CN112496104B

CN112496104B - A processing method for one-time bending of large sheet metal workpieces with multiple edges and corners

Info

Publication number: CN112496104B
Application number: CN202011532831.5A
Authority: CN
Inventors: 王克文; 张迎年; 张先进
Original assignee: ANHUI LIYUAN NUMERICAL CONTROL CUTTING TOOL AND PATTERNS MANUFACTURING CO LTD
Current assignee: ANHUI LIYUAN NUMERICAL CONTROL CUTTING TOOL AND PATTERNS MANUFACTURING CO LTD
Priority date: 2020-12-23
Filing date: 2020-12-23
Publication date: 2022-01-04
Anticipated expiration: 2040-12-23
Also published as: CN112496104A

Abstract

The invention discloses a processing method for a large-scale plate material one-time bending multi-edge workpiece, and belongs to the technical field of machining equipment. The multi-edge workpiece is formed by bending an automatic forming die at one time, the automatic forming die comprises an upper die part and a lower die part, and the processing method comprises the following steps: s1, placing a plate-shaped workpiece on the upper surface of a lower die part of an automatic forming die, performing downward stamping on an upper die part, and during die assembly, attaching a male die of the upper die part to the upper surface of the workpiece to form a plurality of edges, attaching a first female die of the lower die part to the lower surface of the workpiece to form two obtuse-angle edges, and simultaneously attaching a second female die and a third female die of the lower die part to the lower surface of the workpiece respectively to form a plurality of edges; s2, moving the upper die part upwards, and enabling the male die to be far away from the upper surface of the workpiece to obtain a multi-edge workpiece; the processing method can form the workpiece with the multi-edge angle in one step.

Description

Machining method for large-scale plate material one-time bending multi-edge-angle workpiece

Technical Field

The invention belongs to the technical field of machining equipment, and particularly relates to a machining method for bending a multi-edge workpiece once by a large plate.

Background

The die is various dies and tools for obtaining required products by injection molding, blow molding, extrusion, die casting or forging forming, smelting, stamping, stretching and other methods in industrial production. In short, a mold is a tool used to shape an article, the tool being made up of various parts, and different molds being made up of different parts. The processing of the appearance of an article is realized mainly through the change of the physical state of a formed material. The bending machine is used for bending plate materials, and the bending principle is that a workpiece is placed on the plane of a lower die, and when an upper die presses the lower die, the workpiece forms a bending angle under the action of the upper die and the lower die.

With the rapid development of the rail transit industry, the demand of workpieces with multi-edge angles on rail transit vehicle bodies is increased year by year, and the bending forming die of the sheet metal structural part of the rail transit vehicle body is taken as key equipment of the vehicle body processing technology, is widely applicable to the manufacturing fields of rail transit vehicle bodies such as motor cars, high-speed rails and subways and various vehicles, and has wide application space. At present, for a workpiece needing to be bent for multiple times, the existing machining method is formed by multiple times of bending operation, but the multiple times of bending on one workpiece are time-consuming and labor-consuming, and the working efficiency is not high.

For example, chinese patent application No. 201620693395.2, filed 2016, 11, 16, discloses a steel plate bending die. The mold comprises a mold body, wherein a V-shaped notch is formed in the middle of the mold body, circular grooves are formed in the edge angles on the two sides of the V-shaped notch, and matched circular rolling shafts are arranged in the circular grooves; two sides of the V-shaped notch on the top surface of the die body are respectively provided with a round hole, and a tension spring matched with the round hole is arranged in the round hole; the upper part of the die body is connected with two backing plates through tension springs, and the backing plates are rotatably connected through a rotating shaft positioned right above the V-shaped notch. However, if the die is used to bend a workpiece at a plurality of positions, a plurality of bending operations are required, and the manufacturing process cycle is long.

In the prior art, a mold for bending a multi-section bent part at a time is also sought, for example, a patent application publication No. 201911126515.5, whose publication date is 2020, 1 month and 10 days, discloses a mold for forming a U-shaped multi-section arc bent plate at a time for an oil tank. The patent die comprises an upper pressing block and a lower pressing groove matched with the upper pressing block; the lower pressure tank comprises a lower die center module in the middle, and a left L-shaped module and a right L-shaped module which are respectively arranged at two sides of the lower die center module, wherein the inner surfaces of the corners of the left L-shaped module and the right L-shaped module are arc surfaces; the left module limiting baffle, the right module limiting baffle and the plate limiting baffle are fixed on the base station; a left L-shaped module overturning area is arranged between the left module limiting baffle and the lower die center module, and a right L-shaped module overturning area is arranged between the right module limiting baffle and the lower die center module; the left L-shaped module and the right L-shaped module are respectively arranged in the left L-shaped module overturning area and the right L-shaped module overturning area in an overturning way; through using this application forming die, once only with the shaping of the board of bending of U-shaped multistage circular arc, improved the efficiency of processing greatly. However, the die is used for processing multi-segment arcs, and the workpiece is only processed by arcs at two ends, so that the demolding process is relatively easy, and if a sharp corner needs to be bent, the demolding structure needs to be redesigned.

Therefore, in order to form a workpiece structure with multiple bending sharp angles at one time, a processing method for bending a large-scale plate workpiece with multiple edges at one time is urgently needed.

Disclosure of Invention

1. Problems to be solved

The invention provides a processing method for a large-scale plate material one-time bending multi-edge workpiece, and aims to solve the problem that the existing die cannot process the one-time forming multi-edge workpiece.

2. Technical scheme

In order to solve the above problems, the present invention adopts the following technical solutions.

A processing method for bending a multi-edge workpiece at one time by a large plate is characterized by comprising the following steps of: the multi-edge workpiece is formed by bending an automatic forming die at one time, the automatic forming die comprises an upper die part and a lower die part, and the processing method comprises the following steps:

s1, placing a plate-shaped workpiece on the upper surface of a lower die part of an automatic forming die, performing downward stamping on an upper die part, and during die assembly, attaching a male die of the upper die part to the upper surface of the workpiece to form a plurality of edges, attaching a first female die of the lower die part to the lower surface of the workpiece to form two obtuse-angle edges, and simultaneously attaching a second female die and a third female die of the lower die part to the lower surface of the workpiece respectively to form a plurality of edges;

s2, moving the upper die part upwards, and enabling the male die to be far away from the upper surface of the workpiece to obtain a multi-edge workpiece;

the upper die part comprises an upper die pressing plate and two male dies, the two male dies are respectively slidably mounted at two side ends of the upper die pressing plate, and the upper ends of the two male dies are respectively connected with the upper die pressing plate through springs;

the lower die part comprises a first female die, a second female die, a third female die and a lower die holder, a die cavity is formed in the lower die holder and is used for fixedly connecting the first female die, the second female die and the third female die, the bottom of the first female die is telescopically connected with the lower die holder through a plurality of springs, and the second female die and the third female die are respectively positioned on two sides of the first female die and are telescopically connected with the lower die holder through the springs;

when the die is closed, the upper die pressing plate drives the two male dies to move downwards, and the two male dies, the first female die, the second female die and the third female die jointly form a bending working position of a workpiece.

Furthermore, two side faces of the upper die pressing plate are respectively provided with a mounting groove, the male die is fixed in the mounting grooves through bolts, a sliding groove is formed in the middle of the male die, and a nut of each bolt slides in the sliding groove.

Furthermore, a positioning column is further arranged in the mounting groove, a spring for connecting the male die and the upper die pressing plate is sleeved outside the positioning column, and when the spring is compressed, the positioning column is matched with the upper end of the male die to be inserted for positioning.

Further, the bolt is fixed in the sliding groove through the shaft sleeve.

Furthermore, the corner of the lower end part of the male die is in arc transition, and the radius of the arc corresponding to the arc is 3 mm.

Furthermore, the upper end of the upper die pressing plate is fixedly connected with an upper die fixing seat, and the upper die fixing seat is clamped and fixed on a die of the bending machine and used for controlling the upper die part to move up and down.

Further, first die internally mounted has telescopic suspension platform, and suspension platform passes through the spring to be connected with first die, and when the spring was in original state, suspension platform was located the die cavity of first die, and when the spring was compressed, suspension platform was inlayed inside first die.

Furthermore, a first positioning boss and a first working cutter head are arranged on one side, close to the first female die, of the second female die, and a second positioning boss and a second working cutter head are arranged on one side, close to the first female die, of the third female die; when the die is assembled, the first positioning boss and the second positioning boss are clamped on the side face of the first female die and used for limiting the relative movement between the first female die, the second female die and the third female die; and the first working tool bit and the second working tool bit are clamped on the upper surface of the first female die and used for forming a bending angle of a workpiece.

Furthermore, the second concave die, the third concave die and the first concave die are respectively in bolt connection, wherein the bolt is connected with the first concave die through a spring in the first concave die, and the expansion of the spring drives the bolt to slide in the first concave die.

Furthermore, the lower end of the first female die is fixedly connected with the positioning bolt, and the other end of the positioning bolt is movably connected into the lower die holder, so that the positioning bolt can stretch in the lower die holder.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) according to the invention, the plurality of male dies and the plurality of female dies are arranged, the bending working positions are formed through spring connection, the resetting effect of the male dies and the female dies is realized, and after the male dies and the female dies are reset, the formed workpiece is easy to demould, so that the purpose of one-time bending automatic forming is achieved;

(2) the middle part of the male die is fixedly connected with the upper die pressing plate through a bolt so as to limit the male die to deviate in the direction far away from the upper die pressing plate under the action of gravity, and meanwhile, the middle part of the male die is provided with a sliding groove for the bolt to slide so as to realize the purpose that the male die closely abuts against the upper die pressing plate to slide; in addition, the bolts are connected in the sliding grooves through shaft sleeves, so that the bolts are prevented from loosening during sliding;

(3) according to the invention, the positioning column is sleeved in the spring for connecting the male die and the upper die pressing plate, and the positioning column is inserted into the male die after the spring is compressed, so that the positioning function is achieved, and the male die is prevented from having a tendency of being far away from the mounting groove of the upper die pressing plate when the male die is subjected to the counter extrusion force of a workpiece;

(4) the joint of the lower end part of the male die and the upper die pressing plate is provided with a fillet, so that the sharp corner can be prevented from damaging the plane structure of the workpiece;

(5) in order to avoid the convenience of stripping the first female die, the suspension table is arranged, when the die is opened, the suspension table receives the spring restoring force to push up the workpiece, so that the workpiece is prevented from being clamped at the position where the first female die cannot be demoulded or being damaged by pulling when the first female die is demoulded, meanwhile, the suspension table is positioned below the joint of the male die and the upper die pressing plate, the suspension table buffers the punching force applied to the workpiece, and the probability that the workpiece is clamped at the joint of the lower end part of the male die and the upper die pressing plate is reduced;

(6) according to the second male die and the third male die on the two side faces of the first female die, when the dies are closed, the positioning bosses on the second male die are clamped on the first male die, and the two working tool bits are clamped on the two ends of the upper surface of the first female die and used for forming the bending angle of a workpiece.

Drawings

FIG. 1 is a schematic structural view of an upper molding plate of the present invention;

FIG. 2 is a schematic view of the assembly of the male mold and the upper platen of the present invention;

FIG. 3 is a schematic structural view of the lower die holder of the present invention;

FIG. 4 is a schematic structural view of the mold of the present invention;

FIG. 5 is a schematic structural diagram of a second concave die or a third concave die according to the invention;

FIG. 6 is a first view illustrating a first usage state of the mold according to the present invention;

FIG. 7 is a second view showing the usage state of the mold of the present invention;

FIG. 8 is a schematic structural diagram of a workpiece formed in one step by using the mold of the present invention;

in the figure:

100. an upper die portion; 110. an upper die pressing plate; 111. mounting grooves; 1111. a positioning column; 120. a male die; 121. a chute; 122. a first working surface; 123. a second working surface; 124. a third working surface; 125. a fourth working surface; 126. a fifth working surface; 130. a bolt; 131. a shaft sleeve; 140. a first spring; 150. an upper die fixing seat; 200. a lower die portion; 210. a first female die; 211. a suspension stage; 212. a second spring; 220. a second female die; 221. positioning a first boss; 222. a first working tool bit; 230. a third female die; 231. a second positioning boss; 232. a second working tool bit; 240. a third spring; 250. a fourth spring; 260. a lower die holder; 261. a first cavity surface; 262. a second cavity surface; 263. a third cavity surface; 264. a fourth cavity surface; 265. a fifth cavity surface; 266. a sixth cavity surface; 267. a seventh cavity surface; 270. positioning the bolt; 300. and (5) a workpiece.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1

The automatic forming die for bending the large-scale plate into the multi-edge angle at one time comprises an upper die part 100 and a lower die part 200, wherein the upper die part 100 comprises an upper die pressing plate 110, a left male die 120, a right male die 120 and an upper die fixing seat 150; the lower mold part 200 includes a first concave mold 210, a second concave mold 220, a third concave mold 230, and a lower mold base 260.

Specifically, as shown in fig. 1, two square grooves, namely, mounting grooves 111, are respectively formed on the left side surface and the right side surface of the upper pressing plate 110, a male die 120 is respectively mounted in the mounting grooves 111, as shown in fig. 2, a sliding groove 121 is formed in the middle of the male die 120, a bolt 130 is mounted in the sliding groove 121 to fix the male die 120 on the mounting grooves 111, it should be noted that the width of the sliding groove 121 is greater than the width of a nut of the bolt 130, and the nut of the bolt 130 can slide in the sliding groove 121, in another embodiment of the present embodiment, in order to avoid loosening of the bolt 130, a shaft sleeve 131 is disposed between the nut of the bolt 130 and the sliding groove 121; in addition, the upper end of the male die 120 is fixedly connected with the middle of the mounting groove 111 through a first spring 140, and the extension and contraction of the first spring 140 drives the male die 120 to slide along the mounting groove 111, that is, the nut of the bolt 130 slides in the sliding groove 121; in another embodiment of this embodiment, in order to avoid that the male die 120 tends to move downward due to gravity, so that the bolt 130 is easily loosened due to excessive stress, as shown in fig. 1, the end portions of the two mounting grooves 111 are respectively provided with the positioning posts 1111, when the first spring 140 is compressed, the two positioning posts 1111 are respectively inserted into the holes on the upper end surfaces of the corresponding male dies 120 in a matching manner, so as to not only support the gravity of the male dies 120, but also position the male dies 120, so that the male dies 120 move close to the mounting grooves 111, and the moving track of the male dies 120 is prevented from deviating from the mounting grooves 111, which results in inaccurate bending precision of the workpiece.

It should be noted that the lower end of the punch 120 is a contact working surface of the punching workpiece 300, and as shown in fig. 2, in this embodiment, the lower end of the punch 120 is formed by sequentially connecting a first working surface 122, a second working surface 123, a third working surface 124, a fourth working surface 125 and a fifth working surface 126 end to end (wherein the first working surface 122 and the fifth working surface 126 form a four-sided structure of the punch 120 through the upper end surfaces), and the working surfaces are connected through an arc surface with a radius of 3 mm; the first working surface 122 is used for sliding tightly to the mounting groove 111, the second working surface 123 is in a horizontal position and forms an included angle of 60 degrees with the first working surface 122, the third working surface 124 forms an included angle of 120 degrees with the second working surface 123, the fourth working surface 125 forms an included angle of 60 degrees with the third working surface 124, the fifth working surface 126 is horizontal with the first working surface 122 and forms an included angle of 60 degrees with the fourth working surface 125, and in a die closing state, the second working surface 123, the third working surface 124, the fourth working surface 125 and the fifth working surface 126 tightly cling to the workpiece 300 to form a plurality of bending angles.

Next, in the lower mold portion 200, a lower mold base 260 opens a mold cavity from the lower end surface to the inside, as shown in fig. 3, that is, the mold cavity is composed of a first mold cavity surface 261, a second mold cavity surface 262, a third mold cavity surface 263, a fourth mold cavity surface 264, a fifth mold cavity surface 265, a sixth mold cavity surface 266 and a seventh mold cavity surface 267 which are connected in sequence, wherein an included angle formed by the first mold cavity surface 261 and the seventh mold cavity surface 267 with the side surface of the lower mold base 260 is 25 °, an included angle formed between the first mold cavity surface 261 and the second mold cavity surface 262 is 90 °, an included angle formed between the second mold cavity surface 262 and the third mold cavity surface 263 is 66 °, an included angle formed between the third mold cavity surface 263 and the fourth mold cavity surface 264 is 90 °, an included angle formed between the fourth mold cavity surface 264 and the fifth mold cavity surface 265 is 90 °, an included angle formed between the fifth mold cavity surface 265 and the sixth mold cavity surface 266 is 66 °, an included angle formed between the sixth mold cavity surface 266 and the seventh mold cavity surface 267 is 90 °, the first concave die 210, the second concave die 220 and the third concave die 230 are respectively arranged in the die cavities.

Specifically, as shown in fig. 4, the second concave die 220 is connected to the seventh cavity surface 267 through a bolt, the bolt is connected to the third spring 240 and slides along the seventh cavity surface 267, that is, the second concave die 220 slides along the seventh cavity surface 267, similarly, the third concave die 230 slides along the first cavity surface 261, and when the die is closed, the lower surfaces of the second concave die 220 and the third concave die 230 respectively cling to the sixth cavity surface 266 and the second cavity surface 262; the middle part of the lower end surface of the first concave die 210 is fixedly connected with the fourth cavity surface 264 through a positioning bolt 270, the positioning bolt 270 can move up and down in the lower die holder 260, meanwhile, four corners of the lower end surface of the first concave die 210 are respectively provided with a fourth spring 250 which penetrates through the fourth cavity surface 264 to be connected with the lower die holder 260, when the fourth springs 250 stretch out and draw back, the first concave die 210 contacts the third cavity surface 263, and the fifth cavity surface 265 slides up and down, and when die assembly is carried out, the lower end surface of the first concave die 210 contacts the fourth cavity surface 264. In the process of mold closing, the first female mold 210 descends first until the first positioning boss 221 and the second positioning boss 231 of the second female mold 220 and the third female mold 230 (the structural schematic diagram is shown in fig. 5) enter the clamping groove of the first female mold 210, at this time, the first working tool bit 222 and the second working tool bit 232 on the upper portions of the second female mold 220 and the third female mold 230 are located on the upper end surface of the first female mold 210, the first female mold 210 drives the second female mold 220 and the third female mold 230 to descend together until the bottom end of the first female mold 210 contacts the fourth cavity surface 264, at this time, the first positioning boss 221 and the second positioning boss 231 are completely clamped in the first female mold 210, and the first working tool bit 222 and the second working tool bit 232 are completely located on the upper end surface of the first female mold 210, namely, the second concave die 220 and the third concave die 230 respectively hug the first concave die 210 at both sides, at this time, the trapezoidal cavity formed on the upper surface of the first concave die 210, the first working tool bit 222 and the second working tool bit 232 are communicated to form the workpiece 300 shown in fig. 8.

In another embodiment of this embodiment, in order to facilitate material releasing, a suspension table 211 is disposed in the middle of the upper end surface of the first concave die 210, the suspension table 211 is mounted below a trapezoidal cavity formed in the upper surface of the first concave die 210 in an embedded manner through the second spring 212, that is, during die closing, the second spring 212 is compressed, the suspension table 211 is embedded inside the first concave die 210, the upper surface of the suspension table 211 and the bottom surface of the trapezoidal cavity are on the same horizontal plane, during die opening, the second spring 212 returns to an original state, the suspension table 211 is sprung into the trapezoidal cavity of the first concave die 210, and meanwhile, the workpiece 300 is pushed up to realize material releasing.

The embodiment of the invention provides a processing method for bending a large-scale plate into a multi-corner workpiece at one time, which comprises the following steps:

(1) placing the plate-shaped workpiece 300 on the upper surfaces of the first concave die 210, the second concave die 220 and the third concave die 230, wherein the upper surfaces of the first concave die 210, the second concave die 220 and the third concave die 230 are in the same horizontal plane, as shown in fig. 4;

(2) the upper die part 100 descends, the two male dies 120 contact the workpiece 300 and press the workpiece downwards until the second spring 212 is compressed, the upper surface of the suspension platform 211 is flush with the bottom surface of the trapezoidal cavity formed in the first female die 210, the first spring 140 is compressed until the two male dies 120 are positioned above the mounting groove 111, and the second working surface 123 is flush with the upper pressing plate 110 and presses the upper surface of the workpiece; the two third springs 240 are stretched, the first positioning bosses 221 and the second positioning bosses 231 of the second concave die 220 and the third concave die 230 are provided with positioning holes entering the side surface of the first concave die 210, the first working tool bits 222 and the second working tool bits 232 start to enter the upper surface of the first concave die 210, and at the moment, the workpiece forms two 120-degree bending angles, as shown in fig. 6;

(3) the upper die part 100 continues to move downwards, the fourth spring 250 is compressed, the first female die 210 moves downwards, the third spring 240 continues to be stretched, the second female die 220 and the third female die 230 are driven to move downwards and move towards the direction close to the first female die 210 until the first positioning boss 221 and the second positioning boss 231 are completely clamped in the first female die 210, the first working cutter head 222 and the second working cutter head 232 are completely connected to the upper surface of the first female die 210, namely the second female die 220 and the third female die 230 respectively clamp the first female die 210 at two sides, and as shown in fig. 7, the upper die part and the lower die part are completely closed;

(4) the upper die portion 100 moves upward and the springs return to their original state to complete stripping, resulting in the workpiece 300 shown in fig. 8.

The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching, without departing from the spirit of the invention, the person skilled in the art shall not inventively design the similar structural modes and embodiments to the technical solution, but shall fall within the scope of the invention.

Claims

1. a processing method for a large-scale sheet metal one-time bending multi-angle workpiece, characterized in that: the multi-angle workpiece is formed by one-time bending using an automatic forming mold, and the automatic forming mold includes an upper mold part (100) and the lower die part (200), the processing method steps are:

S1. Place the plate-shaped workpiece on the upper surface of the lower mold part (200) of the automatic forming mold, and the upper mold part (100) is punched downward. When the mold is closed, the punch (120) of the upper mold part (100) fits the workpiece. (300) to form a plurality of edges and corners, the first concave mold (210) of the lower mold part (200) fits the lower surface of the workpiece (300) to form two obtuse-angled edges and corners, and at the same time, the lower mold part (200) ) of the second concave die (220) and the third concave die (230) are respectively attached to the lower surface of the workpiece (300) to form a plurality of edges and corners;

S2, the upper mold part (100) goes up, and the punch (120) is far away from the upper surface of the workpiece (300), so as to obtain a polygonal workpiece;

Wherein, the upper mold part (100) includes an upper molding plate (110) and a punch (120), and there are two punches (120), which are respectively slidably installed on the two sides of the upper molding plate (110). At the same time, the upper ends of the two punches (120) are respectively connected with the upper moulding plate (110) through springs; the two sides of the upper moulding plate (110) are respectively provided with installation grooves (111), the punches (120) ) is connected in the installation groove (111) by the bolt (130), the middle of the punch (120) is provided with a chute (121), the nut of the bolt (130) slides in the chute (121), the installation groove (111) ) is also provided with a positioning column (1111), and the spring connecting the punch (120) and the upper die plate (110) is sleeved outside the positioning column (1111). The upper end of the mold (120) is positioned;

The lower mold part (200) includes a first concave mold (210), a second concave mold (220), a third concave mold (230) and a lower mold seat (260), and a mold is opened in the lower mold seat (260). A cavity for fixedly connecting the first female mold (210), the second female mold (220) and the third female mold (230), the bottom of the first female mold (210) is connected to the lower mold seat (260) through several springs Telescopic connection, the second concave mold (220) and the third concave mold (230) are respectively located on both sides of the first concave mold (210), and are telescopically connected to the lower mold base (260) through springs.

2 . The processing method for one-time bending of a large sheet metal workpiece with polygonal corners according to claim 1 , wherein the bolt ( 130 ) is fixed in the chute ( 121 ) through the shaft sleeve ( 131 ). 3 .

3 . The processing method for one-time bending of a large sheet metal workpiece with polygonal corners according to claim 1 , wherein the corners of the lower end of the punch ( 120 ) are arc transitions. 4 .

4. A processing method for one-time bending of a large sheet metal workpiece with polygonal corners according to any one of claims 1 to 3, characterized in that: the upper end of the upper die plate (110) is fixedly connected to the upper die. Block (150).

5. The processing method for one-time bending of a large sheet metal workpiece with polygonal corners according to claim 4, wherein a retractable suspension table (211) is installed inside the first die (210). , the suspension table (211) is connected to the first female die (210) through a spring. When the spring is in the original state, the suspension table (211) is located in the cavity of the first female die (210). When the spring is compressed, the suspension The stage (211) is embedded inside the first female mold (210).

6 . The processing method for one-time bending of a large sheet metal workpiece with polygonal corners according to claim 5 , wherein the second concave die ( 220 ) is close to the side of the first concave die ( 210 ). 7 . A positioning boss (221) and a working cutter head (222) are provided, and a positioning boss (231) and a working cutter are provided on the side of the third die (230) close to the first die (210). The second head (232); when the mold is closed, the first positioning boss (221) and the second positioning boss (231) are clamped on the side of the first female die (210), respectively, to limit the first female die (210) , The relative movement between the second concave die (220) and the third concave die (230), the working cutter head one (222) and the working cutter head two (232) are clamped on the upper surface of the first concave die (210) , for forming the bending angle of the workpiece.

7. The processing method for one-time bending of a large sheet metal workpiece with polygonal corners according to claim 6, characterized in that: the lower end of the first die (210) is fixedly connected with the positioning bolt (270), At the same time, the other end of the positioning bolt (270) is movably connected in the lower mold base (260), so that the positioning bolt (270) is retractable in the lower mold base (260).