The stretch-bending process of a stretch-bending machine

Abstract

The present invention discloses a stretch-bending process for a stretch-bending machine. The stretch-bending machine includes a workbench, a left chuck mechanism located on the left side of the workbench, a right chuck mechanism located on the right side of the workbench, a frame located below the workbench, and a stretch-bending die located above the workbench. By utilizing the coordinated actions of the various mechanisms in the stretch-bending machine, a stretch-bending process is implemented on the workpiece, enabling the workpiece to be subjected to stretching, bending, and twisting processes, achieving full-automatic processing, and greatly improving the efficiency of stretch-bending processing of the workpiece. In addition, steps for eliminating tensile springback, bending springback, and twisting springback are introduced in the stretch-bending process steps of the present invention, improving the accuracy of stretch-bending processing of the workpiece.

Description

Technical Field

[0001] The present invention belongs to the technical field of stretch bending machines, and particularly relates to a stretch bending process of a stretch bending machine. Background Art

[0002] Stretch bending is a stamping forming process that bends metal plates, tubes, and profiles into workpieces with a certain curvature, shape, and size. Stretch bending forming is widely used in the manufacture of high-pressure vessels, boiler drums, boiler tubes, steel plates and ribs of ship hulls, various vessels, instrument components, and cabinet moldings.

[0003] In the existing stretch bending process, the workpiece is generally stretch bent and formed by a multi-stage stretch bending method. For example, in a Chinese invention application document with the patent application number: 201710860055.3 and the title: Stretch Bending Machine and Stretch Bending Process of Profiles, a stretch bending process of profiles is disclosed. The profiles are clamped and fixed on one side of a stretch bending die by two chucks of a stretch bending device. The profile surface of the stretch bending die includes multiple arc surfaces connected end to end. The following steps of stretch bending the profiles are also included: First-stage stretch bending: Rotate the two chucks to drive the profiles to fit with one arc surface to stretch bend one section of the profiles; Remaining-section stretch bending: Move the pressing block of the pressing device forward to press the previously stretch bent section of the profiles onto the corresponding arc surface; Then rotate the chucks to drive the profiles to fit with the next arc surface of the profile surface to stretch bend the next section of the profiles. This stretch bending process requires first-stage stretch bending and then remaining-section stretch bending, and the workpiece stretch bending requires a longer processing time. In addition, after the workpiece is stretch bent, the elastic recovery is not eliminated at the corresponding deformation amount. Therefore, there is a certain difference between the elastic recovery after the workpiece is stretch bent and the actual processing requirements of the workpiece, resulting in the problem of low stretch bending accuracy of the workpiece. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a high-precision and fully automatic stretch bending process for a stretch bending machine.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0006] A stretch bending process of a stretch bending machine includes the following steps:

[0007] S1: The stretch bending machine starts and performs initialization actions, and each mechanism returns to the initial state;

[0008] S2: Both the left chuck mechanism and the right chuck mechanism open and are in an open state, and the left telescopic mechanism and the right telescopic mechanism synchronously extend;

[0009] S3: Place the workpiece on the workbench, and place the left and right ends of the workpiece into the left chuck mechanism and the right chuck mechanism respectively;

[0010] S4: The left chuck mechanism and the right chuck mechanism are clamped synchronously to clamp the left and right ends of the workpiece to be bent in the left chuck mechanism and the right chuck mechanism;

[0011] S5: The left telescopic mechanism and the right telescopic mechanism perform the material pulling action synchronously. During the material pulling process, the left telescopic mechanism and the right telescopic mechanism stretch the workpiece in the length direction according to the set pressure value, so that the workpiece is gradually stretched;

[0012] S6: The left front-to-back swing mechanism and the right front-to-back swing mechanism synchronously pull back, so that the workpiece is close to the stretch-bending die and gradually bends along the pull-back direction of the left front-to-back swing mechanism and the right front-to-back swing mechanism;

[0013] S7: The left telescopic mechanism and the right telescopic mechanism synchronously release pressure;

[0014] S8: The left telescopic mechanism and the right telescopic mechanism extend synchronously, driving the two ends of the workpiece to offset a certain degree of stretching and rebounding in the tensile deformation;

[0015] S9: The left front-to-back swing mechanism and the right front-to-back swing mechanism extend synchronously, driving the two ends of the workpiece to offset a certain degree of bending springback in the bending deformation;

[0016] S10: The left chuck mechanism and the right chuck mechanism both open, and the left chuck mechanism and the right chuck mechanism simultaneously release the left and right ends of the workpiece;

[0017] S11: Take out the workpiece;

[0018] S12: The left telescopic mechanism and the right telescopic mechanism are fully extended and reset;

[0019] S13: The left front-to-back swing mechanism and the right front-to-back swing mechanism are fully extended and reset.

[0020] As a further improvement of the present invention, the following steps are also included between step S5 and step S6:

[0021] S5-1: The left up-and-down moving mechanism and the right up-and-down moving mechanism move upward synchronously, so that the workpiece moves upward and leaves the workbench;

[0022] S5-2: The left-rotating mechanism and the right-rotating mechanism rotate synchronously in opposite directions to achieve twisting processing of the workpiece;

[0023] S5-3: The left up-and-down moving mechanism and the right up-and-down moving mechanism move downward synchronously, so that the workpiece returns to the workbench;

[0024] The following steps are also included between step S9 and step S10:

[0025] S9-1: The left and right rotating mechanisms rotate synchronously, driving both ends of the workpiece to offset a certain degree of torsional springback in torsional deformation.

[0026] As a further improvement of the present invention, in step S5, the drawing pressure values of the left and right telescopic mechanisms can be adjusted manually. By means of manual intervention, the pressure value of the workpiece during the drawing process is adjusted, so that the workpiece is fully stretched.

[0027] As a further improvement of the present invention, in step S6, during the retraction process of the left and right front-back swing mechanisms, the retraction speeds of the left and right front-back swing mechanisms can be adjusted, thereby adjusting the bending speed of the workpiece.

[0028] As a further improvement of the present invention, in step S4, after the left and right chuck mechanisms clamp the left and right ends of the workpiece, they continue to clamp for 5 - 10 seconds before proceeding to the next step.

[0029] As a further improvement of the present invention, in step S6, the retraction strokes of the left and right front-back swing mechanisms are limited by limiters. Limiters are respectively provided on the movement strokes of the left and right front-back swing mechanisms, and the positions of the limiters on the movement strokes are adjusted according to the degree to which the workpiece needs to be bent.

[0030] As a further improvement of the present invention, when the left and right front-back swing mechanisms retract and move to the preset positions, after the limiters sense the actions of the left and right front-back swing mechanisms, the limiters send induction signals to the left and right front-back swing mechanisms to control the left and right front-back swing mechanisms to stop acting.

[0031] As a further improvement of the present invention, in step S8, the sum of the extended lengths of the left and right telescopic mechanisms is equal to the tensile springback length of the workpiece.

[0032] As a further improvement of the present invention, in step S9, the sum of the extended lengths of the left and right front-back swing mechanisms is equal to the bending springback length of the workpiece.

[0033] As a further improvement of the present invention, in step 9-1, the sum of the rotation angles of the left and right rotating mechanisms is equal to the torsional springback angle of the workpiece.

[0034] The beneficial effects of the present invention are as follows: By utilizing the coordinated actions of various mechanisms in the stretch-bending machine, the present invention implements the stretch-bending process on the workpiece, enabling the workpiece to be subjected to stretching, bending, and twisting processing, achieving fully automatic processing, and greatly improving the efficiency of the stretch-bending processing of the workpiece; in addition, steps for eliminating stretching springback, bending springback, and twisting springback are introduced in the stretch-bending process steps of the present invention, improving the accuracy of the stretch-bending processing of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a perspective view of the stretch-bending machine of this embodiment in one view direction;

[0036] Figure 2 is a perspective view of the stretch-bending machine of this embodiment in another view direction;

[0037] Figure 3 is a perspective view of the left chuck mechanism of this embodiment in one view direction;

[0038] Figure 4 is a perspective view of the left chuck mechanism of this embodiment in another view direction;

[0039] Figure 5 is a perspective view of the left rotation mechanism of this embodiment;

[0040] Figure 6 is an exploded view of the left rotation mechanism of this embodiment;

[0041] Figure 7 is a schematic diagram of the internal transmission structure of the left rotation mechanism of this embodiment;

[0042] Figure 8 is a schematic diagram of the installation structure between the left telescopic mechanism, the left upper and lower swing mechanism, and the left upper and lower moving mechanism of this embodiment;

[0043] Figure 9 is a schematic diagram of this embodiment capable of showing the internal structure of the vertical box girder;

[0044] Figure 10 is a schematic diagram of the installation structure of the left left-right moving mechanism and the left front-back swing mechanism of this embodiment in one view direction;

[0045] Figure 11 is a schematic diagram of the installation structure of the left left-right moving mechanism and the left front-back swing mechanism of this embodiment in another view direction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0047] Embodiment:

[0048] As shown Figures 1 to 11 in the figure, this embodiment discloses a stretch bending process of a stretch bender, wherein the stretch bender includes a workbench 1, a left chuck mechanism 2 on the left side of the workbench 1, a right chuck mechanism 2' on the right side of the workbench 1, a frame 3 under the workbench 1, and a stretch bending die 4 above the workbench 1; the left chuck mechanism 2 is connected with a left rotation mechanism 5 for driving the left chuck mechanism 2 to rotate, and the left rotation mechanism 5 drives the left chuck mechanism 2 to rotate around the Y-axis; the left rotation mechanism 5 is connected with a left telescopic mechanism 6 for driving the left rotation mechanism 5 to move left and right, and the left telescopic mechanism 6 drives the left rotation mechanism 5 to move along the Y-axis; the left telescopic mechanism 6 is connected with a left upper and lower swing mechanism 7 for swinging up and down to adjust the position of the left telescopic mechanism 6, and the left upper and lower swing mechanism 7 drives the left telescopic mechanism 6 to rotate around the X-axis; the left upper and lower swing mechanism 7 is connected with a left upper and lower moving mechanism 8 for moving up and down to adjust the position of the left upper and lower swing mechanism 7, and the left upper and lower moving mechanism 8 drives the left upper and lower swing mechanism 7 to move along the Z-axis; the left upper and lower moving mechanism 8 is connected with a left left and right moving mechanism 9 for moving left and right to adjust the position of the left upper and lower moving mechanism 8, and the left left and right moving mechanism 9 drives the left upper and lower moving mechanism 8 to move along the Y-axis; the left left and right moving mechanism 9 is connected with a left front and rear swing mechanism 10 for driving the left left and right moving mechanism 9 to swing back and forth, and the left front and rear swing mechanism 10 drives the left left and right moving mechanism 9 to rotate around the Z-axis; correspondingly, on the right side of the workbench 1, there is also a right rotation mechanism 5', a right telescopic mechanism 6', a right upper and lower swing mechanism 7', a right upper and lower moving mechanism 8', a right left and right moving mechanism 9', and a right front and rear swing mechanism 10' which are mirror-symmetrically configured corresponding to the left rotation mechanism 5, the left telescopic mechanism 6, the left upper and lower swing mechanism 7, the left upper and lower moving mechanism 8, the left left and right moving mechanism 9, and the left front and rear swing mechanism 10. Correspondingly, the connection structures between the right chuck mechanism 2', the right rotation mechanism 5', the right telescopic mechanism 6', the right upper and lower swing mechanism 7', the right upper and lower moving mechanism 8', the right left and right moving mechanism 9', and the right front and rear swing mechanism 10' are the same as those between the left chuck mechanism 2, the left rotation mechanism 5, the left telescopic mechanism 6, the left upper and lower swing mechanism 7, the left upper and lower moving mechanism 8, the left left and right moving mechanism 9, and the left front and rear swing mechanism 10.

[0049] Specifically, when the stretch bender performs stretch bending work, the stretch bending process of the stretch bender includes the following steps:

[0050] S1: The stretch bender starts and initializes, and each mechanism returns to the initial state;

[0051] S2: Both the left chuck mechanism 2 and the right chuck mechanism 2' open and are in an open state, and the left telescopic mechanism 6 and the right telescopic mechanism 6' perform synchronous extension actions;

[0052] S3: Place the workpiece on the workbench 1, and place the left and right ends of the workpiece into the left chuck mechanism 2 and the right chuck mechanism 2' respectively;

[0053] S4: The left chuck mechanism 2 and the right chuck mechanism 2' perform synchronous clamping actions to clamp the left and right ends of the workpiece to be bent between the left chuck mechanism 2 and the right chuck mechanism 2';

[0054] S5: The left telescopic mechanism 6 and the right telescopic mechanism 6' perform synchronous material pulling actions. During the material pulling process, the left telescopic mechanism 6 and the right telescopic mechanism 6' stretch the workpiece in the length direction according to the set pressure value, so that the workpiece is gradually elongated; of course, the material pulling pressure values of the left telescopic mechanism 6 and the right telescopic mechanism 6' can be adjusted manually. By means of manual intervention, the pressure value of the workpiece during the material pulling process is adjusted, so that the workpiece is fully stretched;

[0055] S5-1: The left up and down moving mechanism 8 and the right up and down moving mechanism 8' move upward synchronously to move the workpiece upward away from the workbench 1;

[0056] S5-2: The left rotating mechanism 5 and the right rotating mechanism 5' perform synchronous rotating actions in opposite directions to twist the workpiece;

[0057] S5-3: The left up and down moving mechanism 8 and the right up and down moving mechanism 8' move downward synchronously to make the workpiece return to the workbench 1 again;

[0058] S6: The left front and rear swinging mechanism 10 and the right front and rear swinging mechanism 10' perform synchronous pulling-back actions to make the workpiece gradually bend along the pulling-back direction of the left front and rear swinging mechanism 10 and the right front and rear swinging mechanism 10' close to the bending die 4. During the pulling-back process of the left front and rear swinging mechanism 10 and the right front and rear swinging mechanism 10', the pulling-back speed of the left front and rear swinging mechanism 10 and the right front and rear swinging mechanism 10' can be adjusted, so as to adjust the bending speed of the workpiece;

[0059] S7: The left telescopic mechanism 6 and the right telescopic mechanism 6' perform synchronous pressure relief actions;

[0060] S8: The left telescopic mechanism 6 and the right telescopic mechanism 6' perform synchronous extending actions, driving the two ends of the workpiece to offset a certain degree of tensile springback in the tensile deformation. The sum of the extending lengths of the left telescopic mechanism 6 and the right telescopic mechanism 6' is equal to the tensile springback length of the workpiece;

[0061] S9: The left front and rear swinging mechanism 10 and the right front and rear swinging mechanism 10' perform synchronous extending actions, driving the two ends of the workpiece to offset a certain degree of bending springback in the bending deformation. The sum of the extending lengths of the left front and rear swinging mechanism 10 and the right front and rear swinging mechanism 10' is equal to the bending springback length of the workpiece;

[0062] S9-1: The left rotation mechanism 5 and the right rotation mechanism 5' rotate synchronously, driving both ends of the workpiece to offset a certain degree of torsional springback in torsional deformation. The sum of the rotation angles of the left rotation mechanism 5 and the right rotation mechanism 5' is equal to the torsional springback angle of the workpiece;

[0063] S10: Both the left chuck mechanism 2 and the right chuck mechanism 2' open, and the left chuck mechanism 2 and the right chuck mechanism 2' release both ends of the workpiece simultaneously;

[0064] S11: Remove the workpiece;

[0065] S12: The left telescopic mechanism 6 and the right telescopic mechanism 6' fully extend and reset;

[0066] S13: The left front-back swing mechanism 10 and the right front-back swing mechanism 10' fully extend and reset.

[0067] In step S4, after the left chuck mechanism 2 and the right chuck mechanism 2' clamp both ends of the workpiece, they continue to clamp for 5 - 10 seconds before proceeding to the next step.

[0068] In step S6, the retraction stroke of the left front-back swing mechanism 10 and the right front-back swing mechanism 10' is limited by the position limiter. Position limiters are respectively set on the action strokes of the left front-back swing mechanism 10 and the right front-back swing mechanism 10'. The position of the position limiter on the action stroke is adjusted according to the degree to which the workpiece needs to be bent. When the left front-back swing mechanism 10 and the right front-back swing mechanism 10' retract and move to the preset position, after the position limiter senses the actions of the left front-back swing mechanism 10 and the right front-back swing mechanism 10', the position limiter sends an induction signal to the left front-back swing mechanism 10 and the right front-back swing mechanism 10' to control the left front-back swing mechanism 10 and the right front-back swing mechanism 10' to stop operating.

[0069] As a preferred embodiment, the left chuck mechanism 2 includes a chuck block 21, a chuck connecting shaft member 22, a fine-thread plate 23, an inclined pressure plate 24, a lower pressure plate 25 and a chuck oil cylinder 26. The chuck connecting shaft member 22 is fixedly installed on the back of the chuck block 21, and a connecting shaft hole 221 for connecting the left rotation mechanism 5 is provided on the back of the chuck connecting shaft member 22; a clamping opening 211 is provided on the front of the chuck block 21, the fine-thread plate 23 and the inclined pressure plate 24 are installed on both sides of the clamping opening 211, the lower pressure plate 25 is installed at the bottom of the clamping opening 211, the chuck oil cylinder 26 is fixedly installed on one side of the chuck block 21, and the telescopic rod of the chuck oil cylinder 26 passes through the side wall of the chuck block 21 and enters the clamping opening 211 to connect the back of the fine-thread plate 23; the bottoms of the fine-thread plate 23 and the inclined pressure plate 24 are cooperatively connected with the lower pressure plate 25. The operating principle of the left chuck mechanism 2 is as follows: the chuck oil cylinder 26 makes a telescopic movement, thereby driving the fine-thread plate 23 to move closer to or away from the inclined pressure plate 24, so as to realize the clamping and loosening actions of the left chuck mechanism 2; when the chuck oil cylinder 26 drives the fine-thread plate 23 to move, the fine-thread plate 23 uses the lower pressure plate 25 as a moving guide rail for movement limit, so that the movement of the fine-thread plate 23 is stable and reliable; at the same time, the bottoms between the inclined pressure plate 24 and the lower pressure plate 25 are also cooperatively connected, so that the fine-thread plate 23 and the inclined pressure plate 24 are oppositely arranged, which is convenient for the installation and positioning between the fine-thread plate 23 and the inclined pressure plate 24.

[0070] As a preferred embodiment, the left rotation mechanism 5 includes a rotary oil cylinder 51, a gear shaft 52, an oil cylinder fixing member 53, a rotating shaft support plate 54, an anti-rotation fixing plate 55 and an oil cylinder locking nut 56. There are two oil cylinder fixing members 53 and two rotating shaft support plates 54. The oil cylinder locking nut 56 is fixedly installed on the back of the anti-rotation fixing plate 55, and two oil cylinder fixing members 53 are fixedly installed on the front of the anti-rotation fixing plate 55. The two oil cylinder fixing members 53 are arranged in parallel at intervals. The two rotating shaft support plates 54 are fixedly installed between the two oil cylinder fixing members 53. An oil cylinder through hole 531 for inserting the rotary oil cylinder 51 is provided in the oil cylinder fixing member 53. The rotary oil cylinder 51 is inserted into the oil cylinder through hole 531 and is supported and fixed by the oil cylinder fixing member 53. A shaft hole 541 for supporting the installation of the gear shaft 52 is provided in the rotating shaft support plate 54. The gear shaft 52 includes a gear 521 and rotating shafts 522 located at both ends of the gear 521. The two rotating shaft support plates 54 are respectively connected to the rotating shafts 522 at both ends of the gear 521. The rotating shafts 522 at both ends of the gear 521 are respectively sleeved into the shaft holes 541 of the two rotating shaft support plates 54, and the gear shaft 52 is supported to rotate through the shaft holes 541. The rotating shaft 522 located at the front end of the gear 521 passes through the shaft hole 541 of the rotating shaft support plate 54 and is connected to the coupling hole 221 of the chuck coupling member 22. The rotary oil cylinder 51 includes a cylinder sleeve 511, end covers 512, a piston rod 513, piston heads 514 and an inner copper sleeve 515. There are two end covers 512 and two piston heads 514. The two end covers 512 are respectively installed at both ends of the cylinder sleeve 511, and the two piston heads 514 are respectively installed at both ends of the piston rod 513. The inner copper sleeve 515 is installed in the cylinder sleeve 511. The piston rod 513 is sleeved in the inner copper sleeve 515, and sealing is achieved between the piston heads 514 and the cylinder sleeve 511. A rack 516 for meshing and driving with the gear 521 is provided on the outer side wall of the piston rod 513. A notch 517 for the gear 521 to enter and mesh with the rack 516 is provided on the side wall of the cylinder sleeve 511. The two end covers 512 are provided with oil holes 518 for introducing hydraulic oil. The operating principle of the left rotation mechanism 5 is as follows: By introducing hydraulic oil into the oil hole 518 of one of the end covers 512 and discharging the hydraulic oil from the oil hole 518 of the other end cover 512, the pressure at both ends of the cylinder sleeve 511 changes, driving the piston rod 513 and the piston heads 514 at both ends of the piston rod 513 to move in the cylinder sleeve 511. Under the meshing and driving action of the rack 516 and the gear 521, the piston rod 513 drives the gear shaft 52 to rotate, and the gear shaft 52 drives the left chuck mechanism 2 to rotate.

[0071] As a preferred embodiment, the left telescopic mechanism 6 includes a telescopic pull cylinder 61, a pull cylinder rotating base 62, and four anti-rotation shafts 63; the left up-and-down swing mechanism 7 includes an inner rotating base 71, an outer rotating base 72, a vertical base 73, a rotating base hanging ear 74, and an inclined ejector cylinder 75; the left up-and-down moving mechanism 8 includes a lifting base hanging ear 81, a lifting slider 82, a lifting slide rail 83, a vertical box girder 84, a lifting cylinder 85, a cylinder rotating base 86, and a movable bottom plate 87; both the top and bottom of the pull cylinder rotating base 62 are provided with inner support rotating shafts 64 for rotatably connecting and cooperating with the inner rotating base 71. The inner rotating base 71 is internally provided with a first inner cavity 76 capable of accommodating the pull cylinder rotating base 62. The pull cylinder rotating base 62 is movably supported and installed in the first inner cavity 76 of the inner rotating base 71 through the inner support rotating shaft 64. The telescopic pull cylinder 61 is fixedly installed through the pull cylinder rotating base 62. The telescopic end of the telescopic pull cylinder 61 is connected to the cylinder locking nut 56 of the left rotating mechanism 5. One end of the anti-rotation shaft 63 passes through the pull cylinder rotating base 62 and is fixedly connected to the anti-rotation fixing plate 55 of the left rotating mechanism 5, so that when the pull cylinder rotating base 62 rotates around the inner support rotating shaft 64, the left telescopic mechanism 6 rotates synchronously together with the left rotating mechanism 5 and the left chuck mechanism 2. Both the left and right sides of the inner rotating base 71 are provided with outer support rotating shafts 77 for rotatably connecting and cooperating with the outer rotating base 72. The outer rotating base 72 is internally provided with a second inner cavity 78 capable of fitting the inner rotating base 71. The inner rotating base 71 is movably supported and installed in the second inner cavity 78 of the outer rotating base 72 through the outer support rotating shaft 77. The vertical base 73 is fixedly installed on the top of the outer rotating base 72. The rotating base hanging ear 74 is installed on the top of the inner rotating base 71. The bottom of the inclined ejector cylinder 75 is rotatably connected to the rotating base hanging ear 74. The telescopic end of the inclined ejector cylinder 75 is rotatably connected to the vertical base 73. The inclined ejector cylinder 75 is inclined and connected to the rotating base hanging ear 74 and the vertical base 73. Both the lifting base hanging ear 81 and the lifting slider 82 are fixedly installed on one side of the outer rotating base 72. The telescopic end of the lifting cylinder 85 is connected to the lifting base hanging ear 81. The lifting slide rail 83 is fixedly installed on the outside of the vertical box girder 84. The lifting slider 82 is slidably connected and cooperated with the lifting slide rail 83. Both sides of the cylinder rotating base 86 are provided with lifting rotating shafts 88 for rotatably connecting and cooperating with the vertical box girder 84. The vertical box girder 84 is internally provided with a third inner cavity 89 capable of accommodating the cylinder rotating base 86. The cylinder rotating base 86 is movably supported and installed in the third inner cavity 89 of the vertical box girder 84 through the lifting rotating shafts 88. The lifting cylinder 85 is fixedly installed through the cylinder rotating base 86. The vertical box girder 84 is fixedly installed on the movable bottom plate 87. The operating principle of the left telescopic mechanism 6 is: the telescopic movement of the telescopic pull cylinder 61 drives the left rotating mechanism 5 to move along the Y-axis, and the four anti-rotation shafts 63 play a guiding role. The operating principle of the left up-and-down swing mechanism 7 is: the telescopic movement of the inclined ejector cylinder 75 drives the inner rotating base 71 to rotate around the outer support rotating shaft 77, so that the left telescopic mechanism 6 swings up and down.The operating principle of the left up and down moving mechanism 8 is as follows: the telescopic movement of the lifting oil cylinder 85 drives the left up and down swinging mechanism 7 to move up and down, and the sliding guide is realized through the cooperation of the lifting slider 82 and the lifting slide rail 83.

[0072] As a preferred embodiment, the left left and right moving mechanism 9 includes a boom box girder 91, a guide rail top plate 92, a live cylinder adjusting seat 93, a nut seat 94, a lead screw nut 95, a lead screw 96, a lead screw fixing seat 97, a first motor 98 and a motor mounting seat 99. The guide rail top plate 92 is fixedly installed on the top of the boom box girder 91. The live cylinder adjusting seat 93 is installed at the bottom of the movable bottom plate 87. The live cylinder adjusting seat 93 is slidably connected with the guide rail top plate 92. The nut seat 94 is installed on one side of the live cylinder adjusting seat 93. The lead screw nut 95 is installed in the nut seat 94. The lead screw 96 is in transmission cooperation with the lead screw nut 95. The lead screw fixing seat 97 and the motor mounting seat 99 are both fixedly installed on one side of the boom box girder 91. The first motor 98 is fixedly installed through the motor mounting seat 99. One end of the lead screw 96 is rotatably connected with the lead screw fixing seat 97. The other end of the lead screw 96 passes through the motor mounting seat 99 and is connected with the rotating shaft of the first motor 98 through a coupling. The operating principle of the left left and right moving mechanism 9 is as follows: the first motor 98 rotates, driving the lead screw 96 to rotate. Under the transmission action of the lead screw 96 and the lead screw nut 95, the lead screw nut 95 moves along the Y-axis, and drives the left up and down moving mechanism 8 to move along the Y-axis through the live cylinder adjusting seat 93.

[0073] As a preferred embodiment, the left front and rear swing mechanism 10 includes a boom connecting plate 101, a boom hanger 102, a boom rotating shaft 103, a shaft plate 104, an oil cylinder hanger 105, an oil cylinder rotating shaft 106, a T-shaped joint 107 and a boom oil cylinder 108. The boom connecting plate 101 is fixedly installed on the end face of the boom box girder 91. There are two boom hangers 102, which are arranged at the upper and lower parts on the side of the boom connecting plate 101. The boom hanger 102 is installed on the side of the boom connecting plate 101 facing away from the boom box girder 91. There are two shaft plates 104. Both ends of the boom rotating shaft 103 are supported and rotated by the two shaft plates 104. The boom hanger 102 and the boom rotating shaft 103 are rotatably connected through a boom bronze bushing 109. The T-shaped joint 107 is installed at the telescopic end of the boom oil cylinder 108. The oil cylinder rotating shaft 106 passes through the T-shaped joint 107 and is rotatably connected. Both ends of the oil cylinder rotating shaft 106 are respectively supported and rotated by the two oil cylinder hangers 105. The two oil cylinder hangers 105 are installed on the side of the boom connecting plate 101 facing the boom box girder 91. The working principle of the left front and rear swing mechanism 10 is as follows: the telescopic movement of the boom oil cylinder 108 drives the left left and right moving mechanism 9 to swing back and forth around the boom rotating shaft 103. Both ends of the boom oil cylinder 108 are rotatably connected, so that the boom oil cylinder 108 rotates during the process of driving the left left and right moving mechanism 9 to swing back and forth to offset its swing variable.

[0074] As a preferred embodiment, a hydraulic oil tank 11 is further provided at the bottom of the frame 3. Hydraulic oil is added to the hydraulic oil tank 11. The hydraulic oil in the hydraulic oil tank 11 is supplied to each hydraulic mechanism through a hydraulic pump. The hydraulic pump is connected to the chuck oil cylinder 26, the rotary oil cylinder 51, the telescopic pull cylinder 61, the inclined top oil cylinder 75, the lifting oil cylinder 85 and the boom oil cylinder 108 through pipelines. A cooling fan 13 is provided on one side of the drive motor 12 of the hydraulic pump.

[0075] The above are only the preferred embodiments of the present invention. As long as the technical solutions that achieve the purpose of the present invention by basically the same means fall within the protection scope of the present invention.

Claims

1. A stretch-bending process of a stretch-bending machine, characterized in that: It includes the following steps: S1: The stretch-bending machine starts and initializes, and each mechanism returns to the initial state; S2: Both the left chuck mechanism and the right chuck mechanism open and are in an open state, and the left telescopic mechanism and the right telescopic mechanism perform synchronous extension actions; S3: Place the workpiece on the workbench, and place the left and right ends of the workpiece into the left chuck mechanism and the right chuck mechanism respectively; S4: The left chuck mechanism and the right chuck mechanism perform synchronous clamping actions to clamp the left and right ends of the workpiece to be stretch-bent in the left chuck mechanism and the right chuck mechanism; S5: The left telescopic mechanism and the right telescopic mechanism perform synchronous material pulling actions. During the material pulling process, the left telescopic mechanism and the right telescopic mechanism stretch the workpiece in the length direction according to the set pressure value, so that the workpiece is gradually elongated; S5-1: The left and right vertical movement mechanisms move upward synchronously to move the workpiece upward away from the workbench; S5-2: The left rotation mechanism and the right rotation mechanism perform synchronous rotation actions in opposite directions to twist-process the workpiece; S5-3: The left and right vertical movement mechanisms move downward synchronously to make the workpiece return to the workbench again; S6: The left and right front-back swing mechanisms perform synchronous pulling-back actions to make the workpiece closely adhere to the stretch-bending die and gradually bend along the pulling-back direction of the left and right front-back swing mechanisms; S7: The left telescopic mechanism and the right telescopic mechanism perform synchronous pressure relief actions; S8: The left telescopic mechanism and the right telescopic mechanism perform synchronous extension actions to drive the two ends of the workpiece to offset a certain degree of tensile springback in the tensile deformation; the sum of the extension lengths of the left telescopic mechanism and the right telescopic mechanism is equal to the tensile springback length of the workpiece; S9: The left and right front-back swing mechanisms perform synchronous extension actions to drive the two ends of the workpiece to offset a certain degree of bending springback in the bending deformation; the sum of the extension lengths of the left and right front-back swing mechanisms is equal to the bending springback length of the workpiece; S9-1: The left rotation mechanism and the right rotation mechanism perform synchronous rotation actions to drive the two ends of the workpiece to offset a certain degree of torsional springback in the torsional deformation; the sum of the rotation angles of the left rotation mechanism and the right rotation mechanism is equal to the torsional springback angle of the workpiece; S10: Both the left chuck mechanism and the right chuck mechanism perform opening actions, and the left chuck mechanism and the right chuck mechanism simultaneously release the left and right ends of the workpiece; S11: Take out the workpiece; S12: The left telescopic mechanism and the right telescopic mechanism fully extend and reset; S13: The left and right front-back swing mechanisms fully extend and reset.

2. The bending process of a stretch-bending machine according to claim 1, characterized in that: In step S5, the material pulling pressure values of the left telescopic mechanism and the right telescopic mechanism can be adjusted manually. By means of manual intervention, the pressure value of the workpiece during the material pulling process is adjusted, so that the workpiece is fully stretched.

3. The bending process of a stretch bending machine according to claim 1, characterized in that: In step S6, during the pulling-back process of the left and right front-back swing mechanisms, the pulling-back speeds of the left and right front-back swing mechanisms can be adjusted, so as to adjust the bending speed of the workpiece.

4. The bending process of a stretch bending machine according to claim 1, characterized in that: In step S4, after the left chuck mechanism and the right chuck mechanism clamp the left and right ends of the workpiece, they continue to clamp for 5 - 10 seconds and then proceed to the next step.

5. The stretch bending process of a stretch bender according to claim 1, characterized in that: In step S6, the retraction strokes of the left and right front-back swing mechanisms are limited by limiters. Limiters are respectively arranged on the movement strokes of the left and right front-back swing mechanisms, and the positions of the limiters on the movement strokes are adjusted according to the degree of bending required for the workpiece.

6. The bending process of a stretch-bending machine according to claim 5, characterized in that: When the left and right front-back swing mechanisms retract and move to the preset positions, after the limiters sense the actions of the left and right front-back swing mechanisms, the limiters send induction signals to the left and right front-back swing mechanisms to control the left and right front-back swing mechanisms to stop operating.

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