JP4684482B2 - Exhaust device for water jet propulsion boat engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust device for a water jet propulsion boat engine.
[0002]
[Prior art]
A water jet propulsion boat propels a jet flow generated by a jet propulsion device driven by an engine from a jet nozzle.
[0003]
As an exhaust device for such an engine for a water jet propulsion boat, in order to suppress the vibration of the engine from being transmitted to the exhaust pipe, the middle of the exhaust pipe is divided in the length direction, and the divided ends are separated from each other. Some are connected by a rubber sleeve with a gap.
[0004]
[Problems to be solved by the invention]
However, since the rubber sleeve exposes the gap between the split ends of the exhaust pipe to high-temperature exhaust gas, it is necessary to take measures to improve the durability.
[0005]
The present invention has been made in order to meet the above-mentioned demands, and an object of the present invention is to provide an exhaust device for a water jet propulsion boat engine devised to improve the durability of a rubber sleeve.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a water jet propulsion boat that propels a jet generated by a jet propulsion device driven by an engine from a jet nozzle, and has a length in the middle of the exhaust pipe of the engine. The split ends are connected to each other by a rubber sleeve with a gap therebetween, and a heat insulating rubber seal ring is fitted into the gap, and a heat resistant metal elastic is provided on the exhaust passage side of the seal ring. An exhaust system for an engine for a water jet propulsion boat, characterized in that a ring is attached .
[0007]
According to the present invention, since the heat insulating rubber seal ring tightly closes the gap portion between the split ends of the exhaust pipe, the gap portion between the split ends of the exhaust pipe of the rubber sleeve becomes high-temperature exhaust gas. Since it is not exposed, the durability of the rubber sleeve is improved.
[0008]
Further , if the heat-resistant metal elastic ring is attached to the exhaust passage side of the seal ring, the elastic ring tightly closes the gap portion on the exhaust passage side. Since the portion is not exposed to the high temperature exhaust gas, the durability of the seal ring is improved.
[0009]
Further, the present invention provides a water jet propulsion boat that propels a jet generated by a jet propulsion device driven by an engine from a jet nozzle and propels the first exhaust pipe in the longitudinal direction of the exhaust pipe of the engine. And a second exhaust pipe, and a downstream end portion of the first exhaust pipe and an upstream end portion of the second exhaust pipe are connected to each other by a rubber sleeve with a gap therebetween. An exhaust device for a water jet propulsion boat engine is provided, in which an L-shaped insulating rubber seal ring is fitted.
According to a third aspect of the present invention, when the seal ring is made of silicon rubber, the silicone rubber is excellent in at least heat resistance and corrosion resistance, so that the durability of the seal ring is further improved, and the rubber sleeve The cost is lower than the case where the whole is made of silicon rubber.
[0010]
As in claim 4 , when the elastic ring is formed by compression-molding a stainless steel wire to give elasticity and rubber bite, the stainless steel wire is excellent in at least heat resistance and corrosion resistance. , The durability of the seal ring is further improved, and the gap portion can be closed more tightly by elasticity, and the seal ring gets into the gap of the stainless steel wire and the biting property is improved, so the installation of the elastic ring is ensured Become.
[0011]
As in claim 5, when is obtained by vulcanizing the sealing ring to the elastic ring facilitates handling of the seal ring and the elastic ring.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
As shown in FIGS. 1 and 2, in the water jet propulsion boat 1, a hull 2 includes a hull member 3 and a deck member 4, and a steering handle 5 is provided above the deck member 4. On the upper part of the deck member 4 behind the handle 5, a seat base 4a raised upward from the deck member 4 is provided to extend rearward. The upper part of the seat base 4a extends to the rear. The seat type seat 6 is detachably mounted, and the inspection opening 4b formed on the upper surface of the seat base 4a can be opened and closed by the attachment and detachment of the straddle type seat 6.
[0014]
On both sides of the seat base 4a of the deck member 4, foot steps 4c for the rider to put both feet are formed between the deck member 4 and the bulwark 7 protruding upward from both sides.
[0015]
The interior of the hull 2 is divided into front and rear by a bulkhead 8, and an engine chamber 9 is formed on the front side and a pump chamber 10 is formed on the rear side. A four-cycle four-cylinder engine 20 is mounted on the hull member 3 via an engine mount 21 at a position below the seat base 4a in the engine chamber 9, and a resin fuel tank is disposed at a front position of the engine 20. 22 is fixed to the hull member 3. The engine 20 may have two cycles, and the number of cylinders is not limited to four.
[0016]
A jet propulsion device 30 is disposed in the pump chamber 10. Although not specifically illustrated, the propulsion device 30 is rotated from the water suction port at the bottom of the ship by the impeller being rotated by the engine 20 via the impeller shaft. The hull 2 is propelled by sucking water and spraying the water backward from the nozzle 30a of the jet propulsion machine 30. Further, the hull 2 is turned by swinging the deflector 30b left and right by operating the steering handle 5.
[0017]
A front intake duct 23 is provided at the front position of the engine compartment 9 of the hull 2 so as to open to the upper surface of the bow portion of the deck member 4 and introduce air outside the boat into the engine compartment 9. A rear intake duct 24 is provided at the front position of the pump chamber 10 on the rear side of the bulkhead 8 so as to open to the upper surface of the seat base 4a of the deck member 4 and introduce air outside the boat into the pump chamber 10. It has been.
[0018]
An intake box 41 which is a part of the intake device is installed on the upper portion of the engine 20.
[0019]
As shown in detail in FIGS. 3 to 6, the exhaust system of the engine 20 has an exhaust manifold (a part of the exhaust pipe) 42 connected to the starboard side of the cylinder block of the engine 20, and a downstream end of the exhaust manifold 42. The exhaust pipe 43 is connected to the upstream end of the exhaust pipe 43. The exhaust pipe 43 bypasses the upper front of the engine 20 in a U-shape, and the upstream end is connected to the downstream end of the exhaust pipe 43. The muffler (a part of the exhaust pipe) 44 extends rearward on the port side upper side of the engine 20, curves downward on the rear side of the engine 20, and then extends rearward to penetrate the bulkhead 8 to the pump. A downstream end is connected to an inlet of a water lock 45 (see FIGS. 1 and 2) disposed on the starboard side in the chamber 10.
[0020]
A downstream end of a discharge pipe (a part of the exhaust pipe) 46 is connected to the outlet of the water lock 45, and the discharge pipe 46 bypasses the upper part of the pump chamber 10 and extends to the port side. A downstream end is connected to the left side wall of the pump chamber 10, and exhaust gas is discharged into the pump chamber 10. In FIG. 3, reference numeral 25 denotes an oil tank attached to the rear part of the engine 20.
[0021]
As shown in FIGS. 6 and 7, the exhaust pipe 43 is formed with four independent exhaust passages 43a communicating with the independent exhaust passages of the exhaust manifold 42, and the outer periphery of the exhaust pipe 43 is heat resistant. The cooling water passage 34 is formed between the inner periphery of the rubber jacket 33 and the outer periphery of the exhaust pipe 43.
[0022]
The muffler 44 is formed with one collective exhaust passage 44a having a cross-sectional area equal to or larger than the sum of the cross-sectional areas of the four independent exhaust passages 43a of the exhaust pipe 43, and is formed on the outer periphery of the collective exhaust passage 44a. A cooling water passage 44b is formed.
[0023]
At the downstream end (divided end) 43c of the exhaust pipe 43 (first exhaust pipe) , a step portion 43d cut from the outer peripheral side to the inner peripheral side is formed, and the muffler 44 (second exhaust pipe) is formed. At the upstream end portion (divided end portion), a step portion 44d cut from the inner peripheral side to the outer peripheral side is formed, and the step portion 43d of the exhaust pipe 43 and the step portion 44d of the muffler 44b are L-shaped in a side view. A gap t is formed.
[0024]
Then, by covering the rubber sleeve 35 across the outer periphery of the downstream end of the exhaust pipe 43 and the outer periphery of the upstream end of the muffler 44, the independent exhaust passage 43a of the exhaust pipe 43 and the collective exhaust passage 44a of the muffler 44 are formed. The exhaust gas flows as shown by an arrow a in series, and the exhaust pipe 43 is cooled by covering the outer circumference of the downstream end of the rubber jacket 33 of the exhaust pipe 43 over the outer circumference of the upstream end of the muffler 44. The water passage 34 and the cooling water passage 44b of the muffler 44 are connected in series so that the cooling water flows as shown by the arrow b.
[0025]
The rubber sleeve 35 is watertightly fixed to the exhaust pipe 43 and the muffler 44 by a band 36 with a fastening tool, and the rubber jacket 33 is watertightly fixed to the muffler 44 by a band 37 with a fastening tool. .
[0026]
As shown in detail in FIG. 7, an L-shaped heat insulating rubber seal ring 38 is hermetically sealed in an L-shaped gap t between the step 43d of the exhaust pipe 43 and the step 44d of the muffler 44b. It is inserted. The seal ring 38 is preferably formed of silicon rubber having at least heat resistance and corrosion resistance.
[0027]
A heat-resistant metal elastic ring 39 is attached to the seal ring 38 on the exhaust passage 43a side. For example, the elastic ring 39 is compression-molded so that stainless steel wires of about 0.5 mmφ are entangled with each other, the exhaust passage 43a side is a slightly larger spherical portion 39a than the gap t, and the opposite side is a flat ring shape. It forms in the part 39b.
[0028]
The seal ring 38 and the elastic ring 39 are integrated by vulcanizing and molding the seal ring 38 on the flat ring-shaped portion 39b of the elastic ring 39. It should be noted that the seal ring 38 may be vulcanized and formed on the spherical portion 39a of the elastic ring 39 with a small thickness for practical purposes.
[0029]
With the configuration as described above, the gap t between the exhaust pipe 43 and the downstream end portion 43c and the upstream end portion 44c of the muffler 44 is airtightly closed by the seal ring 38, so that compared with the case without the seal ring 38. As a result, the gap t of the rubber sleeve 35 is not exposed to the high-temperature exhaust gas, so that the durability of the rubber sleeve 35 is improved.
[0030]
Further, since the elastic ring 39 is attached to the exhaust ring 43a side of the seal ring 38, the elastic ring 39 hermetically closes the gap t on the exhaust passage 43a side, so the portion of the seal ring 38 on the exhaust passage 43a side. Is not exposed to the high-temperature exhaust gas, so that the durability of the seal ring 38 is improved.
[0031]
Furthermore, since the seal ring 38 is made of silicon rubber, the silicon rubber is excellent in at least heat resistance and corrosion resistance, so that the durability of the seal ring 38 is further improved. In particular, when there is no seal ring 38, the gap t of the rubber sleeve 35 is exposed to high-temperature exhaust gas. Therefore, the entire rubber sleeve 35 needs to be made of silicon rubber having excellent heat resistance and corrosion resistance. However, the cost can be reduced because the rubber sleeve 35 may be formed of an inexpensive nitrile rubber or the like and only the seal ring 38 may be formed of silicon rubber. The seal ring 38 is not necessarily made of silicon rubber as long as it has at least heat resistance and corrosion resistance.
[0032]
Furthermore, since the elastic ring 39 compression-molds the stainless steel wire to give elasticity and rubber bite, the stainless steel wire is excellent in at least heat resistance and corrosion resistance. Become more improved. The elastic ring 39 can more tightly close the gap t by the elasticity of the spherical portion 39a. Furthermore, since a part of the seal ring 39 enters into the minute gap of the stainless steel wire between the spherical portion 39a and the flat ring-shaped portion 39b of the elastic ring 39 and the biting property is improved, the elastic ring 39 may fall off. Installation is reliable.
[0033]
In addition, since the seal ring 38 is vulcanized and formed on the elastic ring 39, the seal ring 38 and the elastic ring 39 are integrated, so that parts management and handling during assembly become easy.
[0034]
As shown in FIG. 8, the downstream end of the muffler 44 is not directly connected to the inlet 45a of the water lock 45, but is connected via a rubber hose 46, so that the muffler 44, the water lock 45, It is designed to absorb bending and vibrations. Further, by discharging the cooling water flowing through the cooling water passage 44b of the muffler 44 into the rubber hose 46, the rubber hose 46 is cooled to prevent the exhaust gas from rising in temperature. Reference numeral 47 denotes a pipe tail for preventing the cooling water discharged from the cooling water passage 44b from flowing back into the collective exhaust passage 44a of the muffler 44.
[0035]
Since the rubber hose 46 has a relatively long shape, if the rubber hose 46 vibrates due to vibration (pulsation) of the engine 20, vibration due to the vibration may be transmitted to the hull 2 and become noise.
[0036]
Therefore, a synthetic resin or metal hard cover member (outer cylinder) 48 is fitted to the outer periphery of the rubber hose 46 excluding the upstream portion 46a and the downstream portion 46b necessary for absorbing vibration. The vibration of the rubber hose 46 is restrained by the cover member 48, and vibration due to the vibration of the rubber hose 46 can be suppressed.
[0037]
Protrusions 46 c and 46 d are formed on the outer circumferences of the upstream portion 46 a and the downstream portion 46 b of the rubber hose 46, and a notch 48 a is formed at the upstream end of the cover member 48. When the upstream end of the cover member 48 is fitted from the downstream end of the rubber hose 46, the notch 48a engages with the projection 46c, so that the upstream side of the cover member 48 is positioned and at the same time rotates with respect to the rubber hose 46. At the same time, the downstream end of the cover member 48 gets over the protrusion 46d, so that the downstream side of the cover member 48 is positioned.
[0038]
As shown in FIG. 9, a fuel rail 51 is attached to the throttle body 50 of the engine 20 in the intake box 41 installed at the top of the engine 20, and fuel is supplied from the fuel rail 51 to the fuel injection nozzle 52. The supply is distributed.
[0039]
The inlet pipe portion 51 a of the fuel rail 51 protrudes outside from the through hole 41 a on the side wall of the intake box 41, and a fuel hose 53 is inserted and connected to the outer periphery and fixed by a clamp 54.
[0040]
Conventionally, the inlet pipe portion 51a of the fuel rail 51 penetrates a grommet attached to the through hole 41a of the intake box 41 and is watertightly sealed. However, the fuel rail 51 on the engine 20 side and the intake box 41 side are closed. Since the vibration system is different from that of the grommet, a bending stress may act on the inlet pipe portion 51a of the fuel hose 52 that is rigidly fixed to the grommet.
[0041]
Therefore, the grommet is omitted, and the inlet pipe portion 51a of the fuel rail 51 is loosely fitted in the through hole 41a of the intake box 41, and extends in the direction of the fuel hose 53 to the side wall near the through hole 14a of the intake box 41. A base portion of the existing stay 55 is fixed with a bolt 56, and a fuel hose 53 slightly behind the clamp 54 is fixed to a tip portion of the stay 55 with a U-shaped metal fitting 57. The stay 55 and the U-shaped bracket 57 firmly fix the fuel hose 53 so as not to come off from the inlet pipe portion 51 a of the fuel rail 51.
[0042]
Further, the tip of the flexible boot 58 sandwiched and fixed between the base of the stay 55 and the side wall of the intake box 41 is fixed to the outer periphery of the inlet pipe portion 51 a of the fuel rail 51 with a clamp 59. Thus, the through hole 41a is sealed in a watertight manner.
[0043]
With this configuration, the inlet pipe 51a of the fuel rail 51 is loosely fitted into the through hole 41a of the intake box 41 and the fuel hose 53 is fixed to the stay 55 of the intake box 41 with the U-shaped bracket 57. The vibration of the fuel rail 51 on the engine 20 side and the stay 55 on the intake box 41 side are absorbed by the deflection of the fuel rail 51 between the fuel pipe 51 and the inlet pipe portion 51 a of the fuel rail 51. Bending stress does not act on the tube portion 51a. Further, since the through hole 14 a is sealed watertight by the boot 58, water does not enter the intake box 41.
[0044]
【The invention's effect】
As is apparent from the above description, the present invention has a heat insulating rubber seal ring that tightly closes the gap between the exhaust pipe split ends. Since the gap portion is not exposed to the high-temperature exhaust gas, the durability of the rubber sleeve is improved.
[0045]
Further, if the elastic ring made of a heat-resistant metal is attached to the exhaust passage side of the seal ring ( Claim 1 ), the elastic ring closes the gap portion on the exhaust passage side. Since the portion on the exhaust passage side is not exposed to the high-temperature exhaust gas, the durability of the seal ring is improved.
[0046]
Further, when the seal ring is made of silicon rubber (Claim 3 ), since the silicone rubber is excellent in at least heat resistance and corrosion resistance, the durability of the seal ring is further improved and the entire rubber sleeve is made of silicon rubber. The cost is lower than when it is made of rubber.
[0047]
Furthermore, when the elastic ring is formed by compression-molding stainless steel wire to give elasticity and rubber bite (Claim 4 ), the stainless steel wire is excellent in at least heat resistance and corrosion resistance. , The durability of the seal ring is further improved, and the gap portion can be closed more tightly by elasticity, and the seal ring gets into the gap of the stainless steel wire and the biting property is improved, so the installation of the elastic ring is ensured Become.
[0048]
Further, when the seal ring is vulcanized and formed on the elastic ring (Claim 5 ), handling of the seal ring and the elastic ring becomes easy.
[Brief description of the drawings]
FIG. 1 is a side view of a jet propulsion boat.
FIG. 2 is a plan view of a jet propulsion boat.
FIG. 3 is a perspective view of an engine.
FIG. 4 is a side view of the engine.
FIG. 5 is a plan view of the engine.
FIG. 6 is a front view of the engine.
7A is an enlarged view of a main part of FIG. 6, and FIG. 7B is an enlarged view of a main part of FIG.
8A and 8B are rubber hoses, where FIG. 8A is a plan view and FIG. 8B is a side sectional view.
9A and 9B are a fuel rail and a fuel hose of the intake box, where FIG. 9A is a plan sectional view of the main part, and FIG. 9B is a sectional view taken along line AA of FIG.
[Explanation of symbols]
1 water jet propulsion boat 20 engine 30 jet propulsion machine 35 rubber sleeve 38 seal ring 39 elastic ring 43 exhaust pipe 44 muffler t clearance

Claims (5)

In a water jet propulsion boat that propels a jet generated by a jet propulsion device driven by an engine by jetting from a jet nozzle,
The middle of the exhaust pipe of the engine is divided in the length direction, and the divided end portions are connected with a rubber sleeve with a gap therebetween, and a heat insulating rubber seal ring is fitted into the gap, and the seal ring An exhaust system for an engine for water jet propulsion boats, wherein a heat-resistant metal elastic ring is attached to the exhaust passage side of the water jet propulsion boat. In a water jet propulsion boat that propels a jet generated by a jet propulsion device driven by an engine by jetting from a jet nozzle,
A middle portion of the exhaust pipe of the engine is divided into a first exhaust pipe and a second exhaust pipe in the longitudinal direction, and a downstream end portion of the first exhaust pipe and an upstream end portion of the second exhaust pipe are spaced apart from each other. An exhaust device for an engine for water jet propulsion boats , which is connected with a rubber sleeve and is fitted with an L-shaped heat insulating rubber seal ring in a side view . The exhaust system for a water jet propulsion boat engine according to claim 1 or 2, wherein the seal ring is made of silicon rubber . 2. The exhaust system for an engine for water jet propulsion boat according to claim 1, wherein the elastic ring is formed by compression molding a stainless steel wire to give elasticity and rubber biting property . The exhaust system for a water jet propulsion boat engine according to claim 1 or 4, wherein a seal ring is vulcanized and formed on the elastic ring .

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