JP2008030546A - Vehicular air duct - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain low noise of air-conditioning operation by preventing leakage of noise into a vehicle cabin by outstanding enhancement of sound-shutting off property in a vehicular air duct arranged at an inner side of an interior member in order to deliver temperature-regulated air fed from an air conditioner of the vehicle such as an automobile into the vehicle cabin. <P>SOLUTION: An outer skin superposed with hard resin layers 3, 4 provided with air-tight property and rigidity on an inner peripheral surface and an outer peripheral surface of a foamed resin layer 2 provided with heat insulation property and sound absorption property is integrally molded to a predetermined hollow shape by a multi-layer blow molding means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle air duct that is disposed inside an interior member for indoor air conditioning in a vehicle such as an automobile.

  As a member for indoor air conditioning of vehicles including automobiles, in order to guide the temperature-controlled air sent from the air conditioner to the discharge port and discharge it into the vehicle interior, it is inside the interior member such as an instrument panel. An air duct is disposed. Generally, this air duct is formed into a predetermined hollow shape body having a deformed cross section corresponding to an arrangement path by blow molding a resin material such as polyethylene.

  In such an air duct for a vehicle, since the outer skin is formed to be relatively thin, there is a problem that condensation occurs on the duct surface due to a temperature difference between the inside of the duct through which the temperature-controlled air flows and the outside of the duct. In order to prevent the occurrence of this dew condensation, measures are taken to wrap and paste a foam sheet such as urethane foam around the outer peripheral surface of the air duct and cover the air duct with a foam sheet having a predetermined heat insulating property. ing. However, since the air duct for vehicles is arranged between various vehicle equipment housed inside the interior member, its outer shape becomes a complex three-dimensional shape with a continuous bent surface, depending on the arrangement position. Since the shapes are different from each other, the above-described foam sheet coating operation is difficult to automate and is performed manually, which is extremely complicated. Therefore, workability and productivity are remarkably inferior, and the production cost of an air duct having a dew condensation prevention function is high.

  On the other hand, the applicant, in the previous application, Japanese Patent Application No. 2005-18622, has a predetermined outer skin obtained by laminating a hard resin layer having airtightness and rigidity and a foamed resin layer having heat insulation. A vehicular air duct integrally formed in a hollow body was proposed. This is a multi-layer blow molding means that uses a shell layered with a hard resin layer and a foamed resin layer and integrally molded into a predetermined hollow shape, eliminating the need for conventional foam sheet coating operations and manufacturing costs. This is intended to reduce the above.

  In this way, the air duct for a vehicle, which is integrally formed with an outer skin in which a hard resin layer and a foamed resin layer are laminated, has a function of preventing condensation, but it can prevent noise leakage due to blower operating noise and airflow disturbance. It is not perfect and there is a problem in sound insulation. In addition, in the multi-layer blow molding means, there are manufacturing problems such as difficulty in increasing the foaming ratio of the foamed resin layer that is molded with a high blow pressure.

  The present invention is intended to solve these problems. By significantly improving the sound insulation, the leakage of noise into the vehicle interior is prevented to reduce noise in the air conditioning operation, and the foamed resin layer is expanded. The present invention proposes a vehicular air duct with improved performance by means of production capable of increasing the magnification.

  In order to achieve the above object, the present invention provides a vehicle air duct disposed inside an interior member for discharging temperature-controlled air sent from an air conditioner of a vehicle such as an automobile into a vehicle interior. An outer skin in which hard resin layers 3 and 4 having airtightness and rigidity are laminated on an inner peripheral surface and an outer peripheral surface of a foamed resin layer 2 having heat insulating properties and sound absorbing properties, and a predetermined hollow shape body is formed by multilayer blow molding means. It is characterized by being integrally formed.

  The vehicle air duct according to the present invention is integrally formed into a predetermined hollow body by vacuum blow molding means.

  The air duct for a vehicle according to the present invention is an outer skin in which hard resin layers 3 and 4 having airtightness and rigidity are laminated on an inner peripheral surface and an outer peripheral surface of a foamed resin layer 2 having heat insulating properties and sound absorbing properties. The outer skin is formed in a three-layer structure in which the foamed resin layer 2 that is a sound absorbing material is sandwiched between hard resin layers 3 and 4 that are sound reflecting materials. As a result, the sound insulation is remarkably improved, and the noise caused by the operating sound of the blower of the air conditioner and the turbulence of the airflow is prevented from leaking into the vehicle interior, and the noise and silence of the air conditioning operation can be realized. .

  Moreover, since the foamed resin layer 2 has a predetermined heat insulating property, it is possible to prevent the occurrence of condensation due to a temperature difference between the inside and outside of the duct through which the temperature-controlled air sent from the air conditioner flows. This eliminates the need to cover the foam sheet at all, which is excellent in productivity and can greatly reduce the production cost.

  In addition, by integrally molding with vacuum blow molding means, the foamed resin layer 2 can be molded with a low blow pressure to increase the foaming ratio, and the heat insulation and sound absorption can be improved. The problem can be solved.

Hereinafter, the best embodiment of the present invention will be specifically described with reference to the drawings.
1 and 2 show an embodiment of a vehicle air duct according to the present invention. FIG. 1 shows the entire air duct 1 and FIG. 2 shows an end face obtained by cutting the air duct 1. As shown in FIG. 1, the air duct 1 disposed inside the interior member is formed in a predetermined hollow shape body having a modified cross section corresponding to the disposition path.

  This air duct 1 is formed by a multilayer blow molding means, and a hard resin layer 3 or 4 having airtightness and rigidity is laminated on an inner peripheral surface and an outer peripheral surface of a foamed resin layer 2 having heat insulating properties and sound absorbing properties. It is molded integrally with the outer skin. As shown in FIG. 2, the air duct 1 has a three-layer structure in which the front and back of the foamed resin layer 2 are sandwiched between hard resin layers 3 and 4. 2 has a multilayer structure excellent in sound insulation, sandwiching the front and back surfaces of hard resin layers 3 and 4 which are sound reflecting materials.

  The vehicle air duct is preferably formed by vacuum blow molding means. The foamed resin layer 2 is molded with a low-pressure blow pressure by the vacuum blow molding means, and the foaming ratio of the foamed resin layer 2 is increased, and the heat insulation and sound absorption can be improved.

The perspective view of the whole air duct in the Example of this invention. The expanded end view cut | disconnected by the AA line in FIG.

Explanation of symbols

2 Foamed resin layer 3 Hard resin layer 4 Hard resin layer

Claims (2)

In a vehicle air duct disposed inside an interior member in order to discharge temperature-controlled air sent from an air conditioner of a vehicle such as an automobile into the vehicle compartment,
An outer skin in which hard resin layers 3 and 4 having airtightness and rigidity are laminated on the inner and outer peripheral surfaces of the foamed resin layer 2 having heat insulation and sound absorption properties, and is formed into a predetermined hollow shape body by multilayer blow molding means. A vehicle air duct characterized by being integrally molded. The vehicle air duct according to claim 1, wherein the air duct is integrally formed into a predetermined hollow shape by vacuum blow molding means.

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