阅读说明：本技术 一种低成本的玻纤复材起落架支柱结构及制作方法 (Low-cost glass fiber composite landing gear support structure and manufacturing method ) 是由 郑超 张志超 李仁鹏 侯学佳 吴昊 于 2020-12-01 设计创作，主要内容包括：本发明公开了一种低成本的玻纤复材起落架支柱结构及制作方法,包括支柱结构本体,所述支柱结构本体由复材大板排版、切割下料并机加成型,所述复材大板由中间层及设置在该中间层外表面的表面层铺贴并高温高压而成,且中间层和表面层均由若干玻纤单向带的单向预浸料铺贴而成,所述中间层由70-120层单向预浸料铺贴而成,所述表面层由6-20层单向预浸料铺贴而成；所述制作方法包括：设计起落架的支柱外形并确定中间层及表面层的铺层数量；确定复材大板的长度和宽度以及板料的排版；对单向带预浸料进行下料,铺贴复材大板；通过模压或者热压罐高温高压将压实后的复材大板固化成型；从已固化的复材大板中切取板料；将板料机加成起落架支柱。(The invention discloses a low-cost glass fiber composite landing gear support structure and a manufacturing method thereof, wherein the support structure comprises a support structure body, the support structure body is formed by typesetting, cutting, blanking and adding composite large plates, each composite large plate is formed by paving and pasting an intermediate layer and a surface layer arranged on the outer surface of the intermediate layer at high temperature and high pressure, the intermediate layer and the surface layer are formed by paving and pasting unidirectional prepreg of a plurality of glass fiber unidirectional tapes, the intermediate layer is formed by paving and pasting 70-120 layers of unidirectional prepreg, and the surface layer is formed by paving and pasting 6-20 layers of unidirectional prepreg; the manufacturing method comprises the following steps: designing the appearance of a strut of the landing gear and determining the number of layers of the middle layer and the surface layer; determining the length and width of the large composite board and the typesetting of the board; blanking the prepreg of the unidirectional tape, and paving and pasting the composite large board; curing and molding the compacted composite large plate through mould pressing or autoclave high temperature and high pressure; cutting a plate material from the solidified composite material large plate; and (4) forming the plate machine into a landing gear support.)

1. The utility model provides a fine combined material undercarriage strut structure of glass of low cost, includes the strut structure body that is used for the fixed undercarriage of general aircraft, its characterized in that: the pillar structure body is composed of composite large boards, is subjected to cutting and blanking and is subjected to additive molding, the composite large boards are formed by laying and pasting a middle layer of main bearing force and a surface layer which is arranged on the outer surface of the middle layer and plays a role in maintaining the shape at high temperature and high pressure, the middle layer and the surface layer are formed by laying and pasting one-way prepreg of a plurality of glass fiber one-way belts, the middle layer is formed by laying and pasting 70-120 layers of one-way prepreg, and the surface layer is formed by laying and pasting 6-20 layers of one-way prepreg.

2. A low cost glass fiber composite landing gear leg structure as claimed in claim 1, wherein: the surface layer comprises an inner surface layer and an outer surface layer which are arranged in sequence, and the number of the layers of the inner surface layer is greater than that of the layers of the outer surface layer; the fiber laying direction of the middle layer is 0 degree, the fiber laying direction of the inner surface layer is 90 degrees, and the fiber laying direction of the outer surface layer is 0 degree.

3. A low cost glass fiber composite landing gear leg structure as claimed in claim 2, wherein: the composite large plate is formed by autoclave molding or compression molding.

4. A method of manufacturing a glass fibre composite landing gear strut structure according to any one of claims 1 to 3, wherein: the method comprises the following steps:

1) designing the appearance of a strut of the landing gear according to the overall layout of the airplane and the load of the landing gear, and determining the layering quantity of the middle layer and the surface layer according to the appearance size;

2) determining the length and width of the large composite board and the typesetting of the board material according to the breadth of the prepreg of the unidirectional tape and the appearance of the strut and according to the principle of fully utilizing the material as much as possible;

3) blanking the prepreg of the unidirectional tape, paving and pasting the composite large board, and compacting once when 20 layers are paved and pasted;

4) curing and molding the compacted composite large plate through mould pressing or autoclave high temperature and high pressure;

5) cutting a plate from the cured large composite plate, wherein the processing edge is perpendicular to the surface of the part, and the layering direction is consistent with the engineering drawing;

6) and (4) adding the plate machine into a landing gear support finished product.

5. The method of manufacturing according to claim 4, wherein: the composite large board is compacted by vacuum pressure in a compaction procedure which is a cyclic process of repeatedly pressurizing, pressure maintaining and pressure relieving every time 20 layers of the composite large board are paved in the paving process to remove residual air between the paved layers.

Technical Field

The invention relates to the field of research and development and manufacturing of aircraft landing gears, in particular to a low-cost glass fiber composite landing gear support structure and a manufacturing method thereof.

Background

The landing gear system is an important bearing part of the airplane and has great influence on the safe taking off and landing of the airplane. The landing gear design takes into account structural layout, system definition, static and dynamic characteristics, weight cost and other factors, and small and light aircraft usually adopt fixed landing gears, wherein the plate spring type main landing gear is particularly common in application. The plate spring support column can be made of metal materials or composite materials, the metal support column is heavy in weight, and the composite material support column has natural advantages in weight reduction.

The composite material support column produced in China at present generally has the following defects: 1. the molding process is complex, and the cost of raw materials and molds is high; 2. the rigidity is large, the deformable quantity is small, and the weight-reducing and energy-absorbing characteristics are poor; 3. the process control is unstable, and the material dispersion coefficient is large; 4. the removability is poor and it is difficult to make rapid structural adjustments to specific design requirements. In addition, the general-purpose aircraft is sensitive to weight and cost, and the landing gear strut has high requirements on mechanical property and process stability, so that the existing landing gear strut manufacturing technology cannot be adapted to meet the increasingly strong market requirements of the general-purpose aircraft.

Disclosure of Invention

The invention aims to solve the technical problems that the undercarriage supporting column structure and the manufacturing method of the undercarriage supporting column structure are simple in principle, high in production efficiency and simple in design flow, a large amount of mould cost is not required, the development progress of the undercarriage can be accelerated, the development cost is reduced, and the market competitiveness is improved.

The invention aims to provide a low-cost glass fiber composite landing gear support column structure, which comprises a support column structure body for a fixed landing gear of a general airplane, wherein the support column structure body is formed by typesetting, cutting, blanking and machining composite large plates, each composite large plate is formed by paving and pasting a main force bearing intermediate layer and a surface layer which is arranged on the outer surface of the intermediate layer and plays a role in dimensional shape at high temperature and high pressure, the intermediate layer and the surface layer are formed by paving and pasting a plurality of unidirectional prepreg of glass fiber unidirectional tapes, the intermediate layer is formed by paving and pasting 70-120 unidirectional prepreg layers, and the surface layer is formed by paving and pasting 6-20 unidirectional prepreg layers.

Further, the surface layer comprises an inner surface layer and an outer surface layer which are sequentially arranged, and the number of the layers of the inner surface layer is greater than that of the layers of the outer surface layer; the fiber laying direction of the middle layer is 0 degree, the fiber laying direction of the inner surface layer is 90 degrees, and the fiber laying direction of the outer surface layer is 0 degree.

Further, the composite large plate is formed by autoclave molding or compression molding.

A manufacturing method of a glass fiber composite landing gear support structure comprises the following steps:

1) designing the appearance of a strut of the landing gear according to the overall layout of the airplane and the load of the landing gear, and determining the layering quantity of the middle layer and the surface layer according to the appearance size;

2) determining the length and width of the large composite board and the typesetting of the board material according to the breadth of the prepreg of the unidirectional tape and the appearance of the strut and according to the principle of fully utilizing the material as much as possible;

3) blanking the prepreg of the unidirectional tape, paving and pasting the composite large board, and compacting once when 20 layers are paved and pasted;

4) curing and molding the compacted composite large plate through mould pressing or autoclave high temperature and high pressure;

5) cutting a plate from the cured large composite plate, wherein the processing edge is perpendicular to the surface of the part, and the layering direction is consistent with the engineering drawing;

6) and (4) adding the plate machine into a landing gear support finished product.

Further, in the paving and pasting process of the large composite board, a compaction process is carried out once every 20 layers are paved and pasted to remove residual air between the paved layers, the compaction process adopts vacuum pressure for compaction, and the vacuum compaction method is a cyclic process of repeatedly carrying out pressurization-pressure maintaining-pressure relief for a plurality of times.

The invention has the beneficial technical effects that: the manufacturing of the large plate can be completed only by a simple flat plate tool without manufacturing a part die, so that the manufacturing cost is greatly saved; the curing and forming method is mature and stable, the yield is greatly improved, and the stability of the mechanical property of the landing gear strut is ensured; by adopting a water cutting or conventional machining method, parts are quickly machined on the large plate, so that the manufacturing efficiency of the parts is greatly improved; when the design of the structure is changed, the large plate is only needed to be paved again, or new parts are directly added on the original large plate, a die is not needed to be changed, and the design change process is greatly simplified.

Drawings

FIG. 1 is a schematic cross-sectional structural view of the pillar structure body according to the present invention;

FIG. 2 is a schematic view of a composite large panel according to the present invention under vacuum pressure;

FIG. 3 is a schematic diagram of the composite material large board during typesetting;

fig. 4 is a schematic view of the strut structure body added by the plate material machine according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood by those skilled in the art, the present invention is further described with reference to the accompanying drawings and examples.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "inside", "outside", "lateral", "vertical", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, and thus, should not be construed as limiting the present invention.

The curing and forming technology for the composite large board adopts glass fiber composite unidirectional tape prepreg for paving and pasting, and the composite large board is formed by high-temperature and high-pressure curing, specifically can adopt compression molding or autoclave molding, and has the advantages of simple required tool, stable process and high yield. The landing gear support design and manufacture technology is to typeset, blank and machine-add composite large plates into the composite support, so that the design link and the manufacturing cost of a die are saved, the support manufacture efficiency is greatly improved, the design change is easy, and the design change flow of the structure is simplified.

As shown in fig. 1-4, the low-cost glass fiber composite landing gear support column structure comprises a support column structure body 1 for a fixed landing gear of a general airplane, wherein the support column structure body 1 is formed by typesetting, cutting, blanking and machining a composite large plate 2, the composite large plate 2 is formed by paving and pasting a main force bearing intermediate layer 3 and a surface layer 4 which is arranged on the outer surface of the intermediate layer 3 and plays a role of dimensional type at high temperature and high pressure, the intermediate layer 3 and the surface layer 4 are formed by paving and pasting a plurality of unidirectional prepreg of glass fiber unidirectional tapes, the unidirectional tape prepreg of the glass fiber unidirectional tapes is good in toughness, impact-resistant and suitable for manual paving and high-temperature curing, and when the unidirectional tapes are selected, a material test and a full-size drop test are carried out to show that the mechanical property of the materials meets the design requirements. The middle layer 3 is formed by paving 70-120 layers of unidirectional prepreg, the surface layer 4 is formed by paving 6-20 layers of unidirectional prepreg, and the paving quantity of the middle layer can be properly adjusted according to the requirement to meet the thickness requirement.

Referring to fig. 1, the surface layer 4 includes an inner surface layer 41 and an outer surface layer 42, which are arranged in sequence, and the number of layers of the inner surface layer 41 is greater than that of the outer surface layer 42; the fiber laying direction of the intermediate layer 3 is 0 °, the fiber laying direction of the inner surface layer 41 is 90 °, and the fiber laying direction of the outer surface layer 42 is 0 °. The composite material large plate 2 is formed by autoclave molding or compression molding.

A manufacturing method of a glass fiber composite landing gear support structure comprises the following steps:

1) designing the appearance of a strut of the landing gear according to the overall layout of the airplane and the load of the landing gear, and determining the layering quantity of the middle layer and the surface layer according to the appearance size;

2) determining the length and width of the large composite board and the typesetting of the board material according to the breadth of the prepreg of the unidirectional tape and the appearance of the strut and according to the principle of fully utilizing the material as much as possible;

3) blanking the prepreg of the unidirectional tape according to the length and the width of the large composite board and the fiber direction of each ply, wherein the fiber orientation error of the unidirectional tape is within +/-3 degrees; under a controllable environment, paving and pasting the prepreg sheets according to the requirement of a tolerance drawing, manually compacting the prepreg sheets, and removing air bubbles; paving and pasting the composite large board, and compacting once when 20 layers are paved;

4) after paving and pasting are finished, bag making and vacuumizing are carried out on the composite large plate, vacuum pressure of one atmosphere is applied, the vacuum leakage rate is detected, and the leakage rate is ensured not to exceed 3' Hg every 5 minutes; vacuum pressure must be maintained for 30 minutes before entering the autoclave; the composite large plate enters an autoclave, high-temperature and high-pressure curing molding is carried out according to a specified curing curve, the lowest autoclave pressure is 22' Hg, and a reading is read every 30 minutes; after reaching the autoclave pressure, the vacuum pressure can be released; curing and molding the compacted composite large plate through mould pressing or autoclave high temperature and high pressure;

5) cutting a plate from the cured large composite plate, wherein the processing edge is perpendicular to the surface of the part, and the layering direction is consistent with the engineering drawing; the porosity and defects of the large molded plate and the finished strut products are strictly controlled through nondestructive testing of the large cured composite plate;

6) adding a sheet metal machine into a landing gear support finished product;

the method comprises the following steps of carrying out a compaction procedure once when 20 layers of the composite large board are paved in the paving process to remove residual air between the paved layers, compacting by adopting vacuum pressure in the compaction procedure, vacuumizing, applying vacuum pressure of one atmosphere and keeping for 2.5 minutes, then releasing the pressure, reducing the vacuum degree to be below about 5' Hg, repeating the operation for 3 times, and completing the compaction procedure, wherein the vacuum compaction method is a cyclic process of repeating pressurization-pressure maintaining-pressure releasing for a plurality of times.

Referring to fig. 2, the laid large composite board is subjected to vacuum compaction or gravity compaction, then a bag is made, vacuum pressure is applied and maintained on the large composite board, and then the large composite board enters an autoclave and is cured and molded according to a predetermined curing curve. And (3) typesetting, cutting and blanking the cured large composite board according to the graph shown in fig. 3, and finally adding the support post finished product on the board by using a special composite machine tool.

According to the manufacturing method, a part die does not need to be manufactured, and the large plate can be manufactured only by a simple flat plate tool, so that the manufacturing cost is greatly saved; the curing and forming method is mature and stable, the yield is greatly improved, and the stability of the mechanical property of the landing gear strut is ensured; by adopting a water cutting or conventional machining method, parts are quickly machined on the large plate, so that the manufacturing efficiency of the parts is greatly improved; when the design of the structure is changed, the large plate is only needed to be paved again, or new parts are directly added on the original large plate, a die is not needed to be changed, and the design change process is greatly simplified.

The specific embodiments described herein are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.