JP2010095179A - Noise-shutting off structure for front part of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance sound-shutting off property of a front part of a vehicle while having excellent general use property. <P>SOLUTION: An upper end 120T is closely adhered to a lower surface 32A of a joint flange 32 of a cowl 30 in the state that an auxiliary silencer 120 is elastically deformed and deflected. Thereby, a transmission sound from a clearance L2 between an upper end 110T of a dash inner silencer 110 and the joint flange 32 is reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sound insulation structure at the front of a vehicle.

  A sound insulation structure is known in which the interior of a dash panel that partitions an engine room and a vehicle compartment at the front of the vehicle is covered with a dash inner silencer to prevent the engine sound from being transmitted into the vehicle interior.

  Here, as shown in FIG. 4, in Patent Document 1, a clip 220 is attached to the dash panel 30, and a pin 230 formed on the instrument panel 40 is pushed into the clip 220, thereby providing an instrument. A structure in which the panel 40 is fixed is described.

Then, an upper end portion 212 extended to the upper surface portion 20A of the cowl 20 is formed on the dash inner silencer 210, and an extension portion 222 extending from the outer peripheral edge along the upper surface portion 220A is formed on the clip 220. The extended portion 222 presses the upper end portion 212 of the dash inner silencer 210. With such a configuration, the dash inner silencer 210 can be extended to the upper surface portion 20A of the cowl 20 without providing a sound insulating material or a sound absorbing material separately from the dash inner silencer 210 provided on the dash panel 30. Yes. That is, the sound insulation is improved without providing a sound insulation material or a sound absorption material different from the dash inner silencer 210.
JP-A-9-156431

  However, in the case of a structure for fixing the instrument panel 40 other than the fixing method for fixing the instrument panel 40 with the clip 220 provided on the dash panel 30 as in Patent Document 1, the sound insulation is improved by applying Patent Document 1. It may not be possible or difficult to apply.

  For example, as shown in FIG. 5, a sandwiching portion 42 having a substantially U-shaped cross section formed in the instrument panel 40 is inserted into (inserted into) the joint portion 33 between the cowl 20 and the dash panel 30. In the case of a fixing method for fixing the instrument panel 40, since the clip 220 (see FIG. 4) is not provided, the configuration of Patent Document 1 cannot be applied to improve the sound insulation.

  Therefore, there is a demand for a sound insulation structure for the front portion of a vehicle that is applicable to a wide (various) instrument panel fixing structure and is excellent in versatility.

  In view of the above, an object of the present invention is to provide a sound insulation structure for a front portion of a vehicle with improved sound insulation while having excellent versatility.

  The invention of claim 1 is a dash panel that partitions an engine room and a vehicle compartment at the front of the vehicle, and extends from the upper end of the dash panel to the vehicle interior side and is joined to a cowl provided on the upper side of the dash panel. A dash inner silencer having an upper end attached to the side surface of the interior of the dash panel with a gap therebetween, and a lower end portion of the dash inner silencer on the side of the interior of the vehicle interior. And an auxiliary silencer whose upper end is in close contact with the joint flange in a state of being elastically deformed.

  Therefore, since the upper end of the auxiliary silencer attached to the dash inner silencer attached to the side of the interior of the dash panel is in close contact with the joining flange, transmission from the gap between the upper end of the dash inner silencer and the joining flange Sound is reduced. Therefore, the sound insulation of the front part of the vehicle is improved. In other words, NV performance (noise vibration performance) is improved.

  Further, for example, even if the instrument panel mounting method provided on the interior side of the dash panel is a structure in which the instrument panel is fixed to a clip provided on the dash panel, or the joining flange of the dash panel and the cowl Even if it is the structure which clamps and fixes the joining site | part of this, this sound-insulation structure is applicable. In other words, the sound insulation structure can be applied to a wide (various) instrument panel fixing structure. That is, this sound insulation structure has excellent versatility.

  According to a second aspect of the present invention, in the sound insulation structure for a front portion of the vehicle according to the first aspect, the auxiliary silencer is made of a rubber foam.

  Therefore, the upper end of the auxiliary silencer improves the adhesion to the joining flange, so that the sound insulation of the front part of the vehicle is further improved (NV performance is further improved).

  According to the first aspect of the present invention, it is possible to improve the sound insulation of the front portion of the vehicle while having excellent versatility.

  According to invention of Claim 2, the sound insulation of a vehicle front part can further be improved.

  Hereinafter, an example of an embodiment of a sound insulation structure for a vehicle front according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a side cross-sectional view (longitudinal cross-sectional view along the vehicle front-rear direction) showing the sound insulation structure of the vehicle front portion according to the present invention. FIG. 2A is an enlarged side cross-sectional view of the main part (auxiliary silencer) of FIG. FIG. 2B is a side cross-sectional view showing a state in which the auxiliary silencer hits the lower surface of the joint flange (surface contact). FIG. 3 is a front view showing the sound insulating member before being attached. In addition, arrow UP in a figure shows a vehicle up direction, arrow FR shows a vehicle front direction, and arrow OUT shows a vehicle width direction outer side direction.

  As shown in FIG. 1, the cowl 20 has an inclined surface 24 that is inclined downward toward the front side of the vehicle, and a front end lower portion of the front windshield glass 18 is fixed to the inclined surface 24 by an adhesive 19 or the like. ing.

  A dash panel 30 that partitions the engine room 12 and the vehicle compartment 14 is disposed below the cowl 20. A joining flange 32 that is bent toward the vehicle interior side (the vehicle rear side) and disposed substantially horizontally is formed at the upper end portion of the dash panel 30. Therefore, the longitudinal cross-sectional shape along the vehicle front-rear direction of the upper end portion of the dash panel 30 is an inverted L shape.

  The dash panel 30 is joined by superimposing a joining flange 32 and a joining portion 22 at a vehicle rear side end portion (a vehicle interior side end portion) of the cowl 20 vertically. The overlapped and bonded portion is referred to as a bonded portion 33.

  On the vehicle interior side of the dash panel 30, an instrument panel 40 constituting the interior of the front of the vehicle interior 14 is provided.

  On the front upper end side of the instrument panel 40, a sandwiching portion 42 (see FIG. 1) that protrudes toward the vehicle front side is formed. The sandwiching portion 42 is configured by an upper piece portion 42A and a lower piece portion 42B, and has a substantially U-shaped longitudinal section arranged with the front side in the vehicle width direction as an opening side. Note that a plurality of the clamping portions 42 are formed at intervals in the vehicle width direction. Then, the instrument panel 40 is fixed by inserting (inserting) the joint portion 33 between the upper piece portion 42A and the lower piece portion 42B constituting the sandwiching portion 42 (see also FIG. 5). ).

  An extension portion 44 extending between the front windshield glass 18 and the cowl 20 is formed at the upper end portion of the instrument panel 40. The front end portion 44 </ b> A of the extension portion 44 of the instrument panel 40 is fixed by the seal member 17 provided between the front windshield glass 18 and the cowl 20.

  Further, a defroster nozzle 16 having a substantially square columnar cross section for guiding conditioned air from an air conditioner (not shown) to the vehicle compartment 14 is disposed between the dash panel 30 and the instrument panel 40.

  On the vehicle interior side of the dash panel 30, there is provided a sound insulation member 100 that insulates engine sound or the like of the engine room 12 (reduces transmission of engine sound to the vehicle interior 14). The sound insulation member 100 is composed of a dash inner silencer 110 and an auxiliary silencer 120 (see also FIG. 3).

  A dash inner silencer 110 made of felt, foamed urethane, or the like and having sound insulation and sound absorption is attached to the vehicle interior side surface 30A of the dash panel 30 (the vehicle interior side surface 30A of the dash panel is covered by the dash inner silencer 110). Have been). The upper end 110T of the dash inner silencer 110 is attached to the lower surface 32A of the joining flange 32 of the dash panel 30 with a slight gap.

  In other words, the upper end 110T of the dash inner silencer 110 and the lower surface 32A of the joining flange 32 of the dash panel 30 are designed not to interfere with each other, that is, not the interference design, but the upper end 110T of the dash inner silencer 110 and the dash panel 30. This is a design (configuration) in which the lower surface 32 </ b> A of the joint flange 32 is disposed in proximity.

  The auxiliary silencer 120 is a plate-like elastic body having sound insulating properties and sound absorbing properties. The auxiliary silencer 120 has a thickness direction that is the front-rear direction of the vehicle, and a lower end portion 120K is attached (joined) to the side surface 110A of the passenger compartment at the upper end portion of the dash inner silencer 110. The upper end 120C of the auxiliary silencer 120 is a free end, and the upper end 120C is in close contact with the lower surface 32A of the joining flange 32 of the dash panel 30. Precisely, the front edge 120TE of the upper end 120T of the auxiliary silencer 120 is in close contact with the lower surface 32A of the joint flange 32.

  Note that the length L1 (see FIG. 3) of the free end of the auxiliary silencer 120 is the gap L2 between the upper end 110T of the dash inner silencer 110 and the lower surface 32A of the joining flange 32 of the dash panel 30 (FIG. 2A). Longer than (see) (L1> L2). Therefore, the auxiliary silencer 120 is in a state where the upper end portion 120 </ b> C is in close contact with the lower surface 32 </ b> A of the joining flange 32 in a state where the auxiliary silencer 120 is elastically deformed and bent. In other words, the interference is designed so that the upper end portion 120C of the auxiliary silencer 120 interferes with the joint flange 32 of the dash panel 30.

  As shown in FIG. 3, a plurality of auxiliary silencers 120 are provided at intervals in the vehicle width direction. And the clamping part 42 (refer FIG. 1, FIG. 5) of the instrument panel 40 mentioned above is arrange | positioned between the auxiliary silencer 120 and the auxiliary silencer 120 (gap S of FIG. 3).

  Here, the auxiliary silencer 120 of the present embodiment uses foamed rubber whose main component is EPDM rubber processed into a plate shape. In the present embodiment, the auxiliary silencer (foam rubber) 120 has a characteristic that the thickness is reduced to a fraction of a few tenths with a low stress of several tens to several hundreds Pa. In the present embodiment, EPT SEALER (registered trademark) manufactured by Nitto Denko Corporation is used as the foam rubber having such characteristics.

  Next, the operation of this embodiment will be described.

  As shown in FIG. 1, since the sound insulation member 100 is provided on the dash panel 30 on the vehicle interior side, the engine sound or the like of the engine room 12 is sound-insulated (the transmission of engine sound to the vehicle interior 14 is reduced). To do).

  As shown in FIG. 2A, the upper end portion 120C is in close contact with the lower surface 32A of the joining flange 32 of the cowl 30 in a state where the auxiliary silencer 120 is elastically deformed and bent. Therefore, compared with the structure in which the auxiliary silencer 120 is not provided, the transmitted sound from the gap L2 between the upper end 110T of the dash inner silencer 110 and the joint flange 32 is reduced, so that the sound insulation of the front portion of the vehicle is improved. . In other words, by providing the auxiliary silencer 120, the NV performance (noise vibration performance) is improved.

  Here, it is difficult to attach the upper end 110T of the dash inner silencer 110 so as to be in contact with the lower surface 32A of the joining flange 32 (without a gap between the lower surface 32A) in consideration of manufacturing variations and productivity. (It is difficult to make an interference design). Therefore, the upper end 110T of the dash inner silencer 110 and the lower surface 32A of the joint flange 32 are close to each other (there is a slight gap). Further, even if the upper end 110T of the dash inner silencer 110 contacts the lower surface 32A of the joining flange 32, the adhesion is low due to its own weight or the like. That is, it is difficult to improve sound insulation by bringing the upper end 110T of the dash inner silencer 110 into close contact with the lower surface 32A of the joining flange 32.

  On the other hand, in the present embodiment, as described above, the upper end portion 120C is in close contact with the lower surface 32A of the joint flange 32 of the cowl 30 in a state where the auxiliary silencer 120 is elastically deformed and bent. Even if manufacturing variation is taken into account, the interference setting is always performed so that L1> L2 (see FIGS. 2A and 3), and the amount of bending of the auxiliary silencer 120 may be changed. The upper end 120C of the silencer 120 is always in close contact with the lower surface 32A of the joining flange 32 of the cowl 30 (high adhesion).

  Therefore, as compared with a sound insulation structure in which the auxiliary silencer 120 is not provided (only the dash inner silencer 110 is provided) (a sound insulation structure to which the present invention is not applied), the upper end 110T of the dash inner silencer 110 and the joining flange 32 Sound transmitted through the gap between the two is reliably reduced, and sound insulation is improved.

  Further, for example, as in the sound insulation structure of Patent Document 1 shown in FIG. 4, a clip 220 is attached to the dash panel 30, and a pin 230 formed on the instrument panel 40 is pushed into the clip 220 to insert the instrument. The sound insulation structure can be easily applied even to a structure that fixes the ment panel 40. For example, the auxiliary silencer 120 can be provided by setting a portion corresponding to the pin 230 and the clip 220 as a gap S (see FIG. 3) between the auxiliary silencers 120 as in the present embodiment. That is, it can be applied to a wide structure for fixing the instrument panel 40. In other words, the sound insulation structure has excellent versatility.

  The auxiliary silencer 120 is composed of an elastic body (Eptosealer (registered trademark) in the present embodiment) that has a low stress of several tens to several hundreds Pa and has a thickness that is crushed to a fraction of a few tenths. . Therefore, the adhesion between the upper end portion 120C of the auxiliary silencer 120 and the lower surface 32A of the joining flange 32 of the cowl 30 is improved. That is, the sound insulation is further improved by using the auxiliary silencer 120 having such characteristics.

  Further, for example, there are few gaps between the instrument panel 40 and the auxiliary silencer 120 due to design restrictions and design relationships, and protrusions and ribs formed on the back surface of the instrument panel 40, or the periphery of the defroster nozzle 16, etc. Even if this part interferes (contacts) with the auxiliary silencer 120, the auxiliary silencer 120 at the interference site (contacting site) is only recessed, and no problem occurs. That is, the sound insulation structure is excellent in versatility with a high degree of freedom in design of the instrument panel 40 and less design restrictions.

  As described above, the sound insulation structure for a vehicle according to the present embodiment has excellent versatility and improved sound insulation.

  In the above embodiment, as shown in FIG. 2A, the vehicle front side edge 120TE of the upper end 120T of the auxiliary silencer 120 is in intimate contact with the lower surface 32A of the joining flange 32. However, the present invention is not limited to this. As shown in FIG. 2B, the vehicle front side surface 120 </ b> B at the upper end portion 120 </ b> C of the auxiliary silencer 120 may be in close contact with the lower surface 32 </ b> A of the joint flange 32. That is, as shown in FIG. 2 (A), it may not be per edge 120TE, but as shown in FIG. 2 (B), it may be abdomen ((vehicle front side surface 120B contact (surface contact)).

  The auxiliary silencer 120 may be made of a material other than foamed rubber. Any material may be used as long as it is an elastic body that is elastically deformed. For example, a urethane sponge may be used. Further, the thickness and material of the auxiliary silencer may be adjusted so that optimum NV performance can be obtained in accordance with the gap between the instrument panel 40 and the like.

  The present invention is not limited to the above embodiment. Needless to say, various embodiments can be implemented without departing from the scope of the present invention.

It is side surface sectional drawing which shows the sound insulation structure of the vehicle front part of this invention. (A) is the side surface sectional drawing which expanded the principal part (auxiliary silencer) of FIG. 1, (B) is a side surface sectional view which shows the state in which the auxiliary silencer contacted the abdomen (surface contact). It is a front view which shows the sound insulation member before attaching to a dash panel. It is side surface sectional drawing which shows the sound insulation structure of the vehicle front part by which the sound insulation property was improved by methods other than this invention. It is side surface sectional drawing of the vehicle front part by which the instrument panel is fixed by the fixing method different from FIG. 4, and the sound-insulating member is not provided.

Explanation of symbols

18 Front windshield glass 20 Cowl 30 Dash panel 32 Joint flange 110 Dash inner silencer 110T Upper end 120 Auxiliary silencer 120C Upper end

Claims (2)

A dash panel that partitions the engine room and the vehicle compartment at the front of the vehicle;
A joining flange that extends from the upper end of the dash panel to the vehicle interior side and is joined to a cowl provided on the upper side of the dash panel;
A dash inner silencer having an upper end attached to the side surface of the dash panel with a space between the joint flange;
An auxiliary silencer having a lower end attached to the side surface of the passenger compartment at the upper end of the dash inner silencer and having an upper end closely adhered to the joint flange in an elastically deformed state;
A sound insulation structure for the front portion of the vehicle.   The sound insulation structure for a vehicle front portion according to claim 1, wherein the auxiliary silencer is made of a rubber foam.

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