WO2022172459A1

WO2022172459A1 - Engine unit

Info

Publication number: WO2022172459A1
Application number: PCT/JP2021/005555
Authority: WO
Inventors: 昂翔田中
Original assignee: ヤマハ発動機株式会社
Priority date: 2021-02-15
Filing date: 2021-02-15
Publication date: 2022-08-18

Abstract

An engine unit (1) comprises a speaker (50) provided to an intake unit (20). The engine unit (1) is configured so that: an independent intake passage portion (40) connected to a combustion chamber (11) and provided with a throttle valve (30) is opened to a first expansion chamber (21) for expanding the internal space of the intake unit (20) first in the course from the combustion chamber; and the drive of an engine body (10) generates intake noise having a frequency higher than at least 300 Hz and lower than 500 Hz in the intake unit (20). The speaker (50) is provided in the first expansion chamber (21) or in a speaker-installed tube (22) opened to the first expansion chamber (21) and is controlled by a control device (60) so as to generate speaker sound having a frequency higher than at least 300 Hz and lower than 500 Hz in order to reduce intake noise generated in the intake unit (20).

Description

engine unit

This invention relates to an engine unit having an intake unit that generates intake noise.

Conventionally, in order to reduce the intake noise generated inside the intake unit of the engine unit and emitted to the outside of the intake unit, an engine unit equipped with a resonator or a large-capacity chamber in the intake unit has been proposed. It is
However, adding a resonator and a chamber will increase the size of the air intake unit.
In view of this, it has been proposed to provide a speaker in the air intake unit in order to suppress the increase in size of the air intake unit and to reduce the intake noise, as in Patent Document 1 and Patent Document 2, for example.

Japanese Patent No. 2579966 Japanese Utility Model Laid-Open No. 64-27465

However, conventional intake units equipped with speakers to reduce intake noise can be made smaller than intake units equipped with resonators and chambers to reduce intake noise, but are still large.

An object of the present invention is to provide an engine unit that can reduce intake noise generated within the intake unit and emitted to the outside of the intake unit while downsizing the intake unit.

An engine unit according to one embodiment of the present invention has the following configuration. The engine unit includes an engine body having a combustion chamber, an air intake having a throttle valve that is connected to the engine body and configured to pass air supplied to the combustion chamber, and that adjusts the flow rate of the air supplied to the combustion chamber. a unit, a speaker provided in the air intake unit, and a control device that controls the speaker to generate speaker sound that reduces intake noise generated in the air intake unit. The engine unit has an independent intake passage connected to a combustion chamber and provided with a throttle valve. Intake noise having a frequency of at least 300 Hz and less than 500 Hz is generated within. The speaker is installed in a first expansion chamber or a speaker installation pipe that opens to the first expansion chamber, which is connected to the combustion chamber and has an independent intake passage portion in which a throttle valve is provided. and controlled by the control device to generate a speaker sound having a frequency of at least greater than 300 Hz and less than 500 Hz in order to reduce intake noise generated within the intake unit.

According to this configuration, the independent intake passage portion connected to the combustion chamber and provided with the throttle valve opens from the combustion chamber to the first expansion chamber that first expands the internal space of the intake unit. As a result, the intake unit can be made smaller than in the case where no throttle valve is provided in the intake passage that opens from the combustion chamber to the first expansion chamber that first expands the internal space of the intake unit and is connected to the combustion chamber. be. Since the intake unit is small, the frequency of the intake noise generated in the intake unit by driving the engine body can be at least higher than 300 Hz and lower than 500 Hz. Therefore, the frequency of the speaker sound generated by the speaker can be at least higher than 300 Hz and lower than 500 Hz in order to reduce intake noise. Since the frequency of the speaker sound is high, the size of the speaker can be reduced. Moreover, the speaker is installed in the first expansion chamber or the first expansion chamber where the internal space of the intake unit is first expanded from the combustion chamber by opening the independent intake passage portion connected to the combustion chamber and provided with the throttle valve. provided in the pipe. The intake noise whose sound pressure is attenuated by entering the first expansion chamber can be reduced by the speaker. Therefore, intake noise can be efficiently reduced, and the speaker can be made smaller. Due to the small size of the speaker, the air intake unit can be made smaller.
As described above, the engine unit of the present invention can reduce the intake noise generated in the intake unit and released to the outside of the intake unit while downsizing the intake unit.

An engine unit according to one embodiment of the present invention may have the following configuration.
The engine unit includes a noise information acquisition section that acquires information related to intake noise. Based on the information acquired by the noise information acquiring section, the control device controls the speaker so as to generate a speaker sound that reduces intake noise generated within the intake unit.

According to this configuration, it is possible to control the timing at which the speaker generates the speaker sound, the frequency of the speaker sound, and the sound pressure of the speaker sound, based on the information obtained by the information obtaining unit. Therefore, the intake noise can be more reliably reduced by the speaker sound generated by the speaker.

An engine unit according to one embodiment of the present invention may have the following configuration.
A part including the open end of the independent intake passage is arranged in the internal space of the first expansion chamber.

According to this configuration, compared to the case where the opening end of the independent intake passage is connected to the first expansion chamber, the length of the independent intake passage can be secured while the intake unit can be made more compact.

An engine unit according to one embodiment of the present invention may have the following configuration.
An open end of the independent intake passage is connected to the first expansion chamber.

An engine unit according to one embodiment of the present invention may have the following configuration.
A part including the open end of the speaker installation tube provided with the speaker is arranged in the internal space of the first expansion chamber.

According to this configuration, compared to the case where the open end of the speaker installation pipe is connected to the first expansion chamber, the length of the speaker installation pipe can be secured while the air intake unit can be made more compact.

An engine unit according to one embodiment of the present invention may have the following configuration.
An open end of a speaker installation tube provided with a speaker is connected to the first expansion chamber.

An engine unit according to one embodiment of the present invention may have the following configuration.
The engine unit is configured such that air passing through a speaker installation pipe provided with a speaker is supplied to the combustion chamber via the first expansion chamber and the independent intake passage.

According to this configuration, the speaker installation pipe in which the speaker is installed forms part of the air intake path in the air intake unit. Therefore, compared to the case where the speaker installation pipe does not form a part of the air intake path, the air intake unit can be made smaller.
Also, the sound pressure of intake noise is reduced when it enters the speaker installation pipe from the first expansion chamber. Since the speaker is provided in the speaker installation pipe, the speaker can reduce intake noise in a state where the sound pressure is reduced by entering the speaker installation pipe. Therefore, compared to the case where the speaker is provided in the first expansion chamber, the sound pressure of the speaker sound can be reduced. Therefore, the speaker can be made smaller. Therefore, the intake unit can be made more compact.

An engine unit according to one embodiment of the present invention may have the following configuration.
A speaker installation pipe provided with a speaker is formed so as not to allow air to pass therethrough.

According to this configuration, the speaker installation pipe in which the speaker is installed does not form part of the air intake path in the air intake unit. Since the speaker installation pipe can be provided independently of the air intake path, there is a high degree of freedom in the position and shape of the speaker installation pipe. Therefore, even if the air intake unit has a speaker installation pipe that is not an air intake path, it is possible to suppress the enlargement of the air intake unit.
Also, the sound pressure of intake noise is reduced when it enters the speaker installation pipe from the first expansion chamber. Since the speaker is provided in the speaker installation pipe, the speaker can reduce intake noise in a state where the sound pressure is reduced by entering the speaker installation pipe. Therefore, compared to the case where the speaker is provided in the first expansion chamber, the sound pressure of the speaker sound can be reduced. Therefore, the speaker can be made smaller. Therefore, the intake unit can be miniaturized. Furthermore, as described above, since there is a high degree of freedom in the position and shape of the speaker installation pipe, it is possible to design the speaker installation pipe so that the intake noise is further reduced by entering the speaker installation pipe. If the speaker installation pipe is designed so that intake noise can be further reduced by entering the speaker installation pipe, the speaker can be made smaller. As a result, the air intake unit can be made more compact.

An engine unit according to one embodiment of the present invention may have the following configuration.
The sound wave propagation path from the open end of the independent intake passage in the first expansion chamber to the open end of the speaker installed in the first expansion chamber or the speaker installation pipe provided with the speaker in the first expansion chamber is the independent intake passage. Shorter than the propagation path of sound waves inside.

An engine unit according to one embodiment of the present invention may have the following configuration.
The engine unit includes a plurality of combustion chambers included in the engine body, a plurality of throttle valves included in the intake unit, a plurality of independent intake passages connected to the combustion chambers and provided with respective throttle valves, and It has a single first expansion chamber that first expands the internal space of the intake unit and opens into a plurality of independent intake passages.

In the above configuration, the plurality of combustion chambers includes the combustion chamber of claim 1, the plurality of throttle valves includes the throttle valve of claim 1, and the plurality of independent intake passage portions include the independent intake passage portion of claim 1. Including, the single first expansion chamber corresponds to the first expansion chamber of claim 1 .

An engine unit according to one embodiment of the present invention may have the following configuration.
The engine unit consists of a single combustion chamber included in the engine body, a single throttle valve included in the intake unit, and a single independent air intake connected to the single combustion chamber and provided with a single throttle valve. It has a passageway and a single first expansion chamber extending the interior space of the intake unit initially from the combustion chamber and opening into a single independent intake passageway.

In the above configuration, the single combustion chamber corresponds to the combustion chamber of claim 1, the single throttle valve corresponds to the throttle valve of claim 1, and the single independent intake passage portion corresponds to the throttle valve of claim 1. It corresponds to an independent intake passage portion, and the single first expansion chamber corresponds to the first expansion chamber of claim 1 .

<Engine unit>
The type of engine unit in the present invention and embodiments is not particularly limited. The type of engine unit may be, for example, a gasoline engine or a diesel engine. The engine unit of the present invention may have a fuel injection device that injects fuel into the independent intake passage, or may have a fuel injection device that injects fuel into the combustion chamber. The type of engine unit may be a 4-stroke engine or a 2-stroke engine. The engine unit may or may not have a canister. The engine unit may or may not have a forced induction device. The supercharger may be a turbocharger or a supercharger. The type of engine unit may be a single-cylinder engine with a single combustion chamber or a multi-cylinder engine with multiple combustion chambers. The form of arrangement of the plurality of cylinders (plurality of combustion chambers) in the multi-cylinder engine is not particularly limited. The multi-cylinder engine may be, for example, any of a V-type engine, an in-line engine, and a horizontally opposed engine. In a V-type engine, the plurality of combustion chambers includes first combustion chambers and second combustion chambers arranged on a straight line parallel to a direction perpendicular to the central axis of the crankshaft. The number of first combustion chambers may be one or plural. The number of second combustion chambers is the same as the number of first combustion chambers. In an in-line engine, all of the combustion chambers are aligned on a straight line parallel to the central axis of the crankshaft. Applications of the engine unit according to the present invention and the embodiments are not particularly limited. The engine unit according to the present invention and embodiments may be mounted on vehicles such as automobiles, motorcycles, and ships, or may be used as a stationary engine for power generation.

<Intake noise>
In the present invention and the embodiments, the intake noise generated within the intake unit is the sound generated by intake pulsation within the intake unit.

<Reduction of intake noise>
In the present invention and the embodiments, the sound (speaker sound) that reduces the intake noise is the sound that reduces the intake noise by interfering with the intake noise. The sound that reduces the intake noise is the sound that is in opposite phase or substantially in opposite phase to the intake noise.

<Speaker>
In the present invention and embodiments, a speaker is a device that converts an electrical signal into sound. A speaker is electrically connected to the controller. The loudspeakers may be connected to the controller, for example via amplifiers.
In the present invention and the embodiments, the speaker provided in the first expansion chamber is a speaker arranged so as to emit speaker sound into the internal space of the first expansion chamber. The speaker provided within the first expansion chamber may or may not form part of the inner wall of the first expansion chamber.
In the present invention and the embodiments, the speaker provided in the speaker installation pipe is a speaker arranged so that the speaker sound is emitted into the internal space of the speaker installation pipe. The speaker provided in the speaker installation pipe may or may not form part of the inner wall of the speaker installation pipe.
In the present invention and the embodiments, the speaker provided in the speaker installation pipe may be a speaker arranged in the portion of the speaker installation pipe that is arranged in the first expansion chamber. That is, in the present invention and the embodiments, the speaker provided in the first expansion chamber or the speaker installation pipe includes the speaker arranged in the first expansion chamber and the speaker installation pipe. In the present invention and the embodiments, the speaker provided inside the speaker installation pipe may be a speaker arranged in a portion of the speaker installation pipe located outside the first expansion chamber.
In the present invention and embodiments, the engine unit may have only one speaker or may have a plurality of speakers. If the engine unit has multiple speakers, at least one of the multiple speakers should satisfy the requirements of claim 1 . The number of speakers provided in the speaker installation pipe may be one or may be plural. The number of speakers provided in the first expansion chamber may be one or plural. The engine unit may have both a speaker provided in the speaker installation pipe and a speaker provided in the first expansion chamber.

<Generation of sound with a frequency greater than at least 300 Hz and less than 500 Hz>
In the present invention and embodiments, generating sound with a frequency greater than 300 Hz and less than 500 Hz (intake noise or speaker sound) means generating at least sound within a frequency range greater than 300 Hz and less than 500 Hz. . At least sound with a frequency greater than 300 Hz and less than 500 Hz (intake noise or speaker sound) is generated when only the sound within the frequency range greater than 300 Hz and less than 500 Hz is generated, or within the frequency range greater than 300 Hz and less than 500 Hz In addition to sound, this includes cases where sounds outside this frequency range occur. Sounds outside this frequency range may occur when sounds within this frequency range occur, and sounds outside this frequency range may occur when sounds within this frequency range do not occur.
For example, the following method can be used to check whether intake noise with a frequency greater than 300 Hz and less than 500 Hz is generated in the intake unit. The sound is measured with a microphone placed in the internal space of the air intake unit or in the vicinity of the air intake port of the air intake unit while the engine is running without operating the speaker. Then, it is determined whether a sound within a frequency range greater than 300 Hz and less than 500 Hz has been measured. Note that the air inlet is an opening through which air is drawn from the atmosphere.

<Independent air intake passage>
In the present invention and embodiments, the independent intake passage portion may be composed of a plurality of parts, may be composed of a single non-separable part, or may be a part of a single non-separable part. good too. The independent intake passage portion may be composed of a separate part separable from the first expansion chamber, and at least a portion of the independent intake passage portion may be integrally formed with at least a portion of the first expansion chamber.
In the present invention and the embodiments, the expression that the independent intake passage opens to the first expansion chamber means that the open end of the independent intake passage is connected to the first expansion chamber, or that the open end of the independent intake passage is connected to the first expansion chamber. It means that the part containing the gas is arranged in the internal space of the first expansion chamber.
In accordance with the present invention and embodiments, the independent intake passageway section is connected to the combustion chamber. Therefore, part of the independent intake passage is included in the engine body, and the rest of the independent intake passage is included in the intake unit. A first expansion chamber is included in the intake unit. The independent intake passage section is connected to at least one intake port formed in the combustion chamber. When a plurality of intake ports are formed in the combustion chamber, the independent intake passage section is connected to all the intake ports. When a plurality of intake ports are formed in the combustion chamber, the independent intake passage has a branched shape. The branch point may be inside or outside the engine body.

<First expansion chamber>
In the present invention and embodiments, the first expansion chamber may be composed of multiple parts, may be composed of a single non-separable part, or may be part of a single non-separable part. good too.
In the present invention and embodiments, expanding the internal space of the intake unit first from the combustion chamber means expanding the internal space of the intake unit first from the combustion chamber in the propagation direction of intake noise in the intake unit. do. The propagation direction of intake noise in the intake unit is the direction opposite to the flow direction of the air supplied to the combustion chamber.
In the present invention and the embodiments, the expansion of the internal space of the intake unit means that the cross-sectional area of the internal space of the intake unit perpendicular to the propagation direction of intake noise expands discontinuously. In the present invention and the embodiments, the first expansion chamber that expands the internal space of the intake unit is a chamber that discontinuously and abruptly changes the cross-sectional area of the internal space of the intake unit perpendicular to the propagation direction of intake noise. . The first expansion chamber that expands the internal space of the intake unit does not include a structure that discontinuously and slightly changes the cross-sectional area perpendicular to the direction of propagation of intake noise in the internal space of the intake unit. The independent intake passage opens to the first expansion chamber. Therefore, the cross-sectional area perpendicular to the propagation direction of intake noise in the vicinity of the open end of the independent intake passage in the internal space of the first expansion chamber is larger than the cross-sectional area of the open end of the independent intake passage that opens to the first expansion chamber. is also big. Even if the maximum cross-sectional area perpendicular to the propagation direction of intake noise in the internal space of the first expansion chamber is, for example, 1.5 times or more the cross-sectional area of the open end of the independent intake passage portion that opens to the first expansion chamber. good. The cross-sectional area perpendicular to the direction of propagation of intake noise in the vicinity of the open end of the independent intake passage in the internal space of the first expansion chamber is any cross-sectional area perpendicular to the direction of propagation of intake noise in the internal space of the independent intake passage. may be greater than An average cross-sectional area orthogonal to the direction of propagation of intake noise in the internal space of the first expansion chamber may be larger than an average of cross-sectional areas orthogonal to the direction of propagation of intake noise of the internal space of the independent intake passage portion.
In the present invention and embodiments, the intake unit may or may not have an expansion chamber that expands the internal space of the intake unit in the propagation direction of intake noise in addition to the first expansion chamber. However, the expansion chamber that is not the first expansion chamber is located away from the first expansion chamber in the propagation direction of the intake noise.

<Speaker installation tube>
In the present invention and embodiments, the speaker installation pipe may be composed of a plurality of parts, may be composed of a single inseparable part, or may be a part of a single inseparable part. good. The speaker installation tube may be configured as a separate part separable from the first expansion chamber, and at least a portion of the speaker installation tube may be integrally formed with at least a portion of the first expansion chamber.
In the present invention and the embodiments, the expression that the speaker installation tube opens to the first expansion chamber means that the open end of the speaker installation tube is connected to the first expansion chamber, or that a part including the open end of the speaker installation tube is connected to the first expansion chamber. is arranged in the inner space of the first expansion chamber.
The number of open ends of the speaker installation tube that opens to the first expansion chamber may be one or plural.
In the present invention and the embodiments, the expression that air passes through the speaker installation pipe means that the air that has flowed into the speaker installation pipe from the opening end of the speaker installation pipe that opens to the first expansion chamber passes through a speaker installation pipe that is different from the opening end of the speaker installation pipe. means that it flows out from the opening of the The speaker installation tube may have a plurality of openings that do not open to the first expansion chamber.
In the present invention and the embodiments, the speaker installation tube, which is formed so as not to pass air, has no opening except for the open end that opens to the first expansion chamber.

<Noise information acquisition part>
In the present invention and the embodiments, the information related to the intake noise acquired by the noise information acquisition unit may be information related to the intake noise itself, or may be information related to the driving state of the engine main body.
In the present invention and the embodiments, the noise information acquisition section may be arranged in the intake unit, or may be provided in a portion of the engine unit other than the intake unit. The noise information acquisition unit includes, for example, a microphone for detecting intake noise, and a sensor for detecting information related to the driving state of the engine body. Sensors that detect information related to the driving status of the engine body include, for example, an intake pressure sensor that detects the air pressure in the internal space of the intake unit, an intake air flow sensor that detects the flow rate of air passing through the intake unit, and an engine rotation speed sensor. It may be an engine rotation speed sensor that detects, a sensor that detects the opening of the throttle valve, or any combination thereof.
The noise information acquisition section may be arranged upstream of the speaker in the air flow direction within the intake unit. In this case, the noise information acquisition unit may be a microphone that detects the intake noise after it has been reduced by the speaker sound. The noise information acquisition section may be arranged downstream of the speaker in the air flow direction within the intake unit. In this case, the noise information acquisition unit may be a microphone that detects the intake noise before it is reduced by the speaker sound. The noise information acquisition section may be arranged at the same position as the speaker in the air flow direction within the intake unit. In the present invention and embodiments, the engine unit may have only one noise information acquiring section, or may have a plurality of noise information acquiring sections. A plurality of noise information acquisition units may be arranged upstream and downstream of the speaker, for example, in the direction of air flow in the intake path.

<Others>
If a claim does not explicitly specify the number of an element and that element appears in the singular when translated into English, the invention may include a plurality of that element. good. Also, the invention may have only one of this component.

In the present invention and embodiments, the terms including, comprising, having and derivatives thereof are intended to encompass additional items in addition to the recited items and their equivalents. are being used.

At least one (one) of multiple options in the present invention and embodiments includes all possible combinations of multiple options. At least one (one) of the multiple options may be any one of the multiple options, or may be all of the multiple options. For example, at least one of A, B, or C may be A only, B only, C only, A and B, A and C , B and C, or A, B, and C.

In this specification, the term "may" is non-exclusive. "May be" means "may be, but is not limited to." As used herein, "may" implicitly includes "may not". In this specification, the configuration described as "may" has at least the above effect obtained by the configuration of claim 1.

Unless defined otherwise, all terms (including technical and scientific terms) used in the specification and claims have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be construed to have a meaning consistent with their meaning in the context of the relevant technology and this disclosure, and are not idealized or overly formal. not be interpreted in any meaningful way.

Before describing embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. be. The present invention is also possible in embodiments other than those described below. The present invention is also possible in embodiments in which various modifications are made to the embodiments described later.

Purpose of invention

The engine unit of the present invention can reduce intake noise generated within the intake unit and emitted outside the intake unit while downsizing the intake unit.

1 is a schematic diagram of an engine unit of first and second embodiments of the present invention and an engine unit of a comparative example; FIG. 1 is a schematic diagram of an engine unit of a specific example of the first embodiment; FIG. FIG. 6 is a schematic diagram of an engine unit of a specific example of the second embodiment; FIG. 5 is a schematic diagram of an engine unit according to a third embodiment of the present invention; FIG. 5 is a schematic diagram of an engine unit according to a fourth embodiment of the present invention; (a) shows the inside of the engine room of an automobile in which the engine unit of the fifth embodiment of the present invention is arranged, (b) is a schematic diagram of the engine unit of the fifth embodiment, and (c) is a comparative example. 12(d) is a schematic diagram of the engine unit of Comparative Example 3. FIG.

<First Embodiment and Second Embodiment>
An engine unit 1 according to a first embodiment and a second embodiment of the present invention will be described with reference to FIGS. 1(a) to 1(d). FIG. 1(a) shows the engine unit 1 of the first embodiment, and FIGS. 1(b) and 1(c) show the engine unit 1 of the second embodiment. FIG. 1(d) shows an engine unit 701 of Comparative Example 1. FIG. The engine unit 1 of the first embodiment and the second embodiment includes an engine body 10 having a combustion chamber 11, an intake unit 20 connected to the engine body 10, a speaker 50 provided in the intake unit 20, and a control device. 60. The intake unit 20 is configured such that the air supplied to the combustion chamber 11 passes through it. The intake unit 20 has a throttle valve 30 that adjusts the flow rate of air supplied to the combustion chamber 11 . The control device 60 controls the speaker 50 so as to generate speaker sound that reduces intake noise generated within the intake unit 20 . The throttle valve 30 may be an electronically controlled throttle valve 30 controlled by the control device 60 or may be a mechanically controlled throttle valve 30 .

The engine unit 1 has an independent intake passage portion 40 connected to the combustion chamber 11 and provided with a throttle valve 30 . The independent intake passage portion 40 opens from the combustion chamber 11 to the first expansion chamber 21 that expands the internal space of the intake unit 20 first. A first expansion chamber 21 is included in the intake unit 20 . The engine unit 1 is configured such that the driving of the engine body 10 generates an intake noise having a frequency of at least 300 Hz and less than 500 Hz in the intake unit 20 . The control device 60 controls the speaker 50 so as to generate a speaker sound with a frequency greater than 300 Hz and less than 500 Hz at least in order to reduce intake noise generated within the intake unit 20 . In the first embodiment, the speaker 50 is provided inside the first expansion chamber 21 . The engine unit 1 of the second embodiment has a speaker installation pipe 22 opening into the first expansion chamber 21 . In the second embodiment, the speaker 50 is provided inside the speaker installation tube 22 .

An engine unit 701 of Comparative Example 1 shown in FIG. The intake unit 720 includes a first expansion chamber 721 that expands the internal space of the intake unit 720 first from the combustion chamber 711 and a second expansion chamber 722 that expands the internal space of the intake unit 720 second from the combustion chamber 711 . have. The engine unit 701 has an intake passage portion 740 that opens to the first expansion chamber 721 and is connected to the combustion chamber 711 . The intake unit 720 has a throttle valve 730 provided upstream of the first expansion chamber 721 in the direction of air flow. Throttle valve 730 is not provided in intake passage portion 740 that opens to first expansion chamber 721 and is connected to combustion chamber 711 . The air intake unit 20 of the first embodiment and the second embodiment is smaller than the air intake unit 720 of the engine unit 701 of the first comparative example. The engine unit 1 of the first embodiment and the second embodiment can reduce the intake noise generated in the intake unit 20 and released to the outside of the intake unit 20 while downsizing the intake unit 20 .

The type of the engine unit 1 shown in FIGS. 1(a) to 1(c) is a multi-cylinder engine. The engine body 10 has multiple combustion chambers 11 . The engine unit 1 has a plurality of independent intake passages 40 connected to the plurality of combustion chambers 11 respectively. A plurality of independent intake passage portions 40 open to a single first expansion chamber 21 . The intake unit 20 has multiple throttle valves 30 . A plurality of throttle valves 30 are provided in a plurality of independent intake passage portions 40, respectively.

<Specific example of the first embodiment>
A specific example of the first embodiment will be described with reference to FIGS. 2(a) to 2(f). However, the specific example of the first embodiment is not limited to the configurations shown in FIGS. 2(a) to 2(f). The display of the control device 60 is omitted in FIGS. 2(a) to 2(f). As described above, the speaker 50 is provided inside the first expansion chamber 21 in the first embodiment. As shown in FIG. 2( a ), the open end 40 a of the independent intake passage portion 40 of the first embodiment may be connected to the first expansion chamber 21 . As shown in FIG. 2B, a portion of the independent intake passage portion 40 of the first embodiment, including the open end 40a, may be arranged in the internal space of the first expansion chamber 21. As shown in FIG. The configuration of the independent intake passage portion 40 in FIGS. 2(c) to 2(f) may be either of the configurations of the independent intake passage portion 40 in FIGS. 2(a) and 2(b). As shown in FIGS. 2(c) to 2(e), the intake unit 20 of the first embodiment may have at least one air intake pipe 123 opening into the first expansion chamber 21. As shown in FIG. Air passing through the atmospheric air intake pipe 123 is supplied to the combustion chamber 11 via the first expansion chamber 21 and the independent intake passage portion 40 . 2(c) and 2(d), a part of the air intake pipe 123 including the open end 123a is arranged in the internal space of the first expansion chamber 21. In FIG. In FIG. 2C, the air intake pipe 123 protrudes outside the first expansion chamber 21 . 2(d), the air intake pipe 123 does not protrude outside the first expansion chamber 21. In FIG. In FIG. 2(e), the open end 123a of the air intake pipe 123 is connected to the first expansion chamber 21. As shown in FIG. In FIG. 2( e ), the air intake pipe 123 protrudes outside the first expansion chamber 21 . Further, as shown in FIG. 2( f ), in the first embodiment, instead of providing the air intake pipe 123 that opens to the first expansion chamber 21 , the first expansion chamber 21 has at least one air intake port 124 . may have. Air is supplied to the first expansion chamber 21 from the air intake port 124 .

In the first embodiment, the sound wave propagation path from the open end 40a of the independent intake passage portion 40 to the speaker 50 in the first expansion chamber 21 may be shorter than the sound wave propagation path in the independent intake passage portion 40. . That is, the longest propagation path of the sound waves from the opening end 40 a of the plurality of independent intake passage portions 40 to the speaker 50 in the first expansion chamber 21 is the longest among the sound wave propagation paths of the plurality of independent intake passage portions 40 . Shorter than the shortest propagation path. For example, in the case of the engine unit 1 shown in FIGS. 2(a) and 2(b), the length of the sound wave propagation path from the open end 40a of the independent intake passage portion 40 to the speaker 50 in the first expansion chamber 21 is represented by the symbol This is the length indicated by D1. In the first embodiment, the sound wave propagation path from the open end 40a of the independent intake passage portion 40 to the speaker 50 in the first expansion chamber 21 does not have to be shorter than the sound wave propagation path in the independent intake passage portion 40. good. That is, the longest propagation path of the sound waves from the opening end 40 a of the plurality of independent intake passage portions 40 to the speaker 50 in the first expansion chamber 21 is the longest among the sound wave propagation paths of the plurality of independent intake passage portions 40 . It may be equal to or longer than the shortest propagation path.

<Specific example of the second embodiment>
A specific example of the second embodiment will be described with reference to FIGS. 3(a) to 3(g). However, the specific example of the second embodiment is not limited to the configurations shown in FIGS. 3(a) to 3(g). The display of the control device 60 is omitted in FIGS. 3(a) to 3(g). As described above, in the second embodiment, the speaker 50 is provided on the speaker installation tube 22 opening into the first expansion chamber 21 . The configuration of the independent intake passage portion 40 shown in FIGS. 3(a) to 3(g) may be either of the configurations of the independent intake passage portion 40 shown in FIGS. 2(a) and 2(b).

As shown in FIGS. 3(a) to 3(e), in the engine unit 1 of the second embodiment, air passing through the speaker installation pipe 22 is combusted through the first expansion chamber 21 and the independent intake passage portion 40. It may be configured to supply chamber 11 . 3(a) and 3(b), a portion of the speaker installation tube 22 including the open end 22a is arranged in the internal space of the first expansion chamber 21. As shown in FIG. In FIG. 3( a ), the speaker installation tube 22 protrudes outside the first expansion chamber 21 . In FIG. 3A, the speaker 50 is arranged in a portion of the speaker installation tube 22 that is arranged inside the first expansion chamber 21 . 3(a), the speaker 50 may be arranged in a portion of the speaker installation pipe 22 outside the first expansion chamber 21, as indicated by a chain double-dashed line. In FIG. 3B, the speaker installation tube 22 does not protrude outside the first expansion chamber 21 . 3(c), the open end 22a of the speaker installation tube 22 is connected to the first expansion chamber 21. As shown in FIG. In the engine unit 1 shown in FIGS. 3(a) to 3(c), the first expansion chamber 21 may be connected to an air intake pipe 123 as shown in FIGS. 2(c) to 2(e). Alternatively, in the engine unit 1 shown in FIGS. 3(a) to 3(c), the first expansion chamber 21 may have an air intake port 124 as shown in FIG. 2(f).

As shown in FIG. 3( d ), the engine unit 1 of the second embodiment may have a plurality of speaker installation pipes 22 opening into the first expansion chamber 21 . A speaker 50 is provided in each speaker installation tube 22 . In FIG. 3D, a part of the speaker installation tube 22 including the open end may be arranged in the internal space of the first expansion chamber 21, and the open end of the speaker installation tube 22 is connected to the first expansion chamber 21. may be In FIG. 3( d ), a plurality of speaker installation tubes 22 protrude outside the first expansion chamber 21 . Note that the plurality of speaker installation tubes 22 do not need to protrude outside the first expansion chamber 21 .

As shown in FIG. 3(e), the speaker installation pipe 22 of the second embodiment includes a plurality of main pipe portions 22b opening into the first expansion chamber 21 and a communication pipe portion 22c connecting the plurality of main pipe portions 22b. may have. In FIG. 3(e), the speaker 50 is provided inside the communicating tube portion 22c. Note that the speaker 50 may be provided inside the main pipe portion 22b, as indicated by the two-dot chain line in FIG. 3(e). For example, the speaker 50 may be provided downstream of the connecting pipe portion 22c in either one of the two main pipe portions 22b in the direction of air flow. Further, for example, the speaker 50 may be provided upstream of the connecting pipe portion 22c in each of the two main pipe portions 22b in the air flow direction. In FIG. 3(e), a portion of the speaker installation tube 22 including the open end may be arranged in the internal space of the first expansion chamber 21, and the open end of the speaker installation tube 22 is connected to the first expansion chamber 21. may be In FIG. 3(e), the speaker installation tube 22 protrudes outside the first expansion chamber 21. As shown in FIG.

As shown in FIGS. 3(f) and 3(g), the speaker installation pipe 22 of the second embodiment may be formed so as not to allow air to pass through. In this case, the first expansion chamber 21 is connected to an air intake pipe 123 as shown in FIGS. air inlet 124. A speaker installation tube 22 formed so as not to pass through the air protrudes outside the first expansion chamber 21 . In FIG. 3( f ), a portion of the speaker installation tube 22 including the open end 22 a is arranged in the internal space of the first expansion chamber 21 . In FIG. 3( f ), the speaker 50 is arranged in the portion of the speaker installation pipe 22 that is arranged inside the first expansion chamber 21 . 3(f), the speaker 50 may be arranged in a portion of the speaker installation pipe 22 outside the first expansion chamber 21, as indicated by a chain double-dashed line. 3(g), the open end 22a of the speaker installation tube 22 is connected to the first expansion chamber 21. In FIG.

In the second embodiment, the sound wave propagation path from the open end 40a of the independent intake passage portion 40 in the first expansion chamber 21 to the open end 22a of the speaker installation pipe 22 in the first expansion chamber 21 is the independent intake passage portion. It may be shorter than the propagation path of sound waves in 40 . That is, the longest propagation path of sound waves from the opening ends 40a of the plurality of independent intake passage portions 40 in the first expansion chamber 21 to the opening end 22a of the speaker installation pipe 22 in the first expansion chamber 21 is It may be shorter than the shortest propagation path of sound waves in the plurality of independent intake passage portions 40 . For example, in the case of the engine unit 1 shown in FIG. 3A, sound waves propagate from the open end 40a of the independent intake passage portion 40 in the first expansion chamber 21 to the open end 22a of the speaker installation pipe 22 in the first expansion chamber 21. The path length is the length indicated by D2. However, the position of the opening end 40a of the independent intake passage portion 40 in FIG. 3(a) may be either the position of the opening end 40a of the independent intake passage portion 40 in FIG. 2(a) or FIG. 2(b). good. In the second embodiment, the sound wave propagation path from the open end 40a of the independent intake passage portion 40 in the first expansion chamber 21 to the open end 22a of the speaker installation pipe 22 in the first expansion chamber 21 is the independent intake passage portion. It need not be shorter than the propagation path of the sound wave within 40 . That is, the longest propagation path of sound waves from the opening ends 40a of the plurality of independent intake passage portions 40 in the first expansion chamber 21 to the opening end 22a of the speaker installation pipe 22 in the first expansion chamber 21 is It may be equal to or longer than the shortest propagation path of sound waves in the plurality of independent intake passage portions 40 .

<Third Embodiment>
An engine unit 1 according to a third embodiment of the present invention will be described with reference to FIGS. 4(a) to 4(d). 4(a) to 4(c) show the engine unit 1 of the third embodiment. FIG. 4(d) shows an engine unit 801 of Comparative Example 2. As shown in FIG. The engine unit 1 of the third embodiment has an air filter 231 arranged inside the first expansion chamber 21 in addition to the configuration of the first embodiment or the second embodiment. The display of the control device 60 is omitted in FIGS. 4(a) to 4(c). Engine unit 801 of Comparative Example 2 has an air filter 831 arranged in second expansion chamber 722 in addition to the configuration of engine unit 701 of Comparative Example 1. As shown in FIG.

<Fourth Embodiment>
An engine unit 1 according to a fourth embodiment of the present invention will be described with reference to FIGS. 5(a) to 5(c). The engine unit 1 of the fourth embodiment may have the configuration of the third embodiment. The engine unit 1 of the fourth embodiment includes at least one noise information acquisition section 270 that acquires information related to intake noise, in addition to the configuration of the first embodiment or the second embodiment. The noise information acquisition section 270 is electrically connected to the control device 60 . The control device 60 controls the speaker 50 based on the information acquired by the at least one noise information acquiring section 270 so as to generate a speaker sound that reduces intake noise generated within the intake unit 20 . The noise information acquisition section 270 may be provided inside the first expansion chamber 21 as indicated by the solid line or the two-dot chain line. The noise information acquisition unit 270 may be provided inside the speaker installation pipe 22 in which the speaker 50 is provided, as indicated by the two-dot chain line. The noise information acquisition section 270 may be provided upstream of the first expansion chamber 21 in the air flow direction. The noise information acquisition section 270 may be provided downstream of the first expansion chamber 21 in the air flow direction. The arrangement position of the noise information acquisition unit 270 is not limited to the positions shown in FIGS. 5(a) to 5(c).

<Fifth Embodiment>
An engine unit 1 according to a fifth embodiment of the present invention will be described with reference to FIGS. 6(a) to 6(d). FIG. 6(a) shows the inside of the engine room of an automobile in which the engine unit 1 of the fifth embodiment is arranged. FIG. 6(b) shows the engine unit 1 of the fifth embodiment. FIG. 6(c) shows the inside of the engine room of an automobile in which the engine unit 901 of Comparative Example 3 is arranged. FIG. 6B shows an engine unit 901 of Comparative Example 3. FIG. The engine unit 1 of the fifth embodiment and the engine unit 901 of the comparative example 3 are V-type engines. The engine unit 1 of the fifth embodiment may have the configuration of the third embodiment. The engine unit 1 of the fifth embodiment may have the configuration of the fourth embodiment. The engine unit 1 of the fifth embodiment has the following configuration in addition to the configuration of the first or second embodiment. The engine unit 1 of the fifth embodiment includes an engine body 10 having a plurality of combustion chambers 11, an intake unit 20, at least one speaker 50, and a control device 60. The engine body 10 has a first cylinder section 312 having at least one combustion chamber 11 and a second cylinder section 313 having at least one combustion chamber 11 . The engine unit 1 has a plurality of independent intake passage sections 40 connected to at least one combustion chamber 11 of the first cylinder section 312 and at least one combustion chamber 11 of the second cylinder section 313 . A plurality of independent intake passage portions 40 open to the first expansion chamber 21 . The intake unit 20 has multiple throttle valves 30 . A plurality of throttle valves 30 are provided in a plurality of independent intake passage portions 40, respectively. The internal space of the first expansion chamber 21 is partitioned into a first space 321a and a second space 321b by a partition wall 325 and a closed control valve 332 . The first space 321a and the second space 321b are communicated with each other by the open control valve 332 . The first space 321 a of the first expansion chamber 21 communicates with the inside of at least one combustion chamber 11 of the first cylinder portion 312 via the internal space of at least one independent intake passage portion 40 . The second space 321b of the first expansion chamber 21 communicates with the interior of at least one combustion chamber 11 of the second cylinder portion 313 via the internal space of at least one independent intake passage portion 40 . The air intake unit 20 has an air intake pipe 326 connected to the first expansion chamber 21 . The internal space of the air intake pipe 326 communicates with both the first space 321 a and the second space 321 b of the first expansion chamber 21 . An upstream end of the air intake pipe 326 in the air flow direction is connected to an air cleaner 327 . The control valve 332 is controlled by the control device 60 based on the engine speed and the like. For example, the control valve 332 may be controlled such that the control valve 332 is closed during low rotation and is open during high rotation. The at least one speaker 50 may be one speaker 50 provided within the atmospheric intake tube 326 . In this case, the air intake pipe 326 corresponds to the speaker installation pipe of the present invention. The control device 60 may control the speaker 50 to generate a speaker sound that reduces intake noise when the control valve 332 is closed. In this case, the at least one speaker 50 may be two speakers 50 provided in the first space 321 a and the second space 321 b of the first expansion chamber 21 . Alternatively, at least one speaker 50 may be two speakers 50 provided in two speaker installation tubes 22 that are open to the first expansion chamber 21 and are formed so as not to allow air to pass through. The two speaker installation pipes 22 communicate with the first space 321a and the second space 321b of the first expansion chamber 21, respectively. The control device 60 may control the speaker 50 to generate a speaker sound that reduces intake noise only when the control valve 332 is open. In this case, the at least one speaker 50 may be the two speakers 50 described above. Alternatively, the at least one speaker 50 may be one speaker 50 provided in the first space 321 a or the second space 321 b of the first expansion chamber 21 . Alternatively, at least one speaker 50 is provided in one speaker installation tube 22 that communicates with the first space 321a or the second space 321b of the first expansion chamber 21 and is formed so as not to allow air to pass through. It may be the speaker 50 .

An engine unit 901 of Comparative Example 3 includes an engine body 910 having a plurality of combustion chambers 911, an intake unit 920, and a control device (not shown). Engine body 910 has a first cylinder portion 912 and a second cylinder portion 913 . The engine unit 901 has a plurality of downstream intake passages 940 connected to a plurality of combustion chambers 911 . A plurality of downstream intake passage portions 940 open from the combustion chamber 911 to a first expansion chamber 921 that expands the internal space of the intake unit 920 first. The internal space of the first expansion chamber 921 is partitioned into a first space 921a and a second space 921b by a first partition 925 and a closed first control valve 932 . The first space 921a and the second space 921b are communicated with each other by the first control valve 932 in the open state. The intake unit 920 includes a separation pipe 926 connected to the first expansion chamber 921, two intake pipes 927 connected to the separation pipe 926, an intake pipe 928 connected to the two intake pipes 927, and an intake pipe 928 has an air cleaner 929 connected to the . The internal space of the separation pipe 926 is partitioned into two spaces by the second partition wall 926a and the closed second control valve 933 . The two spaces in the separation pipe 926 are communicated with each other by the open second control valve 933 . The first control valve 932 and the second control valve 933 are controlled by a control device (not shown) based on the engine speed and the like. For example, both the first control valve 932 and the second control valve 933 are closed during low rotation, both the first control valve 932 and the second control valve 933 are open during high rotation, and the first control valve 933 is closed during medium rotation. The first control valve 932 and the second control valve 933 may be controlled such that the valve 932 is closed and the second control valve 933 is open. Intake unit 920 has two throttle valves 930 . Two throttle valves 930 are provided in the two intake pipes 927 respectively. The intake unit 20 of the fifth embodiment is smaller than the intake unit 920 of the engine unit 901 of the third comparative example. The engine unit 1 of the fifth embodiment can reduce the intake noise generated in the intake unit 20 and released to the outside of the intake unit 20 while making the intake unit 20 smaller than the engine unit 901 of the comparative example 3.

It should be noted that the present invention is not limited to the above-described embodiments and specific examples of the embodiments, and various modifications are possible within the scope of the claims.

When the engine unit of the present invention has a plurality of independent intake passages, the intake unit may have two first expansion chambers. At least one independent intake passage opens to one of the two first expansion chambers, and the remaining independent intake passage opens to the other of the two first expansion chambers. The intake unit of the present invention may have a second expansion chamber that expands the internal space of the intake unit second from the combustion chamber. The air intake unit of the present invention may have an air filter arranged upstream of the first expansion chamber in the direction of air flow.

The type of engine unit of the present invention may be a single cylinder engine. When the type of the engine unit of the present invention is a single-cylinder engine, the engine unit of the present invention may have the configuration of the specific example of the first embodiment and the specific example of the second embodiment. When the type of the engine unit of the present invention is a single-cylinder engine, the engine unit of the present invention may have the configuration of the third embodiment or the configuration of the fourth embodiment. For example, a single-cylinder engine unit to which the present invention is applied is connected to a single combustion chamber 11 included in the engine body 10, a single throttle valve 30 included in the intake unit, and the single combustion chamber 11. a single independent intake passage provided with a single throttle valve 30 and a single first expansion section which initially expands the interior space of the intake unit from the combustion chamber 11 and opens into the single independent intake passage. room.

The engine unit of the present invention may be configured to generate intake noise having a frequency of at least 350 Hz and less than 500 Hz in the intake unit when the engine body is driven. The engine unit of the present invention may be configured to generate intake noise having a frequency of at least 400 Hz to less than 500 Hz in the intake unit when the engine body is driven. The engine unit of the present invention may be configured to generate intake noise having a frequency of at least greater than 300 Hz and less than 450 Hz in the intake unit when the engine body is driven. The engine unit of the present invention may be configured to generate intake noise having a frequency of at least 300 Hz and less than 400 Hz in the intake unit when the engine body is driven.

1: engine unit, 10: engine main body, 11: combustion chamber, 20: intake unit, 21: first expansion chamber, 22: speaker installation pipe, 22a: opening end of speaker installation pipe, 30: throttle valve, 40: independent Intake passage 40a: Open end of independent intake passage 50: Speaker 60: Control device 270: Noise information acquisition unit

Claims

an engine body having a combustion chamber;
an intake unit connected to the engine body, configured to pass air supplied to the combustion chamber, and having a throttle valve for adjusting the flow rate of the air supplied to the combustion chamber;
a speaker provided in the intake unit;
a control device that controls the speaker to generate speaker sound that reduces intake noise generated in the intake unit;
An engine unit comprising
The engine unit is
An independent intake passage portion connected to the combustion chamber and provided with the throttle valve opens from the combustion chamber to a first expansion chamber that first expands the internal space of the intake unit, and is driven by the engine body. configured to generate at least the intake noise with a frequency greater than 300 Hz and less than 500 Hz in the intake unit;
The speaker is
The independent intake passage portion connected to the combustion chamber and provided with the throttle valve opens, and opens from the combustion chamber to the first expansion chamber or the first expansion chamber that expands the internal space of the intake unit first. It is provided in a speaker installation pipe, and is controlled by the control device so as to generate a speaker sound having a frequency greater than 300 Hz and less than 500 Hz at least in order to reduce the intake noise generated in the intake unit. engine unit.
The engine unit includes a noise information acquisition unit that acquires information related to the intake noise,
The control device controls the speaker so as to generate the speaker sound that reduces the intake noise generated in the intake unit based on the information acquired by the noise information acquisition unit. 2. An engine unit according to claim 1.
The engine unit according to claim 1 or 2, wherein a part including the open end of the independent intake passage portion is arranged in the internal space of the first expansion chamber.
The engine unit according to claim 1 or 2, wherein the open end of the independent intake passage portion is connected to the first expansion chamber.
The engine according to any one of claims 1 to 4, wherein a part including an open end of the speaker installation pipe provided with the speaker is arranged in the internal space of the first expansion chamber. unit.
The engine unit according to any one of claims 1 to 4, characterized in that an open end of said speaker installation pipe provided with said speaker is connected to said first expansion chamber.
The engine unit is configured such that air passing through the speaker installation pipe provided with the speaker is supplied to the combustion chamber via the first expansion chamber and the independent intake passage. The engine unit according to any one of claims 1 to 6.
The engine unit according to any one of claims 1 to 6, wherein the speaker installation pipe provided with the speaker is formed so as not to allow air to pass through.
sound wave from the open end of the independent air intake passage in the first expansion chamber to the open end in the first expansion chamber of the speaker provided in the first expansion chamber or the speaker installation pipe provided with the speaker. The engine unit according to any one of claims 1 to 8, wherein a propagation path is shorter than a propagation path of sound waves in the independent intake passage.
The engine unit is
a plurality of the combustion chambers included in the engine body;
a plurality of the throttle valves included in the intake unit;
a plurality of independent intake passage portions each connected to the combustion chamber and each provided with the throttle valve;
10. The unit according to claim 1, further comprising a single first expansion chamber that first expands an internal space of the intake unit from the combustion chamber and opens to the plurality of independent intake passages. 2. The engine unit according to item 1.
The engine unit is
a single combustion chamber contained in the engine body;
a single throttle valve included in the intake unit;
a single independent intake passage connected to the single combustion chamber and provided with the single throttle valve;
10. The unit according to any one of claims 1 to 9, further comprising a single first expansion chamber that expands an internal space of the intake unit first from the combustion chamber and that opens into the single independent intake passage. or the engine unit according to item 1.