RU2155673C2 - Method for filling of configured cavities with thick viscous medium - Google Patents

Abstract

FIELD: procedure of filling of configured cavities with thick viscous medium, in particular with epoxy compound, applicable for filling of holes in vital parts when filling is a construction member and must withstand high loads, because of it no gas, oil and other inclusions resulting in reduction of filling strength are allowed in it and on its walls. SUBSTANCE: the cavity in the part is preliminarily filled with solvent not interacting with thick viscous medium. Then, the part is joined to the charging device filled with thick viscous medium, and this assembly is subjected to centrifugation. The charging device has a hole through which the thick viscous medium can flow to the part cavity under the action of centrifugal force displacing the solvent from it to the charging device. Centrifugation is continued up to the beginning of medium curing. EFFECT: facilitated procedure. 3 cl, 1 dwg

Description

 The invention relates to the field of technology for pouring a viscous fluid, in particular an epoxy compound, of cavities of complex configuration, and can be used to fill holes in critical parts, when the filling, being a structural element, must hold high loads, which is why it and its walls are not allowed gas, oil and other inclusions, leading to a decrease in the pouring strength.

 The invention is known when a centrifuge is used to introduce a fluid, in particular a viscous medium such as an encapsulating resin. A certain amount of resin is placed in a dispensing vessel in a centrifuge opposite the cavity being filled. When centrifugal forces are applied, all the resin flows through the hole in the vessel into the filled cavity / 1 /.

The invention is also known when the centrifugal molding method / 2 / is used to form articles of complex configuration from glass and glass. A device for centrifugal molding of glassware contains a rotating table and an axis mounted along its radius with an additional table having the ability to rotate 180 ^o . On an additional table, a melting furnace and a mold are coaxially located. Initially, under the influence of centrifugal force, clarification occurs due to degassing of the glass when it is melted in the melting furnace, and then after turning the additional table due to centrifugal force, the clarified glass melt flows from the furnace into the mold and fills it.

 These inventions have the following disadvantage: when filling with epoxy compounds having low fluidity, cavities of complex configuration, the presence of residual gas, oil and other inclusions on the walls of the cavity is possible, which leads to an unacceptable decrease in the strength properties of the fill.

 The technical task is to improve the quality of casting parts working under load.

 The technical result consists in increasing the strength characteristics of the fill by removing gas, oil and other inclusions from the fill and from its walls, as well as improving adhesion.

 The essence of the invention lies in the fact that in this method of filling cavities of complex configuration with a viscous fluid by centrifugation, the cavity in the part is pre-filled with a solvent that does not interact with the viscous fluid, and then the part is docked with a loading device filled with a viscous fluid and having an opening through which the medium can flow out under the action of centrifugal force, displacing the solvent, and this assembly is centrifuged. As a viscous fluid, an epoxy compound may be selected. After the solvent is displaced with a viscous fluid, additional centrifugation can be carried out before the medium begins to cure.

 With the introduction of the solvent, oil and fat inclusions dissolve and moisture droplets trapped in the cavity are bound. Due to the greater wettability than the compound, the solvent does not allow the formation of air bubbles on the walls of the cavity, and then it is replaced by a compound having a higher density under the influence of centrifugal force on the centrifuge. Further centrifugation before curing of the epoxy compound begins to remove gas inclusions from the fill.

 When checking for novelty, the authors did not find a set of features claimed in the proposed invention with a new technical result, therefore, the proposed solution meets the patentability criterion.

The proposed method is illustrated in the drawing, which shows a sketch of the assembly before centrifugation. In the figure, the numbers indicate:
1 - epoxy compound;
2 - boot device;
3 - solvent poured into the cavity of the part;
4 - detail;
5 - hole through which the epoxy compound flows from the loading device into the cavity of the part.

 The solvent (3) is poured into the cavity of the part (4). It dissolves oil-fatty inclusions and binds moisture droplets that have fallen into the internal cavity and, due to its greater wettability than that of the compound, prevents the formation of air bubbles on the walls of the cavity. The loading device (2) is docked to the part, so that the epoxy compound (1), poured into the loading device, can flow into the cavity of the part under the action of centrifugal force. Then this assembly is placed in a centrifuge.

 When the centrifuge is turned on by centrifugal force, the epoxy compound completely displaces the less dense solvent from the cavity of the part into the loading device. With further centrifugation, prior to curing, gas bubbles are removed from the compound itself by increasing the buoyancy force.

 The proposed method was experimentally tested on mock-ups and the results confirmed the high quality of the filling, carried out according to the inventive technology, in comparison with the control samples. To obtain samples, metal sleeves with a cylindrical cavity with a diameter of 6 mm and a length of 80 mm were used. The epoxy compound EK-34 was poured into the cavity of the sleeve. Ethyl alcohol was used as a solvent. The samples were centrifuged in a medical centrifuge for 2 hours. The samples were located at a distance of 180 mm from the bottom of the sleeve to the axis of rotation, the rotation frequency was 1900 rpm. After the polymerization of the epoxy compound, the fill samples were removed from the sleeves. These samples did not have gas inclusions inside the fill, unlike control samples that did not undergo centrifugation, and samples obtained without preliminary pouring ethanol into the cavity had defects on the outer surface (gas bubbles adhering to the inner surface of the sleeve), unlike the samples made with pre-filled solvent.

 Thus, the result obtained is to increase the strength characteristics of the fill by removing gas, oil and other inclusions from the fill and from its walls, as well as improve adhesion.

Sources of information:
1. Mcgrane Kevin, ELEKTRONIC TECHNIQUES (ANGLIA) LIMITED, Method for introducing fluid into a cavity, WO 9511790 A1, 10.21.94, B 29 C 39/08, Publ. Inventions of the countries of the world. 1996, N 5.

 2. A. P. Yumankov. Device for centrifugal molding of glass products. Author's certificate N 1671618 from 06/14/89 C 03 V 19/04, Publ. BI 31.08.08.91.

Claims (3)

 1. A method of filling a cavity of a complex configuration with a viscous fluid by centrifugation, characterized in that the cavity in the part is pre-filled with a solvent that does not interact with the viscous fluid, and then the part is docked with a loading device filled with a viscous fluid and having an opening through which the medium can flow out under centrifugal force, displacing the solvent, and subjected to this assembly by centrifugation.  2. The method according to claim 1, characterized in that the epoxy compound is selected as a viscous fluid.  3. The method according to claim 1 or 2, characterized in that after the solvent is displaced with a viscous fluid, additional centrifugation is carried out before the medium begins to cure.