JP2004232590A - Intake device of outboard motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device of an outboard motor, having excellent machinability and effectively realizing a measure against heat. <P>SOLUTION: Right and left cylinder banks of an upright mounted V-shaped engine 2 are expanded backward, and a collector 61 is connected to an intake port 42 of each cylinder opened to the inside of the cylinder back from the back through an intake manifold 37. The intake manifold 37 having a plurality of intake passages corresponding to the respective cylinders is formed wedge-shaped in plan view, the intake passages are extended right and left along the wedge-shape to the corresponding intake port 42, and the intake port is formed substantially by the extended part. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention particularly relates to an air intake device for an outboard motor having an engine mounted vertically and having a V-shape with left and right cylinder banks.
[0002]
[Prior art]
When a four-cycle V-type engine in which left and right cylinders having cylinders are arranged in a V-shape is mounted, the cylinders are arranged vertically so that the crankshaft faces substantially vertically during cruising. In this type of outboard motor, in a conventional vertical V-type engine, an intake manifold has a structure in which, for example, an intake port extends long to near a top of a cylinder head, and a carburetor or the like is disposed thereon. (See Patent Document 1).
[0003]
[Patent Document 1]
62-184122
[0004]
[Problems to be solved by the invention]
However, in the conventional intake structure, since the intake port of the cylinder head is too long, it has been difficult to form and process the die-cast cylinder head. In addition, since the cylinder head that generates heat during operation of the engine and the long intake port are integrally formed, the intake port causes the intake temperature to rise more than necessary. Particularly, in an outboard motor entirely covered by the engine cover, the temperature inside the engine cover may be too high.
[0005]
The present invention has been made in view of the above circumstances, and has as its object to provide an outboard motor intake device that is excellent in workability and effectively implements a countermeasure against heat.
[0006]
[Means for Solving the Problems]
In the intake device for an outboard motor according to the present invention, the left and right cylinder banks of a V-type engine mounted vertically are expanded rearward, and the intake ports of the respective cylinders opening inside the cylinder bank are viewed from the rear. An intake device for an outboard motor to which a collector is connected via an intake manifold, wherein the intake manifold having a plurality of intake passages corresponding to the respective cylinders is formed in a wedge shape in a plan view, and the intake passages correspond to the intake passages. It is characterized in that the intake port is extended right and left along the wedge shape, and the intake port is formed substantially at this extended portion.
[0007]
Further, in the intake device for an outboard motor according to the present invention, a water jacket is vertically provided at a central portion of the right and left intake passages extending toward the left and right cylinder banks. I do.
[0008]
Further, in the outboard motor intake device of the present invention, a straight through hole is formed in a vertical direction at a branch portion of the intake passage that expands forward toward the left and right cylinder banks by being sandwiched therebetween. The through hole is used as a water channel of the water jacket.
[0009]
Further, in the outboard motor intake device according to the present invention, a heat insulating means is interposed at a joint between the intake manifold and the intake port.
[0010]
According to the present invention, the intake manifold is formed in a wedge shape, and the intake port of the cylinder head is formed to be short, so that the shape of the cylinder head can be simplified, and the manufacture becomes easy. In addition, by connecting the intake port to a separate intake manifold, typically through a heat insulating means, it is possible to make the structure less susceptible to heat from the cylinder head.
[0011]
Furthermore, a water jacket is provided in the vicinity of the intake passage of the intake manifold, and cooling water is circulated in the water jacket, so that the intake passage can be effectively cooled.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a left side view showing an example of the overall configuration of an outboard motor 1 according to the present invention, and FIG. 2 is a plan view of an engine block disposed on an upper portion of the outboard motor 1. In these figures, the arrow Fr indicates the front side of the outboard motor 1 (the forward direction of the hull equipped with the outboard motor 1), and the arrow Rr indicates the rear side of the outboard motor 1 (the outboard motor 1 is installed). Indicates the hull's reverse direction). In this case, the outboard motor 1 is fixed to the rear plate P of the hull at the front side as shown in FIG.
[0013]
In the schematic configuration of the outboard motor 1, an engine block A having an engine 2 disposed thereon, a drive shaft housing B having a drive shaft 3 for transmitting the output of the engine 2 to the propeller side, and a drive of the drive shaft 3 A gear housing C having a drive unit 5 for rotating and driving the propeller 4 by force is sequentially arranged vertically. The engine block A, the drive shaft housing B, and the gear housing C are respectively covered with covers 6a, 6b, 6c as outer shells. Since these covers 6a, 6b, and 6c are smoothly joined to each other, the outboard motor 1 is covered with the cover 6 so as to have a form having a sense of unity as a whole. It has a roughly oval configuration. Inside, an intake system, an exhaust system, and a lubrication system are arranged, and as described in detail later, they have a compact structure in addition to their technical effects, thereby creating an excellent design effect. .
[0014]
In this example, the engine 2 employs a V-type six-cylinder (so-called “V6”) engine, and the cylinder bore axes S of the cylinders in the left and right cylinder banks intersect to form a V-shape. As shown in FIG. 2, the engine 2 is disposed such that the pointed end of the V-shape faces forward Fr. In this case, the engine 2 is mounted and supported by the engine base 8 so that the crankshaft 7 of the engine 2 is vertically set so as to face the vertical direction.
[0015]
A pair of left and right upper mounts 9 is disposed at the front edge of the engine base 8, and a pair of left and right lower mounts 10 are disposed at the front edge of the drive shaft housing B. The engine block A, the drive shaft housing B and the gear housing C are supported via these mounts 9 and 10 so as to be integrally rotatable around a support shaft 12 set on the swivel bracket 11. Clamp brackets 13 are provided on both left and right sides of the swivel bracket 11, and are fixed to the rear plate P of the hull via the clamp brackets 13. The clamp bracket 13 is rotatably supported around a tilt shaft 14 set in the left-right direction.
[0016]
A water tank 15 for cooling water disposed adjacent to the rear side of the drive shaft 3 is mounted on an upper portion in the drive shaft housing B, and an oil pan 16 for lubricating oil is mounted on the rear side. . At the bottom of the water tank 15, a cooling water pipe 17 is hung, and the cooling water pipe 17 is connected to a water supply pipe 19 for supplying water taken in from a water intake port 18 provided in the gear housing C. A cooling water pump 20 driven by the drive shaft 3 is attached to a connection between the cooling water pipe 17 and the water supply pipe 19. The cooling water pump 20 takes in water from the outside of the outboard motor 1 through a filter 21 attached to the water intake 18 and sends the water to the cooling water pipe 17 and further to the water tank 15.
[0017]
In the gear housing C, the drive shaft 3 extending downward from the drive shaft housing B is gear-coupled to the drive unit 5. A propeller shaft 22 that extends orthogonally to the drive shaft 3 and extends rearward from the drive unit 5 is rotatably supported in the gear housing C by, for example, a ball bearing 23 or a needle bearing 24, and the propeller 4 is fixed to the rear end thereof. I have.
[0018]
The drive unit 5 includes a forward (forward) gear 25 and a reverse (reverse) gear 26 which are rotatably supported by being loosely fitted to the propeller shaft 22. These gears 25 and 26 are provided at the lower end of the drive shaft 3. It is always meshed with the provided drive gear 27. In this example, the forward gear 25 is disposed on the front Fr side, and the reverse gear 26 is disposed on the rear Rr side, and a clutch dog 28 is disposed on these gears 25, 26. The clutch dog 28 is selectively connected to the forward gear 25 and the reverse gear 26, and by this operation, the driving force of the drive shaft 3 is transmitted to the propeller shaft 22.
[0019]
In this case, the clutch rod 29 extending downward from the vicinity of the engine 2 of the engine block A is connected to the shift rod 30 near the joint between the drive shaft housing B and the gear housing C. The clutch rod 29 can be operated by a shift lever operated by the operator. The shift rod 30 operates the clutch dog 28 via a shift cam 31 or a push rod 32 constituting a clutch mechanism, thereby rotating the propeller shaft 22 forward or backward.
[0020]
Here, as shown in FIG. 2, the engine 2 of the engine block A has six cylinders arranged alternately in the vertical direction along the V-shape in the vertical direction. , A cylinder block 34, a cylinder head 35 and a cylinder head cover 36 are arranged and connected. The crankshaft 7 is pivotally supported on the mating surface of the crankcase 33 and the cylinder block 34. As described above, in a V6 engine in which each cylinder expands left and right (in plan view) with the crankshaft 7 as a base, a V-shaped cylinder bank is formed by the left and right three cylinders. An intake manifold 37 to be described later is provided inside the cylinder bank.
[0021]
As shown in FIG. 3, a cylinder bore 38 is formed for each cylinder inside the cylinder block 34, and a piston 39 is fitted in the cylinder bore 38 so as to reciprocate. The piston 39 is connected to the crankpin 7a of the crankshaft 7 via a connecting rod 40, whereby the reciprocating motion of the piston 39 in the cylinder bore 38 is converted into the rotational motion of the crankshaft 7, and further, as the output of the engine 2, the drive shaft 3 Is transmitted to
[0022]
The cylinder head 35 has a combustion chamber 41 aligned with the cylinder bore 38, and an intake port 42 and an exhaust port 43 communicating with the combustion chamber 41, respectively. The inlet of the intake port 42 opens inside the above-described V-shape of the cylinder bank, and the communication portion with the combustion chamber 41 is controlled to be opened and closed by an intake valve 44. In this case, the intake valve 44 is driven by a cam 46 provided on a camshaft 45. Further, the inlet of the exhaust port 43 opens to the outside of the V shape of the cylinder bank, and the communication portion with the combustion chamber 41 is controlled to be opened and closed by an exhaust valve 47. In this case, the exhaust valve 47 is driven by a cam 49 provided on a cam shaft 48. In this embodiment, each cylinder may have four valves each having two valves on the intake side and the exhaust side.
[0023]
As a cam or camshaft driving mechanism, for example, a cam chain 50 (FIG. 1) is provided between a sprocket provided at the lower end of two camshafts 45 extending vertically and a sprocket provided at the upper end of the drive shaft 3. And the drive shaft 3 and the camshaft 45 are connected. In this case, the camshaft 45 and the camshaft 48 are mutually connected via a chain or the like on the intake side and the exhaust side, respectively. Further, the upper end of the drive shaft 3 and the lower end of the crankshaft 7 are connected via a reduction gear 51 as shown in FIG. The shaft 45 and the camshaft 48 are driven to rotate, whereby the plurality of cams 46 and 49 can be driven synchronously.
[0024]
A spark plug 52 is mounted on the top of the combustion chamber 41 of each cylinder, and a plurality (six in this example) of intake passages 37a (37a) connected to each intake port 42 from the intake manifold 37. ₁ ~ 37a ₆ ; See FIG. 4). From the injector 53 mounted on the intake manifold 37, fuel is injected toward a deep portion of each intake port 42. The combustion gas exploded and burned in the cylinder is discharged from the exhaust port 43 to an exhaust manifold 54 described later.
[0025]
In each of the left and right three cylinders of the V6 engine, an exhaust manifold 54 is connected to each of the exhaust ports 43, and is connected to the vicinity of the right and left side surfaces of the engine base 8 as a collective exhaust passage. The exhaust gas passes through the collective exhaust passage, and is discharged into water through the exhaust passage formed in the drive shaft housing B to the gear housing C.
[0026]
As shown in FIG. 3, a cooling water jacket 55 is additionally provided around the cylinder bore 38 and the exhaust system, that is, around the exhaust port 43 to the exhaust manifold 54 along the vertical direction of the engine block A. The cooling water flows through the water jacket 55. In this case, the cooling water pump 20 sends water to the water tank 15, and sends water from the water tank 15 to the water jacket 55.
[0027]
In general, the cooling water flowing through the water jacket 55 as shown by the arrow D in FIG. 1 passes through a drain pipe 56 from the top of the engine block A to a drain passage formed in the drive shaft housing B to the gear housing C. Through the water. In the cooling system thus configured, the drain pipe 56 is compactly accommodated in the space inside the V-shape of the cylinder bank as shown in FIG. 1 or FIG. A thermostat 57 is attached to a connection portion of the drain pipe 56 so as to control the flow of cooling water.
[0028]
An oil pump 58 is attached to a lower portion of the engine block A as shown in FIG. An oil suction pipe 59 suspended in the oil pan 16 is connected to an oil suction port of the oil pump 58, and oil is supplied from an oil discharge port. In this lubrication system, the oil in the oil pan 16 is sucked up by the oil pump 58 and distributed and supplied to each oil passage formed in the engine block A. The lubricating oil lubricates the main lubrication points in the engine block A, and is thereafter collected in the oil pan 16.
[0029]
Now, in the intake system, a collector 61 is provided via the intake manifold 37 behind the center of the engine 2. The collector 61 has a hermetically sealed structure in which a collector body 62 typically formed of a synthetic resin material and a metal (typically aluminum alloy) cover 63 that covers the collector body 62 are closed. As shown in FIG. 5, air is taken in from throttle bodies 64 provided on the upper left and right sides. As described later, air taken in from the throttle body 64 is switched to a high-speed passage and a low-speed passage by the variable intake length system.
[0030]
A throttle type throttle valve 65 is mounted on the throttle body 64 as shown in FIG. 2 to FIG. 3 or FIG. 4, and the opening of the throttle valve 65 is controlled by a control lever 66. Further, as shown in FIG. 1, the throttle body 64 opens into a silencer 67 mounted on the upper rear of the engine block A, and the air taken in from the outside of the outboard motor 1 through the opening is as shown by an arrow E. Is taken in through a silencer 67. The silencer 67 has an accommodating portion 67a for an actuator 68 that drives a high / low speed switching valve described later.
[0031]
As shown in FIG. 6, a plurality of (six in this example) high-speed air suction passages 69 (six in this example) formed linearly in the front-rear direction at predetermined vertical intervals in the left and right central portions of the collector main body 62. 69A to 69F) are arranged in a line. As shown in FIG. 6 (b), each high-speed air suction passage 69 extends from the front surface of the collector main body 62 appropriately, and the corresponding intake passage 37a of the intake manifold 37. ₁ ~ 37a ₆ Communicate with
[0032]
In addition, six low-medium speed air suction passages 70 (70A to 70F) are provided corresponding to each high speed air suction passage 69. Each low-medium-speed air suction passage 70 has an opening 70a formed facing the corresponding high-speed air suction passage 69, and is left or right outward from the opening 70a as shown in FIG. It is directed to the high-speed air suction passage 69 in the form of a U-shaped or arcuate curved U-turn, and joins the corresponding high-speed air suction passage 69 as shown in FIG. 6B.
[0033]
For example, as shown in FIG. 6A, the low-medium speed air suction passage 70A has an opening 70a at the left and right sides of the outboard motor 1 with respect to the high speed air suction passage 69B and at a position substantially corresponding to the vertical direction. Then, it curves upward from the opening 70 a and joins the high-speed air suction passage 69. The low-medium speed air suction passage 70B has an opening 70a at the right side in the left-right direction of the outboard motor 1 with respect to the high speed air suction passage 69A and at a position substantially corresponding to the up-down direction, and extends downward from the opening 70a. It curves and joins the high-speed air suction passage 69. The low-medium speed air suction passages 70C to 70F are similarly arranged and configured.
[0034]
In this way, the low-medium speed air suction passages 70A-70F are arranged alternately on the left and right with respect to the high speed air suction passages 69A-69F. The intake passage 37a of the intake manifold 37 described above. ₁ , 37a ₃ , 37a ₅ Low-medium-speed air suction passages 70A, 70C, 70E connected to the three cylinders of the right cylinder bank via the right-hand cylinder bank (see FIG. 4) are arranged on the left side of the collector 61 with the high-speed air suction passage 69 interposed therebetween. Is established. Also, the intake passage 37a of the intake manifold 37 ₂ , 37a ₄ , 37a ₆ The air suction passages 70B, 70D, and 70F for low and medium speeds respectively connected to the three cylinders of the left cylinder bank via the air passage are disposed on the right side of the collector 61 with the air suction passage 69 for high speed interposed therebetween. As shown in FIG. 6B, the low-medium-speed air suction passage 70 diagonally joins the high-speed air suction passage 69 at the connection portion with the intake manifold 37, and the low-medium-speed air suction passage near the junction. Air intake passages 70A to 70F are connected to intake passages 37a of intake manifold 37 to be connected. ₁ ~ 37a ₆ And the passage axis directions substantially coincide with each other.
[0035]
As shown in FIG. 6B, a butterfly type high / low speed switching valve 71 is provided on the suction port side of each high speed air suction passage 69 (upstream of the junction with the low / medium speed air suction passage 70). Be attached. Each of the high / low speed switching valves 71 is rotatably supported in the high speed air suction passage 69 by a drive shaft 72 arranged in the vertical arrangement direction of the high speed air suction passage 69. As shown in FIG. 2 or FIG. 5, an actuator 68 is attached to the upper part of the collector body 62 at the upper rear of the engine block A, and the drive shaft 72 is driven by a drive lever or rod 73 and a crank 74 which advance and retreat by the actuator 68. Is rotated forward and backward. Therefore, the high / low speed switching valve 71 can open and close all the high speed air suction passages 69 in synchronization with the operation of the actuator 68.
[0036]
In addition, funnels 75 (75A to 75F) for intake air flow rectification are provided separately from the collector main body 62 at the suction ports of the high-speed air suction passages 69. The funnel 75 may be, for example, an elbow-shaped synthetic resin hollow cylindrical body having a circular cross-sectional shape. Although the arrangement method (direction) is particularly different, the funnel 75 is the same component as a single product. Each funnel 75 is connected at its base to a suction port of a high-speed air suction passage 69 so that air flows into an inflow port 75a which is appropriately expanded like a trumpet.
[0037]
Here, in the present invention, the intake manifold 37 to which the collector 61 is particularly connected has a substantially wedge-like shape (in a top view) in which the intake passages 37a open toward the left and right cylinder banks as shown in FIG. ). In this case, the intake manifold 37 is fastened and fixed to an appropriate position of the cylinder head 35 in the front-rear direction (vertical direction on the paper in FIGS. 2 and 3) by a plurality of bolts 76. The intake passages 37a extend alternately left and right along the wedge shape in the vertical direction toward the corresponding intake port. As a result, the intake port 42 of the cylinder head 35 is shortened, and an intake port is substantially formed in the intake passage 37a.
[0038]
Also, as shown in FIG. 4, right and left intake passages 37a extending toward the left and right cylinder banks. ₁ , 37a ₃ , 37a ₅ And intake passage 37a ₂ , 37a ₄ , 37a ₆ , A water jacket 77 extends vertically. In this case, a typically linear through-hole is formed in the vertical direction at the branch portion of the intake passage 37a which expands forward toward the left and right cylinder banks, and is sandwiched between them. 77 waterways. The cooling water injected from the water supply port 78 provided at the lower end of the water jacket 77 flows upward in the water jacket 77 and is drained from the drain port 79 at the upper end.
[0039]
As the cooling water supplied to the water jacket 77, the water sent to the water tank 15 by the cooling water pump 20 described above can be used. In this case, a cooling water passage is formed at an appropriate position of the engine base 8, and the cooling water is supplied from the cooling water passage to the water supply port 78.
[0040]
Further, a gasket (not shown) is interposed between the cylinder head 35 and the intake manifold 37, that is, a joint between the intake port 42 and the intake passage 37, and is sealed by the gasket. In this case, when a gasket using a heat insulating means such as an insulator is used, a high heat insulating effect can be obtained.
[0041]
In the above configuration, when the engine 2 is operated, air taken in from the outside of the outboard motor 1 is drawn into the collector 61 through the throttle body 64. In this case, the air in the collector 61 passes through the low / medium speed air suction passage 70 if the high / low speed switching valve 71 is closed, and the high speed air suction passage if the high / low speed switching valve 71 is open. It is supplied to the intake manifold 37 through 69. The air supplied to the intake manifold 37 is supplied to an intake passage 37a. ₁ ~ 37a ₆ The fuel is injected and supplied from the injector 53 when passing through, and is supplied to the intake port 42 of each cylinder of the engine 2 as an air-fuel mixture.
[0042]
In each cylinder, the intake valve 42 and the exhaust valve 47 control opening and closing of the intake port 42 and the exhaust port 43, respectively. Thus, the air-fuel mixture is supplied to the combustion chamber 41 at a predetermined timing, and the combustion gas after the explosion is discharged from the exhaust port 43 to the outside of the outboard motor 1 through the exhaust manifold 54.
[0043]
In the present invention, in particular, the intake manifold 37 is formed in a wedge shape, and the intake port 42 of the cylinder head 35 is formed short. Thereby, first, the shape of the cylinder head 35 can be simplified, and the production by die casting becomes easy. Further, by shortening the intake port 42 and connecting the intake port 42 to a separate intake manifold 37, the influence of heat from the cylinder head 35 can be reduced.
[0044]
Further, a water jacket 77 is provided near the intake passage 37 of the intake manifold 37, and the cooling water flows in the water jacket 77. As a result, the intake passage 37 is effectively cooled, and the intake air temperature can be reduced while the engine 2 is covered by the cover 6 and is in a substantially hermetically closed state. As a result, the intake efficiency can be improved.
[0045]
In this case, a high heat insulating effect can be obtained by providing a gasket between the cylinder head 35 and the intake manifold 37 and further connecting the both using an insulating means such as an insulator. Thus, transmission of heat from the cylinder head 35 can be suppressed, and a rise in the intake air temperature can be further prevented.
[0046]
As described above, the present invention has been described with the embodiment. However, the present invention is not limited to this embodiment, and can be modified within the scope of the present invention.
For example, in the above-described embodiment, an example has been described in which the water jacket 77 is formed by the through-hole formed in the branch portion of the intake passage 37a. However, the through-hole portion is formed in a concave shape, and the concave portion is covered with a cover to form a sealed structure. To form a water jacket.
[0047]
Although the example of the V6 engine has been described, the present invention can be effectively applied to an engine having six or less cylinders and an engine having six or more cylinders, and the same operational effects as those of the above embodiment can be obtained. Further, the device of the present invention is effectively applicable not only to outboard motors but also to vehicles and the like.
[0048]
【The invention's effect】
As described above, according to the present invention, by shortening the intake port of the cylinder head, the shape of the cylinder head can be simplified, the production becomes easy, and as a result, the cost can be reduced. . Also, the intake port is typically connected to a separate intake manifold via a heat insulating means, or a water jacket is provided near the intake passage of the intake manifold to effectively cool the intake passage. Temperature rise can be suppressed. In this way, by effectively taking measures against heat particularly in the intake system, the engine output can be increased, and therefore, the performance of the outboard motor can be improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing the overall configuration of an outboard motor intake device according to an embodiment of the present invention.
FIG. 2 is a plan view around an engine block in the embodiment of the outboard motor intake device of the present invention.
FIG. 3 is a cross-sectional view of an engine block in an embodiment of the outboard motor intake device of the present invention.
FIG. 4 is a side view and a sectional view showing an intake manifold according to the outboard motor intake device of the present invention.
FIG. 5 is a view seen from the rear around an engine block in the embodiment of the intake device for an outboard motor of the present invention.
FIG. 6 is a plan view and a cross-sectional view of a collector according to the outboard motor intake device of the present invention.
[Explanation of symbols]
1 Outboard motor, 2 engines, 3 drive shafts, 4 propellers, 5 drive units, 6 covers, 7 crankshafts, 8 engine bases, 9, 10 mounts, 11 swivel brackets, 13 clamp brackets, 15 water tanks, 16 oil pans , 17 cooling water pipe, 19 water supply pipe, 20 cooling water pump, 21 filter, 22 propeller shaft, 25 forward (forward) gear, 26 reverse (reverse) gear, 27 drive gear, 28 clutch dog, 29 clutch rod, 30 shift Rod, 31 shift cam, 33 crankcase, 34 cylinder block, 35 cylinder head, 36 cylinder head cover, 37 intake manifold, 38 cylinder bore, 39 piston, 40 connecting rod, 41 combustion chamber, 42 intake port, 43 d Exhaust port, 44 intake valve, 45, 48 camshaft, 46, 49 cam, 47 exhaust valve, 50 cam chain, 51 reduction gear, 52 spark plug, 53 injector, 54 exhaust manifold, 55 water jacket, 56 drain pipe, 58 oil Pump, 59 oil suction pipe, 61 collector, 62 collector body, 63 cover, 64 throttle body, 65 throttle valve, 68 actuator, 69 high-speed air suction passage, 70 high-speed air suction passage, 71 high-low speed switching valve, 72 Drive shaft, 75 funnel, 77 water jacket 77, A engine block, B drive shaft housing, C gear housing C.

Claims (4)

The left and right cylinder banks of a V-type engine mounted vertically extend rearward, and an outboard to which a collector is connected via an intake manifold from the rear to an intake port of each cylinder opening inside the cylinder bank. The air intake device of the machine,
The intake manifold having a plurality of intake passages corresponding to the respective cylinders is formed in a wedge shape in a plan view, and the intake passage is extended right and left along the wedge shape to the corresponding intake port. An intake device for an outboard motor, characterized in that an intake port is substantially formed in the outboard motor. 2. The outboard motor intake device according to claim 1, wherein a water jacket extends vertically in a central portion of the intake passages on the right and left sides extending toward the left and right cylinder banks. 3. . A straight through-hole is formed in the branch portion of the intake passage that expands forward toward the left and right cylinder banks in a vertical direction so as to be sandwiched therebetween, and this through-hole serves as a water channel of the water jacket. The intake device for an outboard motor according to claim 2, wherein: The air intake device for an outboard motor according to any one of claims 1 to 3, wherein a heat insulating means is interposed at a joint between the intake manifold and the intake port.

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