JP2009030451A - Vehicular intake sound transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular intake sound transmission device easily installable in an engine room much in restriction on a space, and capable of transmitting an intake sound by a desirable frequency-sound pressure characteristic by resonating by a desired frequency. <P>SOLUTION: A vibrator 14 blocking up the inside of a transmission pipe 11 and vibrating by intake pulsation, is arranged inside the transmission pipe 11 branching off from an intake pipe 4B and having the opening tip, and a tip side part more than the vibrator 14 in the transmission pipe 11, is formed as a cylindrical resonator 13. With this constitution, the resonator 13 is formed so that its passage cross-sectional area monotonously reduces toward the tip side from the base end side of a passage. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle intake sound transmission device for transmitting intake sound of an internal combustion engine into a vehicle compartment.

This type of intake sound control device is intended to positively incorporate engine intake sound into the passenger compartment in order to produce a sporty feeling, and is disclosed in, for example, Patent Document 1. As shown in FIGS. 10 (a) and 10 (b), this apparatus has a transmission pipe 51 branched from the middle of the intake pipe 50 and having an end opened into the engine compartment. Is provided with a vibrating body 52 that closes the inside of the transmission tube 51 and vibrates due to intake pulsation. A portion of the transmission tube 51 on the tip side of the vibrating body 52 is a resonance body 53 that resonates in the air column based on the vibration of the vibrating body 52. In this apparatus, when the vibrating body 52 vibrates due to the intake pulsation, the resonator 53 resonates at a predetermined pulsation frequency, and the intake sound having the frequency adjusted by the resonance is diffused into the engine sound.
Japanese Patent Laying-Open No. 2005-139882 (paragraph [0029] on page 6 of the specification, FIGS. 12 and 13)

  By the way, the resonance frequency when the resonator 53 resonates is determined mainly by the passage length of the resonator 53. However, there are many space restrictions in the engine room where the intake sound transmission device is installed, and it is often difficult to install the transmission pipe 51 having the resonator 53 having a desired passage length. As a result, there is a problem in that the resonance body 13 cannot be resonated at a desired frequency and a preferable intake sound cannot be transmitted.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a vehicle intake sound transmission device that can be easily installed in an engine room with many space constraints and can transmit a preferable intake sound by resonating at a desired frequency. There is.

  In order to achieve the above-described object, the present invention provides a vibrating body that is branched from an intake pipe of an internal combustion engine and that has an opening at the tip, closes the inside of the transmission pipe, and vibrates due to intake pulsation. In the vehicle intake sound transmission device in which the tip side portion of the transmission tube has a cylindrical resonance body, the resonance cross section of the resonance body extends from the proximal end side of the passage toward the distal end side. It is formed so as to change monotonously. Here, “the passage cross-sectional area of the resonator changes monotonously from the base end side of the passage toward the tip end side” means that the coordinate from the base end side of the resonator passage toward the tip end side is X, and this coordinate This means that x1 <x2 and S (x1) <S (x2) are satisfied, where S (x) is the passage cross-sectional area at an arbitrary position x of X.

According to this configuration, the resonance frequency can be lowered or increased while keeping the passage lengths of the resonators equal.
Further, the present invention is characterized in that the vibrating body is integrally formed with a branch portion interposed between the intake pipe and the vibrating body or the resonance body.

According to this configuration, it is possible to simplify the shape of each member to facilitate molding, to prevent an increase in the number of parts, and to prevent an increase in assembly man-hours.
Further, according to the present invention, the vibrating body is separated from the branching portion interposed between the intake pipe and the vibrating body and the resonance body, and is sandwiched between the branching portion and the resonance body. It is characterized by that.

  According to this configuration, the shape of each member can be further simplified to facilitate molding.

  According to the present invention, the intake sound can be easily installed in the engine room where there are many space restrictions, and the intake sound of a desired frequency can be resonated to transmit the intake sound with a preferable frequency-sound pressure characteristic.

(First embodiment)
Next, a first embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, intake pipes 4 </ b> A and 4 </ b> B for supplying combustion air to the engine 3 are provided in series through an air cleaner 5 in the engine compartment 2 of the vehicle 1. Further, a silencer resonator 6 is provided in the intake pipe 4 </ b> A on the upstream side of the air cleaner 5. Each intake pipe 4A, 4B is formed of a synthetic resin. The intake pipe 4B on the downstream side of the air cleaner 5 is provided with an intake sound transmission device 10 for transmitting intake sound to the driver in the passenger compartment 7.

  As shown in FIGS. 2 and 3, the intake sound transmission device 10 includes a transmission pipe 11 that is branched from the intake pipe 4 </ b> B and has an open end. The transmission tube 11 includes a branch portion 12 formed integrally with the intake pipe 4B, and a cylindrical resonator 13 joined to the tip of the branch portion 12. As shown in FIG. 1, the opening 11 a of the transmission tube 11 is directed into the passenger compartment 7 through a through hole 8 a formed in the dash panel 8.

  A sheet-like vibrating body 14 that integrally closes the inside of the branching portion 12 and vibrates due to intake air pulsation in the intake pipe 4B is integrally formed at the tip of the branching portion 12. In addition, a flange-like joint 15 is integrally formed around the vibrating body 14, and an end surface thereof is an annular welding surface 15a.

  The resonator 13 is formed in a conical shape so that the cross-sectional area of the passage linearly and monotonously decreases from the base end side (that is, the branching portion 12 side) of the passage toward the distal end side. A flange-shaped joint 16 is integrally formed on the outer peripheral edge of the proximal end opening of the resonator 13, and its end surface is an annular welding surface 16 a. The resonator 13 is joined to the branch portion 12 by welding the weld surface 16a of the joint portion 16 to the weld surface 15a of the joint portion 15 of the vibrating body 14.

  When outside air is sucked through the intake pipes 4A and 4B as the engine 3 is operated, intake pulsation having a frequency corresponding to the rotational speed of the engine 3 is generated in the intake pipe 4B. The intake pulsation is transmitted to the vibrating body 14 through the branch portion 12 of the transmission tube 11. For this reason, the vibrating body 14 vibrates at a frequency corresponding to the rotational speed of the engine 3. As a result, in the resonance body 13 of the transmission tube 11, sound vibration is generated using the vibration of the vibration body 14 as a sound source. A plurality of frequencies included in the sound vibration resonate (hereinafter referred to as air column resonance) due to the air column vibration of the resonator 13.

  Here, as shown by a thick solid line in the graph of FIG. 4A, the air column resonance generated in the resonator 13 of this embodiment is such that the sound pressure level peaks at a certain resonance frequency f1. Indicates. The resonance frequency f1 of this embodiment (the first embodiment shown in FIG. 4 (b)) has the same passage length L and the conventional intake sound transmission device (see FIG. It becomes lower than the resonance frequency f0 of the conventional product shown in FIG. That is, when the resonance frequency f1 is to be obtained in the configuration including the straight tubular resonator 13, it is necessary to increase the passage length L of the resonator 13 and increase the wavelength of vibration during air column resonance. there were. On the other hand, according to this embodiment, it is possible to obtain a resonance frequency f1 lower than the conventional one without increasing the length of the resonator 13.

  The reason is presumed as follows. That is, as shown in FIG. 5A, the vibration of the resonance frequency when air column resonance occurs in the straight tubular resonator 13 takes the position of the resonator 14 as a node, and is substantially at the open end of the resonator 13. The wavelength is a quarter wavelength with the position of. On the other hand, in the case of this embodiment, as shown in FIG. 5B, the passage cross-sectional area of the resonator 13 monotonously decreases from the proximal end side to the distal end side of the passage. It is presumed that the position of the vibration node at the resonance frequency has moved to the back side of the vibrating body 14, and therefore the wavelength has become longer and the resonance frequency has become lower.

  For example, in the conventional configuration, when the path length L of the resonator 13 is 250 mm, the resonance frequency is 340 Hz. The resonance frequency in the case of monotonously decreasing to 290 Hz was 290 Hz. This corresponds to the case where the path length L of the resonator 13 is 340 mm in the conventional configuration.

Therefore, according to this embodiment, the following effects can be obtained.
(1) The resonance body 13 of the transmission tube 11 is formed so that the passage cross-sectional area decreases monotonously from the proximal end side to the distal end side of the passage. For this reason, unlike the configuration in which the resonator 13 is formed in a straight tube shape, a low resonance frequency can be obtained even if the passage length L is short. Therefore, when the resonance sound is realized at the resonance frequency f1, the intake sound transmission device 10 can be easily installed in the engine chamber 2 even if the length of the transmission pipe 11 is limited due to space restrictions in the engine chamber 2. Can do.

  (2) The transmission pipe 11 is constituted by the branch part 12 formed integrally with the intake pipe 4B and the resonance body 13 joined to the branch part 12, and the vibrating body 14 is formed integrally with the branch part 12. For this reason, the shapes of the intake pipe 4B and the resonator 13 can be simplified and can be easily formed, and an increase in the number of parts can be prevented and the number of assembling steps can be reduced.

(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIGS. In the description of the second and subsequent embodiments, the description will focus on parts that are different from the first embodiment.

  As shown in FIGS. 6 and 7, in this embodiment, the vibrating body 14 is not formed at the tip of the branch portion 12 formed integrally with the intake pipe 4B, and the inner peripheral side of the joint portion 15 is opened. Yes.

  On the other hand, the resonator 13 is formed in a conical shape so that the passage sectional area increases linearly and monotonously from the base end side to the tip end side of the passage. The base end of the resonance body 13 not only has the joint portion 16, but the vibration body 14 is integrally formed on the inner peripheral side thereof. The resonator 13 is joined by welding the joints 15 and 16 together.

  As shown by a thin solid line in the graph of FIG. 4A, the resonance frequency f2 of this embodiment (the second embodiment shown in FIG. 4B) is a straight tubular resonator having the same passage length L. It becomes higher than the resonance frequency f0 of the conventional intake sound transmission device having the above (the conventional product shown in FIG. 4B). Therefore, according to this embodiment, the resonance frequency f2 higher than before can be obtained without shortening the passage length L of the resonator 13.

  The reason is presumed as follows. That is, as shown in FIG. 5C, in the case of this embodiment, the passage cross-sectional area of the resonator 13 monotonously increases from the proximal end side to the distal end side of the passage. It is presumed that the position of the node of the resonance vibration moves to the opening 11a side, and therefore the wavelength is shortened and the resonance frequency is increased.

  For example, as described above, the resonance frequency is 340 Hz when the path length L of the resonator 13 is 250 mm in the conventional configuration, but the inner diameter of the circular path of the resonator 13 in this embodiment, that is, the path cross-sectional area. The resonance frequency was 420 Hz in a case where the frequency was increased monotonically from Φ30 mm to Φ50 mm. This corresponds to a case where the path length L of the resonator 13 is 200 mm in the conventional configuration.

Therefore, this embodiment has the following effects.
(3) The resonator 13 is formed such that the passage cross-sectional area increases monotonously from the proximal end side to the distal end side of the passage. For this reason, for example, when the interval between the intake pipe 4B and the dash panel 8 is fixed, the intake sound transmission device 10 can be easily installed in the engine compartment 2 without making a design change to bring the intake pipe 4B closer to the dash panel 8. can do. Therefore, the intake sound having a desired high resonance frequency f2 can be transmitted into the passenger compartment 7.

  (4) The transmission pipe 11 is constituted by the branch part 12 formed integrally with the intake pipe 4 </ b> B and the resonance body 13 joined to the branch part 12, and the vibrating body 14 is formed integrally with the resonance body 13. For this reason, the shape of the intake pipe 4B and the resonator 13 can be simplified to facilitate the molding thereof, the increase in the number of parts can be prevented, and the number of assembly steps can be reduced.

(Third embodiment)
Next, a third embodiment embodying the present invention will be described with reference to FIGS.

  As shown in FIGS. 8 and 9, in this embodiment, the vibrating body 14 is separated from the branching section 12 and the resonance body 13, and an annular step formed on the inner peripheral edge of the joint portion 16 of the resonance body 13. It is sandwiched between the branch portion 12 and the resonator 13 while being accommodated in the portion (shown in FIG. 9) 17.

Therefore, this embodiment has the following effects in addition to the effect described in (1) of the first embodiment.
(5) The vibrating body 14 is separated from the branching section 12 (intake pipe 4B) and the resonator 13 and is sandwiched between the branching section 12 and the resonator 13. Therefore, it is possible to simplify the shape of the branch portion 12 and the resonator 13 and facilitate the molding.

(Other embodiments)
In addition, this embodiment can also be changed and embodied as follows.
In the first and third embodiments, as shown by a two-dot chain line in FIG. 3 and FIG. 9, the resonator 13 has a substantially circular passage cross-sectional area with a quadratic curve from the proximal end side to the distal end side of the passage. It forms so that it may decrease.

In the second embodiment, as indicated by a two-dot chain line in FIG. 7, the resonator 13 is formed so that the substantially circular passage cross-sectional area increases in a quadratic curve from the proximal end side to the distal end side of the passage. Form.
In the first to third embodiments, for example, a plurality of engagement claws are integrally formed on the branching portion 12 instead of the joint portion 15, and a plurality of engagements are engaged with the respective engagement claws instead of the joint portion 16. A joint hole is formed integrally with the resonator 13. And the branch part 12 and the resonance body 13 are joined by engaging an engagement piece with each engagement hole, respectively. In this case, there is no need for welding and the assembly workability is improved.

In the first to third embodiments, the transmission pipe 11 is not connected to the through hole 8a of the dash panel 8 but is opened so as to face the back surface of the dash panel 8 in the engine compartment 2.
-In 1st-3rd embodiment, let the shape of the channel | path cross section of the resonator 13 be a substantially elliptical shape, a substantially polygonal shape, and a different shape.

  The first to third embodiments are provided in the intake pipe 4 </ b> A on the upstream side of the air cleaner 5.

The top view which shows the intake sound transmission apparatus provided in the engine room of the vehicle. The disassembled perspective view which shows the intake sound transmission apparatus of 1st Embodiment. The cross-sectional view which shows an inhalation sound transmission apparatus. (A) is a graph which shows the frequency characteristic of the sound pressure level of an intake sound, (b) is a schematic diagram which shows each intake sound transmission apparatus from which the shape of the front end side part differs. (A), (b), (c) is a schematic diagram which shows air column resonance in the front end side part. The disassembled perspective view which shows the intake sound transmission apparatus of 2nd Embodiment. The cross-sectional view which shows an inhalation sound transmission apparatus. The disassembled perspective view which shows the intake sound transmission apparatus of 3rd Embodiment. The cross-sectional view which shows an inhalation sound transmission apparatus. (A) is a perspective view which shows the conventional intake sound transmission apparatus, (b) is a plane sectional view similarly.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Engine as an internal combustion engine, 4A, 4B ... Intake pipe, 10 ... Intake sound transmission device, 11 ... Transmission pipe, 11a ... Opening, 12 ... Branching part, 13 ... Resonator, 14 ... Vibrating body

Claims (3)

A vibration body that closes the inside of the transmission pipe and vibrates due to the intake pulsation is provided inside the transmission pipe branched from the intake pipe of the internal combustion engine and opened at the tip. In a vehicle intake sound transmission device with a cylindrical resonator,
An inspiratory sound transmission device for a vehicle, wherein the resonance body is formed so that a cross-sectional area of the passage changes monotonously from a proximal end side to a distal end side of the passage.   2. The vehicle intake sound transmission device according to claim 1, wherein the vibration body is formed integrally with a branch portion interposed between the intake pipe and the vibration body, or the resonance body.   The vibration body is separated from the resonance part and the branch part interposed between the intake pipe and the vibration body, and is sandwiched between the branch part and the resonance body. Item 2. The vehicle intake sound transmission device according to Item 1.

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