JP4673106B2 - Engine sound introduction structure for vehicles - Google Patents

Description

  The present invention relates to an engine sound introduction structure that introduces intake sound of a vehicle engine into a passenger compartment.

For passenger cars and other vehicles, in order to respond to user preferences, the intake sound generated by the intake system in which the engine inhales outside air is actively introduced into the passenger compartment where the passengers live, creating a sense of sportiness and high performance. It is known to do.
For example, it is known that a flexible tube branched from a part of an intake duct connected to the intake side of the engine is provided and the other end is connected to a bulkhead between the engine room and the passenger compartment. (For example, Patent Document 1).
JP 2004-218458 A

However, while the engine intake noise and the vibration sound resulting from the explosion in the cylinder include a wide range of frequency components, the effective frequency band for production in the passenger compartment is limited to a specific frequency, for example, near 250 Hz. Therefore, when the sound generated by the intake duct is introduced as it is into the vehicle compartment as in the above-described prior art, an unnecessary frequency component may be included to give the user an impression of simple noise.
In view of the above-described problems, an object of the present invention is to provide a vehicle engine sound introduction structure that effectively introduces a specific frequency component.

The present invention solves the above-described problems by the following means.
According to a first aspect of the present invention, there is provided a vibrating body that is vibrated by vibration caused by a vehicle engine and amplifies a component of a specific frequency band of the vibration relative to a component of another frequency band, A body panel part constituting a part of the passenger compartment, and a vibration transmitting part connected to the vibrating body and the body panel part at both ends thereof, and transmitting the vibration of the vibrating body to the body panel part by individual propagation; The connection portion of the body panel portion with the vibration transmission portion is disposed at a location showing a vibration mode of a frequency included in the specific frequency band when the body panel portion is vibrated, and the vibration transmission The unit is an engine sound introduction structure for a vehicle, wherein the natural frequency is included in the specific frequency band .

Invention 請 Motomeko 2, in the engine sound introduction structure of claim 1, wherein the vibrating body of the vehicle via a displacement absorbing member having flexibility and being connected to said engine engine Sound introduction structure.
According to a third aspect of the present invention, in the engine sound introduction structure according to the first or second aspect , the vibration transmitting portion is responsive to a relative displacement between the vibrating body and the body panel caused by the displacement of the engine. An engine sound introduction structure for a vehicle, comprising a connecting portion that deforms.
According to a fourth aspect of the present invention, in the engine sound introduction structure according to any one of the first to third aspects, the vibrating body is a resonance chamber provided in an intake pipe of the engine. This is an engine sound introduction structure for a vehicle.

According to the present invention, the following effects can be achieved.
(1) Since a vibration body that emphasizes a component of a specific frequency band of vibration caused by the engine of the vehicle is provided and the vibration of this vibration body is transmitted to the body panel portion by individual propagation, the frequency characteristics of the vibration body are By appropriately tuning, a desired frequency component can be effectively introduced.
(2) Since the vibration transmission unit is connected to a portion showing the vibration mode of the frequency included in the specific frequency band of the body panel, resonance occurs when the vibration transmission unit vibrates the body panel, and this frequency component is further increased. The sound pressure that is emphasized and introduced into the vehicle can be increased.
(3) Since the natural frequency of the vibration transmitting unit is included in the specific frequency band, when the vibration from the vibrating body is transmitted to the body panel unit side, the frequency component corresponding to the natural frequency is further increased. be able to.
(4) Since the vibrating body is connected to the engine via the displacement absorbing member, when the vibrating body is fixed to the body panel side, the engine is deformed with respect to the vehicle body by deformation of the engine mount that is usually formed by an elastic body. This displacement can be absorbed even if it is displaced.
(5) Since the vibration transmitting portion includes the deformable connecting portion, the displacement of the engine relative to the vehicle body when the vibrating body is fixed to the engine side can be absorbed.
(6) Since the vibrating body is a resonance chamber provided in the intake pipe of the engine, any frequency component can be emphasized by tuning its size and surface rigidity. In addition, since such a resonance chamber can use existing components such as an air cleaner case, a resonator, a side branch, a throttle chamber, and a surge tank provided in the intake pipe of the engine, it can be easily applied to a vehicle. It is.

  The object of the present invention is to provide a vehicle engine sound introduction structure that effectively introduces a specific frequency component by providing a stay that transmits the vibration of a chamber having a specific natural frequency to a toe board by solid propagation. It was realized.

A first embodiment of an engine sound introduction structure to which the present invention is applied will be described below with reference to the drawings.
1 and 2 are schematic views showing the configuration of the engine sound introduction structure of the first embodiment, and are views showing a state seen from a side surface side and an upper side of the vehicle, respectively. FIG. 3 is an external perspective view of the engine.

The vehicle 1 is, for example, a sedan type or a station wagon type passenger car, and includes a cabin (vehicle compartment) 110, an engine room 150, a power train 200, and an engine sound introduction unit 300.
The cabin 110 is a room in which a passenger is accommodated, and is formed by a toe board 111, a bulkhead 112, a floor panel 113, a floor tunnel 114, and the like, and a dashboard 115, a steering shaft 116, a steering support beam. 117.

  The toe board (body panel portion) 111 is provided at the front end portion of the cabin 110, and is a partition wall that partitions the cabin 110 and the engine room 150, and is provided at a position corresponding to the feet of the front seat passenger and the upper portion thereof. Yes. In addition, a sound insulating material (insulator) 111 a is partially attached to a surface portion of the toe board 111 on the vehicle inner side.

The bulkhead 112 is a tray-like member that protrudes from the upper portion of the toe board 111 toward the engine room 150 and opens upward, and includes a space portion that accommodates a wiper motor (not shown) therein.
The floor panel 113 is a floor surface portion of the cabin 110, and is continuously formed extending from the lower end portion of the toe board 111 to the rear side of the vehicle.
The floor tunnel 114 is formed such that a center portion of the floor panel 113 in the vehicle width direction is recessed in the vehicle interior and extends in the vehicle front-rear direction, and will be described later in a space portion formed below the floor tunnel 114. A rear portion of the transmission 230, a propeller shaft extending to the rear side of the vehicle, an exhaust pipe, and the like are accommodated.
The toe board 111, the bulkhead 112, the floor panel 113, and the floor tunnel 114 described above are formed by pressing a steel plate, and each constitutes a part of the vehicle body monocoque.

The dashboard 115 is provided on the inner surface of the toe board 111 and accommodates an air conditioner, instruments, audio equipment, an SRS passenger seat airbag, etc. (not shown). It is formed along the lower end portion of the windshield, and the lower end portion side opens to the vehicle interior side.
The steering shaft 116 is a rotating member that connects a steering wheel and a steering gear box (not shown), and a part of the steering shaft 116 is disposed in the dashboard 115 described above.
The steering support beam 117 is a beam-like structural member provided in the dashboard 115 and provided in the vehicle width direction, and supports the steering shaft 116 and other components not shown.

  The engine room 150 is provided on the front side of the vehicle with respect to the cabin 110 and includes a space in which the power train 200 is accommodated.

  The power train 200 includes an engine body 210, an intake system 220, and a transmission 230.

  The engine body 210 is, for example, a four-stroke gasoline engine, for example, a horizontally opposed four-cylinder naturally aspirated engine. However, the type of the engine is not limited to this, and an explosion or intake pulsation in the combustion chamber occurs during operation. Any device that generates periodic vibrations due to exhaust pulsation, other mechanical vibrations, or the like may be used.

  The intake system 220 includes an intake duct 221, a resonator 222, an air cleaner case 223, a side branch 224, a chamber 225, a throttle body 226, and an intake manifold 227.

The intake duct 221 is provided with an intake port that is open to the outside at one end thereof, and the other end is connected to the air cleaner case 223 and communicates with the inside thereof.
The resonator 222 is a container-like member connected to an opening (not shown) formed in the side wall portion of the intake duct 221, and uses a pressure fluctuation in the intake duct 221 caused by intake pulsation or the like as a vibration source. It functions as a resonance chamber and is used for tuning the intake sound.
The air cleaner case 223 is formed in a container shape, and accommodates therein an air cleaner element (not shown) that filters fine dust and the like contained in the intake air.
The branch pipe 224 is provided by branching from the intake pipe between the air cleaner case 223 and the chamber 225, and the pipe is closed at the tip, and utilizes the air column resonance generated inside the branch pipe 224. It is used for tuning the intake sound.
The chamber 225 is a resonance chamber which is provided in the middle of the intake pipe line between the air cleaner case 223 and the throttle body 226 and is formed in a container shape by a material such as resin, for example, and exhibits a known resonance supercharging effect. By doing so, the output of the engine main body 210 is improved. The chamber 225 is disposed at an upper portion of the engine main body 210 and at a front portion of the toe board 111 of the vehicle body 100, and is fixed to the toe board 111 by a stay described later.
The throttle body 226 is provided between the chamber 225 and the intake manifold 227, and accommodates a throttle valve that limits the intake air amount of the engine 210 in accordance with an operation of an operation unit such as a throttle pedal (not shown). It should be noted that at least a part of the duct connecting the throttle body 226 and the chamber 225 is made flexible by an elastic material such as silicon rubber, for example, and accompanies elastic deformation of an engine mount (not shown). The displacement absorbing member absorbs the displacement of the engine body 210 with respect to the vehicle body 100.
The intake manifold 227 is connected to the downstream side of the throttle body 226 and includes branch pipes respectively connected to intake ports of cylinders (not shown) of the engine 210.

  The transmission 230 is coupled to a rigid side by a plurality of bolts (not shown) on the rear side of the engine body 210, and a transmission unit that decelerates or increases the rotational output of the engine body 210, and a transfer unit that distributes the output of the transmission unit to the front and rear wheels. The front differential part for transmitting the rotational output of the transfer part to the drive shafts of the left and right front wheels is accommodated in the same case.

The engine sound introduction unit 300 includes a stay 310 for fixing the chamber.
FIG. 4 is an external perspective view of the stay 310.
The stay 310 is a vibration transmission unit that is provided between the chamber 225 of the engine intake system 220 and the toe board 111 of the vehicle body 100 and transmits the vibration of the chamber 225 to the toe board 111 side by solid propagation.
The stay 310 is formed by pressing a steel plate, for example, and includes a chamber side connection portion 311, an intermediate portion 312 and a toe board side connection portion 313 in order from the vehicle front side.

The chamber-side connection portion 311 includes a surface portion that is disposed substantially horizontally in contact with the lower surface portion of the chamber 225. In addition, the surface portion is formed with a pair of bolt holes 311a formed apart from each other in the vehicle width direction, and the stay 310 is arranged on the lower surface portion of the chamber 225 by inserting a fixing bolt (not shown) into the bolt hole 311a. The chamber 225 is fixed by fastening to a nut portion (not shown).
The intermediate portion 312 is formed continuously from the rear end portion of the chamber side connection portion 311 described above, and includes a surface portion that extends in the front-rear direction of the vehicle and is disposed substantially horizontally. A joint portion between the intermediate portion 312 and the chamber side connection portion 311 is bent in a step shape, and the intermediate portion 312 is disposed at a lower position than the chamber side connection portion 311.
The toe board side connection part 313 is formed by bending the rear end part of the intermediate part 312 downward, and has a surface part that comes into contact with the front surface of the toe board 111. The surface portion is formed with a pair of bolt holes 313a that are formed apart from each other in the vehicle width direction, and is fixed to the toe board 111 by being fastened to a nut portion (not shown) disposed on the interior side of the toe board 111. Is done.
As shown in FIG. 1, the connecting portion between the toe board 111 and the stay 310 is provided in a region inside the dashboard 115 and below the steering support beam 117 when viewed from the cabin 110 inside. Note that the insulator 111 a attached to the surface of the toe board 111 on the vehicle interior side is disposed avoiding the vicinity of the connection portion with the stay 310.

Next, the vibration frequency characteristics of the above-described chamber 225, toe board 111, and stay 310 will be described below.
FIG. 5 is an external perspective view of the chamber 225 as viewed from the lower surface side. As shown in FIG. 5, the chamber 225 is provided with a stay connecting portion 225 a to which the front end portion 311 of the stay 310 is fixed in a partial range of the lower surface thereof.
FIG. 6 is a graph showing an example of the frequency characteristics of the vibration of the surface of the chamber 225 in the region A in the vicinity of the stay connection portion 225a during operation of the engine body 210. The horizontal axis represents frequency and the vertical axis represents sound pressure. Show.

When the engine main body 210 is operated, the air in the chamber 225 is vibrated by the intake pulsation caused by the air sucked into the combustion chamber from the intake port intermittently flowing by opening and closing of the intake valve. At this time, the surface portion of the chamber 225 is also vibrated and vibrated by this air, but this frequency characteristic can be tuned to some extent by adjusting the shape, structure, size, surface rigidity, etc. of the chamber 225.
As shown in FIG. 6, in the present embodiment, in the region A in the vicinity of the stay connecting portion 225a of the chamber 225, for example, the natural frequency nf of the natural vibration mode exists in the vicinity of 250 Hz, and the components in this frequency band are the other components. The chamber 225 is designed to be emphasized relative to the frequency components of
Note that such a frequency is set in consideration of, for example, a rendering effect that appeals the driver to the high-performance feeling of the vehicle, and may be another frequency.

FIG. 7 is a graph showing an example of the natural vibration mode of the entire toe board 111, where the horizontal axis represents frequency and the vertical axis represents sound pressure. FIG. 8 is a schematic diagram showing the toe board 111 as viewed from the front side of the vehicle.
As shown in FIG. 7, when the toe board 111 is vibrated and vibrated, it can be seen that a peak Pt exists in the vicinity of 250 Hz, which is substantially the same as the frequency emphasized in the region A of the chamber 225 described above. Therefore, the toe board 111 has a portion showing a vibration mode having a frequency in the vicinity of 250 Hz in a partial region thereof.
Such a location can be found by oscillating the toe board 111 and observing the vibration mode over the surface using a Doppler velocimeter or the like.
As shown in FIG. 8, when a frequency mode in the vicinity of 250 Hz is detected in the upper part of the notch 111a to which the floor tunnel 114 of the toe board 111 is connected and offset in the vehicle width direction. The region B is designed to be provided with a connecting portion with the stay 310.

FIG. 9 is a graph showing the characteristic of the natural vibration of the stay 310. In this graph, the stay 310 is suspended by a rubber string or the like and hammered, and the inertia is detected by an accelerometer.
As shown in FIG. 9, the natural frequency of the stay 310 is set, for example, in the vicinity of 250 Hz that is substantially the same as the frequency emphasized in the region A of the chamber 225.

Next, the operation of the engine sound introduction structure of this embodiment will be described.
When the engine main body 210 is started, intake pulsation due to the intermittent intake described above in the intake port is generated, and this intake pulsation is propagated to the chamber 225 via the intake manifold 227 and the throttle body 226, and the chamber 225 The surface portion of the plate is vibrated and vibrated acoustically.
As described above, the chamber 225 has a natural frequency in the vicinity of 250 Hz in the vicinity of the connection portion with the stay 310, so that the frequency component in the vicinity of 250 Hz is emphasized relative to other frequency components by resonance.
The stay 310 is vibrated by the vibration of the surface portion of the chamber 225, and the stay 310 transmits the vibration of the surface portion of the chamber 225 to the toe board 111 side by solid propagation. At this time, since the natural frequency of the stay 310 is set in the vicinity of 250 Hz, resonance also occurs here, and the frequency component in the vicinity of 250 Hz is further emphasized.
The toe board 111 is vibrated by the vibration transmitted from the stay 310 by the solid propagation. Since the connection portion of the toe board 111 with the stay 310 is provided at a location showing a natural vibration mode near 250 Hz, resonance also occurs here, and the frequency component near 250 Hz is further emphasized. Then, the air in the cabin 110 is vibrated by such vibration of the toe board 111, and the vibration of the air is diffused into the vehicle from the lower side of the dashboard 115 by acoustic propagation, thereby causing the engine in the cabin 110. Intake sound is introduced.

As described above, according to this embodiment, the following effects can be obtained.
(1) The stay 310 is vibrated by the surface portion of the chamber 225 that emphasizes a component in a specific frequency band near 250 Hz from the intake sound of the engine main body 210, and the stay 310 vibrates the toe board 111 by solid propagation. Since sound is introduced into 110, engine sound having such a specific frequency component can be effectively introduced.
(2) Since the portion where the toe board 111 is vibrated by the stay 310 is provided in the portion showing the vibration mode in the frequency band near 250 Hz, such a frequency component is further emphasized by the resonance, and the cabin 110 The sound pressure of the introduced engine sound can be increased.
(3) Since the natural frequency of the stay 310 is set in the vicinity of 250 Hz, resonance occurs when the vibration of the chamber 225 propagates through the solid, and such frequency components can be further emphasized.
(4) Since the chamber 225 is connected to the throttle body 260 fixed to the engine body 210 via a flexible duct, the chamber 225 absorbs the displacement of the engine body 210 due to the elastic deformation of the engine mount, Input to the chamber 225 and the stay 310 can be reduced.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention.
(1) In the embodiment described above, a chamber is used as a vibrating body and this vibration is transmitted to the passenger compartment side by solid propagation. However, the present invention is not limited to this. For example, a resonator, an air cleaner case, a side branch, a surge tank, etc. Other members capable of tuning frequency characteristics may be used as the vibrator.
(2) The shape of the vibration transmitting portion is not limited to the stay of the embodiment, and may be other shapes and structures. For example, instead of the plate-like stay, the stay may be formed by a bar having a circular or polygonal cross-sectional shape. Further, such a stay may be hollow. Further, it may be a metal bracket formed by sheet metal processing or casting, a resin bracket formed by injection molding or the like.
(3) In the embodiment, for example, a frequency band near 250 Hz is emphasized and produced, but such a frequency may be changed and a plurality of engine sound introduction structures each having different frequency characteristics May be used in combination.
(4) In the embodiment, the vibration body (chamber) is fixed to the vehicle body, and the displacement of the engine is absorbed by providing a flexible member between the vibration body and the engine. The vibration body is fixed to the engine so as to follow the displacement of the engine, and a connecting portion having a function of solidly propagating vibration such as a ball joint or a slide mechanism is provided in a part of the vibration transmitting portion, and the bending thereof Alternatively, the displacement of the engine may be absorbed by deformation such as expansion and contraction.
(5) Although the toe board is used as the body panel portion that is vibrated by the vibration transmitting portion in the embodiment, the present invention is not limited thereto, and may be other members such as a floor panel.
(6) The engine in the embodiment is a four-stroke four-cylinder gasoline engine, but may be an engine using an alternative fuel such as CNG, methanol, hydrogen, or a diesel engine. Furthermore, the number and arrangement of cylinders are not limited to this, and may be a Wankel rotary engine or the like.

It is the schematic which shows the structure of Example 1 of the engine sound introduction structure to which this invention is applied, Comprising: It is a figure which shows the state seen from the side surface side of the vehicle. It is the schematic which shows the structure of the engine sound introduction structure of FIG. 1, Comprising: It is a figure which shows the state seen from the upper direction of the vehicle. It is an external appearance perspective view of the engine provided with the engine sound introduction structure of FIG. FIG. 2 is an external perspective view of a stay in the engine sound introduction structure of FIG. 1. It is an external appearance perspective view of the chamber in the engine sound introduction structure of FIG. It is a graph which shows the vibration frequency characteristic in the area | region A of the chamber surface of FIG. It is a graph which shows an example of the natural vibration mode of the whole toe board in the engine sound introduction structure of FIG. It is a schematic diagram of the toe board in the engine sound introduction structure of FIG. It is a graph which shows the natural vibration characteristic of the stay of FIG.

Explanation of symbols

1 Vehicle 110 Cabin 111 Toeboard 115 Dashboard 150 Engine Room 210 Engine Body 220 Intake System 225 Chamber 310 Stay

Claims (4)

A vibrator that is vibrated by vibration caused by a vehicle engine and amplifies a component of a specific frequency band of the vibration relative to a component of another frequency band;
A body panel portion constituting a part of a compartment of the vehicle;
The vibration body and the body panel portion are both connected at both ends thereof , and a vibration transmission portion that transmits the vibration of the vibration body to the body panel portion by solid propagation ,
The connection portion of the body panel portion with the vibration transmitting portion is disposed at a location that indicates a vibration mode of a frequency included in the specific frequency band when the body panel portion is vibrated,
The vibration transmission unit has its natural frequency included in the specific frequency band.
Engine sound introduction structure of a vehicle according to claim. The engine sound introduction structure for a vehicle according to claim 1 ,
The structure for introducing engine sound of a vehicle, wherein the vibrating body is connected to the engine via a flexible displacement absorbing member. The engine sound introduction structure for a vehicle according to claim 1 or 2 ,
The structure for introducing an engine sound of a vehicle, wherein the vibration transmission unit includes a connecting part that is deformed in accordance with a relative displacement between the vibrating body and the body panel due to the displacement of the engine. The engine sound introduction structure according to any one of claims 1 to 3 ,
The structure for introducing engine noise of a vehicle, wherein the vibrating body is a resonance chamber provided in an intake pipe of the engine.

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