Patent Application
20100083930
This invention relates to internal combustion engines. More particularly, this invention relates to a lower valve cover and an intake manifold of an internal combustion engine having an exhaust gas recirculation (EGR) system.
Most internal combustion engines have some type of emission control device and system. One common type of control system is an exhaust gas recirculation (EGR) system that recirculates exhaust gas from an exhaust system to an intake system of the engine. A high pressure EGR system typically recirculates exhaust gas from upstream of a turbine to downstream of a compressor. Other EGR systems recirculate gas at a low pressure, and are called low-pressure systems. An engine having a high-pressure EGR system has a junction in the air intake system where the EGR gas and the intake air mix to form a mixture. This mixture of exhaust gas and intake air is consumed during engine operation.
A drawback of EGR systems is the amount of space they require. The vehicle packaging becomes larger when EGR systems are incorporated. In addition to having a larger packaging, EGR systems also have an increased amount of parts, more complex designs, and increased noise, vibration and harshness (NVH) than an engine without an EGR system. Further, increased amounts of parts and more complex designs typically translates to increased costs to produce the vehicle.
A lower valve cover and intake manifold assembly for an engine having a cylinder head and a valve cover includes an intake manifold portion having a first surface attached to the cylinder head. The assembly also includes a valve cover portion extending from the intake manifold portion and having a first surface attached to the cylinder head and a second surface attached to the valve cover. The assembly is disposed on the engine between the cylinder head and the valve cover.
The following describes an apparatus for an internal combustion engine having an exhaust gas recirculation (EGR) system associated therewith. The EGR system described herein mixes exhaust gas with intake air to yield a mixture. The mixture is consumed by the engine by combustion within a plurality of cylinders.
A block diagram of an exemplary, prior art engine 100 having an EGR system, as installed in a vehicle, is shown in
Each of the plurality of cylinders 126 of the engine is connected to an exhaust system, generally shown as 130. The exhaust system 130 of the engine 100 is connected to an inlet 131 of the turbine 104. An exhaust pipe 132 is connected to an outlet of the turbine 104. Other components, such as a muffler, catalyst, particulate filter, and so forth, may be connected to the exhaust pipe 132 and are not shown for the sake of simplicity.
The engine 100 has an EGR system, generally shown as 134. The EGR system 134 includes an EGR cooler 136 and an EGR valve 138 connected in a series configuration with each other for passage of exhaust gas therethrough. The EGR cooler 136 fluidly communicates with the exhaust system 130 through an EGR gas supply passage 142. The EGR valve 138 is disposed in line with a cooled-EGR gas passage 148 that is in fluid communication with a junction 146 that is part of the intake air conduit 122. A mixer 150 is located at the junction 146 and fluidly communicates with and connects the cooled-EGR gas passage 148 with the intake air conduit 122.
During operation of the engine 100, air is filtered in the filter 110 and enters the compressor 106 through the inlet 108 where it is compressed. Compressed, or charged, air exits the compressor 106 through the outlet 112 and is cooled in the CAC 114 before passing through the ITH 118. Air from the ITH 118 is mixed with exhaust gas from the cooled-EGR gas passage 148 at the junction 146 through the mixer 150 to yield a mixture. The mixture passes to the intake system 124 by continuing through the intake pipe 122 after the mixer 150 and enters the cylinders 126. While in the cylinders 126, the mixture is additionally mixed with fuel and combusts yielding useful work to the engine 100, heat, and exhaust gas. The exhaust gas from each cylinder 126 following combustion is collected in the exhaust system 130 and routed to the turbine 104. Exhaust gas passing through the turbine 104 yields work that is consumed by the compressor 106.
A portion of the exhaust gas in the exhaust system 130 bypasses the turbine 104 and enters the EGR gas supply passage 142. Exhaust gas entering the passage 142 is exhaust gas that will be recirculated into the intake system 124. The recirculated exhaust gas is cooled in the EGR cooler 136, its amount is metered by the EGR valve 138, and then the gas is routed to the junction 146 for mixing with the charge air exiting the ITH 118 in the mixer 150.
It should be appreciated that the engine 100 and the EGR system 134 provides an overview of how an EGR system works. One problem associated with engines having an EGR system, such as engine 100 having an EGR system 134, is amount of additional components required, and the amount of space that the components take up in the vehicle packaging.
Referring now to
Referring to
Referring now to
The first wall 28, the second wall 30, the third wall 32 and the fourth wall 34 define a surface 36 that is configured to engage the cylinder head 14 (
The valve cover portion 18 of the lower assembly 12 has four walls to the generally rectangular ring shape. A first wall 39 has a first height. It is contemplated that the second wall 30 of the intake manifold portion 20 is common to the first wall 39 of the valve cover portion 18. A second wall 40 is located opposite the first wall 39 and has a second height. Extending between the first wall 39 and the second wall 40 are a third wall 42 and a fourth wall 44 having decreasing height from the first wall to the second wall.
A first surface 46 and a second surface 48 are defined by the four walls 39, 40, 42, 44, with the first surface configured to engage the cylinder head 14, and the second surface configured to engage valve cover 16. A plurality of fastener holes 50 are disposed around the valve cover portion 18 to fasten the valve cover portion to the valve cover 16 and the cylinder head 14. When assembled, the valve cover portion 18 of the lower assembly 12 becomes an extension of the valve cover 16. An exhaust gas outlet 52 is disposed in the third wall 42 of the valve cover portion 18 for allowing exhaust gases to exit the engine 10.
As seen in
Referring back to
The lower assembly 12 combines an intake manifold, a valve cover and an EGR cooler support into a single, less complex assembly. The lower assembly 12 decreases the numbers of parts, and improves the noise, vibration and harshness (NVH) as compared to a conventional engine with EGR system. Further, the lower assembly 12 yields a smaller packaging, and an overall lower EGR system mounting on the engine. A lower mounting on the engine allows for any air that could potentially be trapped in the cooler 24 to vent to the de-gas bottle on the engine. A lower mounting also tends to improve the structural rigidity of the cooler 24.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
