RU193818U1 - Mandrel for making composite shells - Google Patents

Abstract

The utility model relates to the technology of manufacturing parts from composite materials, namely, shells of revolution for power structures. The mandrel for the manufacture of shells from composite material contains a forming part provided with a base and a cover. The forming part of the mandrel is made in the form of a series of shells strung on a hollow cylindrical glass, disks located between the disks covering the hollow cylindrical glass. The mandrel disks protrude beyond the outer surface of the shells with the formation of annular partitions to separating the manufactured shells from composite material. The technical result is to provide a new mandrel with removable forming parts, devoid of the disadvantages of the known structures, as well as having a low weight, simple structure and not requiring large costs for its manufacture. Practical use of the utility model has confirmed the high the reliability of the mandrel for the manufacture of annular shells of composite material.

Description

The utility model relates to the technology of manufacturing parts from composite materials, namely, shells of rotation for power structures.

In the manufacture of shells from composite materials, ring winding of a material band pre-impregnated with a binder is carried out on the mandrel.

After that, a package of material impregnated with a binder is cured in a hydroclave with an elastic diaphragm covering the mandrel, through which pressure and temperature of the working medium in the hydroclave are transferred to the material package.

Known mandrels for the manufacture of shells containing a forming part made in the form of a hollow truncated cone or cylinder (see, for example, I.M. Bulanov, V.V. Vorobey. Technology of rocket and aerospace structures from composite materials. - M.: Publishing House MSTU named after N.E.Bauman, 1998 - pp. 197-198, 449, 452).

These mandrels make it possible to obtain the required geometry of the internal configuration of the fabricated thin-walled shell of conical or cylindrical shape, have sufficient strength, are easily removed after curing of the shell, are reusable mandrels.

However, the design of these mandrels is not intended for the simultaneous manufacture of several shells on the same mandrel.

Also known is a mandrel for the manufacture of shells made of composite material containing a forming part provided with a base and a lid (see RF patent No. 2445207), which is the closest analogue to the proposed utility model.

The use of this mandrel allows you to provide the required quality of manufacture of shells from composite material.

However, the design of this mandrel, as well as other known designs of mandrels, is not intended for the manufacture of several shells on the same mandrel.

If you need to make several shells, then a single shell made using this mandrel should be cut into pieces of the required length, which is associated with an additional volume of machining and requires the use of special tools and additional equipment.

In addition, the design of this mandrel is quite complex and its manufacture is a metal-consuming and labor-intensive process.

The forming part of the known mandrel is monolithic, which during repair or replacement requires significant material costs.

Thus, despite the wide variety of known mandrels for the manufacture of shells made of composite material, the implementation of technological processes periodically necessitates the development of new mandrel designs.

When developing a utility model, a technical problem was solved by expanding the arsenal of mandrel designs used in the manufacture of shells from composite material.

The technical result consists in providing a new mandrel with removable forming parts, devoid of the disadvantages of the known structures and allowing to produce a number of shells on one mandrel at the same time, as well as having a low weight, simple design and not requiring large expenses for its manufacture.

The technical result is achieved by the fact that in the mandrel for the manufacture of shells from a composite material containing a forming part provided with a base and a cover, the forming part is made in the form of a series of shells strung on a hollow cylindrical glass located between the disks enclosing the hollow cylindrical glass protruding beyond the outer surface of the shells with the formation of annular partitions separating the manufactured shell from composite material.

The mandrel for the manufacture of shells of composite material can be equipped with a removable squeeze ring mounted on the base of the mandrel, interacting with the end of the lower shell.

The execution of the forming part in the form of a series of shells strung on a hollow cylindrical glass located between the disks enclosing the hollow cylindrical glass allows the manufacture of a number of shells of the required length on one mandrel, eliminating the need for cutting, which is advisable, for example, in the manufacture of samples for fracture tests .

The design of the mandrel allows you to provide the curing of a number of shells on one mandrel for one technological step in one hydroclave or furnace.

The presence of a removable squeezing ring interacting with the end face of the lower shell makes it easier to remove from the mandrel a fabricated shell made of composite material.

In FIG. The diagram of the mandrel assembly is shown.

The mandrel for the manufacture of shells made of composite material is made in the form of a forming part, equipped with a base 1 and a cover 2.

The forming part contains a number of shells 3 strung on a hollow cylindrical glass 4.

The shells 3 are located between the disks 5, covering the hollow cylindrical glass 4.

The disks 5 protrude beyond the outer surface of the shells 3 with the formation of annular partitions separating the manufactured shells 6 from composite material.

Based on the mandrel 2, a removable squeezing ring 7 is installed, interacting with the end face of the lower shell 3.

When preparing the mandrel for work, install a hollow cylindrical glass 4 on the base 1 and fasten the glass 4 with the base 1.

Install on the base 1 of the mandrel removable squeeze ring 7.

String the lower shell 3 on a hollow cylindrical glass 4, install the first disk 5, thread the middle shell 3 on the glass 4, install the second disk 5, then string the upper shell 3 on the glass 4.

Then install the lid 2 on the hollow cylindrical glass 4 and fasten the lid 2 with the glass 4.

The mandrel prepared in this way is installed in the winding machine and, alternately, on the shells 3, the ring winding of the composite material impregnated with a binder is carried out.

After winding, the composite material is cured on a mandrel in a hydroclave with an elastic diaphragm covering the mandrel.

In this case, a uniform fit of the elastic diaphragm over the entire surface of the composite material under the action of pressure of the working medium in the hydroclave is ensured by the creation of a vacuum from the inner surface of the elastic diaphragm.

After curing, the mandrel is dismantled, while the cover 2 is removed from the hollow cylindrical cup 4

They act on the removable squeezing ring 7, turning the process screws all the way into the base (not shown in Fig.), While the ring 7 interacts with the end of the lower shell 3, which moves up the cup 4, which greatly simplifies and simplifies the removal of the shells 3 with wound shells of composite material with a hollow cylindrical glass 4.

The practical application of the utility model confirmed the high reliability of the mandrel for the manufacture of annular shells of composite material.

Claims (2)

1. A mandrel for the manufacture of shells of composite material containing a forming part provided with a base and a lid, characterized in that the forming part is made in the form of a series of shells strung on a hollow cylindrical glass located between the disks enclosing the hollow cylindrical glass protruding beyond the outer surface of the shells with the formation of annular partitions separating the manufactured shell from composite material. 2. A mandrel for the manufacture of shells of composite material according to claim 1, characterized in that it is equipped with a removable squeeze ring mounted on the base of the mandrel and interacting with the end face of the lower shell.

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