JP2010209821A - Engine sound adding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a harmonious engine sound in a cabin by efficiently converting vibration generated by intake pulsation into sound by a comparatively simple structure. <P>SOLUTION: A box-shaped member 2 is placed in an intake duct 1, and one wall surface 3a of the box-shaped member 2 is composed of an outwardly bulging curved surface in order to reduce the in-plane rigidity thereof. Wall surfaces 3b made to serve as side surfaces when the wall surface 3a is regarded as an upper surface are composed of planar surfaces. Thereby, the wall surface 3a as the curved surface is subjected to in-plane deformation. With the in-plane deformation of the wall surface 3a, the wall surfaces 3b as the planar surfaces are subjected to wide out-of-plane deformation to produce the sound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sound adding device for an automobile engine that efficiently converts vibration caused by intake pulsation into sound and produces a pleasant engine sound in a passenger compartment.

  As a conventional sound adding device for an automobile engine, as disclosed in Patent Document 1, a resonance tube and a vibrating body are connected to an intake system, and a sound wave having a specific frequency is amplified by the resonance and the resonance frequency. It is known that it is configured to deliver powerful intake sound.

  Further, in Patent Document 2, as an intake noise reduction device, among the constituent walls of an intake resonator having a substantially rectangular parallelepiped shape, at least a side wall opposite to an intake passage side wall having an opening to the intake passage is curved. It has been disclosed to reduce the intake radiated sound by suppressing the membrane vibration of the opposing side wall even if the constituent wall of the intake resonator is thinned by improving the shape and rigidity.

JP 2007-170228 A Japanese Utility Model Publication No. 63-104666

  However, the conventional technique described in Patent Document 1 suddenly increases the sound at a specific engine speed, and feels strange. Since the resonance mechanism and resonance frequency of the resonance tube and the vibrating body are used as an amplification mechanism, only a specific frequency is amplified. As a result, sudden noise becomes loud at the engine speed at which the intake sound explosion component matches the emphasized frequency. Because it becomes.

  There is also a problem with the ease of mounting in an engine room where space is limited. This is because since the resonance of the tube is used, the length of the tube is required to amplify a desired frequency.

  The prior art described in Patent Document 2 attempts to reduce the intake radiated sound (membrane vibration) by increasing the rigidity of the box-shaped member that constitutes the resonator. It does not attempt to convert and convert sound characteristics.

  In view of such a situation, the present invention has an object to provide an engine sound adding device that converts vibration caused by intake pulsation into sound efficiently with a relatively simple configuration and produces a pleasant engine sound in the passenger compartment. And

  In order to solve the above-mentioned problems, the present invention is configured such that one wall surface of a box-shaped member installed in an intake passage is configured with a curved surface that bulges outward so as to reduce the in-plane rigidity thereof. When the wall surface is the top surface, the side wall surface is configured as a flat surface, and the side wall surface vibrates due to intake pressure fluctuation and generates a sound.

  According to the present invention, by configuring one wall surface of the box-shaped member with a curved surface that bulges outward, the out-of-plane rigidity is increased while the in-plane rigidity is decreased. For this reason, the wall surface constituted by the curved surface is deformed in the plane by the intake pulsation, and accordingly, the entire wall surface serving as the side surface is deformed out of the plane and pronounced. Therefore, it is greatly deformed by the intake pulsation and can be efficiently converted into sound.

Schematic showing one embodiment of the present invention along with its deformation modes Schematic showing a reference example with its deformation mode The figure which shows the frequency-inertance characteristic by embodiment same as the above Schematic showing another embodiment of the present invention together with its deformation mode

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1A shows an embodiment of the present invention.

  A box-shaped member 2 as a sound adding device is installed in a direction intersecting with a flow direction of intake air with respect to an intake passage of an automobile engine, particularly an intake duct 1 between an air cleaner and a throttle chamber.

  The box-shaped member 2 as the sound adding device is made of, for example, a resin, and includes a wall surface 3a, and a wall surface 3b serving as a side surface when the wall surface 3a is an upper surface, and a wall surface 3c serving as a bottom surface. Therefore, hereinafter, for convenience, the wall surface 3a is referred to as “upper wall surface 3a”, the wall surface 3b is referred to as “side wall surface 3b”, and the wall surface 3c is referred to as “bottom wall surface 3c”.

  An opening 4 is formed in the central portion of the bottom wall surface 3 c of the constituent wall surfaces of the box-shaped member 2, and the opening 4 coincides with the opening formed in the passage wall of the intake duct 1. It becomes a communication part with.

  Here, among the constituent wall surfaces of the box-shaped member 2, the upper wall surface 3a is configured by a curved surface that bulges outward, and the other side wall surfaces 3b and the bottom wall surface 3c are configured by planes.

  The case where the wall surface has a curved surface as shown in FIG. 1A will be described in comparison with the case where the wall surface is only a flat surface as shown in FIG.

  As shown in FIG. 2A, when the wall surface is only a plane (when the upper wall surface 3a ′ is also a plane), the plane has low out-of-plane rigidity and the ridge line has high rigidity and does not deform. As shown in the deformation mode in B), only the central portion of each plane is deformed, the deformation amount is small, and the sound generation amount is also small.

  In contrast, as shown in FIG. 1A, when the wall surface has a curved surface (when the upper wall surface 3a is a curved surface), the curved surface has high out-of-plane rigidity and low in-plane rigidity. For this reason, as shown in the deformation mode in FIG. 2 (B), the upper wall surface 3a formed of a curved surface is deformed in-plane due to the intake pressure fluctuation accompanying the intake pulsation, and accordingly, the entire side wall surface 3b is a surface. Transform outside and pronounce. In particular, the side wall surface 3b vibrates greatly around the ridge line with the bottom wall surface 3c. Therefore, it is greatly deformed by the intake pulsation and the sound generation amount becomes large.

  In this way, a desired sound can be produced by radiating sound / vibration from the side wall surface 3b by greatly vibrating the side wall surface 3b constituted by a plane.

  In particular, in the present embodiment, a linear engine sound that emphasizes the engine intake sound over a wide range of engine speeds is realized using the rigidity of the box-shaped member 2 installed in the intake passage 1.

  The structure using resonance and resonance can emphasize only a specific frequency, and it is inevitable that sudden noise increases when the number of rotations to be enhanced is reached. Therefore, in this embodiment, a sound emphasizing system using stiffness instead of resonance is provided.

  Unlike resonance, where the level of a single frequency is increased, if rigidity reduction is used, the level (spring line) at a lower frequency than resonance is uniform in rigidity reduction, as shown in the frequency-inertance characteristic in FIG. Change. From this, it is possible to emphasize a wide range of frequencies by utilizing rigidity, and therefore, it is possible to enhance the intake sound at a wide range of engine speeds and realize a linear engine sound. Therefore, in this embodiment, linear engine sound is realized by adjusting the rigidity of the box-shaped member 2 newly installed in the intake duct 1.

  For example, in the V6 engine, the primary explosion component is 300 Hz at 6000 rpm, so if the rigidity is lowered and the resonance frequency of the wall is set to around 350 Hz, the intake line can be emphasized at all engine speeds by increasing the spring line. It becomes possible.

  In other words, by emphasizing the spring line of the wall surface inertia of the box-shaped member having the wall surface of the vehicle intake system, the sound enhancement is realized in a wide range of frequencies.

  Under such a technical idea, in order to efficiently convert the vibration of the box-shaped member into sound, the upper wall surface 3a of the box-shaped member 2 has a curved surface structure as described with reference to FIG. The curved surface structure has high out-of-plane rigidity and low in-plane rigidity. Therefore, the upper wall surface 3a of the curved surface configuration is deformed so as to be pulled by the side wall surface 3b due to the intake pulsation, and the side wall surface 3b is greatly deformed accordingly, so that the intake pulsation can be efficiently converted into sound. is there.

  As an incidental effect of the configuration of the present embodiment, unlike a device that uses the resonance of a conventional tube, the structure does not use a length, and thus there are few space restrictions and excellent mountability.

  Further, the curved surface structure has high out-of-plane rigidity, and can be compatible with reliability.

  Further, in order to prevent a sudden increase in sound pressure due to resonance, the resonance of the box-shaped member is also advantageous in that it is sufficiently attenuated and does not have peak characteristics.

  In the above embodiment, the upper wall surface of the box-shaped member is configured with a curved surface, but the other wall surface can be configured with a curved surface to exhibit the same effect. However, when the wall surface configured by this curved surface is the upper surface, at least one of the wall surfaces serving as the side surfaces is configured as a flat surface.

  In the above embodiment, the installation place of the box-shaped member is the intake duct, but it is not limited to this, and it may be any place in the intake passage regardless of the clean side or the dirty side. Even if attached, the same effect can be exhibited.

  In the above embodiment, a box-shaped member is newly installed as a sound adding device in the intake passage (intake duct 1). However, the wall surface of an existing box-shaped member such as a resonator (resonance silencer) or an air cleaner is used. By adopting a curved surface structure, vibrations due to intake pulsation may be efficiently converted into sound, and a comfortable engine sound may be produced in the passenger compartment.

  When using existing box-type members such as resonators and air cleaners, the wall surface should be curved, and if necessary, the rigidity should be reduced by reducing the plate thickness or eliminating reinforcing ribs. It is good to consider. At this time, by making the wall surface a curved surface, the out-of-plane rigidity can be made higher than that in the case of a flat surface, so that deterioration of reliability due to the reduced rigidity can be suppressed.

  When the resonator is used as a box-shaped member, the basic structure is the same as that shown in FIG. 1 except that the communication part 4 has a certain length as a neck part.

  When the air cleaner is used as a box-shaped member, it becomes as shown in the embodiment of FIG.

  That is, the box-shaped member 5 constituting the air cleaner is composed of an upper wall surface 6a, a side wall surface 6b, and a bottom wall surface 6c.

  Here, among the constituent wall surfaces of the box-shaped member 5, the upper wall surface 6a is configured by a curved surface that bulges outward, and the other side wall surfaces 6b and the bottom wall surface 6c are configured by planes.

  The box-shaped member 5 constituting the air cleaner is arranged in series so as to constitute a part of the intake passage, and the wall surface constituted by the curved surface is arranged substantially parallel to the flow direction of the intake air. Therefore, the intake air flows in a direction orthogonal to the paper surface in FIG.

  Even in such a configuration, as shown in the deformation mode in FIG. 4B, the upper wall surface 6a formed of a curved surface is deformed in-plane due to the intake pressure fluctuation accompanying the intake pulsation. The entire side wall surface 6b is deformed out of the surface and pronounced. In particular, the side wall surface 6b vibrates greatly around the ridge line with the bottom wall surface 6c. Therefore, it is greatly deformed by the intake pulsation and the sound generation amount becomes large. Therefore, the same effect as that of the embodiment of FIG. 1 can be obtained.

  When an air cleaner or the like is used, not only radiated sound but also vibrations to the body can be transmitted efficiently.

DESCRIPTION OF SYMBOLS 1 Air intake duct 2 Box-shaped member as a sound addition apparatus 3a Upper wall surface (curved surface)
3b Side wall surface 3c Bottom wall surface 4 Opening part (communication part)
5 Box-shaped member constituting the air cleaner 6a Upper wall surface (curved surface)
6b Side wall surface 6c Bottom wall surface

Claims (6)

  One wall surface of the box-shaped member installed in the intake passage is formed of a curved surface that bulges outward so as to reduce the in-plane rigidity thereof, while the wall surface serving as a side surface when the wall surface is the upper surface Is a plane, and the wall surface serving as the side surface vibrates and generates sound due to fluctuations in intake pressure.   The engine sound adding device according to claim 1, wherein the wall surface serving as the side surface vibrates around a ridge line with the wall surface serving as the bottom surface.   3. The engine according to claim 1, wherein the box-shaped member is disposed in a direction crossing the intake flow direction with respect to the intake passage, and communicates with the intake passage on a wall surface serving as a bottom surface. Sound addition device.   4. The engine sound adding device according to claim 3, wherein the box-shaped member also serves as a resonator.   The box-shaped member is arranged in series so as to constitute a part of the intake passage, and the wall surface formed by the curved surface is arranged substantially parallel to the flow direction of intake air. The engine sound adding device according to claim 2.   6. The engine sound adding device according to claim 5, wherein the box-shaped member also serves as an air cleaner.

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