RU-2861295-C1 - METHOD FOR MANUFACTURING CURVILINEAR HONEYCOMB CORE OF MULTILAYER PANEL

Abstract

FIELD: vehicles. SUBSTANCE: invention relates to the field of highly loaded structural elements of vehicles, in particular to methods for manufacturing honeycomb cores for three-layer panels, including alternating tubular elements in the form of a four-pointed star, capable of being laid on surfaces of double curvature of a wide range of radii without saddle formation. According to the method, weakenings are applied to strips of sheet material by creasing or perforation methods. The segment of the workpiece required for shaping one tubular element in the form of a four-pointed star contains six weakening lines. The extreme weakening line is the weakening line for the next segment of the workpiece. The areas between lines 2-3 and 3-4 are glued, and lines 2 and 4 are combined into line 6. At the next stage, folding is carried out along lines 3 and 5 until pressed against lines 1. Adhesive strips are applied to the areas between lines 3 and 6. Formation of a package of fully folded strips is ensured with the formation of a tubular element in the form of a square, wherein each subsequent strip is connected to the previous one along the area between lines 3 and 6 with the applied adhesive layer. The package is placed in a press, where gluing is carried out according to a specified technological mode, after which it is stretched to the required geometric dimensions, then the flat block is given a curvilinear shape by stretch forming over a punch or using shaping tooling. EFFECT: curvilinear honeycomb core is formed using a stretching operation. 1 cl, 6 dwg

Inventors

• KHALIULIN VALENTIN ILDAROVICH
• Demidovich Viktoriia Nikolaevna
• Savinov Dmitrii Vadimovich

Dates

Publication Date

20260504

Application Date

20250808

Claims (1)

1. A method for producing a curved honeycomb core for a multilayer panel, the structure of which is formed by periodically repeating tubular elements of two types, namely a tubular element in the form of a four-pointed star and a tubular element in the form of a square, characterized in that weakenings are applied to the strips of sheet material by creasing or perforation methods, wherein the segment of the workpiece required for shaping one tubular element in the form of a four-pointed star contains six lines of weakening, wherein the outer line of weakening is a line of weakening for the next segment of the workpiece, then the sections between lines 2-3 and 3-4 are glued together, and lines 2 and 4 are combined into line 6; at the next stage, folding is carried out along lines 3 and 5 until pressing towards lines 1; adhesive strips are applied to the sections between lines 3 and 6; provide the formation of a package from completely folded strips, with the formation of a tubular element in the form of a square, while each subsequent strip is connected to the previous one along the section between lines 3 and 6 with an applied adhesive layer, then the package is placed in a press, where gluing is carried out according to a given technological mode, after which it is stretched to the required geometric dimensions, after which the flat block is given a curvilinear shape by the method of stretching along a punch or with the help of forming equipment.

Description

The invention relates to methods for producing honeycomb cores for three-layer panels and shells and concerns a method for producing a honeycomb core that can be used in various industries: shipbuilding, automotive, aviation, and rocket and space. A known method for producing a honeycomb core for a multilayer panel (V.N. Krysin, "Layered Glued Structures in Aircraft Construction." Moscow: Mashinostroenie, 1980, 228 p.) involves pre-corrugating the sheet material before gluing and assembling the honeycomb block. A disadvantage of this manufacturing method is the formation of a saddle shape when laid on a curved surface, making it impossible to impart a double curvature to the core. A method for producing curved honeycomb panels is known (A.s. 1453716 USSR, MKI D 21 D 47/00. Method for producing curved honeycomb panels / Maksimenkov V.I., Zhilyaev A.I., Chernykh I.A., Tensky I.A., Bobrovnikov S.V. (USSR) No. 4189625/27; Claimed 02.02.1987; Published 20.08.1995). In this method, curvature is imparted to the honeycomb core in a multilayer panel by stretching it along a punch of a given geometry while simultaneously applying a tensile load to the ends of the panel. A disadvantage of this method is the distortion of the shape of the honeycomb core, the occurrence of defects in the adhesive joint between the core and the skins and the possibility of loss of stability of the walls of the tubular elements. A method for producing a honeycomb core for a multilayer panel is known (A.s. 440266, IPC B 29d 9/00, B 32b 1/00. Method for producing a non-flat honeycomb core / V.N. Paimushin, V.I. Matushkin, V.F. Subbotin (USSR). No. 1803530/23-5; Cl. 29.06.72; Published 25.08.74, Bulletin No. 31). The manufacturing method includes cutting sheet material, applying trapezoidal adhesive strips arranged in a staggered pattern, gluing the sheets of material with subsequent stretching and fixing the shape. This filler allows it to be given a curvilinear shape. The disadvantage of this manufacturing method is the technological complexity of applying trapezoidal adhesive strips. A known method for producing a curved honeycomb core for a multilayer panel (Patent RU 2843022 C1, IPC B32B 5/00. Method for producing a curved honeycomb core for a multilayer panel / V.I. Khaliulin, V.N. Demidovich, A.A. Malysheva. Claimed 09.12.2024; Published 07.07.2025; Bulletin No. 19) has a structure formed by periodically repeating tubular elements of two types: a tubular element in the form of a four-pointed star and a tubular element in the form of a square. The method consists in separately forming the tubular elements and then joining them into a flat block. The disadvantages of this method include the high labor intensity of manufacturing the tubular elements separately and, as a consequence, a decrease in manufacturability and production culture. This method is the closest to the claimed one and is accepted as a prototype. The problem that the claimed invention is aimed at solving is the development of a productive method for manufacturing a curved honeycomb core for a multilayer panel, the structure of which is formed by periodically repeating tubular elements of two types: a tubular element in the form of a four-pointed star and a tubular element in the form of a square. The technical result, which the claimed invention is aimed at achieving, consists in reducing the production cycle for the manufacture of a curved honeycomb core of a multilayer panel, the structure of which is formed by periodically repeating tubular elements of two types: a tubular element in the form of a four-pointed star and a tubular element in the form of a square. The technical result is achieved in that the method for producing a curved honeycomb core, the structure of which is formed by periodically repeating tubular elements of two types (a tubular element in the form of a four-pointed star and a tubular element in the form of a square) includes the operations of cutting sheet material into strips, folding the strips to form a blank, assembling a package from the folded strips, gluing in a press, stretching the glued package to the required geometric dimensions and giving the package a curvilinear shape. The essence of the invention is shown in Fig. 1-6. Fig. 1 - curved honeycomb core of a multilayer panel, capable of being laid on a double-curved surface; Fig. 2 - stages of folding a strip of sheet material; Fig. 3 - gluing blanks from strips of sheet material; Fig. 4 - assembly of a flat block of honeycomb core; Fig. 5 - imparting curvature to a flat block; Fig. 6, a - demonstrator of a flat block of filler, Fig. 6, b - demonstrator of a curved block of filler. The method for producing a curved honeycomb core for a multilayer panel (Fig. 1) includes the following operations: weakenings are applied to strips of sheet material by creasing or perforating methods to facilitate subsequent folding (Fig. 2, a ). Segment a of the blank, necessary for forming one tubular el