JP3151846B2 - Outboard air intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outboard motor intake system for injecting fuel with an injector.

[0002]

2. Description of the Related Art There are various types of outboard motors, and there are many types in which fuel is atomized and mixed into an intake air by a carburetor. In this type, although not shown, a flange at the tip of an intake manifold is mounted on a cylinder head of an engine, and a carburetor is connected to an inlet of the intake manifold. As this type of prior art document, Japanese Utility Model Application Laid-Open No. 53-154912 is known.
No. gazette.

[0003]

The conventional intake system for an outboard motor is constructed as described above, and the intake manifold is simply cantilevered by the cylinder head. For this reason, there is a problem that the rigidity of the intake manifold is poor, the carburetor swings, the opening / closing link of the carburetor does not operate correctly, or the oil level fluctuates. Also,
Regardless of the case of injecting fuel with a carburetor, the case of injecting fuel with an injector, it is preferable to lengthen the intake manifold to obtain an inertial supercharging effect. However, when the intake manifold is lengthened, the rigidity is insufficient, and the above problem is caused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can improve the rigidity of an intake manifold to solve the problem associated with insufficient rigidity. It is an object of the present invention to provide an outboard motor intake device capable of producing a supercharging effect.

[0005]

According to the present invention, in order to attain the above object, a cylinder block, a cylinder head having a combustion chamber behind the cylinder block, and
A front crankcase separate from a rear crankcase located in front of the cylinder block, and an intake manifold are provided, and the cylinder block is provided with a plurality of cylinders arranged substantially horizontally in the up-down direction. The rear crankcase and the front crankcase are integrally formed with the rear crankcase in front of the shaft center, and the rear crankcase and the front crankcase rotatably support a crankshaft that is orthogonal to the axis of the cylinder and that is directed vertically. A plurality of intake branch pipes, each having a rear end connected to the combustion chamber at one end and a front end at the other end extending forward along one side of the cylinder block, are provided with a plurality of intake branch pipes extending in the front-rear direction. Rear ends of a plurality of intake branch pipes which are integrally formed of a light alloy or the like with a surge tank having a capacity space, and constitute a rear portion of the intake manifold. These are integrally connected to each other with a flange at a certain interval in the vertical direction, and a mounting portion is provided on this flange, and the rear portion of the intake manifold is screwed and fixed to the cylinder head using this mounting portion. ,
At least a front portion of a surge tank constituting a front portion of the intake manifold is disposed forward of a mating surface of the rear crankcase and the front crankcase, and a mating surface of the rear crankcase and the front crankcase. A mounting portion is provided on the surge tank ahead of the cylinder head, and a front portion of the intake manifold is screwed and fixed to the front crankcase using the mounting portion, and the cylinder head fixed to a rear portion of the cylinder block. The front crankcase fixed to the front of the cylinder block is connected via the intake manifold made of a light alloy or the like.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. A cylinder block 1 of a four-cycle fuel injection engine to be mounted, and a combustion chamber 6 behind the cylinder block 1
, A front crankcase 9 separate from the rear crankcase 3 located in front of the cylinder block 1, and an intake manifold 10 that guides outside air to the cylinder 2 of the cylinder block 1.

As shown in FIG. 4, the cylinder block 1 is composed of a plurality of cylinders arranged substantially horizontally and vertically, in other words, a plurality of cylinders 2 and a rear crankcase 3 in front of the axis of the plurality of cylinders 2. It is integrally molded from. The rear crankcase 3 and the front crankcase 9 hold a rotatable crankshaft 4 that is perpendicular to the axis of the horizontal cylinder 2 and that is oriented in the up-down direction. The drive shaft 5 is connected to the portion.

As shown in FIGS. 1 to 4, the cylinder head 7 is provided with an intake hole 8 for each cylinder 2, and functions to overlap the cylinder block 1.

The intake manifold 10 is shown in FIGS.
And the like, the rear end of one end is connected to the combustion chamber 6,
A plurality of intake branch pipes 11 whose front ends at the other ends extend forward along one side of the cylinder block 1 in the front-rear direction, and a surge tank 12 having a space of a predetermined capacity therein and integrally formed of a light alloy or the like. Have been. Intake manifold 10
The rear end portions of the plurality of intake branch pipes 11 constituting the rear portion are integrally connected to each other by a flange 13 at a predetermined interval in the vertical direction. The flange 13 is provided with a mounting hole 15 for the injector 14, and the rear portion of the intake manifold 10 is connected to the cylinder head 7 through the mounting hole 15.
Is fixedly screwed with a plurality of bolts 16.

At least the front part of the surge tank 12 constituting the front part of the intake manifold 10 is disposed forward of the mating surface MF of the rear crankcase 3 and the front crankcase 9. The surge tank 12 has a throttle valve 17 pivotally supported at an entrance thereof, and functions to reduce pulsation. Further, a mounting portion 18 is provided on the surge tank 12 in front of the mating surface MF between the rear crankcase 3 and the front crankcase 9, and the front portion of the intake manifold 10 is connected to the front crankcase via the mounting portion 18. 9
Is fixedly screwed with a plurality of bolts 16. Such an intake manifold 10 made of a light alloy or the like functions to connect the cylinder head 7 fixed to the rear of the cylinder block 1 and the front crankcase 9 fixed to the front of the cylinder block 1.

According to the above configuration, the intake manifold 10
A cylinder head 7 fixed to the rear of the cylinder block 1 and a front crankcase fixed to the front of the cylinder block 1 with the intake branch pipe 11 traversing the side surface of the cylinder block 1 while straddling the cylinder block 1 9, the rigidity of the cylinder block 1 can be utilized. Therefore, rigid attachment can be greatly expected, and the rigidity of the engine can be improved.

Further, through the rigid mounting, the generation of vibration noise can be suppressed, the vibration of the throttle valve 17 can be reduced, and a smooth operation can be performed. Further, since the intake manifold 10 can be lengthened, an inertial supercharging effect can be obtained in cooperation with the surge tank, and the intake efficiency can be improved. Furthermore, since the rear ends of the plurality of intake branch pipes 11 are integrally connected to each other by the flange 13, the strength of the intake manifold 10 can be further improved.

[0013]

As described above, according to the present invention, the rear ends of a plurality of intake branch pipes constituting the rear part of the intake manifold are integrally connected to each other by a flange at predetermined intervals in the vertical direction. , While providing a mounting part on this flange,
Using this mounting part, the rear part of the intake manifold is screwed and fixed to the cylinder head, and at least the front part of the surge tank constituting the front part of the intake manifold is located forward of the mating surface of the rear crankcase and the front crankcase. It is installed, and a mounting part is provided on the surge tank ahead of the mating surface of the rear crankcase and the front crankcase, and the front part of the intake manifold is screwed and fixed to the front crankcase using this mounting part. The cylinder head fixed to the rear of the block and the front crankcase fixed to the front of the cylinder block are connected via an intake manifold made of light alloy or the like, so the rigidity of the intake manifold is improved and rigidity is insufficient. There is an excellent effect that the accompanying problem can be solved.

In addition, a surge tank can be provided at the entrance of the long intake manifold, so that an inertial supercharging effect can be generated. Further, the rear ends of the intake branch pipes are not individually fixed to each other, but the rear ends of the intake branch pipes are integrally connected by flanges, so that the strength of the intake manifold can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory side view showing an embodiment of an outboard motor intake device according to the present invention.

FIG. 2 is an explanatory front view showing an embodiment of an outboard motor intake device according to the present invention.

FIG. 3 is an explanatory sectional view showing a state of crossing an engine in the embodiment of the outboard motor intake device according to the present invention;

FIG. 4 is a longitudinal sectional side view showing an engine in the embodiment of the outboard motor intake device according to the present invention.

FIG. 5 is an explanatory side view showing an intake manifold in the embodiment of the intake device for an outboard motor according to the present invention.

FIG. 6 is an explanatory front view showing an intake manifold in the embodiment of the outboard motor intake device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder 3 Rear crankcase 4 Crankshaft 6 Combustion chamber 7 Cylinder head 9 Front crankcase 10 Intake manifold 11 Intake branch pipe 12 Surge tank 13 Flange 14 Injector 17 Throttle valve MF

Claims (1)

(57) [Claims] A cylinder block, a cylinder head having a combustion chamber behind the cylinder block, a front crankcase separate from a rear crankcase located in front of the cylinder block, and an intake manifold. The cylinder block is integrally formed with a plurality of cylinders arranged substantially horizontally and vertically and a rear crankcase in front of the axis of the plurality of cylinders, and the rear crankcase and the front crankcase are formed as described above. The crankshaft, which is perpendicular to the axis of the cylinder and is vertically oriented, is rotatably supported. The intake manifold has one end connected to the combustion chamber at the rear end, and the other end connected to the cylinder block at the front end. A plurality of intake branch pipes extending in the front-rear direction extending forward along one side and a surge tank having a space with a predetermined capacity inside are lightly combined. An outboard motor intake device integrally formed by, for example, connecting rear ends of a plurality of intake branch pipes constituting a rear portion of the intake manifold with flanges at a predetermined interval in a vertical direction. A mounting portion is provided on the flange, and a rear portion of the intake manifold is screwed and fixed to the cylinder head using the mounting portion, and at least a front portion of a surge tank constituting a front portion of the intake manifold is fixed. A mounting portion is provided in front of the mating surface of the rear crankcase and the front crankcase, and a mounting portion is provided in the surge tank in front of the mating surface of the rear crankcase and the front crankcase. The front part of the intake manifold is screwed and fixed to the front crankcase using the cylinder head fixed to the rear part of the cylinder block. Intake system for an outboard motor, characterized in that the said front crank case fixed to a front portion of the cylinder block and connected through the intake manifold made of light alloy or the like.