Composite hybrid material wing tip skin forming tooling

Abstract

The present invention provides a composite mixed material wing tip skin molding tool, which belongs to the field of composite material molding technology. The tool includes a base, a sealing box, an air guide joint, a connecting plate, a clamping plate, a molding core mold, a support plate, a discharge plate, a spiral ejector rod, an ejector seat, a drilling jig seat, a positioning pin and a drilling jig. The present invention solves the problems of stacking, assembling and molding of wing tip parts, and solves the problem that a large amount of resin flows out of the fiberglass raw material during the stacking process and is difficult to clean.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material forming, and relates to a composite mixed material wing tip skin forming tool, which is mainly used for composite fiberglass prepreg layup forming, and ensures the bonding of glass cloth skin with foam inserts and metal sheets, so as to obtain a defect-free, high-precision wing tip skin part composed of three materials. Background Art

[0002] The sandwich structure of composite wing tip materials has the advantages of light weight, high bending stiffness and strength, strong anti-instability ability, fatigue resistance, sound absorption, heat insulation, etc., so it has been widely used in aircraft structures. Research and practice have proved that adding wing tips to the wings can effectively reduce resistance and improve the fuel efficiency of the aircraft, so wing tips have been widely used in aircraft. In order to reduce the weight of the structure and ensure the stiffness of the parts, more and more wing tips use foam sandwich and metal reinforced composite structures.

[0003] The composite fiberglass wing tip parts are located at the tip, so the wing tip profile is generally more complicated. During the part molding process, the wing tip profile dimensions must be accurate, the internal quality of the outer skin and the sandwich structure bonding surface must be guaranteed, and the sealing of the outer fiberglass skin and edge banding to the foam core must be guaranteed, which puts high demands on the design of the process plan. In order to ensure the complex external dimensions and high internal quality of the wing tip structure, it is necessary to design the component mold according to the characteristics of the part. During the mold design process, how to design the molding tooling to pressurize different positions of the part is another process difficulty. During the layup process of the wing tip skin, due to the complex profile, the difficulty of prepreg layup, and the high resin content of the prepreg, it is easy to cause defects such as fiber buckling and bridging due to the large layup curvature. It is necessary to design a reasonable layup plan during the layup process to improve the layup quality.

[0004] There are three main types of composite sandwich structure curing and forming, namely co-curing, co-bonding and secondary bonding. The composite wing tip is composed of three materials: fiberglass skin, foam core and metal sheet. The co-curing scheme can better ensure the bonding quality of the three materials. Due to the high resin content of fiberglass prepreg, a lot of resin will remain on the tooling during the curing process, making the tooling difficult to clean. Therefore, it is necessary to design a set of tooling that can complete the curing and forming of the parts and ensure that the tooling is easy to clean and can be used repeatedly. Summary of the invention

[0005] In order to solve the problems of stacking, assembling and forming of composite wing tip parts composed of multiple materials, the present invention provides a composite mixed material wing tip skin forming tool. The use of this tool can solve the positioning problem of inner surface foam and metal sheet. At the same time, it takes into account the problem that a large amount of resin flows out of the fiberglass skin during the curing process and remains on the tool, making the tool difficult to clean.

[0006] The technical solution of the present invention is:

[0007] A composite mixed material wing tip skin forming tool comprises a supporting packaging system, a positioning forming system and a demoulding system.

[0008] The support packaging system is used to support the positioning molding system, and complete the part packaging and resin cleaning on the support packaging system; it includes a base 1, a sealing box 2 and an air guide joint 3. Among them, the base 1 is the positioning reference of the tooling. It is a table structure formed by welding square steel pipes, metal angles and metal flat plates according to the outline of the parts. The square steel pipe is located at the bottom for forklift-specific tooling, and the metal angle is located in the middle welding position. There is a metal flat plate above and below the base 1, and the upper metal flat plate is provided with multiple circular holes for collecting resin. The sealing box 2 is welded to the inner side of the upper metal flat plate of the base 1 to ensure that the sealing box 2 is firmly welded to the metal flat plate and requires that it does not leak under high temperature. A circular tube is led out from one end of the sealing box 2, and the circular tube is connected to the air guide joint 3, which is equivalent to integrating the vacuum nozzle and the air guide pipeline into the tooling. The vacuum pump can be directly connected to the air guide joint 3 to complete the vacuuming.

[0009] The positioning and molding system is used to complete the positioning of foam and metal sheets, the stacking of fiberglass prepreg, the bonding of the three materials, and the drilling of subsequent parts; it includes a connecting plate 4, a clamping plate 5, a molding core mold 6, a support plate 7, a drilling jig seat 11, a positioning pin 12 and a drilling jig 13. Among them, the connecting plate 4 is connected to the middle position of the circular hole on the metal plate above the base 1, and a semicircular notch is left at the corresponding position of the connecting plate 4 according to the circular hole. Each clamping plate 5 is connected by two L-shaped angle bars, which clamp the connecting plate 4 and are connected to the connecting plate 4 and the molding core mold 6 at the same time, so that the molding core mold 6 stands in the center of the tooling. According to the length of the molding core mold 6, multiple clamping plates 5 and connecting plates 4 are distributed on the base 1 according to the positioning requirements.

[0010] The material of the forming core mold 6 is ordinary steel, and its profile is the same as the inner profile of the wing tip part; a foam positioning groove is provided on the profile of the forming core mold 6 at the position corresponding to the foam; and multiple grooves are provided on both sides of the forming core mold 6 outside the height margin for positioning the support plate 7. The support plate 7 is a rectangular plate, which is placed in the groove of the forming core mold 6 and is fixed in position with a flat head screw to position the metal sheet.

[0011] The jig seat 11 is arranged below the part hole and connected to the base 1. The positioning hole on the jig seat 11 is connected to a cylinder, and the upper end of the cylinder is connected to the jig 13; a circular hole is provided at the connection between the two. When the jig 13 reaches the specified position, the position of the jig 13 is fixed by the positioning pin 12, and drilling is performed at this time. The positioning pin 12 is a rectangular block with a triangular drilling block on it, and the drilling block is provided with a jig hole and a drill sleeve.

[0012] The demoulding system includes a discharge plate 8, a spiral ejector rod 9 and an ejector seat 10; since the FRP prepreg has a large resin content, a large amount of resin flows out during the curing process, causing the part to be tightly combined with the molding core mold 6, and the demoulding system is needed to realize the demoulding of the part.

[0013] The stripper plate 8 is located at the margin of the forming core mold 6, and a corresponding notch is provided in the middle of the stripper plate 8 according to the outer profile of the forming core mold 6, and the notch is 0.5 mm larger than the outer profile of the forming core mold 6 (it can be a different value according to the thickness of the parts); threaded holes are evenly distributed around the stripper plate 8. The spiral ejector rod 9 is formed by connecting a spiral rod and a threaded rod, and is installed in the threaded hole of the stripper plate 8 through the threaded rod. The ejector seat 10 is a cylindrical block, which is installed at the lower end of the threaded rod of the spiral ejector rod 9.

[0014] Beneficial effects of the present invention: The present invention solves the problems of stacking, assembling and molding of wing tip parts, and solves the problem of large amount of resin flowing out of FRP raw materials during the stacking process and being difficult to clean up. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the supporting packaging system; (a) is the main view and (b) is the top view.

[0016] Figure 2 Schematic diagram of the positioning molding system.

[0017] Figure 3 This is a schematic diagram of the drilling template structure.

[0018] Figure 4 Schematic diagram of the demoulding system; (a) is the main view and (b) is the top view.

[0019] Figure 5 This is a schematic diagram of the tooling assembly.

[0020] Among them: 1 base; 2 sealing box; 3 air guide joint; 4 connecting plate; 5 clamping plate; 6 forming core mold; 7 support plate; 8 unloading plate; 9 spiral ejector rod; 10 ejector seat; 11 drilling jig seat; 12 positioning pin; 13 drilling jig. DETAILED DESCRIPTION

[0021] The specific implementation of the present invention is further explained below in conjunction with the examples and drawings, but is not intended to limit the present invention.

[0022] A composite mixed material wing tip skin forming tool comprises a supporting packaging system, a positioning forming system and a demoulding system.

[0023] The support packaging system is used to support the positioning molding system, and complete the parts packaging and resin cleaning on the support packaging system; it includes a base 1, a sealing box 2 and an air guide joint 3. Among them, the base 1 is the positioning reference of the tooling. It is a table structure formed by welding square steel pipes, metal angles and metal flat plates according to the outline of the parts. The square steel pipe is located at the bottom for forklift-specific tooling, and the metal angle is located in the middle welding position. There is a metal flat plate above and below the base 1, and the upper metal flat plate is provided with multiple circular holes for collecting resin. The sealing box 2 is welded to the inner side of the upper metal flat plate of the base 1 to ensure that the sealing box 2 is firmly welded to the metal flat plate and is required to be leak-proof under high temperature. A circular tube is led out from one end of the sealing box 2, and the circular tube is connected to the air guide joint 3. The vacuum pump can be directly connected to the air guide joint 3 to complete the vacuuming.

[0024] The positioning and molding system is used to complete the positioning of foam and metal sheets, the stacking of glass fiber reinforced plastic prepreg, the bonding of the three materials, and the drilling of subsequent parts; it includes a connecting plate 4, a clamping plate 5, a molding core mold 6, a support plate 7, a drilling jig seat 11, a positioning pin 12 and a drilling jig 13. Among them, the connecting plate 4 is connected to the middle position of the circular hole on the metal plate above the base 1, and a semicircular notch is left at the corresponding position of the connecting plate 4 according to the circular hole. Each clamping plate 5 is connected by two L-shaped angle bars, which clamp the connecting plate 4 and are connected to the connecting plate and the molding core mold 6 at the same time, so that the molding core mold 6 is placed in the center of the tooling.

[0025] The material of the forming core mold 6 is ordinary steel, and its profile is the same as the inner profile of the wing tip part; a foam positioning groove is provided on the profile of the forming core mold 6 at the position corresponding to the foam; and multiple grooves are provided on both sides of the forming core mold 6 outside the height margin for positioning the support plate 7. The support plate 7 is a rectangular plate, which is placed in the groove of the forming core mold 6 and is fixed in position with a flat head screw to position the metal sheet.

[0026] The jig seat 11 is arranged below the part hole and is connected to the base 1 by screws and pins. The positioning hole on the jig seat 11 is connected to a cylinder, and the upper end of the cylinder is connected to the jig 13; a circular hole is provided at the connection between the two. When the jig 13 reaches the specified position, the jig 13 is fixed by the positioning pin 12, and drilling is performed at this time. The positioning pin 12 is a rectangular block with a triangular drilling block on it, and the drilling block is provided with a jig hole and a drill sleeve.

[0027] The demoulding system includes a stripper plate 8, a spiral ejector rod 9 and an ejector seat 10. The stripper plate 8 is located at the margin of the forming core mold 6, and a corresponding notch is provided in the middle of the stripper plate 8 according to the outer profile of the forming core mold 6, and the notch is 0.5 mm larger than the outer profile of the forming core mold 6; threaded holes are evenly distributed around the stripper plate 8. The spiral ejector rod 9 is formed by connecting a spiral rod and a threaded rod, and is installed in the threaded hole of the stripper plate 8 through the threaded rod. The ejector seat 10 is a cylindrical block, which is installed at the lower end of the threaded rod of the spiral ejector rod 9.

[0028] The specific implementation steps of the above-mentioned composite hybrid material wing tip skin forming tooling are as follows:

[0029] 1) Install the support plate 7 on the groove of the forming core mold 6, with the support plate 7 protruding 2mm relative to the forming core mold 6; after all the support plates 7 are installed, place the metal sheet on the protruding part of the support plate 7, and the metal sheets on both sides are positioned. Insert the T-shaped foam in the length direction into the foam positioning groove on the forming core mold 6 to position the foam.

[0030] 2) Position the forming core mold 6, the metal sheet and the foam, and start laying the fiberglass prepreg on the outside. When all the fiberglass skins are laid, they are packaged on the metal flat plate above the base 1. During the packaging process, it is not necessary to reserve a vacuum nozzle and an air guide groove. After the packaging is completed, the vacuum pump can be directly connected to the air guide joint 3 to achieve the vacuum effect.

[0031] 3) Put the tooling and parts into the tank for curing and keep the vacuum pumped throughout the process. During the curing process, as the temperature rises, the fluidity of the resin increases, and a lot of resin will be retained from top to bottom on the metal plate of the base 1 under the action of gravity. At this time, the vacuum suction will be transmitted to various positions in the vacuum belt through the round holes reserved on the metal plate of the base 1, and the outflowing resin will also flow into the sealed box 2 through the round holes on the metal plate of the base 1 with the suction.

[0032] 4) After curing, no excess resin will remain on the metal plate of the base 1, and all the resin that flows out will be collected in the sealed box 2, so that the tooling can be used again without cleaning the resin residue on the surface. Install the jig seat 11 on the base 1, connect the jig 13 to the jig seat 11 through the cylinder, use the positioning pin 12 to position the jig 13, and then drill. After drilling, remove the jig seat 11, the positioning pin 12 and the jig 13.

[0033] 5) Synchronously rotate the spiral ejector rod 9 to make it press against the ejector seat 10 and drive the stripper plate 8 to move upward. When the stripper plate 8 contacts the lower end of the wing tip part, it is necessary to rotate the spiral ejector rod 9 one by one. When the part at the ejection point shows signs of loosening, stop rotating, and then operate each spiral ejector rod 9 again in this way. At this time, the part is loose, and the spiral ejector rod 9 is synchronously rotated again to drive the stripper plate 8 and the part to move upward, and then the part is ejected.

[0034] The combination of some components of this tooling structure solves the problems of stacking, assembling, forming, demoulding and cleaning tooling for composite wingtip parts composed of multiple materials, and realizes the manufacture of wingtip parts with complex structures.

Claims

1. A composite mixed material wing tip skin forming tool, characterized in that: The tooling includes a supporting packaging system, a positioning molding system, and a demoulding system; The support packaging system comprises a base (1), a sealing box (2) and an air guide joint (3); wherein the base (1) is a positioning reference for the tooling, and is a table structure formed by welding square steel tubes, metal angle bars and metal flat plates according to the outer contour of the parts, the square steel tubes are located at the bottom for use in forklift-specific tooling, the metal angle bars are located at the middle welding position, the base (1) has a metal flat plate on the top and bottom, and the upper metal flat plate is provided with a plurality of circular holes for collecting resin; the sealing box (2) is welded to the inner side of the upper metal flat plate of the base (1); a circular tube is led out from one end of the sealing box (2), the circular tube is connected to the air guide joint (3), and the air guide joint (3) is connected to a vacuum pump to complete vacuuming; The positioning and forming system comprises a connecting plate (4), a clamping plate (5), a forming core mold (6), a supporting plate (7), a drilling jig seat (11), a positioning pin (12) and a drilling jig (13); wherein the connecting plate (4) is connected to the middle position of the circular hole on the metal plate above the base (1), and a semicircular notch is left at the corresponding position of the connecting plate (4) according to the circular hole; each clamping plate (5) is formed by connecting two L-shaped angle bars, the two L-shaped angle bars clamp the connecting plate (4) and are connected to the connecting plate (4) and the forming core mold (6) at the same time, so that the forming core mold (6) is placed at the center position of the tooling; The molding core mold (6) has a molding surface that is identical to the inner molding surface of the wing tip part; a foam positioning groove is provided on the molding core mold (6) at a position corresponding to the foam; a plurality of grooves are provided on both sides of the molding core mold (6) outside the height margin for positioning the support plate (7); the support plate (7) is a rectangular plate, which is placed in the groove of the molding core mold (6) and is fixed in position using a flat head screw, for positioning the metal sheet; The drilling jig seat (11) is arranged below the part hole and is connected to the base (1); the positioning hole on the drilling jig seat (11) is connected to a cylinder, and the upper end of the cylinder is connected to the drilling jig (13); a circular hole is provided at the connection portion between the two, and when the drilling jig (13) reaches a specified position, the position of the drilling jig (13) is fixed by a positioning pin (12), and drilling is then performed; The demoulding system comprises a stripper plate (8), a spiral ejector rod (9) and an ejector seat (10); wherein the stripper plate (8) is located at the margin of the forming core mold (6), and a corresponding notch is provided in the middle of the stripper plate (8) according to the outer surface of the forming core mold (6); threaded holes are evenly distributed around the stripper plate (8); the spiral ejector rod (9) is formed by connecting a spiral rod and a threaded rod, and is installed in the threaded hole of the stripper plate (8) through the threaded rod; the ejector seat (10) is a cylindrical block, which is installed at the lower end of the threaded rod of the spiral ejector rod (9).

2. A composite hybrid material wing tip skin forming tool according to claim 1, characterized in that: The positioning pin (12) is a rectangular block with a triangular drilling block on it, and the drilling block is provided with a drilling template hole and a drilling sleeve.

3. A composite hybrid material wing tip skin forming tool according to claim 1 or 2, characterized in that: The notch on the discharge plate (8) is 0.5 mm larger than the outer profile of the forming core mold (6).

4. A composite hybrid material wing tip skin forming tool according to claim 1 or 2, characterized in that: According to the length of the forming core mold (6), a plurality of clamping plates (5) and connecting plates (4) are distributed on the base (1) according to positioning requirements.

5. The composite hybrid material wing tip skin forming tool according to claim 3, characterized in that: According to the length of the forming core mold (6), a plurality of clamping plates (5) and connecting plates (4) are distributed on the base (1) according to positioning requirements.

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