A forming method of a special-shaped cavity part based on a memory air bag core mold

Abstract

The application discloses a forming method of a special-shaped cavity part based on a memory air bag core mold, and comprises the following steps: step S1, tool preparation; S2, laying memory air bag sheets (31, 32) on the outer surface of a memory air bag forming mold, bag making, tank feeding, curing and demolding; S3, laying a layer of polytetrafluoroethylene adhesive tape on the outer surface of a deformable memory air bag core mold (3); S4, laying prepreg on the outer surface of the memory air bag core mold, and then placing the memory air bag core mold on a composite S-shaped air inlet pipeline forming mold, bag making, tank feeding, curing and demolding; the deformable memory air bag core mold is substantially rectangular in section, and the memory air bag sheets at least comprise first and second memory air bag sheets, and the width of the memory air bag sheets gradually decreases from the middle to the corners of the rectangle in the long side direction of the rectangle. The application can improve the thickness of the S-shaped air inlet pipeline, the uniformity of stress distribution and the performance of the S-shaped air inlet pipeline.

Description

Technical Field

[0001] This invention relates to the technical field of molding methods for irregularly shaped hollow parts, and specifically to a molding method for irregularly shaped hollow parts based on a memory airbag core mold. Background Technology

[0002] The domestic aerospace industry is developing rapidly, and the manufacturing level and performance of composite materials used are gradually improving. The application rate of composite materials in aircraft is constantly increasing, and more and more complex aircraft parts are beginning to be designed and manufactured using composite materials. The S-shaped air intake is one such example. These composite material parts are difficult to manufacture and have complex tooling designs.

[0003] Existing technologies have been used to study the molding process of irregularly shaped cavity parts. Deformable memory materials are used to replace traditional metal core molds. Deformable memory materials are hard at room temperature and can be directly laid on top. After the product is cured, it will soften when heated to a certain temperature and can be directly removed from the inner cavity. This simplifies tooling design, reduces manufacturing difficulty, and improves the production efficiency of such products.

[0004] For example, prior art CN110774610A discloses a multi-channel composite material shaped tube and its molding method, wherein a prototype of a multi-channel shaped tube mandrel with shape memory properties is obtained by using shape memory polymer material through 3D printing technology. CN109910208A discloses a mandrel and its preparation method and a composite material shaped tube molding method, wherein the mandrel is made of shape memory material and a resin-based composite material prepreg is pasted on the mandrel. CN110154287A discloses a bidirectional shape memory mandrel and a method for using the bidirectional shape memory mandrel.

[0005] However, the shape memory core molds in the existing technology have different degrees of deformation and compressive stress during the curing stage, which leads to uneven thickness and stress distribution of irregular cavity parts, affecting the performance of irregular cavity parts, and cannot be well applied to the convenient and low-cost production of S-shaped air intake pipes. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a molding method for irregular cavity parts based on memory airbag core mold. By improving the design of the width and thickness of the memory airbag sheet, it can effectively improve the influence of the deformable memory airbag core mold on the deformation degree and extrusion stress of the S-shaped air intake pipe (composite product) during the curing stage. This can improve the thickness and stress distribution uniformity of the S-shaped air intake pipe, ensure the performance of the S-shaped air intake pipe, and is well applicable to the convenient and low-cost production and manufacturing of S-shaped air intake pipes.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for molding irregularly shaped cavity parts based on a memory airbag core mold, comprising the following steps:

[0009] Step S1: Tooling preparation: Clean the memory airbag molding mold and the composite S-shaped air intake pipe molding mold (1). Apply release agent to the molding surface of the molding mold as required. The memory airbag molding mold is used to make the deformable memory airbag core mold (3). The composite S-shaped air intake pipe molding mold (1) is set on the outer surface of the S-shaped air intake pipe (2).

[0010] Step S2: Deformable memory airbag core mold (3) molding: Memory airbag sheets (31, 32) are laid on the outer surface of the memory airbag molding mold, and then vacuum bag making, hot press, curing and demolding are carried out in sequence;

[0011] Step S3: Apply a layer of polytetrafluoroethylene tape to the outer surface of the deformable memory airbag core mold (3) to facilitate demolding;

[0012] Step S4: S-shaped air inlet pipe (2) lay-up: lay prepreg on the outer surface of the deformable memory airbag core mold (3), and then place it on the composite S-shaped air inlet pipe forming mold (1). The deformable memory airbag core mold is set on the inner periphery of the composite S-shaped air inlet pipe forming mold. Then, vacuum bag making, autoclave entry, curing, and demolding are performed in sequence.

[0013] The feature is that, in step S2, the cross-section of the deformable memory airbag core mold (3) and the composite S-shaped air intake pipe (2) is roughly or generally rectangular, and the memory airbag sheet includes at least a first memory airbag sheet (31) and a second memory airbag sheet (32). In the long side direction of the rectangle, from the middle to the corner of the rectangle, the width of the first memory airbag sheet (31) is greater than the width of the second memory airbag sheet (32), or the width of the memory airbag sheet gradually decreases.

[0014] Furthermore, along the shorter side of the rectangle, the width of the memory airbag sheet gradually decreases from the middle to the corner of the rectangle.

[0015] Furthermore, the thickness of the memory airbag sheet located along the long and short sides of the rectangle is greater than the thickness of the memory airbag sheet located at the corners of the rectangle.

[0016] Furthermore, along the airflow direction of the S-shaped intake pipe (2), the thickness of the memory airbag sheet in the flat part of the S-shaped intake pipe (2) is greater than the thickness of the memory airbag sheet in the curved part of the S-shaped intake pipe.

[0017] Compared to existing deformable memory material core molds, the present invention provides a molding method for irregular cavity parts based on a memory airbag core mold. Through improved design of the width and thickness of the memory airbag sheet, it can effectively reduce the impact of the deformable memory airbag core mold on the deformation degree and extrusion stress of the S-shaped air intake pipe (composite product) during the curing stage. This improves the thickness and stress distribution uniformity of the S-shaped air intake pipe, ensures the performance of the S-shaped air intake pipe, and is well-suited for convenient and low-cost production of S-shaped air intake pipes. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the memory airbag core mold structure of the present invention.

[0019] In the figure: composite product molding mold 1, composite product 2 (S-shaped air inlet pipe), deformable memory airbag core mold 3, first memory airbag sheet 31, and second memory airbag sheet 32. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings.

[0022] like Figure 1 As shown, a method for molding irregularly shaped cavity parts based on a memory airbag core mold includes the following steps:

[0023] Step S1: Tooling preparation: Clean the memory airbag molding mold and the composite S-shaped air intake pipe molding mold 1. Apply release agent to the molding surface of the molding mold as required. The memory airbag molding mold is used to make the deformable memory airbag core mold 3. The composite S-shaped air intake pipe molding mold 1 is set on the outer surface of the S-shaped air intake pipe 2.

[0024] Step S2: Deformable memory airbag core mold 3 molding: Memory airbag sheets (31, 32) are laid on the outer surface of the memory airbag molding mold, and then vacuum bag making, autoclave injection, curing, and demolding are carried out in sequence;

[0025] Step S3: Apply a layer of polytetrafluoroethylene tape to the outer surface of the deformable memory airbag core mold 3 to facilitate demolding;

[0026] Step S4: Laying up the S-shaped air inlet pipe 2: Lay prepreg on the outer surface of the deformable memory airbag core mold 3, and then place it on the composite S-shaped air inlet pipe forming mold 1. The deformable memory airbag core mold 3 is set on the inner circumference of the composite S-shaped air inlet pipe forming mold 1. Then, vacuum bag making, autoclave entry, curing, and demolding are performed in sequence.

[0027] The feature is that, in step S2, the cross-section of the deformable memory airbag core mold 3 and the composite S-shaped air intake pipe 2 is roughly or generally rectangular, and the memory airbag sheets (31, 32) include a first memory airbag sheet 31 and a second memory airbag sheet 32. In the long side direction of the rectangle, from the middle to the corner of the rectangle, the width of the first memory airbag sheet 31 is greater than the width of the second memory airbag sheet 32, or the width of the memory airbag sheet gradually decreases.

[0028] Furthermore, along the shorter side of the rectangle, the width of the memory airbag sheet gradually decreases from the middle to the corner of the rectangle.

[0029] Furthermore, the thickness of the memory airbag sheet located along the long and short sides of the rectangle is greater than the thickness of the memory airbag sheet located at the corners of the rectangle.

[0030] Furthermore, along the airflow direction of the S-shaped intake duct 2, the thickness of the memory airbag sheet in the flat part of the S-shaped intake duct 2 is greater than the thickness of the memory airbag sheet in the curved part of the S-shaped intake duct 2.

[0031] Compared to existing deformable memory material core molds, the present invention provides a molding method for irregular cavity parts based on a memory airbag core mold. Through improved design of the width and thickness of the memory airbag sheet, it can effectively reduce the impact of the deformable memory airbag core mold 3 on the deformation degree and extrusion stress of the S-shaped air intake pipe 2 (composite product) during the curing stage. This can improve the thickness and stress distribution uniformity of the S-shaped air intake pipe 2, ensure the performance of the S-shaped air intake pipe 2, and is well-suited for convenient and low-cost production of the S-shaped air intake pipe 2.

[0032] The above embodiments are illustrative of the present invention and not intended to limit the invention. It is understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for molding irregularly shaped cavity parts based on a memory airbag core mold, comprising the following steps: Step S1: Tooling preparation: Clean the memory airbag molding mold and the S-shaped air intake pipe molding mold (1). Apply release agent to the molding surface of the molding mold as required. The memory airbag molding mold is used to make the deformable memory airbag core mold (3). The S-shaped air intake pipe molding mold (1) is set on the outer surface of the S-shaped air intake pipe (2). Step S2: Deformable memory airbag core molding: Memory airbag sheets (31, 32) are laid on the outer surface of the memory airbag molding mold, followed by vacuum bag making, autoclaving, curing, and demolding. Step S3: Apply a layer of polytetrafluoroethylene tape to the outer surface of the deformable memory airbag core mold to facilitate demolding; Step S4: S-shaped air intake pipe layering: lay prepreg on the outer surface of the deformable memory airbag core mold, and then place it on the S-shaped air intake pipe forming mold. The deformable memory airbag core mold is set on the inner periphery of the S-shaped air intake pipe forming mold. Then, vacuum bag making, autoclave entry, curing, and demolding are performed in sequence. The feature is that: in step S2, the cross-section of the deformable memory airbag core mold (3) and the composite S-shaped air inlet pipe (2) is rectangular, and the width of the memory airbag sheet gradually decreases from the middle to the corner of the rectangle along the long side of the rectangle. Along the shorter side of the rectangle, the width of the memory airbag sheet gradually decreases from the middle to the corner of the rectangle; The thickness of the memory airbag sheet located along the long and short sides of the rectangle is greater than the thickness of the memory airbag sheet located at the corners of the rectangle. Along the airflow direction of the S-shaped intake pipe (2), the thickness of the memory airbag sheet in the flat part of the S-shaped intake pipe is greater than the thickness of the memory airbag sheet in the curved part of the S-shaped intake pipe.

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