# Patent

## Title
Outboard motor

## Abstract

An outboard motor having an engine cover formed from a lower cover fixed to a casing and an upper cover joined to the lower cover at a first mating surface. A linear member lead-out part is formed from a case part integrally connected to the lower cover. The linear member lead-out part is closer to one side wall and projects forward from a front wall of the lower cover. A lid member is joined to the case part by a second mating surface disposed below the first mating surface. A water entrance chamber is formed in the lower cover and has front and rear walls defined by a pair of wall portions integrally provided with the lower cover while being spaced in a fore-and-aft direction. The water entrance chamber is disposed on the side on which a small gap is formed between the lid member and the lower cover.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority of Japan Application No. 2008-22997, filed Feb. 1, 2008, the entire specifications, claims and drawings of which are incorporated herewith by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an outboard motor including a vertically extending casing adapted to be supported on a hull; an engine mounted on an upper part of the casing; an engine cover covering the engine, the engine cover having a lower cover fixed to the casing and an upper cover joined to the lower cover via a first mating surface along one plane; a linear member lead-out part guiding a linear member from out of the interior of the engine cover, the linear member lead-out part having a case part that is integrally connected to the lower cover so that, among left and right side walls of the lower cover, it is closer to one side wall and projects forward from a front wall of the lower cover; and a lid member joined to the case part via a second mating surface disposed below the first mating surface.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 11-245891 discloses a conventional outboard motor in which an engine cover is formed from a lower cover fixed to a casing and an upper cover joined to the lower cover, and a linear lead-out part for guiding a linear member from out of the interior of the engine cover wherein the linear lead-out part projects forward from a front wall of the lower cover.
In the arrangement of the components for the conventional outboard motor disclosed in Japanese Patent Application Laid-open No. 11-245891, a lead-out part having an entire periphery that is integrally connected projects from the lower cover. In order to insert a linear member, such as a throttle cable or a wire harness, into the lead-out part while maintaining liquid tightness, from the viewpoint of workability, etc., it is desirable to divide the lead-out part into upper and lower portions, that is, a case part that is integral with the lower cover and a lid member joined to the case. In the disclosed arrangement, if mating surfaces of the case part and the lid member are disposed below mating surfaces of the lower cover and the upper cover, a small gap is formed between the lower cover and the lid member and there is a possibility of water entering the interior of the engine cover via the small gap when operating in turbulent waters. It is therefore necessary to take measures against the entrance of water, and it is desirable that, when taking these measures, any increase in the number of components is avoided.
SUMMARY OF THE INVENTION
The present invention has been accomplished in view of such circumstances, and it is an aspect thereof to provide an outboard motor in which a linear member lead-out part is formed by joining a case part and a lid member below mating surfaces of a lower cover and an upper cover, wherein the entrance of water under an engine cover is minimized while avoiding any increase in the number of components.
In order to at least achieve the above-discussed aspect and other aspects, according to a first feature of the present invention, there is provided an outboard motor including a vertically extending casing adapted to be supported on a hull; an engine mounted on an upper part of the casing; an engine cover covering the engine, the engine cover having a lower cover fixed to the casing, and an upper cover joined to the lower cover via a first mating surface along one plane; and a linear member lead-out part guiding a linear member from out of the interior of the engine cover. The linear member lead-out part includes a case part integrally connected to the lower cover and projecting forward from a front wall of the lower cover. A lid member is joined to the case part via a second mating surface disposed below the first mating surface. A water entrance chamber is formed in the lower cover and includes front and rear walls defined by a pair of wall portions integrally provided with the lower cover while being spaced in a fore-and-aft direction. The water entrance chamber is disposed among left and right sides of the linear member lead-out part on the side on which a small gap is formed between the lid member and the lower cover.
With the first feature of the present invention, a water entrance chamber is formed among left and right sides of the lead-out part in the lower cover so the water entrance chamber is located on the side where a small gap is formed between the lid member and the lower cover. It is possible to minimize the entrance of water into the engine cover by temporarily receiving, via the water entrance chamber, water that is about to enter the engine cover via the small gap between the lid member and the lower cover when operating in turbulent waters. Moreover, the two wall portions that define the front and rear walls of the water entrance chamber are integrally provided with the lower cover, and it is possible to minimize the entrance of water into the engine cover by using a simple structure while suppressing any increase in the number of components.
According to a second feature of the present invention, the lower cover is provided with a drain hole defined in the water entrance chamber for discharging water to the exterior, wherein the drain hole defines an opening in a bottom part of the water entrance chamber.
With the second feature of the present invention, since water that has entered the water entrance chamber is effectively discharged via the drain hole, water does not accumulate in the water entrance chamber and it is possible to more reliably suppress the entrance of water into the engine cover.
A throttle wire, shift wire, and electric wire of an embodiment described below correspond to the linear member of the present invention, and a connecting wall portion and an extended wall portion of the embodiment described below correspond to the wall portion of the present invention.
A mode for carrying out the present invention is explained below by reference to an embodiment of the present invention shown in the attached drawings.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an outboard motor intake port system according to a preferred embodiment of the present invention;
FIG. 2 is an enlarged cross-sectional view taken along line 2-2 in FIG. 1;
FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2;
FIG. 4 is an enlarged cross-sectional view taken along line 4-4 in FIG. 6;
FIG. 5 is a rear view from arrow 5 in FIG. 4; and
FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 4.



DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, an outboard motor 10 includes a stern bracket 13 clamped onto the stern of a hull 12 and a vertically extending casing 11 joined to the stern bracket 13 via a swivel shaft 14 so that the casing 11 can swing in a left-to-right direction. An engine E is mounted on an upper part of the casing 11 and is covered by an engine cover 15. Rotational power produced by the engine E is transmitted to a propeller shaft 17 that is supported on a lower part of the casing 11. A propeller 16 is attached to a rear end part of the propeller shaft 17.
The engine cover 15 is formed from a lower cover 18, which is fixed to the upper part of the casing 11, and an upper cover 19, which is joined to the lower cover 18 via a first mating surface 20. The lower and upper covers 18 and 19 are joined along a first plane PL1 that inclines upward in a forward direction. The lower cover 18 and the upper cover 19 are joined to each other by a plurality of lock levers 21.
Referring to FIGS. 2-3, a linear member lead-out part 25 for guiding a linear member, such as, for example, a throttle wire 22, a shift wire 23, an electric wire 24, and the like, from out of the interior of the engine cover 15 projects forward from a front wall of the engine cover 15. The linear member lead-out part 25 is disposed among left and right side walls of the lower cover 18, closer to the right side wall to avoid the lock lever 21 provided between the front walls of the lower cover 18 and the upper cover 19. The throttle wire 22, the shift wire 23, the electric wire 24, and the like, run in a liquid-tight manner through a grommet 26 that is attached to the linear member lead-out part 25 and are guided to the exterior.
The linear member lead-out part 25 is formed from a case part 27 and a lid member 28. The case part 27 is integrally connected to the lower cover 18 and projects forward from the front wall of the lower cover 18. The lid member 28 is joined to the case part 27 via a second mating surface 29 that is disposed below the first mating surface 20. The second mating surface 29 follows a second plane PL2 which obliquely intersects the first plane PL1.
A right side wall of the case part 27 is positioned inward of the right side wall of the lower cover 18. A connecting wall portion 31, which joins the right side wall of the case part 27 and the right side wall of the lower cover 18 at substantially right angles, is integrally provided with the lower cover 18.
The lid member 28 is secured to the case part 27 with a gasket 30 that is configured to correspond to the external shape of the lid member 28 and is disposed between the lid member 28 and the case part 27 (see FIG. 2). The lid member 28 and the gasket 30 are provided with integral first projections 28a and 30a, respectively, that abut, via the interior, against the front wall of the lower cover 18 on the left-hand side of the linear member lead-out part 25. The lid member 28 and gasket 30 are also provided with second projections 28b and 30b, respectively, that project toward the inner face of the right side wall of the lower cover 18 and overlap the connecting wall portion 31 on the right-hand side of the linear member lead-out part 25.
A gasket 32 is mounted between the lower cover 18 and the upper cover 19 in a location that is remote from a location of the linear member lead-out part 25. The gasket 32 is fitted onto the upper cover 19 side, and a flat seal face 33, which contacts the gasket 32, is formed on an upper face of a peripheral wall of the lower cover 18 in a location that is remote from a location of a portion for the case part 27. A seal member, which is not illustrated, is mounted between the upper cover 19 and the lid member 28.
Since the second mating surface 29 is positioned below the first mating surface 20, part of the lid member 28 is located below the first mating surface 20. The seal member is not located in the part between the lid member 28 and the lower cover 18, and even if the lid member 28 abuts against the lower cover 18, it is impossible to prevent a small gap from being formed between the lid member 28 and the lower cover 18.
Since the first projection 28a of the lid member 28 abuts, via the interior, against the front wall of the lower cover 18 on the left-hand side of the linear member lead-out part 25, the gap formed between the linear member lead-out part 25 and the engine cover 15 on the left-hand side of the linear member lead-out part 25 has a serpentine shape, and the entrance of water into the engine cover 15 is therefore minimized. On the other hand, since the second projection 28b of the lid member 28 abuts, via the interior, against the right side wall of the lower cover 18 on the right-hand side of the linear member lead-out part 25, there is a possibility of water entering the engine cover 15 via a gap formed between the second projection 28b of the lid member 28 and the right side wall of the lower cover 18 on the right-hand side of the linear member lead-out part 25.
Because of the above-described situation, the lower cover 18 is integrally provided with an extended wall portion 18a that smoothly joins to the right side wall of the lower cover 18 and extends close to the linear member lead-out part 25. As such, the extended wall portion 18a is disposed in front of the connecting wall portion 31. A water entrance chamber 34 is defined in the lower cover 18 and is disposed on the right-hand side of the linear member lead-out part 25, wherein front and rear walls of the water entrance chamber 34 are defined by the connecting wall portion 31 and the extended wall portion 18a, which are spaced in the fore-and-aft direction. Moreover, the lower cover 18 is provided with a drain hole 35 for discharging water from the water entrance chamber 34 and out of the outboard motor to the exterior environment via the drain hole 35 opening defined in a bottom part of the water entrance chamber 34.
In FIGS. 4-6, the upper cover 19 of the engine cover 15 is provided with an intake port 38 that opens on the rear side, and an intake chamber 39 that is disposed above the engine E and is formed to communicate with the intake port 38.
The intake chamber 39 is formed from the upper cover 19 of the engine cover 15, and an internal cover 41 that is mounted on the upper cover 19 from the inside to segregate or separate the intake chamber 39 from an engine compartment 40 housing the engine E.
The internal cover 41 is formed from a synthetic resin and is integrally provided with a bottom plate portion 41a, a front wall portion 41b, and a pair of tubular portions 41c and 41d. The bottom plate portion 41a faces an inner face of the upper part of the upper cover 19 and has a rear edge part and two side edge parts connected to the inner face of the upper part of the upper cover 19. The front wall portion 41b extends upward from a front edge of the bottom plate portion 41a and is connected to the inner face of the upper part of the upper cover 19. The tubular portions 41c and 41d form passage holes 42 and 43, which provide communication between the intake chamber 39 and the interior of the engine compartment 40, and extend upward from the bottom plate portion 41a. A central region of a rear part of the bottom plate portion 41a is secured, via a screw member 44, to the upper cover 19 below the intake port 38. Opposite sides of a front part of the bottom plate portion 41a are secured, via screw members 46, to a pair of mounting bosses 45 provided integrally with the inner face of the upper cover 19. The center of the upper end of the front wall portion 41b is secured to the inner face of the upper part of the upper cover 19 by a screw member 47.
The tubular portions 41c and 41d are arranged side by side in a left-to-right direction so water that has entered the intake chamber 39 via the intake port 38 passes through the tubular portions 41c and 41d. A pair of drain holes 48 and 48, which discharge water that has branched to the left and right after abutting against the front wall portion 41b within the intake chamber 39, are formed in the left and right sides of the upper cover 19 and communicate with the left and right frontal parts within the intake chamber 39.
Moreover, a width D, in a left-to-right direction, of the intake port 38 is smaller than a distance L between outer ends of the tubular portions 41c and 41d in the left-to-right direction. Side walls 41ca and 41da, which face the intake port 38 of the tubular portions 41c and 41d, are inclined so that they approach each other in the forward direction.
Furthermore, the bottom plate portion 41a inclines upward toward the front wall portion 41b from the intake port 38, while the front wall portion 41b inclines upward to the front while curving convexly to the rear.
The operation of the invention will now be explained. The engine cover 15 covering the engine E is formed from the lower cover 18 fixed to the casing 11 and the upper cover 19 joined to the lower cover 18 via the first mating surface 20. The linear member lead-out part 25 is formed from the case part 27 and is integrally connected to the lower cover 18 and projects forward from the front wall of the lower cover 18. The lid member 28 is joined to the case part 27 via the second mating surface 29 disposed below the first mating surface 20. The water entrance chamber 34, which is formed in the lower cover 18 so that front and rear walls thereof are defined by the connecting wall portion 31 and the extended wall portion 18a provided integrally with the lower cover 18 while being spaced in the fore-and-aft direction, is disposed among left and right sides of the linear member lead-out part 25 on the side on which a small gap is formed between the lid member 28 and the lower cover 18. It is therefore possible to minimize the amount of water entering into the engine cover 15 by temporarily receiving, via the water entrance chamber 34, water that is about to enter the engine cover 15 through the small gap between the lid member 28 and the lower cover 18 when the outboard motor is operating in turbulent waters. Moreover, the connecting wall portion 31 and the extended wall portion 18a are integrally provided with the lower cover 18. As such, it is possible to minimize the water from entering the engine cover 15 by using a simple structure while preventing any increase in the number of components.
Moreover, since the drain hole 35 is provided in the lower cover 18 and defines an opening in the bottom part of the water entrance chamber 34, water that has entered the water entrance chamber 34 is effectively discharged to the exterior through the drain hole 35. Subsequently, water does not accumulate in the water entrance chamber 34, and it is possible to more reliably prevent water from getting into the engine cover 15.
Furthermore, the intake chamber 39 is formed from the upper cover 19 of the engine cover 15 and the internal cover 41 mounted on the upper cover 19 to segregate the engine compartment 40 from the intake chamber 39. The internal cover 41 integrally has the bottom plate portion 41a facing the inner face of the upper part of the upper cover 19, a rear edge part and two side edge parts connected to the inner face of the upper part of the upper cover 19, the front wall portion 41b, extending upward from the front edge of the bottom plate portion 41a and connected to the inner face of the upper part of the upper cover 19, and the pair of tubular portions 41c and 41d extending upward from the bottom plate portion 41a while forming the passage holes 42 and 43, which provides communication between the intake chamber 39 and the interior of the engine compartment 40. The tubular portions 41c and 41d are arranged side-by-side in the left-to-right direction so water that enters the intake chamber 39 via the intake port 38 passes through the tubular portions 41c and 41d. The pair of drain holes 48, which discharge water, are formed on left and right sides of the upper cover 19 while communicating with the left and right front parts of the intake chamber 39.
Water that has entered the intake chamber 39 via the intake port 38 reaches the front wall portion 41b by passing through the pair of tubular portions 41c and 41d, branches to the left and right after abutting against the front wall portion 41b, and is discharged from the outboard motor to the exterior via the drain holes 48. As such, even if a large amount of water suddenly enters the intake chamber 39 through the intake port 38, the water is efficiently discharged via the drain holes 48 on opposite sides. It is therefore possible to effectively prevent water from entering the engine compartment 40 via the intake chamber 39. Moreover, it is possible to prevent water from entering the engine compartment 40 using a uniquely configured and simplified shape of the internal cover 41 mounted, from the inside, on the upper cover 19 of the engine cover 15.
Furthermore, since the width D in the left-to-right direction of the intake port 38 is smaller than the distance L between the outer ends of the two tubular portions 41c and 41d in the left-to-right direction, water that has entered the intake chamber 39 via the intake port 38 is effectively guided between the pair of tubular portions 41c and 41d. Also, since the side walls 41ca and 41da of the tubular portions 41c and 41d, which face the intake port 38, are formed in an inclined manner, water that has entered the intake chamber 39 via the intake port 38 is effectively guided through the pair of tubular portions 41c and 41d. 
Moreover, since the bottom plate portion 41a is formed to incline upward toward the front wall portion 41b from the intake port 38, the discharge of water from the intake chamber 39 is effectively carried out by returning water that has entered the intake chamber 39 to the intake port 38 side.
Although a preferred embodiment of the present invention is explained above, the present invention is not limited to the above-mentioned embodiment and may be modified in a variety of ways as long as the modifications do not depart from the spirit and scope of the present invention described in the appended claims.

## Claims

1. An outboard motor comprising:
a vertically extending casing;
an engine mounted on an upper part of the casing;
an engine cover covering the engine, the engine cover comprising:
a lower cover fixed to the casing; and
an upper cover joined to the lower cover at a first mating surface defined along one plane;

a linear member lead-out part for guiding a linear member from out of the interior of the engine cover, the linear member lead-out part comprising:
a case part integrally connected to the lower cover and projecting forward from a front wall of the lower cover; and
a lid member joined to the case part at a second mating surface disposed below the first mating surface; and

a water entrance chamber defined in the lower cover, the water entrance chamber having front and rear walls defined by a pair of wall portions integrally provided with the lower cover while being spaced in a fore-and-aft direction,
wherein the water entrance chamber is disposed, among left and right sides of the linear member lead-out part, on a side on which a small gap is formed between the lid member and the lower cover.

2. The outboard motor according to claim 1, wherein the lower cover is provided with a drain hole for discharging water from within the water entrance chamber to the exterior, the drain hole defining an opening in a bottom part of the water entrance chamber.