The subject invention relates to a pneumatically actuated valve system of a muffler of a vehicle exhaust system, and, more particularly, to a pneumatically actuated valve system enabling components of a vehicle's muffler system to be selectively bypassed.
Exhaust systems are widely known and used with combustion engines. Typically, an exhaust system includes exhaust pipes that convey exhaust gases from the engine to other exhaust system components, such as mufflers, etc. Conventional exhaust mufflers include acoustic chambers and baffling that are configured to work together to cancel out sound waves carried by the exhaust gases. In performing this function, however, mufflers can reduce engine performance and artificially modify the true sound of the vehicle's engine and exhaust.
A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures.
The following description recites various aspects and embodiments of the invention disclosed herein. No particular embodiment is intended to define the scope of the invention. Rather, the embodiments provide non-limiting examples of various configurations, and methods that are included within the scope of the claimed invention. The description is to be read from the perspective of one of ordinary skill in the art. Therefore, information that is well known to the ordinarily skilled artisan is not necessarily included.
Referring now to the drawings, like reference numerals are used to identify identical components in the various views. Referring to
Engine 102 includes an exhaust manifold coupled to exhaust system 104. Exhaust gas generated by engine 102 passes through exhaust system 104 to an exhaust pipe outlet. Such gases pass through exhaust system 104 at relatively high and varying pressures and generate acoustic signals throughout exhaust system 104 and at the output of exhaust system 104.
In a typical automotive vehicle 100, exhaust system 104 includes a muffler 106. Muffler 106 is configured to control the flow of exhaust gases through exhaust system 104 to moderate the volume of sounds generated by exhaust system 104. In many implementations, by interfering with exhaust flow through exhaust system 104, a muffler 106 can impede the normal operation of the engine 102 of automotive vehicle 100, sometimes resulting in reduced power output of engine 102. In other cases, the muffler 106 will not only reduce the overall volume of sounds generated by the exhaust gases passing through exhaust system 104, but will also change those sounds so as to affect the overall timbre or sound quality of the exhaust system 104.
Although the volume reductions that result from conventional muffler 106 operation can be beneficial to some driving environments (e.g., such as when navigating a local neighborhood, or driving late at night), muffler 106 operations can sometimes be undesirable as they can prevent efficient operation of engine 102 and may also interfere with appreciation of the true sound of the vehicle's engine 102.
The present system, therefore, provides an improved muffler design in which the muffler includes first and second exhaust gas flow paths. When the exhaust gases flow through the first path, the muffler provides dampening of acoustic energy within the exhaust gases to reduce the overall volume of sound generated by an attached exhaust system. However, when the exhaust gases flow through the second path of the muffler, the muffler does not impede the flow of exhaust gases and does not provide any (or only minimal) acoustic dampening. Accordingly, when the exhaust gases flow through the second path, the original unadulterated engine noises will flow through and emanate from the vehicle's exhaust system.
To control the operation of the improved muffler, a controllable valve is disposed within the flow path of exhaust gases. When the valve is in a first position, the second flow path is closed and exhaust gases are forced through the first, muffled, flow path. However, when the gate is open (or vice versa), the uninhibited exhaust gases are free to flow through the second flow path to generate an unmuffled exhaust output.
In an embodiment, the valve is pneumatically operated and, specifically, the valve may be vacuum-driven. In that case, in a default position (e.g., when no vacuum is applied to the valve) the valve is closed and causes the muffler to operate to reduce exhaust volume. However, when a vacuum is applied to the valve's control port, the valve opens and allows exhaust gases to flow through the second flow path.
Although the valve could be operated electro-mechanically, such valves increase unneeded complexity over vacuum-controlled valves, which may be undesirable in an automotive application. For example, electro-mechanically controlled valves can have reliability issues, have issues that are difficult to diagnose, and include small, delicate components that are prone to breaking. Vacuum-controlled valves, in contrast, include fewer parts, are more robust, and are easier to diagnose and repair.
Although engines generate vacuum due to normal operation it can be difficult to route a vacuum hose all the way from the vehicle's engine compartment to the exhaust system and, specifically, the muffler of the exhaust system. Accordingly, in embodiments, the present system may include a separate vacuum pump that is configured to generate an adequate vacuum that can be selectively applied to the valve to control the valve position. The separate vacuum pump can be located anywhere within the vehicle (e.g., within the trunk or boot of the vehicle, mounted under the chassis or within the chassis of the vehicle) to provide convenient placement proximate to the vacuum-controlled valve. The vacuum pump can be electrically powered via any suitable means, such as via a direct electrical connection to the vehicle's battery, via suitable coupling to a vehicle's cigarette lighter power, via connection to a separate battery system, and the like.
In some embodiments, to open the valve, the vacuum pump is turned on to deliver an appropriate vacuum to the valve's control port to cause the valve to open (allowing by-pass of portions of the muffler). To close the valve, the vacuum pump is turned on or disabled to remove the vacuum to the valve's control port allowing the valve to close.
In various embodiments of the present system, the operation of the vacuum pump is controlled by a controller. The controller may include switches or buttons configured to control particular vacuum pump operations. The controller may be hardwired to the vacuum pump or may be wireless, in which case the controller may be a key fob-type device.
Muffler control system 200 includes valve 210 disposed within flow path 204. As illustrated, valve 210 is located within flow path 204 at a point in the exhaust gas flow between the point where gas flow path 206 branches away from flow path 204 and the point where gas flow path 206 returns to flow path 204. When valve 210 is closed, flow path 204 is bypassed and exhaust gases flowing from input 201 to output 203 is forced through path gas flow path 206 towards output 203. As such, when valve 210 is closed, the muffler operates to reduce volume and noise being generated by exhaust gases flowing through gas flow path 206.
In the present system, valve 210 has an optimized valve body that can be computer numerical control (CNC) casted. Valve 210 is designed with an easily replaceable bladder design enabling the valve bladder to be easily replaced if the valve bladder should ever fail. Specifically, valve 210 has been optimized using a cast design the ensure high quality. Within valve 210, a three-stud design allows the vacuum bladder to be swapped out in a short amount of time. In an embodiment, the shaft mechanism is designed to provide 5 pounds of negative pressure to operate and therefore a 6-pound threshold on the vacuum bladder is provided enabling the control box to allow for proper operation of the valve. Specifically, the present control system is aware of when the valve is opened or closed depending on the pressure throughout the valve control system.
When valve 210 is open, however, exhaust gases pass directly from has input 201 to output 203 through flow path 204. This results in a “straight pipe” exhaust configuration in which exhaust noise generated by exhaust gases passing through flow path 204 is not diminished by muffler 202 and the vehicle engine can run at improved efficiency.
As shown in
In a specific embodiment, vacuum pump 212 may include a robust vacuum pump design to improve reliability and longevity. Vacuum pump 212 may incorporate an automated sensor that senses when the valve is fully opened at an appropriate vacuum (e.g., −6 pounds per square inch (PSI)). Once the target vacuum threshold is achieved, vacuum pump 212 may be configured to halt generation of further vacuum and hold or maintain vacuum pump 212 in an open position.
Vacuum pump 212 (or other components of muffler control system 200) may be configured to periodically check (e.g., every 100 millisecond, every 1 second, or every 10 seconds) to confirm that vacuum pump 212 is holding at the desired vacuum level (e.g., at 6 PSI with a 0.5 PSI margin). If vacuum pump 212 (or other components of muffler control system 200) upon performing such a periodic check determines that the vacuum pressure generated by vacuum pump 212 has fallen below the desired vacuum level (or falls below some other threshold), vacuum pump 212 may operate to restore the vacuum to the desired vacuum level. In various embodiments, an electrical connection may be formed between vacuum pump 212 (or other components of muffler control system 200) and a vehicle's onboard diagnostic port (e.g., an OBDII port) to provide enhanced control thereof. For example, using such a connection, muffler control system 200 may be configured to control the operation of vacuum pump 212 and/or valve 210 to achieve a desired operation of muffler 202.
Specifically, in an embodiment, engine speed data (e.g., revolutions per minute (RPM)) may be transmitted from the OBD port to controller 214 and controller 214 could use the RPM data as a factor in how controller 214 controls the operation of vacuum pump 212 and valve 210. For example, if the engine speed falls below a particular threshold, controller 214 may operate vacuum pump 212 and valve 210 to close valve 210 to enable muffled operation of the exhaust (e.g., with exhaust flow through gas flow path 206). If, however, the engine speed exceeds the threshold, controller 214 may operate vacuum pump 212 and valve 210 to open valve 210 to enable non-muffled operation of the exhaust (e.g., with exhaust flow through flow path 204. In some embodiments, controller 214 may be configured to implement a control algorithm so that the status of valve 210 does not continue to oscillation between opened and closed positions if drive revs fall below the threshold, even momentarily. For example, controller 214 may be programmed so that the valve will only open if the revs exceed the threshold for a percentage of a given time period. For example, controller 214 may open the valve 210 if the engine speed exceeds the threshold for 75% of the last 5 minutes. Conversely, once valve 210 has been opened, controller 214 may only again close valve 210 when the engine speed falls below the threshold for 75% of the last 5 minutes. In this manner, momentary changes in engine speed won't cause the valve position to change (e.g., a moment of low revs when breaking in a race condition won't cause the valve 210 to close and a moment of high revs when driving slowly through a neighborhood won't cause the valve 210 to open.
Similarly, vehicle speed could be used as an input to controller 214 to control valve 210 position. For example, when the vehicle exceeds a particular valve-open speed threshold (e.g., over 75 mph), the valve 210 may be opened, however when the vehicle is traveling less than a valve-closed speed threshold (e.g., 40 mph) valve 210 may be closed.
In this manner, muffler control system 200 may be used to control vehicle noise in densely populated areas or noise restricted areas allowing for the driver of the vehicle to keep the valves closed until a certain RPM, throttle position, and/or speed is achieved. In embodiments, controller 214 may be connected to a location system (e.g., GPS) allowing for control of valve 210 position based upon a location of the vehicle.
In various embodiments of muffler 202, the interior diameter of flow path 204 (designated Idiam_204 in
Instead, as illustrated in
Typically, muffler control system 200 may be implemented so that valve 210 has a default position of being closed. This implementation can alleviate aggressive cold start functionality of some vehicles. If any part of muffler control system 200 should break or become non-functional valve 210 will automatically close and the vehicle will be able to operate in a quiet/stock mode until the problem is repaired. It may be preferable that muffler control system 200 operate as a ‘stock’ muffler, rather than be stuck in a loud mode.
In muffler control system 200 of
Muffler 300 includes an input 301 (e.g., input 201,
Muffler 300 includes a control valve 310 (e.g., valve 210 of
As shown in
A key fob controller 520 may be in wireless communication with vacuum pump 512 to control the operation thereof. By selecting a first user input on key fob controller 520 a user can cause vacuum pump 512 to put control valve 510 into the first position. By selecting a second user input on key fob controller 520 the user can cause vacuum pump 512 to put control valve 510 into the second position.
In various embodiments, key fob controller 520 may be a 3D printed key fob with a distinctive and unique visual design. Portions of key fob controller 520 may be 3D printed out of metal to provide a solid robust feeling to key fob controller 520.
Muffler 600 includes an input 601 (e.g., input 201,
In the depicted embodiment, gas flow path 606 includes a 90-degree elbow configuration 607. The elbow shape of gas flow path 606 within muffler 600 is configured to ensure proper exhaust flow when re-entering the main pathway of the exhaust. Specifically, the 90-degree elbow configuration provides for a smoother flow of exhaust gases through gas flow path 606 as compared to exhaust flow paths having U-bends or other convoluted shapes, such as gas flow path 306 of muffler 300). In this configuration, the proximal end 650 (e.g., the input end) of the pipe of flow path 604 and the proximal end 652 (e.g., the input end) of the pipe of flow path 606 are parallel to one another, while the distal end 654 (e.g., the output end) of the pipe of flow path 604 and the distal end 656 (e.g., the output end) of the pipe of flow path 606 are orthogonal to one another.
Additionally, within muffler 600 the diameter of the piping making up first flow path 604 is generally equal (or at least approximately equal to) the diameter of the piping making up gas flow path 606. This consistent sizing may allow for muffler 600 to generate a more pleasing sound, even when control valve 610 is closed and exhaust gasses are flowing through gas flow path 606. In some embodiment of muffler 600, in which the muffled exhausted flow path has a diameter that is significantly reduced as compared to the diameter of the non-muffled path, exhaust flow through the narrow, muffled path can sometimes result in excessive and unpleasant noise resulting from the necessary increase in exhaust gas velocity as it passes through the narrow exhaust flow path.
Muffler 600 includes a control valve 610 (e.g., valve 210 of
As shown in
Muffler 700 includes an input 701 (e.g., input 201,
Second flow path 706 is made up of a number of connected volumes. Specifically, muffler body 702 includes internal baffle 753 and internal baffle 755. Internal baffle 753 extends across the interior of muffler body 702 to define end volume 757. Internal baffle 755 extends across the interior of muffler body 702 to define end volume 759. A central volume 781 is defined by and between internal baffle 753 and internal baffle 755. This design ensures the exhaust gases spent reasonable time inside the muffler, slowing down the gasses' velocity, reducing drone, and ensuring a quiet sound experience.
Second flow path 706 includes pipe 783 that extends from internal baffle 753, through internal baffle 755 and to muffler body 702. Second flow path 706 includes pipe 785 that extends between internal baffle 753 and internal baffle 755. As illustrated in
In this configuration, the second flow path 706 extends from port 787 into end volume 759, through pipe 785, end volume 757, and pipe 783 (and, optionally, pipe 789) at which point the flow path exits muffler body 702.
As illustrated in
In a specific embodiment, a diameter 791 of pipe 751 is approximately 76 millimeters (mm). A diameter 793 of pipe 783 is approximately 60 mm and a diameter 795 of pipe 785 (and optional pipe 789) is approximately 25 mm. In such an embodiment, a length of pipe 751, pipe 783, pipe 785 and optional pipe 789 may be about 100 mm.
Muffler 700 includes a control valve 710 (e.g., valve 210 of
In various embodiments, muffler 700 may be configured in multiple different sizes in order to fit multiple Vehicles, including 2.5 inch/63 mm, 3.0 inch/76 mm, and 3.5 inch/89 mm configurations.
The various mufflers described herein may include short extensions or stubs on the pipes entering and exiting the respective muffler bodies to facilitate installation in a vehicle by welding.
In some aspects, the techniques described herein relate to a system, including: a muffler body, including: a first pipe defining a first flow path through the muffler body, wherein the first flow path is a non-muffled flow path, and a second pipe defining a second flow path through the muffler body, wherein the second pipe is a muffled flow path and includes a plurality of perforations configured to allow exhaust gasses flowing therethrough to disperse out of the second pipe and into an interior volume of the muffler body, wherein the second pipe includes a 90-degree elbow, and a first end of the first pipe and a first end of the second pipe are in parallel and a second end of the first pipe and a second end of the second pipe are orthogonal; a valve disposed in the first flow path, wherein when the valve is in an open position exhaust gases flow through the first flow path and when the valve is in a closed position exhaust gases flow through the second flow path; and a controller configured to selectively cause the valve to transition from the open position to the closed position.
In some aspects, the techniques described herein relate to a system, further including a baffling material disposed into the interior volume of the muffler body outside the first pipe and the second pipe.
In some aspects, the techniques described herein relate to a system, wherein the controller is a remote controller enabling a user to control a position of the valve wirelessly.
In some aspects, the techniques described herein relate to a system, wherein a diameter of the first pipe is equal to a diameter of the second pipe.
In some aspects, the techniques described herein relate to a system, wherein the valve is vacuum operated and further including a vacuum pump connected to the valve, wherein the controller is configured to control an operation of a vacuum pump to cause the valve to transition from the open position to the closed position.
In some aspects, the techniques described herein relate to a system, wherein an output of the second pipe is in fluid connection with the first pipe within the muffler body.
In some aspects, the techniques described herein relate to a system, including: a muffler body, including: a first internal baffle, a second internal baffle, wherein the first internal baffle defines a first end volume between the first internal baffle and the muffler body, the second internal baffle defines a second end volume between the second internal baffle and the muffler body, and the first internal baffle and the second internal baffle define a central volume between the first end volume and the second end volume, a first pipe defining a first flow path through the muffler body, wherein the first flow path is a non-muffled flow path, a second pipe extending between the first internal baffle and the second internal baffle, a third pipe extending between the first internal baffle and the second internal baffle, and a second flow path defined through the muffler body, wherein the second flow path extends through the second pipe, the first end volume, the third pipe, and the second end volume, the second flow path is a muffled flow path and at least one of the second pipe and the third pipe includes a plurality of perforations configured to allow exhaust gasses flowing therethrough to disperse out of the at least one of the second pipe and the third pipe and into the central volume of the muffler body; a valve disposed in the first flow path, wherein when the valve is in an open position exhaust gases flow through the first flow path and when the valve is in a closed position exhaust gases flow through the second flow path; and a controller configured to selectively cause the valve to transition from the open position to the closed position.
In some aspects, the techniques described herein relate to a system, further including a fourth pipe extending between the first internal baffle and the second internal baffle, wherein the second flow path includes the fourth pipe.
In some aspects, the techniques described herein relate to a system, further including a baffling material disposed in the central volume and outside the first pipe, the second pipe, and the third pipe.
In some aspects, the techniques described herein relate to a system, wherein the first internal baffle includes perforations configured to allow exhaust gasses flowing through the first end volume to disperse out of the first end volume and into the central volume of the muffler body.
In some aspects, the techniques described herein relate to a system, wherein the second internal baffle includes perforations configured to allow exhaust gasses flowing through the second end volume to disperse out of the second end volume and into the central volume of the muffler body.
In some aspects, the techniques described herein relate to a system, wherein a diameter of the second pipe is from 70 percent to 80 percent of a diameter of the first pipe and a diameter of the third pipe is from 30 percent to 50 percent of the diameter of the second pipe.
In some aspects, the techniques described herein relate to a system, wherein a distance between the first internal baffle and the second internal baffle is between 120 percent and 140 percent of the diameter of the first pipe.
In some aspects, the techniques described herein relate to a system, wherein the valve is vacuum operated and further including a vacuum pump connected to the valve, wherein the controller is configured to control an operation of a vacuum pump to cause the valve to transition from the open position to the closed position.
In some aspects, the techniques described herein relate to a muffler, including: a muffler body; a first internal baffle disposed within the muffler body; a second internal baffle disposed within the muffler body, wherein the first internal baffle defines a first end volume between the first internal baffle and the muffler body, the second internal baffle defines a second end volume between the second internal baffle and the muffler body, and the first internal baffle and the second internal baffle define a central volume between the first end volume and the second end volume; a first pipe defining a first flow path through the muffler body, wherein the first flow path is a non-muffled flow path; a second pipe extending between the first internal baffle and the second internal baffle; a third pipe extending between the first internal baffle and the second internal baffle; and a second flow path defined through the muffler body, wherein the second flow path extends through the second pipe, the first end volume, the third pipe, and the second end volume, the second flow path is a muffled flow path and at least one of the second pipe and the third pipe includes a plurality of perforations configured to allow exhaust gasses flowing therethrough to disperse out of the at least one of the second pipe and the third pipe and into the central volume of the muffler body.
In some aspects, the techniques described herein relate to a muffler, further including a fourth pipe extending between the first internal baffle and the second internal baffle, wherein the second flow path includes the fourth pipe.
In some aspects, the techniques described herein relate to a muffler, further including a baffling material disposed in the central volume and outside the first pipe, the second pipe, and the third pipe.
In some aspects, the techniques described herein relate to a muffler, wherein the first internal baffle includes perforations configured to allow exhaust gasses flowing through the first end volume to disperse out of the first end volume and into the central volume of the muffler body.
In some aspects, the techniques described herein relate to a muffler, wherein the second internal baffle includes perforations configured to allow exhaust gasses flowing through the second end volume to disperse out of the second end volume and into the central volume of the muffler body.
In some aspects, the techniques described herein relate to a muffler, wherein a diameter of the second pipe is from 70 percent to 80 percent of a diameter of the first pipe and a diameter of the third pipe is from 30 percent to 50 percent of the diameter of the second pipe.
Although the invention(s) is/are described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present invention(s), as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention(s). Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.
Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. The terms “a” and “an” are defined as one or more unless stated otherwise. The terms “comprise” and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements but is not limited to possessing only those one or more elements. Similarly, a method or process that “comprises,” “has,” “includes” or “contains” one or more operations possesses those one or more operations but is not limited to possessing only those one or more operations.
This application claims priority to and incorporates by reference U.S. Provisional Patent Application No. 63/342,747 entitled “MUFFLER SYSTEM WITH PNEUMATICALLY ACTUATED BYPASS VALVE” and filed on May 17, 2023.
Number | Date | Country | |
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63342747 | May 2022 | US |