US-20260125997-A1 - Variable Muffler

US20260125997A1US 20260125997 A1US20260125997 A1US 20260125997A1US-20260125997-A1

Abstract

A variable engine muffler comprising an interior acoustic chamber and peripheral conduit elements defining a conduit through the muffler. A peripheral conduit element may be movable over a range from closed a position where the conduit is closed to the acoustic chamber and to an open position where the conduit is open to the acoustic chamber.

Inventors

Lars Reinhard

Assignees

Lars Reinhard

Dates

Publication Date: 20260507
Application Date: 20241104

Claims (15)

1 . An engine muffler, comprising: a housing; a chamber interior of the housing; an inlet for receiving engine exhaust; an outlet for discharging the engine exhaust; a conduit defining a periphery of a pathway for fluid communication between the inlet and outlet; said conduit comprising a first peripheral member defining a first part of the pathway periphery and a second peripheral member disposed in a first position defining a second part of the pathway periphery; and said second peripheral member movable from the first position to a second position in which said conduit and chamber are in fluid communication through a space between the first member and second member.
2 . The engine muffler of claim 1 , further comprising: said second peripheral member rotatable between the first position and the second position.
3 . The engine muffler of claim 2 , further comprising: said conduit extending in a longitudinal direction; and said second member rotatable about a pivot axis; said pivot axis oriented at an angle to the longitudinal direction.
4 . The engine muffler of claim 1 , further comprising: a first piece of insulation disposed in the chamber a distance away from the conduit.
5 . The engine muffler of claim 4 , further comprising: a second piece of insulation disposed in the chamber a distance away from the conduit.
6 . The engine muffler of claim 1 , further comprising: the housing comprising a first end panel disposed at a first end of the housing and a second end panel disposed at a second end of the housing; a first perforated partition disposed in the chamber and spaced apart from the first end panel; a second perforated partition disposed in the chamber between the first perforated partition and the second end panel; a first piece of insulation disposed between the first end panel and first perforated partition; and a second piece of insulation disposed between the second end panel and second perforated partition.
7 . The engine muffler of claim 6 , further comprising: a first perforated tube disposed around the conduit between the first end panel and first perforated partition; a second perforated tube disposed around the conduit between the second end panel and second perforated partition; said first piece of insulation disposed between the first perforated tube and the housing; and said second piece of insulation disposed between the second perforated tube and the housing.
8 . The engine muffler of claim 7 , further comprising: said first perforated tube spaced radially outward from the conduit; and said second perforated tube spaced radially outward from the conduit.
9 . The engine muffler of claim 7 , further comprising: a third piece of insulation disposed between the first perforated partition and second perforated partition.
10 . The engine muffler of claim 7 , further comprising: a perforated basket disposed between the first perforated partition and second perforated partition; and a third piece of insulation disposed in the perforated basket.
11 . The engine muffler of claim 1 , further comprising: said second peripheral member translatable between the first position and the second position.
12 . The engine muffler of claim 1 , further comprising: a lip extending from the second peripheral member; said lip disposed over a surface of the first peripheral member when the second peripheral member is in the first position.
13 . An engine muffler, comprising: a housing; a chamber interior of the housing; an inlet through the housing for receiving engine exhaust; an outlet through the housing for discharging the engine exhaust; a conduit defining a periphery of a pathway through the muffler for fluid communication between the inlet and outlet; said conduit comprising a first conduit segment defining a first part of the pathway periphery, a second conduit segment in a first position adjacent to and aligned with the first conduit segment and defining a second part of the pathway periphery, and a third conduit segment adjacent to and aligned with the second conduit segment in a first position and defining a third part of the pathway periphery; said second conduit segment in the first position providing fluid communication between the first conduit segment and third conduit segment; said second conduit segment movable from the first position to a second position out of alignment with the first conduit segment and second conduit segment; and said conduit and chamber in fluid communication through a space between the periphery of the first conduit segment and periphery of the second conduit segment when the second conduit segment is in the second position.
14 . The engine muffler of claim 13 , further comprising: said conduit and chamber in fluid communication through a space between the periphery of the second conduit segment and periphery of the third conduit segment when the second conduit segment is in the second position.
15 . An engine muffler, comprising: an inlet conduit segment for receiving engine exhaust; a middle conduit segment in a first position aligned with and adjacent to the inlet conduit segment; and an outlet conduit segment for discharging the engine exhaust, said outlet conduit segment aligned with and adjacent to the middle conduit segment in the first position; said middle conduit segment movable from the first position to a second position out of alignment with the inlet conduit segment and outlet conduit segment.

Description

TECHNICAL FIELD The present invention relates to an improved muffler for internal combustion engines. BACKGROUND OF THE INVENTION Internal combustion engines, such as automobile engines, generate exhaust gases that are discharged to the atmosphere through an exhaust system. Typical exhaust systems, such as those for automobiles and other motor vehicles, comprise a muffler. Mufflers are acoustic devices that reduce the loudness of the sound created by the engine. Mufflers come in a variety of designs to produce a range of acoustic characteristics, such as volume and harmonics. Mufflers may have a series of passages and chambers lined with acoustic insulation and/or resonating chambers harmonically tuned to cause destructive interference in which sound waves cancel each other out. Mufflers may restrict exhaust gas flow, create back pressure, and decrease engine efficiency. Achieving acoustic performance with minimum loss of engine efficiency is desirable. While most mufflers have fixed configurations, some mufflers have adjustable configurations so that muffler performance may be adjusted. With reference to FIGS. 10A and 10B, adjustable mufflers of the prior art may comprise a pathway for exhaust gases and sound comprising an insulated acoustic chamber that abates and tunes the sound, and an alternate pathway (commonly called a “straight pipe” pathway) through the muffler that bypasses the acoustic chamber, and an adjustable valve disposed in the straight pipe pathway that regulates what proportion of the sound and exhaust flow goes through the alternate pathways. The straight pipe pathway provides louder sound and higher engine efficiency. Adjustable mufflers of the prior art have shortcomings. Valves obstruct exhaust flow and sound waves even when fully open. Mufflers of the prior art typically direct exhaust flow and sound waves through common pipes, which creates an unnecessary association of gas flow and sound propagation, resulting in sub-optimum treatment of these two separate and independent phenomena. Additionally, some soundwaves in the straight pipe configuration will propagate into the acoustic chambers where they will be quieted contrary to the intent of the straight pipe configuration. For example, with reference to prior art FIG. 10A, some of the sound will propagate through the upper pipe into the acoustic chamber causing acoustic inefficiencies. There is a need for a valveless adjustable muffler controllable by means other than a valve. The present invention fulfills this need by providing a continuous unbroken pathway through the muffler defined by a conduit, a peripheral element of which conduit is openable to allow sound waves to enter one or more acoustic chambers in the muffler so that the sound may be quieted and tuned in the one or more chambers, while at the same time allow exhaust gases to find a path of least resistance through the muffler independently of the pathways of acoustic transmission. The conduit may be controlled back and forth between a closed position and a range of open positions to control the acoustic properties of the muffler. SUMMARY OF THE INVENTION In a first aspect, the present invention provides an engine muffler, comprising: a housing; a chamber interior of the housing; an inlet for receiving engine exhaust; an outlet for discharging the engine exhaust; a conduit defining a periphery of a pathway for fluid communication between the inlet and outlet; said conduit comprising a first peripheral member defining a first part of the pathway periphery and a second peripheral member disposed in a first position defining a second part of the pathway periphery; and said second peripheral member movable from the first position to a second position in which said conduit and chamber are in fluid communication through a space between the first member and second member In a second aspect, the present invention provides an engine muffler, comprising: a housing; a chamber interior of the housing; an inlet through the housing for receiving engine exhaust; an outlet through the housing for discharging the engine exhaust; a conduit defining a periphery of a pathway through the chamber for fluid communication between the inlet and outlet; said conduit comprising a first conduit segment defining a first part of the pathway periphery, a second conduit segment in a first position adjacent to and aligned with the first conduit segment and defining a second part of the pathway periphery, and a third conduit segment adjacent to and aligned with the second conduit segment in a first position and defining a third part of the pathway periphery; said second conduit segment in the first position providing fluid communication between the first conduit segment and third conduit segment; said second conduit segment movable from the first position to a second position out of alignment with the first conduit segment and second conduit segment; and said conduit and chamber in fluid communication t