RU2421314C1 - Method of repairing parts with cracks and punctured holes - Google Patents

Abstract

FIELD: process engineering. ^ SUBSTANCE: invention relates to repair and recovery and may be used in recovery of ICE units and cylinder blocks, transmission and transfer box housings, fuel tanks, etc. Damaged zone is cut out to prepare bottom with small cavity to be filled with the mix of epoxy glue with filler. Patch is laid atop. Damaged edges are trimmed at 30-45, part surface is ground and layer of epoxy composition is applied thereon, modified by PSU, while cavity bottom is produced by layer of fiber glass to be laid over aforesaid epoxy layer. Perforated patch is made from material with similar properties of repaired part. Said patch is laid to overlap damaged surface by 25-45 mm along its edges to allow part holes to be filled with epoxy glue for joint formation. ^ EFFECT: higher efficiency of repair and stiffness of joint, reduced strain in said joint. ^ 3 dwg

Description

The invention relates to the field of repair and restoration of products from both thick-walled and thin-sheet metal and non-metallic materials, and can be used at repair enterprises for the restoration of hull and sheet parts, for example, blocks and heads of ICE cylinder blocks, gearbox cases, transfer cases, fuel tanks, etc.

A known method of repairing blocks and heads of cylinder blocks, gearboxes, transfer boxes, which consists in installing and attaching a metal patch on top of the damage in the form of a crack. A metal patch is used, overlapping said crack by 20-40 mm, 2-4 mm thick. Drill through the entire area of the metal patch at a distance of 4-6 mm from one another and 2 mm from the edge of the through holes with a diameter of 3 mm, included in the wall of the body part to a depth equal to 0.2-0.4 of the thickness of the latter. Then, the metal patch is attached by dusting by the method of “cold” gas-dynamic spraying of the aforementioned holes to a level corresponding to the thickness of the patch, as well as along the perimeter of the metal patch in the place of its contact with the wall of the body part [1].

The disadvantages of this method are significant energy and labor costs, a high coefficient of stress concentration at the edges of the joints, a large number of preparatory operations, the high cost of the used repair equipment and materials, as well as the inability to use it to eliminate cracks and holes in thin-walled products and products made from non-metallic materials.

A known method of sealing a defect in the product, which consists in filling the defect with a sealing composition, including 100 mh anaerobic sealant based on oligoester acrylates epoxy resin in an amount of 50-300 m.h. and iron-containing metal powder in an amount providing a thixotropic state of the composition. After curing, the outer surface of the cured composition is cleaned until a metallic luster appears. Then the surface is moistened with the same anaerobic sealant and the sealing composition is again applied with overlapping the surface of the applied layer [2].

The disadvantages of this method are the impossibility of its use in eliminating defects such as a hole, the high fragility of the cured sealant composition, low strength when exposed to repeated temperature fluctuations and the application of mechanical loads.

The closest in technical essence and the achieved result to the proposed method is a method of repairing thin-walled structures, which consists in determining the boundary of the damage zone and its cutting, the manufacture of compensating patches from several layers of the overgrowth and a mixture of liquid glue with filler. The size of each subsequent layer, except the first, is selected larger than the previous one by the amount of overlap and fill the damaged area with epoxy glue. The bottom of the damaged area forms the bottom of the damaged area and partially presses it into the structure. Fill the cavity of the defect with a mixture of liquid epoxy adhesive with a filler. Lay other layers on top of the mixture of glue with filler and form a compensating patch [3].

The specified method does not provide a sufficient quality of repair, since significant stresses are formed at the edges of the lap, which lead to peeling of the first layer of the prepreg and, as a result, of the entire compensating patch. Another disadvantage is the decrease in the sealing ability of the joint due to cracking of the cured epoxy adhesive under the influence of repeated temperature fluctuations and vibration loads.

The technical result of the invention is aimed at improving the efficiency of repairing parts with cracks and holes, increasing the rigidity of the structure while reducing the concentration coefficient of stresses in the connection.

The technical result is achieved due to the fact that in the method of repairing parts with cracks and holes, in which the boundaries of the damage zone are determined, the damaged zone is cut out, a compensating patch is made from several layers of the overgrowth and a mixture of liquid glue with filler, the size of each subsequent layer, except the first, choose an overlap larger than the previous one and fill the damaged area with epoxy glue, form the bottom of the damaged area from the first layer of the overreg and partially push it into the structure, filling If the defect cavity is filled with a mixture of liquid epoxy adhesive with a filler, other layers are laid on top of the mixture of adhesive with filler and form a compensating patch, while the edges of the damage are cut at an angle of 30-45 °, a sublayer is applied to the cleaned surface of the part (epoxy composition modified with polysulfone) and instead of a compensating patch, a patch is used, made of a material having similar physical and mechanical properties with the surface of the part being repaired 1-3 mm thick, covering the plane ad damage to 25-45 mm around the perimeter of the patch through holes 2-3 mm in diameter, fastening patches by using an epoxy adhesive.

A distinctive feature of the prototype is that the edges of the damage are cut at an angle of 30-45 °, a sublayer is applied to the cleaned surface of the part (an epoxy composition modified with polysulfone), and instead of a compensating patch, a patch made of a material having similar physical and mechanical properties with the surface of the part to be repaired 1-3 mm thick, covering the damage area by 25-45 mm, through holes along the perimeter of the patch are made through holes with a diameter of 2-3 mm, fixing the patch It is used with epoxy glue.

In figure 1 - patch with holes drilled around the perimeter; figure 2 is a cross section of a part with an attached patch, figure 3 is an image of the layers of the obtained compound.

The method is implemented as follows.

The boundaries of the damage zone of the part are determined. A damaged area is cut out if the defect is in the form of a hole, if it is in the form of a crack, holes 3 mm in diameter are drilled at its ends. Then, grinding is performed by grinding with sandpaper or a grinding wheel on the surface of the part at a distance of 40-50 mm along the edges of the defect. The edges of the defect are cut at an angle of 30-45 °. The cleaned place is degreased with acetone or solvent.

Patch 4 is cut out in a predetermined shape so that it overlaps the defect by 25-45 mm around the entire perimeter, 1-3 mm thick.

In the patch, through holes with a diameter of 2-3 mm are drilled around the perimeter, they are cleaned and degreased from the inside.

On the cleaned and degreased surface of the part 1 and patches, a sublayer 5 is applied (epoxy composition consisting of the following components, parts by weight:

epoxy diane resin brand ED-20 one hundred polyamide resin 40 organosilicon amine 1,2 AF-2 25 polysulfone thirty).

Lay on the surface of the part, on top of the underlayer, fiberglass 2 with a thickness of 0.5-1 mm, depending on the size of the through defect, forming a bottom from it (in case of repair of holes), and partially press it into the part with the formation of a small hole, while the fiberglass is tight adjoins to the inclined edges of the defect and is saturated with excess epoxy composition.

An epoxy adhesive 3 with a filler is prepared and the well formed is filled with it so that a clot of glue protrudes above the surface of the part. The prepared patch is laid on top of the clot, and a joint is formed under pressure, making sure that excess glue fills the holes in the patch and forms a uniform layer around its perimeter.

After the epoxy adhesive has fully cured, the recovered area is machined and stained.

The implementation of the claimed method allows the repair of parts with cracks and holes from both thick-walled and thin-sheet metal and non-metallic materials with high efficiency, to increase the rigidity of the connection, to reduce the stress concentration coefficient in the connection.

Information sources

1. Pat. 2306214 Russian Federation, IPC7 В23Р 6/00, С23С 4/00. The method of repair of hull parts / Kobernichenko A.B. and etc.; applicant and patent holder: Ryazan Military Automobile Institute named after Army General V.P. Dubinin. - No. 2005136103/02; declared 11/21/05; publ. 09/20/07, Bull. No. 26. - 5 p.: Ill.

2. Pat. 2084323 Russian Federation, IPC7 В23Р 6/00. The method of sealing a defect in the product / Vorobeva T.V .; Applicant and patent holder: Vorobyova Tatyana Vasilievna. - No. 92007577/02; declared 11/23/92; publ. 07/20/97, Bull. No. 20. - 4 p.

3. Pat. 2181083 Russian Federation, IPC7 В29С 73/04 // В23К 101: 00, В29L 31:00. The method of repair of thin-walled structures / Wilenz B.C .; Applicant and patent holder: Vilents Viktor Semenovich. - No.2000116223 / 12; declared 06/26.00; publ. 04/10/02, Bull. No. 10. - 3 p.: Ill.

Claims (1)

A method of repairing damaged parts, including cutting out a damaged zone, forming a bottom in it with the formation of a hole, filling it with a mixture of liquid epoxy glue with a filler and laying a patch on top of it, characterized in that the edges of the damage are cut at an angle of 30-45 °, the surface is cleaned the details and apply a layer of the epoxy composition modified with polysulfone on it, and the bottom of the cavity is formed by a layer of fiberglass, laid on top of the layer of said epoxy composition, while the patch is made of material Having similar physico-mechanical properties of the material component to be repaired, with the through holes 2-3 mm in diameter and is laid with its surface damage overlap by 25-45 mm around the perimeter with providing filling holes patches epoxy glue to form a compound.

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