Serviceable cooling water strainers for straining cooling water in marine propulsion devices

A marine propulsion device has an engine; an exhaust manifold for conveying exhaust gas from the engine; a cooling water jacket on the exhaust manifold, wherein a cooling water passage for conveying cooling water alongside the exhaust manifold is defined between the cooling water jacket and exhaust manifold; and a cooling water sprayer that sprays cooling water into the exhaust manifold. A manually serviceable cooling water strainer configured to strain cooling water supplied from the cooling water passage to the cooling water sprayer. The manually serviceable cooling water strainer can be manually coupled to and manually uncoupled from the marine propulsion device without use of a tool.

FIELD

The present disclosure relates to marine propulsion devices, and particularly to cooling systems for marine propulsion devices having cooling water strainers.

BACKGROUND

The following U.S. Patents are incorporated herein by reference in entirety.

U.S. Pat. No. 9,616,987 discloses a marine engine having a cylinder block with first and second banks of cylinders disposed along a longitudinal axis and extending transversely with respect to each other in a V-shape so as to define a valley there between. A catalyst receptacle is disposed at least partially in the valley and contains at least one catalyst that treats exhaust gas from the marine engine. A conduit conveys the exhaust gas from the marine engine to the catalyst receptacle. The conduit receives the exhaust gas from the first and second banks of cylinders and conveys the exhaust gas to the catalyst receptacle. The conduit reverses direction only once with respect to the longitudinal axis.

U.S. Pat. No. 9,365,275 discloses an outboard marine propulsion device having an internal combustion engine with a cylinder head and a cylinder block, and an exhaust manifold that discharges exhaust gases from the engine towards a catalyst housing. The exhaust manifold has a plurality of horizontally extending inlet runners that receive the exhaust gases from the engine and a vertically-extending collecting passage that conveys the exhaust gases from the plurality of horizontally-extending inlet runners to a bend that redirects the exhaust gases downwardly towards the catalyst housing.

U.S. Pat. No. 8,540,536 discloses a cooling system for a marine engine having an exhaust manifold with a first end receiving hot exhaust gas from the marine engine and a second end discharging the exhaust gas, and an elongated cooling water jacket extending adjacent to the exhaust manifold. The cooling water jacket receives raw cooling water at a location proximate to the second end of the exhaust manifold, conveys raw cooling water adjacent to the exhaust manifold to thereby cool the exhaust manifold and warm the raw cooling water, and thereafter discharges the warmed cooling water to cool the internal combustion engine.

U.S. Pat. No. 8,500,501 discloses an outboard marine drive including a cooling system drawing cooling water from a body of water in which the outboard marine drive is operating and supplying the cooling water through cooling passages in an exhaust tube in the driveshaft housing, a catalyst housing, and an exhaust manifold, and thereafter through cooling passages in the cylinder head and the cylinder block of the engine. A three-pass exhaust manifold is provided. A method is provided for preventing condensate formation in a cylinder head, catalyst housing, and exhaust manifold of an internal combustion engine of a powerhead in an outboard marine drive.

U.S. Pat. No. 7,001,231 discloses a water cooling system for an outboard motor having a water conduit that extends through both an idle exhaust relief passage and a primary exhaust passage. Water within the water conduit flows through first and second openings to distribute sprays or streams of water into first and second exhaust manifolds, which can be the primary and idle exhaust relief passages of an outboard motor.

SUMMARY

This Summary is provided to introduce a selection of concepts that are further disclosed herein below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting scope of the claimed subject matter.

In certain non-limiting examples, a marine propulsion device has an engine, an exhaust manifold for conveying exhaust gas from the engine, a cooling water jacket on the exhaust manifold, wherein a cooling water passage for conveying cooling water alongside the exhaust manifold is defined between the cooling water jacket and exhaust manifold, and a cooling water sprayer that sprays cooling water into the exhaust manifold. A manually serviceable cooling water strainer is configured to strain cooling water supplied from the cooling water passage to the cooling water sprayer. The manually serviceable cooling water strainer has a plug with a plurality of holes that separates solids from the cooling water. The plug further has an internal bore that receives cooling water from the cooling water passage via the plurality of holes and a plug outlet through which the cooling water flows from the internal bore. The plug outlet is located axially between the first and second ends. The second end is configured for manual grasping by a service technician for removal and replacement of the plug with respect to the exhaust manifold. A boss on the exhaust manifold has a bore into which the plug extends when the cooling water strainer is coupled to the exhaust manifold. First and second seals are located on opposite sides of the plug outlet, respectively, and form a water-tight seal with respect to the plug and the boss when the plug is manually coupled to the boss. The boss further has a radially extending boss outlet through which cooling water from the plug outlet is conveyed.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1is taken from U.S. Pat. No. 9,616,987 and depicts an internal combustion engine10configured for use in an outboard motor. The internal combustion engine10has a cylinder block12with first and second banks of cylinders14,16that are disposed along a vertical axis18and extend transversely with respect to each other in a V-shape so as to define a valley20therebetween. The number and configuration of cylinders can vary from what is shown. An exhaust manifold22is configured to convey exhaust gas from the internal combustion engine10. The configuration of the exhaust manifold22can also vary from what is shown. In the illustrated example, the exhaust manifold22is disposed in the valley20and initially conveys the exhaust gas vertically upwardly from cast-in exhaust conduits15on the respective banks of cylinders14,16, through a 180-degree bend24, and then vertically downwardly through an elongated conduit25, which includes an optional catalyst receptacle26having a catalyst therein for treating the exhaust gas, all as disclosed in the '987 patent.

FIGS. 2-5depict an exhaust manifold23for use an internal combustion engine for an outboard motor configuration, such as the exemplary internal combustion engine10shown inFIG. 1. Like reference numbers are used for features that are similar to the exhaust manifold22. Similar to the example inFIG. 1, the exhaust manifold23has a 180-degree bend24and elongated conduit25. Flanges27on the 180-degree bend24mate with upwardly-facing flanges29(seeFIG. 1) on the cast-in conduits15on the first and second banks of cylinders14,16. As disclosed in the '987 patent, exhaust gases from the respective cast-in conduits15are merged in the 180-degree bend24and then conveyed downwardly through the elongated conduit25. A flange31is mated with a downstream exhaust tube41to further convey the exhaust gas away from the internal combustion engine10. As shown inFIGS. 4 and 5, a cooling jacket17is disposed on the exhaust manifold23and defines a cooling water passage13configured to convey cooling water upwardly and/or downwardly alongside the exhaust manifold23, in a heat exchange relationship with a sidewall33of the exhaust manifold23and the relatively hot exhaust gas flowing there through. Unlike the example shown inFIG. 1, the exhaust manifold23does not have the optional catalyst receptacle26and catalyst therein.

It is desirable to cool relatively hot exhaust gases emitted from the internal combustion engine. It is also desirable to do so in a reliable, uniform and complete manner by for example pumping cooling water through the cooling water passage13and/or by injecting the cooling water into the flow of exhaust gas at various water pressures and flow rates.

Referring now toFIGS. 2-5, a cooling system is provided for cooling the exhaust manifold23and the exhaust gas flowing through the exhaust manifold23. In the illustrated example, the cooling system includes first and second cooling water sprayers28,30that are configured to spray first and second flows of cooling water into the exhaust gas, respectively. The cooling water sprayers28,30are vertically aligned (e.g., stacked) with respect to each other and with respect to the exhaust manifold23. A first conduit32is connected to the first cooling water sprayer28and a separate, second conduit34is connected to the second cooling water sprayer30. The first and second conduits32,34convey the separate, first and second flows of cooling water, respectively, to the cooling water sprayers28,30. The first and second conduits32,34are separate from each other such that the first and second flows of cooling water remain separate as they are conveyed to the respective cooling water sprayers28,30, in parallel. In the illustrated example, the second conduit34receives the second flow of cooling water from the cooling water passage13via a cooling water strainer100, as will be further described herein below. The first and second flows of cooling water can both derive from a conventional upstream cooling water pump that pumps raw water from the body of water in which the outboard motor is operating. The raw water can be obtained from, for example, one or more conventional cooling water inlets on the gearcase of the outboard motor.

Referring toFIG. 3, the first cooling water sprayer28is fitted in a first radial through-bore36in the exhaust manifold23. The second cooling water sprayer30is fitted in a second radial through-bore38in the exhaust manifold23. The first and second radial through-bores36,38each extend through the sidewall33of the exhaust manifold23, and through the cooling jacket17on the sidewall33. Optionally, the first and second radial through-bores36,38can have different sizes (e.g. diameters) with respect to each other, which correspond to differently-sized base portions21of the cooling water sprayers28,30, to prevent an incorrect assembly of the cooling water sprayers28,30with the exhaust manifold23. A retainer40retains both of the cooling water sprayers28,30with respect to the exhaust manifold23. In the illustrated example, both of the cooling water sprayers28,30have an outer circumference with a radial notch42in which the retainer40, in this example a bolt, is registered, to thereby retain the cooling water sprayers28,30in place. The retainer40has a threaded shank that is received in a threaded hole44located in between the first and second radial through-bores36,38. The retainer40further has an outer flange46that registers with radial engagement surfaces48located within the respective radial notches42. Threading the retainer40into the threaded hole44sandwiches the radial engagement surfaces48between the outer flange46and a boss50on the exhaust manifold23, through which the first and second radial through-bores36,38are formed, thereby retaining the cooling water sprayers28,30in place.

Referring toFIGS. 4 and 5, the cooling water sprayers28,30are specially configured to spray the respective first and second flows of cooling water radially outwardly toward the inner diameter52of the sidewall33of the exhaust manifold23. In certain examples, each cooling water sprayer28,30is configured to spray the flow of cooling water so that a swirling flow of cooling water results, i.e. circumferentially around and spirally downwardly along the inner diameter52. Each of the cooling water sprayers28,30has an elongated sprayer body54that radially extends into the exhaust manifold23and conveys the respective flow of cooling water radially inwardly through the cooling jacket17, through the cooling water passage13, and through the sidewall33of the exhaust manifold23and toward the interior of the conduit25. As noted inFIGS. 3 and 4, each of the cooling water sprayers28,30also has first and second pairs of diametrically-opposing nozzles56,58that are each configured to spray the flow of cooling water radially outwardly in a fan-shaped pattern61(seeFIG. 4) toward the inner diameter52of the radially exhaust manifold23. The sprayer body54includes a cylinder62that radially extends into the conduit25. As shown inFIG. 4, the flows of cooling water are sprayed radially outwardly from the nozzles56,58, radially outwardly from the cylinder62. The first and second pairs of nozzles56,58are spaced apart from each other along the sprayer body54. Each of the nozzles56,58have the same or roughly the same shape, size and orientation.

Referring toFIGS. 4 and 5, the nozzles56,58are defined by a tangential cutout in the outer surface of the cylinder62. Each tangential cutout has radially extending endwall66upon which the flow of cooling water impinges as it flows through the cylinder62. Each cutout also has tangentially tapered group of sidewalls68that extend tangentially outwardly and extend from the outer surface64of the cylinder62to the endwall66. Each tangentially tapered group of sidewalls68defines a three-sided radial aperture in the cylinder62. Stated another way, the sprayer body54is elongated along a sprayer body axis70and the endwall66extends approximately perpendicularly radially outwardly with respect to the sprayer body axis70. The tangentially tapered group of sidewalls68extends at an approximately tangential angle to the sprayer body axis70and at a substantially perpendicular angle to the endwall66. Other configurations can be employed to achieve the fan-shaped pattern61.

Thus, according to examples disclosed herein, the cooling water system for the outboard motor has redundant sprayers and filters, which provide an added layer of protection against a loss of function. Each cooling water sprayer28,30is fed by an independent water source which protects the system from external and internal contamination clogging the cooling water sprayers28,30. The cooling water sprayers28,30are stacked on top of each other and spray into the exhaust gas. To ensure the cooling water sprayers28,30are installed correctly, the sprayer bodies54are configured so that one retainer40can be used to hold both cooling water sprayers28,30in their intended position. The sprayer bodies54have base portions21having different diameters to “poke-a-yoke” their installation with the correct through-bores36,38. The radial notch42in each sprayer body54allows the retainer40to hold the sprayer bodies54in position and maintain their rotation.

During research and experimentation, the present inventors have also determined that a blockage or other failure of one or both of the cooling water sprayers28,30can cause an excessively high exhaust gas temperature, which can damage the internal combustion engine and/or components thereof. A failure of the cooling water sprayers28,30can result from impassible debris from the inlet port of the cooling system and/or impassible debris that is built up and liberated from inside the cooling system. As such, the present inventors have determined that it is desirable to provide one or more strainers in the cooling water system for straining solid materials from the cooling water, upstream of the sprayers. The present inventors have further determined that it is desirable to provide a strainer that is easily serviced in the field, without the use of tools. This is advantageous because the strainer can sometimes become clogged with solid materials.

Referring now toFIGS. 2 and 5-7, a manually serviceable cooling water strainer100is configured to strain the cooling water supplied from the cooling water passage13to the cooling water sprayer30. As described herein below, the manually serviceable cooling water strainer100advantageously can be manually coupled to and manually uncoupled from the exhaust manifold23without use of tools. The cooling water strainer100has a plug102with a plurality of holes104that separates solids from the cooling water as the cooling water flows through the manually serviceable cooling water strainer100towards the cooling water sprayer30, see arrows A and B inFIG. 7. The plug102has an axially elongated body106with a first end108and an axially opposite, second end110. The plurality of holes104is located at the first end108and faces the cooling water passage13when the plug102is coupled to the exhaust manifold23, seeFIG. 7. In the illustrated example, the first end108has a generally flat surface112and the plurality of holes104is formed through the generally flat surface112. Referring toFIG. 7, the generally flat surface112lies flush with a radially inner surface109of the cooling water jacket17when the plug102is coupled to the exhaust manifold23. In the alternate example shown inFIG. 8, the first end108has a convex surface114and the plurality of holes104is formed through the convex surface114. Optionally, the convex surface114can protrude into the cooling water passage13when the plug102is installed onto the exhaust manifold23. In the alternate examples shown inFIG. 9, the first end108has a sunken or concave surface116and the plurality of holes104is formed through the concave surface116.

Referring toFIG. 7, the plug102further includes an internal bore118that receives cooling water from the cooling water passage13via the plurality of holes104and a radially oriented plug outlet120through which the cooling water flows from the internal bore118to the cooling water sprayer30. One or more plug outlets120are located axially between the first end108and second end110. First and second seals122,124are located on opposite sides of the plug outlet120. The first and second seals122,124together form a water-tight seal with respect to the exhaust manifold23and internal bore118when the plug102is manually coupled to the exhaust manifold23.

In the illustrated example, a boss126is either formed on or fixedly connected to a corresponding boss125and through-bore129in the cooling water jacket17on the exhaust manifold23. In the illustrated example, the boss126is coupled to the exhaust manifold23by a fastener127. The boss126has an internal bore128into which the plug102extends when the cooling water strainer100is coupled to the exhaust manifold23. In this position, the first and second seals122,124form the water-tight seal via a press-fit with the inner surface130of the internal bore128and/or with an internal surface on the through-bore129on the cooling water jacket17.

The boss126has a radially extending boss outlet132through which cooling water from the plug outlet120is conveyed to the cooling water sprayer30via conduit34(seeFIG. 2). The boss outlet132can be sized to control the amount of water that is passed to the sprayer30to optimize spray pattern. The second end110of the plug102has a handle tab103that is configured for pinching between the fingers of a service technician for removal and replacement of the plug102with respect to the exhaust manifold23. In the illustrated example, the plug102is manually coupled to the boss126via a threaded connection134, seeFIG. 7, that is configured (sized and located) so that the plug outlet120automatically becomes radially aligned with the boss outlet132when the plug102is axially inserted into and manually rotated until it is completely engaged with the boss126. A third seal136is located between the first and second seals122,124, proximate to the first end108of the plug102. The third seal136sealingly abuts a shoulder138in the internal bore128of the boss126and thus forms a seal with the shoulder138when the plug102is rotated into complete threaded engagement with the boss126.

In the present description, certain terms have been used for brevity, clearness and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The different apparatuses disclosed herein may be used alone or in combination with other apparatuses. Various equivalents, alternatives and modifications are possible within the scope of the appended claims.