Molding method for sharp-mouth-shaped front edge structure made of composite material

Abstract

A forming method of a composite material sharp-mouth-shaped front edge structure comprises the steps that firstly, a part is positioned through a forming device of the composite material sharp-mouth-shaped front edge structure, after the part is positioned, the part is subjected to vacuum packaging through an auxiliary material, and a prefabricated body is formed; clamping and pressing the prefabricated body through a clamp, a clamping strip and a vertical tool of the composite material sharp-mouth-shaped front edge structure forming device to form a sharp-mouth-shaped front edge structure prefabricated body; and finally, placing the sharp mouth type front edge structure prefabricated body in a curing oven, and curing according to the curing parameters of the glue film used by the front edge assembly. The clamping strip and the clamp are additionally arranged on the vertical tool for mechanical pressing, repeated use is achieved, energy consumption is greatly reduced, and the purpose of low-cost manufacturing is achieved; vertical tool forming can guarantee symmetry of skin shapes on the two sides of the front edge, tolerance can be evenly distributed on the two sides, and the aerodynamic shape precision of the front edge is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material manufacturing, and particularly relates to a forming method for a composite material pointed-edge leading edge structure. Background Art

[0002] With the rapid development of aviation technology, the application proportion of composite materials on aircraft is increasing, greatly improving the flight performance of the aircraft. To reduce aerodynamic drag, the leading edges of various wings and tails of the aircraft need to have a more pointed profile, so the application demand for leading edge structures with a pointed edge is increasing. As shown in the attached figure, the current forming method for this kind of leading edge structure is autoclave forming in a horizontal position, that is, from bottom to top are the left skin, pointed edge strip, and right skin, which are placed on the tooling and cured by heating and pressurizing in the autoclave. As shown in the attached figure, this forming method has the following deficiencies: Figure 1 Figure 2 As shown in the attached figure, this forming method has the following deficiencies: (1) Since it is horizontal forming, the dimensional tolerances of the left and right skins, edge strips, adhesive films, and tooling are all accumulated on one side of the leading edge, resulting in asymmetry on both sides of the leading edge shape and low dimensional accuracy; (2) Because the autoclave forming method is adopted, a high-pressure gas source needs to be prepared first, and the high-pressure gas source is released to the product during the curing period of the product to ensure that the left and right skins are pressed tightly against the edge strip. However, the gas source is disposable, and a high-pressure gas source needs to be prepared for each product, resulting in high energy consumption. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a forming method for a composite material pointed-edge leading edge structure to solve the problems in the above background art.

[0004] The technical problem to be solved by the present invention is achieved by the following technical solutions: A forming method for a composite material pointed-edge leading edge structure forms the pointed-edge leading edge structure by using a forming device for a composite material pointed-edge leading edge structure. The forming device for a composite material pointed-edge leading edge structure includes an edge strip, skins, a vertical tooling, a left stop block, a lower stop block, a right stop block, a left clip strip positioning block, a right clip strip positioning block, clip strips, clip strip connection blocks, and clips. The specific steps are as follows: (1) Part positioning Position the edge strip through the positioning holes on the vertical tooling. The positioning holes are arranged 5 - 10 mm outside the edge of the edge strip. Then cover the skins with adhesive films on both sides of the edge strip, and position the left, lower, and right sides of the skins on both sides of the leading edge through the left stop block, lower stop block, and right stop block respectively; (2) Assembly airtightness Use auxiliary materials to vacuum package the leading edge assembly positioned in step (1) to form a preform; (3) Clip strip fixing Connect each clamping strip through a clamping strip connection block, and then place the connected clamping strips on the left clamping strip positioning block and the right clamping strip positioning block in the film area of the vertical tooling. (4) Clamping Use clamps to clamp the clamping grooves provided on the clamping strips. The clamping grooves are arranged at intervals on the outer side of the clamping strips, and the clamps are evenly distributed from the middle to both sides to form a preform of the pointed-edge leading edge structure. (5) Curing Place the preform of the pointed-edge leading edge structure in a curing furnace and cure it according to the curing parameters of the film used for the leading edge assembly.

[0005] In the present invention, in step (1), the up-down directions of the left stop block, the lower stop block, and the right stop block are flush with the edge of the part. At the same time, there is a 5-mm gap between the left-right directions of the left stop block, the lower stop block, and the right stop block and the edge of the part respectively.

[0006] In the present invention, in step (1), after the left stop block, the lower stop block, and the right stop block are positioned, they are fixed by positioning pins.

[0007] In the present invention, in step (2), the auxiliary materials include a vacuum bag, a breather felt, and putty strips.

[0008] In the present invention, in step (3), the length of the clamping strip is less than 1 m.

[0009] In the present invention, in step (5), a spring is provided on the handle of the clamp. As the film softens, the clamp clamps tighter, which is beneficial to curing. Beneficial effects

[0010] 1) In the present invention, the one-time pressure application to the leading edge bonding area by a special high-pressure air source is changed to mechanical pressure application using additional clamping strips and clamps on the tooling, which can be reused, greatly reducing energy consumption and achieving the goal of low-cost manufacturing. 2) The vertical tooling forming adopted in the present invention can ensure the symmetry of the outer shapes of the skins on both sides of the leading edge, and the tolerances can be evenly distributed on both sides, ensuring the aerodynamic shape accuracy of the leading edge. Description of the drawings

[0011] Figure 1 It is a schematic diagram of the leading edge part structure.

[0012] Figure 2 It is a schematic diagram of the horizontal forming of the leading edge in the prior art.

[0013] Figure 3 It is a top view of the composite pointed-edge leading edge structure forming device in the preferred embodiment of the present invention.

[0014] Figure 4Front view of the forming device for the composite material pointed leading edge structure in the preferred embodiment of the present invention. Detailed implementation manners

[0015] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below with reference to specific illustrations.

[0016] A forming method for a composite material pointed leading edge structure uses a forming device for the composite material pointed leading edge structure to form the pointed leading edge structure. As Figure 3 、 4 shown, the forming device for the composite material pointed leading edge structure includes a stringer 1, a skin 2, a vertical tooling 3, a left stop block 4, a lower stop block 5, a right stop block 6, a left spline positioning block 7, a right spline positioning block 8, a spline 9, a spline connection block 10 and a clip 11. The specific steps are as follows: (1)Part positioning Position the stringer 1 through the positioning holes on the vertical tooling 3. The positioning holes are arranged 5 - 10 mm outside the edge of the stringer 1. Then, cover the skin 2 with the laid adhesive film on both sides of the stringer 1. Next, position the left, lower, and right sides of the skin 2 on the front edge on the left, lower, and right sides through the left stop block 4, the lower stop block 5, and the right stop block 6 respectively. The up and down directions of the left stop block 4, the lower stop block 5, and the right stop block 6 are flush with the part edge. At the same time, a 5 - mm gap is left between the left, lower, and right directions of the left stop block 4, the lower stop block 5, and the right stop block 6 and the part edge respectively. Finally, fix them with positioning pins on the left stop block 4, the lower stop block 5, and the right stop block 6; (2)Assembly airtightness Use auxiliary materials such as a vacuum bag, a breather felt, and a putty strip to perform vacuum packaging on the front edge assembly positioned in step (1) to form a preform; (3)Spline fixation Connect each spline 9 through the spline connection block 10. Then, place the connected splines 9 on the left spline positioning block 7 and the right spline positioning block 8 in the adhesive film area of the vertical tooling 3. The length of each spline 9 is less than 1 m; (4)Clamping Use the clip 11 to clamp the clamping groove arranged on the spline 9. A clamping groove is arranged on the outside of the spline 9 every 50 mm. Select to install a clip 11 every 1 - 2 clamping grooves. The clips 11 are evenly distributed from the middle to both sides to form a preform of the pointed leading edge structure; (5)Curing Place the preform of the pointed leading edge structure in a curing furnace and cure it according to the curing parameters of the adhesive film used for the front edge assembly. A spring is arranged on the handle of the clip 11. As the adhesive film softens, the clip 11 clamps tighter, which is beneficial to curing.

[0017] The specific embodiments described herein are merely illustrative of the present invention, and those skilled in the art to which the present invention pertains may make various modifications or supplements to the described specific embodiments or use similar means for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for forming a composite material pointed front edge structure, characterized in that: The composite material pointed leading edge structure forming device is used to form the pointed leading edge structure. The composite material pointed leading edge structure forming device includes a rim, a skin, a vertical tooling, a left block, a lower block, a right block, a left clamping strip positioning block, a right clamping strip positioning block, a clamping strip, a clamping strip connecting block and a clamp. The specific steps are as follows: (1) Parts positioning Position the edge strip through the positioning holes on the vertical tooling. The positioning holes are arranged 5 to 10 mm outside the edge of the edge strip. Then, the skin covered with adhesive film is covered on both sides of the edge strip. Then, the left side, bottom side, and right side of the skin on both sides of the leading edge are positioned through the left stopper, bottom stopper, and right stopper respectively. (2) Airtight assembly Using auxiliary materials to vacuum pack the leading edge component positioned in step (1) to form a preform; (3) Fixing with clamp strips Connect each clamping strip through the clamping strip connecting block, and then place the connected clamping strip on the left clamping strip positioning block and the right clamping strip positioning block of the vertical tooling with the film area; (4) Clamping A clamp is used to clamp the clamping grooves arranged on the clamping strip, and the clamping grooves are arranged at intervals on the outside of the clamping strip, and the clamps are evenly distributed from the middle to both sides to form a pointed front edge structure preform; (5) Curing The pointed leading edge structure preform is placed in a curing furnace and cured according to the curing parameters of the adhesive film used for the leading edge component.

2. A composite material pointed front edge structure forming method according to claim 1, characterized in that: In step (1), the left stopper, the lower stopper, and the right stopper are flush with the edge of the part in the vertical direction, and a 5 mm gap is left between the left stopper, the lower stopper, and the right stopper and the edge of the part in the left and right directions.

3. The method for forming a composite material pointed leading edge structure according to claim 1, characterized in that: In step (1), after the left stopper, the lower stopper, and the right stopper are positioned, they are fixed with positioning pins.

4. The method for forming a composite material pointed leading edge structure according to claim 1, characterized in that: In step (2), the auxiliary materials include vacuum bags, air felt, and putty strips.

5. The method for forming a composite material pointed leading edge structure according to claim 1, characterized in that: In step (3), the length of the clamping strip is less than 1 m.

6. The method for forming a composite material pointed leading edge structure according to claim 1, characterized in that: In step (5), a spring is provided on the clamp handle.

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