JPS62165043A - Damping material for vehicle - Google Patents

Abstract

PURPOSE:To reduce car weight and man-hour without combination of steel plates while maintaining damping performance by providing plural openings through out in the thickness direction on a flat type damping material (Melsheet(R)) made of heat fusing material. CONSTITUTION:Melsheet(R) 5 is fit on a floor plate 1. Plural through openings 6 are formed in the Melsheet(R) 5. The area of these openings is made less than 70% of the surface area of the Melsheet(R). And a noise insulating layer made of vinyl chloride foamed body 3 and felt 4 is provided over the Melsheet(R) 5. If only openings are provided simply on the Melsheet(R), damping performance is reduced, then it is required to increase the thickness in comparison with that of the Melsheet(R) of the previous condition with no opening. Therefore, if the thickness of the Melsheet(R) with openings is increased and the mass of unit surface area is made to the same as that of the conventional Melsheet(R), damping performance is improved and can be maintained even if steel plates for binding layer for improvement of damping performance are removed, then the car weight can be reduced and man-hour can be also decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flat plate-shaped vibration damping material that is mainly attached to the floor surface of a vehicle for vibration damping and heat recovery.

On the upper surface of the floorboard 1 or the lower surface of the floorboard of a regular car, a flat heat-adhesive damping material 2 called Melsheet, whose main component is asphalt, is applied by heat-fusion. , or affixed using a stone contact agent, and if necessary, the surface is covered with vinyl chloride foam 3. The floor structure is covered with sound insulating material such as Felt 4 and has excellent vibration damping and heat insulation properties (see Figures 1 and 2).

Furthermore, in recent years, in order to further improve vibration damping performance, a sandwich structure has been adopted in which a steel plate is placed on the upper surface of the Mel sheet as a restraining layer.

゛ Let's do it +1- However, in this improved floor structure, in order to make the steel plate with high rigidity adhere to the top of Null Seat 1 as a restraining layer,
For example, it is necessary to fix it to the floor plate with tapping screws or weld a pole 1- to the floor plate and fix it with the bolt, which is complicated and increases the number of man-hours, which increases the vehicle manufacturing cost (a. Was.

In addition, if a steel plate is used in combination with Melsheet, which has a relatively large specific gravity, the city K and nffi will increase, which will soon go against the key point of reducing the weight of the car body.
-J: and -1 The purpose of the present invention is to change the structure (or shape) of Melsheet itself without using a single large JA i:1 such as a steel plate. , the purpose is to improve its vibration damping performance.

This purpose is accomplished by forming a plurality of holes in a flat plate-shaped vibration damping material (melsheet) made of a heat-fusible material.

To reduce the weight of Melsheet, for example, see Figures 3 and 4.
As shown in the diagram, the melter! - It is effective to provide openings such as forming a plurality of through holes 6 in 5 to increase the width of the groove. However, simply performing planking will not only reduce the mass of melters 1 to 5 per medium surface area and inevitably reduce vibration damping performance, but also cause poor sound insulation performance. , it is necessary to increase the thickness of the Melsheet compared to the thickness before handling the meat. In addition, regarding the form of the openings, if the openings are formed over 70% of the Melsheet surface area, the vibration damping performance will deteriorate, so it is preferable to form the openings within a range of 70% or less. Formation depth is light fit
Considering the value of Q, it is preferable to set the upper limit to 20% and set the value to 20 to 100% of the null thickness.

Furthermore, covering the melters 1 to 5 having the through holes 6,
Similar to the structure shown in Figure 2, if a sound insulation layer made of vinyl chloride foam 3 and felt 4 is provided (see Figure 5), since 1η of air exists inside, especially in the high frequency range, By reducing the wall thickness of melters 1 to 5 while maintaining vibration damping performance,
('It is possible to do Ihl conversion.

In addition, the openings formed in the Mel sheet are not necessarily limited to through holes, but the openings 6A with bottoms as shown in FIGS.
may be formed.

W Kanoyu■ Made of 0.8# thick steel plate, which is equivalent to the floorboard material for automobiles, and 3# thick steel plate.
A sample Ao was prepared in which Melsheet was laminated.

■ A steel plate with a wall thickness of 3 mm, as shown in Figures 3 and 4, has curved hole formation area ratios (hereinafter referred to as flowering ratios) of 10%, 20%, and 50%, respectively, on a 0.8-thickness steel plate. Samples A+, A2, and As, in which Melsheet was laminated, were prepared.

■Each sample Ao, A+, Δ2. Loss coefficient of A3 (
η) and compare the damping performance (the larger the loss coefficient (η), the better the damping performance).

The loss coefficient (η) is the secondary resonance frequency (fo
) and the image frequency (f+), (f2) J:S, which is applied to the part 3 dB lower than the peak value of the resonance curve.
This was calculated based on the formula: η-(f2 f+)/fo.

FIG. 8 shows the results, and shows the change in the 1q lapse coefficient (η) of each sample with increasing temperature.

Evaluation of Figure 8> Sample Ao using melter 1~ without openings
The vibration damping performance of I@tJ is excellent, and the porosity is the largest (5
0%) Sample A3 using melter 1- had the poorest vibration damping performance.

ULL1 2 0.8mm thick steel plate equivalent to automatic small floor board material, wall thickness 1
．． Sample B is made by laminating 5mm Melsheet.

prepared.

■0.8nrm thick steel plate, 50% porosity, wall thickness 3In
Sample B+ (same as sample A3) in which IR Melsheet was laminated was prepared.

(2) Next, the loss coefficient (η) of samples Bo and B+ was investigated, and the results are shown in FIG. 9, which is a graph similar to FIG. 8.

<Evaluation of FIG. 9> It can be seen that even if holes are formed, if the thickness of Melsheet is increased and the mass per unit surface area is made the same, the damping performance will be improved.

Also, Makuhan Yu ■ 0.8-thick steel plate, which is equivalent to the flooring material for automobiles, with a wall thickness of 3
Sample C is made by laminating Melsheet of mm.

(same as thimble Ao) was prepared.

■ Sample C+ was prepared by laminating Melsheet with a porosity of 50% and a wall thickness of 6 mm on a 0.8M thick steel plate.

(2) Next, the loss coefficient (η) of samples Co and C+ was investigated, and the results are shown in FIG. 10, which is a graph similar to FIG. 8.

<Evaluation of Figure 10> Even if an opening is formed, Mercu! By increasing the wall thickness and increasing the mass per unit surface area, Mercu 1, which has no holes,
It can be seen that if the value is 9, which is the same as that of -, the damping performance is improved.

Further, from the comparison between the sample B1 and the sample C1, it can be seen that the vibration damping performance is improved by increasing the thickness of the Mel sheet with a porosity of 50% and increasing the mass per unit area.

Grave rat plate A ■Made of 0.8mm thick steel plate, which is equivalent to the floorboard material of a car, with a wall thickness of 3
A sample Do was prepared in which Merck l- of mm was laminated.

■ 0.8M thick steel plate with 10% porosity each.

Samples D+, D2, and Ds were prepared by laminating Melsheet with a wall thickness of 3 mm, which is 20% and 50%.

λ on the steel plate surface of each sample Do, D+, D2, D3
The sound pressure level of Melsheet was investigated using the combined pressure of the steel plate as a reference by applying sound waves with different frequencies. The results are shown in FIG.

<Evaluation of Figure 11 Sample D using Mercu 1- without openings.

It can be seen that the sound pressure level of J is the highest, and that by forming holes in the Mel sheet of the same thickness, the high pressure level decreases (sound insulation performance decreases).

A sample made by laminating 1.5 mm thick Mercu 1 on a 0.8 m 1 I + thick steel plate, which is equivalent to an automobile bulb.

prepared.

■0.8mm thick steel plate, 50% open area, wall thickness 3mm
A sample E+ was prepared in which Melsheet was laminated.

■Samples Eo and E+ have the same structure, and as shown in Figures 2 and 5, vinyl chloride foam (3.5 Ky/m) and felt (thickness 2
Samples Fo, F+ with laminated sound insulation layers consisting of
prepared.

■ Apply sound waves with different frequencies to the steel plate surface of each sample Eo, E+, Fo, and F+, check the sound pressure level of the surface Mel sheet or surface layer felt based on the sound pressure of the steel plate, and check the binding. It is shown in Figure 12.

<Evaluation of Figure 12> Even if holes are formed, if the thickness of Melsheet is increased and the 'el Ex per unit surface area is made equal to that of Melsheet without holes, the sound insulation performance will be improved. (Sample Eo).

E+).

Further, whether the Melsheet has no holes or holes are formed, by providing a sound insulating layer on the Melsheet, the sound insulation performance in a high frequency range can be dramatically improved. Similarly, in the high frequency sound range, Rimple F1, which has a sound insulation layer on Melku sheet with holes, is better than sample Fo, which has a sound insulation layer on Melku 1, which has no holes. Demonstrates excellent sound insulation performance. The reason for this is that an air layer exists within the Mel sheet in which the openings are formed.

As is clear from the above explanation, in the present invention, a plurality of holes are formed in the plate-shaped 1111 vibration material for II vehicles (mel sheet) made of heat-fusible material, so that the conventional control material cannot be used. It is possible to improve the damping performance while maintaining the cross-over performance by using a damping material with a weight equivalent to that of the conventional damping material. It is possible to reduce the The damping structure using the damping material of the present invention can be assembled at reduced costs or compared to a damping structure in which iron plates are laminated on Mel sheet, or a damping structure in which Melku 1-'s thickness is increased. It is possible to cut back on material savings.

[Brief explanation of drawings]

Fig. 1 and Fig. 2 are cross-sectional views of main parts showing a known floor structure of an automobile, respectively, and Fig. 3 shows a floor structure using a damping material (Merku 1~) according to an embodiment of the present invention. Main part sectional view,
FIG. 4 is a perspective view of the vibration damping material, and FIG. 5 is a sectional view of the main part showing the floor structure in which a sound insulation layer is installed on the damping layer shown in FIG. 3.
FIG. 6 is a diagram similar to FIG. 3 according to a modification, FIG. 7 is a diagram similar to FIG. 5 according to a modification, and FIGS. Graphs showing vibration damping performance (horizontal axis - temperature (°C), vertical axis -1 (1 lapse coefficient (η)), Figures 11 and 12 respectively show the sound insulation ↑ ability of each vibration damping (A) It is a graph (horizontal axis - frequency, vertical Ttll - sound pressure level). 1... Floorboard, 2... Vibration damping (A, 3... 122 vinyl foam, 4... Fell 1 ~.5... Merci 1-16... Through hole. Agent Ben 111 Jiang Il: Mi Hokkai 2 Name Leather 1 Fig. 2 Fig. 3 Fig. 4)・' Ama 5 Inn 6A 5 Atsushi 7th figure (-*yl Atsushi 8th figure Rinji JI (cI Figure 10 -C0 ・・・・・・・・・--C1 ... Ma ° [ (Hell 5 Gokeiji C) 帛11 figure Katana ηS leather trade (Hell sword)

Claims (3)

[Claims] (1) A flat plate-shaped vibration damping material for vehicles made of a heat-fusible material and having a plurality of holes. (2) The vibration damping material for a vehicle as set forth in claim 1, wherein the aperture penetrates in a thickness direction thereof. (3) The vibration damping material for a vehicle as set forth in claim 1, characterized in that a sound insulating layer is provided on the surface thereof.