JPS63265606A - Molding method for sound insulating material for automobile - Google Patents

Abstract

PURPOSE:To reduce the weight without spoiling sound insulating property, by molding integrally a porous material and a skin in a mold in such a manner that the thickness of the skin is made thicker successively in the order of a steering part, a lower part and an upper part. CONSTITUTION:A sound insulation for a dash part consists of a porous material 7 and a skin 8. The porous material 7a of an upper part 2, the porous material 7b of a lower part 3 and the porous material 7c of a steering part 4 are all formed in the same thickness and as the corresponding skins, a skin 8b of the lower part 3 is thicker than a skin 8a of the upper part 2, and a skin 8c of the steering part 4 is thicker than the skin 8b of the lower part 3. A mold is used for molding the insulation and the skin poured and molded in the mold contains a binder such as a synthetic resin, rubber, pitch and so on and a filler. As the porous material integrally molded with the skin, a bulky non-woven fablic and a urethane foamed material can be cited.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a method for forming a soundproofing material that is commonly used in automobile dash parts, and which does not impair soundproofing properties such as sound absorption and sound insulation properties (and realizes weight reduction). The present invention relates to a method for forming the obtained soundproofing material for automobiles.

BACKGROUND OF THE INVENTION Conventionally, various soundproofing measures have been taken on the interior side of a dash panel, for example, in order to prevent noise generated in the engine room of an automobile from entering the interior of the vehicle. One approach is to apply a soundproofing material that integrates a skin and a porous material, but conventional skins have approximately the same thickness regardless of the distance from the engine.

Problems to be Solved by the Invention However, from the standpoint of energy conservation, it is required to reduce the weight of the vehicle, and in turn, it is required to reduce the ff1jf of each component, and it is also necessary to reduce the weight of soundproofing materials. It was wanted.

Means for Solving the Problems Therefore, the present inventors have developed a soundproofing material that is made of a skin and a porous material that can efficiently exhibit the performance of soundproofing and soundabsorbing properties, without impairing the soundproofing properties in any way. As a result of intensive research to develop soundproofing materials that can reduce weight, we found that by making the skin of the upper part thinner than the lower part, and furthermore, making the lower part thinner than the steering part, it would be possible to achieve the opposite effect without having the same effect on soundproofing properties. It was discovered that the weight of the thinner portion can be reduced, leading to the present invention.

The present invention is a method of forming a soundproofing material that integrates a porous material and a skin to be provided on the interior side of an automobile dash. A soundproofing method for automobiles characterized by injecting a skin solution into a mold with a deeper part, molding the lower part thicker than the upper part and the steering part thicker than the lower part, and then integrating the parts with a porous material. The present invention provides a method for forming a material.

Next, the present invention will be explained in detail based on FIGS. 1 and 2.

FIG. 1 shows a soundproofing material 1 for the dash of an automobile, which consists of an upper part 2 far from the engine, a lower part 3 close to the engine, and a steering part 4 having many holes.

Note that 5 is a through hole for a steering shaft, wires, etc.

This soundproofing material 1 for a dash part consists of a porous material 7 and a skin 8.

The porous material Ta of the upper part 2, the porous material 7b of the lower part 3, and the porous material 7c of the steering part 4 are all formed to have the same thickness, but the corresponding skins are different from those of the upper part 2. The skin 8b of the lower part 3 is thicker than the skin 8a of the steering part 4, and the skin 8b of the steering part 4 is thicker than the skin 8a of the lower part 3.
c is formed thickly.

A mold is used to form the soundproofing material, and the skin that is injected into the mold and molded contains a binder and filler such as synthetic resin, rubber, and bituminous material.

The above synthetic resins include urethane resin, petroleum resin, polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer resin, and the rubber component includes natural rubber, polybutadiene, styrene-butadiene rubber, butyl rubber, neoprene rubber, chloroprene rubber, etc. Examples of rubber and bituminous materials include straight asphalt, blown asphalt, semi-brown asphalt, and mixtures of one or more of them.

Other fillers contained as main ingredients include talc, clay,
It is preferable to use any inorganic filler such as calcium carbonate, defibrated waste paper, fibrous materials such as slang wool, scaly materials such as mica, mica, silica balloons, etc. alone or in combination, and in combination with organic fillers. When used, synthetic resin powder, synthetic fiber waste, etc. are used.

Examples of porous materials that integrate with the epidermis include bulky nonwoven fabrics and urethane foam materials. Bulky nonwoven fabric is made by forming a fleece mixture of discontinuous fiber material and thermosetting resin as a binder into a predetermined thickness.
Discontinuous fiber materials include synthetic resin fibers such as °ζ, viscose rayon, acetate, acrylic, nylon, polyester, vinyl chloride, etc., and animal and vegetable fibers such as wool, cotton, Examples of mineral fibers include fiber materials such as glass wool, rock wool, and asbestos fibers.

Needless to say, fiber materials obtained by opening industrial waste such as recycled wool, fallen cotton, and fiber waste can also be suitably used.

A bulky nonwoven fabric is made from these fiber materials, a binder, and a moldability-imparting resin such as epoxy resin, urethane resin, phenol resin, or thermosetting acrylic resin.

The manufacturing process for manufacturing a bulky nonwoven fabric may be a conventionally known process; for example, a fibrous material is first opened using a bale feeder, a web of considerable thickness is formed using a wrapper, and the web is then The thermosetting resin powder component is sprayed using a resin spreader, and then the beater in the homing machine is used.
The fibers are opened again and mixed with the above resin powder, and the desired thickness is made into a fleece using a wrapper.The fleece is then sequentially passed onto a net conveyor in a heating furnace. Alternatively, in order to make handling easier, the mixed resin powder may be heated in a heating furnace and taken out in a semi-cured state to harden a portion of the mixed resin powder and molded under heat and pressure. Alternatively, the mixed resin powder may be sufficiently hardened to make it elastic. , it may be taken out as a felt-like material with excellent cushioning properties.

Urethane foam material is made by injecting urethane stock solution into the mold.
The stock solution is formed by foaming, and the stock solution is made by reacting a polydisocyanate compound and a polyol as main ingredients together with auxiliary agents such as a blowing agent, a catalyst, a foam stabilizer, and a crosslinking agent. Furthermore, it is also preferable to add asphalt or rubber to these stock solution components in order to improve the soundproofing effect.

Examples of the polyisocyanate component include tolylene diisocyanate (TD I), 4,4'-diphenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), 1,5-naphthylene diisocyanate (SDI), and hexamethylene diisocyanate (H
DI), hydrogenated TDI, hydrogenated MDI, isophorone diisocyanate (IPDI), lysine isocyanate (LDI)
), isopropylidene bis(4-cyclohexyl isocyanate) (IPCI), and any known diisocyanate can be used.

As the polyol, polyether polyol, polyester polyol, polymer polyol, polycarbonate diol, etc. can be used.

As a catalyst, it is preferable to use an organometallic compound such as an organotin compound or an organolead compound, or an amine compound such as triethylenediamine, or to use it alone. It is preferable to use an organic tin compound and a tertiary amine compound.

The blowing agent to be blended is, for example, trichlorofluoromethane,
Dichlorodifluoromethane, methylene chloride, other halogenated hydrocarbons and water can be used. Moreover, a foam stabilizer such as an organic silane compound can also be used together with the foaming agent.

Other additives that can be used include crosslinking agents such as jetanolamine and triethanolamine, flame retardants, colorants, and stabilizers.

The soundproofing material forming method of the present invention can be realized by using a mold in which the concave portion of the skin mold is made deeper in the upper portion than the bellows portion, and deeper on the steering side.

The skin of the soundproofing material is formed by making the recesses of the mold the deepest at the steering section, then shallower at the lower and upper sections, so that the steering section can be made thicker, the lower section thinner, and the upper section thinnest. As a result, the skin near the engine can be made thicker to provide soundproofing effects where it is needed, and thinner where it can be done, reducing the overall weight.

Example An example will be described below based on FIGS. 2 and 3.

Naturally, the present invention is not limited to the following examples.

First, in order to form the skin 8 shown in FIG. 2, 100 parts by weight of polyether polyol as a polyol component and ethylene glycol as a crosslinking agent were placed in an injection mold with a deeper velor part and a deeper steering part in the upper part. 15M parts, 2 parts by weight of triethylenediamine as a catalyst, 0.5 parts of dibutyltin dilaurate as a metal catalyst
80 parts by weight of modified MDI was injection-molded into a mold as an M placement part and an incyanate component.

The M amount of the obtained epidermis is 2.5 kg/rr for the upper part.
r lower part 3.5kg/rd, steering part 5k
g/rrr, and the total mW was 3.6 kg.

On the epidermis, polyether polyol 100! it part, 3 parts by weight of water, 0.3 parts by weight of amine catalyst, 1 part of foam stabilizer, 3 parts of jetanolamine, and 30 parts of crude MDI.
A urethane foam stock solution consisting of parts by weight was injected and foamed to form porous materials 7a, 7b, and 7c shown in FIG. 2, and these and the skin 8 were integrated.

Comparative Example A skin having the same composition as in the example was injection molded into a conventionally used injection mold with the same depth of recesses. The weight of the obtained skin was 4.0 kg for the entire part.

The same urethane foam material stock solution components as in the example were injected and foamed onto the skin to form an integrated product.

Next, the soundproofing effect was investigated using the following method.

The soundproofing material of the test method example was bonded to the dash board 1a in Figure 2, and the soundproofing material of the comparative example was bonded to the dash board in the same manner. These were installed on an actual vehicle, and the third gear was tested. The acoustic effects of the ear position of the front seat center passenger during full throttle acceleration were determined. 100~5000H
The average values from 1000 to 6000 rpo+ at z are graphically represented in FIG.

Effects of the Invention According to the present invention, the porous material and the skin are integrally molded using a mold, and at this time, the thickness of the skin can be increased in the order of the steering part, the lower part, and the upper part. It is possible to provide a soundproofing material that can optimally prevent engine noise at the position where it is received, and also to reduce the weight of the parts where the skin is made thinner, thereby contributing to energy saving.

[Brief explanation of the drawing]

Fig. 1 is a front view of the dash of an automobile using the soundproofing material of one embodiment of the present invention, and Fig. 2 is a diagram of the soundproofing material shown in Fig. 1A-
A sectional view and FIG. 3 are measurement graphs of the soundproofing effects of this soundproofing material and a comparative example. In the figure, 1 is a soundproofing material for the dash part, 2 is an upper part, 3 is a lower part, 4 is a steering part, 7 is a porous material, 8 is a skin, 8a is a skin of the upper part, 8b is a skin of a lower part,
8c is the skin of the steering portion. April 24, 1985 Patent applicant Honda Motor Co., Ltd. Japan Special Paint Co., Ltd. Figure 1 Figure 2 Figure N3

Claims (1)

[Claims] (1) In a forming method using a mold of a soundproof material that integrates a porous material and a skin to be installed on the interior side of an automobile dash, the concave part for molding the skin is made deeper than the upper part, and the velor part is deeper than the upper part, and the steering part A soundproofing material for automobiles characterized by injecting a skin-forming stock solution into a mold with a deeper layer, molding the lower part to be thicker than the upper part and the steering part to be thicker than the lower part, and then integrating it with a porous material. How to form.