A method for filling the filling holes of a honeycomb panel

Abstract

This invention relates to a method for filling the cells of a honeycomb panel, comprising the following steps: inserting the honeycomb block into the filling cell, allowing the potting compound to flow from the lower opening to the upper opening of the filling cell, filling the honeycomb cells of the honeycomb block, while air in the honeycomb cells is expelled from the upper opening; after insertion, the honeycomb block is flush with the honeycomb panel; since the density of the potting compound is much greater than that of air, the potting compound will flow into the honeycomb cells of the honeycomb block, expelling air, with the air expulsion direction consistent with the potting compound filling direction, preventing air from flowing backward through the potting compound and thus preventing the formation of air bubbles. The rapid honeycomb filling method of this invention is simple to operate, low in cost, and efficient, and after filling, the cells are completely filled without air bubbles, making it applicable to the filling of honeycomb cores of different thicknesses and sizes.

Description

Technical Field

[0001] This invention relates to composite material honeycomb core processing technology, and to a method for filling the filling holes of a honeycomb panel. Background Technology

[0002] Composite honeycomb sandwich structures possess advantages such as light weight, high flexural strength and stiffness, strong resistance to instability, fatigue aging resistance, and good sound absorption, sound insulation, and heat insulation properties, and are currently widely used in the aerospace field. When composite honeycomb sandwich structures have assembly relationships within the honeycomb area, potting is required to prevent damage to the sandwich structure and improve the mechanical properties of the parts. However, due to the high viscosity of the potting compound and the small size and large number of pores in the honeycomb, the potting area is difficult to completely fill; furthermore, gas is easily trapped within the potting compound, resulting in numerous air bubbles that affect the quality of the potted area and the subsequent manufacturing and assembly efficiency of the potted area. In existing technologies, since the honeycomb panel is fixed to the workbench, the potting compound is injected through the potting holes, causing air to escape in the opposite direction through the potting compound, leading to air bubble formation.

[0003] Recent inventions regarding honeycomb filling methods are as follows:

[0004] 1) An apparatus for resin potting a honeycomb structure and a method for resin potting a honeycomb structure using the apparatus (application number CN112109255A): This patent describes a method for sealing the non-potting area of ​​a honeycomb, placing the honeycomb on a device with a vacuum power component, a vacuum adsorption component, and an isolation and ventilation component, pouring potting adhesive into the potting positioning component on the honeycomb, and then activating the vacuum power component under the honeycomb to create a vacuum condition under the honeycomb, allowing the potting adhesive to flow into the honeycomb cells. This invention requires the design and manufacture of a potting device, resulting in high potting costs. Furthermore, it requires accurate control of the vacuum pressure. If the vacuum pressure is too high, the potting adhesive will flow into the pores of the vacuum adsorption component after passing through the isolation and ventilation component, causing the vacuum adsorption component to malfunction. If the vacuum pressure is too low, the vacuum potting effect will not be achieved, affecting the potting quality and efficiency.

[0005] 2) Pre-filling molding fixture and process method for honeycomb sandwich components (Authorization No.: CN102275342B): The method involves placing the honeycomb core on a mold, connecting the mold to the honeycomb core via positioning pins, and placing baffles around the honeycomb core. After placing a filling template on the honeycomb core, the filling adhesive is placed on the honeycomb core, and a pressure plate is placed on top of the adhesive. A vacuum bag is used to create a vacuum, and the pressure plate fills the honeycomb cells with the filling adhesive. This invention is not suitable for filling honeycomb components with a pre-formed shape after processing, and the gas inside the honeycomb cells is not easily expelled, easily becoming trapped in the filling adhesive, forming air bubbles, resulting in poor filling quality.

[0006] 3) A method for molding honeycomb sandwich parts with potting adhesive (application number: CN115352101A): potting adhesive is uniformly injected into the core cells of the honeycomb sandwich material, and after curing, it is processed into a filling module. According to the shape of the potting area, potting holes are opened on the honeycomb. The filling module is wrapped with a compensation adhesive layer and then placed into the honeycomb potting hole to realize the manufacturing of honeycomb potted parts. However, the potting operation of the potting module still has the problems of low efficiency and low potting quality, and the subsequent curing, processing and bonding of the filling module has high manufacturing costs.

[0007] In summary, while the aforementioned honeycomb potting fixtures and methods can achieve honeycomb potting operations, they suffer from problems such as complex potting operations, high manufacturing costs, and low potting quality, failing to meet the manufacturing requirements of high quality, high efficiency, and low cost. Summary of the Invention

[0008] The purpose of this invention is to propose a method that effectively solves the technical problems of low efficiency and numerous air bubbles in the potting compound during honeycomb potting operations, improves the quality and efficiency of honeycomb potting, and achieves low-cost, high-efficiency, and high-quality operation for large-area honeycomb potting. This method can be widely applied to the potting operations of honeycomb cores of different specifications and sizes.

[0009] The technical solution of this invention is:

[0010] This invention provides a method for filling the pores of a honeycomb panel, which can solve the problems of incomplete filling, air bubbles and cracking in the filling, and improve the efficiency and quality of honeycomb filling.

[0011] To achieve the objective of this invention, a method for filling the filling holes of a honeycomb panel includes the following steps:

[0012] Step 1: Determine the location of the potting opening in the honeycomb panel, and machine the potting opening; obtain a honeycomb block with the same size as the potting opening.

[0013] Use tape to isolate and protect the non-filled areas of the honeycomb panel, fix the honeycomb panel on the workbench, and place baffles around the filling holes on the honeycomb panel;

[0014] Step 2: Fill the potting compound by injecting it into the potting holes;

[0015] Step 3: Insert the honeycomb block into the potting hole, allowing the potting compound to flow from the bottom to the top of the potting hole, filling the honeycomb pores of the honeycomb block. Air in the honeycomb pores is expelled from the top. After insertion, the honeycomb block is flush with the honeycomb board. (Because the density of the potting compound is much greater than that of air, the potting compound will flow into the honeycomb pores of the honeycomb block, expelling air. The direction of air expulsion is the same as the direction of filling with the potting compound; air will not flow backward through the potting compound, and air bubbles will not form.)

[0016] Step 4: Remove the retaining strip around the potting hole and remove excess potting compound so that the potting compound protrudes above the potting hole; then cure the potting compound in the potting hole by first curing at room temperature and then curing at high temperature so that the cured potting compound protrudes above the potting hole.

[0017] Step 5: Machin the protruding potting compound after curing so that the potting compound is flush with the honeycomb panel.

[0018] Furthermore, the pore size of the honeycomb cells is less than 3.2 mm.

[0019] Furthermore, the machining method for opening and sealing the cells is to punch open the cells with a punch, and the punched-out honeycomb blocks are used for filling in step 3.

[0020] Furthermore, the machining method for opening and sealing the cells is to use a bar milling cutter for destructive opening, and the honeycomb blocks are machined individually by the milling cutter.

[0021] Furthermore, the potting compound is a two-component epoxy resin adhesive. Preferably, the grade is FM490A. Even further, the weight percentage of the matrix and the curing agent in the two-component epoxy resin adhesive is 100:20.

[0022] Furthermore, before injection in step 2, the potting compound is evacuated to remove air.

[0023] Furthermore, the diameter of the potting hole is not less than 15 mm.

[0024] Furthermore, the outer diameter of the honeycomb block is 1-2 mm smaller than the inner diameter of the filling hole.

[0025] Furthermore, the heat dissipation time for curing at room temperature is no less than 24 hours.

[0026] Furthermore, the high-temperature curing temperature is 120-127℃, the curing time is 90 minutes, and the heating and cooling rate is no higher than 1.5℃ / min.

[0027] The advantages of this invention are: the rapid honeycomb filling method of this invention is simple to operate, low in cost, and fast in efficiency. After filling, the filling is complete and there are no air bubbles in the honeycomb cells. It can be applied to the filling operation of honeycomb cores of different thicknesses and filling sizes. Attached Figure Description

[0028] Figure 1 This is a diagram showing the relative positions of the various parts in this invention;

[0029] Wherein: 1-workbench surface, 2-tape, 3-honeycomb panel, 4-potting compound, 5-stop strip, 6-cut-off honeycomb block. Detailed Implementation

[0030] The disclosed examples will be described more fully with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples may be described, and these examples should not be construed as limited to those set forth herein. Rather, these examples are described so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0031] This invention provides a method for filling the pores of a honeycomb panel, which can solve the problems of incomplete filling, air bubbles and cracking in the filling, and improve the efficiency and quality of honeycomb filling.

[0032] To achieve the objective of this invention, a rapid filling method for large-area honeycomb structures is provided, comprising the following steps:

[0033] Step 1: Determine the location of the potting opening in the honeycomb panel, and machine the potting opening; obtain a honeycomb block with the same size as the potting opening.

[0034] Use tape to isolate and protect the non-filled areas of the honeycomb panel, fix the honeycomb panel on the workbench, and place baffles around the filling holes on the honeycomb panel;

[0035] Step 2: Fill the potting compound by injecting it into the potting holes;

[0036] Step 3: Insert the honeycomb block into the potting hole, allowing the potting compound to flow from the bottom to the top of the potting hole, filling the honeycomb pores of the honeycomb block. Air in the honeycomb pores is expelled from the top. After insertion, the honeycomb block is flush with the honeycomb board. (Because the density of the potting compound is much greater than that of air, the potting compound will flow into the honeycomb pores of the honeycomb block, expelling air. The direction of air expulsion is the same as the direction of filling with the potting compound; air will not flow backward through the potting compound, and air bubbles will not form.)

[0037] Step 4: Remove the retaining strip around the potting hole and remove excess potting compound so that the potting compound protrudes above the potting hole; then cure the potting compound in the potting hole by first curing at room temperature and then curing at high temperature so that the cured potting compound protrudes above the potting hole.

[0038] Step 5: Machin the protruding potting compound after curing so that the potting compound is flush with the honeycomb panel.

[0039] The pore size of the honeycomb is 3.2mm.

[0040] The machining method for opening and sealing the cells is to punch open the cells with a punch, and the punched-out honeycomb blocks are used for filling in step 3.

[0041] The machining method for opening and sealing the cells is to use a bar milling cutter for destructive opening, and the honeycomb blocks are machined individually using a milling cutter.

[0042] The potting compound is a two-component epoxy resin adhesive, brand name FM490A. The weight percentage of matrix to curing agent in the two-component epoxy resin adhesive is 100:20.

[0043] Before injection in step 2, the potting compound is evacuated to remove air.

[0044] The diameter of the filling hole is not less than 15mm.

[0045] The outer diameter of the honeycomb block is 1-2 mm smaller than the inner diameter of the filling hole.

[0046] The heat dissipation time for curing at room temperature shall not be less than 24 hours.

[0047] The high-temperature curing temperature is 120-127℃, the curing time is 90 minutes, and the heating and cooling rate is no higher than 1.5℃ / min.

[0048] Descriptions of various advantageous arrangements have been shown for illustrative and descriptive purposes, but such descriptions are not intended to be exclusive or limited to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different advantageous examples may describe different advantages compared to other advantageous examples. One or more examples have been selected and described in order to best illustrate the principles and practical application of the examples, and to enable those skilled in the art to understand that this disclosure contains various examples with various modifications suitable for the particular intended use.

Claims

1. A method for filling the filling holes of a honeycomb panel, characterized in that, Includes the following steps: Step 1: Determine the location of the potting opening in the honeycomb panel, and machine the potting opening; obtain a honeycomb block with the same size as the potting opening. Use tape to isolate and protect the non-filled areas of the honeycomb panel, fix the honeycomb panel on the workbench, and place baffles around the filling holes on the honeycomb panel; Step 2: Fill the potting compound by injecting it into the potting holes; Step 3: Insert the honeycomb block into the potting hole, so that the potting adhesive flows from the lower opening to the upper opening of the potting hole to fill the honeycomb holes of the honeycomb block, and the air in the honeycomb holes is discharged from the upper opening; After insertion, the honeycomb block is flush with the honeycomb panel; Step 4: Remove the retaining strip around the potting hole and remove excess potting compound so that the potting compound protrudes above the potting hole; then cure the potting compound in the potting hole by first curing at room temperature and then curing at high temperature so that the cured potting compound protrudes above the potting hole. Step 5: Machin the protruding potting compound after curing so that the potting compound is flush with the honeycomb panel.

2. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The pore size of the honeycomb cells is less than 3.2 mm.

3. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The machining method for opening and sealing the cells is to punch open the cells with a punch, and the punched-out honeycomb blocks are used for filling in step 3.

4. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The machining method for opening and sealing the cells is to use a bar milling cutter for destructive opening, and the honeycomb blocks are machined individually using a milling cutter.

5. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The potting compound is a two-component epoxy resin adhesive, brand name FM490A, in which the weight percentage of matrix and curing agent is 100:

20.

6. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: Before injection in step 2, the potting compound is evacuated to remove air.

7. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The diameter of the filling hole is not less than 15mm.

8. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The outer diameter of the honeycomb block is 1-2 mm smaller than the inner diameter of the filling hole.

9. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The heat dissipation time for curing at room temperature shall not be less than 24 hours.

10. The method for filling the filling holes of a honeycomb panel as described in claim 1, characterized in that: The high-temperature curing temperature is 120-127℃, the curing time is 90 minutes, and the heating and cooling rate is no higher than 1.5℃ / min.

Images