JPH051816U - Engine exhaust muffler - Google Patents

Abstract

(57) [Summary] [Constitution] The pre-expansion chamber 3 and the final expansion chamber 4 are partitioned by the partition wall 2, and the exhaust outlet 5 opened in this partition wall 2 leads to the partition wall facing wall 11 of the final expansion chamber 4. Out the exhaust guide tube 6 toward
The exhaust muffler of the engine in which a plurality of exhaust ejection holes 7 are formed in the cylinder wall of the exhaust guide cylinder 6 is as follows.
A shield cylinder 10 that covers the exhaust gas ejection hole forming portion 9 of the exhaust guide cylinder 6 is led out from the partition wall facing wall 11 of the final expansion chamber 4 toward the partition wall 2, and a lead-out end 12 of the shield cylinder 10 and the partition wall 2 are provided. An exhaust gas reversal space 13 was formed between them, and an exhaust gas discharge port 8 was arranged near the partition wall facing wall 11 of the final expansion chamber 4. [Effect] Even if air is sucked in from the exhaust gas discharge port 8 when the engine is stopped, it is difficult for the air to reach the vicinity of the exhaust gas ejection hole 7, and the air does not come into contact with the air near the wall of the exhaust gas ejection hole 7 which becomes a heat point. Mixing with combustion fuel can be avoided. For this reason, an explosion is less likely to occur in the muffler body 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to an engine exhaust muffler.

[0002]

[Prior art]

  2. Description of the Related Art As a conventional exhaust muffler for an engine, there is one shown in FIG. This is A partition wall 102 is provided in the hula main body 101, and the partition wall 102 serves as a pre-expansion chamber 103. From the exhaust outlet 105 opened in the partition wall 102 by partitioning from the final expansion chamber 104 Guide the exhaust guide tube 106 toward the partition wall facing wall 111 of the final expansion chamber 104, and A plurality of exhaust ejection holes 107 are formed in the cylinder wall of the exhaust guide cylinder 106 of The exhaust emission port 108 is opened in the structure.

[0003]   According to such a configuration, the exhaust gas expanded in the pre-expansion chamber 103 is indicated by the arrow 109. As described above, the final expansion chamber 10 is guided from the exhaust ejection hole 107 by being guided through the exhaust guide cylinder 106. 4 and further expands in the final expansion chamber 104, the pressure of which is weakened, and the exhaust discharge port The exhaust noise at 108 can be reduced.

[0004]   By the way, in this conventional technique, the exhaust emission port 108 is exposed to the exhaust ejection hole 107. Are provided.

[0005]

[Problems to be solved by the device]

  The above conventional technique has the following problems.   Generally, when the engine stops, the crankshaft reverses slightly before it completely stops. In this case, air is sucked from the exhaust gas outlet. The above conventional technique In the operation, since the exhaust emission port 108 is provided so as to face the exhaust ejection hole 107, The air sucked from the exhaust emission port 108 when the gin is stopped and the uncombusted state from the combustion chamber The fuel discharged from the exhaust gas is mixed in the vicinity of the exhaust gas ejection hole 107, The wall of the hole, etc. becomes a heat point and ignites, causing an explosion in the muffler body 101. Sometimes.

[0006]   Since the exhaust gas outlet 108 is provided so as to face the exhaust gas ejection hole 107, the final expansion Mutual interference of exhaust noise in the final expansion chamber 104 due to the short passage of exhaust gas in the chamber 104 There is little silencing due to, and the silencing performance is low.

[0007]   In the present invention, the exhaust outlet and the exhaust outlet are isolated, and the exhaust gas in the final expansion chamber is The task is to lengthen the passage.

[0008]

[Means for Solving the Problems]

  (First device)   The first invention is to provide a partition wall 2 in a muffler body 1 as illustrated in FIG. The partition wall 2 divides the pre-expansion chamber 3 and the final expansion chamber 4, and the exhaust gas guide provided in the partition wall 2 The exhaust guide tube 6 is led out from the outlet 5 toward the partition facing wall 11 of the final expansion chamber 4. A plurality of exhaust gas ejection holes 7 are formed in the cylinder wall of the exhaust guide cylinder 6 so that the exhaust gas is discharged into the final expansion chamber 4. The engine exhaust muffler with the air discharge port 8 opened has the following features. To collect.

[0009]   That is, the exhaust gas from the exhaust guide tube 6 is discharged from the partition wall facing wall 11 of the final expansion chamber 4. A shielding cylinder 10 that covers the ejection hole forming portion 9 is led out toward the partition wall 2, and the shielding cylinder 10 is provided. An exhaust gas reversal space 13 is formed between the lead-out end 12 of 10 and the partition wall 2. The exhaust gas discharge port 8 is arranged near the partition wall facing wall 11 of the expansion chamber 4. .

[0010]   (2nd device)   The second invention, as illustrated in FIG. 1, is located in the exhaust muffler of the engine of the first invention. The peripheral wall portion 14 of the exhaust outlet 5 of the partition wall 2 to the partition wall pair of the final expansion chamber 4. It is characterized in that it is formed in a funnel shape in which the diameter is gradually reduced toward the facing wall 11.

[0011]

[Action]

  (First device)   From the wall 11 facing the partition wall of the final expansion chamber 4 to the exhaust gas ejection hole forming portion 9 of the exhaust guide cylinder 6. The shielding tube 10 that covers the wall is led out toward the partition wall 2 and is separated from the lead-out end 12 of the shielding tube 10. An exhaust gas reversal space 13 is formed between the partition wall 2 and the partition wall facing wall 11 of the final expansion chamber 4. Since the exhaust gas discharge port 8 is arranged in the vicinity, the air is discharged from the exhaust gas discharge port 8 when the engine is stopped. Even if it is sucked in, the air does not easily reach the vicinity of the exhaust gas ejection hole 7, which causes a heat point. The mixture of air and unburned fuel near the hole wall of the exhaust outlet 7 You can For this reason, an explosion is less likely to occur in the muffler body 1.

[0012]   The exhaust gas that has flowed into the final expansion chamber 4 through the exhaust gas ejection hole 7 is, as indicated by the arrow 15, After passing through the inner space 16 of the shielding cylinder 10, it is inverted in the exhaust reversal space 13 After passing through the outer space 17 of 10, the exhaust gas is discharged from the exhaust gas discharge port 8. Because of this, The exhaust passage in the final expansion chamber 4 is long, which causes mutual interference of exhaust noise in the final expansion chamber 4. Therefore, the silencing performance is improved.

[0013]   (2nd device)   The second device operates in the following manner in addition to the action and function of the first device.   The peripheral wall portion 14 of the exhaust gas outlet 5 of the partition wall 2 is provided with the partition wall facing wall 11 of the final expansion chamber 4. Since it is formed in a funnel shape in which the diameter is gradually reduced toward the The exhaust gas that flows into the exhaust gas 5 is smoothly guided by the peripheral portion 14 of the exhaust gas outlet 5. At the same time, the exhaust gas that is about to be inverted in the exhaust inversion space 13 in the final expansion chamber 4 is also exhausted. It is smoothly guided by the peripheral wall portion 14 of the outlet 5, and the back pressure of exhaust gas is reduced. For this reason The output of the engine can be improved by a slight modification of the partition wall 2.

[0014]

[Effect of device]

  (First device)   Shield that covers the exhaust gas injection hole forming part of the exhaust guide tube from the partition facing wall of the final expansion chamber The cylinder is led out toward the partition wall, and the exhaust reversal space is provided between the partition wall and the outlet end of this shielding cylinder. And the exhaust outlet was located near the partition facing wall of the final expansion chamber. Even if air is sucked in from the exhaust outlet when the It is difficult to reach the exhaust air Mixing with the ingredients can be avoided. For this reason, an explosion occurs inside the muffler body. It becomes difficult to get along.

[0015]   The exhaust gas that flowed into the final expansion chamber from the exhaust gas ejection hole passed through the inner space of the shielding cylinder. Later, it reverses in the exhaust reversal space, passes through the outer space of the cutoff cylinder, and then from the exhaust emission port. Is released. Therefore, the exhaust passage in the final expansion chamber is long, and the exhaust path in the final expansion chamber is long. Muting interference of exhaust noise enhances muffling performance.

[0016]   (2nd device)   The second device has the following effects in addition to the effects of the first device.   Gradually the peripheral wall of the exhaust outlet of the partition wall toward the partition facing wall of the final expansion chamber Since it has a funnel shape that reduces the diameter, it tries to flow from the pre-expansion chamber to the exhaust outlet. The exhaust gas is smoothly guided by the surrounding wall of the exhaust outlet, and Exhaust gas that is about to be reversed in the exhaust gas reversal space is also smoothly guided by the peripheral wall of the exhaust gas outlet port. This reduces the back pressure of exhaust gas. Therefore, the engine output can be improved by a slight improvement of the partition wall. Can be improved.

[0017]

【Example】

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an engine according to an embodiment of the present invention. FIG. 1 (A) is a vertical cross-sectional side view of the exhaust muffler illustrating the gin exhaust muffler. 1 (B) is a sectional view taken along line BB of FIG. 1 (A).

[0018]   The exhaust muffler shown in FIG. 1 is as follows. As shown in FIG. 1 (A), A partition wall 2 is provided in the cylindrical muffler body 1, and the partition wall 2 is closer to the starting end of the muffler body 1. The first expansion chamber 3 on the side and the second expansion chamber 4 on the side closer to the terminal end of the muffler body 1 are partitioned and formed. It An exhaust inflow cylinder 18 is introduced into the first expansion chamber 3 from the outside of the muffler body 1, and the exhaust flow A plurality of exhaust passage holes 19 are opened in the cylinder wall of the inlet cylinder 18.

[0019]   Further, an exhaust outlet port 5 is opened in the partition wall 2, and the inside of the second expansion chamber 4 is opened from this exhaust outlet port 5. The exhaust guide tube 6 is led out to the outside, and the lead-out end 20 of the exhaust guide tube 6 is a partition of the second expansion chamber 4. It reaches to the wall opposite wall 11. On the cylinder wall of this exhaust guide cylinder 6, near the outlet end 20 A plurality of exhaust gas ejection holes 7 are formed in the. Exhaust from outside the muffler body 1 into the second expansion chamber 4. The discharge cylinder 21 is introduced, and the exhaust discharge port 8 is formed at the outer end of the exhaust discharge cylinder 21. .

[0020]   In this exhaust muffler, the exhaust gas emitted from the combustion chamber (not shown) of the engine is As shown by the arrow in FIG. 1 (A), the inside of the exhaust inflow cylinder 18 is guided and the exhaust passage hole 19 From the first expansion chamber 3 into the exhaust guide tube 6 while expanding from the first expansion chamber 3 Inside the second expansion chamber 4 while flowing into the second expansion chamber 4 while expanding from the exhaust ejection hole 7. From the exhaust emission port 8 through the exhaust emission cylinder 21.

[0021]   In this exhaust muffler, in order to prevent the explosion in the muffler body 1, My husband is doing it. Shielding the partition wall facing wall 11 of the second expansion chamber 4 toward the partition wall 2 The cylinder 10 is led out, and as shown in FIG. 1 (B), the shielding cylinder 10 is used to discharge the exhaust guide cylinder 6. It covers the gas ejection hole forming portion 9. As shown in FIG. 1 (A), An exhaust gas reversal space 13 is formed between the outlet end 12 and the partition wall 2. Of the shield cylinder 10 An annular porous plate 22 is interposed in the middle of the surrounding space. Partition of the second expansion chamber 4 An exhaust emission cylinder 21 is arranged near the wall facing wall 11.

[0022]   The exhaust gas ejected from the exhaust gas ejection hole 7 into the second expansion chamber 4 is, as shown by an arrow 15, After passing through the inner space 16 of the shielding cylinder 10, it is inverted in the exhaust reversal space 13 After passing through the outer space 17 of 10, the exhaust gas is discharged from the exhaust gas discharge port 8.

[0023]   Also, in this exhaust muffler, in order to reduce the back pressure of the exhaust, the exhaust guide of the partition wall 2 The diameter of the peripheral wall portion 14 of the outlet 5 is gradually reduced toward the partition wall facing wall 11 of the second expansion chamber 4. It has a funnel shape.

[0024]   The embodiment of the present invention is as described above, but the present invention is not limited to the above embodiment. It is not something that can be done. For example, in the above embodiment, the number of expansion chambers is two, but there are three or more. It may be one.

[Brief description of drawings]

1 is a diagram illustrating an exhaust muffler of an engine according to an embodiment of the present invention, FIG. 1 (A) is a vertical cross-sectional side view of the exhaust muffler, and FIG. 1 (B) is a diagram of FIG. 1 (A). It is a BB line sectional view.

FIG. 2 is a vertical sectional side view of an exhaust muffler of an engine according to the related art.

[Explanation of symbols]

1 ... Muffler body, 2 ... Partition wall, 3 ... Pre-expansion chamber (first expansion chamber), 4 ... Final expansion chamber (second expansion chamber), 5 ... Exhaust outlet, 6 ... Exhaust guide tube, 7 ... Exhaust gas ejection Holes, 8 ... Exhaust gas discharge port, 9 ... Exhaust gas ejection hole forming part, 10 Shielding wall, 11 ... 4 partition wall facing wall, 12 ... Outgoing end of 10, 13 ... Exhaust reversal space, 14 ...

Claims (2)

[Scope of utility model registration request] 1. A partition wall (2) is provided in the muffler body (1),
The partition wall (2) divides the pre-expansion chamber (3) from the final expansion chamber (4), and the exhaust outlet (5) opened in the partition wall (2) partitions the final expansion chamber (4). The exhaust guide cylinder (6) is led out toward the wall facing wall (11), a plurality of exhaust ejection holes (7) are opened in the cylinder wall of the exhaust guide cylinder (6), and the exhaust gas is discharged into the final expansion chamber (4). Outlet
In the exhaust muffler of the engine in which (8) is opened, the exhaust guide tube from the partition facing wall (11) of the final expansion chamber (4).
The shielding cylinder (10) covering the exhaust gas ejection hole forming portion (9) of (6) is led out toward the partition wall (2), and the leading end (12) of the shielding cylinder (10) and the partition wall (2). ) And exhaust reversal space (13)
An exhaust muffler for an engine, characterized in that an exhaust gas discharge port (8) is formed in the vicinity of the partition wall facing wall (11) of the final expansion chamber (4). 2. The exhaust muffler of the engine according to claim 1, wherein a peripheral portion of an exhaust outlet (5) of the partition wall (2).
An exhaust muffler for an engine, characterized in that (14) is formed in a funnel shape in which the diameter is gradually reduced toward the partition wall facing wall (11) of the final expansion chamber (4).