JP2010101218A - Muffler, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a muffler achieving further miniaturization and weight saving without sacrificing silencing performance. <P>SOLUTION: This muffler includes a flat case (21) with its height formed shorter than its width and depth, and a silencing structure (22) installed inside of the case (21) and muffling exhaust gas. The silencing structure (22) is composed of a partitioning plate (30) formed of a plate member, and an exhaust gas passage (32) and a silencing chamber (40) are composed of a space surrounded by the case (21) and partitioning plate (30). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a silencer for reducing the generated sound of exhaust gas, and more particularly to a silencer that can be reduced in size and weight without sacrificing the silencer performance and a method for manufacturing the silencer.

  In recent years, the required performance of silencers used in vehicle exhaust systems has increased due to the quietness of the vehicle and consideration for the environment. The silencer performance of the silencer is improved by increasing the size of the silencer.

  On the other hand, hybrid vehicles are increasing in response to energy savings. In such a vehicle, a motor, a generator, a battery, and the like are mounted and occupy most of the engine room and the floor under the vehicle. Therefore, there is a limit to the size of the silencer installed. Moreover, it is desired that the weight of the silencer is small for energy saving.

  Conventional silencers have been assembled by inserting pipes or baffles into a cylindrical shell. For this reason, there existed a problem that processing man-hours were many and the weight was also large.

In order to solve such problems, there is known an internal combustion engine muffler (see Patent Document 1) in which press-molded shell members are stacked and flattened.
JP 2006-9739 A

  As described above, the silencer is required to be smaller and lighter.

  On the other hand, in the structure in which the pipe is inserted into the vertically divided shell member as in the invention described in the cited document 1, both edges for joining the shell are required, which increases the weight.

  Moreover, since the structure which inserts a pipe in a shell is not different from the conventional silencer, it does not contribute to weight reduction.

  The present invention has been made in view of such problems, and an object thereof is to provide a silencer that can be reduced in size and weight without sacrificing the silencing performance.

  The invention according to claim 1 is constituted by a flat case having a height smaller than a width and a depth, and a silencing structure that is built in the case and silences exhaust gas, and the silencing structure Is constituted by a partition plate formed of a plate material, and an exhaust gas passage and a sound deadening chamber are constituted by a space surrounded by the case and the partition plate.

  The invention according to claim 2 is the silencer according to claim 1, wherein the exhaust gas passage is curved with respect to a flow direction of the exhaust gas.

  Invention of Claim 3 is a silencer of Claim 1, Comprising: The said partition plate is provided with the small hole which connects the said exhaust-gas channel | path and the said silencer chamber. .

  A fourth aspect of the present invention is the silencer according to the first aspect, wherein the partition plate is formed of a corrugated plate material.

  A fifth aspect of the present invention is the silencer according to the first aspect, wherein the case has a plurality of protrusion shapes on an outer periphery thereof.

  A sixth aspect of the present invention is the silencer according to the fifth aspect, wherein the protruding shape is a fin structure that stands on the outer periphery of the case.

  A seventh aspect of the present invention is the silencer according to the fifth aspect of the present invention, wherein the protrusion shape is a dimple structure raised on an outer periphery of the case.

  The invention according to claim 8 includes a step of bending a plate material to form a partition plate, and an opening portion opened in a part of a flat case having a height smaller than a width and a depth. A step of inserting the partition plate into the case; a step of closing an opening of the case with a flat plate; and a step of joining an inlet portion and an outlet portion of exhaust gas to the case. To do.

  According to the first aspect of the present invention, the case is flat and the silencer structure is made of a plate material, so that the silencer can be reduced in size and weight, the rigidity of the silencer can be increased, and the silencing effect can be enhanced. .

  According to the invention described in claim 2, since the exhaust gas passage has a curved structure, it is possible to increase the silencing effect from the low frequency range to the middle frequency range.

  According to the third aspect of the present invention, since the exhaust gas passage is provided with the small hole, the exhaust gas passage functions as an expansion chamber, and the silencing effect can be enhanced.

  According to the fourth aspect of the invention, since the partition plate is a corrugated plate, the rigidity of the case can be increased and the radiated sound from the case can be reduced.

  According to the invention described in claim 5, since the protrusion is provided on the outer periphery of the case, the rigidity of the silencer can be further increased and the silencing effect can be enhanced.

  According to the invention described in claim 6, since the fin structure is provided on the outer periphery of the case, the rigidity of the silencer can be further increased, the silencer can be cooled, and the silencing effect can be enhanced.

  According to the seventh aspect of the present invention, since the dimple structure is provided on the outer periphery of the case, the rigidity of the silencer can be further increased and the silencer can be cooled by a simpler process, thereby enhancing the silencing effect. Can do.

  According to the invention described in claim 8, it is possible to manufacture a silencer capable of reducing the size and weight of the silencer, increasing the rigidity of the silencer, and enhancing the silencing effect.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an explanatory diagram showing the structure of a silencer (muffler) 10 according to an embodiment of the present invention.

  The muffler of the present invention is mainly mounted on a vehicle and silences exhaust gas discharged from the vehicle engine. The silencer 10 is provided under the floor on the vehicle rear side.

  The silencer (muffler) 10 includes a substantially rectangular parallelepiped case 21 and a silencer structure 22 (see FIG. 2) housed in the case 21. Further, on the outer peripheral side of the case 21, fins 23 having a structure standing upright on the outer periphery of the case are provided.

  The silencer 10 includes an inlet portion 24 that introduces exhaust gas into the interior and an outlet portion 25 that leads exhaust gas from the inside.

  The fins 23 are provided upright on the outer periphery of the case 21. The fins 23 are provided for the purpose of lowering the temperature of the exhaust gas by cooling the silencer 10 with traveling wind.

  The case 21 that determines the outer shape of the silencer 10 has a substantially rectangular parallelepiped space therein. As will be described later, the interior is partitioned into several spaces, thereby forming a sound deadening structure 22.

  FIG. 2 is an explanatory view showing an example of the silencer structure 22, and is a perspective view of the silencer 10.

  As described above, the inside of the case 21 has a substantially rectangular parallelepiped space. The sound deadening structure 22 is configured by appropriately arranging the partition plate 30 in this space.

  The partition plates 30 are configured so that each of the partition plates 30 stands upright with respect to the bottom surface and the top surface of the case 21, and the top and bottom of the partition plate 30 abut against the inner wall of the case 21. Thereby, the inside of the case 21 is partitioned into a plurality of spaces.

  In the example shown in FIG. 2, the inside of the case is partitioned into several spaces by four partition plates (30a, 30b, 30c, 30d), whereby two exhaust gas passages 32 (inlet side exhaust gas passages 32a). The outlet side exhaust gas passage 32b) and three chambers 40 (40a, 40b, 40c) are configured. The chamber 40 configures a silencing function such as an expansion chamber or a resonance chamber depending on its shape.

  The example shown in FIG. 2 will be specifically described. The space surrounded by the partition plate 30 a, the partition plate 30 b, and the case 21 constitutes an inlet side exhaust gas passage 32 a that communicates with the inlet portion 24. Further, the space surrounded by the partition plate 30 c, the partition plate 30 d, and the case 21 constitutes an outlet side exhaust gas passage 32 b that communicates with the outlet portion 25.

  The chamber 40a is configured by a space surrounded by the partition plate 30a, the partition plate 30c, and the case 21. The partition plate 30a is provided with a plurality of small holes 31 communicating with the chamber 40a. With such a structure, when the exhaust gas passes through the small hole 31 and flows into the chamber 40a, the cross-sectional area of the exhaust gas passage is enlarged. Thereby, the chamber 40a functions as an expansion chamber.

  A chamber 40b is configured by a space surrounded by the partition plate 30b, the partition plate 30c, and the case 21. The end of the inlet side exhaust gas passage 32a opens to the chamber 40b. With such a structure, when the exhaust gas flows from the inlet side exhaust gas passage 32a to the chamber 40b, the cross-sectional area of the exhaust gas passage is enlarged. Thereby, the chamber 40c functions as an expansion chamber.

  The expansion chamber is configured so that the cross-sectional area of the exhaust gas passage is enlarged, and the sound wave of the exhaust gas is expanded to attenuate the sound wave.

  A chamber 40c is configured by a space surrounded by the partition plate 30d and the case 21. The chamber 40c communicates with the chamber 40b, and is configured to have a predetermined depth from this communicating portion. Thereby, the chamber 40c functions as a resonance chamber.

  The resonance chamber attenuates sound waves by resonating sound waves of a specific frequency of the exhaust gas according to the Holmhertz principle. This specific frequency is determined by the volume and shape of the resonance chamber.

  The chamber 40b communicates with the outlet side exhaust gas passage 32b. The exhaust gas passes through the outlet side exhaust gas passage 32 b and is then discharged through the outlet portion 25.

  As described above, the sound deadening structure 22 having a desired sound deadening function can be configured inside the case 21 by appropriately arranging the partition plate 30.

  The silencing structure 22 is not limited to the structure shown in FIG. For example, a baffle structure may be provided between the inlet side exhaust gas passage 32a and the outlet side exhaust gas passage 32b. Further, any one of the chambers 40 may be filled with a sound absorbing member.

  Next, a method for assembling the silencer 10 configured as described above will be described.

  The silencer 10 of the present embodiment is configured by incorporating a silencer structure 22 inside a case 21 having a substantially rectangular parallelepiped shape having fins 23 on the outside.

  First, the partition plate 30 constituting the sound deadening structure 22 is processed. As shown in FIG. 2, the partition plate 30 bends a metal plate material into a predetermined shape. If necessary, the small holes 31 are opened.

  In addition, what was made into the integral structure by joining the some partition plate 30 previously may be made into a muffling structure, and this may be comprised so that it may insert in the case 21 inside. Alternatively, the muffler structure 22 may be formed as an integral part by a press or the like and inserted.

  Next, the partition plate 30 is inserted into the case 21.

  FIG. 3 is an explanatory diagram showing an example of the case 21 used for assembling the silencer 10.

  The case 21 is provided with an opening 21a in a part thereof in order to insert the silencing structure 22 therein. In the example illustrated in FIG. 3, the case 21 has a substantially rectangular parallelepiped shape, and an opening portion 21 a is provided on one of the six surfaces of the rectangular parallelepiped.

  In consideration of workability, the case 21 may be formed in a cylindrical shape by extrusion molding or the like. In this case, two opposing faces among the six faces of the rectangular parallelepiped shape are the opening portions 21a.

  The flat plate 11 for closing the opening portion 21a is formed in advance in a shape corresponding to the shape of the opening portion 21a.

  Then, the partition plate 30 configured as described above is inserted into the case 21 through the opening 21 a of the case 21.

  After inserting the partition plate 30, the partition plate 30 and the case 21 are joined. Several methods are conceivable for joining, but it is conceivable that spot welding is performed from the outside of the case 21 to a portion where the partition plate 30 contacts the inner surface of the case 21. Note that the case 21 and the partition plate 30 may be joined by other joining methods.

  Next, the opening 21a of the case 21 is closed. The flat plate 11 is fitted into the opening 21a of the case 21, and these are joined by a method such as welding.

  Next, the inlet portion 24 and the outlet portion 25 are attached to the case 21.

  In the example shown in FIG. 2, the inlet portion 24 is provided in the flat plate 11 joined to the opening portion 21 a of the case 21. Further, an exit portion 25 is provided on a surface facing the flat plate 11.

  The inlet portion 24 and the outlet portion 25 are provided with an opening 11a in the flat plate 11 in advance, and are joined to the opening 11a. For example, a tubular member in which one cylindrical shape is a rectangle corresponding to the flat plate 11 and the other cylindrical shape is processed into a circle is used as the inlet portion 24. By joining this tubular member to the opening of the flat plate 11, the inlet 24 is formed.

  The outlet portion 25 is similarly configured by joining a tubular member to the opening portion 11b provided at a predetermined position.

  As shown in FIGS. 1 and 2, the inlet portion 24 and the outlet portion 25 do not necessarily have to be attached obliquely to the facing surfaces. For example, both the inlet part 24 and the outlet part 25 may be provided on one surface. Further, the inlet portion 24 and the outlet portion 25 may be provided on different surfaces, and the axial directions thereof may be orthogonal to each other.

  The silencer 10 is configured by the above procedure.

  In the example shown in FIG. 3, the opening portion 21 a is a surface on which the inlet portion 24 or the outlet portion 25 is provided, but the present invention is not limited to this.

  For example, as in the example shown in FIG. 4, the silencer 10 may be configured such that the upper surface of the silencer 10 is the opening portion 21 a and the flat plate 11 provided with the fins 23 in advance is joined.

  In the case of the configuration as shown in FIG. 4, even if the silencing structure 22 is a more complicated structure, since the opening area of the opening portion 21 a is large, it is easier to insert the silencing structure 22 into the case 21. It becomes.

  Next, the operation of the silencer 10 configured as described above will be described.

  As shown in FIG. 2, the exhaust gas flows from the inlet portion 24 into the inlet side exhaust gas passage 32a. In the inlet side exhaust gas passage 32a, a small hole 31 is provided in the middle of the passage, and the inlet side exhaust gas passage 32 and the chamber 40a communicate with each other. The chamber 40a is an expansion chamber, so that sound waves are attenuated.

  Next, the exhaust gas flows from the inlet side exhaust gas passage 32 into the chamber 40b. Similarly, the chamber 40b is an expansion chamber, so that sound waves are attenuated.

  The chamber 40b communicates with the chamber 40c. The chamber 40c is a resonance chamber, which attenuates a sound wave having a specific frequency.

  The chamber 40b communicates with the outlet side exhaust gas passage 32b, and the exhaust gas flowing into the outlet side exhaust gas passage 32b flows out from the outlet portion 25 to the outside.

  The outlet-side exhaust gas passage 32b has a U-turn structure that is curved from the inlet to the outlet, and by increasing the length of the outlet tube, the silencing effect from the low frequency range to the middle frequency range is increased. This long tube becomes easier to design longer as the flatness ratio increases.

  With such a structure, the exhaust gas can be silenced.

  As described above, the silencer 10 of the present embodiment has a rectangular parallelepiped flat structure, so that the expansion ratio of the expansion chamber (change in the aspect ratio of the cross-sectional area) is greater than that of a cylindrical or elliptical silencer. Can be taken large. Thereby, the silencer 10 can be reduced in size and the silencing effect can be further enhanced.

  Moreover, since the muffler 10 includes the muffler structure 22 having a muffler function by the partition plate 30 made of a flat plate, the muffler 10 can be reduced in weight as compared to a combination of pipes and the like.

  Also, with such a structure, in particular, when the silencer 10 is mounted on a vehicle, the degree of freedom in arrangement such as under the floor is increased, so that the space efficiency of the vehicle can be increased. Furthermore, the fuel efficiency of the vehicle can be increased by reducing the weight of the silencer 10.

  An opening / closing lid that opens and closes according to the exhaust gas flow rate may be provided in the middle of the exhaust gas passage 32 so that the exhaust gas passage 32 or the chamber 40 can be selected.

  Moreover, although the partition plate 30 is a flat plate, the partition plate 30 may be curved in the horizontal direction in order to reduce the influence of the acoustic wave echo on the plane.

  Moreover, the silencer 10 includes fins 23 around the silencer 10. The fins 23 can increase the rigidity of the silencer 10. Moreover, since the silencing structure 22 of the silencer 10 is joined to the upper surface and the bottom surface of the silencer by the partition plate 30, the rigidity of the silencer can be further increased. Thereby, the level of a radiation sound can be lowered | hung and the silencing effect can be improved more.

  Further, the fin 23 radiates heat to the outside air by expanding the surface area of the silencer 10. Thereby, exhaust gas temperature can be reduced. When the exhaust gas temperature decreases, the sound wave level also decreases, so that the silencing effect can be further enhanced.

  Further, by cooling the silencer 10, it is possible to prevent the influence of heat due to the exhaust gas. For example, the exhaust gas temperature of a gasoline engine is 900 ° C. or higher at the maximum, and in order to withstand this, the silencer 10 needs to be made of a heat-resistant metal such as steel or stainless steel. On the other hand, if the exhaust gas temperature can be lowered, an aluminum alloy, a magnesium alloy, a resin, or the like can be used as the material. Moreover, when using for the exhaust system of a fuel cell, it does not necessarily need to be heat resistant.

  These aluminum alloys, magnesium alloys, resins, and the like can reduce the weight compared to steel and stainless steel. Further, by using these taxes, it becomes possible to easily form a complicated structure by extrusion molding, and the manufacturing cost can be reduced.

  Note that a heat dissipation mechanism such as a bellows structure may be provided in the middle of the exhaust pipe in front of the silencer 10 so as to further reduce the exhaust gas temperature.

  FIG. 5 is a top view and a side view of the silencer 10 according to the second embodiment of the present invention.

  The silencer of the first embodiment shown in FIGS. 1 and 2 includes the fins 23 around the case 21. Further, the sound deadening structure 22 is constituted by a flat partition plate 30.

  On the other hand, in the second embodiment, a so-called dimple structure in which predetermined protrusion processing is performed around the case 21 is employed.

  Moreover, the partition plate 30 was formed by bending a corrugated plate material into a predetermined shape.

  More specifically, as shown in FIG. 5, a plurality of substantially circular dome-shaped protrusions (dimples) 35 are provided around the case 21. The protrusion 35 is formed by, for example, pressing.

  Thus, by providing a plurality of protrusions 35 around the case 21, the surface area of the case 21 can be increased and the heat dissipation effect can be enhanced. Further, the rigidity of the case 21 can be increased.

  Further, the partition plate 30 constituting the sound deadening structure 22 is formed by bending a corrugated plate material into a predetermined shape. In the example shown in FIG. 5, similarly to the example shown in FIG. 3, the four partition plates 30 constitute the inlet side exhaust gas passage 32a, the outlet side exhaust gas passage 33, and the chambers 40a, 40b, and 40c, respectively. ing. The mute function according to this configuration is the same as that of the first embodiment shown in FIG.

  By using the partition plate 30 as a corrugated plate, the bending strength of the partition plate 30 is increased, so that the rigidity of the case 21 can be increased. Since the case 21 has a substantially rectangular parallelepiped flat shape, the rigidity of the surface becomes low, and radiated sound may be generated outside due to resonance or the like. On the other hand, when the partition plate 30 inscribed in the case 21 is a corrugated plate, the rigidity of the case 21 can be increased, and the radiated sound from the case 21 can be reduced.

  Further, by using the partition plate 30 as a corrugated plate, the reflection of the sound wave in the exhaust gas passage and the chamber 40 changes. Therefore, by appropriately selecting the plate material of the partition plate 30, it is possible to appropriately tune the silencing effect.

  As described above, in the second embodiment of the present invention, the same effect as that of the first embodiment described above can be obtained.

  In particular, in the second embodiment, the outer periphery of the case 21 is dimpled and the partition plate 30 is a corrugated plate. Since these can be easily processed by press working or the like, the silencing effect can be appropriately tuned without increasing the cost.

  As in the first embodiment described above, the sound deadening structure 22 of the case 21 provided with the fins 23 may be constituted by a partition plate 30 made of a corrugated plate. Further, the outer periphery of the case 21 may be dimple processed, and the sound deadening structure 22 may be constituted by a partition plate made of a flat plate.

  In the embodiment of the present invention, the noise reduction of exhaust gas from an internal combustion engine and a fuel cell mounted on a vehicle has been described. However, the present invention is not limited to this. It can also be used to silence pulsations from

It is explanatory drawing which shows the structure of the silencer of the 1st Embodiment of this invention. It is explanatory drawing which shows an example of the silencing structure of the silencer of the 1st Embodiment of this invention. It is explanatory drawing which shows an example of the case of the silencer of the 1st Embodiment of this invention. It is explanatory drawing which shows the other example of the case of the silencer of the 1st Embodiment of this invention. It is explanatory drawing which shows the structure of the silencer of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Silencer 11 Flat plate 21 Case 21a Opening part 22 Silencer structure 23 Fin 24 Inlet part 25 Outlet part 30 Partition plate 31 Small hole 32a Inlet side exhaust gas passage 32b Outlet side exhaust gas path 35 Projection part 40 Chamber

Claims (8)

A flat case (21) whose height is smaller than the width and depth;
A silencing structure (22) that is built in the case (21) and silences exhaust gas;
Composed of
The silencing structure (22) is constituted by a partition plate (30) formed of a plate material, and an exhaust gas passage (32) and a silencing chamber are defined by a space surrounded by the case (21) and the partition plate (30). (40) is comprised, The silencer characterized by the above-mentioned. The muffler according to claim 1,
The muffler characterized in that the exhaust gas passage (32) is curved with respect to the flow direction of the exhaust gas. The muffler according to claim 1,
The silencer, wherein the partition plate (30) is provided with a small hole (31) communicating the exhaust gas passage (32) and the silencer chamber (40). The muffler according to claim 1,
The silencer, wherein the partition plate (30) is made of a corrugated plate material. The muffler according to claim 1,
The case (21) is provided with a plurality of protrusions (23, 35) on the outer periphery thereof. The muffler according to claim 5, wherein
The muffler characterized in that the protruding shape (23) is a fin structure (23) standing on the outer periphery of the case (21). The muffler according to claim 5, wherein
The muffler characterized in that the protruding shape (35) is a dimple structure (35) raised on the outer periphery of the case (21). Bending the plate material to form the partition plate (30);
The partition plate (30) is inserted into the case (21) from the opening (21a) opened in a part of the flat case (21) having a height smaller than the width and depth. Process,
Closing the opening (21a) of the case (21) with a flat plate (11);
Joining the exhaust gas inlet (24) and outlet (25) to the case (21);
A method of manufacturing a silencer, comprising:

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