JP5325445B2 - Dash insulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dash insulator which includes an improved sound insulating property without increasing a manufacturing cost largely, and is excellent in lightweight property and moldability. <P>SOLUTION: The dash insulator 2 having a laminated structure is attached on the side surface of an operating room of a dash panel 1 under tension. A sound absorbing layer 3, a sound insulating material 4, a thermoplastic resin film 5, and a sound absorbing layer 6 are laminated in the order from the operating room side. The sound insulating material is partially disposed only in a required portion, and a thermal fusion film 5b having a lower melting point than the thermoplastic resin film is previously attached on both the surfaces of the thermoplastic resin film. The sound absorbing layer 3 and the sound insulating material 4 and the sound absorbing layer 3 and the sound absorbing layer 6 are fusion bonded on both the surfaces of the thermoplastic resin film by melting the thermal fusion film through heat-pressure molding of the laminated body. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a structure of a dash insulator (sound insulation / soundproof mat) mounted on a dash panel of an automobile.

  Conventionally, a soundproof material (also called a dash insulator or a dash silencer) is stretched on the side of the cab of the dash panel in order to prevent the noise in the engine room from propagating to the cab. As this soundproofing material, for the purpose of promoting weight reduction of automobiles, a lightweight soundproofing material made of a fiber synthetic material such as felt or glass wool or a porous synthetic resin material such as urethane foam has been mainly used conventionally. However, the fiber assembly material and the porous synthetic resin material are excellent in sound absorption, but have a problem that sound insulation is inferior. On the other hand, olefin-based and rubber-based resins have a problem that although they have excellent sound insulation, they are heavy and have high material costs.

Patent Document 1 below discloses a lightweight two-layered soundproofing material in which a sound absorbing layer such as a felt and a resonance layer such as a film are bonded to each other with an adhesive with a predetermined adhesive strength. However, since this soundproofing material has a two-layer structure, there are problems that it is difficult to absorb noise in the passenger compartment and that the required shape stability cannot be obtained due to insufficient rigidity.
Patent Document 2 and Patent Document 3 below disclose a sound insulation material having a three-layer structure in which sound absorbing layers such as felt are provided on both sides of a non-breathable film. Since the film and the sound absorbing layer are bonded to each other by impregnating or applying an adhesive, the manufacturing process is increased and the cost is increased, and the film and the sound absorbing layer are molded into a free three-dimensional shape following the shape of the vehicle body. There was a problem that it was difficult.

Therefore, the soundproofing material described in the following Patent Document 4 relating to the previous patent application of the present patent applicant has a three-layer structure including a sound absorbing layer, an intermediate layer, and a sound absorbing layer, and the intermediate layer is a non-breathable thermoplastic. A heat fusion film made of a thermoplastic resin having a low melting point is bonded and laminated on both surfaces of the resin film, and this heat fusion film is melted by heating and pressure molding to form a sound absorbing layer of the thermoplastic resin film. It is possible to improve lightness and moldability by fusing both sides.
Japanese Patent No. 3498085 JP 2001-347900 A Japanese Patent No. 3264230 JP 2007-22183 A

  By the way, the dash panel has openings such as the steering shaft penetrating part and heater pipe penetrating part, and there are several parts where noise in the engine room can easily leak into the cab from other parts. However, there was a problem that sufficient sound insulation was not obtained at these locations. However, if a sound insulating material such as an olefin resin or a rubber resin having excellent sound insulating properties is provided on the entire surface of the dash insulator, there are problems that the material cost increases, the manufacturing process increases, and the weight of the vehicle body increases.

The present invention is intended to solve the above-mentioned problem, and the dash insulator according to claim 1 is a dash insulator having a laminated structure that is attached to a side surface of the cab of the dash panel, and the sound absorbing layer in order from the cab side. And a sound insulating material, a thermoplastic resin film, and a sound absorbing layer are laminated, and the sound absorbing layer on the cab side is made of any one selected from the group consisting of a fiber assembly material and a porous synthetic resin material. .5～15Mm, basis weight 100 to 2000 g / ^m and the ^two ones, the thickness of the sound absorbing layer of the engine room side to the one selected from the group consisting of fiber aggregate material and a porous synthetic resin material 5 to 40 mm, and that of the basis weight 500~3000g / ^{m 2,} sound insulation material thickness 1~3m to material any one selected from the group consisting of olefin-based resin and rubber resin Of a plate-like flexible non-foamed molded article is the total area of the shielding sound material provided on predetermined portions office so as not to exceed 50% of the total area of the dashboard insulator, a thermoplastic resin film is previously heat on both sides A heat-sealing film having a lower melting point than that of the plastic resin film is attached, and the sound insulating material is disposed so as to be in contact with the heat-sealing film on the operator's cab side of the thermoplastic resin film, and the engine is attached to the thermoplastic resin film. A sound absorbing layer on the room side, a sound absorbing layer on the cab side, and the sound insulating material are fused together .
Further, in the dash insulator according to the second aspect of the present invention, in the dash insulator, a laminate formed by laminating a sound absorbing layer, a sound insulating material, a thermoplastic resin film, and a sound absorbing layer in order from the cab side is heated and pressurized, and the thermoplastic By melting a low-melting-point heat-sealing film that has been bonded in advance to both surfaces of the resin film, the sound-absorbing layer on the engine room side, the sound-absorbing layer on the cab side, and the sound insulating material are fused to the thermoplastic resin film. characterized in that it comprises Te.

  The dash insulator according to the present invention is improved in sound insulation without significantly increasing the manufacturing cost, and is excellent in lightness and moldability.

FIG. 1 shows a dash panel 1 made of steel plate and a dash insulator 2 having a laminated structure that is attached to the side surface of the cab. As shown in the exploded perspective view of FIG. 2, the dash insulator 2 is formed by laminating a sound absorbing layer 3, a sound insulating material 4, a thermoplastic resin film 5, and a sound absorbing layer 6 in order from the cab side. The sound-absorbing layer 3 on the cab side has a thickness of 0.5 to 15 mm and a basis weight of 100 to 2000 g / m ² made of a fiber synthetic material such as felt or glass wool or a porous synthetic resin material such as urethane foam. The other sound-absorbing layer 6 has a thickness of 5 to 40 mm and a basis weight of 500 to 3000 g / m ² , which are also made of a fiber assembly material such as felt and glass wool or a porous synthetic resin material such as urethane foam.

As shown in FIG. 3, the thermoplastic resin film 5 has a thickness of 7 to 50 μm on both sides of a film made of a thermoplastic resin such as nylon or polyester having a thickness of 7 to 50 μm and a melting point of 160 to 250 ° C. Heat-bonded films 5b and 5b made of a low- melting thermoplastic resin such as polyethylene or polypropylene having a melting point of 100 to 130 ° C. are bonded and laminated through adhesive layers 5c and 5c.

  The sound insulating material 4 is a non-foamed molded body obtained by molding an olefin resin or rubber resin having flexibility and a specific gravity of 1.5 to 2.5 into a plate shape having a thickness of 1 to 3 mm. As shown in FIG. 4, the sound insulating material 4 includes a steering shaft penetrating part (indicated by reference numeral 4a), a heater pipe penetrating part (indicated by reference numeral 4b), and other necessary parts (indicated by reference numeral 4c). Divided into a plurality of required parts and partially arranged. The total area should not exceed 50% of the total area of the dash insulator.

  Thus, after arrange | positioning the sound-insulating material 4 in the appropriate location of a dash insulator, this is inserted in oven (not shown), 160-200 degreeC hot air is blown on both surfaces, and it heats, and the said heat | fever The fused films 5b and 5b are melted. At this time, the binder fibers mixed in advance in the sound absorbing layer 3 and the sound absorbing layer 6 are also melted. And immediately after the heating, this is moved to the cold forming die 7 as shown in FIG. The cold molding die 7 includes a movable upper die 7a and a lower die 7b in which a large number of intake holes are formed on the molding surface and can be vacuumed. Reference numeral 8 denotes a cooling pipe provided in the upper mold 7a. Then, the upper die 7a is lowered and pressurized simultaneously with vacuum suction from the lower die 7b. By this vacuum suction, the thermoplastic resin film 5 is sucked to the sound absorbing layer 3 side, and the sound absorbing layer 3 is contracted, and the sound absorbing layer 6 is pressure-bonded to the thermoplastic resin film 5 by the applied pressure of the upper mold 7a. The melted heat-sealing films 5b and 5b and the binder fiber are rapidly cooled and solidified by the air flowing in by the vacuum suction, so that the required three-dimensional structure in which the dash insulator fits the uneven shape of the dash panel 1 is obtained. The shape is formed and the shape is maintained. At this time, since the thermoplastic resin film 5 is fused to the sound absorbing layer 3, the sound absorbing layer 6 and the sound insulating material 4 by the heat sealing films 5b and 5b, the sound absorbing layer 3, the sound absorbing layer 6 and the sound insulating material 4 are While being adhered to each other through the plastic resin film 5, the dash insulator can be improved in rigidity and shape retention.

  The dash insulator 2 formed in this way can suppress noise from the engine room by sticking to the side of the cab of the dash panel 1. In this case, particularly by providing the sound insulating material 4 in a portion where noise leakage is likely to occur, noise can be effectively blocked and the cab can be quiet.

  As described above, according to the present invention, the dash insulator is formed into the required three-dimensional shape by heating and pressurizing, and at the same time, the sound insulating material 4 disposed at the required portion is disposed through the thermoplastic resin film 5 with the sound absorbing layer 3 and the sound absorbing layer 6. Therefore, it is possible to manufacture a material having excellent sound insulation performance at low cost without increasing the number of production steps by simply arranging the plurality of sound insulation materials 4 at appropriate locations. In addition, since the area of the sound insulating material 4 does not exceed 50% of the total area of the dash insulator 2, the cooling can be performed without hindering the air flow when vacuum suction is performed by the cold mold 7. , Shortening the molding time and improving productivity. If the area ratio of the sound insulating material 4 exceeds 50%, inconveniences in formability and heat dissipation occur, the position stability of the sound insulating material 4 is impaired, and the weight and material cost are increased. The area ratio should not exceed 50%.

Table 1 uses an olefin resin plate having a thickness of 2 mm as a sound insulating material, sets the ratio of the sound insulating material to the area of the sound absorbing layer to 100%, 75%, and 50%, respectively, and does not have the thermoplastic resin film. It is the result of having prototyped each of the conventional products A to D, the comparative products A and B having the thermoplastic resin film, and the invention products A and B, and verifying the moldability and heat dissipation states in the molding process. These prototypes use a PET felt having a thickness of 3 mm and a basis weight of 1000 g / m ² as the sound absorbing layer 3, and a PET felt having a thickness of 20 mm and a basis weight of 1000 g / m ² as the sound absorbing layer 6. The hot air temperature was set to 180 ° C., and the heating time was set to 60 seconds or 90 seconds.

  As a result, in the conventional product A having a heating time of 60 seconds, heating unevenness occurs in the oven due to the heat insulation of both sound absorbing layers, and the moldability is not good. The conventional product B having a heating time of 90 seconds has a drawback that the sound insulating material is difficult to cool in the cold forming process due to the heat insulation of both sound absorbing layers, and the whole heat is easily trapped and the molded shape becomes bulky. In the conventional product C with the ratio of the sound insulation material being 75%, the vacuum forming cannot be performed in the cold forming process, and the molded shape becomes large, and if the heating time is lengthened, the sound insulation material becomes difficult to be cooled, and the whole heat is easily trapped. There is a drawback that the molded shape is further increased. The conventional product D with the proportion of the sound insulating material being 50% is slightly improved in heat dissipation compared with the conventional product C, but has a disadvantage that the molded shape is not good. The comparative product A and the comparative product B have a thermoplastic resin film, so that the moldability is improved. However, since the heat dissipation is poor and it takes time to cool down, the productivity is not good.

  On the other hand, Invention A has a thermoplastic resin film, so that the moldability is good, and since the heating time is long, there is some heat accumulation, but the productivity is also generally good. And invention B which shortened heating time to 60 seconds was good in both moldability and productivity.

The longitudinal cross-sectional view which showed the attachment state to the dash panel of the dash insulator which concerns on this invention. The disassembled perspective view of the dash insulator which concerns on this invention. The longitudinal cross-sectional view of the thermoplastic resin film of the dash insulator which concerns on this invention. The perspective view which shows the outline of the whole dash insulator which concerns on this invention. The longitudinal cross-sectional view of the cold forming metal mold | die which manufactures the dash insulator which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dash panel 2 Dash insulator 3 Sound absorption layer 4 Sound insulation material 5 Thermoplastic resin film 5b Thermal fusion film 6 Sound absorption layer

Claims (2)

A dash insulator with a laminated structure that is stuck to the side of the cab of the dash panel, in which a sound absorbing layer, a sound insulating material, a thermoplastic resin film, and a sound absorbing layer are laminated in order from the cab side, and the sound absorbing layer on the cab side is A sound absorbing layer on the engine room side having a thickness of 0.5 to 15 mm and a basis weight of 100 to 2000 g / m ² made of any one selected from the group consisting of a fiber assembly material and a porous synthetic resin material Is one having a thickness of 5 to 40 mm and a basis weight of 500 to 3000 g / m ² made of any one selected from the group consisting of a fiber assembly material and a porous synthetic resin material , and the sound insulating material is an olefin resin and A plate-like flexible non-foamed molded article having a thickness of 1 to 3 mm made of any one selected from the group consisting of rubber-based resins, and the total area of the sound insulating material is the entire surface of the dash insulator Provided the required part plant so as not to exceed 50%, the thermoplastic resin film heat-sealed film of a low melting point than previously thermoplastic resin film on both surfaces is adhered, the cab of the thermoplastic resin film The sound insulating material is disposed so as to be in contact with the heat sealing film on the side, and the sound absorbing layer on the engine room side, the sound absorbing layer on the cab side, and the sound insulating material are fused to the thermoplastic resin film. A dash insulator. A low-melting-point heat melt bonded in advance to both surfaces of the thermoplastic resin film by heating and pressurizing a laminate comprising a sound absorbing layer, a sound insulating material, a thermoplastic resin film, and a sound absorbing layer in order from the cab side. The dash insulator according to claim 1, wherein a sound absorbing layer on the engine room side, a sound absorbing layer on the cab side, and the sound insulating material are fused to the thermoplastic resin film by melting the adhesive film. .

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