Titanium alloy U-shaped section profile flexible bending and twisting forming method based on induction heating

Abstract

The invention belongs to the technical field of advanced manufacturing of complex metal components, and particularly discloses a flexible bending and twisting forming method for a titanium alloy U-shaped section profile based on induction heating, which is used for solving the problem of poor bending effect in the prior art. The invention discloses a flexible bending and twisting forming method for a titanium alloy U-shaped section profile based on induction heating. The titanium alloy U-shaped section profile component is heated through the induction coil, so that bending and twisting forming of the titanium alloy profile component is achieved. An induction coil is additionally arranged between a bending die and a guide, when a profile component is bent and formed, the heating position and the current of the induction coil are adjusted, a profile is heated instantly, the threshold bending moment of the profile component is reduced, and bending and twisting forming of the high-strength profile component is finally completed under the action of a thermal field.

Description

Technical Field

[0001] The invention belongs to the technical field of advanced manufacturing of complex metal components, and in particular refers to a flexible bending and twisting forming method of a titanium alloy U-section profile component based on induction heating. Background Art

[0002] Compared with traditional bending forming methods, flexible bending forming technology achieves one-time overall precise forming of spatial components by controlling the motion trajectory of the mold. However, it is still unable to achieve the bending forming of high-strength difficult-to-deform materials. In response to this situation, the present invention adopts a flexible bending and torsion forming method based on induction heating, which heats the difficult-to-deform profile to reduce its deformation resistance and reduce the torsion angle caused by the asymmetric cross-section, thereby achieving flexible bending and torsion forming of titanium alloy U-section profile components. Summary of the invention

[0003] The purpose of the present invention is to provide a flexible bending and twisting forming method of a titanium alloy U-section profile based on induction heating, which solves the problem of poor bending effect of pipe fittings in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] The method for flexible bending and twisting of titanium alloy U-section profiles based on induction heating comprises the following steps:

[0006] Step 1: The titanium alloy profile is bent and deformed under the axial thrust of the propulsion mechanism and the translation and rotation of the bending die;

[0007] Step 2: During the bending process, the heating device works continuously, and the profile is instantly heated by coil induction heating, thereby achieving the bending forming of high-strength profiles;

[0008] Step 3: The method of using the induction heating device includes the following steps:

[0009] (1) Turn on the power supply and water circulation device, and check whether the water pressure is normal;

[0010] (2) Set the output power and heating time;

[0011] (3) starting the device to heat;

[0012] The coil input current generates induced eddy currents on the surface of the profile. Most of the magnetic flux lines pass through the interior of the profile, generating a high-frequency alternating magnetic field that generates an induced electromotive force through the profile, generating eddy currents on the outer wall of the profile. The Joule heat generated by the eddy currents heats the profile. The deformation resistance of the profile component is reduced at high temperature, the threshold bending moment is reduced, the forming difficulty is significantly reduced, and the final forming is facilitated.

[0013] On the basis of the above technical solution, the present invention also provides the following optional technical solution:

[0014] In an optional solution: the method described, different heating positions affect the initial bending point when the profile is bent and deformed, and thus ultimately affect the bending radius of the profile. Assume that the distance between the center of the heating position and the front end of the guide is a, the eccentricity is U, the deflection angle of the bending die is θ, the theoretical bending radius is R0, the actual bending radius is R1, and the actual torsion angle is γ (such as Figure 4 As shown), the relationship between them is as follows:

[0015]

[0016] Among them, m is the length of the plastic deformation zone, n is a constant, and x is the average distance from the center to the side of the profile.

[0017] The method described above, the final component torsion angle γ 2 The relationship with temperature T is as follows:

[0018]

[0019] Among them, γ 1 is the torsion angle of the U-shaped section at room temperature, M is the torque, L is the bending length of the component, G is the shear modulus of the material, k is the linear coefficient of the shear modulus of the material changing with temperature, and T0 is the room temperature. It can be seen that different heating temperatures affect the final torsion angle of the U-shaped section profile, and the higher the temperature, the smaller the torsion angle.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. In traditional cold working flexible bending forming, it is difficult to achieve bending processing for high-strength profiles, and for asymmetric special-shaped sections, the torsional deformation can only be corrected by a torsion axis, but the value of the torsion axis C is too large, which will affect the final forming quality. Therefore, high-quality forming cannot be achieved for profiles with severe torsion. In view of the shortcomings existing in this scheme, the present invention proposes a flexible bending and twisting forming method for titanium alloy U-section profiles based on induction heating. An induction coil is added between the bending die and the guide. When the profile component is bent and formed, the heating position and current of the induction coil are adjusted to instantly heat the profile, reduce the threshold bending moment of the profile component, and finally complete the bending and twisting forming of the high-strength profile component under the action of the thermal field. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the appearance of the induction heating of the present invention;

[0023] Figure 2 This is a schematic diagram of profile heating;

[0024] Figure 3 Schematic diagram of the change of torsion angle after heating;

[0025] Figure 4 Schematic diagram of induction heating results.

[0026] Heating arm 100, induction coil 200, guide structure 300, bending die 400, actual initial bending point M, theoretical initial bending point N. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The flexible bending and twisting forming method of titanium alloy U-section profile based on induction heating uses an induction heating device to instantaneously heat the high-strength profile component during the bending process, including the following steps:

[0029] (1) The titanium alloy profile is bent and deformed under the axial thrust of the propulsion mechanism and the translation and rotation of the bending die;

[0030] (2) During the bending process, the heating device works continuously and instantly heats the profile through coil induction heating, thereby achieving the bending forming of high-strength profiles.

[0031] The method for using the induction heating device comprises the following steps:

[0032] (1) Turn on the power supply and water circulation device, and check whether the water pressure is normal;

[0033] (2) Set the output power and heating time;

[0034] (3) Start the device to heat.

[0035] The coil input current generates induced eddy currents on the surface of the profile. Most of the magnetic flux lines pass through the interior of the profile, generating a high-frequency alternating magnetic field that generates an induced electromotive force through the profile, generating eddy currents on the outer wall of the profile. The Joule heat generated by the eddy currents heats the profile.

[0036] The deformation resistance of the material of the profile component is reduced at high temperature, the threshold bending moment is reduced, the forming difficulty is significantly reduced, and the final forming is facilitated.

[0037] Example 1

[0038] The first step is to perform three-dimensional modeling on the target profile component, which is a 60*80 U-shaped cross-section with no torsion angle;

[0039] The second step is to design the induction heating coil and the related forming die according to the cross-sectional shape of the profile component;

[0040] The third step is to conduct induction heating test before bending to test the heating effect of different powers and time on the profiles and understand the output power corresponding to different temperatures.

[0041] The fourth step is to turn on the power of the bending forming equipment and the induction heating device, check the operation of the equipment and the device to avoid malfunctions, and load the profile material to be formed;

[0042] Step 5: Set the output power and advancement rate required to heat the profile component to 400°C. The distance between the heating position and the front end of the guide is 15 mm, the eccentricity is 20 mm, the bending die deflection angle is 16°, and the theoretical radius and actual radius are:

[0043]

[0044] At 400°C, the final torsion angle of the profile section is:

[0045]

[0046] The sixth step is to calculate and assign the C-axis value according to the torsion angle of the heated profile component, perform a small angle torsion correction, and obtain the final target formed component without torsion.

[0047] Example 2

[0048] The first step is to perform three-dimensional modeling on the target profile component, which is a 60*80 U-shaped cross-section with no torsion angle;

[0049] The second step is to design the induction heating coil and the related forming die according to the cross-sectional shape of the profile component;

[0050] The third step is to conduct induction heating test before bending to test the heating effect of different powers and time on the profiles and understand the output power corresponding to different temperatures.

[0051] The fourth step is to turn on the power of the bending forming equipment and the induction heating device, check the operation of the equipment and the device to avoid malfunctions, and load the profile material to be formed;

[0052] Step 5: Set the output power and advancement rate required to heat the profile component to 600°C. The distance between the heating position and the front end of the guide is 20 mm, the eccentricity is 18 mm, the bending die deflection angle is 14°, and the theoretical radius and actual radius are:

[0053]

[0054] At 600℃, the final torsion angle of the profile section is:

[0055]

[0056] The sixth step is to calculate and assign the C-axis value according to the torsion angle of the heated profile component, perform a small angle torsion correction, and obtain the final target formed component without torsion.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible bending and twisting forming method for titanium alloy U-section profiles based on induction heating, characterized in that: The following steps are involved: Step 1: The titanium alloy profile is bent and deformed under the axial thrust of the propulsion mechanism and the translation and rotation of the bending die; Step 2: During the bending process, an induction heating device is used to instantaneously heat the high-strength profile components. The deformation resistance of the profile components is reduced at high temperatures, the threshold bending moment is reduced, and the forming difficulty is significantly reduced, which facilitates the final forming.

2. The method for flexible bending and twisting of titanium alloy U-section profile components based on induction heating according to claim 1 is characterized in that: Different heating positions affect the initial bending point of the profile during bending deformation, which ultimately affects the bending radius of the profile; assuming that the distance between the heating position and the front end of the guide is a, the eccentricity is U, the deflection angle of the bending die is θ, the theoretical bending radius is R0, the actual bending radius is R1, and the actual torsion angle is γ, then the relationship between them is as follows: Among them, m is the length of the plastic deformation zone, n is a constant, and x is the average distance from the center to the side of the profile.

3. The method for flexible bending and twisting of titanium alloy U-section profile components based on induction heating according to claim 2 is characterized in that: The final component torsion angle γ 2 The relationship with temperature T is as follows: Among them, γ 1 is the torsion angle of the U-shaped section at room temperature, M is the torque, L is the bending length of the component, G is the shear modulus of the material, k is the linear coefficient of the shear modulus of the material changing with temperature, and T0 is the room temperature; it can be seen that different heating temperatures affect the final torsion angle of the U-shaped section profile, and the higher the temperature, the smaller the torsion angle.

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