RU2607575C2 - Sectional shell for internal pressure from layered composite material - Google Patents

Abstract

FIELD: manufacturing technology.

SUBSTANCE: shell is intended for articles of aircraft and rocket engineering. Shell comprises two sections 1 and 2, each of which consists of cylindrical part 3 and 4, convex bottoms 5 and 6, flanges in the bottoms pole holes 7 and 8, inner protective coating 9 and 10. Sections consist of a set of spiral 11 and annular 12 layers based on impregnated with a binder unidirectional bundles and annular bulges 13, 14 near cylindrical ends with located in them connecting pins 15, 16 and studs 17. Between connected ends of sections there is metal ring 18 along the external and the internal diameters equipped with centering belts 19, 20, the inner of which are made on their outer surfaces with local annular grooves 21 for locating sealing elements, for example, rubber bundles. Outer ones are made with conical, facing the section and converging to the ring surfaces 22, on the outer surface of the sections bulges there are mating conical surfaces, and along the circumference in the ring there are holes 23 coaxial with located in them connecting studs.

EFFECT: simplified assembling process.

5 cl, 5 dwg

Description

The invention relates to mechanical engineering and can be used in the construction of gas and hydraulic filters or accumulators and all similar containers using shells made of composite materials, as well as in aircraft and rocket technology products, for example, as fuel tanks and solid fuel rocket engine bodies.

The known design of the fuel tank of a helicopter, made in the form of two sections by winding a power shell of composite material onto a metal liner (Bulanov I.M., Vorobey V.V. Technology of rocket and aerospace structures from composite materials: Textbook for universities. M .: Publishing House of MSTU named after N.E.Bauman, 1998.516 s., Ill., Fig. 6.38, 6.39 p. 484, 485).

The disadvantage of this design is the design complexity and high cost due to the use of a metal liner.

Known reinforced casing for internal pressure of a layered composite material, in the form of two sections connected to each other with a cylindrical section and a convex bottom, each consisting of a set of spiral-bonded and annular layers of unidirectional strands and annular thickenings at the cylindrical ends with connecting pins and studs and a centering protrusion with a groove corresponding to it on the inner surface (RU 2514980 C1, 7 F17C 1/06, 05/10/2014).

The disadvantage of this design is the lack of strength and reliability of the connection section, which is determined by the following.

The structures under consideration are made of a layered composite material (CM), which has maximum strength characteristics along the location of the reinforcing material (layers) and minimal across the layers, and the strength across the layers is several times lower than along.

Under the action of axial tensile forces on the shell caused by the action of internal pressure, contact pressure arises on the contact surface of the CM with the pin, which causes the CM to collapse in the axial direction and to burst in the transverse direction. Bursting across the layers (along the thickness of the shell) leads to delamination and tearing of the layers and ultimately the destruction of the shell in the area of the junction.

The reinforced casing for high internal pressure from a layered composite material according to the patent RU 2514980 is the closest to the claimed technical essence and the achieved result and is selected as the closest analogue (prototype).

The technical problem to which the invention is directed is to increase the strength and reliability of the shell for high internal pressure, made in the form of two sections interconnected, with improved performance characteristics.

The technical result that can be obtained by using the invention is to increase the operational efficiency of the structure by increasing the strength and reliability of the connection node, increasing the manufacturability of the structure through the use of rings with centering belts, which simplifies the assembly process, expanding the scope of applicability due to the possibility of increasing functional qualities of an intermediate metal ring depending on specific conditions.

The technical problem is solved, and the technical result is achieved by the fact that the sectional shell is made of layered composite materials in the form of two sections interconnected with a cylindrical section and a convex bottom, each consisting of a set of spiral and ring layers, on the basis of unidirectional strands impregnated with a binder, and ring thickenings at cylindrical ends with connecting pins and pins located in them, according to the invention is made with a metal joint located between the joined ends of the sections a face equipped with centering outer and inner diameters symmetrical with respect to its median, perpendicular axis of the shell, cross-section, belts, the inside of which are made on its outer surface with local annular grooves for the location of the sealing elements - rubber bands, the outer ones are made with conical facing sections and tapering to the ring surfaces, on the outer surface of the thickenings of the sections mating conical surfaces are made, and around the circumference in the ring are made about the holes coaxial to the connecting pins located in them, and in particular cases of the invention, the ring is made in axial section in the form of a box-shaped profile consisting of two side walls and a cylindrical shell located along the inner diameter of the ring, the pins are made in the form of two shortened parts, each of which pulls together one section with the box-shaped profile wall adjacent to it, the ring contains jumpers distributed around the circumference and oriented along the body axis, made in one piece with the side Vym walled cylindrical shell, between which, in the circumferential direction are located bolts, rings on a cylindrical shell provided with holes or nozzles for connecting functional devices, such as gas ducts or sensors.

Distinctive features of the prototype signs of the claimed sectional shell are the following:

a) the signs that ensure the receipt of a technical result in all cases to which the requested amount of legal protection applies:

- between the joined ends of the sections is a metal ring;

- equipped with centering belts on the outer and inner diameters;

- symmetric with respect to its median, perpendicular to the axis of the shell section;

- internal of which are made on its outer surface with local annular grooves for the location of the sealing elements - rubber bands;

- the exterior is made with conical, facing the section and tapering to the ring surfaces;

- on the outer surface of the thickening sections are made mating conical surfaces;

- around the circumference in the ring holes are made, coaxial to the connecting studs located in them;

b) signs characterizing the invention in special cases:

- the ring is made in axial section in the form of a box-shaped profile, consisting of two side walls and a cylindrical shell located along the inner diameter of the ring;

- the studs are made in the form of two shortened parts, each of which pulls together one section with the box-shaped profile wall adjacent to it;

- the ring contains jumpers distributed around the circumference and oriented along the body axis, made in one piece with the side walls and the cylindrical shell, between which, in the circumferential direction, the studs are located;

- holes or nozzles are made on the cylindrical ring shell for connecting functional devices, such as flues or sensors.

These distinctive features, individually and collectively, are aimed at achieving the stated result and are significant. In the prior art, the totality of the known and distinctive features presented in the claims is not known and, therefore, the invention meets the criterion of "novelty."

Sectional shell, unlike the prototype shell, is more durable and reliable, since the layered thickening of the CM in the area of action of the bursting forces is clamped by two bands, which prevents the occurrence of delamination and destruction of the CM. The use of conical surfaces on the belts, when assembling the sections, leads to compression of the thickening and layers between themselves, which virtually eliminates the possibility of delamination and increases the reliability of the structure. The use of two centering belts simplifies the assembly process of sections, especially large diameters, when local adjustment of the position of the sections relative to each other is impossible. Also in this case, the radial displacement of the mating ends of the sections relative to each other is minimized, which increases the strength and reliability of hairpin connections by eliminating the warps and bends of the studs.

The use of a ring with a section of a box-shaped profile allows us to expand the field of applicability of sectional shells by increasing the functional qualities of the ring.

The studs can pass through the ring through fastening on the pins or pull each section with the ring separately. In the latter embodiment, the studs (nuts) can be positioned more tightly in the circumferential direction, which allows to increase the bearing capacity of the connection node.

Cross jumpers increase the strength of the box profile under the action of tensile loads from the studs and can be located through one, two or more studs, depending on specific conditions.

The shell design using the proposed technical solution is industrially feasible using known means and methods and ensures the implementation of this purpose.

The invention is illustrated by the description of a specific, but not limiting example of implementation and the accompanying drawings.

In FIG. 1 shows the claimed sectional casing; FIG. 2 - node connecting sections with a ring between them, in FIG. 3 - connection unit of sections with a box-shaped ring, in FIG. 4 is a view of the arrangement of jumpers in the ring of the box-shaped profile, in FIG. 5 is a view of a box-shaped profile with a branch pipe located.

The sectional shell contains two sections 1 and 2, each of which consists of a cylindrical part 3 and 4, convex bottoms 5 and 6, flanges in the pole holes of the bottoms 7 and 8, an inner protective coating 9 and 10. The sections consist of a set of spiral 11 and ring 12 layers, based on unidirectional harnesses impregnated with a binder, and annular thickenings 13, 14 at the cylindrical ends with connecting pins 15, 16 and studs 17 located therein. A metal ring 18 is provided between the joined ends of the sections, provided with an outer and inner diameter centering, symmetrical about their middle, perpendicular axis of the shell section, belts 19, 20, the inner of which are made on its outer surface with local annular grooves 21 for the location of the sealing elements - rubber bands, the outer ones are made of conical, facing the section and tapering to ring surfaces 22, on the outer surface of the thickenings of the sections mating conical surfaces are made, and around the circumference in the ring holes 23 are made, coaxial to the joints located in them itelnym studs 17.

In the particular case of execution, the ring 18 is made in axial section in the form of a box-shaped profile, consisting of two side walls 24, 25 and a cylindrical shell 26 located along the inner diameter of the ring; the studs 17 are made in the form of two shortened parts, each of which pulls together one section 1 with the adjacent wall 24 and section 2 with the box-shaped wall 25; the ring contains jumpers 27 distributed around the circumference and oriented along the body axis, made integrally with side 24, 25 walls and a cylindrical shell 26, between which, in the circumferential direction, studs 17 are located; holes or nozzles 28 are made on the cylindrical ring shell 26 of the ring for connecting functional devices, such as flues or sensors.

An experimental test in the factory confirmed the high strength and reliability of the proposed design.

Claims (5)

1. A sectional shell of layered composite materials in the form of two sections interconnected with a cylindrical section and a convex bottom, each consisting of a set of spiral and annular layers, based on unidirectional bundles impregnated with a binder, and annular thickenings at the cylindrical ends with connecting pins located in them and studs, characterized in that between the joined ends of the sections there is a metal ring equipped with centering symmetrical from the outer and inner diameters from relative to their middle, perpendicular axis of the shell section, belts, the inner of which are made on its outer surface with local annular grooves for the location of the sealing elements - rubber bands, the outer ones are made with conical, facing the section and tapering to the ring surfaces on the outer surface of the thickening sections mating conical surfaces are made, and holes circumferentially made in the ring are aligned with the connecting studs located therein. 2. Sectional casing according to claim 1, characterized in that the ring is made in axial section in the form of a box-shaped profile consisting of two side walls and a cylindrical shell located along the inner diameter of the ring. 3. Sectional casing according to claim 2, characterized in that the studs are made in the form of two shortened parts, each of which pulls together one section with an adjacent box-shaped wall. 4. The sectional casing according to claim 2, characterized in that the ring contains jumpers distributed around the circumference and oriented along the body axis, made integrally with side walls and a cylindrical shell, between which, in the circumferential direction, the studs are located. 5. The sectional shell according to claim 2, characterized in that holes or nozzles are made on the cylindrical ring shell for connecting functional devices, such as flues or sensors.

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