Honeycomb processing method for automatic fiber placement

Abstract

The invention discloses a honeycomb processing method for automatic fiber placement. The method comprises the following steps: S1, paving a circle of first structural adhesive film (4) on the edge of the outer surface of a honeycomb (3); s2, paving a circle of expansion adhesive film (2) on the whole corner cutting area of the honeycomb (3); s3, paving a second structural adhesive film (1) on the whole inner surface of the honeycomb (3); and S4, carrying out vacuum preforming on the honeycomb (3) paved with the adhesive film. The method has the advantages of being simple, high in universality and convenient to implement. The method has the advantages of being simple, high in universality and convenient to implement.

Description

Technical Field

[0001] The invention belongs to the technical field of honeycomb structure design, and in particular relates to a honeycomb processing method for automatic wire laying. Background Art

[0002] As a new type of low-cost and high-efficiency composite material automated manufacturing technology, automatic wire placement technology has outstanding advantages such as high forming accuracy, stable quality, and wide adaptability. It can realize the opening and reinforcement of the ply during laying, and improve production efficiency and material utilization. Automatic wire placement technology is one of the composite material automated forming and manufacturing technologies with the fastest development speed and best forming effect in recent years.

[0003] Currently, automatic wire placement technology is widely used in the manufacture of laminated structures, but is less used in the manufacture of composite honeycomb sandwich structures. In the aerospace field, composite honeycomb sandwich structures account for a high proportion of composite parts. Applying automatic wire placement technology to the manufacture of composite honeycomb sandwich structures will greatly improve the overall manufacturing efficiency and quality of composite parts.

[0004] The invention patent with publication number CN112644100A discloses a large curvature honeycomb sandwich composite material structure and its integrated forming method. The method uses an automatic wire laying method to lay down the lower panel, then uses a 3D printing method to print and form the honeycomb on the upper panel, and finally uses an automatic wire laying method to lay down the upper panel on the honeycomb. The method uses a 3D printing method to form a honeycomb to achieve integrated forming of a large curvature honeycomb sandwich structure, but does not explain how to solve the problems of honeycomb core cell crushing and poor laying effect that are easily encountered when laying fibers on the honeycomb.

[0005] The invention patent with publication number CN109177436A discloses an automatic wire laying forming method for honeycomb sandwich composite materials. This method makes a concave forming mold according to the shape of the composite material part, and adjusts the laying order of the honeycomb panels to avoid the automatic wire laying machine laying layers on the honeycomb cut corners, solving the problem of easy slippage of the honeycomb core at the honeycomb cut corners. However, this method cannot solve the problem of easy crushing of the honeycomb core.

[0006] The invention patent with publication number CN105269830A discloses a method for high-thickness, low-density honeycomb preforming. This method uses adhesive film and glass cloth prepreg to lay around the honeycomb, and combines with anti-skid tape to solve the problem of honeycomb slippage during honeycomb preforming. The prepreg and adhesive film used in this method during honeycomb preforming have been solidified, and when the honeycomb sandwich structure is formed, the solidified area is in a co-bonded connection form. The main purpose of the honeycomb preforming method is to prevent the honeycomb from slipping when the honeycomb sandwich structure is formed, and it cannot avoid the problem of easy crushing of the honeycomb core during automatic wire laying. Summary of the invention

[0007] The purpose of the present invention is to provide a honeycomb processing method for automatic wire laying, which has the characteristics of simple method, strong versatility and easy implementation.

[0008] The technical solution of the present invention is: a honeycomb processing method for automatic wire laying, comprising the following steps:

[0009] S1. Laying a first structural adhesive film around the outer edge of the honeycomb;

[0010] S2. Lay a circle of expansion film on the entire cut corner area of ​​the honeycomb;

[0011] S3. Laying a second structural adhesive film on the entire inner surface of the honeycomb;

[0012] S4. Vacuum preform the honeycomb with the adhesive film applied.

[0013] In the aforementioned honeycomb processing method for automatic wire laying, the laying width of the first structural adhesive film is 10 to 15 mm.

[0014] In the aforementioned honeycomb processing method for automatic wire laying, the first and second structural adhesive films are both high-temperature curing carrier adhesive films with a thickness of 0.25 mm.

[0015] In the aforementioned honeycomb processing method for automatic wire laying, the expanded film is a film that cures at medium temperature.

[0016] In the aforementioned honeycomb processing method for automatic wire laying, step S4 is specifically as follows: placing the honeycomb with the adhesive film laid in a preforming mold, evacuating the vacuum bag and putting it into the furnace for preforming.

[0017] In the aforementioned honeycomb processing method for automatic wire laying, during preforming, the expansion film is solidified, and the structural film is melted but not solidified.

[0018] In the aforementioned honeycomb processing method for automatic wire laying, the preforming temperature is 120°C ± 5°C.

[0019] In the aforementioned honeycomb processing method for automatic wire laying, the cut corner area of ​​the honeycomb is arranged at a right angle or an oblique angle relative to the outer surface of the honeycomb.

[0020] The advantages of the present invention are:

[0021] 1. The honeycomb processing method for automatic wire laying of the present invention has the advantages of simple method, strong versatility, and easy implementation. It can simultaneously solve the problems that when the automatic wire laying method is used to manufacture honeycomb sandwich structures, the honeycomb is easily crushed and the laying effect on the honeycomb surface is poor, and various faults are prone to occur. It is convenient for the use of automatic wire laying technology in the manufacture of honeycomb sandwich structures, and can improve product quality and production efficiency.

[0022] 2. The honeycomb preformed by the present invention has the following advantages over the traditional honeycomb: the adhesive film and the honeycomb core cell bear the load of the pressure roller of the laying head as a whole, which can avoid the collapse of the honeycomb core cell; the adhesive film increases the contact area of ​​the fiber bundle during laying, and the uncured adhesive film can be heated during laying to increase the viscosity, which is convenient for laying and pasting the fiber bundle; the expanded adhesive film in the cut corners around the honeycomb can achieve good bonding at the position where the vacuum bag is underpressurized, thereby improving the stiffness of the honeycomb edge and ensuring the automatic laying quality at the honeycomb boundary; the structural adhesive film is not cured during the preforming process and does not affect the mechanical properties of the structural component after forming.

[0023] 3. The structural adhesive film and expansion adhesive film used in honeycomb preforming are commonly used materials; the preforming process is similar to the medium-temperature curing composite material part process. This method is applicable to both right-angle honeycombs and bevel-angle honeycombs, has strong versatility and is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Illustration of the laying of adhesive film during right-angle honeycomb preforming.

[0025] Figure 2 This is an illustration of the laying of adhesive film during bevel-cut honeycomb preforming. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0028] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] Example 1. A honeycomb processing method for automatic wire laying, see Figure 1-Figure 2 , comprising the following steps:

[0030] S1. Complete the honeycomb cutting according to the model or unfold the template 3; Lay a circle around the edge of the outer surface of the honeycomb 3 for a first structural adhesive film 4;

[0031] S2. A circle of expansion film 2 is laid on the entire cut corner area of ​​the honeycomb 3;

[0032] S3. Laying the second structural adhesive film 1 on the entire inner surface of the honeycomb 3;

[0033] S4. The honeycomb 3 with the adhesive film applied thereto is vacuum preformed; the preformed honeycomb can be used for manufacturing an automatic wire-laying honeycomb sandwich structure.

[0034] The laying width of the first structural adhesive film 4 is 10-15 mm. This size structure reduces the structural weight while meeting the honeycomb preforming requirements.

[0035] The first and second structural adhesive films are both high temperature curing carrier adhesive films with a thickness of 0.25 mm.

[0036] The expansion film 2 is a film that cures at medium temperature.

[0037] The structural film uses a high-temperature curing carrier film with a thickness of 0.25 mm. The film with this thickness can be well combined with the honeycomb to meet the needs of subsequent automatic wire laying, while balancing the molding weight requirements of composite parts; the expansion film uses a film that can be cured at medium temperature.

[0038] Step S4 is specifically as follows: placing the honeycomb 3 with the adhesive film laid on it in a preforming mold, evacuating the vacuum bag and putting it into a furnace for preforming.

[0039] During preforming, the expansion film is cured and the structural film is melted but not cured.

[0040] The preforming temperature is 120℃±5℃. The honeycomb with the film laid is placed in the preforming mold, and the vacuum bag is put into the furnace for preforming. The preforming temperature is set to a temperature at which the expansion film is cured at a medium temperature and the structural film is melted but not cured (such as 120℃±5℃). After the honeycomb is preformed, the film melts, the expansion film is cured and combined with the honeycomb to form a whole with good rigidity on the inner surface and the cut corner area.

[0041] The cut corner area of ​​the honeycomb 3 is arranged at a right angle or an oblique angle relative to the outer surface of the honeycomb 3 .

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A honeycomb processing method for automatic wire laying, characterized in that: The steps include: S1. Laying a first structural adhesive film (4) around the outer edge of the honeycomb (3); S2. A circle of expansion film (2) is laid around the entire cut corner area of ​​the honeycomb (3); S3. Laying a second structural adhesive film (1) on the entire inner surface of the honeycomb (3); S4. Preform the honeycomb (3) with the adhesive film applied thereon by vacuum forming.

2. The honeycomb processing method for automatic wire laying according to claim 1, characterized in that: The laying width of the first structural adhesive film (4) is 10 to 15 mm.

3. The honeycomb processing method for automatic wire laying according to claim 1, characterized in that: The first and second structural adhesive films are both high temperature curing carrier adhesive films with a thickness of 0.25 mm.

4. The honeycomb processing method for automatic wire laying according to claim 1, characterized in that: The expansion film (2) is a film that cures at medium temperature.

5. The honeycomb processing method for automatic wire laying according to claim 1, characterized in that: Step S4 is specifically as follows: placing the honeycomb (3) with the adhesive film laid on it in a preforming mold, evacuating the vacuum bag and putting it into a furnace for preforming.

6. The honeycomb processing method for automatic wire laying according to claim 5, characterized in that: During preforming, the expansion film is cured and the structural film is melted but not cured.

7. The honeycomb processing method for automatic wire laying according to claim 5, characterized in that: The preforming temperature is 120℃±5℃.

8. The honeycomb processing method for automatic wire laying according to claim 1, characterized in that: The cut-off area of ​​the honeycomb (3) is arranged at a right angle or an oblique angle relative to the outer surface of the honeycomb (3).

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