JPH08337147A - Damping material for body panel of vehicle - Google Patents

Abstract

PURPOSE: To provide a damping material for a body panel of a vehicle to eliminate the orientation of the asphalt sheet, improve the low temperature resistance, have the sufficient follow-up property, increase the production efficiency, and contribute much to the weight reduction of the vehicle. CONSTITUTION: In a damping material 1 for body panel of a vehicle, an expandable net 4 of net structure is held between two asphalt sheets 2, 3, and the asphalt sheets 2, 3 and the expandable net 4 are pressurized in the stacked condition to be integrated through the heat melting.

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,
For example, asphalt sheets are used on the surfaces of floor panels and dash panels for the purpose of damping and sound insulation. This asphalt sheet uses petroleum asphalt as a main component and is manufactured by mixing various components for improving performance. In other words, asphalt is used to have soundproofing / vibrationproofing and heat-sealing properties, and inorganic materials (talc, calcium carbonate, etc.) increase the amount of asphalt sheet, increase oil absorption and increase sound transmission loss. It is used to try. 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. 5, for example. In this manufacturing method,
First, the inorganic material, the organic material, and the fibrous material 51 are mixed well with a kneader, and these are mixed with the heat-melted asphalt 52. 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. 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 adhere the asphalt sheet to the vehicle body panel, first, the asphalt sheet 54 is overlaid on the vehicle sheet metal member. Then, the vehicle body is coated and softened by the heat of the baking oven, and is adhered and coated with a uniform thickness (for example, 3 mm). 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 a drawback that orientation is generated and cold resistance is insufficient. (1) Generation of Orientation When the asphalt sheet 54 is roll-formed by the calendar roll 53, the fiber material 51 as a compounding material is oriented in the rolling direction, and as shown in FIG.
4 will have orientation. That is, since the orientation direction (direction of arrow a in FIG. 6) is the flow direction of the fiber, the strength is increased, but conversely, the direction perpendicular to the orientation direction (direction of arrow b in FIG. 6) is the flow direction of the fiber. Since it is orthogonal to the direction, the strength becomes smaller. By the way, the sheet metal member for a vehicle usually does not have a flat surface with a horizontal surface, but has uneven portions of various shapes. For example, when the asphalt sheet 54 is bonded to the convex portion 55a of the vehicle sheet metal member 55 as shown in FIG. A force is applied in the c direction. 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. 8, a force is applied in the c direction as in the case shown in FIG. However, since the c direction is a 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.

(2) Insufficient cold resistance Further, the asphalt sheet 54 is soft and elastic at normal temperature (around 10 to 30 ° C), but hardens and becomes brittle in cold and cold (below 10 ° C). . 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
Since workability is poor and heating equipment is required, there is a problem in that work efficiency cannot be improved and equipment cost increases.

As a conventional technique, a sandwich type vibration damping structure has been proposed in which a steel plate, an aluminum plate or the like as a constraining material is laminated on the upper surface of an asphalt type vibration damping material. However, in this damping structure, a metal plate with high rigidity is brought into close contact with the upper surface of the asphalt damping material, so when it is attached to the sheet metal member for a vehicle, it is mechanically fixed or screwed with a bolt or the like. It is necessary to fix it by stopping it. However, as described above, since the vehicle sheet metal member 55 is generally uneven, the restraining metal plate must be manufactured in a shape corresponding to the sheet metal member 55, and an extra step is required. Therefore, there is a risk that this will lead to higher costs. In addition, since it is not easy to accurately position the asphalt damping material and the restraining metal plate at a predetermined position of the sheet metal member 55, there is a problem in workability. Further, since the steel plate or the aluminum plate has a large specific gravity, the weight of the vehicle body may increase.

As another conventional technique, there has been proposed a method in which an uncured thermosetting resin is placed on a damping layer and applied in the step of coating to be used as a constraining layer by curing. . 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.

The present invention has been made in view of such circumstances, and its purpose is to eliminate orientation of the asphalt sheet, improve cold resistance, have sufficient followability, and improve production efficiency. (EN) Provided is a vibration damping material for a vehicle body panel of a vehicle, which is capable of making a great contribution to weight reduction of the vehicle.

[0010]

In order to solve the above-mentioned problems of the prior art, in the present invention, a stretchable net having a mesh structure is sandwiched between two asphalt sheets, and the asphalt sheet and the stretchable net are sandwiched. Are formed in an integrated manner by applying pressure and heat-sealing in a state of overlapping.

[0011]

In the damping material for the vehicle body panel of the vehicle according to the present invention,
Stretchable nets are stretched in all directions of 360 degrees because a stretchable net having a mesh structure is sandwiched between two asphalt sheets and these asphalt sheets and stretchable nets are integrated by being heat-fused to each other by applying pressure. Due to the presence of the stretchable net, the orientation of the asphalt sheet is lost, and the asphalt sheet is retained even when the temperature is lowered in the winter and the like, so that the asphalt sheet does not break or break. Further, the damping material for a vehicle body panel of the present invention has followability to a sheet metal member for a vehicle, so that it is not necessary to form an asphalt sheet corresponding to the uneven shape of the sheet metal member, and the damping characteristic is not impaired. Absent.

Furthermore, in order to place the asphalt sheet on the relevant portion of the sheet metal member for a vehicle which has been subjected to electrodeposition coating and soften the asphalt sheet by the heat of the intermediate coating baking oven to closely coat the sheet metal member and the asphalt sheet, In addition to the need for bolts and the like, no adhesive or the like is used to bond the stretch net and the asphalt sheet. Moreover, according to the structure of the vibration damping material for a vehicle body panel of the present invention, its specific gravity is considerably smaller than that of a steel plate or an aluminum plate, and it is also smaller than the existing asphalt sheet, so that the total weight of the vehicle is also reduced. , Greatly contributes to the improvement of the driving performance of the automobile and the reduction of fuel consumption. When the melting point of the elastic net is 160 ° C. or higher, the heat resistant temperature of the elastic net is 160 ° C., so that the elastic net can be stored for a long period of time without denaturing even at high temperatures in summer.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

1 to 4 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 mesh structure stretchable net 4 sandwiched between two asphalt sheets 2 and 3, and these two asphalt sheets 2 are provided. , 3 and the stretchable net 4 are overlapped with each other and pressure is applied to heat-bond them to be integrally formed. 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 elastic net 4 is stretchable, has a mesh structure, and has heat resistance. It is desirable that the direction of expansion and contraction is 360 degrees,
The orientation of the asphalt sheets 2 and 3 disappears 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 stretch ratio of the stretchable net 4 is 1 to 9%.
In the range of 4 to 6%, and optimally 5%. The range in which the expansion / contraction rate is 1 to 9% is the range in which the elastic net 4 expands. When the elastic ratio is 1% or less, the elastic net 4 does not expand, and when the elastic ratio is 9% or more, the elastic net 4 is fully expanded and the net structure is The effect is in the required range. By the way, the damping material 1 is required to have followability and tensile strength. That is, when the damping material 1 is baked on a sheet metal member for a vehicle, the elastic net 4 is attached until it comes into close contact with the uneven portion of the sheet metal member.
Must follow the asphalt sheets 2 and 3. This expansion / contraction rate is 1 to 9%. On the other hand, after closely contacting the sheet metal member, it is necessary to maintain strength against its own weight and a load from the other. Therefore, the net structure of the elastic net 4 holds the asphalt sheets 2 and 3 to increase the tensile strength.
Since the effect of the net structure is exhibited only after the stretchable net 4 is fully stretched, the stretch ratio must be 9% or less.

The above-mentioned followability is necessary for bringing the damping material 1 into close contact with the unevenness of the sheet metal member when baking it on the sheet metal member for vehicles under the condition of 150 ° C. × 30 minutes.
As a method of measuring this followability, there is a drop test. Outline of dropability test A test piece 11 having a size of 100 × 100 × 3 mm was used for this test. Then, as shown in FIGS. 3 and 4,
This test piece 11 was placed on a steel plate 12 which had been subjected to electrodeposition coating, and heat treatment was performed in an oven under the conditions of 150 ° C. for 30 minutes, and the dropability was observed. In addition, this steel plate 1
2 has a vertical and horizontal dimension L of 150 mm and a rising dimension H of 20 m
m, the hole dimension D of the central portion is 60 mm, and the plate thickness dimension T is 0.8
It is formed in mm. According to such a dropability test, the drop depth h of the test piece 11 is preferably 6 to 20 mm. Therefore, the elastic net 4 has a falling depth h of 6 to 2
It must exhibit elasticity in the range of 0 mm. Without this stretchability, it would be peeled off from the steel plate 12, that is, the vehicle sheet metal member, without exhibiting follow-up properties during the baking process. When the depth of depression h is 6 to 20 mm, the stretch ratio of the stretchable net 4 is 1 to 9%.

Further, it is desirable that the diameter of the elastic net 4 is formed so that the asphalt sheets 2 and 3 having fluidity can be exuded by heating. For example, in the elastic net 4 of the present embodiment, the diameter is in the range of 0.02 mm to 1 cm, particularly 0.05.
A range of up to 5 mm is preferred.

Further, since the stretchable net 4 needs to withstand the forming temperature (120 ° C.) of the asphalt sheets 2 and 3 and the baking temperature (150 ° C.) for the sheet metal member for vehicles, its melting point (heat resistance) A temperature of 160 ° C. or higher is used. If the heat-resistant temperature is 160 ° C. or less, the elastic net 4 will be melted by the baking process on the vehicle sheet metal member, and the effect will be lost. Therefore, the stretchable net 4 may be made of any material as long as it can withstand the above conditions. For example, nylon, urethane fiber, cotton or the like can be used. Of these, nylon is inexpensive and It is preferable because it has the necessary strength.

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.
Next, the kneaded asphalt mixture is rolled by a calender roll to form a sheet having a thickness half that of the final product. Thereafter, a product is cut out from this sheet material by punching to obtain asphalt sheets 2 and 3. Then, the two obtained asphalt sheets 2 and 3 and the stretchable net 4 having a mesh structure are prepared, and as shown in FIG.
A stretchable net 4 is sandwiched between the upper and lower sides of the asphalt sheets 2 and 3 and rolled by a calendar roll again to form a sheet-shaped 3
Form a layered structure. After that, if this three-layer structure is processed into a shape and size corresponding to a floor panel,
The damping material 1 of this embodiment is manufactured (see FIGS. 1 and 2).

In another manufacturing method, first, asphalt sheet 2 having a thickness half that of the final product 2, similar to the above.
Mold 3. Next, the stretchable net 4 is sandwiched between the two obtained asphalt sheets 2 and 3, and 100 to 130
Heat to ° C. However, since the adhesive force is weak only by this, a pressure of 100 to 300 g / cm ² is applied by a press machine or the like to complete the adhesion. After that, if the above-mentioned procedure is performed, the vibration damping material 1 of this embodiment is manufactured.

Further, in another manufacturing method, first, asphalt sheets 2 and 3 having a thickness half that of the final product are formed in the same manner as described above. Then, the asphalt melted at 300 ° C is applied to the upper and lower surfaces of the elastic net 4, and the asphalt sheets 2 and 3 each having a thickness of ½ are sandwiched between the upper and lower portions of the asphalt 100 to 130 ° C. After heating to
A pressure of 100 to 300 g / cm ² is applied by a press machine or the like to bond.

As described above, the stretchable net 4 and the asphalt sheets 2 and 3 above and below the stretchable net 4 adhere to each other based on the following principle. That is, the heated asphalt or asphalt mixture is softened and fluidized. The elastic net 4 is placed on the lower asphalt sheet 3, and the upper asphalt sheet 2 is further placed thereon. In this state, the asphalt oozes out from the hole of the elastic net 4 by the pressure, and the upper and lower asphalt sheets 2 and 3 are heat-sealed, and as a result, the elastic net 4 and the upper and lower asphalt sheets 2 and 3 are separated. It will come into close contact.

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), and the average of three samples was obtained. As a result, the specific gravity of the damping material 1 of this example is 1.593,
The specific gravity of the conventional asphalt sheet was 1.644. From this result, it can be seen that by sandwiching the elastic net 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.

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 elastic net 4 constituting the vibration damping material 1 of the present embodiment.
The two asphalt sheets 2 and 3 may be bonded to each other by a method other than the bonding method of the above-described embodiment.

[0027]

As described above, the damping material for a vehicle body panel of a vehicle according to the present invention has an elastic net having a mesh structure sandwiched between two asphalt sheets, and the asphalt sheet and the elastic net are superposed on each other. Since it is integrally formed by applying pressure and heat fusion in the state, the presence of the elastic net that expands and contracts in all directions,
Sufficient followability can be exhibited, and the orientation of the asphalt sheet will be 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 hardens when the temperature is below 10 ° C, the asphalt sheet is held by the mesh structure of the stretchable net sandwiched between the asphalt sheet, so the asphalt sheet will not be broken or cracked when dropped. It does not happen and has excellent quality characteristics. Therefore, by using the vibration damping material for a vehicle body panel of the present invention, it is not necessary to soften the asphalt sheet with an incandescent lamp or the like at the time of working, so that the facility cost does not increase unlike the conventional case, and the assembling of the product does not occur. The work efficiency can be improved and the occurrence of defective products can be reduced.

Further, in the vibration damping material for vehicle body panels of the present invention, the asphalt sheet fluidized by heating oozes out from the holes of the mesh structure of the stretchable net, and the upper and lower asphalt sheets of the stretchable net are heat-sealed, Since the stretchable net and the asphalt sheet are in close contact with each other, an adhesive agent is not required as in the conventional case, and the product cost can be reduced. Moreover, according to the damping material for a vehicle body panel of the present invention, since the stretchable net is sandwiched between the two asphalt sheets, the weight of the vehicle can be reduced as compared with the conventional one, and as a result, the four-wheeled vehicle can be obtained. The driving performance can be improved and the fuel consumption can be reduced.

[Brief description of 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 an electrodeposited steel plate to which the damping material for vehicle body panel is adhered.

FIG. 4 is a cross-sectional view showing a vehicle body panel damping material in a state of being bonded to the steel plate.

FIG. 5 is a conceptual diagram showing a process of manufacturing a conventional asphalt sheet.

FIG. 6 is a perspective view showing a conventional asphalt sheet.

FIG. 7 is a perspective view showing a state in which the asphalt sheet in FIG. 6 is bonded to a vehicle metal plate member having a convex portion.

FIG. 8 is a perspective view showing a state in which the asphalt sheet in FIG. 6 has different orientation directions and is adhered to a vehicle sheet metal member having a convex portion.

[Explanation of symbols]

 1 Body panel damping material 2, 3 Asphalt sheet 4 Stretchable net

Claims (3)

[Claims] 1. A stretchable net having a mesh structure is sandwiched between two asphalt sheets, and the asphalt sheet and the stretchable net are integrally formed by applying pressure and heat-sealing them in a state of being superposed on each other. A damping material for vehicle body panels, which is characterized in that 2. The elastic net has a melting point of 160 ° C.
It is above, The damping material for vehicle body panels of the vehicle of Claim 1 characterized by the above-mentioned. 3. The vibration damping material for a vehicle body panel of a vehicle according to claim 1, wherein the elastic net has an expansion / contraction ratio of 9% or less.