Drawing-bulging forming method for complex variable curvature mouth frame structure

Abstract

The present invention discloses a method for forming a complex variable curvature mouth frame structure by deep drawing and bulging, which relates to the technical field of metal component forming, and comprises the following steps: pretreatment: performing solid solution treatment on the blank by a heating furnace and keeping the blank warm, and then cooling the blank to obtain a pretreated part; drawing treatment: performing pre-deep drawing on the pretreated part by a drawing die to obtain a drawn part, and the characteristic maximum deformation of the drawn part is less than the characteristic maximum deformation of the formed part; bulging treatment: performing bulging and pressure holding on the drawn part by a bulging die to obtain a bulged part, and the characteristic size of the bulged part is consistent with the characteristic size of the formed part; aging treatment: performing pressure holding and aging treatment on the bulged part by an aging die to obtain a preformed part, and the characteristic size of the preformed part is consistent with the characteristic size of the formed part; cutting treatment: clamping the preformed part by a clamping tool and cutting off the excess by a cutting device to obtain a formed part. The forming requirements of complex variable curvature aviation mouth frame structure parts can be met.

Description

Technical Field

[0001] The invention relates to the technical field of metal component forming, in particular to a method for deep drawing and bulging forming of a complex variable curvature mouth frame structure. Background Art

[0002] Mouth frame structure (such as Figure 1 ) is a major key structure of aerospace equipment. The main geometric features of this type of structure are complex variable curvature outer frame and positive and negative machined steps; in order to meet the requirements of stress corrosion resistance of aviation components, the service heat treatment state of the components is required to be the over-aged state T7x, and the microstructure has a relatively coarse over-aged precipitation phase to improve the corrosion resistance. The forming difficulties of this type of component are: 1) The curvature of the closed outer frame changes suddenly, and there is a forming difficulty with the coexistence of positive and negative curvatures; 2) The component is T7x hard material with poor plasticity, and deep cavity feature forming is prone to cracking; 3) The assembly requires high precision, and the accuracy of characteristic dimensions such as machined steps must be guaranteed.

[0003] The traditional method of machining thick plates is to fix the thick plates in the machining center and use the cutting equipment to rotate and cut the thick plates into mouth frame parts. This method is difficult to apply to thin-walled aluminum alloy parts. To turn thick plates into thin-walled parts, first of all, the processing volume is large, the efficiency is low, and materials are wasted. In addition, due to the small cross-sectional area and large size of thin-walled parts, it is difficult to ensure the processing technology. There are large processing deformations and cutting vibrations. At the same time, under the action of cutting heat during high-speed cutting, the parts are easily deformed, so it is difficult to ensure the accuracy and surface quality of the parts. If the thick plate pressing process is used, the aluminum alloy is hard in the over-aging T74x state and has poor plasticity. High-strength aluminum alloys have large springbacks, and it is difficult to ensure precision, requiring repeated mold repairs. At the same time, compared with thin plates, thick plates have poor thickness consistency, poor surface quality, and low elongation. For parts with high tolerance precision requirements such as mouth frames, secondary shaping is required to ensure dimensional requirements. In addition, the dimensional consistency of thick plate parts in the same batch is poor. The press tonnage required for thick plate profiling is larger, the mold wears severely, and the service life is lower than that of thin plate molds. If a cold drawing process is used, for mouth frame parts, the curvature of the flange area is complex. It is difficult to move the material during deep drawing. At the same time, the high-strength aluminum alloy is in an over-aged T74x state, with poor plasticity and prone to cracking during deep drawing. If the blank is heat treated to an annealed state for forming, solid solution-aging is required after forming. For sheet metal parts, shape distortion occurs after solid solution quenching and cannot meet the use requirements. If a hot forming process is used, the main disadvantages of this method for mouth frame parts are: in order to obtain the T74x state, +The blank needs to be solution-quenched-artificially aged, and the deformation of the strong heat transfer non-isothermal deformation component is uneven. At the same time, when using a rigid mold for stamping, the point contact between the mold and the blank is prone to local thinning problems, and the deformation cannot be controlled. At the same time, the hot forming process has strict requirements on the friction performance of the mold, and it is difficult to ensure the stability of mass production. The scrap rate is high, the rebound is serious under large-size macro-domain, the component size accuracy is low, and the formed component cannot meet the subsequent machining and equipment requirements. Therefore, the existing conventional forming technologies such as traditional machining, thick plate pressing, room temperature deep drawing process, hot forming process, etc., cannot be used to form variable curvature aviation frame structural parts. Summary of the invention

[0004] The purpose of the present invention is to provide a method for deep drawing and bulging forming of complex variable curvature mouth frame structures to solve the problems existing in the above-mentioned prior art and to meet the forming requirements of complex variable curvature aviation mouth frame structures.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a method for drawing-expanding a complex variable curvature mouth frame structure, comprising the following steps: pretreatment: performing a solution treatment on a blank in a heating furnace and keeping the blank warm, and then cooling the blank to obtain a pretreated part; drawing treatment: performing pre-deep drawing on the pretreated part by a drawing die to obtain a drawn part, wherein the characteristic maximum deformation of the drawn part is less than the characteristic maximum deformation of the formed part; bulging treatment: performing bulging and pressure-maintaining on the drawn part by a bulging die to obtain a bulged part, wherein the characteristic size of the bulged part is consistent with the characteristic size of the formed part; aging treatment: performing pressure-maintaining aging treatment on the bulged part by an aging die to obtain a preformed part, wherein the characteristic size of the preformed part is consistent with the characteristic size of the formed part; cutting treatment: performing a clamping handle on the preformed part by a clamping tool to cut off the excess by a cutting device to obtain the formed part.

[0007] Preferably, in the pretreatment step: the blank is solution treated and kept warm, and then water-cooled and quenched to obtain the pretreated piece.

[0008] Preferably, in the step of deep drawing: the areas of the pre-treated part used for producing small deformation and large deformation are sequentially locally deep drawn.

[0009] Preferably, the heating furnace has a heating chamber for heating and keeping the blank warm; the drawing die has a drawing chamber for drawing the pre-treated part, and the inner wall features of the drawing chamber are used to match the features of the formed part; the bulging die has a bulging cavity for bulging the drawn part, and the inner wall features of the drawing cavity are used to match the features of the formed part; the aging die has an aging cavity for pressure-maintaining aging treatment of the bulged part, and the inner wall features of the aging cavity are used to match the features of the formed part; the clamping tool is used to clamp the pre-formed part.

[0010] Preferably, the drawing die includes a first pressurizing mechanism, a drawing support platform, an upper fixed plate, an upper drawing die, a lower drawing die and a edge holding component, the lower drawing die is fixedly arranged on the drawing support platform, the lower drawing die is provided with the drawing cavity, and the upper end surface of the lower drawing die is used to place the blank; the lower end of the first pressurizing mechanism is connected to the drawing support platform, the upper drawing die is arranged above the lower drawing die and is fixedly connected to the first pressurizing mechanism through the upper fixed plate, the edge holding component is arranged between the upper drawing die and the lower drawing die and is used to press the edge of the pre-treated part; the first pressurizing mechanism is used to drive the upper fixed plate to move vertically, thereby driving the upper drawing die to move synchronously.

[0011] Preferably, the upper drawing die is made of elastic material, and the edge holding component comprises a plurality of nitrogen springs, which are used to be distributed circumferentially along the edge of the pre-processed part.

[0012] Preferably, the bulging die includes a second pressurizing mechanism, a bulging support platform, a bulging upper die and a bulging lower die; the bulging lower die is arranged on the bulging support platform, the lower end of the second pressurizing mechanism is connected to the bulging support platform, the bulging upper die is arranged above the bulging lower die and is relatively fixed to the second pressurizing mechanism; the bulging lower die is provided with the bulging cavity, the bulging lower die and the bulging upper die are used to press the drawn part, and the bulging upper die is provided with a fluid channel connected to the outside; the second pressurizing mechanism is used to drive the bulging upper die to move vertically.

[0013] Preferably, the bulging mold also includes a bulging insulation plate and a bulging insulation part. The bulging insulation plate is fixedly arranged between the bulging lower mold and the second pressurizing mechanism and between the bulging upper mold and the bulging support platform. The bulging insulation part is circumferentially arranged on the outer walls of the bulging lower mold and the bulging upper mold; and the bulging lower mold is also provided with a first heating mechanism for heating the bulging lower mold and the bulging cavity fluid, and the bulging upper mold and the bulging lower mold are also provided with a first temperature measuring hole, and the first temperature measuring hole is used to be provided with a first temperature measuring component, and the first temperature measuring component and the first heating mechanism are both used for communication connection with an external control component.

[0014] Preferably, the aging mold includes a third pressurizing mechanism, an aging support platform, an aging upper mold, an aging lower mold, an aging heat insulation board and an aging heat preservation part; the lower end of the third pressurizing mechanism is connected to the aging support platform, the aging upper mold is arranged above the aging lower mold and is used to compress the bulging part, and the aging lower mold is provided with the aging cavity; the aging heat insulation board is fixedly arranged between the aging lower mold and the aging support platform and between the aging upper mold and the third pressurizing mechanism, and the aging heat preservation part is circumferentially arranged on the outer walls of the aging lower mold and the aging upper mold; and the aging lower mold and the aging upper mold are both provided with a second heating mechanism for heating, and the aging upper mold and the aging lower mold are also provided with a second temperature measuring hole, and the second temperature measuring hole is used to be provided with a second temperature measuring component, and the second temperature measuring component and the second heating mechanism are both used for communication connection with an external control component.

[0015] Preferably, the clamping tool includes a cutting support platform, a support body and a clamp, the support body is fixedly arranged on the cutting support platform, and the end surface features of the support body match the features of the formed part; the support body is used to place the preformed part, and the clamp is connected to the support body and is used to press the circumferential edge of the preformed part; the cutting device is used to cut the excess of the preformed part.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The complex variable curvature mouth frame type structure drawing-bulging forming method provided by the present invention can dissolve the coarse second phase in the initial structure to obtain a uniform solid solution structure by performing a solid solution treatment on the blank in the pretreatment step, and then cool it to obtain a pretreated part; then the pretreated part is transferred to a drawing die for deep drawing to obtain a drawn part, wherein the characteristic maximum deformation of the drawn part is less than the characteristic maximum deformation of the formed part, that is, the drawing die performs preliminary deep drawing on the pretreated part, controls the drawing strain amount to make the strain as uniform as possible, avoids direct deep drawing to the characteristic size of the formed part, and avoids the phenomenon of excessive deformation and unevenness; then the drawn part is transferred to a bulging die for bulging treatment, and the bulging process forms the characteristic size to the characteristic size of the formed part, and then the pressure is maintained to obtain to the bulged part; then the bulged part is subjected to pressure-holding aging treatment through an aging die to obtain a preformed part; finally, the preformed part is transferred to a clamping fixture for clamping and the excess is cut off through a cutting device to obtain a formed part, i.e., a mouth frame-like structure; during the drawing process, the pretreated part is subjected to tensile stress and compressive stress, and the drawn part is subjected to tensile stress during the bulging process. The combined forming can make the stress inside the bulged part uniform, so the combined forming of drawing and bulging can ensure that the workpiece is deformed uniformly to an appropriate deformation amount; then, during the pressure-holding aging treatment, the pressure-holding aging relaxes the stress while ensuring the dimensional accuracy of the formed part to meet the subsequent machining and cutting requirements. Due to the drawing and bulging process, there are excess margins in the edge pressing part and the middle area in the preformed part, and after cutting, the formed part, i.e., a mouth frame-like structure, is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is an example of a structure of a mouth frame type structure;

[0020] Figure 2 The process flow of the deep drawing-bulging forming method for the complex variable curvature mouth frame structure provided in the first embodiment;

[0021] Figure 3 The process flow chart and workpiece microscopic evolution diagram provided for Example 1;

[0022] Figure 4 A schematic diagram of the initial state of the drawing die provided in Example 1;

[0023] Figure 5 A schematic diagram of the forming state of the drawing die provided in Example 1;

[0024] Figure 6A schematic diagram of the structure of the bulging die and the aging die integrated into one provided in the first embodiment;

[0025] Figure 7 A schematic diagram of the structure of the aging mold provided in Example 1;

[0026] Figure 8 This is a schematic diagram of the structure of the clamping tool provided in Example 1.

[0027] Icons: 1-pretreatment part; 2-drawing part; 3-bulging part; 4-preformed part; 10-drawing die; 11-drawing cavity; 12-first pressurizing mechanism; 13-drawing support platform; 14-upper fixed plate; 15-drawing upper die; 16-drawing lower die; 17-edge holding component; 20-bulging die; 21-bulging cavity; 22-second pressurizing mechanism; 23-bulging support platform; 24-bulging upper die; 25-bulging lower die; 26-bulging heat insulation board; 27-bulging shaped insulation part; 28-first heating mechanism; 30-aging mold; 31-aging cavity; 32-third pressurizing mechanism; 33-aging support platform; 34-aging upper mold; 35-aging lower mold; 36-aging insulation board; 37-aging insulation part; 38-second heating mechanism; 40-clamping tool; 41-cutting support platform; 42-support body; 43-clamp; 50-upper support platform; 60-connecting platform; 70-pressurizing member; 80-guide rod; 90-cutting device. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The purpose of the present invention is to provide a method for deep drawing and bulging forming of complex variable curvature mouth frame structures to solve the problems existing in the above-mentioned prior art and to meet the forming requirements of complex variable curvature aviation mouth frame structures.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Embodiment 1

[0032] This embodiment provides a method for forming a complex variable curvature mouth frame structure by deep drawing and bulging. Figure 1-Figure 8 , including the following steps:

[0033] Pretreatment: The blank is solution treated in a heating furnace and kept warm, and then cooled to obtain a pretreated part 1; the blank can be a 2xxx series aluminum alloy, the solution temperature should be 525-550°C, and the solution time should be 25-50min; the blank can be a 7xxx series aluminum alloy, the solution temperature should be 450-500°C, and the solution time should be 30-60min, to avoid excessively high temperature and overburning of the structure.

[0034] Drawing treatment: The pre-treated part 1 is pre-drawn by a drawing die 10 to obtain a drawn part 2, wherein the characteristic maximum depth of the drawn part 2 is less than the characteristic maximum depth of the formed part; the drawn part 2 is drawn to 80-90% of the total depth.

[0035] Bulging treatment: The drawn part 2 is bulged by a bulging die 20 and the pressure is maintained to obtain a bulged part 3, and the characteristic size of the bulged part 3 is consistent with the characteristic size of the formed part; the bulging pressure is 10-20MPa, and the pressure holding time is 30-60s.

[0036] Aging treatment: The bulging part 3 is subjected to pressure-maintaining aging treatment by the aging die 30 to obtain a preform 4, the characteristic dimensions of the preform 4 being consistent with those of the formed part; when the billet is 2xxx aluminum alloy, the internal temperature of the aging die 30 is 160-170°C, and the aging time is 16-20h; when the billet is 7xxx aluminum alloy, a secondary aging system is adopted, the internal temperature of the mold is 115-125°C, the aging time is 3-5h, and then the mold is heated to 160-170°C, and the aging time is 24-30h.

[0037] Cutting process: The preform 4 is clamped by the clamping tool 40 and the excess is cut off by the cutting device 90 to obtain a formed part.

[0038] Among them, see Figure 3, by performing a solution treatment on the blank in the pretreatment step, the coarse second phase in the initial structure can be dissolved to obtain a uniform solid solution structure, and then cooled to obtain a pretreated part 1; then the pretreated part 1 is transferred to a drawing die 10 for drawing to obtain a drawn part 2, wherein the characteristic maximum deformation of the drawn part 2 is less than the characteristic maximum deformation of the formed part, that is, the drawing die 10 performs a preliminary drawing on the pretreated part 1, controls the drawing strain to make the strain as uniform as possible, and avoids directly drawing to the characteristic size of the formed part, resulting in excessive deformation and unevenness; then the drawn part 2 is transferred to a bulging die 20 for bulging treatment, and the bulging process forms the characteristic size to the characteristic size of the formed part, and then the pressure is maintained to obtain a bulged part 3; then the bulged part 3 is passed through The over-aging die 30 is subjected to a holding pressure aging treatment to obtain a preformed part 4; finally, the preformed part 4 is transferred to the clamping fixture 40 for clamping and the excess is cut off by the cutting device 90 to obtain a formed part, i.e., a mouth frame-like structure; during the drawing process, the pretreated part 1 is subjected to tensile stress and compressive stress, and during the bulging process, the drawn part 2 is subjected to tensile stress. The combined forming can make the stress inside the bulged part 3 uniform, so the combined forming of drawing and bulging can ensure that the workpiece is deformed uniformly to an appropriate deformation amount; then, during the holding pressure aging treatment, the holding pressure aging relaxes the stress while ensuring the dimensional accuracy of the formed part to meet the subsequent machining and cutting requirements. Due to the drawing and bulging process, there are excess margins in the edge pressing part and the middle area in the preformed part 4, and after cutting, a formed part, i.e., a mouth frame-like structure, is obtained.

[0039] In the optional scheme of this embodiment, it is more preferred that in the pretreatment step: the blank is solution treated and kept warm, and then water-cooled and quenched to obtain a pretreated part 1; the cooling time is not less than 5 minutes.

[0040] Among the optional schemes of this embodiment, it is more preferred that in the step of deep drawing: the areas of the pre-treated part 1 used to produce small deformation and large deformation are locally drawn in sequence; by first pre-drawing the areas of the pre-treated part 1 with smaller deformation, and after the deep drawing is completed, the areas of the pre-treated part 1 with larger deformation are drawn, so that the strain control of the mouth frame parts is achieved by rushing the material.

[0041] Specifically, taking 2219 aluminum alloy as an example, the following steps are specifically included:

[0042] Pretreatment: The blank is solution treated in a heating furnace. First, the temperature of the heating furnace is raised to the solution temperature and kept warm for a certain period of time to make the alloy elements evenly distributed in the aluminum matrix; Blank 8 is 2219 aluminum alloy, the solution temperature should be 535°C, and the solution time should be 30 minutes; after the solution treatment, the blank is quickly transferred to water for cooling using a transfer tool, and the cooling time is not less than 5 minutes.

[0043] Drawing treatment: after quenching, the pre-treated part 1 is transferred to the drawing die 10 for pre-drawing;

[0044] Bulging treatment: transfer the drawn part 2 to the bulging die 20, close the die and maintain the pressure, the bulging pressure is 15 MPa, and the pressure is maintained for 60 seconds after forming.

[0045] Aging treatment: send the bulging part 3 to the aging mold 30, close the mold and maintain the pressure, set the mold temperature to 165°C, and after keeping the temperature for 18 hours, open the mold and take out the part, and then air cool it.

[0046] Cutting treatment: After the aging treatment is completed, it is transferred to the clamping fixture 40 for mechanical processing to obtain the mouth frame parts.

[0047] In the optional scheme of this embodiment, it is more preferred that the heating furnace has a heating chamber for heating and keeping the blank warm; the drawing die 10 has a drawing cavity 11 for drawing the pre-treated part 1, and the inner wall features of the drawing cavity 11 are used to match the features of the formed part; the bulging die 20 has a bulging cavity 21 for bulging the drawing part 2, and the inner wall features of the drawing cavity 11 are used to match the features of the formed part; the aging die 30 has an aging cavity 31 for pressure-holding aging treatment of the bulged part 3, and the inner wall features of the aging cavity 31 are used to match the features of the formed part; the clamping tool 40 is used to clamp the pre-formed part 4.

[0048] Among the optional solutions of this embodiment, it is more preferred to refer to Figure 4 and Figure 5 The drawing die 10 includes a first pressurizing mechanism 12, a drawing support platform 13, an upper fixed plate 14, an upper drawing die 15, a lower drawing die 16 and a pressure-bearing component 17. The lower drawing die 16 is fixedly arranged on the drawing support platform 13. The lower drawing die 16 is provided with a drawing cavity 11, and the upper end surface of the lower drawing die 16 is used to place the blank. The lower end of the first pressurizing mechanism 12 is connected to the drawing support platform 13. The upper drawing die 15 is arranged above the lower drawing die 16 and is fixed to the first pressurizing mechanism 12 through the upper fixed plate 14. The edge holding component 17 is arranged between the upper drawing die 15 and the lower drawing die 16 and is used to press the edge of the pre-treated part 1; the first pressurizing mechanism 12 is used to drive the upper fixed plate 14 to move vertically, and drive the upper drawing die 15 to move synchronously, so as to realize the drawing and mold opening of the pre-treated part 1, wherein the edge holding component 17 is used to fix the edge of the pre-treated part 1 to prevent the pre-treated part 1 from moving during the drawing process; specifically, the upper fixed plate 14 can be fixed by a pressure plate which can be detachably connected to the first pressurizing mechanism 12, so as to facilitate assembly and disassembly.

[0049] In the optional scheme of this embodiment, it is more preferred that the upper drawing die 15 is set to an elastic material, such as a nylon material, and the nearly uniform loading characteristics of the elastomer are used to achieve uniform deformation, avoid local thinning, and control the deformation of the preform within a reasonable range; the edge holding component 17 includes a plurality of nitrogen springs, and the plurality of nitrogen springs are used to be distributed circumferentially along the edge of the pretreatment part 1. The specific number is determined according to actual needs, and the clamping force of the nitrogen spring can be controlled by controlling the nitrogen inflation amount, thereby improving the flexibility of use.

[0050] Among the optional solutions of this embodiment, it is more preferred to refer to Figure 6 The bulging die 20 includes a second pressurizing mechanism 22, a bulging support platform 23, a bulging upper die 24 and a bulging lower die 25; the bulging lower die 25 is arranged on the bulging support platform 23, the lower end of the second pressurizing mechanism 22 is connected to the bulging support platform 23, the bulging upper die 24 is arranged above the bulging lower die 25 and is relatively fixed with the second pressurizing mechanism 22, wherein the bulging upper die 24 and the bulging lower die 25 can be connected to the second pressurizing mechanism 22 and the bulging support platform 23 respectively through a pressing plate; a bulging cavity 21 is provided on the bulging lower die 25, and the bulging lower die 25 and the bulging upper die 24 are used to press the deep drawing part 2, and the bulging upper die 24 is provided with a fluid channel connected to the outside, wherein the fluid channel is connected to the external fluid, and a high-pressure fluid is introduced into the bulging cavity 21 for bulging and pressure maintenance; the second pressurizing mechanism 22 is used to drive the bulging upper die 24 to move vertically, so as to realize mold closing and pressure maintenance and mold opening and taking out; at this time, the bulging die 20 can be used only for bulging.

[0051] In the optional scheme of this embodiment, it is more preferred that the bulging die 20 can also be used as the aging die 30, that is, the bulging die 20 and the aging die 30 are integrated, and after the bulging is completed, the aging treatment can be performed without changing the die operation; specifically, see Figure 6The bulging die 20 also includes a bulging heat insulation plate 26 and a bulging heat preservation part 27. The bulging heat insulation plate 26 is fixedly arranged between the bulging lower die 25 and the second pressurizing mechanism 22 and between the bulging upper die 24 and the bulging support platform 23. The bulging heat preservation part 27 is circumferentially arranged on the outer wall of the bulging lower die 25 and the bulging upper die 24; and the bulging lower die 25 is also provided with a first heating mechanism 28 for heating the bulging lower die 25 and the bulging cavity 21 fluid, and the bulging upper die 24 and the bulging lower die 25 are also provided with a first temperature measuring hole, and the first temperature measuring hole is used to be provided with a first temperature measuring component, and the first temperature measuring component and the first heating mechanism 28 are both used to pass The signal is connected to the external control component; by setting the bulging insulation plate 26 and the bulging insulation part 27 to perform insulation treatment under the aging state, the bulging lower mold 25 and the fluid in the bulging cavity 21 are heated by the first heating mechanism 28 on the bulging lower mold 25 to achieve aging treatment; specifically, the bulging insulation plate 26 is connected to the bulging lower mold 25 or the bulging upper mold 24 by bolts, the bulging insulation part 27 is set as insulation cotton, the first heating mechanism 28 is set as a plurality of heating rods, and is embedded in the bulging lower mold 25, and the first temperature measuring component is set as a thermocouple to monitor temperature information and transmit it to the external control component to control the action of the first heating mechanism 28.

[0052] In the optional scheme of this embodiment, it is more preferred that the complex variable curvature mouth frame structure drawing-bulging forming device provided in this embodiment also provides a separate aging mold 30, see Figure 7The aging mold 30 includes a third pressurizing mechanism 32, an aging support platform 33, an aging upper mold 34, an aging lower mold 35, an aging heat insulation board 36 and an aging heat preservation part 37; the lower end of the third pressurizing mechanism 32 is connected to the aging support platform 33, the aging upper mold 34 is arranged above the aging lower mold 35 and is used to press the bulging part 3, and the aging lower mold 35 is provided with an aging cavity 31, wherein the aging upper mold 34 and the aging lower mold 35 can be respectively connected with the third pressurizing mechanism 32 through a pressing plate The third pressurizing mechanism 32 is connected to the aging support platform 33; an aging heat insulation plate 36 is fixedly arranged between the aging lower mold 35 and the aging support platform 33, and between the aging upper mold 34 and the third pressurizing mechanism 32, and an aging heat insulation part 37 is circumferentially arranged on the outer wall of the aging lower mold 35 and the aging upper mold 34; and the aging lower mold 35 and the aging upper mold 34 are both provided with a second heating mechanism 38 for heating, and the aging upper mold 34 and the aging lower mold 3 A second temperature measuring hole is also provided, in which a second temperature measuring component is provided, and the second temperature measuring component and the second heating mechanism 38 are both used for communication connection with an external control component; the pressure holding treatment in the aging process is realized by the third pressurizing mechanism 32, the insulation treatment in the aging state is carried out by arranging the aging heat insulation board 36 and the aging heat insulation part 37, and the aging upper mold 34 and the aging lower mold 35 are heated by the second heating mechanism 38 on the aging upper mold 34 and the aging lower mold 35 to realize the aging treatment; specifically, the aging heat insulation board 36 is connected to the aging upper mold 34 or the aging lower mold 35 by bolts; the aging heat insulation part 37 is provided as heat insulation cotton, the second heating mechanism 38 is provided as a plurality of heating rods, and is embedded in the aging upper mold 34 and the aging lower mold 35, and the second temperature measuring component is provided as a thermocouple to monitor temperature information and transmit it to the external control component to control the action of the second heating mechanism 38.

[0053] Further preferably, the first pressurizing mechanism 12, the second pressurizing mechanism 22 and the third pressurizing mechanism 32 all include an upper support platform 50, a connecting platform 60, a pressurizing member 70 and a plurality of guide rods 80, wherein the plurality of guide rods 80 are fixedly arranged between the upper support platform 50 and the corresponding drawing support platform 13, the bulging support platform 23 or the aging support platform 33, and are slidably passed through the corresponding connecting platform 60, the pressurizing member 70 is arranged between the upper support platform 50 and the connecting platform 60, and the lower side of the connecting platform 60 is connected to the corresponding upper fixed plate 14, the bulging upper mold 24, the bulging heat insulation board 26, the aging upper mold 34 or the aging heat insulation board 36; wherein the pressurizing member 70 is arranged as an electric cylinder or a hydraulic cylinder.

[0054] Among the optional solutions of this embodiment, it is more preferred to refer to Figure 8The clamping tool 40 includes a cutting support platform 41, a support body 42 and a clamp 43. The support body 42 is fixedly arranged on the cutting support platform 41, and the end surface features of the support body 42 match the features of the formed part; the support body 42 is used to place the preformed part 4, and the clamp 43 is connected to the support body 42 and is used to press the circumferential edge of the preformed part 4; the cutting device 90 cuts the excess of the preformed part 4; specifically, the clamp 43 can be connected to the cutting support platform 41 by bolts, and presses the circumferential edge of the preformed part 4, and then the cutting device 90 can be set as a CNC machine tool to cut the excess of the preformed part 4 to form a mouth frame-like structure; wherein the support body 42 supports the preformed part 4 outwardly, so that the preformed part 4 protrudes, which is convenient for cutting the excess.

[0055] Embodiment 2

[0056] The present embodiment provides a complex variable curvature mouth frame structure drawing-bulging forming device, which is different from the first embodiment in that: the drawing die 10, bulging die 20 and aging die 30 provided in the present embodiment can share a set of foundations, that is, the first pressurizing mechanism 12, the second pressurizing mechanism 22 and the third pressurizing mechanism 32 are shared as a set, the drawing support platform 13, the bulging support platform 23 and the aging support platform 33 are shared as a set, and the drawing lower die 16, the bulging lower die 25 and the aging lower die 35 are shared as a set; when different steps need to be performed, it is only necessary to replace the drawing upper die 15, the bulging upper die 24 or the aging upper die 34.

[0057] The other structures provided in this embodiment are the same as those in the first embodiment and will not be described in detail here.

[0058] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for deep drawing and bulging of a complex variable curvature mouth frame structure, characterized in that: The following steps are involved: Pretreatment: subjecting the blank to a solution treatment in a heating furnace and keeping the temperature, and then cooling the blank to obtain a pretreated part (1); the blank is a 2xxx series aluminum alloy, the solution temperature is 525-550° C., and the solution time is 25-50 min; or, the blank is a 7xxx series aluminum alloy, the solution temperature is 450-500° C., and the solution time is 30-60 min; Drawing treatment: the pre-treated part (1) is pre-drawn by a drawing die (10) to obtain a drawn part (2), wherein the characteristic maximum deformation of the drawn part (2) is smaller than the characteristic maximum deformation of the formed part; Bulging treatment: the drawn part (2) is bulged by a bulging die (20) and the pressure is maintained to obtain a bulged part (3), wherein the characteristic dimensions of the bulged part (3) are consistent with the characteristic dimensions of the formed part; Aging treatment: performing pressure-maintaining aging treatment on the bulging part (3) through an aging die (30) to obtain a preformed part (4), wherein the characteristic dimensions of the preformed part (4) are consistent with the characteristic dimensions of the formed part; When the blank is a 2xxx aluminum alloy, the internal temperature of the aging mold (30) is 160-170° C., and the aging time is 16-20 hours; when the blank is a 7xxx aluminum alloy, a secondary aging system is adopted, the internal temperature of the aging mold (30) is 115-125° C., and the aging time is 3-5 hours, and then the aging mold (30) is heated to 160-170° C., and the aging time is 24-30 hours; Cutting process: the preformed part (4) is clamped by a clamping tool (40), and the excess is cut off by a cutting device (90) to obtain the formed part.

2. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 1, characterized in that: In the pretreatment step: the blank is subjected to solution treatment and heat preservation, and then water-cooled quenching is performed to obtain the pretreated piece (1).

3. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 1, characterized in that: In the step of deep drawing, the areas of the pre-treated part (1) used to produce small deformation and large deformation are locally deep drawn in sequence.

4. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 1, characterized in that: The heating furnace has a heating chamber for heating and keeping the blank warm; the drawing die (10) has a drawing chamber (11) for drawing the pre-treated part (1), and the inner wall features of the drawing chamber (11) are used to match the features of the formed part; the bulging die (20) has a bulging chamber (21) for bulging the drawn part (2), and the inner wall features of the drawing chamber (11) are used to match the features of the formed part; the aging die (30) has an aging chamber (31) for pressure-maintaining aging treatment of the bulged part (3), and the inner wall features of the aging chamber (31) are used to match the features of the formed part; the clamping tool (40) is used to clamp the pre-formed part (4).

5. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 4, characterized in that: The drawing die (10) comprises a first pressurizing mechanism (12), a drawing support platform (13), an upper fixing plate (14), an upper drawing die (15), a lower drawing die (16) and a pressure-bearing component (17); the lower drawing die (16) is fixedly arranged on the drawing support platform (13); the drawing cavity (11) is arranged on the lower drawing die (16); and the upper end surface of the lower drawing die (16) is used for placing the blank; the lower end of the first pressurizing mechanism (12) is connected to the drawing support platform (13); The support platform (13) is provided with the upper drawing die (15) above the lower drawing die (16) and is fixedly connected to the first pressurizing mechanism (12) through the upper fixed plate (14); the edge pressing component (17) is provided between the upper drawing die (15) and the lower drawing die (16) and is used to press the edge of the pre-treated part (1); the first pressurizing mechanism (12) is used to drive the upper fixed plate (14) to move vertically, thereby driving the upper drawing die (15) to move synchronously.

6. The method for deep drawing and bulging of a complex variable curvature mouth frame structure according to claim 5, characterized in that: The upper drawing die (15) is made of elastic material, and the edge holding component (17) comprises a plurality of nitrogen springs, which are used to be distributed circumferentially along the edge of the pre-processed component (1).

7. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 4, characterized in that: The bulging die (20) comprises a second pressurizing mechanism (22), a bulging support platform (23), a bulging upper die (24) and a bulging lower die (25); the bulging lower die (25) is arranged on the bulging support platform (23), the lower end of the second pressurizing mechanism (22) is connected to the bulging support platform (23), the bulging upper die (24) is arranged above the bulging lower die (25) and is relatively fixed to the second pressurizing mechanism (22); the bulging lower die (25) is provided with the bulging cavity (21), the bulging lower die (25) and the bulging upper die (24) are used to press the drawn part (2), and the bulging upper die (24) is provided with a fluid channel connected to the outside; the second pressurizing mechanism (22) is used to drive the bulging upper die (24) to move vertically.

8. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 7, characterized in that: The bulging die (20) further comprises a bulging heat insulation plate (26) and a bulging heat preservation part (27); the bulging heat insulation plate (26) is fixedly arranged between the bulging lower die (25) and the second pressurizing mechanism (22) and between the bulging upper die (24) and the bulging support platform (23); the bulging heat preservation part (27) is circumferentially arranged on the outer wall of the bulging lower die (25) and the bulging upper die (24); and the bulging lower die (25) is also provided with a first heating mechanism (28) for heating the fluid of the bulging lower die (25) and the bulging cavity (21); the bulging upper die (24) and the bulging lower die (25) are also provided with a first temperature measuring hole, the first temperature measuring hole is used to be provided with a first temperature measuring component, and the first temperature measuring component and the first heating mechanism (28) are both used to communicate and connect with an external control component.

9. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 4, characterized in that: The aging mold (30) comprises a third pressurizing mechanism (32), an aging support platform (33), an aging upper mold (34), an aging lower mold (35), an aging heat insulation board (36) and an aging heat preservation part (37); the lower end of the third pressurizing mechanism (32) is connected to the aging support platform (33); the aging upper mold (34) is arranged above the aging lower mold (35) and is used to press the bulging part (3); the aging lower mold (35) is provided with the aging cavity (31); there is a heat insulation board (36) between the aging lower mold (35) and the aging support platform (33) and between the aging upper mold (34) and the aging heat preservation part (37); The aging heat insulation plate (36) is fixedly arranged between the third pressurizing mechanism (32), and the aging heat insulation part (37) is circumferentially arranged on the outer wall of the aging lower mold (35) and the aging upper mold (34); and the aging lower mold (35) and the aging upper mold (34) are both provided with a second heating mechanism (38) for heating, and the aging upper mold (34) and the aging lower mold (35) are also provided with a second temperature measuring hole, and a second temperature measuring component is arranged in the second temperature measuring hole, and the second temperature measuring component and the second heating mechanism (38) are both used for communication connection with an external control component.

10. The method for forming a complex variable curvature mouth frame structure by deep drawing and bulging according to claim 4, characterized in that: The clamping tool (40) includes a cutting support platform (41), a support body (42) and a clamp (43); the support body (42) is fixedly arranged on the cutting support platform (41), and the end surface features of the support body (42) match the features of the formed part; the support body (42) is used to place the preformed part (4), and the clamp (43) is connected to the support body (42) and is used to press the circumferential edge of the preformed part (4); the cutting device (90) is used to cut the excess of the preformed part (4).

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