The present invention relates generally to the field of passive exhaust valves, and more particularly to spring biased valve plates assembled to pivot within an exhaust conduit and the corresponding methods of forming and installing such assemblies.
To control back flow pressure and reduce low frequency engine noise in exhaust systems of combustion engines, it is generally understood that a passive valve may be provided in the exhaust line to alter characteristics of exhaust flow and to attenuate exhaust system noise by actuating in response to changes in exhaust pressure. Other known means for addressing these issues typically involve increasing exhaust system capacity and mass. Although passive valves can reduce exhaust system mass and weight, other potential issues with passive exhaust valve assemblies, such as valve noises, reliability, and manufacturing cost, have been deterrents to widespread adoption in combustion engine exhaust systems for vehicles.
In accordance with one aspect of the present invention, a passive exhaust valve assembly includes an exhaust conduit having a first pipe section attached to a second pipe section with the first pipe section mated partially within the second pipe section to form an overlapping interface between end portions of the first and second pipe sections. The end portions of the first and second pipe sections each include an outward protruding flange that interrupts a circumferential segment of the overlapping interface. The outward protruding flanges align with each other to form an axle seat, whereby a support shaft extends laterally across an interior volume of the exhaust conduit and rotatably engages the axle seat. A valve plate is coupled to the support shaft within the interior volume of the exhaust conduit for operating the valve plate between open and closed positions.
Optionally, an interior surface of the first or second pipe section may include a recessed pocket that protrudes radially outward for containing a flexible bumper element, such as a metal mesh pad and/or a resilient leaf spring, arranged to contact the valve plate and dissipate impact of the valve plate moving toward the closed position. The end portion of the opposing pipe section without the recessed pocket may also include a tab that extends longitudinally to overlap with the recessed pocket and support the flexible bumper element in the recessed pocket, such as with a pair of arm portions or members that extend longitudinally to the recessed pocket to supporting edge portions of a flexible bumper element in a manner that allows movement of the flexible bumper element when resiliently flexing upon contact with valve plate.
In accordance with another aspect of the present invention, a method of assembling of a passive exhaust valve assembly includes selecting a first pipe section having an end portion with a first diameter and a second pipe section having an end portion with a second diameter, where the end portion of first pipe section is sized to matably fit at least partially within the end portion of the second pipe. An outward protruding flange may then be formed about the circumference at each end portion of the first and second pipe sections. A first seat portion and a second seat portion may be formed on the outward protruding flanges of the respective first and second pipe sections, such that, upon attaching the pipe sections together, alignment of the first and second seat portions form an axle seat. A circumferential section of each of the outward protruding flanges adjacent to the respective seat portion may then be bent or formed back to or near the respective original diameter of the first or second pipe section. A support shaft with a valve plate fixed to an intermediate portion of the support shaft may then be placed in one of the seat portions. The smaller diameter pipe section is then inserted within the other pipe section with the seat portions aligned to form the axel seat around the support shaft and to define an overlapping interface between the end portions of the first and second pipe sections. The overlapping interface may then be welded to attach the first pipe section to the second pipe section and form an exhaust conduit of a valve assembly.
In accordance with yet another aspect of the present invention, a method of assembling a passive exhaust valve assembly may include cutting an edge portion away from the first and second metal blanks to define a cutout area. A first seat portion may be formed at an edge of the cutout area of the first metal blank, and a second seat portion may similarly be formed at an edge of the cutout area of the second metal blank. The first metal blank may then be stamped into a tubular shape and the tubular shaped piece may be stamped with a plurality of successive dies to form a first pipe section with the first seat at an end thereof. Likewise, the second metal blank may be stamped to form a second pipe section with the second seat at an end thereof. A support shaft may then be placed in one of the first and second seat portions, where the support shaft includes a valve plate fixed to an intermediate portion of the support shaft. An end portion of the first pipe section may then be inserted within the second pipe section with the first seat portion aligned with the second seat portion to form an axel seat around the support shaft. The end portion of the second pipe section overlaps the first pipe section to define an overlapping interface, which may be welded to attach the first and second pipe sections together to form an exhaust conduit.
Optionally, the overlapping interface may include an exterior surface of the first pipe section abutting an interior surface of the second pipe section, such as at the circumferential sections of the first and second pipe sections that are each bent back to the original diameter. Also, a recessed pocket may optionally be formed on an interior surface of the first or second pipe section that protrudes radially outward from an exhaust flow path that extends axially through the exhaust conduit. A flexible bumper element, such as a metal mesh pad and/or a resilient leaf spring, may optionally be placed in the recessed pocket on an interior surface of the second pipe section in a location arranged to contact the valve plate and dissipate impact of the valve plate moving toward a closed position. Further, a tab may optionally be formed at the end portion of one of the pipe sections that extends longitudinally inside the other pipe section to overlap with the recessed pocket on an interior of the other pipe section, whereby the tab supports a flexible bumper element in the recessed pocket. Such a tab may include a pair of arms or members that extend longitudinally to the recessed pocket on the interior of the other pipe section, where the pair of arms may support edge portions of a flexible bumper element disposed in the recessed pocket in a manner that allows sliding movement of the flexible bumper element at the edge portions when resiliently flexing into the recessed pocket upon contact with valve plate.
These and other objects, advantages, purposes, and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.
Referring now to the drawings and the illustrative embodiments depicted therein, a passive exhaust valve assembly 10, 110 includes an exhaust conduit 12, 112, such as tube or pipe, that has a support shaft or axle 14, 114 extending laterally across an interior portion or volume 16, 116 of the of the exhaust conduit 12, 112 for supporting a vane or valve plate 18, 118 or the like. The valve plate 18, 118 is attached or coupled with the support shaft 14, 114 to pivot within the interior volume 16, 116 of the exhaust conduit 12, 112 between an open position 120 (
To form such an overlapping joint, one of the pipe sections (such as the first pipe section 24, 124) may be mated partially within the other pipe section (such as the second pipe section 26, 126) to form an overlapping interface 29 (
As illustrated, for example, in
The end portions of the pipe sections 24, 26 that form the overlapping interface 29, such as shown in
The outward protruding flanges 30 are shown spaced longitudinally away from the end edges of the overlapping interface 29, such that the portions of the pipe sections 24, 26 that form the overlapping interface 29 may define longitudinal projections that generally maintain the circular curvature of the pipe section. For example, as shown in
The outward protruding flanges 30 may also include an indentation 38 or seat portion formed on the surface of each flange 30 to abut together and form the axle seat 38, as shown in
As shown in
In accordance with another aspect of the present invention, a method of assembling of a passive exhaust valve assembly 10, 110 includes selecting a first pipe section having an end portion with a first diameter and a second pipe section having an end portion with a second diameter, where the end portion of first pipe section is sized to matably fit at least partially within the end portion of the second pipe. An outward protruding flange may then be formed about the circumference at each end portion of the first and second pipe sections. A first seat portion and a second seat portion may be formed on the outward protruding flanges of the respective first and second pipe sections, such that upon mating and alignment of the first and second seat portions, an axle seat is generally formed. A circumferential section of each of the outward protruding flanges adjacent to the respective seat portion may then be bent or formed back to or near the respective original diameter of the first or second pipe section. A support shaft with a valve plate fixed to an intermediate portion of the support shaft may then be placed in one of the seat portions. The smaller diameter pipe section is then inserted within the other pipe section with the seat portions aligned to form the axel seat around the support shaft and to define an overlapping interface between the end portions of the first and second pipe sections. The overlapping interface may then be welded to attach the first pipe section to the second pipe section and form an exhaust conduit of a valve assembly.
In accordance with yet another aspect of the present invention, a method of assembling of a passive exhaust valve assembly may provide first and second metal blank, whereby an edge portion is cut from the first and second metal blanks to define a cutout area. A first seat portion may be formed at an edge of the cutout area of the first metal blank, and a second seat portion may similarly be formed at an edge of the cutout area of the second metal blank. The first metal blank may then be stamped into a tubular form and the tubular form may be stamped with a plurality of successive dies to form a first pipe section with the first seat at an end thereof. Likewise, the second metal blank may be stamped to form a second pipe section with the second seat at an end thereof. A support shaft may then be placed in one of the first and second seat portions, where the support shaft includes a valve plate fixed to an intermediate portion of the support shaft. An end portion of the first pipe section may then be inserted within the second pipe section with the first seat portion and aligned with the second seat portion to form an axel seat around the support shaft. The end portion of the second pipe section overlaps the first pipe section to define an overlapping interface, which may be welded to attach the first and second pipe sections together to an exhaust conduit.
Optionally, the overlapping interface may include an exterior surface of the first pipe section abutting an interior surface of the second pipe section, such as at the circumferential sections of the first and second pipe sections that are bent back to the original diameters. Also, a recessed pocket may optionally be formed on an interior surface of the first or second pipe section that protrudes radially outward from an exhaust flow path that extends axially through the exhaust conduit. A flexible bumper element, such as a metal mesh pad and/or a resilient leaf spring, may optionally be placed in a recessed pocket on an interior surface of the second pipe section in a location arranged to contact the valve plate and dissipate impact of the valve plate moving toward a closed position. Further, a tab may optionally be formed at the end portion of one of the pipe sections that extends longitudinally inside the other pipe section to overlap with a recessed pocket on an interior of the other pipe section, whereby the tab supports a flexible bumper element in the recessed pocket. Such a tab may include a pair of arms or members that extend longitudinally to a recessed pocket on an interior of the other pipe section, where the pair of arms may support edge portions of a flexible bumper element disposed in the recessed pocket in a manner that allows sliding movement of the flexible bumper element at the edge portions when resiliently flexing into the recessed pocket upon contact with valve plate.
The exhaust conduit of the passive exhaust valve assembly may include an inlet end and an outlet end on opposing ends of the exhaust conduit to respectively receive and dispense exhaust gases longitudinally though the exhaust conduit. The exhaust conduit may have an elongated tube or pipe shape with a curved exterior surface and a similarly curved interior surface. The interior section or volume of the exhaust conduit may thereby define a flow path along the longitudinal, central axis of the exhaust conduit, which extends generally through the internal section or volume of the exhaust conduit between the inlet and outlet ends. The valve plate may be positioned within the flow path of the internal volume and pivoted to the closed position for generally preventing exhaust gases from transferring through the tubular conduit. Although illustrated in
The valve plate may be operably coupled within the interior section of the exhaust conduit and pivotal about a pivot axis between the open position, where the body portion of the valve plate is generally parallel with the exhaust flow path to provide a minimized resistance to the exhaust flow, and the closed position, where the body portion of the valve plate is at an angle that substantially reduces flow of exhaust gases through the exhaust conduit to provide a maximized resistance to the exhaust flow. The body portion of the valve plate may be rigidly coupled, such as by welding, with a support shaft or axel that defines the pivotal axis of the valve plate. The pivotal axis is generally perpendicular relative to the exhaust flow path, and, as shown, may be off-center within the exhaust conduit to define a longer portion of the valve plate and a shorter portion of the valve plate. The valve plate in the illustrated embodiments has a dimension between the upper and lower arcuate edges that is greater than the inside diameter of the exhaust conduit, such that the valve plate is oriented an angle less than ninety degrees in the closed position. However, it is contemplated that the valve plate in other embodiments may have a shape or dimension that allows it to pivot substantially perpendicular to the flow path. The valve plate may include end portions on opposing sides of a pivotal axis of the valve plate, where the short end portion of the valve plate may contact the bumper element in the close position, such as shown in the embodiment of
As illustrated for example herein, the support shaft may extend through the exhaust conduit, with end portions of the support shaft pivotally engaging the axle seats or supports, which may include bushings 132a (
In the illustrated embodiment shown in
When the valve plate moves toward the closed position, the end portion of the valve plate may contacts the bumper element 142 (
As shown in
Optionally, the bumper element 142a may be floating or movably engaged within the recessed pocket 140 of the exhaust conduit to allow for movement of the bumper element relative to the exhaust conduit, such as in a resilient range or distance defined when the valve plate moves between the open position 120 and the closed position 122. However, it is also contemplated that the bumper element 142a may also be fixedly coupled with the exhaust conduit, such as by welding or high temperature adhesives. As shown in
The floating or movable engagement of the mesh pad with the exhaust conduit allows the mesh pad to have a greater range of resiliency with the spring. An example of providing such moveable engagement of the mesh pad is by at least one of the end portions of the mesh pad to be loosely or movably engaged in a channel, which can, for example, be provided between overlapping sections of the pipe sections of the exhaust conduit. The recessed pocket, such as shown in
For the bumper element to contact a greater surface area than the edge of the valve plate would otherwise provide, the first end portion of the valve plate may also include a stop member protruding from a body portion of the valve plate. As illustrated in
Optionally, support shaft or axel may have an external section that is configured to stop the valve plate in the open and/or closed positions, such as illustrated in
Optionally, an opposing end of the tension spring may be attached to a spring anchor that is fixed relative to the exhaust conduit, as shown for example in
To stop rotation of the support shaft at an angle that corresponds with the open position of the valve plate a stop feature may optionally be provided separately or integrally with the exhaust conduit. As illustrated in
The disclosure has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings, and the disclosure may be practiced otherwise than as specifically described.
For purposes of this disclosure, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in
For purposes of this disclosure, the term “coupled” (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature; may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components; and may be permanent in nature or may be removable or releasable in nature, unless otherwise stated.
Changes and modifications in the specifically-described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law including the doctrine of equivalents.
The present application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 62/279,471, entitled PASSIVE EXHAUST VALVE ASSEMBLY WITH OVERLAPPING SLIP JOINT AND METHOD OF FORMING AND INSTALLATION, filed Jan. 15, 2016, which is hereby incorporated herein by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
62279471 | Jan 2016 | US |