Method and system for shape control of four-way differential extrusion formed three-dimensional curved profile

Abstract

The application discloses a shape control method and system for four-way differential extrusion forming of a three-dimensional curved profile, wherein by controlling extrusion speeds in four directions, three-dimensional curved profiles with different bending radii and deflection angles can be obtained; according to bending radii of the curved profile under different extrusion speed combinations, a functional relationship between the profile bending radius and a bending radius control factor is established, so that the bending radius of the three-dimensional curved profile can be accurately regulated and controlled; according to deflection angles of the curved profile under different extrusion speed combinations, a functional relationship between the profile deflection angle and a deflection angle control factor is established, so that the deflection angle of the three-dimensional curved profile can be accurately regulated and controlled. The method can accurately control the bending radius and the deflection angle of the three-dimensional curved profile, and further realize accurate control of the shape of the three-dimensional curved profile formed by four-way differential extrusion.

Description

Technical Field

[0001] This invention relates to the field of metal and composite material plastic forming technology, specifically to a shape control method and system for four-way differential speed extrusion forming of three-dimensional curved profiles. Background Technology

[0002] Three-dimensional bending profiles made of metal and composite materials have significant advantages in improving the overall strength and stiffness of structures, achieving structural lightweighting, saving space, and reducing air resistance. They have wide applications and important status in aerospace, ground transportation, pipeline transportation, nuclear power industry and other fields.

[0003] The traditional manufacturing method for three-dimensional curved profiles involves first extruding straight profiles and then bending them. This traditional externally induced bending deformation process not only separates the extrusion and bending processes but also makes the produced curved profiles prone to problems such as tearing, wrinkling, springback, and cross-sectional distortion. Multi-directional differential speed extrusion technology, which uses the internal speed ratio of the material to induce bending deformation, is an integrated extrusion and bending forming process. It not only overcomes many defects of traditional bending forming technology but also has the advantages of refining grain structure and improving mechanical properties. Although methods for directly forming curved profiles by simultaneously extruding at multiple different speeds have been proposed, a precise control method for the geometry and dimensions of three-dimensional curved profiles has been lacking. It is difficult to achieve precise control over the geometry and dimensions of multi-directional differential speed extruded three-dimensional curved profiles, making the establishment of a precise control method for the shape and dimensions of multi-directional differential speed extruded three-dimensional curved profiles urgently needed. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a shape control method and system for four-way differential speed extrusion forming of three-dimensional curved profiles, which can quantitatively control the bending radius and deflection angle of three-dimensional curved profiles, and achieve precise forming of complex three-dimensional curved profiles.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect of the present invention, a method for shape control of a three-dimensional curved profile formed by four-axis differential extrusion is provided, comprising the following steps:

[0007] Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations, measure the bending radius of the profile corresponding to the different extrusion speed combinations, calculate the profile bending radius control factor corresponding to the different extrusion speed combinations, and obtain the functional relationship between the two by fitting the relationship curve between the bending radius of the profile and the profile bending radius control factor.

[0008] Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations, measure the deflection angle of the bent profile corresponding to different extrusion speed combinations, calculate the profile deflection angle control factor corresponding to different extrusion speed combinations, and obtain the functional relationship between the two by fitting the relationship curve between the deflection angle of the bent profile and the profile deflection angle control factor.

[0009] Based on the established two functional relationships, the required four-way extrusion speed of the curved profile to be extruded is calculated with the bending radius and deflection angle of the profile to be extruded as the target.

[0010] In some embodiments of the present invention, the first extrusion speed and the second extrusion speed are on the same plane and symmetrically distributed, and the angle between the first extrusion speed and the discharge direction is equal to the angle between the second extrusion speed and the discharge direction.

[0011] The third and fourth extrusion speeds are on the same plane and symmetrically distributed; the angle between the third extrusion speed and the discharge direction is equal to the angle between the fourth extrusion speed and the discharge direction.

[0012] In some embodiments of the present invention, the plane containing the first extrusion speed and the second extrusion speed makes an angle of 90° with the plane containing the third extrusion speed and the fourth extrusion speed; the angle between the direction of the four extrusion speeds and the discharge direction ranges from 90° to 180°.

[0013] In some embodiments of the present invention, the formula for calculating the profile bending radius control factor is as follows:

[0014] F r =[(1-g x ) 2 +(1-g y ) 2 ×(1 / G)

[0015] In the formula, F r Indicates the profile bending radius control factor, g x This represents the first speed ratio, i.e., the modulus of the first extrusion speed. With the second extrusion speed of the die The ratio of small to medium values ​​to large values; g y The modulus representing the second speed ratio, i.e., the third extrusion speed. With the fourth extrusion speed of the die The ratio of small to large values; G represents the velocity gradient ratio, which is the ratio of the small to large velocity ratio in the first and second velocity ratios.

[0016] In some embodiments of the present invention, the process for obtaining the functional relationship between the bending radius of the bent profile and the bending radius control factor of the profile is as follows:

[0017] Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations and conduct a four-way differential extrusion experiment. The bending radius of the bent profile corresponding to the different extrusion speed combinations is obtained by measurement.

[0018] Calculate the profile bending radius control factor based on the four-way extrusion speed;

[0019] By fitting the bending radius of the curved profile and the bending radius control factor, a functional relationship between the bending radius of the curved profile and the bending radius control factor is obtained.

[0020] In some embodiments of the present invention, based on the first velocity ratio g x The ratio of the second speed to g y Size, first extrusion speed of the die The second extrusion speed of the die Size and third extrusion speed of the die and the fourth extrusion speed of the die The size of the profile deflection angle control factor F is determined by the size of the profile. θ .

[0021] In some embodiments of the present invention, when g y ≤g x , hour,

[0022] The formula for calculating the deflection angle control factor is:

[0023] When g y ≤g x , hour,

[0024] The formula for calculating the deflection angle control factor is:

[0025] When g y ≤g x , hour,

[0026] The formula for calculating the deflection angle control factor is:

[0027] When g y ≤g x , hour,

[0028] The formula for calculating the deflection angle control factor is:

[0029] In some embodiments of the present invention, when g x ≤gy , hour,

[0030] The formula for calculating the deflection angle control factor is:

[0031] When g x ≤g y , hour,

[0032] The formula for calculating the deflection angle control factor is:

[0033] When g x ≤g y , hour,

[0034] The formula for calculating the deflection angle control factor is:

[0035] When g x ≤g y , hour,

[0036] The formula for calculating the deflection angle control factor is:

[0037] In some embodiments of the present invention, the process for obtaining the functional relationship between the deflection angle of the bent profile and the profile deflection angle control factor is as follows:

[0038] Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations and conduct a four-way differential extrusion experiment. The deflection angle of the bent profile corresponding to different extrusion speed combinations is obtained by measurement.

[0039] The profile deflection angle control factor is calculated based on the four-way extrusion speed.

[0040] By fitting the bending radius and the profile deflection angle control factor of the curved profile, a functional relationship between the bending radius and the profile deflection angle control factor of the curved profile is obtained.

[0041] In a second aspect of the invention, a shape control system for four-axis differential extrusion forming of three-dimensional curved profiles is provided, comprising:

[0042] The first functional relationship establishment module is configured to: select no less than six different extrusion speed combinations within the allowable extrusion speed range of the extruded material, measure the bending radius of the bent profile corresponding to the different extrusion speed combinations, calculate the profile bending radius control factor corresponding to the different extrusion speed combinations, and obtain the functional relationship between the two by fitting the relationship curve between the bending radius of the bent profile and the profile bending radius control factor.

[0043] The second function relationship establishment module is configured to: select no less than six different extrusion speed combinations within the allowable extrusion speed range of the extruded material, measure the deflection angle of the bent profile corresponding to the different extrusion speed combinations, calculate the profile deflection angle control factor corresponding to the different extrusion speed combinations, and obtain the function relationship between the two by fitting the relationship curve between the deflection angle of the bent profile and the profile deflection angle control factor.

[0044] The solver module is configured to: calculate the required four-axis extrusion speed of the curved profile to be extruded, based on the two established functional relationships and with the bending radius and deflection angle of the curved profile to be extruded as the target.

[0045] One or more technical solutions of the present invention have the following beneficial effects:

[0046] The shape control method for four-way differential extrusion forming of three-dimensional curved profiles provided by the present invention can accurately and quantitatively control and predict the bending radius and deflection angle of three-dimensional curved profiles based on the functional relationship between the bending radius of the curved profile and the bending radius control factor, and the functional relationship between the deflection angle of the curved profile and the deflection angle control factor.

[0047] The method for controlling the shape of three-dimensional curved profiles by four-way differential extrusion forming provided by this invention can obtain three-dimensional curved profiles with different bending radii and deflection angles by controlling the extrusion speed in four directions. At the same time, it can also obtain the extrusion speed in four directions according to the required three-dimensional curved profiles with different bending radii and deflection angles, thus realizing precise control of the shape of three-dimensional curved profiles by four-way differential extrusion forming. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the four-axis differential speed extrusion forming method of the present invention;

[0049] Figure 2 This is a schematic diagram showing the range of the angle α between the extrusion speed and the discharge direction in the four-way differential extrusion molding of the present invention;

[0050] Figure 3 The present invention reduces g x or g y And obtain the actual effect of keeping G constant or decreasing, so as to reduce the bending radius r of the bent profile;

[0051] Figure 4 The bending radius control factor F obtained by the present invention based on experimental values ​​is... r The curve showing the relationship between the bending radius r;

[0052] Figure 5 For the present invention when gy ≤g x , At that time, by increasing g x Or reduce g y and make Keep it unchanged, or keep g x and g y Unchanged and make The actual effect of increasing the angle of deflection θ of the bent profile is to decrease;

[0053] Figure 6 The deflection angle control factor F obtained by the present invention based on experimental values ​​is... θ The curve showing the relationship between the curve and the deflection angle θ;

[0054] Figure 7 The basis of this invention is r = f(F) r ) and θ=f(F θ A three-dimensional bending profile photograph obtained after extrusion at a determined extrusion speed.

[0055] In the figure: 1. Extrusion die (including extrusion cylinder); 2. Billet; 3. Bending profile; 4. First extrusion bar; 5. Second extrusion bar; 6. Third extrusion bar; 7. Fourth extrusion bar. Detailed Implementation

[0056] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0057] Example 1

[0058] In a typical embodiment of the present invention, a method for shape control of three-dimensional curved profiles formed by four-axis differential extrusion is proposed, comprising the following steps:

[0059] To ensure a relatively smooth fitting curve and sufficient fitting accuracy, at least six different combinations of extrusion speeds were selected within the allowable extrusion speed range of the extruded material. The bending radius of the profiles corresponding to different extrusion speed combinations was measured, and the bending radius control factor of the profiles corresponding to different extrusion speed combinations was calculated. The functional relationship between the two was obtained by fitting the relationship curve between the bending radius of the profiles and the bending radius control factor.

[0060] To ensure a relatively smooth fitting curve and sufficient fitting accuracy, at least six different combinations of extrusion speeds were selected within the allowable extrusion speed range of the extruded material. The deflection angle of the bent profile corresponding to different extrusion speed combinations was measured, and the deflection angle control factor of the profile corresponding to different extrusion speed combinations was calculated. The functional relationship between the two was obtained by fitting the relationship curve between the deflection angle of the bent profile and the profile deflection angle control factor.

[0061] Based on the established two functional relationships, the required four-way extrusion speed of the curved profile to be extruded is calculated with the bending radius and deflection angle of the profile to be extruded as the target.

[0062] Specifically:

[0063] 1. For example Figure 1 and 2 As shown, the billet 2 is placed into the extrusion die (including the extrusion cylinder) 1, and four extrusion speeds are applied to the billet simultaneously by the first extrusion rod 4, the second extrusion rod 5, the third extrusion rod 6, and the fourth extrusion rod 7. The bending radius r of the extruded bending profile 3 is defined as the bending radius of the profile centerline. The bending profile and g x g y The angle between the smaller speed and the corresponding larger speed is defined as the deflection angle θ. The four speeds satisfy the following relationship:

[0064] (1) As Figure 1 and 2 As shown, the angle α between the four extrusion speeds and the discharge direction ranges from 90° to 180°.

[0065] (2) Of the four extrusion speeds, and On the same plane, With respect to the direction of discharge The included angle is equal to With respect to the direction of discharge The included angle, and and They are symmetrically distributed;

[0066] (3) Of the four extrusion speeds, and On the same plane, With respect to the direction of discharge The included angle is equal to With respect to the direction of discharge The included angle, and and They are symmetrically distributed;

[0067] (4) and The plane in which it is located and and The angle between the planes is 90°.

[0068] 2. and The velocity ratio g is obtained by dividing the velocity with the smaller magnitude by the velocity with the larger magnitude. x ;Will and The velocity ratio g is obtained by dividing the velocity with the smaller magnitude by the velocity with the larger magnitude. y ; will g x and g y The smaller of the two velocity ratios is divided by the larger of the two velocity ratios to obtain the velocity gradient ratio G.

[0069] 3. By reducing g x or g y By keeping G constant or decreasing it, the bending radius r of the bent profile can be reduced; by increasing g... x or g y By keeping G constant or increasing it, the bending radius r of the bent profile can be increased. Therefore, the formula for calculating the bending radius control factor of the profile is as follows:

[0070] F r =[(1-g x ) 2 +(1-g y ) 2 ×(1 / G)

[0071] Within the allowable extrusion speed range of the extruded material, at least six different extrusion speed combinations were selected for a four-axis differential extrusion experiment. The bending radius of the bent profiles corresponding to different extrusion speed combinations was measured, and the bending radius control factor F was established. r With g x g y The relationship between G and the bending radius control factor F is calculated. r By fitting, the relationship between the bending radius r and the bending radius control factor F is established. r The functional relationship r = f(F) r This allows for precise control of the bending radius of three-dimensional curved profiles.

[0072] For example Figure 3 Taking the example shown, we will further illustrate the specific implementation method by selecting g. x =g y The extrusion speed combinations with G=1, G=1, and G=1, result in bending radii r of 28.1mm, 20.8mm, and 18.7mm respectively. Selecting g... x When the extrusion speed is 1 / 2, 1 / 3, and 1 / 4, and G=2, the bending radii r are 17.3mm, 15.7mm, and 14.8mm respectively, while simultaneously decreasing g. x and g y Keeping G constant allows for a reduction in the bending radius r; selecting a value when g... x =1 / 2,g yThe extrusion speed combinations at 1 / 3, 1 / 4, and 1 / 6 yield bending halves r of 20.0 mm, 17.3 mm, and 14.7 mm respectively. Decreasing g... y Reducing G will decrease the bending radius r. This can be achieved by calculating the bending radius control factor F. r It is possible to establish such as Figure 4 The bending radius r and bending radius control factor F shown are... r Functional relationship:

[0073] r = f(F) r ) = 44.2 - 33.8F r -14.1F r 2 +48.5F r 3 -33.8F r 4 +9.9F r 5 -1.1F r 6

[0074] The above equation represents r = f(F) r By understanding the relationship between the two, the bending radius r of the curved profile can be precisely controlled.

[0075] 4. According to g x g y Size and Different combinations of sizes, profile deflection angle control factor F θ and and g x g y The relational expressions can be divided into the following eight cases.

[0076] (1) When g y ≤g x , At that time, by increasing g x Or reduce g y and make Keep it unchanged, or keep g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g x Or increase g y And make Keep it unchanged, or keep g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, the formula for calculating the deflection angle control factor is as follows:

[0077]

[0078] (2) When g y ≤g x , At that time, by increasing g x Or reduce g y and make Keep it unchanged, or keep g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g x Or increase g y and make Keep it unchanged, or keep g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, the formula for calculating the deflection angle control factor is as follows:

[0079]

[0080] (3) When g y ≤g x , At that time, by increasing g x Or reduce g y And make Keep unchanged or maintain g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g x Or increase g y And make Keep unchanged or maintain g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, the formula for calculating the deflection angle control factor is as follows:

[0081]

[0082] (4) When g y ≤g x , At that time, by increasing g x Or reduce g y And make Keep unchanged or maintain g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g x Or increase g y And make Keep unchanged or maintain g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, the formula for calculating the deflection angle control factor is as follows:

[0083]

[0084] (5) When g x ≤g y , At that time, by increasing g y Or reduce g x And make Keep unchanged or maintain g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g y Or increase g x And make Keep unchanged or maintain g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, the formula for calculating the deflection angle control factor is as follows:

[0085]

[0086] (6) When g x ≤g y , At that time, by increasing g y Or reduce g x And make Keep unchanged or maintain g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g y Or increase g x And make Keep unchanged or maintain g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, the formula for calculating the deflection angle control factor is as follows:

[0087]

[0088] (7) When g x ≤g y , At that time, by increasing g y Or reduce gx And make Keep unchanged or maintain g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g y Or increase g x And make Keep unchanged or maintain g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, the formula for calculating the deflection angle control factor is as follows:

[0089]

[0090] (8) When g x ≤g y , At that time, by increasing g y Or reduce g x And make Keep unchanged or maintain g x and g y Unchanged and make Increasing g reduces the deflection angle θ of the bent profile; by decreasing g y Or increase g x And make Keep unchanged or maintain g x and g y Unchanged and make Decreasing the angle of the bent profile increases the deflection angle θ. Therefore, a deflection angle control factor F is established. θ The calculation formula is as follows:

[0091]

[0092] Based on the calculation formulas for the deflection angle control factors under the above eight different conditions, at least six different extrusion speed combinations were selected within the allowable extrusion speed range of the extruded material, and a four-way differential extrusion experiment was conducted. The deflection angle θ of the bent profile corresponding to different extrusion speed combinations was measured, and the established deflection angle control factor F was used to determine the deflection angle control factor. θ and and g x g y The relationship between the deflection angle θ and the control factor F is calculated by using a formula, and then a relationship between the deflection angle θ and the control factor F is established through fitting. θ The functional relationship θ=f(F) θ This allows for precise control of the deflection angle of three-dimensional curved profiles.

[0093] Below, gy ≤g x , Taking the case of [example missing] as an example, we will further explain the specific implementation method. For example... Figure 5 As shown, g is selected. x They are 1 / 4, 1 / 3, and 1 / 2 respectively. When the extrusion speed combination is kept at 1, the deflection angles θ of the bent profile are 25.9°, 24.8°, and 20.5°, respectively. Increasing g... x and maintain Keeping it constant reduces the deflection angle θ; choosing g y They are 1 / 2, 1 / 3, and 1 / 6 respectively. When the extrusion speed combination is kept at 1, the deflection angles θ of the bent profile are 45.0°, 20.0°, and 11.7°, respectively. Decreasing g... y and maintain Keeping it constant will decrease the deflection angle θ; choosing g x =g y =1 / 2 and For extrusion speed combinations of 1.5, 2, and 3, the deflection angles θ of the bent profiles are 34.9°, 28.1°, and 20.6°, respectively, while maintaining g x and g y Unchanged and increased This can reduce the deflection angle θ; by calculating the deflection angle control factor, a system can be established as follows: Figure 6 The θ and F shown θ Functional relationship:

[0094] θ=f(F θ ) = 63.5 - 25.0F θ +7.7F θ 2 -1.3F θ 3 +0.1F θ 4 -6.1×10 -3 F θ 5 +1.2×10 -4 F θ 6

[0095] The above equation represents θ = f(F) θ By understanding the relationship between the two, the deflection angle θ of the bent profile can be precisely controlled.

[0096] Furthermore, to verify the accuracy of the method provided in this patent, with the goal of forming and manufacturing curved profiles with r=40mm and θ=45°, r=30mm and θ=20°, and r=20mm and θ=15°, based on the actual extrusion speed range of the extruder and the allowable extrusion speed range of the material being extruded, two of the extrusion speeds are set as fixed values. Then, according to the functional relationships established in steps 3 and 4 (the following four formulas), the extrusion speed can be obtained.

[0097]

[0098] r = f(F) r ) = 44.2 - 33.8F r -14.1F r 2 +48.5F r 3 -33.8F r 4 +9.9F r 5 -1.1F r 6

[0099]

[0100] θ=f(F θ ) = 63.5 - 25.0F θ +7.7F θ 2 -1.3F θ 3 +0.1F θ 4 -6.1×10 -3 F θ 5 +1.2×10 -4 F θ 6

[0101] Specifically as follows:

[0102] When the target component r = 40mm and θ = 45° (-x+y quadrant, angle with -x axis), the calculated...

[0103] The values ​​are 1.00 mm / s, 1.35 mm / s, 1.35 mm / s, and 1.00 mm / s, respectively.

[0104] When the target component r = 40mm and θ = 45° (+x+y quadrant, angle with +y axis), the calculated... The values ​​are 1.35 mm / s, 1.00 mm / s, 1.35 mm / s, and 1.00 mm / s, respectively.

[0105] When the target component r = 30mm and θ = 20° (+x+y quadrant, angle with +y axis), the calculated... The values ​​are 1.30 mm / s, 1.00 mm / s, 1.95 mm / s, and 1.00 mm / s, respectively.

[0106] When the target component r = 20mm and θ = 15° (+xy quadrant, angle with -y axis), the calculated... The values ​​are 1.44 mm / s, 1.00 mm / s, 1.00 mm / s, and 2.78 mm / s, respectively.

[0107] Obtained from calculation Extrusion experiments were conducted to obtain the following results: Figure 7 The bending profile shown was used to measure the bending radius and deflection angle, and the error between the theoretical calculation value and the experimental value of the bending radius and deflection angle was determined, as shown in Table 1.

[0108] The target values ​​for section A are r = 40 mm and θ = 45°. The theoretical calculation values ​​are r = 39.5 mm and θ = 45°. The actual values ​​obtained by extruding according to the calculated extrusion speed are r = 40.4 mm and θ = 45°. The errors between the theoretical calculation values ​​and the experimental values ​​of bending radius and deflection angle are 2.3% and 0%, respectively.

[0109] The target values ​​for section B are r = 40 mm and θ = 45°. The theoretical calculation values ​​are r = 39.5 mm and θ = 45°. The actual values ​​obtained by extruding according to the calculated extrusion speed are r = 38.5 mm and θ = 45°. The errors between the theoretical calculation values ​​and the experimental values ​​of bending radius and deflection angle are 2.5% and 0%, respectively.

[0110] The target values ​​for segment C are r = 30 mm and θ = 20°. The theoretically calculated values ​​are r = 29.7 mm and θ = 19.1°. The actual values ​​obtained by extruding at the calculated extrusion speed are r = 29.1 mm and θ = 18.5°. The errors between the theoretically calculated values ​​and the experimental values ​​for bending radius and deflection angle are 2.0% and 3.1%, respectively.

[0111] The target values ​​for segment D are r = 20 mm and θ = 15°. The theoretical calculation values ​​are r = 20.1 mm and θ = 15.2°. The actual values ​​obtained by extruding according to the calculated extrusion speed are r = 21.1 mm and θ = 15.6°. The errors between the theoretical calculation values ​​and the experimental values ​​of bending radius and deflection angle are 4.8% and 2.6%, respectively.

[0112] As can be seen from the above four cases (Table 1), the error range between the theoretical calculation result and the experimental result of the bending radius is only 2.0 to 4.8%, and the error range between the theoretical calculation value and the experimental value of the deflection angle is only 0 to 3.1%, indicating that the shape control method for four-way differential extrusion forming of three-dimensional bending profiles provided in this application has good accuracy.

[0113] Table 1 Comparison of errors between theoretical calculations and experimental values.

[0114]

[0115] Example 2

[0116] In a typical embodiment of the present invention, a shape control system for four-axis differential extrusion forming of three-dimensional bending profiles is proposed, comprising:

[0117] The first functional relationship establishment module is configured to: select no less than six different extrusion speed combinations within the allowable extrusion speed range of the extruded material, measure the bending radius of the bent profile corresponding to the different extrusion speed combinations, calculate the profile bending radius control factor corresponding to the different extrusion speed combinations, and obtain the functional relationship between the two by fitting the relationship curve between the bending radius of the bent profile and the profile bending radius control factor.

[0118] The second function relationship establishment module is configured to: select no less than six different extrusion speed combinations within the allowable extrusion speed range of the extruded material, measure the deflection angle of the bent profile corresponding to the different extrusion speed combinations, calculate the profile deflection angle control factor corresponding to the different extrusion speed combinations, and obtain the function relationship between the two by fitting the relationship curve between the deflection angle of the bent profile and the profile deflection angle control factor.

[0119] The solver module is configured to: calculate the required four-axis extrusion speed of the curved profile to be extruded, based on the two established functional relationships and with the bending radius and deflection angle of the curved profile to be extruded as the target.

[0120] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for shape control of a three-dimensional curved profile formed by four-axis differential extrusion, characterized in that, Includes the following steps: Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations, measure the bending radius of the profile corresponding to each extrusion speed combination, and calculate the profile bending radius control factor corresponding to each extrusion speed combination. The formula for calculating the profile bending radius control factor is as follows: In the formula, F r Indicates the profile bending radius control factor. g x This represents the first speed ratio, i.e., the modulus of the first extrusion speed. With the second extrusion speed of the die The ratio of small to medium values ​​to large values; g y The modulus representing the second speed ratio, i.e., the third extrusion speed. With the fourth extrusion speed of the die The ratio of small to medium values ​​to large values; G It represents the velocity gradient ratio, which is the ratio of the smaller velocity ratio to the larger velocity ratio in the first velocity ratio and the second velocity ratio; The functional relationship between the bending radius of the curved profile and the bending radius control factor is obtained by fitting the curve. Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations, measure the deflection angle of the bent profile corresponding to each extrusion speed combination, and calculate the profile deflection angle control factor corresponding to each extrusion speed combination; based on the first speed ratio g x Second speed ratio g y Size, first extrusion speed of the die The second extrusion speed of the die Size and third extrusion speed of the die and the fourth extrusion speed of the die The size of the profile is used to establish different profile deflection angle control factors. F θ ; when g y ≤ g x , , hour, The formula for calculating the deflection angle control factor is: ; when g y ≤ g x , , hour, The formula for calculating the deflection angle control factor is: ; when g y ≤ g x , , hour, The formula for calculating the deflection angle control factor is: ; when g y ≤ g x , , hour, The formula for calculating the deflection angle control factor is: ; when g x ≤ g y , , hour, The formula for calculating the deflection angle control factor is: ; when g x ≤ g y , , hour, The formula for calculating the deflection angle control factor is: ; when g x ≤ g y , , hour, The formula for calculating the deflection angle control factor is: ; when g x ≤ g y , , hour, The formula for calculating the deflection angle control factor is: ; The functional relationship between the deflection angle of the bent profile and the deflection angle control factor is obtained by fitting the curve. Based on the established two functional relationships, the required four-way extrusion speed of the curved profile to be extruded is calculated with the bending radius and deflection angle of the curved profile to be extruded as the target.

2. The shape control method for four-axis differential extrusion forming of three-dimensional curved profiles as described in claim 1, characterized in that, First extrusion speed Second extrusion speed On the same plane and symmetrically distributed, the angle between the first extrusion speed and the discharge direction is equal to the angle between the second extrusion speed and the discharge direction. Third extrusion speed and the fourth extrusion speed They are symmetrically distributed on the same plane; the angle between the third extrusion speed and the discharge direction is equal to the angle between the fourth extrusion speed and the discharge direction.

3. The shape control method for four-axis differential extrusion forming of three-dimensional curved profiles as described in claim 2, characterized in that, The plane containing the first and second extrusion speeds forms a 90° angle with the plane containing the third and fourth extrusion speeds; the angle between the directions of the four extrusion speeds and the discharge direction ranges from 90° to 180°.

4. The shape control method for four-axis differential extrusion forming of three-dimensional curved profiles as described in claim 1, characterized in that, The process for obtaining the functional relationship between the bending radius of the curved profile and the bending radius control factor is as follows: Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations and conduct a four-way differential extrusion experiment. The bending radius of the bent profile corresponding to the different extrusion speed combinations is obtained by measurement. Calculate the profile bending radius control factor based on the four-way extrusion speed; By fitting the bending radius of the curved profile and the bending radius control factor, a functional relationship between the bending radius of the curved profile and the bending radius control factor is obtained.

5. The shape control method for four-axis differential extrusion forming of three-dimensional curved profiles as described in claim 1, characterized in that, The process for obtaining the functional relationship between the deflection angle of the bent profile and the profile deflection angle control factor is as follows: Within the allowable extrusion speed range of the extruded material, select no fewer than six different extrusion speed combinations and conduct a four-way differential extrusion experiment. The deflection angle of the bent profile corresponding to different extrusion speed combinations is obtained by measurement. The profile deflection angle control factor is calculated based on the four-way extrusion speed. By fitting the deflection angle of the bent profile and the profile deflection angle control factor, a functional relationship between the deflection angle of the bent profile and the profile deflection angle control factor is obtained.

6. A shape control system for four-axis differential speed extrusion forming of three-dimensional curved profiles, used to implement the shape control method for three-dimensional curved profiles according to any one of claims 1-5, characterized in that, include: The first functional relationship establishment module is configured to: select no less than six different extrusion speed combinations within the allowable extrusion speed range of the extruded material, measure the bending radius of the bent profile corresponding to the different extrusion speed combinations, calculate the profile bending radius control factor corresponding to the different extrusion speed combinations, and obtain the functional relationship between the two by fitting the relationship curve between the bending radius of the bent profile and the profile bending radius control factor. The second function relationship establishment module is configured to: select no less than six different extrusion speed combinations within the allowable extrusion speed range of the extruded material, measure the deflection angle of the bent profile corresponding to the different extrusion speed combinations, calculate the profile deflection angle control factor corresponding to the different extrusion speed combinations, and obtain the function relationship between the two by fitting the relationship curve between the deflection angle of the bent profile and the profile deflection angle control factor. The solver module is configured to: calculate the required four-axis extrusion speed of the curved profile to be extruded, based on the two established functional relationships and with the bending radius and deflection angle of the curved profile to be extruded as the target.

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