WO2020158091A1 - Water exposure suppressing mechanism for outboard motor - Google Patents

Abstract

Provided is a water exposure suppressing mechanism for an outboard motor, the mechanism being capable of preventing an increase in the size of an engine. A water exposure suppressing mechanism 50 is provided in an outboard motor 10, and comprises: an engine E; an exhaust pipe 44 which includes an exhaust port 47 that opens inside a casing C, and which discharges exhaust gas from the engine E to the inside of the casing C; and a catalytic converter 48 that is provided in the exhaust pipe 44 and cleans the exhaust gas. A plate 52 is provided near the exhaust port 47 to prevent infiltration of water via the exhaust port 47.

Description

Outboard motor water suppression mechanism

The present invention relates to a water suppression mechanism for an outboard motor.

In an outboard motor having an engine, a configuration is known in which a catalyst housing chamber is integrally provided next to a cylinder block, and a catalyst for purifying exhaust gas is arranged in the catalyst housing chamber (for example, see Patent Document 1). ..

JP, 2016-142153, A

The configuration of Patent Document 1 has a problem that the cylinder block becomes large and the engine cannot be housed in the existing casing.
It is an object of the present invention to provide a water suppression mechanism for an outboard motor that can prevent the engine from increasing in size.

This specification includes the entire contents of Japanese Patent Application/Japanese Patent Application No. 2019-012755 filed on January 29, 2019.
The present invention includes an engine, an exhaust pipe having an exhaust port opened in a casing, and exhausting exhaust gas of the engine into the casing, and a catalyst provided in the exhaust pipe for purifying the exhaust gas. A water-suppressing mechanism for an outboard motor, which is provided in an outboard motor, wherein a plate for preventing water from entering through the exhaust port is provided near the exhaust port.

According to the present invention, in the water suppression mechanism for an outboard motor, a plurality of the plates are provided in the vicinity of the exhaust port, and each of the plates has a triangular shape having a fixing margin on one side for fixing. It is characterized by

The present invention is characterized in that, in the water suppression mechanism for an outboard motor, the fixing margin is fixed by welding or rivets.

The present invention is characterized in that, in the water suppression mechanism for an outboard motor, the plate is bent so that a corner portion facing the fixing margin is located below the fixing margin.

The present invention is characterized in that, in the above water suppression mechanism for an outboard motor, the plates are provided in a plurality of vertical stages.

The present invention is characterized in that, in the water suppression mechanism for an outboard motor, the plates are arranged at positions displaced from each other between the steps as viewed in the vertical direction.

The present invention is characterized in that, in the water suppression mechanism for an outboard motor, a plurality of the plates are provided rotatably around the exhaust port by the exhaust gas.

The present invention is characterized in that, in the water suppression mechanism for an outboard motor described above, a rotation direction restricting portion that restricts the rotation direction of the plate in one direction is provided.

According to the present invention, it is possible to prevent the engine from becoming large.

FIG. 1 is a vertical cross-sectional side view of essential parts of an outboard motor according to a first embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the catalyst device. FIG. 3 is a sectional view taken along the line III-III in FIG. FIG. 4 is a sectional view taken along line IV-IV of FIG. FIG. 5: is a figure which shows typically the structure of the water suppression mechanism which concerns on 2nd Embodiment of this invention. FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7: is sectional drawing which shows typically the structure of the water suppression mechanism which concerns on 3rd Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings. (First embodiment)
FIG. 1 is a vertical cross-sectional side view of essential parts of an outboard motor 10 according to this embodiment. In the following description, the terms “front, rear, left and right” are based on the plan view of the boat B to which the outboard motor 10 is attached.
As shown in FIG. 1, the outboard motor 10 includes a casing C. The casing C includes a mount case 1, an extension case 2 coupled to a lower end surface of the mount case 1, and a lower portion of the extension case 2. And a gear case 3 coupled to the end face. A multi-cylinder engine E is mounted on the upper end surface of the mount case 1 with the crankshaft 4 vertically placed.

The outboard motor 10 is provided with a pair of left and right upper arms 12 that support the mount case 1 through the upper mount rubber 11, and a pair of left and right lower arms 14 that support the extension case 2 through the lower mount rubber 13. A swivel shaft 15 is connected between the upper arm 12 and the lower arm 14. A swivel case 16 that rotatably supports the swivel shaft 15 is supported by a stern bracket 17 attached to the transom Ba of the boat B so as to be vertically swingable via a horizontal tilt shaft 18.

An annular under cover (not shown) made of synthetic resin is fixed to the mount case 1. The under cover covers the periphery of the section from the lower part of the engine E to the upper part of the extension case 2, and an engine hood 21 that covers the engine E from above is detachably attached to the upper end of the under cover. The engine hood 21 and the undercover define an engine room 23 that houses the engine E. An air intake 24 to the engine room 23 is provided in the upper part of the engine hood 21.

The drive shaft 6 is connected to the lower end of the crank shaft 4 together with the flywheel 5. The drive shaft 6 extends downward inside the extension case 2, and its lower end is connected to a horizontal propeller shaft 8 through a forward/reverse switching mechanism 7 provided inside the gear case 3, and the rear of the propeller shaft 8 is connected to the propeller shaft 8. The propeller 9 is fixed to the end.

The engine E has a crankcase 25 supporting the vertically mounted crankshaft 4, a cylinder block 26 extending rearward from the crankcase 25, and a cylinder head 27 joined to the rear end of the cylinder block 26. The lower surface of the crankcase 25 is bolted to the mount case 1. The cylinder bracket includes a plurality of cylinders 28 arranged vertically.

The lower part of the gear case 3 is provided with an intake port 30 that opens on one side to take in external water. The external water taken in through the water intake 30 is pressure-fed as cooling water to the engine E by the water pump 32 to cool each part of the engine E. The cooling water that has finished cooling the engine E is discharged to the extension case 2 and is discharged to the outside through the discharge hole 33 formed in the boss of the propeller shaft 8.

An oil pan 35 arranged at the center of the upper part of the extension case 2 is coupled to the lower surface of the mount case 1, and the oil pan 35 stores lubricating oil supplied to each part of the engine E.

The cylinder head 27 rotatably supports left and right camshafts 36 for valve actuation, which are parallel to the crankshaft 4, and is a belt type timing mechanism for driving the camshafts 36 from the crankshaft 4 at a predetermined reduction ratio. A transmission device 37 is arranged above the cylinder block 26.

The cylinder head 27 is provided with an exhaust manifold 39 communicating with a plurality of exhaust ports, and an exhaust outlet 39A opening at the lower end of the exhaust manifold 39 communicates with a tubular exhaust passage 40 extending to the lower surface of the mount case 1. The exhaust passage 40 is joined to an exhaust guide 41, which is connected to the oil pan 35 in the extension case 2, on the lower surface of the mount case 1. A connecting flange 45 formed at the upper end of the exhaust pipe 44 is flange-fitted to the lower end of the exhaust guide 41 by a bolt 46. The exhaust pipe 44 extends downward inside the extension case 2, an exhaust port 47 of a lower end portion 44A thereof opens in the casing C, and exhaust gas of the engine E is discharged in the casing C. Below the height of the exhaust port 47 of the lower end portion 44A, the waterline W of the boat B during normal traveling is located.

In the outboard motor 10 of the present embodiment, the catalyst device 48 is provided inside the exhaust pipe 44, and the lower end portion 44A of the exhaust pipe 44 is provided with the water suppression mechanism 50 that suppresses water exposure of the catalyst device 48. ..

FIG. 2 is a diagram showing the configuration of the catalyst device 48.
The catalyst device 48 is a device in which a catalyzer element (also referred to as “catalyst”) 61 for purifying exhaust gas is housed in an outer cylinder 60, and the outer cylinder 60 is attached to a pipe wall 49 (FIG. 3) of the exhaust pipe 44. It is fixed by welding. The catalyzer element 61 is a so-called metal honeycomb catalyst in which a flat plate 63 and a corrugated plate 64 each made of a metal foil are stacked and wound into a columnar shape, and a metal catalyst is supported on the flat plate 63 and the corrugated plate 64 by plating. It is fixed to the inner peripheral surface of the outer cylinder 60 by brazing, welding or the like. The exhaust gas flows through a plurality of cells 65, which are exhaust passages formed between the flat plate 63 and the corrugated plate 64 and extending in the central axis direction of the outer cylinder 60, and acts on the metal catalyst while flowing through the cells 65. HC, CO, NOx, etc. are removed and purified. Platinum (Pt), rhodium (Rh), palladium (Pd), or the like is used as the metal catalyst.

Since the catalyst device 48 is provided in the exhaust pipe 44, the engine E is not complicated or enlarged as compared with the conventional configuration in which the catalyst device 48 is provided beside the cylinder block 26 or the like, and the existing casing C is provided. The engine E can be accommodated in.

The water suppression mechanism 50 is a mechanism that is provided at the lower end portion 44A of the exhaust pipe 44, suppresses water from entering the exhaust port 47, and suppresses water of the catalyst device 48. Even if the water surface in the casing C undulates due to a sudden change in the operating state of the boat B, pulsation of exhaust gas, or the like, the water suppression mechanism 50 suppresses water from the exhaust port 47. As a result, the catalyst device 48 is prevented from being covered with water, and an adverse effect such as a reduction in the purification capability of the catalyst device 48 due to the water can be prevented.

3 is a sectional view taken along line III-III in FIG. 1, and FIG. 4 is a sectional view taken along line IV-IV in FIG.
As shown in FIGS. 3 and 4, the water suppression mechanism 50 includes a plurality of (six in the illustrated example) plates 52. The plate 52 is made of, for example, a metal material having a substantially triangular shape, which is excellent in corrosiveness, durability, and rigidity. One side 52A of the plate 52 has an arcuate shape having a curvature that matches the tube wall 49 inside the exhaust pipe 44, and a fixing margin 53 is provided on the one side 52A. The fixing margin 53 is a fixing piece that extends substantially perpendicular to one side 52</b>A of the plate 52. At the lower end portion 44A of the exhaust pipe 44, a fixing margin 53 is fixed to the pipe wall 49 by welding, and as a result, as shown in FIG. 4, a plurality of fixing margins 53 are provided near the exhaust port 47 at the lower end portion 44A of the exhaust pipe 44. A number of plates 52 are arranged.

As shown in FIG. 3, the plates 52 are attached along the peripheral surface of the pipe wall 49 so as to be substantially equidistant and substantially in contact with each other. By providing these plates 52 at the lower end portion 44A of the exhaust pipe 44, it is possible to prevent the lower end portion 44A from being flooded into the exhaust port 47. The size of each plate 52 is determined by the area of the gap 70 to be formed at the center O of the cross section of the exhaust port 47, and the area of this gap 70 is determined by the allowable value of the exhaust pressure.

The fixing of each plate 52 to the pipe wall 49 is not limited to the method of fixing the fixing margin 53 by welding, but may be the method of fixing the fixing margin 53 with a rivet. In this case, a concave portion for receiving a rivet is formed in advance on the pipe wall 49, and the tip of the rivet passed through the fixing margin 53 is inserted into the concave portion of the pipe wall 49. By caulking the rivet, the fixing margin 53 is fixed. Fix it.

As shown in FIG. 4, in each plate 52, a corner portion 54 facing the fixing margin 53, that is, a corner portion 54 closest to the center O of the exhaust pipe 44 is located below the fixing margin 53 (on the side of the exhaust port 47). It is bent by the fixing margin 53 so as to be located at, so that water that has entered the plate 52 can easily flow down along the upper surface 55.

According to this embodiment, the following effects are achieved.

In the water suppression mechanism 50 of the outboard motor 10 of the present embodiment, a plate 52 for preventing water from entering through the exhaust port 47 is provided near the exhaust port 47 of the exhaust pipe 44. Even if the catalyst device 48 is provided in the unit 44, it is possible to suppress the catalyst device 48 from being exposed to water. Further, by providing the catalyst device 48 in the exhaust pipe 44, it is possible to suppress the size increase of the engine E.

In the water suppression mechanism 50 of the outboard motor 10 of this embodiment, a plurality of plates 52 are provided in the vicinity of the exhaust port 47, and each of the plates 52 has a fixing margin 53 for fixing on one side 52A. It has a triangular shape.
Since each plate 52 includes the fixing margin 53, the plate 52 can be easily fixed. Further, since the plurality of triangular plates 52 are provided in the vicinity of the exhaust port 47, it is possible to effectively prevent the catalyst device 48 from being exposed to water.

In the water suppression mechanism 50 of the outboard motor 10 of the present embodiment, since the plate 52 is fixed to the pipe wall 49 inside the exhaust pipe 44 by fixing the fixing margin 53, the exhaust gas in which the water suppression mechanism 50 is incorporated is exhausted. A tube 44 is obtained.

In the water suppression mechanism 50 of the outboard motor 10 of the present embodiment, the fixing margin 53 is fixed by welding or rivets, so that when the work is incorporated into the exhaust pipe 44, the fixing wall 53 can be easily attached to the pipe wall 49 of the exhaust pipe 44. The plate 52 can be fixed.

In the water suppression mechanism 50 of the outboard motor 10 of the present embodiment, the plate 52 is bent so that the corner portion 54 facing the fixing allowance 53 is located below the fixing allowance 53. The water that has entered can easily flow down along the upper surface 55.

(Second embodiment)
FIG. 5 is a diagram schematically showing the configuration of a water suppression mechanism 150 according to the second embodiment of the present invention, and FIG. 6 is a VI-VI sectional view in FIG.
As shown in FIG. 6, in the water suppression mechanism 150 of the present embodiment, the plate 52 is provided not only in the circumferential direction of the exhaust pipe 44 but also in a plurality of stages (two in the illustrated example) in the vertical direction (extending direction) of the exhaust pipe 44. It is provided in the step.
By providing the plates 52 in multiple stages, the effect of suppressing water exposure can be enhanced.
Here, as the area of one plate 52 is increased and the exhaust port 47 is closed, the effect of suppressing water exposure increases, but then exhaust pressure also increases and engine performance is affected. On the other hand, according to this modification, the effect of suppressing water exposure can be enhanced while suppressing an increase in exhaust pressure without changing the area of each plate 52.

As shown in FIG. 5, in the water suppression mechanism 150 of the present embodiment, the plate 52 at each stage is arranged such that its arrangement position, that is, the position of the corner portion 54 is shifted in the circumferential direction of the exhaust pipe 44 when viewed in the vertical direction. Has been done. This makes it possible to more efficiently suppress the entry of water from the exhaust port 47.

(Third Embodiment)
FIG. 7: is sectional drawing which shows typically the structure of the water suppression mechanism 250 which concerns on 3rd Embodiment of this invention.
In the water suppression mechanism 250 of the present embodiment, as shown in FIG. 7, each plate 52 is configured to be rotatable around the center of the exhaust pipe 44 by the flow of the exhaust gas D.
More specifically, the water suppression mechanism 250 has a circular tubular support plate 280, and the plates 52 are fixed to the inner peripheral surface of the support plate 280 at substantially equal intervals in the circumferential direction. Further, a recess 285 that is recessed in the radial direction is formed over the entire circumference on the pipe wall 49 of the lower end 44A1 of the exhaust pipe 44, and the bearing 281 is fixed in this recess 285. The support plate 280 is supported by the bearing 281 so as to be rotatable in the circumferential direction. As a result, the exhaust gas D hits each plate 52, whereby the plate 52 rotates.
The rotation of the plate 52 increases the wind pressure in the direction that suppresses the entry of water into the exhaust port 47 (that is, the exhaust pressure of the exhaust gas D), making it difficult for water to enter and enhancing the effect of suppressing water exposure. ..

Further, the water suppression mechanism 250 of the present embodiment further includes a rotation direction restricting portion 282 that restricts the rotation direction of the support plate 280 in one direction, so that the water effect is further enhanced. An appropriate mechanism such as a ratchet mechanism can be used for the rotation direction restricting portion 282.

The above-described embodiments are merely examples of the present invention, and can be arbitrarily modified and applied without departing from the spirit of the present invention.

Further, in each of the above-described embodiments, the horizontal and vertical directions, various numerical values, and shapes are conscious of these directions, the range around the numerical values, and the approximate shape unless otherwise specified. This does not mean that the numerical value is not excluded, and the same action and effect are exhibited, and the numerical range includes a peripheral range and an approximate shape (so-called equivalent range) as long as the numerical value does not deviate from the critical meaning.

10 Outboard Motor 44 Exhaust Pipe 47 Exhaust Port 48 Catalytic Device 49 Pipe Walls 50, 150, 250 Water Suppression Mechanism 52 Plate 52A Plate One Side 54 Corner 61 Catalyzer Element (Catalyst)
280 Support plate 281 Bearing 282 Rotational direction restricting portion 285 Recess C Casing D Exhaust gas E Engine O center W Water line

Claims (8)

1. An outboard motor having an engine, an exhaust pipe having an exhaust port opened in the casing, and exhausting exhaust gas of the engine into the casing, and a catalyst provided in the exhaust pipe to purify the exhaust gas. An outboard motor water suppression mechanism provided,
   A water exposure suppression mechanism for an outboard motor, comprising a plate provided near the exhaust port to prevent water from entering through the exhaust port.
2. A plurality of the plates are provided in the vicinity of the exhaust port,
   The water suppression mechanism for an outboard motor according to claim 1, wherein each of the plates has a triangular shape having a fixing margin on one side for fixing.
3. The water suppression mechanism for an outboard motor according to claim 2, wherein the fixing margin is fixed by welding or rivets.
4. The water suppression mechanism for an outboard motor according to claim 2, wherein the plate is bent so that a corner portion facing the fixing allowance is located below the fixing allowance.
5. The water suppression mechanism for an outboard motor according to claim 1, wherein the plates are provided in a plurality of vertical stages.
6. The water suppression mechanism for an outboard motor according to claim 5, wherein the plates are arranged at positions displaced from each other between the stages when viewed from the vertical direction.
7. The water suppression mechanism for an outboard motor according to claim 1, wherein the plurality of plates are provided so as to be rotatable around the exhaust port by the exhaust gas.
8. The outboard motor water dampening mechanism according to claim 7, further comprising a rotation direction restricting portion that restricts a rotation direction of the plate in one direction.

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