JPH0911819A - Damping material for vehicle body panel - Google Patents

Abstract

PURPOSE: To provide a damping material for a vehicle body panel which excludes the orientation ability of an asphalt sheet, and improves cold resistance and has sufficient follow-up ability and heightens productive efficiency, and greatly contributes to the weight reduction of the vehicle, and is practicable in the recycle of waste polyurethane foam. CONSTITUTION: A damping material 1 for a vehicle body panel is unitedly formed by sandwiching a polyurethane sheet 4 compressedly formed of polyurethane foam powder between two sheets of asphalt sheets 2, 3, and pressurizing the asphalt sheets 2, 3 and the polyurethane sheet 4 in a piled up state and thermally fusing them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping material for vehicle body panels of vehicles.

[0002]

2. Description of the Related Art Conventionally, sheet metal members for four-wheeled vehicles,
Floor panels, dash panels, tire houses,
Asphalt sheets are used on the surface of the rear luggage compartment for the purpose of damping and sound insulation, or improving the flatness of the surface. This asphalt sheet uses petroleum asphalt as a main component and is manufactured by mixing various components for improving performance. That is, asphalt is used to provide soundproofing / vibrationproofing and heat-sealing properties, and inorganic materials (talc, calcium carbonate, silicon dioxide, etc.) increase the amount of asphalt sheet, increase oil absorption and sound transmission. It is used to increase loss. Fiber materials (polyester fiber, polyvinyl alcohol fiber, etc.) are used to improve damping characteristics and reduce specific gravity, and organic materials (resin, rubber, oil, etc.) are required to have adhesion to the sheet metal member. It is also used to improve cold resistance.

The asphalt sheet is manufactured through the steps shown in FIG. 13, for example. In this manufacturing method,
First, the inorganic material, the organic material, and the fibrous material 51 are well mixed by a kneader, and the asphalt 52 thermally melted at 300 ° C. is put into these and mixed again. Next, this mixture is rolled by a calender roll 53 into a sheet, cooled, and then cut into a predetermined shape to obtain an asphalt sheet 54 (see FIG. 14). The arrow a direction in the drawing indicates the rolling direction (orientation direction) of the asphalt sheet 54.

In addition, such an asphalt sheet 54
In order to bond the vehicle body panel to the vehicle body panel, the body panel 5 which has been subjected to the undercoating process such as electrodeposition coating as shown in FIG.
The asphalt sheet 54 is placed and overlapped on the corresponding portion of 5. Then, the asphalt sheet 54 is softened by the heat of the hot air oven in the next step and thereafter, for example, the middle / upper coating baking oven, and is adhered and coated with a uniform thickness as shown in FIG. After cooling, the carpet is placed on the asphalt sheet 54 and attached with resin clips.

[0005]

However, since the above-mentioned conventional damping material for vehicle body panel is formed by mixing the asphalt 52 with the inorganic material, the organic material and the fibrous material 51, the asphalt sheet 54 is It has the drawbacks that orientation occurs, cold resistance and vibration damping performance are insufficient, and the specific gravity is large. (1) Generation of Orientation As shown in FIG. 13, the fibrous material 51 in the asphalt mixture before forming has no directionality and is randomly mixed, and after heating and softening this, the calender roll 53 When the asphalt sheet 54 is roll-formed, the orientation of the asphalt sheet 54 itself occurs because the direction of the fiber material 51 as the compounding material is constant and oriented in the rolling direction. Then, the alignment direction (arrow a in FIG. 14)
Direction) is the flow direction of the fiber, so the strength is large, but conversely, the direction perpendicular to the orientation direction (direction of arrow b in FIG. 14) is orthogonal to the flow direction of the fiber, so the strength is Get smaller.

By the way, the sheet metal member for a vehicle usually has not a flat surface which is horizontal but an uneven portion having various shapes. For example, a vehicle sheet metal member 56 as shown in FIG.
When the asphalt sheet 54 is adhered to the convex portion 56a, if the asphalt sheet 54 is placed on the sheet metal member 56 and baked, a force is applied in the c direction due to the weight of the asphalt sheet 54 or the like. Since the c direction is the orientation direction of the asphalt sheet 54, the strength is great and the both ends of the asphalt sheet 54 do not hang down. On the other hand, when the asphalt sheet 54 is placed and baked as shown in FIG. 18, a force is applied in the c direction as in the case shown in FIG. However, since the c direction is the direction orthogonal to the orientation direction of the asphalt sheet 54, the strength is low and the cutout portions 54a are formed at both ends of the asphalt sheet 54. Therefore, when cutting out a product from the asphalt sheet 54, attention must be paid to its orientation, and the work is complicated. Further, when the asphalt sheet 54 is placed on the sheet metal member 56 for a vehicle, it is necessary to pay attention to the orientation direction that is difficult to distinguish, and there is a drawback that work efficiency is reduced. Moreover, if the orientation direction is erroneously recognized, the asphalt sheet 54 may have hang-down portions 54a at both ends thereof, resulting in a defective product. In addition, since the unevenness of the body panel 55 becomes the unevenness of the surface of the asphalt sheet 54 as it is after the baking, even if the upper surface is covered with a carpet, the riding comfort is poor (see FIG. 16).

(2) Insufficient cold resistance In addition, the asphalt sheet 54 has a normal temperature (10 to 30 ° C).
It is soft and elastic at (near) but hardens and becomes brittle when cold (10 ° C or less). For this reason, when the asphalt sheet 54 is impacted by being dropped or the like during work such as in winter, the asphalt sheet 54 may be broken or cracked to make it unusable as a product. As a countermeasure against this, conventionally, the asphalt sheet 54 is irradiated with an incandescent lamp or the like to be warmed and softened, and then used. However, this method has problems that workability is poor and that equipment for heating is required, so that work efficiency cannot be improved and equipment cost increases.

(3) Insufficient damping performance An important characteristic of the damping material is the loss coefficient (represented by η) which represents the degree of damping. Η = for damping material
It is required to be 0.08 or more, and η = 0.295 in the conventional product, which is not yet sufficient. In order to further improve the vibration damping performance, it is necessary to increase the thickness of the asphalt sheet 54. However, since the specific gravity of the conventional product is as large as 1.64, an increase in thickness leads to an increase in vehicle weight and causes an increase in cost, which is not an advantageous method.

Further, when the conventional damping material for a vehicle body panel is heated to a high temperature in summer or the like, when the asphalt sheets 54 are piled up (usually, several tens of sheets are piled up and stored), the asphalt sheets are put together. Since they stick to each other, there is a risk that they may not be used due to a blocking phenomenon.

On the other hand, recently, the problem of environmental pollution has arisen with the increase in the number of discarded polyurethane foams.
That is, polyurethane foam is widely used as a seat cushion for two-wheeled vehicles and four-wheeled vehicles. Since this polyurethane foam is a thermosetting resin, it is difficult to recycle it, and it is almost discarded after use. However, polyurethane foam is bulky when discarded,
In addition, because it has elasticity, the ground is not stable even if landfill processing is performed and it is not suitable for landfill. In addition, when incineration is performed, hydrogen chloride is generated during combustion, which causes a problem that the incinerator is easily damaged.

As a conventional technique, a method has been proposed in which an uncured thermosetting resin is used as a constraining layer by being cured in a step of placing it on a damping layer and coating it. However, this method has a drawback in that the uncured thermosetting resin causes a curing reaction during storage, and thus cannot be stored for a long period of time when the temperature rises. Moreover, if the reaction is too fast during curing, it may not be able to follow the uneven shape of the floor plate or the like, or defective fusion with the damping layer may occur, and as a result, the damping characteristics may be impaired.

Further, as another conventional technique, a heat-fusion type sheet adhered to a vehicle floor surface at a fusion-bonding temperature of about 120 to 180 ° C. and a porous layer laminated on the heat-fusion type sheet are used. A vibration damping material has been proposed which comprises an intermediate sheet having a cushioning property and a heat-sensitive sheet which is superposed on the intermediate sheet, has a low softening point, and has a self-adhesive property at about 120 to 180 ° C. However, in the structure of this damping material, the upper and lower asphalt sheets each have a thickness of 1.5 mm so that the intermediate sheet is sandwiched in order to have the same thickness as the existing asphalt sheet having a thickness of about 3.0 mm. When measured, the loss factor was dramatically reduced compared to the current asphalt sheet (η = 0.
161). Therefore, in order to obtain the same level of damping performance in the above damping material, it is necessary to make the asphalt sheet thickness thicker than the current one, so the weight of the vehicle body increases and the construction work also becomes hard labor, resulting in workability There was a problem.
Moreover, the sticking of asphalt sheets to each other during storage in the summer was not improved.

As another conventional technique, a damping material,
A vibration damping material for automobiles has been proposed in which a sound absorbing material and a skin material are integrated, and a vibration damping material is a constraining material made of moldable plastic and a vibration damping sheet having an adhesive property containing petroleum resin. The restraint material is adhered by the adhesiveness of the damping material, and the formed asphalt sheet is attached at room temperature in the automobile outfitting line. However, in this vehicle vibration damping material, the restraint material is adhered only by the adhesiveness of the vibration damping material, so the adhesive strength is weak and it shifts or peels off after long-term use in a place with severe vibration. It happened. Further, since the above-mentioned automobile damping material is placed so as to follow the shape of the sheet metal member for a vehicle having an uneven structure,
It was necessary to form this into a shape complementary to the irregularities of the vehicle sheet metal member, which required a large number of steps and had to be positioned at a predetermined position during the mounting work. Further, the plastic used for the restraint material has a melting point of 150 ° C. or lower, and if the baking treatment is performed at a temperature higher than that, the shape may collapse.

Furthermore, as another conventional technique, a soundproofing method has been proposed in which a soundproofing material is applied to an iron plate portion of a vehicle or the like. In this method, a concavo-convex shape is formed on the surface of the foam material foamed with synthetic resin, which is in contact with the steel plate portion, the convex portion is impregnated with a weight-imparting agent, and the surface is in contact with the iron plate portion of the vehicle or the like. It is being applied. However, this method has the same drawbacks as the above-mentioned conventional techniques, and also has a drawback that the volume of the foam material is very large and the indoor space is narrowed.

As another conventional technique, there has been proposed a floor material for vehicles in which a coating material containing asphalt as a main component is laminated with a sheet material such as a fibrous cloth, a knitted cloth, a non-woven cloth or paper having a thickness of 1 mm or less. There is. This floor material prevents cracks that occur in the coating film, or prevents the coating film from peeling or rising, and does not itself improve the cushioning property or the vibration damping property. Also, if the laminated sheet and the damping sheet are bonded only by heat treatment, the bonding strength will be weak,
Both sheets had a disadvantage that they were easily peeled off.

The present invention has been made in view of the above circumstances, and its purpose is to eliminate the orientation of the asphalt sheet, improve cold resistance, have sufficient followability, and improve production efficiency. Another object of the present invention is to provide a vibration damping material for a vehicle body panel of a vehicle, which can contribute to a reduction in weight of the vehicle and can recycle waste polyurethane foam. Another object of the present invention is to provide a damping material for vehicle body panels of a vehicle, which does not stick even when stacked and stored at high temperatures in the summer and has improved cushioning properties and improved riding comfort.

[0017]

In order to solve the above problems of the prior art, in the present invention, a polyurethane sheet obtained by compression molding of polyurethane foam powder is sandwiched between two asphalt sheets, and The asphalt sheet and the polyurethane sheet are integrally formed by applying pressure and heat-sealing them in a stacked state.

In another aspect of the present invention, a foamable resin sheet is attached to one surface of the asphalt sheet to integrally form it.

[0019]

In the damping material for the vehicle body panel of the vehicle according to the present invention,
Since the polyurethane sheet is sandwiched between two asphalt sheets and the asphalt sheet and the polyurethane sheet are superposed on each other by applying pressure and heat fusion, a 360-degree tensile force in all directions is obtained. Due to the presence of a polyurethane sheet with sufficient strength, the orientation of the asphalt sheet is lost and
Even if the temperature drops in winter, the asphalt sheet will be retained and will not break or break. Further, since the damping material for vehicle body panel of the present invention has a polyurethane sheet having a large loss coefficient value sandwiched between asphalt sheets, the asphalt sheet can be made to follow the uneven shape of the sheet metal member. It becomes possible to improve the vibration damping characteristics as compared with.

Further, according to the structure of the vibration damping material for a vehicle body panel of the present invention, the specific gravity thereof is considerably smaller than that of a steel plate or an aluminum plate, and it is smaller than that of the existing asphalt sheet. It also contributes to the improvement of the driving performance of the car and the reduction of fuel consumption. Moreover, since the polyurethane sheet of the present invention is obtained by compression molding of polyurethane foam powder, waste polyurethane foam can be used, which can contribute to the recycling of polyurethane foam.

Further, in another vibration damping material for vehicle body panels of a vehicle according to the present invention, the foamable resin sheet is integrally formed by sticking the foamable resin sheet on one surface of the asphalt sheet. It serves as an anti-sticking material, can be stored by stacking damping materials even at high temperatures, and has the same cushioning property due to the presence of the foamable resin sheet, and exhibits the same effect as the above invention.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

1 to 7 show an embodiment of a damping material for a vehicle body panel of a vehicle according to the present invention. In the figure, 1
Is a vibration damping material for a vehicle body panel having a three-layer structure used for various sheet metal members such as automobiles for the purpose of vibration and sound insulation. The vibration damping material 1 has a shape and a shape corresponding to a floor panel and a dash panel. It is sized and adapted to be attached to the surface of the floor panel.

As shown in FIGS. 1 and 2, the damping material 1 has a polyurethane sheet 4 sandwiched between two asphalt sheets 2 and 3, and the two asphalt sheets 2 and 3 and the polyurethane sheet 4 are sandwiched between them. The sheets 4 are integrally formed by applying pressure and heat-sealing the sheets 4 in an overlapped state. The asphalt sheets 2 and 3 are formed by thoroughly mixing the same materials as the conventional asphalt sheets (inorganic materials, fiber materials and organic materials) with a kneader, and mixing these materials with heat-melted asphalt (semi-blown, etc.). (120 ° C).

The above-mentioned polyurethane sheet 4 is obtained by compressing and molding the polyurethane foam powder 5, and has a strength and heat resistance capable of withstanding a tensile force in the direction of 360 degrees. When such a polyurethane sheet 4 is used, the asphalt sheets 2 and 3 lose the orientation by expanding and contracting in the direction of 360 degrees. Therefore, the tensile strength of the damping material 1 in all directions increases, and it becomes unnecessary to consider the orientation when cutting the product from the damping material 1.

The asphalt sheets 2 and 3 on the upper and lower parts
Since the polyurethane sheet 4 sandwiched between the two is bonded to the asphalt sheets 2 and 3 to each other, the outer dimensions are formed smaller than the asphalt sheets 2 and 3 (one size smaller). Thereby, the polyurethane sheet 4 is arranged so as not to protrude from the asphalt sheets 2 and 3. When “size of asphalt sheets 2 and 3 ≦ size of polyurethane sheet 4”, the polyurethane sheet 4 covers the surfaces of the asphalt sheets 2 and 3 and the exposed portion is eliminated, so that the upper and lower asphalt sheets are not covered. This is because the sheets 2 and 3 do not adhere.

The polyurethane sheet 4 is shown in FIGS.
It is molded through the steps (1) to (4) shown in FIG. (1) Filling First, the discarded polyurethane foam should have a particle size of 2-10.
The polyurethane foam powder 5 is produced by finely pulverizing it to a size of 00 μm or less (preferably 3 to 500 μm or less). Further, as shown in FIG. 3, a cylindrical molding die 7 is placed on the center of the upper surface of the aluminum plate 6. Then, the polyurethane foam powder 5 is injected into the molding die 7. At this time, the polyurethane foam powder 5 is spread evenly so that the filling height in the molding die 7 is 2 cm or less. Aluminum plate 6
Is used to prevent the polyurethane foam powder 5 from adhering to the compression molding machine when it is heated and pressed by a compression molding machine described later. The size and shape of the molding die 7 are made to correspond to the desired shape of the molded product.

(2) Mold removal Then, the mold 7 is removed, taking care not to disturb the shape of the filled polyurethane foam powder 5. Then, the cylindrical polyurethane foam powder 5 (height s is 2 cm) is formed on the aluminum plate 6, as shown in FIG. (3) Clamping Then, the obtained cylindrical polyurethane foam powder 5
Another aluminum plate 8 is further stacked on top of
The polyurethane foam powder 5 is sandwiched between two aluminum plates 6 and 8 as shown in FIG.

(4) Compression molding Then, as shown in FIG. 6, two aluminum plates 6,
Polyurethane foam powder 5 sandwiched between 8 and 130-2
Set in compression molding machine 9 heated to 00 ° C, pressure 0 kg
Leave at f / cm ^{2 for} 0 to 2 minutes (preheat treatment). If compression molding is performed without pre-heat treatment, bubbles may occur in the polyurethane sheet 4. After pre-heat treatment, compression molding is performed under the following conditions. That is, the temperature is 130 to 200 ° C.
The pressure is 100 to 700 kgf / cm ² , and the compression time is 30 seconds to 6 minutes or less (preferably 1 to 5 minutes). When compression molding is performed under such conditions, the sheet 10 having a powdery periphery and a semi-transparent central portion as shown in FIG.
Is obtained. In the sheet 10, the powdery portion 10a is brittle and easily collapses, so that the central semi-transparent portion 10
The polyurethane sheet 4 is molded using b. The final product, the polyurethane sheet 4, has a thickness of 0.2 to 1 mm.
It is below (preferably 0.3 to 0.4 mm).

Next, in order to manufacture the vehicle body panel damping material 1 of this embodiment, first, an inorganic material, a fiber material and an organic material are mixed by a kneading machine, and the asphalt sheets 2 and 3 are mixed with this mixture. The molten asphalt is mixed and kneaded at a temperature of 120 ° C. for about 15 minutes. Then, the kneaded asphalt mixture is rolled by a calendar roll to have a thickness half that of the final product (1.5 mm thickness).
Is formed into a sheet shape. After that, the product is cut out from this sheet material by punching, and the asphalt sheet 2,
Get 3. Then, the two obtained asphalt sheets 2 and 3 having a thickness of 1.5 mm and the polyurethane sheet 4 obtained by the above-mentioned molding method are prepared, and as shown in FIG.
A polyurethane sheet 4 is sandwiched between the upper and lower sides of the asphalt sheets 2 and 3. Then, these sheets 2, 3 and 4
Put it in an oven at 50 ° C and press it at 20gf / cm.
^A sheet-like three-layer structure is formed by applying a load of about ² . After that, the three-layer structure is processed and formed into a shape and size corresponding to a floor panel or the like, whereby the vibration damping material 1 of this embodiment is manufactured (see FIGS. 1 and 2).

In another manufacturing method, as in the above,
A polyurethane sheet 4 is sandwiched between two asphalt sheets 2 and 3 each having a thickness of 1.5 mm.
3 and 4 are roll-molded with a calendar roll to a thickness of 3 mm. However, the upper and lower asphalt sheets 2 and 3 adhere to each other due to the pressure of the calendar rolls. After that, if the procedure described above is performed, the damping material 1 (2 to 5 mm)
Thickness) is manufactured.

Three pieces of the damping material 1 of the present embodiment thus obtained and three pieces of conventional asphalt sheets were prepared, and the underwater substitution method (JIS K 7112) was performed under the conditions of a temperature of 23 ° C. and a humidity of 50%. The specific gravity was measured based on the measurement method according to 1. to obtain the average of three samples. As a result, the specific gravity of the vibration damping material 1 of this example was 1.593, and the specific gravity of the conventional asphalt sheet was 1.644.
From this result, it can be seen that by sandwiching the polyurethane sheet 4 between the asphalt sheets 2 and 3, the damping material 1 of the present embodiment has a reduced specific gravity as compared with the conventional asphalt sheet. Therefore, by using the damping material 1 of the present embodiment, the total weight of the vehicle is lightened, which can greatly contribute to the improvement of the running performance and the reduction of the fuel consumption of the four-wheeled vehicle.

Then, the vibration damping material 1 of this embodiment and the conventional asphalt sheet were respectively formed into a size of 3.0 × 20 × 200 mm, and these were electrodeposited 0.8 ×.
Each was heat-fused on a steel plate of 20 × 200 mm at 150 ° C. for 30 minutes to prepare a test piece. And JASO
The loss factor (η) was obtained according to the method described in the section of M329 "Asphalt sheet". As a result, the vibration damping material 1 of this example had a loss coefficient η of 0.328, and the conventional asphalt sheet had a loss coefficient η of 0.295.
From these results, it is understood that the vibration damping material 1 of this embodiment has a larger loss coefficient than the conventional asphalt sheet by sandwiching the polyurethane sheet 4 between the asphalt sheets 2 and 3. The larger the value of η is, the higher the vibration damping effect is, and the lower limit at which the vibration damping effect is practically determined is 0.08.

FIGS. 8 to 12 show another embodiment of a vehicle body panel damping material according to another embodiment of the present invention. In the figure, reference numeral 11 is a vibration damping material for a vehicle body panel of a two-layer structure used for various sheet metal members such as four-wheeled automobiles for the purpose of vibration damping and sound insulation. The vibration damping material 11 is the same as the above invention. It is formed into a shape and size corresponding to a dash panel or the like, and is attached to the surface of the floor panel.

As shown in FIGS. 8 to 10, the damping material 11 is integrally formed by adhering the foamable resin sheet 13 on one surface of one asphalt sheet 12 and superposing them. There is. Asphalt sheet 1
In No. 2, the same materials as the conventional asphalt sheet (inorganic material, fiber material and organic material) are well mixed by a kneader, and these materials are mixed with heat-melted asphalt (semi-blown, etc.) (120).
° C).

Since the foamable resin sheet 13 is required to withstand the molding temperature (120 ° C.) of the asphalt sheet 12 and the baking temperature (150 ° C.) for the sheet metal member for vehicles, the polyurethane foam having a melting point of 160 ° C. or higher. (Including chip mold products) are used. If the melting point (heat resistant temperature) is 160 ° C. or less, the foamable resin sheet 13 will be melted by the baking treatment on the vehicle sheet metal member, and the effect will be lost. By the way, the damping material 11 is required to have followability and tensile strength. That is, the foamable resin sheet 13 needs to follow the asphalt sheet 12 until the vibration-damping material 11 is adhered along the uneven portions of the sheet metal member when the vibration damping material 11 is baked on the vehicle sheet metal member. For this reason, the foamable resin sheet 13 is required to have a strength capable of withstanding the tensile force in the direction of 360 degrees. When such a foamable resin sheet 13 is used, the asphalt sheet 12 loses its orientation by expanding and contracting in the direction of 360 degrees. Therefore, the tensile strength of the damping material 11 in all directions increases, and it becomes unnecessary to consider the orientation when cutting the product from the damping material 11.

Next, the damping material 11 for vehicle body panel of this embodiment.
In order to produce the above, first, an inorganic material, a fiber material and an organic material are mixed with a kneader, and the molten asphalt to be the asphalt sheet 12 is mixed with this mixture, and the mixture is kneaded at a temperature of 120 ° C. for about 15 minutes. To do. Next, the kneaded asphalt mixture is rolled by a calender roll to form a sheet having a thickness of 3 mm (a thickness of 2 to 5 mm is sufficient). After cooling, this sheet material is cut into a predetermined shape to obtain an asphalt sheet 12. Then, the obtained one asphalt sheet 12 and the foamable resin sheet 13 cut into the same shape as this sheet are prepared. Also,
The asphalt 14 melted by heating at 120 ° C. or higher is impregnated into one surface of the foamable resin sheet 13 (the surface to be adhered to the asphalt sheet 12). The impregnation treatment is appropriately performed by dipping, brushing, spraying, or the like. Next, as shown in FIG. 8, the surface of the expandable resin sheet 13 impregnated with the asphalt 14 is attached to and adhered to the upper surface of one side of the asphalt sheet 12 to form a sheet-shaped two-layer structure. Then, the two-layer structure is processed and shaped into a shape and size corresponding to a floor panel or the like, whereby the vibration damping material 1 of this embodiment is manufactured (see FIG. 10).

In another manufacturing method, as shown in FIG. 9, the dissolved asphalt 14 is applied to the upper surface on one side (the surface to be adhered to the foamable resin sheet 13) of the same asphalt sheet 12 as described above. Alternatively, the upper surface of one side of the asphalt sheet 12 is heated by a burner or the like at a temperature of 120 ° C. or higher to slightly dissolve it. Next, the foamable resin sheet 13 is attached to the upper surface of one side of the asphalt sheet 12 to form a sheet-shaped two-layer structure. After that, if the above-mentioned procedure is performed, the vibration damping material 11 of this embodiment is manufactured.

Further, in another manufacturing method, the same asphalt sheet (molded to a thickness of 3.5 to 4.0 mm) 12 as described above is heated to 100 to 130 ° C. to be softened and then foamed. The resin sheet 13 is attached. However, since the adhesive strength is weak with this alone, 100 ~ 3
A pressure of 00 g / cm ² is applied for pressure bonding. When such pressure is applied, the asphalt sheet 12 becomes thin and the thickness becomes 3.0 mm. After that, if the above-mentioned procedure is performed, the vibration damping material 11 of this embodiment is manufactured.

In order to mount the damping material 11 of this embodiment on a sheet metal member of a vehicle body (having a concavo-convex structure for strength), first, the damping material 11 is mounted on the sheet metal member. Place and stack. In this state, when the vehicle body is painted and the heat of the baking oven (150 ° C.) is applied, the vibration damping material 11 follows the irregularities of the sheet metal member of the vehicle body and adheres to the heat-sealed asphalt sheet 12. .

The above-mentioned followability is necessary to bring the damping material 11 into close contact with the sheet metal member of the vehicle body along the irregularities of the sheet metal member when baking is performed under the condition of 150 ° C. for 30 minutes. As a method of measuring this followability, there is a drop test. Outline of drop-in test In this test, a conventional test piece having dimensions of 100 × 100 × thickness 3 mm and 100 × 100 × thickness (3 mm for asphalt part, 5 mm for polyurethane foam part of foaming resin) The test piece 15 of this example having the dimensions of 0.017 g / cm ³ was used. In this method, FIG.
As shown in FIG. 1 and FIG. 12, the test pieces 15 of the conventional product and the product of the present embodiment are placed on a steel plate 16 coated with electrodeposition, and heat-treated in an oven at 150 ° C. for 30 minutes. It was carried out and the dropability was observed. In addition, this steel plate 16
Has a vertical and horizontal dimension L of 150 mm, a rising dimension H of 20 mm,
The hole dimension D at the center is 60 mm, and the plate thickness dimension T is 0.8 mm.
It is formed with. According to such a dropability test, the drop depth h of the test piece 11 is preferably 6 to 20 mm. If the drop depth h is out of this range, it will be peeled off from the steel plate 16, that is, the vehicle metal plate member, without exhibiting follow-up properties during the baking process. As a result of this test, the drop depth h of the conventional test piece was 14 mm, and the drop depth h of the test piece 15 of this example was 10 mm. From this, it can be seen that the test piece 15 of the product of this example has followability. Therefore, it was proved that the vibration damping material 11 of the present embodiment can follow the uneven portion of the vehicle body sheet metal member.

The embodiment of the present invention has been described above.
The present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention, and the polyurethane sheet constituting the vibration damping materials 1 and 11 of the present embodiment. 4 or the foamable resin sheet 13 and the asphalt sheets 2, 3 and 12 may be bonded by a method other than the bonding method of the above-described embodiment.

[0043]

As described above, the damping material for a vehicle body panel of a vehicle according to the present invention has a polyurethane sheet sandwiched between two asphalt sheets, and the pressure is applied in a state where the asphalt sheet and the polyurethane sheet are superposed. In addition, because it is integrally formed by heat fusion,
Due to the presence of the polyurethane sheet having the strength capable of withstanding the tensile force in all directions, sufficient followability can be exhibited and the orientation of the asphalt sheet is lost. Therefore, when the vibration damping material for a vehicle body panel of the present invention is cut out from a product, the constraint of orientation is eliminated, and the vibration damping material can be effectively used. Moreover, when the vehicle body panel damping material of the present invention is actually installed in a vehicle at an assembly plant, it is not necessary for the operator to consider the orientation of the vehicle body panel damping material, and the handling is simplified and the workability is improved. The production efficiency can be improved.

Further, in the damping material for vehicle body panel of the present invention,
Even when the asphalt sheet is hardened when the temperature is below 10 ℃, the polyurethane sheet sandwiched between the sheets holds the asphalt sheet, so it may break or crack even if it receives a shock such as a drop. Does not occur and has excellent quality characteristics. Therefore,
If the damping material for a vehicle body panel of the present invention is used, it is not necessary to soften the asphalt sheet with an incandescent lamp or the like at the time of work, so that the facility cost does not increase unlike the conventional case, and the product assembling work The efficiency can be increased and the occurrence of defective products can be reduced.

Further, according to the vibration damping material for a vehicle body panel of the present invention, since the polyurethane sheet having a large loss coefficient value is sandwiched between the two asphalt sheets, the damping characteristic is improved as compared with the conventional one. In addition to being able to improve the weight, the weight of the vehicle can be reduced, which improves the running performance of the four-wheeled vehicle and reduces the fuel consumption. Moreover, since the polyurethane sheet constituting the damping material for vehicle body panel of the present invention is obtained by compression molding of polyurethane foam powder, waste polyurethane foam can be used,
Product cost can be reduced by recycling the waste polyurethane foam.

On the other hand, another vehicle body panel damping material according to the present invention has the same structure as the above-mentioned invention because the foamable resin sheet is attached integrally to one surface of the asphalt sheet. In addition to obtaining the effect, it has the following effect. That is, in the vibration damping material for a vehicle body panel of the present invention, since the foamable resin sheet serves as a sticking preventive material, even if the sheets are stacked and stored at high temperatures in the summer, the sheets stick to each other to prevent a blacking phenomenon. It does not happen, and a certain quality can be maintained. Further, in the vibration damping material for vehicle body panel of the present invention, the cushioning property is improved due to the presence of the foamable resin sheet, and the unevenness of the surface is reduced after baking on the vehicle sheet metal member, so that the riding comfort is improved. In addition to being obtained, it is possible to use a thinner carpet than that of a conventional carpet, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state before molding a vibration damping material for a vehicle body panel of a vehicle according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where the damping material for vehicle body panel is molded.

FIG. 3 is a perspective view showing a state in which finely pulverized polyurethane foam powder is injected into a molding die in a step of molding a polyurethane sheet constituting the vibration damping material for vehicle body panel.

FIG. 4 is a perspective view showing a polyurethane foam powder formed by removing the molding die into a predetermined shape.

FIG. 5 is a perspective view showing a state before the polyurethane foam powder in FIG. 4 is sandwiched between two aluminum plates.

FIG. 6 is a perspective view showing a state where the polyurethane foam powder sandwiched between the aluminum plates is set in a compression molding machine.

FIG. 7 is a perspective view showing a polyurethane sheet in a state of being compression molded by the compression molding machine.

FIG. 8 is a perspective view showing a state in which a foaming resin sheet and an asphalt sheet are bonded by one bonding method before molding a vehicle body panel damping material according to another embodiment of the present invention. It is a figure.

FIG. 9 is a perspective view showing a state in which a foamable resin sheet and an asphalt sheet are bonded by another bonding method before molding a vehicle body panel damping material according to another embodiment of the present invention. It is a figure.

FIG. 10 is a cross-sectional view showing a state where the damping material for vehicle body panel in FIGS. 8 and 9 is molded.

FIG. 11 is a perspective view showing an electrodeposited steel plate to which a test piece of the vibration damping material for vehicle body panel is bonded.

FIG. 12 is a cross-sectional view showing a test piece bonded to the steel plate.

FIG. 13 is a conceptual diagram showing a process of manufacturing a conventional asphalt sheet.

FIG. 14 is a perspective view showing a conventional asphalt sheet.

FIG. 15 is a perspective view showing a state in which a conventional asphalt sheet is placed on a body panel.

16 is a perspective view showing a state in which the asphalt sheet in FIG. 15 is bonded to a body panel.

FIG. 17 is a perspective view showing a state in which the asphalt sheet in FIG. 14 is bonded to a vehicle sheet metal member having a convex portion.

FIG. 18 is a perspective view showing a state in which the asphalt sheet in FIG. 14 has different orientation directions and is bonded to a vehicle sheet metal member having a convex portion.

[Explanation of symbols]

 1,11 Damping material for vehicle body panel 2,3,12 Asphalt sheet 4 Polyurethane sheet 5 Polyurethane foam powder 13 Foaming resin sheet 14 Asphalt

Claims (4)

[Claims] 1. A polyurethane sheet obtained by compression-molding polyurethane foam powder is sandwiched between two asphalt sheets, and the asphalt sheet and the polyurethane sheet are overlapped with each other by applying pressure to heat-bond them. A damping material for vehicle body panels, characterized by being integrally formed. 2. The vehicle body panel according to claim 1, wherein the polyurethane sheet has an outer dimension smaller than that of the asphalt sheet, and is arranged so as not to protrude from the two asphalt sheets. Damping material. 3. A vibration damping material for a vehicle body panel of a vehicle, wherein a foaming resin sheet is attached to one surface of an asphalt sheet to integrally form the same. 4. The damping material for a vehicle body panel of a vehicle according to claim 3, wherein the foamable resin has a melting point of 160 ° C. or higher.