Wave-absorbing honeycomb thin-wall structure machining method

Abstract

The invention discloses a processing method of a wave-absorbing honeycomb thin-wall structure. A process boss is additionally arranged in a thin-wall area of the wave-absorbing honeycomb thin-wall structure to form a wave-absorbing honeycomb thin-wall process structure, a first surface of the wave-absorbing honeycomb thin-wall structure is processed, and a second surface of the wave-absorbing honeycomb thin-wall structure is processed to obtain the wave-absorbing honeycomb thin-wall structure with guaranteed processing quality and processing precision. According to the machining method, after semi-finishing machining, the wave-absorbing honeycomb workpiece is fixedly held again and is fixedly held twice, meanwhile, by changing the milling direction and selecting the thicker side to reversely mill the profile of the thin-wall area towards the thin-wall area in a one-way mode, the problem that the thin-wall area of the wave-absorbing honeycomb thin-wall structure is prone to being pulled up and damaged during machining is effectively solved through combination of the milling direction and the profile of the thin-wall area. The molded surface of the wave-absorbing honeycomb thin-wall structure is subjected to finish milling by adopting the integral piece milling cutter, so that the phenomena of cell crushing, hole wall tearing, more burrs and the like during machining of the wave-absorbing honeycomb can be effectively avoided, the machining error of the molded surface is less than or equal to 0.3 mm, and the machining quality and the machining precision are improved.

Description

Technical Field

[0001] The invention relates to the technical field of wave-absorbing honeycomb processing, and in particular to a method for processing a wave-absorbing honeycomb thin-wall structure. Background Art

[0002] With the development of modern electronic information technology and aviation technology, aircraft have put forward higher requirements for the shielding and absorption of electromagnetic waves, and a large number of new high-performance absorbing materials have been introduced. Among them, absorbing honeycombs have been widely used in aircraft due to their many advantages such as light weight, high axial specific strength and specific stiffness, strong axial compressive resistance, and good electromagnetic wave absorption performance. They are widely used in edge structural parts such as aircraft vertical tails, flaps, ailerons, bulges, lips, etc. At present, absorbing honeycomb materials are mainly processed by high-speed CNC milling, but the absorbing honeycomb is a hexagonal porous structure with a honeycomb cell wall thickness of only 0.06 to 0.1 mm. The side length of the cell is generally between 2 and 5 mm, which makes the absorbing honeycomb have high strength along the cell axis, but the in-plane strength perpendicular to the cell axis is very low. These characteristics of the absorbing honeycomb are prone to surface quality problems such as milling scratches, cell deformation, cell crushing, cell wall tearing, and burrs during processing. At the same time, due to the non-directional in-plane force, a smaller in-plane force will cause a larger deformation or even crushing, and the honeycomb cannot be clamped and fixed using traditional clamps, pressure plates, etc. Usually, the honeycomb is fixed by adhesive, but the holding force is small and it is easy to have loose holding, resulting in low product yield and processing efficiency.

[0003] Some absorbing honeycomb structures in the aviation field have special structures with thin-walled surface features, and their thickness is only 0.5 to 1.0 mm. During processing, this type of absorbing honeycomb thin-walled structure is limited by the small holding force of the adhesive holding method, and when the thickness is thin, the vibration energy generated during milling cannot be completely absorbed by the honeycomb, and the vibration is transmitted to the honeycomb surface bonded to the tape, causing the absorbing honeycomb to separate from the tape. Subsequently, dust adheres to the bonding surface between the honeycomb and the tape, causing the tape's holding force to decrease or even fail, resulting in the absorbing honeycomb thin-walled structure being debonded, damaged by milling, and poor processing accuracy. Summary of the invention

[0004] The purpose of the present invention is to provide a method for processing a wave-absorbing honeycomb thin-wall structure to solve the technical problems in the prior art that the thin-wall area is easily pulled up and milled during processing and the processing accuracy does not meet the requirements.

[0005] To achieve the above object, the present invention provides the following technical solutions: The present invention provides a method for processing a wave-absorbing honeycomb thin-wall structure, comprising the following steps: S1. Adding a process boss in the thin-walled area of ​​the wave-absorbing honeycomb thin-walled structure to form a wave-absorbing honeycomb thin-walled process structure, wherein a certain angle is formed between the inner side surface of the process boss and the upper molding surface of the wave-absorbing honeycomb thin-walled structure; S2, processing the first surface and the second surface of the wave-absorbing honeycomb thin-wall structure; The first surface is processed, specifically including: fixing the absorbing honeycomb blank on a flat pad, statically pressing the absorbing honeycomb blank, using a honeycomb end mill to perform layered circular cutting, and rough milling the absorbing honeycomb thin-walled process structure profile and process boss; using an integral sheet milling cutter to perform fine machining on the upper profile of the absorbing honeycomb thin-walled structure, the top surface of the process boss, the outer side surface of the process boss, and the inner side surface of the process boss; Processing the second surface specifically includes: After the first surface is processed, the absorbing honeycomb workpiece is turned over and fixed on the profile tooling, and the absorbing honeycomb workpiece is statically pressed, and the absorbing honeycomb thin-walled process structure profile of the absorbing honeycomb is rough-milled by layered circular cutting using a honeycomb end milling cutter, leaving a processing allowance of 1 to 2 mm; Use a honeycomb ball-end milling cutter to reciprocate and cut the wave-absorbing honeycomb thin-walled process structure surface, leaving a processing allowance of 0.5 to 1 mm; Remove the absorbing honeycomb workpiece and clean it, and fix the absorbing honeycomb workpiece on the profile tooling again, and statically press the absorbing honeycomb workpiece, and use an integral milling cutter to perform one-way reverse milling along the width direction from the side away from the outer side of the process boss to the thin-walled area to fine-process the lower profile of the absorbing honeycomb thin-wall structure; Use an integral blade milling cutter to vertically cut the thin-walled area of ​​the wave-absorbing honeycomb thin-walled structure to separate the process boss from the thin-walled area; The on-machine measuring system of the machine tool is used to measure the surface machining accuracy of the wave-absorbing honeycomb thin-wall structure; the wave-absorbing honeycomb thin-wall structure is removed and cleaned.

[0006] Furthermore, the angle between the inner side surface of the process boss in S1 and the upper molding surface of the wave-absorbing honeycomb thin-wall structure is 95° to 100°.

[0007] Furthermore, the process boss is intended to increase the connection strength of the thin-walled area.

[0008] Furthermore, when the upper profile of the wave-absorbing honeycomb thin-walled structure is finely machined in S2, the integral milling cutter and the upper profile of the wave-absorbing honeycomb thin-walled structure are swung at a tool angle of 1 to 5°, and the upper profile of the wave-absorbing honeycomb thin-walled structure is finely machined by unidirectional milling along the width direction.

[0009] Furthermore, the profile tooling in S2 is installed and fixed on the workbench of the machine tool, and the installation accuracy of the profile tooling 7 is measured by the on-machine measurement system of the machine tool.

[0010] Furthermore, the cutting parameters of the honeycomb ball end mill in S2 are set to n=18000~24000r / min, V f =2000~3000mm / min, a p =1.0~1.5mm, a e =10%~15% of tool diameter.

[0011] Furthermore, the tool swing angle of the integral milling cutter in S2 and the lower profile of the wave-absorbing honeycomb thin-wall structure is 1 to 5°, and the cutting parameters are set to n=18000 to 20000 r / min, V f =1000~2000mm / min, a p =0.5~1.0mm, a e =2~5mm.

[0012] Furthermore, the wave-absorbing honeycomb blank is fixed by double-sided adhesive tape.

[0013] Furthermore, the static pressure is performed by fully spreading sandbags on the static pressure wave-absorbing honeycomb blanks, and the static pressure time is 0.5 to 1 hour.

[0014] Based on the above technical solution, the embodiments of the present invention can at least produce the following technical effects: (1) The present invention holds the absorbing honeycomb workpiece again after semi-finishing processing, and holds it twice. At the same time, by changing the milling direction, the thicker side is selected to unidirectionally reverse mill the thin-walled area profile. The combination of the two effectively solves the problem that the thin-walled area of ​​the absorbing honeycomb thin-wall structure is easily pulled up and damaged by milling during processing.

[0015] (2) The present invention adopts an integral disc milling cutter to finely mill the profile of the thin-walled structure of the wave-absorbing honeycomb. Compared with the honeycomb-specific combined milling cutter, this type of cutter has an integral structure, and its cutting disc and the cutter bar are ground and formed as a whole. Unlike the honeycomb-specific combined milling cutter, which requires the cutting disc and the cutter bar to be assembled together, this avoids assembly errors and has smaller radial runout and end face runout during use. It can effectively avoid the occurrence of cell crushing, hole wall tearing, and burrs during the processing of the wave-absorbing honeycomb. The profile processing error is ≤0.3mm, which improves the processing quality and processing accuracy.

[0016] (3) The present invention can utilize common five-axis CNC machining equipment for composite materials, without the need to introduce expensive six-axis CNC ultrasonic machining equipment, thus reducing production costs for enterprises. At the same time, the process technology difficulty is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the wave-absorbing honeycomb thin-wall structure according to an embodiment of the present invention; Figure 2 Schematic diagram of the structure of the wave-absorbing honeycomb thin-wall process according to an embodiment of the present invention; Figure 3 Schematic diagram of the processing of the first surface of the wave-absorbing honeycomb thin-wall structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of processing the second surface of the wave-absorbing honeycomb thin-wall structure according to an embodiment of the present invention; In the figure: 1-thin-wall area, 2-process boss, 3-wave-absorbing honeycomb blank, 4-double-sided tape, 5-flat pad, 6-integral milling cutter, 7-surface tooling, 8-wave-absorbing honeycomb workpiece, 11-inner side of the process boss, 12-upper surface of the wave-absorbing honeycomb thin-wall structure, 13-top surface of the process boss, 14-outer side of the process boss, 15-lower surface of the wave-absorbing honeycomb thin-wall structure, 16-side of the thin-wall area. DETAILED DESCRIPTION

[0019] The following will combine the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0020] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application; the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0021] Example 1 like Figure 1-4 As shown, the present invention provides a method for processing a wave-absorbing honeycomb thin-wall structure, comprising the following steps: S1, adding a process boss 2 to the thin-walled region 1 of the wave-absorbing honeycomb thin-walled structure to form a wave-absorbing honeycomb thin-walled process structure with the process boss 2, wherein an inner side surface 11 of the process boss of the wave-absorbing honeycomb thin-walled structure and an upper molding surface 12 of the wave-absorbing honeycomb thin-walled structure form an angle of 95° to 100°; S2, processing of the first surface of the wave-absorbing honeycomb thin-walled structure: fix the wave-absorbing honeycomb blank 3 on the flat pad 5 by double-sided tape 4, use sandbags to fully spread static pressure on the wave-absorbing honeycomb blank 3 for 0.5 to 1h, use a honeycomb end mill to cut in layers, and rough-mill the wave-absorbing honeycomb thin-walled process structure profile and process boss 2; use an integral sheet milling cutter 6 to adopt a tool swing angle of 1 to 5° with the upper profile 12 of the wave-absorbing honeycomb thin-walled structure, and unidirectional milling along the width direction to fine-machine the upper profile 12 of the wave-absorbing honeycomb thin-walled structure; use the integral sheet milling cutter 6 to fine-machine the top surface 13 of the process boss, the outer side surface 14 of the process boss, and the inner side surface 11 of the process boss; S3, Processing of the second surface of the wave-absorbing honeycomb thin-wall structure: S31, installing and fixing the profile tool 7 on the workbench of the machine tool, and measuring the installation accuracy of the profile tool 7 using the machine tool on-machine measurement system; After the first surface of the absorbing honeycomb workpiece 8 is turned over, the absorbing honeycomb workpiece 8 is fixed on the profile tooling 7 by double-sided tape 4, and the absorbing honeycomb workpiece 8 is statically pressed for 0.5 to 1 h by fully paving sandbags, and the absorbing honeycomb thin-walled process structure profile is rough-milled by layered circular cutting using a honeycomb end milling cutter, leaving a processing allowance of 1 to 2 mm; S32, use a honeycomb ball end mill with chip breaking function at the bottom edge, and set the cutting parameters to n = 18000 ~ 24000r / min, V f =2000~3000mm / min, a p =1.0~1.5mm, a e =10%~15% of the tool diameter, reciprocating cutting of the wave-absorbing honeycomb thin-walled process structure surface, leaving 0.5~1mm machining allowance; S33, remove the absorbing honeycomb workpiece 8, clean it, and fix the absorbing honeycomb workpiece 8 on the profile tooling 7 again with the double-sided tape 4, use sandbags to fully spread the absorbing honeycomb workpiece 8 for 0.5 to 1 hour, use the integral milling cutter 6 to use the tool swing angle of 1 to 5 degrees with the lower profile 15 of the absorbing honeycomb thin-wall structure, and set the cutting parameters to n = 18000 to 20000 r / min, V f =1000~2000mm / min, a p =0.5~1.0mm, a e = 2~5mm, along the width direction, unidirectional reverse milling from the thicker side to the thin-walled area to finely machine the lower mold surface 15 of the wave-absorbing honeycomb thin-walled structure; S34, using the integral milling cutter 6 to vertically cut and separate the process boss 2 from the thin-walled area 16 of the wave-absorbing honeycomb thin-walled structure; S35. Use the on-machine measuring system of the machine tool to measure the surface processing accuracy of the wave-absorbing honeycomb thin-walled structure; remove the wave-absorbing honeycomb thin-walled structure and clean it.

[0022] The structures, functions and connection forms disclosed in this article can be implemented in other ways. For example, the embodiments described above are only exemplary, for example, multiple components can be combined or integrated into another component; in addition, each functional component in each embodiment of this article can be integrated into one functional component, or each functional component can exist physically separately, or two or more functional components can be integrated into one functional component.

[0023] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for processing a microwave-absorbing honeycomb thin-wall structure, characterized in that: The following steps are involved: S1. Adding a process boss (2) to the thin-walled region (1) of the wave-absorbing honeycomb thin-walled structure to form a wave-absorbing honeycomb thin-walled process structure, wherein a certain angle is formed between the inner side surface (11) of the process boss and the upper molding surface (12) of the wave-absorbing honeycomb thin-walled structure; S2, processing the first surface and the second surface of the wave-absorbing honeycomb thin-wall structure; The processing of the first surface specifically includes: The wave-absorbing honeycomb blank (3) is fixed on a flat pad (5), and the wave-absorbing honeycomb blank (3) is statically pressed; Use a honeycomb end mill to perform layered circular cutting and down milling to rough-process the wave-absorbing honeycomb thin-walled process structural surface and process boss (2); Using an integral milling cutter (6) to perform fine machining on the upper profile (12), the top surface (13) of the process boss, the outer side surface (14) of the process boss, and the inner side surface (11) of the process boss of the wave-absorbing honeycomb thin-wall structure; Processing the second surface specifically includes: The first surface of the absorbing honeycomb workpiece (8) is turned over and fixed on the profile tooling (7), and the absorbing honeycomb workpiece (8) is statically pressed, and the absorbing honeycomb thin-walled process structure profile of the absorbing honeycomb is rough-milled by layered circular cutting using a honeycomb end milling cutter, leaving a processing allowance of 1 to 2 mm; Use a honeycomb ball-end milling cutter to reciprocate and cut the wave-absorbing honeycomb thin-walled process structure surface, leaving a processing allowance of 0.5 to 1 mm; The absorbing honeycomb workpiece (8) is removed and cleaned, and the absorbing honeycomb workpiece (8) is fixed on the molding tool (7) again, and the absorbing honeycomb workpiece (8) is statically pressed, and the integral milling cutter (6) is used to perform single-direction reverse milling along the width direction from the side away from the outer side surface (14) of the process boss to the thin-walled area (1) to finely machine the lower molding surface (15) of the absorbing honeycomb thin-walled structure; Using an integral blade milling cutter (6) to vertically cut the thin-walled area side surface (16) of the wave-absorbing honeycomb thin-walled structure to separate the process boss (2) from the thin-walled area (1); The on-machine measuring system of the machine tool is used to measure the machining accuracy of the surface of the wave-absorbing honeycomb thin-wall structure; the wave-absorbing honeycomb thin-wall structure is removed and cleaned.

2. The method for processing the wave-absorbing honeycomb thin-wall structure according to claim 1, characterized in that: The angle between the inner side surface (11) of the process boss in S1 and the upper molding surface (12) of the wave-absorbing honeycomb thin-wall structure is 95° to 100°.

3. The method for processing the wave-absorbing honeycomb thin-wall structure according to claim 1, characterized in that: When the upper profile ② of the wave-absorbing honeycomb thin-walled structure in S2 is finely machined, the integral milling cutter (6) and the upper profile (12) of the wave-absorbing honeycomb thin-walled structure are formed at a tool swing angle of 1 to 5°, and the upper profile (12) of the wave-absorbing honeycomb thin-walled structure is finely machined by unidirectional milling along the width direction.

4. The method for processing the wave-absorbing honeycomb thin-wall structure according to claim 1, characterized in that: The S2 intermediate surface fixture (7) is installed and fixed on a machine tool workbench, and the installation accuracy of the surface fixture (7) is measured using an on-machine measurement system of the machine tool.

5. The method for processing the wave-absorbing honeycomb thin-wall structure according to claim 1, characterized in that: The cutting parameters of the honeycomb ball end mill in S2 are set to n=18000~24000r / min, V f =2000~3000mm / min, a p =1.0~1.5mm, a e =10%~15% of tool diameter.

6. The method for processing the wave-absorbing honeycomb thin-wall structure according to claim 1, characterized in that: The included angle between the integral milling cutter (6) and the lower profile (15) of the wave-absorbing honeycomb thin-wall structure in S2 is 1 to 5°, and the cutting parameters are set to n=18000 to 20000 r / min, V f =1000~2000mm / min, a p =0.5~1.0mm, a e =2~5mm.

7. The method for processing the wave-absorbing honeycomb thin-wall structure according to claim 1, characterized in that: During the fixing process, a double-sided adhesive tape (4) is used to fix the wave-absorbing honeycomb blank (3).

8. The method for processing the wave-absorbing honeycomb thin-wall structure according to claim 1, characterized in that: The static pressure is performed by fully spreading sandbags on the static pressure wave-absorbing honeycomb blanks, and the static pressure time is 0.5 to 1 hour.

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