Vacuum bag press forming tool

Abstract

The utility model discloses a vacuum bag press forming tool which comprises a mold and a vacuum bag film, the vacuum bag film is arranged on the mold, stripping cloth, a demolding film, a flexible gasket, a rigid pressing strip and a breathable felt are sequentially arranged in the direction from the mold to the vacuum bag film, and the edge of the vacuum bag film is connected with the mold in a sealed mode through a sealing strip. By introducing the rigid pressing strip and the flexible gasket, it is guaranteed that the non-mold contact face of the product is evenly stressed, and the surface flatness of the product is improved.

Description

Technical Field

[0001] The utility model relates to the field of composite material preparation equipment, in particular to a vacuum bag pressing forming tooling. Background Art

[0002] The vacuum bag pressing forming process is a liquid molding technology that uses a closed preforming cavity composed of a single-sided rigid preforming die and a vacuum bag made of an elastic soft film, fills the preforming cavity with prepreg formed by impregnating a fiber cloth with resin, then evacuates the preforming cavity, and uses negative pressure suction to make the resin adsorbed in the prepreg better combine with the fiber cloth, and realizes the impregnation of the resin on the fabric through vacuum suction.

[0003] As an emerging forming technology, this technology is widely used in the manufacturing of various structural parts in the aerospace field. Firstly, this technology does not require the use of an autoclave; secondly, a single-sided rigid die (the upper die is a flexible vacuum bag film) is used to lay fiber reinforced materials, and the die only ensures the requirements of the structural surface, simplifying the die manufacturing process; in addition, it is only formed under vacuum pressure and does not require additional pressure equipment. Therefore, this method has the characteristics of low cost, low porosity of the finished product, performance close to the autoclave process, and suitability for manufacturing large parts, and has broad application prospects.

[0004] However, in the actual use process, due to the use of a single-sided die design, only one side of the product can be guaranteed to be smooth, and it is difficult to guarantee the surface quality of the non-die contact surface. Since it is impossible to ensure the uniform surface force of the product on the non-die contact surface during the vacuum pumping process, the non-die contact surface of the product is wrinkled. In view of the above problems, this application proposes a solution. Summary of the Invention

[0005] Purpose of the utility model: The purpose of the utility model is to provide a vacuum bag pressing forming tooling, which can ensure the uniform force on the non-die contact surface of the product during the vacuum pumping process and improve the surface flatness of the product.

[0006] Technical solution: A vacuum bag pressing forming tooling described in the utility model includes a die and a vacuum bag film. The vacuum bag film is arranged on the die, and a release cloth, a release film, a flexible gasket, a rigid pressing strip and a breather felt are sequentially arranged in the direction from the die towards the vacuum bag film. The edge of the vacuum bag film is hermetically connected with the die through a sealing strip.

[0007] Preferably, a release agent layer is arranged on the end surface of the die on the side facing the release cloth.

[0008] The arrangement of the release agent layer ensures that the contact surface between the product and the die is flat and smooth, facilitating the detachment of the product from the die.

[0009] Preferably, a prepreg layer is provided on the end face of the stripping cloth facing the release film side.

[0010] Preferably, the shape of the prepreg layer is the same as that of the flexible gasket and the rigid pressing strip.

[0011] Ensure that the flexible gasket and the rigid pressing strip can completely cover the non-mold contact surface of the product.

[0012] Preferably, a vacuum pump for evacuating and a vacuum gauge for detecting the pressure value are provided on the vacuum bag film.

[0013] Preferably, the connection points of the vacuum pump and the vacuum gauge to the vacuum bag film are arranged on the flat outer surface of the vacuum bag film after evacuation.

[0014] Prevent the connection points during evacuation from being located at the folding part of the vacuum bag film and the rigid pressing strip, resulting in an inability to smoothly complete the evacuation.

[0015] Beneficial effects: Compared with the prior art, the present utility model has the following advantages:

[0016] By introducing the rigid pressing strip and the flexible gasket, the present application ensures uniform stress on the non-mold contact surface of the product and improves the surface flatness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a side cross-sectional view of the present utility model.

[0018] Wherein: 1, mold; 2, stripping cloth; 3, prepreg layer; 4, release film; 5, flexible gasket; 6, rigid pressing strip; 7, breather felt; 8, vacuum bag film; 9, vacuum pump; 10, vacuum gauge; 11, sealing strip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The technical solution of the present utility model will be further described below with reference to the drawings.

[0020] Referring to the attached Figure 1 , the vacuum bag molding tooling shown in the present utility model includes a mold 1 and a vacuum bag film 8. The vacuum bag film 8 is arranged on the mold 1. In the direction from the mold 1 towards the vacuum bag film 8, there are successively arranged a stripping cloth 2, a release film 4, a flexible gasket 5, a rigid pressing strip 6, and a breather felt 7. The edge of the vacuum bag film 8 is hermetically connected to the mold 1 through a sealing strip 11.

[0021] In this embodiment, a release agent layer is provided on the end face of the mold 1 facing the stripping cloth 2. The setting of the release agent layer ensures that the contact surface between the product and the mold 1 is flat and smooth, facilitating the separation of the product from the mold 1.

[0022] In this embodiment, a prepreg layer 3 is provided on the end face of the stripping cloth 2 facing the demolding film 4.

[0023] In this embodiment, the outer shape of the prepreg layer 3 is the same as that of the flexible gasket 5 and the rigid pressing strip 6, ensuring that the flexible gasket 5 and the rigid pressing strip 6 can completely cover the non-mold contact surface of the product.

[0024] In this embodiment, a vacuum pump 9 for evacuating and a vacuum gauge 10 for detecting the pressure value are provided on the vacuum bag film 8. The positions where the vacuum pump 9 and the vacuum gauge 10 are connected to the vacuum bag film 7 are set on the flat outer surface of the vacuum bag film 8 after evacuation, preventing the connection positions from being located at the folding part of the vacuum bag film 8 and the rigid pressing strip 6 during the evacuation process, resulting in the inability to smoothly complete the evacuation.

[0025] During the actual use of this application, in the production of the 4 / 5th bulkhead of the middle fuselage of the traditional Seastar aircraft, a "C-shaped" defect of middle depression and protrusion at both sides edges will occur. This is because during the evacuation process, absolute vacuum cannot be achieved, and there are voids at complex structures, resulting in uneven stress on the surface of the prepreg. After adopting the tooling of this application, through the design of introducing the rigid pressing strip 6 and the flexible gasket 5, the stress on the surface of the prepreg layer 4 is made uniform, and the final product meets the surface flatness requirement.

Claims

1. A vacuum bag forming tool, characterized in that: It includes a mold and a vacuum bag film, which is arranged on the mold. A peeling cloth, a demoulding film, a flexible gasket, a rigid pressure strip and a breathable felt are arranged in sequence from the mold to the vacuum bag film. The edge of the vacuum bag film is sealed and connected to the mold through a sealing strip.

2. A vacuum bagging tooling according to claim 1, characterized in that: A release agent layer is provided on the end surface of the mold facing the release cloth.

3. A vacuum bagging tooling according to claim 1, characterized in that: A prepreg layer is provided on the end surface of the release cloth facing the release film.

4. A vacuum bagging tooling according to claim 3, characterized in that: The shape of the prepreg layer is consistent with the shapes of the flexible gasket and the rigid molding.

5. The vacuum bagging tooling according to claim 1, characterized in that: The vacuum bag film is provided with a vacuum pump for evacuating vacuum and a vacuum gauge for detecting the pressure value.

6. A vacuum bagging tooling according to claim 5, characterized in that: The points where the vacuum pump and the vacuum gauge are connected to the vacuum bag film are arranged on the flat outer surface of the vacuum bag film after being evacuated.

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