JP2007145080A - Noise reduction mechanism of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noise reduction mechanism of a vehicle capable of reducing both of ventilation resistance at an opening of a grill installed at a ventilation part communicated with an engine room and leakage of noises through the opening with a simple constitution. <P>SOLUTION: A noise reduction part 4 for restraining leakage of noises from an engine room to the outside of a vehicle is arranged on a rear face side seen from an air flowing direction of an opening 3 of a grill 2 provided to a ventilation part communicated with an engine room of the vehicle. The noise reduction part 4 is installed to rotate around a rotary axis along a peripheral edge of the opening 3 according to the pressure of an air passing through the opening 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a noise reduction mechanism that suppresses noise leakage from an engine compartment of a vehicle.

As a noise reduction mechanism for suppressing noise leakage from the engine compartment of the vehicle to the outside of the vehicle, a plurality of louvers having a sound absorbing effect are provided inside the grill frame of the radiator grill in the engine compartment, and bolts attached to each louver are provided. A noise reduction mechanism that can be operated as necessary to adjust the interval between louvers is known (see Patent Document 1). A mechanism is also known in which a movable member is provided on a front grill of a vehicle, and the movable member is driven by a motor to change the opening ratio of the front grill (see Patent Document 2). Patent documents 3 to 6 exist.
Japanese Utility Model Publication No. 5-35888 No. 6-36985 Japanese Utility Model Publication No. 62-37565 Japanese Utility Model Publication No. 6-3691 Japanese Utility Model Publication No. 62-49456 JP 2000-87725 A

  The conventional noise reduction mechanism described above can appropriately change the ventilation resistance of the radiator grill and the noise reduction effect of the louver by changing the interval between the louvers. However, since the adjustment of the louver interval is left to the manual operation by the operator, it is difficult to adjust the noise reduction effect or the ventilation resistance according to the traveling state of the vehicle. A mechanism that changes the aperture ratio using a motor requires a power source, and the mechanism becomes complicated and an increase in cost is inevitable.

  Therefore, the present invention can appropriately change the ventilation resistance of the opening portion of the grill provided in the ventilation portion communicating with the engine compartment and the effect of reducing noise leakage through the opening portion with a simple configuration. An object is to provide a noise reduction mechanism for a vehicle.

  The noise reduction mechanism for a vehicle according to the present invention is a noise that suppresses noise leakage from the engine compartment to the outside of the vehicle as viewed from the air inflow direction of an opening of a grill provided in a ventilation portion communicating with the engine compartment of the vehicle. The reduction component is attached so as to rotate around the rotation axis along the peripheral edge of the opening according to the wind pressure of the air passing through the opening (claim 1). .

  According to the noise reduction mechanism of the present invention, the noise reduction component is rotated by the wind pressure of the air taken in from the surface side of the opening of the grill, whereby the ventilation resistance and the noise reduction effect at the opening of the grill are changed. That is, if the vehicle traveling speed increases, the wind pressure of the air that attempts to pass through the opening of the grill increases accordingly, and the noise reduction component rotates in a direction away from the opening of the grill. Ventilation resistance decreases. Especially when traveling at high speed, the ventilation resistance can be reduced to the maximum and the engine compartment can be efficiently cooled. Even if the noise reduction effect by the noise reduction component is reduced in exchange for the reduction of the ventilation resistance, there is no particular problem because the noise in the engine compartment becomes less problematic as the vehicle traveling speed is higher. On the other hand, if the traveling speed of the vehicle decreases, the wind pressure of the air that attempts to pass through the opening of the grill decreases accordingly, and the noise reduction component rotates so as to approach the opening. When the vehicle is stopped and the engine is operating in the idling rotation range, or when the vehicle is slowing down at an extremely low speed, the noise reduction effect by the noise reduction component is maximized, and the noise generated in the engine compartment is reduced. Leakage outside the vehicle can be minimized. In this case, even if the ventilation resistance of the opening increases, there is no particular problem because the heat generated in the engine compartment is small in the idle operation region. Since the noise reduction component is rotated by the wind pressure of the air passing through the opening, a power source for driving the noise reduction component is not required, and the mechanism is simplified.

  In one embodiment of the present invention, the noise reduction mechanism may include a rotation limiting unit that limits a rotation range of the noise reduction component so as not to close the opening. According to this aspect, since the rotation restricting means prevents the opening from being closed by the noise reduction component, even when the vehicle is stopped or running at an extremely low speed and almost no wind pressure is applied, the rotation restricting means can It is possible to secure a large amount of ventilation.

  In one aspect of the present invention, the noise reduction component includes a sound insulation member having a sound insulation effect with respect to noise generated in the engine room, and a sound absorption member having a sound absorption effect with respect to noise generated in the engine room. (Claim 3). According to this aspect, a combination of the sound insulation member having a sound insulation effect and the sound absorption member having a sound absorption effect can exhibit an effective reduction effect against broadband noise generated in the engine compartment. For example, in a vehicle equipped with an in-cylinder direct injection engine, high-pressure fuel parts such as a high-pressure injector and a high-pressure pump are installed in the engine compartment as engine accessories to inject high-pressure fuel into the cylinder. In addition to the relatively low frequency noise that occurs, the high pressure equipment generates relatively high frequency noise. As a result, broadband noise is generated in the engine compartment. For such broadband noise, the noise reduction effect can be enhanced by using both of the sound insulating member and the sound absorbing member in combination rather than using only one of them.

  In the form in which the sound insulation member and the sound absorption member are provided in the noise reduction component, the rigidity of the sound insulation member may be further increased than the rigidity of the sound absorption member. By increasing the rigidity of the sound insulation member more than that of the sound absorption member, noise with a relatively low frequency is efficiently absorbed by the sound absorption member, while noise with a relatively high frequency is sounded by the sound insulation member, thereby producing broadband noise. In contrast, an effective noise reduction effect can be exhibited.

  In the configuration in which the rigidity of the sound insulating member is higher than that of the sound absorbing member, the sound insulating member may be rotatably attached to the back side of the grill, and the sound absorbing member may be supported by the sound insulating member. ). According to this embodiment, the sound insulation member having high rigidity can be used as a sound insulation countermeasure part, and the structure for connecting the noise reduction part to the grill and the support means for the sound insulation member can be used.

  In the form in which the sound insulation member and the sound absorption member are provided in the noise reduction component, the sound insulation member may be formed of resin. According to this embodiment, by making the sound insulating member resin, it is possible to increase the rigidity of the sound insulating member and produce a sound insulating effect against noise in a high frequency band.

  In one form of the present invention, a plurality of the noise reduction components may be attached to the back side of the grill so that they can rotate independently of each other (Claim 6). According to this aspect, the ventilation resistance of each of the one or more openings provided in the grill is changed by the plurality of noise reduction components. Since each noise reduction component can rotate independently of each other, it is easy to smooth their operation, and no means for linking the operation of the noise reduction component is required, thereby further simplifying the mechanism.

  In one embodiment of the present invention, the grill may be provided such that a back surface thereof faces the engine compartment side (Claim 8). According to this aspect, since the back side of the grill faces the engine compartment side, the noise reduction component is hidden behind the grill when viewed from the outside of the vehicle. Thereby, the influence which noise reduction components have on the design of a grill can be suppressed.

  As described above, according to the noise reduction mechanism of the present invention, the noise reduction component is rotated by the wind pressure of the air passing through the opening of the grill, so that the ventilation resistance and the noise reduction effect according to the traveling speed of the vehicle. Can be changed appropriately to achieve both. Moreover, since a power source such as a motor is not required to rotate the noise reduction component, the mechanism can be simplified.

  1 is a front view of a front grille of a vehicle to which a noise reduction mechanism of the present invention is attached, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is an enlarged view of noise reduction components in FIG. Show. As shown in FIG. 1, the front grill 2 is attached to a ventilation portion that communicates with an engine compartment (not shown) of the vehicle, for example, an opening of a front panel of the vehicle. The front grill 2 is provided with a plurality of openings 3. As shown in FIGS. 2 and 3, in the noise reduction mechanism 1 of the present embodiment, the openings 3 and 1 are arranged on the back side (right side in FIG. 2) of the front grill 2 when viewed from the air intake direction of the opening 3. : 1 is provided in association with the noise reduction component 4. Each noise reduction component 4 includes a flat sound insulating member 5 and a sound absorbing member 6 joined to both surfaces of the sound insulating member 5. The sound insulation member 5 is for generating a sound insulation effect against noise generated in the engine compartment, and one sound insulation member 5 has a size capable of covering one opening 3. On the other hand, the sound absorbing member 6 is for generating a sound absorbing effect against noise generated in the engine compartment, and covers almost the entire front and back surfaces of the sound insulating member 5.

  The sound insulating member 5 and the sound absorbing member 6 may be formed of an appropriate material suitable for their purpose. For example, the sound insulating member 6 is made of a soft sound absorbing material used for absorbing engine room noise. In addition, the sound insulation member 5 is formed of a material having higher rigidity than the sound insulation member 6. For example, when the sound insulation member 5 is made of resin, a sufficient sound insulation effect can be exhibited against noise in a high frequency range (for example, 5 kHz to 20 kHz) generated in the engine room. In particular, in a cylinder direct-injection engine, an effective sound insulation effect can be obtained against noise generated by high-pressure fuel components such as a high-pressure injector and a high-pressure pump.

  The sound insulation member 5 of the noise reduction component 4 is a rear surface side of the front grill 2 in a state of being rotatable around the center line of the hinge shaft 7 extending in the left-right direction along the peripheral edge of the opening 3, here the upper edge. Is attached. The sound insulation member 6 rotates around the hinge shaft 7 integrally with the sound insulation member 5 while being supported by the sound insulation member 5. In other words, in this embodiment, the sound insulation member 5 having high rigidity is functioned as a sound insulation countermeasure part, and the structure for connecting the noise reduction part 4 to the front grille 2 and a support means for the sound insulation member 6 are used. ing. Further, on the back side of the front grill 2, a rotation range in the direction in which the noise reduction component 4 approaches the front grill 2 (the direction of arrow A in FIG. 3) is set so that the noise reduction component 4 does not close the opening 3. A stopper 8 is provided as rotation limiting means for limiting. The stopper 8 is fixed to the front grill 2 and its position is unchanged. At the position where the noise reduction component 4 is in contact with the stopper 8, there is some gap between the noise reduction component 4 and the opening 3. As a result, even when the vehicle is stopped or traveling at an extremely low speed and the wind pressure of the air passing through the opening 3 hardly acts, the front of the air necessary for the minimum heat exchange between the engine compartment and the outside of the vehicle is obtained. It can be taken into the engine compartment from the grill 2.

  According to the noise reduction mechanism 1 as described above, the noise reduction component 4 rotates around the center line of the hinge shaft 7 according to the wind pressure of the air passing through the opening 3 of the front grill 2. Thereby, according to the speed of a vehicle, the ventilation resistance of the opening part 3 and the noise reduction effect of the noise reduction component 4 can be changed appropriately. For example, when the vehicle is stopped or traveling at a very low speed, the wind pressure of the air passing through the opening 3 is not at all or very small, so the noise reduction component 4 approaches the front grill 2. It rotates in the direction of arrow A in FIG. 3 and is held at a position where it comes into contact with the stopper 3. In this state, since the gap amount between the opening 3 and the noise reduction component 4 is the smallest, the noise reduction effect is maximized. Accordingly, it is possible to effectively suppress the leakage of engine room noise during idling to the outside of the vehicle. Although the ventilation resistance of the air passing through the opening 3 is increased, there is no particular problem because the heat generated by the engine is small when the vehicle is stopped or running at an extremely low speed. On the other hand, the wind pressure of the air passing through the opening 3 increases as the traveling speed of the vehicle increases, and accordingly, the noise reduction component 4 moves away from the front grille 2 around the hinge shaft 7 (in the direction of arrow B in FIG. 3). ). Thereby, the ventilation resistance of the opening part 3 decreases, and an amount of air commensurate with an increase in the heat generation amount of the engine can be taken into the engine compartment. In particular, when the engine generates a large amount of heat, the engine can be efficiently cooled by reducing the ventilation resistance to the maximum. The noise reduction effect by the noise reduction component 4 (especially the sound insulation effect by the sound insulation member 5) is reduced in exchange for the reduction of the ventilation resistance, but the noise in the engine compartment becomes less worrisome as the traveling speed increases. Absent.

  According to this embodiment, since the noise reduction component 4 is attached to the back side of the front grill 2, the noise reduction component 4 is hidden behind the front grill 2 when viewed from the front of the vehicle. Therefore, there is an effect that the design of the front grille 2 is not impaired.

  Furthermore, in this embodiment, the noise reduction component 4 is individually arranged for each of the plurality of openings 3 and the noise reduction component 4 can be rotated independently of each other. Can move freely, and since the inertial mass of the moving part is small, the operation can be easily smoothed. There is no mechanism for operating the noise reduction components 4 in cooperation with each other, and the mechanism is further simplified. In the above embodiment, the noise reduction component 4 is provided at a ratio of 1: 1 with respect to the opening 3. However, a plurality of noise reduction components may be provided in one opening, or the two or more openings may be straddled. In this way, one noise reduction component may be provided.

  This invention is not limited to the form mentioned above, It can implement with a various form. For example, the noise reduction component is not limited to the front grille of the vehicle, but can be provided in a ventilation portion at various positions leading to the engine compartment of the vehicle. For example, the noise reduction mechanism of the present invention can be provided in a grill of an air passage that leads to an engine room provided at the center or rear of the vehicle. The grill is not limited to the one provided in the ventilation portion for taking air into the engine compartment, and may be provided in the ventilation portion for exhausting air from the engine compartment. In the above embodiment, the rotation axis of the noise reduction component (center line of the hinge shaft 7) is installed above the noise reduction component, and is rotated in the direction approaching the grille using the weight of the noise reduction component. The rotation center line may be directed in the vertical direction. A rotation center line may be set below the noise reduction component. A spring for urging the noise reduction component in a direction approaching the grill may be added, and the noise reduction component may be configured to rotate away from the grill against the spring force when the vehicle is running. .

The front view of the front grille of the vehicle to which the noise reduction mechanism of the present invention is applied. Sectional drawing along the II-II line of FIG. The enlarged view of the noise reduction component shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Noise reduction mechanism 2 Grille 3 Opening part 4 Noise reduction parts 5 Sound insulation member 6 Sound absorption member 8 Stopper (rotation restriction means)

Claims (8)

  A noise reduction part that suppresses leakage of noise from the engine compartment to the outside of the vehicle passes through the opening on the back side as viewed from the air inflow direction of the opening of the grill provided in the ventilation section communicating with the engine compartment of the vehicle. A vehicle noise reduction mechanism, wherein the vehicle noise reduction mechanism is mounted so as to rotate around a rotation axis along the periphery of the opening in accordance with the wind pressure of air.   The noise reduction mechanism according to claim 1, further comprising a rotation restriction unit that restricts a rotation range of the noise reduction component so as not to close the opening.   The noise reduction component includes: a sound insulation member having a sound insulation effect with respect to noise generated in the engine room; and a sound absorption member having a sound absorption effect with respect to noise generated in the engine room. The noise reduction mechanism according to claim 1 or 2.   The noise reduction mechanism according to claim 3, wherein a rigidity of the sound insulation member is higher than a rigidity of the sound absorption member.   5. The noise reduction mechanism according to claim 4, wherein the sound insulating member is rotatably attached to a rear surface side of the grill, and the sound absorbing member is supported by the sound insulating member.   The noise reduction mechanism according to any one of claims 3 to 5, wherein the sound insulation member is made of resin.   The noise reduction mechanism according to any one of claims 1 to 6, wherein a plurality of the noise reduction components are attached to the back side of the grill so as to be able to rotate independently of each other. The noise reduction mechanism according to any one of claims 1 to 7, wherein the grill is provided so that a back surface thereof faces the engine compartment side.

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