Catalytic muffler and chain saw using the same

Abstract

The present invention belongs to the technical field of oil saws, and particularly refers to a catalyst muffler and an oil saw using the catalyst muffler, comprising a muffler shell and a muffler cover arranged on the muffler shell, wherein the muffler shell and the muffler cover are fixedly connected to form a cavity, wherein a catalyst is arranged in the cavity, wherein an air inlet is arranged on the muffler shell, and an air outlet is arranged on the muffler cover, wherein a diverter plate, a spark catching net and a guide cover are arranged on the outer side of the muffler cover from the inside to the outside in sequence, and a first exhaust cavity is formed between the muffler cover and the diverter plate, and a second exhaust cavity is formed between the diverter plate and the guide cover. The present invention can effectively prevent fire from being ejected from the exhaust port and effectively reduce the exhaust gas temperature, thereby avoiding safety hazards to users.

Description

Technical field:

[0001] The invention belongs to the technical field of chain saws, and in particular relates to a catalyst muffler and a chain saw using the catalyst muffler. Background technology:

[0002] Oil saw, also known as gasoline chain saw, is mainly used for logging and timber making. Its working principle is to rely on the lateral movement of the staggered L-shaped blades on the saw chain to perform the shearing action. Chain saw is a kind of demolition equipment. According to its function and driving method, it can be divided into motorized chain saw, non-motorized chain saw, concrete chain saw, etc. Chain saw can be divided into gasoline saw, electric saw, pneumatic saw and hydraulic saw according to the different power sources.

[0003] In order to meet the emission standards, the existing hand-held garden tools powered by gasoline engines produced at home and abroad are equipped with catalyst mufflers. Most of the existing chain saws have unsatisfactory original exhaust. After the exhaust gas passes through the catalyst inside the muffler, a large amount of heat and harmful gases such as hydrocarbons and nitrogen oxides are generated. In addition, when the carburetor is working, due to the inertia of the fuel, more fuel will enter the crankcase at the moment of releasing the throttle trigger, and the air will decrease at the moment of closing the throttle, causing the air-fuel ratio to drop instantly and the fuel to be too concentrated. In the above situation, the muffler exhaust port is prone to flame spray and the exhaust gas temperature is too high, especially for large-displacement chain saws, which brings serious safety hazards to users. Summary of the invention:

[0004] The purpose of the present invention is to provide a catalyst silencer and a chain saw using the catalyst silencer, which can effectively prevent fire from being ejected from the exhaust port and effectively reduce the exhaust gas temperature, thereby avoiding safety hazards to users.

[0005] The present invention is achieved in that:

[0006] One of the objects of the present invention is to provide a catalyst muffler, comprising a muffler shell and a muffler cover arranged on the muffler shell, the muffler shell and the muffler cover being fixedly connected to form a cavity, a catalyst being arranged in the cavity, the muffler shell being provided with an air inlet, the muffler cover being provided with an air outlet, the outer side of the muffler cover being provided with a diverter plate, a spark catching net and a guide cover corresponding to the air outlet from the inside to the outside, a first exhaust chamber being formed between the muffler cover and the diverter plate, and a second exhaust chamber being formed between the diverter plate and the guide cover.

[0007] In the above-mentioned catalyst muffler, the muffler cover is concave toward one side of the cavity to form the first exhaust cavity, and the air guide cover is convex toward the side away from the cavity to form the second exhaust cavity.

[0008] In the above-mentioned catalyst muffler, the screw passes through the deflector, the spark arresting net, the splitter plate and the muffler cover in sequence and is screwed and locked with the square nut.

[0009] In the above-mentioned catalyst silencer, a plurality of diverter holes are arranged on the diverter plate, and the total area of ​​the diverter holes at the left position and the total area of ​​the diverter holes at the right position are both larger than the total area of ​​the diverter holes at the middle position. The number of diverter holes at the left position, the right position and the middle position can be the same, and the area of ​​the diverter holes at the left position and the area of ​​the diverter holes at the right position are both larger than the area of ​​the diverter holes at the middle position; or the area of ​​the diverter holes at the left position, the right position and the middle position are equal, and the number of the diverter holes at the left position and the number of the diverter holes at the right position are both larger than the number of the diverter holes at the middle position.

[0010] In the above-mentioned catalytic muffler, the air guide cover is provided with two or more oblique exhaust ports at intervals, and the air guide cover is provided with spoiler holes, the exhaust direction of the spoiler holes intersects with the exhaust direction of the oblique exhaust ports, so that the exhaust gas discharged from the oblique exhaust ports is away from the outer surface of the air guide cover.

[0011] In the above-mentioned catalyst muffler, a plurality of vertical guide plates are arranged at intervals on the outside of the air guide cover, and the oblique exhaust port is formed between two adjacent vertical guide plates.

[0012] In the above-mentioned catalyst muffler, the exhaust direction of the oblique exhaust port and the angle α of the outer surface of the air deflector are greater than or equal to 25° and less than or equal to 45°, and the exhaust direction of the spoiler hole is perpendicular to the outer surface of the air deflector.

[0013] In the above-mentioned catalyst muffler, an exhaust pipe leading to the air outlet is provided on the inner side of the muffler cover.

[0014] In the above-mentioned catalytic muffler, the exhaust pipe is a hollow cylinder, and the ratio of the exhaust pipe length to the inner diameter is not less than 1.3.

[0015] In the above-mentioned catalytic muffler, an installation partition is provided between the muffler shell and the muffler cover, and the installation partition divides the cavity into an air inlet chamber for accommodating initial exhaust gas and an air outlet chamber for accommodating purified exhaust gas, the air inlet chamber is located on one side of the air inlet and is connected to the air inlet, the air inlet is provided in the middle of the muffler shell, the air outlet chamber is located on one side of the air outlet and is connected to the air outlet, the catalyst is located at the lower part of the air inlet chamber, the exhaust gas in the air inlet chamber flows to the air outlet chamber through the catalyst, and the exhaust pipe is located at the upper part of the air outlet chamber.

[0016] In the above-mentioned catalyst muffler, the volume of the air outlet cavity is more than twice the engine displacement.

[0017] In the above-mentioned catalyst muffler, a catalyst mounting shell located in the air inlet cavity is fixed on the mounting baffle, the catalyst is arranged in the catalyst mounting shell, a through hole is arranged at the lower part of the mounting baffle and the position matches the catalyst, a heat insulation board located in the air outlet cavity is arranged on the inner side of the muffler cover, a fixed conduit is arranged in the cavity, the fixed conduit passes through the mounting baffle and the heat insulation board, one end of the fixed conduit is fixedly connected to the muffler cover, and the other end is fixedly connected to the muffler shell through a fixed pressure plate.

[0018] In the above-mentioned catalyst muffler, a vent hole connecting the air inlet cavity and the air outlet cavity is provided in the middle of the mounting baffle, and most of the exhaust gas in the air inlet cavity flows to the air outlet cavity through the catalyst, and a small part flows to the air outlet cavity through the vent hole.

[0019] In the above-mentioned catalyst muffler, the vent hole is circular and is provided with one vent hole.

[0020] In the above-mentioned catalyst muffler, two fixed conduits are provided and are respectively located on both sides of the vent hole.

[0021] Another object of the present invention is to provide a chain saw, comprising a cylinder and a crankcase, wherein the above-mentioned catalyst muffler is fixed on the crankcase, the air inlet of the catalyst muffler is located at the exhaust port of the cylinder, an upper cover plate is provided at the upper end of the catalyst muffler, an air filter cover is provided at the rear upper end of the upper cover plate, a starter assembly is provided on the left side of the crankcase, and a right side cover assembly is provided on the right side.

[0022] In the above-mentioned chain saw, the catalyst muffler is fastened to the crankcase by fasteners.

[0023] The outstanding advantages of the present invention compared with the prior art are:

[0024] 1. The outer side of the muffler cover of the present invention is provided with a diverter plate, a spark catching net and a guide cover facing the air outlet. A first exhaust chamber is formed between the muffler cover and the diverter plate, and a second exhaust chamber is formed between the diverter plate and the guide cover. The exhaust gas is diverted by the diverter plate and guided by the guide cover, which effectively disperses the exhaust gas, prevents the heat of the high-temperature exhaust gas from being too concentrated, and effectively reduces the temperature of the exhaust gas. At the same time, the spark catching net in the second exhaust chamber captures sparks, effectively preventing the exhaust port from spraying fire, and avoiding safety hazards to users;

[0025] 2. The air guide cover of the present invention is provided with two or more oblique exhaust ports at intervals, and most of the exhaust gas is discharged through the oblique exhaust ports. The air guide cover is provided with spoiler holes, and the exhaust direction of the spoiler holes intersects with the exhaust direction of the oblique exhaust ports. Another small part of the exhaust gas is discharged from the spoiler holes and rushes towards the exhaust gas discharged from the oblique exhaust ports, so that the exhaust gas discharged from the oblique exhaust ports is away from the outer surface of the air guide cover and discharged to a distance at a suitable angle, effectively avoiding the high-temperature exhaust gas from gathering on the outer surface of the air guide cover;

[0026] 3. The inner side of the muffler cover of the present invention is provided with an exhaust pipe leading to the air outlet. The exhaust gas flows out from the air outlet after passing through the exhaust pipe, which effectively prevents the flame generated by the secondary combustion of the high-temperature exhaust gas through the catalyst from being discharged outside the muffler, causing the muffler to spray fire;

[0027] 4. The installation partition of the present invention has an air vent in the middle part connecting the air inlet cavity and the air outlet cavity. Most of the exhaust gas in the air inlet cavity flows to the air outlet cavity through the catalyst, and a small part flows to the air outlet cavity through the air vent. The exhaust gas is mixed in the air outlet cavity, effectively reducing the temperature of most of the exhaust gas passing through the catalyst. Description of the drawings:

[0028] Figure 1 is an exploded view of the present invention;

[0029] Figure 2 is a cross-sectional view of the present invention;

[0030] Figure 3 The exhaust gas flow direction of the present invention is shown in FIG. Figure 1 ;

[0031] Figure 4 The exhaust gas flow direction of the present invention is shown in FIG. Figure 2 ;

[0032] Figure 5 is a perspective view of the installation partition of the present invention;

[0033] Figure 6 is a front view of the diverter plate of the present invention;

[0034] Figure 7 is a cross-sectional view of a deflector cover of the present invention;

[0035] Figure 8 The three-dimensional structure of the chain saw of the present invention Figure 1 ;

[0036] Fig. 9 The three-dimensional structure of the chain saw of the present invention Figure 2 .

[0037] Figure numerals: 1, muffler shell; 2, muffler cover; 3, catalyst; 4, air inlet; 5, air outlet; 6, splitter plate; 7, spark catcher net; 8, guide cover; 9, first exhaust chamber; 10, second exhaust chamber; 11, splitter hole; 12, oblique exhaust port; 13, spoiler hole; 14, vertical guide plate; 15, exhaust pipe; 16, mounting partition; 17, air inlet chamber; 18, air outlet chamber; 19, vent hole; 20, catalyst mounting shell; 21, heat insulation board; 22, fixed guide tube; 23, fixed pressure plate; 24, cylinder; 25, crankcase; 26, upper cover plate; 27, air filter cover; 28, starter assembly; 29, right side cover assembly. Specific implementation method:

[0038] The present invention is further described below with reference to specific embodiments. Figure 1 —9:

[0039] One of the objects of the present invention is to provide a catalyst muffler, comprising a muffler shell 1 and a muffler cover 2 arranged on the muffler shell 1, the muffler shell 1 and the muffler cover 2 are fixedly connected to form a cavity, a catalyst 3 is arranged in the cavity, the muffler shell 1 is provided with an air inlet 4, the muffler cover 2 is provided with an air outlet 5, the outer side of the muffler cover 2 is provided with a diverter plate 6, a spark catching net 7 and a guide cover 8 corresponding to the air outlet 5 from the inside to the outside, a first exhaust chamber 9 is formed between the muffler cover 2 and the diverter plate 6, and a second exhaust chamber 10 is formed between the diverter plate 6 and the guide cover 8.

[0040] like Figure 1-4 As shown, the exhaust gas of the present invention enters the cavity from the air inlet 4 and then exits from the air outlet 5. The exhaust gas exiting from the air outlet 5 first flows into the first exhaust cavity 9 to impact the diverter plate 6, flows into the second exhaust cavity 10 after being diverted by the diverter plate 6, and finally flows out through the guide cover 8. The exhaust gas is diverted by the diverter plate 6 and guided by the guide cover 8, which effectively disperses the exhaust gas, prevents the heat of the high-temperature exhaust gas from being too concentrated, and effectively reduces the temperature of the exhaust gas. At the same time, the spark catching net 7 in the second exhaust cavity 10 catches sparks, effectively preventing the exhaust port from spraying fire, and avoiding safety hazards to users.

[0041] In this embodiment, Figure 3 , 4 The direction of the arrow in the middle is the direction of exhaust gas flow.

[0042] The structures of the first exhaust chamber 9 and the second exhaust chamber 10 are as follows: Figure 2 As shown, the muffler cover 2 is concave toward one side of the cavity to form the first exhaust cavity 9, and the air guide cover 8 is convex toward the side away from the cavity to form the second exhaust cavity 10.

[0043] The fixing method of the air deflector 8, the spark catching net 7 and the splitter plate 6 is as follows: the screws pass through the air deflector 8, the spark catching net 7, the splitter plate 6 and the muffler cover 2 in sequence and are screwed and locked with the square nuts.

[0044] In order to evenly divert the exhaust gas to the second exhaust chamber 10, the diverter plate 6 is provided with a plurality of diverter holes 11, and the total area of ​​the diverter holes 11 on the left and the total area of ​​the diverter holes 11 on the right are both larger than the total area of ​​the diverter holes 11 in the middle. The exhaust gas in the first exhaust chamber 9 first hits the center of the diverter plate 6. Since the total area of ​​the diverter holes 11 on the left and the total area of ​​the diverter holes 11 on the right are both larger than the total area of ​​the diverter holes 11 in the middle, the exhaust gas passing through the diverter plate 6 will be relatively evenly diverted to the second exhaust chamber 10. Figure 6As shown, in this embodiment, the diverter hole 11 is a circular diverter hole, and the number of circular diverter holes at the left position, the number of circular diverter holes at the right position, and the number of circular diverter holes at the middle position are all the same, and the aperture of the circular diverter hole at the middle position is smaller than the aperture of the circular diverter holes at the two side positions.

[0045] Furthermore, Figure 1 , 4 As shown in Figures 7 and 8, the air guide 8 is provided with two or more oblique exhaust ports 12 at intervals, and the air guide 8 is provided with spoiler holes 13, and the exhaust direction of the spoiler holes 13 intersects with the exhaust direction of the oblique exhaust ports 12, so that the exhaust gas discharged from the oblique exhaust ports 12 is away from the outer surface of the air guide 8. Most of the exhaust gas is discharged through the oblique exhaust ports 12, so that the heat of the high-temperature exhaust gas is not too concentrated, and the temperature of the exhaust gas is effectively reduced. At the same time, another small part of the exhaust gas is discharged from the spoiler holes 13 and rushes towards the exhaust gas discharged from the oblique exhaust ports 12, so that the exhaust gas discharged from the oblique exhaust ports 12 is away from the outer surface of the air guide 8 and discharged to a distance at a suitable angle, effectively avoiding the high-temperature exhaust gas from gathering on the outer surface of the air guide 8.

[0046] The structure of the oblique exhaust port 12 is as follows: Figure 1 , 7 As shown, a plurality of vertical guide plates 14 are spaced apart on the outside of the air guide cover 8 , and the oblique exhaust port 12 is formed between two adjacent vertical guide plates 14 .

[0047] Preferably, Figure 7 As shown, the exhaust direction of the oblique exhaust port 12 and the angle α of the outer surface of the air deflector 8 is greater than or equal to 25° and less than or equal to 45°, and the exhaust direction of the spoiler hole 13 is perpendicular to the outer surface of the air deflector 8.

[0048] In order to avoid fire from the exhaust port 12, an exhaust pipe 15 leading to the air outlet 5 is provided on the inner side of the muffler cover 2. The exhaust gas passes through the exhaust pipe 15 and then flows out from the air outlet 5, which effectively prevents the flame generated by the secondary combustion of the high-temperature exhaust gas through the catalyst from being discharged outside the muffler and causing the muffler to spray fire.

[0049] Internal structure of catalyst muffler: Figure 1-4As shown, a mounting partition 16 is provided between the muffler shell 1 and the muffler cover 2. The mounting partition 16 divides the cavity into an air inlet chamber 17 for accommodating the initial exhaust gas and an air outlet chamber 18 for accommodating the purified exhaust gas. The air inlet chamber 17 is located on one side of the air inlet 4 and is connected to the air inlet 4. The air inlet 4 is provided in the middle of the muffler shell 1. The air outlet chamber 18 is located on one side of the air outlet 5 and is connected to the air outlet 5. The catalyst 3 is located at the lower part of the air inlet chamber 17. The exhaust gas in the air inlet chamber 17 flows to the air outlet chamber 18 through the catalyst 3. The exhaust pipe 15 is located at the upper part of the air outlet chamber 18. After the exhaust gas discharged from the cylinder exhaust port enters the air inlet chamber 17 from the air inlet 4, most of the impurities and other particulate matter in the exhaust gas will be directly blown to the middle part of the mounting partition 16, effectively reducing the impurities attached to the surface of the catalyst 3 and causing the catalyst 3 to have a reduced effect, and at the same time effectively reducing the impact of the exhaust gas on the catalyst 3. The exhaust gas first impacts the middle part of the mounting baffle 16, and then generates a large amount of heat through the oxidation reaction of the catalyst 3, and then enters the air outlet chamber 18, and then reaches the first exhaust chamber 9 through the exhaust pipe 15. The catalyst 3 is located at the lower part of the air inlet chamber 17, and the exhaust pipe 15 is located at the upper part of the air outlet chamber 18. The exhaust pipe 15 is not opposite to the catalyst 3, which effectively prevents the flame generated by the secondary combustion of the high-temperature exhaust gas through the catalyst from being discharged outside the muffler, causing the muffler to spray fire.

[0050] In order to prevent the exhaust pipe 15 from affecting the air flow, the mounting baffle 16 is concave at the exhaust pipe 15 toward the air inlet cavity 17 to form a concave cavity, and the exhaust gas from the air outlet cavity 18 enters the concave cavity and flows into the exhaust pipe.

[0051] Preferably, the volume of the air outlet cavity 18 is more than twice the engine displacement, the exhaust pipe 15 is a hollow cylinder, and the ratio of the length to the inner diameter of the exhaust pipe 15 is not less than 1.3, further ensuring that the flame burning through the catalyst 3 will not appear from the outside of the exhaust pipe 15.

[0052] Furthermore, a catalyst mounting shell 20 located in the air inlet cavity 17 is fixed on the mounting baffle 16, and the catalyst 3 is arranged in the catalyst mounting shell 20. A through hole is arranged at the lower portion of the mounting baffle 16, and a heat insulation board 21 located in the air outlet cavity 18 is arranged on the inner side of the muffler cover 2. A fixed conduit 22 is arranged in the cavity, and the fixed conduit 22 passes through the mounting baffle 16 and the heat insulation board 21. One end of the fixed conduit 22 is fixedly connected to the muffler cover 2, and the other end is fixedly connected to the muffler shell 1 through a fixed pressure plate 23. Two fixed conduits 22 are arranged, and are respectively located on both sides of the vent 19.

[0053] like Figure 1 , 3As shown in Figure 5, a vent hole 19 connecting the air inlet chamber 17 and the air outlet chamber 18 is provided in the middle of the mounting partition 16. Most of the exhaust gas in the air inlet chamber 17 flows to the air outlet chamber 18 through the catalyst 3, and a small part flows to the air outlet chamber 18 through the vent hole 19. The exhaust gas is mixed in the air outlet chamber 18, which effectively reduces the temperature of most of the exhaust gas passing through the catalyst 3.

[0054] Preferably, the vent hole 19 is circular and is provided with one vent hole.

[0055] Another object of the present invention is to provide a chain saw, comprising a cylinder 24 and a crankcase 25, the crankcase 25 is fixed with the above-mentioned catalyst muffler by fasteners, the air inlet 4 of the catalyst muffler is located at the exhaust port of the cylinder 24, the catalyst muffler is provided with an upper cover plate 26 at the upper end, an air filter cover 27 is provided at the rear upper end of the upper cover plate 26, a starter assembly 28 is provided on the left side of the crankcase 25, and a right side cover assembly 29 is provided on the right side, such as Figure 8 , 9 shown.

[0056] The above embodiment is only one of the preferred embodiments of the present invention, and is not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes made based on the shape, structure, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A catalyst muffler, comprising a muffler shell (1) and a muffler cover (2) arranged on the muffler shell (1), wherein the muffler shell (1) and the muffler cover (2) are fixedly connected to form a cavity, wherein a catalyst (3) is arranged in the cavity, wherein the muffler shell (1) is provided with an air inlet (4), and the muffler cover (2) is provided with an air outlet (5), ... The outer side of the muffler cover (2) is provided with a flow divider (6) directly opposite to the air outlet (5), a spark catching net (7) and a guide cover (8) in sequence from the inside to the outside. A first exhaust chamber (9) is formed between the muffler cover (2) and the flow divider (6), and a second exhaust chamber (10) is formed between the flow divider (6) and the guide cover (8). The guide cover (8) is provided with more than two oblique exhaust ports (12) at intervals. The guide cover (8) is provided with a spoiler hole (13). The exhaust direction of the spoiler hole (13) intersects with the exhaust direction of the oblique exhaust port (12), so that the exhaust gas discharged from the oblique exhaust port (12) is away from the outer surface of the guide cover (8). The outer side of the guide cover (8) is provided with a plurality of vertical guide plates (14) at intervals. The oblique exhaust port (12) is formed between two adjacent vertical guide plates (14). Towards the exhaust port (12), an exhaust pipe (15) leading to the exhaust port (5) is provided on the inner side of the muffler cover (2), a mounting partition (16) is provided between the muffler shell (1) and the muffler cover (2), the mounting partition (16) divides the cavity into an intake chamber (17) for accommodating initial exhaust gas and an exhaust chamber (18) for accommodating purified exhaust gas, the intake chamber (17) is located on one side of the intake port (4) and communicated with the intake port (4), the intake port (4) is provided in the middle of the muffler shell (1), the exhaust chamber (18) is located on one side of the exhaust port (5) and communicated with the exhaust port (5), the catalyst (3) is located at the lower part of the intake chamber (17), the exhaust gas in the intake chamber (17) flows to the exhaust chamber (18) through the catalyst (3), and the exhaust pipe (15) is located at the upper part of the exhaust chamber (18).

2. A catalyst muffler according to claim 1, characterized in that: The diverter plate (6) is provided with a plurality of diverter holes (11), and the total area of ​​the diverter holes (11) at the left side and the total area of ​​the diverter holes (11) at the right side are both greater than the total area of ​​the diverter holes (11) at the middle.

3. A catalyst muffler according to claim 1, characterized in that: The exhaust direction of the oblique exhaust port (12) is at an angle greater than or equal to 25° and less than or equal to 45° to the outer surface of the air deflector (8), and the exhaust direction of the spoiler hole (13) is perpendicular to the outer surface of the air deflector (8).

4. A catalyst muffler according to claim 1, characterized in that: The exhaust pipe (15) is a hollow cylinder, and the ratio of the length to the inner diameter of the exhaust pipe (15) is not less than 1.

3.

5. A catalyst muffler according to claim 1, characterized in that: A vent hole (19) is provided in the middle of the mounting baffle (16) for connecting the air inlet chamber (17) and the air outlet chamber (18); most of the exhaust gas in the air inlet chamber (17) flows to the air outlet chamber (18) through the catalyst (3), and a small part flows to the air outlet chamber (18) through the vent hole (19).

6. A chain saw using the catalyst muffler according to any one of claims 1 to 5, characterized in that: The invention comprises a cylinder (24) and a crankcase (25), wherein the catalyst muffler is fixed on the crankcase (25), the air inlet (4) of the catalyst muffler is located at the exhaust port of the cylinder (24), an upper cover plate (26) is provided at the upper end of the catalyst muffler, an air filter cover (27) is provided at the rear upper end of the upper cover plate (26), a starter assembly (28) is provided on the left side of the crankcase (25), and a right side cover assembly (29) is provided on the right side.

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