RU1803616C - Method of making joint of parts - Google Patents

Abstract

Usage: in aircraft construction. SUMMARY OF THE INVENTION: prepare the mating surfaces of the parts, apply an adhesive composition to one of them, then apply a metal mesh made of a material with a hardness greater than the hardness of the material of the joined parts, apply one part to another and apply it to them the compressive forces, and its magnitude is taken greater than the magnitude of the forces corresponding to the elastic limit of said material. Using this method allows to increase the fatigue life of the parts to be joined by 1.3-1.5. 5 ill.

Description

The invention relates to mechanical engineering and can be used in the manufacture of shear adhesive, adhesive-molding and adhesive-bolting joints of sheet parts.

The purpose of the invention is to increase the reliability of the joint by increasing fatigue life and crack resistant joint parts.

To achieve this goal, a method of producing joining parts includes preparing the surfaces of the joining parts, applying an adhesive layer to the contact surfaces of the joining parts, placing one of the parts of the metal mesh on the adhesive surface, the diameter of the wire mesh being larger than the thickness of the adhesive layer, and the mesh they are made of material with a hardness greater than the hardness of the material of the parts to be joined.

In FIG. 1-2 is a method for producing an adhesive joint of parts: FIG. 3 shows the construction of a plural kleebolt joint of sheet metal parts: FIG. 4 is a cross-sectional view of a klee-bolt connection of parts (assembly I in Fig. 3); in FIG. 5 is a longitudinal section of a kleebolt joint of parts (section AA in FIG. 4).

The method of obtaining the joining of parts consists in preparing the surface (cleaning, degreasing) of the joined parts 1, 2- (Fig. 1), applying an adhesive layer 3.4 to the prepared surfaces. A mesh 5 is made of wire separately, the material of which has a hardness greater than the hardness of the material of the parts to be joined, and the wire diameter is taken greater than the thickness of the adhesive layer. The fabricated mesh is placed on one of the surfaces of the parts to be joined, then one component is laid on the other, combining the prepared surfaces, and a pressure is applied to the parts by PPR until the adhesive hardens. Moreover, the magnitude of the pressing force should be greater than the magnitude of the forces corresponding to the elastic limit of the material of the parts to be joined. In the process of pressing parts, glue is filled with glue irregularities on top

00

about

CA) (

cЈ

the part of the parts to be joined and the introduction (extrusion) of the wire material into the surface of both parts to be joined. In this case, local hardening of the material of the parts to be joined is made, moreover, of a closed nature (within the same cell). Local surface hardening increases the fatigue life of the joined sheets. In addition, the surface of the parts to be joined strengthened by small cells, the wire helps to increase the crack resistance of the joint, since a fatigue crack has arisen under the influence of cyclic loads, increasing its length and abuts against local hardening by wire.

It is known that local hardening of the crack tip by compression leads to a braking effect for its development, and since wire hardening is closed in the plane, the process of braking the crack is inevitable regardless of the direction of its development, which is very important, since the crack tip can rotate in the open nature of hardening unreinforced area without braking. Since there are many hardened cells on the surface of the joined sheets, even with a small braking effect within the same cell, a significant total inhibitory effect occurs, leading to good crack resistance of the joint structure.

For combined, for example, adhesive-bolt joints (Fig. 3), the method for producing the joint is similar to that described: preparing (after making holes for fasteners) the surfaces of the parts 6, 7 to be joined; applying adhesive layer 8 to prepared surfaces; placing between the connected parts a prefabricated mesh 9; alignment of holes in the package of parts: installation of fasteners, for example, bolts 10 in the holes, and their axial tightening by means of washers 11 and nuts 12. For the adhesive joint, the magnitude of the pressing force of the parts is ensured by the axial tightening of the fasteners. However, the size and tightening of the bolts (riveting force of the rivets) should be sufficient to incorporate a harder mesh into the mating surfaces of the parts to be joined. Otherwise, additional pressing of the parts by external technological forces is required. After tightening the fasteners, the joint is held until the adhesive is removed (polymerized).

The developed method for producing joining parts, in addition to properties common with the prototype — improving the adhesive properties of adhesives, equalizing the temperatures of joined parts, increasing the stability of the thickness of the adhesive layer

a positive property is an increase in fatigue life of the joined sheets, both due to the creation of local zones of increased contact compressive stresses (hardening), and due to the increased

0 fracture toughness of the structure, which leads to an increase in the service life of the joint, or while maintaining the service life to increase its reliability.

In aircraft construction, found wide

5 the use of joining parts from materials D16T, B95 by means of bolts from ZOKHGSA, ZOKHGSNA, 16KHSN, 40KHNMYU and the like. Adhesives of the type VK0 32, K-153 and the like can be recommended for the manufacture of combined compounds, and for the manufacture of mesh, a wire similar to a wire for the manufacture of bolts, or from strong automatic steels of the A10 type. Moreover, the wire diameter is necessary 1.2-1.5 times greater than the required (optimal) thickness of the adhesive layer, which is 0.15-0.25 mm.

The developed method for joining parts is recommended for the formation of adhesive and combined adhesive discrete

0 compounds - kleebolt and glue-rivets.

The developed method for the preparation of compounds contributes to an increase in the fatigue life of the parts to be joined.

5 1.3-1.5 times. This will increase the connection resource by 5-8%, or for a given resource, it will increase the reliability of the connection, which will bring an economic effect during operation of the product.

0 Forms of the invention

The method of obtaining the connection of parts, including preparing the mating surfaces, applying glue to the surface of one of the parts, placing on the same

5 surfaces of the wire metal mesh, applying one part to another, combining the prepared surfaces with the subsequent pressure on them until the adhesive is cured, free of heat and so that, in order to increase the reliability of the connection by increasing its fatigue durability and crack resistance, the diameter of the wire mesh is greater than the thickness of the adhesive layer 5, the mesh is used from a material with a hardness greater than the hardness of the material of the parts to be joined, and the amount of compression is taken more than Ichin effort corresponding to the elastic limit of said material.

v US ////////.////////////// As

FIG. I

 .11 f M I I f f t 1 1 t ft

RPR

SH.2

/ Y

GEN SHE - PIECE

;

L