A large thickness honeycomb core manufacturing apparatus and method

Abstract

The application belongs to the technical field of aviation composite materials, and particularly relates to a large-thickness honeycomb core material preparation device and a preparation method. The device comprises a honeycomb transfer tool, a honeycomb fixing tool and a honeycomb impregnation tool. After the honeycomb is stretched on the honeycomb stretcher, the honeycomb is transferred to the honeycomb transfer tool. After shaping, the honeycomb is taken off from the transfer tool and placed on the honeycomb fixing tool. The honeycomb together with the fixing tool is placed on the impregnation tool, and repeated impregnation is performed to realize the preparation of the large-thickness honeycomb core material. Under the premise of not damaging the original thin honeycomb preparation line, a complete set of auxiliary process equipment for large-thickness honeycomb preparation is provided, and economy and practicability are considered at the same time. The fixing, turning over and transferring problems in the honeycomb preparation process are solved, and the time cost of manufacturing special production equipment is saved.

Description

Technical Field

[0001] This invention belongs to the field of aerospace composite materials technology, specifically relating to a device and method for preparing thick honeycomb core materials. Background Technology

[0002] Honeycomb core material is an anisotropic porous material formed by filling an inner planar region with a large number of polygonal holes arranged in a two-dimensional pattern. It consists of a series of open-cell pillars arranged according to a certain pattern, and these pillars are composed of multiple layers of thin sheet-like materials connected to each other. The upper and lower surfaces of the pillars are typically hexagonal. Due to its ultra-lightweight nature and high compressive strength, honeycomb core material has increasingly wide applications. Since the discovery and utilization of honeycomb structures, people have used various materials to create honeycomb structures to serve various human needs, occupying an important position in the field of materials science.

[0003] Honeycomb core materials have been used in the aerospace field since the 1930s, mainly in sandwich structures under aircraft skin. They are primarily used in components such as aircraft radar radomes, secondary load-bearing structures of the fuselage, and internal structures, playing a significant role in reducing aircraft structural weight, improving the wave transmission, noise reduction, and heat insulation performance of functional components, as well as improving the processing performance of related parts. Summary of the Invention

[0004] Purpose of the invention The fabrication process of thick honeycomb cells is complex and lengthy, requiring specialized auxiliary equipment. This invention addresses the specific characteristics and requirements of the thick honeycomb cell fabrication process, primarily solving problems related to fixation, flipping, and transfer in intermediate stages. This invention provides a complete set of auxiliary equipment for the intermediate stages of thick honeycomb cell fabrication, enabling the fabrication of thick honeycomb cells.

[0005] Technical solution A device for preparing thick honeycomb core material includes a honeycomb transfer fixture, a honeycomb fixing fixture, and a honeycomb impregnation fixture. After the honeycomb is stretched on a honeycomb stretching machine, it is transferred to the honeycomb transfer fixture. After shaping, the honeycomb is removed from the transfer fixture and placed on the honeycomb fixing fixture. The honeycomb, together with the honeycomb fixing fixture, is placed on the honeycomb impregnation fixture and repeatedly impregnated with adhesive to achieve the preparation of thick honeycomb core material.

[0006] Furthermore, the fixed frame of the cellular transfer fixture is a "C"-shaped frame structure. There are two rows of lugs on both sides of the frame for placing support rods. The upper row of lugs is a "U"-shaped groove, and the lower row of lugs is a round hole. The support rods are placed in the "U"-shaped groove and the round hole. The support rods are round rods with a baffle on the side of the round rod near the "U"-shaped groove to limit the height of the support rod and prevent it from slipping. There are two support members on the open side of the "C"-shaped frame. The support members have threads at both ends and cooperate with the lugs with "U"-shaped openings on the frame to ensure that the "C"-shaped frame has a certain rigidity and will not deform.

[0007] Furthermore, the honeycomb fixing fixture includes an upper frame and a lower frame. The main structure of the upper and lower frames is composed of welded hollow square tubes to ensure the sealing of the welds. Both the upper and lower frames are equipped with plates with protruding spikes, which are used to pierce into the honeycomb cells to fix the honeycomb. The upper frame has guide holes around its perimeter, and the lower frame has guide posts around its perimeter. The guide holes cooperate with the guide posts to achieve positioning between the upper and lower frames. A gap is left between the upper and lower frames to ensure that the honeycomb can be used within a range of thickness variations. The upper frame has forklift holes for easy mechanical operation and transfer. The upper and lower frames are connected by a quick-release buckle mechanism for rapid clamping.

[0008] Furthermore, it includes a honeycomb fixing fixture, with the upper and lower frames made of metal.

[0009] Furthermore, the honeycomb impregnation fixture consists of a movable placement frame, a simple glue tank, a lifting net, connecting rods, a quick-connect crossbeam, and C-clamps. One end of the quick-connect crossbeam is placed on the impregnation lifting device and quickly clamped by the C-clamps; the other end of the quick-connect crossbeam has a long slot to adjust the position of the connecting rod; the connecting rod consists of two threaded rods, one end of which passes through the long slot on the quick-connect crossbeam, and a nut is tightened at the end near the long slot; the other end of the connecting rod connects to a hole on the lifting net and is locked with a nut; the lifting net is welded from hollow stainless steel pipes and covered with wire mesh; the lifting net is smaller than the simple glue tank and can move within the simple glue tank without interference.

[0010] Furthermore, the frame of the cellular transfer fixture is welded from hollow square tubing.

[0011] Furthermore, the lower frame of the honeycomb fixing fixture has four handles for easy manual operation.

[0012] A method for preparing a thick honeycomb core material includes the following steps: Step 1: Attach a fabric strap buckle of the same width as the core paper to the outside of the cut and glued continuous core paper along the stretching direction. Step 2: Install the fabric strap buckle on the pull rod of the stretching machine; Step 3: The stretching machine drives the fabric belt buckle to stretch the core paper into a honeycomb paper core; Step 4: After the core paper is stretched, it has a large shrinkage force before it is set. The honeycomb cannot be set on the stretching machine. The honeycomb needs to be transferred off the stretching machine while maintaining the stretched state.

[0013] Step 5: After stretching on the stretching machine, remove all the support rods and support pieces on both sides of the "C"-shaped frame. Insert the "C"-shaped frame into the honeycomb to surround it. The positions of the support rods on both sides of the frame should be slightly offset from the positions of the pull rods on the stretching machine. Insert the support rods into the corresponding fabric strap buckles and place them in the corresponding lug holes on the frame. Slowly release the stretching machine so that the fabric strap buckles are pressed against the support rods of the honeycomb fixing frame. Then remove the pull rods from the stretching machine. Install the two support pieces at the opening of the "C"-shaped frame and transfer the honeycomb along with the honeycomb transfer fixture from the stretching machine.

[0014] Step 6: Shape the honeycomb together with the honeycomb transfer tool.

[0015] Step 7: After shaping, impregnation is carried out; during the impregnation process, the honeycomb blocks need to be fixed, flipped and transferred by honeycomb fixing fixtures for impregnation, drying and curing. Step 8: Remove all support rods from the honeycomb transfer fixture, remove the honeycomb and transfer it to the lower frame of the honeycomb fixing fixture, align the protruding spikes with the honeycomb grid holes; install the upper frame of the honeycomb along the four guide posts and fasten the buckles.

[0016] Step 9: Place the honeycomb along with the honeycomb fixing fixture on the lifting net of the honeycomb impregnation fixture. The honeycomb impregnation fixture is clamped on the impregnation equipment by C-clamps and moves up and down with the impregnation machine multiple times to repeatedly impregnate. Step 10: After impregnation, dry and cure together with the honeycomb fixing fixture.

[0017] Step 11: After curing, remove the honeycomb to complete the preparation of the thick honeycomb.

[0018] Technical effect The fabrication and testing of thick-cell honeycomb is a complex and lengthy process. Existing thin-cell honeycomb fabrication equipment is insufficient to meet the needs of thick-cell honeycomb testing, necessitating the design and manufacture of specialized auxiliary equipment. This invention, based on the process characteristics and specific requirements of thick-cell honeycomb fabrication, provides a complete set of auxiliary equipment for thick-cell honeycomb fabrication without disrupting the existing thin-cell honeycomb fabrication line. It also considers economic efficiency and practicality, solving the problems of fixing, flipping, and transferring in intermediate stages of honeycomb fabrication. This enables rapid testing and trial production of thick-cell honeycomb based on existing thin-cell honeycomb equipment, saving time and costs associated with manufacturing specialized equipment. Furthermore, this invention supplements key processes in the complex workflow, and its content can be referenced for subsequent thick-cell honeycomb testing and the design and use of specialized equipment, providing important guidance for the construction of dedicated thick-cell honeycomb manufacturing lines. Attached Figure Description

[0019] Figure 1 Schematic diagram of honeycomb core structure; Figure 2 Schematic diagram of honeycomb transfer fixture; Figure 3 A schematic diagram of a honeycomb fixed to a tooling. Figure 4 Schematic diagram of honeycomb impregnation fixture; Figure 5 Schematic diagram of adhesive impregnation auxiliary tooling. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0021] Example 1 The preparation of a thick honeycomb core material test piece first involves the preparation of a honeycomb transfer fixture, a honeycomb impregnation fixture, and an impregnation auxiliary fixture.

[0022] The honeycomb transfer fixture has a "C"-shaped frame structure 1-1 for fixing the honeycomb frame. The frame is welded from hollow square tubes, ensuring that the overall frame is lightweight and easy to operate. There are two rows of lugs on both sides of the frame for placing support rods 1-4. The upper row of lugs 1-5 are "U"-shaped grooves, and the lower row of lugs 1-3 are round holes. The support rods 1-4 are placed in the "U"-shaped grooves and round holes. The support rods 1-4 are round rods with a baffle on one side to limit the height of the support rods and prevent them from slipping. There are two support members 1-6 on the open side of the "C"-shaped frame structure 1-1. The support members 1-6 have threads at both ends and cooperate with the lugs 1-2 with "U"-shaped openings on the frame to ensure that the "C"-shaped frame structure 1-1 has a certain rigidity and will not deform.

[0023] The honeycomb impregnation fixture includes an upper frame 2-2 and a lower frame 2-1. The main structure of the upper and lower frames is composed of welded hollow square tubes to ensure the sealing of the welds and prevent glue from entering during the impregnation process. The upper and lower frames have plates 2-10 with protruding spikes 2-9, which pierce into the honeycomb cells to fix the honeycomb size. There are positioning guide posts 2-3 between the upper and lower frames, leaving a gap to ensure that the fixture can be used within the range of thickness variation. The lower frame has four handles 2-8 for easy manual operation. The upper frame has forklift holes 2-4, which facilitate mechanical operation and transfer after the honeycomb is heavy. The upper and lower frames are connected by quick-release buckles 2-6 and 2-7 for quick clamping.

[0024] The honeycomb impregnation fixture consists of a movable placement frame 3-1, a simple glue tank 3-2, a lifting net 3-3, a connecting rod 3-4, a quick-connecting crossbeam 3-5, and a C-clamp 3-6. One end of the quick-connecting crossbeam 3-5 is placed on the impregnation lifting device and quickly clamped by the C-clamp 3-6; the other end of the quick-connecting crossbeam 3-5 has a long slot to adjust the position of the connecting rod 3-4; the connecting rod 3-4 consists of two threaded rods, one end of which passes through the long slot on the quick-connecting crossbeam 3-5, and a nut is tightened at the end near the long slot; the other end of the connecting rod 3-4 connects to a hole on the lifting net 3-3 and is locked with a nut; the lifting net is welded from hollow stainless steel pipes and covered with wire mesh; the lifting net 3-3 is smaller than the simple glue tank 3-2 and can move within the simple glue tank 3-2 without interference.

[0025] The preparation is completed using the following steps 1 to 11.

[0026] Step 1: Attach a fabric strap buckle of the same width as the core paper to the outside of the cut and glued continuous core paper along the stretching direction. Step 2: Install the fabric strap buckle on the pull rod of the stretching machine; Step 3: The stretching machine drives the fabric belt buckle to stretch the core paper into a honeycomb paper core; Step 4: After the core paper is stretched, it has a large shrinkage force before it is set. The honeycomb cannot be set on the stretching machine. The honeycomb needs to be transferred off the stretching machine while maintaining the stretched state.

[0027] Step 5: After stretching on the stretching machine, remove all the support rods 1-4 and support pieces 1-6 on both sides of the "C"-shaped frame 1-1. Insert the "C"-shaped frame 1-1 into the honeycomb to surround it. The positions of the support rods 1-4 on both sides of the frame 1-1 should be slightly offset from the positions of the pull rods on the stretching machine. Insert the support rods 1-4 into the corresponding fabric strap buckles and place them in the corresponding lug holes on the frame 1-1. Slowly loosen the stretching machine so that the fabric strap buckles are pressed against the support rods 1-4 of the honeycomb fixing frame. Then remove the pull rods from the stretching machine. Install the two support pieces 1-6 at the opening of the "C"-shaped frame 1-1 and transfer the honeycomb along with the honeycomb transfer fixture from the stretching machine.

[0028] Step 6: Shape the honeycomb along with the honeycomb transfer fixture. Honeycomb shaping needs to be carried out in a high-temperature oven. Under high temperature and time according to a specific temperature curve, the paper honeycomb can initially maintain a certain shape.

[0029] Step 7: After shaping, impregnation is carried out; during the impregnation process, the honeycomb blocks need to be fixed, flipped and transferred by honeycomb fixing fixtures for impregnation, drying and curing. Step 8: Remove all support rods 1-4 from the honeycomb transfer fixture, remove the honeycomb and transfer it to the lower frame 2-1 of the honeycomb fixing fixture, align the protruding spikes 2-9 with the honeycomb grid holes; install the upper frame of the honeycomb along the four guide posts 2-3, and fasten the buckles 2-6 and 2-7.

[0030] Step 9: Place the honeycomb along with the honeycomb fixing fixture on the lifting net of the honeycomb impregnation fixture. The honeycomb impregnation fixture is clamped on the impregnation equipment by C-clamps 3-6 and moves up and down with the impregnation machine multiple times to repeatedly impregnate.

[0031] Step 10: After impregnation, dry and cure the honeycomb fixing fixture together in a high-temperature oven according to a certain temperature curve and time.

[0032] Step 11: After curing, remove the honeycomb to complete the preparation of the thick honeycomb.

[0033] Example 2 Nest transfer tooling, such as Figure 2 As shown: (1) The frame of the transfer fixture has two rows of lugs on both sides for placing support rods 1-4. The upper row of lugs 1-5 is a "U" shaped groove, and the lower row of lugs 1-3 is a round hole. The support rods 1-4 are placed in the "U" shaped groove and the round hole. The upper row of lugs is set as a "U" shaped groove and the lower row of lugs is set as a round hole. This is because the operating space is limited when the support rods 1-4 are replaced on the stretching machine. If both the upper and lower sides are round holes, it will be inconvenient to operate. The lower side is a round hole and the upper side is a "U" shaped hole, which can be positioned and is convenient to operate. If both the upper and lower sides are "U" shaped holes, it may cause the stress of the paper honeycomb to be released during the shaping process in the oven, the tension of the cloth belt buckle on the support rods 1-4 to be relaxed, and the vibration during transportation may cause the support rods 1-4 to fall off.

[0034] (2) Support rod 1-4 is a round rod with a baffle on one side to limit the height of the support rod and prevent it from slipping. At the same time, support rod 1-4 is a hollow round rod, which achieves lightweighting while ensuring rigidity.

[0035] (3) There are two support members 1-6 on the open side of the “C”-shaped frame 1-1. The support members 1-6 have threads at both ends and cooperate with the lugs 1-2 with “U”-shaped openings on the frame to ensure that the “C”-shaped frame 1-1 has a certain rigidity and will not deform. The “C”-shaped design is to wrap the honeycomb from one side without interfering with the stretching equipment and the honeycomb. However, the rigidity of the “C”-shaped frame is not good. Therefore, after the honeycomb is transferred from the stretching machine, two support members are added to the front end of the “C”-shaped frame to change the “C”-shaped structure to a “U”-shaped structure to ensure the overall rigidity of the honeycomb transfer fixture.

[0036] Honeycomb fixing fixtures, such as Figure 3 As shown: (1) It includes an upper frame 2-2 and a lower frame 2-1. The main structure of the upper and lower frames is composed of hollow square tubes welded together to ensure the sealing of the weld and prevent the glue from entering during the impregnation process. At the same time, the hollow square tubes are made of stainless steel. Since the honeycomb fixing fixture needs to be impregnated with the honeycomb together, impurities such as rust on the surface of the steel pipe will damage the composition of the glue, thereby affecting the performance of the honeycomb.

[0037] (2) There are positioning guide posts 2-3 between the upper and lower frames, with a gap, which can ensure that the tooling can be used within the range of thickness variation. The gap between the upper and lower frames is to ensure that the upper frame can contact the honeycomb and ensure that the position of the honeycomb on the tooling is relatively stable. If there is no gap between the upper and lower frames, and the honeycomb thickness is less than the height of the lower frame, then the upper frame will contact the lower frame first. The distance between the upper and lower frames is constant, and there is a certain gap between the upper frame and the upper surface of the honeycomb. During the glue impregnation process, the buoyancy of the glue may cause the honeycomb to have a certain floating space on the fixed frame. As the fixed frame and the honeycomb are raised, the honeycomb will fall under the action of gravity. With repeated up and down glue impregnation, the honeycomb will also move up and down. Since there are positioning protruding spikes 2-9 on the upper and lower frames, the spikes 2-9 penetrate the honeycomb grid holes. As the honeycomb moves up and down, the spikes 2-9 may damage the honeycomb grid holes. Therefore, there is a gap between the upper and lower frames, and the depth of the lower frame is less than the theoretical thickness of the honeycomb. This design can ensure that there is no gap between the upper and lower frames and the upper and lower surfaces of the honeycomb, that is, the honeycomb will not sway up and down in the honeycomb fixed frame.

[0038] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Within the spirit and principles of the present invention, any person skilled in the art may use the disclosed technical content to make changes or modifications to create equivalent embodiments applicable to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A device for preparing thick honeycomb core material, characterized in that, The preparation apparatus includes a honeycomb transfer fixture, a honeycomb fixing fixture, and a honeycomb impregnation fixture; after the honeycomb is stretched on the honeycomb stretching machine, the honeycomb paper core is transferred to the honeycomb transfer fixture. After shaping, the honeycomb paper core is removed from the honeycomb transfer fixture and placed on the honeycomb fixing fixture. The honeycomb paper core, along with the honeycomb fixing fixture, is placed on the honeycomb impregnation fixture and repeatedly impregnated to achieve the preparation of a large-thickness honeycomb core material. The fixing frame of the honeycomb transfer fixture is a "C"-shaped frame structure with two rows of lugs on both sides for placing support rods. The upper row of lugs is a "U"-shaped groove, and the lower row of lugs is a round hole. The support rods are placed in the "U"-shaped groove and the round hole. The support rods are round rods with a baffle on the side near the "U"-shaped groove to limit the height of the support rods and prevent them from slipping. There are two support members on the open side of the "C"-shaped frame. The support members have threads at both ends and cooperate with the lugs with "U"-shaped openings on the frame. The honeycomb fixing fixture includes an upper frame and a lower frame. The main structure of the upper and lower frames is composed of welded hollow square tubes. Both the upper and lower frames are equipped with plates with protruding spikes. The protruding spikes are used to pierce into the honeycomb cells to fix the honeycomb paper core. The upper frame has guide holes around its four sides, and the lower frame has guide posts around its four sides. The guide holes cooperate with the guide posts to achieve positioning between the upper and lower frames. A gap is left between the upper and lower frames. The upper frame has forklift holes, and the upper and lower frames are connected by a quick-locking mechanism. The honeycomb impregnation fixture consists of a movable placement frame, a simple glue tank, a lifting net, connecting rods, a quick-connecting crossbeam, and C-clamps. One end of the quick-connecting crossbeam is placed on the impregnation lifting device and quickly clamped by the C-clamps. The other end of the quick-connecting crossbeam has a long slot hole to adjust the position of the connecting rod. The connecting rod consists of two threaded rods. One end of the connecting rod passes through the long slot hole on the quick-connecting crossbeam, and a nut is tightened at the end near the long slot hole. The other end of the connecting rod connects to a hole on the lifting net and is locked by a nut. The lifting net is welded from hollow stainless steel pipes and covered with wire mesh. The size of the lifting net is smaller than the simple glue tank, allowing it to move within the simple glue tank without interference.

2. The apparatus as claimed in claim 1, characterized in that, It includes a honeycomb fixing fixture, with the upper and lower frames made of metal.

3. The apparatus as described in claim 1, characterized in that, The frame of the cellular transfer fixture is welded from hollow square tubing.

4. The apparatus as claimed in claim 1, characterized in that, The lower frame of the honeycomb fixing fixture has four handles.

5. A method for preparing a thick honeycomb core material using the apparatus described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Attach a fabric strap buckle of the same width as the core paper to the outside of the cut and glued continuous core paper along the stretching direction. Step 2: Install the fabric strap buckle on the pull rod of the stretching machine; Step 3: The stretching machine drives the fabric belt buckle to stretch the core paper into a honeycomb paper core; Step 4: After the core paper is stretched, it has shrinkage force before it is set. The honeycomb paper core cannot be set on the stretching machine. The honeycomb paper core needs to be transferred off the stretching machine while maintaining the honeycomb stretching state. Step 5: After stretching on the stretching machine, remove all the support rods and support pieces on both sides of the "C"-shaped frame. Insert the "C"-shaped frame into the honeycomb paper core to surround it. The positions of the support rods on both sides of the frame should be offset from the positions of the pull rods on the stretching machine. Insert the support rods into the corresponding fabric strap buckles and place them in the corresponding lug holes on the frame. Slowly release the stretching machine so that the fabric strap buckles are pressed against the support rods of the honeycomb fixed frame. Then remove the pull rods from the stretching machine. Install the two support pieces at the opening of the "C"-shaped frame and transfer the honeycomb paper core along with the honeycomb transfer fixture from the stretching machine. Step 6: Shape the honeycomb paper core together with the honeycomb transfer fixture; Step 7: After shaping, impregnation is carried out; during the impregnation process, the honeycomb blocks need to be fixed, flipped and transferred by honeycomb fixing fixtures for impregnation, drying and curing. Step 8: Remove all support rods from the honeycomb transfer fixture, remove the honeycomb paper core and transfer it to the lower frame of the honeycomb fixing fixture, and align the protruding spikes with the honeycomb grid holes. Install the upper frame along the four guide posts and fasten the quick-release buckle connection mechanism; Step 9: Place the honeycomb paper core along with the honeycomb fixing fixture on the lifting net of the honeycomb impregnation fixture. The honeycomb impregnation fixture is clamped on the impregnation equipment by C-clamps and moves up and down with the impregnation machine multiple times to repeatedly impregnate. Step 10: After impregnation, dry and cure together with the honeycomb fixing fixture; Step 11: After curing, remove the honeycomb paper core to complete the preparation of the thick honeycomb core material.

6. A thick honeycomb core material, characterized in that, It is prepared using the method described in claim 5.

7. The thick honeycomb core material as described in claim 6, characterized in that, It is used in the field of aerospace composite materials.

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