JP4719609B2 - Outboard motor - Google Patents

Description

  The present invention relates to an outboard motor equipped with a vertical crankshaft vertical engine that efficiently cools the generator and prevents the influence of exhaust air after the generator is cooled on engine intake. It is.

The outboard engine has a vertical crankshaft and a so-called vertical engine with cylinders and pistons facing sideways. The engine is covered with an engine cover, and the engine cover has an outside air intake for cooling the engine and for intake of the engine. It is a structure provided with.
A generator (ACG) is disposed at the top of the engine, the generator is covered with a cover, and cooling air is introduced into the cover to cool the generator.

Conventionally, a cooling structure for a generator attached to an engine of an outboard motor is known (see, for example, Patent Document 1 and Patent Document 2).
JP-A-8-1000064 JP-A-6-117491

  Patent Document 1 relates to a structure for cooling a generator provided at the upper end of a vertically placed crankshaft, and the technique disclosed here is a ventilation inlet 51e facing downward in a cover covering the generator (Patent Document 1). In this case, the air around the engine block is taken into the cover from the suction port.

  Patent Document 2 shows air cooling of electrical components in an outboard motor, and a flywheel 51 (the reference numeral used in the publication of Patent Document 2 is used hereinafter) includes an opening 111 and a plurality of blades 21 inclined in the axial direction. It has a structure in which air is sucked from the upper surface side of the flywheel 51.

  The technique disclosed in Patent Document 1 has a structure in which cooling air is taken into the cover 50 from the ventilation inlet 51e into the cover 50. In order to cool the generator more actively, I want to introduce air at a temperature lower than the air temperature.

  The technology disclosed in Patent Document 2 has no guidance and control of exhaust air, and there is no consideration for the balance with intake air. Therefore, when the air is sucked from the engine intake port, the intake air temperature of the engine increases and the engine output decreases. There is a possibility of bringing about.

  In view of the above, the present invention suppresses the influence of the generator exhaust air on the engine intake air temperature that is taken into the engine cover and sucked into the engine, and improves the engine output. It is an object of the present invention to provide an outboard motor that enables a more preferable cooling structure.

The invention according to claim 1 forms a generally vertical crankshaft, an engine block that accommodates the crankshaft, an engine that includes an intake port to the combustion chamber of the engine, and a space that accommodates the engine. An outboard motor comprising an engine cover having an intake port, the generator being provided at an upper portion of the crankshaft, wherein a generator including a rotating body is provided between the outside air intake port and the intake port of the engine, and the rotating body of the generator A wall means is provided between the engine block and the engine intake port is provided in the intake box upstream of the throttle valve, and the wall means is constituted by a wall surface other than the wall surface on which the intake port of the intake box is not formed. A part of the intake box is interposed between the rotating body of the generator and the upper surface of the engine block, and the intake port is provided in a part other than the interposed part .

According to a second aspect of the present invention, in the first aspect, a concave step portion is provided at an end of the engine block, and a rotating body of the generator faces above the engine block including the concave step portion. wall means formed in a portion of the intake box between the lower rotating body and said recessed step portion is interposed, characterized in that to cover the rotating body below the generator in the wall means.

The invention according to claim 3 includes a generator cover that covers the rotating body of the generator according to claim 2 , and a part of the cover is arranged above the wall means of the intake box and a part above the intake box. It is characterized by covering.

In the invention according to claim 1, a generator including a rotating body is provided between the outside air intake and the engine intake port, the generator being provided at an upper portion of the crankshaft of the engine block. Since the wall means is provided in between, the cooling exhaust air that has passed through the generator is less likely to flow directly to the engine intake port by the wall means, and with respect to the amount of intake air directly from the outside air intake of the engine intake amount, The amount of air sucked through the generator is reduced, the intake amount of exhaust air (warm air) after cooling the generator to the engine intake temperature is suppressed, the influence of the generator cooling on the engine intake temperature is suppressed, The influence on the engine output due to the suction of the generator exhaust air can be prevented.
Further, the engine intake port is provided in the intake box upstream of the throttle valve, and the wall means is constituted by a wall surface other than the wall surface where the intake port of the intake box is not formed. By using the wall surface, it is not necessary to prepare a special shielding member in the narrow engine cover for the wall means, which is advantageous in reducing the number of parts, and the shape of the intake box limits the direct flow of intake air In addition, a wall effect that suppresses the influence on the intake air temperature can be obtained, the structure is simple, and a part of the intake box is used as the wall means, so that an increase in cost can be suppressed.
Furthermore, a part of the intake box is interposed between the rotating body of the generator and the upper surface of the engine block, and the intake port is provided in a part other than this interposed part. The exhaust air after cooling the machine is prevented from going around the wall, and the role of the wall can be surely played with a simple structure.

In the invention according to claim 2, in claim 1, the end portion of the engine block is provided with a recessed step portion, the generator rotating body faces above the engine block including the recessed step portion, and the generator rotating body Since the wall means formed in a part of the intake box is interposed between the lower part and the concave step part so as to cover the lower part of the rotating body of the generator with the wall means , in addition to the effect of claim 1 , the engine block The recessed step at the end and the wall means of the intake box intervene, and the exhausted air after cooling that has passed through the generator is highly shielded, suppressing the wraparound of the exhausted air after cooling the generator to the engine inlet be able to.

According to a third aspect of the present invention, in the second aspect, a generator cover for covering the rotating body of the generator is provided, and a part of the cover is disposed above the wall means of the intake box and a part above the intake box. In addition to the effect of claim 2 , since the exhaust air after cooling the generator passes through the wall means and the upper surface of the intake box, the influence of the exhaust air on the engine intake is effectively suppressed. be able to.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view showing the entire outboard motor, and is a diagram showing main components of the internal mechanism in broken lines.
Reference numeral 1 denotes an outboard motor. The direction indicated by the arrow Fr on the right side of the drawing is the front of the propulsion direction, the direction indicated by the arrow Rr on the left side is the rear, and the engine 2 arranged at the top is covered with the engine cover 30. Yes.

The engine 2 is a four-stroke multi-cylinder engine in which a cylinder and a piston are substantially horizontal (referred to as horizontal orientation) and a crankshaft is substantially vertical (referred to as vertical orientation).
The engine 2 includes a cylinder head cover 3b on the rear side, a cylinder head 3 having a combustion chamber 3a on the inner top, a cylinder 4a in the middle portion having a cylinder 4a and a piston 4b, and a front crankcase 5 having a crankshaft 5a. Prepare.
The crankcase 5 and the cylinder block 4 constitute an engine block.

An engine intake device including an intake silencer constituting an intake box is disposed on the front side of the crankcase 5 of the engine 2, and air (fresh air) is introduced into the engine intake through the intake silencer 6.
The wall means for suppressing the flow of exhaust air after cooling of the generator, which will be described later, to the intake port is configured by a part of the wall surface of the intake silencer 6 which is an intake box.

Also, on the side where the intake silencer 6 of the engine is provided, an electrical box 7 having a base such as an electronic control unit for controlling the ignition of the engine or the control of the fuel injection device is provided. An oil pan 8c is disposed in an oil case 8b that is disposed, supports the engine with the mount case 8a, and is coupled to the lower surface of the mount case 8a.
The engine 2 is covered with an engine cover 30. The engine cover 30 is composed of an upper and lower divided cover, and includes an upper cover 31 and a lower cover 35. The upper and lower covers 21 are formed by front and rear locking mechanisms 15 and 15. , 25 are integrated so as to be openable and closable.

  As described above, the crankshaft 5a is disposed vertically, and has a flywheel 5b at the lower end and is connected to a drive shaft 9 that hangs downward. The drive shaft 9 is connected to the lower cover 35. The extension case 10 extending downward is vertically passed through and connected to a gear transmission mechanism 12 in a gear case 11 fixed to the lower end of the extension case 10.

The gear transmission mechanism 12 transmits the power of the drive shaft 9 to a horizontal driven shaft 12a arranged in the front-rear direction in the gear case 11, and the rear end portion of the driven shaft 12a protrudes rearward from the rear portion of the gear case 11, A propeller 13 is fixed to the rear end, and the propeller 13 is driven by the power of the engine 2 and is switched by a pair of dog clutches, thereby switching forward and reverse rotation of the propeller to obtain forward or reverse propulsive force.
In the drawing, reference numeral 14 denotes a stern bracket for detachably attaching the outboard motor to the stern of the ship.

2 is a vertical side view of the upper part of the outboard motor according to the present invention, FIG. 3 is a front view of the vertical section, FIG. 4 is a plan view of the outboard motor, and FIG. 5 is a cutaway view of the engine cover. FIG. 6 is a plan view of the generator with the rotor cover removed, FIG. 7 is a plan view of the chain drive mechanism cover removed, and FIG. 8 is an intake silencer on the inlet manifold side throttle valve device. It is a perspective view of the front side of the engine part of the outboard motor showing the assembled state.
9 to 11 show the rotating body cover alone, FIG. 9 is a perspective view seen from the rear, FIG. 10 is a perspective view seen from the front, and FIG. 11 is a longitudinal side view.
This will be described in detail with reference to these drawings.

In FIG. 2, the right side of the figure is the front (Fr) of the outboard motor, the left side is the rear (Rr), and the engine block 2 is the crankcase 5, the cylinder block 4, the cylinder head 3, and the rear surface of the cylinder head from the front. Has a cylinder head cover 3b.
On the upper surface 2a of the engine 2, an upper part 5b of the crankshaft 5a projects above the boundary between the cylinder block 4 and the crankcase 5, and a drive sprocket 16 is fixed to the lower part of the projecting part of the crankshaft 5a.

  On the other hand, a driven sprocket 17 is fixed to the upper end portion 3d of the camshaft 3c (see FIG. 1) vertically installed in the cylinder head 3 that protrudes from the engine block upper surface 2a. A chain drive mechanism for driving a camshaft includes a chain 18 wound between the driven and driven sprockets 16 and 17, and slipper-like guides 19 and 19 on both sides of the chain 18 as shown in FIGS. 20 (chain transmission mechanism).

A concave step portion 5d that is one step lower is formed on the upper portion 5b of the crankcase 5 that constitutes a part of the engine block, so as to be L-shaped in side view.
The concave step portion 5d is formed in a portion above the shoulder portion of the uppermost portion of the crank portion because the crank portion of the crankshaft becomes a laterally concave portion.

  That is, the crankcase 5 has a rear wall portion 5f that forms a small diameter portion corresponding to the bearing at the top of the crankshaft and a front end wall portion 5g that forms part of the crank chamber corresponding to the rotation of the crank web immediately below the bearing. And a horizontal lateral wall portion 5e that connects the rear wall portion 5f and the front end wall portion 5g, and constitutes a concave step portion 5d.

Since the silent chain drive mechanism 20 disposed on the engine block upper surface 2a of the engine 2 described above requires lubrication, the lubricating oil may be scattered around.
Therefore, on the upper surface 2a of the engine 2, the periphery of the camshaft chain drive mechanism 20 is covered with a chain drive mechanism case or cover 40 (hereinafter referred to as a first cover).

  The first cover 40 has the rear driven sprocket 17 side opened to the rear 40a, the open portion 40a is closed from the rear by the U-shaped portion 3f provided on the upper portion 3e of the cylinder head cover 3b, and is in contact with the U-shaped portion 3f. The part was sealed with an O-ring 41.

The rear portion 40b of the first cover 40 is set one step higher because the sprocket 17 is positioned, the intermediate portion to the front portion following the first cover 40 are set one step lower, the front end portion 40d hangs downward in an inverted L shape, Except for the rear opening 40a, it is formed as an edge 40c over the entire circumference, and a vertical through hole sealed with an oil seal 42 is provided in the front, and the upper part 5b of the crankshaft 5a is placed on the cover 40 through the vertical through hole. Protruding.
The bent edge portion 40c of the front end portion of the first cover 40 is an upper end portion of the concave step portion 5d of the crankcase 5, and the front end portion on this side of the engine block upper surface 2a (the front end of the high portion of the crankcase). This forms a cover that seals the chain drive mechanism 20 entirely.

  A generator 50 (alternator generator, ACG) is disposed on the upper portion 5b of the crankshaft 5a protruding on the first cover 40. The generator 50 includes a rotating body 51 fixed to a crankshaft and having a magnet 51a fixed to the inner periphery thereof, and a power generation coil 52 having a coil 52a wound around an iron core 52b.

  A recoil starter flange 53 is fixed to the outer periphery of the rotating body 51, and the recoil starter flange 53 provided on the outer periphery of the ACG rotating body 51 is partially above the concave step portion 5 d of the crankcase 5. Bulges outward in the radial direction. The gap below the bulging portion is shown as A in FIG.

As shown in FIG. 6, the ceiling portion 51b of the reverse cup-shaped rotator 51 is provided with an outside air introduction portion 54 for taking outside air into the rotator, and a plurality of outside air introduction portions 54 are provided radially. .
The above rotating body 51 rotates in the clockwise direction (arrow a direction) in FIG. 6 so that the outside air inlet 54a is directed in the rotating direction, and the outside air is introduced into the rotating body 51 from the outside air introducing portion 54. The main part of the internal generator is cooled with the introduction cooling air.

The intake silencer 6 described above is disposed in the front portion of the engine 2, that is, the front portion of the crankcase 5 in the engine cover 30 as shown in FIGS. 2, 5, 6, and 7.
The intake silencer is disposed on the starboard side of the outboard motor as shown in FIGS. 3, 5, 6, and 7, and as shown in FIG. 2, the crankcase 5 of the engine 2 in a side view. It has a protruding upper portion 6a that protrudes toward the concave step portion 5d (rear) formed in the upper portion of the front half.

The projecting upper part 6a faces the space A between the recoil starter flange 53 of the rotating body 51 that protrudes backward from the rear half part 6b of the intake silencer 6 and faces the concave step part 5d and above the concave step part 5d. It is configured to close the front lower part.
Therefore, the air after cooling the ACG 50 is shielded by the projecting upper portion 6a of the intake silencer 6, and the air after the ACG 50 is cooled is connected to the intake silencer 6 and the throttle body (combustion supply device) connected to the outside air outlet that is the outlet. Can be prevented from flowing immediately.

As shown in FIG. 2, the intake silencer 6 constituting the intake box is provided with a suction port 6c for taking in outside air forward and downward in an intermediate portion, and a discharge port 6d (outlet for fresh air) at the lower portion (outlet port 6d ( 8).
The intake silencer 6 is connected to the intake port on the upstream side of the throttle body 21 through the outlet 6d (see FIGS. 3, 5, 6, 7, and 8). The downstream side of the throttle body 21 is The cylinder head 3 is connected to the upstream portion 22b of the inlet manifold 22 in which the downstream portion 22a is connected to the combustion chamber 3a (see FIG. 1).

As is apparent from FIGS. 5, 6, and 7, the inlet manifold 22 extends forward from the rear through the left side of the engine 2.
The projecting upper part 6a that has entered so as to overlap with the concave step part 5d of the intake silencer 6 is placed in a lateral space A opened forward between the concave step part 5d and the lower surface of the rotating body 51 of the generator 50. It protrudes like a ridge with the upper and lower surfaces facing each other and a gap (see FIG. 2).

  And the downstream shelf surface part 67 located in the front part of the rotary body cover 60 (2nd cover) mentioned later is the upper surface of the intake silencer 6 extended continuously ahead from the protrusion part 6a of the intake silencer. 6e is extended to an intermediate portion in the front-rear direction, and the flow of the exhaust air after cooling the generator 50 is directed in a direction other than the intake port 6c of the intake silencer 6.

The upper cover 31 of the engine cover 30 includes a concave portion 32 that faces the rear half portion 31b of the upper surface 31a and opens rearward, and includes an outside air inlet 33 that opens upward in the middle portion of the concave portion 32 in the front-rear direction. In the embodiment, the outside air inlet 33 has a substantially pentagonal cylindrical shape in plan view as shown in FIG.
The upper surface 31a of the upper cover 31 is high at the portion of the front half portion 31c facing the rear of the outside air inlet 33 and bulges upward, and the front end portion of the front half portion 31c is gently curved downward and inclined to form a front wall. The upper end 31a merges with the portion 31d, and the rear end of the upper surface 31a merges with the rear wall 31e to surround the upper surface as a peripheral wall.

A tilt handle or lid 34 as a lid is provided so as to cover the concave portion 32 formed in the rear half portion 31b of the upper surface 31a. The lid 34 is a leg portion 34a ... around the outside air inlet 33 of the rear half portion 31b of the upper surface 31a. Installed and supported.
A gap S for taking in outside air is formed between the rear end portion 34 b of the lid 34 and the recess 32, and outside air is taken into the engine cover 30 from the gap S through the outside air inlet 33. An outside air intake opening of the engine room is configured between the lid 34 and the recess 32.

The periphery of the rotating body 51 of the ACG 50 is covered with a rotating body cover 60 (hereinafter referred to as a second cover).
The single unit of the second cover 60 is as shown in FIGS.
The second cover 60 covering the rotating body has a function of protecting outside air guiding means, rectification and ACG 50 taken into the engine cover 30 from the environment in the engine room.

The second cover 60 has an inverted cap-shaped main body 61. The main body 61 includes a disc-shaped and curved roof-shaped canopy portion 62 and a peripheral wall portion 63 that hangs downward from the periphery of the lower end portion thereof. Prepare.
A plurality of upward U-shaped locking portions 64... And a downward U-shaped locking portion 65 are integrally provided at the outer edge of the lower end of the peripheral wall portion 63. And a downward U-shaped locking portion 65 for fixing the second cover 60 to the engine block together with a grommet 65b having a through hole that engages with a protrusion (not shown) of the engine block. Is.

A shelf surface portion 66 extends rearward between a part of the lower end portion of the canopy portion 62 and the peripheral wall portion 63.
In the embodiment, the shelf surface portion 66 is formed of a plate-like body having a right triangle shape in plan view, and the plate-like body includes a plurality of uneven portions 66a.
The front end portion of the shelf surface portion 66 is continuous with the canopy portion 62 and forms a continuous surface with the upper surface 62a of the intermediate portion in the width direction of the canopy portion 62 curved upward, and the shelf surface portion extends from the horizontal shelf surface portion 56 to the upper surface of the canopy portion 52. The upper surface 56a of 56 is continuous (see FIGS. 9 and 11).

On the outer periphery of the canopy 52, a shelf surface portion 67 projects forward on the opposite side of the shelf surface portion 66, the shelf surface portion 67 extending forward is referred to as a downstream shelf surface portion, and extends backward as described above. The completed shelf surface portion 66 is referred to as an upstream shelf surface portion.
The shelf surface portions 66 and 67 are such that the upstream shelf surface portion 66 is long in the front-rear direction, the downstream shelf surface portion 67 is short, the upper surface 67a of the shelf surface portion 67 is flat, the upper surface 67a is continuous with the canopy portion 62, and curves upward. The above-mentioned upper surface 62a of the intermediate part of the width direction of the canopy part 62 and a continuous surface are comprised.
The downstream shelf surface portion 67, the upper surface 62a of the canopy portion 62, and the upstream shelf surface portion 66 constitute a continuous guide surface for the outside air (air) taken into the engine cover 30.

Plate-like guide walls 68 and 69 constituting side guide surfaces are installed upright on both sides of the shelf surfaces 66 and 67 before and after the canopy 62 and the top surface of the canopy 62.
One of the guide walls 68 and 69 starts from a portion joining the canopy portion 62 at the front portion of the oblique side portion 66b of the upstream shelf surface portion 66, and rises slightly from this portion to form an upright portion 68a, from the front end portion thereof. An oblique side 68b that is inclined obliquely upward, and a wall front half 68c that extends forward from this portion and slightly slightly forwardly tilts downward, extends to the side of the downstream shelf surface portion 67, and stands upright. Is done.

The other guide wall 69 includes a low upstream portion 69a starting from the straight side 66c of the upstream shelf surface portion 66, and a high wall portion 69b that stands upright from the front end portion of the top surface 62a of the canopy portion and extends forward. 69 b is installed up to one side of the downstream shelf surface portion 67.
The left and right guide walls 68 and 69 are asymmetric in shape, height, and length in the front-rear direction on the left and right.

The above guide walls 68 and 69 are provided substantially in parallel on the left and right sides, and as is apparent from FIG. 5, the upstream side as a whole is slightly biased to the left side (upper side of FIG. 5) and the downstream side is slightly right side (lower side of FIG. 5). ).
By the way, the upper and lower surfaces 62b and 62c of the left and right portions excluding the upper surface 62a surrounded by the left and right guide walls 68 and 69 of the canopy 62 penetrate through a plurality of elongated holes vertically from the center of the canopy 62. The air introduction holes 70... Into the main body 61 are formed.

  The upstream side shelf surface portion 66, the downstream side shelf surface portion 67, the left and right guide walls 68 and 69 projecting from the front and rear of the main body 61, and the upper surface 62a of the canopy portion 62 curved upward between them constitute an intake guide means. It becomes.

Further, on one side of the peripheral wall 63 of the main body 61, specifically, on the left side (the right side is the front side of the outboard motor in FIG. 3 and the right side is the front side in FIG. A duct portion 71 that swells in a substantially square shape is provided.
The duct portion 71 is clearly shown in FIG. 10 which is a perspective view showing the state seen from the left front, and FIG. 11 which is a longitudinal side view, and leftward and outward in the middle portion of the inner surface 63a of this surface of the peripheral wall 63. The bulged duct portion 71 has an upper surface 71a, front and rear surfaces 71b and 71c closed, and a lower portion opened 71d.

As a result, the duct portion 71 communicates with the inside of the canopy portion 62 of the main body 61, bulges outward from a part of the peripheral wall portion 63, and opens downward into the engine cover (inside the engine room) by the opening portion 71d. 61 was formed integrally on one side.
The outside air taken into the engine cover 30 from the cooling air intake part 70... Into the second cover 60 is taken inside, and the outside air is sent from the outside air introduction part 54 provided on the upper surface of the rotating body 51 of the generator 50 to the generator. 50, the heat generating portion of the generator 50 is cooled, and is discharged from the duct portion 71 and the like into the engine room.

The above-described second cover 60 is attached to the engine block, and is put on the generator 50 protruding above the fixed first cover 40, and covers the generator 50 from the outside. The outer side including the rotating body 51 is covered with the main body 61 of the second cover 60 and is positioned with a space below the ceiling of the middle part to the front half part 31 c in the upper cover 31 of the engine cover 30.
The upstream shelf surface 66 is located below the outside air inlet 33 provided in the rear half of the upper cover 31 of the engine cover 30, and guide walls 68 and 69, the upstream shelf surface 66, the top surface 62 a of the canopy 62 b, and the downstream side. The shelf surface portion 67 forms an air guide passage 72 (see FIG. 2) from the upstream side (rear of the outboard motor) to the downstream side (front of the outboard motor) in the upper part in the engine cover.
The intake guide passage 72 constitutes an intake passage by the intake guide means.

On the upstream side of the second cover 60, the front portion of the main body 61 (the front portion that is the upstream side of the air guide passage 72) is on the concave step portion 5 d side (rear side) formed in the upper part of the front half of the crankcase 5 of the intake silencer 6. ) Facing the projecting upper part 6a projecting with a small gap.
The upstream side shelf surface portion 67 at the front end portion of the main body 61 of the second cover 60 extends from above the protruding upper portion 6a protruding toward the recessed step portion 5d side (rear side) of the intake silencer 6 to above the intermediate portion of the upper surface portion 6e. It is located with a slight gap (see FIG. 2).

The duct portion 71 bulged to the side of the main body 61 of the second cover 60 is provided so as to be positioned on the left side above the engine 2 as shown in FIGS. 3 and 5. The duct portion 71 is provided on the side opposite to the installation site of the electrical component 7 disposed on the right side of the engine 2.
It arrange | positions so that it may be located under the opening part 71d of the duct part 71 above the inlet manifold 22 which comprises the intake passage of an engine.

The generator 50 is cooled by the cooling air (cooling air) introduced into the second cover 60, and the warm air after cooling is discharged from the open portion 71 d below the duct portion 71, and the electrical equipment box 7 having the control base and Since the warm air after cooling is discharged to the opposite side, the heat influence of the exhaust air after cooling the generator 50 on the electrical equipment box 7 having the control base can be prevented.
Further, from the front portion of the second cover body 61 to the upper surface of the intake silencer 6, the lower surface of the rotating body 51 and the upstream shelf surface portion 67 provided on the front portion of the main body 61 of the second cover 60 face, and the front portion of the intake silencer 6 An air guide wall is formed over 6f, and the flow of warm air after cooling the generator between the intake silencer 6 and the crankcase 5 of the engine is gracefully prevented.

  The air introduction hole 70 to the inside of the main body 61 provided in the canopy portion 62 of the second cover 60, the space inside the main body, the duct 71 as the discharge portion, and the rotating silencer at the front of the main body are opened below the intake silencer 6. And the lower surface of the upstream shelf surface portion 67 constitute a generator cooling air passage for the rotating body cover.

FIG. 12 is an explanatory diagram showing the flow of air taken into the engine cover, and constituent elements are only given reference numerals.
The outside air is indicated by an arrow (a) between the lid 34 and the recess 32 from the space S (outside air intake) between the lid 34 and the recess 32 provided in the rear half of the upper cover 31 of the engine cover 30. Break into.
The intruded air enters from the air intake 33 as indicated by an arrow (b) in the engine cover, and hits the upstream shelf surface portion 66 of the second cover 60 directly below the intake 23.

  The air hitting the upstream shelf surface 66 flows in the direction of arrow (c) and is regulated by the left and right guide walls 68 and 69, and is composed of the upstream shelf surface 66, the upper surface 62a of the canopy 62, the downstream shelf surface 67, and the like. Is guided to the curved inner surface 31g along the ceiling surface 31f of the upper cover 31 of the engine cover, flows to the lower front wall inner surface 31h, and fresh air enters the intake port 6c of the intake silencer 6. As sucked.

In this way, the air to be sucked by the engine flows while being rectified as indicated by an arrow (d).
This air flow is guided to the curved corner portion in the front end portion of the upper cover 31 of the engine cover, and flows downward along the inner wall of the front portion as described above.
First, the intake silencer 6 constituting the intake device faces, and air is sucked from the downward intake port 6c of the intake silencer 6 and supplied as fresh air into the throttle body which is a fuel supply device.

By the way, the air taken into the engine cover flows as indicated by the arrows (a), (b), (c), and (d), but the rear side of the shelf surface portion 66 is opened below the outside air inlet 33. Since the left and right guide walls 68 and 69 are asymmetrical, they also flow to the left and right upper surfaces of the canopy 62.
By the way, the rotating body 51 of the generator 50 is rotating in the main body 61, and the action of the air introducing guide part 54 provided on the upper surface of the rotating body 51 causes the air introducing hole 70 provided in the canopy part 62 to Air is sucked into the generator 50 from the flow on the left and right upper surfaces of the canopy 62.

The outside air sucked from the air introduction holes 70 provided in the canopy 62 is introduced into the generator 50 through the air introduction guides 54 of the rotating body 51 and cools a heat generation source such as a power generation coil.
A part of the exhaust air composed of warm air after cooling is discharged from above from the duct portion 71 on the side of the second cover 60 to the inlet manifold 22 below.

Exhaust air exhausted from the front part of the exhaust air after cooling the generator 50 is a projecting upper part 6 a that closes the aforementioned recessed step part 5 d of the intake silencer 6, a lower part of the front part of the rotating body 51, and an upper surface of the intake silencer 6. 6e passes through the clearance A between the downstream side shelf surface portion 67 of the second cover 60 as indicated by the arrow (e), and merges with the flow indicated by the arrow (d) to flow on the outer surface of the front outer wall surface 6h of the intake silencer 6. Then, it merges with the fresh air, is cooled, and flows to the engine cover front inner wall surface 31h as indicated by an arrow (d).
Therefore, the exhaust air generated by the flow (e) after cooling the generator does not directly reach the intake port of the intake silencer 6, that is, the engine intake port.

  The air flowing in the downstream direction of the air guide passage 72 (arrow (c)) passes between the intake silencer 6 and the front wall inner surface of the upper cover 31 through the upper surface of the downstream shelf surface portion 67 and is guided downward. Then, the air is sucked from the suction port 6 c of the intake silencer 6.

  The outboard motor according to the present invention is suitable for cooling a generator attached to the outboard motor.

It is the side view which shows the whole outboard motor, and is the figure which showed the main thing of the internal mechanism with the broken line. It is a vertical side view of the upper part of the outboard motor which concerns on this invention. 1 is a longitudinal front view of an upper portion of an outboard motor according to the present invention. 1 is a plan view of an outboard motor according to the present invention. It is the top view which fractured and showed the engine cover of the outboard motor concerning the present invention. It is a top view of the engine part of the outboard motor which concerns on this invention, and the top view of the state which removed the rotary body cover of the generator. It is a top view of the engine part of the outboard motor which concerns on this invention, and the top view of the state which removed the chain drive mechanism cover. FIG. 3 is a front perspective view of the engine unit of the outboard motor showing a state where the intake silencer is assembled to the throttle valve device on the inlet manifold side. It is the perspective view which looked at the rotary body cover single-piece | unit from the back. It is the perspective view which looked at the rotary body cover single-piece | unit front. It is a vertical side view of a rotating body cover alone. It is explanatory drawing which shows the flow of the air taken in in the engine cover.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Outboard motor, 2 ... Engine, 3a ... Combustion chamber, 4, 5 ... Engine block, 5a ... Crankshaft, 5d ... Recessed step part, 6 ... Intake silencer which is an intake box, 6a ... Projection part which is wall means 6c ... Engine intake port, 21 ... Throttle valve, 33 ... Outside air intake port, 30 ... Engine cover, 50 ... Generator, 51 ... Rotating body, 60 ... Generator cover, 67 ... Portion covered by generator cover.

Claims (3)

A generally vertical crankshaft, an engine block that accommodates the crankshaft, an engine that includes an intake port for the combustion chamber of the engine, and an engine cover that forms a space for accommodating the engine and has an outside air intake An outboard motor
Provided at the upper part of the crankshaft, a generator including a rotating body is provided between the outside air intake and the engine intake port,
Providing wall means between the rotating body of the generator and the engine block;
The intake port of the engine is provided in an intake box upstream of the throttle valve, and the wall means is constituted by a wall surface other than a wall surface where the intake port of the intake box is not formed,
A part of the intake box is interposed between the rotating body of the generator and the upper surface of the engine block, and the intake port is provided in a part other than the interposed part.
Outboard motor characterized by that. A concave step portion is provided at an end of the engine block, a rotating body of the generator faces above the engine block including the concave step portion, and between the lower portion of the rotating body of the generator and the concave step portion. It said wall means formed on a part of the intake box is interposed, outboard motor according to claim 1, characterized in that to cover the rotating body below the generator in the wall means. Comprising a generator cover for covering the rotating body of the generator, according to claim 2, wherein a part of said cover and to cover a portion above the upper and the intake box wall means of the intake box Outboard motor.

Images