JP2015000676A - Intake structure of outboard engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake structure of an outboard engine which prevents intake air temperature rise and thereby improves the intake air filling efficiency.SOLUTION: An intake structure of an outboard engine 10 supplies intake air to an internal combustion engine 12 for the outboard engine and includes: an engine cover 42 which covers the internal combustion engine 12 for the outboard engine; a heat shielding member 120 which shields heat radiated from the internal combustion engine 120 for the outboard engine; and an intake manifold 131 which is disposed between the engine cover 42 and the heat shielding member 120 and supplies the intake air to the internal combustion engine 12 for the outboard engine. Travel wind flowing in from an inflow port 122 formed at a front plate part 47 of the engine cover 42 is placed in contact with an outer surface of the intake manifold 131 to be exhausted from an exhaust port 123 formed at a side surface part 45 of the engine cover 42.

Description

  The present invention relates to an outboard motor intake structure that supplies intake air to an outboard motor internal combustion engine.

  Generally, in an outboard motor, an intake manifold for supplying intake air to the engine is disposed in the engine cover at a position close to the engine. Therefore, the intake manifold is warmed by heat dissipation from the engine and high-temperature air in the engine cover, and the temperature of intake air in the intake manifold increases. Therefore, there is an outboard motor having a structure for cooling the intake manifold.

  Patent Document 1 discloses an outboard motor in which a water jacket for intake air cooling is provided only at an engine side portion of an intake branch pipe constituting an intake manifold provided on one side in the traveling direction of a cylinder block. The cooling water of the water jacket for cooling the intake air is supplied by a cooling water circulation path different from the cooling water circulation path for engine cooling. With the water jacket for cooling the intake air, it is possible to prevent the temperature of the intake manifold from rising due to heat on the engine side.

Japanese Patent No. 3139176

  However, in the intake manifold cooling structure disclosed in Patent Document 1 described above, the cooling water circulation path needs to be routed, so that the structure becomes complicated and the weight of the outboard motor increases. Further, only the engine side portion of the intake manifold is in contact with the water jacket for cooling the intake air. Therefore, on the opposite side of the intake manifold from the engine side, there is a risk that the intake air temperature rises due to contact with the hot air in the engine cover, and the intake charging efficiency decreases.

  The present invention has been made in view of the above-described problems, and provides an outboard motor intake structure capable of improving intake charging efficiency by preventing an increase in intake air temperature. Objective.

  An outboard motor intake structure according to the present invention is an outboard motor intake structure for supplying intake air to an outboard motor internal combustion engine, the engine cover covering the outboard motor internal combustion engine, and the outboard motor A heat shield member that shields heat radiation from the internal combustion engine, and an intake manifold that is disposed between the engine cover and the heat shield member and supplies intake air to the outboard motor internal combustion engine, The running wind introduced from the inlet formed in the front surface portion of the engine cover is brought into contact with the outer surface of the intake manifold and discharged from the discharge port formed in the side surface portion of the engine cover.

  According to the present invention, it is possible to prevent an increase in intake air temperature and improve intake charging efficiency.

It is a left view of an outboard motor. It is a top view of an outboard motor. It is a left side sectional view of an outboard motor. It is sectional drawing of the II-II line | wire shown in FIG. It is a right view of an outboard motor. It is a right side sectional view of an outboard motor. It is sectional drawing of the III-III line shown in FIG.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In each drawing, the front side of the outboard motor 10 (the forward direction of the hull 1 on which the outboard motor 10 is mounted) is indicated by an arrow Fr as necessary, and the rear side of the outboard motor 10 (the outboard motor 10). (Reverse direction of the hull 1) is indicated by an arrow Rr, the right side of the outboard motor 10 is indicated by an arrow R, and the left side of the outboard motor 10 is indicated by an arrow L.
FIG. 1 is a left side view of an outboard motor 10 mounted on the hull 1. The outboard motor 10 is mounted on a transom 2 located at the rear of the hull 1 via a bracket device 3.

  As shown in FIG. 1, the outboard motor 10 includes an engine holder 11, and an engine (an outboard motor internal combustion engine) 12 is installed above the engine holder 11. An oil pan 13 is disposed below the engine holder 11. The periphery of the engine 12, the engine holder 11, and the oil pan 13 of the outboard motor 10 is covered with a synthetic resin cover 14 including an upper cover 40 and a lower cover 41. The engine 12 is a vertical type engine in which a crankcase 15, a cylinder block 16, and a cylinder head 17 are connected from the front side, for example, and the crankshaft 18 is arranged substantially vertically. In this embodiment, for example, a water-cooled four-cycle four-cylinder engine is used.

  A drive shaft housing 19 is installed below the oil pan 13. A drive shaft 20 is disposed substantially vertically in the engine holder 11, the oil pan 13 and the drive shaft housing 19, and an upper end portion thereof is connected to a lower end portion of the crankshaft 18. The drive shaft 20 extends downward in the drive shaft housing 19 and is configured to drive the propeller 24 via a bevel gear 22 and a propeller shaft 23 in a gear case 21 provided at the lower portion of the drive shaft housing 19. .

  A shift device 25 that switches the rotation direction of the propeller shaft 23 between forward / reverse (forward / reverse) and neutral (neutral) by remote control is provided in the gear case 21. A shift rod 26 extends upward from the shift device 25 and is connected to the operation rod 28 via a link 27.

  The bracket device 3 mainly includes a swivel bracket 29 and a transom bracket 30. The swivel bracket 29 is fixed to the outboard motor 10, and the transom bracket 30 is fixed to the transom 2 of the hull 1.

  The swivel bracket 29 is pivotally supported by a tilt shaft 31 installed between a pair of left and right transom brackets 30 so as to be tiltable in the vertical direction, and a pilot shaft 32 can be rotated in the vertical direction in the swivel bracket 29. It is pivotally supported. Further, an upper mount bracket 33 and a lower mount bracket 34 are respectively provided integrally with the upper and lower ends of the pilot shaft 32. The upper mount bracket 33 is provided with a steering bracket 35 and is connected to a cable or the like (not shown).

  On the other hand, a pair of left and right upper mount units 36 are provided at the front portion of the engine holder 11 and connected to the upper mount bracket 33. A pair of lower mount units 37 are provided on both sides of the drive shaft housing 19 and are connected to the lower mount bracket 34.

  Next, the upper cover 40 will be described with reference to FIGS. FIG. 2 is a plan view of the outboard motor 10. FIG. 3 is a cross-sectional view taken along the line I-I shown in FIG. FIG. 4 is a cross-sectional view taken along the line II-II shown in FIG.

As shown in FIG. 3, the upper cover 40 of the present embodiment includes an engine cover 42 that covers the periphery of the upper portion of the engine 12, and an intake air that is disposed so as to cover the upper side of the engine cover 42 and a partial front side of the engine cover 42. And a duct 54.
The engine cover 42 includes an intake manifold 131 (see FIG. 4), a silencer 135, a throttle body 139 (see FIG. 4), and a power generator 140 (see FIG. 3) disposed around the engine 12 and the engine 12. And so on. Here, as shown in FIG. 4, the intake manifold 131 is coupled to an intake port 134 disposed on the right side surface of the cylinder head 17, and is curved toward the front side through the right side of the engine 12. . A synthetic resin first heat shield member 120 is disposed between the intake manifold 131 and the engine 12.

  The silencer 135 is disposed on the front side of the engine 12 and substantially in the center in the vertical direction of the engine 12, and is fixed to the crankcase 15. Between the silencer 135 and the front surface of the crankcase 15, a second heat insulating member 121 made of synthetic resin is disposed along the vertical direction and the horizontal direction. The silencer 135 has a vertical dimension that is within the vertical dimension of the engine 12, and is formed so that its width dimension (left-right direction) decreases toward the front side. An opening 136 to which a throttle body 139 is connected is formed on the right side surface of the silencer 135. As shown in FIG. 3, the opening 136 is located above the lower surface of the silencer 135 and prevents water that has entered the silencer 135 together with intake air from flowing into the throttle body 139 from the opening 136. Further, on the upper surface of the silencer 135, a suction portion 137 for sucking in intake air from the intake duct 54 is formed to protrude upward.

The throttle body 139 is disposed on the diagonally right front side of the engine 12 and between the intake manifold 131 and the silencer 135. The throttle body 139 adjusts the amount of intake air that flows into the intake manifold 131 by opening and closing a throttle valve (not shown).
The power generation device 140 is disposed on the upper side of the engine 12 so that a part of the power generation device 140 projects forward from the front end of the engine 12. In the present embodiment, a ventilation fan 141 having a centrifugal fan structure is configured by the flywheel and flywheel cover of the power generation device 140. The ventilation fan 141 rotates in conjunction with the crankshaft 18 and ventilates the air in the engine cover 42 that has become hot due to heat radiation from the engine 12 and the power generation device 140.

The engine cover 42 will be further described. The engine cover 42 has an upper surface portion 43, a rear surface portion 44, a right side surface portion 45, a left side surface portion 46 and a front surface portion 47. A part of the rear surface portion 44, the right side surface portion 45, the left side surface portion 46 and the front surface portion 47 of the engine cover 42 is an appearance surface of the outboard motor 10 and is formed in a gently curved shape.
The upper surface portion 43 is formed such that the front portion is curved along the shape of the upper surface of the ventilation fan 141, and the rear portion is formed in a flat shape along the shape of the engine 12 at a position lower than the front portion.

The front surface portion 47 includes a first front plate 48 formed vertically from the front end of the upper surface portion 43 toward the lower side, and a horizontal plate 50 formed horizontally from the lower end of the first front plate 48 toward the front side. And a second front plate 53 formed in the vertical direction from the front end of the horizontal plate 50 toward the lower side.
A space is formed between the first front plate 48 and the engine 12 as much as the ventilation fan 141 is disposed so as to protrude from the front end of the engine 12.

  The horizontal plate 50 is substantially at the center in the vertical direction of the engine 12 and is located above the upper surface of the silencer 135. In the present embodiment, as shown in FIG. 3, a part of the horizontal plate 50 is disposed so as to overlap with a part of the upper surface of the silencer 135 in the vertical direction. A substantially rectangular opening 51 is formed in the horizontal plate 50 so that the suction part 137 of the silencer 135 is inserted upward. A seal member 52 is attached to the periphery of the opening 51 and between the lower surface of the horizontal plate 50 and the upper surface of the silencer 135 so as to surround the suction portion 137 of the silencer 135. Prevent the intrusion. The second front plate 53 is disposed away from the front end of the silencer 135.

The intake duct 54 is formed by integrally connecting an inner cover 55 disposed outside the engine cover 42 and a top cover 65 covering the inner cover 55 from the outside by bonding or the like, thereby forming an intake passage 56 therein. Configured.
The inner cover 55 includes a first bottom plate 57 formed along the shape of the upper surface portion 43 of the engine cover 42, an inner front plate 58 formed in the vertical direction from the front end of the first bottom plate 57, and A second bottom plate 59 formed from the lower end of the inner front plate 58 toward the front side.

  The first bottom plate 57 is formed substantially parallel to the upper surface portion 43 with a gap g1 between the first bottom plate 57 and the upper surface portion 43 of the engine cover 42. The first bottom plate 57 does not reach the rear end of the upper surface portion 43 of the engine cover 42 and covers the front portion of the upper surface portion 43. The inner front plate 58 is formed substantially in parallel with the first front plate 48 with a gap g2 between the inner front plate 58 and the first front plate 48 of the engine cover 42. Further, the second bottom plate 59 is formed substantially parallel to the horizontal plate 50 with a gap g3 between the second bottom plate 59 and the horizontal plate 50 of the engine cover 42. The second bottom plate 59 is formed with an opening 60 through which the suction portion 137 of the silencer 135 is inserted into the intake duct 54. Here, the suction port 138 of the silencer 135 is located above the lower surface (second bottom plate 59) of the intake duct 54, and water that has entered the intake duct 54 together with intake air is prevented from flowing into the silencer 135. To do. In addition, a seal member 61 is attached between the lower surface of the second bottom plate 59 and the upper surface of the horizontal plate 50 so as to surround the suction portion 137, thereby preventing water from entering the intake duct 54 and the engine cover 42. To do.

The top cover 65 has an upper surface portion 66, a rear surface portion 67, a right side surface portion 68, a left side surface portion 69, and a front surface portion 70, and is formed in a gently curved shape as an outer appearance surface.
The upper surface portion 66 is formed such that the front portion covers the first bottom plate 57 of the inner cover 55 and is inclined downward toward the front side. On the other hand, the rear portion of the upper surface portion 66 covers the upper surface portion 43 of the engine cover 42, is inclined upward as it goes to the rear side, is inclined downward, and is formed continuously with the rear surface portion 67. A lid 80 that can be opened and closed is provided at the rear of the upper surface 66.

  The rear surface portion 67 is formed to be inclined downward. The rear end of the rear surface portion 67 is located away from the boundary portion 71 between the upper surface portion 43 of the engine cover 42 and the rear surface portion 44 of the engine cover 42. A space between the rear end of the rear surface portion 67 and the boundary portion 71 constitutes an outside air introduction port 72 for introducing outside air into the intake passage 56 as intake air. When the outboard motor 10 is viewed as a whole, the outside air inlet 72 is disposed at the upper part and the rear part of the outboard motor 10.

The right side surface 68 and the left side surface 69 are formed so as to cover the inner cover 55 from the right and left, respectively. Lower ends of the right side surface portion 68 and the left side surface portion 69 are formed substantially parallel to the shapes of the upper surface portion 66 and the front surface portion 70. Lower ends of the rear portions of the right side surface portion 68 and the left side surface portion 69 are inclined upward so as to be separated from the engine cover 42 toward the rear side, and are connected to the rear end of the rear surface portion 67.
As shown in FIGS. 1 and 2, the left side surface 69 is formed with an exhaust port 100 facing the outside. The ventilation fan 141 exhausts the air in the engine cover 42 from the exhaust port 100.

  The front surface portion 70 is formed so as to cover the inner front plate 58 of the inner cover 55 from the front side, and is connected to the front end of the second bottom plate 59 of the inner cover 55. The front surface portion 70 is continuously inclined from the upper surface portion 66 toward the lower side, and the front end is located slightly above the boundary portion 73 between the horizontal plate 50 and the second front plate 53 of the engine cover 42. Yes. Between the front end of the front surface portion 70 and the boundary portion 73, a traveling wind introduction port 74 for introducing traveling wind into the gap g3 is configured. The traveling wind introduced from the traveling wind introduction port 74 flows out from the outside air introduction port 72 through the gap g3, the gap g2, and the gap g1.

  In the intake duct 54 configured as described above, outside air is introduced from the outside air inlet 72 into the wide space 81 formed in the intake passage 56 and then passes through the air filter 82. The intake air that has passed through the air filter 82 passes through a narrow passage in the intake passage 56 that is formed between the front portion of the upper surface portion 66 of the top cover 65 and the front portion of the first bottom plate 57 of the inner cover 55. Flow into the front side. The intake air flowing into the front side flows into a wide space 96 in the intake passage 56 formed between the front surface portion 70 of the top cover 65 and the inner front plate 58 of the inner cover 55. The intake air flowing into the space 96 flows into the silencer 135 through the suction port 138. At this time, even if water is contained in the intake air, the suction port 138 of the silencer 135 is located above the lower surface of the intake duct 54, so that the water only accumulates in the intake duct 54 and the intake port 138. Through, the water is prevented from flowing into the silencer 135.

  Further, the intake duct 54 is disposed between the engine cover 42 and the gaps g1 to g3. These gaps g1 to g3 have the function of an air jacket. Therefore, the intake air flowing through the intake passage 56 of the intake duct 54 flows into the silencer 135 in a state where the heat from the engine cover 42 is blocked. Further, as described above, the traveling wind introduced from the traveling wind introduction port 74 flows into the gaps g1 to g3. Therefore, the intake air flowing through the intake passage 56 is cooled by the traveling wind, and the cooled intake air can flow into the silencer 135.

  The intake air that flows into the silencer 135 flows into the throttle body 139 through the opening 136. At this time, even if water is contained in the intake air, the opening 136 is located above the lower surface of the silencer 135, so that the water only accumulates in the silencer 135, and the throttle body 139 passes through the opening 136. To prevent water from flowing into. The intake air flowing into the throttle body 139 flows from the intake manifold 131 through the intake port 134 into the combustion chamber 142 formed between the cylinder block 16 and the cylinder head 17. At this time, an air-fuel mixture is generated by injecting fuel from the fuel injector 143, and the air-fuel mixture is combusted in the combustion chamber 142. When the air-fuel mixture is combusted, the piston 144 reciprocates in the front-rear direction, and the crankshaft 18 is rotated via the connecting rod 145. Exhaust gas combusted by the combustion chamber 142 is exhausted from the exhaust port 146.

  By forming the intake duct 54 with the top cover 65 and the inner cover 55 as described above, the intake passage 56 with the volume changed such as the wide spaces 81 and 96 can be easily formed. The intake sound can be attenuated by allowing the intake air to flow into the spaces 81 and 96 whose volumes have been changed. The intake duct 54 is coupled so as to cover a part of the upper side and the front side of the engine cover 42 by fixing the top cover 65 to the engine cover 42 at a plurality of locations with fixing screws (not shown). Therefore, by removing the engine cover 42 from the lower cover 41, the intake duct 54 can be removed together with the engine cover 42, and the engine 12 and the like can be easily inspected.

Next, a structure for cooling the intake manifold 131 will be described with reference to FIGS. FIG. 5 is a right side view of the outboard motor 10. FIG. 6 is a right side sectional view of the outboard motor 10. 7 is a cross-sectional view of the III-III line shown in FIG. 6 as viewed from the direction of the arrow.
As shown in FIG. 6, the intake manifold 131 is formed, for example, by welding synthetic resin, and includes a surge tank 132 and a first intake branch pipe 133 a to a fourth intake branch pipe 133 d coupled to the surge tank 132. Have.

  The surge tank 132 is formed along the up-down direction on the diagonally right front side of the engine 12. A throttle body 139 is coupled to the upstream side of the surge tank 132, and a first intake branch pipe 133a to a fourth intake branch pipe 133d are coupled to the downstream side. In the present embodiment, the first intake branch pipe 133a to the fourth intake branch pipe 133d are arranged in parallel in a state of being separated from each other in the vertical direction. The first intake branch pipe 133a to the fourth intake branch pipe 133d extend from the surge tank 132 to the front side, and then curve to the left and are coupled to the intake port 134.

  A first heat shield member 120 for shielding heat radiation from the engine 12 is coupled to the left side surface of the intake manifold 131 by a fixing screw, welding, or the like. Specifically, as shown in FIG. 7, the upper portion of the first heat shield member 120 is fixed to the left side surface of the first intake branch pipe 133a, and the lower portion is fixed to the left side surface of the fourth intake branch pipe 133d. Therefore, a gap is formed between the first heat shield member 120 and the second intake branch pipe 133b and the third intake branch pipe 133c. As shown in FIG. 4, the first heat shield member 120 is formed to extend in the front-rear direction, and the front part reaches the inside and front part of the surge tank 132. A second heat shielding member 121 for shielding heat radiation from the engine to the silencer 135 is disposed at a position adjacent to the first heat shielding member 120. The first heat shield member 120 and the second heat shield member 121 may be integrally formed continuously.

  As shown in FIGS. 4 and 6, an inflow port 122 is formed at the right end of the first front plate 48 of the engine cover 42 to allow the traveling wind to flow into the engine cover 42. The traveling wind flowing in from the inflow port 122 is a part of traveling wind introduced from the traveling wind introduction port 74 described above. In FIG. 4, the first front plate 48 and the inflow port 122 are indicated by a two-dot chain line. The traveling wind flowing in from the inflow port 122 passes between the inner side surface of the right side surface 45 of the engine cover 42 and the outer side surface of the surge tank 132, and the outer surface of the first intake branch pipe 133a to the fourth intake branch pipe 133d. While coming into contact, it flows toward the rear side.

  As shown in FIGS. 5 and 6, the right side surface portion 45 of the engine cover 42 is formed with a first discharge port 123 a to a third discharge port 123 c for discharging the traveling wind flowing into the engine cover 42 to the outside. ing. In the present embodiment, the first discharge port 123a to the third discharge port 123c are formed in parallel in a state where they are separated from each other in the vertical direction. Specifically, as shown in FIGS. 6 and 7, when viewed from the right side, the first exhaust port 123a to the third exhaust port 123c are located between the first intake branch pipe 133a and the fourth intake branch pipe 133d, respectively. Is formed. That is, the first exhaust port 123a to the third exhaust port 123c are formed at positions where the traveling wind flowing between the first intake branch pipe 133a to the fourth intake branch pipe 133d is easily discharged to the outside. In FIG. 6, the first discharge port 123a to the third discharge port 123c are indicated by two-dot chain lines.

  As shown in FIG. 6, a seal member 124 (124 a to 124 e) is attached to the right side surface of the intake manifold 131 so as to surround the intake manifold 131 along a substantially outer shape. Specifically, the upper seal member 124a is coupled to the outer surface of the first intake branch pipe 133a and the outer surface of the surge tank 132 (see also FIG. 7). The lower seal member 124b is coupled to the outer surface of the fourth intake branch pipe 133d and the outer surface of the surge tank 132 (see also FIG. 7). Further, as shown in FIG. 4, the rear seal member 124c is coupled to an extending portion 129 extending toward the right side from the first intake branch pipe 133a to the fourth intake branch pipe 133d. As shown in FIG. 6, the seal member 124d is coupled to the front and lower outer surfaces of the surge tank 132 (see also FIG. 4). Further, the seal member 124e is coupled to the front end and the upper outer surface of the surge tank 132 (see also FIG. 4).

The seal members 124 a to 124 d are in close contact with the inner surface of the right side surface 45 of the engine cover 42. Therefore, a space 125 surrounded by the seal members 124 a to 124 d is formed between the engine cover 42 and the first heat shield member 121. This space 125 is closed except for the inlet 122, the outlet 123, and the drains 126 and 128 described later.
In addition, the seal member 124e allows the traveling wind flowing from the inlet 122 to flow into the intake manifold 131 and blocks the flow into the throttle body 139.

  As shown in FIG. 7, a first drain port 126 is formed in the lower part between the fourth intake branch pipe 133 d and the first heat shield member 120 on the rear side of the space 125. A drain pipe 127 is connected to the first drain port 126, and water that has entered the space 125 is drained from the drain pipe 127 to the outside of the lower cover 41 through the first drain port 126. Further, as shown in FIG. 7, a second drain port 128 is formed in the right side surface portion 45 of the engine cover 42 on the rear side of the space 125. The water that has entered the space 125 is drained from the second drain port 128 to the outside of the engine cover 42.

  In the cooling structure described above, part of the traveling wind introduced from the traveling wind introduction port 74 flows into the intake manifold 131 through the inlet 122 formed in the first front plate 48 of the engine cover. At this time, the space 125 between the engine cover 42 in which the intake manifold 131 is disposed and the first heat shield member 120 is sealed by the seal member 124. Therefore, the traveling wind flowing in from the inflow port 122 can be brought into contact with the outer surface of the intake manifold 131 efficiently, and the intake air flowing into the intake manifold 131 can be efficiently cooled.

  In addition, since the first intake branch pipe 133a to the fourth intake branch pipe 133d of the intake manifold 131 are spaced apart from each other in the vertical direction, it is possible to secure a wide area for bringing the intake manifold 131 into contact with the traveling airflow. The intake air flowing in can be efficiently cooled. The traveling air whose temperature has risen by cooling the intake manifold 131 is exhausted to the outside of the engine cover 42 through the first exhaust port 123a to the third exhaust port 123c.

  Further, even when water enters the space 125 together with the traveling wind, the first heat shield member 120 can prevent the engine 12 from getting wet. Further, the water that has entered the space 125 together with the traveling wind is drained to the outside through the first drain port 126 and the second drain port 128.

  As described above, according to the present embodiment, the traveling wind introduced from the inflow port 122 formed in the front surface portion 47 of the engine cover 42 is brought into contact with the outer surface of the intake manifold 131 and formed on the right side surface portion 68 of the engine cover 42. Since exhaust is performed from the first exhaust port 123a to the third exhaust port 123c, the intake air of the intake manifold 131 can be cooled by the traveling air. Therefore, when the intake air is cooled, the charging efficiency of the intake air is improved, and the output of the engine 12 can be improved.

As mentioned above, although this invention was demonstrated by embodiment mentioned above, this invention is not limited only to embodiment mentioned above, A change etc. are possible within the scope of the present invention.
In the above-described embodiment, the case where the intake manifold 131 is disposed between the right side surface 45 of the engine cover 42 and the right side surface of the engine 12 has been described. However, the present invention is not limited to this case. For example, the intake manifold 131 may be disposed between the left side surface portion 46 of the engine cover 42 and the left side surface of the engine 12. In this case, it is preferable that the inlet 122 and the outlet 123 are also arranged on the left side of the engine cover 42 in the same manner.

  Further, in the above-described embodiment, the case where the intake manifold 131 has the four first intake branch pipes 133a to the fourth intake branch pipe 133d has been described. You may have a branch pipe. Moreover, although the case where the three first outlets 123a to 123c are formed in the engine cover 42 has been described, one or a plurality of outlets may be formed.

1: Hull 10: Outboard motor 12: Engine (internal combustion engine for outboard motor) 14: Cover 40: Upper cover 41: Lower cover 42: Engine cover 43: Upper surface portion 44: Rear surface portion 45: Right side surface portion 46: Left side surface portion 47: Front part 54: Intake duct 55: Inner cover 56: Intake passage 65: Top cover 72: Outside air introduction port 74: Traveling air introduction port 80: Cover part 82: Air filter 83: Intake surface 100: Exhaust port 120: No. DESCRIPTION OF SYMBOLS 1 Heat shield member 211: 2nd heat shield member 122: Inflow port 123: Exhaust port 131: Intake manifold 135: Silencer 137: Suction part 138: Suction port 139: Throttle body 141: Ventilation fan

Claims (3)

An outboard motor intake structure for supplying intake air to an outboard motor internal combustion engine,
An engine cover covering the outboard motor internal combustion engine;
A heat shield member that shields heat from the internal combustion engine for the outboard motor;
An intake manifold that is disposed between the engine cover and the heat shielding member and supplies intake air to the outboard motor internal combustion engine;
A ship that flows in from an inlet formed in a front portion of the engine cover is brought into contact with an outer surface of the intake manifold and discharged from an outlet formed in a side portion of the engine cover. Intake structure of the external unit. A seal member attached between an outer surface of the intake manifold and an inner surface of the engine cover;
The outboard motor intake structure according to claim 1, wherein the traveling wind is caused to flow into a space surrounded by the engine cover, the heat shield member, and the seal member. A muffler disposed in the engine cover and on the front side of the internal combustion engine for an outboard motor, wherein intake air is introduced into the intake manifold;
2. A second heat shield member disposed between the silencer and the outboard motor internal combustion engine and configured to shield heat radiation from the outboard motor internal combustion engine. 2. The outboard motor intake structure described in 2.

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