Source: http://www.google.com/patents/US6412458?ie=ISO-8859-1
Timestamp: 2015-07-01 07:44:23
Document Index: 110792959

Matched Legal Cases: ['Application No. 11', 'Application No. 11', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09', 'application No. 09']

Patent US6412458 - Valve timing control for engine - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA control system controls an intake air quantity to an engine by controlling an intake valve closing timing, instead of, or in cooperation with, a throttle valve. A controller estimates a quantity of internal EGR gases remaining in a cylinder, and controls the intake valve closing timing to a desired...http://www.google.com/patents/US6412458?utm_source=gb-gplus-sharePatent US6412458 - Valve timing control for engineAdvanced Patent SearchPublication numberUS6412458 B2Publication typeGrantApplication numberUS 09/728,477Publication dateJul 2, 2002Filing dateDec 4, 2000Priority dateDec 3, 1999Fee statusLapsedAlso published asDE60031074D1, DE60031074T2, EP1104844A2, EP1104844A3, EP1104844B1, EP1707782A2, EP1707782A3, US20010011541Publication number09728477, 728477, US 6412458 B2, US 6412458B2, US-B2-6412458, US6412458 B2, US6412458B2InventorsTakao Kawasaki, Masahiro AraiOriginal AssigneeNissan Motor Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (3), Non-Patent Citations (14), Referenced by (11), Classifications (31), Legal Events (6) External Links: USPTO, USPTO Assignment, EspacenetValve timing control for engine
US 6412458 B2Abstract
A control system controls an intake air quantity to an engine by controlling an intake valve closing timing, instead of, or in cooperation with, a throttle valve. A controller estimates a quantity of internal EGR gases remaining in a cylinder, and controls the intake valve closing timing to a desired target timing determined in due consideration of the estimated internal EGR quantity. The estimated internal EGR quantity is a sum of a base quantity and an increase correction quantity determined in accordance with a valve overlap period, its middle angular position in crankshaft rotation and intake pressure. The target intake valve closing timing is determined in accordance with a target intake air quantity and the estimated internal EGR quantity.
What is claimed is: 1. A control apparatus for controlling an intake air quantity to the engine by varying an intake valve closing timing of the engine, the control apparatus comprising:
a controller configured to calculate a target air quantity in accordance with an engine operating state, to calculate an estimated internal EGR quantity of the engine in accordance with the engine operating state, to calculate a target intake valve closing timing in accordance with the target air quantity and the estimated internal EGR quantity, and to control an actual intake air quantity to the engine by controlling an actual intake valve closing timing of the engine to achieve the target intake valve closing timing. 2. The control apparatus as claimed in claim 1, wherein the control apparatus further comprises a variable valve timing actuator comprising a solenoid to vary the actual intake valve closing timing in response to an electric control signal produced by the controller, and a sensor system to sense engine operating conditions to determine the engine operating state.
3. The control apparatus as claimed in claim 1, wherein the controller is configured to calculate the estimated internal EGR quantity in accordance with a target exhaust valve closing timing for the engine and an engine speed of the engine.
4. The control apparatus as claimed in claim 3, wherein the controller is configured to calculate a base internal EGR quantity in accordance with the target exhaust valve closing timing and the engine speed, and to determine the estimated internal EGR quantity by modifying the base internal EGR quantity with an overlap correction quantity determined in accordance with a valve overlap condition of the engine.
5. The control apparatus as claimed in claim 4, wherein the controller is configured to determine a valve overlap quantity in accordance with an interval between a target intake valve opening timing and the target exhaust valve closing timing, and to determine the estimated internal EGR quantity by addition of the overlap correction quantity to the base internal EGR quantity.
6. The control apparatus as claimed in claim 5, wherein the controller is configured to increase the base internal EGR quantity with increase in an interval from one of an exhaust top dead center and the target exhaust valve closing timing to the other.
7. The control apparatus as claimed in claim 5, wherein the controller is configured to increase the base internal EGR quantity as the engine speed increases when the target exhaust valve closing timing is before an exhaust top dead center.
8. The control apparatus as claimed in claim 5, wherein the controller is configured to decrease the base internal EGR quantity as the engine speed increases when the target exhaust valve closing timing is after an exhaust top dead center.
9. The control apparatus as claimed in claim 5, wherein the controller is configured to increase the estimated internal EGR quantity by increasing the overlap correction quantity with increase in the valve overlap quantity representing a valve overlap period.
10. The control apparatus as claimed in claim 8, wherein the controller is configured to increase the estimated internal EGR quantity by increasing the overlap correction quantity with increase in an absolute value of an intake pressure on a negative pressure side.
11. The control apparatus as claimed in claim 8, wherein the controller is configured to calculate the overlap correction quantity by modifying a base correction quantity determined by the valve overlap quantity, with an intake pressure modification quantity determined in accordance with an intake pressure and the target exhaust valve closing timing.
12. The control apparatus as claimed in claim 11, wherein the controller is configured to determine the valve overlap quantity by converting a valve overlap angular interval expressed as an angular distance in crankshaft rotation to a valve overlap time period.
13. The control apparatus as claimed in claim 11, wherein the controller is configured to determine an intermediate quantity in accordance with the valve overlap quantity, to set the base correction quantity equal to the intermediate quantity when the target exhaust valve closing timing is before an exhaust top dead center, and to determine the base correction quantity by subtraction from the intermediate quantity, of a subtrahend proportional to a retard quantity of the exhaust valve closing timing with respect to the exhaust top dead center when the target exhaust valve closing timing is after the exhaust top dead center.
14. The control apparatus as claimed in claim 11, wherein the controller is configured to determine a modification coefficient, as the modification quantity, in accordance with the intake pressure, the target exhaust valve closing timing and the valve overlap quantity; and wherein the controller is configured to calculate the overlap correction quantity by multiplying the base correction quantity by the modification coefficient.
15. The control apparatus as claimed in claim 11, wherein the controller is configured to increase the modification quantity as an absolute value of the intake pressure increases on a negative side, and to increase the modification quantity in accordance with a retard quantity of the exhaust valve closing timing from an exhaust top dead center when the exhaust valve closing timing is after the exhaust top dead center and the absolute value of the intake pressure is higher than a predetermined level.
16. The control apparatus as claimed in claim 5, wherein the controller is configured to calculate the estimated internal EGR quantity by decreasing the overlap correction quantity with increase in a retard of the target exhaust valve closing timing from an exhaust top dead center when the target exhaust valve closing timing is after the exhaust top dead center.
17. The control apparatus as claimed in claim 5, wherein the controller is programmed to determine the estimated internal EGR quantity by addition, to the base internal EGR quantity, of an overlap increase correction quantity which is increased as the valve overlap quantity increases; and wherein the controller is programmed to modify the base internal EGR quantity with the overlap increase correction quantity when the target exhaust valve closing timing is after the target intake valve opening timing, and to set the estimated internal EGR quantity equal to the base internal EGR quantity when the target exhaust valve closing timing is not after the target intake valve opening timing.
18. The control apparatus as claimed in claim 17, wherein the controller is programmed to increase the base internal EGR quantity with increase in an advance of the exhaust valve closing timing from the exhaust top dead center when the exhaust valve closing timing is before the exhaust top dead center, and to increase the base internal EGR quantity with increase in a retard of the exhaust valve closing timing from the exhaust top dead center when the exhaust valve closing timing is after the exhaust top dead center; and wherein the controller is programmed to determine the overlap increase correction quantity in accordance with the valve overlap quantity, the target exhaust valve closing timing and an intake pressure controlled by a throttle valve.
19. A control apparatus for controlling an intake air quantity to an engine by controlling an intake valve closing timing of the engine, the control apparatus comprising:
means for determining an estimated internal EGR quantity in accordance with an engine operating state; means for determining a target intake valve closing timing in accordance with at least the estimate internal EGR quantity; and means for controlling the intake air quantity to the engine by controlling an actual intake valve closing timing of the engine to the target intake valve closing timing. 20. A control process for varying valve timings of intake and exhaust valves of an engine, the control process comprising:
estimating an internal EGR quantity in accordance with an engine operating state; and controlling an intake valve closing timing in accordance with a required intake air quantity and the internal EGR quantity.
It is, therefore, an object of the present invention to provide control apparatus and/or method capable of controlling the intake valve closing timing accurately and thereby controlling the intake air quantity and hence engine torque adequately.
According to the present invention, a control apparatus for controlling an intake air quantity to the engine by varying an intake valve closing timing of the engine comprises a controller that is configured or programmed:
FIG. 1 is a schematic view showing an engine provided with a variable valve timing actuator and a control unit according to one embodiment of the present invention.
FIG. 3 is a flowchart showing a routine for setting an intake valve closing timing according to the embodiment.
FIG. 4 is a flowchart showing a subroutine for determining a base internal EGR quantity in a non-overlap state according to the embodiment.
OLTIME=(EVC−IVO)/Ne Then, at step S35, control unit 10 determines an intermediate quantity OLEGC0 from valve overlap time OLTIME by lookup from a map table. Thus, step 35 determines a value of quantity (intermediate quantity) OLEGC0 corresponding to the current value of valve overlap time OLTIME.
Wh65 to step S38, and determines base overlap (increase) correction quantity OLEGR0 by modifying the obtained value of OLEGC0 in accordance with target closing timing EVC by the following equation.
OLEGR0=OLEGC0−EVC(retard quantity after TDC)�constant The variation quantity (or increase quantity) of the internal EGR between the base internal EGR quantity in the non-overlap state and the internal EGR quantity in the valve overlap state varies, even for the same valve overlap quantity (or time), since the influence of back-flow differs in dependence on exhaust valve closing timing EVC. FIG. 8 shows variation of the increase quantity of the internal EGR quantity with respect to EVC for different values of the overlap quantity (time) on the condition that engine speed Ne is constant and the intake pressure is constant.
Step S41 reads the target intake pressure calculated by the above-mentioned intake pressure control process of controlling the intake pressure by controlling the throttle opening degree. Step S42 reads target closing timing EVC of exhaust valve 6. In accordance with the values of these input quantities, step S43 obtains a value of intake pressure modification coefficient OLEGCB by lookup from a map table prepared on the basis of characteristic data, as shown in FIG. 9. FIG. 9 shows a magnification (or multiplying factor) which is a ratio of the internal EGR increase quantity under the condition of intake pressure (negative pressure) being equal to −100 mmHg or −300 mmHg to the internal EGR increase quantity under the condition of intake pressure being equal to −50 mmHg. For each of the intake pressure conditions of −100 mmHg and −300 mmHg, there are shown two characteristic lines in the two cases of overlap quantity (crank angle) being equal 20� and 40�. As shown in FIG. 9, at an intake pressure of −100 mmHg, the magnification remains constant at about 2 irrespective of variation in EVC (the middle of the valve overlap period). At an intake pressure of −300 mmHg, on the other hand, the magnification is held constant at about 3˜4 when EVC is before TDC, and the magnification is increased linearly with increase in the extent of separation of EVC from TDC when EVC is after TDC. When EVC is after TDC at a constant intake pressure (−50 mmHg), as mentioned before, the pressure difference in the cylinder due to the existence and nonexistence of a valve overlap becomes smaller as EVC is shifted away from TDC, so that the increase quantity of the exhaust back-flow quantity tends to decrease. However, when the intake negative pressure increases to −300 mmHg, the pressure difference in the cylinder due to the existence and nonexistence of a valve overlap becomes greater, so that the increase quantity is held at a larger level, and hence the magnification is increased as compared to the example of −50 mmHg.
Thus, the control system of this example increases the modification quantity OLEGCB as an absolute value of the intake pressure increases on the negative side, and increases the modification quantity OLEGCB in accordance with the retard quantity or angle of the exhaust valve closing timing EVC from the exhaust top dead center when the exhaust valve closing timing EVC is after the exhaust top dead center and the absolute value of the intake pressure is higher than a predetermined level.
Reverting to FIG. 3, step S7 calculates a final overlap correction quantity OLEGR1 by multiplying base correction quantity OLEGR0 calculated at step S5 by intake pressure modification coefficient OLEGCB calculated at step S6 (OLEGR1=OLEGR0�OLEGCB).
EGRREM=EVEGR0+OLEGR1
HQH0FM=FQH0EM�(1+EGRREM)
In the illustrated embodiment, engine 1 is a prime mover of a motor vehicle, and control unit 10 includes, as a main component, at least one onboard computer.
This application is based on a Japanese Patent Application No. 11-344216. The entire contents of this Japanese Patent Application No. 11-344216 with a filing date of Dec. 3, 1999 are hereby incorporated by reference.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS6178934Nov 4, 1999Jan 30, 2001Nissan Motor Co., Ltd.System and method for controlling internal combustion engineUS6189512 *Sep 7, 1999Feb 20, 2001Nissan Motor Co., Ltd.Variable valve timing engineJPH1037727A Title not available* Cited by examinerNon-Patent CitationsReference1U.S. application No. 09/442,031, filed Nov. 17, 1999, Arai et al.2U.S. application No. 09/634,008, filed Aug. 7, 2000, Hirasawa et al.3U.S. application No. 09/634,880, filed Aug. 7, 2000, Hirasawa et al.4U.S. application No. 09/635,685, filed Aug. 10, 2000, Toriumi.5U.S. application No. 09/686,992, filed Oct. 11, 2000, Arai et al.6U.S. application No. 09/725,710, filed Nov. 30, 2000, Kawasaki et al.7U.S. application No. 09/727,552, filed Dec. 4, 2000, Arai et al.8U.S. application No. 09/727,554, filed Dec. 4, 2000, Arai et al.9U.S. application No. 09/727,787, filed Dec. 4, 2000, Kawasaki et al.10U.S. application No. 09/727,789, filed Dec. 4, 2000, Arai et al.11U.S. application No. 09/727,790, filed Dec. 4, 2000, Kawasaki et al.12U.S. application No. 09/734,611, filed Dec. 13, 2000, Arai et al.13U.S. application No. 09/736,576, filed Dec. 15, 2000, Hori et al.14U.S. application No. 09/764,071, filed Jan. 19, 2001, Toriumi.Referenced byCiting PatentFiling datePublication dateApplicantTitleUS6755182 *Apr 16, 2003Jun 29, 2004Ford Global Technologies, LlcAdaptive control for engine with electronically adjustable valve operationUS6840235 *Jul 21, 2003Jan 11, 2005Nissan Motor Co., Ltd.Internal exhaust gas recirculation amount estimation system of internal combustion enginesUS6915790 *Jan 24, 2003Jul 12, 2005Daimlerchrysler AgPiston engine and associated operating processUS6959692Apr 15, 2003Nov 1, 2005Ford Global Technologies, LlcComputer controlled engine valve operationUS6999864 *Jul 14, 2003Feb 14, 2006Hitachi, Ltd.Apparatus and method for estimating residual gas amount of internal combustion engine, and apparatus and method for controlling intake air amount of internal combustion engine using estimated residual gas amountUS7021298 *Feb 28, 2005Apr 4, 2006Nissan Motor Co., Ltd.Internal EGR parameter estimating device for internal combustion engineUS7143753 *Apr 21, 2005Dec 5, 2006Denso CorporationAir amount calculator for internal combustion engineUS7219004May 27, 2004May 15, 2007Ford Global Technologies, LlcAdaptive control for engine with electronically adjustable valve operationUS7559304 *Jun 10, 2005Jul 14, 2009Toyota Jidosha Kabushiki KaishaControl device and control method for stopping and starting an internal combustion engineUS20110174248 *Jan 14, 2011Jul 21, 2011Guillaume BressionResidual burnt gas scavenging method in a direct-injection supercharged internal-combustion multi-cylinder engineCN1317502C *Feb 17, 2004May 23, 2007丰田自动车株式会社Internal combustion engine internal EGR volume constructing apparatus and method* Cited by examinerClassifications U.S. Classification123/90.15, 123/348, 123/568.14International ClassificationF02M25/07, F01L9/04, F02D37/02, F02D41/00, F02D13/02Cooperative ClassificationF02D2041/002, F02D41/0062, Y02T10/18, F02D13/0253, F01L9/04, F02D2013/0292, F02D41/0002, F02D37/02, F02D2200/0406, F02M25/0752, F02D13/0261, F02D13/0215, F02D2041/001, Y02T10/47, Y02T10/42European ClassificationF01L9/04, F02D13/02H, F02D13/02L, F02D41/00D, F02D37/02, F02D13/02A4, F02M25/07R, F02D41/00F6D2Legal EventsDateCodeEventDescriptionMar 16, 2001ASAssignmentOwner name: NISSAN MOTOR CO., LTD., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KAWASAKI, TAKAO;ARAI, MASAHIRO;REEL/FRAME:011594/0993;SIGNING DATES FROM 20010120 TO 20010123Owner name: NISSAN MOTOR CO., LTD. 2, TAKARA-CHO, KANAGAWA-KU,Owner name: NISSAN MOTOR CO., LTD. 2, TAKARA-CHO, KANAGAWA-KU,Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KAWASAKI, TAKAO;ARAI, MASAHIRO;REEL/FRAME:011594/0993;SIGNING DATES FROM 20010120 TO 20010123Owner name: NISSAN MOTOR CO., LTD. 2, TAKARA-CHO, KANAGAWA-KU,Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KAWASAKI, TAKAO /AR;REEL/FRAME:011594/0993;SIGNING DATESFROM 20010120 TO 20010123Dec 9, 2005FPAYFee paymentYear of fee payment: 4Dec 2, 2009FPAYFee paymentYear of fee payment: 8Feb 7, 2014REMIMaintenance fee reminder mailedJul 2, 2014LAPSLapse for failure to pay maintenance feesAug 19, 2014FPExpired due to failure to pay maintenance feeEffective date: 20140702RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services