Reversion control device for watercraft exhaust system

Abstract

The present invention is a reversion control device including a housing with a proximal end and a distal end. The reversion control device further includes at least one reversion cone, a stationary vane and a flapper. In one example, the reversion control device includes an oxygen sensor for monitoring the oxygen content of the engine for routine operations or for diagnostic purposes. In an example, the housing includes an expansion chamber to house the reversion cone, the stationary vane and the flapper. In another example, the stationary vane is housed within the reversion cone. In yet another example, the reversion control device is integrated within an exhaust manifold elbow.

Description

This application is a continuation-in-part of application Ser. No. 11/401,627, filed Apr. 10, 2006.

FIELD

The field of the present invention relates generally to watercraft exhaust systems. More particularly, the present invention relates to a device attached to the exhaust system for controlling water reversion back to the engine.

BACKGROUND

In a typical motorized watercraft, the exhaust system includes an exhaust manifold elbow. The exhaust manifold elbow includes an exhaust gas passage and a water passage with the two passages juxtaposed. Exhaust gas from the engine exits the exhaust system through the exhaust gas passage. Water from the lake or ocean, injected into the exhaust system for cooling the running engine, passes near the exhaust gas passage, where it further cools the exhaust gas. The exhaust gas and cooling water exit the elbow mixing area of the exhaust manifold elbow and are mixed with each other. Ideally, both are then expelled.

In motorized watercraft, portions of the exhaust system can be immersed in the water (e.g., lake or ocean) while the engine is running. This arrangement may cause water to move back towards the engine through the gas passage. This is known as water reversion. Water reversion is undesirable for many reasons. Water in the engine may damage it. Water reversion may also decrease engine performance and increase fuel consumption since water moving upstream through the gas passage impedes the flow of exhaust exiting from the engine. In addition, reversion of cooling water may also occur to cause the above-mentioned problems, even in exhaust systems where the exhaust ejection point is not immersed in water so long as the system uses water for cooling the engine and/or exhaust gas.

Watercraft exhaust manufacturers have attempted several solutions to the problem of water reversion, such as placing a stationary, semi-perforated cap-like structure or a stationary plate in the exhaust manifold elbow area. While these attempted solutions may prevent some amount of water backflow, they also have the tendency to impede the flow of exhaust gas out of the exhaust system. Impeding exhaust gas flow decreases performance and increases fuel consumption.

Accordingly, it would be desirable to provide a device for controlling water reversion without decreasing engine performance or increasing fuel consumption.

SUMMARY

According to one aspect, the present invention provides a reversion control device comprising a housing with a proximal end and a distal end; a first reversion cone housed in the housing; and a flapper housed in the housing. In one embodiment, the reversion control device further comprises a stationary vane housed in the housing. In another embodiment, the reversion control device further comprises a second reversion cone housed in the housing.

According to another aspect, the present invention provides a reversion control device comprising a housing with a proximal end, a distal end and an expansion chamber, a first reversion cone housed within the expansion chamber near the distal end; a stationary vane housed within the expansion chamber near the distal end; and a flapper housed within the expansion chamber near the proximal end. In one embodiment, the reversion control device further comprises a second reversion cone housed near the proximal end.

According to another aspect, the present invention provides an exhaust system for controlling water reversion comprising a reversion control device comprising a housing with a proximal end, a distal end, and an expansion chamber between the proximal end and the distal end; a first reversion cone housed within the expansion chamber; a stationary vane housed within the expansion chamber; and a flapper housed within the expansion chamber; at least one exhaust mixture hose support attached to the reversion control device on the housing; and an exhaust mixture hose coupled to at least one exhaust mixture hose support, the exhaust mixture hose surrounding the reversion control device. In one embodiment, the reversion control device further comprises a second reversion cone housed within the expansion chamber.

According to another aspect, the present invention provides an exhaust manifold elbow comprising a reversion control device housed within the exhaust manifold elbow, the reversion control device comprising a proximal end, a distal end, a first reversion cone housed near the distal end, a stationary vane housed near the distal end, and a flapper housed near the proximal end. In one embodiment, the reversion control device further comprises a diffuser edge housed near the distal end. In another embodiment, the reversion control device further comprises a second reversion cone housed near the proximal end.

According to another aspect, the present invention provides an exhaust manifold elbow comprising a reversion control device housed within the exhaust manifold elbow, the reversion control device comprising a proximal end, a distal end, an expansion chamber between the distal end and the proximal end, a first reversion cone housed within the expansion chamber, a stationary vane housed within the expansion chamber, a flapper housed within the expansion chamber, and a second reversion cone housed in the proximal direction of the exhaust manifold elbow.

Other embodiments will be readily apparent to those skilled in the art from the following detailed description, wherein various embodiments are shown and described by way of illustration. The drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a shows the reversion control device next to an exhaust manifold elbow.

FIG. 1b shows another embodiment of the reversion control device.

FIG. 2a is a side view of an exhaust manifold elbow.

FIG. 2b is the bottom view of the exhaust manifold elbow shown in FIG. 2a.

FIGS. 2c and 2d are the side view and bottom view, respectively, of an alternatively shaped exhaust manifold elbow.

FIGS. 2e and 2f are the side view and bottom view, respectively, of yet another alternatively shaped exhaust manifold elbow.

FIG. 3a is a front view of the stationary vane.

FIG. 3b shows the blades of the stationary vane.

FIG. 4a shows the flapper as seen from the distal end.

FIG. 4b shows the side view of the flapper in FIG. 4a.

FIG. 4c shows the flapper as seen from the proximal end.

FIG. 4d shows the flapper in a closed position.

FIG. 4e shows the distal end of the reversion control device with the flapper mounted.

FIG. 4f shows the flapper in an open position.

FIG. 5a shows the reversion control device mounted to the exhaust manifold elbow at the elbow mixing area.

FIG. 5b shows a circularly shaped exhaust mixture hose support 108.

FIG. 6 shows the circumference of one embodiment of the proximal end of the housing.

FIG. 7a shows a second embodiment of the housing.

FIG. 7b shows a third embodiment of the housing.

FIG. 8a shows another embodiment of the reversion control device with a reversion cone.

FIG. 8b shows a reversion control device with two reversion cones.

FIG. 9a shows a side view of the reversion cone 180.

FIG. 9b shows a top view of the reversion cone 180.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention, and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. It will be apparent to those skilled in the art, however, that the present invention may be practiced without these specific details.

The present invention discloses a reversion control device 100. FIG. 1a shows the reversion control device 100 next to an exhaust manifold elbow 200. The reversion control device includes a housing 110 for a stationary vane 120 near the proximal end 101 and a flapper 130 near the distal end 102. The proximal end 101 is the portion of the reversion control device 100 that connects with the exhaust manifold elbow 200. The distal end 102 is the exit portion of the reversion control device 100 distal from the exhaust manifold elbow 200. Within the reversion control device 100, the stationary vane 120 organizes the exhaust gas flow, which increases fuel economy, while the flapper 130 at its closed position minimizes water reversion, and hence, minimizes degradation in engine performance or engine damage. It has also been observed that the flapper 130 can increase the back pressure of the engine, allowing better control of the engine's torque curve. During the emission of exhaust gas, the flapper 130 is at its open position. In the event of back pulsing by the engine, which can cause a suction, the flapper 130 flips to its closed position to minimize water reversion. In one embodiment, a flapper stop pin 136 limits the pivoting action of the flapper 130 along pivot point 133. The reversion control device 100 adds additional length to the typical exhaust outlet of the exhaust manifold elbow 200. The additional extension in length provided by the reversion control device 100 moves the mixture point of the exhaust gas and cooling water further away from the engine. An exhaust mixture hose 105 (not shown) surrounds the reversion control device 100 and connects to the exhaust manifold elbow 200 at the proximal end 101. FIG. 1b shows another embodiment of the present invention where the reversion control device 100 includes a reversion cone 180, a diffuser edge 170 at the distal end 102, and an exhaust mixture hose support 108 mounted to housing 110.

FIG. 2a is a side view of an exhaust manifold elbow 200. The exhaust manifold elbow 200 includes an elbow mixing area 210 which connects to the reversion control device 100. FIG. 2b shows the bottom view of the exhaust manifold elbow 200. The exhaust manifold elbow 200 includes cooling water passage 230 and an exhaust gas passage 220.

Exhaust manifold elbows can be shaped differently than what is showed in FIGS. 2a and 2b. For example, FIGS. 2c and 2d show an alternatively shaped exhaust manifold elbow while FIGS. 2e and 2f show yet another alternatively shaped exhaust manifold elbow. One skilled in the art would understand that the reversion control device 100 can adapt to a multitude of exhaust manifold elbow shapes, not limited to the examples shown here.

FIG. 3a is a front view of the stationary vane 120. In the embodiment depicted, the stationary vane 120 includes four stationary blades 122. One skilled in the art would understand that the quantity of blades is not limited to four. The number of blades is a design choice and typically ranges from two to eight blades. In one embodiment, holes 121 are included for exiting water. FIG. 3b shows the blades 122 of the stationary vane 120. Although the blades 122 are shown as slightly “D” shaped, one skilled in the art would understand that the shape of the blades 122 may vary as a design choice. In one embodiment, the blades 122 each tilt at an angle φ (phi) relative to an imaginary vertical plane 123 within the housing 110 as shown in FIG. 3b. Typical tilt angles can range from 20 degree to 60 degree relative to the vertical plane 123. In one embodiment, the stationary blades 122 each tilt at an angle of about 35 degrees relative to an imaginary vertical plane 123 within the housing 110. One skilled in the art would understand that other degrees of tilt may be possible depending on the design choice.

FIG. 4a shows the flapper 130 as seen from the distal end. The flapper 130 includes a hinge tube 131. A rod 132 (shown in FIG. 4d) is inserted into the hinge tube 131 at the pivot point 133 on the housing (shown in FIG. 1a) to allow the flapper 130 to open and to close. FIG. 4b is the side view of the flapper 130 and shows the location of the hinge tube 131 relative to the vertical height of the face 135 of the flapper 130. Typically, the hinge tube 131 is located on the top half of the face 135. However, one skilled in the art would understand that the location of the hinge tube 131 is a design choice and may depend on the angle at which the flapper is mounted to the housing 110. In one embodiment, the hinge tube 131 is an integral part of the face 135. In another embodiment, the hinge tube 131 is a separate piece secured to the face 135 through conventional techniques such as, but not limited, to welding. Yet other embodiments that will be readily apparent to one skilled in the art could have hinging mechanisms that do not require a tube and a separate rod.

FIG. 4c shows the flapper 130 as seen from the proximal end 102. FIG. 4d shows the flapper in a closed position within the housing 110, and FIG. 4f shows the flapper in an open position within the housing 110. In one embodiment, the flapper is mounted to the housing 110 at an angle Θ (theta) of about 30 degrees as shown in FIG. 4e. A typical range of the angle Θ (theta) is about 20 to 60 degrees. One skilled in the art would understand that angles outside this typical range are possible without substantially diminishing the effectiveness of the present invention. The reversion control device 100 is mounted to the exhaust manifold elbow 200 at the elbow mixing area 210 as shown in FIG. 5a. As shown in FIG. 5a, exhaust mixture hose supports 108 are mounted to housing 110 to keep the reversion control device 100 centered inside the exhaust mixture hose 105. In one embodiment, the exhaust mixture hose supports 108 are in a “V” shape. FIG. 5b shows a circularly shaped exhaust mixture hose support 108. One skilled in the art would understand that other shapes for the exhaust mixture hose supports 108 may be used as a design choice. In one embodiment, a clamp is placed around the exhaust mixture hose 105 at the location of the exhaust mixture hose supports 108 to further secure the reversion control device 100.

In one embodiment, the attachment of the reversion control device 100 to the elbow mixing area 210 is by press fitting the proximal end 101 of the housing 110 into the elbow mixing area 210 and then further securing the connection with a clamp, usually over the exhaust mixture hose 105. One skilled in the art would understand that other types of fasteners may also be used.

In one embodiment, proximal end 101 has a circumference that is substantially circular for fitting into the elbow mixing area 210. In another embodiment, the proximal end 101 has a circumference that is partially circular, with a flat portion as shown in FIG. 6. The circumferential shape of the proximal end 101 can vary as needed to fit the shape of the elbow mixing area 210. The circumferential shape of the proximal end 101 can include, but is not limited to, square shape, rectangular shape, triangular shape and any polygon shape necessary to fit the circumferential shape of the elbow mixing area 210.

In one embodiment, the housing 110 is a circular tube with one of a variety of shapes for its proximal end 101 to ensure appropriate fitting into the elbow mixing area 210. In two other embodiments, the housing 110 includes an expansion chamber 112 to house the stationary vane 120 and the flapper 130 as shown in FIGS. 7a and 7b. The transition from the proximal end 101 or the distal end 102 to the expansion chamber 112 can be a substantially straight linear transition as shown in FIG. 7b or a substantially curved transition as shown in FIG. 7a. In one embodiment, the ratio between the diameter d₁ of the distal end to the diameter d₂ of the expansion chamber is 1.5 times The ratio between the diameter d₁ of the distal end to the diameter d₂ of the expansion chamber can range from about 1.5 to 3 times One skilled in the art would understand that other ratios between and beyond the two diameters d₁ and d₂ are possible based on design choices.

In the embodiments shown in FIGS. 7a and 7b, the proximal end 101 can be a variety of shapes to insure appropriate fitting into the elbow mixing area 210. It is a feature of the embodiments referred to above that the proximal end 101 fits into the elbow mixing area 210. One skilled in the art, however, would understand that, in other embodiments, the elbow mixing area 210 may fit into the proximal end 101. Additionally, in an alternative embodiment, the reversion control device 100 fits within the elbow mixing area 210.

In one embodiment, the length L of the housing 110 (shown in FIG. 1a) is about 8 inches while the diameter D of the housing 110 is about 3 inches. One skilled in the art would understand that the dimensions of the housing are not limited to this one embodiment and can vary according to the design choice with the limitation that the length L is always greater than the diameter D by at least two-fold.

In one embodiment, the flapper 130 is made of titanium. Other embodiments of the flapper 130 could be made of ceramic, stainless steel or carbon fiber. In one embodiment, the stationary vane 120 is made of stainless steel. Other embodiments of the stationary vane 120 could be made of titanium, carbon fiber or ceramic. In one embodiment, the housing 110 is made of stainless steel or a steel alloy. In another embodiment, the housing 110 is made of titanium. One skilled in the art would understand that the housing 110 can be made of other materials without affecting the effectiveness of the present invention. Material choices for the housing 110 are limited by the material's tolerance to endure the maximum exhaust gas temperature (typically at 1400 degrees Fahrenheit) and to endure the corrosive environment of the mixture of exhaust gas and cooling water.

In one embodiment, the flapper 130 and the housing 110 are made of the same material. In another embodiment, the stationary vane 120 and the housing 110 are made of the same material. In another embodiment, the flapper 130, the stationary vane 120 and the housing 110 are all made of the same material. In yet another embodiment, the flapper 130, the stationary vane 120 and the housing 110 are each made of a different material.

It is not essential to the present invention that the stationary vane 120 be proximal to the flapper 130 or that the flapper 130 be near the distal end of the device. In an alternative embodiment, the stationary vane 120 is located distal to the flapper 130 with the flapper 130 located near the distal end. In yet another embodiment, the flapper 130, which is located distal to the stationary vane 120, is located in an approximate middle location between the proximal end and the distal end. It will be appreciated by those skilled in the art that the relative positions of the vane 120 and the flapper 130 can be altered without departing from the scope of the present invention.

It is not essential to the present invention that the reversion control device be separate or separable from the exhaust manifold elbow. It will be appreciated by those skilled in the art that, in yet another embodiment of the present invention, the distal portion of the exhaust manifold elbow 200 may comprise the housing 110 for the stationary vane 120 such that the stationary vane 120, or a portion of it, lies within the distal portion of the exhaust manifold elbow. In yet another embodiment of the present invention, the distal portion of the exhaust manifold elbow may comprise the housing 110 for the stationary vane 120 and the flapper 130 such that the stationary vane 120 lies within the distal portion of the exhaust manifold elbow as does the flapper 130, or a portion of it.

In another embodiment, the reversion control device 100 includes a reversion cone 180 as shown in FIG. 8a. The reversion cone 180 prevents water from migrating back to the engine along the wall surface of housing 110. As shown in FIG. 8a, the reversion cone 180 is mounted near the distal end 102 and fits within housing 110. In one embodiment, the reversion cone 180 is located approximately 0.75 to 1 inch from the distal end 102. One skilled in the art would understand that the location of the reversion cone within housing 110 may vary without impacting performance. As an example, the location of the reversion cone 180 may range from 0.250 to 3.5 inches away from the distal end 102 without significant impact to performance. Another embodiment is a reversion control device 100 which includes two reversion cones 180, one near the distal end 102 and one near the proximal end 101, shown in FIG. 8b. One skilled in the art would understand that the quantity of reversion cones is not limited to two. In another embodiment, more than two reversion cones 180 may be included in the reversion control device 100.

FIGS. 8a and 8b also show a threaded hole 190 for mounting an oxygen sensor 192. In one embodiment, an oxygen sensor 192 is included in the reversion control device 100. The oxygen sensor 192 can be used to monitor the oxygen content of the engine for routine operations or for diagnostic purposes.

FIG. 9a shows a side view of the reversion cone 180. The reversion cone 180 includes a cone proximal end 181 and a cone distal end 182. As shown in FIG. 8a, the stationary vane 120 is mounted near the cone proximal end 181. One skilled in the art would understand that the location for mounting the stationary vane 120 is a design choice. In one embodiment, the stationary vane 120 is mounted closer to the cone distal end 182 while in another embodiment, the stationary vane 120 is mounted proximal to the reversion cone 180.

As shown in FIG. 9a, the cone distal end 182 includes a distal edge 183 which curves toward an imaginary center axis 185 of the reversion cone 180. FIG. 9b shows a top view of the reversion cone 180. One skilled in the art would understand that the curvature of the distal edge 183 is a design choice. Typical range for the curvature of the distal edge 183 is 45 degrees. In an alternative embodiment, the distal edge 183 is straight and tilts toward the imaginary center axis 185.

In yet another embodiment, the reversion control device 100 includes a diffuser edge 170 at the distal end 102. The diffuser edge 170 flares outwardly from the center of the reversion control device 100 to deflect water away from the exhaust gas exit passage.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention.

Claims

1. A reversion control device comprising:

a housing with a proximal end and a distal end;

a first reversion cone housed in the housing; and

a flapper housed in the housing.

2. The reversion control device of claim 1 further comprising a stationary vane housed in the housing.

3. The reversion control device of claim 1, wherein the first reversion cone is housed near the distal end of the housing.

4. The reversion control device of claim 3, wherein the stationary vane is housed within the first reversion cone.

5. The reversion control device of claim 1, wherein the first reversion cone includes a distal edge that is substantially curved.

6. The reversion control device of claim 1, wherein the first reversion cone includes a distal edge that is substantially straight.

7. The reversion control device of claim 1, wherein the stationary vane is housed distal to the flapper.

8. The reversion control device of claim 1, wherein the stationary vane is housed proximal to the flapper.

9. The reversion control device of claim 1 further comprising a diffuser edge at the distal end.

10. The reversion control device of claim 1, wherein a portion of an exhaust manifold elbow comprises the housing.

11. The reversion control device of claim 1, wherein the reversion control device is connected to an exhaust manifold elbow at the proximal end.

12. The reversion control device of claim 1, wherein the reversion control device includes a second reversion cone housed in the housing.

13. The reversion control device of claim 12 wherein the first reversion cone is housed at the distal end and the second reversion cone is housed at the proximal end.

14. The reversion control device of claim 11, wherein the exhaust manifold elbow includes an exhaust gas passage for exiting exhaust gas, a water passage for exiting water and an elbow mixing area for connecting to the proximal end.

15. The reversion control device of claim 14, wherein the proximal end fits into the elbow mixing area.

16. The reversion control device of claim 14, wherein the elbow mixing area fits into the proximal end.

17. The reversion control device of claim 1, wherein the stationary vane comprises a plurality of stationary blades with each stationary blade comprising a slightly D shape.

18. The reversion control device of claim 17, wherein each of the plurality of stationary blades tilts at an angle of about 45 degrees relative to a vertical plane within the housing.

19. The reversion control device of claim 1, wherein the housing includes a pivot point; and

the flapper includes a hinge tube wherein a rod is inserted into the hinge tube at the pivot point to pivot the flapper from an open position to a closed position or from a closed position to an open position.

20. The reversion control device of claim 19 further comprising a flapper stop pin to limit the pivoting action of the flapper.

21. The reversion control device of claim 19, wherein the hinge tube is an integral part of the flapper.

22. The reversion control device of claim 19, wherein the flapper includes a face and wherein the hinge tube is located on the face such that, when the flapper is mounted within the housing, the face of the flapper is at an angle Θ (theta) between about 20 to about 60 degrees.

23. The reversion control device of claim 22, wherein the angle Θ (theta) is about 35 degrees.

24. The reversion control device of claim 1, wherein the proximal end includes a circumference that is substantially circular.

25. The reversion control device of claim 1, wherein the proximal end includes a circumference that is partially circular, with a flat portion.

26. The reversion control device of claim 1, wherein the housing has a length L of about 8 inches.

27. The reversion control device of claim 1, wherein the housing has a diameter of about 3 inches.

28. The reversion control device of claim 1, wherein the housing includes an expansion chamber to house the first reversion cone, the stationary vane and the flapper.

29. The reversion control device of claim 28, wherein the transition from the expansion chamber to the proximal end is a substantially straight linear transition.

30. The reversion control device of claim 28, wherein the transition from the expansion chamber to the proximal end is a substantially curved transition.

31. The reversion control device of claim 28, wherein the ratio between a first diameter d1 of the distal end to a second diameter d2 of the expansion chamber is between about 1.5 to about 3 times.

32. The reversion control device of claim 1 further comprising an oxygen sensor for monitoring oxygen content.

33. The reversion control device of claim 32 wherein the housing further comprises a threaded hole for mounting the oxygen sensor.

34. A reversion control device comprising:

a housing with a proximal end, a distal end and an expansion chamber,

a first reversion cone housed within the expansion chamber near the distal end;

a stationary vane housed within the expansion chamber near the distal end; and

a flapper housed within the expansion chamber near the proximal end.

35. The reversion control device of claim 34, wherein the stationary vane is housed within the first reversion cone.

36. The reversion control device of claim 34 further comprising a second reversion cone housed near the proximal end.

37. An exhaust system for controlling water reversion comprising:

a reversion control device comprising a housing with a proximal end, a distal end, and an expansion chamber between the proximal end and the distal end; a first reversion cone housed within the expansion chamber; a stationary vane housed within the expansion chamber; and a flapper housed within the expansion chamber;

at least one exhaust mixture hose support attached to the reversion control device on the housing; and

an exhaust mixture hose coupled to at least one exhaust mixture hose support, the exhaust mixture hose surrounding the reversion control device.

38. The exhaust system of claim 37, wherein the reversion control device further comprises a second reversion cone housed within the expansion chamber.

39. An exhaust manifold elbow comprising:

a reversion control device housed within the exhaust manifold elbow, the reversion control device comprising a proximal end, a distal end, a first reversion cone housed near the distal end, a stationary vane housed near the distal end, and a flapper housed near the proximal end.

40. The exhaust manifold elbow of claim 39, wherein the reversion control device further comprises a diffuser edge housed near the distal end.

41. The exhaust manifold elbow-of claim 39, wherein the reversion control device further comprises a second reversion cone housed near the proximal end.

42. An exhaust manifold elbow comprising:

a reversion control device housed within the exhaust manifold elbow, the reversion control device comprising a proximal end, a distal end, an expansion chamber between the distal end and the proximal end, a first reversion cone housed within the expansion chamber, a stationary vane housed within the expansion chamber, a flapper housed within the expansion chamber, and a second reversion cone housed in the proximal direction of the exhaust manifold elbow.