JP2014189230A - Structure of vehicular floor carpet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of vehicular floor carpet capable of improving sound insulation performance while suppressing weight increase.SOLUTION: A structure of vehicular floor carpet 30 comprises: a skin material layer 31; and an intermediate layer 34 which is a rear face side of the skin material layer, and is configured so that the skin material layer 31 disposed in a separated state from a floor panel 10 via the intermediate layer 34 when the carpet is provided on the floor panel 10 of the vehicle constitutes a double wall structure by cooperation with the floor panel 10. The intermediate layer 34 has thinner parts 33 whose thickness is equal to or less than predetermined thickness partially. Partial sound insulation layers 32 are provided on only the thinner parts 33.

Description

  The present invention relates to a structure of an automobile floor carpet laid on an automobile floor panel.

2. Description of the Related Art Conventionally, floor carpets for automobiles (hereinafter simply referred to as “carpets”) that have been configured to reduce noise that enters the vehicle interior from outside the vehicle compartment have been developed. Such a carpet is used by being laid on a floor panel of an automobile.
FIG. 7 schematically shows an example of the structure of a conventional carpet. As shown in the cross-sectional view in the vehicle width direction in FIG. 7, the floor panel 110 is generally provided with a center tunnel portion 111 for passing a propeller shaft (not shown) and a side sill coupling portion 112 coupled with a side sill 120 to reinforce. In some cases, a corrugated section 113 is provided. The corrugated cross section 113 is also called a floor frame because it is a structural element corresponding to the frame. The center tunnel portion 111, the side sill joint portion 112, and the corrugated cross-section portion 113 are formed to extend in the front-rear direction of the floor panel 110 and are higher than the floor panel base surface 115. Collectively called “protrusion”.

Usually, the carpet is laid on the floor panel after being molded by a press or the like according to the shape of the floor panel so that the carpet does not partially float on the floor panel. Alternatively, it is laid on the floor panel by laying the lower layer portion without gaps according to the shape of the floor panel, flattening the upper surface and then placing the upper layer portion.
That is, as shown in FIG. 7, the carpet 130 is formed such that the lower surface thereof has irregularities corresponding to the protrusions 111, 112, 113 of the floor panel 110. On the other hand, the surface of the carpet 130 is formed in a flat shape at a low position while suppressing the protrusion to the upper side (vehicle compartment side) as much as possible so as to widen the vehicle interior space and make it easier for passengers to get on.

  Patent Document 1 discloses a carpet provided with a raising material so as to fill unevenness on a floor panel (a step between a floor panel base surface and a floor frame upper surface formed at a higher position). . In this carpet, the first felt material (sound insulation layer), the sound insulation sheet body (resin sheet body), the second felt material (sound absorption layer) and the skin material layer are arranged on the upper surface of the raising material in order from the bottom (floor panel side). Lamination is used to reduce noise inside and outside the vehicle interior, and by using a sound insulation sheet having high tensile strength, the rigidity of the entire carpet is ensured.

JP 2008-285027 A

  By the way, as shown in FIG. 7, the carpet generally has a laminated structure of a skin material layer 131 having a high ventilation resistance and a felt material (intermediate layer) 134 having a lower ventilation resistance than the skin material layer 131. By making a double wall with the skin material layer 131 and the floor panel 110, the sound insulation performance (transmission loss) is proportional to the logarithm of the product of the surface density (or mass) of the material and the frequency (so-called mass law) ) Is much better than

  In this way, the degree of the double wall effect that enhances the sound insulation performance by the double wall varies depending on the thickness of the intermediate layer 134 that is configured between the skin material layer 131 and the floor panel 110. That is, when the thickness of the intermediate layer 134 is larger than the predetermined thickness, a double wall effect is obtained, but when the thickness of the intermediate layer 134 is equal to or less than the predetermined thickness, the double wall effect is difficult to be obtained, and the sound insulation performance is It becomes close to the one based on the law of mass.

  As shown in FIG. 7, in the carpet 130, the thickness of the intermediate layer 134 formed between the skin material layer 131 and the floor panel base surface 115 is larger than a predetermined thickness, and a double wall effect can be obtained. However, the intermediate layer 134 engaged with the protrusions 111, 112, 113 of the floor panel 110 becomes thin portions 133a, 133b, 133c, 133d, 133e having relatively small thicknesses.

That is, the side sill joint 112 and the corrugated cross-section 113 of the floor panel 110 are higher than the floor panel base surface 115, whereas the surface of the carpet 130 that covers the floor panel 110 is easy for an occupant to step on. Thus, the intermediate layer 134 of these portions becomes the thin portions 133b and 133e.
Further, as described above, the carpet 130 in the portion covering the center tunnel portion 111 and the side sill portions 120 and 120 protruding upward is thinly formed so as to widen the vehicle interior space, thereby suppressing the protrusion to the vehicle interior side. Therefore, the intermediate layer 134 of these portions becomes the thin portions 133a, 133c, and 133d.

In such thin portions 133a, 133b, 133c, 133d, and 133e, since the thickness of the intermediate layer 134 is small, it is difficult to obtain a double wall effect. As a result, the sound insulation performance of the carpet 130 is degraded. When the carpet 130 does not satisfy a certain sound insulation performance, a measure for improving the sound insulation performance of the carpet 130 is required.
In this case, it is necessary to improve the sound insulation performance without increasing the thickness of the carpet 130. As long as the double wall effect cannot be expected, for example, the skin material layer 131 may be made to have a higher surface density, but this also has a limit. Therefore, for example, as shown by a two-dot chain line in FIG. 7, it may be considered to add a sound insulation layer to the entire back surface of the skin material layer 131. In any case, it is necessary to improve the sound insulation performance based on the mass law by increasing the mass of the carpet 130.

When the sound insulation layer is used, the sound insulation performance based on the mass rule can be further improved by using a material having a larger mass (high density) for the sound insulation layer.
On the other hand, since the carpet has a weight limit so that the worker can carry it with ease when assembled, adding an excessive sound insulation layer will increase the weight of the carpet, resulting in an increase in the weight of the carpet. If you exceed the weight limit, you can't handle it with a single sheet.

  The present application has been devised in view of such problems, and provides a structure of an automobile floor carpet that can suppress an increase in weight while efficiently improving sound insulation performance. Objective.

  (1) In order to achieve the above object, the structure of an automobile floor carpet according to the present invention includes a skin material layer and an intermediate layer on the back side of the skin material layer, and is laid on a floor panel of an automobile. The skin material layer disposed separately from the floor panel via the intermediate layer is a structure of an automobile floor carpet that forms a double wall structure in cooperation with the floor panel, and the intermediate layer Is characterized in that a thin portion having a thickness equal to or less than a predetermined thickness is partially provided, and a partial sound insulation layer is provided only in the thin portion.

In the present invention, the thin-walled portion includes a portion that is partially provided in the intermediate layer and has no thickness.
(2) A tunnel portion projecting upward from the floor panel base surface is formed at the center portion of the floor panel so as to extend in the front-rear direction. A side sill joint portion that is higher than the surface is formed to extend in the front-rear direction, and the thin portion is provided corresponding to a portion that is higher than the floor panel base surface, including the tunnel portion and the side sill joint portion. It is preferable.

(3) Moreover, it is preferable that the said partial sound-insulation layer is the one sheet | seat which cut the sheet-like material.
(4) The skin material layer is made of a high-density and non-ventilated or air-permeable resistance material, and the intermediate layer is made of a low-density and low air-permeable resistance material. Is preferably made of a material having a high density and a high non-ventilation or ventilation resistance.

  (5) Moreover, it is preferable that the said partial sound insulation layer is interposed between the said skin material layer and the said thin part of the said intermediate | middle layer.

  (1) According to the structure of the floor carpet for automobiles of the present invention, the thin wall portion has a thin intermediate layer, so that it is difficult to obtain a double wall effect, and it becomes a relatively weak portion of sound insulation. Since the layer is provided, the sound insulation performance of the weak point portion can be improved by the partial sound insulation layer. Further, the higher the density of the sound insulation layer, the higher the sound insulation performance. However, if the sound insulation layer is provided on the entire surface of the carpet, the weight of the entire carpet becomes excessive and may not be used. However, since the partial sound insulation layer is provided only in the thin wall portion that is a part of the carpet, even if a high-density and high sound insulation material is used for the partial sound insulation layer, the weight increase of the entire carpet can be suppressed. A high sound insulation effect can be obtained efficiently.

  (2) Further, the floor panel is formed with a portion that is higher than the floor panel base surface, such as a tunnel portion or a side sill joint portion, and the thickness of the intermediate layer is equal to or less than a predetermined thickness corresponding to such a portion. By providing the thin-walled portion, the height of the surface of the floor carpet can be suppressed and a vehicle interior space can be secured. However, this thin-walled part is not only difficult to obtain the double-wall effect because the intermediate layer is thin, but it is relatively close to the occupant's ears, so it is an important part to be sound-insulated. In contrast, the sound insulation performance can be improved efficiently.

(3) Further, if the partial sound insulation layer is a single sheet-shaped material cut out, the partial sound insulation layer becomes one point, so that parts management becomes easy and the assembly workability can be improved.
(4) Further, if a material having a high density and no ventilation or a large air resistance is used for the skin material layer and the partial sound insulation layer, and a material having a low density and a low air resistance is used for the intermediate layer, the skin material is used. High sound insulation performance can be reliably obtained by the double wall effect of the layer and the floor panel, and sound insulation performance based on the mass law can be obtained reliably by the partial sound insulation layer.

  (5) Further, if the partial sound insulation layer is interposed between the skin material layer and the thin portion of the intermediate layer, for example, the partial sound insulation layer is attached to the back surface of the skin material layer in advance. As a result, assembly workability can be improved.

It is a typical sectional view of the whole vehicle width direction showing the structure of the floor carpet for automobiles concerning one embodiment of the present invention. It is typical sectional drawing which expands and shows the vehicle width direction center part of the floor carpet for motor vehicles concerning one Embodiment of this invention. It is typical sectional drawing which expands and shows the vehicle width direction one end part of the floor carpet for motor vehicles concerning one Embodiment of this invention. It is a top view which shows the partial sound insulation layer provided in the floor carpet for motor vehicles based on one Embodiment of this invention. It is a graph which shows the relationship between the sound insulation performance (transmission loss) of the Example which concerns on this invention, and a sound frequency. It is typical sectional drawing which shows the structure of the Example and comparative example which concern on this invention, (a) is the structure of Example 1, (b) is the structure of Example 2, (c) is the comparative example 1. (D) has shown the structure of the comparative example 2, respectively. It is typical sectional drawing of the whole vehicle width direction which shows the structure of the conventional automotive floor carpet which comprises a double wall structure.

Embodiments of the present invention will be described below with reference to the drawings. Note that the front-rear direction in the following description corresponds to the front-rear direction of the automobile provided with the automobile floor carpet according to the present embodiment, and the left-right direction in the following description is the automobile floor carpet according to the present embodiment. It corresponds to the left-right direction when facing the front of a car equipped with.
FIG. 1 shows the structure of a floor carpet for an automobile according to an embodiment of the present invention. FIG. 1 is a schematic cross-sectional view in the vehicle width direction at the foot portion of the front seat. 30 shows a state where it is laid. In addition, the structure of the floor carpet for automobiles according to the present embodiment is a symmetrical structure in the cross section of FIG.

First, the structure of the floor panel 10 will be described. As shown in FIG. 1, the floor panel 10 is formed by press-molding a steel plate, for example, a portion protruding upward such as a tunnel portion 11, a side sill coupling portion 12, and a corrugated cross-sectional portion 13 described later, and other horizontal surfaces. (Floor panel base surface) 15.
At the center in the vehicle width direction of the floor panel 10, there is a tunnel portion 11 that is substantially U-shaped in cross section and protrudes vertically above the floor panel base surface 15 (vehicle compartment side) in order to pass a propeller shaft (not shown). It is extended and formed. In addition, side sill coupling portions 12 and 12 that are slightly higher vertically above the floor panel base surface 15 are formed to extend in the front-rear direction at locations where the floor panels 10 are coupled to the side sills 20 and 20 at the left and right ends. Yes. The side sill joints 12 and 12 and the side sills 20 and 20 are joined by spot welding or the like. Although omitted in FIG. 1, a tunnel for attaching a center console is provided at the upper end of the tunnel 11 between the driver seat and the passenger seat at the front of the passenger compartment.

Further, in order to reinforce the floor panel 10 between the tunnel portion 11 of the floor panel 10 and the side sill coupling portions 12, 12, the cross section is substantially U-shaped and slightly above the floor panel base surface 15. The raised corrugated cross sections 13 and 13 are formed to extend in the front-rear direction. Since the corrugated cross section 13 is a structural element corresponding to a frame, it is also called a floor frame.
In addition, the structure of the floor carpet for automobiles according to the present invention is not limited to the floor panel having the shape as described above. For example, the floor carpet is laid on a floor panel that does not have a tunnel portion, a side sill joint portion, and a corrugated cross section. It can also be applied to carpets.

Next, the carpet 30 laid on the upper surface of the floor panel 10 will be described.
As shown in FIG. 1, the carpet 30 has a skin material layer 31 and an intermediate layer 34 on the back side thereof, and the skin material layer 31 is interposed via the intermediate layer 34 when laid on the floor panel 10. The floor panel 10 is spaced apart from the floor panel 10 to form a double wall structure in cooperation with the floor panel 10.

  FIG.2 and FIG.3 is typical sectional drawing which expands and shows the vehicle width direction center part and one end part of the structure of the floor carpet for motor vehicles based on this embodiment. As shown in FIGS. 2 and 3, for example, a needle punch carpet made of a non-woven fabric layer 31 a on the front side and a backing layer 31 b on the back side is used for the skin material layer 31. The backing layer 31b is composed of a synthetic resin as a layer having a high density and a high non-ventilation or ventilation resistance.

For the intermediate layer 34, for example, a low-density material having a low airflow resistance such as felt is used. In the present embodiment, the skin material layer 31 is formed to have a substantially uniform thickness of about 2 to 3 mm.
As shown in FIG. 1, the skin material layer 31 forming the upper layer portion of the carpet 30 is flat so that an occupant can easily put his / her feet on the floor panel 10 except for portions corresponding to the tunnel portion 11 and the side sills 20 and 20. Is formed. Moreover, in the skin material layer 31, the part laid along the part corresponding to the tunnel part 11 and the side sills 20 and 20 of the floor panel 10 is formed flat along the plane of each part.

  Further, the intermediate layer 34 that forms the lower layer portion of the carpet 30, except for portions corresponding to the tunnel portion 11 and the side sills 20, 20, has a lower surface that forms the side sill coupling portions 12, 12 and the corrugated cross-section portions 13, 13. The floor panel 10 is formed so as to have irregularities according to the shape of the floor panel 10 so as to be engaged without gaps, and the upper surface thereof is formed flat so as to be engaged with the skin material layer 31 without gaps. Has been.

  Further, the tunnel portion 11 and the side sills 20 and 20 of the floor panel 10 are each composed of a plurality of surfaces (planar or substantially flat), but correspond to the tunnel portion 11 and the side sills 20 and 20 of the floor panel 10 in the intermediate layer 34. The portion laid along the portion to be formed is formed flat along the plane of each portion and with a constant thickness on each surface. Thus, the carpet 30 is laid on the floor panel 10 so that the carpet 30 does not partially float on the floor panel 10 when laid on the upper surface of the floor panel 10.

  In the present embodiment, the skin material layer 31 is formed into a predetermined shape by pressing or the like. Further, the intermediate layer 34 is also formed into a predetermined shape according to the shape of the floor panel 10 and the skin material layer 31 by pressing or the like, but the intermediate layer 34 made of a soft material such as felt is specially formed. Without forming, a sheet having a predetermined thickness corresponding to each part of the floor panel 10 may be cut according to each part shape of the floor panel 10 and laid on each surface. .

  When the carpet 30 is laid on the floor panel 10, the skin material layer 31 and the floor panel 10 cooperate to form a double wall structure. This double wall structure can obtain a double wall effect that greatly improves the sound insulation performance if the distance between both walls, that is, the distance between the skin material layer 31 and the floor panel 10 is secured to a certain level or more. it can. Since the intermediate layer 34 is interposed between the skin material layer 31 and the floor panel 10, the distance between the skin material layer 31 and the floor panel 10 depends on the thickness of the intermediate layer 34.

In other words, in order to obtain good sound insulation performance by the double wall structure, it is necessary to secure a thickness enough to obtain the double wall effect in the intermediate layer 34. On the other hand, in order to widen the vehicle interior space, it is desirable to form the carpet 30 as thin as possible.
Therefore, the carpet 30 of the present embodiment is set so that the thickness of the intermediate layer 34 can provide a double wall effect that is more than a certain level in terms of sound insulation performance, and the top surface of the carpet 30 can be set as low as possible. Yes. In the present embodiment, the standard thickness of the intermediate layer 34 is 10 to 20 mm.

  However, as shown in FIGS. 1 to 3, the intermediate layer 34 has a location higher than the floor panel base surface 15, that is, the tunnel portion 11, the side sill coupling portion 12, and the corrugated cross-section portion 13 of the floor panel 10. Correspondingly, thin portions 33a, 33b, 33c, 33d, 33e (hereinafter referred to simply as “thin portions 33” if they are not distinguished) are provided, which are thinner than other portions.

  That is, as shown in FIG. 1, the side sill coupling portion 12 and the corrugated cross-sectional portion 13 of the floor panel 10 are higher than the floor panel base surface 15, and a step is formed between the floor panel base surface 15. On the other hand, since the surface of the carpet 30 covering these portions is formed flat, the intermediate layer 34 has a relative thickness corresponding to the side sill joint 12 and the corrugated cross section 13. Small thin portions 33b and 33e are provided.

  Further, as shown in FIGS. 2 and 3, the carpet 30 is formed with a thin portion covering the tunnel portion 11 and the side sill 20 of the floor panel 10 in order to suppress the protrusion to the passenger compartment side. For this reason, as shown in FIG. 2, the part which covers the tunnel part 11 among the intermediate | middle layers 34 becomes the thin part 33a. Moreover, as shown in FIG. 3, the part which coat | covers the side surface and upper surface of the side sill 20 among the intermediate | middle layers 34 becomes the thin part 33c, 33d, respectively.

In the present embodiment, the thickness of the thin portions 33b, 33d, and 33e is 3 to 4 mm, and the thickness of the thin portions 33a and 33c is about 1 mm.
The thin-walled portion is not limited to the above, and any portion is applicable as long as it is a portion that is partially provided in the intermediate layer 34 and the thickness is equal to or less than a predetermined thickness and it is difficult to obtain the double wall effect. obtain. For example, a non-thick part provided partially in the intermediate layer 34 is also a thin part.

  As shown in FIGS. 1-3, between these thin-walled portions 33a, 33b, 33c, 33d, 33e and the skin material layer 31, partial sound insulation layers 32a, 32b, 32c, 32d, 32e (hereinafter, When these are not distinguished, they are simply referred to as “partial sound insulation layer 32”. The partial sound insulation layer 32 is provided only in the thin portion 33 having a thickness where a desired double wall effect cannot be obtained (that is, a thickness equal to or less than a predetermined thickness), and a desired double wall effect can be obtained. It is not provided at a location of thickness (thickness greater than a predetermined thickness).

For the partial sound insulation layer 32, for example, a material having high density and high non-ventilation or ventilation resistance, such as olefin, is used. In the present embodiment, the partial sound insulation layer 32 has a thickness of about 1 mm and a substantially uniform thickness.
FIG. 4 shows a top view of the carpet 30 and the partial sound insulation layer 32. As shown in FIG. 4, the partial sound insulation layer 32 is a single sheet obtained by punching out a sheet-like olefin, and is formed corresponding to the thin portion of the carpet 30. Further, the carpet 30 is provided with a hole portion 35 for interposing the center console between a driver seat and a passenger seat (not shown) in correspondence with the hole portion provided in the tunnel portion 11 of the floor panel 10. ing. The solid line shown in FIG. 4 is a boundary line between a plurality of surfaces (planar or substantially plane) constituting the carpet 30, and the dotted line shown in FIG. 4 is the floor when the carpet 30 is laid on the floor panel 10. This is a portion corresponding to the corrugated cross sections 13 and 13 of the panel 10.

In the present embodiment, the carpet 30 is assembled by laminating a material in which a partial sound insulation layer 32 is attached to the back surface of the skin material layer 31 in advance on the upper surface of the intermediate layer 34 laid on the floor panel 10. It is said.
The intermediate layer 34 may be provided with a recess for laminating the partial sound insulation layer 32. That is, unevenness corresponding to the partial sound insulation layer 32 is formed on the upper surface of the intermediate layer 34 so that the intermediate layer 34 and the partial sound insulation layer 32 are engaged with each other without any gap between the floor panel 10 and the skin material layer 31. It may be configured.

However, in the case where a relatively soft material is used for the intermediate layer 34 and the intermediate layer 34 can be compressed and deformed in accordance with the partial sound insulating layer 32, it is not necessary to provide the above-described recess. In this embodiment, since the felt used for the intermediate layer 34 can be compressed and deformed in accordance with the partial sound insulation layer 32, no particular recess is provided on the upper surface of the intermediate layer 34.
In the present embodiment, the intermediate layer 34 is uniformly filled with a material such as felt. For example, the thin portion 33e is filled with a material such as felt at a lower density than other portions. Also good. That is, since the thin-walled portion 33e is only a relatively small portion of the carpet 30, if the carpet 30 has sufficient rigidity at other portions, a material such as felt has a slight gap in the thin-walled portion 33e. It may be provided.

Moreover, in this embodiment, although the thickness of the skin material layer 31 and each partial sound-insulation layer 32 was made substantially uniform, respectively, these may be formed in what has a different thickness in an appropriate location, respectively.
Since the structure of the automobile floor carpet according to the present embodiment is configured as described above, the following operations and effects can be obtained.
As described above, the carpet 30 forms a double wall structure with the skin material layer 31 and the floor panel 10, and thereby, a double wall effect of a certain level or more can be obtained in terms of sound insulation performance. Yes. Moreover, since the upper surface of the carpet 30 is set as low as possible, a vehicle interior space is secured.

In particular, thin portions 33 b and 33 e are provided in the intermediate layer 34 corresponding to the side sill joint portion 12 and the corrugated cross-sectional portion 13 that are higher than the floor panel base surface 15, and the surface of the carpet 30 in these portions is flattened. Therefore, not only does it become easier for an occupant to get on the foot, but the height of the surface of the carpet 30 can be suppressed, so that a vehicle interior space can be secured.
Further, since the thin portions 33a, 33c, and 33d are provided corresponding to the tunnel portion 11 and the side sill 20 protruding upward from the floor panel base surface 15, the carpet 30 in these portions can be formed thin. As a result, the vehicle interior space can be secured.

  On the other hand, by setting the upper surface of the carpet 30 as low as possible, the thickness of the intermediate layer 34 becomes equal to or less than a predetermined thickness at the thin portion 33, and it becomes difficult to obtain the double wall effect. For this reason, the thin-walled portion 33 becomes a weak point of sound insulation, and the sound insulation performance of the carpet 30 is lowered. Therefore, the deterioration of the sound insulation performance in this portion can be suppressed.

  That is, for example, even when a high sound insulation performance can be obtained due to the double wall effect in the majority of the carpet 30, if the thin wall portion 33 exists in the carpet 30, the vehicle passes through the thin wall portion 33 with a relatively low sound insulation performance. Outdoor noise intrudes into the passenger compartment. Therefore, in order to improve the sound insulation performance of the carpet 30, it is important to improve the sound insulation performance of the thin portion 33 which is a weak portion of the sound insulation as much as possible.

Furthermore, for example, the thin portion 33a along the tunnel portion 11 is located relatively close to the occupant's ear, so that noise entering from the thin portion 33a can easily reach the occupant's ear, and is particularly important to be sound-insulated, Since the sound insulation performance of this part can be improved by the partial sound insulation layer 32a, the sound insulation effect is great.
In addition, since the partial sound insulation layer 32 is provided only in the thin portion 33, the sound insulation performance of the weak spot portion is efficiently improved while avoiding giving the sound insulation performance to the portion where the double wall effect was originally obtained. be able to.

  In other words, a high-density material that cannot be used for the sound insulation layer provided on the entire carpet surface as in the prior art can be used for the partial sound insulation layer 32. For this reason, since the mass of the weak spot part can be increased by the partial sound insulation layer 32, the sound insulation performance can be improved based on the mass rule, and the mass other than the weak spot part does not increase. Can be suppressed.

  Further, as shown in FIG. 1, when the partial sound insulation layer 32 is interposed between the skin material layer 31 and the thin portion 33 of the intermediate layer 34, the partial sound insulation layer 32 is previously provided on the back surface of the skin material layer 31. After the intermediate layer 34 is laid on the floor panel 10, the carpet 30 can be easily assembled by laying the skin material layer 31 with the partial sound insulation layer 32 attached on the upper surface of the intermediate layer 34. it can. Therefore, the assembly workability can be improved.

  In addition, as shown in FIG. 4, the partial sound insulation layer 32 is made of a single sheet-shaped material, which facilitates the positioning of the partial sound insulation layer 32 with respect to the intermediate layer 34 and the skin material layer 31. As a result, workability is improved. Furthermore, since the number of parts is also reduced, parts management becomes easy.

(simulation result)
FIG. 5 models the structure of each part of the carpet 30 according to the present invention obtained by simulation, and the relationship between the sound insulation performance (transmission loss) and the sound frequency, that is, the sound insulation characteristics, is shown in the comparative example model. It is a graph shown with a sound insulation characteristic.
FIG. 5 shows the characteristics of each model of Example 1, Example 2, Comparative Example 1 and Comparative Example 2. Of these, Example 1 shows a floor panel 10 as shown in FIG. In the carpet 30 laid on the top, a portion where the partial sound insulation layer 32 is provided at the thin portion 33 is modeled. Further, in the second embodiment, as shown in FIG. 6B, in the carpet 30 laid on the floor panel 10, the intermediate layer 34 has a thickness larger than a predetermined thickness, and a double wall effect can be obtained. Is modeled.

  In addition, as shown in FIG. 6C, Comparative Example 1 is not provided with the partial sound insulation layer 32 of Example 1, that is, on the floor panel 110 in the same manner as a part of the conventional carpet 130. A model composed of only the thin-walled portion 133 and the skin material layer 131 is modeled. In Comparative Example 2, as shown in FIG. 6D, the floor panel 110 alone is modeled.

  In addition, each layer corresponding to Example 1, Example 2, Comparative Example 1 and Comparative Example 2 (the skin material layer 31 of Example 1 and Example 2, the skin material layer 131 of Comparative Example 1, the thin portion of Example 1) 33 and the thin-walled portion 133 of Comparative Example 1, the floor panel 10 of Example 1 and Example 2, and the floor panel 110 of Comparative Example 1 and Comparative Example 2 were substantially the same. Moreover, the thickness, surface density ratio, and ventilation resistance ratio of each layer were set to values shown in Table 1.

図５に示すように、実施例２は、比較例２と比較すると、周波数が９００Ｈｚ以上の中高周波数領域では遮音性能が大幅に高くなることが分かる。このような周波数領域の音は耳障りであり、自動車の車室内の遮音対策の上で重要な対象となるものであるが、実施例２は、このような周波数領域の音に対して二重壁効果による良好な遮音性能が得られることが分かる。

As shown in FIG. 5, it can be seen that the sound insulation performance of Example 2 is significantly higher in the middle and high frequency region where the frequency is 900 Hz or higher than that of Comparative Example 2. Such sound in the frequency domain is annoying and is an important target for sound insulation measures in the interior of an automobile. Example 2 is a double wall against such sound in the frequency domain. It can be seen that good sound insulation performance due to the effect can be obtained.

  In Example 2, the sound insulation performance in the low frequency region is slightly degraded as compared with other Examples and Comparative Examples, but this is considered to be due to the resonance effect. FIG. 5 shows the sound insulation characteristics of each model. For example, the floor of the actual vehicle is provided with a structure for enhancing rigidity such as the corrugated cross section 13 to avoid such resonance in the low frequency region. Since it is possible, there is no problem.

  Further, it can be seen that the sound insulation performance in the middle and high frequency region is higher in Example 1 than in Comparative Example 1. In other words, it can be seen that the thin wall portion 133 of the conventional carpet 130 modeled as Comparative Example 1 has a low sound insulation performance in the middle and high frequency range. On the other hand, in Example 1, it can be seen that the sound insulation performance in all simulated frequency regions is higher than that in Comparative Example 1.

From the above results, according to the structure of the floor carpet for automobiles of the present invention, in the portion where the double wall effect can be obtained, it is possible to obtain a good sound insulation performance for the sound in the middle and high frequency range, and the double wall effect is obtained. It was found that the sound insulation performance for the sound in the entire frequency region is reliably improved by the partial sound insulation layer 32 in the thin-walled portion 33 that is difficult to be formed.
Further, since the partial sound insulation layer 32 improves the sound insulation performance based on the mass rule, by using a higher density material for the partial sound insulation layer 32, as shown by a two-dot chain line in FIG. It is considered that the sound insulation performance for sound in the frequency range can be further improved. According to the structure of the floor carpet for an automobile of the present invention, as described above, a high-density material that could not be used conventionally can be used for the partial sound insulation layer 32. Sound insulation performance can be improved effectively.

[Others]
Although the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications may be made to the embodiment without departing from the gist of the present invention. Can do.
For example, the materials of the skin material layer 31, the partial sound insulation layer 32, and the intermediate layer 34 are not limited to the above materials, and various materials can be used depending on the weight limit of the carpet, the required sound insulation performance, and the feeling of use. It is possible to apply. In this case, for the skin material layer 31 and the partial sound insulation layer 32, the sound insulation performance of the carpet 30 is further improved based on the mass law by using a material having a higher density within a range not exceeding the weight limit of the carpet 30. Can do. Further, if a sound absorbing material (porous material) is used for the intermediate layer 34, a sound absorbing effect can be obtained in addition to the above-described sound insulating effect.

  In the above-described embodiment, the partial sound insulation layer 32 is a single sheet-shaped one, but the partial sound insulation layer 32 may not be a single sheet. When the partial sound insulation layer 32 is constituted by a plurality of sheets, a different material can be used for each sheet. For example, for the thin portions 33a and 33c having a smaller thickness, the sound insulation performance at these portions can be effectively enhanced by configuring the partial sound insulation layers 32a and 32c with a sheet using a higher density material. Can do.

  A vibration damping material layer may be provided between the floor panel 10 and the intermediate layer 34. With such a configuration, the vibration of the floor panel 10 can be suppressed by the damping material layer, so that the sound absorbing performance of the carpet 30 can be enhanced.

DESCRIPTION OF SYMBOLS 10 Floor panel 11 Tunnel part 12 Side sill joint part 13 Corrugated cross-section part 15 Floor panel base surface 20 Side sill 30 Carpet 31 Skin material layer 32 Partial sound insulation layer 33 Thin-walled part 34 Intermediate layer

Claims (5)

Having a skin material layer and an intermediate layer on the back side of the skin material layer,
An automobile floor carpet in which, when laid on a floor panel of an automobile, the skin material layer disposed apart from the floor panel via the intermediate layer forms a double wall structure in cooperation with the floor panel. The structure of
The intermediate layer is partially provided with a thin portion having a thickness equal to or less than a predetermined thickness,
A structure of a floor carpet for an automobile, wherein a partial sound insulation layer is provided only in the thin portion. A tunnel portion projecting upward from the floor panel base surface is formed in the center of the floor panel so as to extend in the front-rear direction, and is connected to the side sill at the left and right ends of the floor panel than the floor panel base surface. A raised side sill joint is formed to extend back and forth,
2. The automobile floor carpet according to claim 1, wherein the thin portion is provided in correspondence with a portion including the tunnel portion and the side sill joint portion and higher than the floor panel base surface. Structure. The structure of an automobile floor carpet according to claim 1 or 2, wherein the partial sound insulation layer is a single sheet-shaped material cut out. The skin material layer is made of a high-density and non-ventilated or air-resistant material,
The intermediate layer is made of a material with low density and low ventilation resistance,
The structure of a floor carpet for an automobile according to any one of claims 1 to 3, wherein the partial sound insulation layer is made of a material having a high density and a high non-ventilation or ventilation resistance. The said floor sound-insulating layer is interposed between the said skin material layer and the said thin part of the said intermediate | middle layer, The structure of the floor carpet for motor vehicles in any one of Claims 1-4 characterized by the above-mentioned. .

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