JP2012071707A - Device for reducing vehicle noise - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for reducing vehicle noise (muffled sound) without adversely influencing comfort of an occupant.SOLUTION: A resonator 4 is included in seat cushion 2 of a vehicular seat (front passenger seat 1) by utilizing a part of space where a seat holding member 3 is arranged, and an opening (outlet pipe 4a) of the resonator 4 communicates with the inside of a vehicle compartment 5. No additional space is needed for the resonator 4 in the vehicle compartment 5, and vehicle noise (muffled sound) can be reduced by arranging the resonator 4 in the vehicle compartment 5 so as not to adversely influence comfort of an occupant in the vehicle compartment 5.

Description

  The present invention relates to an in-vehicle noise reduction device for reducing low-frequency noise generated in a vehicle interior due to rotational vibration of an engine, that is, muffled noise.

  Since the interior of an automobile is a closed space, there is always a cavity resonance, but the acoustic mode due to this cavity resonance is excited in combination with the vibration of the car body, resulting in unpleasant noise (buzzing noise). You may be invited.

  Conventionally, as a countermeasure against this kind of in-vehicle noise (buzzing noise), the vibration characteristic of the vehicle body is separated from the eigenvalue of the cavity resonance. Major changes such as review are required.

  For this reason, a resonator capable of reducing noise at a specific frequency by applying Holzhelm's resonance principle is arranged in the vehicle interior, so that the vehicle interior noise (booming noise) can be reduced without changing the vehicle body to a large scale. It is considered to be.

  In addition, as prior art document information related to this type of in-vehicle noise reduction device, the following Patent Document 1 and the like by the same applicant as the present invention already exist.

Japanese Utility Model Publication No. 6-44681

  However, in order to reduce in-vehicle noise (buzzing noise), a resonator having a relatively large capacity is required. If such a resonator having a large capacity is arranged in a narrow vehicle compartment, the occupant's comfortability may be adversely affected. There was this.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an in-vehicle noise reduction device capable of reducing in-vehicle noise (humid noise) without adversely affecting the comfortability of a passenger.

  The present invention relates to a vehicle interior noise reduction device characterized in that a resonator is built in a seat cushion of a vehicle seat using a part of a space for arranging a seat holding member, and an opening of the resonator is communicated with a vehicle interior. , Related to

  Thus, in this way, since the resonator is built in the seat cushion using a part of the arrangement space of the seat holding member, it is not necessary to newly secure the arrangement space of the resonator in the vehicle interior. In order not to adversely affect the occupant's comfortability in the passenger compartment, it is possible to provide a resonator in the passenger compartment to reduce in-vehicle noise.

  In addition, by providing the resonator with sufficient strength, it is possible to cause the resonator to play a role as a sheet holding member. Therefore, the resonator is used by utilizing a part of the arrangement space of the sheet holding member. Even if it is arranged, the occupant holding performance of the seat cushion is not adversely affected, and the cost and mass can be reduced by downsizing the seat holding member.

  In addition, the silencing action by the resonator is based on the well-known principle of Holzhelm resonance, and the vibration system uses the gas in the neck forming the opening as the mass and the gas in the cavity inside the resonator as the spring. Is formed, and the system is resonated (resonated), so that the booming sound and the like are absorbed.

  Furthermore, in the present invention, when the resonator is built in the seat cushion, it is possible to incorporate the urethane foam that embraces the seat holding member into the foam foam and to incorporate it into the seat cushion. Since the resonator is integrally held during molding, there is no need for parts to mount the resonator, fewer assembly steps are required, and the assembly accuracy can be kept high, and the urethane foam and the resonator are in close contact. In addition, since no gap is generated between the resonators, it is possible to efficiently arrange the resonators in a small space.

  Further, in the present invention, when the resonator is incorporated in the seat cushion, the resonator may be fixed to the floor side, and the seat cushion may be placed from above and located in the concave portion of the bottom surface. .

  Further, in the present invention, it is preferable that the sheet holding member and the resonator are spaced apart from each other with a required interval. In this way, the seat holding member and the resonator that are spaced apart from each other with a required interval are preferably used. Cost and mass can be further reduced by further reducing the size of the sheet holding member while maintaining the holding property.

  According to the vehicle interior noise reduction device of the present invention described above, various excellent effects as described below can be obtained.

  (I) Since the resonator is incorporated in the seat cushion by using a part of the seat holding member arrangement space, the resonator is provided in the vehicle interior without adversely affecting the occupant's comfort in the vehicle interior ( Can be reduced.

  (II) Since the resonator can be provided with sufficient strength and can serve as a seat holding member, the seat cushion occupant even if the resonator is arranged using a part of the arrangement space of the seat holding member. It is possible to avoid adversely affecting the holding property, and it is possible to reduce the cost and mass by reducing the size of the sheet holding member as compared with the related art.

  (III) If the configuration incorporated in the foam foam molding of the urethane foam that embraces the seat holding member when the resonator is built in the seat cushion, the parts for mounting the resonator are unnecessary and the number of assembly steps is reduced. In addition, the assembling accuracy can be kept high, and the resonator can be arranged efficiently in a small space.

  (IV) If a configuration in which the seat holding member and the resonator are spaced apart from each other is employed, good occupant retention can be maintained by the seat holding member and the resonator spaced apart from each other at a required interval. In addition, the sheet holding member can be further reduced in size, and the cost and mass can be further reduced.

It is a perspective view which shows roughly an example of the form which implements this invention. It is sectional drawing which shows the built-in state to the seat cushion of a resonator. It is a perspective view which shows the detail of the structure of a resonator. It is sectional drawing which shows the structure of the exit pipe vicinity of a resonator. It is a front view of the cab explaining the generation | occurrence | production state of in-vehicle noise. It is a perspective view which shows another example of a form of this invention. It is a perspective view which shows another example of a form of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 show an example of an embodiment for carrying out the present invention. FIG. 1 is a perspective view schematically showing an arrangement state of resonators in this embodiment example, and FIG. 2 shows a built-in state of the resonator in a seat cushion. FIG. 3 is a perspective view showing details of the structure of the resonator shown in FIG. 2, and FIG. 4 is a cross-sectional view showing a structure near the outlet pipe of the resonator shown in FIG.

  As shown in FIG. 1, in the present embodiment, a resonator 4 is built in a part of the arrangement space of the seat holding member 3 outside the seat cushion 2 in the passenger seat 1 (seat) of the vehicle. The outlet pipe 4a (opening) of the resonator 4 is opened toward the front of the vehicle so as to communicate with the interior of the passenger compartment 5.

  Here, as shown in FIG. 2, the portion of the seat cushion 2 excluding the seat holding member 3 and the resonator 4 is made of urethane foam 6, and when the urethane foam 6 is foamed, the resonator 4 is formed. The resonator 4 is integrally held together with the sheet holding member 3 (see FIG. 1).

  The urethane foam 6 is covered with a skin 7 having a mesh structure, and the hole of the outlet pipe 4a of the resonator 4 is concealed by the skin 7 so as not to impair the silencing function, thereby avoiding deterioration in appearance. It is like that.

  Further, as shown in FIGS. 3 and 4, the resonator 4 is a hollow member (see FIG. 4) made of a PP blow molded product, and its upper surface is flush with the upper surface of the adjacent sheet holding member 3 (see FIG. 4). 1) and has a curved surface along the shape of the occupant's thigh (see the chain double-dashed line in FIG. 2) so as not to adversely affect the occupant's sitting comfort. It is.

  Further, the resonator 4 has sufficient strength so that the resonator 4 can also serve as the sheet holding member 3. More specifically, the resonator 4 has a thickness of about 4.0 mm and a plurality of thicknesses. The reinforcing bead 4b is formed.

  The resonance frequency of the resonator 4 can be changed by adjusting the diameter D (see FIG. 4) and length L (see FIG. 4) of the outlet pipe 4a and the volume of the resonator 4. 4, an appropriate resonance frequency is set in accordance with the frequency of in-vehicle noise (booming sound).

  Thus, since the resonator 4 is built in the seat cushion 2 by using a part of the arrangement space of the seat holding member 3 in this way, the arrangement space of the resonator 4 is newly provided in the passenger compartment 5. It is not necessary to secure the resonator 4, and the resonator 4 is provided in the passenger compartment 5 so as not to adversely affect the occupant's comfortability in the passenger compartment 5, so that it is possible to reduce in-vehicle noise.

  Further, by providing the resonator 4 with sufficient strength, it is possible to cause the resonator 4 to play a role as the sheet holding member 3, so that a part of the arrangement space of the sheet holding member 3 is used. Even if the resonator 4 is disposed, the occupant retention of the seat cushion 2 is not adversely affected, and the cost and mass can be reduced by reducing the size of the seat holding member 3 as compared with the conventional one.

  Incidentally, the silencing action by the resonator 4 is based on the well-known principle of resonance of Holtz Helm, and the mass of the gas in the outlet pipe 4a as the neck portion forming the opening is determined. A vibration system using a gas as a spring is formed, and the system resonates to absorb a booming sound or the like.

  Therefore, according to the above-described embodiment, the resonator 4 is built in the seat cushion 2 by using a part of the arrangement space of the seat holding member 3, thereby adversely affecting the occupant's comfortability in the passenger compartment 5. In addition, the resonator 4 can be provided in the passenger compartment 5 to reduce in-vehicle noise (buzzing noise).

  In particular, in the case of the present embodiment, the resonator 4 is disposed outside the seat cushion 2 in the vehicle width direction, but as shown by chain line curves α and β in FIG. 5, between the left and right side panels in the passenger compartment 5. The noise (bumping noise) generated by the cavity resonance has a high sound pressure level on both sides in the vehicle width direction when viewed from the front of the cab 8. Therefore, if the resonator 4 is arranged as in this embodiment, the resonator 4 Can be applied at a high sound pressure level, and it is possible to more effectively reduce in-vehicle noise (bumping noise).

  Further, since the resonator 4 can be given sufficient strength to serve as the sheet holding member 3, even if the resonator 4 is arranged using a part of the arrangement space of the sheet holding member 3, the sheet It is possible to avoid an adverse effect on the occupant holding performance of the cushion 2, and the seat holding member 3 can be made smaller than before to reduce cost and mass.

  Further, in particular, in the present embodiment, when the resonator 4 is incorporated in the seat cushion 2, a configuration is adopted that is incorporated at the time of foam molding of the urethane foam 6 that holds the seat holding member 3, so that the resonator 4 is attached. These components can be made unnecessary, the number of assembling steps can be reduced, the assembling accuracy can be kept high, and the resonator 4 can be arranged efficiently in a small space.

  However, as shown in FIG. 6, when the resonator 4 is incorporated in the seat cushion 2, the resonator 4 is fixed to the floor (not shown), the seat cushion 2 is placed from above, and is positioned in the concave portion 6a on the bottom surface. It is also possible to incorporate it. The recess 6a on the bottom surface may be formed so that a mold cavity is formed when the urethane foam 6 is foam-molded.

  In addition, as shown in FIG. 7, the sheet holding member 3 and the resonator 4 may be spaced apart from each other with a required interval. In such a case, the sheets spaced apart with a required interval are disposed. The holding member 3 and the resonator 4 can maintain a good occupant holding property, and the seat holding member 3 can be further reduced in size, and the cost and mass can be further reduced.

  The in-vehicle noise reduction device of the present invention is not limited to the above-described embodiment. Resonators can be reinforced not only by reinforcing beads as shown, but also by forming ribs, etc. Of course, it may be incorporated in a seat cushion such as a driver's seat or a rear seat, and other various modifications may be made without departing from the scope of the present invention.

1 Passenger seat (seat)
2 Seat cushion 3 Seat holding member 4 Resonator 4a Outlet pipe (opening)
5 Car compartment 6 Urethane foam 6a Recess

Claims (4)

  A vehicle interior noise reduction device characterized in that a resonator is built in a seat cushion of a vehicle seat using a part of a space for arranging a seat holding member, and an opening of the resonator is communicated with a vehicle interior.   2. The vehicle interior noise reduction device according to claim 1, wherein, when the resonator is built in the seat cushion, it is integrated and incorporated during foam molding of the urethane foam holding the seat holding member.   2. The resonator according to claim 1, wherein when the resonator is incorporated in the seat cushion, the resonator is fixed to the floor side, and the seat cushion is placed from above and is located in the recess on the bottom surface thereof. In-car noise reduction device.   The in-vehicle noise reduction device according to claim 2 or 3, wherein the sheet holding member and the resonator are spaced apart from each other with a predetermined interval.

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