JP2009144670A - Silencer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silencer capable of obtaining bigger silencing effects and preventing both ends of a thin-film inner duct (vibration film) 4 in the long-axis direction from being crushed inward. <P>SOLUTION: Two of first and second bending sections 51, 52 bent at a designated angle so as to project toward the outside of the inner duct 4 in the long-axis direction are arranged on both ends of the flat polygonal cylinder-shaped inner duct 4 in the long-axis direction having a long-axis and a short-axis. The inner duct 4 can be easily vibrated by forming a plurality of plane sections 41-43 in the peripheral direction of the inner duct 4, and greater silencing effects can be obtained in comparison with a conventional technology. When deforming two of the first and second bending sections 51, 52 which are deformed in projection outward in the long-axis direction of the inner duct 4, two of first and second holding-down sections 71, 72 for holding down the first and second bending sections 51, 52 from the outside in the long-axis direction of the inner duct 4 are arranged in an outer duct 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a silencer having a double-pipe structure comprising a thin-film duct (inner cylinder film body) and a covering (outer cylinder wall body).

[Conventional technology]
Conventionally, there has been a problem that air column resonance occurs inside the intake duct due to pulsating waves from the internal combustion engine (engine), and radiated sound is generated from the intake duct along with the resonance of the intake duct due to this air column resonance. It was.
Therefore, an intake silencer having a double-pipe structure consisting of an outer pipe and an inner pipe is installed in the middle of the intake passage communicating with the combustion chamber of the engine, and the inner pipe is made into a thin film so that the air inside the intake duct is removed. Intake ducts that reduce the radiated sound transmitted from the outer tube to the outside by increasing the rigidity of the outer tube and suppressing membrane vibration by making column resonance less likely to occur (for example, Patent Document 1).

  As shown in FIG. 13, the intake silencer described in Patent Literature 1 includes a cylindrical inner pipe (a thin film inner duct) 102 that forms an intake passage 101 therein, and an outer peripheral portion of the inner duct 102. And a cylindrical outer tube (outer duct) 104 that forms a cylindrical air layer 103. In this intake silencer, the thickness of the inner duct 102 is made thin to set the rigidity low, and the outer duct 104 is made thick to set the rigidity high.

[Conventional technical problems]
However, in the intake silencer described in Patent Document 1, the cross-sectional shape perpendicular to the flow direction of the intake air of the thin-film inner duct 102 is a perfect circular cylindrical shape. The shape is difficult to vibrate. As a result, there has been a problem that a large silencing effect cannot be obtained. Further, in the intake silencer described in Patent Document 1, since the inner duct 102 is thinned, there is a problem that the pressure resistance strength of the inner duct 102 is insufficient.

  Therefore, for the purpose of obtaining a large silencing effect, the cross-sectional shape perpendicular to the flow direction of the intake air of the thin-film inner duct 102 is made polygonal as in Comparative Example 1 shown in FIG. Conceivable. That is, the inner duct 102 of the comparative example 1 has a plurality of first to fourth vibration surfaces in the circumferential direction, and a flat rectangular shape in which a cross-sectional shape perpendicular to the flow direction of the intake air has a major axis and a minor axis. It has become a shape. And each 1st-4th vibration surface of the inner duct 102 is planarized. Thereby, by making a plane in the circumferential direction of the inner duct 102, the inner duct 102 is more likely to vibrate, and a greater silencing effect can be obtained.

  However, in the case of the flat rectangular inner duct 102 having the major axis and the minor axis shown in FIG. 1B, when the intake air passes through the inner duct 102 (intake passage 101), the suction negative When pressure is generated, the first and third vibration surfaces of the inner duct 102 located at both ends in the long axis direction of the inner duct 102 are crushed inward due to insufficient pressure resistance due to the thinning of the inner duct 102. Accordingly, concave bent portions 105 that are bent at a predetermined angle so as to protrude toward the inner side in the major axis direction of the inner duct 102 are formed at both ends in the major axis direction of the inner duct 102.

Thus, if the first and third vibration surfaces located at both ends of the inner duct 102 in the longitudinal direction are crushed inward, the passage cross-sectional area inside the inner duct 102 (the intake passage 101) becomes narrower. There was a problem that the intake air amount required for the engine could not be obtained and the engine output was insufficient.
JP-A 63-266492

  An object of the present invention is to provide a silencer capable of obtaining a greater silencing effect and at the same time preventing the both ends of a long axis direction of a duct (thin film) from being crushed inward. Furthermore, it is providing the silencer which can improve the pressure | voltage resistance of a duct.

  According to invention of Claim 1, the duct is equipped with the thin film which has a some surface in the circumferential direction. The duct (thin film) has a flat shape in which a cross-sectional shape perpendicular to the flow direction of the fluid flowing through the fluid flow path has a major axis and a minor axis. When a force is applied to the duct (thin film) at both ends in the longitudinal direction of the duct (for example, the pressure (negative pressure, for example) in the environment surrounding the duct (thin film)) (negative pressure, for example) ) Is applied), it has a deformable portion that can be deformed so as to protrude outward in the longitudinal direction of the duct.

That is, when a force is applied to the duct (thin film) by setting the cross-sectional shape of the duct (thin film) to a flat shape having a major axis and a minor axis (for example, a polygonal cylindrical shape, an elliptical cylindrical shape, or a long cylindrical shape). (Specifically, when negative pressure is applied to the inside of the duct), the deformed portions provided at both ends of the duct (thin film) in the long axis direction are not crushed inward in the long axis direction of the duct (thin film). The duct (thin film) is deformed so as to protrude outward in the major axis direction of the duct (thin film) having a large projected area as compared to the minor axis direction of the duct (thin film).
Further, by flattening at least one of a plurality of surfaces provided in the duct (thin film), the duct (thin film) is more likely to vibrate, and a greater silencing effect can be obtained compared to the conventional technology. it can.
Here, the short axis is an axis in the shortest length direction when the cross-sectional shape is projected from the outer peripheral direction, and the long axis is an axis in the longest length direction in a direction orthogonal to the short axis.
Therefore, even if the pressure resistance strength of the duct (thin film) is insufficient due to the thinning of the duct, by devising the cross-sectional shape of the duct (thin film), a greater silencing effect can be obtained and at the same time ) In the major axis direction can be prevented from being crushed inward. As a result, it is possible to prevent a reduction in the channel cross-sectional area of the fluid channel.
In addition, when the covering is deformed so that the deformed portions provided at both ends of the long axis direction of the duct (thin film) always come into contact with each other, or the deformed portions protrude outwardly in the long axis direction of the duct (thin film). It is installed so that the deformed portion abuts. As a result, when the deformed portion is deformed so as to protrude outward in the major axis direction of the duct (thin film), the deformed portion can be pressed from the outer side of the duct (thin film) in the major axis direction. Even when the film is thinned, the pressure resistance of the duct (thin film) can be improved.

According to invention of Claim 2, a duct is a thin film-shaped inner duct. The covering is a hard outer duct that surrounds the inner duct (thin film) through a gas layer.
According to the invention described in claim 3, the covering is a hard belt surrounding the periphery of the duct (thin film). This belt has a deformed portion when the deformed portions provided at both ends of the long axis direction of the duct (thin film) are always in contact, or when the deformed portion is deformed so as to protrude outward in the long axis direction of the duct (thin film). Are installed so that they contact each other.

According to invention of Claim 4, a covering body has a holding | suppressing part which hold | suppresses the deformation | transformation part provided in the both ends of the major axis direction of a duct (thin film) from the outer side of the major axis direction of a duct (thin film). Yes. The pressing portion is provided so that the deforming portion abuts constantly, or when the deforming portion is deformed so as to protrude outward in the longitudinal direction of the duct (thin film).
Further, when the deforming portions provided at both ends in the long axis direction of the duct (thin film) are deformed so as to protrude outward in the long axis direction of the duct (thin film), the presser portion further exceeds the duct (thin film). ) Has a function as a restricting portion that restricts deformation to the outside in the major axis direction.
As a result, when the deformed portion is deformed so as to protrude outward in the major axis direction of the duct (thin film), the deformed portion can be pressed from the outer side of the duct (thin film) in the major axis direction. Even when the film is thinned, the pressure resistance of the duct (thin film) can be improved.

According to the fifth aspect of the invention, substantially the entire circumference in the circumferential direction of the duct is formed by the thin film.
According to the invention described in claim 6, the thin film is a flat resin film.
According to invention of Claim 7, the deformation | transformation part provided in the both ends of the major axis direction of a duct (thin film) is a shape which does not deform | transform so that it may become concave inside the major axis direction of a duct (thin film).

According to invention of Claim 8, the deformation | transformation part provided in the both ends of the major axis direction of a duct (thin film) is a predetermined angle so that it may protrude toward the outer side of the major axis direction of a duct (thin film). It is a bent part. The bent portions are arranged to face each other with a fluid flow path therebetween. When the pressure (negative pressure) lower than the pressure (for example, atmospheric pressure) in the surrounding environment of the duct (thin film) is applied, the bent portion protrudes outward in the major axis direction of the duct (thin film). Transforms into
According to the ninth aspect of the present invention, the deformed portions provided at both ends of the duct (thin film) in the major axis direction are curved surfaces that are curved so as to protrude outward in the major axis direction of the duct (thin film). It is. Then, when a pressure (negative pressure) lower than the pressure (for example, atmospheric pressure) in the surrounding environment of the duct (thin film) is applied to the curved surface parts (curved surface parts located at both ends in the long axis direction of the thin film), the duct The thin film is deformed to be convex outward in the major axis direction.

According to invention of Claim 10, the deformation | transformation part provided in the both ends of the longitudinal direction of a duct (thin film) is a planarized planar part. The flat portions are arranged to face each other with a fluid flow path therebetween. Then, when a pressure (negative pressure) lower than the pressure (for example, atmospheric pressure) in the surrounding environment of the duct (thin film) is applied to the plane section (the plane sections located at both ends in the long axis direction of the thin film), the duct The thin film is deformed to be convex outward in the major axis direction.
According to the eleventh aspect of the present invention, the fluid flow path is an intake passage communicating with the combustion chamber of the internal combustion engine. The fluid is intake air flowing through the intake passage of the internal combustion engine. And the deformation | transformation part provided in the both ends of the major axis direction of a duct (thin film) is outside the major axis direction of a duct (thin film), when a negative pressure generate | occur | produces when intake air passes through the intake passage of an internal combustion engine. Deform to be convex.

  The best mode for carrying out the present invention is to obtain a greater silencing effect and at the same time prevent the ends of the long axis direction of the duct (thin film) from collapsing inward. A thin film having a surface, a cross-sectional shape perpendicular to the flow direction of the fluid flowing through the fluid flow path is a flat shape having a major axis and a minor axis, and at least one of the plurality of surfaces is planar Furthermore, this is realized by providing deformable portions that can be deformed so as to protrude outward in the long axis direction of the duct (thin film) at both ends of the duct (thin film) in the long axis direction.

[Configuration of Example 1]
1 to 4 show a first embodiment of the present invention, FIG. 1 (a) shows an inner duct, FIG. 2 shows an intake control device for an internal combustion engine, and FIG. It is the figure which showed the intake silencer of the internal combustion engine.

  The control device (engine control system) for the internal combustion engine of the present embodiment supplies intake air to the combustion chamber of each cylinder of an internal combustion engine (for example, a 4-cylinder gasoline engine: hereinafter referred to as an engine) E having a plurality of cylinders. An intake passage opening / closing device that opens and closes an intake passage (an outside air introduction passage 10, a common intake passage 13, an intake introduction passage 14, a communication passage 15, an intake introduction passage 16, a common intake passage 17, a branch intake passage 20, etc.), and an engine E An intake vortex generator capable of generating an intake vortex for accelerating the combustion of the air-fuel mixture in the combustion chamber of each cylinder, and an intake noise reduction for reducing the intake noise generated with the intake air pulsation of the engine E The present invention is used as an intake control device for an internal combustion engine including a device (intake noise reduction device for an internal combustion engine). The intake control device including the intake noise reduction device is incorporated in the intake system of the engine E, and is installed in the engine room of a vehicle such as an automobile.

Here, the engine E is a thermal energy obtained by burning a mixture of clean intake air filtered by an air cleaner (air cleaner of an internal combustion engine) 1 and fuel injected from an injector (not shown) in a combustion chamber. A four-cycle engine is adopted that repeats four strokes (strokes) of an intake stroke, a compression stroke, an expansion (combustion) stroke, and an exhaust stroke as a cycle.
The engine E has an intake duct (intake duct, intake pipe) 2 for supplying intake air (intake air) into the combustion chamber of each cylinder, and exhaust gas flowing out from the combustion chamber of each cylinder of the engine E. An exhaust duct (exhaust duct, exhaust pipe) for discharging to the outside via an exhaust purification device is provided.

The engine E includes a cylinder head, a cylinder block, and the like. The plurality of intake ports formed on one side of the cylinder head are opened and closed by poppet type intake valves (intake valves), and the plurality of exhaust ports formed on the other side of the cylinder head are poppet type exhaust valves. It is opened and closed by (exhaust valve).
Further, in a cylinder bore formed inside the cylinder block, a piston connected to the crankshaft via a connecting rod is supported so as to be slidable in the sliding direction. Further, a spark plug is attached to the cylinder head of the engine E so that the tip end portion is exposed in the combustion chamber of each cylinder. The cylinder head is provided with an injector (electromagnetic fuel injection valve) that injects fuel into the intake port at an optimal timing.

The air cleaner 1 includes an outside air introduction duct (an inlet duct of the air cleaner 1) 21 installed at the most upstream part of the intake duct 2 of the engine E, an air cleaner case 22 to which a downstream end of the outside air introduction duct 21 is connected, and the air cleaner case 22. Air cleaner element (filter element) 23 and the like housed and held in the interior space (dust side space 11 and clean side space 12).
The filter element 23 filters the intake air (outside air) introduced into the internal space of the air cleaner case 22 from the outside air introduction port (intake port of the intake duct 2) 24 opened at the upstream end of the outside air introduction duct 21. That is, the filter element 23 captures and removes impurities (dust such as dust, dust and sand) contained in the outside air introduced from the outside air introduction port 24, so that hard impurities are sucked into the combustion chamber of the engine E. This is a filter (air filter) that prevents engine sliding wear and the like caused by the

The intake passage opening / closing device according to the present embodiment is an electronic throttle control device for an internal combustion engine, and is in the middle of an intake duct (intake pipe of the internal combustion engine) 2 of the engine E, that is, the intake air flow direction (intake flow) from the air cleaner 1. ), A throttle valve 26 accommodated in the throttle body 26 (common intake passage 17) so as to be opened and closed, and the throttle valve 27 in a valve closing operation direction (or valve opening). It is constituted by a return spring (or default spring) or the like that biases in the operation direction).
The throttle body 26 is provided with an actuator (such as an electric motor 29) that drives the throttle valve 27 in the valve opening operation direction (or valve closing operation direction) via the shaft 28. In addition, the throttle valve 27 variably controls the flow rate (intake air amount) of the intake air flowing through the throttle body 26 (common intake passage 17) according to the throttle opening corresponding to the valve opening. It is a valve.
The electric motor 29 is configured to be driven (energization control) by an engine control unit (hereinafter referred to as ECU).

The intake vortex generator of the present embodiment includes a plurality of intake flow control valves (tumble flow control valves: hereinafter referred to as TCVs) that generate a longitudinal intake vortex (tumble flow) in the combustion chamber of each cylinder of the engine E. I have. This TCV is the most downstream portion of the intake duct 2 of the engine E, that is, each branch duct portion 32 of the intake manifold 31 installed downstream of the surge tank 30 in the intake flow direction, and the inside (branch) of this branch duct portion 32. The intake flow control valve 33 is accommodated in the intake passage 20) so as to be freely opened and closed, and a return spring that urges the intake flow control valve 33 in the valve opening operation direction (or the valve closing operation direction).
The intake manifold 31 is provided with an actuator (such as an electric motor 35) that drives the intake flow control valve 33 in the valve closing operation direction (or the valve opening operation direction) via a single shaft 34. In addition, when the intake flow control valve 33 is fully closed or half-opened, the intake cross-sectional area inside each branch duct portion 32 (branch intake passage 20) of the intake manifold 31 is narrowed, so that each cylinder of the engine E can be controlled. It is a tumble flow control valve that generates a tumble flow in a combustion chamber.
The electric motor 35 is configured to be driven (energization control) by the ECU.

Here, the ECU includes a CPU for performing control processing and arithmetic processing, a storage device (memory such as ROM and RAM) for storing a control program or control logic and various data, an input circuit (input unit), and an output circuit (output unit). ), A microcomputer having a known structure configured to include functions of a power supply circuit, a timer, and the like.
Further, the ECU is configured to energize the electric motors 29 and 35 based on a control program or a control logic stored in the memory when the ignition switch is turned on (IG / ON). Thus, during operation of the engine E, the intake air amount (throttle opening), the valve opening of the TCV, and the like are controlled so as to become the control command values (control target values).
In addition, when the ignition switch is turned off (IG / OFF), the ECU performs engine control including throttle opening control and TCV valve opening control based on a control program or control logic stored in the memory (and further, Air-fuel ratio control, ignition control, fuel injection control, etc.) are forcibly terminated.

Next, the intake duct 2 of the engine E is a casing that forms an intake passage (fluid flow passage) for supplying intake air to the combustion chamber of each cylinder of the engine E, and is partially in the middle of the intake passage. The intake silencer 3 having a double pipe structure is installed.
That is, the intake duct 2 has an air cleaner case 22 having an outside air introduction duct 21, an intake pipe 25 coupled to the downstream side in the passage direction (intake air flow direction) from the air cleaner case 22, and intake air from the intake pipe 25. An intake silencer 3 having a double-pipe structure coupled to the downstream side in the flow direction, a throttle body 26 coupled to the downstream side in the intake flow direction with respect to the intake silencer 3, and an intake flow direction with respect to the throttle body 26 The surge tank 30 is coupled to the downstream side, and the intake manifold 31 is coupled to the downstream side of the surge tank 30 in the intake flow direction.

In addition, an outside air introduction passage 10 communicating with the inner space (dust side space 11 and clean side space 12) of the air cleaner case 22 is formed inside the outside air introduction duct 21. A common intake passage 13 communicating with the inside of the intake silencer 3 (communication passage 15) is formed inside the intake pipe 25. Further, a common intake passage (throttle bore) 17 communicating with the internal space (expansion chamber) 19 of the surge tank 30 is formed in the throttle body 26. Further, the cylinder head of the engine E is airtightly coupled to the downstream end of each branch duct portion 32 of the intake manifold 31.
The intake duct 2 of the engine E, in particular the intake pipe 25, has an air flow meter 36 for converting the amount of intake air supplied into the combustion chamber of each cylinder (all cylinders) of the engine E into an electric signal and outputting it to the ECU. It is installed.

The intake noise reduction device of the present embodiment is integrally installed in an intake duct 2 that introduces intake air into the combustion chamber of each cylinder of the engine E. As described above, the intake duct 2 has a double pipe structure intake silencer 3 or the like partially installed in the intake passage.
As shown in FIG. 2, the intake silencer 3 of the present embodiment is installed on the downstream side (clean side) in the intake air flow direction with respect to the filter element 23 of the air cleaner 1. The intake silencer 3 is hermetically connected between the intake pipe 25 and the throttle body 26. As shown in FIGS. 2 and 3, the intake silencer 3 has a polygonal cylindrical shape (in this example, hexagonal) in which intake passages (the intake introduction passage 14, the communication passage 15, and the intake introduction passage 16) are formed. Cylindrical (or polygonal cylindrical) cylinder tube (inner tube, inner cylinder: hereinafter referred to as an inner duct) 4 and a cylindrical silencer chamber 5 surrounding the inner duct 4. An outer cylinder wall (hereinafter referred to as an outer duct) 6 is provided.
Here, the intake introduction passage 14, the communication passage 15, and the intake introduction passage 16 constitute a first space (fluid flow path) having a polygonal cross section. Moreover, the muffler chamber 5 constitutes a second space (gas layer, air layer) having a cylindrical cross section. The silencer chamber 5 constitutes a sound wave interference air layer that causes sound waves to interfere and attenuate.

In the inner duct 4 of the present embodiment, the entire circumference (the whole) in the circumferential direction is formed by a vibration film (thin film) made of a thin resin film.
The diaphragm, which is the inner duct 4, is formed of a resin material (for example, a synthetic resin such as aromatic polyamide resin (PA), polyethylene terephthalate (PET), polypropylene (PP), polyethylene-2,6-naphthalate (PEN)). And a predetermined cylindrical resin film (for example, a thin PEN film).
The inner duct 4 constitutes a cylindrical thin film resonator that resonates and vibrates with the intake sound propagating in the intake duct 2, and the intake sound having a desired (specific) frequency is transferred from the communication path side to the muffler chamber side. A cylindrical inspiratory sound transmitting body that can be transmitted toward the surface is configured. A communication passage 15 communicating with the combustion chamber for each cylinder of the engine E is formed in the inner duct (vibration membrane) 4. The communication passage 15 constitutes a relay intake passage (fluid flow passage) that connects the inside of the intake pipe 25 (common intake passage 13) and the inside of the throttle body 26 (common intake passage 17).

As shown in FIGS. 1 to 4, the vibrating membrane that is the inner duct 4 is installed so as to surround the periphery of the communication path 15 in the circumferential direction. The inner duct 4 has a flat polygonal cylinder shape (hexagonal cylinder shape) having a long axis and a short axis in a cross-sectional shape perpendicular to the flow direction (intake flow direction) of intake air flowing in the communication passage 15. . That is, the inner duct 4 has a flat polygonal cylindrical shape that satisfies the relationship of a> b, where a is the length in the major axis direction and b is the length in the minor axis direction.
The inner duct 4 has a plurality of flat portions 41 to 43 disposed at predetermined intervals in the circumferential direction of the inner duct 4.

The plurality of flat portions 41 to 43 constituting the inner duct 4 are first to sixth thin film portions that are flattened, and are thinner than the thickness of the outer duct 6. Each of the flat portions 41 to 43 of the inner duct 4 constitutes a thin film partition that hermetically partitions the inner communication path 15 and the outer silencing chamber 5 and has a predetermined width and a predetermined length.
Each of the flat portions 41 to 43 is provided with a vibration surface that vibrates in resonance with a desired (specific) frequency of the intake sound that has propagated from the engine E through the intake duct 2. That is, each of the flat portions 41 to 43 constitutes a vibrating membrane (thin film) having a plurality of vibrating surfaces arranged at predetermined intervals in the circumferential direction of the inner duct 4.
A plurality of bent portions 44 and 45 bent at a predetermined angle are formed between the two adjacent flat portions 41 and 42 and between the two adjacent flat portions 42 and 43.
The plurality of flat portions 41 to 43 and the plurality of bent portions 44 and 45 constituting the inner duct 4 are parallel to the axial direction (intake flow direction) of the intake passage (such as the communication passage 15) of the engine E. It is formed to extend straight.

Further, the two first and second bent portions 51, 52 bent at a predetermined angle so as to protrude toward the outside in the major axis direction of the vibration film between the two adjacent flat portions 43, 41. Is formed. These first and second bent portions 51, 52 are arranged to face each other across the communication path 15 in the major axis direction of the inner duct 4. The two first and second bent portions 51 and 52 are disposed at both ends of the inner duct 4 in the major axis direction, and as shown in FIGS. When a suction negative pressure is applied to the inside (communication path 15), a deforming portion is formed that deforms so as to protrude outward in the major axis direction of the inner duct 4 as shown in FIG. Yes. In addition, the deforming portion has a shape that does not deform so as to be concave on the inner side in the long axis direction of the vibrating membrane.
Each of the first and second bent portions 51 and 52 of the inner duct 4 extends straight in a direction parallel to the axial direction (intake flow direction) of the intake passage (such as the communication passage 15) of the engine E. Is formed.

The outer duct 6 is a resin body formed of a resin material having higher rigidity (hardness) than the inner duct 4 (for example, a synthetic resin such as polypropylene (PP) or polyamide resin (PA)). The outer duct 6 is integrally formed in the middle of the intake duct 2. The upstream opening end of the outer duct 6 in the intake flow direction is airtightly coupled to the downstream end of the intake pipe 25. The opening end of the outer duct 6 on the downstream side in the intake flow direction is airtightly coupled to the upstream end of the throttle body 26.
As shown in FIGS. 2, 3, and 4 (c), the outer duct 6 is formed of a hard covering (outer pipe, Outer cylinder). The outer duct 6 has a cylindrical cross section perpendicular to the intake air flow direction.

Further, as shown in FIG. 3 and FIG. 4C, the outer duct 6 includes first and second bent portions (deformed portions) 51 of the inner duct 4 from the outer side in the major axis direction of the inner duct 4. , 52 are provided, two first and second pressing portions 71, 72 are provided. The first and second pressing portions 71 and 72 are provided on a curved surface portion curved with a predetermined curvature. The two first and second pressing portions 71 and 72 are deformed so that the first and second bent portions 51 and 52 of the inner duct 4 are convex outward in the major axis direction of the inner duct 4. A gap is formed between each of the first and second bent portions 51 and 52 of the inner duct 4 so as to come into contact later (see FIG. 3B). Alternatively, the first and second bent portions 51 and 52 of the inner duct 4 are always in contact with the two first and second pressing portions 71 and 72 (see FIG. 3D).
Here, the two first and second pressing portions 71 and 72 are deformed so that the first and second bent portions 51 and 52 of the inner duct 4 protrude outward in the major axis direction of the inner duct 4. When it does, it has the function as a control part which controls the deformation | transformation to the outer side of the major axis direction of the inner duct 4 beyond it.

[Operation of Example 1]
Next, the operation of the intake silencer 3 of the engine E of this embodiment will be briefly described with reference to FIGS.

When the ignition switch is turned on (IG / ON), the outside air is drawn from the outside air introduction port 24 according to the throttle opening of the throttle valve 27, and the engine E starts operation. At this time, when the specific cylinder of the engine E shifts from the exhaust stroke to the intake stroke where the intake valve opens and the piston descends, the negative pressure (pressure lower than atmospheric pressure) in the combustion chamber of the cylinder as the piston descends The air-fuel mixture is sucked into the combustion chamber from the intake port that is open.
Further, the engine E sequentially opens and closes the intake stroke, the compression stroke, the expansion (combustion) stroke, and the exhaust stroke by performing the opening / closing operation of the intake valve and the piston lifting / lowering movement. 2, vibration of intake air, that is, intake pulsation occurs. Then, along with the intake pulsation, intake pulsation sound, that is, intake sound propagates through the intake duct 2.

  When the intake noise that has propagated through the intake duct 2 reaches the intake silencer 3 from the engine side, the intake noise that has been propagated through the intake duct 2 by the plurality of flat portions 41 to 43 of the inner duct 4 of the intake silencer 3. Vibrates in resonance with a desired (specific) frequency (including a specific frequency band). Then, sound waves generated by the vibrations of the plurality of flat portions 41 to 43 of the inner duct 4 of the intake silencer 3 propagate from the plurality of flat portions 41 to 43 of the inner duct 4 into the silencer chamber 5 of the intake silencer 3. . The sound wave that has propagated to the inner periphery of the outer duct 6 of the intake silencer 3 is first attenuated in the silencer chamber 5 of the intake silencer 3.

Next, the sound wave propagating to the inner peripheral portion of the outer duct 6 of the intake silencer 3 is reflected by the inner peripheral portion of the outer duct 6 and becomes a reflected wave on the side of the plurality of flat portions 41 to 43 of the inner duct 4. Head for. Thereby, the sound wave generated by the vibration of the inner duct 4 of the intake silencer 3 is attenuated by interference between the sound wave traveling toward the outer duct and the reflected wave traveling toward the inner duct.
Therefore, since sound waves generated by the vibrations of the plurality of flat portions 41 to 43 of the inner duct 4 of the intake silencer 3 are attenuated (silenced), it is possible to reduce radiated sound transmitted from the outer duct 6 to the outside. It becomes.

[Effect of Example 1]
As described above, in the double-pipe structure air intake silencer 3 of the present embodiment, the long axis of the diaphragm is provided at both ends of the flat polygonal cylindrical inner duct 4 having the long axis and the short axis in the long axis direction. Two first and second bent portions (deformed portions) 51 and 52 bent at a predetermined angle are provided so as to protrude outward in the direction.
On the other hand, the outer duct 6 is provided with two first and second pressing portions 71 and 72 that press the two first and second bent portions 51 and 52 from the outside in the major axis direction of the inner duct 4. In these first and second pressing portions 71 and 72, negative pressure is applied to the inside (communication path 15) of the inner duct 4, and the two first and second bent portions 51 and 52 are the length of the inner duct 4. Provided so that the two first and second bent portions 51 and 52 are in contact with each other when they are deformed so as to protrude outward in the axial direction, or the two first and second bent portions 51 and 52 are always in contact with each other. It has been.
Thus, when the two first and second bent portions 51 and 52 are deformed so as to protrude outward in the major axis direction of the inner duct 4, the two first Since further deformation of the first and second bent portions 51 and 52 can be suppressed, the pressure resistance of the inner duct 4 can be improved even when the inner duct 4 is thinned.

Further, in the intake silencer 3 having a double-pipe structure according to the present embodiment, the inner duct 4 has a cross-sectional shape that is a flat polygonal cylinder having a major axis and a minor axis. When intake negative pressure is generated when intake air passes through the passage 15), the two first and second bent portions 51, 52 are not crushed inward in the longitudinal direction of the inner duct 4, and the inner duct The inner duct 4 is deformed so as to protrude outward in the major axis direction of the inner duct 4 having a larger projected area than the minor axis direction 4.
In addition, by forming the plurality of flat portions 41 to 43 in the circumferential direction of the inner duct 4, the inner duct 4 is more easily vibrated, and a greater silencing effect can be obtained as compared with the conventional technique.

  Therefore, even if the inner duct 4 is made thin, the inner duct 4 has insufficient pressure resistance, and by devising the cross-sectional shape of the inner duct 4, a greater silencing effect can be obtained and at the same time the inner duct 4. It is possible to prevent both ends in the long axis direction from being crushed inward. As a result, it is possible to prevent a reduction in the passage cross-sectional area inside the inner duct 4 (communication passage 15), so that the engine E, which is set corresponding to the amount of depression of the accelerator pedal (accelerator opening), is set. The required intake air amount can be easily obtained, and the engine output can be improved.

FIG. 5 shows a second embodiment of the present invention, and FIG. 5 shows an intake silencer.
The inner duct 4 of the present embodiment is configured by divided ducts 4a and 4b that are divided into two in the vertical direction in the figure. Similarly to the first embodiment, the divided ducts 4a and 4b are thin-film resin films, and the tops of the two first and second bent portions 51 and 52 are straightened in a direction approaching the outer duct 6. Two extending first and second plate-like protrusions 53 and 54 are integrally formed.

The outer duct 6 includes divided ducts 6a and 6b that are divided into two in the vertical direction in the figure. The divided ducts 6a and 6b have a pair of first and second facing portions 73 and 74 that face each other with a predetermined gap therebetween. These first and second facing portions 73 and 74 extend straight along the passage direction (intake flow direction) of the communication passage 15.
Here, the two first and second plate-like protrusions 53 and 54 are sandwiched and held and fixed between the first and second facing portions 73 and 74, respectively. Thereby, the diaphragm which is the inner duct 4 is fixed to the outer duct 6.

  Also in the intake silencer 3 of the present embodiment, the inner duct 4 has a cross-sectional shape that is a flat polygonal cylinder having a major axis and a minor axis. When intake negative pressure is generated when intake air passes through (communication passage 15), the two first and second bent portions 51 and 52 are not crushed inward in the longitudinal direction of the inner duct 4, The inner duct 4 is deformed so as to protrude outward in the major axis direction of the inner duct 4 having a larger projected area than the minor axis direction of the inner duct 4. As a result, the same effect as in the first embodiment can be achieved.

FIG. 6 shows a third embodiment of the present invention, and FIG. 6 shows an intake silencer.
In the intake silencer 3 of the present embodiment, as shown in FIGS. 6A and 6B, the cross-sectional shape of the inner duct (vibrating membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. Moreover, the cross-sectional shape of the outer duct 6 is a flat elliptic cylinder having a major axis and a minor axis.
And in the case of the inner duct 4 of a present Example, the two 1st, 2nd bending parts 51 and 52 are provided so that the two 1st, 2nd holding | suppressing parts 71 and 72 may always contact | abut. In addition, a plurality of bent portions 44 and 45 are provided so as to always contact the inner peripheral portion of the outer duct 6. Thereby, in the intake silencer 3 of the present embodiment, the pressure resistance of the inner duct 4 can be improved as compared with the first embodiment.

In addition, the intake silencer 3 of the present embodiment employs a hard belt 7 as a covering surrounding the inner duct (vibrating membrane) 4 as shown in FIGS. 6 (c) and 6 (d). Yes. A plurality of belts 7 are arranged at predetermined intervals along the intake flow direction.
In the case of the inner duct 4 of the present embodiment, the two first and second bent portions 51 and 52 are always in contact with the first and second pressing portions 71 and 72 provided on the plurality of belts 7. It is provided as follows.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

FIG. 7 shows a fourth embodiment of the present invention, and FIG. 7 shows an intake silencer.
In the intake silencer 3 of the present embodiment, the inner duct (vibration membrane) 4 has a cross-sectional shape that is a flat polygonal cylinder having a major axis and a minor axis, and the outer duct 6 has a sectional shape that is a major axis and a minor axis. The shape is a flat polygonal cylinder having an axis.
The inner duct 4 includes a polygonal cylindrical duct main body (vibration membrane) 90, a first connection joint portion 91 that is airtightly coupled to an upstream rubber hose 9a in the intake flow direction, and a rubber hose 9b downstream in the intake flow direction. The second connection joint portion 92 and the like that are hermetically coupled to each other. The two first and second connection joint portions 91 and 92 are formed of a resin material having higher rigidity (hardness) than the duct body 90 (for example, a synthetic resin such as polypropylene (PP) or polyamide resin (PA)). Resin body. In the inner duct 4 of this embodiment, a duct body 90 and two first and second connection joint portions 91 and 92 are integrally formed.
Further, the first and second pressing portions 71 and 72 of the outer duct 6 are applied with negative pressure inside the inner duct 4 (communication passage 15), and the two first and second bent portions 51 and 52 are connected to the inner duct 4. When the duct 4 is deformed so as to protrude outward in the major axis direction, the two first and second bent portions 51 and 52 come into contact with each other, or the two first and second bent portions 51 and 52 are always in contact with each other. It is provided to touch.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

FIG. 8 shows a fifth embodiment of the present invention, and FIG. 8 shows an intake silencer.
In the intake silencer 3 of the present embodiment, as shown in FIGS. 8A and 8B, the cross-sectional shape of the inner duct (vibrating membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. The cross-sectional shape of the outer duct 6 is a flat polygonal cylinder having a major axis and a minor axis.
In the case of the inner duct 4 of the present embodiment, the two first and second bent portions 51 and 52 are provided so as to always contact the first and second pressing portions 71 and 72 of the outer duct 6. It has been.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

In addition, as shown in FIGS. 8C and 8D, the intake silencer 3 of the present embodiment is a flat polygonal cylinder having a cross-sectional shape of the inner duct (vibrating membrane) 4 having a major axis and a minor axis. The cross-sectional shape of the outer duct 6 is a flat polygonal cylinder shape (an octagonal cylinder shape) having a major axis and a minor axis.
In the case of the inner duct 4 of the present embodiment, the two first and second bent portions 51 and 52 are provided so as to always contact the first and second pressing portions 71 and 72 of the outer duct 6. It has been.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

  FIGS. 9C to 9F show a sixth embodiment of the present invention, and FIG. 9 shows an inner duct. In the intake silencer 3 of the first embodiment, as shown in FIGS. 9A and 9B, the cross-sectional shape of the inner duct (vibrating membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. (Hexagonal cylinder shape).

In the intake silencer 3 of the present embodiment, as shown in FIGS. 9C and 9D, the inner duct (vibration membrane) 4 has a cross-sectional shape that is a flat long cylindrical shape having a major axis and a minor axis. It is said. The inner duct 4 has a plurality of flat surface portions 42 and a plurality of curved surface portions 46.
In addition, two planarized first and second planar portions 55 and 56 are formed between the two curved surface portions 46 respectively disposed at both ends of the inner duct 4 in the major axis direction. These first and second flat portions 55 and 56 are arranged to face each other across the communication passage 15 in the major axis direction of the inner duct 4.

The two first and second flat portions 55 and 56 are disposed at both ends of the inner duct 4 in the major axis direction, and when suction negative pressure is applied to the inside of the inner duct 4 (communication passage 15). The deformation part which deform | transforms so that it may become convex on the outer side of the major axis direction of the inner duct 4 is comprised.
Each of the first and second flat portions 55 and 56 of the inner duct 4 extends straight in a direction parallel to the axial direction (intake flow direction) of the intake passage (such as the communication passage 15) of the engine E. Is formed.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

In the intake silencer 3 of the present embodiment, as shown in FIGS. 9 (e) and 9 (f), the cross-sectional shape of the inner duct (vibrating membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. (Pentagonal cylinder shape). The inner duct 4 has a plurality of flat portions 41 to 43 and a plurality of bent portions 44 and 45.
Further, the two first and second bent portions 51, 52 bent at a predetermined angle so as to protrude toward the outside in the major axis direction of the vibration film between the two adjacent flat portions 43, 41. Is formed. These first and second bent portions 51, 52 are arranged to face each other across the communication path 15 in the major axis direction of the inner duct 4.

The two first and second bent portions 51 and 52 are disposed at both ends of the inner duct 4 in the major axis direction, and when suction negative pressure is applied to the inside of the inner duct 4 (communication path 15). The deformation part which deform | transforms so that it may become convex on the outer side of the major axis direction of the inner duct 4 is comprised.
Each of the first and second bent portions 51 and 52 of the inner duct 4 extends straight in a direction parallel to the axial direction (intake flow direction) of the intake passage (such as the communication passage 15) of the engine E. Is formed.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

FIG. 10 shows a seventh embodiment of the present invention, and FIG. 10 shows an inner duct. In the intake silencer 3 of the present embodiment, as shown in FIGS. 10A and 10B, the cross-sectional shape of the inner duct (vibration membrane) 4 is a flat, substantially elliptic cylinder having a major axis and a minor axis. It has a shape. The inner duct 4 has a plurality of vibration surfaces in the circumferential direction. In addition, at least one of the plurality of vibration surfaces is a flat surface. That is, the inner duct 4 has one flat surface portion 42 and a curved surface portion 47.
Further, between the flat surface portion 42 and the curved surface portion 47, two first and second curved surface portions 61 and 62 that are curved so as to protrude outward in the major axis direction of the inner duct (vibration membrane) 4. Is formed. The first and second curved surface portions 61 and 62 are disposed to face each other with the communication passage 15 therebetween in the major axis direction of the inner duct 4. Further, the two first and second curved surface portions 61 and 62 have a smaller radius of curvature than the curved surface portion 47.

The two first and second curved surface portions 61 and 62 are disposed at both ends of the inner duct 4 in the long axis direction, and suction negative pressure is applied to the inside of the inner duct 4 (communication passage 15). The deformation part which deform | transforms so that it may become convex on the outer side of the major axis direction of the inner duct 4 is comprised.
The first and second curved surface portions 61 and 62 of the inner duct 4 extend straight in a direction parallel to the axial direction (intake air flow direction) of the intake passage (such as the communication passage 15) of the engine E. Is formed.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

In the intake silencer 3 of the present embodiment, as shown in FIGS. 10C and 10D, the cross-sectional shape of the inner duct (vibrating membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. (Square tube shape, parallelogram tube shape). The inner duct 4 has a plurality of flat portions 41 and 43 and a plurality of bent portions 44.
In addition, two first and second bent portions bent at a predetermined angle are formed between the two adjacent flat portions 43 and 41 so as to protrude outward in the major axis direction of the vibration film. ing. Here, in this embodiment, two first and second chamfered portions (planar portions) 63 and 64 that are planarized are formed by chamfering the two first and second bent portions. The first and second chamfered portions 63 and 64 are disposed to face each other with the communication passage 15 therebetween in the major axis direction of the inner duct 4.

The two first and second chamfered portions 63 and 64 are disposed at both ends of the inner duct 4 in the major axis direction, and when suction negative pressure is applied to the inside of the inner duct 4 (communication passage 15). The deformation part which deform | transforms so that it may become convex on the outer side of the major axis direction of the inner duct 4 is comprised.
The first and second chamfered portions 63 and 64 of the inner duct 4 extend straight in a direction parallel to the axial direction (intake flow direction) of the intake passage (such as the communication passage 15) of the engine E. Is formed.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

FIG. 11 shows an eighth embodiment of the present invention, and FIG. 11 shows an inner duct. In the intake silencer 3 of the present embodiment, as shown in FIGS. 11A and 11B, the cross-sectional shape of the inner duct (vibrating membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. (Hexagonal cylinder shape). The inner duct 4 has a plurality of flat portions 41 to 43 and a plurality of bent portions 44 and 45.
In addition, two first and second bent portions bent at a predetermined angle are formed between the two adjacent flat portions 43 and 41 so as to protrude outward in the major axis direction of the vibration film. ing. Here, in this embodiment, two first and second chamfered portions (planar portions) 63 and 64 that are planarized are formed by chamfering the two first and second bent portions. The first and second chamfered portions 63 and 64 are disposed to face each other with the communication passage 15 therebetween in the major axis direction of the inner duct 4.

The two first and second chamfered portions 63 and 64 are disposed at both ends of the inner duct 4 in the major axis direction, and when suction negative pressure is applied to the inside of the inner duct 4 (communication passage 15). The deformation part which deform | transforms so that it may become convex on the outer side of the major axis direction of the inner duct 4 is comprised.
The first and second chamfered portions 63 and 64 of the inner duct 4 extend straight in a direction parallel to the axial direction (intake flow direction) of the intake passage (such as the communication passage 15) of the engine E. Is formed.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

In the intake silencer 3 of the present embodiment, as shown in FIGS. 11C and 11D, the cross-sectional shape of the inner duct (vibration membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. (Square tube shape, parallelogram tube shape). The inner duct 4 has a plurality of flat portions 41 and 43 and a plurality of bent portions 44.
Further, the two first and second bent portions 65 and 66 bent at a predetermined angle so as to protrude toward the outside in the major axis direction of the vibration film between the two adjacent flat portions 43 and 41. Is formed. These first and second bent portions 65, 66 are arranged to face each other across the communication path 15 in the major axis direction of the inner duct 4.

The two first and second bent portions 65 and 66 are disposed at both ends of the inner duct 4 in the major axis direction, and suction negative pressure is applied to the inside of the inner duct 4 (communication passage 15). The deformation part which deform | transforms so that it may become convex on the outer side of the major axis direction of the inner duct 4 is comprised.
Each of the first and second bent portions 65 and 66 of the inner duct 4 extends straight in a direction parallel to the axial direction (intake flow direction) of the intake passage (such as the communication passage 15) of the engine E. Is formed.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

FIG. 12 shows a ninth embodiment of the present invention, and FIG. 12 shows an inner duct. In the intake silencer 3 of the present embodiment, as shown in FIGS. 12A and 12B, the cross-sectional shape of the inner duct (vibrating membrane) 4 is a flat polygonal cylinder having a major axis and a minor axis. (Hexagonal cylinder shape). The inner duct 4 has a plurality of flat portions 41 to 43 and a plurality of bent portions 44 and 45.
Further, the two first and second bent portions 51, 52 bent at a predetermined angle so as to protrude toward the outside in the major axis direction of the vibration film between the two adjacent flat portions 43, 41. Is formed.

Here, in this embodiment, the widths of the two flat portions 42 arranged opposite to each other with the communication passage 15 therebetween are the same, and the widths of the flat portions 43 and 41 on both sides of the first bent portion 51 are the first width. The width of the flat portions 43 and 41 on both sides of the two bent portions 52 is shorter. For this reason, the angle of the first bent portion 51 is larger than the angle of the second bent portion 52. That is, the cross-sectional shape of the inner duct 4 is a flat polygonal cylinder shape that is asymmetrical to the left and right.
As described above, the intake silencer 3 of the present embodiment can achieve the same effects as those of the first embodiment.

[Modification]
In this embodiment, the intake passage opening and closing device and the intake vortex generator are installed in the intake duct 2 of the engine E. However, even if the intake passage opening and closing device or the intake vortex generator is not installed in the intake duct 2 of the engine E, good. It is only necessary that at least an intake sound reduction device (intake sound control device) is installed in the intake duct 2 of the engine E.
In this embodiment, a cylindrical space formed between the inner duct 4 and the outer duct 6 is used as the sound deadening chamber 5, but a cylindrical shape formed between the inner duct 4 and the outer duct 6. This space may be used as a sound absorption chamber or a resonance chamber.

  Here, when used as a resonance chamber, a branch opening (communication hole) is provided in the outer duct 6, and the dash panel (or side panel) is penetrated from the branch opening to open in the vehicle interior of the automobile. A branch duct extending to the opening is connected to the intake silencer 3. Then, by tuning the shape, thickness, area or position of the inner duct 4, the intake sound having a desired (specific) frequency (including a specific frequency band including, for example, about 100 to 400 Hz), for example, comfortable for the driver The intake sound is transmitted through the inner duct 4 and propagates from the resonance chamber and the branch opening of the intake silencer 3 into the branch duct penetrating the dash panel (or side panel), and then from the opening of the branch duct. Released into the car cabin. In this case, the intake silencer 3 is a resonator.

In this embodiment, the outer duct 6 having a polygonal cylinder shape (for example, a hexagonal cylinder shape) or a cylindrical shape is adopted as the outer duct. However, as the outer duct, a triangular cylindrical shape, a rectangular cylindrical shape, a pentagonal cylindrical shape, a heptagonal shape. You may employ | adopt the cylindrical covering body which has a plane part which has a predetermined area at least in part, such as polygonal cylinder shape more than a cylinder, or a long cylindrical shape or an elliptical cylinder shape.
In this embodiment, a flat polygonal cylinder shape (for example, a hexagonal cylinder shape) or an elliptical cylindrical vibration film (thin film, inner cylinder film) is adopted as the inner duct 4, but a triangular cylinder shape is used as the inner duct 4. Adopt a cylindrical vibrating membrane (thin film) that has a flat part with a predetermined area at least in part, such as a rectangular cylindrical shape, a pentagonal cylindrical shape, a polygonal cylindrical shape more than a heptagonal cylinder, or a long cylindrical shape. You may do it. Further, as the inner duct 4, a bilaterally symmetric flat diaphragm (thin film, inner cylinder film) is adopted. However, as the inner duct 4, a bilaterally asymmetric flat diaphragm (thin film, inner cylinder film) is adopted. ) May be adopted. Further, as the inner duct 4, a vibration film (thin film, inner cylinder film) having a flat shape that is asymmetrical in the front-rear direction (upstream side and downstream side is asymmetrical) or vertically asymmetrical may be adopted.

  In the present embodiment, the silencer of the present invention is used for the intake sound generated by the engine E, that is, the flow direction of intake air (fluid, particularly gas) flowing through the intake passage (fluid flow path) from the inner duct 4 (intake flow direction). ) Is applied to the intake silencer 3 for attenuating the sound generated on the downstream side, but the silencer of the present invention attenuates the sound generated on the upstream side in the flow direction of the fluid flowing through the fluid flow path rather than the duct. You may apply to the silencer to be made. Or you may apply the silencer of this invention to the silencer which attenuates the sound generated inside the duct.

In this embodiment, the entire circumference of the inner duct 4 in the circumferential direction is formed by a vibration film (thin film) made of a resin film. However, if at least one of the plurality of faces is flat, the circumference of the inner duct 4 is Only a part of the direction may be formed by a thin film.
In the present embodiment, the cylindrical covering body surrounding the duct via the gas layer is formed by the hard outer duct 6, but the covering body may be formed by a soft covering material. The silencer chamber (gas layer) 5 may be configured such that a part of the inner duct 4 in the circumferential direction is sealed and the remaining part of the inner duct 4 in the circumferential direction is opened.
Further, the outer duct (covering body) 6 may be provided with a communication hole that communicates the sound deadening chamber (gas layer) 5 with the outside of the outer duct (covering body) 6. Further, the outer duct (covering body) 6 may not be provided.
Further, the air layer (silence chamber 5) may be changed to a gas layer (gas layer) in which an inert gas such as argon, helium or xenon, nitrogen gas or the like is enclosed.

In this embodiment, the outer duct 6 is formed of a resin material that is harder (higher rigidity) than the inner duct 4, but the outer duct 6 is made of a metal material that is harder (higher rigidity) than the inner duct 4 (for example, (Aluminum, iron, etc.) may be used.
In this embodiment, the silencer of the present invention is applied to an intake silencer 3 having a double pipe structure partially installed in the middle of the intake duct 2 of the engine E. However, the silencer of the present invention is You may apply to the exhaust silencer (car muffler) partially installed in the middle of the exhaust duct of the internal combustion engine. The silencer of the present invention may be applied to a silencer that is partially installed in the middle of an intake duct for an air conditioner (air conditioner) or an exhaust duct of a combustion heating apparatus.

(A) is sectional drawing which showed the inner duct (Example 1). (B) is sectional drawing which showed the inner duct (thin film) (comparative example 1). FIG. 1 is a schematic view showing an intake control device for an internal combustion engine (Example 1). (A) is AA sectional drawing of (b), (b) is sectional drawing which showed the intake silencer, (c) is BB sectional drawing of (d), (d) is intake silencer (Example 1) which is sectional drawing which showed the container. (A), (b) is explanatory drawing which showed the deformation | transformation of the inner duct, (c) is sectional drawing which showed the intake silencer of the internal combustion engine (Example 1). (A) is CC sectional drawing of (b), (b) is sectional drawing which showed the intake silencer (Example 2). (A) is a DD sectional view of (b), (b) is a sectional view showing an intake silencer, (c) is an EE sectional view of (d), and (d) is an intake silencer. (Example 3) which is sectional drawing which showed the container. (Example 4) which is the perspective view which showed the intake silencer. (A) is FF sectional drawing of (b), (b) is sectional drawing which showed the intake silencer, (c) is GG sectional drawing of (d), (d) is intake silencer (Example 5) which is sectional drawing which showed the container. (A), (b) is the top view and sectional drawing which showed the inner duct (Example 1). (C), (d) is the top view and sectional drawing which showed the inner duct, (e), (f) is the top view, sectional drawing which showed the inner duct (Example 6). (A), (b) is the top view and sectional drawing which showed the inner duct, (c), (d) is the top view, sectional drawing which showed the inner duct (Example 7). (A), (b) is the top view and sectional drawing which showed the inner duct, (c), (d) is the top view, sectional drawing which showed the inner duct (Example 8). (A), (b) is the top view and sectional drawing which showed the inner duct (Example 9). It is sectional drawing which showed the intake silencer (prior art).

Explanation of symbols

E engine (internal combustion engine)
2 Engine intake duct 3 Double pipe structure intake silencer 4 Inner duct (thin film, vibrating membrane, inner tube, inner cylinder membrane)
5 Silence room (gas layer, air layer)
6 Outer duct (cover, outer tube, outer cylinder wall)
7 Belt (cover)
14 Intake introduction passage (fluid flow passage, intake passage)
15 Communication passage (fluid flow passage, intake passage)
16 Intake intake passage (fluid flow passage, intake passage)
41 Plane portion of inner duct 42 Plane portion of inner duct 43 Plane portion of inner duct 51 First bent portion (deformed portion) of inner duct
52 Second bent part (deformed part) of inner duct
55 1st plane part (deformation part) of inner duct
56 2nd plane part (deformation part) of inner duct
61 First curved surface part (deformation part) of inner duct
62 Second curved surface part (deformation part) of inner duct
63 1st chamfered part (deformed part) of inner duct
64 Second chamfered part (deformed part) of inner duct
65 First bent part (deformed part) of inner duct
66 Second bent part (deformed part) of inner duct
71 1st holding part (regulation part) of outer duct
72 2nd holding part (regulator part) of outer duct

Claims (11)

A cylindrical duct having a fluid flow path formed therein, and a covering body surrounding the duct,
In the silencer that attenuates the sound generated in the duct or upstream or downstream of the duct in the flow direction of the fluid flow path,
The duct includes a thin film having a plurality of surfaces in the circumferential direction, and a cross-sectional shape perpendicular to the flow direction of the fluid flowing through the fluid flow path is a flat shape having a major axis and a minor axis,
At least one of the plurality of surfaces is a plane,
The thin film has deformable portions that can be deformed so as to protrude outward in the major axis direction of the duct at both ends in the major axis direction of the duct when negative pressure is applied to the inside of the duct. And
The silencer is characterized in that the deforming portion contacts the covering body when the deforming portion is always in contact or when the deforming portion is deformed so as to protrude outward in the long axis direction of the duct. The silencer according to claim 1,
The duct is a thin film inner duct,
The silencer, wherein the covering is a hard outer duct that surrounds the inner duct with a gas layer. The muffler according to claim 1 or 2,
The covering is a hard belt surrounding the duct,
The silencer, wherein the deformable portion abuts on the belt when the deformable portion is always in contact with the belt, or when the deformable portion is deformed so as to protrude outward in the longitudinal direction of the duct. The silencer according to any one of claims 1 to 3,
The covering includes a pressing portion that presses the deforming portion from the outside in the long axis direction of the thin film, and the pressing portion is always in contact with the deforming portion, or the deforming portion is in the long axis direction of the duct. The muffler, wherein the deformed portion contacts when deformed so as to be convex outward. The muffler according to any one of claims 1 to 4,
A silencer characterized in that the duct is formed by the thin film over substantially the entire circumference in the circumferential direction. The muffler according to any one of claims 1 to 5,
The silencer, wherein the thin film is a flat resin film. The silencer according to any one of claims 1 to 6,
The muffler according to claim 1, wherein the deforming portion has a shape that does not deform so as to be recessed inside the long axis of the thin film. The silencer according to any one of claims 1 to 7,
The muffler characterized in that the deforming portion is a bent portion that is arranged to face each other across the fluid flow path and is bent at a predetermined angle so as to protrude outward in the major axis direction of the thin film. vessel. The silencer according to any one of claims 1 to 7,
The muffler, wherein the deforming portion is a curved portion that is curved so as to be convex toward the outside in the major axis direction of the thin film. The silencer according to any one of claims 1 to 7,
The muffler according to claim 1, wherein the deforming portion is a flattened flat portion disposed opposite to the fluid flow path. The muffler according to any one of claims 1 to 10,
The fluid flow path is an intake passage communicating with a combustion chamber of an internal combustion engine,
The fluid is intake air flowing through the intake passage,
The muffler is characterized in that the deforming portion deforms so as to protrude outward in the long axis direction of the thin film when a negative pressure is generated when intake air passes through the intake passage.

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