Patent Application
20150292375
The present invention relates to sound-attenuating mufflers for use with internal combustion engines and, in particular, it concerns improvements to such sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.
Numerous muffler constructions have been proposed for the attenuation of the sound component of an exhaust gas stream from an internal combustion engine. The present invention is an improvement to the low back-pressure sound-attenuating mufflers of U.S. Pat. Nos. 6,286,623, 6,776,257, 7,708,114 and 7,708,115 to the present inventor and incorporated herein by reference.
As new automobiles become smaller in size, the components used to build such vehicles need to be smaller. The current technology in the art of automobile mufflers provides for mufflers having a muffler housing volume displacement to engine displacement ratio of greater than 8:1, and generally in the range of 8:1-15:1. For a 2 L engine, for example, the muffler could be as large as 30 L, which is too large for some models of small sporty automobiles with powerful engines.
It must be noted, however, that the aspects of exhaust noise level, muffler size and exhaust back pressure are so related that reducing one or more aspects may adversely affect the other aspects. That is to say, generally, reducing the size of the muffler tends to increase the noise level. However, reducing both the size of the muffler and adding elements in order to maintain the noise reduction level generally results in an increase in back pressure. As noted in the prior art, increased back pressure adversely affects fuel economy and overall engine performance.
Larger size also involves greater weight and material costs.
There is therefore a need for sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.
The present invention relates to sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.
According to the teachings of the present invention there is provided, a sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1; (b) the muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1; (c) a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough; and (d) a deflection element deployed in the muffler housing and attached to an upstream side of the partition, the deflection element having a width, height and length such that the attached to the partition is along its width and height so as to provide at least one side opening on each side along the width and at least one end opening on each end along the height for the passage of exhaust gases therethrough, such that a ratio of an open area of both the end openings to an open area of the partition opening is in a range of 0.7:1-3.7:1 and a ratio of an open area of both the side openings to the open area of the partition opening is in a range of 0.3:1-3.5:1.
According to a further teaching of the present invention, the deflection element is a hollow pyramid configured with: (a) a side-view apex angle measuring between 70°-179°; (b) an end-view apex angle measuring between 35°-115°; (c) a side-view shoulder angle measuring between 89°-180°; (d) an end-view shoulder angle measuring between 110°-180°; (e) a side opening apex angle measuring between 90°-180°; and the partition is configured with a base section and sloping end sections to which the deflection element is attached such that an angle of the sloping sections to the base section measures between 83°-180°.
According to a further teaching of the present invention, (a) the side-view apex angle is 122°; (b) the end-view apex angle is 65°; (c) the side-view shoulder angle is 155°; (d) the end-view shoulder angle is 155°; (e) the side opening apex angle is 105°; and (f) the angle of the sloping sections to the base section is 135°.
According to a further teaching of the present invention, the muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.
According to a further teaching of the present invention, the muffler housing width to height ratio is 1.8:1.
According to a further teaching of the present invention, the ratio of the open area of both the end openings to the open area of the partition opening is 1.8:1 and the ratio of the open area of both the side openings to the open area of the partition opening is 0.9:1.
There is also provided according to the teachings of the present invention, a sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough, the partition configured with a base section and sloping end sections such that an angle of the sloping sections to the base section measures between 83°-180°; and (b) a deflection element deployed in the muffler housing and attached to an upstream side of the partition, the deflection element is a hollow pyramid having: (i) a side-view apex angle measuring between 70°-179°; (ii) an end-view apex angle measuring between 35°-115°; (iii) a side-view shoulder angle measuring between 89°-180°; (iv) an end-view shoulder angle measuring between 110°-180°; and (v) a side opening apex angle measuring between 90°-180°.
According to a further teaching of the present invention, (a) the angle of the sloping sections to the base section is 135°; (b) the side-view apex angle is 122°; (e) the end-view apex angle is 65°; (d) the side-view shoulder angle is 155°; (e) the end-view shoulder angle is 155°; and (f) the side opening apex angle is 105°.
According to a further teaching of the present invention, there is also provided (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1; and (b) the muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1.
According to a further teaching of the present invention, the muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.
There is also provided according to the teachings of the present invention, a sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a muffler housing having a width to height ratio in a range of 1.05:1-3.5:1; and (b) a deflection element deployed in the muffler housing, the deflection element being configured as a hollow pyramid having: (i) a side-view apex angle measuring between 70°-179°; (ii) an end-view apex angle measuring between 35°-115°; (iii) a side-view shoulder angle measuring between 89°-180°; (iv) an end-view shoulder angle measuring between 110°-180°; and (v) a side opening apex angle measuring between 90′-180°.
According to a further teaching of the present invention, the muffler housing has a volume displacement to engine displacement ratio of less than 8:1.
According to a further teaching of the present invention, muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.
According to a further teaching of the present invention, the muffler housing width to height ratio is 1.8:1.
According to a further teaching of the present invention, there is also provided (a) a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough, the partition configured with a base section and sloping end sections such that an angle of the sloping sections to the base section measures between 83°-180°; and (b) the hollow pyramid is attached to an upstream side of the partition, the hollow pyramid having: (i) the angle of the sloping sections to the base section is 135°; (ii) the side-view apex angle is 122°; (iii) the end-view apex angle is 65°; (iv) the side-view shoulder angle is 155°; (v) the end-view shoulder angle is 155°; and (vi) the side opening apex angle is 105°.
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein the terms “top”, “bottom”, “side” and “end” refer to the position of the components of the present invention with respect to their position in a muffler when installed in a vehicle and as shown in
The present invention relates to sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.
The principles and operation of sound-attenuating mufflers according to the present invention may be better understood with reference to the drawings and the accompanying description.
By way of introduction, as mentioned above the current automobile muffler technology requires a muffler housing volume displacement to engine displacement ratio of greater than 8:1, and generally in the range of 8:1-15:1. It should be understood that the combination of improvements disclosed herein result in the ability to meet the same level of noise suppression with a muffler housing volume displacement to engine displacement ratio of less than 8:1, and generally in the range of 4:1-7.9:1. Such a smaller size represents a drastic reduction in size, weight and cost of materials over the current state of the art. However, as noted above and in U.S. Pat. Nos. 6,286,623, 6,776,257, 7,708,114 and 7,708,115 to the present inventor and incorporated herein in their entirety as if fully recited, the design of the muffler of the present invention maintains a reduced back pressure load. Thereby enabling the muffler of the present invention to reduce all three aspects addressed by vehicle muffler, specifically, the aspects of exhaust noise level, muffler size and exhaust back pressure to size/level combinations unattainable in the prior art.
Specifically, these improvements relate to the muffler housing width to height ratio, the shape of the deflection element and the relationship of the partition and deflection element, as will be discussed in more detail below.
It should be understood that the terms width, height and length are used herein, and especially in the claims, to refer to the relative position of the elements of the present invention as they would be oriented in a muffler when installed on an automobile and/or as illustrated in
Referring now to the drawings,
As illustrated in
Although the concept of a hollow pyramid shaped deflection element 100 was disclosed in the patents listed above to the present inventor, the inventor has developed improvements in the shape of the hollow pyramid 100, the partition 200 and the relationship/interconnection of the two as will now be explained.
Specifically, the side-view apex angle 110 may measure between 70°-179°, but the preferred angle is 122°. The end-view apex angle 112 may measure between 35°-115°, but the preferred angle is 65°. The side-view shoulder angle 120 may measure between 89°-180°, but the preferred angle is 155°. The end-view shoulder angle 122 may measure between 110°-180°, but the preferred angle is 155°. The side opening apex angle 130 may measure between 90°-180°, but the preferred angle is 105°.
As illustrated, the partition 200 may optionally, or preferably, be configured with a base section 210 and sloping end sections 220 to which the hollow pyramid deflection element 100 is attached. The angle 222 of the sloping sections 220 to the base section 210 may measure between 83°-180°, but the preferred angle is 135°.
Regarding the relationship between the hollow pyramid 100 and the partition 200, referring back to
Regarding the muffler housing width 170 to height 150 ratio,
It will be appreciated that while any of the improvements described herein may be used individually to benefit in the construction of a sound-attenuating muffler for use with an internal combustion engine, the synergy of the combination of the preferred angles, ratios and relationships of the improvements of the present invention enable the production of muffler having a housing with a volume displacement to engine displacement ratio of less than 8:1, and even in the range of 5:1-6:1, which until now was considered unattainable.
It will be appreciated that the above descriptions are intended only to serve as examples and that many other embodiments are possible within the spirit and the scope of the present invention.
