JP2013241852A - Engine exhaust muffler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine exhaust muffler having a compact cylindrical shell as well as U-shaped first and second silencing pipes.SOLUTION: An engine exhaust muffler comprises: partition walls 9, 10 for partitioning the inside of a shell 2 into a plurality of expansion chambers 6 to 8; a first silencing pipe 14 for guiding the exhaust gas of an engine E to a predetermined expansion chamber 6 through the partition walls 9, 10; and a second silencing pipe 15 for discharging the exhaust gas flow out of the first silencing pipe 14 to another predetermined expansion chamber 8 to the outside. The first silencing pipe 14 comprises a U-shaped pipe with a U-shaped bent part 14c facing the second shell end plate 5. The second silencing pipe 15 comprises a U-shaped pipe with a U-shaped bent part 15c facing the first shell end plate 4. The engine exhaust muffler has the first and second silencing pipes 14, 15 disposed so that they cross on a projection plane orthogonal to the shell 2 axial direction.

Description

  The present invention provides a shell comprising a shell body, first and second shell end plates connected to both ends of the shell body, a partition partitioning the inside of the shell into a plurality of expansion chambers, and penetrating the partition. A first silencing pipe for guiding the exhaust gas of the engine to a predetermined expansion chamber, and a second silencing pipe for discharging the exhaust gas flowing out from the first silencing pipe to the outside from another predetermined expansion chamber, The first silencing pipe is formed of a U-shaped pipe with a U-shaped bent portion directed toward the second shell end plate, and the second silencing pipe has a U-shaped bent portion formed on the first shell. The present invention relates to an improvement of an engine exhaust muffler composed of a U-shaped pipe directed toward an end plate.

  Such an exhaust muffler for an engine is already known as disclosed in Patent Document 1.

Japanese Patent Laid-Open No. 11-200835

  In such an engine exhaust muffler, the first muffler pipe with the U-shaped bend toward the second shell end plate has a silencing effect in the middle frequency range in order to guide the engine exhaust gas to a predetermined expansion chamber. In order to exhaust the exhaust gas flowing out from the first silencing pipe to the outside from another predetermined expansion chamber, the U-shaped second silencing with the U-shaped bent portion directed toward the first shell end plate Since the pipe exhibits a silencing effect in the low frequency range, exhaust noise can be reduced in a relatively wide frequency range.

  However, in the prior art, the first and second silencer pipes are arranged on one plane so as to sandwich each other, so that the cylindrical shell that accommodates them is enlarged in the one plane direction. become.

  The present invention has been made in view of such circumstances, and provides an exhaust muffler for an engine capable of reducing the size of a cylindrical shell while including U-shaped first and second silencing pipes. For the purpose.

  In order to achieve the above object, the present invention partitions a shell comprising a shell body and first and second shell end plates connected to both ends of the shell body into a plurality of expansion chambers. A partition wall, a first silencer pipe that passes through the partition wall to guide engine exhaust gas to a predetermined expansion chamber, and exhaust gas that has flowed out of the first silencer pipe is discharged from another predetermined expansion chamber to the outside. 2 silencer pipes, wherein the first silencer pipe is a U-shaped pipe with a U-shaped bent portion directed toward the second shell end plate, and the second silencer pipe is U-shaped. In an engine exhaust muffler composed of a U-shaped pipe with its bent portion directed toward the first shell end plate, the first and second silencer pipes are projected such that they are orthogonal to the axial direction of the shell. That they are placed so that they intersect on the surface. It is a feature of the.

  According to the present invention, in addition to the first feature, an inlet pipe to which an exhaust pipe of an engine is connected is disposed in the first expansion chamber adjacent to the first shell end plate. A second feature is that a plurality of holes opened in one expansion chamber are provided, and an upstream end of the first silencer pipe is opened in the first expansion chamber.

  In addition to the second feature of the present invention, the shell is provided with first and second partitions that partition the inside of the shell into first, second, and third expansion chambers from the first shell end plate side. The second partition wall has a plurality of holes communicating between the second and third expansion chambers, the downstream end of the first silencer pipe is opened to the second expansion chamber, and the downstream end is the second shell end plate. A third feature is that an upstream end of the second silencing pipe opened to the outside is opened in the second expansion chamber.

  Furthermore, in addition to any one of the first to third features, the present invention provides at least one of the first and second end plates having a U-shape of the first silencer pipe or the second silencer pipe opposed thereto. A fourth feature is that an outwardly bulging portion that accommodates the bent portion is formed.

  According to the first feature of the present invention, a U-shaped first silencer pipe that exhibits a silencing effect on medium frequency noise and a U-shaped first silencer pipe that exhibits a silencing effect on low frequency noise. By arranging the two silencer pipes so that they intersect on the projection plane orthogonal to the axial direction of the shell, the first and second silencer pipes having a long effective length can be compactly accommodated in the shell. Thus, the exhaust muffler shell can be downsized.

  According to the second feature of the present invention, an inlet pipe to which an engine exhaust pipe is connected is disposed in the first expansion chamber adjacent to the first shell end plate, and the inlet pipe is connected to the first expansion chamber. By providing a number of holes to be opened and opening the upstream end of the first muffler pipe into the first expansion chamber, the exhaust gas of the engine flows into the inlet pipe after passing through the exhaust pipe. The high-frequency noise can be absorbed by the first expansion chamber through the first hole, and then the medium-frequency noise can be reduced by the first silencer pipe.

  According to the third feature of the present invention, the shell is provided with first and second partition walls that divide the interior into first, second, and third expansion chambers from the first shell end plate side, and the second partition wall , A plurality of holes communicating between the second and third expansion chambers, the second end of the first silencer pipe being opened to the second expansion chamber, and the second end being opened outside the second shell end plate. By opening the upstream end of the muffler pipe into the second expansion chamber, a muffling effect can be exhibited in a wide frequency range from a high frequency to a low frequency.

  According to the fourth aspect of the present invention, at least one of the first and second end plates is an outward bulge that accommodates a U-shaped bent portion of the first silencer pipe or the second silencer pipe facing it. By forming the portion, the effective length of the silencer pipe can be sufficiently obtained while enhancing the rigidity of the end plate and making the shell compact, and the silencer function can be enhanced.

The top view of the exhaust system of the engine for motor vehicles provided with the exhaust muffler which concerns on embodiment of this invention. FIG. 3 is a vertical plan view of the exhaust muffler. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

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

  First, in FIG. 1, one end of the exhaust muffler M of the present invention is connected to the downstream end of the exhaust pipe 1 connected to the cylinder head of the engine E.

  2 to 4, the shell 2 of the exhaust muffler M includes a cylindrical shell body 3 and first and second shell end plates 4 connected to both ends of the shell body 3 by caulking or welding. And 5. Each of the end plates 4 and 5 has spherical outward bulging portions 4a and 5a with the central portions facing outward, and the rigidity of the end plates 4 and 5 is determined by the outward bulging portions 4a and 5a. Will be strengthened.

  First and second partition walls 9 and 10 that partition the inside of the shell 2 into first, second, and third expansion chambers 6 to 8 from the side of the first shell end plate 4 are welded to the inner peripheral wall of the shell body 3. Although the first partition wall 9 is non-porous, the second partition wall 10 is provided with a large number of holes 12, 12,... Communicating between the second and third expansion chambers 7, 8.

  In the shell 2, an inlet pipe 13 and first and second silencing pipes 14 and 15 each made of a U-shaped pipe are disposed. The inlet pipe 13 passes through the first shell end plate 4 and is disposed in the first expansion chamber 6. The inlet pipe 13 is welded and fixed to the first shell end plate 4 and the first partition wall 9, and its downstream end is closed by the first partition wall 9, and the downstream end of the exhaust pipe 1 is connected to the upstream end thereof. Connected. The inlet pipe 13 has a large number of holes 16, 16... That open to the first expansion chamber 6.

  The first silencing pipe 14 includes an upstream straight portion 14a having an upstream end opened to the first expansion chamber 6, a downstream straight portion 14b having a downstream end opened to the second expansion chamber 7, and the upstream straight portion 14a and A U-shaped bent portion 14c connecting the downstream linear portions 14b in the third expansion chamber 8, and the upstream linear portion 14a penetrates the first and second partition walls 9 and 10, and The downstream straight portion 14b penetrates through the second partition wall 10 and is welded and fixed thereto.

  The second silencer pipe includes an upstream straight portion 15a having an upstream end opened to the third expansion chamber 8, a downstream straight portion 15b having a downstream end opened to the outside of the second shell end plate 5, and the upstream straight portions 15a. And a U-shaped bent portion 15c that connects the downstream linear portion 15b in the first expansion chamber 6, and the upstream linear portion 14a penetrates the second partition walls 9 and 10 and is welded thereto. The downstream straight portion 15b penetrates the first and second partition walls 9 and 10 and is welded and fixed to them. The U-shaped bent portion 15c is formed on the outer side of the first shell end plate 4. It arrange | positions so that it may face in the bulging part 4a. A tail pipe 17 projecting outward from the second shell end plate 5 is connected to the downstream end of the second silencer pipe 15.

  Thus, the first and second silencer pipes 14 and 15 are arranged so as to intersect on a projection plane orthogonal to the axial direction of the shell 2. And the shell 2 is formed in the cross-sectional ellipse shape in order to accommodate these 1st and 2nd muffler pipes 14 and 15 efficiently.

  Next, the operation of this embodiment will be described.

  During operation of the engine E, the exhaust gas discharged to the exhaust pipe 1 passes through the exhaust pipe 1 and then flows into the inlet pipe 13, and the first expansion chamber 6 passes through the numerous holes 16, 16. It is possible to absorb high frequency noise by being widely dispersed.

  The exhaust gas dispersed in the first expansion chamber 6 flows into the first silencer pipe 14 and flows out to the second expansion chamber 7. The first silencer pipe 14 is formed in a U shape so as to penetrate the first and second partition walls 9, 10, make a U-turn in the third expansion chamber 8, and penetrate the second partition wall 10 again. Since the second expansion chambers 6 and 7 communicate with each other, the flow path length is sufficiently longer than the axial length of the shell 2. Therefore, the first silencing pipe 14 can exert a silencing effect on medium frequency noise.

  The exhaust gas discharged from the first silencer pipe 14 to the second expansion chamber 7 passes through the numerous holes 12, 12... Of the second partition wall 10 and is widely dispersed in the third expansion chamber 8. Noise can be absorbed.

  The exhaust gas dispersed in the third expansion chamber 8 flows into the second silencer pipe 15, passes through it, and is then discharged into the atmosphere via the tail pipe 17. The second silencer pipe 15 passes through the first and second partition walls 9 and 10, makes a U-turn in the first expansion chamber 6, and again passes through the first and second partition walls 10, and further passes through the second shell end plate 5. Since the third expansion chamber 8 is opened to the atmosphere, the flow path length is longer than that of the first silencer pipe 14. Therefore, the second silencing pipe 15 can exert a silencing effect against low frequency noise.

  Thus, the exhaust muffler M can exhibit a silencing effect in a wide frequency range from a high frequency to a low frequency.

  Moreover, since the first and second silencer pipes 14 and 15 are arranged so as to intersect on the projection plane orthogonal to the axial direction of the shell 2, they can be accommodated in the shell 2 in a compact manner. 2. That is, the exhaust muffler M can be reduced in size.

  Further, the first shell end plate 4 is formed with an outward bulging portion 4a that accommodates the U-shaped bent portion 15c of the second muffler pipe 15 facing the first shell end plate 4. The effective length of the second silencing pipe 15 can be sufficiently obtained while the shell 2 is made compact, and the silencing function can be enhanced.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, when high-frequency noise absorption is not considered, the upstream end of the first silencer pipe 14 can be extended to the outside of the first shell end plate 4 and the exhaust pipe 1 can be connected thereto. The first muffler pipe 14 can also be formed such that its U-shaped bent portion 14 c is disposed in the outwardly bulged portion 5 a of the second shell end plate 5.

E ... Engine M ... Exhaust muffler 1 ... Exhaust pipe 2 ... Shell 3 ... Shell body 4 ...・ First shell end plate 5... Second shell end plate 6... First expansion chamber 7. Chamber 9... First partition 10... Second partition 12... Many holes 13 in the second partition 13 Inlet pipe 14. Pipe 15 ... second muffler pipe 16 ... many holes in the inlet pipe

Claims (4)

A shell (2) composed of a shell body (3), first and second shell end plates (4, 5) connected to both ends of the shell body (3), and a plurality of insides of the shell (2) Partition walls (9, 10) for partitioning the expansion chambers (6-8), and a first silencing that guides exhaust gas from the engine (E) to the predetermined expansion chamber (6) through the partition walls (9, 10) A pipe (14) and a second silencing pipe (15) for discharging the exhaust gas flowing out of the first silencing pipe (14) from another predetermined expansion chamber (8) to the outside, the first silencing pipe (14) is a U-shaped pipe having a U-shaped bent portion (14c) facing the second shell end plate (5), and the second muffler pipe (15) is U-shaped. Engine exhaust composed of a U-shaped pipe with its bent portion (15c) directed toward the first shell end plate (4) In Hula,
An engine exhaust muffler characterized in that the first and second silencer pipes (14, 15) are arranged so as to intersect on a projection plane orthogonal to the axial direction of the shell (2). The exhaust muffler for an engine according to claim 1,
An inlet pipe (13) to which the exhaust pipe (1) of the engine (E) is connected is disposed in the first expansion chamber (6) adjacent to the first shell end plate (4), and the inlet pipe (13 ), A plurality of holes (16) that open to the first expansion chamber (6) are provided, and the upstream end of the first silencer pipe (14) is opened to the first expansion chamber (6). Exhaust exhaust muffler for engines. The exhaust muffler for an engine according to claim 2,
The shell (2) has first and second partition walls (9, 10) for partitioning the inside thereof from the first shell end plate (4) side into first, second and third expansion chambers (6-8). The second partition wall (10) is provided with a number of holes (12) communicating between the second and third expansion chambers (7, 8), and the downstream end of the first silencer pipe (14) is connected to the second partition wall (10). The second expansion chamber (7) is opened, and the upstream end of the second silencer pipe (15) that opens the downstream end to the outside of the second shell end plate (5) is opened to the second expansion chamber (7). An exhaust muffler for engines. The engine exhaust muffler according to any one of claims 1 to 3,
At least one of the first and second end plates (4, 5) accommodates a U-shaped bent portion (15c) of the first silencing pipe (14) or the second silencing pipe (15) facing the first end plate (4, 5). An exhaust muffler for an engine, characterized in that an outwardly bulging portion (4a) is formed.

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