CN113638796A

CN113638796A - Silencer for internal combustion engine

Info

Publication number: CN113638796A
Application number: CN202111084577.1A
Authority: CN
Inventors: 陈春明; 陈阳; 陈欣; 金松; 朱瑞松
Original assignee: Shandong Pufeng Garden Technology Co ltd
Current assignee: Shandong Pufeng Garden Technology Co ltd
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2021-11-12

Abstract

The invention discloses a silencer for an internal combustion engine, which comprises a bowl-shaped silencer main body arranged on an exhaust gas inflow side and a bowl-shaped silencer cover arranged on an exhaust gas discharge side and covering the silencer main body, wherein the edge of the silencer main body is jointed with the edge of the silencer cover to form the appearance of the silencer for the internal combustion engine; the muffler body has a mounting surface portion facing an exhaust portion of the engine; the outer surface of the mounting surface is a plane, an inlet of exhaust gas is formed at the center of the plane, and a cylindrical oxidation catalyst is arranged in the silencer for the internal combustion engine; a 1 st diaphragm is arranged around the oxidation catalyst, and a 1 st expansion chamber is arranged between the 1 st diaphragm and the silencer main body; the protector is fixed inside the No. 1 diaphragm and the silencer cover. The invention is not only suitable for portable engines, but also suitable for any engine which uses a silencer and a catalyst; that is, it can be applied to all general-purpose engines.

Description

Silencer for internal combustion engine

Technical Field

The invention relates to the technical field of silencers, in particular to a silencer for an internal combustion engine.

Background

Internal combustion engines, during operation, burn to produce large quantities of exhaust gases. The main component of the waste gas is carbon dioxide, and the waste gas needs to be quickly discharged in order to avoid the influence of the waste gas on the subsequent combustion of the internal gas combustion cavity. Exhaust gas often generates large noise due to a large amount of exhaust gas discharged, and in order to avoid pollution caused by the noise, it is necessary to reduce the sound energy of the exhaust gas and reduce the decibel of the exhaust gas sound.

Because the gas displacement of internal combustion is big, it is fast to exhaust, consequently in order to ensure better noise reduction effect, current exhaust silencer need set up longer noise elimination passageway and fall and make an uproar, consumes carminative sound energy, avoids the noise, because the noise elimination passageway is longer, consequently current exhaust silencer is great usually the size to it is very inconvenient to use.

Disclosure of Invention

The invention aims to provide a silencer for an internal combustion engine, aiming at improving the problem that the existing exhaust silencer needs to be provided with a longer silencing channel to reduce noise, consumes sound energy of exhaust and avoids noise in order to ensure better noise reduction effect because the exhaust gas volume is large and the exhaust speed is high. The existing exhaust muffler is generally large in size and inconvenient to use due to the long silencing channel.

The invention is realized by the following steps:

a muffler for an internal combustion engine, the muffler including a bowl-shaped muffler body disposed on an exhaust gas inflow side and a bowl-shaped muffler cover disposed on an exhaust gas discharge side and covering the muffler body, an edge of the muffler body and an edge of the muffler cover being joined to each other to form an outer shape of the muffler for the internal combustion engine;

the muffler body has a mounting surface portion facing an exhaust portion of the engine; the outer surface of the mounting surface is a plane, an inlet of exhaust gas is formed at the center of the plane, and a cylindrical oxidation catalyst is arranged in the silencer for the internal combustion engine; a 1 st diaphragm is arranged around the oxidation catalyst, and a 1 st expansion chamber is arranged between the 1 st diaphragm and the silencer main body;

the protector is fixed on the inner sides of the 1 st diaphragm and the muffler cover, and a 2 nd expansion chamber is arranged between the 1 st diaphragm and the protector;

a tail pipe in a circular pipe shape extending in the horizontal direction in the figure is provided at one end 3a of the muffler cover, the tail pipe is provided adjacent to the 2 nd expansion chamber, and the exhaust gas passing through the 2 nd expansion chamber is discharged from the discharge port;

a 3 rd expansion chamber is arranged between the protector and the muffler cover;

one end 12a of the protector is provided with a protector exhaust pipe in a circular pipe shape extending in the horizontal direction in the figure, and an annular gas flow path is formed between the tail pipe and the protector exhaust pipe.

Further, the diameter of the protector exhaust pipe is smaller than the diameter of the tail pipe, and the tip end portion (end portion on the downstream side in the exhaust direction of the exhaust gas) of the protector exhaust pipe is disposed in the tail pipe; the tail pipe and the protector exhaust pipe are concentrically arranged, and a gas flow path communicating with the expansion chamber 3 is formed between the protector exhaust pipe and the tail pipe of the expansion chamber 2.

Further, a vent hole is formed in the muffler cover, and external air is introduced into the 3 rd expansion chamber through the vent hole.

Further, the vent hole is provided on the opposite side of the tail pipe with respect to the 3 rd expansion chamber.

Further, the protective cover is installed on the protector of the oxidation catalyst; the protective cover is a bottomed cylindrical cover, and the edge of the opening of the protective cover is joined to the 1 st diaphragm; a gas flow path communicating with the No. 2 expansion chamber is formed in the shield cover.

Compared with the prior art, the invention has the beneficial effects that: the invention has the characteristics of reasonable structure, convenient installation and flexible use, is not only suitable for a portable engine, but also suitable for any engine which uses a silencer and a catalyst; that is, it can be applied to all general-purpose engines.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a perspective view of a muffler for an internal combustion engine according to embodiment 1 of the present invention;

FIG. 2 is a perspective view, partially in section, of the muffler for the internal combustion engine of FIG. 1;

FIG. 3 is a cross-sectional view of a muffler for the internal combustion engine of FIG. 1;

FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3;

fig. 5 is a sectional view of the muffler for an internal combustion engine of embodiment 2;

FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5;

fig. 7 is a sectional view of a conventional muffler for an internal combustion engine;

fig. 8 is a sectional view taken along line VIII-VIII of fig. 7.

In the figure: 1. a muffler for an internal combustion engine; 11. 1 st membrane; 11a, a circular opening; 12. a protector; 12b, a protector exhaust pipe; 2. a muffler main body; 21. 1 st expansion chamber; 2a, mounting a face; 22. a 2 nd expansion chamber; 22a, a protector exhaust port; 23. a 3 rd expansion chamber; 3. a muffler cover; 3b, a vent hole; 4. an oxidation catalyst; 6. an inflow port; 7. an outlet port; 8. a tail pipe; 10. bolt holes; p, a gas flow path;

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number.

If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the term "connected" is to be interpreted broadly, and may be, for example, a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or may be connected through one or more other elements or indirectly connected through one or more other elements or in an interactive relationship between two elements.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

A muffler 1 for an internal combustion engine according to embodiment 1 will be described with reference to fig. 1 to 4. As shown in fig. 1 and 2, a muffler 1 for an internal combustion engine is fixed to an internal combustion engine such as a portable engine (not shown), and allows exhaust gas from the engine to flow into the muffler and to pass through the muffler to discharge the muffled exhaust gas. The muffler 1 for an internal combustion engine includes a bowl-shaped muffler main body 2 disposed on an exhaust gas inflow side, and a bowl-shaped muffler cover 3 disposed on an exhaust gas discharge side and covering the muffler main body 2. The edge of the muffler body 2 and the edge of the muffler cover 3 are joined to each other to form the outer shape of the muffler 1 for an internal combustion engine.

The muffler main body 2 has a mounting surface portion 2a facing an exhaust portion of the engine. The outer surface of the mounting surface portion 2a is flat, and an inflow port 6 for exhaust gas is formed in the center thereof. A seal member such as a gasket is provided between the mounting surface portion 2a and the exhaust portion of the engine. Around the inflow opening 6, two bolt holes 10 are provided on both sides of the inflow opening 6. The muffler 1 for an internal combustion engine is fixed to the engine by inserting fastening bolts through the bolt holes 10 and screwing them into the engine, and fastening the muffler cover 3 and the muffler body 2 together to the exhaust part of the engine.

As shown in fig. 2 and 3, a 1 st diaphragm 11 and a protector (2 nd diaphragm) 12 are fixed inside the muffler 1 for an internal combustion engine. The 1 st diaphragm 11 and the protector 12 are sandwiched between the edge of the muffler body 2 and the edge of the muffler cover 3 in a state where the peripheral portions overlap, and are thereby fixed. The 1 st membrane 11 is flat. The protector 12 is fixed to the 1 st diaphragm 11 on the muffler cover 3 side. The protector 12 is opposed to the 1 st diaphragm 11 and the oxidation catalyst 4, and has a shape expanded toward the muffler cover 3. The protector 12 is disposed between the 1 st diaphragm 11 and the muffler cover 3 so as to face the muffler cover 3.

A cylindrical oxidation catalyst (catalyst portion) 4 is provided inside the muffler 1 for an internal combustion engine. The oxidation catalyst 4 is disposed in a circular opening 11a formed in the 1 st diaphragm 11, and the center axis thereof is installed in a direction substantially parallel to the bolt hole 10. The exhaust gas from the engine passes through the catalyst 4, burning unburned hydrocarbons in the exhaust gas.

As described above, the 1 st membrane 11 is provided around the oxidation catalyst 4. The 1 st diaphragm 11 divides the inside of the muffler 1 for an internal combustion engine into an inflow side and an outflow side. A 1 st expansion chamber 21 is provided between the 1 st diaphragm 11 and the muffler main body 2. That is, the 1 st expansion chamber 21 is provided between the inflow port 6 and the oxidation catalyst 4. The exhaust gas flows into the 1 st expansion chamber 21 through the inflow port 6. The exhaust gas flowing into the 1 st expansion chamber 21 flows out from the 1 st expansion chamber 21 through the oxidation catalyst 4. That is, the muffler body 2 is provided on the inflow side of the 1 st expansion chamber 21, and the 1 st diaphragm 11 is provided on the outflow side of the 1 st expansion chamber 21.

A 2 nd expansion chamber 22 is provided between the 1 st diaphragm 11 and the protector 12. That is, the 2 nd expansion chamber 22 is partitioned by the 1 st diaphragm 11 and the protector 12. The 1 st expansion chamber 21 and the 2 nd expansion chamber 22 communicate with each other through a plurality of pores formed in the oxidation catalyst 4. The exhaust gas passes through the oxidation catalyst 4 and then passes through the 2 nd expansion chamber 22.

As shown in fig. 2 and 4, a tail pipe (discharge pipe) 8 having a circular pipe shape extending in the horizontal direction is provided at one end 3a (lower end portion shown in fig. 2) of the muffler cover 3. The tail pipe 8 is disposed adjacent to the 2 nd expansion chamber 22, and discharges the exhaust gas passing through the 2 nd expansion chamber 22 from the discharge port 7.

More specifically, a protector exhaust pipe (outlet portion) 12b having a circular pipe shape extending in the horizontal direction is provided at one end 12a (lower end portion shown in fig. 2) of the protector 12. The protector exhaust pipe 12b discharges the exhaust gas from the 2 nd expansion chamber 22 protector exhaust port 22 a.

The diameter of the protector exhaust pipe 12b is smaller than the diameter of the tail pipe 8, and the tip end portion (end portion on the downstream side in the exhaust gas discharge direction) of the protector exhaust pipe 12b is disposed in the tail pipe 8. The tail pipe 8 and the protector exhaust pipe 12b are arranged concentrically.

As shown in fig. 4, the front end portion of the protector exhaust pipe 12b slightly protrudes into the rear end of the tail pipe 8. The tip end portion of the protector exhaust pipe 12b overlaps the tail pipe 8 in the axial direction of the tail pipe 8 and the protector exhaust pipe 12b, and this overlapping portion is an overlapping portion a. With this configuration, an annular gas flow path P is formed between the tail pipe 8 and the protector exhaust pipe 12 b.

A 3 rd expansion chamber 23 is provided between the protector 12 and the muffler cover 3. That is, the 3 rd expansion chamber 23 is partitioned by the protector 12 and the muffler cover 3. The 3 rd expansion chamber 23 covers the 2 nd expansion chamber 22 from the muffler cover 3 side. The high-temperature exhaust gas that has passed through the oxidation catalyst 4 and the 2 nd expansion chamber 22 does not flow in the 3 rd expansion chamber 23.

As described above, the protector exhaust pipe 12b of the protector 12 and the tail pipe 8 are separated without being directly joined. Therefore, the gas flow path P formed around the protector exhaust pipe 12b communicates with the 3 rd expansion chamber 23. In other words, the discharge port 7 communicates with the 2 nd expansion chamber 22 through the protection discharge port 22a, and further communicates with the 3 rd expansion chamber 23 through the gas flow path P. When the exhaust gas is discharged from the discharge port 7 of the tail pipe 8, the 3 rd expansion chamber 23 is lower in pressure than the outside air.

According to the muffler 1 for an internal combustion engine, exhaust gas passes through the oxidation catalyst 4 and the 2 nd expansion chamber 22, and is then discharged from the discharge port 7 of the tail pipe 8 to the outside. A 3 rd expansion chamber 23 is provided between the 2 nd expansion chamber 22 and the muffler cover 3, and the high-temperature exhaust gas does not flow into the 3 rd expansion chamber 23. Therefore, the surface temperature of the muffler cover 3 can be reduced. In the muffler 1 for an internal combustion engine, a gas flow path P communicating with the 3 rd expansion chamber 23 is formed between the protector exhaust pipe 12b of the 2 nd expansion chamber 22 and the tail pipe 8. The gas flow path P regulates the function (i.e., function) of the resonance chamber, which is the expansion chamber of the 3 rd expansion chamber 23, or the function (i.e., function) of the resonance chamber, thereby exhibiting a sound deadening effect. In this case, since the gas flow path P is provided only between the protector exhaust pipe 12b of the 2 nd expansion chamber 22 and the tail pipe 8, the same number of components as in the conventional configuration can be used. Therefore, the noise reduction effect can be exerted while the number of control members is increased.

Further, when the exhaust gas is discharged from the discharge port 7 of the tail pipe 8, the 3 rd expansion chamber 23 is lower in pressure than the outside air, and therefore the silencing effect is further improved.

In addition, since the high-temperature exhaust gas contacts the protector 12, the protector 12 becomes high-temperature. However, since the 3 rd expansion chamber 23 is provided, the radiation heat is suppressed from being transmitted from the muffler cover 3 to the external decorative member. Therefore, the temperature rise of the external decorative member is suppressed.

By changing the shape of the overlapping portion a, the noise reduction effect can be adjusted. In more detail, the back pressure can be adjusted by adjusting the inner diameter of the protector exhaust pipe 12 b. Even if the inner diameter of the protector exhaust pipe 12b is smaller than that of the conventional one, the increase in back pressure is suppressed, and the influence on the output is small. In the muffler 1 for an internal combustion engine, exhaust noise can be the same as or greater than that of the conventional structure while increasing output power.

The muffler 1 for an internal combustion engine can be configured with the same number of components as the conventional configuration. Therefore, the cost is not increased.

Next, an engine muffler 1A of embodiment 2 will be described with reference to fig. 5 and 6. The internal combustion engine muffler 1A is different from the internal combustion engine muffler 1 of embodiment 1 in that a hood 14 for covering the oxidation catalyst 4 is provided, and the muffler cover 3 is provided with a vent hole 3 b. The protection cover 14 is attached to the oxidation catalyst 4 on the protector 12 side (i.e., the muffler cover 3 side). The hood 14 is a bottomed cylindrical hood, and an edge of an opening (an edge on the engine side) thereof is joined to the 1 st diaphragm 11. A gas flow path (another gas flow path) 14a communicating with the 2 nd expansion chamber 22 is formed in the hood 14.

As shown in fig. 6, the vent hole 3b is provided on the opposite side of the tail pipe 8 with respect to the 3 rd expansion chamber 23. The outside air is introduced into the 3 rd expansion chamber 23 through the vent hole 3 b.

The muffler 1A for an internal combustion engine according to embodiment 2 can also provide the same effects as those of the muffler 1 for an internal combustion engine. Further, since the outside air is introduced into the 3 rd expansion chamber 23 through the vent hole 3b, the cooling efficiency inside the muffler 1A for the internal combustion engine is improved.

The outside air temperature in the vicinity where the tail pipe 8 is provided is relatively high. In the muffler 1A for an internal combustion engine, by providing the vent hole 3b on the opposite side of the tail pipe 8, the relatively low-temperature outside air can be introduced into the 3 rd expansion chamber 23.

Protection from sparks is achieved by the shield 14. The exhaust gas can be made to flow from the oxidation catalyst 4 to the 2 nd expansion chamber 22 through the gas flow path 14a formed in the hood 14.

The above description has been made of the embodiments of the present invention, but the present invention is not limited to the above embodiments. For example, the tail pipe 8 and the protector exhaust pipe 12b may not be concentric. The gas flow path P is not limited to an annular shape. It may be formed on a part of the periphery of the protective exhaust pipe 12 b. The overlapping portion a may not be provided. That is, the protector exhaust pipe 12b may not extend into the tail pipe 8.

The form of the catalyst portion is not limited to the oxidation catalyst 4. The muffler 1 for an internal combustion engine according to embodiment 1 may also employ the vent hole 3b of the muffler cover 3. The present invention is applicable not only to portable engines but also to any engine using a muffler and a catalyst for the muffler. That is, it can be applied to all general-purpose engines.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A muffler for an internal combustion engine, characterized in that: the muffler (1) for the internal combustion engine comprises a bowl-shaped muffler main body (2) arranged on the exhaust gas inflow side and a bowl-shaped muffler cover (3) arranged on the exhaust gas discharge side and covering the muffler main body (2), wherein the edge of the muffler main body (2) is jointed with the edge of the muffler cover (3) to form the appearance of the muffler (1) for the internal combustion engine;

the muffler body (2) has a mounting surface section (2a) that faces the exhaust section of the engine; the outer surface of the mounting surface part (2a) is a plane, an inflow port (6) of exhaust gas is formed at the center of the plane, and a cylindrical oxidation catalyst (4) is arranged in the silencer (1) for the internal combustion engine; a 1 st diaphragm (11) is arranged around the oxidation catalyst (4), and a 1 st expansion chamber (21) is arranged between the 1 st diaphragm (11) and the muffler main body (2);

the protector (12) is fixed on the inner sides of the 1 st diaphragm (11) and the muffler cover (3), and a 2 nd expansion chamber (22) is arranged between the 1 st diaphragm (11) and the protector (12);

a tail pipe (8) in a circular pipe shape extending in the horizontal direction is arranged at one end (3 a) of the muffler cover (3), the tail pipe (8) is arranged adjacent to the 2 nd expansion chamber (22), and the exhaust gas passing through the 2 nd expansion chamber (22) is discharged from the discharge port (7);

a 3 rd expansion chamber (23) is arranged between the protector (12) and the muffler cover (3);

one end 12a of the protector 12 is provided with a protector exhaust pipe 12b in a circular pipe shape extending in the horizontal direction in the figure, and an annular gas flow path P is formed between the tail pipe 8 and the protector exhaust pipe 12 b.

2. The muffler for an internal combustion engine according to claim 1, wherein the diameter of the protector exhaust pipe (12b) is smaller than the diameter of the tail pipe (8), and a tip end portion (an end portion on the downstream side in the exhaust gas discharge direction) of the protector exhaust pipe (12b) is disposed in the tail pipe (8); the tail pipe (8) and the protector exhaust pipe (12b) are arranged concentrically, and a gas flow path (P) communicating with the 3 rd expansion chamber (23) is formed between the protector exhaust pipe (12b) of the 2 nd expansion chamber (22) and the tail pipe (8).

3. The muffler for an internal combustion engine according to claim 1, wherein the muffler cover (3) is provided with a vent hole (3b), and outside air is introduced into the 3 rd expansion chamber (23) through the vent hole (3 b).

4. The muffler for an internal combustion engine according to claim 3, wherein the vent hole (3b) is provided on the opposite side of the tail pipe (8) with respect to the 3 rd expansion chamber (23).

5. The muffler for an internal combustion engine according to claim 1, wherein the protective cover (14) is mounted on the protector (12) of the oxidation catalyst (4); the protective cover (14) is a bottomed cylindrical cover, the edge of the opening of which is joined to the 1 st diaphragm 11; a gas flow path (14a) communicating with the 2 nd expansion chamber (22) is formed in the hood (14).