Manufacturing method of vehicle floor carpet and vehicle floor carpet

Abstract

To provide a manufacturing method of a vehicle floor carpet which can suppress deformation of a product shape after formation.SOLUTION: A manufacturing method of a vehicle floor carpet 1 comprises: a carpet 2 which is formed in a three-dimensional shape having a bottom wall 4 and vertical walls 5a, 5b along a floor part of a vehicle; and a noise insulation sheet 3 which is pasted in a rear surface side of the vertical wall 5a. The noise insulation sheet includes a deformable fragile site. The noise insulation sheet and a heated carpet are pressed by a form block so that the carpet is formed in a three-dimensional shape and the noise insulation sheet and the carpet are integrally formed.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a manufacturing method of a vehicle floor carpet and a vehicle floor carpet, and more particularly to a manufacturing method of a vehicle floor carpet in which a sound insulation sheet is attached to the back side of the carpet and a vehicle floor carpet. [Background technology]

[0002] A conventional vehicle floor carpet is generally known that includes a carpet formed into a three-dimensional shape that has a bottom wall and vertical walls rising from the bottom wall and conforms to the floor of the vehicle, and a sound insulation sheet (e.g., an EPDM sound insulation sheet) attached to the back side of the carpet. This sound insulation sheet is often attached to the vertical walls of the carpet by rear attachment to block noise from a tunnel installed in the floor of the vehicle. However, rear attachment of the sound insulation sheet increases the parts cost generated by an additional process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-023275 A [Patent Document 2] WO2015 / 181901 publication [Patent Document 3] JP 2008-044459 A [Patent Document 4] Japanese Patent Application Publication No. 5-069772 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, as a manufacturing method for vehicle floor carpet that solves the above problems, a technology has been proposed in which a sound-insulating sheet is set in a mold in advance, and the mold presses the sound-insulating sheet and the heated carpet to form the carpet into a three-dimensional shape and mold the sound-insulating sheet and carpet as a single unit.

[0005] However, with the above proposed technology, there is a large difference in thermal shrinkage (molding shrinkage) due to the difference in materials between the sound-proofing sheet and the carpet, so the carpet warps toward the inside of the vehicle cabin after molding. Specifically, after being integrally molded, the sound insulation sheet 103 and the carpet 102 shrink Q as the temperature drops (see FIG. 10(a)). At this time, the carpet 102 shrinks more easily than the sound insulation sheet 103. Therefore, even after the sound insulation sheet 103 has finished shrinking, the carpet 102 is still shrinking, so stress R is generated so that the sound insulation sheet 103 is not pulled by the carpet 102 (see FIG. 10(b)). As a result, the stress R of the sound insulation sheet 103 increases, causing the carpet 102 to warp (see FIG. 10(c)).

[0006] Patent Document 1 discloses a mat that is placed in a necessary portion to maintain the bent state. Patent Document 2 discloses that the density of the resin layer of the floor mat and the content of inorganic filler affect curling after thermoforming. Patent Document 3 discloses a sound-absorbing mat in which a synthetic resin film with ventilation holes is laminated on the back surface of the skin substrate. Patent Document 4 discloses a method in which felt (sound-absorbing material) that has been heated to eliminate thermal deformation is backed by a carpet and thermoformed together with another felt. However, Patent Documents 1 to 4 do not disclose any technology for obtaining a vehicle floor carpet in which a sound insulation sheet is attached to the back side of the carpet while suppressing deformation of the product shape after molding.

[0007] The present invention has been made in consideration of the above-mentioned current situation, and aims to provide a manufacturing method for a vehicle floor carpet and a vehicle floor carpet that can suppress deformation of the product shape after molding. [Means for solving the problem]

[0008] In order to solve the above problems, the invention described in claim 1 is a manufacturing method for a vehicle floor carpet comprising a carpet molded into a three-dimensional shape that conforms to the floor of a vehicle, having a bottom wall and a standing wall formed by squeezing so as to rise from the bottom wall, and a sound-insulating sheet attached to the back side of the standing wall, wherein the sound-insulating sheet has a deformable weak portion, and the carpet is molded into a three-dimensional shape by applying pressure to the sound-insulating sheet and the carpet in a heated state using a molding die, and the sound-insulating sheet and the carpet are molded integrally. The invention described in claim 2 is characterized in that, in the invention described in claim 1, the weak portion extends in one or both of the rising direction of the standing wall and a direction intersecting the rising direction of the standing wall. The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the weak portions are arranged in multiple positions along one or both of the rising direction of the vertical wall and the direction intersecting the rising direction of the vertical wall. The invention described in claim 4 is characterized in that in the invention described in any one of claims 1 to 3, the fragile portion is formed of a slit. In order to solve the above problem, the invention described in claim 5 is a vehicle floor carpet comprising a carpet having a bottom wall and a standing wall rising from the bottom wall and molded into a three-dimensional shape that conforms to the floor of the vehicle, and a sound-insulating sheet attached to the back side of the carpet, wherein the sound-insulating sheet is provided with a deformable weak portion, and the sound-insulating sheet is molded integrally with the carpet. Effect of the Invention

[0009] According to the manufacturing method of the vehicle floor carpet of the present invention, the sound insulation sheet is provided with a deformable weak part, and the sound insulation sheet and the heated carpet are pressed by a molding die to mold the carpet into a three-dimensional shape, and the sound insulation sheet and the carpet are molded integrally. As a result, the weak part deforms in accordance with the expansion and contraction of the carpet due to the integral molding, and the difference in thermal shrinkage (molding shrinkage) due to the difference in materials between the sound insulation sheet and the carpet is absorbed. Therefore, deformation of the product shape after molding can be suppressed, and the product shape as intended can be realized. Furthermore, since the sound insulation sheet of the desired size can be attached to the back side of the carpet by integral molding, the NV (Noise Vibration) performance can be ensured, and the parts cost incurred in the additional process of attaching the sound insulation sheet after the conventional method can be reduced. Furthermore, when the weak portion extends in one or both of the rising direction of the vertical wall and a direction intersecting the rising direction of the vertical wall, the weak portion can be configured to easily deform in the rising direction of the vertical wall, thereby improving the ability to follow the expansion and contraction of the vertical wall. Furthermore, when multiple weak portions are arranged along one or both of the rising direction of the vertical wall and the direction intersecting the rising direction of the vertical wall, the desired amount of shrinkage difference between the sound-insulating sheet and the carpet is effectively absorbed by deformation of the multiple weak portions. Furthermore, when the fragile portion is constituted by a slit, the slit opens in response to the expansion of the carpet during integral molding, and deforms in a direction in which the slit closes in response to the contraction of the carpet after integral molding, thereby effectively absorbing the difference in contraction between the sound insulation sheet and the carpet. In particular, when the slit closes in response to the contraction of the carpet after integral molding, sound insulation is further improved.

[0010] According to the vehicle floor carpet of the present invention, the sound insulation sheet is provided with a deformable weak portion, and the sound insulation sheet is molded integrally with the carpet. This allows the weak portion to deform in accordance with the expansion and contraction of the carpet due to the integral molding, absorbing the difference in thermal shrinkage (molding shrinkage) due to the difference in materials between the sound insulation sheet and the carpet. This makes it possible to suppress deformation of the product shape after molding, and to realize the intended product shape. Furthermore, since the sound insulation sheet of the desired size can be attached to the back side of the carpet by integral molding, it is possible to ensure NV (Noise Vibration) performance while reducing the parts cost incurred in the additional process of back-attaching the sound insulation sheet as in the past. [Brief description of the drawings]

[0011] The present invention will be further described in the following detailed description by way of non-limiting examples of exemplary embodiments according to the invention and with reference to the several drawings mentioned, in which like reference numerals refer to like parts throughout the several views of the drawings. [Figure 1] 1A and 1B are explanatory views for explaining a manufacturing method of a vehicle floor carpet according to an embodiment, in which (a) shows a placement step and (b) shows a pressing step. [Diagram 2] 2A is an enlarged view of a portion of FIG. 1 along the line A, and FIG. 2B is an enlarged view of a portion of FIG. 1 along the line B. [Diagram 3] FIG. 2 is a plan view of the sound insulation sheet. [Figure 4] FIG. 11 is an explanatory diagram of the action of the integral molding of the sound-proofing sheet and carpet, where (a) shows the state immediately before integral molding, (b) shows the state in which the sound-proofing sheet and carpet stretch during integral molding, (c) shows the state in which the sound-proofing sheet and carpet have begun to shrink after integral molding, and (d) shows the state in which the carpet has further shrunk after integral molding. [Diagram 5] 1 is a perspective view of a vehicle floor carpet according to an embodiment; [Figure 6] FIG. 6 is an enlarged cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] FIG. 7 is an image processing diagram showing the appearance of a main part viewed from the arrow VII in FIG. 6. [Figure 8] FIG. 11 is a plan view of a sound insulation sheet according to another embodiment. [Figure 9] 10A and 10B are explanatory diagrams for explaining sound insulation sheets according to further other embodiments, where (a) shows an embodiment having a long hole, (b) shows an embodiment having a groove, and (c) shows an embodiment having a thin portion. [Figure 10] 1A and 1B are diagrams for explaining the effect of the integral molding of a sound-proofing sheet and a carpet using the proposed technology. (a) shows the state in which the sound-proofing sheet and the carpet have begun to shrink after integral molding, (b) shows the state in which the carpet has further shrunk after integral molding, and (c) shows the state in which the carpet has warped after integral molding. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The matters shown herein are illustrative and are intended to exemplify the embodiments of the present invention, and are described for the purpose of providing what is believed to be the most effective and easily understandable explanation of the principles and conceptual features of the present invention. In this respect, it is not intended to show structural details of the present invention beyond the extent necessary for a fundamental understanding of the present invention, and the description in conjunction with the drawings will make it clear to those skilled in the art how some forms of the present invention can be actually embodied.

[0013] <Method of manufacturing vehicle floor carpet> The manufacturing method of the vehicle floor carpet according to this embodiment is a manufacturing method of the vehicle floor carpet 1 including a carpet 2 molded into a three-dimensional shape along a floor part 6 of a vehicle, having a bottom wall 4 and standing walls 5a, 5b molded by drawing so as to rise from the bottom wall 4, and a sound insulation sheet 3 attached to the back side of the standing walls 5a, 5b, as shown in Figures 5 and 6. And, for example, as shown in Figures 1 to 3, the sound insulation sheet 3 is provided with a deformable fragile part (weakened part) 20, and by applying pressure to the sound insulation sheet 3 and the heated carpet 2 with a molding die 15, the carpet 2 is molded into a three-dimensional shape, and the sound insulation sheet 3 and the carpet 2 are molded integrally.

[0014] The structure, shape, material, etc. of the carpet 2 are not particularly limited. The standing wall 5a constituting this carpet 2 can be arranged, for example, along the side of a tunnel 6a that is provided in a bulging manner in the center of the floor portion 6 of the vehicle in the vehicle width direction D2 (see FIG. 6). This standing wall 5a is usually formed by squeezing with a forming die 15. Furthermore, the standing wall 5b constituting the carpet 2 can be arranged, for example, along a dash panel provided on the front side of the floor portion 6 of the vehicle in the vehicle front-rear direction D1. This standing wall 5b is usually formed by squeezing with a forming die 15.

[0015] The carpet 2 may, for example, have only a single layer (e.g., a resin layer containing a thermoplastic resin), but from the viewpoints of design, sound absorption, sound insulation, etc., it preferably has a surface layer 8 and a backing layer 9 arranged on the back side of the surface layer 8 (see FIG. 2(a)). One or more other intermediate layers (e.g., an adhesive layer, a ventilation control layer, etc.) may further be provided between the surface layer 3 and the backing layer 9.

[0016] For example, a known needle punch carpet, tufted carpet, etc. can be used for the surface layer 8. This surface layer 8 may be coated with synthetic resin latex to increase durability.

[0017] The backing layer 9 may contain, for example, a thermoplastic resin. Examples of the thermoplastic resin include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), ethylene vinyl acetate copolymer (EVA), etc. These may be used alone or in combination of two or more.

[0018] There are no particular limitations on the structure, shape, material, etc., of the sound insulation sheet 3. This sound insulation sheet 3 is usually attached to a partial area on the back side of the carpet 2 so as to block or suppress noise from entering the vehicle interior through the floor part 6 of the vehicle. Examples of noise that infiltrates into the vehicle cabin include noise caused by a driving source such as an engine, road noise during driving, and the like.

[0019] Examples of the material of the sound insulation sheet 3 include rubber, thermoplastic elastomer, thermoplastic resin, etc. Examples of the rubber include synthetic rubber such as ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), styrene-butadiene rubber (SBR), and acrylonitrile-butadiene rubber (NBR). Examples of the thermoplastic elastomer include olefin-based (TPO) and styrene-based (TPS) elastomers. Examples of the thermoplastic resin include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and ethylene vinyl acetate copolymer (EVA). These may be used alone or in combination of two or more.

[0020] There are no particular limitations on the thickness t of the sound insulation sheet 3, but from the viewpoints of light weight and sound insulation, it is preferable that it is 1 to 2 mm (particularly 1 mm) (see FIG. 2(b)). The thickness t of this sound insulation sheet 3 usually remains almost unchanged before and after the sound insulation sheet 3 and the carpet 2 are integrally molded. Furthermore, the planar shape of the sound insulation sheet 3 is appropriately selected depending on, for example, the sound insulation area to be set on the carpet 2, etc.

[0021] The sound insulation sheet 3 may have, for example, a fiber layer 11 attached to the surface that is to be attached to the carpet 2 (see FIG. 2(b)). This fiber layer 11 may be, for example, a nonwoven fabric, felt, woven fabric, knitted fabric, etc. Furthermore, in a configuration in which a plurality of sound insulation sheets 3 are attached to the carpet 2, it is preferable from the standpoint of ease of handling, etc. that the fiber layer 11 be attached to the surface of each sound insulation sheet 3 so as to connect the individual sound insulation sheets 3 (see, for example, FIG. 1(a)).

[0022] The fiber layer 11 may contain, for example, a thermoplastic resin. Examples of the thermoplastic resin include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and ethylene vinyl acetate copolymer (EVA). These may be used alone or in combination of two or more. The thermoplastic resin constituting the fiber layer 11 may be the same type as the thermoplastic resin constituting the carpet 2, or may be a different type.

[0023] There are no particular limitations on the structure, arrangement, etc. of the weak portion 20. The weak portion 20 is usually a portion that has lower rigidity than other portions of the sound insulation sheet 3. Examples of the structure of the weak portion 20 include slits 21, elongated holes 22, grooves 23, thin portions 24, etc. (see Figs. 3 and 9). Of these, the slits 21 are preferable from the viewpoint of sound insulation, etc.

[0024] The slits 21 usually extend in a straight or curved shape. For example, the slits 21 may be formed by cutting out the sound insulation sheet 3 in the thickness direction, but from the viewpoint of the ability to follow the expansion and contraction of the carpet 2, it is preferable that the slits 21 are formed so as to penetrate the sound insulation sheet 3 in the thickness direction. Furthermore, it is preferable that one end of the slits 21 is formed away from the side edge of the sound insulation sheet 3.

[0025] 5 and 6, the standing wall 5a is disposed in the center of the carpet 2 in the vehicle width direction and extends in the vehicle front-rear direction, and therefore, compared to the bottom wall 4 and the standing wall 5b, the material is stretched more in the rising direction A by drawing with the forming die 15. In a configuration in which the sound insulation sheet 3 is attached to the back side of the standing wall 5a, as shown in FIG. 4, for example, the weak part 20 deforms in accordance with the expansion and contraction in the rising direction A of the standing wall 5a by integral molding, thereby absorbing the difference in thermal shrinkage (molding shrinkage) due to the difference in materials between the sound insulation sheet 3 and the standing wall 5a. Furthermore, even in a configuration in which the sound-insulating sheet 3 is attached to the back side of the vertical wall 5b or the bottom wall 4, the weak portion 20 deforms in response to the expansion and contraction of the vertical wall 5b and the bottom wall 4 that are formed as a single unit, thereby absorbing the difference in thermal shrinkage (molding shrinkage) due to the difference in materials between the sound-insulating sheet 3 and the vertical wall 5b or the bottom wall 4.

[0026] In a configuration in which the sound insulation sheet 3 is attached to the back side of the standing walls 5a, 5b, from the viewpoint of the ability to follow the expansion and contraction of the standing walls 5a, 5b, it is preferable that the fragile parts 20 extend in one or both of the rising direction A of the standing walls 5a, 5b and the direction B intersecting (particularly perpendicular) to the rising direction of the standing walls 5a, 5b (see, for example, FIG. 3). There are no particular restrictions on the length L of the fragile parts 20, but from the viewpoint of the ability to follow the expansion and contraction of the standing walls 5a, 5b, it is preferable that the length L be 20 to 100 mm (particularly 60 to 100 mm). The above "orthogonal" means approximately orthogonal, and may be a direction B that intersects with the rising direction A of the standing walls 5a, 5b at an angle including an allowable error range (for example, 90±5 degrees) other than the direction B that is orthogonal to the rising direction A of the standing walls 5a, 5b at an angle of exactly 90 degrees. This point is also applied to the following description.

[0027] In a configuration in which the sound-proofing sheet 3 is attached to the back side of the vertical walls 5a, 5b, from the standpoint of, for example, the ability to follow the expansion and contraction of the vertical walls 5a, 5b, it is preferable that multiple weak portions 20 are arranged along one or both of the rising direction A of the vertical walls 5a, 5b and the direction B that intersects (particularly perpendicular to) the rising direction A of the vertical walls 5a, 5b (see, for example, Figures 3 and 8). The interval S1 between adjacent weak portions 20 in the rising direction A of the standing walls 5a, 5b can be set to, for example, a value smaller than the length L of the weak portions 20. Moreover, the interval S1 may be, for example, 15 to 25 mm (particularly, 15 to 20 mm). The interval S2 between adjacent weak portions 20 in a direction B intersecting with the rising direction A of the standing walls 5a, 5b can be set to, for example, a value smaller than the length L of the weak portions 20. Moreover, the interval S2 may be, for example, 15 to 25 mm (particularly, 15 to 20 mm). One end of the weak portion 20 adjacent to the rising direction A of the vertical wall 5a may, for example, be misaligned in a direction B that intersects (particularly perpendicular to) the rising direction A of the vertical walls 5a, 5b (see Figure 3), or may be aligned in the same position in direction B (see Figure 8).

[0028] The mold 15 usually comprises a pair of molds 15a, 15b which can move towards and away from each other. There are no particular restrictions on the pressing conditions (e.g., pressure, pressing time, etc.) of this mold 15 as long as the floor carpet 1 can be molded. Furthermore, in the pressing process using the mold 15, for example, the carpet 2 may be heated by the heating mechanism of the mold 15, but from the standpoint of moldability, etc., it is preferable to place a pre-heated carpet 2 in the mold 15. This carpet heating can be performed by, for example, a heating furnace, a hot plate, hot air, etc.

[0029] In the pressing process using the mold 15, for example, the sound insulation sheet 3 having the fiber layer 11 and the carpet 2 in which the thermoplastic resin is in a softened state can be pressed together. This allows, for example, the softened thermoplastic resin of the carpet 2 to penetrate into the fiber layer 11 (preferably the thermoplastic resins constituting the carpet 2 and the fiber layer 11 to melt and mix together), thereby firmly integrating the sound insulation sheet 3 and the carpet 2.

[0030] In the pressing process using the molding die 15, when slits 21 are used as the fragile parts 20, the slits 21 can open in response to the expansion of the carpet 2 during integral molding, and can deform in a direction to close in response to the contraction of the carpet 2 after integral molding, as shown in Fig. 4. From the viewpoint of shielding properties, etc., it is preferable that the slits 21 close after integral molding. In addition, in the case where a long hole 22 or a groove 23 is used as the fragile portion 20, for example, the long hole 22 or the groove 23 can deform in a direction in which the opening expands in response to the expansion of the carpet 2 during integral molding, and the long hole 22 or the groove 23 can deform in a direction in which the expanded opening shrinks in response to the contraction of the carpet 2 after integral molding. Furthermore, in the case where a thin-walled portion 24 is used as the fragile portion 20, for example, the thin-walled portion 24 can expand in response to the expansion of the carpet 2 during integral molding, and the expanded thin-walled portion 24 can shrink in response to the contraction of the carpet 2 after integral molding.

[0031] The carpet 2 after the pressing step may be cooled, for example, within the mold 15, or may be cooled after being removed from the mold 15. This cooling may be natural cooling, or active cooling using a cooling mechanism. Furthermore, the carpet 2 after the pressing step is usually subjected to a trimming process as necessary.

[0032] A manufacturing method for the vehicle floor carpet 1 according to this embodiment may include, for example, an arrangement process in which a sound-insulating sheet 3 and a heated carpet 2 are arranged in a mold 15, and a pressing process using the mold 15, as shown in FIG.

[0033] In the arrangement step, for example, the sound insulation sheet 3 is arranged on the vertical wall-like portion 17a of the molding surface 17 of one of the dies 15b constituting the molding die 15, and the heated carpet 2 can be arranged between the pair of dies 15a, 15b constituting the molding die 15. In particular, when multiple sound insulation sheets 3 are connected with the fiber layer 11, it is preferable to arrange the multiple sound insulation sheets 3 by positioning the portion of the fiber layer 11 that is not attached to the sound insulation sheet 3 with respect to one of the dies 15b. This is because the multiple sound insulation sheets 3 can be attached in accurate positions to the back side of the vertical wall 5a. In the placing step, a sheet-like carpet 2 is usually placed. This sheet-like carpet 2 can be obtained, for example, by cutting it from a raw material roll.

[0034] <Vehicle floor carpet> 5 and 6, the vehicle floor carpet according to this embodiment is a vehicle floor carpet 1 including a carpet 2 formed into a three-dimensional shape along a floor portion 6 of a vehicle, the carpet 2 having a bottom wall 4 and standing walls 5a, 5b rising from the bottom wall 4, and a sound insulation sheet 3 attached to the back side of the carpet 2. And, as shown in Figs. 1 to 3, for example, the sound insulation sheet 3 is provided with a deformable fragile portion 20, and the sound insulation sheet 3 is integrally formed with the carpet 2.

[0035] As each component of the vehicle floor carpet of this embodiment (e.g., the carpet 2, the sound-insulating sheet 3, and the fragile portion 20, etc.), for example, each component described in the manufacturing method of the vehicle floor carpet of the above embodiment can be applied.

[0036] The reference numerals of the components described in the above embodiment indicate the corresponding relationship with the specific components described in the examples described later. EXAMPLES

[0037] The present invention will now be described in detail with reference to the accompanying drawings.

[0038] As shown in Figures 5 and 6, the vehicle floor carpet 1 of this embodiment comprises a carpet 2 having a bottom wall 4 and upright walls 5a, 5b rising from the bottom wall 4 and molded into a three-dimensional shape that conforms to the floor 6 of the vehicle, and a sound-proofing sheet 3 attached to the back side of the carpet 2 (i.e., the side facing toward the outside of the vehicle compartment).

[0039] The standing wall 5a is disposed along the side of a tunnel 6a that bulges out from the center of the floor 6 of the vehicle in the vehicle width direction D2 (see FIG. 6). The standing wall 5b is disposed along a dash panel (not shown) that is disposed on the front side of the floor 6 of the vehicle in the vehicle front-rear direction D1. The soundproof sheet 3 is attached to the rear side of the standing wall 5a so as to block or suppress noise from entering the vehicle interior through the tunnel 6a.

[0040] The carpet 2 comprises a surface layer 8 and a backing layer 9 arranged on the back side of the surface layer 8 (see FIG. 2(a)). This backing layer 9 contains a thermoplastic resin such as polyethylene. The sound insulation sheet 3 is formed of rubber such as EPDM. The thickness t of the sound insulation sheet 3 is set to about 1 to 2 mm (see FIG. 2(b)). Furthermore, a fiber layer 11 is attached to the surface of the sound insulation sheet 3 on the side that will be attached to the carpet 2. This fiber layer 11 is formed of nonwoven fabric. Furthermore, the fiber layer 11 is attached to the surface of each of the multiple sound insulation sheets 3 (two on the left and right in the figure) so as to connect the sound insulation sheets 3 (see FIG. 1(a)).

[0041] 3 and 7, the sound insulation sheet 3 is provided with a weak portion 20 that is deformable in the surface direction of the sound insulation sheet 3. The weak portion 20 is composed of a slit 21. A plurality of the slits 21 are arranged along the rising direction A of the standing wall 5a and along a direction B perpendicular to the rising direction A of the standing wall 5a.

[0042] Each slit 21 is formed penetrating the sound insulation sheet 3 and the fiber layer 11 in the thickness direction. Each slit 21 extends linearly in a direction B perpendicular to the rising direction A of the standing wall 5a. The length L of each slit 21 is about 20 to 100 mm. The interval S1 between adjacent slits 21 in the rising direction A of the standing wall 5a is about 15 to 25 mm. The interval S2 between adjacent slits 21 in the direction B perpendicular to the rising direction A of the standing wall 5a is about 15 to 25 mm.

[0043] Next, a method for manufacturing the vehicle floor carpet 1 having the above-mentioned configuration will be described. As shown in Figure 1, the manufacturing method of this floor carpet 1 includes an arrangement process (see Figure 1(a)) of arranging a sound-insulating sheet 3 and a heated carpet 2 in a molding mold 15, and a pressing process (see Figure 1(b)) of pressing the sound-insulating sheet 3 and the heated carpet 2 by closing the molding mold 15 to form the carpet 2 into a three-dimensional shape and integrally mold the sound-insulating sheet 3 and the carpet 2.

[0044] The molding die 15 includes an upper die 15a (movable die) and a lower die 15b (fixed die) that can move toward and away from each other. The upper die 15a has a concave molding surface 16 for forming the vertical walls 5a, 5b. The lower die 15b has a convex molding surface 17 for forming the vertical walls 5a, 5b. In this embodiment, an upper mold 15a which is a movable mold and a lower mold 15b which is a fixed mold are illustrated, but this is not limited to this, and for example, it is sufficient that at least one of the upper mold 15a and the lower mold 15b is a movable mold.

[0045] In the arrangement step, the sound insulation sheet 3 is arranged on the upright wall portion 17a of the molding surface 17 of the lower mold 15b, and the heated sheet-like carpet 2 is arranged between the upper mold 15a and the lower mold 15b. Specifically, the fiber layer 11 is positioned with the positioning pins 18, and the sound insulation sheet 3 is arranged on the lower mold 15b with the fiber layer 11 facing outward, and the carpet 2 is arranged between the upper mold 15a and the lower mold 15b with the backing layer 9 facing downward.

[0046] In the pressing process, pressure is applied to the sound insulation sheet 3 and carpet 2 while the thermoplastic resin constituting the carpet 2 is in a softened state. This pressure causes the softened thermoplastic resin of the carpet 2 to penetrate into the fiber layer 11 of the sound insulation sheet 3, firmly integrating the sound insulation sheet 3 and the standing wall 5a. Furthermore, in the pressing process, the standing wall 5a is formed by squeezing, and the sound insulation sheet 3 and the standing wall 5a are integrally formed.

[0047] In addition, in the pressing process, as shown in FIG. 4, the slits 21 open in accordance with the expansion of the carpet 2 during integral molding, and close in the longitudinal and depth directions in accordance with the contraction of the carpet 2 after integral molding.

[0048] Specifically, just before the sound insulation sheet 3 and the carpet 2 are molded together, the slits 21 are closed (see FIG. 4(a)). Next, the sound insulation sheet 3 and the carpet 2 are molded together while stretching P (see FIG. 4(b)). At this time, the sound insulation sheet 3 stretches while opening due to the presence of the slits 21. Next, after the integral molding, the sound insulation sheet 3 and the carpet 2 begin to shrink Q due to the decrease in temperature (see FIG. 4(c)). When the sound insulation sheet 3 shrinks, the shrinkage of the material itself and the opening of the slits 21 also return to their original size. After that, the carpet 2 shrinks further, but the amount of shrinkage of the carpet 2 is reduced by the opening of the slits 21, so the amount of tension on the sound insulation sheet 3 is reduced, and the stress (reaction force) R of the sound insulation sheet 3 is reduced (see FIG. 4(d)). As a result, deformation of the product shape after molding is suppressed.

[0049] As described above, according to the manufacturing method of the vehicle floor carpet 1 in this embodiment, the sound insulation sheet 3 is provided with a deformable fragile portion 20, and the sound insulation sheet 3 and the carpet 2 in a heated state are pressed by the molding die 15 to mold the carpet 2 into a three-dimensional shape, and the sound insulation sheet 3 and the carpet 2 are molded together. As a result, the fragile portion 20 deforms in accordance with the expansion and contraction of the carpet 2 due to the integral molding (i.e., the expansion of the carpet 2 during the integral molding and the contraction of the carpet 2 after the integral molding), and the difference in thermal contraction (molding contraction) due to the difference in materials between the sound insulation sheet 3 and the carpet 2 is absorbed. Therefore, the deformation of the product shape after molding can be suppressed, and the product shape as intended can be realized. Furthermore, since the sound insulation sheet 3 of a desired size can be attached to the back side of the carpet 2 by integral molding, the cost of parts generated by the additional process of attaching the sound insulation sheet to the back as in the conventional case can be reduced while ensuring NV (Noise Vibration) performance.

[0050] In this embodiment, the fragile portion 20 is formed by a slit 21. As a result, the slit 21 opens in response to the expansion of the standing wall 5a during integral molding, and closes in response to the contraction of the standing wall 5a after integral molding, thereby effectively absorbing the contraction difference between the sound-insulating sheet 3 and the standing wall 5a, and the closing of the slit 21 enhances sound insulation.

[0051] In this embodiment, the sound insulation sheet 3 is attached to the back side of the standing wall 5a, and the standing wall 5a is formed by drawing. As a result, the fragile portion 20 deforms in accordance with the expansion and contraction of the standing wall 5a in the rising direction due to the integral molding, and the shrinkage difference between the sound insulation sheet 3 and the standing wall 5a is effectively absorbed.

[0052] In this embodiment, the weak portion 20 extends in a direction B perpendicular to the rising direction A of the standing wall 5a. This allows the weak portion 20 to be easily deformed in the rising direction A of the standing wall 5a, and improves the ability to follow the expansion and contraction of the standing wall 5a.

[0053] Furthermore, in this embodiment, a plurality of the weak portions 20 are arranged along the rising direction A of the standing wall 5a and along the direction B perpendicular to the rising direction A of the standing wall 5a. As a result, the deformation of the plurality of weak portions 20 effectively absorbs a desired amount of shrinkage difference between the sound insulation sheet 3 and the carpet 2.

[0054] The present invention is not limited to the above embodiment, and various modifications may be made within the scope of the present invention depending on the purpose and application. That is, in the above embodiment, the multiple slits 21 are arranged in a staggered pattern (see FIG. 3), but the present invention is not limited to this. For example, the multiple slits 21 may be arranged in a line as shown in FIG. 8. In this embodiment, one end of the slits 21 adjacent to the rising direction A of the standing wall 5a coincides with the position of the direction B perpendicular to the rising direction A of the standing wall 5a.

[0055] In addition, in the above embodiment, a slit 21 is exemplified as the weak portion 20, but this is not limited to this. For example, the weak portion 20 can be a long hole 22 (see Figure 9(a)), a groove 23 having a substantially V-shaped or U-shaped cross section (see Figure 9(b)), a thin-walled portion 24 (see Figure 9(c)), etc.

[0056] In the above embodiment, the slits 21 are closed in the longitudinal direction after integral molding, but the present invention is not limited to this and may be, for example, the slits 21 that are partially closed in the longitudinal direction after integral molding. Furthermore, for example, the slits 21 may be open in the longitudinal direction after integral molding.

[0057] In the above embodiment, the sound insulation sheet 3 is attached to the back side of the standing wall 5a, but the present invention is not limited to this. For example, as shown by the imaginary line in Fig. 5, the sound insulation sheet 3 may be attached to the back side of the standing wall 5b, or the sound insulation sheet 3 may be attached to the back side of the bottom wall 4. Furthermore, for example, the sound insulation sheet 3 may be attached to both the standing wall 5a (or the standing wall 5b) and the back side of the bottom wall 4.

[0058] Furthermore, in the above embodiment, a sound-insulating sheet 3 having a fiber layer 11 is exemplified, but this is not limited to this, and for example, the sound-insulating sheet 3 may not have a fiber layer 11 and its surface may be directly attached to the back side of the carpet 2.

[0059] The above examples are merely illustrative and should not be construed as limiting the present invention. Although the present invention has been described with reference to exemplary embodiments, the words used in describing and illustrating the present invention are understood to be descriptive and exemplary, rather than limiting. As detailed herein, changes may be made within the scope of the appended claims without departing from the scope or spirit of the present invention in its form. Although the present invention has been described herein with reference to specific structures, materials and examples, it is not intended that the present invention be limited to the disclosures therein, but rather that the present invention extends to all functionally equivalent structures, methods and uses within the scope of the appended claims.

[0060] The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the claims of the present invention. [Industrial Applicability]

[0061] The present invention is widely used as a technology relating to vehicle floor carpets used in automobiles, industrial vehicles, railway cars, etc. [Explanation of symbols]

[0062] 1; vehicle floor carpet, 2; carpet, 3; sound insulation sheet, 4; bottom wall, 5a, 5b; standing wall, 15; molding die, 20; weak portion, 21; slit, A; rising direction of the standing wall, B; direction perpendicular to the rising direction of the standing wall.

Claims

1. A method for manufacturing a floor carpet for a vehicle, comprising: a carpet formed into a three-dimensional shape that fits a floor portion of a vehicle, the carpet having a bottom wall and a standing wall formed by drawing so as to rise from the bottom wall; and a sound insulation sheet attached to a back surface side of the standing wall, The sound insulation sheet is provided with a deformable weak portion, The weak portion extends in a direction intersecting a rising direction of the standing wall, The fragile portion is arranged in a plurality of portions along a rising direction of the standing wall and a direction intersecting the rising direction of the standing wall, a distance between adjacent weak portions in a rising direction of the standing wall and a distance between adjacent weak portions in a direction intersecting the rising direction of the standing wall are smaller than a length of the weak portions in an extending direction, A manufacturing method for a vehicle floor carpet, characterized in that the sound-insulating sheet and the heated carpet are pressed together using a molding die to mold the carpet into a three-dimensional shape and to integrally mold the sound-insulating sheet and the carpet.

2. A method for manufacturing a vehicle floor carpet as described in claim 1, wherein a fiber layer is attached to the surface of the sound-proofing sheet that is attached to the carpet.

3. The method for manufacturing a vehicle floor carpet according to claim 1 or 2, wherein the fragile portion is formed by a slit.

4. A floor carpet for a vehicle, comprising: a carpet having a bottom wall and a standing wall rising from the bottom wall and molded into a three-dimensional shape along a floor portion of a vehicle; and a sound insulation sheet attached to a back side of the carpet, The sound insulation sheet is provided with a deformable weak portion, The weak portion extends in a direction intersecting a rising direction of the standing wall, The fragile portion is arranged in a plurality of portions along a rising direction of the standing wall and a direction intersecting the rising direction of the standing wall, a distance between adjacent weak portions in a rising direction of the standing wall and a distance between adjacent weak portions in a direction intersecting the rising direction of the standing wall are smaller than a length of the weak portions in an extending direction, The sound insulation sheet is integrally formed with the carpet.

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