Cold bending method for variable curvature profiles

Abstract

The invention discloses a cold bending method for a variable curvature profile, comprising the steps of: performing different heat treatments on the profile, respectively monitoring the deformation amount and stress of each part of the profile under different heat treatment states, and respectively fitting to form corresponding function curves; comparing a plurality of the function curves and selecting the most gentle one as the first function curve, and taking the heat treatment state forming the first function curve as the first heat treatment state; selecting the profile in the first heat treatment state as the profile to be cold-bent; filling a polyurethane block in the cavity of the profile to be cold-bent; stretching and bending the profile to be cold-bent, and improving the cold bending effect of the profile by the cold bending method.

Description

Technical Field

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

[0002] With the continuous development of modern construction technology, more and more special-shaped buildings appear. For example, special-shaped curved curtain walls are loved and favored by people. The artistic and unique sense they show is also used in various scenes.

[0003] In order to achieve diversified shapes, curtain wall profiles often need to be cold-bent. The traditional cold-bending process directly heats the profile and uses a stretch-bending machine to control the bending of the profile. Profiles under the traditional cold-bending process are prone to forming defects such as thinning of the profile wall, surface wrinkling, and cross-sectional distortion during the stretching and bending process, which affects the strength and appearance of the profile. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a cold bending method for variable curvature profiles, so that the stress distribution in various parts of the profile during the cold bending process is uniform, 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 object, the technical solution adopted by the present invention is a cold bending method of a variable curvature profile, comprising the steps of:

[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 states, and fit them to form corresponding function curves;

[0007] Step 2: Compare the multiple function curves and select the most gentle one as the first function curve, and use 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: Filling the cavity of the profile to be cold-bent with a polyurethane block;

[0010] Step 5: bend the profile to be cold-bent.

[0011] A further improvement of the cold bending method of the variable curvature profile 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 of the variable curvature profile of the present invention is that when executing the above step 4, the polyurethane block fills the cavity of the profile to be cold bent, and after executing the above step 5, the polyurethane block is taken out and circulated.

[0013] A further improvement of the cold bending method of a variable curvature profile of the present invention is that, when the above step 5 is performed, when the profile to be cold bent undergoes deformation and rebound, the stretching amount is adaptively increased immediately.

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

[0015] 1. Through experiments, the profile in the first heat treatment state is selected as the profile to be cold-bent, so that the stress distribution in each part is uniform during the bending process, thereby obtaining a better cold-bending effect.

[0016] 2. By using polyurethane blocks to fill the interior of the cold-bent profile, the cross-sectional bearing capacity and energy absorption capacity of the cold-bent profile are improved, so that the forming accuracy and quality of the cold-bent profile are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a stress distribution function curve diagram of the profile of the present invention under different heat treatment states. DETAILED DESCRIPTION

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

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

[0021] See also Figure 1 As shown, the cold bending method of the variable curvature profile 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 states, and fit them to form corresponding function curves;

[0023] Step 2: compare the multiple function curves and select the most gentle one as the first function curve, and use the heat treatment state that forms the first function curve 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: Filling the cavity of the cold-bent profile with a polyurethane block;

[0026] Step 5: Stretch-bend the cold-bent profile.

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

[0028] Specifically, Figure 1 The x-axis of this coordinate system is the deformation variable, and the y-axis is the stress. The black dotted function curve reflects the stress distribution of the T4 aluminum alloy profile, and the red solid function curve reflects the stress distribution of the T6 aluminum alloy profile. Obviously, the curve of the T4 profile is flatter, that is, the stress distribution of each part of the T4 aluminum alloy profile is more uniform.

[0029] Specifically, it is found through experiments that the cold bending performance of the T4 aluminum alloy profile is the best. The T4 aluminum alloy profile is an aluminum alloy that has been solution treated and then naturally aged at room temperature for a period of time.

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

[0031] Preferably, when executing the above step 4, the polyurethane block fills the cavity of the profile to be cold-bent, and after executing the above step 5, the polyurethane block is taken out and circulated.

[0032] The polyurethane block is provided to improve the cross-sectional bearing capacity and energy absorption capacity of the cold-bent profile, and the surface of the cold-bent profile is not easy to wrinkle during the stretching and bending process, so that the forming accuracy and quality of the cold-bent profile are improved.

[0033] By removing and recycling the polyurethane block, material costs are saved.

[0034] Preferably, when executing the above step 5, when the cold-bent profile deforms and rebounds, the stretching amount is adaptively increased immediately.

[0035] Specifically, when executing the above step 5, the profile to be cold-bent is first heated to the design temperature, and then a pre-stretching force is applied to the profile to be cold-bent until the material yield strength is reached. The bending rotation is loaded by the rotary cylinder of the bending machine, and the stretching cylinder makes the profile to be cold-bent move around the bending die according to the designed axial tension to bend the material.

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

[0037] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0038] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A cold bending method for a variable curvature profile, characterized in that: Includes 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 states, and fit them to form corresponding function curves; Step 2: Compare the multiple function curves and select the most gentle one as the first function curve, and use 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: Filling the cavity of the profile to be cold-bent with a polyurethane block; Step 5: bend the profile to be cold-bent.

2. The cold bending method of a variable curvature profile according to 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 of a variable curvature profile according to claim 1, characterized in that: When executing the above step 4, the cavity of the profile to be cold-bent is filled with the polyurethane block, and after executing the above step 5, the polyurethane block is taken out and circulated.

4. The cold bending method of a variable curvature profile according to claim 1, characterized in that: When executing the above step 5, when the cold-bent profile deforms and rebounds, the stretching amount is immediately and adaptively increased.

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