Vannoy funnel exhaust system

Abstract

The passive energy saving device, disclosed herein, may be integrated directly into or added to the exhaust system of an internal combustion engine, to increase the system's fuel efficiency, by acting to reduce the overall backpressure of the total engine and exhaust system. It is a well known fact, accepted by those knowledgeable in the art, that a reduction of exhaust backpressure generally increases the overall fuel efficiency of an internal combustion engine. This passive device consists of a generally funnel shaped outer housing which is open at both ends, and surrounds a smaller diameter, cylindrical exhaust extension tube, which passes longitudinally, on the inside, through the center of the funnel. When airflow is introduced into this funnel, a resulting pressure drop, at the small end of the funnel reduces the backpressure on the vehicle's exhaust system. The net result of the lower exhaust pressure is the increased fuel economy of the vehicle.

Description

This application is based on provisional application No. 61/189,329 filed on Aug. 18, 2008.

Additionally, this non-provisional application Ser. No. 12/583,244 was revised to include the invention “specification” which was requested by the PTO in writing on Oct. 6, 2009. And, further this substitute specification is being filed in response to the “Notice of Missing Parts of a Nonprovisional Application” dated Dec. 21, 2009 regarding application Ser. No. 12/583,244.

The substitute specification contains no new matter.

SPECIFICATION

The present invention relates to a passive energy saving device that improves the fuel economy of any internal combustion engine in a moving vehicle, by lowering the exhaust system backpressure of the vehicle, without the use of moving parts within the device itself.

Energy saving devices, designed to lower the backpressure of the engine's exhaust system, have previously been deployed, in an effort to improve the fuel economy of moving vehicles. Historically, these efforts have largely employed the use of moving fans or turbines which require some form of energy input into the system, in order to create a pressure reduction on the exhaust system. This required energy input reduces the efficiency of these devices.

U.S. Pat. No. 4,012,907, by Crayton, relates to one such device which employs a moving fan to reduce the overall exhaust system backpressure. While effective in reducing the backpressure, this device depends on the function of moving fan parts within the device. These parts will quickly become corroded and likely cease to function correctly, due to the highly corrosive nature of the exhaust gases and moisture expelled from a typical internal combustion engine. Also, the energy required to turn the fan reduces the overall efficiency of the system.

U.S. Pat. No. 4,439,983, by Gertz, relates to another such device which employs the use of an exhaust gas turbine to improve the power output of the internal combustion engine. While the addition of a gas turbine serves to increase the power output of the engine, the actual energy required to power the turbine DECREASES the overall efficiency of the engine system. Furthermore, the addition of the gas turbine also INCREASES the backpressure of the engine's exhaust system by diverting the exhaust flow into the turbine housing before it exits into the normal exhaust system. This increased backpressure further reduces the overall fuel efficiency of the internal combustion engine.

Therefore, it is apparent that the industry is in need of the passive, energy saving exhaust funnel device, described as the invention herein, which provides an overall reduction in engine backpressure, without employing any moving parts or reducing the efficiency of the system by requiring additional energy input for the system to function.

It is an object of the present invention, to provide a method of reducing the overall vehicle exhaust backpressure of any moving vehicle that is powered by an internal combustion engine.

It is a further object of the present invention to improve the overall fuel efficiency of the vehicle by lowering the exhaust system backpressure without the use of moving parts or requiring additional energy input, other than the natural airflow induced by the normal movement of the vehicle.

SUMMARY OF THE INVENTION

The present invention consists of a generally funnel shaped outer housing, open at both ends, which surrounds a smaller diameter, cylindrical exhaust extension tube, that passes longitudinally, through the inside, of the funnel's center. The outside opening of the exhaust extension tube is affixed to the open end of vehicle's engine exhaust system. The cylindrical exhaust extension tube is suspended uniformly within center of the tapered funnel by a semi-circular mounting bracket affixed to the inside of the funnel housing. The open end of the exhaust extension tube is recessed inside of the funnel, behind the smaller diameter opening of the funnel housing. This arrangement, as described, generates an airflow inside the tapered funnel housing, as the vehicle attains an operating speed and motion. The airflow is introduced into the larger diameter end of the funnel and passes around the exhaust extension tube, passing through the center of the funnel housing. Most importantly, the velocity of this airflow increases as it moves over the exhaust extension tube, toward the smaller end of the funnel housing. The INCREASE in airflow velocity creates a DECREASE in the relative pressure at the smaller end of the funnel. The open end of the exhaust extension tube is located just inside (approximately ⅛ to ¼ inches inside) the smaller open end of the funnel. The decreased relative pressure, present at the smaller end of the funnel housing, creates a reduced backpressure effect on the overall exhaust system of the vehicle. The relative pressure reduction, which occurs inside the funnel, is the result of Bernoulli's Principle, which is an accepted law of fluid dynamics that states: “As the speed of a moving fluid increases, the pressure within the fluid decreases.” The moving fluid, which relates to the present invention, is the airflow present within the funnel.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1. is a view of the device from the open end of the exhaust extension tube. The air flow enters the larger open end of the funnel and passes around the exhaust extension tube, and exits at the smaller discharge end of the funnel. The exhaust extension tube is affixed to the end of the vehicle's exhaust system by use of a pipe clamp.

FIG. 2. depicts a cutaway view of the funnel and illustrates the airflow process which occurs inside the funnel. As the outside airflow proceeds into the tapered funnel, the air velocity increases as it approaches the smaller, open end of the funnel. The Bernoulli Principle creates a drop in relative pressure at the small, discharge end of the funnel and is presented at the open end of the exhaust extension tube. This pressure drop creates a reduced pressure zone which occurs at the open end of the exhaust extension tube. This reduced pressure zone serves to reduce the overall engine backpressure, and thereby improves the fuel economy of the engine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, there is depicted a passive funnel shaped device, of the present invention, which is attached to the exhaust system of a moving vehicle or could be integrated directly into the exhaust system of a motor vehicle. The generally funnel shaped device is open at both ends and surrounds a smaller diameter, exhaust extension tube, which passes longitudinally, through the center of the funnel. One end of the exhaust extension tube is affixed to the vehicle's exhaust system. The exhaust extension tube is suspended uniformly within center of the funnel by a semi-circular mounting bracket affixed to the inside of the funnel. The open end of the exhaust extension tube is recessed inside the funnel, ⅛ inch to ¼ behind the smaller diameter opening of the funnel housing. This design generates an airflow inside the tapered funnel housing, when the vehicle is in motion. The airflow is introduced into the larger diameter end of the funnel and passes around the exhaust extension tube, passing through the center of the funnel. The velocity of this airflow increases as it moves through the funnel, toward the smaller end of the housing. The INCREASED air velocity creates a DECREASE in relative air pressure at the smaller end of the funnel. The decreased relative pressure, present at the smaller end of the funnel housing, creates a reduced backpressure effect on the overall exhaust system of the vehicle. The relative pressure reduction, which occurs inside the funnel, is due to Bernoulli's Principle, which states that: “As the speed of a moving fluid increases, the pressure within the fluid decreases.” The moving fluid, in this case, is the airflow within the funnel.

The design has been tested in practice on multiple vehicles and has indicated an improved fuel economy in before/after comparisons on the same vehicle under the same road and weather conditions. The results indicated below in Table 1. are typical examples of these tests.

TABLE 1
Without Funnel (mpg)	With Funnel (mpg)	% Delta
199.8 miles/6.48 gal = 30.8	197.2 miles/4.92 gal = 40.1	23.2%
194.1 miles/6.24 gal = 31.1	202.4 miles/4.83 gal = 41.9	25.8%
201.3 miles/7.19 gal = 28.0	210.1 miles/5.27 gal = 39.9	29.8%

The above tests were conducted on a 2001 Toyota Camry with a 4 Cylinder engine and with an average road speed of 65-68 miles per hour. The road conditions were dry and average temperatures were the same 60-75 degrees Fahrenheit. Tests were performed on other vehicle types and models with similar but varied results.

Claims

1. A passive funnel device, when attached to a moving vehicle, that lowers the vehicle's exhaust system backpressure.

2. A passive funnel device which requires no moving parts to function correctly.

3. A passive funnel device which improves the overall fuel efficiency of the vehicle's internal combustion engine by reducing the vehicle's exhaust system backpressure.

4. A passive funnel device, that requires no additional energy input to operate, aside from the regular air flow generated by the vehicle's normal motion.