RU2356673C1 - Method for manufacture of chevron filler with contact areas - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention is related to technologies for production of light volume fillers from sheet materials and may be used in production of multilayer panels used in aircrafts, construction and other industries. Sheet billet is marked with folding lines, which create alternating pairs of zigzag strips with design value of size difference along width of strips in every pair, which represent combinations of sections in the form of parallelograms. Billet is transformed into relief condition and pressed to limit condition defined by complete mutual contact of corrugation facets, with creation of filler block with wedge-like protrusions in block areas. Then filler block is pressed along height to produce protrusions as a result of crumpling, and therefore, flat double-sided folds are created in their place - areas of variable width along length of zigzag strips joint within the limits of every facet. Afterwards filler block is stretched to preset condition defined by rated value of block height, and height of wedge-like protrusions is defined by value of size difference along width of zigzag strips assigned from condition of provision of required area of contact area.

EFFECT: strength and reliability of multilayer panel is increased, and its specific mass characteristics are improved.

2 cl, 5 dwg

Description

Technical field

The invention relates to technologies for the production of light bulky fillers from sheet materials and can be used in the manufacture of multilayer panels used in aircraft, construction and other industries.

The strength of multilayer panels substantially depends on the area of connection of the filler with the casing, and it is natural to find ways to increase the contact surface area of the filler and casing of the multilayer panels.

State of the art

A known method of manufacturing a folded filler from a layered composite material. The method consists in forming a folded structure from a layered composite material (fiberglass, organoplastics, etc.). Grooves along the zigzag lines of the protrusions and troughs are filled to a small height with a mixture of chopped fiberglass or glass microspheres with a binder and, after curing the binder, the ridges are ground and, as a result, flat pads are formed along the lines of the protrusions and troughs (Khaliulin V.I. Technological schemes for manufacturing multilayer structures. Kazan: Publishing House of Kazan State Technical University, 1999, 168 pp. ISBN 5-7579-0295-7, p.99).

The disadvantage of this method is that this method of manufacturing a filler significantly impairs the weight characteristics of the multilayer panel and violates the continuity of the material of the filler. The laboriousness of manufacturing also increases due to the manual labor of applying the compound into the grooves and machining it.

There is a method of manufacturing a folded filler, which consists in the fact that for certain marking parameters along the crests of the lines of protrusions and depressions, triangles are made, filled with a composition based on a microsphere and flat surfaces are obtained for gluing with skin (A.S. No. 1646196 USSR, MKI6 : B29D 9/00. Multilayer panel / V.I. Khaliulin, V.E. Desyatov No. 4708093; Declaration 19.06.89; Publ. 21.08.91, Bull. No. 31).

The disadvantages of this method are the excess weight of the panel and the high complexity of filling the filler grooves with any compound and providing a common plane of contact with the skin.

As a prototype, a method of manufacturing a chevron aggregate of multilayer panels having contact areas with flat panel layers was selected (V. Khaliulin. Technological schemes for manufacturing multilayer structures. Kazan: Kazan State Technical University, 1999, 168 pp. ISBN 5-7579-0295-7, p. 100, Fig. 6.8, b).

The method includes marking on a flat blank of bending lines, subsequent bending and folding of the blank with the simultaneous formation of chevron corrugations with side faces in the form of parallelograms, as well as the formation of complex flat folds along the tops and troughs of the corrugations due to the overlap of additional external and internal parallelogram elements, filling the folds with adhesive material and fixing them.

The disadvantage of this method is the need for complex equipment for bending and folding the blank sheet with many small fragments - the faces of the aggregate structure, as well as significant difficulties with applying adhesive material and fixing the folds. Recent operations also require complex additional equipment. In view of the above, this method is applicable only for the manufacture of aggregates with relatively large sizes of its structural elements.

In addition, due to the technological difficulties of shaping, a flat fold has to be performed on a larger area than is necessary to ensure the required strength of the joint of the filler with the flat layers of the panel. In this case, the mass of the aggregate and the applied adhesive material accordingly increases, which reduces the specific mass characteristics of the panel as a whole. The latter is especially important in the manufacture of multilayer panels for aircraft.

Disclosure of invention

The main task to be solved by the claimed invention is directed is to increase the strength and reliability of a multilayer panel and improve its specific mass characteristics.

The technical result achieved by the implementation of the claimed invention is the expansion of the range of sizes of chevron aggregates with contact areas, reducing the complexity of their manufacture and improving the specific mass characteristics of the panels through the use of new technological methods.

The specified technical result is achieved by the fact that in the known method of manufacturing a chevron aggregate of multilayer panels with contact areas, including marking the fold lines on a flat workpiece, the formation of a filler block with chevron corrugations with side faces in the form of parallelograms and contact areas along the vertices and troughs of the corrugations, according to the proposed the technical solution, the marking of the fold lines is carried out along zigzag lines with the formation of alternating pairs of zigzag bands with a calculated value the difference in size along their width in each pair in the form of a set of sections in the form of parallelograms, a filler block with chevron corrugations with parallel faces in the form of parallelograms is obtained by compressing the workpiece from the sides to form a folded structure of a stepped shape with wedge-shaped protrusions in the nodal zones of zigzag lines of protrusions and depressions wherein said compression is carried out to the limit state determined by the complete mutual contact of the corrugation faces with the block skins, the contact pads are crimped block height by squeezing the wedge-shaped protrusions to obtain flat areas of variable width along the junction of the zigzag stripes within each face, after which the filler block is stretched to a predetermined state determined by the nominal value of the height of the block, while the wedge-shaped protrusions perform a height equal to the size difference in width zigzag stripes assigned from the conditions for obtaining the required area of the contact area.

The analysis of the prior art cited by the applicant made it possible to establish that there are no analogs characterized by sets of features identical to all the features of the claimed technical solution. Therefore, the claimed technical solution meets the condition of patentability "novelty."

The search results for known solutions in the art in order to identify features that match the distinctive features of the prototype of the features of the claimed technical solution have shown that they do not follow explicitly from the prior art. From the prior art determined by the applicant, the influence of the transformations provided for by the essential features of the claimed technical solution on the achievement of the specified technical result has not been revealed. Therefore, the claimed technical solution meets the condition of patentability "inventive step".

A brief description of the drawings.

The essence of the new method is illustrated by drawings, in which Fig. 1 shows a scan of the filler, in Fig. 2 is an intermediate state of the filler block (side view) with the point contact of the nodal zones of the zigzag lines of the protrusions of the filler with the skin, in Fig. 3 is a general view of the multilayer panel, figure 4 is a fragment of a folded filler with flat contact areas of variable width, figure 5 is a section bb in figure 2.

In figures 1-5, the numbers indicate the following positions: 1 - zigzag bending line, 2, 3 - zigzag stripes of different widths, 4 - aggregate block in an intermediate state, 5 - flat contact pads of variable width.

The implementation of the invention

The proposed method is implemented as follows.

On the sheet blank, bending lines 1 are marked, forming zigzag stripes 2 and 3 of different widths. The magnitude of the difference in the values of the width of the strips determines the height of the step of the nodal zone from the nominal height of the filler, which in turn determines the required size of the contact area. Next, the workpiece is transformed into a relief state in which it takes the form of a block 4 of a folded structure of a stepped shape with wedge protrusions in the nodal zones of the zigzag lines of the protrusions and hollows of the filler. Compression of the aggregate block from the sides continues until it reaches an extremely compressed state determined by the complete mutual contact of the faces. After that, the block is crimped in height until flat contact pads 5 of variable width are obtained along the entire length of the joint of each pair of strips. The resulting block is stretched to a predetermined state determined by the nominal value of the height of the block.

Industrial applicability

The use of this invention will allow to obtain a chevron aggregate with an increased contact area with the skin of the multilayer panel, which will increase its operational characteristics, for example, shear, bending and tearing of the skin.

Claims (2)

1. A method of manufacturing a chevron filler of multilayer panels with contact areas, including marking the fold lines on a flat workpiece, forming a filler block with chevron corrugations with side faces in the form of parallelograms and contact areas along the tops and troughs of the corrugations, characterized in that the folding lines are marked according to zigzag lines with the formation of alternating pairs of zigzag bands with the calculated value of the difference in size along their width in each pair in the form of a set of sections in the form of parallel ellograms, a filler block with chevron corrugations with parallelogram-shaped lateral faces is obtained by compressing the workpiece from the sides to form a folded structure of a stepped shape with wedge-shaped protrusions in the nodal zones of zigzag lines of protrusions and depressions, while the said compression is carried out to the limit state determined by full mutual contact corrugated faces with block skins, contact pads are crimped by height by squeezing the wedge-shaped protrusions in the form of flat areas of variable width the length along the junction of the zigzag stripes within each face, after which the aggregate block is stretched to a predetermined state, determined by the nominal value of the block height. 2. The method according to claim 1, characterized in that the wedge-shaped protrusions perform a height equal to the size difference in width along the width of the zigzag strips, assigned from the condition of obtaining the required area of the contact area.

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