JP2863620B2 - Outboard exhaust gas purification system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an exhaust gas purification device for an outboard motor.

[Prior Art] The present inventor has disclosed in Japanese Patent Application No. 1-156653, "When constructing an exhaust gas purifying apparatus that prevents heat damage due to heat generation of a catalyst and does not reduce the function of the catalyst, While securing an exhaust expansion chamber sufficient to obtain a sufficient noise reduction effect,
With the aim of preventing the backflow of cooling water into the engine, an exhaust expansion chamber is formed at a position adjacent to the engine inside the casing in an exhaust gas purification device for an outboard motor in which the engine is located at the top of the casing. The exhaust pipe communicating with the exhaust port of the engine is extended in the exhaust expansion chamber, the exhaust gas purifying catalyst is disposed in the exhaust pipe, and the heat insulating material is disposed on the outer periphery of the exhaust gas purifying catalyst. A special feature is to propose an exhaust gas purifying device for an outboard motor, which aims to prevent backflow of outside water into the engine when tilting up or following waves occur. A partition wall for partitioning the exhaust expansion chamber and an exhaust passage communicating with a discharge port for discharging exhaust gas to the outside of the casing, wherein the exhaust expansion chamber and the exhaust passage are separated by an exhaust expansion chamber of the exhaust pipe. Exit to An exhaust gas purifying device for an outboard motor configured to communicate with each other at a higher position and a rearward position in the propulsion direction is proposed.

That is, in the above-described exhaust gas purifying apparatus, when the water flowing through the inner wall surface of the casing rises during tilt-up due to driftwood collision, or when the water level in the casing rises due to the following wave caused by sudden deceleration, the outer water expands and exhausts. The intrusion into the room is prevented by the partition wall, thereby preventing the backflow of outside water into the engine.

[Problems to be Solved by the Invention] It is possible to sail a large horsepower outboard motor at a low speed from the water surface to the upper end of the transom board on which the outboard motor is mounted, and at a flat high speed. When mounted on a board and subjected to severe sudden acceleration or deceleration, or when sailing in rough seas, the intense flow of water back from the outside through the exhaust passage is expected. However, the backflow to the exhaust expansion chamber cannot be sufficiently prevented by providing a partition wall in the above, and the water flowing backward in the exhaust passage jumps over the partition wall and vigorously jumps into the exhaust expansion chamber, directly hitting the outside of the case supporting the catalyst. In addition, it is expected that the temperature of the catalyst decreases and the water splashed directly touches the catalyst, resulting in a decrease in the catalytic function.

In addition, when the propulsion unit at the time of driftwood collision instantly tilts up, water on the trajectory of the exhaust port flows backward from the exhaust port into the exhaust passage, rides over the partition wall, and jumps out to the exhaust expansion chamber. . At this time, since the propulsion unit is in the tilt-up state, it is expected that the water that has flowed out into the exhaust expansion chamber spills over the catalyst from above, thereby deteriorating the catalyst function.

The present invention uses a heat insulating material to prevent heat damage due to heat generation of the catalyst, controls the temperature around the catalyst so as not to lower the function of the catalyst, and also prevents heat damage to exhaust gas after purification by the catalyst. When constructing an exhaust gas purification device that can be used, the strong flow of external water that flows backward from the outside into the exhaust passage when the propulsion unit is instantaneously tilted up during severe acceleration or deceleration on a high speed boat or during driftwood collision The purpose of the present invention is to prevent water from splashing around the catalyst.

Means for Solving the Problems According to the present invention, an engine is disposed at an upper portion of a casing, an exhaust expansion chamber is formed at a position adjacent to the engine in the casing, and an exhaust pipe communicating with an exhaust port of the engine is subjected to exhaust expansion. An exhaust gas purifying apparatus for an outboard motor, comprising: an exhaust gas purifying device that extends in a room, arranges an exhaust gas purifying catalyst in an exhaust pipe, and arranges a heat insulating material on an outer periphery of the exhaust gas purifying catalyst. When the exhaust passage for communicating the outside of the casing is extended into the casing, the exhaust passage is partitioned from the exhaust expansion chamber by a shielding wall installed at least on the side of the exhaust pipe and behind the propulsion direction. At the same time, from the communication port with the exhaust gas expansion chamber located below the shielding wall, the exhaust gas is discharged to the outside of the casing through an intermediate path portion above the outlet level of the exhaust pipe to the exhaust gas expansion chamber and behind the propulsion direction. To the exit It is designed to be extended.

[Action] According to the present invention, the following actions are provided.

Insulation material is placed around the catalyst and the heat capacity around the catalyst is small, so the temperature rise of the catalyst after the cold start is fast, the catalyst can be warmed up in a short time, and the catalyst is emitted by the insulation material It is possible to prevent heat from being transmitted to the outside.

Since the exhaust expansion chamber is provided at a position adjacent to the engine in the casing, it is possible to form the exhaust expansion chamber sufficient to obtain a sufficient noise reduction effect and cooling effect.

Since the cooling water is not injected into the end of the exhaust pipe, there is no possibility that the cooling water flows back into the engine due to the exhaust pulsation.

When the propulsion unit instantaneously tilts up during intense sudden acceleration / deceleration on a high speed board or during driftwood collision,
It is possible to prevent the outside water from flowing backward through the exhaust passage and entering the exhaust expansion chamber at the intermediate path portion located above the outlet level of the exhaust pipe in the exhaust passage and behind the propulsion direction.

In the above, even if the intense backflow of external water may get over the intermediate passage portion of the exhaust passage and enter the exhaust expansion chamber, the water entering the exhaust expansion chamber is arranged in the exhaust pipe due to the presence of the shielding wall. Can be prevented from splashing around the catalyst.

[Embodiment] FIG. 1 is a side view showing a first embodiment of the present invention, partially cut away, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is a sectional view showing the second embodiment, and FIG.
FIG. 5 is a sectional view taken along the line IV-IV, FIG. 5 is a sectional view showing the third embodiment of the present invention, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5, and FIG. It is a schematic diagram which shows a state.

(First Embodiment) As shown in FIGS. 1 and 2, an outboard motor 10 includes a clamp bracket 12 attached to a hull 11, and a swivel bracket 14 connected to the clamp bracket 12 via a tilt shaft 13. And a propulsion unit 16 connected to the swivel bracket 14 via a turning shaft 15. The propulsion unit 16 can tilt up / down around the tilt shaft 13 as a rotation center, and can turn around the steering shaft 15 as a rotation center.

The propulsion unit 16 includes upper and lower casings 19 connected to upper and lower ends of the steered shaft 15 via upper and lower connecting members 17 and 18,
20 and two upper and lower intermediate plates 21A, 21A on the upper part of the upper casing 19.
The engine 22 includes an engine 22 disposed via 1B and a propeller 23 disposed below the lower casing 20. The output of the engine 22 is output from a drive shaft 24, a forward / reverse switching gear train 25, and a propeller shaft disposed inside the casings 19 and 20.
It is transmitted to propeller 23 via 26.

The engine 22 of this embodiment is a four-stroke engine. In the figure, reference numeral 27 denotes an oil tank, 28 denotes an oil pump, and 29 denotes an oil filter.

Further, the outboard motor 10 includes a cooling water pump 30. The cooling water pump 30 is disposed around the drive shaft 24 inside the upper casing 19, and is driven by the rotation of the drive shaft 24,
The cooling water sucked in through the outside water inlet 31 and the suction passage 32 is pumped to the cooling water jacket of the engine 22 by the pumping pipe 33.

Therefore, in the outboard motor 12, an exhaust expansion chamber 34 is formed at an upper position adjacent to the engine 22 in the upper casing 19,
A cooling water jacket 35 is formed around the exhaust expansion chamber 34 in the upper casing 19. The cooling water jacket 35 supplies cooling water after cooling the engine 22 from a drain port of the engine 22 to cool the inner wall 36 of the upper casing 19 and the outer wall thereof.
37 to prevent the temperature of peripheral components from rising.

Further, an exhaust pipe 38 communicating with the exhaust port of the engine 22 is provided.
Are fixed to the lower surface of the lower intermediate plate 21B so as to be connected to the upstream exhaust passage 39 provided in the above-described intermediate plates 21A and 21B, and are separated from the peripheral wall of the exhaust expansion chamber 34 in the exhaust expansion chamber.
It is extended inside 34.

An exhaust gas purifying catalyst 40 is disposed in the exhaust pipe 38, and a heat insulating material 41 is disposed between the inner periphery of the exhaust pipe 38 as a heat-resistant container and the outer periphery of the catalyst 40.

The lower casing 22 is provided with a downstream exhaust passage 42 to which the lower end of the exhaust expansion chamber 34 communicates.
Reference numeral 42 is connected to an exhaust discharge port 43 provided in a boss portion of the propeller 23 to discharge exhaust gas into water.

The intermediate plates 21A and 21B have a sub-first expansion chamber 44 connected to the upper end of the exhaust expansion chamber 34.
A second sub-expansion chamber connected to the first sub-expansion chamber 44 is provided at the rear upper end.
A sub second expansion chamber 45 is communicated with the external space through a sub discharge port 46 provided at the rear upper end of the upper casing 19. These sub-exhaust passage systems function as exhaust passages at the time of stoppage of a boat with a high water level entering the casing or at low speed. L is the sea level at the time of the stop.

Here, in the outboard motor 10, a partition wall 61 that is sufficiently higher than the water level L when the boat is stopped is provided in a region surrounded by the cooling water jacket 35 in the upper casing 19, and the above-described partition in the upper casing 19 is provided. In front of the upper part of the wall 61, a barrier wall 62 extending between the inner walls 36 on both sides of the upper casing 19 is provided on the side of the exhaust pipe 38 and behind the exhaust direction. As a result, the outboard motor 10 includes the shielding wall 62, the intermediate plate 21B, and the partition wall 61.
And the inner wall 36 of the upper casing 19, form an intermediate exhaust passage 63 connecting the exhaust expansion chamber 34 and the downstream exhaust passage 42.

The intermediate exhaust passage 63 is separated from the exhaust expansion chamber 34 by a barrier wall 62 installed on the side of the exhaust pipe 38 and behind the exhaust direction, and the exhaust expansion chamber located below the barrier wall 62. From the communication port 62A with the chamber 34, via the intermediate path portion 64 located above the partition wall 61, above the outlet level of the exhaust pipe 38 to the exhaust expansion chamber 34, and behind the propulsion direction, the downstream exhaust passage 42
Is extended toward the exhaust outlet 43 of the propeller 23.

The partition wall 61 is hollow and has a built-in cooling water jacket 65 that communicates with the cooling water jacket 35 so that the exhaust gas in contact with the cooling water jacket 65 can be cooled.

Further, in the outboard motor 60, the bottom of the exhaust expansion chamber 34 is lower than the water level L when the boat is stopped, and the bottom of the exhaust expansion chamber 34 is provided with a drain hole 66 having a sufficiently narrowed area. The drain hole 66 is
It is set to a position where no water remains when tilting up.

In the case of the outboard motor 60, the area of the intermediate exhaust passage 63 is set to be sufficiently larger than the area of the drainage hole 66, and
Is set so as not to cause exhaust resistance.

 According to the first embodiment, the following effects are obtained.

Since the cooling water jacket 35 is formed around the exhaust expansion chamber 34, heat generated by the catalyst 40 can be shielded by the cooling water jacket 35. As a result, heat generated by the catalyst 40 does not hinder handling of the outboard motor 10 and does not cause heat damage to the casings 19 and 20 and other components.

Since the heat insulating material 41 is arranged around the outer periphery of the catalyst 40 and the heat capacity around the catalyst 40 is small, the temperature of the catalyst 40 rises quickly after the cold start, so that the catalyst 40 can be warmed up in a short time and the heat insulation The material can prevent the heat generated by the catalyst from being transmitted to the outside.

The exhaust gas that has been purified by contact with the catalyst 40 contacts the wall surface of the exhaust expansion chamber 34 cooled by the cooling water jacket 35 and is cooled. As a result, it is possible to prevent the exhaust heat from causing heat damage to the rubber parts and the like around the propeller shaft 26 and inside the propeller 23.

Since the exhaust expansion chamber 34 is provided at a position adjacent to the engine 22 in the upper casing 19, the exhaust expansion chamber 34 sufficient to obtain a sufficient noise reduction effect and a cooling effect by adiabatic expansion can be formed.

Since the cooling water is not injected into the exhaust pipe 38, there is no fear that the cooling water flows back into the engine due to the exhaust pulsation.

When the propulsion unit instantaneously tilts up during intense sudden acceleration / deceleration on a high speed boat or during driftwood collision,
It is possible to prevent the outside water from flowing backward through the exhaust passage 63 and entering the exhaust expansion chamber 34 by the intermediate path portion 64 located above the outlet level of the exhaust pipe 38 in the exhaust passage 63 and located rearward in the propulsion direction.

In the above case, even if the strong backflow of the external water gets over the intermediate path portion 64 of the exhaust passage 63 and enters the exhaust expansion chamber 34, the water entering the exhaust expansion chamber 34 does not
Of the catalyst 40 around the catalyst 40 disposed in the exhaust pipe 38 can be prevented.

Exhaust expansion chamber of exhaust passage 63 located below shield wall 62
Since the communication port 62A to 34 faces downward, the flow of water flowing backward through the exhaust passage 63 can be directed to the direction without the catalyst 40 in the above.

(Second Embodiment) The difference between the outboard motor 70 and the outboard motor 10 is shown in FIGS.
As shown in the figure, a first exhaust expansion chamber 71 formed by the partition wall 61 is formed.
A lower portion of the water level L at the time of stoppage of the vessel, and a second exhaust expansion chamber 72 that connects the intermediate exhaust passage 63 and the downstream exhaust passage 42 below the partition wall 61; 62 has been extended so as to extend under the catalyst 40.

According to the second embodiment, the obstruction wall 62 is turned to the lower side of the catalyst 40 so that, for example, at the time of tilt-up due to driftwood collision as shown in FIG. Water that enters and scatters can be more reliably prevented from directly touching the catalyst 40.

In addition, a portion of the exhaust passage 63 formed between the inner wall 36 on both sides of the upper casing 19 and the partition wall 61 and closer to the exhaust expansion chamber 71 can function as an exhaust expansion chamber, thereby further reducing exhaust noise. Can also be reduced.

(Third Embodiment) The difference between the outboard motor 80 and the outboard motor 70 is that
The partition wall without passing between the inner walls 36 on both sides of the upper casing 19
Around the rear inner wall 36 so as to surround 61,
The communication port 62A to the first exhaust gas expansion chamber 71 is extended to a horizontal portion below the exhaust gas expansion chamber 71, and is opened at a position farther from the catalyst 40 and in a direction without the catalyst 40. .

According to the third embodiment, since the communication port 62A of the barrier wall 62 is opened at a position farther from the catalyst 40 and in a direction without the catalyst 40, the communication port 62A enters the first exhaust expansion chamber 71. Spattering water can be more reliably prevented from directly splashing on the catalyst 40.

[Effects of the Invention] As described above, according to the present invention, when constructing an exhaust gas purification device that prevents heat damage due to heat generation of the catalyst and does not reduce the function of the catalyst, a high speed boat When the propulsion unit is instantaneously tilted up at the time of severe acceleration / deceleration or at the time of driftwood collision, it is possible to prevent a violent flow of external water flowing backward from the outside into the exhaust passage from splashing around the catalyst.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of the present invention, partially cut away, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is a sectional view of FIG.
FIG. 5 is a sectional view taken along the line IV-IV, FIG. 5 is a sectional view showing the third embodiment of the present invention, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5, and FIG. It is a schematic diagram which shows a state. 10, 70, 80 ... outboard motor, 19, 20 ... casing, 22 ... engine, 34, 71, 72 ... exhaust expansion chamber, 35 ... cooling water jacket, 38 ... exhaust pipe, 40 ... Catalyst 41 Insulation material 43 Exhaust discharge port 61 Partition wall 62 Blocking wall 62A Communication port 63 Intermediate exhaust passage 64 Intermediate path section

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01N 3/24 F01N 7/12 B63H 21/26

Claims (1)

(57) [Claims] An engine is disposed at an upper portion of a casing, an exhaust expansion chamber is formed at a position adjacent to the engine in the casing, and an exhaust pipe communicating with an exhaust port of the engine is extended and disposed in the exhaust expansion chamber. An exhaust gas purifying device for an outboard motor, comprising: an exhaust gas purifying catalyst disposed in the outer periphery of the exhaust gas purifying catalyst; When extending the exhaust passage into the casing, the exhaust passage is separated from the exhaust expansion chamber by a shielding wall installed at least laterally of the exhaust pipe and behind the propulsion direction, and below the shielding wall. From the communication port with the exhaust expansion chamber located at a position higher than the outlet level of the exhaust pipe to the exhaust expansion chamber and through the intermediate path portion rearward in the propulsion direction toward the exhaust discharge port to the outside of the casing. It is characterized by Exhaust gas purifying apparatus that the outboard motor.