JP2004198801A - Soundproof cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a soundproof cover to be easily fixed to a noise source without using a grommet or a fixing tool. <P>SOLUTION: The soundproof cover comprises an elastically deformable sheet-like sound insulating layer 1 and a sound absorbing layer 2 integrally joined to the rear side of the sound insulating layer 1, and a projection 30 comprising a head part and a neck part having a diameter smaller than that of the head part projects from a noise source 3, and an attachment recessed part 10 to which the projection 30 is to be fitted is formed in at least a part of the sound insulating layer 1. The soundproof cover has the attachment recessed part 10 engaged with the projection 30 and is pressed from the surface, and thus the soundproof cover is fixed to the noise source 3 in one operation. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a soundproof cover capable of absorbing and insulating noise generated from components mounted in an engine room of an automobile, thereby preventing the noise.
[0002]
[Prior art]
In the engine room of the vehicle, an engine cover made of sheet metal or hard resin, a side cover, an oil pan cover, an under cover, and the like are arranged in order to shield sound radiation from a noise source such as an engine.
[0003]
However, it is difficult for these covers to absorb sound by sound absorption. Therefore, conventionally, a molded polyurethane foam molded into a predetermined shape has been laminated on the back surface side of these covers, thereby absorbing noise to prevent sound.
[0004]
For example, Japanese Patent Application Laid-Open No. 08-270889 describes a sound insulation cover composed of a sound insulation layer and a sound absorbing material layer made of a polymer foam and disposed in a compressed state between the sound insulation layer and the noise source. .
[0005]
However, since the sound insulation layer is generally formed of metal or hard resin, when the vibration of the noise source is transmitted, the sound insulation layer vibrates up to the sound insulation layer, and the sound insulation layer itself sometimes becomes a noise source. Therefore, conventionally, as described in Japanese Patent No. 3100863 or the like, a bolt is fixed to a noise source via a grommet made of a soft elastic body.
[0006]
However, in this case, since a grommet as a separate member is required, the number of parts increases, and there is a problem that the number of assembly steps and the cost are high. Japanese Patent Application Laid-Open No. 2002-273795 discloses a soundproof cover in which a soundproof layer is formed from rubber. By forming the sound insulation layer from rubber, the sound insulation layer itself is prevented from vibrating and becoming a noise source. The publication also describes a method in which a sound insulation layer is arranged together with a fixture in a foaming mold, and a sound absorbing material layer made of a urethane foam resin is integrally formed. It is described that it is fixed to the noise source by means.
[0007]
[Patent Document 1] Japanese Patent Application Laid-Open No. 08-270889 [Patent Document 2] Japanese Patent No. 3100863 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-273795
[Problems to be solved by the invention]
When using a soundproof cover having a sound absorbing layer formed of a molded polyurethane foam or the like, the sound absorbing cover is used with the sound absorbing layer in contact with the surface of the noise source. This is because when a gap is formed between the surface of the noise source and the soundproof cover, a standing wave is generated in the gap.
[0009]
However, since the conventional soundproof cover is fixed to the noise source via the grommet or the fixing device, parts such as the grommet or the fixing device are required, and the number of parts is large, the assembling man-hour is increased, and cost is reduced. There is a problem. Also, when fixing to the noise source by bolting, a space for rotating the wrench or wrench is required, and the spatial position of the fixing position is large, so the sound absorbing layer of the soundproof cover must be more than necessary. In some cases, it was unavoidable. In such a case, it is difficult to cover the entire noise source with the soundproof cover, and there is a problem that noise is generated from an exposed portion of the noise source.
[0010]
Further, when the fixture is integrally formed with the sound absorbing material layer, a mechanism for arranging the fixture in the foaming mold is required, and it is often necessary to perform a pre-treatment on the fixture itself. There is a problem that the cost is high due to the increase.
[0011]
The present invention has been made in view of such circumstances, and can be easily fixed to a noise source without using grommets and fixtures, and can reduce costs by reducing the number of parts and assembly steps. Aim.
[0012]
[Means for Solving the Problems]
The feature of the soundproof cover of the present invention that solves the above-mentioned problem is that the soundproof cover includes an elastically deformable sheet-like sound insulation layer and a sound absorption layer integrally joined to the back side of the sound insulation layer, and the sound absorption layer faces the noise source. A soundproof cover arranged such that a projection consisting of a head and a neck smaller in diameter than the head projects from the noise source, and at least a part of the sound insulation layer has a mounting recess to which the head fits. Is to be formed.
[0013]
The mounting recess is preferably a mounting hole penetrating the front and back of the sound insulation layer. It is also preferable that the surface of the sound insulation layer opposite to the mounting recess forms the same surface as the surface of the sound insulation layer.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
The soundproof cover of the present invention has an elastically deformable sheet-like sound insulation layer, and a projection composed of a head and a neck having a smaller diameter than the head projects from the noise source, and at least a part of the sound insulation layer has a head. Are formed in the mounting recesses. In other words, by simply engaging the mounting recess with the head of the projection and pressing from the surface, the diameter of the mounting recess is expanded by the elastic deformation of the sound insulation layer, and the head of the projection is fitted into the mounting recess, thereby forming the soundproof cover. Can be fixed to the noise source.
[0015]
In addition, since the sound insulation layer is elastically deformable and the sound absorption layer is also deformable, even if there is a displacement between the projection and the mounting recess, the sound insulation cover can be easily assembled by deformation. In other words, it is possible to assemble the soundproof cover even when the positional accuracy between the soundproof cover and the mounting side is low, so that one soundproof cover can be assembled to a plurality of parts and can be shared.
[0016]
Only the head of the projection is fitted into the mounting recess, and the sound insulation layer can be elastically deformed. As a result, even when the vibration from the noise source is transmitted to the sound insulation layer, the sound insulation layer itself is not easily vibrated, and in addition, the relative movement between the projection and the mounting recess occurs, so that the sound insulation layer is further prevented from vibrating. I have. Therefore, the vibration of the sound insulation layer can be prevented without using a grommet, and the sound insulation layer itself is prevented from becoming a noise source.
[0017]
Therefore, according to the soundproof cover of the present invention, bolts and the like become unnecessary, and the number of assembly steps can be greatly reduced. Furthermore, the space for rotating the spanner or wrench is not required, so the size and shape of the soundproof cover are reduced, and the sound-absorbing layer, which has been drilled for fastening bolts, etc., is near the fixed part. Such arrangement can increase the degree of freedom of design, so that noise can be more effectively reduced.
[0018]
Further, since no grommet or fixture is required, the number of parts can be reduced, the cost can be reduced, and the weight in the assembled state can be reduced.
[0019]
The soundproof cover of the present invention includes a sheet-like sound-insulating layer that can be elastically deformed, and a sound-absorbing layer that is integrally joined to the back side of the sound-insulating layer. The sound insulation layer can be formed from rubber, thermoplastic elastomer, or the like. The sound absorbing layer can be made of a fiber assembly or a polymer foam such as urethane foam. The sound insulation layer and the sound absorption layer are integrally joined, and sound is prevented from leaking from the interface.
[0020]
In order to integrally join the sound insulation layer and the sound absorption layer, the formed sound insulation layer and the sound absorption layer can also be joined by bonding, welding, or the like. It is desirable to integrally form the sound absorbing layer from resin. As a result, the number of joining steps can be reduced.
[0021]
The mounting recess may be, for example, a through hole penetrating the front and back of the sound insulation layer. According to this configuration, the head of the projection appears on the surface of the sound insulation layer when assembled to the noise source, so that it can be visually confirmed that the assembly has been normally performed. Further, at the time of assembling, since the projection can be visually recognized through the through hole, positioning can be easily performed.
[0022]
When the mounting recess is a recess formed from the back surface of the sound insulating layer toward the inside, the surface of the sound insulating layer opposite to the mounting recess may be bulged to cover the head of the projection. And the same surface as the surface of the sound insulation layer. With such a configuration, the sound insulating layer has excellent surface design, so that it can be suitably used in a region where design is important.
[0023]
The portion of the sound insulation layer where the mounting recess is formed has a lower strength than other portions, and stress tends to concentrate on the mounting recess. Therefore, it is preferable that the portion be thicker than the other portions.
[0024]
If a through hole or a slit is formed in a portion of the sound absorbing layer facing the mounting recess, the projection can easily penetrate when the projection is fitted. However, since the sound-absorbing layer is generally easily deformable, no through-holes or slits are provided, and the sound-absorbing layer is pressed and deformed by the head of the protrusion so that it is sandwiched between the head and the mounting recess. It is also possible.
[0025]
The projection protruding from the noise source comprises a head and a neck portion having a smaller diameter than the head portion, and may be formed integrally with the noise source, or a separate member having an external thread formed at the tip of the neck portion may be used as a noise source. It can also be screwed and fixed to the female screw part formed in the source.
[0026]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples.
[0027]
(Example 1)
FIG. 1 is a sectional view of a principal part of the soundproof cover of the present embodiment, and FIG. 2 is a sectional view of a principal part in a state where the soundproof cover is fixed to a noise source. This soundproof cover is composed of a rubber-like sound-insulating layer 1 made of rubber and a sound-absorbing layer 2 made of urethane foam integrally laminated on the back side of the sound-insulating layer 1.
[0028]
Although only one is shown in the figure, a plurality of mounting recesses 10 are formed in the sound insulating layer 1. The mounting recess 10 is formed of a through-hole penetrating the front and back of the sound insulating layer 1, and has a thicker portion 11 formed at a peripheral portion thereof, which is thicker than other portions. By partially increasing the thickness, the strength of the mounting recess 10 can be increased without increasing the weight of the entire sound insulating layer 1. The sound absorbing layer 2 is not formed at a position facing the mounting recess 10.
[0029]
In order to manufacture this soundproof cover, the surface of the sound insulating layer 1 having the mounting recess 10 formed in advance and facing the sound absorbing layer 2 is blasted as described in JP-A-2002-273795, and then the foam molding die Are arranged along one of the mold surfaces. At this time, a projection is formed on one of the mold surfaces in advance, and the sound insulation layer 1 is positioned by engaging the projection with the mounting recess 10. Then, a predetermined amount of urethane foam resin is injected between the sound insulation layer 1 and the other mold surface, the mold is closed, and foam molding is performed, whereby the sound absorption layer 2 integrally joined with the sound insulation layer 1 is formed.
[0030]
This soundproof cover is attached to a part of the engine body 3 as shown in FIG. A plurality of projections 30 protrude from the engine body 3. The projection 30 has a spherical head 31 and a columnar neck 32 having a smaller diameter than the head 31, and is fixed to the engine body 3 by screwing. The diameter of the head 31 of the projection 30 is larger than the diameter of the mounting recess 10, and the diameter of the neck 32 is slightly smaller than the diameter of the mounting recess 10.
[0031]
The soundproof cover is first oriented so that the sound absorbing layer 2 faces the engine main body 3, and is positioned so that the mounting recess 10 and the projection 30 coincide. At this time, on the surface side of the sound insulation layer 1, the projection 30 can be visually recognized through the mounting recess 10, so that positioning can be easily performed. By pressing the soundproof cover against the engine body 3, the head 31 of the projection 30 penetrates the mounting recess 10 while expanding the diameter of the mounting recess 10. The main body 3 is fitted and fixed. When the head 31 is exposed on the surface side of the sound insulating layer 1, it can be visually recognized that the fitting and fixing have been normally performed, and the fitting failure can be prevented.
[0032]
Therefore, according to the soundproof cover of this embodiment, it is possible to assemble the engine body 3 with one touch, and the number of assembling steps can be greatly reduced. In addition, since no metal parts such as fixtures are used, the production of the soundproof cover itself is easy and the weight is reduced.
[0033]
In the present embodiment, the shape of the head 31 of the projection 30 is spherical, but the shape is not limited to this, and it goes without saying that the shape can be various shapes such as conical and prismatic.
[0034]
Further, in this embodiment, since the sound absorbing layer 2 is not formed in the portion of the mounting concave portion 10, it is difficult to prevent sound from being absorbed in that portion. However, as shown in FIG. 3, such a problem can be avoided by providing the sound absorbing layer 2 also in a portion facing the mounting concave portion 10. In the soundproof cover shown in FIG. 3, since the through hole 20 communicating with the mounting recess 10 is formed in the sound absorbing layer 2, the protrusion 30 can be easily penetrated.
[0035]
Further, since the sound absorbing layer 2 is also formed on the portion facing the mounting concave portion 10, the strength of the mounting concave portion 10 is ensured. Therefore, it is not necessary to form the thick portion 11 on the sound insulation layer 1, and the thickness may be the same as other portions as shown in FIG. 4.
[0036]
(Example 2)
FIG. 5 is an enlarged view of a main part in a state where the soundproof cover of the present embodiment is assembled to the engine body 3. In this embodiment, the structure is the same as that of the first embodiment except that the mounting recess 10 of the sound insulating layer 1 does not penetrate the surface of the sound insulating layer 1 and the surface of the sound insulating layer 1 is flat.
[0037]
According to the soundproof cover of the present embodiment, when assembled to the engine body 3, the projections 30 do not appear on the surface of the sound insulation layer 1, and the surface of the sound insulation layer 1 is a uniform flat surface. Is excellent.
[0038]
In the case of the present embodiment, the thickness of the sound insulating layer 1 may be unnecessarily thick, and if so, the weight may increase and a problem may occur in terms of space. In such a case, as shown in FIG. 6, it is desirable to form the thick portion 11 only in the vicinity of the mounting concave portion 10. As a result, the strength of the mounting recess 10 can be ensured, and an increase in weight can be minimized.
[0039]
(Example 3)
FIG. 7 is an enlarged view of a main part in a state where the soundproof cover of the present embodiment is assembled to the engine body 3. In the present embodiment, a bulge 12 is formed on the surface of the sound insulation layer 1, and a mounting recess 10 is formed inside the bulge 12. The structure is the same as that of the first embodiment except that the head 31 of the projection 30 is fitted and fixed to the bulging portion 12.
[0040]
According to the soundproof cover of the present embodiment, the projections 30 do not appear when assembled to the engine body 3 and only the material of the sound insulation layer 1 is exposed, so that the design is superior to that of the first embodiment. In addition, the mounting workability is better than that of the second embodiment.
[0041]
【The invention's effect】
That is, according to the soundproof cover of the present invention, it is possible to assemble the noise source with one touch, and the number of assembling steps can be greatly reduced. In addition, since metal parts such as fixtures are not used, the production of the soundproof cover itself is easy, the weight is reduced, the degree of freedom in design is increased, and the soundproof performance is improved.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of a soundproof cover according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part showing a state where the soundproof cover according to one embodiment of the present invention is assembled to a noise source.
FIG. 3 is a sectional view of a main part showing another embodiment of the soundproof cover of one embodiment of the present invention.
FIG. 4 is a sectional view of a main part showing another embodiment of the soundproof cover of one embodiment of the present invention.
FIG. 5 is a cross-sectional view of a main part illustrating a state where the soundproof cover according to the second embodiment of the present invention is assembled to a noise source.
FIG. 6 is a cross-sectional view of a main part of another embodiment of the soundproof cover according to the second embodiment of the present invention, showing the soundproof cover assembled to a noise source.
FIG. 7 is a cross-sectional view of a principal part showing a state where a soundproof cover according to a third embodiment of the present invention is assembled to a noise source.
[Explanation of symbols]
1: sound insulation layer 2: sound absorption layer 3: engine body (noise source)
10: Mounting recess 11: Thick part 30: Projection
31: Head 32: Neck

Claims (3)

An elastically deformable sheet-like sound insulation layer, comprising a sound absorption layer integrally joined to the back side of the sound insulation layer, wherein the sound absorption layer is disposed so as to face the noise source,
A projection consisting of a head and a neck smaller in diameter than the head protrudes from the noise source, and at least a part of the sound insulation layer is formed with a mounting recess for fitting the head. Soundproof cover. The soundproof cover according to claim 1, wherein the mounting recess is a mounting hole penetrating the front and back of the sound insulating layer. The soundproofing cover according to claim 1, wherein a surface of the soundproofing layer opposite to the mounting recess forms the same surface as a surface of the soundproofing layer.

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