JP4726495B2 - Interior parts for vehicles - Google Patents

Description

  The present invention relates to vehicle interior parts such as door trims and rear quarter trims.

  Generally, vehicle interior parts such as door trims have a core material and a skin material as described in Patent Document 1 below. The core material is made of a resin such as polypropylene and has a solid solid structure. On the other hand, the skin material is composed of a foam layer and a skin that are fixed to each other, and the foam layer is fixed to the inner surface of the core material facing the vehicle inside.

JP2004-50862

  The door trim is intended to improve the aesthetics and tactile sensation of the inner surface facing the interior of the door. It is desirable that the door trim has a noise prevention effect such as sound insulation and sound absorption. This is because a large number of holes are formed in the inner panel of the door to which the door trim is attached in order to attach various parts such as a power window unit, and noise outside the vehicle enters the vehicle through the holes. This is because if the intrusion of noise can be prevented by the door trim, quietness in the vehicle can be improved. However, the conventional door trim having the above configuration does not have a high noise prevention effect.

The present invention, in order to solve the above problems, in the vehicle interior trim having a skin material which is adhered to the surface of the core material as the core material, the first layer and the interior side the core material of the exterior The skin material is fixed to the second layer, the first layer is configured with a higher density than the second layer, and the second layer is embedded in the resin. It is characterized by having a porous structure by forming a large number of cavities between a large number of glass wools.
In this case, the first layer is preferably made of a solid solid material, and the weight ratio of the resin constituting the second layer and the glass wool is preferably set to 60:40 to 30:70.

  According to the present invention having the above-described characteristic configuration, the first layer made of a high-density material has a high sound insulation property, and prevents noise outside the vehicle from entering the vehicle. The second layer made of a material having a density lower than that of the first layer has a high sound absorption property, and prevents noise outside the vehicle from propagating through the first layer and entering the vehicle. Prevent reflection in one layer.

Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. 1 and 2. FIG.
FIG. 1 is a sectional view showing a first embodiment of the present invention. The door trim 1 of this embodiment includes a core material 2 and a skin material 3.

  As shown in FIG. 2, the core material 2 includes a first layer 21 on the vehicle outer side (right side in FIG. 2) and a second layer 22 on the vehicle inner side. The first layer 21 and the second layer 22 are fixed to each other by means such as adhesion. The first layer 21 is attached to an inner panel (not shown) of the door in a state of being positioned on the vehicle outer side with respect to the second layer 22.

  The first layer 21 functions as a sound insulator that prevents noise outside the vehicle from entering the vehicle through a hole or the like formed in the inner panel. For this purpose, the first layer 21 is formed as a solid structure having a solid inside by a resin such as polyethylene or polypropylene. The first layer 21 is preferably thicker from the viewpoint of improving sound insulation, but if the thickness is increased, the first layer 21 is solid, and thus the weight of the entire door trim 1 increases. Therefore, the thickness of the first layer 21 is preferably determined in consideration of the balance between sound insulation and weight.

  On the other hand, the second layer 22 functions as a sound absorber, and prevents noise outside the vehicle from propagating through the first layer 21 and entering the vehicle. It is prevented from being reflected by the layer 21 and returning into the vehicle. The second layer 22 has at least a porous structure in order to improve sound absorption. The thickness of the second layer 22 is usually set thicker than that of the first layer 21. However, if the thickness of the second layer 22 is increased under the condition that the weight of the core material 2 is kept constant, the thickness of the first layer 21 is reduced accordingly. As a result, the sound insulation of the first layer 21 is reduced, and the second layer 22 is porous and its strength is lower than that of the first layer 21, so that the core material 2 is entirely composed of the first layer 21. As a result, the strength of the core material 2 decreases. Therefore, the thickness of the second layer 22 is determined in consideration of the sound insulation of the first layer 21 and the strength of the core material 2.

  The 2nd layer 22 which has a porous structure can be manufactured by foam-molding resin, such as polyethylene and a polypropylene, about 5 to 15 times, for example. In this embodiment, it is manufactured as follows.

  That is, when the second layer 22 is manufactured, a plate material made of a resin such as polyethylene or polypropylene is first manufactured. The plate material is foamed (actually not foamed) in the foaming process described below to form a porous structure. Accordingly, the thickness of the plate is always set to be thinner than that of the second layer 22, but the exact thickness is determined in consideration of the thickness of the second layer 22 and the foaming ratio of the plate. A large number of glass wool bent elastically and randomly is built in the plate material. The weight ratio between the resin constituting the plate and the glass wool is determined based on the expansion ratio. For example, when the expansion ratio of the plate material is 5 to 15 times, the weight ratio of glass wool to resin (glass wool weight: resin weight) is set to 60:40 to 30:70.

  The plate material configured as described above is inserted into a cavity of a mold (not shown) for forming the second layer 22. In this case, the plate material can be easily inserted into the cavity by preheating and softening. Thereafter, the plate material is heated to a predetermined temperature and softened to a state just before melting. Then, there is almost no constraint on the glass wool by the resin constituting the plate material. Moreover, since the thickness of the plate material is thinner than that of the second layer 22, the internal dimension of the cavity corresponding to the thickness of the second layer 22 is also larger than the thickness of the plate material. Therefore, the glass wool that has been bent is restored to a state in which the bent portion has a large curvature due to its own elasticity, and a large number of glass wools are in a discrete state. As a result, a large number of cavities are formed between the glass wool inside the plate material, and the resin is pressed against the inner surface of the mold constituting the cavity. Thereby, the second layer 22 is formed. Since the second layer 22 molded in this manner has a large number of cavities formed between a large number of glass wools, it exhibits the same situation as when the resin is foamed, and the inside thereof has a porous structure.

  As shown in FIG. 2, the skin material 3 includes a foam layer 31 and a skin 32. The foam layer 31 is formed by foaming a resin such as polypropylene or polyethylene, and has an appropriate flexibility in order to give a soft touch. Therefore, the expansion ratio of the foam layer 31 is 3 to 8 times that of the second layer 22 constituting the core material 2 that requires strength, whereas the expansion ratio of the foam layer 31 is 15 to 15. 30. The foam layer 31 is fixed to the second layer 22 by means such as adhesion. The skin 32 is for improving the appearance of the surface of the door trim 1 facing the vehicle, and is manufactured by vacuum forming a thin film made of a resin such as polyethylene or polypropylene. The skin 32 is fixed to the foam layer 31 by means such as adhesion. The skin material 3 may be composed of only the skin 32 without the foam layer 31. In that case, the skin 32 is directly fixed to the second layer 22.

  In the door trim 1 having the above-described configuration, the first layer 21 of the core member 2 has a solid internal structure. Therefore, when noise outside the vehicle attempts to enter the vehicle through a large number of holes formed in the inner panel. The first layer 21 prevents the intrusion. However, since the first layer 21 is solid, it is difficult to prevent noise from propagating through the first layer 21 and entering the vehicle. However, the external noise propagated through the first layer 21 is prevented from entering the vehicle further by the second layer 22 having a porous internal structure. Therefore, according to this door trim 1, compared with the conventional door trim, the amount of intrusion of noise outside the vehicle into the vehicle can be greatly reduced.

  Further, if the second layer 22 is not present, the noise in the vehicle is reflected by the first layer 21 and the quietness in the vehicle deteriorates. However, in the door trim 1, noise generated inside the vehicle or entering from the outside of the vehicle is absorbed by the second layer 22 before reaching the first layer 21. Moreover, it is absorbed again by the second layer 22 when it is reflected by the first layer 21 and returns to the vehicle interior. Therefore, quietness in the vehicle can be improved.

FIG. 3 is an enlarged cross-sectional view showing a part of another embodiment of a vehicle interior product according to the present invention. In the vehicle interior product shown in this figure, the core material 2 has first and second reinforcing layers 23 and 24 in addition to the first layer 21 and the second layer 22. The first and second reinforcing layers 23 and 24 are both made of glass fiber mats or carbon fiber mats. The first reinforcing layer 23 is disposed between the first layer 21 and the second layer 22 and bonded to the first layer 21 and the second layer 22. The second reinforcing layer 24 is disposed between the second layer 22 and the foam layer 31 and is bonded to the second layer and the foam layer 31.

Next, experimental examples performed to confirm the above-described effects of the present invention will be described. In this experimental example, the former embodiment was compared with a conventional door trim. The first layer 21 of the core material 2 according to the present invention was made of polypropylene, its thickness was 1.5 mm, and its weight was 750 g / m ² . The second layer 22 of the core material 2 was made of polypropylene and glass wool. Their weight ratio was 50:50. The thickness of the second layer 22 was 6 mm, and its weight was 750 g / m ² . On the other hand, a conventional core material as a comparative example was made of solid with the same resin. The thickness was 3 mm, and the weight was the same as the core material 2. That is, it was 1500 g / m ² . And the transmission loss of the sound by the core material 2 and the conventional core material was measured. As a result, the transmission loss of the core material 2 was 30.3 dB, 41.9 dB, and 52.8 dB when the sound frequencies were 250 Hz, 500 Hz, and 1000 Hz, respectively. In contrast, the transmission loss of the conventional core material was 18.6 dB, 31.9 dB, and 46.4 dB, respectively, for the same frequency. Therefore, the core material 2 according to the present invention was able to improve the noise insulation and absorption ability to about 1.3 to 1.5 times that of the conventional core material.

In addition, this invention is not limited to said embodiment, In the range which does not deviate from the summary, it can change suitably.
For example, in the above embodiment, the first layer 21 having a solid structure and the second layer 22 having a porous structure are used one by one, but a plurality of first layers 21 are used, You may provide in the vehicle outer side and vehicle inner side of the layer 22, respectively. Alternatively, a plurality of second layers 22 may be used and provided on the vehicle inner side and the vehicle outer side of the first layer 21, respectively. Of course, a plurality of the first layers 21 and the second layers 22 may be used, and they may be alternately arranged from the vehicle outer side toward the vehicle inner side.
Moreover, in said embodiment, although the 1st layer 21 is comprised with the solid solid material, you may comprise the 1st layer 21 with a foam material. However, it is needless to say that the first layer 21 should have a lower foaming ratio and a higher density than the second layer 22 and have higher sound insulation than the second layer 22.

It is sectional drawing which shows 1st Embodiment of this invention. It is sectional drawing which expands and shows a part of the embodiment. It is sectional drawing which expands and shows a part of 2nd Embodiment of this invention.

Explanation of symbols

1 Door Trim 2 Core Material 3 Skin Material 21 First Layer 22 Second Layer

Claims (2)

In a vehicle interior comprising a core material and a skin material fixed to the surface of the core material,
The core material has a first layer on the vehicle exterior side and a second layer on the vehicle interior side , the skin material is fixed to the second layer, and the first layer is configured with a higher density than the second layer. The interior of the vehicle is characterized in that the second layer has a porous structure by forming a number of cavities between a number of glass wool incorporated in the resin. The first layer is made of a solid solid material, and the weight ratio of the resin constituting the second layer and the glass wool is set to 60:40 to 30:70. Vehicle interior parts as described in 1.

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