JPH03235797A - Intake air duct for outboard motor - Google Patents

Abstract

PURPOSE:To prevent entrance of water to an engine and an electric accessory system by forming an inclination recessed part, opened upwardly rearwardly, in the central part of the rear of the upper surface of a cowling, forming openings, each surrounded with a partition wall, in the bottoms of the two sides of the recessed part, and covering the recessed part with a cover plate. CONSTITUTION:An inclination recessed part 3 opened upwardly rearwardly is formed on the central part of the rear of the upper surface of a cowling 1 of an outboard motor. An induction passage 5 spreading from the front toward the rear and inclined downward is formed continuously to a position on the front side of the recessed part, and openings 4 are formed in the bottoms on both sides of the recessed part 3, and a partition wall 6 surrounding the opening hole 4 has an upper end erected around the each opening 4 at the same height as that of the bottom of the induction passage 5. The outer peripheral surface of the partition wall 6 is formed in a manner to be inclined toward each other in a throttle shape from the rear and the front. A cover plate 7 containing a top plate 10 having a suction port 9 formed in the rear thereof is mounted on the bottom of the recessed part 3 by using a guide rib 12 and a mounting boss 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The intake duct of a conventional outboard motor is, for example, as shown in FIGS. 5 and 6 (see Japanese Patent Publication No. 61-49157).
A recess 14 that opens upward and rearward is formed in the rear central part of the upper surface of the cowling 1, and a back surface 16 that slopes toward the left and right side walls of the recess 14 is formed in front of the recess 14.

The left and right side walls of the recess 14 are cut and raised to form an inner wall 15 and an outer wall 17. Here, the tips of the inner wall 15 and the outer wall 17 are cut out in an arc shape, and an intake port 19 is formed. Further, the upper opening side of the recess 14 is covered with a cover plate consisting of a top plate and a suction port 20 having an aperture 21 formed on the rear side of the top plate.

The air taken in from the suction port 20 is once throttled by the aperture 21, and then distributed to the left and right by the central convex portion of the back surface 16 as shown in the direction of the arrow in FIG. It will be sucked into the cowling 1 through the mouth 19. At this time, the moisture sucked in together with the air is separated by collision with the back surface 16 and the inner wall 15, and is discharged downward along the wall surface.

[Problem to be solved by the invention]

However, in such conventional intake ducts for outboard motors, when hit by a following wave, seawater can cross the inner wall 15 and enter the cowling 1 through the intake port 19, adversely affecting the engine or electrical system. There were drawbacks.

The present invention aims to provide an intake duct for an outboard motor that eliminates this conventional drawback.

[Means to solve the problem]

In the present invention, an inclined recess opening upward and rearward is formed in the rear central part of the upper surface of the cowling, and a guiding path is formed continuously on the front side of the recess and widens from the front to the rear and slopes downward, and the guide path is formed on the left and right sides of the recess. An opening is formed at the bottom of both sides, a partition wall is erected around the opening, and the recess is covered with a cover plate consisting of a top plate and a suction port formed on the rear side of the top plate, This intake duct for an outboard motor is characterized in that the lower surface of the top plate is located close to the upper end surface of the partition wall.

[Function] When there is a following wave from behind, the lower surface of the top plate of the cover plate is brought close to the upper end surface of the bulkhead, so seawater hardly crosses the bulkhead and enters the intake port. In addition, the intake air is introduced from the rear and the front, and when the ship is sailing, it is drawn in from the front introduction path by dynamic pressure, so there is no reduction in intake efficiency and a predetermined engine intake is achieved.

Further, since the outer circumferential surfaces of the partition wall are inclined from the rear and the front in a constricted shape, the streamline of the air is stabilized by the constriction effect, and the moisture contained in the intake air is smoothly separated.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 to 4. The cowling 1 has an inclined recess 3 that opens upward and rearward in the rear central part of the upper surface, and continues to the front side of the recess 3. A guiding path 5 is formed that widens from the front to the rear and slopes downward, and openings 4 are formed at the bottoms of both left and right sides of the recess 3. Around the aperture 4 of the cowling 1, a partition wall 6 surrounding the aperture is erected with its upper end at approximately the same height as the bottom of the guideway 5.

Here, the outer circumferential surface of the partition wall 6 has an aperture shape that is inclined from the rear and the front.

The cover plate 7 includes a top plate IQ and a suction port 9 formed on the rear side of the top plate 10. A diaphragm 11 is formed on both sides of the suction port 90, and a guide rib is provided on the bottom surface of the top plate 10. 12 and a post 13 are provided for attachment.

The cover plate 7 has a top plate 10 above the recess 3.
So that the top surface is on the same streamline as the top surface of cowling 1,
The guide knob 12 and attachment boss 13 are attached to the bottom of the recess 3 to cover the recess 3 and to bring the lower surface of the top plate 10 and the upper end surface of the partition wall 6 close to each other. The gap between the lower surface of the top plate 10 and the upper end surface of the partition wall 6 forms an air intake port 8. In addition, in FIG. 1, 2 indicates an air filter.

With this configuration, intake air enters from the rear and front sides, and especially when the ship is sailing, it is sufficiently taken in from the front side via the taxiway 5 due to dynamic pressure, and the moisture taken in with the air is absorbed by the bulkhead 6. separated by collision with the front sloped wall and the rear sloped wall.

Further, the partition wall 6 also has a restricting function, and the intake air flow line is made constant, thereby making it possible to stably intake air. In addition,
In the event of a following wave, since the lower surface of the top plate 10 and the upper end of the partition wall 6 are placed close to each other, water will not cross the upper surface of the partition wall 6 and enter the intake port. When the upper end surface of the bulkhead and the lower surface of the top plate come close to each other, the gap between the intake ports 8 becomes narrower, resulting in a decrease in intake efficiency, but dynamic pressure intake from the front taxiway side prevents the decrease in intake efficiency. be done.

〔Effect of the invention〕

In the present invention, an inclined recess opening upward and rearward is formed in the rear central part of the upper surface of the cowling, and a guiding path is formed continuously on the front side of the recess and widens from the front to the rear and slopes downward, and the guide path is formed on the left and right sides of the recess. An opening is formed at the bottom of both sides, a partition wall is erected around the opening, and the recess is covered with a cover plate consisting of a top plate and a suction port formed on the rear side of the top plate, Since the lower surface of the top plate is placed close to the upper end surface of the partition wall, when a wave is generated, the water is blocked by the partition wall and does not come into contact with the engine or electrical system. Also,
The decrease in suction efficiency when the ship is running is compensated for by suction from the front side via the taxiway by dynamic pressure.

Further, since the outer circumferential surfaces of the partition walls are inclined to each other in a constricted shape from the rear and the front, the /A line of the intake air is stabilized and stable intake is achieved.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG.
3 is a sectional view in the +-IvA direction of FIG. 2, FIG. 4 is a bottom view of the cover plate, and FIG. 5 is a vertical sectional view showing the conventional example. FIG. 6 is a plan view of FIG. 5 with the Kahabret removed. DESCRIPTION OF SYMBOLS 1... Cowling, 2... Air filter, 3... Recessed part, 4... Opening, 5... Guideway, 6... Partition wall, 7
...Cover plate, 8...Intake port, 9...Intake port, 10...Top plate, 11...Aperture, 12...Rib,
13...Mounting boss. Figure 4

Claims (2)

[Claims] (1) A sloping recess opening upward and rearward is formed in the rear center portion of the upper surface of the cowling, and a guiding path is formed that continues on the front side of the recess and widens from the front to the rear and slopes downward, and on both left and right sides of the recess. An opening is formed in the bottom, a partition wall is erected around the opening, and the recess is covered with a cover plate consisting of a top plate and a suction port formed on the rear side of the top plate. An intake duct for an outboard motor, characterized in that a lower surface of the plate is located close to an upper end surface of the partition wall. (2) The intake duct for an outboard motor according to claim 1, wherein the outer circumferential surfaces of the partition wall are inclined from the rear and the front in a constricted shape.