JP2015171863A - outboard motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suction passage of an outboard motor which facilitates assemble work while achieving improvement of the engine efficiency.SOLUTION: An outboard motor includes a suction passage 40 which guides air suctioned from the exterior into an engine cover 24 covering an engine 14 to a throttle body of the engine 14. The suction passage 40 includes: an upstream side duct 41 which is fixed to the engine cover 24 and formed extending from the upper side to the lower side; and a downstream side duct 42 which is fixed to the engine 14 and formed extending from the lower side to the upper side so as to be arranged parallel to the upstream side duct 41. In the upstream side duct 41, a suction port 43 communicating with the exterior is formed at an upper part and a discharge port 45 is formed on a lower part side surface. In the downstream side duct 42, a suction port 46 is formed at a position facing the discharge port 45 of the upstream side duct 41 so as to be separated from the discharge port 45 and a discharge port communicating with the throttle body is formed at an upper part.

Description

  The present invention relates to an outboard motor having an intake passage that guides air sucked from outside into an engine cover to a throttle body.

  In general, the engine has a characteristic that the output increases as the intake air temperature is lower. Therefore, in the case of an outboard motor in which the engine is covered by the engine cover, an opening for taking outside air into the engine cover is provided. Is provided.

  However, if such an opening is simply provided in the engine cover, the air sucked into the engine cover from the opening becomes a high temperature due to the heat generated by the engine, and the intake temperature of the engine may rise.

  Therefore, conventionally, an intake passage is provided above and outside the cowling (engine cover) that covers the engine, the introduction side of the intake passage communicates with an opening for taking in outside air, and the discharge side thereof is connected to an intake port or an engine room above the engine silencer. An outboard motor configured to communicate is proposed (see, for example, Patent Document 1).

JP 2007-69823 A

  However, in the outboard motor described in Patent Document 1 described above, since the intake passage is provided above and outside the cowling (engine cover), the size of the cowling (engine cover) is increased, and the outboard motor is downsized. There is a problem that it is difficult to plan.

  Further, since the intake passage is fixed to the cowling (engine cover) and the connection work with the engine silencer takes time, there is a problem that the assembly work is not easy.

  Furthermore, there is a problem that corrosion is likely to occur inside the engine because it is difficult to drain water when splashing water, rainwater, or the like enters the intake passage from the outside air intake opening.

  The present invention has been made in view of the above-described problems, and provides an outboard motor capable of easily performing assembly work while improving engine efficiency and suppressing corrosion inside the engine. With the goal.

  In order to achieve the above-described object, the present invention provides an outboard motor having an intake path for guiding air sucked from outside into an engine cover that covers the engine to the throttle body of the engine, and the intake path includes the engine cover. An upstream duct that is fixed to the upper side and extends downward from above, and a downstream duct that is fixed to the engine and extends upward from the lower side in parallel with the upstream side duct. The upstream duct has a suction port communicating with the outside formed in the upper portion and a discharge port formed in the lower side surface. The downstream duct has the discharge port of the upstream duct. A suction port is formed away from the discharge port at a position facing the outlet, and a discharge port communicating with the throttle body is formed at the top.

  By adopting such a configuration, it is possible to prevent the upstream duct and the downstream duct from coming into contact with each other when the engine cover is attached or removed. Therefore, the assembling work of the outboard motor can be simplified, and the intake path can be easily formed in the engine cover. Further, since external air can be directly guided to the engine throttle body via the intake path, the engine intake temperature can be lowered and the engine output can be increased.

  Further, in the outboard motor according to the present invention, the suction port of the upstream duct is opened upward, a rising portion is formed around the suction port, and a drain hole is formed at the lower end of the upstream duct. Preferably it is formed.

  By adopting such a configuration, before the outside air is taken into the intake passage or before the air is separated in the intake passage and drained to the outside, moisture can be prevented from entering the engine. be able to. Therefore, the occurrence of corrosion inside the engine can be suppressed.

  In the outboard motor according to the present invention, a partition wall is formed between the discharge port of the upstream duct and the drain hole in a direction that inhibits the flow of air in the upstream duct. It is preferable.

  By adopting such a configuration, a stagnation space on the upstream side of the partition wall is formed even if water droplets such as splashes and rainwater during navigation enter the intake path directly or when moisture-containing air enters the intake path from the outside. As a result, the flow rate of the air is reduced, so that water and water droplets separated from each other can be reliably discharged to the outside. Therefore, it is possible to prevent water droplets and moisture from entering the engine, and to suppress the occurrence of corrosion inside the engine.

  According to the present invention, various excellent effects can be obtained such that the intake air temperature of the engine can be lowered to increase the output of the engine and the assembly work can be easily performed.

1 is a side view showing an outboard motor according to an embodiment of the present invention. 1 is a perspective view showing an outboard motor according to an embodiment of the present invention. FIG. 3 is a view as seen from an arrow A in FIG. 2.

  Hereinafter, an outboard motor according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the directions of front, rear, left and right are based on the traveling direction of the hull.

  First, the overall configuration of the outboard motor 10 according to the embodiment of the present invention will be described with reference to FIG. Here, FIG. 1 is a side view showing an outboard motor 10 according to an embodiment of the present invention.

  As shown in FIG. 1, the outboard motor 10 is attached to a transom 12 of the hull 11 via a mounting bracket 13 so as to be rotatable up and down. The outboard motor 10 includes an engine 14, and the output from the engine 14 is transmitted to the propulsion device 16 via the power transmission device 15. The propulsion unit 16 includes a propeller shaft 17 to which engine output is transmitted and a propeller 18 fixed to the propeller shaft 17.

  The engine 14 is a vertical four-cylinder engine in which a crankshaft 19 is disposed substantially vertically, and engine output is taken out from the lower end of the crankshaft 19. The lower end portion of the crankshaft 19 is connected to the upper end portion of the drive shaft 21 via the primary gear device 20. The drive shaft 21 extends substantially vertically downward in the main body housing 22, and a lower end portion thereof is connected to the propeller shaft 17 via a bevel gear device 23. The power transmission device 15 includes a primary gear device 20, a drive shaft 21, and a bevel gear device 23.

  An engine cover 24 is liquid-tightly provided on the upper portion of the main body housing 22, and the inside of the engine cover 24 is largely divided into an engine room 70 and an intake space 71 formed from the upper side to the rear side of the engine room 70. Separated. The engine room 70 accommodates the engine 14 and the engine holder 25, and the engine 14 is attached to the upper part of the engine holder 25.

  The engine cover 24 is assembled in a liquid-tight manner by an engine lower cover 26 and an engine upper cover 27 so as to be split into two in the vertical direction. An engine holder 25 is accommodated in the engine lower cover 26, and the mounting bracket 13 is attached to the engine holder 25. The engine upper cover 27 has an open air inlet 28 at the upper rear side and an exhaust port 29 at the upper left side.

  An oil pan 30 is provided below the engine holder 25, and the oil pan 30 is stored in the main body housing 22. The main body housing 22 accommodates the drive shaft 21 of the power transmission device 15 so as to be freely inserted in the vertical direction. A gear case 31 is liquid-tightly provided at a lower portion of the main body housing 22, and a bevel gear device 23 is stored in the gear case 31.

  Next, the configuration in the engine cover 24 of the outboard motor 10 according to the embodiment of the present invention will be described with reference to FIGS. 2 and 3. Here, FIG. 2 is a perspective view showing the outboard motor according to the embodiment of the present invention, and FIG. 3 is a view taken in the direction of arrow A in FIG.

  The engine 14 includes a crankcase 32 disposed at a front portion, a cylinder block 33 provided integrally behind the crankcase 32, and a cylinder head 34 provided integrally behind the cylinder block 33. An engine block 35 is provided. The engine 14 is provided with a throttle body 36 that supplies an air-fuel mixture to each cylinder of the cylinder block 35, and an intake manifold 38 extends from the throttle body 36 for each cylinder and is connected to an intake port 39 formed in the cylinder head 34. Has been.

  In the intake space 71 in the engine cover 24, an intake path 40 is formed in a U-shape as viewed from the rear as well shown in FIG. The intake passage 40 is fixed to the engine cover 24 and is formed to extend from the upper side to the lower side, and the upstream side duct 41 is fixed to the engine 14 and extends in parallel with the upstream side duct 41 from the lower side to the upper side. And a downstream duct 42 formed out of the air.

  The upstream duct 41 is formed so as to cover the rear upper part of the engine 14 and is provided so as to be inclined downward toward the outside air intake port 28, and is connected to the lower side of the first duct 41a and connected to the engine. A flat second duct 41b that bends and extends from the upper left side of 14 toward the lower left side of the engine 14.

  A suction port 43 is opened upward in the upper part of the first duct 41 a of the upstream duct 41. A rising portion 43 a is formed around the suction port 43, and the suction port 43 and the outside air intake port 28 communicate with each other via an upper space 71 a of the intake space 71. A partition plate 69 is erected on the front edge portion and the left and right edge portions of the first duct 41 a, and the upper end of the partition plate 69 has a shape along the inner surface of the engine upper cover 27.

  On the right side of the lower part of the second duct 41b of the upstream duct 41, a vertically long discharge port 45 is opened toward the right. A drain hole 54 is formed on the bottom surface of the lower end of the second duct 41 b, and a partition wall 55 is formed between the drain hole 54 and the discharge port 45.

  The partition wall 55 is formed in a direction that obstructs the flow of air in the upstream duct 41. For example, the partition wall 55 is perpendicular to the bottom surface of the lower end of the second duct 41b as shown by a solid line in FIG. Alternatively, as shown by a broken line in FIG. 3, it is formed slightly inclined toward the discharge port 45 so as to be perpendicular to the air flow.

  The downstream duct 42 has a flat shape that bends and extends from the lower right side lower part of the engine 14 toward the upper right side of the engine 14, and also functions as a silencer. On the left side of the lower portion of the downstream duct 42, a vertically long suction port 46 is opened toward the left at a position facing the discharge port 45 of the upstream duct 41. The suction port 46 is separated from the discharge port 45 by a predetermined distance, and an open portion 47 is formed vertically between the discharge port 45 and the suction port 46. A discharge port (not shown) is formed in the upper part of the downstream duct 42, and this discharge port is connected to the intake port of the throttle body 36.

  Next, the flow of air in the engine cover 14 when the outboard motor 10 having the above-described configuration is traveling will be described with reference to FIGS. 2 and 3.

  When the engine 14 is started, first, external air flows into the engine cover 24 from the outside air inlet 28, and this air passes through the upper space 71 a of the intake space 71 and passes through the upper duct 71 of the upstream duct 41 from the intake port 43. It is sucked into 41b. At this time, the water splashed from the outside air intake port 28 and the moisture contained in the air are separated from each other by colliding with the rising portion 43a of the suction port 43, and the moisture flows into the second duct 41b. Can be prevented. In addition, the water separated at the rising portion 43a of the suction port 43 is prevented from falling from the first duct 41a into the lower engine room 70 by the partition plate 69, and the outside air intake port according to the inclination of the first duct 41a. 28 is discharged to the outside.

  Thereafter, the air sucked into the second duct 41b of the upstream duct 41 descends in the second duct 41b, changes the flow direction toward the discharge port 45 at the lower end of the second duct 41b, and enters the partition wall 55. collide. At this time, the moisture in the air is separated by the centrifugal force when the air changes the flow direction and the collision with the partition wall 55. In addition, since the separated moisture forms a stagnation space S (refer to a two-dot chain line in FIG. 3) on the upstream side of the partition wall 55 at the lower end of the second duct 41b, the flow rate of air decreases. The water is reliably discharged from the drain hole 54 to the outside of the second duct 41b.

  The air from which moisture has been separated in this way is discharged from the discharge port 45, flows into the downstream duct 42 from the suction port 46, rises in the downstream duct 42, and is sucked into the intake port of the throttle body 36. Then, the air is supplied to each cylinder of the engine 14 through each intake manifold 38.

  According to the outboard motor 10 according to the embodiment of the present invention described above, the upstream duct 41 fixed to the engine cover 24 and the downstream duct 42 fixed to the engine 14 are formed in parallel to each other. Since the discharge port 45 and the suction port 46 are provided apart from each other, it is possible to prevent the upstream duct 41 and the downstream duct 42 from contacting each other when the engine cover 24 is attached or removed. it can. Therefore, the assembling work of the outboard motor 10 can be simplified, and the intake passage 40 can be easily formed in the engine cover 24.

  In addition, since the intake passage 40 is formed in the intake space 71 formed from the upper side to the rear side of the engine room 70, the size of the engine cover 24 can be minimized and the outboard motor can be increased in size. Can be prevented.

  Further, before the outside air is taken into the throttle body 36 or the engine room 70 of the engine 14, air / water separation is performed at the rising portion 43 a of the suction port 43, so that the air enters the throttle body 36 or the engine room 70 of the engine 14. Infiltration of moisture can be suppressed.

  Furthermore, even if water droplets such as water splash or rain water at the time of navigation are directly or air containing moisture enters the intake passage 40 from the outside air intake port 28, the water is reliably separated in the stagnation space S, and thus generated. Water droplets and moisture that have been removed can be easily drained from the drain hole 45. Accordingly, it is possible to prevent water droplets and moisture from entering the engine 14 and to suppress the occurrence of corrosion inside the engine.

  Furthermore, since external air can be directly guided to the throttle body 36 of the engine 14 via the intake path 40, the intake temperature of the engine 14 can be lowered and the output of the engine 14 can be increased.

  The above description of the embodiment of the present invention describes a preferred embodiment of the outboard motor according to the present invention, and may have various technically preferable limitations. The technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

DESCRIPTION OF SYMBOLS 10 Outboard motor 14 Engine 24 Engine cover 36 Throttle body 40 Intake path 41 Upstream duct 42 Downstream duct 43 Suction port 43a Standing part 45 Discharge port 46 Suction port 54 Drain hole 55 Partition wall

Claims (3)

In an outboard motor having an intake path that guides air sucked from outside into an engine cover that covers the engine to the throttle body of the engine, the intake path includes:
An upstream duct fixed to the engine cover and extending downward from above;
A downstream duct fixed to the engine and extending from the lower side to the upper side in parallel with the upstream duct; and
The upstream duct is formed with a suction port communicating with the outside and formed with a discharge port on the lower side surface, and the downstream duct faces the discharge port of the upstream duct. An outboard motor characterized in that a suction port is formed at a position apart from the discharge port, and a discharge port communicating with the throttle body is formed at an upper portion.   The suction port of the upstream duct is opened upward, a rising portion is formed around the suction port, and a drain hole is formed at a lower end of the upstream duct. The outboard motor according to 1.   The partition wall is formed between the discharge port of the upstream duct and the drain hole in a direction that obstructs the flow of air in the upstream duct. Outboard motor.

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