T-shaped stiffened wall plate hot bending molding forming mold with controllable temperature field and deformation field

Abstract

The utility model belongs to the field of manufacturing of stiffened wallboards of airplane fuselages, and discloses a T-shaped stiffened wallboard hot bending molding forming mold with a controllable temperature field and a controllable deformation field. Comprising an upper template, an upper module, a lower template and a lower module, the upper mold plate and the lower mold plate are rectangular plates, a rectangular block is formed after the upper mold plate and the lower mold plate are closed, the bottom of the upper mold plate is concave inwards to form an arc-shaped curved surface, the top of the lower mold plate is convex outwards to form an arc-shaped curved surface, and the radian of the two arc-shaped curved surfaces is the same as that of a wall plate formed after hot bending molding of the T-shaped stiffened wall plate; the upper die plate, the upper die block, the lower die plate and the lower die block are the same in length and width, the length direction is the left-right direction, and the width direction is the front-back direction. Due to the design of the hot bending molding forming mold structure, uniform heat transfer and high-precision forming manufacturing of the T-shaped stiffened wall plate in the hot bending molding process can be achieved, the stress concentration phenomenon caused by thermal deformation of a product is reduced, and the production efficiency of the product and the yield of the product are improved.

Description

A T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields Technical Field

[0001] This utility model belongs to the field of aircraft fuselage stiffening panel manufacturing, specifically relating to a T-shaped stiffening panel hot bending molding die with controllable temperature and deformation fields. Background Technology

[0002] Among existing composite material stiffened panel structures for fuselages, the T-shaped stiffened panel is simple in structure, has good strength and rigidity, requires fewer modules, does not require specialized equipment, has a high manufacturing success rate, and low production cost. However, in the hot pressing and remolding process of resin materials, the mold plays a crucial role. It not only determines the shape and size of the final product but also directly affects its quality and performance. In particular, the uniformity of the thermal and deformation fields of the mold at high temperatures has a significant impact on the internal stress and resilience of the product. Therefore, the mold's shape design, the position of heating rods and cooling pipes, and the accuracy of thermocouple detection are especially important. Thus, designing a resin material hot pressing and remolding mold with uniform and controllable temperature and deformation fields is particularly necessary. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a T-shaped stiffened wall panel hot bending molding die with controllable temperature field and deformation field.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields includes an upper template, an upper module, a lower template, and a lower module. The upper and lower templates are rectangular plates, and the upper and lower modules, when closed, form a rectangular block. The bottom of the upper module is concave and has an arc-shaped curved surface, while the top of the lower module is convex and has an arc-shaped curved surface. The curvature of the two arc-shaped curved surfaces is the same as the curvature of the wall panel after hot bending molding. The upper template, upper module, lower template, and lower module have the same length and width, with the length direction being the left-right direction and the width direction being the front-back direction.

[0006] The lower module includes, from left to right, several lower mold segments distributed according to the curvature of the wall panel after hot bending and molding of the T-shaped stiffened wall panel. The number of lower mold segments is equal to the number of reinforcing ribs on the T-shaped stiffened wall panel plus 1. A gap is reserved between two adjacent lower mold segments. The size of the gap is adapted to the thickness of the reinforcing rib web of the T-shaped stiffened wall panel. Each lower mold segment has a flange groove at the top of its left and right sides that is adapted to the flange thickness of the reinforcing rib of the T-shaped stiffened wall panel.

[0007] The upper module has several upper mold heating rod holes and several thermocouple pre-drilled holes evenly arranged horizontally near its bottom. Each thermocouple pre-drilled hole is located below the space between two adjacent upper mold heating rod holes. All upper mold heating rod holes and all thermocouple pre-drilled holes are on the same arc-shaped curved surface, and the curvature of the arc-shaped curved surfaces containing the upper mold heating rod holes and thermocouple pre-drilled holes is the same as the curvature of the arc-shaped curved surface at the bottom of the upper module. Several upper mold first cooling water channels are evenly arranged above the upper mold heating rod holes on both the left and right sides of the upper module. All upper mold first cooling water channels are on the same arc-shaped curved surface. The curvature of the arc surface where the first cooling water channel is located is the same as the curvature of the arc surface at the bottom of the upper module; several upper mold second cooling water channels are evenly arranged horizontally at positions corresponding to the middle part of the upper module, and all upper mold second cooling water channels are on the same horizontal plane; the arc length distance between two adjacent upper mold heating rod holes is 4~5cm, the arc length distance between two adjacent upper mold first cooling water channels is 5.5~6cm, the horizontal distance between two adjacent upper mold second cooling water channels is 7~10cm; the arc length distance between two adjacent thermocouple reserved holes is 5~8 times the arc length distance between two adjacent upper mold heating rod holes;

[0008] Each lower mold segment has several lower mold heating rod holes and several lower mold first cooling water channels evenly arranged horizontally near its top position. The lower mold first cooling water channels are located below the lower mold heating rod holes. All lower mold heating rod holes and all lower mold first cooling water channels are on the same arc-shaped curved surface. The curvature of the arc-shaped curved surfaces where the lower mold heating rod holes and lower mold first cooling water channels are located is the same as the curvature of the arc-shaped curved surface at the top of the upper module. The two lower mold segments located at the left and right ends of the lower module each have a lower mold second cooling water channel at the end of their arc-shaped curved surfaces. The arc length distance between two adjacent lower mold heating rod holes is 3.5~4.5cm, and the arc length distance between two adjacent lower mold first cooling water channels is 4.5~5.5cm.

[0009] The top of the upper module is evenly provided with several countersunk holes for upper mold bolts, and the upper template is provided with upper mold bolt through holes that correspond one-to-one with the countersunk holes for upper mold bolts. The upper template and the upper module are fixed together by upper mold bolts that connect the upper mold bolt through holes and upper mold bolt countersunk holes from top to bottom. The bottom of each lower mold segment is evenly provided with several countersunk holes for lower mold bolts, and the lower template is provided with lower mold bolt through holes that correspond one-to-one with the countersunk holes for lower mold bolts. The lower template and the lower mold segment are fixed together by lower mold bolts that connect the lower mold bolt through holes and lower mold bolt countersunk holes from bottom to top.

[0010] Ideally, in order to prevent the product from being squeezed by the two lower mold segments and thus making demolding difficult, each lower mold segment has chamfered angles on its left and right side walls so that after the reinforcing rib web of the T-shaped stiffened wall plate is inserted into the gap reserved between two adjacent lower mold segments, the left and right side walls of the lower mold segment form an inverted V-shaped angle of 4 to 6° with the reinforcing rib web of the T-shaped stiffened wall plate.

[0011] Ideally, in order to more securely connect the upper template and the upper module, the bottom of the upper template is provided with an upper mold recess, and the top of the upper module is provided with an upper mold protrusion that matches the upper mold recess.

[0012] In order to more securely connect the lower template and the lower module, the top of the lower template is provided with several lower mold recesses, which are adapted to the bottom of each lower mold segment.

[0013] Preferably, the upper module comprises, from left to right, several upper mold sub-blocks distributed according to the curvature of the wall panel after hot bending and molding of the T-shaped stiffened wall panel.

[0014] Preferably, the bottom of the upper template is provided with an upper mold recess, and the top of each upper mold block is provided with an upper mold protrusion that matches the upper mold recess.

[0015] Preferably, when the length of the T-shaped stiffened wall panel is 1000mm and there are 5 stiffeners: the number of upper mold segments is 3, and from left to right they are the first upper mold segment, the second upper mold segment, and the first' upper mold segment. The first upper mold segment and the first' upper mold segment are symmetrical. The number of lower mold segments is 6, and from left to right they are the first lower mold segment, the second lower mold segment, the third lower mold segment, the third' lower mold segment, the second' lower mold segment, and the first' lower mold segment. The third lower mold segment and the third' lower mold segment, the second lower mold segment and the second' lower mold segment, and the first lower mold segment and the first' lower mold segment are all symmetrical.

[0016] The total number of heating rod holes in the upper mold is 21, and the number of heating rod holes on the first upper mold split block is 6, the number of heating rod holes on the second upper mold split block is 9, and the number of heating rod holes on the first upper mold split block is 6.

[0017] The total number of heating rod holes in the lower mold is 22, and the number of heating rod holes on the first lower mold segment block is 3, the number of heating rod holes on the second lower mold segment block is 4, the number of heating rod holes on the third lower mold segment block is 4, the number of heating rod holes on the third' lower mold segment block is 4, the number of heating rod holes on the second' lower mold segment block is 4, and the number of heating rod holes on the first' lower mold segment block is 3.

[0018] The total number of cooling water channels for the upper mold is 12, and the number of cooling water channels for the upper mold on the first upper mold split block is 3, the number of cooling water channels for the upper mold on the upper mold plate is 6, and the number of cooling water channels for the upper mold on the first upper mold split block is 3.

[0019] The total number of cooling water channels for the lower mold is 16, and the number of cooling water channels for the first lower mold segment is 1 and the number of cooling water channels for the second lower mold is 1. The number of cooling water channels for the second lower mold segment is 3. The number of cooling water channels for the third lower mold segment is 3. The number of cooling water channels for the third lower mold segment is 3. The number of cooling water channels for the second lower mold segment is 3. The number of cooling water channels for the first lower mold segment is 1 and the number of cooling water channels for the second lower mold is 1.

[0020] The total number of thermocouple pre-drilled holes is 3, and the number of thermocouple pre-drilled holes on the first upper mold split block, the second upper mold split block, and the first' upper mold split block is 1 each.

[0021] Ideally, the upper module has a limiting notch at each of the four bottom corners, while the lower module has limiting protrusions at the four top corners corresponding to the limiting notches.

[0022] To better enable more accurate mold temperature detection at the parting surface of the upper and lower modules, the thermocouple pre-drilled hole is positioned 8-12mm above the bottom arc surface of the upper module.

[0023] Preferably, the mold is made of 45# steel with a surface roughness Ra≤0.4µm and a thermal conductivity of 45~55W / m·K.

[0024] Beneficial effects: The design of the hot bending molding die structure of this utility model can realize uniform heat transfer and high-precision molding of T-shaped stiffened wall panels during hot bending molding process, reduce stress concentration caused by thermal deformation of products, and improve product production efficiency and yield of finished parts. Attached Figure Description

[0025] Figure 1: Main view structural schematic diagram of the hot bending molding die for the T-shaped stiffened wall panel of this utility model;

[0026] Figure 2: Location distribution diagram of heating rod holes and cooling water channels in the mold. a, c, and e are the heating rod hole distributions of Example 1, Comparative Example 1, and Comparative Example 2, respectively. b, d, and f are the cooling water channel distributions of Example 1, Comparative Example 1, and Comparative Example 2, respectively.

[0027] Figure 3: Temperature field diagram of the mold cross-section during the heating process;

[0028] Figure 4: Temperature field diagram of mold cross-section during cooling process;

[0029] Figure 5: The change in mold deformation with heating and cooling time;

[0030] Figure 6: Comparison of the appearance quality of the T-shaped stiffened wall panel before and after hot bending molding in Example 1;

[0031] The attached figures are labeled as follows: 1-Upper template; 2-Upper module; 21-First upper mold split block; 22-Second upper mold split block; 23-First' upper mold split block; 3-Lower template; 4-Lower module; 41-First lower mold split block; 42-Second lower mold split block; 43-Third lower mold split block; 44-Third' lower mold split block; 45-Second' lower mold split block; 46-First' lower mold split block; 5-Gap; 6-Flange groove; 7-Limiting notch; 8-Limiting protrusion; 9-Upper mold heating rod hole; 10-Thermocouple reserved hole; 11-Upper mold first cooling water channel; 12-Upper mold second cooling water channel; 13-Lower mold heating rod hole; 14-Lower mold first cooling water channel; 15-Lower mold second cooling water channel; 16-T-shaped stiffened wall plate. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described below with reference to specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the described embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0033] The T-shaped reinforced wall panels in Example 1 and Comparative Examples 1-2 were manufactured by laying and curing carbon fiber reinforced Vitrimer resin prepreg tape.

[0034] The resin required for the prepreg is epoxy-based remolded Vitimer resin, and the required carbon fiber is T700 unidirectional carbon fiber fabric (area density of 200 g / m²). 3Bisphenol A diglycidyl ether (DGEBA) and zinc acetylacetonate (Zn(acac)2) were weighed at a molar ratio of 1:0.05 and stirred at 130°C. After Zn(acac)2 dissolved, polyethersulfone (PES) powder was added at 45% of the total mass of the mixed solution, and stirring was continued at 130°C until PES dissolved. The temperature of the resulting mixture was lowered to 80°C, and after the temperature stabilized, GA was weighed at a molar ratio of DGEBA to glutaric anhydride (GA) of 1:0.5 and added to the mixture. Stirring was continued, and the viscosity of the mixed liquid was adjusted by adjusting the stirring time according to the actual required viscosity. Then, the mixed liquid was vacuumed to remove bubbles to obtain Vitrimer resin. The prepared Vitrimer resin was used to prepare carbon fiber reinforced Vitrimer resin prepreg tape with a resin content of 35% (mass fraction) by a film transfer process.

[0035] The prepared carbon fiber reinforced Vitrimer resin prepreg tape was laid on the mold surface according to a certain layup angle and sequence. After rolling and vacuuming, it was placed in an autoclave for pressurization and curing to obtain an integrated carbon fiber reinforced Vitrimer resin T-shaped stiffened wall panel. The autoclave curing procedure consisted of holding at 80℃ for 2 hours, maintaining at 120℃ for 2 hours, then heating to 160℃ and holding for 2 hours, and finally naturally cooling to room temperature. The temperature rise / fall rate was 1.5℃ / min, and the autoclave filling pressure was 1 MPa. The layup information for the T-shaped stiffened wall panel is as follows: ① The skin layer consists of 16 layers, with an actual measured thickness of 2.9~3.1 mm. mm, the skin ply sequence is [45° / 90° / -45° / 0° / -45° / 90° / 45° / 0°]s (s indicates symmetrical ply); ② The lower flange ply is 13 layers, the actual measured thickness is 2.4~2.7mm, and the lower flange ply sequence is 45° / 90° / -45° / 0° / 0° / 90° / -45° / 0° / 0° / 45° / 0° / -45° / 45°.

[0036] Example 1

[0037] Taking a T-shaped reinforced wall panel with a hot bending molding length of 1000mm and 5 reinforcing ribs as an example, as shown in Figure 1, a hot bending molding mold for a T-shaped reinforced wall panel includes an upper template 1, an upper module 2, a lower template 3, and a lower module 4; the upper template 1 and the lower template 3 are rectangular plates, and the upper module 2 and the lower module 4 form a rectangular block after being molded together. The bottom of the upper module 2 is concave and has an arc-shaped curved surface, and the top of the lower module 4 is convex and has an arc-shaped curved surface, and the curvature of the two arc-shaped curved surfaces is the same as the curvature of the wall panel after the T-shaped reinforced wall panel 16 is hot bent and molded; the upper template 1, the upper module 2, the lower template 3, and the lower module 4 have the same length and width, with the length direction being the left-right direction and the width direction being the front-back direction;

[0038] The upper module 2 includes three upper mold split blocks from left to right, which are distributed according to the arc of the wall panel after the T-shaped stiffened wall panel 16 is hot-bent and molded. They are, in order, the first upper mold split block 21, the second upper mold split block 22 and the first' upper mold split block 23. The first upper mold split block 21 and the first' upper mold split block 23 have a left-right symmetrical structure.

[0039] The lower module 4 comprises, from left to right, six lower mold segments distributed according to the curvature of the wall panel after hot bending and molding of the T-shaped stiffened wall panel 16. These segments are, in order: first lower mold segment 41, second lower mold segment 42, third lower mold segment 43, third lower mold segment 44, second lower mold segment 45, and first lower mold segment 46. The third lower mold segment 43 and third lower mold segment 44, the second lower mold segment 42 and second lower mold segment 45, and the first lower mold segment 41 and first lower mold segment 46 are symmetrically arranged on the left and right sides. Adjacent segments... A gap 5 is reserved between each lower mold segment, the size of which is adapted to the thickness of the reinforcing rib web of the T-shaped stiffened wall plate 16. Each lower mold segment has a flange groove 6 at the top of its left and right sides, which is adapted to the thickness of the reinforcing rib flange of the T-shaped stiffened wall plate 16. Each lower mold segment has a chamfered angle on its left and right side walls so that after the reinforcing rib web of the T-shaped stiffened wall plate 16 is inserted into the gap 5 reserved between two adjacent lower mold segments, the left and right side walls of the lower mold segment form a 5° inverted V-shaped angle with the reinforcing rib web of the T-shaped stiffened wall plate 16.

[0040] A limiting notch 7 is provided at each of the four bottom corners of the upper module 2, namely the front and rear corners of the first upper mold split block 21 and the front and rear corners of the first ' upper mold split block 23. A limiting protrusion 8 corresponding to the limiting notch 7 is provided at each of the four top corners of the lower module 4, namely the front and rear corners of the first lower mold split block 41 and the front and rear corners of the first ' lower mold split block 46.

[0041] The first upper mold segment 21 and the first' upper mold segment 23 have a number of upper mold heating rod holes 9 and a number of thermocouple reserved holes 10 evenly arranged horizontally near their bottom positions. The thermocouple reserved holes 10 are located 10mm above the bottom arc-shaped surface of the upper module 2. Each thermocouple reserved hole 10 is located below two adjacent upper mold heating rod holes 9. All upper mold heating rod holes 9 and all thermocouple reserved holes 10 are on the same arc-shaped surface, and the curvature of the arc-shaped surfaces where the upper mold heating rod holes 9 and thermocouple reserved holes 10 are located is the same as the curvature of the arc-shaped surface at the bottom of the upper module 2. The left and right ends of the upper module 2, namely the first upper mold segment 21 and the first' upper mold segment 23, have a number of upper mold heating rod holes 9 evenly arranged above the upper mold heating rod holes 9. The first cooling water channel 11, all the upper mold first cooling water channels 11 are on the same arc surface, and the arc of the arc surface where the upper mold first cooling water channel 11 is located is the same as the arc of the bottom arc surface of the upper module 2; several upper mold second cooling water channels 12 are evenly arranged horizontally in front and behind the upper template 1 at the position corresponding to the middle part of the upper module 2, i.e. the second upper mold split block 22, and all the upper mold second cooling water channels 12 are on the same horizontal plane; the arc length distance between two adjacent upper mold heating rod holes 9 is 4.5cm, the arc length distance between two adjacent upper mold first cooling water channels 11 is 6cm, the horizontal distance between two adjacent upper mold second cooling water channels 12 is 8.5cm, and the arc length distance between two adjacent thermocouple reserved holes 10 is 5 to 8 times the arc length distance between two adjacent upper mold heating rod holes 9;

[0042] Each lower mold segment has several lower mold heating rod holes 13 and several lower mold first cooling water channels 14 evenly arranged horizontally near its top position. The lower mold first cooling water channels 14 are located below the lower mold heating rod holes 13. All lower mold heating rod holes 13 and all lower mold first cooling water channels 14 are on the same arc surface. The curvature of the arc surface where the lower mold heating rod holes 13 and the lower mold first cooling water channels 14 are located is the same as the curvature of the arc surface at the top of the upper module 2. The first lower mold segment 41 and the first lower mold segment 46 located on the left and right sides of the lower module 4 are respectively provided with a lower mold second cooling water channel 15 at the end of their arc surface. The arc length distance between two adjacent lower mold heating rod holes 13 is 4cm, and the arc length distance between two adjacent lower mold first cooling water channels 14 is 5cm.

[0043] The bottom of the upper template 1 is provided with an upper mold recess (omitted, not shown). The top of each upper mold segment is provided with an upper mold protrusion (omitted, not shown) that matches the upper mold recess. The top of the upper module 2 is provided with several upper mold bolt countersunk holes (omitted, not shown). The upper template 1 is provided with upper mold bolt through holes (omitted, not shown) that correspond one-to-one with the upper mold bolt countersunk holes. The upper template 1 and the upper module 2 are connected by the upper mold protrusions being inserted into the corresponding upper mold recesses, and the upper mold bolts are connected from top to bottom to the upper mold bolt through holes and the upper mold bolt countersunk holes. And fixed together; the top of the lower template 3 is provided with 6 lower mold recesses (omitted, not shown), the lower mold recesses are adapted to the bottom of each lower mold segment, and the bottom of each lower mold segment is evenly provided with several lower mold bolt countersunk holes (omitted, not shown), and the lower template 3 is provided with lower mold bolt through holes (omitted, not shown) that correspond one-to-one with the lower mold bolt countersunk holes. The lower template 3 and the lower mold segment are fixed together by inserting the bottom of each lower mold segment into the lower mold recess and the lower mold bolts connecting the lower mold bolt through holes and the lower mold bolt countersunk holes from bottom to top.

[0044] The upper template 1, upper module 2, lower template 3 and lower module 4 are all made of 45# steel with a surface roughness value Ra≤0.4µm and a thermal conductivity of 50W / m·K.

[0045] The total number of upper mold heating rod holes 9 is 21, and the number of upper mold heating rod holes 9 on the first upper mold split block 21 is 6, the number of upper mold heating rod holes 9 on the second upper mold split block is 9, and the number of upper mold heating rod holes 9 on the first upper mold split block 23 is 6.

[0046] The total number of lower mold heating rod holes 13 is 22, and the number of lower mold heating rod holes 13 on the first lower mold split block 41 is 3, the number of lower mold heating rod holes 13 on the second lower mold split block 42 is 4, the number of lower mold heating rod holes 13 on the third lower mold split block 43 is 4, the number of lower mold heating rod holes 13 on the third lower mold split block 44 is 4, the number of lower mold heating rod holes 13 on the second lower mold split block 45 is 4, and the number of lower mold heating rod holes 13 on the first lower mold split block 46 is 3.

[0047] The total number of the upper mold first cooling water channel 11 and the upper mold second cooling water channel 12 is 12, and the number of the upper mold first cooling water channel 11 on the first upper mold split block 21 is 3, the number of the upper mold second cooling water channel 12 on the upper mold plate 1 is 6, and the number of the upper mold first cooling water channel 11 on the first upper mold split block 23 is 3.

[0048] The total number of the first cooling water channel 14 and the second cooling water channel 15 of the lower mold is 16. The number of the first cooling water channel 14 on the first lower mold split block 41 is 1 and the number of the second cooling water channel 15 on the lower mold is 1. The number of the first cooling water channel on the second lower mold split block 42 is 3. The number of the first cooling water channel on the third lower mold split block 43 is 3. The number of the first cooling water channel on the third lower mold split block 44 is 3. The number of the first cooling water channel on the second lower mold split block 45 is 3. The number of the first cooling water channel 14 and the number of the second cooling water channel 15 on the first lower mold split block 46 is 1.

[0049] The specific locations of the upper mold heating rod hole 9, thermocouple reserved hole 10, upper mold first cooling water channel 11, upper mold second cooling water channel 12, lower mold heating rod hole 13, lower mold first cooling water channel 14 and lower mold second cooling water channel 15 are shown in Figure 2.

[0050] Work process:

[0051] (1) Insert a single 1KW heating rod into the heating rod hole 9 of the upper mold and the heating rod hole 13 of the lower mold respectively, and insert a thermocouple into the thermocouple reserved hole 10; at the same time, connect the water circuit of the first cold zone of the upper mold and the second cooling water circuit 12 of the upper mold with high temperature resistant plastic water pipes, and connect the water circuit of the first cold zone of the lower mold and the second cooling water circuit 15 of the lower mold with high temperature resistant plastic water pipes. After the connection is completed, the upper mold has only one cooling water inlet and one cooling water outlet, and the lower mold has only one cooling water inlet and one cooling water outlet.

[0052] (2) Assemble the upper template 1 and upper module 2, and the lower template 3 and lower module 4 respectively, and fix the upper template 1 and lower template 3 to the upper and lower pressure plates of the hot press respectively;

[0053] (3) Place the straight T-shaped stiffened wall panel 16 on the lower module 4, and insert the tail ends of the web of the five stiffeners of the T-shaped stiffened wall panel 16 into the gap 5 reserved between the two adjacent lower module blocks.

[0054] (4) Set the mold temperature to 180℃ (softening point temperature of the product);

[0055] (5) Start the hot press, set the hot press mold closing speed to 100mm / min, so that the upper template 1 gradually moves downward, driving the upper module 2 to move downward, and then gradually press the web of the 5 reinforcing ribs of the T-shaped stiffened wall panel 16 into the corresponding gap 5 until the upper module 2 and the lower module 4 are closed. Then turn off the hot press and keep the mold closed for 20 minutes.

[0056] (6) Turn on the cooling water and introduce 25°C cooling water into the upper and lower molds respectively;

[0057] (7) After the mold temperature cools down to room temperature, restart the hot press and gradually move the upper template 1 upward, which will drive the upper module 2 upward. After the upper module 2 moves away from the lower module 4, turn off the hot press. Pull the web of the five reinforcing ribs of the T-shaped stiffened wall panel 16 out of the corresponding gap 5 to obtain the hot-bent stiffened wall panel 16.

[0058] Compare with Example 1

[0059] The difference from Embodiment 1 is that the specific number and location distribution of the upper mold heating rod hole 9, the upper mold first cooling water channel 11, the upper mold second cooling water channel 12, the lower mold heating rod hole 13, the lower mold first cooling water channel 14, and the lower mold second cooling water channel 15 are changed (see Figure 2); everything else is the same as Embodiment 1.

[0060] The total number of upper mold heating rod holes 9 is 15, and the number of upper mold heating rod holes 9 on the first upper mold split block 21 is 4, the number of upper mold heating rod holes 9 on the second upper mold split block is 7, and the number of upper mold heating rod holes 9 on the first upper mold split block 23 is 4.

[0061] The total number of lower mold heating rod holes 13 is 16, and the number of lower mold heating rod holes 13 on the first lower mold split block 41 is 2, the number of lower mold heating rod holes 13 on the second lower mold split block 42 is 3, the number of lower mold heating rod holes 13 on the third lower mold split block 43 is 3, the number of lower mold heating rod holes 13 on the third lower mold split block 44 is 3, the number of lower mold heating rod holes 13 on the second lower mold split block 45 is 3, and the number of lower mold heating rod holes 13 on the first lower mold split block 46 is 2.

[0062] The total number of the upper mold first cooling water channel 11 and the upper mold second cooling water channel 12 is 8, and the number of the upper mold first cooling water channel 11 on the first upper mold split block 21 is 2, the number of the upper mold second cooling water channel 12 on the upper mold plate 1 is 4, and the number of the upper mold first cooling water channel 11 on the first upper mold split block 23 is 2.

[0063] The total number of the lower mold first cooling water channel 14 and the lower mold second cooling water channel 15 is 12. The number of the lower mold first cooling water channel 14 on the first lower mold split block 41 is 1 and the number of the lower mold second cooling water channel 15 is 1. The number of the first cooling water channel on the second lower mold split block 42 is 2. The number of the first cooling water channel on the third lower mold split block 43 is 2. The number of the first cooling water channel on the third lower mold split block 44 is 2. The number of the first cooling water channel on the second lower mold split block 45 is 2. The number of the lower mold first cooling water channel 14 and the number of the lower mold second cooling water channel 15 on the first lower mold split block 46 is 1.

[0064] Compare with Example 2

[0065] The difference from Embodiment 1 is that the specific number and location distribution of the upper mold heating rod hole 9, the upper mold first cooling water channel 11, the upper mold second cooling water channel 12, the lower mold heating rod hole 13, the lower mold first cooling water channel 14, and the lower mold second cooling water channel 15 are changed (see Figure 2); everything else is the same as Embodiment 1.

[0066] The total number of upper mold heating rod holes 9 is 11, and the number of upper mold heating rod holes 9 on the first upper mold split block 21 is 3, the number of upper mold heating rod holes 9 on the second upper mold split block is 5, and the number of upper mold heating rod holes 9 on the first upper mold split block 23 is 3.

[0067] The total number of lower mold heating rod holes 13 is 13, and the number of lower mold heating rod holes 13 on the first lower mold split block 41 is 2, the number of lower mold heating rod holes 13 on the second lower mold split block 42 is 2, the number of lower mold heating rod holes 13 on the third lower mold split block 43 is 3, the number of lower mold heating rod holes 13 on the third lower mold split block 44 is 2, the number of lower mold heating rod holes 13 on the second lower mold split block 45 is 2, and the number of lower mold heating rod holes 13 on the first lower mold split block 46 is 2.

[0068] The total number of the upper mold first cooling water channel 11 and the upper mold second cooling water channel 12 is 8, and the number of the upper mold first cooling water channel 11 on the first upper mold split block 21 is 2, the number of the upper mold second cooling water channel 12 on the upper mold plate 1 is 4, and the number of the upper mold first cooling water channel 11 on the first upper mold split block 23 is 2.

[0069] The total number of the first cooling water channels 14 and the second cooling water channels 15 of the lower mold is 10. The number of the first cooling water channels 14 on the first lower mold split block 41 is 0, and the number of the second cooling water channels 15 on the lower mold is 1. The number of the first cooling water channels on the second lower mold split block 42 is 2. The number of the first cooling water channels on the third lower mold split block 43 is 2. The number of the first cooling water channels on the third lower mold split block 44 is 2. The number of the first cooling water channels on the second lower mold split block 45 is 2. The number of the first cooling water channels 14 on the first lower mold split block 46 is 0, and the number of the second cooling water channels 15 on the lower mold is 1.

[0070] The temperature field and deformation field of the molds in Example 1 and Comparative Examples 1-2 were simulated using Ansys software.

[0071] Figure 3 shows the temperature field diagram of the mold cross section during the heating process of Example 1 and Comparative Examples 1-2. As can be seen from the figure, the heating method of Example 1 is more uniform, so that the mold reaches a completely uniform temperature state in 1326s, while Comparative Examples 1 and 2 require 1515s to achieve the same effect. This shows that the present invention (Example 1) can heat the mold to the required temperature more quickly and uniformly.

[0072] Figure 4 shows the temperature field diagram of the mold cross section during the cooling process of Example 1 and Comparative Examples 1-2. As can be seen from the figure, the mold interior of Example 1 and Comparative Example 1 can be uniformly cooled to room temperature at 3600s. In Example 1, the mold temperature in the mold closing area of ​​the product is reduced to 25°C at 3031s. This indicates that the present invention (Example 1) can maintain better temperature field uniformity during the mold cooling process.

[0073] Figure 5 shows the changes in mold deformation with heating and cooling time for Example 1 and Comparative Examples 1-2. As can be seen from the figure, the maximum deformation of the mold in Example 1, Comparative Example 1 and Comparative Example 2 is 0.07025, 0.09179 and 0.11111 mm, respectively, and is mainly distributed at the corners, indicating that the present invention (Example 1) exhibits a smaller deformation.

[0074] Figure 6 shows a comparison of the appearance quality of the T-shaped stiffened panel before and after hot bending molding in Example 1. The left column shows the appearance before hot bending molding, and the right column shows the appearance after hot bending molding. As can be seen from the figure, the product has a good appearance after hot bending molding using the hot bending molding mold of Example 1, with no oxidation defects or cracking. At the same time, the chord length of the T-shaped stiffened panel after hot bending molding was measured to evaluate the springback of the panel. The theoretical chord length of the product is 975 mm, and the actual measured length is 976.5 mm, with a springback rate of about 0.15%, both of which are maintained at a low level. The product shows excellent hot bending molding accuracy.

Claims

1. A T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields, characterized in that: The system includes an upper template, an upper module, a lower template, and a lower module. The upper and lower templates are rectangular plates. After the upper and lower modules are joined, they form a rectangular block. The bottom of the upper module is concave, forming an arc-shaped surface, and the top of the lower module is convex, forming an arc-shaped surface. The curvature of these two arc-shaped surfaces is the same as the curvature of the T-shaped stiffened wall panel after hot bending and molding. The upper template, upper module, lower template, and lower module have the same length and width, with the length direction being left-right and the width direction being front-back. The lower module includes several lower mold sub-blocks distributed from left to right according to the curvature of the T-shaped stiffened wall panel after hot bending and molding. The number of lower mold sub-blocks equals the number of reinforcing ribs on the T-shaped stiffened wall panel plus one. A gap is reserved between two adjacent lower mold sub-blocks. The thickness of the reinforcing rib web of the T-shaped stiffened wall panel is adapted to the thickness of the reinforcing rib flange of the T-shaped stiffened wall panel. Each lower mold segment has flange grooves on the top left and right sides that match the flange thickness of the reinforcing rib flange of the T-shaped stiffened wall panel. The upper module has several upper mold heating rod holes and several thermocouple pre-drilled holes evenly distributed horizontally near its bottom. Each thermocouple pre-drilled hole is located below two adjacent upper mold heating rod holes. All upper mold heating rod holes and thermocouple pre-drilled holes are on the same arc-shaped curved surface, and the curvature of the arc-shaped curved surfaces containing the upper mold heating rod holes and thermocouple pre-drilled holes is the same as the curvature of the arc-shaped curved surface at the bottom of the upper module. Several upper mold heating rod holes are evenly distributed above the upper mold heating rod holes on the left and right sides of the upper module. The first cooling water channel of all upper molds is located on the same arc-shaped surface, and the curvature of the arc-shaped surface containing the first cooling water channel is the same as that of the arc-shaped surface at the bottom of the upper module. Several second cooling water channels are evenly distributed horizontally on the upper mold plate at positions corresponding to the middle of the upper module, and all second cooling water channels are on the same horizontal plane. The arc length distance between two adjacent upper mold heating rod holes is 4-5 cm, the arc length distance between two adjacent upper mold first cooling water channels is 5.5-6 cm, and the horizontal distance between two adjacent upper mold second cooling water channels is 7-10 cm. The arc length distance between two adjacent thermocouple pre-drilled holes is 5-8 times the arc length distance between two adjacent upper mold heating rod holes. Each lower mold... The split blocks have several lower mold heating rod holes and several lower mold first cooling water channels evenly arranged horizontally near their top positions. The lower mold first cooling water channels are located below the lower mold heating rod holes. All lower mold heating rod holes and all lower mold first cooling water channels are on the same arc-shaped curved surface, and the curvature of the arc-shaped curved surfaces containing the lower mold heating rod holes and lower mold first cooling water channels is the same as the curvature of the arc-shaped curved surface at the top of the upper module. The two lower mold split blocks located at the left and right ends of the lower module each have a lower mold second cooling water channel at the end of their arc-shaped curved surfaces. The arc length distance between two adjacent lower mold heating rod holes is 3.5~4.5cm, and the arc length distance between two adjacent lower mold first cooling water channels is 4.5~5cm.5cm; The top of the upper module has several evenly spaced countersunk holes for upper mold bolts, and the upper template has corresponding through holes for upper mold bolts. The upper template and the upper module are fixed together by upper mold bolts connected from top to bottom through the through holes and countersunk holes. The bottom of each lower mold segment has several evenly spaced countersunk holes for lower mold bolts, and the lower template has corresponding through holes for lower mold bolts. The lower template and the lower mold segment are fixed together by lower mold bolts connected from bottom to top through the through holes and countersunk holes.

2. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 1, characterized in that: Each lower mold segment has chamfered angles on its left and right side walls so that after the reinforcing rib web of the T-shaped stiffened wall plate is inserted into the gap reserved between two adjacent lower mold segments, the left and right side walls of the lower mold segment form an inverted V-shaped angle of 4 to 6° with the reinforcing rib web of the T-shaped stiffened wall plate.

3. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 1, characterized in that: The bottom of the upper template is provided with an upper mold recess, and the top of the upper module is provided with an upper mold protrusion that matches the upper mold recess.

4. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 1, characterized in that: The top of the lower template has several lower mold recesses, which are adapted to the bottom of each lower mold segment.

5. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 1, characterized in that: The upper module comprises, from left to right, several upper mold sub-blocks distributed according to the curvature of the wall panel after hot bending and molding of the T-shaped stiffened wall panel.

6. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 5, characterized in that: The bottom of the upper template is provided with an upper mold recess, and the top of each upper mold block is provided with an upper mold protrusion that matches the upper mold recess.

7. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 5, characterized in that, When the T-shaped stiffened panel is 1000mm long and has 5 stiffeners: there are 3 upper mold segments, arranged from left to right as the first upper mold segment, the second upper mold segment, and the first' upper mold segment. The first upper mold segment and the first' upper mold segment are symmetrical. There are 6 lower mold segments, arranged from left to right as the first lower mold segment, the second lower mold segment, the third lower mold segment, the third' lower mold segment, the second' lower mold segment, the first' lower mold segment, the third lower mold segment, the third' lower mold segment, the second lower mold segment, and the second' lower mold segment. The lower mold segment and the first 'lower mold segment are both symmetrical structures. The total number of heating rod holes in the upper mold is 21, with 6 holes on the first upper mold segment, 9 holes on the second upper mold segment, and 6 holes on the first 'upper mold segment. The total number of heating rod holes in the lower mold is 22, with 3 holes on the first lower mold segment, 4 holes on the second lower mold segment, 4 holes on the third lower mold segment, and 4 holes on the third 'lower mold segment. The number of heating rod holes is 4, the number of heating rod holes on the second lower mold segment is 4, and the number of heating rod holes on the first lower mold segment is 3; the total number of cooling water channels for the upper mold is 12, with 3 cooling water channels on the first upper mold segment, 6 cooling water channels on the upper mold plate, and 3 cooling water channels on the first upper mold segment; the total number of cooling water channels for the lower mold is 16, with 1 cooling water channel on the first lower mold segment. The number of cooling water channels on the first and second lower molds is 1, the number of cooling water channels on the second lower mold segment is 3, the number of cooling water channels on the third lower mold segment is 3, the number of cooling water channels on the third lower mold segment is 3, the number of cooling water channels on the second lower mold segment is 3, the number of cooling water channels on the first lower mold segment is 1, and the number of cooling water channels on the lower mold is 1. The total number of thermocouple reserved holes is 3, and the number of thermocouple reserved holes on the first upper mold segment, the second upper mold segment, and the first lower mold segment is 1 each.

8. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 1, characterized in that: The upper module has a limiting notch at each of the four bottom corners, while the lower module has limiting protrusions at the four top corners corresponding to the limiting notches.

9. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in claim 1, characterized in that: The thermocouple pre-drilled hole is located 8-12mm above the bottom curved surface of the upper module.

10. The T-shaped stiffened wall panel hot bending molding die with controllable temperature and deformation fields as described in any one of claims 1 to 9, characterized in that: The mold is made of 45# steel with a surface roughness Ra≤0.4µm and a thermal conductivity of 45~55W / m·K.

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