Engine breathing system valve and products including the same

One embodiment may include an engine breathing system valve (10) for an internal combustion engine breathing system (12) including a valve body (60), a stem (62), and a valve member (64). The valve body (60) has a port (66) with a center axis (CP). The valve body (60) may have a seating surface (68) lying along a cone outer surface (CS) of an imaginary cone (C). The imaginary cone (C) has a cone center axis (CA). The stem (62) is carried by the valve body (60) so that it can rotate. The stem (62) has an axis of rotation (R-i) radially offset from the port center axis (CP). The valve member (64) is connected to the stem (62) and may have a valve member plane (M) axial Iy offset from the axis of rotation (R-i).

TECHNICAL FIELD

The technical field generally relates to products including valves that regulate fluid-flow in an internal combustion engine breathing system.

BACKGROUND

Internal combustion engines are often equipped with breathing systems to, among other things, decrease emissions and increase engine efficiency. The systems may include one or more turbochargers, one or more exhaust gas recirculation (EGR) assemblies, and other components. Valves and passages are commonly located throughout the systems to regulate fluid-flow between the exhaust breathing system components.

SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION

One exemplary embodiment includes a product which may include an engine breathing system valve. The engine breathing system valve may be located within a passage of an engine breathing system in order to regulate fluid-flow in the passage. The engine breathing system valve may include a valve body, a stem, and a valve member. The valve body may have a port with a center axis and may have a seating surface. The seating surface may lie along a cone outer surface of an imaginary cone. The imaginary cone has a cone center axis which may be at an acute angle with respect to the port center axis so that, in cross-sectional profile, an upper portion of the seating surface may be at a different angle with respect to the port center axis than a lower portion of the seating surface. The stem may be carried by the valve body so that it can rotate thereabout. The stem may be carried at a location that may be away from the seating surface. The stem has an axis of rotation that may be radially offset from the port center axis. The valve member may be connected to the stem so that it can rotate with the stem. The valve member has a valve member plane lying parallel to a valve face of the valve member. The valve member plane may, when in a closed position, be axially offset from the axis of rotation.

One exemplary embodiment includes a product which may include an engine breathing system valve. The engine breathing system valve may be located in a passage of an engine breathing system and may regulate fluid-flow in the passage. The engine breathing system valve may include a valve body, a stem, and a valve member. The valve body may have a port and a seating surface. The seating surface may lie along a cone outer surface of an imaginary cone. The imaginary cone may have a cone center axis which may be parallel to a center axis of the port. In cross-sectional profile, an upper portion of the seating surface may be at an acute angle with respect to the port center axis, and a lower portion of the seating surface may be at an acute angle with respect to the port center axis. The stem may be rotatably carried by the valve body at a location that may be away from the seating surface. The stem may have an axis of rotation that is radially offset from the port center axis. The valve member may be connected to the stem and may rotate with the stem. The valve member may have a valve member plane that is defined parallel to a valve face of the valve member. The valve member plane may be, when the valve member is in a closed position, at an acute angle with respect to a vertical axis of the port.

One exemplary embodiment includes a product which may include an upper housing of a turbocharger component, a lower housing of the turbocharger component, and an engine breathing system valve positioned between the upper housing and the lower housing. The engine breathing system valve may regulate fluid-flow in the turbocharger component. The engine breathing system valve may include a valve body, a stem, and a valve member. The valve body may have a port and a seating surface. The seating surface may lie along a cone outer surface of an imaginary cone. The imaginary cone may have a cone center axis which may be parallel to a center axis of the port. In cross-sectional profile, an upper portion of the seating surface may be at an acute angle with respect to the port center axis, and a lower portion of the seating surface may be at an acute angle with respect to the port center axis. The stem may be rotatably carried by the valve body at a location that may be away from the seating surface. The stem may have an axis of rotation that is radially offset from the port center axis. The valve member may be connected to the stem and may rotate with the stem. The valve member may have a valve member plane that is defined parallel to a valve face of the valve member. The valve member plane may be, when the valve member is in a closed position, at an acute angle with respect to a vertical axis of the port.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description of the embodiment(s) is merely exemplary (illustrative) in nature and is in no way intended to limit the invention, its application, or uses.

The figures illustrate an exemplary embodiment of an engine breathing system valve10that may be used in an internal combustion engine breathing system12for internal combustion engines including, but not limited to, gasoline, diesel, and alternative fuels. The valve10may be used at various locations in the engine breathing system12including, but not limited to, in a turbocharger14and in an exhaust gas recirculation (EGR) assembly16. The valve10may be designed to prevent leakage when the valve is at a closed position, even at low engine speeds. The valve10may also improve the resolution of mass fluid-flow through the valve as compared to other valves such as flap valves. In exemplary embodiments, the valve10and an associated port may have a generally cylindrical and elliptical shape which define various directions with respect to the shape; in this sense, the term “radially” refers to a direction that is generally along an imaginary radius of the shape, the term “axially” refers to a direction that is generally parallel to an imaginary center axis of the shape, and the term “circumferentially” refers to a direction that is generally along an imaginary circumference of the shape.

Referring toFIG. 1, an internal combustion engine18combusts fuel and expels fluid in the form of exhaust gasses to the engine breathing system12. The internal combustion engine18may be a spark-ignited engine or a diesel engine. The example shown is a diesel engine that may be of different types having different arrangements and different numbers of cylinders (e.g., in-line, V-type, V-6, V-8, etc.). A cylinder block20may define multiple piston bores. An exhaust manifold22may be equipped on an exhaust side of the internal combustion engine18to direct fluid-flow, such as the exhaust gasses, exhaled from the engine and to the engine breathing system12. An intake manifold24may be equipped on an intake side of the internal combustion engine18to direct and supply air and/or air-fuel mixture to the engine.

The engine breathing system12may be used with the internal combustion engine18to manage fluid-flow supplied to, and expelled from the engine. The engine breathing system12may have various arrangements and various engine breathing system components. The example shown inFIG. 1may include the EGR assembly16, the high pressure stage turbocharger14, and a low pressure stage turbocharger26.

The EGR assembly16may direct exhaust gas back into the intake manifold24. The EGR assembly16may have various arrangements and various components. The example shown may include an EGR passage28that allows fluid-flow between the exhaust and intake manifolds22and24, an EGR cooler30, and an EGR valve such as the valve10. The EGR cooler30may be a heat exchanger that cools the exhaust gasses that flow therethrough. The EGR valve regulates exhaust gas fluid-flow from an exhaust passage32and to an intake passage34. The example EGR assembly16is a high pressure EGR assembly; in other examples, a first low pressure EGR assembly35, a second EGR assembly37, or both may also be included. Like the high pressure EGR assembly16, the low pressure EGR assemblies35,37may also include an EGR cooler39,41, an EGR passage43,45, and an EGR valve such as the valve10.

The high pressure stage turbocharger14is driven by exhaust gas fluid-flow to force an additional amount of air into the internal combustion engine18. The turbocharger14may be various types, and may include a turbine36that is directly driven by the exhaust gas fluid-flow and that in turn drives a compressor38via a shaft. The compressor38pressurizes air that eventually enters the internal combustion engine18. The turbocharger14may also include a bypass passage40, or a waste gate passage, which diverts exhaust gasses around the turbine36. A bypass valve, such as the valve10, may be located within the bypass passage40to regulate fluid-flow through the bypass passage. Another bypass passage42may be included to divert intake air around the compressor38. Again, a bypass valve, such as the valve10, may be located within the bypass passage42to regulate fluid-flow through the bypass passage.

The turbocharger14may further include a housing to support the turbine36and the compressor38. The housing may include a portion covering the turbine36and a separate portion covering the compressor38. One of the portions or both of the portions may include the bypass passage(s)40,42. Referring toFIG. 9, a turbine housing44may include an upper housing46and a separate lower housing48. The upper housing46may have a first flange50for mounting, and the lower housing48may have a second flange52for mounting. The first and second flanges50,52may be connected together or may be connected to the valve10when the upper and lower housings46,48are brought together for assembly. When assembled, the upper and lower housings46,48may sandwich the valve10to position the valve between the housings. Though not shown, a compressor housing may also include an upper housing with a first flange and a lower housing with a second flange that, when assembled, may sandwich the valve10to position the valve between the housings.

Referring toFIG. 1, the low pressure stage turbocharger26may in some ways be similar to the high pressure stage turbocharger14. Together, the turbochargers14and26make up a two-stage turbocharging system. The turbocharger26may be of various types and may include a turbine54and a compressor56. A bypass passage55may divert exhaust gasses around the turbine54, another bypass passage57may divert intake air around the compressor56, or both. And a bypass valve, such as the valve10, may be located in the bypass passages55,57to regulate fluid-flow through the bypass passages. Like the turbocharger14, the turbocharger26may include a housing for the turbine54and compressor56that may have an upper and lower housing with respective flanges for sandwiching the valve10.

In other embodiments, the engine breathing system12may have more, less, and/or different components than shown and described. For example, one or more coolers58may be located between the components, a diesel particulate filter (DPF) may be provided, and only a single turbocharger may be provided constituting a one-stage turbocharging system.

The valve10may be used in the engine breathing system12at the various locations discussed above, and may be located at other places in the engine breathing system. Wherever the valve10is located, the valve may control and regulate fluid-flow thereat to permit (open) fluid-flow therethrough or prevent (close) fluid-flow therethrough. The valve10may have various configurations and components. Referring toFIGS. 2-6and8, in one exemplary embodiment the valve10may include a valve body60, a stem62, and a valve member64.

The valve body60may constitute the casing through which fluid-flow travels in the valve10. The valve body60may be a one-piece structure, or may be made of separate pieces that are subsequently put together. The valve body60may be composed of a material that is impervious to engine fluids such as, but not limited to, a ductile iron, a high silicon iron, a steel alloy such as a stainless steel, a ceramic, or a high temperature plastic. In some cases, the exact material will be dictated by the temperature which the valve body60is exposed to. The exact dimensions of the valve body60may vary among different internal combustion engine breathing systems, and may depend on, among other things, the type of the associated internal combustion engine and the desired fluid-flow characteristics through the valve10. In the embodiment shown, the valve body60may have a port66, a first seating surface68, a flange70, and one or more hubs71.

Fluid-flow traveling through the valve10passes through the port66. The port66may have an interior surface72that defines a cylindrical or elliptical shape. An inlet74may be located at one end of the port66for entering fluid-flow, and an outlet76may be located at the other end for exiting fluid-flow. A center axis CP of the port66may go through a cylindrical or elliptical centerpoint of the port.

The first seating surface68contacts and mates with a complementary seating surface of the valve member64to form a seal therebetween. Referring toFIGS. 4 and 5, the first seating surface68may be shaped at least in part by an imaginary cone C (shown in phantom as a truncated cone). The cone C has a cone outer surface CS and a cone center axis CA. The center axis CA may go through an apex (not shown) of the cone C, and may go through a centerpoint of a base CB of the cone. As shown in cross-section, the cone C may be positioned so that one side of the outer surface CS lies in the horizontal direction and is parallel with the port66. In this position, the center axis CA may be at an acute angle θ with respect to the center axis CP of the port66. The first seating surface68may follow and lie along a portion of the outer surface CS. The first seating surface68may have different angles with respect to the center axis CP at different points along its circumference so that an upper portion78of the first seating surface68is at a different angle with respect to the center axis CP than a lower portion80. For example, as shown in cross-section, the upper portion78may be at an acute angle with respect to the center axis CP, while the lower portion80may be parallel with the center axis CP. In other embodiments, the cone C may be positioned at different orientations whereby the upper and lower portions78,80may have different angles with respect to the center axis CP. For example, the lower portion80need not necessarily be parallel with the center axis CP.

The flange70may be used to connect the valve10in the various locations discussed above. For example, referring toFIG. 9, the flange70may interfit with a connecting structure81that in turn connects to the first and second flanges50,52in order to position the valve10between the upper housing46and the lower housing48. As another example, the flange70may connect to the EGR passage28. The flange70may extend continuously around a periphery of the valve10, or may have discontinuous and separate pieces spaced around the periphery. In other embodiments, the flange70need not be provided, or the connecting structure81can be unitary with the valve body60.

The hub71may be located on each side of the valve body60to rotatably receive the stem62, or may be located on only one side of the valve body. The hub71may be unitary with the valve body60. The hub71may define one or more holes85for receiving the stem62.

The stem62may be a rod that may be carried by the valve body60at a location away from the first seating surface68. The stem62may connect with, and may translate rotation to the valve member64. Referring toFIG. 3, the stem62may have an outer surface82with a recess84defined therein. The recess84may be a diametrically reduced section of the stem62, or may be another shape. When assembled, a control pin87may be inserted through the valve body60, and may be received in the recess84. Once received, the control pin87limits axial slack between the stem62and the hub71to substantially prevent relative movement therebetween, such as axial movement.

In the embodiment shown, the stem62may also define a hole86for receiving a pin as will be described. At one end, a lever88may be connected to the stem62for rotation by an actuator90(FIG. 1). A seal92and/or bushing may be fit into the hubs71to seal the hub and/or facilitate rotation of the stem62. In other embodiments, the stem62may have different configurations and components. For example, the stem62may include a pair of concentric rods, with one being solid and the other being hollow. In use, one of the rods may rotate while the other rod remains stationary.

Referring toFIGS. 2 and 5, when in use, the stem62and the valve member64rotate about an axis of rotation R1. The axis of rotation R1may lie along the center axis of the stem62. The axis of rotation R1may be radially offset from the center axis CP of the port66as best shown by the imaginary line R2which intersects with the axis of rotation R1. That is, the axis of rotation R1may be spaced away from the center axis CP a set distance. The axis of rotation R1may be parallel with the center axis CP. Though shown inFIG. 5as being radially offset in a downward direction, the axis of rotation R1may also be radially offset from the center axis CP in an upward direction.

The valve member64may be rotated by the stem62in order to open and close the valve10. The valve member64and the stem62may be one-piece, or may be, as shown, separate pieces that are attached together. The valve member64may be sized and shaped to complement the port66and may be obtained by intersecting an imaginary plane with the cone C, in this case the valve member may have a disc, ellipse, or oval shape. In one example, the valve member64has an oval shape with a major diameter measuring between 30 and 60 mm. Referring toFIGS. 3,4,6, and8, the valve member64may have a valve front face94and a valve rear face96. As shown, the valve rear face96may confront fluid-flow traveling through the valve10. A boss98may extend from the valve rear face96, and may have a passage100for receiving the stem62. A retaining pin102may be inserted through the boss98and through the stem62to interlock the stem to the valve member64. A clearance or gap104may be defined between the outer surface82of the stem62and a confronting inner surface of the passage100, and may also be defined between the outer surface of the retaining pin102and the confronting outer surfaces of the boss98and stem. In one example, the clearance104may be about 1/10 mm; of course other values are possible. The clearance104may provide space, and thus may accommodate manufacturing tolerances between the respective components, and may accommodate relative thermal expansion and contraction between the components that may occur during use with the associated fluctuations in temperature. The clearance104may also allow for misalignment that may occur during closing between respective seating surfaces of the valve body60and the valve member64.

Referring toFIG. 4, the valve member64may define a valve member plane M. The valve member plane M may go through the valve member64, and may be parallel with the valve front face94. As shown in cross-section, when the valve member64is in the closed position, the valve member plane M may be directed vertically. Also, the valve member plane M may be axially offset from the axis of rotation R1when in the closed position. In other words, the valve member plane M may be spaced away from the axis of rotation R1a set distance.

Referring toFIGS. 3,4,6, and8, the valve member64may also have a second seating surface106that contacts and mates with the first seating surface68to form a seal when the valve10is closed. The second seating surface106may complement the shape of the first seating surface68, and like the first seating surface68, the second seating surface106may be shaped at least in part by the cone C. The second seating surface106may follow and lie along a portion of the outer surface CS. The second seating surface106may have different angles with respect to the center axis CP at different points along its circumference so that an upper portion108is at a different angle with respect to the center axis CP than a lower portion110. For example, as shown in cross-section, the upper portion108may be at an acute angle with respect to the center axis CP, while the lower portion110may be parallel with the center axis CP.

Referring toFIG. 1, the actuator90selectively rotates the stem62and the valve member64in order to open and close the valve10. The actuator90may be of various types including electromechanical such as an electric motor or solenoid, pneumatic, or hydraulic. The actuator90may be located outside of the valve body60, and may be operatively connected to the stem62via the lever88and through a mechanical linkage. The operation of the actuator90may be controlled by an electronic control unit (ECU)107through a closed-loop or open-loop control system using feedback control.

In use, the actuator90operates the valve10and rotates the valve member64between an open position (FIG. 6) and the closed position (FIG. 4). In the example ofFIG. 1, when open, exhaust gasses are permitted to bypass the turbine36. The valve member64is rotated to a position where it is generally parallel with the center axis CP of the port66. When rotated to the closed position, the first and second seating surfaces68,106mate to form a circumferentially continuous seal therebetween. The seal is uninterrupted by any intervening structure or component, such as may be the case in some valves where the associated stem extends through the associated seating surface. In the example where the axis of rotation R1may be axially offset from the valve member plane M, the stem62may extend through the valve body60at the location spaced axially away from the first seating surface68. Also when in the closed position, the valve10has no, or very little, leakage.

The pressure exerted against the valve rear face96from fluid-flow may urge the valve10in the closed position because the pressure exerted on an upper portion of the valve may be greater than the pressure exerted on a lower portion due to the axis of rotation R1being radially offset from the center axis CP. This may help keep the upper portion78of the first seating surface68against the opposing portion of the second seating surface106, without requiring excessive force to then move the valve10to the open position. From the closed position and to the open position, the valve member64revolves a total angle of rotation of about 90°.

FIGS. 10-12show another embodiment of the engine breathing system valve10in a closed position. In this embodiment, the inlet74may have a larger diameter value than the outlet76. The first seating surface68may be shaped at least in part by the imaginary cone C (shown in phantom). The cone C may be positioned so that the center axis CA may be parallel and radially offset with respect to a port center axis CPoat an outlet portion77. At an inlet portion75, a port center axis CPimay be concentric with the center axis CA as shown, or may be parallel and radially offset with respect to the center axis CA. As shown in cross-section, the upper portion78may form an acute angle Ω1with respect to the center axis CA and with respect to the center axis CPo. In one embodiment, the angle Ω1is less than 90° and greater than 0°, and may be about 25-30° or about 27°. The lower portion80may form an acute angle Ω2with respect to the center axis CA and with respect to the center axis CPo. In one embodiment, the angle Ω2is less than 90° and greater than 0°, and may be about 25-30° or about 27°. The angles Ωiand Ω2may, though need not, have the same value which may facilitate machining and manufacture of the first and second seating surfaces68,106.

Though not shown inFIGS. 10-12, the axis of rotation R1of the stem62may be radially offset from the center axis CA, and the port center axes CPiand CPoin the downward direction.

In one example of this embodiment, the valve member64has an oval shape with a major diameter of about 44 mm and a minor diameter of about 43 mm. In this embodiment, the retaining pin102may be inserted through a single side of the boss98and partly through the stem62to interlock the stem and the valve member64. As shown best inFIG. 11, the valve member64may be positioned eccentric in the valve body60with respect to the flange70. When in the closed position, the valve member plane M may be tilted and may be directed at an acute angle Ω3with respect to a vertical axis VP of the port66; in one embodiment, the angle Ω3may be less than 90° and greater than 0°, and may be about 6-12° or about 9°. The second seating surface106may complement the shape of the first seating surface68. As shown, the upper portion108may form the angle Ω1with respect to the center axis CA and with respect to the center axis CPo. The lower portion110may form the angle Ω2with respect to the center axis CA and with respect to the center axis CPo. In use, the valve member64may rotate in a direction A, and gasses may come from a direction B.

In some cases, when the engine breathing system valve10ofFIGS. 10-12is approaching completely close or almost completely close, the resulting gas pressure biases the valve member64so that the second seating surface106contacts the first seating surface68at a single point rather than at all points (i.e., flush) with respect to each other, causing an incomplete close or misalignment between the seating surfaces68,106. The single point may occur at the lower portion110, while the upper portion108forms a slight gap with respect to the upper portion78of the first seating surface68. Oftentimes, an additional torque may be required via the actuator90to bring the first and second seating surfaces68,106flush and further bring the engine breathing system valve10to complete close. Referring toFIG. 12, the position of the retaining pin102and the clearance104may help prevent the incomplete close from occurring. Orienting and positioning the retaining pin102generally toward the lower portion110as shown inFIGS. 10 and 12and with the clearance104may generate a reaction force F generally perpendicular to the lengthwise dimension of the retaining pin102. The reaction force F may, in cooperation with the resulting gas pressure against the valve member64, bring the upper portion108flush against the upper portion78. The reaction force F may cause flush contact between the first and second seating surfaces68,106without the need for additional torque from the actuator90.

FIG. 7is a graph showing the mass fluid-flow rate of the valve10in use, versus that of a conventional flap valve. As can be observed, the valve10has an improved resolution as compared to the flap valve. This may be desirable in some cases to avoid a relatively sudden rush of fluid-flow through the valve10and through the associated downstream components. It should be noted that the results ofFIG. 7are theoretical and that all experiments may not yield this exact data.

The above description of embodiments of the invention is merely exemplary in nature and, thus, variations thereof are not to be regarded as a departure from the spirit and scope of the invention.