`Oleksiewicz
`
`I IIIII IIIIIIII Ill lllll lllll lllll lllll lllll lllll lllll lllll 111111111111111111
`US006006732A
`6,006,732
`[11] Patent Number:
`[45] Date of Patent:
`Dec. 28, 1999
`
`[54]
`
`BAIANCED FLOW EGR CONTROL
`APPARATUS
`
`[75]
`
`Inventor: Radek A. Oleksiewicz, Riverwoods, Ill.
`
`[73]
`
`Assignee: Navistar International Transportation
`Corp, Chicago, Ill.
`
`[21]
`
`Appl. No.: 09/145,874
`
`[22]
`
`Filed:
`
`Sep. 3, 1998
`
`[51]
`[52]
`
`[58]
`
`[56]
`
`..................................................... F02M 25/07
`Int. Cl.6
`U.S. Cl . ................................... 123/568.2; 123/568.11;
`123/568.23
`Field of Search .......................... 123/568.11, 568.18,
`123/568.2, 568.21, 568.19, 568.23, 568.24,
`568.26
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`2,014,968
`2,717,003
`3,530,843
`3,884,268
`4,142,492
`4,350,013
`4,506,633
`5,388,613
`5,562,086
`5,762,051
`
`9/1935 Hughes .
`9/1955 Jay et al. .
`9/1970 Fessenden .......................... 123/568.11
`5/1975 Wagner et al. .
`3/1979 Kobayashi et al. ................ 123/568.11
`9/1982 Yoshiba ................................ 123/568.2
`3/1985 Britsch ............................... 123/568.11
`2/1995 Kruger.
`10/1996 Asada et al. ....................... 123/568.21
`6/1998 Okamoto .............................. 123/568.2
`
`5,911,681
`
`6/1999 Tanaka et al. ..................... 123/568.21
`
`Primary Examiner-Willis R. Wolfe
`A.ttorney, A.gent, or Firm-Dennis K. Sullivan; Jeffrey P.
`Calfa
`[57]
`
`ABSTRACT
`
`An internal combustion engine of the V-type configuration
`includes a balanced flow EGR control apparatus having a
`valve comprising a stem having two linearly aligned, sub(cid:173)
`stantially similarly plug valve bodies engaged thereto with a
`predetermined distance therebetween. The valve housing
`has separate ports for receiving exhaust flow from each
`cylinder bank and a common outlet passageway communi(cid:173)
`cating with the intake manifold, the ports being in linear
`alignment. One valve body is disposed to plug the exhaust
`port from the exhaust port side while the other valve body
`plugs the other exhaust port from the intake outlet side. Each
`valve body is configured, sized and positioned over a
`respective port in a manner where pressure of flow against
`one valve body effectively cancels out the pressure of flow
`against the other valve body, producing a valve that is easily
`maintained in an appropriate seated position thereof and
`opened with minimum force. The apparatus is disclosed in
`two embodiments, one of which accommodates rotary
`actuation and another of which accommodates linear
`actuation, with each embodiment being operable under
`control of an engine ECU in response to readings of opera(cid:173)
`tional parameters of the engine.
`
`16 Claims, 1 Drawing Sheet
`
`10~
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`15
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`"Jlt---30
`--32
`~-34
`36
`
`
`
`U.S. Patent
`
`Dec. 28, 1999
`
`6,006,732
`
`FIG. 1
`
`1 0~
`
`15
`
`FIG. 2 c::::3'-
`52
`L0-55
`
`100
`
`FIG. 3
`108
`
`40 1
`1,.110
`
`-----
`
`54
`
`11 72
`
`~--
`
`.
`
`----- ------.
`
`64~
`
`(_62
`
`102
`
`53
`
`
`
`6,006,732
`
`1
`BAIANCED FLOW EGR CONTROL
`APPARATUS
`BACKGROUND OF THE INVENTION
`The present invention relates to internal combustion
`engines, particularly engines of the V-type having two banks
`of cylinders, and more particularly to a controllable porting
`apparatus for an exhaust gas recirculation (EGR) system for
`an engine where there are two sources of pressurized flow,
`one from each bank, merging into one outflow stream to the
`intake manifold wherein the porting apparatus includes a 10
`valve of such configuration that the force of the pressurized
`flow from one bank acting upon one surface thereof effec(cid:173)
`tively cancels out the opposed force of the pressurized flow
`from the other bank acting upon an opposing surface thereof.
`
`THE PRIOR ART
`Although balanced valve arrangements per se are known,
`for example, in U.S. Pat. Nos. 2,014,968; 2,717,003; 3,884,
`268; and 5,338,613, it is not known to incorporate such
`arrangements in internal combustion engines or in EGR 20
`systems, to produce a valve structure requiring decreased
`force to maintain same closed or to open same, while at the
`same time balancing the flow from both banks in response
`to control signals from an ECU of the engine and maintain(cid:173)
`ing the engine at an optimal level of performance.
`
`15
`
`2
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`Referring now to the dra,vings in greater detail, there is
`illustrated in FIG. 1 a schematically exemplary embodiment
`5 of a turbocharged internal combustion engine 16 having an
`exhaust gas recirculation system generally identified by the
`reference numeral 10. The engine 16 is of V-type configu(cid:173)
`ration having left and right banks of cylinders 11, 13.
`Typically, pressurized air from a compressor 12 of a
`turbocharger 14 enters a common intake manifold 15 feed(cid:173)
`ing into both banks of the engine 16 where air mixes with
`fuel which, when compressed by piston action, undergoes
`combustion, with chemical remnants of combustion, such as
`NOx, being carried away from the engine 16 via an exhaust
`manifold 22 of the engine 16 disposed on each bank 11, 13,
`the exhaust manifolds 22 feeding first and second passages
`18 and 20, respectively, connected to a turbine 24 of the
`turbocharger 14 which drivingly engages the compressor 12
`thereof.
`To remove the NOx from the engine exhaust gas, such
`exhaust gas is preferably recirculated back through EGR
`valve 40 and passage 17 into the intake manifold 15, directly
`or indirectly, and is reburned, the instantaneous amount of
`25 exhaust gas capable of being accommodated for recircula(cid:173)
`tion without compromising optimal engine 16 performance
`being dependent upon operational parameters of the engine
`16 monitored by an ECU 25 thereof. In this respect, if there
`is an excessive amount of exhaust gas being recirculated into
`30 the intake manifold 15, it will cause the engine 16 to operate
`at a level of performance which is less than optimal, as well
`as potentially causing damage thereto.
`Consequently, the amount of exhaust gas to be recircu(cid:173)
`lated (level of recirculation) is controlled by the ECU 25 in
`35 response to sensed operational parameters of the engine 16
`as compared to those required for optimal engine 16 per(cid:173)
`formance. The ECU 25 analyzes readings received from
`various engine sensors, compares the readings to parameter
`values stored in a memory 26 thereof which are predeter-
`40 mined to produce optimal engine 16 performance and causes
`necessary actions in various devices controlled thereby to
`maintain the engine 16 at an optimal level of performance.
`Specific sensors which could be used in establishing appro(cid:173)
`priate control of exhaust gas recirculation could be, as an
`45 example, one or more of an intake manifold temperature
`sensor 30, a mass air flow sensor 32, an engine speed sensor
`34 and a pedal position sensor 36.
`Turning now to FIG. 2, there is illustrated therein a first
`embodiment of a balanced flow EGR control valve assembly
`50 40 made in accordance with the teachings of the present
`invention.
`As will be understood, this embodiment incorporates a
`valve 50 which is adapted for use with a linear actuator 52,
`such as a solenoid 52. As illustrated, there is a valve housing
`55 53 having two separate inlets for pressurized exhaust, such
`as the first and second passages 18 and 20 of the two engine
`banks 11,13, and a single outlet port connected to passage 17
`connected to the engine intake manifold 15. In a preferred
`embodiment, the single outlet passage 17 is sandwiched
`60 between passage 18 and 20 sharing common walls there(cid:173)
`with.
`The valve 50 includes an elongate main stem 54 disposed
`in the housing 53 which engages the linear actuator 52 at a
`proximal end 56 thereof. At a distal end 58 thereof, a first
`valve body 60, preferably in the form of a hollow inverted
`cone, is disposed on the stem and engages within a corre(cid:173)
`sponding first inlet port 62 created in a housing wall 64
`
`SUMMARY OF THE INVENTION
`Accordingly, it is a primary object of the invention to
`provide an EGR flow control apparatus for an internal
`combustion engine which includes a valve that is balanced
`by its configuration to effectively cause cancellation of the
`forces resulting from two separate and opposing sources of
`pressurized flow acting thereupon while also balancing the
`controlled level of flow from the cylinder banks.
`This object, as well as others which may become more
`apparent hereinafter, is specifically met by the EGR porting
`apparatus of the present invention which includes an internal
`combustion engine of the V-type having two banks of
`cylinders, each bank having a source of exhaust flow which
`engages a respective inlet port in a valve housing having a
`common outlet connected to an intake manifold, and a valve
`having a pair of valve bodies which are linearly aligned and
`engaged upon a single stem, one of which closes an inlet port
`from the exhaust side and the other of which closes the inlet
`port from the intake manifold side so that pressure in the first
`path of exhaust flow acting upon the valve effectively
`cancels out an equal and opposite pressure in the second path
`of exhaust flow acting upon the valve, thereby resulting in
`the valve being easily opened or closed, as well as balancing
`flow from the banks into the common destination in
`response to signals from an ECU, the flow being controlled
`by the ECU so as not to compromise optimal engine
`performance. Preferably, one valve body is slightly larger
`than the other to produce a small pressure bias to close the
`valve.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a simplified diagram of an exemplary exhaust
`bas recirculation system of engine of V-type configuration
`incorporating the balanced flow EGR control apparatus and
`valve of the present invention.
`FIG. 2 is a cross sectional view through a linearly actuated
`embodiment of the valve of the present invention.
`FIG. 3 is a cross sectional view through a second embodi(cid:173)
`ment of the valve of the present invention, this embodiment 65
`being more suitable for use where rotary actuation is
`required.
`
`
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`6,006,732
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`3
`common to the second bank passage 20 and the single
`outflow passage 17 connecting to the intake manifold 15,
`with a tip portion 66 of the valve body 60 extending into the
`passage 20.
`A second substantially similar valve body 70 is disposed 5
`in fixed position on the stem 54 at a position which will
`ensure secure seating of the second valve body 70 within a
`second inlet port 72 created in a wall 74 common to the first
`bank passage 18 and the single outlet path 17. To secure
`simultaneous engagement of the first valve body 60, the 10
`distance between the entrance wall to port 72 and the
`entrance wall to port 62 must be taken into careful consid(cid:173)
`eration. In this respect, when the ports 62 and 72 and valve
`bodies 60 and 70 are of identical size, the distance between
`identical points on each valve body 60 and 70 should equal 15
`the dimension X.
`However, as shown herein, it may be desirable to provide
`valve bodies 60, and 70, and/or ports 62, and 72 which are
`of dissimilar size, or to accommodate thermal expansion or
`tolerance variations in the parts. In such a situation, it is
`contemplated to slidingly dispose the first valve body 60 on
`the distal end 58 or, alternatively, to engage the first valve
`body 60 at a free end 76 of a telescoping terminal stem
`portion 78 (substituting for distal end 58 of main stem 54)
`,vhile securing the second valve body 70 directly onto the 25
`main stem 54, a biasing spring 80 being disposed either
`between the valve bodies 60, 70 or between the telescoping
`terminal stem portion 78 and the main stem 54 from within
`which the terminal stem portion 78 extends, the spring 80
`biasing the first valve body 60 into the corresponding port 30
`62, regardless of the size of the port 62 (obviously not of an
`extent greater than that of the valve body 60), by over(cid:173)
`accommodating slightly for the dimension X. It will be
`understood that a length of the telescoping stem portion 78
`must be limited so as not to interfere with opening of the 35
`valve port 62 engaged by the first valve body 60 when the
`main valve stem 54 is retracted by the associated actuator
`52.
`In the embodiment disclosed, the port 62 engaging the
`first valve body 60 is shown as being of a diameter less than
`a diameter of the second port 72 and its corresponding valve
`body 70, such smaller first valve body 60 easing passage
`thereof through the larger diameter second port 72 during
`installation of the valve 50 into the EGR apparatus 40.
`Turning now to the aspect of the valve 50 being balanced,
`it will first be understood that the air pressure against an
`open end or inner surface 82 of the second valve body 70
`produces a force that assures a sealing engagement of the
`second valve body 70 within the corresponding port 72.
`This force is translated down the length of the terminal
`stem portion 58, 78 and, by virtue of the biasing spring 80,
`also ensuring a sealing engagement of the first valve body 60
`within the corresponding port 62.
`Further, because pressure is applied against the smaller 55
`outer surface area 66 defining a tip 66 of the first valve body
`60, this pressure ,vill necessarily be at least overcome by the
`pressure applied against the larger area of the inner surface
`82 of the second valve body 70, biasing the valve 50 to be
`appropriately seated. Further, even if the biasing spring 80 60
`were not incorporated in the telescoping stem configuration,
`pres'Sure applied against the tip 66 of the first valve body 60
`will be compensated for by the pressure applied against the
`inner surface 82 of the second valve body 70, the valve 50
`thus remaining balanced between the opposing forces acting 65
`thereupon. Since the exhaust pressure forces offset, a small
`amount of force equal to the difference between the force on
`
`4
`surface 82 and the force on the outer surface 66 is all that is
`required of actuator 52 to open the valve 50 when com(cid:173)
`manded to do so by the ECU 25.
`Turning now to FIG. 3, there is illustrated therein a second
`embodiment of the apparatus 40 wherein a balanced valve
`10 thereof, also made in accordance with the teachings
`herein, is particularly suited for use in an environment
`requiring rotary actuation of the valve 100.
`In this embodiment, first and second valve bodies 102 and
`104, respectively are configured to define plate-like mem(cid:173)
`bers which seat across and seal a corresponding ports 62 and
`72, with a separation therebetween again equal to the
`distance X and a similar telescoping stem, v,rith or without
`a biasing spring, to the embodiment of FIG. 2 being
`employed. The valve stem 54 here, however, incorporates a
`terminal arm 106 extending radially outwardly from a
`proximal end 108 of the stem 54, the arm 106 terminating in
`a rotary connector 108 such as a shaft 108, allowing for
`engagement of the valve stem 54 to an appropriate rotary
`20 actuator 110.
`The rotary force of the actuator 110 applied to the
`connector 108, at the end 108 of the terminal arm 106,
`produces a vertical pivoting of the arm 106 about the
`connector 108 with the stem 54 attached to the arm 106
`pivoting out of closure of the ports 62 and 72, with the
`maintained alignment between the valve bodies 102 and 104
`causing their disengagement from their seated positions
`across the respective ports 62 and 72.
`With respect to being a balanced valve 100, it will again
`be understood that opposing forces exerted upon opposed
`surfaces of the plate-like valve bodies 102 and 104 negate
`one another, thereby providing a valve 100. Further, flow
`through the ports 62 and 72 is also balanced, with rotary
`action of the valve 50 as described above, causing an equal
`unseating of the valve bodies 102 and 104, producing an
`equalized flow through the ports 62 and 72.
`The ports 62 and 72 need not be only fully open or closed,
`with a desired level of exhaust gas recirculation being
`40 produced by the ECU 25 in a manner predefined to allow a
`maximum instantaneous level of recirculation based on the
`sensed operating parameters of engine 16 without compris(cid:173)
`ing optimal performance of the engine.
`As described above the balanced flow EGR control appa-
`45 ratus of the present invention provides a number of
`advantages, some of which have been described above and
`others of which are inherent in the invention. Also, modi(cid:173)
`fications may be proposed to the apparatus without departing
`from the teachings herein. Accordingly the scope of the
`50 invention is only to be limited as necessitated by the
`accompanying claims.
`What is claimed is:
`1. An internal combustion engine comprising:
`a plurality of cylinder banks, each bank having an exhaust
`manifold and an associated exhaust passage fluidly
`separated from an exhaust passage of another bank, and
`an intake manifold shared with the other bank;
`an exhaust gas recirculation valve apparatus comprising a
`housing having separate exhaust inlet ports connected
`exclusively respectively to each of said banks and a
`single outlet port communicating with the intake
`manifold, and a valve member including a linear valve
`stem upon which two plug valve bodies are mounted,
`each at a predetermined position there along so that
`each effectively seal'S one of said inlet ports from said
`outlet port, one of said valve bodies sealing said one
`inlet port from the inlet port side and the other of said
`
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`6,006,732
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`valve bodies sealing the other of said inlet ports from
`the outlet port side, the valve stem being functionally
`engaged to an actuator;
`and an engine ECU operatively associated with said
`actuator to cause the valve stem to unseat the valve 5
`bodies to open the inlet ports in a predetermined
`manner based on readings of operational parameters of
`the engine being monitored by the ECU.
`2. The engine of claim 1 wherein the ports are not
`identically sized.
`3. The engine of claim 2 wherein the valve bodies are not
`identically sized.
`4. The engine of claim 3 wherein each valve body is sized
`sealingly engaged within a cooperating port.
`5. The engine of claim 1 wherein the ports are linearly 15
`aligned and have entrances thereto separated from each
`other a specific distance.
`6. The engine of claim 5 wherein the bodies of the valve
`are also separated from each other by the specific distance.
`7. The engine of claim 6 wherein exhaust pressure forces 20
`from each engine bank act upon the respective valve body in
`a substantially similar, opposed manner, effectively cancel(cid:173)
`ing each other and maintaining the valve seated.
`8. The engine of claim 7 wherein each valve body is
`configured in the form of a plate.
`
`10
`
`6
`9. The engine of claim 8 wherein the valve stem is suited
`to rotary actuation.
`10. The engine of claim 9 wherein the valve stem pivots
`out of alignment with the ports producing a balanced pivotal
`unseating of the valve bodies.
`11. The engine of claim 2 wherein the valve stem incor(cid:173)
`porates a telescoping terminal section of predefined length
`extending outwardly of a main section thereof, with one
`valve body being suitably engaged to a free end of the
`telescoping terminal section and with another valve body
`being securely engaged to the main section.
`12. The engine of claim 11 wherein said predefined length
`of said telescoping section of said valve stem is at least equal
`to the specific distance.
`13. The engine of claim 12 wherein said predefined length
`is slightly greater than the specific distance.
`14. The engine of claim 13 wherein a spring is engaged to
`and between said main section and said telescoping section
`of the valve stem, the spring biasing the telescoping section
`outwardly of the main section.
`15. The engine of claim 14 wherein each valve body is
`configured in the form of an inverted hollow cone.
`16. The engine of claim 14 wherein the valve stem is
`suited to linear actuation.
`
`* * * * *
`
`