RU2376166C2 - Method of heat-and-noise insulation of vehicle - Google Patents

Abstract

FIELD: automotive industry.

SUBSTANCE: foam material is gun-sprayed onto vehicle carcass metal surfaces to make 10-to-50 mm-thick coat. Said foam material represents mix of polyisocyanate, polyol and fire retardant components to be mixed in two steps. Fire retardant is mixed with polyol at 15° to 25°C in the ratio of 5% to 35% of fire retardant and 65% to 95% of polyol. Obtained mix is forced in sprayer gun together with polyisocyanate premixed at the same temperature in the other vessel. Second mixing step is realised in sprayer gun with the following ratio, i.e. polyisocyanate makes 47% to 53% and mix of polyol with fire retardant making the rest.

EFFECT: preventing corrosion of body panels and reduced fire risks.

2 cl

Description

The invention relates to a technology for thermal noise insulation of vehicles, and more particularly to methods for applying thermal insulation and reducing vehicle noise.

Known methods of soundproofing vehicles by manufacturing panels and other sound-absorbing elements (screens) that repeat the surface and outlines of the reliefs of the body and other parts of the vehicle from special soundproofing materials. Soundproofing elements are glued to a soundproofing surface. As a rule, these soundproofing packages are a combination of an elastic spring layer with a heavy airtight layer and are used primarily for soundproofing the engine compartment, drive and auxiliary mechanisms, vehicle exhaust gas system [1].

Such methods of heat and sound insulation of vehicles are based on the use of materials based on a dense weight layer, which significantly increases the weight of the vehicle. It should also be noted that such materials are of high cost, complex and often not harmless manufacturing technology. In addition, if the noise-insulating panels are peeled off from the surface, air can penetrate and corrode metal surfaces of the vehicle frame.

In the automotive industry, methods are also known for eliminating airborne noise, for example, in cavities near the axle bearings, by introducing a foam element into the vehicle’s insulated cavity, which is compressed and welded into the airtight film before entering the vehicle’s cavity and easily inserted into the cavity in this state through a hole in the cavity. Then the film is opened (by tearing or piercing), and with the access of air the foam element expands in the form limited by at least two walls of the cavity [2].

There is also a known method of manufacturing an element for sealing cavities. A flat sealing element contains a base consisting of a structured polymer and a sealing layer consisting of an unstructured foam polymer that comes into tight contact with the base and covers the sealing part [3].

However, the use of known methods is associated with a deterioration in the corrosion resistance of the body frame in the areas of hollow box-shaped elements limited by acoustic plugs due to the possible accumulation of condensate in them.

The closest technical solution to the claimed is a method of noise insulation of a vehicle by attaching sound-insulating material on steel panels of the body, in which protrusions and depressions are formed on the surface of the foam obtained by foaming synthetic resin. The protrusions are covered with a binder material, such as bitumen, rubber, and pressed against a steel panel [4].

In the known method, the presence of alternating protrusions and depressions creates an additional soundproofing effect. However, when using this method, as a result of attaching the soundproofing material to the steel panel of the vehicle, condensation is formed due to its loose fit, and as a result, the panels become corroded and damage to the interior of the vehicle. In addition, the known method cannot be used on parts with a large surface, such as a ceiling, front walls of the body, side linings, which, due to their insignificant aerodynamic stability, exhibit a tendency to deformation, vibration and vibrations during movement.

The objective of the proposed technical solution is to provide a thermal noise insulation system of the vehicle eliminating corrosion and increasing fire safety, providing coating of the vehicle at the installation site.

The problem is solved in that in the method of thermal noise insulation of a vehicle, including the application of foam, the foam is applied by spraying with a spray gun on the metal surface of the vehicle frame 10-50 mm thick. As the foam, a mixture of polyisocyanate, polyol and flame retardant components is used, while before spraying, the polyol and flame retardant are initially mixed in the ratio: 5-35% flame retardant and 95-65% polyol at a temperature of 15-25 ° C. The resulting mixture and polyisocyanate are fed to the spray gun and mixed in the spray gun immediately before spraying in the following ratio of components:

polyisocyanate 47-53%

a mixture of polyol with a flame retardant rest.

The foam is applied in layers in several stages.

Application of thermo-noise-insulating material by spraying with a spray gun directly on the metal surface of the vehicle frame allows avoiding gaps, leaks and, consequently, serious heat losses. Spraying the coating on large horizontal surfaces of the body, which are prone to the formation and accumulation of condensate at temperature extremes, eliminates corrosion, dropping in the passenger compartment, as well as damage to the interior trim. The use of such components as polyol, flame retardant and polyisocyanate during spraying as a thermal noise insulation coating makes it possible to obtain a fireproof coating with good strength properties, which can be easily applied to vertical and horizontal surfaces, and also provides a tight adherence to the coating, which not only protects against corrosion, but and increases the rigidity of metal panels, preventing them from vibrating and making noise.

The method was carried out as follows: directly at the installation site of the vehicle frame, the structural elements not subject to spraying were protected by paper, flexible tape and grease. Then degreased with soapy water or solvent to remove preservation grease the inner surface of the lining of the vehicle frame to be sprayed. A foam material from a mixture of polyol, flame retardant, and polyisocyanate components was used as thermo noise insulation material. The components were mixed in two stages. Each of the components — polyol and polyisocyanate — was loaded into its corresponding container. A flame retardant was added to the container with a polyol in the ratio: flame retardant from 5 to 35%, polyol 65-95%. The introduction of a flame retardant component in the polyol of more than 35% led to the loss of thermal noise insulation properties of the foam due to an increase in the density of the applied material. The introduction of a flame retardant below 5% did not provide the necessary flame retardant properties. At the same time, mechanical mixing of the polyol components with a flame retardant was carried out in one container, and a polyisocyanate was mixed in another. To obtain a homogeneous composition of the components and to prevent separation of the polyol into components, mixing was carried out by heating the components to 15-25 ° C for 3-5 minutes. Given that the method was carried out directly at the installation site of the vehicle, heating was performed using a flexible heating tape. Then, at a pressure of 3 atm along the low pressure hoses with gear pumps, a mixture of a polyol with a flame retardant and a polyisocyanate were separately supplied to the spray gun. The 2nd stage of mixing the components took place in the mixing chamber of the spray gun: a mixture of polyol with a flame retardant was mixed with a polyisocyanate with a ratio of components: 47-53% of a polyisocyanate, the rest was a mixture of a polyol with a flame retardant, and the material was immediately sprayed directly onto the metal surfaces of the vehicle frame . Due to the strength properties of the foam used, no swelling of the material was observed on vertical and horizontal surfaces. The thickness of the first layer was at least 10 mm. The surface formed when applied by the spray gun had protrusions and recesses, which creates an additional acoustic effect compared to smooth surfaces. The second layer was applied with a spray gun after curing the first layer after 5 minutes to obtain an even-strength layer. The total thickness of the coating ranged from 20 to 50 mm. Chemical curing of the thermal noise insulation coating occurred after 20 minutes.

Using this method, you can get any coating thickness that is necessary for thermal insulation of a particular vehicle by applying a multilayer coating.

The inventive method is universal and can be used for thermal insulation of any surfaces of vehicles, both large horizontal and vertical surfaces, and cavities of complex geometric shape, located in places difficult to fill. This method can be used directly at the workplace in places of installation of the vehicle.

As tests have shown, the coating applied by this method retains its properties over the entire temperature range that arise during the operation of automotive vehicles. Due to the tight fit of the foam to the metal surface of the vehicle frame, there is no exchange of air with the surrounding atmosphere, which is an effective protection against corrosion.

The proposed method of thermal noise insulation can be used in the production of any type of land or water transport. For example, for thermal insulation of trolley buses, buses, trams, freight and passenger vehicles, electric and diesel trains, passenger and freight cars, ships, ships, ferries.

Information sources

1. RF patent No. 2198798, IPC B60R 13/08, publ. 02/20/2003 g.

2. RF patent No. 2155689, IPC B61D 17/18, publ. 09/10/2000

3. US patent No. 5931474, IPC B60R 13/08, ISM, issue 29. No. 15, 2000

4. Japan patent No. 6026953 B4, IPC B60R 13/08, publ. ISM, issue 29, No. 2, 1997 - prototype.

Claims (2)

1. The method of thermal noise insulation of a vehicle, including applying foam, characterized in that the foam is applied by spraying with a spray gun on the surface of the carcass of a vehicle with a thickness of 10-50 mm, a mixture of components of polyisocyanate, polyol and flame retardant is used as the foam, first mixed polyol and flame retardant at a temperature of 15-25 ° C in the ratio of 5-35% flame retardant and 65-95% polyol, the resulting mixture and polyisocyanate are separately fed to the spray gun, in which the comp components immediately before sputtering in the following ratio: polyisocyanate - 47-53%, a mixture of polyol with flame retardant - the rest. 2. The method according to claim 1, characterized in that the foam is applied in layers in several stages.