Catalytic coatings and techniques for applying the catalytic coatings may be utilized in connection with a number of engine system components including fuel injectors components, exhaust gas recirculation (EGR) valve components, EGR cooler components, piston components, spark plugs, engine valves (intake valves and exhaust valves), engine valve seats, oxygen sensors, NOx sensors, and particulate sensors.

A valve assembly for an exhaust gas recirculation system includes a housing defining an inlet bore and including a second interior surface defining a housing bore. The valve assembly also includes a valve seat and a valve. The valve includes a valve stem and a valve sealing member. The valve assembly optionally includes a baffle at least partially disposed in the housing bore. A first interior radius is defined between the valve stem and the second interior surface. A second interior radius is defined between at least one of the valve stem and the second interior surface, the valve stem and the baffle, and the baffle and the second interior surface. The second interior radius is different from the first interior radius and is configured to direct the flow of the exhaust gas in the housing bore to reduce swirl of exhaust gas in the housing bore.

A valve assembly for an exhaust gas recirculation system includes a housing defining an inlet bore and including a second interior surface defining a housing bore. The valve assembly also includes a valve seat and a valve. The valve includes a valve stem and a valve sealing member. The valve assembly optionally includes a baffle at least partially disposed in the housing bore. A first interior radius is defined between the valve stem and the second interior surface. A second interior radius is defined between at least one of the valve stem and the second interior surface, the valve stem and the baffle, and the baffle and the second interior surface. The second interior radius is different from the first interior radius and is configured to direct the flow of the exhaust gas in the housing bore to reduce swirl of exhaust gas in the housing bore.

A valve device increases or decreases a flow rate of EGR gas. The valve device includes a housing, a bypass valve body, an EGR valve body. The housing includes a first upstream passage into which the EGR gas cooled by an EGR cooler flows, a second upstream passage into which the EGR gas that bypasses the EGR cooler flows, a junction connected to each of a gas-flow downstream side of the first upstream passage and a gas-flow downstream side of the second upstream passage, and a downstream passage connected to the first upstream passage and the second upstream passage via the junction. The bypass valve body opens and closes the second upstream passage. The EGR valve body is provided in the downstream passage, rotates around an EGR valve axis.

A valve device increases or decreases a flow rate of EGR gas. The valve device includes a housing, a bypass valve body, an EGR valve body. The housing includes a first upstream passage into which the EGR gas cooled by an EGR cooler flows, a second upstream passage into which the EGR gas that bypasses the EGR cooler flows, a junction connected to each of a gas-flow downstream side of the first upstream passage and a gas-flow downstream side of the second upstream passage, and a downstream passage connected to the first upstream passage and the second upstream passage via the junction. The bypass valve body opens and closes the second upstream passage. The EGR valve body is provided in the downstream passage, rotates around an EGR valve axis.

An EGR valve includes: an inner housing including a flow passage; a valve element which opens and closes the flow passage; a valve shaft on which the valve element is provided; an outer housing in which the inner housing is assembled; and a drive unit which drives the valve shaft. The flow passage of the inner housing includes an inlet and an outlet. The outer housing includes an assembly hole and separate flow passages. When the inner housing is assembled in the assembly hole, the inlet and the outlet of the inner housing communicate with the separate flow passages of the outer housing; an inlet sealing member is provided between the inner housing and the outer housing to correspond to the periphery of the inlet; and an outlet sealing member is provided between the inner housing and the outer housing to correspond to the periphery of the outlet.

An EGR valve includes: an inner housing including a flow passage; a valve element which opens and closes the flow passage; a valve shaft on which the valve element is provided; an outer housing in which the inner housing is assembled; and a drive unit which drives the valve shaft. The flow passage of the inner housing includes an inlet and an outlet. The outer housing includes an assembly hole and separate flow passages. When the inner housing is assembled in the assembly hole, the inlet and the outlet of the inner housing communicate with the separate flow passages of the outer housing; an inlet sealing member is provided between the inner housing and the outer housing to correspond to the periphery of the inlet; and an outlet sealing member is provided between the inner housing and the outer housing to correspond to the periphery of the outlet.

A poppet-type EGR valve includes: a housing that includes a flow passage; a valve seat; a valve body allowed to be seated on the valve seat; a valve shaft on which the valve body is provided at one end section thereof; and a drive unit reciprocally driving the valve shaft. The flow passage has an inlet and an outlet and includes a bent passage portion that is bent downstream from the valve seat in a direction perpendicular to the direction toward the inlet. The bent passage portion includes at least one of a section in which the passage area is constant and a section in which the passage area increases toward the downstream direction, and does not include a section in which the passage area decreases toward the downstream direction. In the section in which the passage area increases toward the downstream direction, the passage area changes gradually.

A poppet-type EGR valve includes: a housing that includes a flow passage; a valve seat; a valve body allowed to be seated on the valve seat; a valve shaft on which the valve body is provided at one end section thereof; and a drive unit reciprocally driving the valve shaft. The flow passage has an inlet and an outlet and includes a bent passage portion that is bent downstream from the valve seat in a direction perpendicular to the direction toward the inlet. The bent passage portion includes at least one of a section in which the passage area is constant and a section in which the passage area increases toward the downstream direction, and does not include a section in which the passage area decreases toward the downstream direction. In the section in which the passage area increases toward the downstream direction, the passage area changes gradually.

This EGR valve system is provided with a valve assembly, and a plurality of housing adapters. The valve assembly is provided with a housing including a flow passage, a valve seat provided in the flow passage, a valve element provided in the flow passage in such a way as to be capable of seating against the valve seat, a valve shaft on which the valve element is provided, and a driving unit for driving the valve shaft. The housing adapters include assembly holes, inlet flow passages which communicate with the assembly holes, and outlet flow passages. One of the housing adapters is selectively combined with the valve assembly, the housing of the valve assembly is assembled in the assembly hole of the selected housing adapter. In this assembled state, the inlet flow passage communicates with an inlet port, and the outlet flow passage communicates with an outlet port.