OUTBOARD MOTOR

Abstract

An outboard motor can be mounted on a transom plate of a hull, and can have an engine disposed in an upright position in a cowling so that a crankshaft thereof extends generally vertically during cruising. A surge tank can be located on the hull side of the engine in the cowling, and a mounting portion for an electric component can be provided on a front face of the surge tank.

Description

PRIORITY INFORMATION

This application is based on and claims priority to Japanese Patent Application No. 2005-114817, filed Apr. 18, 2006, the entire contents of which is hereby expressly incorporated by reference.

BACKGROUND OF THE INVENTIONS

1. Field of the Inventions

The present inventions relate to outboard motors, and more particularly, to outboard motors which have an engine disposed in an upright position so that the crankshaft thereof extends generally vertically during cruising.

2. Description of the Related Art

Outboard motors have long been known in the marine propulsion arts. One commonly used design is one in which the crankshaft of the engine in the outboard motor extends generally vertically.

In more recent designs, a surge tank can be provided in an intake passage of the engine located in front of the engine (the propeller side is defined as the rear side). Additionally, an electric component such as an engine control unit (ECU) can be mounted in front of the surge tank in the cowling. Such an outboard motor design is disclosed in Japanese Patent Document JP-A-Hei 9-88623.

SUMMARY OF THE INVENTIONS

An aspect of at least one of the inventions disclosed herein includes the realization that in the outboard motor described in JP-A-Hei 9-88623, there are constrains on the assembly because the electric component must be attached after the intake manifold and the surge tank have been connected because the electric component is attached to a member integrated with an intake manifold and the surge tank. Also, unless the electric component is removed, the surge tank or the intake manifold cannot be removed since the electric component interferes with the removal of them.

Thus, in accordance with at least one embodiment, an outboard motor can comprise a cowling, an engine disposed in an upright position in the cowling such that a crankshaft of the engine thereof extends generally vertically during cruising, a surge tank located on the hull side of the engine in the cowling, and a mounting portion for an electric component provided on a front face of the surge tank.

In accordance with at least another embodiment, an outboard motor can comprise a cowling, an engine disposed in the cowling, a surge tank located on the hull side of the engine in the cowling, and a mounting portion configured to connect with an electric component provided on a front face of the surge tank

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features of the inventions disclosed herein are described below with reference to the drawings of the preferred embodiments. The illustrated embodiments are intended to illustrate, but not to limit the inventions. The drawings contain the following Figures.

FIG. 1 is a schematic side elevational view of an outboard motor in accordance with an embodiment.

FIG. 2 is an enlarged schematic side elevational view of the outboard motor of FIG. 1 illustrating the configuration of an engine within the outboard motor.

FIG. 3 is a schematic top plan view illustrating the configuration of the engine of the outboard motor of FIG. 1.

FIG. 4 is a schematic front elevational view of the outboard motor of FIG. 1.

FIG. 5 is a partial sectional and top plan view of a portion of the induction system of the outboard motor of FIG. 1.

FIG. 6 is a partial schematic sectional and side elevational view of the induction system of the outboard motor of FIG. 1.

FIG. 7 is a cross-sectional view illustrating an attachment of an electric component a surge tank of the induction system.

FIG. 8 is a top plan view of an exhaust guide member of the outboard motor of FIG. 1.

FIG. 9 is an enlarged plan view of a part of the exhaust guide.

FIG. 10 is a cross-sectional view taken along the line X-X of FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The embodiments disclosed herein are described in the context of a small watercraft powered by an outboard motor because the embodiments disclosed herein have particular utility in this context. However, the embodiments and inventions herein can also be applied to other boats having other types of propulsion units as well as other types of vehicles.

In the following description, the front side of the outboard motor 1 is defined as hull side, the rear side of the outboard motor 1 indicates the side opposite the hull side, and a direction perpendicular to a horizontal direction is defined as vertical direction.

As shown in FIG. 1, an outboard motor 1 can have a propulsion unit 2 having a housing portion consisting of a cowling 3, an upper case 4 and a lower case 5. An engine 10 can be housed in the cowling 3 on the upper side with its crankshaft 10a extending vertically, and a propeller 6 which can be rotatably driven by the engine 10, can be attached to the lower case 5 on the lower side.

The engine 10 can be disposed with the crankshaft 10a disposed on the hull side of the engine 10 and with its cylinders 10b on the opposite side from the hull side. A power transmission mechanism 11 and an exhaust passage (not shown) extending from the engine 10, and so on, can be housed in the upper case 4 in the middle and the lower case 5. The propeller 6 can be rotatably driven by the engine 10 via the power transmission mechanism 11. The power transmission mechanism 11 can be constituted of a drive shaft 12, a shift switching mechanism 13, a propeller shaft 14, and other components.

The cowling 3 can be considered as forming an engine room 15. The cowling 3 can comprise a top cowling 3a and a bottom cowling 3b. Air can be introduced into the engine room 15 through an air intake port 3a1 for the engine 10 formed through a rear part of the top cowling 3a. An exhaust guide 16 can be disposed at the upper end of the upper case 4, and the engine 10 can be secured to the top surface of the exhaust guide 16.

The bottom cowling 3b can be secured to an upper periphery of the exhaust guide 16 with bolts. The upper end of the upper case 4 can be secured to a lower periphery of the exhaust guide 16 with bolts. An apron 17 can be attached to surround an upper part of the upper case 4 and the exhaust guide 16. The top cowling 3a covering the engine 10 from above can be openably attached from above to the bottom cowling 3b secured to the exhaust guide 16, and removably joined to the bottom cowling 3b.

The outboard motor 1 can be attached to the rear end of the hull 20. The hull 20 can have a transom plate 20a to which a clamp bracket 21 can be secured. A swivel bracket 22 can be rotatably pivoted to the clamp bracket 21 by a tilt shaft 23, and the propulsion unit 2 can be pivoted to the swivel bracket 22 for rotation about a steering shaft 24.

As shown in FIG. 2 to FIG. 7, the engine 10 can be a four-cycle V-type eight-cylinder engine. However, engines having other cylinder configurations (e.g., inline, opposed, W), operating on other combustion principles (e.g., diesel, 2 stroke, rotary, etc.), and having other numbers of cylinders can also be used.

The outboard motor 1 can be mounted on the transom plate 20a for swinging movement between a cruising state in which the crankshaft 10a extends vertically and a retracted position in which the crankshaft 10a extends generally horizontally. A crankcase 31 can be joined to the front mating face of the cylinder block 30 of the engine 10, and a crankcase cover 31a can be joined to the crankcase 31.

Cylinder heads 32 can be joined to the rear mating faces of the cylinder block 30, and each of the cylinder heads 32 has a cam chamber side opening covered with a head cover 33. In the cruising state, the head covers 33 and the cylinder heads 32 of the engine 10 face backward in the longitudinal direction of the hull. A flywheel 100 connected to the crankshaft 10a can be disposed on the engine 10.

In the cylinder block 30, right and left cylinders 10b are formed with their axes forming a V-bank and extending toward the crankshaft 10a. In each cylinder head 32, intake valve openings 32a and exhaust valve openings 32b are formed for each cylinder, and each of the intake valve openings 32a and the exhaust valve openings 32b can be communicated with its corresponding combustion chamber 32d in the V-bank.

Each of the exhaust valve openings 32b can be communicated with its corresponding one of exhaust manifolds 34 through its corresponding exhaust port 32c extending to the V-bank, and exhaust gas can be discharged into the water below the engine through exhaust manifolds 34.

Each of the intake valve openings 32a opens in a side wall of its corresponding cylinder head 32 through its corresponding intake port 32e. Each of the intake ports 32e can have an external connecting opening 32f which can be connected to its corresponding one of intake manifolds 36. The intake ports 32e and the intake manifolds 36 can form curved portions 39 extending forward toward the hull from the intake valve openings 32a in a generally arcuate form, and the curved portions 39 can be connected to a surge tank 200 to form intake passages A extending forward.

A throttle body 37 including a throttle valve 37a can be connected to the surge tank 200. An intake silencer 38 can be connected to the upstream side of the throttle body 37. The intake silencer 38, which can be located in front of the engine 10, can be of a size extending almost across the entire width of the cowling 3 and can have an intake opening 38a through which air can be introduced.

The surge tank 200, which can consist of a first surge tank 200a and two second surge tanks 200b, can be of a vertically elongated shape corresponding to the intake manifolds 36 formed by aluminum die-casting and has a prescribed capacity. However, other configurations can also be used.

Each of the intake manifolds 36 connected to the surge tank 200, can have long intake pipes 36a and short intake pipes 36b. The first surge tank 200a can be located in front, that is, on the hull side, of the engine 10, and the first surge tank 200a can be communicated with each of the long intake pipes 36a. Each of the long intake pipes 36a can be communicated with the intake port 32e of its corresponding cylinder 10b. The intake ports 32e can be formed on the outside of the cylinder banks of the V-type engine 10.

The two second surge tanks 200b can be communicated with the first surge tank 200a and located along the inside, that is, the engine side of the long intake pipes 36a. The two second surge tanks 200b on both sides of the first surge tank 200a can be communicated with each other to ensure a larger capacity. Also, in the V-type engine, the long intake pipes 36a are located outside the cylinder banks, and dead spaces are formed among the cylinder banks, the crankcase 31 and the long intake pipes 36a. Thus, the two second surge tanks 200b extend from the crankcase cover 31a to a midportion of the crankcase 31 to ensure the capacities of the second surge tank 200b without increasing the size of the outboard motor 1.

Each of the short intake pipes 36b extends into its corresponding second surge tank 200b, and can be located on the inside, that is, the engine side, of an intermediate portion of its corresponding long intake pipe 36a. Each of the short intake pipes 36b can also have an opening 200c communicated with the second surge tank 200b. Each of the short intake pipes 36b can also be provided with an on-off valve 201 for opening and closing the short intake pipe 36b at its opening 200c to the long intake pipe 36a.

The on-off valves 201 can be attached to their corresponding one of valve shafts 202 extending vertically, and an actuator 203 can be disposed at the upper end of each of the valve shafts 202. The valve shafts 202 can be rotated by the actuators 203 to open and close the openings 200c with the on-off valves 201.

Since the actuators 203 are located coaxially with the valve shafts 202 for the on-off valves 201, the number of parts can be small and the costs can be reduced. Also, since the actuators 203 can be directly connected to the valve shafts 202, the reliability of operation can be improved.

In some embodiments, the on-off valves 201 are butterfly-type valves and can be connected to their corresponding valve shafts 202 extending along the crankshaft 10a. Driving motors used as the actuators 203 at the upper ends of the valve shafts 202 can be negative pressure diaphragms, DC motors, stepping motors or the like. Although the actuators 203 are located immediately above the on-off valves 201, they can also be located immediately below the on-off valves 201 and coaxially with the valve shafts, or other locations.

When the actuators 203 are located immediately above the on-off valves 201 as described above, the actuators 203 can be disposed in a dead space surrounded by the uppermost intake manifold 36, the flywheel 100, and the top cowling 3a. When the actuators 203 are located immediately below the on-off valves 201, the actuators 203 can be disposed in a dead space between the lowermost intake manifold 36 and the bottom cowling 3b. In either case, the actuators 203 can be installed without increasing the external dimensions of the cowling 3.

The engine 10 can be provided with an electric component 300 such as a controller and an electric auxiliary component 301 including a relay and a fuse. However, other electric devices can also be considered as the “electric component”.

The electric component 300, which can be attached to an upper central portion of the front wall of the surge tank 200 and located in the cowling 3, can receive detection values from sensors (not shown) such as an engine rotational speed sensor, a hull speed sensor, a throttle opening sensor, an intake pressure sensor, an O2 sensor and so on. The electric component 300 can be configured to control the fuel injection amount, the injection timing and the ignition timing based on the detection values and according to various operation control maps incorporated therein. Also, the electric component 300 can be configured to control the actuators 203 to open and close the openings 200c with the on-off valves 201. The electric auxiliary component 301 including a relay and a fuse can be attached to an upper right portion of the front wall of the surge tank 200 and located in the cowling 3.

By controlling the actuators 203 to open or close the openings 200c with the on-off valves 201, for example, to open the on-off valves 201 in the high-speed operation range and close the on-off valves 201 in the low- and intermediate-speed operation range, the intake pipe length can be selected between a length suitable for low- and intermediate-speed operation and a length suitable for high-speed operation. In other words, an intake pipe length suitable for the operating condition of the engine 10 can be obtained. Therefore, an inertia supercharging effect can be achieved and target torque characteristics can be obtained in all the operating ranges of the engine 10.

The open/close control of the on-off valves 201 can be performed based on the engine rotational speed and the load although it can also depend on the operating range, and the open/close speed of the on-off valves 201 can be arbitrarily set depending on the operating range.

Since the second surge tanks 202 are located along the engine side of the long intake pipes 36a as described above, the curvature of the long intake pipes 36a can be minimum. Also, since the first surge tank 200a located on the hull side of the engine 10 has less restrictions in shape than the intake manifolds 36, the gap between the long intake pipes 36a and the engine 10 can be used to the maximum extent for the surge tank 200 and the distance between the surge tank 200 and the engine 10 can be narrowed. As a result, the outboard motor 1 can be prevented from increasing in size.

Also, since the on-off valves 201 for opening and closing the short intake pipes 36b can be located on the inside, that is, the engine side, of the long intake pipes 36a, the actuators 203 for driving the on-off valves 201 can be located on the engine side of the outside of the long intake pipes 36a as viewed in a top plan view. Therefore, it can be possible to prevent the actuators 203 from protruding to the extent that the outboard motor 1 can be increased in size, and the effective pipe length of the intake pipes can be changed with a simple structure without increasing the size of the outboard motor.

Also, as shown in FIG. 5, dead spaces K3 and K4 are formed between the cylinder block 30 of the engine 10 and the right and left long intake pipes 36a as viewed in a top plan view. A large-size electric component 400, such as a starter motor, as an auxiliary component, can be disposed in the dead space K3, and a fuel system component 401 can be disposed in the dead space K4. Since the dead spaces K3 and K4 between the engine 10 and the long intake pipes 36a are used effectively to dispose auxiliary components, the outboard motor 1 can be prevented from increasing in size.

Fuel injection valves 40 for each cylinder can be inserted into the portions of the cylinder heads 32 corresponding to the intake ports 32e. Each fuel injection valve 40 can have an injection nozzle facing its corresponding combustion chamber 32d, and cylindrical fuel supply rails 41 which can extend along the crankshaft 10a, can be located outside the cylinder heads 32.

A fuel supply device 50 for supplying fuel to the fuel injection valves 40 can be constituted as follows: a fuel filter 57, a low-pressure primary pump 52 housed in a sealed container 58 for supplying fuel, and a vapor separator 53 can be attached to a front part of a side wall of the engine 10.

In the fuel supply device 50, fuel in a fuel tank 55 mounted on the hull can be supplied to the vapor separator 53 through a low-pressure fuel pipe 54a, the fuel filter 57, a low-pressure fuel pipe 54b, and a primary pump 52 by driving the low-pressure primary pump 52. Excessive fuel discharged from a delivery port 52a of the primary pump 52 can be returned to the side of a suction port 52c of the primary pump 52 through a return passage 52b.

The fuel can be supplied to a high-pressure secondary pump 42 through a fuel pipe 56 by driving the primary pump 52 incorporated in the vapor separator 53. The fuel pressurized by the secondary pump 42 can be supplied to the upper ends of the right and left fuel supply rails 41 through a high-pressure fuel pipe 43 and right and left branch hoses 44. Then, while the injection nozzles of the fuel injection valves 40 are opened, the fuel can be injected into the combustion chambers 32d. Thus, the present fuel injection system can be considered as a “direct” fuel injection system. However, other types of fuel injection systems can also be used, such as, for example, induction injection systems in which fuel is injected into air traveling through the induction system of the engine.

A canister 60 can be fixedly attached to the vapor separator 53. The canister 60 can be made up of a case 60a directly connected to the vapor separator 53 and filled with an adsorptive activator 60b such as activated charcoal. The vapor in the vapor separator 53 flows into the canister 60, and fuel in the vapor can be adsorbed therein. The air separated from fuel by adsorption can be discharged into the cowling 3 through a discharge pipe 61. The canister 60 can be located below the left intake manifold 36, and the vapor separator 53 and the canister 60 constituting the fuel system component 401 can be disposed in the dead space K4 formed on the left side of the cylinder block 30 by the V-bank in a compact manner as shown in FIG. 2, FIG. 4 and FIG. 5.

The fuel filter 57 can be located on the opposite side of the cylinder heads 32 with respect to the crankshaft 10a of the engine 10 in the cowling 3 consisting of the top cowling 3a and the bottom cowling 3b. The fuel filter 57 can have a main body 57a, a cap 57b and a filter 57c, and the main body 57a can be fixedly fastened to a bracket 59. The bracket 59 can be secured to the hull side of the surge tank 200.

The main body 57a can have a recess with female threads and the cap 57b can have a mounting portion with male threads so that the cap 57b can be removably attached to the main body 57a by a thread structure. The main body 57a can have a supply port 57a2 and a discharge port 57a3. The low-pressure fuel pipe 54a can be connected to the supply port 57a2 and the low-pressure fuel pipe 54b can be connected to the discharge port 57a3.

The fuel filter 57 can be covered with at least a heat insulating material 70. The heat insulating material 70 can have a shape consistent with the shape of the fuel filter 57. The heat insulating material 70 can consist of a plurality of portions. For example, the heat insulating material 70 can comprise a portion 70a covering the main body 57a and a portion 70b covering the cap 57b. The heat insulating material 70 can be made of a foamed rubber, however, other materials can also be used.

The portion 70a covering the main body 57a can be shaped in advance into a shape consistent with the external shape of the main body 57a. Similarly, the portion 70b covering the cap 57b can be shaped in advance into a shape consistent with the external shape of the cap 57b.

Since the fuel filter 57 can be covered with at least the heat insulating material 70, the fuel filter 57 can be prevented from being heated by the engine 10 and the fuel therein can be prevented from being evaporated. Also, the heat insulating material 70 can have a shape consistent with the shape of the fuel filter 57. Since the heat insulating material 70 can be consistent with the filter shape, a gap is unlikely to be formed between the fuel filter 57 and the heat insulating material 70. Therefore, heat-insulating efficiency can be improved.

In addition, the heat insulating material 70 can comprise a plurality of portions and the fuel filter 57 can be covered with the plurality of portions. Thus, the portion 70a for the main body 57a and the portion 70b for the cap 57b can be easily attached to the main body 57a and the cap 57b, respectively. Also, when the cap 57b is removed from the main body 57a to clean the filter 57c or replace the filter 57c with new one, the heat insulating material 70 can be easily attached to the fuel filter 57. Therefore, the fuel filter 57 can be easily assembled, and the work for replacement or maintenance thereof can be improved.

Also, at the time of such maintenance, since the fuel filter 57 can be located in the hull side of the engine 10 in the cowling 3, a worker can easily remove the top cowling 3a from the bottom cowling 3b and attach the top cowling 3a to the bottom cowling 3b from the hull side. Therefore, the fuel filter 57 can be easily assembled, and the work for replacement or maintenance of the fuel filter 57 can be improved.

In addition, since the fuel filter 57 can be located on the opposite side of the cylinder heads 32 with respect to the crankshaft 10a of the engine 10 in the cowling 3, the fuel filter 57 can be apart from the exhaust manifolds 34 extending from the cylinder heads 32 and prevented from being heated more reliably.

In the engine room 15, air X introduced through the air intake port 3a1 and air Y heated by the engine 10 flow to the intake opening 38a of the intake silencer 38. However, since the fuel filter 57 can be located below the intake opening 38a of the engine 10 opening in the cowling 3, where it is not affected by the flow of the air Y, the fuel filter 57 can be prevented from being heated.

In some embodiments, at least a part of the fuel pipe 54 can be connected to the fuel filter 57, that is, the fuel pipes 54a and 54b can also be covered with heat insulating materials 71 and 72, respectively. The fuel pipe 54a can extend through a front right part 3b11 of the bottom cowling 3b into an inner right part of the bottom cowling 3b, extend in a curve in the vicinity of and below the surge tank 200, can be bent upward from a position below the fuel filter 57, and can be connected to the supply port 57a2 from the left side of the fuel filter 57. The fuel pipe 54b can be connected to the discharge port 57a3 on the right side of the fuel filter 57, extend downwardly from the right side of the fuel filter 57 along the fuel filter 57, extend leftward below the fuel filter 57, and can be connected to the primary pump 52 housed in the sealed container 58.

As shown in FIG. 2 and FIG. 4, since the low-pressure fuel pipe 54a for supplying the fuel in the fuel tank 55 mounted on the hull and the low-pressure fuel pipe 54b from the fuel filter 57 to the primary pump 52 can be installed around the fuel filter 57 using a dead space K2 below the surge tank 200, and since the low-pressure fuel pipe 54a for supplying the fuel in the fuel tank 55 mounted on the hull and the low-pressure fuel pipe 54b from the fuel filter 57 to the primary pump 52 can be covered with the heat insulating materials 71 and 72, respectively, not only the fuel filter 57 but also at least some part of the fuel pipe 54 can prevent the fuel therein from being heated. For example, the section of the fuel pipe 54 up to the low-pressure primary pump 52 can be covered with the heat insulating materials 71 and 72. Since a negative pressure can be produced and the fuel tends to be evaporated in the fuel pipes 54a and 54b as well as in the fuel filter 57 when the low-pressure primary pump 52 is driven, the heat insulating materials 71 and 72 covering the fuel pipes 54a and 54b prevent the fuel therein from being heated more reliably.

The heat insulating materials 71 and 72, as well as the heat insulating material 70, can be made of a foamed rubber, although other materials can also be used. Although water is likely to enter the cowling 3, even if water enters, their heat insulating properties and durability are not deteriorated. In addition, the heat insulating materials 70, 71 and 72 can be produced inexpensively and can be easily attached. Therefore, the heat insulating materials 70, 71 and 72 can be easily assembled, and the work for replacement or maintenance thereof can be improved.

Referring next to FIG. 2 to FIG. 4 and FIG. 7, the attachment of an electric component E is described in greater detail. In the outboard motor 1, an electric component 300 such as a controller including an IC integrated circuit, resistors, a printed circuit board, memory devices, processors, and so on, is shown as the electric component E. However, the electric component E is not limited thereto and may include electric auxiliary components such as a relay and a fuse or any other electric device. The electric component E can be housed in an electric component box 500. The electric component box 500 can comprise a box body 500a and a lid 500b. Mounting portions 500a1 and 500b1 formed respectively thereon can be removably fastened with screws 500c. The electric component E can be supported by and attached to mounting bosses 500a2 in the box body 500a.

The surge tank 200 can be made of aluminum, and formed by, for example, aluminum die-casting. Since the surge tank 200 can be made of aluminum, the surge tank 200 can be strong and lightweight.

The surge tank 200 can have four mounting portions 200f for the electric component E formed integrally therewith at top and bottom of both sides. The box body 500a can have grommets 501 at positions corresponding to the mounting portions 200f. The box body 500a can be fixed by fastening bolts 502 with the grommets 501 placed on the mounting portions 200f. Therefore, the electric component E can be attached by first attaching the box body 500a, to which the electric component E has been attached, to the surge tank 200 and then attaching the lid 500b to the box body 500a.

As described above, the surge tank 200 can be located on the hull side of the engine 10 in the cowling 3, and the electric component E can be attached to the front side of the surge tank 200. Since the surge tank 200 has the mounting portions 200f for the electric component E formed integrally therewith, there is no need for a mounting stay or the like. Therefore, the number of parts can be reduced and the number of assembly steps can be reduced.

Also, the fuel filter 57 can be located in front of, that is, on the hull side of the electric component box 500. Since the fuel filter 57 can be located in front of the electric component E as described above, the fuel filter 57 can be located apart from the engine 10 to prevent the fuel therein from being heated. In addition, maintenance of the fuel filter 57 can be carried out easily without interference of the electric component E.

In addition, since the electric component E can be housed in the electric component box 500, it is only necessary to attach the electric component box 500 to the surge tank 200. Therefore, the number of the mounting portions can be minimized and the work efficiency can be improved.

Since the electric component E can be attached by fixedly securing the electric component box 500 only on the front side of the surge tank 200 as described above, the surge tank 200 can be connected to the intake manifolds 36 after the electric component E has been attached to the surge tank 200. Therefore, the flexibility in assembly can be improved. Also, since the intake manifolds 36 can be removed from the surge tank 200 with the electric component E attached to the surge tank 200, the maintainability can be high.

In addition, since the surge tank 200 can be located between the electric component E and the engine 10, the influence of the heat from the engine 10 on the electric component E can be reduced. Also, since the front side of the surge tank 200 faces the hull, when the top cowling 3a of the cowling 3 is removed from the bottom cowling 3b for maintenance of the electric component E, the worker can easily reach the electric component E from the hull side. Therefore, the maintainability can be improved.

Referring next to FIG. 8 to FIG. 10, the constitution of the exhaust guide 16 of the outboard motor 1 is described. In some embodiments, a pair of right and left dampers 601 can be provided in a mount bracket 600, and fixing bolts 602 can be inserted through the paired right and left dampers 601. The mount bracket 600 can be located at the center in a space surrounded by a guide rib 16a of the exhaust guide 16. A mount cover 610 can be used to cover the mount bracket 600 from above and can be fixedly secured with four fixing bolts 611.

The fixing bolts 602 can extend through the swivel bracket 22 via collars 612, and can be fixedly fastened with nuts 613. The exhaust guide 16 can be thereby secured to the swivel bracket 22, making the propulsion unit 2 rotatable about the steering shaft 24.

The exhaust guide 16 can have a drive shaft through hole 16b in front of the mount cover 610 and a pair of right and left exhaust passages 16c behind the mount cover 610, that is, on the other side of the drive shaft through hole 16b with respect to the guide rib 16a.

The mount cover 610 can have a pawl 610a extending toward an exhaust passages 16c side portion 16a1 of the guide rib 16a, and a damper 630 can be interposed between the mount cover 610 and the exhaust passages 16c side portion 16a1 of the guide rib 16a. The damper 630 can be made of a rubber material or the like, although other materials can also be used. The damper 630 can also have a laterally extending portion 630a facing heads 602a of the fixing bolts 602, a backwardly extending portion 630b engaged with a recess 16a2 of the guide rib 16a, and a forwardly extending portion 630c engaged with a lower side of the pawl 610a of the mount cover 610.

When the backwardly extending portion 630b is engaged with the recess 16a2 of the guide rib 16a and the forwardly extending portion 630c is engaged with a lower side of the pawl 610a of the mount cover 610, the damper 630 can be fixed with the laterally extending portion 630a facing the heads 602a of the fixing bolts 602.

Even if the paired right and left dampers 601 of the mount bracket 600 are displaced largely when the outboard motor 1 is driven in reverse or hit some driftwood, the heads 602a of the paired right and left fixing bolts 602 abut against the laterally extending portion 630a of the damper 630 to protect the guide rib 16a of the exhaust guide 16 and prevent generation of unpleasant noise.

As described above, when the damper 630 is inserted between the guide rib 16a and the mount cover 610 with the backwardly extending portion 630b engaged with the recess 16a2 of the guide rib 16a and the forwardly extending portion 630c engaged with a lower side of the pawl 610a of the mount cover 610, the laterally extending portion 630a faces the heads 602a of the fixing bolts 602 and the damper 630 can be attached easily. Also, the forwardly extending portion 630c of the damper 630 can be engaged with a lower side of the pawl 610a of the mount cover 610 and can be prevented from coming off upwardly, and the backwardly extending portion 630b can be engaged with the recess 16a2 of the guide rib 16a to prevent the damper 630 from moving laterally. In addition, since the damper 630 has the laterally extending portion 630a formed integrally therewith and facing the heads 602a of the fixing bolt 602, the number of parts can be reduced.

The present inventions are applicable to outboard motors in which an engine is disposed in an upright position so that the crankshaft thereof extends generally vertically during cruising, and allows an electric component to be attached easily with a simple structure.

Although these inventions have been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present inventions extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the inventions and obvious modifications and equivalents thereof. In addition, while several variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combination or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above.

PRIORITY INFORMATION

This application is based on and claims priority to Japanese Patent Application No. 2006-114817, filed Apr. 18, 2006, the entire contents of which is hereby expressly incorporated by reference.

Claims

1. An outboard motor comprising a cowling, an engine disposed in an upright position in the cowling such that a crankshaft of the engine thereof extends generally vertically during cruising, a surge tank located on the hull side of the engine in the cowling, and a mounting portion for an electric component provided on a front face of the surge tank.

2. The outboard motor according to claim 1, wherein the mounting portion for the electric component is formed integrally with the surge tank.

3. The outboard motor according to claim 1, wherein the surge tank is made of aluminum.

4. The outboard motor according to claim 2, wherein the surge tank is made of aluminum.

5. The outboard motor according to claim 1 additionally comprising an electric component box, the electric component being housed in the electric component box.

6. The outboard motor according to claim 2 additionally comprising an electric component box, the electric component being housed in the electric component box.

7. The outboard motor according to claim 3 additionally comprising an electric component box, the electric component being housed in the electric component box.

8. The outboard motor according to claim 1 additionally comprising a fuel filter, the fuel filter being located in front of the electric component.

9. The outboard motor according to claim 2 additionally comprising a fuel filter, the fuel filter being located in front of the electric component.

10. The outboard motor according to claim 3 additionally comprising a fuel filter, the fuel filter being located in front of the electric component.

11. The outboard motor according to claim 5 additionally comprising a fuel filter, the fuel filter being located in front of the electric component.

12. An outboard motor comprising a cowling, an engine disposed in the cowling, a surge tank located on the hull side of the engine in the cowling, and a mounting portion configured to connect with an electric component provided on a front face of the surge tank.

13. The outboard motor according to claim 12, wherein the mounting portion for the electric component is formed integrally with the surge tank.

14. The outboard motor according to claim 12 additionally comprising an electric component box, the electric component being housed in the electric component box, and the mounting portion being configured to connect with the electric component box.

15. The outboard motor according to claim 12 additionally comprising a fuel filter, the fuel filter being located in front of the electric component.