WO2006080441A1

WO2006080441A1 - Muffler for small engine

Info

Publication number: WO2006080441A1
Application number: PCT/JP2006/301325
Authority: WO
Inventors: Hidenori Mukaida
Original assignee: Hiraoka Manufacturing Co., Ltd.
Priority date: 2005-01-28
Filing date: 2006-01-27
Publication date: 2006-08-03
Also published as: JPWO2006080441A1; US20090013673A1

Abstract

A muffler for a small engine having a large muffling effect and exhaust gas purification effect, enabling the easy manufacturing of an exhaust gas purifier, and manufacturable at low cost. The muffler comprises a first expansion chamber (12) for exhaust gas having an exhaust gas inlet (11) connected to the exhaust port of the engine, a second expansion chamber (15) for exhaust gas partitioned from the first expansion chamber (12) through a partition plate (14) and communicating with the first expansion chamber (12) through a first air hole (13) in the partition plate (14), and a third expansion chamber (18) for exhaust gas partitioned from the second expansion chamber (15) through the partition plate (14) communicating with the second expansion chamber (15) through a second air hole (16) in the partition plate (14) and having an exhaust gas outlet (17). The muffler is characterized in that a first heat resistant mesh catalyst (19) is installed at the exhaust gas inlet (11), and the first exhaust gas purifier (20) formed by coating a catalyst for purifying the exhaust gas on a heat resistant knit fabric (20a) is installed at the first air hole (13) in the partition plate (14).

Description

Specification

Muffler for small engines

Technical field

[0001] The present invention relates to a muffler for a small engine suitable for use in a small engine used in, for example, a brush cutter or a chain saw.

Background art

A muffler used in a conventional small engine has an exhaust gas first expansion chamber 2 having an exhaust gas inlet 1 connected to an exhaust port of the engine and an exhaust gas outlet 3 as shown in FIG. The second expansion chamber 4 is provided. Between the first expansion chamber 2 and the second expansion chamber 4, for example, a stainless-steel having countless small holes in the form of a hard cam along the axial direction is provided. The substrate was provided with an exhaust gas purifier 5 coated with a catalyst for purifying exhaust gas, for example, one or a combination of two or more of platinum, rhodium and palladium.

Further, as shown in FIG. 22, the muffler used in the conventional small engine includes a first expansion chamber 2 for exhaust gas having an exhaust gas inlet 1 connected to the exhaust port of the engine, and an exhaust gas outlet 3. A second expansion chamber 4 having a concave exhaust gas receiving member 6 in which a plurality of vent holes 6b are formed in the concave surface 6a, and the first exhaust gas receiving member 6 so that the concave surface 6a faces the exhaust gas inlet 1. For example, a stainless steel base having an infinite number of small holes in the axial direction between the first and second expansion chambers 2 and 4 is provided in the expansion chamber 2 and exhausted. The exhaust gas purifier 5 coated with the catalyst was used to purify the gas. 21 and 22, reference numeral 2 a is a wall forming the first extension chamber 2, reference numeral 4 a is a wall forming the second extension chamber 4, and reference numeral 7 is the first extension chamber 2. And a partition plate separating the second expansion chamber 4 from each other.

[0004] Various mufflers for conventional small engines have been developed. For example, the catalyst carrier used in the muffler is formed by superposing thin metal plates having a large number of openings on both sides of the cross catalyst, and the catalyst carrier is curved in a waveform and then the thin metal plate of the catalyst carrier is formed. The plate is configured to be parallel to the exhaust flow (Patent Document 1). [0005] Further, the following are known as conventional exhaust mufflers. The exhaust muffler accommodates a plurality of coarse cylindrical cross catalysts and a narrow cylindrical cross catalyst inside. Each cylindrical cross catalyst is relatively soft, and is formed into a cylindrical shape having an elliptical cross section by bonding the catalyst to a heat resistant fabric. The coarse-cylindrical cross catalyst is arranged on the upper part of the exhaust muffler so as to surround the two reinforcing beams, and the exhaust port of the engine goes through the opening of the exhaust muffler and passes through the opening of the exhaust muffler. Communicated to The coarse cylindrical cross catalyst of the eyes surrounds the two reinforcing beams at the lower part of the exhaust muffler, and the peripheral edge of the cylindrical cross catalyst is partially arranged in close contact with the inner wall surface of the exhaust muffler. Is done. Therefore, the inside of the exhaust muffler includes a chamber inside the coarse-shaped cylindrical cross catalyst, a chamber outside the cylindrical cross catalyst, a chamber of the narrow cylindrical cross catalyst, and a chamber of the cylindrical cross catalyst. The exhaust muffler is configured to be partitioned on the outside into a lowermost chamber of the exhaust muffler (Patent Document 2).

[0006] The following are known as conventional exhaust mufflers. In this exhaust muffler, a plurality of catalyst carriers are coupled in series in an exhaust passage. Each catalyst carrier is covered with a metal mesh by stacking the catalyst on a holding plate having an opening. One catalyst carrier holding plate is connected almost horizontally to the upper case of the exhaust muffler. The other catalyst carrier holding plate is connected almost horizontally to the lower case of the exhaust muffler. The exhaust muffler is divided into three chambers in the exhaust flow direction by the holding plate. This exhaust muffler is constituted by the catalyst support metal mesh on the exhaust inlet side being coarse and the catalyst support metal mesh on the outlet side being narrow (patent document 3).

[0007] The following is known as a conventional exhaust muffler structure. This exhaust muffler structure is divided into an inner exhaust muffler piece and an outer exhaust muffler piece, and a substantially box-shaped exhaust muffler configured to be freely integrated, and an exhaust gas from an internal combustion engine provided in the exhaust muffler. In the exhaust muffler structure of an internal combustion engine, which has a communication hole for guiding the gas into the exhaust muffler, and a cylindrical member having appropriate elasticity and sandwiching a catalyst between holding networks, the cylindrical member is The body portion is arranged in a space in the exhaust muffler so as to be sandwiched between the two muffler pieces. According to such an exhaust muffler structure, the cylindrical member can be adapted to the surrounding shape as long as it is installed in the space between the inner and outer exhaust muffler pieces when integrated. The body is freely elastically deformed and held (Patent Document 4). [0008] Further, the following are known as conventional engine mufflers. That is, a cylindrical spark arrester is formed by a cylindrical wire mesh member, which is a means for preventing the scattering of sparks, and this cylindrical spark arrester force is inserted between the tail pipe end and the inner surface of the muffler mounting body. (Patent document 5).

[0009] Further, the following is known as a conventional exhaust muffler structure. A partition plate is provided in the muffler along the axial center direction of the cylinder in the engine, and in the muffler, the partition plate separates the first chamber on the side close to the engine body and the engine chamber on the side away from the engine body force. It is divided into two rooms. The catalyst is held in the lower part of the partition plate. This catalyst has a function of recombusting the unburned gas in the exhaust gas by an oxidation reaction. Therefore, the catalyst is formed by coating the catalyst on the surface of the passage of a stainless steel hard cam structure. Yes. An inner catalyst cover that is located in the first chamber and covers almost the inner half of the catalyst and an outer catalyst cover that is located in the second chamber and covers the outer half of the catalyst are attached to the partition plate. It has been. A space surrounded by the inner catalyst cover and the partition plate is a first catalyst chamber, and an inlet-side communication port that communicates the first catalyst chamber and the first chamber is formed in the inner catalyst cover. A space surrounded by the outer catalyst cover and the partition plate is a second catalyst chamber, and an outlet-side communication port that connects the second catalyst chamber and the second chamber is formed in the outer catalyst cover. A catalyst storage case for storing the catalyst is formed by attaching the inner catalyst cover and the outer catalyst cover to the partition plate (Patent Document 6).

[0010] Further, the following are known as mufflers of conventional internal combustion engines. This muffler includes an expansion chamber into which exhaust gas ejected from an exhaust port of an internal combustion engine is introduced, and an outer wall of the expansion chamber is appropriately separated so that a gap space is formed between them. A double-wall portion comprising a panel and an outer wall panel, and a blow-out opening for guiding exhaust gas in the expansion chamber to the gap space is formed in the inner wall panel, and the gap space is formed in the outer wall panel. A discharge opening for discharging the exhaust gas from the outside is formed, and a spark arrester screen is disposed so as to cover the discharge opening. In addition, a columnar oxidation catalyst made of a metal carrier is disposed as an exhaust gas purification member so as to protrude into both the first expansion chamber and the second expansion chamber (Patent Document 7). [0011] Further, the following is known as a conventional catalyst muffler structure. In this catalyst muffler structure, the muffler is divided into a main case and a lid case, and a ceramic woven cloth, cloth catalyst and stainless steel steel mesh are three-dimensionally molded into the shape of each case, and the entire inner wall of each case is formed. A ceramic woven fabric, a cloth catalyst, and a stainless steel wire mesh are stacked and bonded in this order (Patent Document 8).

In addition, the following are known as conventional silencers. This silencer is a silencer for a general-purpose internal combustion engine in which the outer peripheral portion of a separator is sandwiched between crimping surfaces of an upper casing and a lower casing that are divided into two vertically, and the inner space of the silencer is divided by the separator. An inlet opening and an outlet opening for communicating the first and second chambers 1 divided by the separator with the exhaust port and the outside air of the internal combustion engine are provided in the silencer, and the first chamber 1 A cylindrical body having a small hole or a gap is attached to the inlet opening, and an exhaust gas purification catalyst is attached to the cylindrical body (Patent Document 9).

Patent Document 1: JP-A-6-248939 (see paragraphs 0012, 0014 and FIG. 2) Patent Document 2: JP-A-6-66137 (see paragraphs 0010, 0011 and FIG. 2) Patent Document 3: JP-A-6- No. 33754 (see paragraph 0010 and figure 1)

Patent Document 4: Japanese Patent Application Laid-Open No. 7-293231 (see paragraphs 0010 and 0012 and FIGS. 1 and 2) Patent Document 5: Japanese Utility Model Publication No. 7-40648 (see FIGS. 3 and 4)

Patent Document 6: Japanese Patent Laid-Open No. 2002-242666 (see paragraphs 0034, 0035, 0036 and FIG. 1)

Patent Document 7: Japanese Patent Laid-Open No. 10-8942 (see paragraphs 0006, 0014, 0024 and FIGS. 1 and 2)

Patent Document 8: Japanese Utility Model Publication No. 6-18617 (Refer to the scope of request for registration of utility model and Figures 1 and 2)

Patent Document 9: Japanese Utility Model Publication No. 5-21114 (Refer to the scope of utility model registration request and Figure 1 and Figure 2)

However, in the conventional engine muffler shown in FIG. 21, for example, a hammer-shaped stainless steel substrate is coated with a catalyst for purifying exhaust gas. Since the exhaust gas purifier 5 is used, its production is complicated and the production cost is high.

Further, an exhaust gas receiving member 6 which is a conventional improved muffler constituent member as shown in FIG. 22 is formed in a concave shape in which a plurality of vent holes 6b are formed in a concave surface 6a. The function of purifying the exhaust gas was not enough.

[0015] In the exhaust process muffler of the two-stroke engine as described in Patent Document 1, the catalyst carrier used in the muffler is formed by laminating thin metal plates having many openings on both sides of the cross catalyst. Since the catalyst carrier is curved in a waveform and the thin metal plate of the catalyst carrier is configured to be parallel to the exhaust gas flow, there is a problem in that the production is complicated and the production cost is increased.

[0016] The exhaust process muffler of the two-stroke engine as described in Patent Document 2 is not provided with a heat-resistant mesh catalyst at the exhaust gas inlet, and is provided with a heat-resistant mesh catalyst at the exhaust gas outlet. Therefore, there is a problem that sparks may be ejected from the exhaust gas outlet when the engine is operating.

[0017] Also in the exhaust treatment muffler of the two-stroke engine as described in Patent Document 3, a heat-resistant mesh catalyst is not provided at the exhaust gas inlet, and a heat-resistant mesh catalyst is provided at the exhaust gas outlet. Therefore, when the engine is in operation, there is a problem that the exhaust gas outlet force may also spew sparks.

[0018] In the exhaust muffler structure of an internal combustion engine as described in Patent Document 4, the interior of the exhaust muffler is divided into a first expansion chamber, a second expansion chamber, and a third expansion chamber via a partition plate. There was a problem that the silencing effect was not good.

[0019] In the engine muffler described in Patent Document 5, a cylindrical spark arrester force formed by a cylindrical wire mesh member is sandwiched between the tail pipe end and the inner surface of the muffler mounting body. It is difficult to replace it with a new one.

[0020] In the exhaust muffler structure of a small engine as described in Patent Document 6, the catalyst having the function of recombusting the unburned gas in the exhaust gas by an acid-oxidation reaction is made of stainless steel. By coating the catalyst on the surface of the passage of the hard cam structure Therefore, there is a problem that the manufacturing is troublesome and the manufacturing cost is high.

[0021] In the muffler of the internal combustion engine as described in Patent Document 7, a columnar oxidation catalyst made of a metal carrier is provided so as to protrude into both the first expansion chamber and the second expansion chamber. Although it is arranged as a cleansing member, the cylindrical oxidation catalyst has a problem that the manufacturing cost is high. Also, between the inner wall panel and the outer wall panel forming the double wall portion, the exhaust gas flows to the discharge opening provided in the outer wall panel, and the outer wall panel is heated by heat. There was a problem that the outer wall had no effect of preventing heating.

[0022] In the catalyst muffler structure as described in Patent Document 8, since the inside of the muffler is not divided into the first expansion chamber, the second expansion chamber, and the third expansion chamber via the partition plate, The effect is not good. In addition, the catalyst provided inside the muffler is divided into two parts: the case and the lid case, and the entire inner wall of each case is laminated and bonded in the order of ceramic woven cloth, cloth catalyst, and stainless steel steel mesh. Therefore, there is a problem that the structure is complicated and the manufacturing cost is high.

[0023] In the silencer as described in Patent Document 9, since the exhaust gas purification catalyst is not provided in the separator that divides the silencer into two, the exhaust gas purification action is insufficient. There was a problem.

Disclosure of the invention

[0024] A muffler for a small engine as an embodiment of the present invention includes a first expansion chamber (12) for exhaust gas having an exhaust gas inlet (11) connected to an exhaust port of the engine, a partition plate ( 1

4) The exhaust gas that is separated from the first expansion chamber (12) through 4) and communicates with the first expansion chamber (12) through the first vent (13) of the partition plate (14). Second expansion chamber (1

5) and the second expansion chamber (15) through the partition plate (14) and the second expansion chamber (15) through the second vent (16) of the partition plate (14). 15) and a third expansion chamber (18) for exhaust gas having an exhaust gas outlet (17) communicating with the first exhaust gas inlet (11), the first heat-resistant mesh catalyst (19) The first vent (13) of the partition plate (14) is coated with a heat-resistant knitted fabric (20a) coated with a catalyst for purifying exhaust gas. The manufactured first exhaust gas purifier (20) is provided.

[0025] In the muffler, the first exhaust gas purifier (20) is a heat-resistant knitted fabric (20a) coated with a catalyst for purifying the exhaust gas. It can be formed by being held by a heat resistant cover (20b) having an inlet (20d).

[0026] Further, in the muffler, the first exhaust port (13) of the partition plate (14) is provided with the first exhaust gas purifier (20) on the inlet side of the exhaust gas, and the outlet thereof A second heat-resistant mesh catalyst (21) is provided on the side, a heat-resistant cover (22) having a plurality of exhaust gas outlets (22a) is provided, and the exhaust gas outlet (17) is replaceable. It may be provided with 3 heat-resistant mesh catalyst (23)! /.

[0027] In the muffler, the first exhaust gas purifier (20) is a heat-resistant knit substrate (20a) coated with a catalyst for purifying exhaust gas, and is formed with a heat-resistant mesh. It may be formed by holding it with a cover (20c)!

[0028] Further, the outer wall of the second expansion chamber (15) may be formed of a double wall (15, 15b) at least on the side attached to the engine to the muffler! .

[0029] Further, the outer wall of the second expansion chamber (15), which is not attached to the muffler at least / to the engine, is formed of a double wall (15, 15b). Heat insulation material (15c) may be filled between the heavy walls.

In the muffler, an exhaust gas receiving member (24) is provided in the first expansion chamber (12) facing the exhaust gas inlet (11), and the exhaust gas receiving member (24) An exhaust port (24b) connected to the exhaust gas inlet (11) and facing the exhaust gas inlet (11) is provided, and a heat resistant knit is provided near the exhaust port (24b) in the exhaust gas receiving member (24). A second exhaust gas purifier (25) coated with a catalyst for purifying exhaust gas on the dough is accommodated, and exhaust gas is stored in the exhaust port (24b) of the first exhaust gas purifier (20). The inclined surface (24a) can be formed so as to flow in the direction.

[0031] In the muffler, the first heat-resistant mesh catalyst (19) is formed by coating a mesh made of SUS310s stainless steel with a catalyst for purifying exhaust gas. Moyo.

[0032] In the muffler, the second heat-resistant mesh catalyst (21) is made of SUS310s. The stainless steel mesh is coated with a catalyst for purifying exhaust gas. The heat-resistant cover (22) is made of SUS310s stainless steel plate, and the third heat-resistant mesh catalyst (23). May be made of SUS310s stainless steel mesh coated with a catalyst for purifying exhaust gas.

[0033] In the muffler, the exhaust gas receiving member (24) is made of SUS310s stainless steel.

'It can be made of steel! /

[0034] A muffler for a small engine as another embodiment of the present invention includes an exhaust gas first expansion chamber (12) having an exhaust gas inlet (11) connected to an exhaust port of the engine, The second expansion chamber (15) partitioned from the first expansion chamber (12) through the partition wall plate (14), and the second vent hole (16) of the partition plate (14) A third expansion chamber (18) having an exhaust gas outlet (17) communicating with the second expansion chamber (15). The exhaust gas inlet (11) has a first heat-resistant mesh catalyst ( 19), and the partition plate (14) has at least one first vent (14a) and is integrally formed with a protrusion (14b) projecting toward the first expansion chamber (12). The first exhaust gas purifier (14b) is coated with a catalyst for purifying exhaust gas on the heat-resistant knit fabric (20a) in the recess on the second expansion chamber (15) side (14b) ( 20) and this first The exhaust gas purifier (20) is provided with a heat resistant cover (22) having an exhaust gas outlet (22a) that covers the side force of the second expansion chamber (15).

[0035] Further, a muffler for a small engine as still another embodiment of the present invention includes an exhaust gas first expansion chamber (12) having an exhaust gas inlet (11) connected to an exhaust port of the engine. And the second expansion chamber (15) partitioned from the first expansion chamber (12) via the partition plate (14) and the second vent (16) of the partition plate (14). A third expansion chamber (18) having an exhaust gas outlet (17) communicating with the second expansion chamber (15), and the exhaust gas inlet (11) has a first heat-resistant mesh catalyst (19) is provided, and the partition plate (14) having an exhaust gas outlet (14c) is integrally formed with a projecting portion (14d) projecting toward the second expansion chamber (15). (14d) The exhaust gas inlet side of the first expansion chamber (12) side of the first expansion chamber (12) is fitted with a heat-resistant knitted fabric (20a) coated with a catalyst that purifies the exhaust gas. From the expansion room (12) side of the A first exhaust gas purifier (20) covered with a heat-resistant cover (20b) having at least one exhaust gas inlet (20d) is provided. [0036] Still another embodiment of the muffler for a small engine according to the present invention includes an exhaust gas first expansion chamber (12) having an exhaust gas inlet (11) connected to an exhaust port of the engine, The exhaust gas inlet (11) has a first expansion chamber (12) and a second expansion chamber (15) partitioned through a partition plate (14) having a first vent (13). ) Is provided with a first heat-resistant mesh catalyst (19), and the first vent (13) of the partition plate (14) purifies the exhaust gas to the heat-resistant knitted fabric (20a). A first exhaust gas purifier (20) made of a catalyst coating is provided, communicates with the second expansion chamber (15), and faces the first exhaust gas purifier (20). This part is a double noise, one end of which penetrates the outer wall and communicates with the outside air, and a plurality of suction holes (30b) are drilled in the outer pipe (30a) of the double pipe. (33) Communicating with the exhaust gas outlet 17 through, and is characterized in that disposed outside air suction pipe (30).

[0037] Further, in another embodiment of the muffler for a small engine of the present invention, the exhaust gas guide (33) is connected to the first expansion chamber (12) of the exhaust gas through a noise ( 34) and a check valve (35) is provided on the noise (34).

[0038] Still another embodiment of the muffler for a small engine according to the present invention includes an exhaust gas first expansion chamber (12) having an exhaust gas inlet (11) connected to an exhaust port of the engine, The exhaust gas inlet (11) has a first expansion chamber (12) and a second expansion chamber (15) partitioned through a partition plate (14) having a first vent (13). ) Is provided with a first heat-resistant mesh catalyst (19), and the first vent (13) of the partition plate (14) purifies the exhaust gas to the heat-resistant knitted fabric (20a). A first exhaust gas purifier (20) made of a catalyst coating is provided, and an exhaust gas guide (33) communicating the second expansion chamber (15) and the exhaust gas outlet 17 is provided. The exhaust gas guide (33) is provided with a pipe (34) communicating with the first expansion chamber (12) of the exhaust gas, and a check valve (35) is provided on the pipe (34). Specially Is the Chi to.

[0039] Still another embodiment of the muffler for a small engine of the present invention is the muffler according to one embodiment, another embodiment, or another embodiment of the present invention. A groove (31) having one end communicating with the third expansion chamber (18) and the other end communicating with outside air is formed in the outer wall of the muffler, and a groove cover (32) covering the groove (31) is formed. With the feature To do.

[0040] Still another embodiment of the muffler for a small engine of the present invention is the muffler according to the embodiment of the present invention, the other embodiment, and the other embodiment. The outside air suction pipe (3 () is fixed along the outer wall of the muffler so that one end of the outside air suction pipe (30 ') having an opening communicates with the exhaust gas outlet (17) and the other end communicates with outside air. It is characterized by that.

Brief Description of Drawings

FIG. 1 is a cross-sectional view according to an embodiment of a muffler for a small engine of the present invention.

FIG. 2 is an exploded perspective view according to one embodiment of a muffler for a small engine of the present invention.

FIG. 3 is an assembled perspective view according to one embodiment of a muffler for a small engine of the present invention.

FIG. 4 is a cross-sectional view of a muffler in which a first exhaust gas purifier which is a constituent member according to an embodiment of a muffler for a small engine of the present invention is another embodiment.

FIG. 5 is an exploded perspective view of a muffler according to another embodiment of the first exhaust gas purifier, which is a constituent member according to an embodiment of a muffler for a small engine of the present invention.

FIG. 6 is an assembled perspective view of a muffler according to another embodiment of the first exhaust gas purifier, which is a constituent member according to an embodiment of a muffler for a small engine of the present invention.

FIG. 7 is a cross-sectional view of a muffler in which the outer wall of the muffler has a double structure in the configuration according to the embodiment of the muffler for a small engine of the present invention.

FIG. 8 is a cross-sectional view of the muffler having the structure shown in FIG. 7, in which a heat insulating material is inserted between the outer walls of the double structure.

FIG. 9 is a cross-sectional view of a muffler in which the first exhaust gas purifier is in another embodiment in the muffler having the structure shown in FIG.

FIG. 10 is a cross-sectional view of the muffler having the structure shown in FIG. 9, in which a heat insulating material is inserted between the outer walls of the double structure.

FIG. 11 is a cross-sectional view according to another embodiment of a muffler for a small engine of the present invention.

[FIG. 12] In the muffler having the structure shown in FIG. 11, the first exhaust gas purifier is installed in another implementation. It is sectional drawing of the muffler made into the form.

FIG. 13 is a cross-sectional view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 14 is a cross-sectional view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 15 is a cross-sectional view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 16 is a cross-sectional view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 17 is a cross-sectional view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 18 is an exploded perspective view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 19 is an exploded perspective view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 20 is an exploded perspective view according to still another embodiment of a muffler for a small engine of the present invention.

FIG. 21 is a cross-sectional view of a conventional muffler for a small engine.

FIG. 22 is a cross-sectional view of another conventional muffler for a small engine.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view according to an embodiment of a muffler for a small engine of the present invention. FIG. 2 is an exploded perspective view, and FIG. 3 is an assembled perspective view.

A muffler for a small engine according to an embodiment of the present invention includes a first expansion chamber 12 for exhaust gas having an exhaust gas inlet 11 connected to an exhaust port of the engine, and the first expansion chamber 12 via a partition plate 14. A second expansion chamber 15 for exhaust gas that is partitioned from the expansion chamber 12 and communicates with the first expansion chamber 12 through the first vent 13 of the partition plate 14 and the partition plate 14. Through the second vent hole 16 of the partition plate 14 and the second expansion chamber 15. Thus, an exhaust gas third expansion chamber 18 having an exhaust gas outlet 17 communicating with the second expansion chamber 15 is provided. Further, the exhaust gas inlet 11 is provided with a first heat-resistant mesh catalyst 19, and the first vent 13 of the partition plate 14 is coated with a catalyst for purifying exhaust gas on the heat-resistant knitted fabric 20a. A first exhaust gas purifier 20 made of the above is provided.

[0043] The first exhaust gas purifier 20 is a stainless steel 'heat-resistant knitted fabric 20a coated with a catalyst for purifying exhaust gas, stainless steel having at least one exhaust gas inlet 20d'. It is constructed by holding it with a steel heat-resistant cover 20b.

[0044] The first exhaust gas purifier 20 is provided on the exhaust gas inlet side of the first vent 13 of the partition plate 14, and the second heat-resistant mesh catalyst 21 is provided on the outlet side thereof. In addition, a heat-resistant cover 22 having a plurality of exhaust gas outlets 22a is provided, and a third heat-resistant mesh catalyst 23 is provided in the exhaust gas outlet 17 so as to be replaceable.

[0045] The heat-resistant cover 20b and the heat-resistant cover 22 can be made by press-molding a stainless steel plate, which is welded to the first vent 13 of the partition plate 14.

[0046] The outer wall 12a of the first extension chamber 12, the outer wall 15a of the second extension chamber 15, the partition plate 14, and the partition plate 14 and the outer wall 12a of the first extension chamber 12 The partition plate 18a forming the third expansion chamber 18 constructed by welding is formed by forming a stainless steel plate!

[0047] The outer wall 12a of the first extension chamber 12, the outer wall 15a of the second extension chamber 15, the partition plate 14, the partition plate 18a forming the third extension chamber 18, and the heat-resistant cover When 20b and heat resistant cover 22 are made of stainless steel, preferably SUS310s stainless steel, the heat resistance and acid resistance are excellent, and the life can be extended.

[0048] Further, the first heat-resistant mesh catalyst 19, the second heat-resistant mesh catalyst 21, and the third heat-resistant mesh catalyst 23 are many in a stainless steel steel mesh or a stainless steel plate. For example, one made of platinum, rhodium or palladium, or a combination of two or more catalysts that purify exhaust gas is coated on the stainless steel. Preferably SUS310s stainless steel It has excellent heat resistance and acid resistance, and can extend the service life.

[0049] Further, the heat-resistant knitted fabric 20a is obtained by copying the catalyst for purifying the exhaust gas into one obtained by folding one or several stainless steel wires into a desired thickness. Made with a single ding.

This metathermal knitted fabric 20a is easier to manufacture and less expensive to manufacture than a conventional stainless steel hard cam base.

[0050] As shown in FIGS. 1, 2, and 3, the inside of the muffler is connected to the first expansion chamber 12, the second expansion chamber 15, and the third expansion chamber 18 via the partition plate 14. Since the sound is divided into two, the noise reduction effect is improved. Further, since the first heat-resistant mesh catalyst 19 is provided at the exhaust gas inlet 11, the sparks contained in the exhaust of the engine will not enter the muffler (, loose, spark arrester effect) . The first exhaust gas purifier 20 provided in the first vent 13 formed in the partition plate 14 so that the first extension chamber 12 and the second extension chamber 15 communicate with each other Since the catalyst cloth 20a is formed by coating the catalyst for purifying the exhaust gas, the production is simple and the production cost is low.

[0051] The second heat-resistant mesh catalyst 21 is made by coating the catalyst for purifying exhaust gas on a stainless steel mesh and welding it to the partition plate 14 for attachment. . The third heat-resistant mesh catalyst 23 is made by coating the catalyst for purifying exhaust gas on a stainless steel mesh. When the stainless steel is preferably SUS310s stainless steel, it has excellent heat resistance and acid resistance, and can have a long life.

FIG. 4 is a cross-sectional view of a muffler in which the first exhaust gas purifier 20 is another embodiment, FIG. 5 is an exploded perspective view thereof, and FIG. 6 is an assembled perspective view thereof. The exhaust gas purifier 20 is formed by holding a heat-resistant knitted fabric 20a coated with the catalyst for purifying the exhaust gas, and holding it with a heat-resistant cover 20c formed of a heat-resistant mesh. The heat-resistant mesh is a stainless steel mesh, and the heat-resistant cover 20c made of this heat-resistant mesh, which may be coated with the catalyst for purifying exhaust gas, is welded to the partition plate 14. And attach. The stainless steel is preferably SUS 310s stainless steel, which has excellent heat resistance and acid resistance, and has a long service life. Can be planned.

[0053] As described above, the first exhaust port 13 formed in the partition plate 14 is provided with the first exhaust gas purifier 20 on the exhaust gas inlet side, and the second exhaust port 20 on the outlet side. Since the heat-resistant mesh catalyst 21 is provided and the heat-resistant cover 22 having a plurality of exhaust gas outlets 22a is provided, the first exhaust gas purifier 20 is heated quickly and the temperature is increased, and the exhaust gas is exhausted. The purifier is even better. In addition, since the third heat-resistant mesh catalyst 23 is replaceably provided at the exhaust gas outlet 17, it is possible to prevent sparks from coming out of the muffler and the third heat-resistant mesh catalyst 23 is It can be easily replaced.

As shown in FIGS. 7 and 9, at least the wall of the second expansion chamber 15 that is not on the side attached to the engine may be formed by double walls 15a ′ and 15b.

Further, as shown in FIGS. 8 and 10, at least the wall of the second expansion chamber 15 that is not attached to the engine is formed by double walls 15 and 15b, and a heat insulating material 15c is provided between the double walls. You may fill and comprise.

[0056] By configuring as described above, heating of the outer wall of the muffler is prevented. Furthermore, by filling the insulating material 15c between the double walls, the effect of preventing the heating of the outer wall of the muffler is further improved.

[0057] As shown in Figs. 11 and 12, another embodiment of the present invention has an exhaust gas receiver in the first expansion chamber 12 facing the exhaust gas inlet 11 connected to the exhaust port of the engine. Member 24 may be provided. The exhaust gas receiving member 24 is connected to the exhaust gas inlet 11 and includes an exhaust port 24b facing the exhaust gas inlet 11. The heat exhaust member 24 has a heat-resistant region in the vicinity of the exhaust port 24b. A second exhaust gas purifier 25 coated with the catalyst for purifying the exhaust gas in a knitted fabric is accommodated, and the exhaust gas is caused to flow in the direction of the first exhaust gas purifier 20 through the exhaust port 24b. An inclined surface 24a is formed on the surface.

After the second exhaust gas purifier 25 is accommodated in the exhaust gas receiving member 24, the second exhaust gas purifier 25 is deformed by projecting inwardly in the middle of the exhaust gas receiving member 24. Is held in such a way that it cannot be removed.

When the exhaust gas receiving member 24 is preferably made of SUS310s stainless steel, it has excellent heat resistance and acid resistance, and can extend its life. By configuring as described above, the first exhaust gas exhausted by the engine power is received by the exhaust gas receiving member 24 and purified by the second exhaust gas purifier 25 provided here. As a result, the exhaust gas purification is further improved.

[0059] In addition, the first heat-resistant mesh catalyst 19 is configured by coating the catalyst for purifying exhaust gas on a mesh made of SUS310s stainless steel, the first heat-resistant mesh catalyst 19. The catalyst 19 is excellent in heat resistance and acid resistance, and can achieve a long life.

[0060] Further, the second heat-resistant mesh catalyst 21 is formed by coating a SUS310s stainless steel mesh with the catalyst for purifying exhaust gas, and the heat-resistant cover 22 is made of SUS310s stainless steel. Made of steel plate, the third heat-resistant mesh catalyst 23 is made of SUS 31 Os stainless steel mesh coated with the above catalyst for purifying exhaust gas. Excellent life and longer life.

[0061] Further, the exhaust gas receiving member 24 is formed of a SUS310s stainless steel plate, and a heat resistant knitted fabric made of stainless steel is coated with the catalyst for purifying the exhaust gas. The exhaust gas purifier 25 is housed so that the exhaust gas receiving member 24 and the second exhaust gas purifier 25 have excellent heat resistance and acid resistance, and can have a long life. it can.

[0062] Further, in another embodiment of the muffler for a small engine of the present invention, as shown in Fig. 13, the partition plate 14 has at least one first vent hole 14a. A convex portion 14b protruding toward the expansion chamber 12 is integrally formed, and a concave portion of the convex portion 14b on the second expansion chamber 15 side is coated with the catalyst for purifying exhaust gas on the heat-resistant knitted fabric 20a. The first exhaust gas purifier 20 is attached, and a heat resistant cover 22 having an exhaust gas outlet 22a that covers the first exhaust gas purifier 20 from the second expansion chamber 15 side is provided, and the first exhaust gas purifier 20 is provided. Since the gas purifier 20 is configured, the configuration of the first exhaust gas purifier 20 becomes easy and can be manufactured at low cost. The exhaust gas outlet 22a is provided so that the exhaust gas does not flow in the direction of the outer wall 15a of the second expansion chamber 15 but flows along the partition plate 14. [0063] Still another embodiment of the muffler for a small engine of the present invention has an exhaust gas outlet 14c in the partition plate 14, as shown in Fig. 14, on the second expansion chamber 15 side. A projecting convex portion 14d is integrally formed, and the heat-resistant knitted fabric 20a is coated with the catalyst for purifying exhaust gas on the inlet side of the concave portion on the first expansion chamber 12 side of the convex portion 14d. The first exhaust gas purifier 20 is installed and covered with a heat-resistant cover 20b having the first expansion chamber 12 side force also having at least one exhaust gas inlet 20d, and this first exhaust gas purifier is provided. Since the vessel 20 is configured, the configuration is easy and the device can be manufactured at low cost. The exhaust gas outlet 14c is provided so that the exhaust gas does not flow in the direction of the outer wall 15a of the second expansion chamber 15 but flows along the partition plate 14.

In addition, as shown in FIG. 15, another embodiment of the muffler for a small engine according to the present invention has a first expansion chamber 12 for exhaust gas having an exhaust gas inlet 11 connected to the exhaust port of the engine. And a second expansion chamber 15 partitioned from the first expansion chamber 12 via a partition plate 14 having a first vent hole 13, and the exhaust gas inlet 11 has a first heat resistance The first vent hole 13 of the partition plate 14 is provided with a heat-resistant knitted fabric 20a coated with the catalyst for purifying the exhaust gas. A portion 20 is provided to communicate with the second expansion chamber 15, the portion facing the first exhaust gas purifier 20 is a double pipe, one end of which communicates with the outside air through the outer wall, and A plurality of suction holes 30b are formed in the outer pipe 30a of the double pipe, and the exhaust gas is guided through the other end force exhaust gas guide 33. Communicating with the gas outlet 17, in which is disposed outside air suction pipe 30.

In the embodiment shown in FIG. 15, the first exhaust gas purifier 20 is formed by holding the heat-resistant cloth 20a with a heat-resistant cover 20c formed of a heat-resistant mesh. The first exhaust gas purifier 20 may be formed by holding the heat-resistant knitted fabric 20a with a heat-resistant cover 20b having at least one exhaust gas inlet 20d as shown in FIG.

[0065] Since such an outside air suction pipe 30 is provided, the exhaust gas that has passed through the first exhaust gas purifier 20 is sucked into the outer pipe 30a of the double pipe of the outside air suction pipe 30. The air enters the outer pipe 30a from the inlet 30b, flows through the outside air suction pipe 30, and flows to the exhaust gas outlet 17. Then, since the exhaust gas in the outside air suction pipe 30 is sucked, outside air is sucked into the outside air suction pipe 30 from the outside air inlet 30c at the other end of the outside air suction pipe 30. As a result, the temperature of the exhaust gas discharged from the exhaust gas outlet 17 decreases.

In addition, as shown in FIG. 16, in another embodiment of the muffler for a small engine of the present invention, the exhaust gas guide 33 communicates with the first expansion chamber 12 of the exhaust gas. A pipe 34 is formed, and a check valve 35 is provided on the pipe 34.

The check valve 35 may be a butterfly valve as shown in FIG. 5 (b), or may be a pipe having a small end at the end of the pipe 34 as shown in FIG.

With this configuration, outside air (oxygen) flows into the first expansion chamber 12 through the outside air suction pipe 30 and the check valve 35 provided in the pipe 34 formed in the exhaust gas guide 33. Therefore, the combustion efficiency in which the exhaust gas in the first expansion chamber 12 is combusted in the first exhaust gas purifier 20 is improved, and a part of the exhaust gas is again in the first expansion chamber 12. Enters and is recombusted in the first exhaust gas purifier 20, so that the exhaust gas purification function is improved.

[0067] Still another embodiment of the muffler for a small engine of the present invention, as shown in FIG. 17, is a first extension of exhaust gas having an exhaust gas inlet 11 connected to the exhaust port of the engine. And a second expansion chamber 15 that is partitioned from the first expansion chamber 12 via a partition plate 14 having a first vent hole 13, and the exhaust gas inlet 11 has a first The first air vent 13 of the partition plate 14 is provided with a heat-resistant knitted fabric 20a coated with the catalyst for purifying exhaust gas. An exhaust gas purifier 20 is provided, and an exhaust gas guide 33 that communicates the second expansion chamber 15 and the exhaust gas outlet 17 is provided. The exhaust gas guide 33 includes a first expansion chamber 12 for the exhaust gas. A pipe 34 that communicates with the pipe 34 is formed, and a check valve 35 is provided on the pipe 34.

The check valve 35 may be a notch fly valve as shown in (b), or a pipe 34 having a small end as shown in (c). Further, as shown in FIG. 4 (d), a pipe 34 communicating with the first expansion chamber 12 may be provided separately from the exhaust gas guide 33, and a check valve 35 may be provided at the tip of the pipe 34. .

With this configuration, the partial force of the exhaust gas in the second expansion chamber 15 flows again into the first expansion chamber 12 through the pipe 34 and the check valve 35, and again the first exhaust gas. Since it is burned by the purifier 20, the exhaust gas purification action is improved. [0068] Further, as shown in Fig. 18, in another embodiment of the muffler for a small engine of the present invention, one end of the groove communicates with the third expansion chamber 18 (see Fig. 1). The muffler for a small engine is characterized in that a groove 31 whose end communicates with the outside air is formed on the outer wall of the muffler and a groove cover 32 is provided to cover the groove 31. 18 is sucked into the exhaust gas exhausted through the exhaust gas outlet 17 and the outside air is sucked into the third expansion chamber 18 from the groove 31 formed in the outer wall of the muffler. The temperature of the exhaust gas is lowered. Here, as shown in FIG. 19, the groove cover covering the concave groove 31 includes a lattice member 28 ′ covering the exhaust gas outlet 17 of the third expansion chamber 18 and a groove cover 3 ^ covering the concave groove 31. It can be formed integrally.

[0069] Further, as shown in Fig. 20, in another embodiment of the muffler for a small engine of the present invention, one end of an outside air suction pipe 30 'having both ends opened communicates with the exhaust gas outlet 17, Since the muffler of the small engine is characterized in that the outside air suction pipe 30 'is fixed along the outer wall of the muffler so that the other end communicates with the outside air, the third expansion chamber 18 (see FIG. 1) ) Is sucked into the exhaust gas exhausted through the exhaust gas outlet 17, and the outside air is also sucked into the third expansion chamber 18 by the other end force of the external air suction pipe 3 (). The temperature of the exhaust gas discharged is lowered, and the outside air suction pipe 30 'can be fixed along the outer wall of the muffler by means such as welding.

[0070] As shown in Figs. 1, 3, 4, 6, and 11 to 17, the outer walls 12a, 15a and the end portions of the partition plate 14 are fixed by caulking.

Further, as shown in FIGS. 7 to 10, the double walls 12a and 12b of the first extension chamber, the partition plate 14 and the ends of the double walls 15 and 15b forming the second extension chamber 15 are provided. The part is fixed by caulking.

Further, reference numeral 26 shown in FIGS. 1 to 6 and FIGS. 11 to 20 denotes a space between the outer wall 12a forming the first expansion chamber 12 and the outer wall 15a forming the second expansion chamber 15. A pipe member into which bolts 27 for fixing the muffler to the engine are inserted, symbol 28 is a lattice member, and this lattice member 28 is detachably attached to the outer wall 12a of the muffler with a mounting screw 29. The third heat-resistant mesh catalyst 23 can be exchanged by removing.

Claims

The scope of the claims

[1] Exhaust gas first expansion chamber having an exhaust gas inlet (11) connected to the exhaust port of the engine

(12) and the first expansion chamber (12) through the partition plate (14), and the first expansion through the first vent (13) of the partition plate (14). A second expansion chamber (15) for exhaust gas communicating with the chamber (12) and the second expansion chamber (15) through the partition plate (14), and the partition plate (14) An exhaust gas third expansion chamber (18) having an exhaust gas outlet (17) communicating with the second expansion chamber (15) through a second vent (16), and the exhaust gas The inlet (11) is provided with a first heat-resistant mesh catalyst (19), and the first vent (13) of the partition plate (14) purifies the exhaust gas to the heat-resistant knitted fabric (20a). A muffler for small engines, characterized in that it is equipped with a first exhaust gas purifier (20) made of a coating of the catalyst to be treated.

[2] The first exhaust gas purifier (20) has at least one exhaust gas inlet (20d) formed by coating a heat-resistant knitted fabric (20a) with a catalyst for purifying exhaust gas. 2. The muffler for a small engine according to claim 1, wherein the muffler is formed by being held by a heat-resistant cover (20b).

[3] The first vent (13) of the partition plate (14) is provided with the first exhaust gas purifier (20) on the inlet side of the exhaust gas, and the second heat resistance is provided on the outlet side thereof. In addition to providing the mesh catalyst (21), a heat-resistant cover (22) having a plurality of exhaust gas outlets (22a) is provided, and the exhaust gas outlet (17) can be replaced with a third heat-resistant mesh catalyst ( 23. The muffler for a small engine according to claim 1, wherein 23) is provided.

[4] The first exhaust gas purifier (20) includes a heat-resistant cover (20c) formed by coating a heat-resistant knit fabric (20a) with a catalyst for purifying exhaust gas using a heat-resistant mesh. The muffler for a small engine according to claim 1, wherein the muffler is used for holding a small engine.

[5] The outer wall of the second expansion chamber (15) that is not at least attached to the engine is a double wall.

The muffler for a type J engine according to claim 1 or claim 4, wherein the muffler is formed of (15, 15b).

[6] At least the outer wall of the second expansion chamber (15) that is not on the engine mounting side is a double wall 5. The muffler for a small engine according to claim 1, wherein the muffler is formed of (15, 15b) and is filled with a heat insulating material (15c) between the double walls.

[7] An exhaust gas receiving member (24) is provided in the first expansion chamber (12) facing the exhaust gas inlet (11), and the exhaust gas receiving member (24) is provided in the exhaust gas inlet (11). And an exhaust port (24b) facing the exhaust gas inlet (11). The exhaust gas receiving member (24) has an exhaust port (24b) in the vicinity of the exhaust port (24b) where exhaust gas is passed through the heat-resistant knit fabric. A second exhaust gas purifier (25) coated with a catalyst to be purified is accommodated, and exhaust gas flows through the exhaust port (24b) in the direction of the first exhaust gas purifier (20). The muffler for a small engine according to claim 1 or 4, wherein an inclined surface (24a) is formed.

[8] The first heat-resistant mesh catalyst (19) is formed by coating a SUS310s stainless steel mesh with a catalyst for purifying exhaust gas. 5. A muffler for a small engine according to claim 4.

[9] The second heat-resistant mesh catalyst (21) consists of SUS310s stainless steel mesh coated with a catalyst to purify exhaust gas, and the heat-resistant cover (22) is made of S US310s. Made of stainless steel, the third heat-resistant mesh catalyst (23) is made of SUS 31 Os stainless steel mesh coated with a catalyst for purifying exhaust gas. A muffler for a small engine according to claim 1 or 4.

10. The muffler for a small engine according to claim 7, wherein the exhaust gas receiving member (24) is formed of a SUS310s stainless steel plate.

[11] Exhaust gas first expansion chamber having an exhaust gas inlet (11) connected to the exhaust port of the engine

(12), a second expansion chamber (15) partitioned from the first expansion chamber (12) via a partition plate (14), and a second vent (16) of the partition plate (14) ) And a third expansion chamber (18) having an exhaust gas outlet (17) communicating with the second expansion chamber (15) through

The exhaust gas inlet (11) is provided with a first heat-resistant mesh catalyst (19), and the partition plate (14) has at least one first vent (14a). A convex part (14b) projecting to the chamber (12) side is formed integrally, and exhaust gas is supplied to the heat-resistant knitted fabric (20a) in the concave part of the convex part (14b) on the second expansion chamber (15) side. No. 1 coated with purifying catalyst The exhaust gas purifier (20) is attached, and the first exhaust gas purifier (20) is covered with a heat resistant cover (22a) having an exhaust gas outlet (22a) covering the second expansion chamber (15) side cover. Muffler for small engines.

[12] first expansion chamber for exhaust gas having an exhaust gas inlet (11) connected to the exhaust port of the engine

The exhaust gas inlet (11) is provided with a first heat-resistant mesh catalyst (19), and the partition plate (14) has an exhaust gas outlet (14c) on the second expansion chamber (15) side. A protruding projection (14d) is formed integrally, and the exhaust gas is purified on the heat-resistant knitted fabric (20a) on the exhaust gas inlet side of the projection (14d) on the first expansion chamber (12) side. A first exhaust gas purifier that is coated with a catalyst to be drowned and covered with a heat resistant cover (20b) having at least one exhaust gas inlet (20d) side force of the first expansion chamber (12) (20) A muffler for a small engine characterized by being provided.

[13] exhaust gas first expansion chamber having an exhaust gas inlet (11) connected to the engine exhaust port

(12) and a second expansion chamber (15) partitioned from the first expansion chamber (12) via a partition plate (14) having a first vent (13),

The exhaust gas inlet (11) is provided with a first heat-resistant mesh catalyst (19), and the first vent (13) of the partition plate (14) is exhausted to the heat-resistant knitted fabric (20a). A first exhaust gas purifier (20) made of a coating of a catalyst that purifies the gas,

A portion that communicates with the second expansion chamber (15) and faces the first exhaust gas purifier (20) is a double pipe, one end of which communicates with the outside air through the outer wall. A plurality of suction holes (30b) are drilled in the outer pipe (30a) of the pipe, and an outside air suction pipe (30) is provided which communicates with the exhaust gas outlet 17 through the other end exhaust gas guide (33). A muffler for a small engine characterized by

[14] The exhaust gas guide (33) is formed with a pipe (34) communicating with the first expansion chamber (12) of the exhaust gas, and a check valve (35) is connected to the pipe (34). 15. The muffler for a small engine according to claim 14, wherein the muffler is provided.

[15] The first expansion chamber (12) having an exhaust gas inlet (11) connected to the exhaust port of the engine, and the partition plate (14) having a first vent (13) A first expansion chamber (12) and a second expansion chamber (15) partitioned;

The exhaust gas inlet (11) is provided with a first heat-resistant mesh catalyst (19), and the first vent (13) of the partition plate (14) is exhausted to the heat-resistant knitted fabric (20a). Exhaust gas provided with a first exhaust gas purifier (20) made of a coating of a catalyst for purifying gas and communicating the second expansion chamber (15) with the exhaust gas outlet 17 A guide (33) is provided, and a pipe (34) communicating with the exhaust gas first expansion chamber (12) is formed in the exhaust gas guide (33), and a check valve is provided in the noise (34). (35) A muffler for small engines.

[16] In the muffler for a small engine according to claim 1, claim 11, claim 12, and claim 15, one end of the groove communicates with the third expansion chamber (18), and the other end is A muffler for a small engine, characterized in that a groove (31) communicating with the outside air is formed in the outer wall of the muffler and a groove cover (32) is provided to cover the groove (31).

[17] In the muffler for a small engine according to claim 1, claim 11, claim 12, and claim 15, one end of an outside air suction pipe (3 () that is open at both ends is the exhaust gas outlet (17 ), And the outside air suction pipe (30 ′) is fixed along the outer wall of the muffler so that the other end communicates with outside air.