BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which:
FIG. 1 is a view of a conventional EBV assembly having dual butterfly valves.
FIG. 2 is view of an EBV assembly including a housing and EBV, in accordance with an embodiment of the invention, shown mounted to the housing.
FIG. 3 is a view of the valve member of the EBV of FIG. 2.
FIG. 4 is a sectional view of FIG. 2 showing the valve member of the EBV in a cooler mode position.
FIG. 5 is a sectional view of FIG. 2 showing the valve member of the EBV in a bypass mode position.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
Referring to FIG. 2, an Exhaust Bypass Valve (EBV) assembly for a diesel engine is shown, generally indicated at 20, in accordance with an embodiment of the invention. The assembly 20 is constructed and arranged to be mounted with respect to an exhaust gas cooler of an exhaust manifold of, for example, a diesel engine (none of which are shown). For example, the assembly 20 can be mounted after the cooler such that exhaust gas enters from the back of an exhaust manifold into the cooler during a ‘cooler’ mode and bypasses the cooler during a ‘hot’ or bypass mode by using the external manifold as the bypass tube. The gas exits the exhaust manifold at the front, bypassing the cooler, entering directly into the assembly 20. The assembly 20 can be mounted before the cooler in certain configurations. The assembly is used in bypass mode during 1) cold start conditions to reduce the time it takes to bring the engine up to temperature by ‘dumping’ hot exhaust gas into the intake manifold and 2) DPF regeneration. In the cooler mode, the assembly 20 reduces exhaust gas recirculation temperature to increase air density and improve combustion and emissions.
In the embodiment and with reference to FIGS. 2 and 4, the assembly 20 includes housing 22 having an inlet passageway 21, and a first passageway 24 in communication with a second passageway 26. The inlet passageway communicates with the first and second passageways and is constructed and arranged to receive exhaust gas from an exhaust manifold of a vehicle. The first passageway 24 is constructed and arranged to communicate with a cooler (not shown), and the second passageway 26 is constructed and arranged to communicate with an engine (not shown).
At a juncture 25 of the passageways 21, 24, 26, the housing 22 includes a generally cylindrical bore 28 therein so as to communicate with each of the passageways 21, 24, 26. The assembly 20 includes an EBV cartridge, generally indicated at 30, received in the bore 28. With reference to FIG. 3, the EBV cartridge 30 includes a valve member, generally indicated at 32. In the embodiment, the valve member 32 is generally cylindrical having a cutout 33 that defines a generally U-shape of the valve member 32. Thus, the valve member 32 has a pair or sides 34, 36 and a valve portion 38 joined between the two sides. A shaft structure is provided and in the embodiment is defined by shafts 40, 42 associated with each side 34, 36, respectively. Shaft 42 is coupled with an actuator (not shown) in the conventional manner to actuate (rotate) the valve member.
Thus, as shown in FIG. 4, when the valve member 32 is rotated about axis A to a cooler mode position, the valve portion 38 substantially bocks passageway 26 such that exhaust gas recirculation flow F from an exhaust manifold flows through the inlet passageway 21, through the cutout 33 in the valve member 32, and through the passageway 24 to an exhaust gas recirculation (EGR) cooler that provides a cooled dilutent to lower combustion temperatures and reduce the concentration of nitrogen oxides in the exhaust gases.
With reference to FIG. 5, when the valve member 32 is rotated about axis A to a bypass mode position, the valve portion 38 substantially bocks passageway 24 such that exhaust gas recirculation flow F from the exhaust manifold flows through the inlet passageway 21, through the cutout 33 in the valve member 32, and through passageway 26, bypassing the EGR cooler, which redirects uncooled gasses through the engine to accelerate engine warmup.
Since the EBV cartridge 30 is selectively removable, a defective EBV cartridge 30 can simply be removed and replaced. Since a single valve member 32 is used instead of two conventional butterfly valves, a compact and less expensive EBV is provided.
The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.