Cooling arrangements and cooling water sprayers for marine engines

A marine engine has an internal combustion engine; an exhaust conduit that conveys exhaust gas from the internal combustion engine; a cooling water sprayer that sprays a first flow of cooling water into the exhaust conduit; and a cooling water jacket that conveys a second flow of cooling water alongside the exhaust conduit so that the second flow of cooling water cools the exhaust conduit. The first flow of cooling water and at least part of the second flow of cooling water are merged and then sprayed together into the exhaust conduit via the cooling water sprayer.

FIELD

The present disclosure relates to marine engines, and particularly to cooling arrangements and cooling water sprayers for marine engines.

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 that are disposed along a longitudinal axis and extend 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 vertically-extending 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 elongated exhaust conduit 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 conduit. The cooling water jacket receives raw cooling water at a location proximate to the second end of the exhaust conduit, conveys raw cooling water adjacent to the exhaust conduit to thereby cool the exhaust conduit 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 3-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. 7,942,138 discloses an outboard motor having an exhaust gas recirculation (EGR) system that provides a heat exchanger which reduces the temperature of the exhaust gas prior to introducing the exhaust gas to the cylinders of the engine. The heat exchanger can be integral to the engine, particularly the cylinder head of the engine, or it can be disposed outside the structure of the engine. When disposed outside the structure of the engine, the heat exchanger can comprise a tubular structure that causes exhaust gas and water, from the body of water, to flow in thermal communication with each other. Alternatively, the heat exchanger which is disposed outside the structure of the engine can use a cavity within the driveshaft housing as a heat exchanger with water being sprayed into the stream of exhaust gas as it passes from the engine to the cavity.

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 conduits, 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 described 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 examples disclosed herein, a marine engine has an internal combustion engine; an exhaust conduit that conveys exhaust gas from the internal combustion engine; a cooling water sprayer that sprays a first flow of cooling water into the exhaust conduit; and a cooling jacket that conveys a second flow of cooling water alongside the exhaust conduit so that the second flow of cooling water cools the exhaust conduit. The first flow of cooling water and at least part of the second flow of cooling water are merged and then sprayed together into the exhaust conduit via the cooling water sprayer. In examples disclosed herein, a strainer is disposed in the cooling jacket and configured to strain the second flow of cooling water prior to being sprayed into the exhaust conduit.

In examples disclosed herein, a cooling water sprayer is for a marine engine, in particular for spraying cooling water into an exhaust conduit to thereby cool exhaust gas in the exhaust conduit. The cooling water sprayer comprises a body having a through-bore that is configured to convey a first flow of the cooling water into the exhaust conduit and a cross-bore that is transverse to the through-bore and is configured to convey a separate, second flow of the cooling water into the first flow of cooling water in the through-bore such that the first and second flows of cooling water are merged in the cooling water sprayer.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1depicts an exemplary outboard motor10for propelling a marine vessel in a body of water. The outboard motor10has an internal combustion engine12that is supported with respect to the marine vessel via a conventional mounting arrangement associated with an underlying adapter plate14. A driveshaft housing16extends below the adapter plate14, opposite the internal combustion engine12. The type and configuration of internal combustion engine12can vary from what is shown. In the illustrated example, the internal combustion engine12has a V-shape which discharges exhaust gases inside of the V-shape to a centrally located exhaust conduit22. The internal combustion engine12and exhaust conduit22are configured in the manner disclosed in the above incorporated U.S. Pat. No. 9,616,987. Briefly, combustion within the internal combustion engine12creates exhaust gas, which is centrally conveyed into the valley of the V-shape and then directed upwardly and then downwardly through an exhaust manifold and elbow portion21of the exhaust conduit22. The exhaust conduit22conveys the exhaust gas downwardly from the elbow portion21to the adapter plate14. The exhaust gas is ultimately discharged from the outboard motor10via a conventional underwater exhaust outlet.FIG. 1also schematically depicts an upper cowling18covering the internal combustion engine12and related components and a lower cowling20covering the driveshaft housing16and related components. The upper cowling18is located above the lower cowling20. The shape and configuration of the upper and lower cowlings18,20can vary.

FIGS. 1 and 2also depict portions of a cooling system for cooling certain components of the internal combustion engine12, including for example the above-noted exhaust conduit22. A pump28is configured to pump cooling fluid (e.g., relatively cold water from the body of water in which the outboard motor10is operating) to the internal combustion engine12via a cooling fluid conduit (i.e., a cooling water conduit)26. The pump28is shown schematically inFIG. 2and can include any type of conventional pump device for pumping cooling fluid, including for example a mechanical pump powered by the driveshaft of the internal combustion12or an electrical pump powered by a battery associated with the outboard motor10. In the illustrated example, the pump28is configured to pump cooling water from a conventional underwater inlet on a lower portion of the outboard motor10. The conventional underwater inlet is not shown inFIG. 2however one suitable configuration is disclosed in the incorporated U.S. Pat. No. 8,540,536. Typically the underwater inlet is located in the gear case housing of the outboard motor, below the anti-cavitation plate25shown inFIG. 1. Reference is made to the '536 patent, showing one example. The pump28pumps the cooling water upwardly to the internal combustion engine12via the cooling water conduit26, as shown by arrows inFIGS. 2 and 5. For further background information, the '536 patent also discloses conveyance of the cooling water to an internal combustion engine, as well as an exhaust system for conveying exhaust gas from the internal combustion engine, via cooling water conduits.

Referring toFIGS. 2 and 5, the pump28pumps the cooling water via the cooling water conduit26to a cooling water jacket30disposed on the exhaust conduit22. As the relatively cold cooling water is pumped vertically upwardly through the cooling water jacket30, it naturally exchanges heat with the relatively hot exhaust conduit22and thus also the relatively hot exhaust gas flowing downwardly there through. See e.g. the dashed arrows inFIG. 5. Reference is also made to the above-incorporated U.S. Pat. No. 8,540,536 for further details regarding prior art cooling systems having an exhaust conduit and a cooling water jacket disposed thereon and configured for heat exchange with relatively hot exhaust gas flowing there through. As is conventional, the cooling water flows from upstream to downstream through the cooling water jacket30, under pressure from the pump28, and is then routed to the internal combustion engine12for further heat exchange with components thereof, including for example the cylinder heads, cylinder block, etc. Once the cooling water has completed its path through the cooling system, it typically is discharged back to the body of water in which the outboard motor10is operating via for example an underwater outlet on the outboard motor10.

It is known in the art to provide one or more strainers in the above-described cooling system to strain solid/particulate material of a certain size from the cooling water. In use, prior art strainers can unfortunately become clogged, especially when the outboard motor is operated in a body of water having high debris content. When the strainer becomes clogged, the cooling functionality of the system is compromised and the internal combustion engine is put at risk of overheating. Thus, it is typically recommended that the operator of the outboard motor routinely service the strainer(s). The strainer(s) should be routinely checked for clogs and any other problems. However the present inventors have found that this process can be especially challenging and cumbersome because prior art strainers are usually located below the adapter plate, under the lower cowling. Access to a plugged strainer usually requires the operator or service technician to remove the lower cowling and then remove other connection features associated with the strainer (e.g. fasteners, brackets, etc.).

The present disclosure is a result of the present inventors' efforts to provide cooling systems and strainers for cooling systems that are both more effective and easier to service.

Referring toFIGS. 4-6, according to the present disclosure, a strainer34is disposed in the cooling water conduit26at a location above the adapter plate14. Referring toFIGS. 2-6, the strainer34is easily accessible by the operator, requiring only removal of the upper cowling18and removal of a quick connector36that connects the strainer34to the cooling water conduit26. The quick connector36is manually operable to allow the operator to easily connect and disconnect the strainer from the cooling water conduit26without the need for tools. As explained further herein below, the strainer34is also uniquely configured to more efficiently strain the cooling water flowing into the exhaust conduit22and the cooling water flowing into the cooling water jacket30, as compared to the prior art, and is also less likely to clog. Other advantages and improvements over the prior art will be apparent from the following description of the drawings.

As shown inFIG. 5, the cooling water conduit26includes an elbow fitting37that has a first outlet port39attached to an inlet boss41on the cooling water jacket30. An O-ring seal47is disposed between the elbow fitting37and the inlet boss41so as to form a fluid tight seal there between. The elbow fitting37further includes an inlet port43that receives cooling water from the pump28via a flexible hose45. The flexible hose45is clamped to a barb49on the inlet port43so as to form a fluid tight seal there between. The elbow fitting37also has a second outlet port51to which the strainer34is connected by the quick connector36.

The cooling water conduit26and the quick connector36define a first axially extending flow path38for the cooling water. The cooling water conduit26further defines a second, transversely extending flow path40that transversely branches off from the first axially extending flow path38. The first axially extending flow path38extends through the elbow fitting37and quick connector36to a flexible connection hose53, which leads to an exhaust sprayer32configured to spray cooling water into the exhaust conduit22for mixing with and cooling the exhaust gas flowing downwardly there through. The second transversely extending flow path40leads to the cooling water jacket30on the exhaust conduit22.

Thus, as shown by arrows inFIG. 5, a first portion of the cooling water flows upwardly along the first axially extending flow path38, through the strainer34, and on to the exhaust sprayer32via the connection hose53. A second portion of the cooling water flows through the strainer34and then transversely along the second transversely extending flow path40. The second portion of the cooling water generally includes cooling water flowing on the radially outer side of the inlet port43, diametrically opposite the cooling water jacket30. A shoulder57is formed on the radially outer side of the inlet port43so as to transversely redirect the second portion of the cooling water along the second transversely extending flow path40, through the strainer34, and then into the first outlet port39. A third portion of the cooling water that generally consists of cooling water flowing along the radially inner side of the inlet port43, bypasses the strainer34, and then flows through the second, transversely extending flow path40.

As shown inFIG. 5, the strainer34axially extends into the cooling water conduit26along the first axially extending flow path38. Referring toFIGS. 5 and 6, the strainer34includes a body42that has a through-bore44, a first axial end46that is mated with the quick connector36, and a second axial end48that freely extends into the cooling water conduit26. As shown inFIG. 5, the cooling water conduit26conveys the cooling water from upstream to downstream and the second axial end48is located upstream of the first axial end46, such that the second axial end48faces the cooling water as it is conveyed. Referring toFIG. 6, an end cap50is disposed on the second axial end48of the strainer34. A filter or screen52extends along the body42and is configured to strain the cooling water as it flows from the cooling water conduit26into the through-bore44in the body42. The screen52is located closer to the second axial end48than the first axial end46. A plurality of bumps54extend radially outwardly from the body42and are spaced apart around the body42at the first axial end46. An annular rib56is formed at the first axial end46. The bumps54and annular rib56are configured for engagement with the second outlet port51and quick connector36, respectively, as further described herein below.

The configuration of the quick connector36can vary from what is shown in the drawings. Referring toFIG. 5, the illustrated example is a SAEJ2044 Quick Connect Fitting, which for example is commercially available from Parker Hannifin. The quick connector36is manually operable to easily connect and disconnect the strainer34from the cooling water conduit26and from the quick connector36. The quick connector36includes an elongated body60having a through-bore sized to fit onto the outer diameter of the second outlet port51of the elbow fitting37. The quick connector36has a retention ring62with an inner diameter that is sized slightly smaller than the outer diameter of an annular ring64on the second outlet port51. As shown by an arrow inFIG. 3, the retention ring62is manually deformable by pressing on the outer surface thereof. Manually deforming the retention ring62changes the dimensions of its inner diameter so as to free the quick connector36for axial removal from the second outlet port51. That is, the retention ring62is able to pass over the annular ring64when the retention ring62is manually pressed. SeeFIG. 4.

The quick connector36can be manually re-connected to the second outlet port51by re-inserting the strainer34into the second outlet port51and axially moving the quick connector36downwardly onto the second outlet port51, until the retention ring62is forced to deform over the outer diameter of the annular ring64. The natural resiliency of the retention ring62, which can be made of plastic, causes it to snap back into its natural shape once it axially passes by the retention ring62, thus engaging with the second outlet port51in a snap-fit manner. An inner O-ring seal63is configured to seal with the outer diameter of the second outlet port51. The bumps54on the outer diameter of the body42of the strainer34are configured to engage in a press-fit connection with the inner diameter of the second outlet port51.

Referring toFIGS. 3-6, the quick connector36facilitates quick and easy checking and maintenance of the strainer34, including removal any clogs or other debris.FIG. 3depicts the quick connector36in a connection position on the second outlet port51. When the retention ring62is manually engaged and deformed, the body60is removable from the second outlet port51, as described above and shown inFIG. 4. When the body60of the quick connector36is manually withdrawn from the second outlet port51, the strainer34will tend to remain seated in the second outlet port51due to the frictional engagement between the bumps54and the inner diameter of the second outlet port51. As the body60of the strainer34is removed, the annular rib56on the first axial end46of the strainer34is engaged by an inner mantle piece55on the quick connector36, which pulls the strainer34out of the second outlet port51along with the quick connector36, overcoming the frictional engagement between the bumps54and the inner diameter of the second outlet port51. The inner mantle piece55is sized just slightly larger than the annular rib56so that the engagement there between is strong enough to pull the strainer34out of engagement with the second outlet port51. However the engagement between the inner mantle piece55and annular rib56can be configured so that it can be overcome by a stronger manual force, i.e. manually pulling the strainer34out of the body60of the quick connector36. That is, the inner mantle piece55and/or the annular rib56are made of a resilient material such as plastic, which will slightly deform under a sufficient manual separating force. This allows separation of the strainer34from the quick connector36after the quick connector36has been removed from the second outlet port51, thus facilitating cleaning and/or repair of both components.

The location of the strainer34on the outboard motor10and the configuration of the quick connector36advantageously provide the operator with an accessible arrangement that does not require tools or fasteners for assembly and disassembly. The inline configuration of the strainer facilitates improved flow area and straining functionality over the prior art, thus improving performance. The shape of the strainer and orientation of the strainer in the cooling water conduit is less restrictive for water flow, as compared to the prior art, and also facilitates self-cleaning during shutdown of the internal combustion engine. Large debris is less likely to get stuck on the strainer because of its axial (inline) orientation with the flow of water. Large debris will tend to deflect off of the closed end cap50, without getting stuck. This configuration can also be easily inspected without removal of the lower cowling. In certain examples, the second outlet port51of the elbow fitting37can be made of transparent material (e.g. plastic), thus allowing for easier visual inspection without requiring removal of the quick connector36from the second outlet port51.

Through research and development, the present inventors have also endeavored to improve upon prior art cooling systems having strainers and water sprayers for spraying cooling water into outflowing exhaust gas from an internal combustion engine. The present inventors have determined that it would be advantageous to provide a cooling system with a dual sprayer that operates based on more than one water source. The inventors identified that this type of arrangement would advantageously reduce the chance of the exhaust sprayer becoming totally plugged, thus limiting the risk of overheating of the internal combustion engine. The inventors further identified that it would be advantageous to provide such a dual sprayer in a package that is easily serviced by the operator or technician. The present disclosure arose out of these recognitions by the inventors.

Referring toFIGS. 7-9, a first embodiment of an improved cooling water sprayer100is shown. The cooling water sprayer100includes a body102that extends through a cross-bore104in the cooling water jacket30and a cross-bore105in the exhaust conduit22. The cooling water sprayer100includes a free end106extending into and disposed in the exhaust conduit22and a fixed end108that is seated in the cross-bore104. The fixed end108has an outer O-ring groove107in which a rubber O-ring is seated for fluid-tight sealing with an inner diameter of the cross-bore104in the cooling water jacket30.

The body102defines a through-bore110extending from the fixed end108to the free end106and configured to convey cooling water there through. The free end106defines a nozzle112that is configured to spray cooling water into the downwardly flowing exhaust gas, shown by dash-and-dot arrows inFIG. 7. The configuration of the nozzle112can vary from what is shown in the drawings. In the illustrated example, the nozzle112includes a cutaway114at the free end106. An end wall116at the free end106redirects the flow of cooling water from the through-bore110and causes the cooling water to spray into the exhaust gas traveling downwardly in the exhaust conduit22. The fixed end108of the body102has an inlet boss109for connection to, for example, a hose that supplies a flow of cooling water. An end cap111is disposed on the through-bore110at the fixed end108closing the through-bore110and preventing leakage of cooling water out of the fixed end108.

The body102further includes a cross-bore118that is transversely oriented to the through-bore110and passes completely through the cooling water sprayer100. The cross-bore118includes an inlet120oriented downwardly and facing the oncoming (upward) flow of cooling water in the cooling water jacket30. The cross-bore118further includes an outlet122that is located diametrically opposite to the inlet120with respect to the through-bore110. The outlet122allows cooling water to flow out of the through-bore110and into the cooling water flowing upwardly in the cooling water jacket30.

A strainer124is disposed extends over the cross-bore110and is configured to strain cooling water that flows from the cooling water jacket30into the through-bore110. The configuration of the strainer124can vary from that is shown. In the illustrated example the strainer124is cylindrical and extends coaxially around the body102. The strainer124has a first end126that is retained in a peripheral channel129on the body102on one side of the cross-bore and a second free end128on the opposite side of the cross-bore118. In the illustrated example, the strainer124extends over both the inlet120and the outlet122so as to strain the cooling water flowing into the cross-bore118and the cooling water flowing out of the cross-bore118. The strainer124can have a minimum hole diameter of 1.5 mm so that it effectively screens the cooling water of debris that could plug the cooling water sprayer100. Again however, the configuration of the strainer124can vary from what is shown and described, and for example could be configured to strain cooling water at only one of the inlet120and outlet122.

The cooling water sprayer100can for example be made of stainless steel; however other materials can be used. Advantageously, the cooling water sprayer100is located above the adapter plate14, so that it is accessible by removal of the upper cowling18while the lower cowling20remains in place. The cooling water sprayer100can be removed on the water for service with minimal tools.

FIGS. 10-12depict another example of a cooling water sprayer100′. The cooling water sprayer100′ mostly functions the same as the cooling water sprayer100, except for a few differences. The cooling water sprayer100′ has a two-part body102′, including a base130′ and an extension132′ that is seated in the base130′. The extension132′ has a pair of apertures134′ formed along the extension132′ which are shaped as nozzles112′. The apertures134′ are configured to spray the cooling water into the exhaust gas flowing through the exhaust conduit22. The strainer124′ is formed with the body102′. The extension132′ should be resilient to heat from the exhaust gas flowing through the exhaust conduit22. Connection of the base130′ to the metal exhaust conduit22and cooling water jacket30should preferably be resistant to galvanic corrosion, which can occur at a traditional interface between an aluminum bore and a stainless fitting.

Thus, the base130′ of the cooling water sprayer100′ can for example be made of corrosive resistant injection molded nylon; however other materials can be used. The extension132′ can be made of stainless steel; however other materials can be used. Advantageously, the cooling water sprayer100′ is located above the adapter plate14, so that it is accessible by removal of the upper cowling18while the lower cowling20remains in place. The cooling water sprayer100′ can be removed on the water for service with minimal tools.

The present disclosure thus provides a cooling water sprayer100,100′ that sprays a first flow of cooling water150(seeFIG. 7) into the exhaust conduit22. A cooling water jacket30conveys a second flow of cooling water152(seeFIG. 7) alongside the exhaust conduit22so that the second flow of cooling water152cools the exhaust conduit22. The first flow of cooling water150and at least a portion of the second flow of cooling water152are merged and then sprayed together into the exhaust conduit22via the cooling water sprayer100,100′. As shown inFIG. 7, the first and second flows of cooling water150,152flow in parallel with respect to each other before being merged at the cooling water sprayer100,100′.

The cooling water sprayer100,100′ has a through-bore110,110′ that conveys the first flow of cooling water150into the exhaust conduit22and a cross-bore104,105;104′,105′ that is transverse to the through-bore110,110′ and conveys the portion of the second flow of cooling water152into the first flow of cooling water150in the through-bore110,110′. The cross-bore104,105;104′,105′ extends through the cooling water sprayer100,100′ so that a remaining portion of the second flow of cooling water152passes through the cooling water sprayer100,100′ and continues to flow in the cooling water jacket30.

A strainer34strains the first flow of cooling water150and the second flow of cooling water152, and a strainer124,124′ strains only the second flow of cooling water152. In this combination, the strainer34can be any type of strainer located remotely located with respect to the cooling water sprayer100,100′. The strainer124,124′ is located on the cooling water sprayer100,100′. The cooling water pump28pumps the first flow of cooling water150through the cooling water sprayer100,100′ and the second flow of cooling water152through the cooling water jacket30. The cooling water sprayer100,100′ is located above the adapter plate14so that it is accessible upon removal of the upper cowling20while the lower cowling18remains in place.

The cooling water sprayer100,100′ includes an elongated body102that extends through and is seated in the cross-bores104,105;104′,105′in the cooling water jacket30and the exhaust conduit22, respectively. The cooling water sprayer100,100′ has a free end106having a nozzle112,112′ that extends into the exhaust conduit22and is configured to spray cooling water into the exhaust gas.

Advantageously, the cooling water sprayer100,100′ is less susceptible to total plugging, as compared to the prior art, based at least upon the fact that it operates with dual cooling water sources. In addition, the unique way in which the cooling water sprayer100,100′ merges the first and second flows of cooling water150,152in the through-bore110disturbs particulate matter that collects on the strainer124,124′, thus limiting the chance of a total clog. The location of the strainer124,124′ in the cooling water jacket30provides a compact arrangement having a low profile, thus meeting packaging constraints, wherein space is a premium on marine engine designs. The cooling water sprayer100,100′ and strainer124,124′ are easily serviced by an operator or technician by simply removing the upper cowling18and then removing the cooling water sprayer100,100′ from the cross-bores104,105;104′,105′.

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 described 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.