JP4788458B2 - Outboard motor intake system - Google Patents

Description

  The present invention relates to an outboard motor intake device, and more particularly to an outboard motor intake device including a V-type engine mounted vertically.

  2. Description of the Related Art Conventionally, as an outboard motor intake device equipped with a V-type engine, one having a surge tank arranged for each cylinder bank is generally used (see, for example, Patent Document 1 and Patent Document 2). However, in the conventional intake device, since two surge tanks are provided, the structure becomes complicated and the size of the device is increased. Further, it is necessary to form a bent part in the middle of the intake passage connecting the surge tank and the cylinder head. For this reason, this bent part becomes an intake resistance, leading to a decrease in the intake performance of the outboard motor.

On the other hand, as an outboard motor intake device equipped with a V-type engine, a device provided with a single surge tank has been provided (see, for example, Patent Document 3). This intake device includes a funnel-shaped member as an intake port connected to an intake passage inside a surge tank. Each funnel-shaped member is separated from each other so as not to interfere with the adjacent funnel-shaped member. As a result, the intake efficiency is improved.
Japanese Patent Laid-Open No. 9-42088 JP 2002-242777 A JP 2004-232591 A

  However, the outboard motor intake device of Patent Document 3 has a problem that the funnel-shaped member cannot be provided when the capacity of the surge tank cannot be sufficiently secured due to the structure of the outboard motor. .

  As described above, the conventional outboard motor intake system has a problem that the apparatus is enlarged and the intake performance is deteriorated.

  An object of the present invention is to provide an intake device for an outboard motor capable of improving the intake performance and reducing the size of the device.

In order to achieve the above object, an outboard motor intake system according to claim 1 is a cylinder bank comprising a plurality of cylinders arranged in a vertical direction and expanding in a V shape toward the rear. An intake port of each of the plurality of cylinders formed so as to open inside a V shape, an intake manifold connected to the intake port, a surge tank connected to the intake manifold, and connected to the surge tank A throttle device, and the surge tank is provided between a plurality of intake passages connected to the plurality of cylinders via the intake manifold, and walls provided between adjacent ones of the plurality of intake passages. comprising a member and a lid member for sealing the space formed by the intake passage and the wall member, the intake passage is connected to surfaces of the manifold The throttle device expands in a V-shape toward the rear, and the throttle device is sandwiched between the intake passages in a top view of the wall member located at the top in the vertical direction, and is opened upstream of the intake passage. mounted from the end to the front, characterized in Rukoto.

The outboard motor intake device according to claim 2 is the outboard motor intake device according to claim 1, wherein the intake passage is formed coaxially with the corresponding intake port and extends substantially linearly. and wherein the der Rukoto.

Intake system for an outboard motor according to claim 3, characterized in that it comprises a pre-Symbol silencer and the air intake duct is disposed in a space surrounded by said surge tank and the engine cover and the cylinder banks.

According to an intake system for an outboard motor according to claim 1, it is possible to miniaturize the sub Jitanku, it is possible to miniaturize the apparatus. Thereby, the engine outline can be made compact. In addition, since the capacity of the surge tank can be sufficiently secured even in a small space, the intake performance can be improved. For this reason, the output of an outboard motor can be improved.

According to an intake system for an outboard motor according to claim 2, it is possible to increase the air intake passage, it is possible to reduce the intake resistance. For this reason, intake efficiency can be improved.

According to the outboard motor intake device of the third aspect , since the silencer and the air intake duct are disposed in a space surrounded by the cylinder bank, the surge tank, and the engine cover, the device can be further downsized. Can do. Moreover, the water separation effect of an air intake duct etc. can be improved. For this reason, the output of an outboard motor can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of an upper half portion of an outboard motor 1 provided with an intake device according to an embodiment of the present invention, and FIG. 2 is a partial cross-sectional view of the outboard motor 1 in the horizontal direction. As shown in FIG. 2, the arrow F direction indicates the front direction of the outboard motor 1, and the arrow L direction indicates the port direction.

  The outboard motor 1 includes an engine 2 as shown in FIG. The engine 2 has a V-shaped configuration in which a crankshaft 32 is disposed substantially vertically (vertically) and a left and right cylinder block 50 is installed in a V shape in plan view to open rearward. This is a water-cooled four-cycle V-type six-cylinder engine in which a cylinder bank (V bank) is formed.

  As shown in FIG. 1, the periphery of the engine 2 is covered with an upper cover 10 and a lower cover 11. A top cover (tilt-up handle) 12 is mounted on the upper cover 10, and a louver 13 serving as an outside air inlet is attached between the rear portion of the upper cover 10 and the rear portion of the top cover 12.

  As shown in FIG. 2, the crankcase 31 is disposed at the foremost part (the bow side) of the engine 2, and the cylinder block 50 is disposed behind the crankcase 31. A crankshaft 32 is pivotally supported on the mating surface of the crankcase 31 and the cylinder block 50. The upper end of the crankshaft 32 protrudes above the engine 2, and a power generating magnet device (not shown) is provided at the protruding portion. Hereinafter, the configuration of the cylinder bank on one side (right side) will be mainly described, but the left and right cylinder banks are basically configured similarly.

  The cylinder block 50 has a left bank portion 50L and a right bank portion 50R. A pair of left and right cylinder heads 80 are provided corresponding to the left and right cylinder banks, and the cylinder heads 80L and 80R correspond to the left and right bank portions 50L and 50R, respectively. Three cylinders 51 are formed in each of the left and right bank portions 50L and 50R. On the other hand, each cylinder head 80 is formed with a combustion chamber 52 aligned with each cylinder 51, and an intake port 89 and an exhaust port 90 communicating with the combustion chamber 52. Head covers 33 (33L, 33R) are respectively mounted on the cylinder head 80, and unillustrated intake and exhaust camshafts are rotatably supported in cam chambers defined therebetween. .

  The intake port 89 has an inlet that opens to the inside of the V shape that each cylinder bank exhibits, and a communication portion to the combustion chamber 52 is opened and closed by the intake valve 55. Further, the exhaust port 90 is formed in a V-shaped outer portion (outer portion of the cylinder head 80) exhibited by each cylinder bank, and a communication portion to the combustion chamber 52 is opened and closed by the exhaust valve 54. The reciprocating motion of the piston 53 slidably inserted into each cylinder 51 is converted into the rotational motion of the crankshaft 32 via the connecting rod 34.

  A fuel filter 35 is disposed on the left side of the crankcase 31 and a starter motor 36 is disposed on the right side.

  As shown in FIG. 2, a surge tank 100 is provided behind the center of the engine 2 via an intake manifold 37 connected to the intake port 89. A throttle body 29 is connected to the surge tank 100. As shown in FIG. 12, the throttle body 29 is accommodated in a silencer 19 disposed at the upper rear portion of the engine 2 and takes in outside air introduced into the silencer 19 from an opening thereof. The outside air is taken in from the throttle body 29. The intake manifold 37, the surge tank 100, the throttle body 29, the silencer 19 and the like constitute an intake device of the outboard motor 1.

  Next, the structure of the surge tank 100 will be described.

  FIG. 3 is a rear perspective view showing a schematic structure of the engine 2, FIG. 4 is a top view of the engine 2, and FIG. 5 is a horizontal sectional view of the engine 2. FIG. 6 is a perspective view showing a schematic structure of the surge tank 100, and FIG. 7 is a left side view of the surge tank 100. 3 and 4, the throttle body 29 is omitted.

  As shown in FIGS. 3 to 5, the surge tank 100 is attached to a horizontal attachment surface 38 a extending in the vertical direction of the flange 38 of the intake manifold 37 attached to the cylinder heads 80 </ b> R and 80 </ b> L in parallel in the left-right direction. In the engine 2, the cylinder 2 protrudes rearward from between the cylinder banks 50R and 50L.

  As shown in FIGS. 3 to 7, the surge tank 100 includes a surge tank body 110 and a lid member 120 that seals the surge tank body 110.

  FIG. 8 is a perspective view showing a schematic structure of the surge tank body 110, and FIG. 9 is a cross-sectional view taken along line VIIII-VIIII in FIG.

  As shown in FIGS. 6 to 9, the surge tank main body 110 is adjacent to a flange 111 that is airtightly attached to the flange 38 of the intake manifold 37 and an intake passage 112 that is connected to each cylinder 51 via the intake manifold 37. And a wall member 113 provided between the intake passages 112. The flange 111, the intake passage 112, and the wall member 113 are integrally formed. As shown in FIG. 8, the surge tank main body 110 has a trapezoidal column shape with an open rear end surface and a hollow interior.

  Specifically, as shown in FIGS. 8 and 9, in the engine 2, the intake passage 112 has a first intake passage 112 a connected to the uppermost left cylinder 51 and a second intake passage 112 connected to the uppermost right cylinder 51. An intake passage 112b, a third intake passage 112c connected to the left central cylinder 51, a fourth intake passage 112d connected to the right central cylinder 51, and a fifth intake passage connected to the left bottom cylinder 51 112e and a sixth intake passage 112f connected to the lowermost cylinder 51 on the right side.

  Each intake passage 112 is a cylindrical member having the same shape and extending in a substantially straight line having a circular cross section. Each intake passage 112 has a front end attached to the flange 111 and opens in front of the flange 111. Each intake passage 112 is positioned substantially coaxially with the intake passage 37a of the corresponding intake manifold 37 in a state where the surge tank main body 110 is attached to the intake manifold 37 via the flange 111, and communicates in a substantially straight line. (See FIG. 2). As shown in FIG. 2, each intake passage 37 a of the intake manifold 37 is disposed substantially coaxially with the corresponding intake port 89. For this reason, each intake passage 112 is positioned substantially coaxially with the corresponding intake port 89, and is connected to the intake passage 37 a and the intake port 89 in a straight line. In addition, each intake passage 112 includes a rear end opening 114 (114a to 114f) that opens horizontally rearward at the rear end (see FIG. 8).

  As shown in FIGS. 8 and 9, the wall member 113 includes substantially flat wall members 113 a, 113 b, 113 c, 113 d, 113 e, and 113 f that hermetically seal each side surface except the rear side surface of the surge tank 110. . Specifically, the wall member 113 a is connected to the first intake passage 112 a, the second intake passage 112 b, and the flange 111, and seals between the first intake passage 112 a, the second intake passage 112 b, and the flange 111. The wall member 113a includes an upper surface flat plate member 115 extending substantially horizontally from the intake passage 112a, and a side surface flat plate member 116 extending vertically upward from the second intake passage 112b and connected to the right end of the upper surface flat plate member 115. Yes. A cylindrical opening 101 that protrudes upward and opens vertically is formed at the approximate center of the upper plate member 115 of the wall member 113a.

  The wall member 113b is connected to the fifth intake passage 112e, the sixth intake passage 112f, and the flange 111, and seals between the fifth intake passage 112e, the sixth intake passage 112f, and the flange 111. The wall member 113b has substantially the same shape as the wall member 113a, and a lower surface flat plate member 117 extending substantially horizontally from the sixth intake passage 112f and a left end portion of the lower surface flat plate member 117 extending vertically downward from the fifth intake passage 112e. It is comprised from the side surface flat plate member 118 connected to.

  The wall member 113c is a flat plate-like member extending in the vertical direction, is connected to the first intake passage 112a, the third intake passage 112c, and the flange 111, and is connected to the first intake passage 112a, the third intake passage 112c, and the flange 111. Airtight. The wall member 113d is a flat plate-like member extending in the vertical direction, is connected to the second intake passage 112b, the fourth intake passage 112d, and the flange 111, and is connected to the second intake passage 112b, the fourth intake passage 112d, and the flange 111. Airtight. The wall member 113e is a flat plate-like member extending in the vertical direction, is connected to the third intake passage 112c, the fifth intake passage 112e, and the flange 111, and is connected to the third intake passage 112c, the fifth intake passage 112e, and the flange 111. Airtight. The wall member 113f is a flat plate-like member extending in the vertical direction, is connected to the fourth intake passage 112d, the sixth intake passage 112f, and the flange 111, and is connected to the fourth intake passage 112d, the sixth intake passage 112f, and the flange 111. Airtight.

  Further, as shown in FIG. 8, the surge tank main body 110 has a flange 119 integrally formed on the upper end surfaces of the wall members 113 a to 113 f so as to accommodate the rear end opening 114 of each intake passage 112 therein. Prepare. The flange 119 forms a rear end edge portion of the surge tank main body 110 and allows the lid member 120 to be attached in an airtight manner.

  As described above, in the surge tank body 110, the outer side surface of the first intake passage 112a and the upper surface flat plate member 115 of the wall member 113a are the upper surface, and the outer side surface of the sixth intake passage 112f and the lower surface flat plate member 117 of the wall member 113b are. The lower surface is the outer side surface of the first intake passage 112a, the third intake passage 112c, and the fifth intake passage 112e, the side plate member 118 of the wall member 113b, and the wall members 113c and 113e are the left side surface, and the second intake passage. 112b, the fourth intake passage 112d, the outer side surface of the sixth intake passage 112f, the side plate member 116 of the wall member 113a, and the wall members 113d and 113f form the right side surface, and the flange 111 forms the front surface. That is, the intake passage 112, the wall member 113, and the flange 111 define a substantially trapezoidal columnar space.

  As shown in FIGS. 6 and 7, the lid member 120 has a hollow rectangular parallelepiped shape with an open front end surface, and is formed so that the front end edge portion is in airtight contact with the flange 119 of the surge tank main body 110.

  Further, the surge tank 100 includes a spacer 130 for attaching the lid member 120 to the surge tank body 110 inside the surge tank body 110. As shown in FIG. 10, the spacer 130 extends in a direction perpendicular to the flange 111 and is erected on the wall member 113. The surge tank 100 includes, for example, four spacers 130, and the spacers 130 are screwed and fixed to bosses formed on the wall members 113c, 113d, 113e, and 113f. The surge tank 100 may include a boss formed on the wall member 113 instead of the spacer 130 in order to attach the lid member 120 to the surge tank body 110.

  Further, the surge tank 100 includes a pair of left and right intake rectification funnels 140 and 150, as shown in FIG. The left bank funnel 140 is composed of a plate-like member 141 in which funnel-shaped openings 142, 143, and 144 corresponding to the first intake passage 112a, the third intake passage 112c, and the fifth intake passage 112e are formed. ing. The front ends of the openings 142, 143, and 144 are formed with substantially the same diameter as the openings 114a, 114c, and 114e of the first intake passage 112a, the third intake passage 112c, and the fifth intake passage 112e, The rear end side has a larger diameter than the front end side. Further, the openings 142, 143, and 144 are formed so as to be smoothly connected from the rear end side to the front end side. That is, the openings 142, 143, and 144 are formed in a trumpet shape. The funnel 140 is attached to the inside of the surge tank body 110 by fitting front ends of the openings 142, 143, and 144 to the openings 114a, 114c, and 114e of the intake passage.

  The right bank funnel 150 is formed in line symmetry with respect to the left bank funnel 140, and similarly to the funnel 140, corresponds to the second intake passage 112b, the fourth intake passage 112d, and the sixth intake passage 112f, respectively. It comprises a plate-like member 151 in which funnel-shaped openings 152, 153 and 154 are formed. The surge tank 100 is not limited to the one provided with the funnels 140 and 150, and may be provided with a funnel having another shape.

  As shown in FIG. 10, the surge tank 100 has a spacer 130 and left and right bank funnels 140 and 150 attached to the surge tank main body 110. As shown in FIG. 6, the surge tank 100 is attached to the spacer 130 via the boss 121 of the lid member 120. The bolts are screwed together, and the plurality of bolts 123 are screwed into the flange 119 of the surge tank body 110 via the plurality of bosses 122 at the front edge of the lid member 120, and the surge tank body 110 and the lid member 120 are flanged. 119 and the lid member 120 are joined and fixed in an airtight manner through the front edge portion of the lid member 120 and assembled.

  In the engine 2, as shown in FIG. 4, the surge tank 100 is attached to the intake manifold 37 with the flange 111 hermetically joined and fixed to the flange 38 of the intake manifold 37 by a plurality of bolts 161. In the surge tank 100, a throttle body 29 is attached to an opening 101 formed in the upper wall member 113a (see FIG. 2). As described above, in the outboard motor 1, the surge tank 100 has an internal space defined by the surge tank main body 110 and the lid member 120 sealed.

  As described above, the surge tank 100 is provided with the wall member 113 between the intake passages 112 and forms a box-shaped space together with the lid member 120. Thus, the sirgin tank 100 uses the space between the intake passages, which was a dead space in the conventional outboard motor, as a part of the surge tank. For this reason, the capacity | capacitance of a surge tank can be increased and the intake performance of an intake device can be improved. In addition, since the surge tank 100 uses the dead space as a part thereof as described above, a sufficient capacity can be secured without causing the surge tank to protrude left and right or rearward as in the prior art. For this reason, size reduction can be achieved and the outline of the engine 2 can be made compact.

  Further, since the throttle body 29 is disposed on the upper surface of the surge tank 29, the outline of the engine 2 can be made more compact.

  In the surge tank 100 having the above-described configuration, outside air supplied from the throttle body 29 is stored in the internal space of the surge tank 100 when the engine 2 is in operation. And when the inside of each cylinder 51 becomes a negative pressure according to the motion of the piston 53, the outside air stored in the internal space becomes the openings 142 to 144, 152 to 154 of the funnels 140 and 150, the intake passages 112a to 112f, the intake The gas is supplied to the combustion chamber 52 of the corresponding cylinder 51 through the manifold 37 and the intake port 89. At this time, the air supplied to each intake passage 112 from the internal space of the surge tank 100 through the openings 142 to 144 and 152 to 154 of the funnels 140 and 150 has a trumpet shape in the openings 142 to 144 and 152 to 154. Since it is present, it is rectified. In addition, since each intake passage 112, the intake passage 37a of the intake manifold 37, and the intake port 89 are arranged substantially coaxially and connected in a straight line, the intake resistance can be reduced. For this reason, outside air can be efficiently supplied from the internal space of the surge tank 100 to the combustion chamber 52. Therefore, the intake efficiency of the intake device can be further improved.

  Moreover, in the surge tank 100, since the internal space is defined by using the intake passage 112, the intake passage 112 can be lengthened. For this reason, the intake efficiency of the intake device can be improved.

  The surge tank 100 includes a separate surge tank main body 110 and a lid member 120, and the lid member 120 can be easily removed when the surge tank 100 is attached to the outboard motor 1. For this reason, funnels 140 and 150 can be easily attached and detached, and can be easily replaced with funnels having different shapes. For this reason, the intake efficiency of the intake device can be easily improved.

  Furthermore, the surge tank 100 can be handled as an integral part after the surge tank main body 110, the lid member 120, and the funnels 140, 150 are assembled. For this reason, when attaching to the engine 2, it is not necessary to remove the cover member 120, and assemblability can be improved.

  Next, other components of the intake device will be described.

  FIG. 11 is an exploded perspective view of the engine cover assembly including the upper cover 10 and related parts. FIG. 12 is an external view of the upper half of the outboard motor 1 with the engine cover assembly 60 removed. 13 is an external view in which the louver 13 and the left and right air intake guides are added to FIG.

  As shown in FIG. 11, the engine cover assembly 60 is formed by assembling the upper cover 10 with the left and right air intake guides 14 and 15 in addition to the top cover 12 and the louver 13. There are other parts that can be attached to the upper cover 10, but their illustration and description are omitted.

  A cover portion 18 that covers the silencer 19 (see FIG. 12) is integrally formed at the center of the rear portion of the upper surface 10 a of the upper cover 10. In the rear part of the upper surface 10 a of the upper cover 10, substantially triangular holes 16 and 17 are formed on the left and right sides of the cover part 18. At the front portions of the air intake guides 14 and 15, quadrangular upper openings 14 a and 15 a that open upward are provided. The upper opening 14a is slightly to the right of the front portion of the left air intake guide 14 (near the center of the upper cover 10), and the upper opening 15a is slightly to the left of the front portion of the right air intake guide 15 (near the center of the upper cover 10). ), Respectively. In addition, the air intake guides 14 and 15 are formed with lower openings 14b and 15b that are opened downward with the lower edges 14c and 15c as outer edges and are long in the front-rear direction. The insides of the air intake guides 14 and 15 are hollow.

  The air intake guides 14 and 15 are disposed at positions so as to cover the hole front portions 10ab and 10ac and the holes 16 and 17 which are front portions of the holes 16 and 17 in the upper surface 10a of the upper cover 10, respectively. It is fixed to the upper surface 10a by screws (not shown). At that time, the contact portion between the upper surface 10a of the upper cover 10 and the lower edge portions 14c and 15c is sealed with a liquid gasket or the like. Thus, the hole front portions 10ab and 10ac partition the front half of the lower openings 14b and 15b, so that the passages from the upper openings 14a and 15a to the holes 16 and 17 are in communication.

  The top cover 12 is fixed to the upper part of the upper cover 10 with screws. The louver 13 is fixed to the rear portion of the top cover 12 and the rear portion of the upper cover 10 with screws.

  As shown in FIGS. 2 and 12, left and right air intake ducts 20 and 40 are provided on the left and right sides of the rear of the engine 2. The air intake ducts 20 and 40 are disposed in a space between the surge tank 100 and the left and right cylinder head covers 33L and 33R. Therefore, the air intake ducts 20 and 40 are substantially within the outline of the engine 2 in a plan view (FIG. 2).

  The air intake ducts 20 and 40 are cylindrical members penetrating in the vertical direction up to the lower end position of the engine 2, and the cross section thereof has a substantially triangular shape corresponding to the holes 16 and 17 of the upper cover 10. The outer shape of the air intake ducts 20 and 40 is slightly smaller than the holes 16 and 17 of the upper cover 10. The upper ends 20a, 40a of the air intake ducts 20, 40 serve as an intake port for outside air, and the lower ends of the air intake ducts 20, 40 serve as an exhaust port. Seal members 26 and 46 are attached to the upper ends 20a and 40a.

  As shown in FIG. 12, stays 23 and 24 are integrally formed at the rear portion of the left air intake duct 20. The left air intake duct 20 is screwed and fixed with screws 21 and 22 at two upper portions of the head cover 33L, and stays 23 and 24 are screwed and fixed to the left side of the surge tank 100 with screws 27 and 28. The engine 2 is fixed.

  As shown in FIG. 2, a partition plate 25 is integrally formed to extend from the front left side of the left air intake duct 20. The partition plate 25 extends from a position slightly lower than the upper end of the left air intake duct 20 to a lower end position, and extends rearward to a position substantially covering the left side portion of the head cover 33L. The front end of the partition plate 25 is close to the upper cover 10, and the partition plate 25 allows the space on the left side of the engine 2 in the upper cover 10 to be the main heat source from the engine body (from the crankcase 31 to the vicinity of the head cover 33L). And the intake device side (the side where the intake manifold 37 and the surge tank 100 are provided).

  Further, the right air intake duct 40 is also configured symmetrically with the left air intake duct 20. Then, it is screwed and fixed with screws 41 and 42 at two upper portions of the head cover 33R (see FIG. 12), and is screwed and fixed to the right side portion of the surge tank 100 via a stay (not shown), so that the engine 2 is fixed.

  Further, a partition plate 45 (see FIG. 2) is integrally extended from the front right side portion of the right air intake duct 40. The partition plate 45 is configured to be bilaterally symmetric with respect to the partition plate 25. Therefore, the partition plate 45 allows the space on the right side of the engine 2 in the upper cover 10 to be the engine body (part from the crankcase 31 to the vicinity of the head cover 33R). And the intake device side.

  Further, an upper partition plate 57 having a “H” shape in plan view is provided on the upper rear portion of the flywheel magneto cover 56 that covers the magneto device (not shown) (see FIG. 12). The upper partition plate 57 divides the space above the engine 2 in the upper cover 10 into an engine body side and an intake device side. That is, the upper partition plate 57 and the partition plates 25 and 45 cooperate to partition the space in the upper cover 10 in the front-rear direction, that is, the engine body side and the intake device side. In addition, the exhaust port, which is the lower end of the air intake ducts 20 and 40, opens into the space on the partitioned intake device side.

  When the assembled engine cover assembly 60 (see FIG. 11) is put on the outboard motor 1 in the state shown in FIG. 12 from above, the louver 13 and the air intake guides 14 and 15 in the engine cover assembly 60 are shown in FIG. Located in such a position. In FIG. 13, the top cover 12 and the upper cover 10 are not shown. The upper openings 14a and 15a of the air intake guides 14 and 15 are located substantially at the center of the engine 2 in plan view. That is, the upper openings 14a and 15a are arranged at positions that are separated from any part of the louver 13 that is curved so as to wrap around left and right. In addition, interference between the upper openings 14a and 15a and the magneto device (not shown) is also avoided.

  With the engine cover assembly 60 mounted, the upper ends 20a, 40a (see FIG. 12) of the air intake ducts 20, 40 are substantially flush with the hole front portions 10ab, 10ac (see FIG. 11) of the upper surface 10a of the upper cover 10. It becomes. Accordingly, portions of the lower edge portions 14c and 15c of the air intake guides 14 and 15 corresponding to the upper ends 20a and 40a come into contact with the upper ends 20a and 40a through the holes 16 and 17 and the seal members 26 and 46, respectively. Accordingly, the upper intake openings 14a and 15a of the air intake guides 14 and 15 through the holes 16 and 17 are communicated with the lower ends (exhaust ports) of the air intake ducts 20 and 40, respectively. By the seal members 26 and 46, an outside air passage is formed so as not to leak on the way. As described above, since the passage of the outside air is automatically formed only by covering the engine cover assembly 60 from above, there is no hindrance to the attachment / detachment operation of the engine cover assembly 60.

  In the intake device having the above-described configuration, when the engine 2 is operated, outside air is first taken into the upper cover 10 from the louver 13. An opening 19a is formed in the front part of the silencer 19 (see FIGS. 12 and 13), but the upper part of the opening 19a of the silencer 19 is covered with the front part 18a of the cover part 18 (see FIG. 11). Therefore, outside air does not flow directly into the opening 19a.

  Outside air that has entered from the louver 13 enters the air intake guides 14 and 15 from the upper openings 14 a and 15 a of the air intake guides 14 and 15. At this time, since the upper openings 14a and 15a are separated from the louver 13, water such as mist contained in the outside air is likely to fall on the way, and water entering the air intake guides 14 and 15 can be reduced. it can.

  The outside air that has entered the air intake guides 14 and 15 is introduced into the air intake ducts 20 and 40 from the upper ends 20 a and 40 a of the air intake ducts 20 and 40. Then, the air intake ducts 20 and 40 are discharged into the upper cover 10 from the exhaust ports at the lower ends. Since the lower ends of the air intake ducts 20 and 40 are located in the vicinity of the lower end of the engine 2, it is difficult for water in the outside air to adhere to parts around the engine 2.

  The outside air discharged from the lower ends of the air intake ducts 20 and 40 flows backward in the upper cover 10, rises in front of the surge tank 100, and flows into the throttle body 29. Thereafter, as described above, the fuel is supplied to the combustion chamber 52 through the surge tank 100, the intake manifold 37, and the intake port 89 (see FIG. 2). The air intake ducts 20 and 40 are in a relatively cool space on the intake device side partitioned by the partition plates 25 and 45, and the front space of the surge tank 100 is also a space on the intake device side. It is difficult to warm up on the way and is supplied to the engine 2 in a cold state.

  As described above, in the present embodiment, since the surge tank 100 can be reduced in size, the air intake ducts 20 and 40 can be disposed between the surge tank 100 and the cylinder head covers 33L and 33R. . For this reason, the air intake ducts 20 and 40 can be extended to the lower part of the engine 2, and the air intake ducts 20 and 40 can be lengthened. For this reason, the water separation effect of the air intake ducts 20 and 40 can be improved, and the output of the outboard motor 1 can be improved.

  As described above, in this embodiment, the surge tank 100 can be reduced in size while increasing the internal space of the surge tank 100. For this reason, an intake device can be reduced in size and the outline of an engine can be made compact. In addition, since the capacity of the surge tank can be sufficiently secured even in a small space, the intake performance can be improved while downsizing the intake device. For this reason, the output of an outboard motor can be improved.

  In the present embodiment, it is preferable that the connection position of the wall member 113 with the intake passage 112 is the outermost side of the outer side surface of the intake passage 112. This is because the internal space of the surge tank 100 can be further increased, and the intake efficiency of the intake device can be improved.

  In the present embodiment, the air intake ducts 20 and 40 among the components of the intake device are disposed between the surge tank 100 and the cylinder head covers 33L and 33R. Instead of this, other components of the intake device may be provided.

  In the present embodiment, the air intake guides 14 and 15 are fixed to the upper cover 10 and the top cover 12, but the present invention is not limited to this. For example, the air intake guides 14 and 15 are integrated with the upper cover 10 by integral molding. You may comprise an upper air intake. In that case, if a plate-like member corresponding to the hole front portions 10ab, 10ac (see FIG. 11) of the upper surface 10a of the upper cover 10 is attached to the lower opening of the air intake guide, the configuration is the same as the above (FIG. 11). In addition, a passage of outside air from the air intake guide to the air intake ducts 20 and 40 can be formed.

  Further, in the present embodiment, the V-type 6-cylinder engine is taken as an example, but the intake device according to the present embodiment can be applied to other V-type engines and other types of engines.

It is a perspective view of the upper half part of an outboard motor provided with the air intake device which concerns on one embodiment of this invention. FIG. 2 is a partial cross-sectional view in the horizontal direction of the outboard motor of FIG. 1. FIG. 2 is a rear perspective view showing a schematic structure of an engine in the outboard motor of FIG. 1. FIG. 2 is a top view showing a schematic structure of an engine in the outboard motor of FIG. 1. FIG. 2 is a horizontal sectional view showing a schematic structure of an engine in the outboard motor of FIG. 1. It is a perspective view which shows schematic structure of the surge tank in the engine of FIG. It is a left view of the surge tank of FIG. It is a perspective view which shows schematic structure of the surge tank main body in the surge tank of FIG. It is sectional drawing which follows the line VIIII-VIIII of FIG. It is a disassembled perspective view which shows the component of the surge tank of FIG. FIG. 2 is an exploded perspective view of an engine cover assembly including an upper cover and related parts in the outboard motor of FIG. 1. FIG. 3 is an external view of the upper half of the outboard motor with the engine cover assembly removed. It is the external view which added illustration of the louver and the left and right air intake guides with respect to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outboard motor 2 Engine 20, 40 Air intake duct 29 Throttle body 33 Cylinder head cover 37 Intake manifold 38 Bracket 50 Cylinder block 50L, 50R Cylinder bank 80 Cylinder head 100 Surge tank 110 Surge tank main body 111 Flange 112 Intake passage 113 Wall member 120 Lid member 130 Spacer 140, 150 Funnel

Claims (3)

In a cylinder bank that includes a plurality of cylinders arranged in a vertical direction and expands in a V shape toward the rear, each intake of each of the plurality of cylinders formed to open inside the V shape Port,
An intake manifold connected to the intake port;
A surge tank connected to the intake manifold;
A throttle device connected to the surge tank,
The surge tank includes a plurality of intake passages connected to the plurality of cylinders via the intake manifold, wall members provided between adjacent ones of the plurality of intake passages, and the intake passages. And a lid member for sealing a space formed by the wall member ,
The intake passage is expanded in a V shape toward the rear from the connection surface with the manifold, and the throttle device is arranged on the wall member located at the top in the vertical direction among the wall members in the top view. intake system for an outboard motor, characterized in Rukoto mounted in front of the upstream opening end of the intake passage sandwiched passage. The intake passage corresponding said intake port and coaxially formed with the tubular member der Rukoto intake system for an outboard motor according to claim 1, wherein the extending substantially linearly. 3. The outboard motor intake system according to claim 1, further comprising a silencer and an air intake duct disposed in a space surrounded by the cylinder bank, the surge tank, and the engine cover.

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