JP2013014228A - Cover material for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight cover material for vehicles which exhibits high performance of absorbing engine noise.SOLUTION: The cover material for vehicles is a material for an engine cover (30) covering an engine (21) in an engine room and comprises: a base material (36) formed of a fiber reinforced resin; an air impermeable skin material (37) which is made of an olefin resin such as olefin resin elastomer, and which is provided on the upper surface of the base material (36) to form a design surface (31); and a rear surface material (38) which is provided on the lower surface of the base material (36) and is made of an air permeable film or a nonwoven fabric having an air permeability set to be 5-50 cm/cm/sec.

Description

  The present invention relates to a vehicle cover material that covers a predetermined portion of an engine room, and more particularly to a vehicle cover material that has both sound absorption and design properties.

  In order to improve soundproofing and design in an engine room of a vehicle, various cover materials represented by an engine cover have been put to practical use.

A conventional vehicle cover material will be described with reference to the following drawings.
FIG. 7 is a diagram for explaining the basic configuration of a conventional engine cover. As shown in FIG. 7A, the engine cover 100 includes a polypropylene base 101 manufactured by injection molding, and FIG. As shown in b), it is composed of a sound-absorbing material 102 made of urethane or the like fixed to the back surface of the base material 101 by ultrasonic fusion or hot melt. It is arranged in the engine room so as to cover the upper part etc. from above.

The surface 104 of the substrate 101 forms a design surface, while the sound absorbing material 102 absorbs engine sound. That is, the engine cover 100 is a design part that improves the appearance of the engine room when the hood is opened, and is also a sound absorbing part that reduces noise such as the engine 103 and the electric motor.

By the way, while the weight reduction of a vehicle is calculated | required, the further weight reduction of the engine cover 100 is anticipated. However, in the engine cover 100, since the required strength and sound absorbing performance are obtained by a certain mass of polypropylene and urethane, it is not easy to simply reduce the weight. For example, when the plate thickness t of the substrate 101 is 2.5 mm, the surface density is 2500 g / m ² , and the mass of the sound absorbing material 102 is 35 g, the total mass of the engine cover 100 reaches 550 g.

In view of this, it is conceivable to form a laminate of a base material made of fiber reinforced resin and a sound absorbing material such as a breathable film, and to reduce the weight of the engine cover using this laminate. Conventionally, a vehicle floor undercover using such a laminate has been proposed (see, for example, Patent Document 1 (FIG. 2)).

FIG. 8 is a diagram for explaining the basic configuration of a conventional floor undercover. The floor undercover 110 is a protective cover that protects the lower part of the vehicle body from stones and sand that are rolled up by tires, and includes glass fiber, olefin resin, and the like. A core material 111 mixed with a foaming agent and heated and expanded, a reinforcing layer 112 made of olefin resin, and a road surface side sound absorbing material 115 composed of a breathable film 113 and a nonwoven fabric 114 are laminated.

  In this floor under cover 110, the sound transmitted from the road surface side to the vehicle interior is reduced by the action of the core material 111 and the road surface sound absorbing material 115. Moreover, the core material 111 can be reduced in weight by reinforcing the core material 111 with glass fiber.

JP 2009-298339

  Consider a case where the technique disclosed in Patent Document 1 is applied to an engine cover. When a laminated body such as the floor under cover 110 is used for the engine cover, it is possible to reduce the weight of the engine cover.

However, the road surface side sound absorbing material 115 of the floor under cover 110 is obtained by pasting the air permeable film 113 and the nonwoven fabric 114 to the core material 111, and it is difficult to ensure the quality as a designable part. This problem is not limited to the engine cover, and similarly occurs in various cover materials that cover portions around the engine in the engine room.

  SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a vehicular cover material that can be optimized for high designability and sound absorption performance and can be reduced in weight.

The invention according to claim 1 is a vehicle cover material that covers a predetermined portion of an engine room, and is a non-breathable material that is formed on a top surface of the base material and is formed on a top surface of the base material to form a design surface. And an olefin-based resin or olefin-based resin elastomer skin material, a breathable film or non-woven fabric back material provided on the back surface of the base material and having a permeability of 5 to 50 cm ³ / cm ² / sec, It is characterized by comprising.

In the invention which concerns on Claim 2, a base material is the fiber reinforced resin heat-foamed with the foaming agent, It is characterized by the above-mentioned.

The invention according to claim 3 is characterized in that the design surface is textured.

The invention according to claim 4 is an engine cover in which the vehicle cover material covers the engine from above.

In the first aspect of the present invention, the air permeability of the back surface material is appropriately set from a range (5 to 50 cm ³ / cm ² / sec) suitable for absorbing engine sound, and the skin material is non-breathable and olefinic. Made of resin.

In the present invention, by setting the air permeability of the back material from 5 to 50 cm ³ / cm ² / sec, appropriate sound absorbing performance can be obtained in a wide range from the low frequency range to the high frequency range.
Furthermore, in the present invention, since the skin material is made non-breathable, in addition to the sound absorbing effect of the back material and the base material, the sound absorbing effect by the membrane vibration of the skin material can be obtained. As a result, the sound absorption performance can be further enhanced.

  Therefore, according to the present invention, it is possible to provide a vehicular cover material that can optimize sound absorption performance in an engine room and can be reduced in weight by a fiber reinforced resin.

In the invention of claim 2, the base material is a fiber reinforced resin heated and foamed with a foaming agent.
Since the substrate is a porous body having a large plate thickness, the sound absorbing performance can be further improved.

In the invention of claim 3, the material of the skin material is made of an olefin resin, for example, an olefin resin elastomer, and the design surface is subjected to embossing.
Since the skin material is formed of a material having high texture transferability, a pattern is clearly formed on the design surface. As a result, the design of the vehicle cover material can be improved.

In the invention according to claim 4, the vehicle cover material is an engine cover that covers the engine from above.
According to the present invention, it is possible to provide an engine cover that can achieve high sound absorption performance and can be reduced in weight.

It is a perspective view of the front part of a vehicle, and is a figure showing the form which opened the hood. It is a figure explaining the engine cover which concerns on this invention, (a) is a top view, (b) is the bb sectional view taken on the line of (a). FIG. 3 is an enlarged view of a part 3 in FIG. It is a graph which shows the sound absorption characteristic from the back material surface side when changing an air permeability. It is a figure explaining the manufacturing method of an engine cover, (a) is a heating process, (b) is a raw material setting process, (c) is a figure explaining a shaping | molding process. It is a figure explaining the effect | action of an engine cover. It is a figure explaining the conventional engine cover, (a) is a top view, (b) is the bb sectional view taken on the line of (a). It is sectional drawing of the conventional floor undercover.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the accompanying drawings. Note that the same number is assigned to the same element throughout the description of the embodiment.

  As shown in FIG. 1, the vehicle 10 includes a front body 11. The front body 11 includes a front fender 13 that forms a front side surface of the vehicle body 12, a front mask 14 that connects the front fender 13, and a hood 16 that covers the front fender 13 and the front mask 14.

  The front mask 14 is provided with a radiator grille 17 and headlights 18 and 18. An engine room 22 that houses the engine 21 is formed by the front fender 13, the front mask 14, and the hood 16. In the engine room 22, in addition to the engine 21, various storage bodies such as a power transmission device, an intake device, an exhaust device, and electrical components are arranged at predetermined positions. The engine 21 includes a power source (for example, a power unit of a hybrid vehicle) that combines an electric motor and an internal combustion engine in addition to the power source of the internal combustion engine.

  The engine room 22 includes an engine cover 30 that covers the engine 21 from above, a room side cover 60 that is adjacent to both sides of the engine cover 30 in the vehicle width direction, and a room that is disposed between the engine cover 30 and the front mask 14. A front cover 70 is provided.

  The engine cover 30, the room side cover 60, and the room front cover 70 are equivalent to the vehicle cover material of the present invention, and the upper surfaces of the engine cover 30, the room side cover 60, and the room front cover 70 are the design surfaces 31, 61, 71 that are subjected to the texture processing. It is formed. The patterns 31a and 31b by the texture processing can be selected from various patterns such as satin, sandblast, skin pattern, and geometric pattern.

  As described above, the engine cover 30, the room side cover 60, and the room front cover 70 are arranged in the engine room 22 so that the entire upper part of the engine room 22 is covered with the design surfaces 31, 61, 71. The appearance of the engine room 22 is obtained.

Next, the basic configuration of the engine cover 30 will be described with reference to FIGS.
As shown in FIG. 2A, the engine cover 30 has a substantially rectangular shape in plan view. As shown in FIG. 2B, the engine cover 30 includes a flat plate-like main body portion 32 and side wall portions 33 that are lowered from both ends of the main body portion 32 in the vehicle width direction.

  The thickness of each part of the main body 32 is set according to the required strength and sound absorption performance, or the position and shape of the upper part of the engine 21. As a result, a thick part 34 and a thin part 35 are formed in the main body part 32.

  As shown in FIG. 3, the engine cover 30 has a three-layer structure, and includes a base material 36 formed of fiber reinforced resin and a non-surface that is provided on the upper surface of the base material 36 and forms a design surface 31. It consists of a breathable and olefin-based resin, for example, an olefin-based resin elastomer skin 37, and a breathable film or non-woven fabric back material 38 provided on the lower surface of the substrate 36.

The material of the base material 36 is desirably a fiber reinforced resin made of glass fiber and polypropylene, or a foamed fiber reinforced resin made of glass fiber, polypropylene and a foaming agent. The plate | board thickness of the base material 36 is 1-30 mm, and the surface density of the base material 36 is 400-2000 g / m < ² >.

The material of the skin material 37 is preferably a sheet made of an olefin resin elastomer typified by ethylene-propylene rubber in consideration of transferability and moldability in embossing. However, it can be arbitrarily selected from a film or sheet made of an olefin resin such as polypropylene according to the application. The plate thickness of the skin material 37 is 0.3 to 1.0 mm. The surface density of the skin material 37 is 300 to 1000 g / m ² .

The back material 38 is made of a breathable film or a nonwoven fabric. The surface density of the back material 38 is 10 to 200 g / m ² . The plate | board thickness of the back surface material 38 is 0.04-0.2 mm in the case of a film, and is 0.2-1.2 mm in the case of a nonwoven fabric. The air permeability of the back surface material is set from a range (5 to 50 cm ³ / cm ² / sec) suitable for the engine sound according to the intake performance required for the engine cover 30. This air permeability is a numerical value obtained by the Frazier method.

An experimental example for determining this preferable range (5 to 50 cm ³ / cm ² / sec) will be described below. Note that the present invention is not limited to experimental examples.

(Experimental example)
-Sample Assume a three-layer laminate consisting of a back material, glass wool, and a sheet. Back material: surface density 50 g / m ² plate thickness 0.15 mm
Glass wool: surface density 1000g / m ² thickness 10mm
Skin material: surface density 350 g / m ² plate thickness 0.5 mm
-Method By changing the air permeability of the back material, the following experiments 1 to 8 are set, and in each experiment, the normal incident sound absorption coefficient with respect to the center frequency (Hz) of 1/3 octave band is examined.

Experiment 1 Air permeability of the back surface material: 3.0 cm ³ / cm ² / sec
Experiment 2 Air permeability of the back surface material: 5.7 cm ³ / cm ² / sec
Experiment 3 Air permeability of the back material: 10 cm ³ / cm ² / sec
Experiment 4 Air permeability of the back surface material: 20 cm ³ / cm ² / sec
Experiment 5 Air permeability of the back surface material: 30 cm ³ / cm ² / sec
Experiment 6 Air permeability of the back material: 50 cm ³ / cm ² / sec
Experiment 7 Air permeability of the back material: 70 cm ³ / cm ² / sec
Experiment 8 Air permeability of the back surface material: 100 cm ³ / cm ² / sec

The results of Experiments 1-8 are shown in FIG. In the figure, the horizontal axis represents the 1/3 octave band center frequency (Hz), and the vertical axis represents the normal incident sound absorption coefficient.
As shown in FIG. 4, from the results of Experiments 1 to 4, when the air permeability was small, the sound absorption rate increased in the low frequency range, whereas the sound absorption rate tended to decrease in the high frequency range. In addition, from the results of Experiments 5 to 8, when the air permeability is large, the sound absorption rate is low in the low frequency range, while the sound absorption rate tends to be high in the high frequency range.

From this result, if the air permeability of the back material is set too large, it is difficult to obtain sound absorbing performance in the low frequency range in the engine room, and if it is set too small, it is difficult to obtain sound absorbing performance in the high frequency range. I understand that.
Considering the above experimental results comprehensively, in order to obtain an appropriate sound absorbing performance over a wide range R from the low frequency range to the high frequency range, the air permeability of the back surface material is 5 to 50 cm ³ / cm ² / sec. It can be said that selecting from the range is effective.

Next, a method for manufacturing the engine cover 30 will be described with reference to FIG.
The manufacturing method of the engine cover 30 includes a heating process for heating the three-layer material, a material setting process for setting the heated three-layer material in a mold, and a molding process for press-molding the three-layer material.

  As shown in FIG. 5 (a), in the heating process, a previously manufactured skin material 41, base material 42, and back material 43 are stacked to form a three-layer material 45. This three-layer material 45 Is heated by the heater 46 and softened. When a foaming agent is added to the base material 42, the base material 42 is sufficiently expanded by a thermal reaction.

  As shown in FIG. 5B, in the material setting step, the softened three-layer material 45 is set between the upper die 47 and the lower die 48. A pattern to be transferred to the surface (design surface) 52 of the material is engraved on the molding surface 51 of the upper mold 47. Further, a vacuum pump 53 is connected to the upper mold 47 via a valve 54.

  As shown in FIG. 5 (c), in the molding process, the three-layer material 45 is pressed by the upper mold 47 and the lower mold 48 while the surface 52 is evacuated by the vacuum pump 53, and the main body 32, the side wall 33, The thick part 34 and the thin part 35 are molded to obtain the engine cover 30 having a predetermined size. By this vacuum forming, the surface 52 is in good contact with the forming surface 51 of the upper die 47, so that a textured pattern is clearly formed on the surface 52.

  In this manufacturing method, the three-layer material 45 was heated and molded. However, the two-layer material in which the skin material 41 and the base material 42 are stacked and the back material 43 are heated separately, and these two materials are laminated and pressure-bonded before the molding process, and the three obtained The layer material may be press-molded.

  Further, in the molding process, evacuation is performed only with the upper die 47, but evacuation can be performed with each of the upper die 47 and the lower die 48. In this case, the material 41, the material 42, and the material 43 can be pressure-bonded well, and the molding time and the cooling time can be shortened.

The operation of the engine cover 30 described above will be described.
As shown in FIG. 6, since the air permeability of the back material 38 is set from a suitable range (5 to 50 cm ³ / cm ² / sec), the sound from the engine 21 is wide in a wide range from a low frequency range to a high frequency range. Enters the back material 38 (arrow (1)) and is well absorbed by the back material 38 and the substrate 36 (arrow (2)). Furthermore, if the base material 36 is a fiber reinforced resin heated and foamed with a foaming agent, the base material 36 becomes a porous body having a large plate thickness, so that the sound absorbing performance is further enhanced. In addition, since the skin material 37 is made air-impermeable, in addition to the sound absorbing action of the back material 38 and the base material 36, the sound absorbing action by the membrane vibration of the skin material 37 is also obtained.

Moreover, since the base material 36 is made of fiber reinforced resin, the weight of the engine cover 30 can be reduced. For example, when the surface density of the base material 36 is set to 1000 g / m ² , the surface density of the skin material is set to 400 g / m ² , and the surface density of the back material 38 is set to 100 g / m ² , the total mass of the engine cover 30 is set to 300 g. Can be suppressed. Thereby, compared with the total mass 550g of the conventional engine cover (FIG.7 (b), code | symbol 100), the weight reduction of an engine cover can be implement | achieved significantly.

  Further, if the skin material 37 is made of an olefin resin having a high transferability in the embossing process, for example, an olefin resin elastomer, the pattern (FIG. 2 (a), reference numerals 31a and 31b) becomes clearer on the design surface 31. It is formed. As a result, the design of the engine cover 30 can be further enhanced.

  Although the configuration of the engine cover 30 has been described in the embodiment, the basic configuration of the engine cover 30 is the same for the room side cover (FIG. 1, reference numeral 60) and the front side cover (FIG. 1, reference numeral 70). .

  As mentioned above, although this invention was demonstrated using embodiment, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiments. Further, it is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Vehicle, 21 ... Engine, 22 ... Engine room, 30 ... Engine cover (cover material for vehicles), 31 ... Design surface, 36 ... Base material, 37 ... Skin material 38 ... Back material 60 ... Room side cover (vehicle cover material) 61 ... Design surface 70 ... Room front cover (vehicle cover material) 71 ... Design surface.

Claims (4)

In the vehicle cover material covering a predetermined part of the engine room,
A substrate formed of fiber reinforced resin;
A non-breathable olefin resin or olefin resin elastomer skin material provided on the upper surface of the base material to form a design surface;
A vehicle cover material comprising a breathable film or a non-woven fabric back material provided on the back surface of the base material and having an air permeability of 5 to 50 cm ³ / cm ² / sec.   2. The vehicle cover material according to claim 1, wherein the base material is a fiber reinforced resin heated and foamed with a foaming agent.   3. The vehicle cover material according to claim 1, wherein the design surface is subjected to a textured process.   The vehicle cover material according to any one of claims 1 to 3, wherein the vehicle cover material covers an engine from above.

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