Ventilation type silencer

Abstract

The invention provides a ventilation-type muffler which is provided with an expansion part formed by a resin frame body, and can restrain the enlargement of the muffler and restrain the generation of condensation in a back side space. A ventilation-type muffler having an inlet-side breather pipe, an expansion part that communicates with the inlet-side breather pipe and has a larger cross-sectional area than the inlet-side breather pipe, and an outlet-side breather pipe that communicates with the expansion part and has a smaller cross-sectional area than the expansion part, the ventilation-type muffler being provided with: a resin frame that constitutes the expansion part; a flow path wall which is disposed within the housing, connects the inlet-side breather pipe and the outlet-side breather pipe, and is configured from a first portion of the housing and a porous sound-absorbing material; a back-side space located on the opposite side of the flow path space in the flow path wall with the porous sound-absorbing material interposed therebetween, the back-side space being partitioned by the porous sound-absorbing material and a second portion of the housing different from the first portion; and a heat transfer member thermally connecting the first portion and the second portion and having a higher thermal conductivity than the frame body.

Description

Technical Field

[0001] The present invention relates to a ventilation muffler. Background Art

[0002] Generally, a ventilation muffler is known, which has an inlet side ventilation pipe, a diffusion part communicating with the inlet side ventilation pipe and having a cross-sectional area larger than that of the inlet side ventilation pipe, and an outlet side ventilation pipe communicating with the diffusion part and having a cross-sectional area smaller than that of the diffusion part.

[0003] As such a ventilation muffler, a ventilation muffler is known, which includes: a flow path wall disposed in the diffusion part and made of a porous sound absorbing material; and a back side space located on the side opposite to the flow path space in the flow path wall across the flow path wall, and defined by the flow path wall and the frame of the diffusion part (for example, refer to Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 6-167982 Summary of the Invention

[0007] Technical Problem to be Solved by the Invention

[0008] In such a ventilation muffler, in order to reduce the weight and cost, it is possible to consider making the frame of the diffusion part made of resin. However, according to the research of the present inventors, it is known that if the frame of the diffusion part is made of resin, when the ventilation muffler is installed outdoors and a high-temperature and high-humidity gas having a temperature higher than that of the outside flows in the flow path space, dew condensation may occur in the back side space. This is because the moisture transferred from the flow path space to the back side space through the micropores of the porous sound absorbing material comes into contact with the inner surface of the frame cooled by the outside gas.

[0009] As a method for suppressing the occurrence of dew condensation, a method of disposing a heat insulating material inside or outside the frame can be considered. However, if the heat insulating material is disposed inside the frame, the back side space and the flow path space become narrow, and as a result, the sound absorption performance and the air volume are reduced. Therefore, the heat insulating material is disposed outside the frame, but this causes the device to be enlarged.

[0010] An object of the present invention is to solve the above problems of the prior art and provide a ventilation muffler having a diffusion part formed of a resin frame, which can suppress enlargement and suppress the occurrence of dew condensation in the back side space.

[0011] Means for Solving the Technical Problem

[0012] To solve this problem, the present invention has the following configuration.

[0013] [1] A ventilation muffler having an inlet side ventilation pipe, a dilation part communicating with the inlet side ventilation pipe and having a cross-sectional area larger than that of the inlet side ventilation pipe, and an outlet side ventilation pipe communicating with the dilation part and having a cross-sectional area smaller than that of the dilation part, the ventilation muffler comprising:

[0014] A resin frame forming the dilation part;

[0015] A flow path wall disposed within the frame to connect the inlet side ventilation pipe and the outlet side ventilation pipe, and composed of a first part of the frame and a porous sound absorbing material;

[0016] A back side space located on the side opposite to the flow path space within the flow path wall across the porous sound absorbing material, and demarcated by the porous sound absorbing material and a second part of the frame different from the first part; and

[0017] A heat transfer member thermally connecting the first part and the second part and having a higher thermal conductivity than the frame.

[0018] [2] The ventilation muffler according to [1], wherein

[0019] The heat transfer member is disposed along the frame on the outer side of the frame.

[0020] [3] The ventilation muffler according to [1] or [2], wherein

[0021] The heat transfer member is disposed along the frame on the inner side of the frame.

[0022] [4] The ventilation muffler according to any one of [1] to [3], further comprising a heat insulating material disposed along the inner side of the heat transfer member in the back side space.

[0023] [5] The ventilation muffler according to any one of [1] to [4], further comprising a heat insulating material disposed along the heat transfer member on the side opposite to the frame across the heat transfer member.

[0024] [6] The ventilation muffler according to any one of [1] to [5], wherein

[0025] The temperature of the gas flowing in the flow path space is higher than the temperature on the outer side of the frame.

[0026] Effects of the Invention

[0027] According to the present invention, it is possible to provide a ventilation muffler having a dilation part formed of a resin frame, which can suppress enlargement and suppress dew condensation in the back side space. Description of the Drawings

[0028] Figure 1It is a perspective view schematically showing an example of an embodiment of the ventilation muffler of the present invention.

[0029] Figure 2 It is a cross-sectional view taken along the Figure 1 A-A line of

[0030] Figure 3 It is a perspective view schematically showing another example of an embodiment of the ventilation muffler of the present invention.

[0031] Figure 4 It is a cross-sectional view taken along the Figure 3 B-B line of

[0032] Figure 5 It is a perspective view schematically showing another example of an embodiment of the ventilation muffler of the present invention.

[0033] Figure 6 It is a cross-sectional view taken along the Figure 5 C-C line of

[0034] Figure 7 It is a perspective view schematically showing another example of an embodiment of the ventilation muffler of the present invention.

[0035] Figure 8 It is a cross-sectional view taken along the Figure 7 D-D line of

[0036] Figure 9 It is an exploded perspective view of the ventilation muffler according to the comparative example.

[0037] Figure 10 It is a view obtained by photographing the ventilation muffler according to Example 1 with a camera.

[0038] Figure 11 It is a view obtained by photographing the ventilation muffler according to the comparative example with an infrared thermal imaging camera.

[0039] Figure 12 It is a view obtained by photographing the ventilation muffler according to Example 1 with an infrared thermal imaging camera.

[0040] Figure 13 It is a view obtained by photographing the ventilation muffler according to Example 1 with an infrared thermal imaging camera.

[0041] Figure 14 It is a view obtained by photographing the ventilation muffler according to Example 2 with an infrared thermal imaging camera.

[0042] Figure 15 It is a graph comparing the temperature distributions inside the enclosures in Example 1 and Example 2.

[0043] Figure 16 This is a graph showing the relationship between frequency and transmission loss in Example 1.

[0044] Figure 17 This is a graph showing the relationship between the frequency and the noise radiated to the outside from the ventilation type muffler in Comparative Example 1 and Example 1. DETAILED DESCRIPTION

[0045] Hereinafter, the ventilation type silencer of the present invention will be described in detail.

[0046] The description of the constituent elements described below is based on typical embodiments of the present invention, but the present invention is not limited to these embodiments.

[0047] In addition, in this specification, the numerical range expressed with "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0048] Furthermore, in this specification, "perpendicular" and "parallel" include the error range allowed in the technical field to which the present invention belongs. For example, "perpendicular" and "parallel" mean that the error relative to strict perpendicularity or parallelism is within a range of less than ±10°, and the error relative to strict perpendicularity or parallelism is preferably less than 5°, and more preferably less than 3°.

[0049] In this specification, the terms "same", "identical" and the like include an error range generally allowed in the technical field.

[0050] In this specification, the arrangement direction of the inlet vent pipe, the expansion portion, and the outlet vent pipe is defined as the X direction, the direction perpendicular to the X direction is defined as the Y direction, and the direction perpendicular to the X and Y directions is defined as the Z direction.

[0051] <Ventilation type muffler>

[0052] The ventilation type silencer of the present invention comprises an inlet side vent pipe, an expansion portion communicating with the inlet side vent pipe and having a larger cross-sectional area than the inlet side vent pipe, and an outlet side vent pipe communicating with the expansion portion and having a smaller cross-sectional area than the expansion portion, wherein the ventilation type silencer comprises:

[0053] A resin frame body constituting the expansion portion;

[0054] The flow path wall is arranged in the frame and connects the inlet side vent pipe with the outlet side vent pipe, and is composed of the first part of the frame and the porous sound absorbing material;

[0055] a back space located on the opposite side of the flow path space in the flow path wall across the porous sound absorbing material and divided by the porous sound absorbing material and a second portion of the frame body that is different from the first portion; and

[0056] A heat transfer component that thermally connects the first part and the second part and has a higher thermal conductivity than the housing.

[0057] <An example of an embodiment>

[0058] The structure of the ventilation muffler of the present invention will be described with reference to the accompanying drawings.

[0059] Figure 1 It is a perspective view schematically showing an example of an embodiment of the ventilation muffler of the present invention. Figure 2 It is along Figure 1 The cross-sectional view taken along the line A-A of

[0060] Figure 1 The ventilation muffler 10A shown has: a cylindrical inlet-side ventilation pipe 12; an expansion part 14 connected to one open end face of the inlet-side ventilation pipe 12; a cylindrical outlet-side ventilation pipe 16 connected to the end face of the expansion part 14 opposite to the inlet-side ventilation pipe 12; a backside space 30; a flow path wall 20 disposed in the housing 18 of the expansion part 14; and a heat transfer component 32 having a higher thermal conductivity than the housing 18.

[0061] In Figure 1 In the example shown, the flow direction of the gas flowing in the expansion part 14 is the same as the arrangement direction (X direction).

[0062] The temperature and humidity of the gas flowing in the ventilation muffler 10A vary depending on the usage mode of the ventilation muffler 10A. In an example of the present embodiment, as Figure 2 shown, the temperature of the gas flowing in the flow path space 24 in the expansion part 14 is higher than the temperature outside the ventilation muffler 10A, that is, outside the housing 18 constituting the expansion part 14. For example, assume a usage mode where the expansion part 14 is disposed outdoors. The gas flowing in the flow path space 24 is high-temperature and high-humidity. Specifically, assume a temperature range of 20 to 80 °C and a humidity range of 50 to 95% RH.

[0063] [Ventilation pipe]

[0064] As Figure 1 shown, the inlet-side ventilation pipe 12 is a cylindrical component and conveys the gas flowing in from one open end face to the expansion part 14 connected to the other open end face. The cross-sectional area of the inlet-side ventilation pipe 12 is smaller than that of the expansion part 14.

[0065] As Figure 1 shown, the outlet-side ventilation pipe 16 is a cylindrical component and communicates with the expansion part 14, and conveys the gas flowing in from one open end face connected to the expansion part 14 to the other open end face. The cross-sectional area of the outlet-side ventilation pipe 16 is smaller than that of the expansion part 14.

[0066] The cross-sectional shapes of the inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16 (hereinafter, also collectively referred to as the ventilation pipes) can be various shapes such as circular, rectangular, triangular, etc. Moreover, in the axial direction of the central axis of the ventilation pipe, the cross-sectional shape of the ventilation pipe may not be constant. For example, in the axial direction, the diameter of the ventilation pipe can change.

[0067] The inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16 can have the same cross-sectional shape and cross-sectional area, or the shape and / or cross-sectional area can also be different. And, in Figure 1 In the example shown, the inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16 are arranged with their central axes aligned, but it is not limited thereto, and the central axis of the inlet-side ventilation pipe 12 and the central axis of the outlet-side ventilation pipe 16 can also be offset.

[0068] The dimensions (such as cross-sectional area) of the inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16 can be appropriately set according to the dimensions of the equipment using the ventilation type muffler, the required ventilation performance, etc.

[0069] As the material for forming the ventilation pipe, for example, metal materials, resin materials, reinforced plastic materials, and carbon fiber, etc. can be cited. As metal materials, for example, metal materials such as aluminum, titanium, magnesium, tungsten, iron, steel, chromium, chromium molybdenum, nickel chromium molybdenum, and their alloys can be cited. And, as resin materials, for example, acrylic resin (PMMA), polymethyl methacrylate, polycarbonate, polyamideimide, polyarylate, polyetherimide, polyacetal, polyetheretherketone, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate (PET), polyimide, triacetyl cellulose (TAC), polypropylene (PP), polyethylene (PE), polystyrene (PS), ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin), flame-retardant ABS resin, ASA resin (acrylonitrile, styrene, acrylate copolymer synthetic resin), PVC (polyvinyl chloride) resin, and PLA (polylactic acid) resin, etc. can be cited. And, as reinforced plastic materials, carbon fiber reinforced plastic (CFRP: Carbon Fiber Reinforced Plastics) and glass fiber reinforced plastic (GFRP: Glass Fiber Reinforced Plastics) can be cited.

[0070] [Expansion part and housing]

[0071] The expansion part 14 is arranged between the inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16, and is in communication with the inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16.

[0072] In a cross-section perpendicular to the X direction, the expansion section 14 has a larger cross-sectional area than either the inlet-side ventilation pipe 12 or the outlet-side ventilation pipe 16. For example, when the cross-sectional shapes of the inlet-side ventilation pipe 12, the outlet-side ventilation pipe 16, and the expansion section 14 are circular, the diameter of the cross-section of the expansion section 14 is larger than the diameters of the inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16.

[0073] The cross-sectional shape of the expansion section 14 can be various shapes such as circular, rectangular, and triangular. Also, in the axial direction (X direction) of the expansion section 14, the cross-sectional shape of the expansion section 14 may not be constant. For example, in the X direction, the equivalent circle diameter of the expansion section 14 can change. Additionally, in Figure 1 the example shown, the cross-section of the expansion section 14 is set as rectangular, and the cross-sectional shape is set as constant in the X direction.

[0074] The dimensions (length, cross-sectional area, etc.) of the expansion section 14 can be appropriately set according to the dimensions of the equipment using the ventilation type muffler, the required sound absorption performance, etc.

[0075] The expansion section 14 has a resin-made frame body 18 that constitutes its outer edge. The frame body 18 is a hollow, substantially rectangular parallelepiped shape extending in the X direction. The inlet-side ventilation pipe 12 is connected to one side surface in the X direction, and the outlet-side ventilation pipe 16 is connected to the other side surface facing the one side surface. With respect to the centers of these side surfaces respectively, the centers of the inlet-side ventilation pipe 12 and the outlet-side ventilation pipe 16 are offset to the side ( Figure 1 the lower side) in the direction (Z direction) orthogonal to the flow direction (X direction).

[0076] The frame body 18 is made of resin. Specifically, it is formed of a resin material or a reinforced plastic material. As the resin material, for example, acrylic resin (PMMA), polymethyl methacrylate, polycarbonate, polyamideimide, polyarylate, polyetherimide, polyacetal, polyetheretherketone, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate (PET), polyimide, triacetyl cellulose (TAC), polypropylene (PP), polyethylene (PE), polystyrene (PS), ABS resin (acrylonitrile, butadiene, styrene copolymerized synthetic resin), flame-retardant ABS resin, ASA resin (acrylonitrile, styrene, acrylate copolymerized synthetic resin), PVC (polyvinyl chloride) resin, and PLA (polylactic acid) resin, etc. And, as the reinforced plastic material, carbon fiber reinforced plastic (CFRP: Carbon Fiber Reinforced Plastics) and glass fiber reinforced plastic (GFRP: Glass Fiber Reinforced Plastics) can be cited.

[0077] The housing 18 has a hollow, generally rectangular parallelepiped shape extending in the X direction, as Figure 1 and Figure 2 shown, and is composed of six walls. More specifically, the housing 18 has a pair of first walls 18a, 18b (refer to Figure 2 ) arranged at intervals in the Z direction, a pair of second walls 18c, 18c (refer to Figure 2 ) arranged at intervals in the Y direction, and a pair of third walls 18d, 18d (refer to Figure 1 ) arranged at intervals in the X direction. The walls 18a, 18b, 18c, 18d are plate members that are rectangular in plan view. The housing 18 is formed by joining adjacent walls to each other using an adhesive, binder, solder, welding, etc. Alternatively, in the case where the housing 18 is divided into two parts to be fragmented, each fragment can be manufactured by injection molding and a 3D printer, etc., and the housing 18 can be formed by combining the fragments with each other, or can be formed integrally by blow molding.

[0078] A pair of third walls 18d, 18d arranged at intervals in the flow direction (X direction) are each provided with an opening. An unillustrated connector (also referred to as an adapter, joint) for connecting the inlet side ventilation pipe 12 and the outlet side ventilation pipe 16 to the expansion part 14 is installed in the opening. The inlet side ventilation pipe 12 and the outlet side ventilation pipe 16 are respectively installed at the end portions of each connector. Thus, the gas flowing in the inlet side ventilation pipe 12 is transported to the expansion part 14 through the inside of one connector, and the gas flowing in the expansion part 14 is transported to the outlet side ventilation pipe 16 through the inside of the other connector arranged on the side opposite to one connector.

[0079] [Flow path wall]

[0080] As Figure 2 shown, a flow path wall 20 is arranged inside the housing 18. The flow path wall 20 connects the inlet side ventilation pipe 12 and the outlet side ventilation pipe 16, and is arranged to surround the flow path space 24 when the area connecting the inlet side ventilation pipe 12 and the outlet side ventilation pipe 16 linearly is used as the flow path (also referred to as the flow path space 24). The flow path wall 20 has a cylindrical shape with both ends in the flow direction (X direction) open and extending along the flow direction.

[0081] In this example, the cross-sectional shape of the flow path wall 20, more specifically, the cross-sectional shape perpendicular to the flow direction (X direction) of the gas flowing inside the flow path wall 20, is rectangular. However, it is not limited thereto, and the flow path wall 20 can also have various shapes such as circular or triangular.

[0082] As Figure 2 shown, the flow path wall 20 is arranged on the side of the first wall 18a in the Z direction ( Figure 2on the lower side) and is disposed at the center of the first wall 18a in the Y direction.

[0083] More specifically, the flow path wall 20 includes a part of the first wall 18a (the first part 18e). As Figure 2 shown, the flow path wall 20 is composed of the first part 18e and three porous sound-absorbing materials 21, 22, and 23. The flow path wall 20 is composed of a pair of porous sound-absorbing materials 21, 22 arranged at intervals in the Y direction, a porous sound-absorbing material 23 arranged at intervals in the Z direction, and the first part 18e. In other words, on the first wall 18a, a pair of porous sound-absorbing materials 21, 22 are respectively arranged on the two outer sides in the Y direction with the first part 18e interposed therebetween. And, on the ends of the porous sound-absorbing materials 21, 22 in the Z direction on the side opposite to the first part 18e, a porous sound-absorbing material 23 opposed to the first part 18e in the Z direction is arranged.

[0084] As Figure 2 shown, the first part 18e and the porous sound-absorbing materials 21, 22, 23 together define a flow path space 24. The first part 18e is located at the center of the first wall 18a in the Y direction and extends from one end in the X direction (the end on the inlet side vent pipe 12 side) to the other end (the end on the outlet side vent pipe 16 side) of the first wall 18a. The inner side (inner surface) of the first part 18e faces the flow path space 24 and is in contact with the gas flowing in the flow path space 24. Therefore, the heat of the gas flowing in the flow path space 24 is directly transferred to the first part 18e.

[0085] The porous sound-absorbing materials 21, 22, 23 absorb sound by converting the sound energy of the sound wave passing through the interior into heat energy. The ends of the three porous sound-absorbing materials 21, 22, 23 in the flow direction (X direction) are in contact with the inner surfaces of a pair of third walls 18d, 18d opposed to each other in the X direction. The porous sound-absorbing materials 21, 22, 23 are, for example, plate members having the X direction as the long side direction and being rectangular when viewed from above.

[0086] The porous sound-absorbing materials 21, 22, and 23 are not particularly limited, and conventionally known sound-absorbing materials can be appropriately used. For example, foams, foam materials (foamed polyurethane foams (e.g., CALMFLEX F of INOAC CORPORATION, polyurethane foams manufactured by HIKARI CO., LTD., AchillesAERON manufactured by ACHILLES CORPORATION, etc.), soft polyurethane foams, sintered ceramic particle materials, phenolic foams, melamine foams, polyamide-based foams, etc.), non-woven fabric sound-absorbing materials (ultrafine fiber non-woven fabrics (e.g., Thinsulate of 3M Company), polyester non-woven fabrics (e.g., White Kyuon of TOKYO BOUON Company, QonPET of Bridgestone KBG Co., Ltd., and these products are also provided in a double-layer structure of a thin front non-woven fabric with a high density and a back non-woven fabric with a low density), plastic non-woven fabrics such as acrylic fiber non-woven fabrics, natural fiber non-woven fabrics such as wool and felt, metal non-woven fabrics, and glass non-woven fabrics, etc.), and other materials containing minute air (glass wool, asbestos, nanofiber-based fiber sound-absorbing materials (silica nanofibers, acrylic nanofibers (e.g., XAI manufactured by Mitsubishi Chemical Corporation)), etc.) can be used.

[0087] Moreover, as the porous sound-absorbing materials 21, 22, and 23, a sound-absorbing material having a double-layer structure of a thin front non-woven fabric with a high density and a back non-woven fabric with a low density can be used.

[0088] The size, type, etc. of the porous sound-absorbing materials 21, 22, and 23 may be appropriately set according to the sound absorption performance (sound absorption frequency, sound absorption amount), ventilation volume, etc. required for the ventilation muffler 10A.

[0089] The thickness of the porous sound-absorbing materials 21, 22, and 23 may be appropriately set to a thickness that can obtain the desired sound absorption performance according to the flow resistance, porosity, tortuosity, etc. of the porous sound-absorbing material 22. For example, from the viewpoint of sound absorption performance, the thickness of the porous sound-absorbing materials 21, 22, and 23 is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and most preferably 10 mm to 20 mm.

[0090] [Back side space]

[0091] As Figure 2 shown, the back side space 30 is located on the side opposite to the flow path space 24 (hereinafter, also referred to as the back side) across the flow path wall 20. The back side space 30 is a space obtained by removing the flow path space 24 from the internal space surrounded by the frame body 18. Regarding its cross-sectional shape, asFigure 2 As shown, when the first wall 18a of the housing 18 faces downward, the cross-section perpendicular to the X direction has an inverted U shape.

[0092] The back space 30 suppresses the sound waves entering the porous sound-absorbing materials 21, 22, 23 from the flow path space 24 from being reflected by the housing 18 and returning to the flow path space 24 again. That is, if the back sides of the porous sound-absorbing materials 21, 22, 23 are in direct contact with the housing 18, the sound waves entering the porous sound-absorbing materials 21, 22, 23 from the flow path space 24 are reflected by the housing 18 and return to the flow path space 24. On the other hand, in the ventilation type muffler 10A, by providing the back space 30, a predetermined interval is provided between the porous sound-absorbing materials 21, 22, 23 and the housing 18, so that the sound waves are suppressed from being reflected by the housing 18 and returning to the flow path space 24 again.

[0093] The back space 30 is a space divided by the three porous sound-absorbing materials 21, 22, 23 and a second part of the housing 18 different from the first part 18e. Here, as Figure 2 shown, the "second part" includes a pair of parts 18f, 18f on the two outer sides in the Y direction across the first part 18e in the first wall 18a and the first wall 18b facing the first wall 18a in the Z direction. In addition, the "second part" includes the second walls 18c, 18c arranged at intervals in the Y direction (refer to Figure 2 ) and the third walls 18d, 18d arranged at intervals in the X direction (refer to Figure 1 ). That is, the second part of the housing 18 is composed of a pair of parts 18f, 18f included in the first wall 18a, the first wall 18b, a pair of second walls 18c, 18c, and a pair of third walls 18d, 18d. The second parts 18b, 18c, 18d, 18f face the back space 30 and are in contact with the gas in the back space 30.

[0094] From the viewpoint of sound absorption performance, the depth of the back space 30, that is, the distance from one second wall 18c ( Figure 2 left side) to the porous sound-absorbing material 21, the distance from the other second wall 18c ( Figure 2 right side) to the porous sound-absorbing material 22, and the distance from the first wall 18b ( Figure 2The distance from the upper side of [[ID=]] to the porous sound-absorbing material 23 is preferably 10 mm to 400 mm, more preferably 30 mm to 200 mm. Further, from the viewpoint of sound absorption performance, the depth of the backspace 30 is preferably 2 to 20 times, more preferably 3 to 10 times the thickness of the porous sound-absorbing materials 21, 22, and 23. Further, the porous sound-absorbing material 21 may be filled in the backspace 30. In this case, the inner surface of the frame 18 and the outer surfaces of the porous sound-absorbing materials 21, 22, and 23 are in contact with each other.

[0095] [Heat transfer member]

[0096] Figure 1 The ventilation muffler 10A shown in [[ID=]] further includes a heat transfer member 32 that thermally connects the first portion 18e to the second portions 18b, 18c, 18d, and 18f and has a higher thermal conductivity than the frame 18. As Figure 2 shown, the heat transfer member 32 transfers the heat transferred from the gas flowing in the flow path space 24 to the first portion 18e to each of the second portions 18b, 18c, 18d, and 18f.

[0097] The heat transfer member 32 is disposed along the frame 18 on the outside of the frame 18. The heat transfer member 32 preferably has a structure that covers the entire outside of the frame 18. However, the heat transfer member 32 does not necessarily need to cover the entire outside of the frame 18, and it is sufficient that at least a part of the surface of the first portion 18e is thermally connected to a part of the surface of any one of the second portions 18b, 18c, 18d, and 18f. For example, the heat transfer member 32 may cover the entire surface of the first portion 18e and the entire surfaces of the second portions 18b, 18c, and 18f (excluding the second portion 18d). Further, the heat transfer member 32 may cover, for example, a part of the surface of the first portion 18e and a part of the surface of the second portion 18b.

[0098] The heat transfer member 32 has, for example, a substantially rectangular parallelepiped shape of a hexahedron that is one size larger than the frame 18. More specifically, the heat transfer member 32 includes a pair of first heat transfer walls 32a and 32b (refer to Figure 2 ) disposed at intervals in the Z direction, a pair of second heat transfer walls 32c and 32c (refer to Figure 2 ) disposed at intervals in the Y direction, and a pair of third heat transfer walls 32d and 32d (refer to Figure 1 ) disposed at intervals in the X direction. The heat transfer walls 32a, 32b, 32c, and 32d are each thermally connected to the walls 18a, 18b, 18c, and 18d of the frame 18 located inside thereof.

[0099] A more detailed description of the first heat transfer wall 32a will be given. As Figure 2As shown, the first heat transfer wall 32a has a heat transfer portion 32e that is adjacent to the first portion 18e in the Z direction and is thermally connected, and a pair of heat transfer portions 32f, 32f that are adjacent to the pair of portions 18f, 18f in the Z direction and are thermally connected. The heat transfer portion 32e is located at the center of the first heat transfer wall 32a in the Y direction, and extends from one end of the first heat transfer wall 32a in the X direction (one end on the inlet side ventilation pipe 12 side) to the other end (one end on the outlet side ventilation pipe 16 side). The pair of heat transfer portions 32f, 32f are located on two outer sides in the Y direction with the heat transfer portion 32e interposed therebetween.

[0100] The heat transfer walls 32a, 32b, 32c, 32d are, for example, plate members or sheets that are rectangular in plan view, and their thickness is preferably 3.0 mm or less, more preferably 1.0 mm or less, and most preferably 0.5 mm or less. That is, in order to suppress the enlargement of the ventilation type muffler 10A, the thickness of each of the heat transfer walls 32a, 32b, 32c, 32d is preferably formed to be thin.

[0101] As a material for forming the heat transfer member 32, materials having a higher thermal conductivity than the resin material and the reinforced plastic material forming the frame 18 can be cited. For example, metal materials or carbon fibers can be cited. As metal materials, for example, metal materials such as aluminum, titanium, magnesium, tungsten, iron, steel, chromium, chromium molybdenum, nickel chromium molybdenum, and their alloys can be cited.

[0102] In addition, if the thermal conductivity is higher than the material for forming the frame 18, a resin material or a reinforced plastic material can be applied as the material for forming the heat transfer member 32.

[0103] As long as the heat transfer member 32 is thermally connected, it can be constituted by any one of one or more members. For example, the heat transfer walls 32a, 32b, 32c, 32d are each an independent plate member, and the heat transfer member 32 can be constituted by thermally connecting the adjacent end portions of the heat transfer walls 32a, 32b, 32c, 32d to each other.

[0104] As a method for thermally connecting the heat transfer member 32 to the frame 18, for example, an unillustrated adhesive layer (adhesive) can be provided on the surface of the heat transfer member 32 on the frame 18 side, more specifically, on the inner surfaces of the heat transfer walls 32a, 32b, 32c, 32d. The heat transfer member 32 is thermally connected to the frame 18 via this adhesive layer. The heat transfer member 32 can also be said to be the base material of a tape having an adhesive layer provided on one surface. As a material for forming the adhesive layer, a material having a high thermal conductivity is preferred, and for example, an acrylic adhesive material can be cited. As the thickness of the adhesive layer, 0.01 mm to 0.2 mm is preferred.

[0105] Further, an adhesive layer may be provided on the outer surface of the housing 18, and the heat transfer member 32 is thermally connected to the housing 18 via the adhesive layer. Further, the heat transfer member 32 may be directly formed on the outer surface of the housing 18 by applying a coating or plating treatment to the outer surface of the housing 18 using the forming material of the heat transfer member 32. Further, in a state where the heat transfer member 32 is in contact with the housing 18, the heat transfer member 32 may be thermally connected to the housing 18 by using a fastener such as a screw.

[0106] [Function and Effect]

[0107] As described above, as Figure 1 and Figure 2 shown, the ventilation muffler 10A includes a heat transfer member 32 that thermally connects the first portion 18e to the second portions 18b, 18c, 18d, 18f and has a higher thermal conductivity than the housing 18. Thus, the heat transferred from the gas flowing in the flow path space 24 to the first portion 18e is transferred to the second portions 18b, 18c, 18d, 18f via the heat transfer member 32. Therefore, even when the expansion portion 14 formed of the resin housing 18 is provided outdoors and a high-temperature and high-humidity gas having a temperature higher than that of the outdoors flows in the flow path space, the second portions 18b, 18c, 18d, 18f of the housing 18 are heated, and cooling of the wall of the housing 18 by the external gas can be suppressed. Thus, even when the moisture transferred from the flow path space 24 to the back space 30 through the micropores of the porous sound absorbing materials 21, 22, 23 contacts the inner surface of the housing 18 in the back space 30, condensation in the back space 30 can be suppressed. Further, by providing the heat transfer member 32, it is not necessary to dispose a thick heat insulating material inside or outside the housing 18, and thus enlargement of the device can be suppressed.

[0108] In particular, by making the housing 18 made of resin, the above-described effects are significantly exhibited.

[0109] Specifically, the thermal conductivity of the resin housing 18 is lower than that of a metal housing or the like. Therefore, when the ventilation muffler 10A does not include the heat transfer member 32, a large temperature gradient is generated between the first portion 18e in contact with the flow path space 24 and the second portions 18b, 18c, 18d, 18f in the housing 18. That is, the first portion 18e in contact with the flow path space 24 becomes a high temperature close to the temperature of the gas flowing in the flow path space 24, and the second portions 18b, 18c, 18d, 18f become a low temperature close to the temperature of the external gas.

[0110] Thus, by applying the heat transfer member 32 to the housing 18 with a large temperature gradient, heat is smoothly transferred from the higher temperature side (the first part 18e) to the lower temperature side (the second parts 18b, 18c, 18d, 18f). In other words, when the temperature gradient is small, the heat transfer effect of the heat transfer member 32 also becomes smaller.

[0111] Therefore, for example, the heat transfer coefficient of a metal housing is higher than that of the resin housing 18. Thus, even without the heat transfer member 32, heat can be sufficiently transferred from the first part 18e in contact with the flow path space 24 to the second parts 18b, 18c, 18d, 18f. As a result, the temperature gradient between the first part 18e and the second parts 18b, 18c, 18d, 18f becomes smaller. That is, even if the heat transfer member 32 is applied to a metal housing, due to the small temperature gradient, the heat transfer effect from the higher temperature side (the first part 18e) to the lower temperature side (the second parts 18b, 18c, 18d, 18f) is small. Thus, the larger the temperature gradient, the more the effect of the heat transfer member 32 is exerted. Specifically, by providing the ventilation type muffler 10A with the resin housing 18, the aforementioned effect is fully exerted.

[0112] And, as Figure 1 shown, the cross-sectional area of the expansion part 14 is larger than that of either the inlet side ventilation pipe 12 or the outlet side ventilation pipe 16. That is, the ventilation type muffler 10A is a so-called expansion type muffler. In such an expansion type muffler, the size of the housing 18 is large, so the distance from the first part 18e to the second parts 18b, 18c, 18d, 18f becomes longer. The longer this distance, the larger the temperature gradient in the housing 18 becomes, and thus the aforementioned effect based on the heat transfer member 32 is further exerted.

[0113] And, as Figure 2 shown, the heat transfer member 32 is arranged along the housing 18 on the outside of the housing 18. Thereby, the heat transfer member 32 exists between the housing 18 and the external gas, and direct contact between the external gas and the second parts 18b, 18c, 18d, 18f can be suppressed. As a result, condensation in the back side space 30 is further suppressed.

[0114] Moreover, in the usage mode in an example of the present embodiment, the temperature of the gas flowing in the flow path space 24 is higher than the temperature outside the housing 18, and thus the heat transfer effect in the heat transfer member 32 is further exerted.

[0115] <Another example of the embodiment>

[0116] As described above, an example of an embodiment related to the ventilation muffler of the present invention has been described. However, the above-described embodiment is merely an example for facilitating understanding of the present invention and does not limit the present invention. That is, the present invention can be changed and improved without departing from its gist. And, the present invention naturally includes its equivalents.

[0117] [Modification Example 1]

[0118] Reference Figure 3 and Figure 4 , and a ventilation muffler 10B, which is another example of an embodiment of the present invention, will be described. Figure 3 FIG. is a perspective view schematically showing another example of an embodiment of the ventilation muffler of the present invention. Figure 4 is along Figure 3 sectional view taken along line B-B of.

[0119] The ventilation muffler 10B has a structure in which a heat insulating material 34 is newly added to the aforementioned ventilation muffler 10A. The structure other than the heat insulating material 34 is the same as that of the ventilation muffler 10A.

[0120] As Figure 4 shown, the heat insulating material 34 is disposed along the heat transfer member 32 on the side opposite to the frame body 18 with the heat transfer member 32 interposed therebetween, that is, on the outer side of the heat transfer member 32. The heat insulating material 34 reduces the case where the frame body 18 and the heat transfer member 32 are cooled by the external gas.

[0121] The heat insulating material 34 preferably has a structure that covers the entire outer side of the heat transfer member 32. However, the heat insulating material 34 does not necessarily need to cover the entire outer side of the heat transfer member 32. For example, it may cover a part of at least any one of the heat transfer walls 32a, 32b, 32c, 32d that are particularly cooled by the external gas. For example, the heat insulating material 34 may cover the entire surface of each of the heat transfer walls 32a, 32b, 32c (excluding the heat transfer wall 32d). And, for example, the heat insulating material 34 may cover a part of the surface of the heat transfer wall 32a and a part of the surface of the heat transfer wall 32b.

[0122] The heat insulating material 34 is, for example, a hexahedron having a substantially rectangular parallelepiped shape that is hollow and one size larger than the heat transfer member 32. More specifically, the heat insulating material 34 is composed of a pair of first heat insulating walls 34a, 34b (reference Figure 4 ) disposed at intervals in the Z direction, a pair of second heat insulating walls 34c, 34c (reference Figure 4 ) disposed at intervals in the Y direction, and a pair of third heat insulating walls 34d, 34d (reference Figure 3 ) disposed at intervals in the X direction. As Figure 4As shown, the adiabatic walls 34a, 34b, 34c, and 34d are each in contact with the heat transfer walls 32a, 32b, 32c, and 32d located inside thereof.

[0123] Each of the adiabatic walls 34a, 34b, 34c, and 34d is, for example, a plate member that is rectangular in plan view, and its thickness is preferably 20 mm or less, more preferably 10 mm or less, and most preferably 5 mm or less. That is, in order to suppress the enlargement of the ventilation type muffler 10B, the thicknesses of the adiabatic walls 34a, 34b, 34c, and 34d are preferably formed to be thin.

[0124] There is no particular limitation on the forming material of the heat insulating material 34, and various conventionally known heat insulating materials can be appropriately used. For example, various known heat insulating materials such as fibrous heat insulating materials (non-woven fabrics), foamed heat insulating materials (foamed polyurethane foams), or micro-porous plates (films, sheets) can be used.

[0125] The heat insulating material 34 can be constituted by any one of one or more components.

[0126] As a method of attaching the heat insulating material 34 to the heat transfer member 32, for example, an adhesive layer (adhesive) (not shown) can be provided on the surface of the heat insulating material 34 on the side of the heat transfer member 32, more specifically, on the inner surfaces of the adiabatic walls 34a, 34b, 34c, and 34d. At this time, the heat insulating material 34 can also be said to be the base material of a tape having an adhesive layer provided on one surface. As the forming material of the adhesive layer, a material having a high thermal conductivity is preferred, and for example, an acrylic adhesive material can be cited. As the thickness of the adhesive layer, 0.01 mm to 0.2 mm is preferred.

[0127] In addition, an adhesive layer can also be provided on the outer surface of the heat transfer member 32, and the heat insulating material 34 is attached to the heat transfer member 32 via this adhesive layer. Further, by spraying the forming material of the heat insulating material 34 (for example, a foamed resin) onto the outer surface of the heat transfer member 32, the heat insulating material 34 can be directly formed on the outer surface of the heat transfer member 32. Further, the heat insulating material 34 can also be attached to the heat transfer member 32 by using fasteners such as screws in a state where the heat insulating material 34 is in contact with the heat transfer member 32.

[0128] As described above, according to the ventilation type muffler 10B, as Figure 4As shown, the heat insulating material 34 is disposed along the heat transfer member 32 on the side opposite to the housing 18 with the heat transfer member 32 interposed therebetween. Thereby, the situation where the heat transfer member 32 is cooled by the external gas of the heat transfer member 32 is alleviated, and heat loss during the process of heat transfer from the first part 18e to the second parts 18b, 18c, 18d, 18f can be suppressed. That is, if the heat transfer member 32 is in contact with the external gas, the heat transfer member 32 will be cooled. Therefore, the thermal energy obtained by the first part 18e from the gas flowing in the flow path space 24 will escape to the outside of the heat transfer member 32 during the period until it reaches the second parts 18b, 18c, 18d, 18f, resulting in heat loss. According to the ventilation type muffler 10B, by disposing the heat insulating material 34 outside the heat transfer member 32, this heat loss can be alleviated. As a result, condensation in the back side space 30 is further suppressed.

[0129] [Modification Example 2]

[0130] Reference Figure 5 and Figure 6 , and a ventilation type muffler 10C as another example of the embodiment of the present invention will be described. Figure 5 is a perspective view schematically showing another example of the embodiment of the ventilation type muffler of the present invention. Figure 6 is along Figure 5 a cross-sectional view taken along the line C-C of

[0131] In Figure 1 and Figure 2 the ventilation type muffler 10A shown, the heat transfer member 32 is disposed outside the housing 18, but in Figure 5 and Figure 6 the ventilation type muffler 10C shown, the difference is that the heat transfer member 132 is disposed inside the housing 18. Other structures are the same as those of the ventilation type muffler 10A.

[0132] The heat transfer member 132 thermally connects the first part 18e to the second parts 18b, 18c, 18d, 18f and has a higher thermal conductivity than the housing 18.

[0133] The heat transfer member 132 is disposed along the housing 18 inside the housing 18. The heat transfer member 132 preferably has a structure that covers the entire inside of the housing 18. However, the heat transfer member 132 does not necessarily need to cover the entire inside of the housing 18, as long as at least a part of the surface of the first part 18e is thermally connected to a part of the surface of the second parts 18b, 18c, 18d, 18f. For example, the heat transfer member 132 can cover the entire surface of the first part 18e and the entire surfaces of the second parts 18b, 18c, 18f (excluding the second part 18d). And, for example, the heat transfer member 132 can cover a part of the surface of the first part 18e and a part of the surface of the second part 18b.

[0134] The heat transfer member 132 has, for example, a hexahedron shape of a hollow substantially rectangular parallelepiped that is one size smaller than the housing 18 in all directions. The heat transfer member 132 is composed of a pair of first heat transfer walls 132a and 132b (refer to Figure 6 ) arranged at intervals in the Z direction, a pair of second heat transfer walls 132c and 132c (refer to Figure 6 ) arranged at intervals in the Y direction, and a pair of third heat transfer walls 132d and 132d (refer to Figure 5 ) arranged at intervals in the X direction. The heat transfer walls 132a, 132b, 132c, and 132d are each thermally connected to the walls 18a, 18b, 18c, and 18d of the housing 18 located outside thereof.

[0135] A more detailed description will be given of the first heat transfer wall 132a. As Figure 6 shown, the first heat transfer wall 132a has a heat transfer portion 132e that is thermally connected to the first portion 18e adjacent thereto in the Z direction, and a pair of heat transfer portions 132f and 132f that are thermally connected to the pair of portions 18f and 18f adjacent thereto in the Z direction. The heat transfer portion 132e is located at the center of the first heat transfer wall 132a in the Y direction, and extends from one end (the end on the inlet side vent pipe 12 side) to the other end (the end on the outlet side vent pipe 16 side) of the first heat transfer wall 132a in the X direction. The pair of heat transfer portions 132f and 132f are located on two outer sides in the Y direction with the heat transfer portion 132e therebetween.

[0136] The inner side (inner surface) of the heat transfer portion 132e faces the flow path space 24 and contacts the gas flowing in the flow path space 24. Therefore, the heat of the gas flowing in the flow path space 24 is directly transferred to the heat transfer portion 132e. In addition, when there is a region in the first portion 18e where the heat transfer portion 132e is not arranged, similar to the Figure 1 and Figure 2 ventilated muffler 10A, the heat of the gas flowing in the flow path space 24 is directly transferred to this region.

[0137] In addition, the inner sides (inner surfaces) of the pair of heat transfer portions 132f and 132f and the heat transfer walls 132b, 132c, and 132d face the back space 30 and contact the gas in the back space 30. In addition, when there is a region in the second portions 18b, 18c, 18d, and 18f where the pair of heat transfer portions 132f and 132f and the heat transfer walls 132b, 132c, and 132d are not arranged, similar to the Figure 1 and Figure 2 ventilated muffler 10A, this region contacts the gas in the back space 30.

[0138] The heat transfer member 132 can be constituted by any one of one or more members as long as they are thermally connected. For example, the heat transfer walls 132a, 132b, 132c, and 132d are respectively independent plate members, and the heat transfer member 132 can be constituted by thermally connecting the heat transfer walls 132a, 132b, 132c, and 132d.

[0139] The heat transfer walls 132a, 132b, 132c, and 132d are, for example, plate members or sheets that are rectangular in plan view, and their thickness is preferably 3.0 mm or less, more preferably 1.0 mm or less, and most preferably 0.5 mm or less. That is, in order to suppress the narrowing of the flow path space 24 and the back side space 30, the thicknesses of the respective heat transfer walls 132a, 132b, 132c, and 132d are preferably formed to be thin.

[0140] Regarding the formation material of the heat transfer member 132 and the method of thermally connecting the heat transfer member 132 to the frame 18, it is the same as in the case of the heat transfer member 32, and the description is omitted.

[0141] As described above, according to the ventilation type muffler 10C, the heat transferred from the gas flowing in the flow path space 24 to the heat transfer portion 132e is transferred to the frame 18 and the heat transfer member 132 in the back side space 30, and more specifically, is transferred to the second portions 18b, 18c, 18d, 18f, the pair of heat transfer portions 132f, 132f, and the heat transfer walls 132b, 132c, and 132d. Thereby, even when the moisture in the back side space 30 comes into contact with the inner surfaces of the frame 18 and the heat transfer member 132 in the back side space 30, condensation in the back side space 30 can be suppressed.

[0142] [Modified Example 3]

[0143] Reference Figure 7 and Figure 8 , and a ventilation type muffler 10D, which is another example of an embodiment of the present invention, will be described. Figure 7 is a perspective view schematically showing another example of an embodiment of the ventilation type muffler of the present invention. Figure 8 is Figure 3 a cross-sectional view taken along the line D-D of

[0144] The ventilation type muffler 10D has a structure in which an adiabatic material 134 is newly added to the Figure 5 and Figure 6 shown ventilation type muffler 10C. The structure other than the adiabatic material 134 is the same as that of the ventilation type muffler 10C.

[0145] As Figure 8As shown, the heat insulating material 134 is disposed along the heat transfer member 132 on the side opposite to the housing 1 with the heat transfer member 132 interposed therebetween, that is, on the inner side of the heat transfer member 132. More specifically, the heat insulating material 134 is disposed along the inner side of the heat transfer member 132 in the back side space 30 and is not disposed in the flow path space 24. That is, the inner side (inner surface) of the heat insulating material 134 faces the back side space 30 and is in contact with the gas in the back side space 30. On the other hand, similar to the Figure 5 and Figure 6 ventilated muffler 10C, the first part 18e and the heat transfer part 132e face the flow path space 24 and are in contact with the gas flowing in the flow path space 24. Thereby, the heat of the gas flowing in the flow path space 24 is appropriately transferred to the first part 18e and the heat transfer part 132e.

[0146] The heat insulating material 134 preferably has a structure that covers the entire inner side of the heat transfer member 132 in the back side space 30. However, the heat insulating material 134 does not necessarily need to cover the entire inner side of the heat transfer member 132 in the back side space 30. For example, it may cover at least a part of any one of the heat transfer walls 132a, 132b, 132c, 132d that are particularly cooled by the external gas. For example, the heat insulating material 134 may cover the entire surface of each of the heat transfer walls 132a, 132b, 132c (excluding the heat transfer wall 132d). And, for example, the heat insulating material 134 may cover a part of the surface of the heat transfer wall 132a and a part of the surface of the heat transfer wall 132b.

[0147] The heat insulating material 134 is composed of a pair of heat insulating portions 134f, 134f disposed on both sides in the Y direction with the flow path wall 20 interposed therebetween (refer to Figure 8 ), a first heat insulating wall 134b disposed at an interval in the Z direction with respect to the pair of heat insulating portions 134f, 134f (refer to Figure 8 ), a pair of second heat insulating walls 134c, 134c disposed at an interval in the Y direction (refer to Figure 8 ) and a pair of third heat insulating walls 134d, 134d disposed at an interval in the X direction (refer to Figure 7 ).

[0148] Each of the pair of heat insulating portions 134f, 134f is adjacent to and in contact with each of the pair of heat transfer portions 132f, 132f in the Z direction. One heat insulating portion 134f ( Figure 8 left side) is on the opposite side of the flow path space 24 with the porous sound absorbing material 21 interposed therebetween in the Y direction, and the other heat insulating portion 134f ( Figure 8 right side) is on the opposite side of the flow path space 24 with the porous sound absorbing material 22 interposed therebetween. The heat insulating portion 134f is a plate member having a rectangular cross section with the flow direction (X direction) as the long side direction.

[0149] As Figure 8 shown, the adiabatic walls 134b, 134c, and 134d are each in contact with the heat transfer walls 132b, 132c, and 132d located outside thereof. Each of the adiabatic walls 134b, 134c, and 134d is, for example, a plate member that is rectangular when viewed from above.

[0150] The thickness of the adiabatic portion 134f and the adiabatic walls 134b, 134c, and 134d is preferably 20 mm or less, more preferably 10 mm or less, and most preferably 5 mm or less. In order to suppress the narrowing of the backside space 30, this thickness is preferably formed to be thin.

[0151] Regarding the forming material of the heat insulating material 134 and the method of attaching the heat insulating material 134 to the heat transfer member 132, it is the same as the case of the heat insulating material 34, and the description thereof is omitted.

[0152] The heat insulating material 134 can be constituted by any one of one or more components.

[0153] As described above, according to the ventilation type muffler 10D, as Figure 8 shown, the heat insulating material 134 is disposed along the inner side of the heat transfer member 132 in the backside space 30. Thereby, the situation where the backside space 30 is cooled by the external gas is alleviated, and the generation of dew condensation in the backside space 30 is further suppressed. On the other hand, the inner side (inner surface) of the heat transfer portion 132e faces the flow path space 24. Therefore, the heat of the gas flowing in the flow path space 24 is appropriately transferred to the heat transfer portion 132e. As a result, in the backside space 30, the inner surfaces of the frame 18 and the heat transfer member 132 are appropriately heated.

[0154] Embodiment

[0155] Hereinafter, the present invention will be further described in detail based on embodiments. The materials, amounts used, ratios, processing contents, processing steps, etc. shown in the following embodiments can be appropriately changed as long as they do not depart from the gist of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the embodiments shown below.

[0156] [Comparative Example]

[0157] As Figure 9 shown, a ventilation type muffler 200A according to a comparative example of the present invention was manufactured. Figure 9 is an exploded perspective view showing the ventilation type muffler 200A according to a comparative example of the present invention.

[0158] The frame 218 forming the outer edge of the expansion part 214 is made of six plate members. A hollow rectangular parallelepiped-shaped box 240 with one side open is made of five plate members, and a lid 242 for covering the open side (opening) of the box 240 is made of the remaining one plate member. Regarding the plate members, the thickness is set to 3 mm, and the forming material is acrylic resin (PMMA). The internal dimensions of the frame 218 are set to a width of 150 mm, a length of 150 mm, and a height of 50 mm.

[0159] A pair of connectors 244, 244 are respectively installed on a pair of opposing surfaces of the frame 218 in the gas flow direction. The connector 244 is made using a 3D printer. The forming material of the connector 244 is set to ABS resin. On the inner surface of the bottom wall of the box 240, a pair of porous sound-absorbing materials 221, 222 are arranged at intervals with the connector 244 interposed therebetween in a direction orthogonal to the flow direction. A porous sound-absorbing material 223 is arranged on the upper surfaces of the porous sound-absorbing materials 221, 222. The forming materials of the porous sound-absorbing materials 221, 222, 223 are set to fibrous sound-absorbing materials (QonPET manufactured by Bridgestone KBG Co., Ltd.), and the thickness of each of the porous sound-absorbing materials 221, 222, 223 is set to 15 mm. Finally, the lid 242 is arranged at the opening of the box 240.

[0160] The region surrounded by the porous sound-absorbing materials 221, 222, 223 becomes the flow path space 224, and the space on the back side of the porous sound-absorbing materials 221, 222, 223 becomes the back side space 230.

[0161] [Example 1]

[0162] As Figure 10 shown, the ventilation type muffler 200B according to Example 1 of the present invention was manufactured. Figure 10 is a figure obtained by photographing the ventilation type muffler 200B according to Example 1 of the present invention with a camera. In the ventilation type muffler 200B, the difference from the ventilation type muffler 200A according to the comparative example Figure 9 shown is only that a heat transfer member 232 is newly arranged along the outside of the frame 218. A heat transfer sheet (heat transfer tape) is attached along the outside of the frame 218, and the heat transfer sheet (heat transfer tape) is obtained by using the heat transfer member 232 as a base material and providing an adhesive layer on one surface of the base material. Regarding the base material (heat transfer member 232), the thickness is set to 100 μm, and the forming material is aluminum.

[0163] [Example 2]

[0164] The ventilation type muffler 200C according to Example 2 of the present invention was manufactured (refer to Figure 14)。In the ventilation muffler 200C, the difference from the ventilation muffler 200B related to the first embodiment shown in Figure 10 is only that heat insulating material 234 is newly arranged along the outer side of the heat transfer member 232. A heat insulating sheet (heat insulating tape) is attached along the outer side of the heat transfer member 232, and the heat insulating sheet (heat insulating tape) is obtained by using the heat insulating material 234 as a base material and providing an adhesive layer on one surface of the base material. Regarding the base material (heat insulating material 234), the thickness is set to 3 mm, and the forming material uses AEROFLEX manufactured by NISSHO AERO CO., LTD.

[0165] [Evaluation]

[0166] (Temperature distribution in the expansion part)

[0167] As shown in Figures 11 - 15 , the temperature distribution of the housing 218 was measured for each of the manufactured ventilation mufflers. Figure 11 is a view obtained by photographing the ventilation muffler 200A related to the comparative example with an infrared thermal imaging camera. Figure 12 And Figure 13 is a view obtained by photographing the ventilation muffler 200B related to the first embodiment with an infrared thermal imaging camera. Figure 14 is a view obtained by photographing the ventilation muffler 200C related to the second embodiment with an infrared thermal imaging camera. Figure 15 is a graph comparing the temperature distributions inside the housings in the first embodiment and the second embodiment.

[0168] As a measurement method, first, the expansion part 214 was arranged in a box whose internal space was cooled to 10°C, and the expansion part 214 was placed in such a way that the temperature of the expansion part 214 became the same as the temperature inside the box. Then, hoses were respectively connected to the pair of connectors 244, and air at 30°C and 36% RH was made to flow through the expansion part 214 for 30 minutes. After 30 minutes, the air flow was stopped, the lid 242 of the housing 218 was opened, and the temperature inside the housing 218 was photographed with an infrared thermal imaging camera.

[0169] As a result of the evaluation, it can be seen that in the ventilation muffler 200A related to the comparative example, as shown in Figure 11 , the temperature of the part around the flow path wall 220 in the housing 218 rises. However, it can be seen that the temperature of the part in the housing 218 far from the flow path wall 220 does not rise.

[0170] On the other hand, it can be seen that in the ventilation muffler 200B related to the first embodiment, as shown in Figure 12 , the temperature of the part in the housing 218 far from the flow path wall 220 rises.

[0171] Specifically, as shown in Figure 11 AndFigure 12 As shown, at a position away from the flow path wall 220 in a direction orthogonal to the air flow direction ( Figure 11 and Figure 12 the position on the left side of the flow path wall 220 in), the temperature of the inner surface of the bottom wall of the housing 218 was measured at a fixed point. As a result, at the fixed-point measurement position, it showed 15.1 °C in Comparative Example 1 and 22.9 °C in Comparative Example 2. That is, it was found that the temperature rose by 7.8 °C in Example 1 compared with Comparative Example 1.

[0172] Moreover, it was found that in the ventilation type muffler 200C according to Example 2, the temperature of the portion of the housing 218 away from the flow path wall 220 further rose compared with the ventilation type muffler 200B.

[0173] Specifically, as Figure 13 and Figure 14 shown, at a position away from the flow path wall 220 in a direction orthogonal to the air flow direction ( Figure 13 and Figure 14 the position on the left side of the flow path wall 220 in), an imaginary line parallel to the air flow direction was drawn from the upstream end to the downstream end of the bottom wall of the housing 218, and the temperature distributions of Example 1 and Example 2 on this imaginary line were compared.

[0174] The results are shown in Figure 15 . Figure 15 The horizontal axis of represents the distance starting from 0 with the upstream end of the bottom wall of the housing 218 as the origin on the aforementioned imaginary line, Figure 15 and the vertical axis of represents the temperature of the inner surface of the bottom wall.

[0175] As Figure 15 shown, in the temperatures of the inner surfaces of the bottom walls of Example 1 and Example 2, no difference was observed on the upstream side of the housing 218, but on the downstream side of the housing 218, the temperature of Example 2 was higher than that of Example 1.

[0176] (Transmission loss)

[0177] As Figure 16 shown, the transmission loss of the fabricated ventilation type muffler 200B of Example 1 was measured. For the measurement, it was carried out by four-terminal method measurement using a sound tube. In the Figure 16 curve graph, the horizontal axis represents the frequency and the vertical axis represents the transmission loss. As a result of the evaluation, it was found that the ventilation type muffler 200B of Example 1 had a frequency band of resonance frequency near 1800 Hz.

[0178] (Noise)

[0179] As Figure 17As shown, regarding Comparative Example 1 and Example 1, the noise radiated from the ventilation muffler to the outside was measured respectively. In Figure 17 the graph, the horizontal axis represents the 1 / 3 octave center frequency, and the vertical axis represents the microphone sound pressure level.

[0180] As a measurement method, a measurement microphone was set at a position far from the housing 218 above the housing 218, and the microphone sound pressure level was measured when white noise was input to the flow path space 224.

[0181] As a result of the evaluation, it was found that in Example 1, compared with Comparative Example 1, the microphone sound pressure level near 400 Hz decreased. That is, it was found that the noise (400 Hz) generated by the wall vibration of the housing 218 can be improved by the heat transfer member 232.

[0182] Based on the above results, the effect of the present invention is obvious.

[0183] Explanation of reference numerals

[0184] 10A, 10B, 10C, 10D, 200A, 200B, 200C - ventilation muffler, 12 - inlet side ventilation pipe, 14, 214 - expansion part, 16 - outlet side ventilation pipe, 18, 218 - housing, 18a - first wall, 18b - first wall (second part), 18c - second wall (second part), 18d - third wall (second part), 18e - first part, 18f - part (second part), 20, 220 - flow path wall, 21, 22, 23, 221, 222, 223 - porous sound absorbing material, 24, 224 - flow path space, 30, 230 - back side space, 32, 132, 232 - heat transfer member, 32a, 32b, 132a, 132b - first heat transfer part, 32c, 132c - second heat transfer part, 32d, 132d - third heat transfer part, 32e, 32f, 132e, 132f - heat transfer part, 34, 134, 234 - heat insulating material, 34a, 34b, 134b - first heat insulating wall, 34c, 134c - second heat insulating wall, 34d, 134d - third heat insulating wall, 134f - heat insulating part, 240 - box, 242 - lid, 244 - connector.

Claims

1. A ventilation muffler having an inlet-side ventilation pipe, a dilation part communicating with the inlet-side ventilation pipe and having a cross-sectional area larger than that of the inlet-side ventilation pipe, and an outlet-side ventilation pipe communicating with the dilation part and having a cross-sectional area smaller than that of the dilation part, the ventilation muffler comprising: A resin-made frame that constitutes the dilation part; A flow path wall disposed within the frame that connects the inlet-side ventilation pipe and the outlet-side ventilation pipe and is composed of a first part of the frame and a porous sound-absorbing material; A backside space located on the side opposite to the flow path space within the flow path wall across the porous sound-absorbing material and demarcated by the porous sound-absorbing material and a second part of the frame different from the first part; and A heat transfer member that thermally connects the first part and the second part and has a thermal conductivity higher than that of the frame.

2. The ventilation muffler according to claim 1, wherein the heat transfer member is disposed along the frame on the outside of the frame.

3. The ventilation muffler according to claim 1, wherein the heat transfer member is disposed along the frame on the inside of the frame.

4. The ventilation muffler according to claim 3, further comprising a heat insulating material disposed along the inside of the heat transfer member within the backside space.

5. The ventilation muffler according to claim 2, further comprising a heat insulating material disposed along the heat transfer member on the side opposite to the frame across the heat transfer member.

6. The ventilation muffler according to any one of claims 1 to 5, wherein the temperature of the gas flowing in the flow path space is higher than the temperature on the outside of the frame.

Images