Special-shaped cross-section profile bending and twisting device and method based on gear type bending die

Abstract

The application discloses a special-shaped cross-section profile bending and twisting device and method based on a gear type bending die, which comprises a gear type bending die with a multi-roller structure; a die base plate, a bending die gear, a driving pinion, a rotary motor of the driving pinion, a roller group and a positioning block group; the bending die gear (2) is engaged with the driving pinion (3), the driving gear (3) is connected with the rotary motor (4), the driving pinion (3) is driven to rotate by the rotary motor (4), so that the bending die gear (2) is driven to realize rotary motion; the gear type bending die can adjust the space pose of the bending die at will, expands the space of bending and twisting forming, and can ensure that the profile can smoothly pass through the bending die and feed to the positive direction of the Z axis; when the irregular special-shaped cross-section profile bending and twisting component is formed, the axis offset caused by the irregular cross-section shape can be corrected, and the degree of freedom of the system is further improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of profile bending and twisting flexible forming, and particularly relates to a special-shaped cross-section profile bending and twisting device and method based on a gear type bending die. BACKGROUND

[0002] Profile bending and twisting members are key load-bearing members and impact-resistant members in the fields of aerospace, high-speed rail, new energy vehicles, etc., and are mostly formed by a process combining roll bending and welding. However, the minimum bending radius required by the roll bending forming technology is relatively large, and the axial accuracy is difficult to guarantee, so that the formed members need to be welded after secondary straightening, resulting in poor forming quality and low efficiency. The current six-axis free bending and twisting forming system can realize the overall bending and twisting forming of profile members, but this method still has the following limitations:

[0003] (1) When forming irregular special-shaped cross-section profile bending and twisting members, the members will be unevenly stressed due to the irregular cross-sectional shape during bending and twisting, resulting in axial deviation defects. If the space poses of the bending die and the rotating shaft are adjusted at the beginning to correct the defects, the profile cannot correspond to the bending die, and there is still a lack of a simple device for adjusting the pose of the bending die.

[0004] (2) Most profile members have complex spatial configurations, and during the bending and twisting forming process, the propulsion shaft, translation shaft and rotating shaft of the six-axis free bending and twisting forming system are always in motion, so that the formed part of the profile member will continuously change its spatial position with the movement of the bending die, thereby colliding with and interfering with multiple mechanical structure components such as the equipment head, affecting the forming of the member and damaging the equipment.

[0005] The mechanical structure and device in Chinese invention patent - a six-axis free bending and twisting forming system and method for profile spiral members (CN114346028 A) have been improved in terms of the structure design and movement mode of the bending die. The patent proposes a forming die system and process analysis scheme matched with the six-axis free bending and twisting equipment, but some technical problems are likely to occur during the forming process. For example, when forming irregular special-shaped cross-section profile bending and twisting members, the members will be unevenly stressed due to the irregular cross-sectional shape during bending and twisting, resulting in axial deviation defects. SUMMARY

[0006] The present application proposes a special-shaped cross-section profile bending and twisting device and method based on a gear type bending die in view of the problems and deficiencies in the current six-axis free bending and twisting forming system for forming profile members.

[0007] To achieve the above-mentioned objectives, the present application provides the following technical solutions:

[0008] The application discloses a special-shaped section profile bending and twisting device based on a gear type bending die, which comprises a gear type bending die with a multi-roller structure; the gear type bending die comprises a die base plate (1), a bending die gear (2), a gear (3), a rotary motor (4) for driving the gear (3), a roller group (5) and a positioning block group (6); the roller group (5) is connected with the positioning block group (6) through bearings; the positioning block group (6) is fixed on the bending die gear (2) through bolts; the die base plate (1) is connected with a machine head (7) through a shaft; the bending die gear (2) is engaged with the gear (3); the gear (3) is connected with the rotary motor (4); the rotary motor (4) drives the gear (3) to rotate, so as to drive the bending die gear (2) to realize rotary motion, and then drive the positioning block group (6) and the roller group (5) to realize rotary motion; before free bending and twisting forming, the bending die is located at an original position; the initial angle of the C shaft is adjusted according to the section shape of the profile and the geometric shape requirement of a target component, so that the machine head (7) rotates by a certain angle; meanwhile, the rotary motor (4) starts to operate; the gear (3) drives the bending die gear (2) to rotate through engagement, reversely compensates the deviation between the bending die coordinate system and the original coordinate system caused by the C shaft motion, so that the bending die returns to the original state, and the profile (17) can smoothly pass through the roller group (5) and feed to the positive direction of the Z shaft; the combined motion of the rotary motion of the die driven by the C shaft and the self-rotary motion of the die makes the profile (17) not collide with or interfere with the machine head (7) and other mechanical structures during bending and twisting forming; during the free bending and twisting forming, the profile (17) feeds to the positive direction of the Z shaft, the machine head (7) moves horizontally under the control of the motors of the X shaft and the Y shaft, rotates around the shafts under the control of the motors of the A shaft, the B shaft and the C shaft, and realizes the six-axis free bending and twisting forming of the profile (17) with the corrected axis offset.

[0009] The special-shaped section profile bending and twisting device based on the gear type bending die is characterized in that the left side of the machine head (7) is connected with the A shaft motor (11) through a key, the X shaft motor (10) is installed on an X direction sliding table (14), the X direction horizontal motion of the machine head (7) is realized through the A shaft motor (11), and the rotary motion of the machine head (7) around the X shaft is realized through the X shaft motor (10).

[0010] The special-shaped section profile bending and twisting device based on the gear type bending die is characterized in that the lower side of the machine head (7) is connected with the B shaft motor (8) through a key, the Y shaft motor (9) is installed on a Y direction sliding table (13), the Y direction vertical motion of the machine head (7) is realized through the B shaft motor (8), and the rotary motion of the machine head (7) around the Y shaft is realized through the Y shaft motor (9).

[0011] The special-shaped section profile bending and twisting device based on the gear type bending die is characterized in that the machine head (7) is connected with the C shaft rotary mechanism (15), the C shaft motor (12) drives the C shaft rotary mechanism (15) to realize the rotary motion of the machine head (7) around the Z shaft, so as to realize the twisting motion of the profile (17).

[0012] According to the irregular profiled section profile bending and twisting method, the angle at which the gear type bending die needs to be independently deflected is determined according to the shape characteristics of the irregular profiled section profile or the axis offset angle that occurs when the profile is actually bent and twisted, and the bending die gear (2) is driven by the gear (3) to rotate in the opposite direction by the angle; then the angle of the head (7) is corrected by the gear (3), so that the profile (17) can smoothly pass through the roller set (5) and feed in the positive direction of the Z axis; since the initial coordinate system of the bending die rotates and does not coincide with the X / Y axis coordinate axis, it is necessary to establish the cross-sectional shape, geometric shape parameters of the to-be-formed profile member, and the space pose parameters of the rotated bending die, including the offset amounts U x 、U y of the X axis and the Y axis; the rotation angles of the A axis, the B axis and the C axis , γ and the process parameters of the free bending and twisting system, including the distance A' between the bending die and the guide roller set (16), and the mathematical analysis model between the eccentricity value B of the center of the roller set (5) and the rotation center of the bending die.

[0013] The profiled section profile bending and twisting method comprises the following specific methods: parameter analysis is performed on the movement of the rotated bending die; the center of the bending die moves from the origin O to the S point, and has a torsion angle of γ; since the torsion axis C axis moves, it drives the bending die to rotate around the Z axis direction, and drives the A and B axes to rotate synchronously, so that the direction and size of the original eccentricity U are changed; the components of the original eccentricity U on the X axis and the Y axis are Ux and Uy, and the components of the changed eccentricity U' on the X axis and the Y axis are U'x and U'y; the angle between the original eccentricity U and the X axis is ω, the angle between the self-rotated eccentricity U' and the X axis is ω', and the angle between the two eccentricities, i.e. the angle between OS and OS', is Δω; the S' point moves on a circular ring with the S point as the center and a radius of , the following formula can be obtained: ; ; according to the plane relationship in the figure, the trigonometric function representation of Δω can be obtained: ; thus Δω can be derived as: ; the rotation angles of the A axis and the B axis can be calculated as: ; in the first step, the original angle of the C axis is adjusted according to the cross-sectional shape and geometric shape requirements of the profile numerical model, so that the head (7) rotates by a certain angle θ around the Z axis advancing direction; in the second step, the rotation motor (4) drives the gear (3) to rotate the bending die gear (2) in the opposite direction by an angle θ, and corrects the bending die back to the initial position, so that the profile (17) can smoothly pass through the roller set (5) and feed in the positive direction of the Z axis; in the third step, the eccentricity U x 、U y of the bending radius R is calculated as the deflection angle between the mathematical relationship; the fourth step, according to the shape of the profile member to determine the rotation angle of C axis γ; The fifth step, calculate the forming time of each transition section, stable forming section and return section.

[0014] The present application has the following beneficial effects:

[0015] 1、 The gear type bending die provided by the present application can adjust the spatial pose of the bending die at will, expand the space of bending and torsion forming, and ensure that the profile can smoothly pass through the bending die and feed in the positive direction of the Z axis.

[0016] 2、 The gear type bending die provided by the present application can correct the axis deviation caused by the irregular cross-section shape when forming the bending and torsion member of the irregular cross-section profile, and further improve the degree of freedom of the system.

[0017] 3、 The six-axis free bending and torsion forming system self-rotating device and the analytical algorithm provided by the present application are simple and feasible, have low processing cost and high production efficiency, and have important engineering application value and obvious economic benefits in the fields of aerospace and automobile manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 、 One The overall appearance schematic diagram of the six-axis free bending and torsion forming system adopting the gear type bending die;

[0019] Figure 2 The schematic diagram of the gear type bending die with a multi-roller structure;

[0020] Figure 3 、 Six The process parameter schematic diagram of the six-axis free bending and torsion forming system;

[0021] Figure 4 、 Six The C-axis torsion angle motion parameter schematic diagram of the six-axis free bending and torsion forming system;

[0022] Figure 5 The cross-section schematic diagram of the irregular cross-section profile;

[0023] Figure 6 The three view diagram of the irregular cross-section profile member; DETAILED DESCRIPTION

[0024] The present application will be described in detail below in combination with specific embodiments.

[0025] The present application will be described in detail below in combination with specific embodiments of the free bending and torsion forming of typical irregular cross-section profile members. EMBODIMENT

[0026] The first step, as Figure 5 andFigure 6 The irregular profiled cross-section member shown is a planar bending non-twisted member, but due to its irregular cross-section, it will deviate clockwise around the Z axis during actual bending forming, resulting in the member not being in the same plane.

[0027] Secondly, the irregular profiled cross-section member is placed in the six-axis free bending and twisting system, and a constant pushing speed v = 20 mm / s is set. As shown in Figure 6 The bending radius R = 400 mm of the continuous bending sections 6-2 and 6-4 of the profiled section is obtained. As shown in Figure 3 The process parameter schematic diagram of the six-axis free bending and twisting forming system is shown. The forming zone length A = 110 mm, the eccentricity value B = 40 mm between the center of the roller group (5) and the rotation center of the bending die, the distance A between the bending die and the guide roller group (16), and the relationship between the space pose parameters of the bending die (the offset amount U of the Y axis; the rotation angle of the A axis

[0028] During the forming of the transition section 6-2:

[0029] The offset amount in the Y axis direction:

[0030]

[0031] When the motor controls the die to rotate around the X / Y axis, the profiled section generates bending in the Y / X axis direction. Since the centroid of the profiled section cross-section is not on the same axis as the Z axis, and the cross-section shape is not symmetric about the X / Y coordinate axis, the stress on the profiled section during forming is also not symmetric about the X / Y coordinate axis. To balance the stress on the cross-section of the bending member, the cross-section actively generates twisting around the Z axis direction. To eliminate this cross-section shape defect, the bending die gear (2) needs to be driven to rotate counterclockwise by 2° around the Z axis at this time by driving the pinion gear (3), where 2° is the angle of the cross-section twisting of the defective member after bending, which corrects the axis deviation caused by the irregular cross-section shape.

[0032] Therefore, Δω can be derived as:

[0033]

[0034] The rotation angle around the A axis can be calculated as:

[0035]

[0036] During the forming of the stable section 6-3: in addition to the Z axis pushing, all axes and gear motors remain stationary, allowing the square tube profiled section to be stably formed under the conditions of this eccentricity and twisting angle;

[0037] In the forming return segment 6-4: in addition to the propulsion of the Z axis, each axis returns to the initial position, the Y axis offset and the A axis angle are the same as in the forming transition segment, but in the opposite direction;

[0038] In the fifth step, the time and angular velocity of each forming segment are calculated according to the arc length S of each segment of the irregular profiled section member:

[0039] The straight segment 6-1: t1=S1 / v=100 / 20=5 s;

[0040] The transition segment 6-2: t2=S2 / v=200 / 20=10 s

[0041] The offset speed in the Y direction: v=U / t2=14.98 / 10=1.5 mm / s;

[0042] The angular velocity of the A axis rotation: ω A = =15.95° / 10=1.595° / s;

[0043] The angular velocity of the gear type bending die rotation: ω=2° / 10=0.2° / s;

[0044] The stable forming segment 6-3: t3=S3 / v=1500 / 20=75 s;

[0045] The return segment 6-4: t4=S4 / v=200 / 20=10 s

[0046] The offset speed in the X and Y directions: v=U / t4=14.98 / 10=1.5 mm / s;

[0047] The angular velocity of the A axis rotation: ω A = =15.95° / 10=1.595° / s;

[0048] The angular velocity of the gear type bending die rotation: ω=2° / 10=0.2° / s;

[0049] Wherein the movement direction of each axis is opposite to that in the transition segment 6-2;

[0050] The straight segment 6-5: t5=S5 / v=100 / 20=5 s;

[0051] The finally formed planar continuous bending irregular profiled section member is shown in Figure 6 .

[0052] It should be understood that those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall fall within the protection scope of the appended claims of the present application.

Claims

1. A profile bending and twisting device based on a gear-type bending die, characterized in that, Gear type bending die including multi-roller structure; the gear type bending die includes die seat plate (1), bending die gear (2), gear (3), rotary motor (4) driving gear (3), roller group (5) and positioning block group (6); roller group (5) is connected with positioning block group (6) by bearing; positioning block group (6) is fixed on bending die gear (2) by bolt; die seat plate (1) is connected with headstock (7) by shaft, bending die gear (2) and gear (3) are engaged with each other, gear (3) is connected with rotary motor (4), gear (3) is driven to rotate by rotary motor (4), so that bending die gear (2) is driven to realize rotary motion, and then positioning block group (6) and roller group (5) are driven to realize rotary motion; before free bending and torsion forming, the bending die is in the original position; the initial angle of C shaft is adjusted according to the cross-sectional shape of the profile and the geometric shape requirement of the target component, so that the headstock (7) is rotated by a certain angle; at the same time, the rotary motor (4) starts to operate, the gear (3) rotates the bending die gear (2) through engagement, reversely compensates the deviation of the bending die coordinate system and the original coordinate system caused by the movement of the C shaft, makes the bending die return to the original state, and the profile (17) can smoothly pass through the roller group (5) and feed to the positive direction of Z axis; the compound motion of the rotary motion of the die driven by the equipment C shaft and the self-rotation motion of the die makes the profile (17) not collide and interfere with mechanical structures such as headstock (7) during bending and torsion forming; during free bending and torsion forming, the profile (17) feeds along the positive direction of Z axis, the headstock (7) moves horizontally under the control of the motor of X axis and Y axis, and rotates around the shaft under the control of the motor of A axis, B axis and C axis, so as to realize six-axis free bending and torsion forming of the profile (17) with corrected axis offset.

2. A profile bending and twisting device based on a gear-type bending die according to claim 1, characterized in that, The left side of the headstock (7) is connected with the A-axis motor (11) through a key, the X-axis motor (10) is installed on the X-direction sliding table (14), the X-direction horizontal motion of the headstock (7) is realized through the A-axis motor (11), and the rotary motion of the headstock (7) around the X-axis is realized through the X-axis motor (10).

3. The bent and twisted device for a profile of a special cross section based on a gear type bending die according to claim 1, characterized in that, The lower side of the headstock (7) is connected with the B-axis motor (8) through a key, the Y-axis motor (9) is installed on the Y-direction sliding table (13), the Y-direction vertical motion of the headstock (7) is realized through the B-axis motor (8), and the rotary motion of the headstock (7) around the Y-axis is realized through the Y-axis motor (9).

4. The bent and twisted device for a profile of a special cross section based on a gear type bending die according to claim 1, characterized in that, The headstock (7) is connected with the C-axis rotary mechanism (15), the C-axis motor (12) drives the C-axis rotary mechanism (15) to realize the rotary motion of the headstock (7) around the Z-axis, so as to realize the torsion motion of the profile (17).

5. A method of bending and twisting a profiled section according to any one of claims 1 to 4, characterised in that, According to the shape characteristics of irregular profiled section and the axis offset angle that may appear during actual bending and twisting forming, the angle that the gear type bending die needs to be independently deflected is determined, and the bending die gear (2) is driven by the gear (3) to rotate in the opposite direction by the angle; then the angle of the head (7) is corrected by the gear (3), so that the profiled section (17) can smoothly pass through the roller set (5) and feed to the positive direction of the Z axis; since the initial coordinate system of the bending die rotates and does not coincide with the X / Y axis coordinate axes, it is necessary to establish the cross-sectional shape, geometric shape parameters of the to-be-formed profiled section component, the space pose parameters of the rotated bending die including the offset amount U x 、 U y ; the rotation angle of the A axis, the B axis and the C axis 、 γ and the process parameters of the free bending and twisting system including the distance A' between the bending die and the guide roller set (16), the mathematical analysis model between the eccentric value B of the center of the roller set (5) and the rotation center of the bending die.

6. A method of bending and twisting a profile of irregular cross-section according to claim 5, characterized in that, The specific method is as follows: the parameter analysis is carried out on the bending mode after the rotation; the center of the bending mode moves from the original point O to the point S and has a torsion angle of γ; since the torsion axis C moves, the bending mode rotates around the Z axis direction, and the A and B axes rotate synchronously, so that the direction and size of the original eccentricity U are changed, the components of the changed U' on the X and Y axes are U'x and U'y, the angle between the original eccentricity U and the X axis is ω, the angle between the eccentricity U' and the X axis after the rotation is ω', the angle between the two eccentricities, i.e. the angle between OS and OS', is Δω, the S' point moves on the circular ring with S point as the center, The following formula can be obtained: ; Wherein, A is the length of the forming area, B is the eccentricity value of the center of the B roller group (5) and the rotation center of the bending mode, and R is the bending radius; according to the plane relationship, the trigonometric function expression of Δω is obtained: From which Δω can be derived: The rotation angles of the A and B axes Can be calculated as: Firstly, according to the cross-sectional shape and geometric shape requirements of the profile numerical model, the original angle of the C axis is adjusted, so that the head (7) rotates a certain angle θ around the Z axis advancing direction; secondly, the rotation motor (4) drives the gear (3) to make the bending mode gear (2) rotate in the opposite direction by an angle θ, so as to correct the bending mode back to the initial position, so that the profile (17) can smoothly pass through the roller group (5) and feed to the positive direction of the Z axis; thirdly, the mathematical relationship between the eccentricity U x , U y -bending radius R-deflection angle is calculated according to the bending radius R of the profile member; fourthly, the rotation angle γ of the C axis is determined according to the shape of the profile member; fifthly, the forming time of each transition section, stable forming section and return section is calculated.

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