JP6026806B2 - Insulator for vehicle and manufacturing method thereof - Google Patents

Description

  The present invention relates to an insulator provided on a member to be attached such as a toeboard and a roof trim of a vehicle, and a method of manufacturing the insulator, and particularly when the surface to be attached of the member to be attached has a concave portion or a convex portion. The present invention relates to a suitable insulator and a manufacturing method thereof.

In general, an engine room and a vehicle compartment of a vehicle are partitioned by a toe board. An insulator for absorbing engine noise is provided on the surface of the toe board on the passenger compartment side. As such an insulator, a monolithic (single layer) molded urethane insulator is known which is formed by pouring urethane resin into a mold and performing foam molding.
Moreover, the insulator described in Patent Document 1 has a structure in which a sound absorbing material made of low density felt and a sound absorbing material made of high density felt are laminated. A sound absorbing material made of low density felt faces the toe board, and a sound absorbing material made of high density felt faces the passenger compartment.

JP 2003-127714 A

A conventional monolithic (single layer) molded urethane insulator requires a large thickness to obtain a desired sound absorption performance, and is heavy. Also, felt insulators are similarly heavy due to their relatively high density. Furthermore, since a member to be attached such as a toe board generally has a curved surface shape having a concave surface portion or a convex surface portion, it is necessary to form the felt in conformity with the curved surface shape, and the formation is not easy.
An object of the present invention is to reduce the weight while ensuring sound absorption or sound insulation of a vehicle insulator, and to facilitate manufacture.

In order to solve the above problems, the device of the present invention is a vehicle insulator provided on a mounting surface having a concave surface portion or a convex surface portion in a vehicle,
Three sheet-like foamed resin layers laminated together, and an adhesive layer interposed between the foamed resin layers,
Among the three foamed resin layers, an intermediate foamed resin layer has a large number of small holes in addition to bubbles, and a laminate of the three foamed resin layers is formed so as to fit the mounting surface. ,
The adhesive layer has a property of being cured by a curing reaction after the molding from a fluid state.
Further, the method of the present invention is a method for manufacturing an insulator for a vehicle provided on a mounting surface having a concave surface portion or a convex surface portion in a vehicle,
Three foamed resin layers are formed in a sheet shape, and one foamed resin layer is formed with a large number of small holes in addition to bubbles,
The three foamed resin layers are laminated so that the one foamed resin layer is sandwiched between the other two foamed resin layers, and a fluid adhesive layer is applied between the foamed resin layers. ,
Thereafter, the laminate of the three foamed resin layers is molded according to the shape of the attached surface, and the adhesive layer is cured by a curing reaction after the molding.

According to the insulator of the present invention, in addition to the foamed resin layer having a laminated structure, the intermediate layer has a foamed and porous structure, so that noise in a wide band ranging from high frequency to low frequency can be absorbed. Even if it is small, sufficient sound absorption or sound insulation can be secured. In other words, the thickness required to ensure the desired sound absorption can be made smaller than that of a conventional integral (single layer) molded urethane insulator. Moreover, it can be made into a density lower than the conventional felt insulator by comprising with foamed resin. As a result, the weight can be reduced while maintaining the same sound absorption as that of the prior art. Furthermore, the insulator can be made lighter by the number of the small holes.
In addition, when molding a laminate of three foamed resin layers to match the shape of the mounting surface, the adhesive resin layer has fluidity at this point, so the foamed resin layers are relatively displaced in the in-plane direction. (Slide) Yes. Therefore, even if there is a concave surface portion or a convex surface portion on the mounted surface, the insulator can be easily formed into a shape that matches the mounted surface.

It is preferable to form the three sheet-like foamed resin layers by slicing the foamed resin body, and then form the plurality of small holes in the 1 (intermediate) foamed resin layer.
Accordingly, it is not necessary to separately foam and mold the three foamed resin layers, and the manufacturing process can be made efficient and the manufacturing cost can be reduced. Further, even if the three foamed resin layers have the same material and expansion ratio, the noise absorption band can be reliably widened by making the intermediate foamed resin layer further porous.

  According to the present invention, it is possible to reduce the weight while maintaining the sound absorbing property or sound insulating property of the insulator. Furthermore, even if there is a concave surface portion or a convex surface portion on the mounted surface, the insulator can be easily formed into a shape that matches the mounted surface.

FIG. 1 shows a first embodiment of the present invention and is a longitudinal sectional view of a part of a vehicle. FIG. 2 is a perspective view of the toeboard insulator of the vehicle. FIG. 3 is a cross-sectional view of the insulator. FIG. 4 is a cross-sectional view showing a molding process of the insulator, FIG. 4 (a) is a cross-sectional view of a portion corresponding to the concave surface portion of the toe board in the insulator, and FIG. 4 (a) is in the insulator. It is sectional drawing of the site | part corresponding to the convex part of a toe board. FIG. 5 is a graph showing a result of an experiment comparing sound-absorbing properties in a certain frequency band for a toeboard insulator according to an embodiment of the present invention and a conventional one-piece molded urethane toeboard insulator. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a part of the front side of the vehicle 1. The vehicle 1 has an engine room 2 and a vehicle compartment 3. The body panel 4 defines the bottoms of the engine room 2 and the vehicle compartment 3. A bonnet 5 defines the upper part of the engine room 2. A windshield 6 defines the upper front surface of the passenger compartment 3. An engine 7 is mounted in the engine room 2. The engine room 2 and the vehicle compartment 3 are partitioned by a toe board 8 (blocking panel). An instrument panel 9 is provided on the toe board 8 on the vehicle compartment side. A heater unit 10 is installed between the toe board 8 and the instrument panel 9. The engine 7 and the heater unit 10 are connected by connection means 11 such as a heater hose or a harness. A floor carpet 12 is provided at the bottom of the passenger compartment 3.

  The toe board 8 is composed of a metal plate having a curved shape. The surface 18 of the toe board 8 facing the passenger compartment 3 has a concave surface portion 18a and a convex surface portion 18b. The toe board 8 is formed with a large number of through holes 8e of various sizes and shapes through which the connecting means 11, the steering shaft (not shown) and the like are passed.

  A toe board insulator 20 is provided on the side surface 18 (attached surface) of the toe board 8 (attached member). Although illustration is omitted, either one of the toe board 8 and the insulator 20 is provided with an engaging member such as a hook or a clip, and the other is provided with an engaged portion to which the engaging member is engaged. ing. The toe board insulator 20 is attached to the toe board 8 by attaching means including these engaging members and engaged parts.

  As shown in FIG. 2, the toe board insulator 20 has a shape that matches the shape of the mounted surface 18 of the toe board 8, and a through hole 20e is formed at a position corresponding to the through hole 8e. As shown in FIG. 3, the toeboard insulator 20 includes three foamed resin layers 21, 22, 23 and an adhesive layer 31 interposed between the foamed resin layers 21, 22, 23. The three foamed resin layers 21, 22, and 23 are laminated with each other. The first foamed resin layer 21 faces the toe board 8. The third foamed resin layer 23 faces the passenger compartment 3. A second foamed resin layer 22 is sandwiched between these two foamed resin layers 21 and 23.

  The three foamed resin layers 21, 22, and 23 have the same material and expansion ratio. The material is foamed polyurethane. The expansion ratio is, for example, about 30 to 50 times, preferably about 40 times. The average diameter of the foamed polyurethane foam is, for example, about 300 μm to 600 μm. The bubble is preferably an open cell, but it may be a closed cell or a mixture of open and closed cells. Each of the foamed resin layers 21, 22, and 23 has a thin sheet shape (sliced urethane) and is formed according to the shape of the mounting surface 18 of the toe board 8. Furthermore, the thicknesses of the three foamed resin layers 21, 22, and 23 are substantially equal to each other, preferably about 5 mm to 10 mm, and more preferably about 5 mm. Therefore, the thickness of the entire toeboard insulator 20 is preferably about 15 mm to 30 mm, and more preferably about 15 mm.

  As shown in FIG. 3, the middle (1) foamed resin layer 22 among the three foamed resin layers 21, 22, and 23 has a large number of small holes 22 a in addition to bubbles, resulting in a foamed and porous structure. It has become. Therefore, the apparent density of the intermediate foamed resin layer 22 is smaller than that of the other two foamed resin layers 21 and 23. Each small hole 22a penetrates the foamed resin layer 22 in the thickness direction. The diameter of the small hole 22a is preferably larger than the average diameter of the bubbles, but is not limited thereto, and is, for example, about 10 mm to 50 mm, and more preferably about 10 mm. The opening ratio of the small holes 22a in the foamed resin layer 22, that is, the ratio of the total area of the small holes 22a to the unit area of the foamed resin layer 22 is preferably about 40% to 60%, more preferably about 50%. is there.

  Adjacent foamed resin layers 21 and 22 and foamed resin layers 22 and 23 are bonded and integrated by an adhesive layer 31. The adhesive layer 31 has fluidity before application, and has a property of being cured by causing a curing reaction by heating, pressurization, contact with outside air, and the like after application. The adhesive layer 31 before application may be liquid or gel. Specifically, the adhesive layer 31 is composed of an isocyanate and an amine-based adhesive. The component of the adhesive layer 31 is not limited to the above, and may be a rubber type or an epoxy type. Preferably, the adhesive layer 31 is a thermosetting adhesive. The adhesive layer 31 is provided over the entire area of the foamed resin layers 21, 22, and 23, but may be partially provided, for example, at the peripheral edge of the foamed resin layers 21, 22, and 23.

A method for manufacturing the toeboard insulator 20 will be described.
First, polyurethane is foam-molded. A flat sheet-like slice urethane is produced by slicing the foamed molded product to a certain thickness. Each slice urethane becomes the foamed resin layers 21, 22, and 23. Therefore, the three foamed resin layers 21, 22, and 23 have the same material and the same foaming rate. By doing so, a manufacturing process can be made efficient and manufacturing cost can be reduced. Furthermore, the manufacturing cost can be further reduced by making the three foamed resin layers 21, 22, and 23 have the same thickness. In particular, since the process up to this point does not require the intermediate foamed resin layer 22 to be distinguished from the other foamed resin layers 21 and 23, the manufacturing process can be made more efficient.

Next, a small hole 22a is punched into the slice urethane to be the intermediate foamed resin layer 22 and formed. Thus, the foamed resin layer 22 is a low density and lighter than the other foamed resin layers 21 and 23.

  Next, the three foamed resin layers 21, 22 and 23 are laminated so that the foamed resin layer 22 is sandwiched between the other two foamed resin layers 21 and 23. At this time, the adhesive layer 31 is applied between the foamed resin layers 21, 22, and 23 adjacent to each other. The adhesive layer 31 at the time of application is liquid or gel. Accordingly, the adhesive layer 31 can be applied uniformly and easily over the entire area of the foamed resin layers 21, 22, and 23.

  Next, the laminated body of the three foamed resin layers 21, 22, 23 is molded by a mold so as to match the shape of the mounting surface 18 of the toe board 8. A heating means is incorporated in the mold, and the laminate can be heated simultaneously with pressurization (hot press molding).

  At this stage, since the adhesive layer 31 is liquid (fluid), the adjacent foamed resin layers 21, 22, and 23 can slide (relative displacement in the in-plane direction). As a result, as shown in FIG. 4, the foamed resin layers 21, 22 and 23 are allowed to be partially deformed by different amounts. That is, as shown in FIG. 4A, at the portion corresponding to the concave surface portion 18a of the toe board 8, is the extension amount of the foam resin layer 21 on the toe board side larger than the extension amount of the foam resin layer 23 on the passenger compartment side? Alternatively, the foamed resin layer 21 on the toe board side is stretched and deformed, and the foamed resin layer 23 on the passenger compartment side is contracted and deformed. As shown in FIG. 4 (b), in the portion corresponding to the convex portion 18b of the toe board 8, the extension amount of the foam resin layer 21 on the toe board side is smaller than the extension amount of the foam resin layer 23 on the vehicle compartment side, Alternatively, the foamed resin layer 21 on the toe board side shrinks and deforms, and the foamed resin layer 23 on the passenger compartment side stretches and deforms. The deformation amount of the intermediate foamed resin layer 22 is intermediate between the deformation amounts of the foamed resin layers 21 and 23 on both sides. Thus, even if the foamed resin layers 21, 22, 23 are deformed by different amounts, almost no stress is generated in the liquid adhesive layer 31. As a result, almost no stress is applied to each of the foamed resin layers 21, 22, 23. Does not occur. Therefore, the insulator 20 can be easily formed into a shape that matches the toe board 8.

  The adhesive layer 31 is cured by causing a curing reaction by heating or the like during the molding. As a result, the foamed resin layers 21, 22, and 23 can be joined together to form a toeboard insulator 20. The toe board insulator 20 is affixed to the to-be-attached surface 18 of the toe board 8 by attaching means such as hooks and clips.

According to the insulator 20 having the above-described configuration, a conventional monolithic (single layer) molded urethane or felt insulator is maintained while maintaining the same level of sound absorption or sound insulation as a conventional molded urethane or felt insulator. It is possible to reduce the weight.
More specifically, regarding sound absorption or sound insulation, high-frequency noise can be absorbed by the foamed resin layers 21 and 23 on both sides, and low-frequency noise can be absorbed by the intermediate foamed resin layer 22 with a large number of small holes 22a. Even if the three foamed resin layers 21, 22, and 23 have the same material and expansion ratio, the noise absorption band can be reliably widened by adding a porous structure to the intermediate foamed resin layer 22 in addition to the foamed structure. .
Moreover, regarding the weight, by making the insulator 20 made of urethane, the density can be made lower than that of a conventional felt insulator, and the weight can be reduced. Moreover, by making the insulator 20 into a laminated structure of sliced urethane, it is possible to sufficiently reduce the thickness necessary to ensure the desired sound absorption, compared to the conventional one-piece molded urethane insulator. As a result, the weight can be reduced sufficiently. In addition, by forming a large number of small holes 22a in the intermediate foamed resin layer 22, the weight of the entire insulator 20 can be further reduced by at least about 10%. As a result, the weight can be reduced to about one half to one third as compared with the conventional case.

  As shown in FIG. 5, according to the inventor's experiment, a conventional toeboard insulator made of molded urethane (single layer) ("conventional product" in the figure) has a desired sound absorption performance. Although the thickness of about 25 mm is necessary and the weight was 3155 g, the toe board insulator 20 of this embodiment (“the product of the present invention” in the figure) has a thickness of 15 mm and a weight of 662 g. It was possible to demonstrate the same level of sound absorption performance.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the insulator only needs to have three foamed resin layers, and may have four or more foamed resin layers.
The foaming degree of the intermediate foamed resin layer 22 (the average diameter of the bubbles or the density of the foams) may be different from the foaming degree of the foamed resin layers 21 and 23 on both sides. The degree of foaming of the layers 21 to 23 may be different from each other. The small holes 22a of the foamed resin layer 22 may be omitted.
The small holes 22 a of the foamed resin layer 22 may be formed by the foam molding die simultaneously with the foam molding of the foamed resin layer 22.
The materials and thicknesses of the three foamed resin layers 21, 22, and 23 may be different from each other. The component of the foamed resin is not limited to polyurethane, and may be other resin components such as polyethylene and polypropylene.
The adhesive layer 31 only needs to be cured by causing a curing reaction after molding, and may be cured after molding in addition to the one cured during molding.
As long as the adhesive layer 31 is cured after molding, the method of molding the laminate of the foamed resin layers 21, 22, 23 is pre-heated in place of the hot press molding. In addition, it may be cold press molding in which a metal mold at room temperature is pressed.
The insulator of the present invention is not limited to a toe board, and may be provided on a roof trim or a pillar trim. Generally, an insulator for a roof trim is provided on the upper side of the roof trim, that is, the surface opposite to the vehicle compartment (attached surface). The mounted surface may have only one of the concave surface portion and the convex surface portion.

  The present invention can be applied to, for example, a toeboard insulator of a vehicle.

1 vehicle 2 engine room 3 vehicle compartment 4 body panel 5 bonnet 6 windshield 7 engine 8 toe board (attachment member)
8e Through-hole 9 Instrument panel 10 Heater unit 11 Connection means 18 Attached surface 18a Concave surface 18b Convex surface 20 Toeboard insulator 20e Through-hole 21 First foamed resin layer (other foamed resin layer)
22 Second foamed resin layer (1 foamed resin layer)
22a Small hole 23 Third foamed resin layer (other foamed resin layers)
31 Adhesive layer

Claims (3)

A vehicle insulator provided on a mounting surface having a concave surface portion or a convex surface portion in a vehicle,
Three sheet-like foamed resin layers laminated together, and an adhesive layer interposed between the foamed resin layers,
Among the three foamed resin layers, an intermediate foamed resin layer has a large number of small holes in addition to bubbles, and a laminate of the three foamed resin layers is formed so as to fit the mounting surface. ,
The adhesive layer has a property of being cured by a curing reaction after the molding from a state having fluidity ,
The three foamed resin layers have the same material, the same foaming ratio, and the same thickness, and the apparent density of the intermediate foamed resin layer among the three foamed resin layers is higher than that of the other two foamed resin layers. The vehicle insulator is also smaller by the number of the small holes . A method for manufacturing a vehicle insulator provided on a mounting surface having a concave surface portion or a convex surface portion in a vehicle,
Three foamed resin layers having the same material, the same expansion ratio, and the same thickness are formed in a sheet shape, and a plurality of small holes are formed in one foamed resin layer in addition to bubbles . The apparent density of the one foamed resin layer among the foamed resin layers is made smaller by the number of small holes than the other two foamed resin layers ,
The three foamed resin layers are laminated so that the one foamed resin layer is sandwiched between the other two foamed resin layers, and a fluid adhesive layer is applied between the foamed resin layers. ,
Thereafter, the laminated body of the three foamed resin layers is molded in accordance with the shape of the attached surface, and the adhesive layer is cured by a curing reaction after the molding. Production method.   3. The three sheet-like foamed resin layers are formed by slicing a foamed resin body, and then the plurality of small holes are formed in the one foamed resin layer. A method for manufacturing an insulator for a vehicle.

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