An automated wire-laying forming fixture and forming method for rib structures

Abstract

This invention discloses an automated fiber placement molding fixture and method for reinforcing rib structures, belonging to the field of composite material molding. The molding fixture includes a T-groove mold, a rubber strip, a rubber strip baffle, and a curing baffle. The molding method involves using an automated fiber placement machine to place prepreg onto the rubber strip baffle. After placement, the curing baffle is fixed to the opening of the T-groove. The automated fiber placement molding fixture is heated; when the rubber strip expands due to heat and pushes the rubber strip baffle towards the opening, the prepreg is compressed under the combined action of the rubber strip and the curing baffle, thus completing the curing process. This invention effectively avoids the problem of difficult curing when using automated fiber placement for reinforcing rib structures, effectively increases the upper limit of the placement pressure that can be used during placement, avoids damage to the rubber strip due to excessive placement pressure, and improves the molding quality of the reinforcing rib structure.

Description

Technical Field

[0001] This invention belongs to the field of composite material molding, specifically relating to an automatic wire-laying molding tool and molding method for rib structures. Background Technology

[0002] Fiber-reinforced composites are high-performance composite materials composed of reinforcing fibers and a resin matrix. They possess numerous advantages, including high specific strength, high specific modulus, good fatigue resistance and corrosion resistance, and high designability. Automated Fiber Placement (AFP) is a highly automated digital manufacturing technology for composite materials, developed based on Automated Filament Winding (AFW) and Automated Tap Laying (FTL). It not only combines the strong adaptability to complex surfaces of traditional hand lay-up molding composite manufacturing technology with the high reliability, high molding efficiency, and high molding precision of digital manufacturing technology, but also effectively avoids the shortcomings of both, improving the consistency of large-scale composite material production and ensuring a high yield rate. The molding process, as the final step in product manufacturing, is crucial for ensuring product molding quality.

[0003] Automated fiber placement molding of composite materials has been widely used in the aerospace field, especially in the application of skin-reinforced structures. In existing automated fiber placement processes, the placement of stiffeners is generally achieved using autoclaves or rubber molds for curing. However, both methods have significant drawbacks: autoclave curing is only suitable for structures with relatively low stiffener heights and is ineffective for structures with high stiffeners; rubber mold molding cannot apply sufficient pressure during automated placement, resulting in loose fibers and affecting the final molding quality. Therefore, improving the automated fiber placement molding process for stiffener structures is of great significance for increasing the efficiency and quality of stiffener molding. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic wire-layout forming fixture and forming method for rib structures, used to produce rib structure components made of composite materials. This invention can effectively avoid the problem of difficult curing when using automatic wire-layout process for rib structures, effectively increase the upper limit of the laying pressure that can be used when laying rib structures, avoid damage to rubber strips due to excessive laying pressure, and improve the forming quality of rib structures.

[0005] The technical solution adopted by the present invention to achieve its objective is as follows:

[0006] An automated filament-laying tooling for rib structures includes a T-slot mold, a rubber strip, a rubber strip baffle, and a curing baffle. The T-slot mold contains a T-slot, which consists of a wide slot, a narrow slot, and a step between the two. The rubber strip is placed in the narrow slot of the T-slot, and the rubber strip baffle is placed at the step of the T-slot. The wide slot area on the rubber strip baffle is used to lay prepreg. The curing baffle is detachably fixed to the opening of the T-slot.

[0007] Furthermore, the wide slot of the T-slot has a draft angle.

[0008] Furthermore, the shape and size of the rubber strip are adapted to the shape and size of the narrow groove of the T-slot.

[0009] Furthermore, the width of the rubber strip baffle is the same as the bottom width of the wide groove of the T-slot.

[0010] Furthermore, the curing baffle is provided with longitudinal and transverse guide channels.

[0011] Furthermore, the longitudinal guide channel of the curing baffle has a T-shaped cross-section, and the transverse guide channel of the curing baffle has a rectangular cross-section, with the longitudinal guide channel and the transverse guide channel interconnected.

[0012] An automated wire-laying method for rib structures, based on the aforementioned automated wire-laying fixture for rib structures, includes the following steps:

[0013] Place the rubber strip in the narrow groove of the T-slot;

[0014] Place the rubber strip baffle at the step of the T-slot;

[0015] The prepreg is laid on the rubber strip baffle using an automatic filament laying machine. After laying, the curing baffle is fixed to the opening of the T-slot.

[0016] The automatic wire laying forming tooling for the rib structure is heated. When the rubber strip expands due to heat and pushes the rubber strip baffle towards the groove, the prepreg is compressed under the combined action of the rubber strip and the curing baffle, thus completing the curing process.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] 1) This invention uses rubber mold thermal expansion molding, which allows for greater pressure when the fiber laying machine lays the reinforcing strips, avoiding fiber wrinkles and improving the quality of reinforcing strip forming.

[0019] 2) The rubber strip baffle makes the prepreg more evenly compressed during curing.

[0020] 3) Excess resin can flow out through the guide channel to avoid the formation of resin-rich areas. Attached Figure Description

[0021] Figure 1 This is a 3D diagram of an automated wire-laying forming tool for a ribbed structure.

[0022] Figure 2 This is a top view of the T-slot mold.

[0023] Figure 3 This is a top sectional view of an automated wire-laying forming tool for a ribbed structure.

[0024] Figure 4 This is a structural diagram of the curing baffle.

[0025] Figure 5 This is a side sectional view of an automated wire-laying forming tool for a ribbed structure.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1: T-slot mold;

[0028] 2: Wide slot;

[0029] 3: Narrow groove;

[0030] 4: Steps;

[0031] 5: Rubber strip;

[0032] 6: Rubber strip baffle

[0033] 7: Solidification baffle;

[0034] 8: Longitudinal guide channel;

[0035] 9: Horizontal guide channel. Detailed Implementation

[0036] To make the various technical features, advantages, or effects of the present invention more apparent and understandable, a detailed description is provided below in conjunction with the accompanying drawings.

[0037] This embodiment discloses an automatic wire-laying forming tool for rib structures, such as... Figure 1 As shown, it includes a T-slot mold 1, a rubber strip 5, a rubber strip baffle 6, and a curing baffle 7.

[0038] The structure of T-slot mold 1 is as follows: Figure 2 As shown, it includes a T-shaped groove, divided into a wide groove 2 in the upper part and a narrow groove 3 in the lower part, with a step 4 at the junction of the upper and lower parts. The wide groove 2 has a draft angle to facilitate the outflow of excess resin during curing and smooth demolding after curing.

[0039] like Figure 3As shown, rubber strip 5 is placed in the narrow slot 3 of the T-slot, rubber strip baffle 6 is placed at the step 4, and prepreg is laid on top of rubber strip baffle 6. After laying, curing baffle 7 is fixed to the top opening of the wide slot 2 of the T-slot. The shape and size of rubber strip 5 are adapted to the shape and size of the narrow slot 3 of the T-slot. To facilitate installation and ensure that the rubber strip just contacts the rubber strip baffle 6 under maximum expansion force, rubber strip 5 should be slightly lower than the narrow slot 3 of the T-slot. Furthermore, to ensure molding quality, rubber strip 5 should be a single piece and not segmented. The width of rubber strip baffle 6 is the same as the bottom width of the wide slot 2 of the T-slot, allowing it to be placed at the step 4 of the T-slot. During laying by the filament layer, it can resist greater laying pressure, and during curing, it can move freely upwards to transfer the pressure of rubber strip 5 to the prepreg.

[0040] The structure of the curing baffle 7 is as follows Figure 4 As shown, a longitudinal guide channel 8 and a transverse guide channel 9 are provided. The longitudinal guide channel 8 has a T-shaped cross-section, which ensures the molding accuracy of the ribs while allowing excess resin to flow out smoothly. The transverse guide channel 9 of the curing baffle has a rectangular cross-section and is interconnected with the longitudinal guide channel 8, ensuring that the resin in the longitudinal guide channel 8 can flow out smoothly through the transverse guide channel 9. Figure 5 The positional relationship of the main structure of the automatic wire laying forming tool for the rib structure is shown. It can be seen that the longitudinal guide groove 8 is perpendicular to the length direction of the rubber strip baffle 6, and it can also be seen that it is perpendicular to the length direction of the T-shaped groove.

[0041] This embodiment also discloses an automatic wire laying forming method for rib structures, which is implemented based on the above-mentioned automatic wire laying forming tooling for rib structures, and includes the following steps:

[0042] 1) Place the rubber strip 5 into the narrow groove 3 of the T-groove.

[0043] 2) Place the rubber strip baffle 6 at the step 4 of the T-slot.

[0044] 3) The prepreg is laid on the rubber strip baffle 6 using an automatic fiber placement machine. After laying, the curing baffle 7 is fixed to the opening of the T-slot. When the automatic fiber placement machine lays the prepreg under high pressure, the pressure cannot be transmitted to the rubber strip 5 due to the presence of the step 4 and the rubber strip baffle 6, thus avoiding damage to the rubber strip 5 and wrinkling of the prepreg fibers.

[0045] 4) When the rubber strip 5 is laid out and placed in the oven for curing, it expands due to heat. Since the rubber strip 5 is molded on three sides, it can only expand upwards. At this time, the rubber strip baffle 6 moves upwards under the pressure from the rubber strip 5. The prepreg is subjected to pressure from the lower rubber strip baffle 6 and the upper curing baffle 7, thus completing the curing process. During the curing process, excess resin flows out along the draft angle of the wide groove 2 of the T-slot and the longitudinal guide groove 8 and transverse guide groove 9 on the curing baffle 7, avoiding resin accumulation.

[0046] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should be covered within the protection scope of the present invention, which is defined by the claims.

Claims

1. An automatic wire-laying forming tool for rib structures, characterized in that, The device includes a T-slot mold, a rubber strip, a rubber strip baffle, and a curing baffle. The T-slot mold contains a T-slot, which consists of a wide slot, a narrow slot, and a step between them. The rubber strip is placed in the narrow slot of the T-slot, and the rubber strip baffle is placed at the step of the T-slot. The wide slot area on the rubber strip baffle is used to lay the prepreg. The curing baffle is detachably fixed to the opening of the T-slot and has longitudinal and transverse guide channels that are interconnected.

2. The automatic wire laying and forming tooling for rib structures as described in claim 1, characterized in that, The wide slot of the T-slot has a draft angle.

3. The automatic wire laying and forming tooling for rib structures as described in claim 1, characterized in that, The shape and size of the rubber strip are adapted to the shape and size of the narrow groove of the T-slot.

4. The automatic wire laying and forming tooling for rib structures as described in claim 1, characterized in that, The width of the rubber strip baffle is the same as the bottom width of the wide groove of the T-slot.

5. The automatic wire laying and forming tooling for rib structures as described in claim 1, characterized in that, The longitudinal guide channel of the curing baffle has a T-shaped cross section.

6. The automatic wire laying and forming tooling for rib structures as described in claim 1, characterized in that, The cross-section of the transverse guide channel of the curing baffle is rectangular.

7. An automated wire-laying method for rib structures, implemented using the automated wire-laying tooling for rib structures as described in any one of claims 1-6, comprising the following steps: Place the rubber strip inside the narrow groove of the T-slot; Place the rubber strip baffle at the step of the T-slot; The prepreg is laid on the rubber strip baffle using an automatic filament laying machine. After laying, the curing baffle is fixed to the opening of the T-slot. The automatic wire laying forming tooling for the rib structure is heated. When the rubber strip expands due to heat and pushes the rubber strip baffle towards the groove, the prepreg is compressed under the combined action of the rubber strip and the curing baffle, thus completing the curing process.

Images