4=0.2.

[0038] ​Third step, the determined transition section 1 program, in the straight section 1 program tail start execution, straight section 1 program is replaced by the arc length in transition section 1 arc length k(0≤k≤1) ratio, straight section 1 program is replaced by the arc length into the stable forming section program, first take k = 0, experiment, through the laser scanning device obtains the experimental component model and target component model comparison if the maximum error is less than 1%, namely k can be determined, if not satisfied, k = k + 0.1 continue experiment, finally determine k = 0.7. Transition section 2 program using the same processing. At this time the program is:

[0039] Straight section 1 program: x1 = 0, y1 = 0, z1 = 60-18*0.7 = 47.4, t1 = 3;

[0040] Transition section 1 program: x2 = 0, y2 = 6, z2 = 18, t2 = 0.2;

[0041] Stable forming section program: x3 = 0, y3 = 6, z3 = 150 + 18*0.7*2 = 175.2, t3 = 175.2 / 20 = 8.76 Transition section 2 program: x4 = 0, y4 = 0, z4 = 18, t4 = 0.2;

[0042] Straight section 2 program: x5 = 0, y5 = 0, z5 = 60-18*0.7 = 47.4, t5 = 3.

[0043] Fourth step, through the laser scanning device obtains the experimental component model of the program determined after the third step, the experimental component model and the target component model forming angle difference θ is measured and calculated, θ = 1°, through the arc length calculation formula Calculate the length of stable forming section needs to compensate or reduce, finally determine the forming program:

[0044] Straight section 1 program: x1 = 0, y1 = 0, z1 = 60-18*0.7 = 47.4, t1 = 3;

[0045] Transition section 1 program: x2 = 0, y2 = 6, z2 = 18, t2 = 0.2;

[0046] Stable forming section program: x3 = 0, y3 = 6, z3 = 150 + 18*0.7*2 = 175.2 + 1.75 = 176.95, t3 = 176.95 / 20 = 8.8475;

[0047] Transition section 2 program: x4 = 0, y4 = 0, z4 = 18, t4 = 0.2;

[0048] Straight section 2 program: x5 = 0, y5 = 0, z5 = 60-18*0.7 = 47.4, t5 = 3.

[0049] The final target member and the axis of the experimental member as prepared are compared as shown in Figure 3 The transition section and the axis of the stable forming section are compared as shown in Figure 4 , 5 The final experimental member as prepared is shown as 6.

[0050] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for high-quality and precise forming of a constant-curvature curved member, characterized by: The following steps are involved: Step 1: Extract the axis of the target component and obtain its corresponding program through theoretical analysis. Then, use the free bending forming equipment to reduce the arc length l and forming time t of the transition section program through experiments while ensuring the forming quality, so as to improve the forming quality and forming accuracy. Step 2: Replace some straight line segments with transition segment programs to compensate for transition segment errors in advance and avoid error accumulation caused by multiple transition segments. Step 3: After the final experiment, the experimental component model is obtained by laser scanning equipment, and the forming angle difference θ between the experimental component model and the target component model is measured and calculated. Calculate the length that needs to be compensated or reduced in the stable forming section and finally determine the forming procedure.

2. A high-quality and precise forming method for a constant curvature curved member according to claim 1, characterized in that: In step one: the axis of the target component is extracted through the numerical modeling software. Secondly, each stable arc bend section of the constant curvature curved component must have certain straight line segments on both sides. That is, the corresponding program obtained through theoretical analysis for each stable arc bend section includes: straight line segment 1 program, transition segment 1 program, stable forming segment program, transition segment 2 program, and straight line segment 2 program.

3. A high-quality and precise forming method for a constant curvature curved member according to claim 2, characterized in that: The smaller the arc length l of the transition section program, the shorter the time t, the greater the eccentric speed Vu of the bending die, the higher the axis accuracy and the smaller the error; the experiment was conducted using a free bending forming device. At the beginning of the experiment, the arc length l of the transition section 1 of each stable arc bending section program was set to 5U; To stabilize the eccentricity of the arc bending section, that is, the distance from the center of the bending die to the origin; The advancement speed of the pipe is Vz = 20 mm / s, and the time is t = 1 / 20 s. First, fix the time t and gradually reduce the arc length l, reducing it by 0.1U each time. As long as there are no scratches and wrinkles on the forming surface, continue to proceed, and finally determine the arc length of transition section 1 as lmin. Secondly, on the basis of determining lmin, gradually reduce the time t, that is, Vu = U / t and gradually increase it. If there are no scratches and wrinkles on the forming surface, continue to proceed, and finally determine the time tmin of transition section 1, and then determine the transition section 1 program. The transition section 2 program adopts the same processing method.

4. A high-quality and precise forming method for a constant curvature curved member according to claim 3, characterized in that: The determined transition segment 1 program is executed at the end of the straight segment 1 program. The arc length replaced by the straight segment 1 program accounts for k in the arc length of the transition segment 1, 0≤k≤1. The arc length replaced by the straight segment 1 program is added to the stable forming segment program. First, k=0 is taken and an experiment is conducted. The experimental component model is obtained by laser scanning equipment and compared with the target component model. If the maximum error is less than 1%, k can be determined. The transition segment 2 program is processed in the same way. The experimental component model of the determined program is obtained by laser scanning equipment, and the forming angle difference θ between the experimental component model and the target component model is measured and calculated. Calculate the length that needs to be compensated or reduced in the stable forming section and finally determine the forming procedure.

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