CN102941264B - Bent blank manufacture method of section bar of aluminum alloy flash-welded thin-wall ring - Google Patents

Abstract

The invention discloses a profile bending method for an aluminum alloy flash welding thin-walled ring. The steps include: dividing the aluminum alloy profile blanked according to the specifications into five sections of mn, no, op, pq and qw and heating to 330°C± After 20°C, put it into the bending machine for positioning. Bending the op section first, the rotation speed of the upper roller and the two lower rollers of the bending machine is 2400mm/min, the speed of the upward movement of the two lower rollers is 15mm/min, and the bending is repeated twice. At this time, the op arc The section reaches a predetermined radius of curvature; then bend the no section and the pq section, the rotation speed of the upper roller and the two lower rollers is 1200mm/min, the speed of the two lower rollers moving upwards is 19mm/min, and the bending is repeated 2 times , at this time, the no and pq arc segments reach a predetermined radius of curvature. The profile is bent and deformed into a "D"-shaped ring blank, and the two straight sides of the ring blank are connected to the arc portion through a transitional arc section, which eliminates the knuckles caused by the connection between the two straight sides and the arc portion. The phenomenon of indentation on the surface of the ring blank.

Description

Profile Bending Method for Aluminum Alloy Flash Welded Thin-walled Rings

technical field

The invention relates to a profile bending method, in particular to a profile bending blank-making method for an aluminum alloy flash welding thin-walled ring.

Background technique

With the increasing demand for rings in industries such as aviation, aerospace, ships, gas turbines, wind energy, nuclear energy, and bearings, rings formed by traditional rolling methods not only waste a lot of materials due to large machining allowances and low material utilization , but also keeps the cost of ring parts high. The ring parts produced by the flash welding process have less machining allowance, high material utilization rate, and greatly reduce the cost, which is conducive to the development of ring forming technology in the direction of precision forming technology. The preparation technology of flash welding ring blank is one of the key technologies for producing flash welding ring parts.

In the prior art, the following methods are mainly used for the preparation of flash welded ring blanks: first, put the profile into the bending machine and bend it into an approximate circle, and leave a section of straight edge at each end of the profile; The straight side part and the arc part of the profile are bent into a knuckle, so that the straight sides at both ends of the profile are aligned with each other, which is convenient for the flash butt welding machine to clamp and weld the ring blank. The flash welded ring blank prepared by the above method will produce corners at the junction of the circular arc part of the ring blank and the straight edge parts at both ends, and easily produce indentations on the surface of the ring blank; the ring blank is formed into a ring by flash welding After bulging, it is necessary to carry out bulging and rounding treatment. During bulging, stress concentration is likely to occur at the knuckles and cause the ring to be scrapped. Elimination, the overall ellipticity of the ring after calibration is large; due to the small machining allowance of the flash welding ring, the large ellipticity of the ring and the indentation on the surface will affect the dimensional accuracy of the ring, resulting in low dimensional accuracy. It is beneficial to obtain flash welding ring parts with less and no allowance processing.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method of segmentally bending the profile on the bending machine to realize the bending blank of the aluminum alloy flash welded thin-walled ring profile. Indentation is beneficial to improve the dimensional accuracy and processing quality of flash welding ring parts.

In order to solve the above-mentioned technical problems, the profile bending blank-making method of the aluminum alloy flash welding thin-walled ring according to the present invention, its technical solution includes the following steps:

Divide the aluminum alloy profiles cut according to the specifications into five sections: mn, no, op, pq and qw, the ratio of each section is mn : no : op : pq : qw = 1.0 : 2.0～2.5 : 7.0～8.0 : 2.0 ～2.5 : 1.0 , then heat the profile to 330℃±20℃;

The profile is loaded into the bending machine, and it is positioned by the upper roll and two lower rolls of the bending machine so that the center of the profile is aligned with the center of the upper roll, and the upper roll and the two lower rolls are located the op segment of said profile;

Manipulate the upper roller to rotate counterclockwise and the two lower rollers to rotate clockwise to drive the profile to move to its right end, and simultaneously apply a force of 100KN to the two lower rollers to move upward to press the profile. When contacting the point o of the profile, change the rotation direction of the upper roller and the two lower rollers, and drive the profile to move to its left end; when the lower right roller contacts the point p of the profile, change the upper roller and the two lower rollers again In the direction of rotation, the profile is driven to move towards its right end until the upper roller contacts the midpoint of the op section of the profile; during the bending process, the two lower rollers always move upwards to press the profile; the linear speed of rotation of the upper and lower rollers is equal is 2400mm/min, and the moving speed of the two lower rollers is 15mm/min; repeat the above operation 2 times, at this time, the op arc section reaches the predetermined radius of curvature;

Stop the machine to detect the temperature of the profile, if it is greater than or equal to 200°C, continue the bending operation, if it is less than 200°C, return to the furnace and heat it to 330°C±20°C before continuing to bend the no section;

Position the no section of the profile on the bending machine so that the midpoint is aligned with the center of the upper roller; control the upper roller to rotate clockwise, and the two lower rollers to rotate counterclockwise, drive the profile to move to its left end, and simultaneously The two lower rollers are loaded with a force of 146KN to move upward to press the profile; when the lower right roller contacts the o point of the profile, the rotation direction of the upper roller and the two lower rollers is changed, and the profile is driven to move to the right end; when the lower left When the roller is in contact with the n point of the profile, the rotation direction of the upper roller and the two lower rollers is changed again, and the profile is driven to move to its left end until the upper roller contacts the midpoint of the no section of the profile; during the bending process, the two The lower roller always moves upwards to press the profile; the linear speed of rotation of the upper and lower rollers is 1200mm/min, and the moving speed of the two lower rollers is 19mm/min; repeat the above operation 2 times, at this time , no arc segment reaches the predetermined radius of curvature;

Bend the pq section according to the steps of bending the no section above, until the pq arc section after bending reaches a predetermined radius of curvature, and the mn section and qw section of the profile are aligned.

Preferably, the radius of curvature of each curved arc segment is determined by the following formula:

$\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 8</span>}\mathrm{<span\; class="notranslate">\; \&delta;</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}$

In the formula:

R——the radius of curvature of the corresponding arc segment after bending (mm);

a——the center distance between the two lower rollers (mm);

δ——the rising distance of the lower roller when the bending corresponds to the arc segment (mm);

r——the radius of the lower roller (mm);

d - the thickness of the profile (mm).

Preferably, the speed at which the lower roller moves upwards and the linear speed of rotation of the upper and lower rollers are determined by the following formula:

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}{\mathrm{<span\; class="notranslate">\; n\&pi;R</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}$

In the formula:

V ₂ ——The speed at which the lower roller moves upward when bending the corresponding arc segment (mm/min);

V ₁ ——Rotation speed of the upper roller or lower roller when bending the corresponding arc segment (mm/min);

R——the radius of curvature of the corresponding arc segment after bending (mm);

δ——the rising distance of the lower roller when the bending corresponds to the arc segment (mm);

n——the number of repeated bending times (times) corresponding to the arc segment.

Preferably, the minimum force applied by the bending machine to the lower roller so that it can move upward to press the profile is determined by the following formula:

$\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 8</span>}\mathrm{<span\; class="notranslate">\; EJ</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 4</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 4</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}\mathrm{<span\; class="notranslate">\; arcsin</span>}\frac{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; a\&delta;</span>}}{{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 4</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

In the formula:

F——The minimum force (N) that the bending machine loads on the lower roller so that it can move upward to press the profile;

EJ——the stiffness of the bar, where E is the modulus of elasticity (GPa), and J is the section moment of inertia of the bar (cm ⁴ );

a——the center distance between the two lower rollers (mm);

δ——The distance (mm) that the lower roller moves upward.

Preferably, the aluminum alloy is 2A70.

Preferably, the ring has an axial cross-sectional dimension of at most 65 mm x 30 mm.

The ring blank of the flash welded thin-walled ring bent and formed by the method is in the shape of "D", consisting of two straight sides, a circular arc part and an excessive arc section connecting the straight sides and the circular arc part. Openings are provided at opposite ends of the straight sides.

Compared with the prior art, the beneficial effects of the present invention are as follows:

According to the profile bending method for aluminum alloy flash welding thin-walled rings of the present invention, the profile is divided into five sections mn, no, op, pq and qw during the bending process, and the ratio of each section is mn : no : op : pq : qw = 1.0 : 2.0～2.5 : 7.0～8.0 : 2.0～2.5 : 1.0 , so that the radius of curvature of the op section after bending is greater than that of the no or pq section, which is beneficial to bending deformation and obtaining a "D" shape ring blank. And after bending, the two straight sides of the ring blank are connected with the circular arc part through the transitional arc section, which eliminates the phenomenon of knuckles and indentations on the surface of the ring blank caused by the connection between the two straight sides and the circular arc part, which not only makes the billet The process is easy to carry out, and it also avoids the problem that the welded flash welded ring parts are prone to stress concentration at the knuckles in the subsequent bulging and rounding process, which will cause the ring to be scrapped; at the same time, it also makes the bulging and rounding process easy to carry out , can save a lot of man-hours and energy consumption, eliminate ovality, improve the dimensional accuracy and processing quality of ring parts, and obtain flash welded ring parts with less and no margin processing.

During the profile bending process, when the radius of curvature of each curved arc segment satisfies The speed at which the lower roll moves upward meets the rotational speed of the upper and lower rolls When it is used, it can make the smooth transition and bending shape between the curved arc segments.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic diagram of a ring blank of a flash welded thin-walled ring produced by the prior art.

Figure 2 is a schematic structural view of the bending machine.

Fig. 3 is a schematic diagram of sections of an aluminum alloy profile.

Figure 4 is a schematic diagram of the installation of aluminum alloy profiles.

Fig. 5 is a schematic diagram of the bending process of the op section of the aluminum alloy profile.

Fig. 6 is a schematic diagram of the bending process of the no segment of the aluminum alloy profile.

Fig. 7 is a schematic diagram of the state of the aluminum alloy profile after bending.

Fig. 8 is a schematic diagram of a ring blank of an aluminum alloy flash welded thin-walled ring produced by the present invention.

Detailed ways

The implementation of the profile bending blanking method of the aluminum alloy flash welding thin-walled ring according to the present invention requires the provision of profile bending machines, heating furnaces, manipulators and other equipment.

Fig. 1 shows a schematic diagram of a ring blank 10 of an aluminum alloy flash welding thin-walled ring produced by the prior art, the ring blank 10 is composed of two straight sides 11 and a circular arc portion 13, and has an opening between the two straight sides 14. A knuckle 12 is formed at the intersection between the two straight sides 11 and the arc portion 13 respectively.

Fig. 2 has shown the schematic diagram of bending machine, and described bending machine 1 has upper roller 2 and two lower rollers 3, and described upper roller 2 is fixedly installed on the bearing 5, and described two lower rollers 3 are contained in two respectively. On a crank 4 and can move up and down, the upper roller 2 and the two lower rollers 3 are distributed in a triangle and can rotate clockwise or counterclockwise; the bending machine 1 also has the ability to adjust the upper roller 2, the two lower rollers 3 The speed of rotation of the roller 3 and the control device of the upper and lower moving speeds of the two lower rollers 3; the radius of the upper roller 2 and the two lower rollers 3 is 200mm, and the center distance between the two lower rollers 3 is 450mm.

Next, take the aluminum alloy whose material grade is 2A70 in my country as an example to describe in detail the specific implementation of the profile bending method for aluminum alloy flash welding thin-walled rings according to the present invention:

The main chemical element content (percentage by weight) of the alloy is: 1.9% to 2.5% of Cu, 1.4% to 1.8% of Mg, 0.9% to 1.5% of Fe, 0.9% to 1.5% of Ni, 0.9% to 1.5% of Ni, The content of Ti is 0.02%-0.10%, the content of Mn is 0.20%, the content of Zn is 0.30%, the content of Si is 0.35%, other elements are individually ≤0.05% and the sum is ≤0.10%, and the balance is Al.

The specific process steps of bending billet are as follows:

Step 1: Unloading. As shown in Figure 3, the 2A70 aluminum alloy material with a rectangular cross-section is blanked according to the specifications to form a profile 20. The length of the profile 20 is determined according to the diameter of the welding ring, and its maximum cross-sectional area is 65mm (width) × 30mm (thickness). ). This profile 20 is divided into mn, no, op, pq and qw five sections by m, n, o, p, q, w, in order to make the curvature radius of the op section after bending greater than the curvature radius of the no or pq section and to obtain the shape For "D"-shaped ring blanks, the ratio of each segment is mn : no : op : pq : qw = 1.0 : 2.0～2.5 : 7.0～8.0 : 2.0～2.5 : 1.0 , and the section can be divided into sections 20 Separate the segments by means such as line markers.

Step 2: Heat up. Heat the profile 20 to 330°C±20°C, the holding time is 12min/10mm～15min/10mm, and the total holding time is less than 2h.

Step 3: Install the computer. As shown in Figure 4, the profile 20 is loaded into the bending machine 1, and the profile 20 is placed flat on the top of the two lower rollers 3 after the installation, and its center is aligned with the center of the upper roller 2, and the upper roller 2 and the two lower rollers 3 is located at the op section of the profile 20, the control crank 4 pushes the two lower rollers 3 to move upward until the profile 20 contacts the upper roller 2, and the upper roller 2 and the two lower rollers 3 position the profile 20 on the bending machine 1.

Step 4: Bend the op segment of the profile 20. As shown in Figure 5, control the upper roller 2 to rotate in the counterclockwise direction, and the two lower rollers 3 to rotate in the clockwise direction, and drive the profile 20 to move to its right end direction, and the rotational speeds of the upper and lower rollers 2 and 3 are equal. is 2400mm/min, and at the same time, load the force of 100KN on the two lower rollers 3 to make it move up the pressing profile 20 at a speed of 15mm/min; when the left lower roller 3 contacts the o point of the profile 20, change the upper roller 2 and The direction of rotation of the two lower rollers 3 drives the profile 20 to move towards its left end, and ensures that the rotational speed of the upper roller 2 and the two lower rollers 3 remains unchanged and the speed at which the two lower rollers 3 move upwards remains unchanged; when the right When the lower roller 3 is in contact with the p point of the profile 20, the rotation direction of the upper roller 2 and the two lower rollers 3 is changed again, and the profile 20 is driven to move to its right end, and the rotation of the upper roller 2 and the two lower rollers 3 is guaranteed The line speed is constant and the speed at which the two lower rollers 3 move upwards is constant until the upper roller 2 comes into contact with the midpoint of the op section of the profile 20 . During the bending process, the two lower rollers 3 always move up the pressing profile 20 all the time. Repeat the above operation twice, at this time, the op arc segment reaches the predetermined radius of curvature.

Step 5: Stop the machine and check the temperature of the profile 20. If it is greater than or equal to 200°C, continue the bending operation. If it is less than 200°C, follow step 2 and return to the furnace to heat to 330°C±20°C before continuing to bend the no section, and the holding time is halved.

Step 6: Bend the no segment of the profile 20. As shown in Figure 6, the no section of the profile 20 is placed on the two lower rollers 3 of the bending machine 1, the midpoint of the no section is aligned with the center of the upper roller 2; The upper roller 2 is in contact, and the profile 20 is positioned on the bending machine 1 by the upper roller 2 and the two lower rollers 3 . Control the upper roller 2 to rotate in the clockwise direction, and the two lower rollers 3 to rotate in the counterclockwise direction, and drive the profile 20 to move to its left end. The rotational speed of the upper roller 2 and the two lower rollers 3 are both 1200mm/min , at the same time, load the two lower rollers 3 with a force of 146KN to move upwards at a speed of 19mm/min to press the profile; when the lower right roller 3 is in contact with the o point of the profile 20, change the upper roller 2 and the two lower rollers 3, drive the profile 20 to move towards its right end, and ensure that the rotational speed of the upper roller 2 and the two lower rollers 3 remains unchanged and the speed of the two lower rollers 3 moving upward; when the left lower roller 3 and the profile When the n points of 20 are in contact, change the rotation direction of the upper roller 2 and the two lower rollers 3 again, drive the profile 20 to move to its left end direction, and ensure that the rotational speed of the upper roller 2 and the two lower rollers 3 is constant and The speed at which the two lower rollers 3 move upwards remains constant until the upper roller 2 contacts the midpoint of the no section of the profile 20. During the bending process, the two lower rollers 3 always move up the pressing profile 20 all the time. Repeat the above operation 2 times, at this time, no arc segment reaches the predetermined radius of curvature.

Step 7: Bend the pq section of the profile 20. The operation process is the same as step 6, until the curved pq arc segment reaches the predetermined radius of curvature. FIG. 7 is a schematic diagram of the state when the profile 20 is bent. At this time, the mn segment and the qw segment of the profile 20 are aligned. The radius of curvature of the pq arc segment=the radius of curvature of the no arc segment.

Fig. 8 shows the schematic diagram of the ring blank 20 of the 2A70 alloy flash welded thin-walled ring piece bent and formed by the method of the present invention. The transition arc segment 22 connecting the straight side 21 and the arc portion 23 is composed of an opening 24 at a position opposite to each other between the two straight sides.

Claims (7)

1. A profile bending blank-making method of an aluminum alloy flash welded thin-walled ring, is characterized in that, comprises the following steps: Divide the aluminum alloy profiles cut according to the specifications into five sections: mn, no, op, pq and qw, the ratio of each section is mn : no : op : pq : qw = 1.0 : 2.0～2.5 : 7.0～8.0 : 2 . 0 ～ 2.5 : 1.0 , then heat the profile to 330°C±20°C; The profile is loaded into the bending machine, and it is positioned by the upper roll and two lower rolls of the bending machine so that the center of the profile is aligned with the center of the upper roll, and the upper roll and the two lower rolls are located the op section of said profile; Manipulate the upper roller to rotate counterclockwise and the two lower rollers to rotate clockwise to drive the profile to move to its right end, and simultaneously apply a force of 100KN to the two lower rollers to move upward to press the profile. When contacting the point o of the profile, change the rotation direction of the upper roller and the two lower rollers, and drive the profile to move to its left end; when the lower right roller contacts the point p of the profile, change the upper roller and the two lower rollers again In the direction of rotation, the profile is driven to move towards its right end until the upper roller contacts the midpoint of the op section of the profile; during the bending process, the two lower rollers always move upwards to press the profile; the linear speed of rotation of the upper and lower rollers is equal is 2400mm/min, and the moving speed of the two lower rollers is 15mm/min; repeat the above operation 2 times, at this time, the op arc section reaches the predetermined radius of curvature; Stop the machine to detect the temperature of the profile, if it is greater than or equal to 200°C, continue the bending operation, if it is less than 200°C, return to the furnace and heat it to 330°C±20°C before continuing to bend the no section; Position the no section of the profile on the bending machine so that the midpoint is aligned with the center of the upper roller; control the upper roller to rotate clockwise, and the two lower rollers to rotate counterclockwise, drive the profile to move to its left end, and simultaneously The two lower rollers are loaded with a force of 146KN to move upward to press the profile; when the lower right roller contacts the o point of the profile, the rotation direction of the upper roller and the two lower rollers is changed, and the profile is driven to move to the right end; when the lower left When the roller is in contact with the n point of the profile, the rotation direction of the upper roller and the two lower rollers is changed again, and the profile is driven to move to its left end until the upper roller contacts the midpoint of the no section of the profile; during the bending process, the two The lower roller always moves upwards to press the profile; the linear speed of rotation of the upper and lower rollers is 1200mm/min, and the moving speed of the two lower rollers is 19mm/min; repeat the above operation 2 times, at this time , no arc segment reaches the predetermined radius of curvature; Bend the pq section according to the steps of bending the no section above, until the pq arc section after bending reaches a predetermined radius of curvature, and the mn section and qw section of the profile are aligned. 2. The profile bending method for aluminum alloy flash welding thin-walled ring parts according to claim 1, characterized in that: the radius of curvature of each curved arc segment is determined by the following formula: $\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 8</span>}\mathrm{<span\; class="notranslate">\; \&delta;</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; d</span>}$ In the formula: R——the radius of curvature of the corresponding arc segment after bending (mm); a——the center distance between the two lower rollers (mm); δ——the rising distance of the lower roller when the bending corresponds to the arc segment (mm); r——the radius of the lower roller (mm); d - the thickness of the profile (mm). 3. The profile bending method for aluminum alloy flash welding thin-walled rings according to claim 1, characterized in that: the speed at which the lower roll moves upwards and the speed of rotation of the upper and lower rolls are coordinated by the following: The formula is determined: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}{\mathrm{<span\; class="notranslate">\; n\&pi;R</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}$ In the formula: V ₂ ——The speed at which the lower roller moves upward when bending the corresponding arc segment (mm/min); V ₁ ——Rotation speed of the upper roller or lower roller when bending the corresponding arc segment (mm/min); R——the radius of curvature of the corresponding arc segment after bending (mm); δ——the rising distance of the lower roller when the bending corresponds to the arc segment (mm); n——the number of repeated bending times (times) corresponding to the arc segment. 4. The profile bending method for aluminum alloy flash welding thin-walled rings according to claim 1, characterized in that: the bending machine loads the lower roller so that the minimum force that can move upward to press the profile is determined by the following formula: $\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 8</span>}\mathrm{<span\; class="notranslate">\; EJ</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 4</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 4</span>}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}\mathrm{<span\; class="notranslate">\; arcsin</span>}\frac{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; a\&delta;</span>}}{{\mathrm{<span\; class="notranslate">\; a</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; \&delta;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$ In the formula: F——The minimum force (N) that the bending machine loads on the lower roller so that it can move upward to press the profile; EJ——the stiffness of the bar, where E is the modulus of elasticity (GPa), and J is the section moment of inertia of the bar (cm ⁴ ); a——the center distance between the two lower rollers (mm); δ——The distance (mm) that the lower roller moves upward. 5. The profile bending method for aluminum alloy flash welding thin-walled rings according to any one of claims 1 to 4, characterized in that: the aluminum alloy is 2A70. 6 . The profile bending blanking method for aluminum alloy flash welding thin-walled rings according to any one of claims 1 to 4 , characterized in that: the maximum axial cross-sectional size of the ring is 65 mm×30 mm. 7. The profile bending method for aluminum alloy flash welding thin-walled ring parts according to any one of claims 1 to 4, characterized in that: the ring blank of the flash welded thin-walled ring parts bent and formed by the method is "D" The font is composed of two straight sides, a circular arc part and a transitional arc segment connecting the straight sides and the circular arc part, and has an opening at the opposite end between the two straight sides.