JP4311537B2 - Resin intake manifold for outboard motors - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin intake manifold used for an outboard motor, and more particularly to a structure of a reinforcing rib of the intake manifold.
[0002]
[Prior art]
Conventionally, an intake manifold that is attached to a multi-cylinder engine including an outboard motor is often made of aluminum, but in recent years, an intake manifold that is molded from a synthetic resin is also used (see Patent Document 1). A throttle body for controlling the intake air amount is attached to the upstream side of the intake manifold, and a silencer is attached further to the throttle body. Further, the downstream side of the intake manifold is branched into a plurality of intake pipes and attached to the intake passages of the respective cylinders provided in the cylinder head. In a multi-cylinder outboard motor, the crankshaft is arranged in a substantially vertical direction, and the intake manifold is attached to the side surface of the engine. The intake manifold extends from the cylinder head along the side surface of the engine to a position exceeding the bottom surface of the crankcase, and the throttle body and the silencer are disposed along the outside of the bottom surface of the crankcase. In the case of an intake manifold made of aluminum, there is sufficient rigidity and strength, so the throttle body and the silencer attached to it can be supported without fixing the throttle body mounting part of the intake manifold and the engine. . However, in the case of an intake manifold using resin, it is difficult to support the throttle body and silencer without fixing the throttle body mounting part of the intake manifold and the engine against its own weight and vibration from the viewpoint of rigidity and strength. The throttle body and silencer are separately fixed to the bottom surface of the crankcase (see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-342916
[Problems to be solved by the invention]
An object of the present invention is to enable a throttle body to be supported only by an intake manifold in a resin intake manifold for an outboard motor.
[0005]
[Means for Solving the Problems]
A resin intake manifold for an outboard motor according to the present invention is an intake manifold for performing intake to each cylinder of an engine via a throttle body, and includes a throttle body mounting portion for mounting the throttle body, and a throttle body mounting be one that is located adjacent to the part and a rib to contact the fixing portion for fixing the intake manifold to the engine, and a fixing portion and the throttle body mounting part, through the rib of the throttle body mounting portion In this case, the throttle body is supported integrally by the fixed portion, and the throttle body is supported only by the throttle body mounting portion .
[0006]
The intake manifold extends from the cylinder head along the side of the engine to a position beyond the bottom of the crankcase, and the throttle body mounting part is arranged and fixed so that the throttle body is arranged along the bottom of the crankcase. Preferably, the portion is fixed to the crankcase, and the fixing portion includes a rib communicating with the bottom surface of the intake passage of the intake manifold, and a part of the rib communicates with the throttle body mounting portion . Further, it is preferable that the passage connecting the surge tank of the intake manifold and the throttle body mounting portion is reinforced by a rib, and the fixing portion is provided on the side of the passage.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic partially enlarged side view of an outboard motor to which an intake manifold according to an embodiment of the present invention is attached. FIG. 2 is a schematic cross-sectional view of the outboard motor of FIG. 1 when viewed from above.
[0008]
In FIG. 1, the outboard motor 10 is attached to the stern S, and a 4-cylinder engine 20 is installed in the engine cover 11. The engine 20 is mainly composed of a head cover 21, a cylinder head 22, a cylinder block 23, a skirt portion 24, and a crankcase 25, and the outboard motor 10 is arranged so that a crankshaft 26 in the crankcase 25 is arranged in a substantially vertical direction. It is installed on the engine support 13. The crankshaft 26 is connected at its lower end to a drive shaft 27 arranged substantially vertically, and the power of the engine 20 is propeller (not shown) provided at the lower end of the outboard motor 10 via the drive shaft 27. ). In FIG. 2, reference numerals 29, 30, 31, 32, 33, 34, and 35 respectively indicate an intake valve, an exhaust passage, an exhaust valve, a cylinder, a piston, a connecting rod, and a silencer.
[0009]
A resin intake manifold 40 is attached to one side surface of the engine 20. The downstream side of the surge tank 41 of the intake manifold 40 is branched into four pairs of intake pipes (a total of eight pipes) that form a pair on the upper and lower sides, and then the upper and lower intake pipes merge in each group to form four intake pipes 42a. , 42b, 42c, and 42d. A flange 43 is provided at the tip of each of the intake pipes 42a to 42d, and is attached to the cylinder head 22 by a plurality of (for example, five) bolts. Thus, each of the intake pipes 42a to 42d is connected to four intake passages 28 provided in each cylinder.
[0010]
On the other hand, the upstream side of the surge tank 41 extends along the side surface of the engine 20, extends beyond the bottom surface of the crankcase 25 (the front surface of the engine 20), and a throttle body mounting portion 44 is provided at the tip thereof. A throttle body 60 that controls the amount of intake air is mounted on the throttle body mounting portion 44, and an intake silencer 61 is further mounted on the upstream side of the throttle body 60. That is, the throttle body 60 and the intake silencer 61 are disposed along the outside of the bottom surface of the crankcase 25.
[0011]
Bosses 45 and 46 for attaching the intake manifold 40 to the crankcase 25 are provided between the surge tank 41 and the throttle body attaching portion 44. The bosses 45 and 46 are fixed to the crankcase 25 with bolts via insulators. That is, the intake manifold 40 is fixed to the engine 20 by a flange 43 provided at the tip of the intake pipes 42 a to 42 d and the bosses 45 and 46, and the throttle body 60 is held only by the throttle body mounting portion 44 of the intake manifold 40. Is done.
[0012]
Next, details of the structure of the intake manifold 40 will be described with reference to FIGS. FIG. 3 is an exploded perspective view of the intake manifold 40 of the present embodiment, and FIG. 4 is a perspective view from the bottom surface side (surface attached to the engine 20) of the lower block constituting the intake manifold 40.
[0013]
As shown in FIG. 3, the intake manifold 40 includes an upper block 50, a middle block 51, and a lower block 52, and is integrally formed by vibration welding. The upper block 50 constitutes the upper part of the intake pipes 42 a to 42 d, the upper part of the upper intake pipe that communicates the intake pipes 42 a to 42 d and the surge tank 41, and the upper part of the surge tank 41. The middle block 51 communicates the lower part of the intake pipes 42a to 42d, the upper part of the vacuum chamber, the lower part of the upper intake pipe that connects the intake pipes 42a to 42d and the surge tank 41, and the intake pipes 42a to 42d and the surge tank 41. A lower intake pipe, a central portion of the surge tank 41, and an upper portion of a passage connecting the throttle body mounting portion 44 and the surge tank 41. The lower block 52 is fixed to the vacuum chamber lower portion, the bottom portion of the surge tank 41, the lower portion of the passage connecting the throttle body mounting portion 44 and the surge tank 41, the throttle body mounting portion 44, and the crankcase. The bosses 45 and 46 are configured.
[0014]
Each of the lower intake pipes that connect the intake pipes 42a to 42d and the surge tank 41 is provided with four series of resin valves 53, which are rotatably supported by four holders 53h. One end of the valve shaft of the resin valve 53 is connected to an actuator 54 provided on the side of the middle block 51. A negative pressure check valve 55 is attached to a partition wall that partitions the vacuum chamber and the surge tank 41.
[0015]
As shown in FIG. 4, the bottom surface 57 of the passage connecting the surge tank bottom surface 56 and the throttle body mounting portion 44 has a plurality of ribs extending from the surge tank bottom surface 56 to the throttle body mounting portion 44 along the passage. And the some rib which cross | intersects and extends in the width direction of a channel | path is formed. Thereby, the space between the surge tank bottom portion 56 and the throttle body mounting portion 44 is reinforced.
[0016]
The bosses 45 and 46 are disposed on both sides of the passage bottom surface 57 with the passage bottom surface 57 interposed therebetween, and the bosses 45 are disposed in the vicinity of the connection portion between the surge tank bottom surface 56 and the passage bottom surface 57. The boss 46 is disposed at a position adjacent to the throttle body mounting portion 44 on the side of the passage bottom surface 57 as much as possible, and communicates with the passage bottom surface 57 by a plurality of ribs 58. Further, the boss 46 and the throttle body mounting portion 44 are connected by a rib 59. That is, the throttle body mounting portion 44 is integrally supported by the boss 46 via the rib 59.
[0017]
As described above, according to the resin intake manifold of the present embodiment, the throttle body mounting portion 44 is integrally supported by the boss fixed to the crankcase, and therefore, between the boss and the throttle body mounting portion. Strength and rigidity are increased, and the throttle body can be supported only by the throttle body mounting portion of the intake manifold against its own weight and vibration. This eliminates the need to separately fix the throttle body to the crankcase, thereby reducing the number of parts and improving the assembly efficiency. Further, the effect can be further enhanced by making the boss communicated with the throttle body mounting portion by the rib adjacent to the throttle body mounting portion as much as possible.
[0018]
【The invention's effect】
As described above, according to the present invention, in a resin intake manifold for an outboard motor, the throttle body can be supported only by the intake manifold.
[Brief description of the drawings]
FIG. 1 is a schematic partially enlarged side view of an outboard motor to which an intake manifold according to an embodiment of the present invention is attached.
FIG. 2 is a schematic cross-sectional view of the outboard motor of FIG. 1 when viewed from above.
FIG. 3 is an exploded perspective view of the intake manifold.
FIG. 4 is a perspective view from the bottom side (surface attached to the engine) of the lower block constituting the intake manifold.
[Explanation of symbols]
20 Engine 25 Crankcase 40 Intake manifold 46 Boss (fixed part)
59 Rib S Stern

Claims (3)

An intake manifold for performing intake to each cylinder of the engine via a throttle body , the throttle body mounting portion for mounting the throttle body, and being disposed adjacent to the throttle body mounting portion, A fixing portion for fixing the intake manifold to the engine; and a rib for connecting the fixing portion and the throttle body mounting portion. The throttle body mounting portion is integrated with the fixing portion via the rib. A resin intake manifold for an outboard motor, wherein the throttle body is supported only by the throttle body mounting portion . The throttle body mounting portion is disposed so that the intake manifold extends along the side surface of the engine from the cylinder head to a position exceeding the bottom surface of the crankcase, and the throttle body is disposed along the bottom surface of the crankcase. The fixing portion is fixed to the crankcase, the fixing portion includes a rib that communicates with a bottom surface of the intake passage of the intake manifold, and a part of the rib communicates with the throttle body mounting portion. The resin intake manifold for an outboard motor according to claim 1. The ship according to claim 1 or 2 , wherein a passage connecting the surge tank of the intake manifold and the throttle body mounting portion is reinforced by a rib, and the fixing portion is provided on a side of the passage. Resin intake manifold for external machine.

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