JP3750898B2 - Engine muffler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine muffler.
[0002]
[Prior art]
7 is a side cross-sectional view of a conventional engine muffler 50, and FIG. 8 is a view taken in the direction of arrow D in FIG. The muffler 50 has an exhaust inlet 52 connected to the engine, a first shell 51 that constitutes one side of the outer shell, a second shell 53 that constitutes the other side of the outer shell facing the first shell 51, A partition plate 54 is provided on the first shell 51 and the second shell 53. The first shell 51, the second shell 53, and the partition plate 54 are integrally configured by caulking the outer peripheral portion, and the first shell 51 and the partition plate 54 form a first expansion chamber 55. And the partition plate 54 form a second expansion chamber 56. Two louver-shaped exhaust outlets 60, 60 are provided on the upper part of the second shell 53, and a guide 61 is welded inside the second shell 53 so as to cover the exhaust outlets 60, 60. The guide 61 is closed at one end close to the exhaust outlets 60 and 60 and forms a passage 63 having a predetermined length L4 having an opening 62 at the other end. 9 is a EE arrow view of FIG. 7, and is a front view of the partition plate 54. 7 and 9, a communication passage 57 having a predetermined length L3 is provided in the longitudinal direction at a position that is biased to one side in the left-right direction when viewed from the front.
[0003]
Next, the operation will be described. FIG. 10 is a view taken along the line FF in FIG. As indicated by the arrow, engine exhaust enters the first expansion chamber 55 from the exhaust inlet 52 and then enters the second expansion chamber 56 through the communication passage 57. Next, the gas enters from the opening 62 of the passage 63 and is discharged from the exhaust outlet 60 to the outside. The exhaust noise is reduced while the exhaust gas expands in the first expansion chamber 55 and the second expansion chamber 56 and passes through the communication passage 57 having the length L3 and the passage 63 having the length L4.
[0004]
[Problems to be solved by the invention]
However, in the above configuration, since the length L3 of the communication passage 57 that connects the first expansion chamber 55 and the second expansion chamber 56 is short, a sufficient exhaust noise reduction effect cannot be obtained. Further, since the passage 63 is formed by welding the guide 61 to the second shell 53, there are problems that the number of parts is large, the structure is complicated, the number of processing steps is required, and the cost is high.
[0005]
The present invention pays attention to the above-mentioned problems, and an object thereof is to provide an engine muffler having a large exhaust noise reduction effect, a simple structure, and low cost.
[0006]
[Means, actions and effects for solving the problems]
In order to achieve the above object, a first invention of an engine muffler according to the present invention includes a first shell having an exhaust inlet connected to an exhaust outlet of the engine and constituting one side of an outer shell, A second shell having an outlet and constituting the other side of the outer shell opposite to the first shell, and a partition plate provided between the first shell and the second shell, the first shell and In a muffler of an engine in which a communication hole that communicates between a first expansion chamber formed between partition plates and a second shell and a second expansion chamber formed between partition plates is provided in the partition plate, the second shell (4) and the partition The plate (6) forms a first passage (15) for connecting the first expansion chamber (7) and the second expansion chamber (8) along the partition plate (6) through the communication hole (12). while, connected to the second shell (4) and by a partition plate (6), the second expansion chamber along the partition plate (6) and the exhaust outlet (5) (8) That is the second passage (16) is formed comprising configuration.
[0007]
According to the first invention, the first passage connecting the first expansion chamber and the second expansion chamber, and the second passage connecting the second expansion chamber and the exhaust outlet are connected to the second shell. Since the partition plate is formed along the partition plate, the lengths of the first and second passages can be made longer than before without increasing the length of the muffler in the thickness direction. Therefore, the exhaust noise reduction effect can be increased. In addition, since the first and second passages are formed by the second shell and the partition plate, a muffler with a small number of parts, a simple structure, and low cost can be obtained.
[0008]
The second invention is based on the configuration of the first invention, and the first shell, the second shell, and the partition plate are each a sheet metal molded product.
[0009]
According to the second invention, the first shell, the second shell, and the partition plate can be formed by press molding, respectively, and a muffler with a small number of processing steps and low cost can be obtained.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an engine muffler according to the present invention will be described below in detail with reference to FIGS.
[0011]
FIG. 1 is a rear view of the muffler 1, and an exhaust inlet 3 for introducing exhaust from the engine is provided at a substantially central portion of the first shell 2 that forms one side of the outer shell by press molding.
[0012]
FIG. 2 is a front view of the muffler 1, and an exhaust outlet 5 is provided on an upper portion of the second shell 4 that forms the other side of the outer shell so as to face the first shell 2 by press molding.
[0013]
FIG. 3 is an AA arrow view of FIG. The first shell 2 and the second shell 4 are equipped with a partition plate 6, and the outer peripheral portions thereof are caulked together and formed integrally. The first shell 2 and the partition plate 6 form a first expansion chamber 7, and the second shell 4 and the partition plate 6 form a second expansion chamber 8 below the muffler 1. The first shell 2 and the second shell 4 are coupled by a pair of left and right pipe members 20, and are fastened to the engine by bolts (not shown) inserted into the pipe members 20.
[0014]
FIG. 4 is a view taken along the line BB in FIG. 3 and is an inner view of the second shell 4. A passage groove 10 is formed by press molding on the upper part and one side part in the left-right direction of the second shell 4, and a concave part forming the second expansion chamber 8 is formed on the lower part. A rectangular protruding portion 11 is formed in a portion surrounded by the passage groove 10 and the second expansion chamber 8, and an exhaust outlet 5 is provided in the vicinity of the longitudinal end portion of the protruding portion 11.
[0015]
FIG. 5 is a front view of the partition plate 6 as viewed from the direction of arrows CC in FIG. Two communication holes 12 and 12 are provided at predetermined positions (upper part in the present embodiment) of the partition plate 6. In the partition plate 6, a first passage groove 13 having a predetermined length L 1 that connects the second expansion chamber 8 formed in the lower portion and the communication holes 12, 12 is formed in the second shell 4 by press molding. It is formed at a position facing the passage groove 10. Further, the second passage groove 14 having a predetermined length L2 that connects the second expansion chamber 8 and the exhaust outlet 5 provided in the second shell 4 is opposed to the protruding portion 11 formed in the second shell 4. Is formed.
[0016]
FIG. 6 is a perspective view seen from the front side of the partition plate 6 and a perspective view seen from the inner surface side of the second shell 4. When the two are combined, the hatched portion is in close contact, and as shown in FIGS. A first passage 15 having a cylindrical length L1 that connects the chamber 7 and the second expansion chamber 8 is formed, and a projection 11 of the second shell 4 and a second passage groove 14 of the partition plate 6 are formed below the first passage 15. As a result, a second passage 16 having a length L2 that forms a cylindrical shape connecting the second expansion chamber 8 and the exhaust outlet 5 is formed.
[0017]
Next, the operation will be described with reference to FIGS. In FIG. 3, exhaust from an exhaust pipe of an engine (not shown) is introduced from the exhaust inlet 3 of the first shell 2 and expands in the first expansion chamber 7. Next, in FIG. 3 and FIG. 6, it passes through the communication holes 12, 12, enters the second expansion chamber 8 through the first passage 15, and expands again. Since the first passage 15 is formed along the surface of the partition plate 6 as described above, the length L1 of the first passage 15 can be made without increasing the length of the muffler in the thickness direction. The silencing effect can be increased. Next, the exhaust gas expanded in the second expansion chamber 8 is discharged to the outside from the exhaust outlet 5 through the second passage 16. At this time, since the second passage 16 is also formed along the surface of the partition plate 6, the length L2 of the second passage 16 can be increased, thereby reducing the exhaust noise.
[0018]
As described above, the muffler of the engine of the present invention connects the first expansion chamber 7 and the second expansion chamber 8 via the first passage 15 having a predetermined length L1, and connects the second expansion chamber 8 and the exhaust outlet. 5 is connected via the second passage 16 having a predetermined length L2, the effect of reducing engine exhaust noise can be increased. The first expansion chamber 7, the second expansion chamber 8, the first passage 15 and the second passage 16 are a combination of the first shell 2, the second shell 4 and the partition plate 6 which are formed into a predetermined shape by pressing. Since they are integrally formed by caulking the outer periphery together, the structure is simple and processing is easy, the conventional guide 61 is not required, the number of parts is reduced, and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a rear view of a muffler of the present invention.
FIG. 2 is a front view of the muffler of the present invention.
FIG. 3 is a view taken along arrow AA in FIG. 2;
4 is an inner surface view of a second shell as seen in the direction of arrows BB in FIG. 3;
FIG. 5 is a front view of the partition plate as seen in the direction of arrows CC in FIG. 3;
FIG. 6 is a perspective view of a partition plate and a second shell.
FIG. 7 is a side sectional view of a conventional muffler.
FIG. 8 is a view taken in the direction of arrow D in FIG.
FIG. 9 is a view taken in the direction of arrows EE in FIG.
10 is a view taken along the line FF in FIG.
[Explanation of symbols]
1: muffler, 2: first shell, 3: exhaust inlet, 4: second shell, 5: exhaust outlet, 6: partition plate, 7: first expansion chamber, 8: second expansion chamber, 10: passage groove, 11: protrusion, 12: communication hole, 13: first passage groove, 14: second passage groove, 15: first passage, 16: second passage.

Claims (2)

A first shell having an exhaust inlet connected to the exhaust port of the engine and constituting one side of the outer shell; and a first shell having an exhaust outlet and facing the first shell and constituting the other side of the outer shell. Two shells and a partition plate fitted between the first shell and the second shell, and a first expansion chamber formed between the first shell and the partition plate and a second shell formed between the second shell and the partition plate. 2 In the engine muffler provided with a communication hole in the partition plate for communicating with the expansion chamber,
The first expansion chamber (7) and the second expansion chamber (8) are connected along the partition plate (6) through the communication hole (12) by the second shell (4) and the partition plate (6). Forming the first passage (15),
The second shell (4) and the partition plate (6) form a second passage (16) connecting the second expansion chamber (8) and the exhaust outlet (5) along the partition plate (6). Engine muffler characterized by  The engine muffler according to claim 1, wherein the first shell (2), the second shell (4), and the partition plate (6) are each a sheet metal molded product.

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