JP2006250021A - Intake device for internal combustion engine and method for tuning intake sound using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device for an internal combustion engine being suitable for creating intake sound being comfortable for a vehicle driver and to provide a tuning method for intake sound. <P>SOLUTION: At least two air ducts 14a, 14b having different resonance frequencies are provided on the upstream side of an air cleaner 20. When resonance frequency of main sound is 1, the air ducts 14a, 14b have resonance frequencies expressed by any ratio of 1/1, 16/15, 17/16, 18/17, 25/24, 9/8, 10/9, 6/5, 5/4, 4/3, 17/12, 24/17, 25/18, 36/25, 45/32, 64/45, 3/2, 8/5, 5/3, 27/16, 9/5, 16/9, 30/17, 15/8, and 2/1, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intake device for an internal combustion engine that supplies air to the internal combustion engine, and a method for tuning an intake sound using the intake device.

  For example, Japanese Patent Application Laid-Open No. 2003-113748 discloses a device that adjusts the tone of intake sound by increasing the sound pressure level of a desired frequency. According to this apparatus, the above function is achieved by arranging the resonance box on the upstream side of the air cleaner.

JP 2003-113748 A JP-A-8-74593 JP 2000-124624 A

  However, even if the tone of the intake sound is adjusted by using the above-described conventional device, the obtained intake sound is not always a comfortable intake sound for the vehicle driver. Therefore, the above-described conventional device still leaves room for improvement in terms of obtaining a comfortable intake sound for the driver.

  The present invention has been made to solve the above-described problems, and provides an intake device and an intake sound tuning method for an internal combustion engine suitable for creating a comfortable intake sound for a vehicle driver. Objective.

In order to achieve the above object, a first invention is an intake device for introducing air into an internal combustion engine,
At least two intake pipes having different resonance frequencies are provided on the upstream side of the air cleaner,
When the resonance frequency of a predetermined sound is 1, the intake pipe is 1/1, 16/15, 17/16, 18/17, 25/24, 9/8, 10/9, 6/5, 5/4, 4/3, 17/12, 24 / 17,25 / 18, 36/25, 45/32, 64/45, 3/2, 8/5, 5/3, 27/16, 9 / It has a resonance frequency represented by any ratio among 5, 16/9, 30/17, 15/8, and 2/1.

The second invention is the first invention, wherein
Three intake pipes are provided,
The ratio of the resonance frequency of the three intake pipes is 4: 5: 6 or 3: 4: 5.

The third invention is a method of tuning an intake sound using the first or second invention,
It is characterized in that the intake sound is tuned to a desired harmony by making a hole in at least one intake pipe.

  According to the first invention, by providing at least two intake pipes having different resonance frequencies on the upstream side of the air cleaner, sounds of different frequencies are generated from the intake pipes when air is drawn from the intake pipes. . The sounds having different frequencies interfere with each other to generate a desired harmony. Therefore, it is possible to generate an intake sound that is comfortable for the vehicle driver.

  According to the second aspect of the invention, the ratio of the resonance frequencies of the three intake pipes is 4: 5: 6 or 3: 4: 5, thereby creating an intake sound comfortable for the vehicle driver. Can do.

  According to the third invention, the resonance frequency of the intake pipe can be adjusted by making a hole in the intake pipe. As a result, the timbre emitted by the intake pipe can be tuned, and the intake sound can be tuned to a desired harmony that is comfortable for the vehicle driver.

Embodiment 1 FIG.
FIG. 1 is an external view for explaining an intake device for an internal combustion engine according to Embodiment 1 of the present invention.
As shown in FIG. 1, the intake device includes an air duct 10. A resonator 16 is provided in the air duct 10. The resonator 16 is configured to lower the sound pressure level of the intake sound by shifting the resonance frequency. One end of the air duct 10 is branched into two air ducts 14 a and 14 b at the gathering portion 12. The opening diameters of the two air ducts 14 a and 14 b are configured to be shorter than the opening diameter of the air duct 10. The ends of the two air ducts 14a and 14b are open to the atmosphere.

The lengths of the two air ducts 14a and 14b are different. For this reason, the two air ducts 14a and 14b have different resonance frequencies. Here, the two air ducts 14a and 14b have a frequency ratio that satisfies the relationship of the pure rate scale. That is, the air ducts 14a and 14b have 1/1 (if the main sound is "do") and 16/15 (if the main sound is "de" when the resonance frequency of the main sound (assuming "do") is 1. De #. The same shall apply hereinafter.), 17/16 (De #), 18/17 (De #), 25/24 (De #), 9/8 (Le), 10/9 (Le) , 6/5 (Le #), 5/4 (Mi), 4/3 (Fa), 17/12 (Fa #), 24/17 (Fa #), 25/18 (Fa #), 36/25 (Fa #), 45/32 (Fa #), 64/45 (Fa #), 3/2 (So), 8/5 (So #), 5/3 (La), 27/16 (La), Expressed as a ratio of 9/5 (La #), 16/9 (La #), 30/17 (La #), 15/8 (Shi), 2/1 (1 octave above) Each having a resonant frequency.
Therefore, when air flows through these air ducts 14a and 14b, sounds having resonance frequencies of the air ducts 14a and 14b are generated. When these sounds having different frequencies interfere with each other, a consonant sound is generated.

  The other end of the intake pipe 10 communicates with the air cleaner 20. The air cleaner 20 includes an air filter (not shown) inside in order to remove foreign substances in the sucked air. The air cleaner 20 functions as an expansion chamber.

  One end of the intake pipe 24 is connected to the downstream side of the air cleaner 20. The other end of the intake pipe 24 communicates with the intake manifold 30. A resonator 22 is provided in the intake pipe 24. The intake manifold 30 communicates with an intake port of an internal combustion engine (not shown).

Next, the operation of the above-described intake device for an internal combustion engine will be described.
With the opening operation of the intake valve of the internal combustion engine, air is sucked from the two air ducts 14a and 14b, respectively. The sucked air joins at the collecting portion 12 of the air duct 10 and is then sent to the resonator 16. Further, the air is sent to the air cleaner 20 through the air duct 10. The air from which the foreign matter has been removed in the air cleaner 20 is sent to the resonator 22. Thereafter, the air is sent to the intake manifold 30 through the intake pipe 24. Then, air is supplied into the cylinder of the internal combustion engine that communicates with the intake manifold 30.

  As the intake valve opens and closes, air pulsation occurs in the intake device. Inhalation sound is generated by the pulsation of the air. As already described in the prior art, simply increasing or decreasing the sound pressure level of the intake sound does not necessarily provide a comfortable intake sound for the vehicle driver. Therefore, in the present invention, as described below, an intake sound comfortable for the driver is positively created. That is, in the above intake device, when air flows through the two air ducts 14a and 14b having different resonance frequencies, sounds having different frequencies are generated. When these sounds having different frequencies interfere with each other, a consonant sound is generated. This consonant sound is a sound that is continuously generated as the engine speed increases, and is a comfortable sound for the driver of the vehicle. Therefore, an intake sound comfortable for the driver of the vehicle can be obtained.

As described above, in the first embodiment, the two air ducts 14a and 14b having different resonance frequencies are provided upstream of the air cleaner 20. Thereby, a consonant sound can be generated as an intake sound when air is supplied to the internal combustion engine. Therefore, the intake device according to the first embodiment can generate an intake sound that is comfortable for the vehicle driver.
Further, by making the opening diameters of the two air ducts 14a and 14b shorter than the opening diameter of the air duct 10, the intake noise can be reduced.

  By the way, in the first embodiment, the air ducts 14a and 14b having different resonance frequencies are configured by making the air duct lengths different, but the method for making the resonance frequencies of the air ducts different is not limited to this. Absent. For example, the resonance frequency of the air duct may be made different by making the opening diameter of the air duct different (the same applies to the second embodiment described later).

In the first embodiment, the case where the two air ducts 14a and 14b have a frequency ratio that satisfies the relationship of the pure rate scale has been described, but may have a frequency ratio that satisfies the relationship of the average rate scale. . That is, when the air ducts 14a and 14b set the resonance frequency of the main sound (assumed to be “1”) to 1, 1 (do), 2 ^1/12 (do #), 2 ^2/12 (re), 2 ^{3 / 12} (Le #), 2 ^4/12 (Mi), 2 ^5/12 (Fa), 2 ^6/12 (Fa #), 2 ^7/12 (So), 2 ^8/12 (So #), 2 ^9/12 (La), 2 ^10/12 (La #), 2 ^11/12 (Shi), 2 (1 octave above) It may be configured (the same applies to Embodiment 2 described later). In this case, the same effect as in the first embodiment can be obtained.

Next, a modification of the first embodiment will be described.
(First modification)
FIG. 2 is an external view showing a first modification of the first embodiment of the present invention.
In the first embodiment, the tip of the air duct 10 is branched into the two air ducts 14a and 14b. On the other hand, in the first modification, two air ducts 14a and 14b are directly connected to the air cleaner 20 as shown in FIG. Thereby, the length of air duct 14a, 14b can be made longer than Embodiment 1. FIG. The longer the air duct length, the greater the effect of reducing intake noise. Therefore, since the intake noise can be further reduced as compared with the first embodiment, a resonator is not necessary. Therefore, the intake device can be further simplified as compared with the first embodiment, and the manufacturing cost can be further reduced.
Furthermore, since the air intake device of the first modified example does not have a collecting portion, it is possible to prevent the occurrence of a collecting loss when air sucked from the two air ducts 14a and 14b is collected. The occurrence of this collective loss becomes more prominent as the amount of intake air increases. Therefore, the first modification is a particularly suitable example for an internal combustion engine having a large intake air amount such as a diesel engine.

(Second modification)
FIG. 3 is an external view showing a second modification of the first embodiment of the present invention.
As shown in FIG. 3, in the second modified example, the shape of the opening 15 at the tip of the air ducts 14a and 14b is not a perfect circle but an ellipse. According to such a shape, traveling wind can be efficiently taken into the air ducts 14a and 14b. As a result, the air ducts 14a and 14b can be held at a positive pressure as compared with the first embodiment (the same applies to the second embodiment described later).

Embodiment 2. FIG.
FIG. 4 is an external view for explaining an intake device for an internal combustion engine according to Embodiment 2 of the present invention.
In the first embodiment, the tip of the air duct 10 is branched into two air ducts 14a and 14b. On the other hand, in the second embodiment, as shown in FIG. 4, the tip of the air duct 10 is branched into three air ducts 14a, 14b, and 14c.

Similar to the first embodiment, the lengths of the three air ducts 14a, 14b, and 14c are different. For this reason, the three air ducts 14a, 14b, and 14c have different resonance frequencies. Here, the three air ducts 14a, 14b, and 14c have a frequency ratio that satisfies the relationship of the pure rate scale. That is, the air ducts 14a, 14b, and 14c have 1/1 (if the main sound is de) and 16/15 (if the main sound is de) when the resonance frequency of the main sound (assuming de) is 1. If there is a de #, the same shall apply hereinafter.), 17/16 (de #), 18/17 (de #), 25/24 (de #), 9/8 (re), 10/9 ( ), 6/5 (Le #), 5/4 (Mi), 4/3 (Fa), 17/12 (Fa #), 24/17 (Fa #), 25/18 (Fa #), 36 / 25 (Fa #), 45/32 (Fa #), 64/45 (Fa #), 3/2 (So), 8/5 (So #), 5/3 (La), 27/16 (La ), 9/5 (La #), 16/9 (La #), 30/17 (La #), 15/8 (Si), 2/1 (1 octave above) Each has a resonance frequency represented by
As a ratio of resonance frequencies of the air ducts 14a, 14b, and 14c, 4: 5: 6 or 3: 4: 5 is particularly preferable. That is, “De Mi Seo”, “Fa La Do”, “So Shi Le” with a ratio of 4: 5: 6, and “De Fa” with a ratio of 3: 4: 5.・ The chord of “La” is particularly suitable.
The other apparatus configuration is the same as that of the first embodiment, and thus description thereof is omitted.

Next, the operation of the above-described intake device for an internal combustion engine will be described.
With the opening operation of the intake valve of the internal combustion engine, air is sucked from the three air ducts 14a, 14b, and 14c, respectively. The sucked air joins at the collecting portion 12 of the air duct 10 and is then sent to the resonator 16. Further, the air is sent to the air cleaner 20 through the air duct 10. The air from which the foreign matter has been removed in the air cleaner 20 is sent to the resonator 22. Thereafter, the air is sent to the intake manifold 30 through the intake pipe 24. Then, air is supplied into the cylinder of the internal combustion engine that communicates with the intake manifold 30.

  As the intake valve opens and closes, air pulsation occurs in the intake device. Inhalation sound is generated by the pulsation of the air. As described above, in the present invention, as described below, an intake sound comfortable for the driver is positively created. That is, in the above intake device, when air flows through the three air ducts 14a, 14b, and 14c having different resonance frequencies, sounds having different frequencies are generated. When these sounds having different frequencies interfere with each other, a consonant sound is generated. This consonant sound is a sound that is continuously generated as the engine speed increases, and is a comfortable sound for the driver of the vehicle. Therefore, an intake sound comfortable for the driver of the vehicle can be obtained.

As described above, in the second embodiment, the three air ducts 14a, 14b, and 14c having different resonance frequencies are provided upstream of the air cleaner 20. Thereby, a consonant sound can be generated as an intake sound when air is supplied to the internal combustion engine. Therefore, it is possible to generate an intake sound that is comfortable for the vehicle driver.
Furthermore, by generating a sound of “do mi so”, “fa la de”, “so si le”, or “de fa la” as an intake sound, A particularly comfortable intake sound can be obtained.
Moreover, compared with Embodiment 1, the opening diameter of the three air ducts 14a, 14b, and 14c can be shortened. The shorter the opening diameter, the greater the effect of reducing intake noise. Therefore, intake noise can be further reduced as compared with the first embodiment.

  In the second embodiment, the case where the three air ducts 14a, 14b, and 14c are provided has been described. However, an intake device that includes four or more air ducts may be used. Also in this case, since the opening diameter of the air duct can be further shortened, intake noise can be further reduced.

Next, a modification of the second embodiment will be described.
FIG. 5 is an external view showing a modification of the second embodiment of the present invention.
In the second embodiment, the front end of the air duct 10 is branched into three air ducts 14a, 14b, and 14c. As shown in FIG. 5, in this modification, three air ducts 14 a, 14 b, and 14 c are directly connected to the air cleaner 20. Thereby, the length of air duct 14a, 14b, 14c can be lengthened rather than Embodiment 2. FIG. Therefore, intake noise can be further reduced as compared with the first embodiment, and a resonator is not required. The longer the air duct length, the greater the effect of reducing intake noise. Therefore, the intake device can be further simplified as compared with the second embodiment, and the manufacturing cost can be further reduced.
Furthermore, since the air intake device of the present modification does not have a collecting portion, it is possible to prevent the occurrence of a collecting loss when air sucked from the three air ducts 14a, 14b, and 14c collects. The occurrence of this collective loss becomes more prominent as the amount of intake air increases. Therefore, this modification is particularly suitable for an internal combustion engine having a large intake air amount such as a diesel engine.

Embodiment 3 FIG.
FIG. 6 is a diagram for explaining a method of tuning the intake sound using the intake device of the internal combustion engine shown in FIG.
As described in the first and second embodiments, the sound having the resonance frequency of each air duct is usually generated. However, for some air ducts, the frequency may deviate from a desired value during manufacturing or the like. In this case, it is desirable to adjust the resonance frequency of the corresponding air duct in order to make the intake sound a desired harmony.
FIG. 6 shows a case where the resonance frequency of the air duct 14b is adjusted. As shown in FIG. 6, the resonance frequency of the air duct 14b can be adjusted by forming the opening 18 in the air duct 14b. As a result, the tone emitted from the air duct 14b can be tuned, and consequently the intake sound can be tuned to a comfortable harmony for the vehicle driver.

  In the third embodiment, the method of tuning the intake sound using the intake device shown in FIG. 1 has been described. Of course, the intake sound can also be tuned using the intake device shown in FIGS. . In this case, the same effect as in the third embodiment can be obtained.

It is an external view for demonstrating the intake device of the internal combustion engine by Embodiment 1 of this invention. It is an external view which shows the 1st modification of Embodiment 1 of this invention. It is an external view which shows the 2nd modification of Embodiment 1 of this invention. It is an external view for demonstrating the intake device of the internal combustion engine by Embodiment 2 of this invention. It is an external view which shows the modification of Embodiment 2 of this invention. FIG. 2 is a diagram for explaining a method for tuning an intake sound using the intake device for the internal combustion engine shown in FIG. 1.

Explanation of symbols

10 Air Duct 14a, 14b, 14c Air Duct 16, 22 Resonator 20 Air Cleaner 30 Intake Manifold

Claims (3)

An intake device for introducing air into an internal combustion engine,
At least two intake pipes having different resonance frequencies are provided on the upstream side of the air cleaner,
When the resonance frequency of a predetermined sound is 1, the intake pipe is 1/1, 16/15, 17/16, 18/17, 25/24, 9/8, 10/9, 6/5, 5/4, 4/3, 17/12, 24 / 17,25 / 18, 36/25, 45/32, 64/45, 3/2, 8/5, 5/3, 27/16, 9 / An intake device for an internal combustion engine, having a resonance frequency represented by any ratio of 5, 16/9, 30/17, 15/8, and 2/1. The intake device for an internal combustion engine according to claim 1,
Three intake pipes are provided,
An intake device for an internal combustion engine, wherein a ratio of resonance frequencies of the three intake pipes is 4: 5: 6 or 3: 4: 5. An intake sound tuning method using the internal combustion engine intake device according to claim 1 or 2,
A method for tuning an intake sound, characterized in that an intake sound is tuned to a desired harmony by making a hole in at least one intake pipe.

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