Large-scale multi-rib deep-cavity airplane sheet metal part pre-storage hydroforming equipment

Abstract

The invention belongs to the field of plate forming equipment, and particularly relates to large multi-rib deep-cavity airplane sheet metal part pre-storage liquid-filling forming equipment. Comprising a lower die, an upper die, a guide column, a plurality of guide mechanisms, a plurality of pressure-bearing assemblies, a sealing strip, a high-pressure liquid filling connector assembly, a material storage module I and a material storage module II. The lower die comprises a part reinforcing rib forming area and a part flange edge forming area, the reinforcing rib forming area is divided into a plurality of concave cavities, and each concave cavity is matched with a material storage module I and a material storage module II; a liquid chamber space is formed between the plate and the upper die; a sealing groove is formed in the edge pressing area of the upper die and used for installing a sealing strip and is attached to the upper surface of a plate during use; the upper die further comprises a pressure-bearing surface which is attached to a pressure-bearing block mounted on the lower die during die assembly and is used for protecting the molded surface of the die and adjusting a die assembly gap; the upper die comprises a liquid filling opening and a liquid filling outlet, and the liquid filling opening is connected with the high-pressure liquid filling connector. The problem of material shortage of the root of the reinforcing rib is solved; and a flexible storage module is designed, so that the transition cost is saved.

Description

Technical Field

[0001] The present invention belongs to the field of sheet metal forming equipment, and particularly relates to a pre-storage liquid-filled forming equipment for large multi-ribbed deep cavity aircraft sheet metal parts. Background Art

[0002] The aircraft engine nacelle is one of the important components of an aircraft. It is the protective cover of the aircraft engine, playing a role in protecting and maintaining the operation of the aeroengine. Its design and manufacturing are related to the performance and operation safety of the aircraft. The nacelle reinforcing rib is an important structural part in the engine nacelle. It is a large multi-ribbed deep cavity bow-shaped structure, and its manufacturing quality is directly related to the flight safety of the aircraft. Medium-sized transport aircraft at home and abroad generally use turboprop engines, and the nacelle radius is relatively small. Therefore, the reinforcing rib parts therein have the characteristics of large bow height, large height of the reinforcing ribs, and dense distribution of the reinforcing ribs, making the forming difficult. For reasons of strength and weight, such large multi-ribbed deep cavity aircraft sheet metal parts are usually manufactured by integral drop forming of aviation aluminum plates. For a long time, problems such as poor surface quality of the parts, serious wrinkles in the flange area, long production cycle, high labor intensity, low part accuracy, short fatigue life, and poor quality stability have seriously affected the quality and delivery cycle of aircraft products. As Figure 1 shown, the reinforcing ribs of the medium-sized transport aircraft engine nacelle usually have reinforcing ribs in different directions, dividing the part into several deep cavities, forming a situation of mutual material blocking. Due to the large height of the reinforcing ribs (rib height 32 mm), which is 6-7 times that of conventional reinforcing ribs, the root of the reinforcing ribs is extremely prone to cracking due to lack of material during forming. Summary of the Invention

[0003] Object of the Invention: The present invention overcomes the problems in the prior art that the part blank is subjected to rigid impact, the surface quality of the part is poor, the wrinkles are serious, and the forming difficulty of the root of the reinforcing rib is large, and provides a pre-storage liquid-filled forming equipment for large multi-ribbed deep cavity aircraft sheet metal parts.

[0004] Technical Solution: To achieve the above object of the invention, the present invention specifically designs a pre-storage liquid-filled forming equipment for large multi-ribbed deep cavity aircraft sheet metal parts, including a lower die, an upper die, guide columns, a plurality of guiding mechanisms, a plurality of pressure-bearing components, a sealing strip, a high-pressure liquid filling joint component, a storage module I, and a storage module II;

[0005] In the lower die, there are a part rib forming area and a part flange forming area. The rib forming area is divided into multiple cavities. When forming the part, each cavity mates with the material storage module I and the material storage module II. The lower die includes a blank holding area, which, when in use, clamps the part together with the blank holding area of the upper die to perform the blank holding function. There is a guiding mechanism installation position on the lower die for installing the guiding mechanism assembly, which forms a guide with the guiding surface of the upper die. There is a pressure bearing block installation position on the lower die for installing the pressure bearing block assembly to adjust the die closing clearance between the upper and lower dies and thus control the blank holding effect. There are also guide pillars fixed on the upper end surface of the lower die for guiding during the die closing of the upper and lower dies.

[0006] In the upper die, there is a blank holding area that mates with the lower die. When in use, it clamps the part together with the blank holding area of the lower die to form a liquid chamber space between the sheet metal and the upper die. There is a sealing groove in the blank holding area of the upper die for installing a sealing strip, which, when in use, abuts against the upper surface of the sheet metal to play a sealing role between the blank holding area of the upper die and the sheet metal.

[0007] The upper die also includes a pressure bearing surface, which mates with the pressure bearing block installed on the lower die during die closing to protect the die surface and adjust the die closing clearance. The upper die includes a fluid filling port and a fluid filling outlet, which are used to inject a pressure medium into the liquid chamber to increase the pressure in the liquid chamber. The fluid filling port is connected to a high-pressure fluid filling joint.

[0008] Furthermore, there are exhaust holes in the cavities of the lower die, which are used to timely exhaust the air between the part sheet metal and the lower die during part forming, reduce the forming pressure, and can also exhaust excess liquid when necessary.

[0009] Furthermore, both the material storage module I and the material storage module II include several material storage bumps and cylindrical pins that mate with the material storage bumps. When in use, the material storage bumps are fixed in the cavities of the lower die using the cylindrical pins.

[0010] Furthermore, there are several small blind holes on the upper surface of the guide plate, which are filled with lubricating grease when in use to play a guiding and lubricating role during the opening and closing of the die.

[0011] Furthermore, the upper die adopts an arc-shaped surface, which can bend the part sheet metal during the die closing stage in the use process, simplify the process, and at the same time reduce the size of the liquid chamber space, improve the utilization rate of the pressure medium and the pressurization efficiency.

[0012] Furthermore, the lower die includes several equipment reference holes, which serve as the measurement reference for the lower die and are used for operations such as inspection and maintenance of the lower die. The plane of the equipment reference holes is slightly lower than the die closing plane.

[0013] Furthermore, the lower die includes a center line, which functions to ensure that the lower die can be installed at the center of the machine tool workbench and control the force balance.

[0014] Technical effects: (1) The present invention provides a pre-storage liquid-filled forming device for large multi-ribbed deep-cavity aircraft sheet metal parts, realizing flexible medium forming of large multi-ribbed deep-cavity aircraft sheet metal parts, breaking through the bottleneck of the existing technology, and significantly improving the surface quality of the parts.

[0015] (2) The present invention provides a pre-storage liquid-filled forming device for large multi-ribbed deep-cavity aircraft sheet metal parts, with a reasonable design of the pre-storage function, realizing the forming of large high-rib parts, capable of forming large multi-ribbed deep-cavity aircraft sheet metal parts with a rib height of 30 - 35 mm, and achieving a breakthrough that the rib height of the formed large multi-ribbed deep-cavity aircraft sheet metal parts is 6 - 7 times that of the conventional rib height.

[0016] (3) The present invention provides a pre-storage liquid-filled forming device for large multi-ribbed deep-cavity aircraft sheet metal parts. The upper die adopts an arc-shaped smooth surface, and the part blank is bent when the die is closed, simplifying the process, reducing the liquid chamber space at the same time, improving the utilization rate of the pressure medium, and enhancing the boosting efficiency.

[0017] (4) The present invention provides a pre-storage liquid-filled forming device for large multi-ribbed deep-cavity aircraft sheet metal parts, which has a blank-holder system that can control the material flow state of the part and prevent the part from wrinkling.

[0018] (5) The present invention provides a pre-storage liquid-filled forming device for large multi-ribbed deep-cavity aircraft sheet metal parts, which has a flexible storage module. By disassembling and assembling the storage module, three different surface profiles can be quickly switched, saving the cost of two sets of transition dies.

[0019] (6) The present invention provides a pre-storage liquid-filled forming device for large multi-ribbed deep-cavity aircraft sheet metal parts, which has a reasonable exhaust system that can timely remove the excess air, facilitating the uniform forming of the part; the upper and lower dies are interlocked through the guiding surface, improving the safety and stability of the device. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a large multi-ribbed deep-cavity aircraft sheet metal part;

[0021] Figure 2 It is a schematic structural diagram of a liquid-filled forming device for large multi-ribbed deep-cavity aircraft sheet metal parts;

[0022] Figure 3 It is a schematic diagram of the guiding mechanism;

[0023] Figure 4 It is a schematic diagram of the pressure-bearing component;

[0024] Figure 5 It is a schematic diagram of the high-pressure joint component;

[0025] Figure 6 It is a schematic diagram of the storage module Ⅰ10;

[0026] Figure 7 Schematic diagram of the storage module II 11

[0027] Among them: 1. Lower die, 2. Upper die, 3. Guide pillar, 4. Guide mechanism, 4a. Guide plate, 4b. Bolt, 5. Pressure-bearing component, 5a. Pressure-bearing block, 5b. Bolt, 6. Sealing strip, 7. High-pressure liquid filling joint component, 7a. High-pressure joint, 7b. Sealing ring, 8. Universal lifting point, 9. Bow-shaped ring hanging, 10. Storage module I, 10a - 10e. Storage bumps, 10f. Cylindrical pin, 11. Storage module II, 11a - 11e. Storage bumps, 11f. Cylindrical pin Specific implementation mode

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in combination with the specification drawings or specific implementation cases. It should be noted that some (but not all) of the public examples are shown in the drawings. In fact, many different examples can be described and these examples should not be understood as being limited to the examples set forth herein. On the contrary, these examples are described so as to more fully embody the positive effects of the present invention, and those not elaborated in this text are regarded as well-known technologies or conventional technical means in the art

[0029] Refer to the attached Figures 1 to 7 , as Figure 2 shown, a large multi-rib deep cavity aircraft sheet metal part pre-storage liquid filling forming equipment is provided, including a lower die 1, an upper die 2, 2 guide pillars 3, multiple guide mechanisms 4, multiple pressure-bearing components 5, a sealing strip 6, a high-pressure liquid filling joint component 7, multiple universal lifting points 8, multiple bow-shaped ring hangings 9, 1 set of storage module I 10, and 1 set of storage module II 11. Among them, the guide mechanism 4 includes 1 guide plate 4a and 4 connecting bolts 4b Figure 3 ; the pressure-bearing component 5 includes a pressure-bearing block 5a and 2 connecting bolts 5b, as Figure 4 ; the high-pressure liquid filling joint component 7 includes 1 high-pressure joint 7a and a seal 7b, as Figure 5 ; the storage module I 10 includes 5 storage bumps 10a - 10e and 10 cylindrical pins 10f, as Figure 6 ; the storage module II 11 includes 5 storage bumps 11a - 11e and 11 cylindrical pins 11f, as Figure 7 .

[0030] In the lower die 1, there are a part rib forming area and a part flange forming area. There are 5 cavities left between the ribs, and exhaust holes are made in the cavities. Their function is to timely exhaust the air between the part blank and the lower die during part forming, reduce the forming pressure, and also exhaust excess liquid when necessary. Bump mounting holes are made on the lower die. During operation, the stock storage bumps 10a - 10e are respectively connected to the cavities of the lower die 1 with cylindrical pins 10f. The function of the stock storage module is to store part of the blank in the cavities at the initial stage of part forming for feeding the root of the ribs later to avoid material shortage and cracking at the root of the ribs. The lower die 1 includes a blank holding area, which, when in use, clamps the part together with the blank holding area of the upper die 2 to play a blank holding role. A guiding mechanism installation position is set on the lower die 1 for installing the guiding mechanism assembly 4, which forms a guide with the guiding surface of the upper die. Several small blind holes are made on the upper surface of the guide plate 4, which are filled with grease during use to play a guiding and lubricating role during the mold opening and closing process. A pressure bearing block installation position is set on the lower die 1 for installing the pressure bearing block assembly 5, whose function is to adjust the die closing clearance to control the blank holding effect. The lower die 1 includes mounting U - shaped notches, whose function is to mount the lower die on the working table of the hydroforming machine tool. The lower die 1 includes a center line, whose function is to ensure that the lower die 1 can be installed at the center of the machine tool working table to control the force balance. The lower die 1 includes 3 equipment reference holes, which are the measurement references of the lower die and are used for operations such as inspection and maintenance of the lower die 1. The plane of the equipment reference holes is slightly lower than the die closing plane to prevent the reference from being worn during equipment use and affecting the later measurement accuracy.

[0031] In the upper die 2, there is a blank holding area, which, when in use, clamps the part together with the blank holding area of the lower die to form a liquid chamber space between the blank and the upper die. The upper die adopts an arc - shaped surface, which can bend the part blank during the die closing stage in the use process, simplify the process, and at the same time reduce the size of the liquid chamber space, improve the utilization rate of the pressure medium and the boosting efficiency. A sealing groove is made in the blank holding area of the upper die 2 for installing the sealing strip 6, which, when in use, abuts against the upper surface of the blank to play a sealing role between the blank holding area of the upper die and the blank, improving the liquid chamber pressure. The upper die 2 includes a pressure bearing surface, which fits with the pressure bearing block installed on the lower die during die closing to protect the die surface and adjust the die closing clearance. The upper die 2 includes a liquid filling port and a liquid filling outlet, whose function is to inject the pressure medium into the liquid chamber to increase the liquid chamber pressure. The liquid filling port is connected to the high - pressure liquid filling joint 7. The upper die 2 includes mounting U - shaped notches for connecting with the drawing slider of the machine tool. The upper die includes a guiding surface, a reference, and a center line, whose functions are the same as those of the corresponding parts of the lower die.

[0032] The material storage module I 10 includes five material storage bumps 10a - 10e and ten cylindrical pins 10f. The thickness of the material storage bumps 10a - 10e is slightly lower than that of the part rib by about 1 - 10 mm. The size of the material storage bumps 10a - 10e is smaller than the size of the corresponding concave cavity of the lower die 1. During operation, the bottom boundary of the bump is about 20 - 30 mm away from the part edge line. Its function is to ensure the prior forming of the part rib. When in use during operation, the material storage bumps are assembled in the concave cavity of the lower die 1 with cylindrical pins. Its function is to form material storage in the concave cavity during the first stage of part forming, ensuring sufficient material supply for the later forming of the rib root. The material storage module II 11 includes five material storage bumps 11a - 11e and ten cylindrical pins 11f. The thickness of the material storage module II 11 is 0.5 times that of the material storage bumps 10. The size of the material storage bumps 11a - 11e is smaller than the size of the corresponding concave cavity of the lower die 1. During operation, the bottom boundary of the bump is about 40 - 60 mm away from the part edge line; during the second - stage liquid filling, the material storage module II 11 replaces the material storage module I 10 of the bump and is installed in the lower die concave cavity. Its function is to maintain a certain material storage height, enabling the material storage in the first stage to flow towards the rib root under the action of the pressure medium, and at the same time controlling the material storage absorption amount to prevent wrinkles caused by too fast material storage absorption. The specific material storage bump is a metal block with a trapezoidal cross - section. Its bottom curvature is the same as that of the corresponding concave cavity of the lower die 1. Each material storage bump includes two pin holes for assembling with the lower die and a threaded hole for installing a lifting ring, which is convenient for taking and placing. There is an exhaust groove at the bottom of the material storage bump, running through the entire bump. During operation, the excess air enters the exhaust hole of the lower die 1 through the exhaust groove and then is discharged from the equipment.

[0033] During operation, first install the guiding mechanism 4 and the pressure - bearing component 5 at the corresponding positions of the die. Fix the lower die 1 on the machine tool table through the installation notch, connect the upper die 2 to the moving slider of the machine tool, and install the material storage module I 10 in the corresponding concave cavity of the lower die 1 to form a transitional surface A with the function of material storage. Then position the part blank on the lower die; when the die is closed, the blank is bent by the arc - shaped surface of the upper die 2; then carry out the first - stage liquid filling. Under the action of the pressure medium, the blank will be pressed into the gap between the material storage bump and the rib, thus completing the first - step material storage; during the second - stage forming, disassemble the material storage module I 10 and install the material storage module II 11 to form a second set of transitional surface B. Since the size of the bump of the material storage module II 11 is reduced, under the action of the pressure medium, a part of the material storage formed in the first stage will be absorbed and supplemented to the rib root. During the third - stage forming, disassemble the material storage module II 11 to form the final surface C. After further liquid - filling forming and trimming the surplus, a large - sized multi - rib deep - cavity sheet metal part will be obtained.

[0034] In view of the problem that the root of the stiffener is extremely prone to cracking due to material shortage during the forming process of conventional forming methods, the present invention specifically designs a pre-storage fluid filling forming equipment for large-scale multi-rib deep cavity aircraft sheet metal parts. By using the method of flexible medium semi-mold forming, the rigid impact on the sheet material is avoided, and the part quality and manufacturing efficiency are improved. The storage function during the forming process is developed to solve the problem of material shortage at the root of the stiffener. A flexible storage module is designed to save the transition cost.

[0035] The above specific implementation manners or cases are only used to explain the technical solutions of the present invention and do not limit this application. The parts not detailed are regarded as conventional technical means or common general knowledge in the art. Those of ordinary skill in the art can understand that: based on the design concept of this application, it should be possible to adaptively modify the technical solutions recorded in the foregoing implementation manners, or perform equivalent replacements on some or all of the technical features. These modified, equivalently replaced, and adaptively improved technical solutions do not deviate from the technical essence of the present invention and should all be covered within the protection scope of this application.

Claims

1. A large-scale multi-ribbed deep-cavity aircraft sheet metal parts pre-stock liquid filling forming equipment, characterized in that: It includes a lower die, an upper die, a guide column, multiple guide mechanisms, multiple pressure-bearing components, a sealing strip, a high-pressure liquid-filled joint component, a material storage module I, and a material storage module II; The lower die includes a part reinforcement rib forming area and a part flange edge forming area. The reinforcement rib forming area is divided into multiple concave cavities. When forming the part, each concave cavity matches the material storage module I and the material storage module II. The lower die includes a pressure pressing area, which clamps the part together with the pressure pressing area of ​​the upper die when in use, playing a pressure pressing role. The lower die is provided with a guide mechanism installation position for installing the guide mechanism assembly, which forms a guide with the guide surface of the upper die. The lower die is provided with a pressure block installation position for installing the pressure fast assembly, which is used to adjust the gap between the upper and lower dies to control the pressure pressing effect. A guide column is also fixed on the upper end surface of the lower die for guiding when the upper and lower dies are closed. The upper die includes a pressure zone that matches the lower die. When in use, it clamps the parts together with the pressure zone of the lower die to form a liquid chamber space between the sheet and the upper die. The pressure zone of the upper die is provided with a sealing groove for installing a sealing strip. When in use, it is pressed against the upper surface of the sheet to seal between the pressure zone of the upper die and the sheet. The upper mold also includes a pressure-bearing surface, which fits with the pressure block installed on the lower mold when the mold is closed, and is used to protect the mold surface and adjust the mold clearance; the upper mold includes a filling port and a filling outlet, and its function is to inject pressure medium into the liquid chamber to increase the pressure in the liquid chamber; the filling port is connected to the high-pressure filling joint.

2. A large-scale multi-ribbed deep cavity aircraft sheet metal parts pre-stock liquid filling forming equipment as claimed in claim 1, characterized in that: An exhaust hole is formed in the concave cavity of the lower mold.

3. A large-scale multi-ribbed deep-cavity aircraft sheet metal parts pre-stock liquid filling forming equipment as claimed in claim 1, characterized in that: The material storage module I and the material storage module II both include a plurality of material storage convex blocks and cylindrical pins matched with the material storage convex blocks. When in use, the material storage convex blocks are fixed in the concave cavity of the lower mold by using the cylindrical pins.

4. A large-scale multi-ribbed deep cavity aircraft sheet metal parts pre-stock liquid filling forming equipment as claimed in claim 1, characterized in that: The upper surface of the guide plate is provided with a number of small blind holes, which are filled with grease when in use, and serve as guide lubrication during the opening and closing process of the mold.

5. The large multi-ribbed deep cavity aircraft sheet metal parts pre-stock liquid filling forming equipment as claimed in claim 1, characterized in that: The upper die adopts an arc-shaped surface, which can bend the part sheet during the mold closing stage during use.

6. The large multi-ribbed deep cavity aircraft sheet metal parts pre-stock liquid filling forming equipment as claimed in claim 1, characterized in that: The lower die contains a device reference hole, which serves as the measurement reference for the lower die.

7. A large-scale multi-ribbed deep cavity aircraft sheet metal parts pre-stock liquid filling forming equipment as claimed in claim 6, characterized in that: The lower die includes a centering line, which is used to ensure that the lower die can be installed in the center of the machine tool worktable and control the force balance.

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