JP7192307B2 - Outboard motor intake system - Google Patents

Description

The present invention relates to an intake system for an outboard motor.

Patent Document 1 discloses an intake system for an outboard motor in which one end of an intake introduction pipe is connected to an intake port of a carburetor and the other end of the intake introduction pipe opens to an outside air intake port provided in an upper cowling. . Further, Patent Document 2 discloses an outboard motor top cowl in which a molding having an intake air duct for drawing outside air into an engine room is attached to the top cowl of the outboard motor by adhesion.

JP-A-59-120598 Japanese Patent Application Laid-Open No. 2006-182220

In an intake system for an outboard motor, it is generally necessary to increase the cross-sectional area of the intake passage when increasing the engine output. This is because if the cross-sectional area of the intake passage is small, the flow velocity of the intake air increases and the intake resistance increases, which is disadvantageous in terms of engine output. However, when the cross-sectional area of the intake passage becomes large, intake vibration due to intake pulsation becomes significant, and water entering the intake passage from the outside air intake (outside air intake) of the engine cover that covers the engine of the outboard motor becomes trapped. It becomes easier to absorb.

Further, in the intake system for an outboard motor disclosed in Patent Document 1, the outside air intake is formed by the upper cowling and the separate cover attached to the upper cowling. The appearance of the outboard motor deteriorates.

Furthermore, in the top cowl of an outboard motor disclosed in Patent Document 2, as a countermeasure for reducing intake vibration, the molding, which is adhered to the top cowl and has an intake air duct, is provided with convex portions as ribs to reinforce the molding. ing. However, this convex portion is provided for a plate-like molding.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an intake system for an outboard motor that can suppress vibration caused by intake pulsation, reduce intake noise, and improve drainage performance and appearance. to provide.

In the air intake device for an outboard motor according to the present invention, an upper cover having an outside air intake port is attached to the lower cover so that the engine of the outboard motor is covered by these covers, and outside air is drawn from the outside air intake port. In an intake device for an outboard motor that supplies intake air to the engine, an outside air intake member forming a part of an intake passage is mounted inside the upper cover at a position corresponding to the outside air intake port. The member includes an outside air intake portion positioned on the rear end side of the outboard motor for sucking outside air from the outside air intake port, and a member positioned on the front side of the outboard motor continuously from the outside air intake portion. an outside air delivery portion for delivering outside air to an upstream side intake pipe of the engine, wherein a stepped portion is provided at the bottom of the outside air intake portion, and a drainage groove is formed to intersect the stepped portion. It is something to do.

According to the present invention, since the stepped portion is provided at the bottom of the outside air intake portion of the outside air intake member to ensure the rigidity of the outside air intake portion, vibration of the outside air intake member caused by intake pulsation can be suppressed, and intake noise can be reduced. can be reduced. Furthermore, the bottom of the outside air intake portion of the outside air intake member is formed with a drainage groove that intersects with the stepped portion, so that water that flows in with the outside air can be effectively drained. Also, since the outside air intake member is attached inside the upper cover, the appearance of the outboard motor is not spoiled.

1 is a plan view of an outboard motor showing an embodiment of an intake device for an outboard motor according to the present invention; FIG. Sectional drawing which follows the II-II line of FIG. Sectional drawing which follows the III-III line of FIG. FIG. 2 is a perspective view showing the outside air suction member of FIG. 1;

Hereinafter, embodiments for carrying out the present invention will be described based on the drawings.
FIG. 1 is a plan view of an outboard motor showing an embodiment of an intake device for an outboard motor according to the present invention, and FIG. 2 is a sectional view taken along line II--II in FIG. The outboard motor 10 shown in FIGS. 1 and 2 has an engine holder 12 on which an engine 11 is mounted. This engine 11 is an engine in which a crankshaft 18 is arranged substantially vertically.

In other words, the engine 11 comprises a crankcase 13, a cylinder block 14, a cylinder head 15, and a head cover 16 which are sequentially arranged from the front to the rear of the outboard motor 10. As shown in FIG. A plurality of (four in this embodiment) cylinders 14 in which pistons (not shown) reciprocate are formed in a cylinder block 14 in a substantially horizontal direction. A crankshaft 18 is arranged substantially vertically between the crankcase 13 and the cylinder block 14 . The engine 11 is a four-cycle, four-cylinder engine in which the cylinders 17 are arranged substantially horizontally and the crankshaft 18 is arranged substantially vertically.

The engine 11 , the engine holder 12 , and the oil pan 19 installed below the engine holder 12 are covered with an engine cover 20 . The engine cover 20 includes a lower cover 20B and an upper cover 20A detachably attached to the lower cover 20B. A drive shaft housing and a gear case (both not shown) are sequentially arranged below the lower cover 20B.

The outboard motor 10 is rotatably supported in the horizontal direction by the pilot shaft 21 being rotatably supported by the swivel bracket 22 . A clamp bracket 24 is attached to the transom 25 A of the hull 25 . As a result, the outboard motor 10 is rotatable with respect to the hull 25 in the horizontal direction (operating direction) and the vertical direction (trim and tilt directions).

The driving force generated in the crankshaft 18 of the engine 11 is transmitted to the drive shaft 26 arranged substantially vertically in the drive shaft housing and gear case, and through the shift mechanism and propeller shaft (not shown) arranged in the gear case. is transmitted to a propeller (not shown) to rotate the propeller forward or reverse. As a result, the outboard motor 10 moves the hull 25 forward or backward. 1 and 2 denotes a flywheel magnet cover that covers a flywheel magnet device (not shown) that functions as a generator by rotation of the crankshaft 18. As shown in FIG.

As shown in FIGS. 1 and 3, an intake device 30 is arranged on the right side of the engine 11 . The intake device 30 supplies outside air from an outside air intake port 31 formed in the upper rear portion of the upper cover 20A to an intake port 37 of the cylinder head 15 as intake air. 33, an air box 34, a throttle body 35 and a downstream intake pipe 36 are connected in sequence.

There is one outside air intake port 31 at the rear end of the outboard motor 10 in the upper cover 20A, or a total of two positions on both sides in the width direction of the rear end of the outboard motor 10 in the upper cover 20A (the latter in this embodiment). 2 places) are formed.

The outside air intake member 32, which will be described in detail later, takes in the outside air from the outside air intake port 31 of the upper cover 20A as intake air as indicated by the arrow A, and sends it to the upstream side intake pipe 33 as indicated by the arrow B to the air box 34. lead. The intake air introduced into the air box 34 is supplied to the intake port 37 of the cylinder head 15 through four downstream intake pipes 36 in this embodiment after the flow rate is adjusted by the throttle body 35 .

As shown in FIGS. 1 and 4, the outside air intake member 32 is fixedly attached using a screw 38 at a position corresponding to the outside air intake port 31 inside the upper cover 20A. The external air intake member 32 is attached by inserting a screw or screw 38 into the mounting piece 39 of the external air intake member 32 and screwing the screw or screw 38 into the upper cover 20A. The outside air intake member 32 guides the outside air from the outside air intake port 31 to the upstream side intake pipe 33 as a part of the outside air intake port 31 and the intake passage.

The outside air intake member 32 is configured by integrally molding an outside air intake portion 32A and an outside air delivery portion 32B. The outside air intake portion 32A is positioned on the rear end side of the outboard motor 10 and is a portion that takes in outside air from the outside air intake port 31 of the upper cover 20A. ) is a large box-shaped intake passage with a flat bottom 40 . Further, as shown in FIG. 2, the bottom portion 40 of the outside air intake portion 32A is formed in a shape that slopes down toward the rear of the outboard motor 10. As shown in FIG.

As shown in FIGS. 1 and 4, the external air delivery section 32B is provided continuously with the external air intake section 32A, is positioned on the front side of the outboard motor 10 relative to the external air intake section 32A, and is attached to the engine 11 side. It is a portion that sends outside air (intake air) to the upstream side intake pipe 33 . Particularly, as shown in FIG. 3, when the upper cover 20A is attached to the lower cover 20B, the outside air delivery portion 32B is connected to the upstream side of the upstream intake pipe 33 by butting or fitting (insertion). It is configured in a semi-direct intake structure.

1 and 4, the outside air intake portion 32A has a bottom portion 40 formed with a plurality of stepped portions 41 such as ribs to reinforce the bottom portion 40 and increase the rigidity of the outside air intake portion 32A.

Further, a drain groove 42 crossing the stepped portion 41 is formed in the bottom portion 40 of the outside air intake portion 32A. The drainage groove 42 includes a water collecting portion 42A that intersects with the stepped portion 41 and a drainage portion 42B that continues to the water collecting portion 42A. The water collecting portion 42A intersects with the stepped portions 41 to collect water accumulated between the plurality of stepped portions 41 . The drainage portion 42B is formed along the front-rear direction of the outboard motor 10 at a substantially central position in the width W direction of the outside air intake portion 32A in the bottom portion 40 of the outside air intake portion 32A. As a result, the drain portion 42B of the drain groove 42 drains the collected water by utilizing the obliquely rearwardly downward slope of the bottom portion 40 of the outside air intake portion 32A.

With the configuration as described above, the present embodiment has the following effects (1) to (4).
(1) As shown in FIGS. 1 and 4, in the outside air intake member 32 forming part of the intake passage, the outside air intake portion 32A for sucking outside air from the outside air intake port 31 of the upper cover 20A of the engine cover 20 is , the bottom portion 40 of which is formed in a flat box shape. Therefore, the cross-sectional area of the intake passage in the outside air intake member 32 increases, the intake resistance decreases, and the output of the engine 14 can be improved.

(2) The stepped portion 41 is provided at the bottom portion 40 of the outside air intake portion 32A of the outside air intake member 32 to ensure the rigidity of the outside air intake portion 32A. Therefore, even if the bottom portion 40 of the outside air intake portion 32A is formed in a flat shape, vibration of the outside air intake member 32 caused by intake pulsation can be suppressed, and intake noise can be reduced. Also, at the connecting portion where the outside air delivery portion 32B of the outside air intake member 32 is connected to the upstream side intake pipe 33 by butting or fitting, vibration of the outside air intake member 32 is suppressed, thereby reducing intake noise.

(3) As shown in FIGS. 1, 2 and 4, the bottom 40 of the outside air intake portion 32A of the outside air intake member 32 has a water collecting portion 42A that intersects with the stepped portion 41 and a water collecting portion 42A that is continuous with the water collecting portion 42A. A drainage groove 42 is formed comprising a drainage portion 42B which A bottom portion 40 of the outside air intake portion 32A is provided in a shape that slopes downward toward the rear of the outboard motor 10, and a drainage portion 42B of the drainage groove 42 is formed in the bottom portion 40 along the longitudinal direction of the outboard motor 10. there is As a result, the water that flows in with the outside air and accumulates between the plurality of stepped portions 41 is collected by the water collection portion 42A of the drain groove 42, and the collected water is transferred to the outside air intake portion 32A by the water discharge portion 42B. The slope of the bottom 40 can be used to effectively drain water.

(4) Since the external air intake member 32 is attached inside the upper cover 20A, the appearance of the outboard motor 10 can be improved without spoiling the appearance of the outboard motor 10 .

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention, and these replacements and changes can be made. is included in the scope and gist of the invention, and is included in the scope of the invention described in the claims and its equivalents.

DESCRIPTION OF SYMBOLS 10... Outboard motor 11... Engine 20... Engine cover 20A... Upper cover 20B... Lower cover 30... Air intake device 31... Outside air intake port 32... Outside air intake member 32A... Outside air intake part 32B... Outside air Delivery part 33 Upstream intake pipe 37 Intake port 40 Bottom 41 Step 42 Drain

Claims (4)

By attaching an upper cover having an outside air intake port to the lower cover, the engine of the outboard motor is covered by these covers, and the outside air from the outside air intake port is supplied to the engine as intake air of the outboard motor. in the device,
An outside air intake member forming a part of an intake passage is mounted inside the upper cover at a position corresponding to the outside air intake port,
The outside air intake member includes an outside air intake portion positioned at the rear end side of the outboard motor and sucking in outside air from the outside air intake port, and positioned at the front side of the outboard motor continuously from the outside air intake portion. an outside air delivery unit configured to deliver outside air to an upstream side intake pipe of the engine;
An intake system for an outboard motor, wherein a stepped portion is provided at the bottom of the outside air intake portion, and a drainage groove is formed to cross the stepped portion. The drainage groove includes a water collecting portion that intersects with the stepped portion, and a drainage portion that is continuous with the water collecting portion . 2. The air intake device for an outboard motor according to claim 1, wherein the air intake device is formed along the longitudinal direction of the outboard motor at a center position. 3. The air intake device for an outboard motor according to claim 1, wherein the bottom portion of the outside air intake portion of the outside air intake member is provided in a slanted downward shape toward the rear of the outboard motor. 4. The intake of an outboard motor according to claim 1, wherein the outside air delivery portion of the outside air intake member is connected to an upstream side intake pipe of the engine by butting or fitting. Device.

Images