JP4219011B2 - Outboard motor air duct device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air duct device for an outboard motor disposed at the stern of a hull.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an outboard motor air duct device, for example, there is one having a structure shown in FIGS. This is because a recess 81 is provided at the rear end of the top cowling 80 having an engine storage chamber 80a formed in a substantially watertight manner, and a lid-shaped molding air duct 82 is attached so as to cover the recess 81. An engine storage chamber 80a and an expansion chamber 83 defined are formed.
[0003]
The rear wall of the molding air duct 82 is formed with four outside air inlets 82a for introducing outside air into the expansion chamber 83, and the air in the expansion chamber 83 is taken into the engine storage chamber 80a at the bottom of the recess 81. A cylindrical intake duct 84 having an air intake port 85 is formed to protrude.
[0004]
In the air duct device, the air a introduced from the outside air inlet 82a is separated into the air a and the water b in the expansion chamber 83, and the water a separated is taken into the engine storage chamber 80a from the air intake 85. On the other hand, the water droplets b separated in the expansion chamber 83 are collected at the bottom of the recess 81 and discharged from the gap 88 at the lower end mating surface of the molding air duct 82.
[0005]
When rainwater or splashes adhere to the top surface of the top cowling 80, the water droplet b is sucked into the recess 81 from the gap 89 at the upper end joint surface of the molding air duct 82 and collected at the bottom, and is discharged from the gap 88 in the same manner as described above. .
[0006]
In such an air duct device, it is required to further reduce water droplets that enter the engine storage chamber 80a from the viewpoint of preventing moisture and salt from being sucked into the engine. In order to reduce the water droplets, first, water droplets that enter the engine storage chamber 80a from the expansion chamber 83 are reduced, and second, rainwater or the like adhering to the outer surface of the top cowling 80 enters the expansion chamber 83 from the gap 89. There are two ways to reduce intrusion.
[0007]
For this reason, conventionally, the ingress of water droplets into the engine storage chamber 80a is reduced by disposing the intake duct 84 at a position away from the gap 89 or by reducing the opening area of the air intake port 85. . Further, a method is generally employed in which the opening area of the outside air introduction port 82a is increased to reduce the air flow rate during suction, thereby reducing the amount of water droplets sucked into the expansion chamber 83.
[0008]
[Problems to be solved by the invention]
However, if the opening area of the air intake port is reduced as in the conventional case, the amount of air taken into the engine storage chamber is reduced, and there is a possibility that the intake amount to the engine cannot be secured in some cases.
[0009]
In addition, when the intake duct is separated from the gap through which water droplets enter, it is difficult to set the arrangement position because of the size of the recess.
[0010]
Furthermore, when increasing the opening area of the conventional outside air inlet, there is a problem that the degree of freedom in design is limited.
[0011]
The present invention has been made in view of the above-described conventional situation, without causing a problem of the intake air amount to the engine and a problem of the arrangement position of the intake duct, and without causing a design problem of the outside air inlet, An object of the present invention is to provide an air duct device for an outboard motor that can prevent water droplets from entering the engine storage chamber.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, a recess is formed in a top cowling having an engine storage chamber formed in a substantially watertight manner, a molding air duct is disposed so as to cover the recess, and the engine storage is performed by the molding air duct and the recess. An outboard motor formed with an expansion chamber separated from the chamber, forming an outside air introduction port for introducing outside air into the expansion chamber, and forming an air intake port for taking the air in the expansion chamber into the engine storage chamber In the air duct apparatus, a groove is formed at a peripheral edge of the recess and at a position spaced forward and left and right from the air intake port so as to surround at least a front side portion of the air intake port. , with the outside and a stepped portion periphery is stepped formed on the recess, constituted by an inner peripheral edge standing on the ribs of the step portion at a position away from the air inlet Is allowed, the sealing member is attached to the upper edge of the rib is characterized in that is brought into contact with the molding air duct to the seal member.
[0013]
The invention of claim 2 is characterized in that, in claim 1, the concave groove communicates with the left and right mating surfaces of the top cowling and the molding air duct .
[0014]
The invention of claim 3 is characterized in that, in claim 1 or 2, the concave groove located higher than the air intake port is inclined along the slope of the mating surface of the top cowling and the molding air duct. Yes.
[0016]
[Effects of the invention]
According to the first aspect of the present invention, the concave groove is formed on the periphery of the concave portion constituting the expansion chamber so as to surround the front side portion of the air intake port, and the concave groove communicates with the outside at a position away from the air intake port. As a result, water droplets adhering to the upper surface of the top cowling flow into the concave groove from the mating surface portion, and are discharged to the outside through the concave groove. As a result, it is possible to prevent water droplets from flowing into the expansion chamber from the outside, thereby preventing water droplets from entering the engine storage chamber.
[0017]
In addition, since water droplets adhering to the top cowling are discharged to the outside through the recessed groove, the amount of water entering from the outside air introduction port is reduced, and the absolute amount of water sucked into the expansion chamber from the outside air introduction port is reduced accordingly. From this point, water droplets can be prevented from entering the engine storage chamber.
[0018]
As a result, the opening area of the air intake port can be increased, and the intake amount to the engine can be secured. Further, the setting for the arrangement position of the intake duct can be made unnecessary, the opening area of the outside air introduction port can be reduced, and the degree of freedom in designing the outside air introduction port can be improved.
[0019]
Further, the concave groove is composed of a stepped portion formed on the periphery of the recessed portion and a rib standing on the inner periphery of the stepped portion, and a seal member is mounted on the upper edge of the rib, Since the molding air duct is brought into contact with the seal member, the space between the expansion chamber and the concave groove can be sealed in a watertight manner, and there is an effect that water droplets can be reliably prevented from entering the expansion chamber.
[0020]
In the invention of claim 2, since the concave groove communicates with the left and right mating portions of the top cowling and the molding air duct, water droplets flowing into the concave groove flow out to the outside from the left and right mating portions. Thus, it can be discharged even when the inflow of water drops is large.
[0021]
In the invention of claim 3, since the concave groove positioned higher than the air intake port is inclined along the slope of the mating surface between the top cowling and the molding air duct, the water droplets flowing into the concave groove are quickly combined. It can be discharged from the surface to the outside, and has the effect of preventing the intrusion into the expansion chamber when the concave groove is positioned higher than the air intake port.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIGS. 1 to 8 are views for explaining an air duct device of an outboard motor according to an embodiment of the present invention. FIGS. 1 to 3 are a plan view and a side view of a top cowling in which the air duct device is disposed, respectively. 4 is a plan view of the engine housed in the top cowling, FIGS. 5 to 7 are sectional views of the expansion chamber of the air duct device, and FIG. 8 is a side view of the outboard motor.
[0023]
In the figure, reference numeral 1 denotes an outboard motor. The outboard motor 1 is pivotally supported by a clamp mechanism 1a fixed to the stern 2a of the hull 2 so as to be able to swing in the vertical direction and to be able to turn in the left-right direction. .
[0024]
The outboard motor 1 has a lower mount cover 5 connected to an upper portion of a lower case 4 in which a propulsion device 3 is disposed, an apron 6 connected to the upper portion of the lower mount cover 5, and a bottom mounted on the apron 6. A cowling 7 including a cowling 7a and a top cowling 7b is connected.
[0025]
An engine 10 that rotationally drives the propulsion unit 3 is mounted in the cowling 7. The engine 10 is stored in a watertight engine storage chamber 9 formed by a bottom cowling 7a and a top cowling 7b. Yes.
[0026]
The engine 10 is an in-cylinder fuel injection type V-type two-cycle engine, and as shown in FIG. 4, the crankshaft 11 is arranged vertically so as to be substantially vertical when sailing. The engine 10 includes a cylinder block 12 having left and right cylinder bores forming a V bank at the rear of the hull, left and right cylinder heads 13 and 13 fastened to a rear face of the cylinder block 12, And a crankcase 14 fastened to the front mating surface of the cylinder block 12. Reference numeral 15 denotes a spark plug.
[0027]
A throttle body 17 is connected to the front surface of the crankcase 14 via an intake manifold 16, and a hollow box-like silencer 18 common to each cylinder is connected to the front surface of the throttle body 17. Is formed with an air suction port 18a extending in the vertical direction.
[0028]
The engine 10 is provided with an in-cylinder fuel injection device. This fuel injection device mainly includes an injector 20 that is inserted into the left and right cylinder heads 13 for each cylinder and directly injects fuel into the cylinder, an injector rail 21 that supplies fuel to each injector 20, and And a fuel pump 22 that pumps pressurized fuel to the injector rail 21.
[0029]
The fuel pump 22 is disposed at the upper end of the V bank, and a pulley 24 is attached to the rotating shaft 23 of the pump 22, and the pulley 24 is belted to a crank pulley 25 attached to the upper end of the crankshaft 11. 26 are connected to each other. Reference numeral 27 denotes a flywheel.
[0030]
The outboard motor 1 is provided with an air duct device that characterizes the present embodiment, and the air duct device has the following structure.
[0031]
On the left and right sides of the top wall 7c of the top cowling 7b with the crankshaft 11 in between, recesses 30, 30 extending in the hull front-rear direction are provided. Each of the recesses 30 extends forward from the rear end of the upper wall 7c of the top cowling 7b, and the front end 30c of the recess 30 is located on the front side of the crankshaft 11.
[0032]
The recess 30 includes an inner wall 30a and a bottom wall 30b. The bottom wall 30b includes an inclined portion 31a inclined rearwardly downward from the front end 30c, and a flat portion 31b extending substantially horizontally rearward after the inclined portion 31a. The lower portion 31c is formed in a stepped manner following the flat portion 31b, and an inclined surface 31d connected to the outer surface of the top cowling 7 is formed on the outer edge of the lower portion 31c. As a result, water droplets accumulated in the recess 30 are collected in the low portion 31c and discharged to the outside from the inclined surface 31d.
[0033]
A lid-shaped molding air duct 32 is detachably mounted on the top cowling 7b. The molding air duct 32 is formed so as to form a substantially continuous surface with the outer surface of the top cowling 7b, and a slight gap 33 is provided on the entire surface of the molding air duct 32 and the top cowling 7b. .
[0034]
The molding air duct 32 has a substantially concave shape in plan view covering the left and right recesses 30 and covering the back surface of the top cowling 7b, and is divided into the molding air duct 32 and the left and right recesses 30, respectively. The first and second expansion chambers 35 and 36 are formed.
[0035]
The first and second expansion chambers 35 and 36 are disposed on the left and right sides of the top cowling 7b with the crankshaft 11 interposed therebetween, respectively, extend forward from the rear end of the top cowling 7b, and each of the expansion chambers 35 and 36. The front end is located in front of the crankshaft 11. The first and second expansion chambers 35 and 36 are independent from each other and are separated from the engine storage chamber 9.
[0036]
A notch 32a is cut out at a portion of the molding air duct 32 corresponding to the lower portion 31c on the left and lower right edge. The notch 31a and the lower portion 31c are connected to the respective expansion chambers 35, An outside air introduction port 37 that communicates 36 with the outside is formed.
[0037]
A cylindrical intake duct 38 extending upward is formed on the bottom wall 30b of the left and right recesses 30. The expansion ducts 35 and 36, the engine storage chamber 9, and the like are formed on the upper surface of the intake duct 38. An air intake port 39 that communicates with each other is formed. The intake duct 39 is formed in a substantially rectangular shape extending from the flat portion 31b of the bottom portion 30b to the middle of the inclined portion 31a, thereby setting the opening area of the air intake port 39 large.
[0038]
Next, the waterproof structure of the air duct device will be described.
The outer surfaces of the top cowling 7b and the molding air duct 32 have gentle slopes from the rear end to the front, rear, and left and right, with the rear end as the top. It is supposed to flow down.
[0039]
A step 40 extending in the front-rear direction is formed on the upper edge of the inner wall 30 a of the left and right recesses 30, and a first rib 41 is integrally formed on the lower edge of the step 40. Yes. A first groove 41 is formed by the first rib 41 and the stepped portion 40. The front half of the groove 42 is inclined forward and downward along the slope of the top cowling 7b, and the rear half is the rear. It inclines downward and communicates with the outside through a gap 33 at the lower end joint surface of the molding air duct 32.
[0040]
A second rib 43 extending in a curved manner so as to surround the front of the intake duct 38 is integrally formed at the front end of the first rib 41, and the second rib 43 extends to the outer edge of the bottom wall 30b. It extends. A second groove 44 that communicates with the first groove 42 is formed by the second rib 43 and the front end of the recess 30. The second rib 43 is formed with a drain hole 45 for discharging water that has entered the recess 30 when the outboard motor 1 is tilted up.
[0041]
The second rib 43 is integrally formed with a third rib 46 that extends rearward along the outer edge of the bottom wall 30b. The third rib 46 is inclined rearward and downward along the mating surface of the top cowling 7b, and the rear end of the third rib 46 extends to the center of the flat portion 31b. The third rib 46 and the outer edge portion 30c of the bottom wall 30b form a third groove 47 that communicates with the second groove 44, and the third groove 47 is a gap between the left and right outer mating surfaces. 33 communicates with the outside.
[0042]
As a result, the front half of the air intake port 39 is surrounded by the first to third concave grooves 42, 44, 47. Each of the concave grooves 42, 44, 47 is located higher than the air intake port 39, and is inclined along the slope of the mating surface of the top cowling 7b.
[0043]
A sealing member 50 made of rubber or the like is attached to the upper edge of each of the ribs 41, 43, 46, and the lower surface of the molding air duct 32 is in pressure contact with the sealing member 50. Thereby, the space between the first to third concave grooves 42, 44, 47 and the first and second expansion chambers 35, 36 is sealed in a watertight manner.
[0044]
Next, the effect of this embodiment is demonstrated.
As shown in FIGS. 3 and 7, when the engine 10 is started, outside air is introduced into the first and second expansion chambers 35 and 36 from the left and right outside air introduction ports 37, and the introduced air a is supplied to the respective expansion chambers. Air 35 and 36 are separated into air and water, and the air a thus separated is taken into the engine storage chamber 9 from the left and right air intake ports 39. The air a that has entered from the left and right air intake ports 39 merges in the engine storage chamber 9, is sucked from the suction port 18 a of the silencer 18, and is supplied to the engine 10. On the other hand, the water droplets separated in the expansion chambers 35 and 36 fall on the bottom wall 30b, are collected in the low portion 31c, and are discharged to the outside from the inclined surface 31d.
[0045]
As shown in FIGS. 1 and 2, when water droplets b adhere to the upper surface portion of the top cowling 7 b due to rain water or splashes, the water droplets b are formed in the first concave groove from the gap 33 between the top cowling 7 b and the molding air duct 32. A part of the water droplet b flows into the concave groove 42 along the rear half and is discharged to the outside through the gap 33 at the lower end mating surface of the molding air duct 32. The remaining water droplet b flows along the first half of the concave groove 42 and flows into the second concave groove 44, passes through the second concave groove 44 from the third concave groove 47, and from the left and right gap 33. It is discharged outside.
[0046]
As described above, according to the present embodiment, the expansion chamber is divided into the first and second expansion chambers 35 and 36. Therefore, by reducing the size of the single expansion chamber, the portion that becomes the surplus space of the top cowling 7b is used. It becomes possible to arrange, the degree of freedom with respect to the arrangement layout can be improved, the capacity can be increased, and the water separation function can be improved.
[0047]
In the present embodiment, the first and second expansion chambers 35 and 36 are arranged on the left and right sides of the top cowling 7b with the crankshaft 11 in between, so that the injector 20, the injector rail 21, and the fuel constituting the fuel injection device It can be arranged in a balanced manner on the left and right without interfering with the pump 22 and the like, and can compensate for the lack of capacity when the fuel injection device is mounted, so it is necessary without causing an increase in the size of the cowling 7 and a deterioration in appearance. Capacity can be secured.
[0048]
In the present embodiment, the first and second expansion chambers 35, 35 are arranged so as to extend forward from the rear end of the top cowling 7 b, and the front ends of the respective expansion chambers 35, 36 are positioned in front of the crankshaft 11. Therefore, the capacity can be further increased by effectively utilizing the surplus space around the crankshaft 11 of the top cowling 7b.
[0049]
In addition, since the degree of freedom with respect to the layout of the first and second expansion chambers 35 and 36 can be improved, the degree of freedom with respect to the layout of engine components in the cowling 7 can be improved, and the efficiency in designing the layout can be improved accordingly. The entire cowling 7 can be made compact.
[0050]
In the above embodiment, the case where the first and second expansion chambers 35 and 36 are extended in the front-rear direction on the left and right sides of the upper wall 7c of the top cowling 7b has been described, but the present invention is limited to this. It is not a thing. For example, the first and second expansion chambers may be disposed in the ship width direction or in the vertical direction parallel to the crankshaft, and the first and second expansion chambers may be disposed in different directions. In short, by using the surplus space of the top cowling, the same effects as in the above embodiment can be obtained.
[0051]
According to the present embodiment, the first to third concave grooves 42, 44, 47 are formed on the periphery of the recess 30 so as to surround the front half of the air intake port 39, and the rear half of the first concave groove 42 is molded. Since the third concave groove 47 communicates with the gap 33 between the left and right mating surfaces of the top cowling 7b, the water droplets b adhering to the top cowling 7b are communicated with the gap 33 at the lower end mating surface of the air duct 32. , 44, 47 are discharged to the outside, so that the water droplet b can be prevented from entering the expansion chambers 35, 36, and thus can be prevented from entering the engine storage chamber 9. .
[0052]
Further, since most of the water droplets b adhering to the top cowling 7b are discharged to the outside through the respective concave grooves 42, 44, 47, the amount of water entering from the outside air introduction port 37 can be reduced. The absolute amount of moisture sucked into each of the expansion chambers 35 and 36 can be reduced, and from this point, water droplets can be prevented from entering the engine storage chamber 9.
[0053]
As a result, the opening area of the air intake port 39 can be increased, and the intake amount to the engine can be secured. Further, the setting for the arrangement position of the intake duct 38 can be omitted, and the layout design can be facilitated. Furthermore, the opening area of the outside air introduction port 37 can be reduced as compared with the conventional case, and the layout and design freedom of the outside air introduction port 37 can be improved.
[0054]
In the present embodiment, since each of the concave grooves 42, 44, 47 communicates with the gap 33 on the left and right mating surfaces of the top cowling 7b, the water droplet b flowing into the concave grooves 42, 44, 47 is left and right. Since the water is discharged from the gap 33 to the outside, the water droplet b can be reliably discharged even when the amount of inflow of the water droplet b is large. Also from this point, entry into the expansion chambers 35 and 36 can be prevented.
[0055]
Further, since each of the concave grooves 42, 44, 47 is inclined along the slope of the mating surface of the top cowling 7, the water droplet b flowing into the concave grooves 42, 44, 47 can be immediately discharged to the outside. Intrusion into the expansion chambers 35 and 36 when the grooves 42, 44, and 47 are positioned higher than the air intake port 39 can be reliably prevented.
[0056]
In the present embodiment, the sealing member 50 is mounted on the upper edges of the first to third ribs 41, 43, 46, and the molding air duct 32 is pressed against the sealing member 50. Between 42, 44, and 47 can be sealed in a watertight manner, and water droplets can be prevented from entering the expansion chambers 35 and 36 more reliably.
[0057]
In the above embodiment, the case where the expansion chamber is divided into the first and second expansion chambers 35 and 36 has been described. However, the present invention can be applied to a case where one expansion chamber is provided. The same effect as the above embodiment can be obtained.
[Brief description of the drawings]
FIG. 1 is a plan view of a top cowling for explaining an air duct device for an outboard motor according to an embodiment of the present invention.
FIG. 2 is a side view of the top cowling.
FIG. 3 is an enlarged side view of an expansion chamber of the top cowling.
FIG. 4 is a plan view of an engine housed in the top cowling.
FIG. 5 is a cross-sectional view of the expansion chamber of the air duct device (cross-sectional view taken along the line VV in FIG. 1).
6 is a cross-sectional view of the expansion chamber (a cross-sectional view taken along line VI-VI in FIG. 1).
7 is a cross-sectional view of the expansion chamber (a cross-sectional view taken along line VII-VII in FIG. 1).
FIG. 8 is a side view of the outboard motor.
FIG. 9 is a cross-sectional side view showing a conventional air duct device.
FIG. 10 is a plan view of a conventional air duct device.
FIG. 11 is a rear view of a conventional molding air duct.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outboard motor 9 Engine storage chamber 10 Engine 7b Top cowling 30 Recess 32 Molding air duct 35 First expansion chamber 36 Second expansion chamber 37 Outside air introduction port 39 Air intake ports 42, 44, 47 Concave groove 40 Step portions 41, 43, 46 Rib 50 Seal member

Claims (3)

An expansion chamber in which a recess is formed in a top cowling having an engine storage chamber formed substantially watertight, and a molding air duct is disposed so as to cover the recess, and the engine storage chamber is separated by the molding air duct and the recess. In the air duct device for an outboard motor, the outside air introduction port for introducing outside air into the expansion chamber is formed, and the air intake port for taking the air in the expansion chamber into the engine storage chamber is formed.
Forming a concave groove so as to surround at least a front side portion of the air intake port at a position that is a peripheral edge of the concave portion and spaced forward and left and right from the air intake port;
The concave groove is composed of a stepped portion formed on the peripheral edge of the concave portion and a rib standing on the inner peripheral edge of the stepped portion, and is communicated to the outside at a position away from the air intake port.
An air duct device for an outboard motor, wherein a seal member is mounted on an upper edge of the rib, and the molding air duct is brought into contact with the seal member. 2. The outboard motor air duct device according to claim 1, wherein the concave groove communicates with the left and right mating surfaces of the top cowling and the molding air duct. 3. An air duct device for an outboard motor according to claim 1, wherein a concave groove located at a higher position than the air intake port is inclined along a slope of a mating surface between a top cowling and the molding air duct. .

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