Cold bending method of variable curvature profiles

Abstract

The application discloses a cold bending method of a variable-curvature profile, and comprises the following steps: performing different heat treatments on the profile, respectively monitoring deformation amounts of each part of the profile in different heat treatment states and stresses, and respectively fitting corresponding function curves; comparing a plurality of the function curves and selecting the most gentle one as a first function curve, and selecting a heat treatment state for forming the first function curve as a first heat treatment state; selecting the profile in the first heat treatment state as a to-be-cold-bent profile; filling a polyurethane block in a cavity of the to-be-cold-bent profile; and performing stretch bending on the to-be-cold-bent profile, so that the cold bending effect of the profile is improved.

Description

Technical Field

[0001] This invention relates to the field of building construction, and in particular to a cold bending method for variable curvature profiles. Background Technology

[0002] With the continuous development of modern building technology, irregularly shaped buildings are appearing more and more frequently. For example, irregularly shaped curved curtain walls have become popular and favored, and their artistic and unique appeal has been applied in various scenarios.

[0003] To achieve diverse designs, curtain wall profiles often need to be cold-bent. Traditional cold-bending processes involve directly heating the profiles and using a bending machine to control their bending. During the stretching and bending process, profiles using traditional cold-bending processes are prone to forming defects such as thinning of the profile wall, surface wrinkling, and cross-sectional distortion, which affect the strength and appearance of the profiles. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cold bending method for variable curvature profiles, so that the stress distribution in each part of the profile is uniform during the cold bending process, and the surface is flat and wrinkle-free, thereby improving the cold bending accuracy and the strength of the profile.

[0005] To achieve the above objectives, the technical solution adopted by this invention is a cold bending method for variable curvature profiles, comprising the following steps:

[0006] Step 1: Perform different heat treatments on the profile, monitor the deformation and stress of each part of the profile under different heat treatment conditions, and fit the corresponding function curves respectively;

[0007] Step 2: Compare the multiple function curves and select the flattest one as the first function curve, and take the heat treatment state that forms the first function curve as the first heat treatment state.

[0008] Step 3: Select the profile in the first heat treatment state as the profile to be cold-bent;

[0009] Step 4: Fill the cavity of the profile to be cold-bent with polyurethane blocks;

[0010] Step 5: Perform a stretch bend on the profile to be cold-bent.

[0011] A further improvement of the cold bending method for variable curvature profiles of the present invention is that the profile is an aluminum alloy profile, and the heat treatment state is selected from T0, T1, T2...T10.

[0012] A further improvement of the cold bending method for variable curvature profiles of the present invention is that, when performing step 4 above, the polyurethane block is filled into the cavity of the profile to be cold bent, and after performing step 5 above, the polyurethane block is removed and reused.

[0013] A further improvement of the cold bending method for variable curvature profiles of the present invention is that, when performing step 5 above, the tensile amount is immediately and adaptively increased when the profile to be cold-bent undergoes deformation and springback.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] 1. By selecting profiles in the first heat treatment state as the profiles to be cold-bent through experiments, the stress distribution in various parts of the profiles is made uniform during the bending process, thereby obtaining a better cold-bending effect.

[0016] 2. By filling the interior of the profile to be cold-bent with polyurethane blocks, the cross-sectional load-bearing capacity and energy absorption capacity of the profile to be cold-bent are improved, thereby improving the forming accuracy and quality of the profile to be cold-bent. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a curve showing the stress distribution function of the profile of the present invention under different heat treatment conditions. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0020] The cold bending method for variable curvature profiles of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Please see Figure 1 As shown, the cold bending method for variable curvature profiles includes the following steps:

[0022] Step 1: Perform different heat treatments on the profile, monitor the deformation and stress of each part of the profile under different heat treatment conditions, and fit the corresponding function curves respectively;

[0023] Step 2: Compare multiple function curves and select the flattest one as the first function curve. The heat treatment state that forms the first function curve is taken as the first heat treatment state.

[0024] Step 3: Select the profile in the first heat treatment state as the profile to be cold-bent;

[0025] Step 4: Fill the cavity of the profile to be cold-bent with polyurethane blocks;

[0026] Step 5: Bend the profile to be cold-bent.

[0027] Preferably, the profile is an aluminum alloy profile, and the heat treatment state is selected from T0, T1, T2...T10.

[0028] Specifically, such as Figure 1 In this coordinate system, the x-axis represents deformation and the y-axis represents stress. The function curve with black dashed lines reflects the stress distribution of the T4 state aluminum alloy profile, while the function curve with red solid lines reflects the stress distribution of the T6 state aluminum alloy profile. Obviously, the curve of the T4 state profile is flatter, meaning that the stress distribution in various parts of the T4 state aluminum alloy profile is more uniform.

[0029] Specifically, experiments showed that the T4 state aluminum alloy profile has the best cold bending performance. The T4 state aluminum alloy profile is an aluminum alloy that has undergone solution treatment and then natural aging at room temperature for a period of time.

[0030] The T4 state aluminum alloy profile has better toughness, and the stress distribution in various parts is uniform during the bending process. The thickness of the profile wall is uniform after bending, which improves the bending effect.

[0031] Preferably, when performing step 4 above, the polyurethane block is filled into the cavity of the profile to be cold-bent, and after performing step 5 above, the polyurethane block is removed and reused.

[0032] By setting this polyurethane block, the cross-sectional load-bearing capacity and energy absorption capacity of the profile to be bent are improved. During the bending process, the surface of the profile to be bent is less prone to wrinkling, thus improving the forming accuracy and quality of the profile to be bent.

[0033] By removing and reusing the polyurethane block, material costs were saved.

[0034] Preferably, when performing step 5 above, the amount of stretching is immediately increased adaptively when the profile to be cold-bent deforms and springs back.

[0035] Specifically, when performing step 5 above, the profile to be cold-bent is first heated to the design temperature, and then a pre-tensioning force is applied to the profile to be cold-bent until the material yield strength is reached. The bending machine is then loaded with a bending rotation by a rotary cylinder, and the tension cylinder is pulled along the design axial force to make the profile to be cold-bent make a fitting motion around the bending die to bend the material.

[0036] Specifically, after the cold-bending profile is bent, the profile is subjected to corresponding heat treatment according to the actual performance requirements.

[0037] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A cold bending method for a variable curvature profile, characterized in that, Including the following steps: Step 1: Perform different heat treatments on the profile, monitor the deformation and stress of each part of the profile under different heat treatment conditions, and fit the corresponding function curves respectively; Step 2: Compare the multiple function curves and select the flattest one as the first function curve, and take the heat treatment state that forms the first function curve as the first heat treatment state. Step 3: Select the profile in the first heat treatment state as the profile to be cold-bent; Step 4: Fill the cavity of the profile to be cold-bent with polyurethane blocks; Step 5: Perform a stretch bend on the profile to be cold-bent.

2. The cold bending method for variable curvature profiles as described in claim 1, characterized in that, The profile is an aluminum alloy profile, and the heat treatment state is selected from T0, T1, T2...T10.

3. The cold bending method for variable curvature profiles as described in claim 1, characterized in that, When performing step 4 above, the polyurethane block is filled into the cavity of the profile to be cold-bent. After performing step 5 above, the polyurethane block is removed and reused.

4. The cold bending method for variable curvature profiles as described in claim 1, characterized in that, When performing step 5 above, if the profile to be cold-bent deforms and springs back, the stretching amount should be increased immediately and adaptively.

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