Metal plate creep forming device

Abstract

The utility model relates to the technical field of metal plate processing, in particular to a creep forming device for a metal plate. The device comprises an upper die fixing structure, a lower male die, a plurality of middle dies and an upper female die, and meanwhile, cooling channels are formed in the dies, so that the dies can be cooled; the middle die is a cambered surface die, and the radian of the adjacent cambered surfaces of different dies is the same, the ratio of the curvature radius of the upper cambered surface to the curvature radius of the lower cambered surface of the same middle die is larger than 1 and smaller than 1.5, and the ratio of the concave arc height to the convex arc height is larger than 0.5 and smaller than 1; the two ends of each structure are connected in a penetrating mode through supporting rods to achieve the fixing effect, and thin plates are convenient to take through cooperation of horizontal through holes in the two ends of the middle mold and limiting rods. The forming device disclosed by the utility model is beneficial to realizing batch processing of plates with different radians, is stable in structure, convenient to use and applicable to any box-type heat treatment furnace, avoids the period and the cost of constructing the device, can also be used for performing cryogenic forming by utilizing a cooling channel, and is wide in application range.

Description

TECHNICAL FIELD

[0001] The utility model relates to metal sheet processing technical field, concretely relates to a metal sheet creep forming device. BACKGROUND

[0002] The aerospace vehicle structure is developing towards light weight, and its preparation method also proposes a new direction: using hot pressing creep forming to prepare the required arc structure from thin plate. Generally, when the deformation of the plate is small, it is still in the elastic deformation range of the metal, but through the method of heat treatment combination, plastic deformation can occur under the condition that the stress does not reach the yield strength, and the required shape is achieved.

[0003] At present, the device using creep forming usually uses vacuum hot pressing condition to realize large size aluminum alloy plate surface forming control. For example, a device for vacuum creep aging forming of complex curvature aluminum alloy component is disclosed in Chinese patent CN208116533U. The vacuum hot pressing device in the prior art adopts fixed die, and the die is opened according to the required part appearance. This method can only deform mature fixed parts, and the whole die needs to be changed once there is any change. Some technologies have been optimized, and single-sided or double-sided is changed to top rod array to realize the control of different deformation shapes. For the existing vacuum hot pressing device, on the one hand, vacuum hot pressing cannot use conventional box type heat treatment furnace, and needs to build a special vacuum hot pressing tank device, which has high cost and complex operation, and has certain risk; on the other hand, the current design only considers single processing of one piece of aluminum alloy sheet, and cannot realize simultaneous deformation of multiple pieces of multiple curvature, and if multiple single processing devices are stacked, there is the problem of poor stability.

[0004] In general, the above method is suitable for thin plate parts that have been studied and mature, and is used for single processing verification, but is not suitable for batch evaluation and analysis of plate materials and process exploration in the research and development process. Therefore, a universal mold needs to be developed to avoid the construction of special equipment, and the mold is simple to process and easy to operate, the experimental period is short, and multiple sheets can be efficiently creep formed under the same conditions. CONTENT OF THE UTILITY MODEL

[0005] In order to better adapt to the hot pressing creep forming of the conventional box type heat treatment furnace in the laboratory, and improve the forming effect and stability of the large curvature plate, the utility model provides a metal sheet creep forming device, and the specific scheme is as follows:

[0006] The utility model provides a metal sheet creep forming device, its characterized in be including successively from top to bottom: upper die fixed structure, at least two intermediate die and upper female die, the upper die fixed structure, intermediate die and upper female die both ends are equipped with vertical through -hole, and support rod passes through vertical through -hole and is fixed by nut, and the upper die fixed structure, intermediate die and upper female die all are equipped with cooling channel, the intermediate die upper and lower surface middle part and upper female die upper surface middle part are all the curved surface that bends down, horizontal length is same, and the curvature of adjacent two arc surfaces between intermediate die and its and upper female die is same (i.e. the curvature of adjacent two arc surfaces between different die or structure is same), and the curvature radius ratio of upper arc surface and lower arc surface of same intermediate die is greater than 1 and less than 1.5, and the concave arc height ratio of upper arc surface and convex arc height of lower arc surface is greater than 0.5 and less than 1, the both ends lateral surface of intermediate die is equipped with horizontal through -hole symmetrically, and horizontal through -hole passes through vertical through -hole, and the depth of horizontal through -hole is greater than the farthest distance of vertical through -hole to side, and a plurality of horizontal holes are equipped on the support rod left and right and symmetrically, and the diameter of horizontal through -hole is not greater than the diameter of horizontal hole, and further include limit rod, and the outer diameter of limit rod matches the diameter of horizontal through -hole.

[0007] Further, it further includes a lower male die located between the upper die fixed structure and the uppermost intermediate die, the lower surface middle part of the lower male die is a curved surface that bends down and has the same horizontal length as the upper and lower surface middle parts of the intermediate die and the upper surface middle part of the upper female die, the upper surface of the lower male die is a horizontal surface, and the curvature of adjacent arc surfaces between the lower male die, the intermediate die, and the upper female die is the same.

[0008] Further, the curvature radius of the lower surface arc of the lower male die is less than or equal to 1.15 times the horizontal length of the arc surface, and the convex arc height is greater than or equal to 0.1 times the curvature radius.

[0009] Further, the curvature radius of the upper surface arc of the upper female die is greater than 0.5 times the horizontal length of the arc surface, and the concave arc height is less than the curvature radius.

[0010] Further, the middle part of the bottom surface of the upper female die is lower than the two ends, and the horizontal length of the middle part of the bottom surface is not less than the horizontal length of the upper surface arc.

[0011] Further, the two ends of the upper female die are provided with countersunk holes matching the size of the support rod.

[0012] Further, the cooling channel is a circular cross-section channel, and a plurality of cooling channels are provided along the width direction of the lower male die, the intermediate dies, and the upper female die. This cooling channel can be suitable for liquid or gaseous cooling medium, and the same or different cooling medium can be used at the same time, and the medium temperature is not limited within the range that the device can withstand.

[0013] The metal plate creep forming device of the utility model has the beneficial effects that: the metal plate creep forming device of the utility model does not have a vacuum chamber, does not need to be directly connected with a heating source, can be directly placed in various box-type heat treatment furnaces in a laboratory for heat treatment, meanwhile, the mold in the device gradually increases in the arc from top to bottom, while utilizing the gravity, the upper mold with certain curvature reduces the stress of the lower layer at the end, is beneficial to the forming effect of the large-curvature processing plate, and can obviously improve the stability of the whole device; the device can process multiple and various curvature plates in batches, is convenient for evaluating the control variable of the batch sheet parts in the laboratory, meanwhile, the middle mold and the supporting rod are both provided with matched horizontal holes, cooperating with the limiting rod, the middle mold can be moved upward and limited, and then the sheet can be taken or placed, without disassembling the middle template one by one, being convenient to operate and easy to manage; in addition to the heat pressing forming combined with the box-type heat treatment furnace, the device can also realize cryogenic forming by passing cooling medium such as liquid nitrogen in the cooling channel, and has a wider application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0014] The embodiments of the utility model are further explained below with reference to the drawings, in which:

[0015] Figure 1 A front view of the metal plate creep forming device in the embodiment 1 of the utility model is shown;

[0016] Figure 2 A schematic view of one specific arc surface in the device of the utility model is shown;

[0017] Figure 3 A top view and a side view of the counterbore hole at both ends of the female die in the device of the utility model are shown;

[0018] Figure 4 A top view and a side view of the vertical through hole at both ends of the middle mold in the device of the utility model are shown;

[0019] Figure 5 A schematic view of the metal plate creep forming device in the embodiment 2 of the utility model is shown;

[0020] Figure 6 A schematic view of the limiting structure part of the middle mold of the metal plate creep forming device in the embodiment of the utility model is shown;

[0021] Figure 7 A schematic view of the limiting structure part of the middle mold of the metal plate creep forming device in the embodiment of the utility model is shown; Figure 6 A side view of the circled part.

[0022] Among them: 1-Upper mold fixing structure, 2-Upper concave mold, 3-Lower convex mold, 4-Intermediate mold, 5-Support rod, 6-Nut, 7-Cooling channel, 8-Counterhead hole, 9-Vertical through hole, 10-Aluminum alloy sheet, 11-Limiting rod, 12-Limiting rod head, 13-Horizontal through hole, 14-Horizontal hole. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0024] Example 1

[0025] As attached Figure 1 As shown, a metal sheet creep forming device includes, from top to bottom: an upper mold fixing structure 1, a lower punch 3, four intermediate molds 4, and an upper concave mold 2. Vertical through holes 9 are symmetrically machined at both ends of the upper mold fixing structure 1, the lower punch 3, the four intermediate molds 4, and the upper concave mold 2. A support rod 5 passes through the vertical through holes 9 and is fixed at the top by a nut 6. The vertical through holes 9 at both ends are not threaded, and their diameters differ from the diameter of the support rod 5 by ≤1mm. The support rod 5 is a bolt rod to ensure smooth assembly, fixing, and disassembly of the entire device. The upper mold fixing structure 1 is located at the top of the entire device and is a plate with flat top and bottom surfaces. It is used to fix the top of the mold of the entire device, ensuring the stability of the entire device. Below the upper mold fixing structure 1 is the lower punch 3. The two structures fit tightly together to ensure the stability of the device. The upper die 2 is located at the bottom of the entire device and mainly serves as a support. Its bottom surface is a stepped plane to ensure the stability of the entire device. It has unthreaded countersunk holes 8 at both ends, which are connected and fixed by support rods 5 through other mold structures. The upper part of the countersunk hole 8 has the same diameter as the vertical through holes 9 in other parts, while the bottom hole diameter is enlarged to accommodate the bolt head of the support rod 5. The bolt head size is matched to the bolt head size. The purpose of this setting is to hide the bolt head part and ensure that there are no protruding parts on the bottom platform at both ends of the upper die 2. The middle part of the bottom surface of the upper die 2 is lower than the two ends (i.e., stepped). The horizontal length of the lower bottom surface in the middle is not less than the horizontal length of the upper surface arc. That is, when the entire device is placed horizontally, the middle part of the bottom surface of the upper die 2 is the contact surface, and the two ends are suspended. Under this condition, when the entire device needs to be moved, the two ends can provide a fixed position for the straps when moving by a crane or a support position for the forklift arm when moving by a forklift.

[0026] The middle part of the lower surface of the lower punch 3, the middle parts of the upper and lower surfaces of the intermediate die 4, and the middle part of the upper surface of the upper die 2 are all downwardly curved arc surfaces of the same horizontal length. The curvature of adjacent arc surfaces between the lower punch 3, the intermediate die 4, and the upper die 2 is the same, as shown in the attached figure. Figure 2As shown, the radius of the circular arc is R, the height of the convex arc or concave arc is h, and the horizontal length of the arc surface is L, wherein the parameters of the lower convex mold 3 are R B0 , h B0 , the parameters of the upper concave mold 2 are R T0 , h T0 , the radius of the upper arc surface of the same intermediate mold 4 is R T , the height of the concave arc is h T , the radius of the lower arc surface is R B , and the height of the convex arc is h B , which satisfy 1 < R T / R B < 1.5, 0.5 < h T / h B < 1. It also satisfies R T0 > L / 2, h T0 < R T0 , R B0 ≤ 1.15L, and h B0 ≥ 0.1R B0 . In the present embodiment, the length L of all the arc surfaces described above is 1 m, the h B0 of the lower surface arc of the lower convex mold 3 is 0.3 m, the h T0 of the upper concave mold 2 is 0.5 m, and the four intermediate molds 4 from top to bottom: the h T of the first one is 0.3 m, the h B is 0.35 m; the h T of the second one is 0.35 m, the h B is 0.40 m; the h T of the third one is 0.40 m, the h B is 0.45 m; and the h T of the fourth one is 0.45 m, and the h B is 0.50 m.

[0027] The upper mold fixing structure 1, the lower convex mold 3, the four intermediate molds 4, and the upper concave mold 2 are all provided with cooling channels 7, which are channels with circular cross sections and are provided along the width direction of the lower convex mold 3, the four intermediate molds 4, and the upper concave mold 2. Multiple cooling channels 7 are provided (each cooling channel is provided along the longitudinal direction). The cooling rate can be controlled by using the cooling channels, and long waiting for mold cooling after the experiment is completed can be avoided. Different liquid or gaseous cooling media can be used according to the experimental needs. Similarly, there is no conflict between the cooling structures of each structure, and the same or different cooling media can be used at the same time. It should be noted that the temperature of the medium is not limited within the range that the device can withstand.

[0028] The upper die fixing structure 1, the upper concave die 2, the lower convex die 3 and the intermediate die structure 4 of the whole device have consistent horizontal length and width dimensions, the horizontal lengths of the intermediate arc-shaped parts are consistent, and the hole positions at the left and right ends are the same, so as to ensure the adhesion of the device to the parts during use.

[0029] The two ends of each of the four intermediate dies 4 are symmetrically provided with the same horizontal through holes 13, the horizontal through holes 13 pass through the vertical through holes 9, the diameter of the horizontal through holes 13 is smaller than that of the vertical through holes 9, the depth of the horizontal through holes 13 is greater than the farthest horizontal distance from the vertical through holes 9 to the side of the intermediate die 4, and a plurality of horizontal holes 14 are uniformly provided on the support rod, and the diameter of the horizontal through holes 13 is not greater than that of the horizontal holes 14; the device further comprises a limiting rod 11, the outer diameter of the limiting rod 11 matches the diameter of the horizontal through holes 13, and the end of the limiting rod 11 is further provided with a limiting rod head 12 perpendicular to the limiting rod 11. After forming is completed, one of the intermediate dies 4 and the die thereon are lifted, so that the two side horizontal through holes 13 of the intermediate die 4 are respectively aligned with one of the horizontal holes 14, the limiting rod 11 is inserted into the horizontal through holes 13, and at the same time, the limiting rod 11 penetrates through the horizontal holes 14, so as to suspend and limit the intermediate die 4, at this time, the formed sheet can be taken out, and at the same time, the next sheet to be processed can be put in. The structure arrangement makes it unnecessary to disassemble the plurality of dies layer by layer to realize the taking of the sheet, saves space and is convenient to use.

[0030] Five groups of 1.5mm-thick 5xxx aluminum alloy sheets 10 are respectively placed between the lower convex die 3 and the intermediate die 4, between the plurality of intermediate dies 4, and between the intermediate die 4 and the upper concave die 2 for hot press creep forming, 200℃ and 5h heat preservation conditions are adopted, after deformation is completed, the die is slowly cooled to room temperature in a room temperature air environment, and then the sheet part is taken out, and the completed sheet part is evaluated, and the sheet type curvature does not twist and rebound.

[0031] Another five groups of aluminum alloy sheets 10 are deformed by using the same die, the same deformation condition and the same aluminum alloy sheet, after deformation is completed, the obtained sheet is cooled in a cooling system by circulating water, and then taken out after being cooled to room temperature, and the sheet type effect is the same as that of the slow cooling effect.

[0032] Another five groups of aluminum alloy sheets 10 are deformed by using the same die and the same aluminum alloy sheet under different deformation conditions: the 1.5mm-thick 5xxx aluminum alloy sheet is placed in the die, without heating and heat preservation, liquid nitrogen is directly introduced into the cooling pipeline for deep cooling forming test, after deformation is completed, the sheet part is taken out after recovering to room temperature, and the deformation effect is good.

[0033] Example 2

[0034] As shown in the accompanying drawings Figure 5As shown, a metal plate creep forming device, the device structure does not contain lower punch 3, upper die fixed structure 1 is directly contacted with the uppermost layer of intermediate die 4, there are three layers of intermediate dies, the structural parameters of the intermediate dies are the same as the adjacent three intermediate dies in example 1, and other structures are the same as in example 1.

[0035] Three groups of 1.5mm thickness 5xxx aluminum alloy sheet 10 are respectively placed between the intermediate dies 4 and the intermediate dies 4 and the upper concave die 2 for hot pressing creep forming, 200℃, 5h holding condition is adopted, after deformation is completed, the mold is placed in room temperature air environment condition and slowly cooled to room temperature, then the sheet parts are taken out, and the completed sheet parts are evaluated, the plate type arc does not twist and rebound.

[0036] The above describes some example embodiments of the utility model, it can be understood that the above-mentioned embodiments are only used for explaining the utility model, and do not constitute the limitation of the protection scope of the utility model. The features in these embodiments can be recombined in a suitable manner, and the schemes obtained thereby are still within the protection scope required by the utility model. Based on the above-mentioned embodiments, all other embodiments obtained by those skilled in the art without making creative labor, that is, all modifications, equivalent replacements and improvements etc. made within the spirit and principles of the present application, are within the protection scope required by the utility model.

Claims

1. A metal sheet creep forming apparatus characterized by comprising: From top to bottom, it includes: an upper mold fixing structure (1), at least two intermediate molds (4) and an upper concave mold (2). The upper mold fixing structure (1), the intermediate molds (4) and the upper concave mold (2) are provided with vertical through holes (9) at both ends. The support rod (5) passes through the vertical through holes (9) and is fixed by nuts (6). Cooling channels (7) are provided on the upper mold fixing structure (1), the intermediate molds (4) and the upper concave mold (2). The middle part of the upper and lower surfaces of the intermediate molds (4) and the middle part of the upper surface of the upper concave mold (2) are both downward curved arc surfaces with the same horizontal length. The curvature of the two adjacent arc surfaces between the intermediate molds (4) and between the intermediate molds (4) and the upper concave mold (2) is the same. The ratio of the radius of curvature of the upper arc surface to the radius of curvature of the lower arc surface is greater than 1 and less than 1.5, and the ratio of the concave arc height of the upper arc surface to the convex arc height of the lower arc surface is greater than 0.5 and less than 1; the two ends of the intermediate mold (4) are symmetrically provided with horizontal through holes (13), the horizontal through holes (13) pass through the vertical through holes (9), the depth of the horizontal through holes (13) is greater than the farthest distance from the vertical through holes (9) to the side surface, and multiple horizontal holes (14) are symmetrically provided on the left and right support rods (5), the diameter of the horizontal through holes (13) is not greater than the diameter of the horizontal holes (14); it also includes a limiting rod (11), the outer diameter of the limiting rod (11) matches the diameter of the horizontal through holes (13).

2. The apparatus for creep forming of sheet metal according to claim 1, wherein It also includes a lower punch (3), which is located between the upper die fixing structure (1) and the uppermost intermediate die (4). The middle part of the lower surface of the lower punch (3), the middle part of the upper and lower surfaces of the intermediate die (4), and the middle part of the upper surface of the upper die (2) are all downward curved arc surfaces with the same horizontal length. The upper surface of the lower punch (3) is a horizontal surface. The curvature of adjacent arc surfaces between the lower punch (3), the intermediate die (4), and the upper die (2) is the same.

3. The apparatus for creep forming of sheet metal according to claim 2, wherein The radius of curvature of the lower surface arc of the lower punch (3) is less than or equal to 1.15 times the horizontal length of the arc, and the height of the arc is greater than or equal to 0.1 times its radius of curvature.

4. The apparatus for creep forming of sheet metal according to claim 1, wherein The radius of curvature of the upper surface arc of the upper die (2) is greater than 0.5 times the horizontal length of the arc, and the height of the arc is less than its radius of curvature.

5. The apparatus for creep forming of sheet metal according to claim 1, wherein The middle part of the bottom surface of the upper die (2) is lower than both ends, and the horizontal length of the lower bottom surface in the middle part is not less than the horizontal length of the upper surface arc.

6. The apparatus for creep forming of sheet metal according to claim 1, wherein The upper die (2) has countersunk holes (8) at both ends that match the size of the support rod (5).

7. The apparatus for creep forming of sheet metal according to claim 1, wherein The cooling channel (7) is a channel with a circular cross-section, and multiple cooling channels (7) are opened along the width direction of the lower punch (3), multiple intermediate molds (4) and upper die (2).

Images