5655365
`__...._~~-PATENT-DATE-~P.~ATEN~T ~ IIQII~IIIl
`
`NUMBER
`
`~zs·~
`DAVID R. WORTH, SHENTON PARK, AUSTRALIA; STEPHEN J. WATSON, GREENWOOD,
`~AUSTRALIA: JORGE M.P. DA SILVA, NORTH BEACH, AU.TRALIA.
`
`GR9~~ f~ UNIT
`·- "+ .......
`
`EXAMINER
`
`SERIAL NUMBER
`en:::/ 446 ,, 739
`
`AUG
`I 2 1997
`yQ ~ U
`__ ,I:.IL!NG_DATE C1~~
`Ubi U6/'':15
`
`SUBCLASS
`
`**CONTINUINGi [:o(..ff(-~*********************
`VERIFIED
`THIS APPLN IS A 371 OF
`... _ .. _,.lha ......
`
`.. /r
`PCT/AU94/00028 01/24/94 ~
`
`**FOREIGN/PCT APPLICATIONS************
`VERIFIED
`AUSTRALIA
`PL 6972
`
`01 /2!.:i/9:3
`
`.......... -~~
`
`Foreign priority claimed
`35 usc 119 conditions met
`
`I 655 15TH STREET NW
`
`~ SUITE 330 - G STREET LOBBY
`WASHINGTON DC 20005-5701
`
`ocr 14 1997
`8f COllECTION
`
`AS
`FILED
`
`sT,; OR SHEETS
`COUNTRY DRWGS.
`AUX
`1
`OR~~M
`
`TOTAL
`CLAIMS
`19
`
`INDEP.
`FlUNG FEE
`CLAIMS RECEIVED
`$·~=1::::0. oo
`1
`
`ATTORNEY'S
`DOCKET NO.
`P80 17--E\009
`
`METHOD OF OPERATING AN INTERNAL COMBUSTION ENGINE
`
`U.S. DEPT. OF COMM./ PAT. & TM-PT0-4361. (Rev.12-94)
`
`Assistant Examiner
`
`ISSUE
`BATCH
`Examiner NUMBER
`
`WARNING: The information disclosed herein may be restricted,....l:11lalJtholrized disclosure may be prohibited
`and 368. Possession outside the U.S.
`by the United States Code litle 35,
`Patent & Trademark Office is restricted
`employees and contractors only.
`
`(FACE)
`
`BOSCH-DAIMLER EXHIBIT 1012
`
`Page 1 of 135
`
`

`

`~------~~ -
`
`•··
`
`',
`
`Date
`Entered
`or
`Counted
`
`PATENT :APPL !GAT I ON
`llllllllllllllllllllllllllllllllllllllllllllllllll
`08446739
`
`- f)) 17(.) /~ ( ., ;'} (( ...
`7Jt.l7 1; (joc~_·?-G
`
`APPROVED FOR LICENSE
`[
`!JUL 1 1 II ~
`
`INITIALS
`
`\I
`
`1. Application
`papers.
`------~2·~~------~--------
`~----~ 3.~~~~~~--------
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`.......___~::;:;..£._ 5.
`~oJ/~1-1
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`'
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`
`-~:::;__ : 1:;d;1!:±:~)
`
`________ 9.
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`:CDA
`--~-10. ~~-----flll!l!!=--......--
`
`'?J~'f$6~
`I
`ilml'-'111
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`
`___ ...,;,._16 . ......___ ____________ __.::;;,_
`
`Yj2-•/q1
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`_______ 17. - - - - - - - - . - - - - - -
`
`~---18. - - - - - - - - - - - - - (cid:173)
`~--------19. - - - - - - - - - - (cid:173)
`____ 20. ------~---
`
`_______ 21. - - - - - - - - - -
`--------~·-------------­
`_______ 23. - - - - - - - - - - -
`
`-------- ---------------
`
`____ 25. ___ _.;..._--o:....-___ - - - -
`
`24 •.
`
`_____ 26. - - - - - - - - - - - (cid:173)
`
`_ ____ 27. - - - - - - - - - - - -
`1 - - - - -28 . ___ _ _..;.,_ ____ _ _
`
`29.
`~---- -----~---------
`____ 30. - - - - - - -_ , . , . . . . - - -
`
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`_____ 32. ---~...,..;.-----~-_~--._·,-....,,;,.;,..· -
`/
`
`(FRONTf
`
`Page 2 of 135
`
`

`

`PATENT APPLICATION SERIAL NO. 0 8/ ·4 <i 6 7 s Q
`
`U.S. DEPARTMENT OF COMMERCE
`PATENT AND TRADEMARK OFFICE
`FEE RECORD SHEET
`
`PT0-1556
`(5/87)
`
`Page 3 of 135
`
`

`

`BAR CODE LABEL
`
`llllllllllllllllllllllllllllllllllllllllllllllllll
`
`U.S. PATENT APPLICATION
`
`SERIAL NUMBER
`
`FILING DATE
`
`CLASS
`
`GROUP ART UNIT
`
`08/446,739
`
`06/06/95
`
`123
`
`3402
`
`DAVID R. WORTH, SHENTON PARK, AUSTRALIA; STEPHEN J. WATSON, GREENWOOD,
`AUSTRALIA; JORGE M.P. DA SILVA, NORTH BEACH, AUSTRALIA.
`
`**CONTINUING DATA*********************
`VERIFIED
`THIS APPLN IS A 371 OF
`
`PCT/AU94/00028 01/24/94
`
`**FOREIGN/PCT APPLICATIONS************
`VERIFIED
`AUSTRALIA
`PL 6972
`
`01/25/93
`
`STATE OR
`COUNTRY
`
`SHEETS
`DRAWING
`
`TOTAL
`CLAIMS
`
`INDEPENDENT
`CLAIMS
`
`FILING FEE
`RECEIVED
`
`ATTORNEY DOCKET NO.
`
`AUX
`
`1
`
`19
`
`1
`
`$980.00
`
`P8017-5009
`
`NIKAIDO MARMELSTEIN MURRAY & ORAM
`METROPOLITAN SQUARE
`655 15TH STREET NW
`SUITE 330 - G STREET LOBBY
`, WASHINGTON DC 20005-5701
`
`METHOD OF OPERATING AN INTERNAL COMBUSTION ENGINE
`
`This is to certify that annexed hereto is a true copy from the records of the United States
`Patent and Trademark Office of the application whrch is identified above.
`By authority of the
`COMMISSIONER OF PATENTS AND TRADEMARKS
`
`Date
`
`Certifying Officer
`
`Page 4 of 135
`
`

`

`lfftec'd PCT/PTO
`
`_0,6 JUN 1995'
`
`08/446790
`
`FORM PT0·1390
`(REV 5·93)
`
`U.S. DEPARTMENT OF COMMERCE
`PATENT AND TRADEMARK OFFICE
`
`ATTORNEY DOCKET NO.
`P8017·5009
`
`TRANSMITTAL LETTER TO THE UNITED STATES
`DESIGNATED/ELECTED OFFICE CDO/EO/US)
`CONCERNING A FILING UNDER 35 U.S.C. 371
`
`INTERNATIONAL APPLICATION NO.
`PCT/AU94/00028
`
`I INTERNATIONAL FILING DATE
`
`24 JANUARY 1994
`
`DATE: June 6, 1995
`
`U.S. APPLN. NO.
`(IF KNOWN, SEE 37 CFR 1.5)
`oEJ'ILft, _739
`,
`PRIO;ITY DATE ~IMED
`25 JANUARY 1993
`
`TITLE OF INVENTION: David Richard WORTH Stephen James WATSON, Jorge Manuel Pereira DA SILVA
`
`APPLICANT(S) FOR DO/EO/US: METHOD OF OPERATING AN INTERNAL COMBUSTION ENGINE
`
`1. XX This is a FIRST submission of items concerning a filing under 35 U.S.C. 371.
`(THE BASIC FILING FEE IS ATTACHED)
`2. __ This is a SECOND or SUBSEQUENT submission of items concerning a filing under 35 u.s.c. 371.
`3. XK This express request to begin national examination procedures (35 u.s.c. 371Cf) at any time rather than delay
`examination until the expiration of the applicable time limit set in 35 u.s.c. 371(b) and PCT articles 22 and
`39(1).
`4. XK A proper demand for International Preliminary Examination was made by the 19th month from the earliest claimed
`priority date.
`5. XK A copy of the International Application as filed (35 U.S.C. 371(c)(2))
`a. XK
`is transmitted herewith (required only if not transmitted by the International Bureau).
`b. __ has been transmitted by the International Bureau.
`c. __
`is not required, as the application was filed in the United States Receiving Office (RO/US)
`
`6. __ A translation of the International Application into English (35 U.S.C. 371(c)(2)).
`
`7. __ Amendments to the claims of the International Application under PCT Article 19 (35 U.S.C. 371(c)(3))
`a. __ a1·e transmitted herewith (required only if not transmitted by the International Bureau).
`b. __ have been transmitted by the International Bureau.
`c. __ h~ve not been made; however, the time limit for making such amendments has NOT expired.
`d. __ have not been made and will not be made.
`8. __ A translation of the amendments to the claims under PCT Article 19 (35 u.s.c. 371(c)(3)).
`9. XK An oath or declaration of the inventor(s) (35 U.S>C. 371(c)(4)).
`
`10. __ A translation of the annexes to the International Preliminary Examination Report under PCT Article 36 (35 U.S.C.
`371(c)(5)).
`
`Items 11. to 16. below concern other document(s) or information included:
`11. XK An Information Disclosure Statement under 37 CFR 1.97 and 1.98.
`
`12. __ An assignment document for recording. A separate cover sheet in compliance with 37 CFR 3.28 and 3.31 is
`included.
`13. XK A FIRST preliminary amendment.
`__ A SECOND or SUBSEQUENT preliminary amendment.
`
`14. __ A substitute specification.
`
`15. __ A change of power of attorney and/or address letter.
`16. XK Other items or information: PCT/IPEA/416, PCT/IPEA/409, PCT/IPEA/402, PCT Request
`CHECK NO. '1~8'7
`Drawings (1 sheet)
`
`Page 5 of 135
`
`

`

`U.S. APPLN. NO.
`C.F.R. 1.50)
`
`(If KNO~N, SEE 37
`
`INTERNATIONAL APPLICATION NO.
`PCT/AU94/00028
`
`17. M
`
`.The following fees are submitted:
`Basic National Fee (37 CFR 1.492(a)(1)-(5):
`Search Report has been prepared by the EPO or JP0 •••••••••••• $850.00
`International preliminary examination fee paid to USPTO (37 CFR
`1.482) •.•••••••.••••••.•••.•••••.••••••.•.••••••••••••••••.•• $660.00
`No international preliminary examination fee paid to USPTO (37 CFR
`1.482) but international search fee paid to USPTO (37 CFR
`1.445(a)(2)) ••••.•••••••••••••••••.•••••••••••.••••••••••.••• $730.00
`Neither international preliminary examination fee (37 CFR 1.482) or
`international search fee (37 CFR 1.445(a)(2)) paid to USPT0 •• $980.00
`International preliminary examination fee paid to USPTO (37 CFR
`1.482) and all claims satisfied provisions of PCT Article 33(2)·(4)
`••••••••••••••••••••••.•.•••••••••••••.•••••.••••••••.••••.•• $ 92.00
`
`ENTER APPROPRIATE BASIC FEE AMOUNT =
`
`Surcharge of $130.00 for furnishing the oath or declaration later than_
`20 __ 30 months from the earliest claimed priority date (37 CFR
`1.492(e)).
`
`Claims
`
`Number Filed
`
`Number Extra
`
`Rate
`
`Total Claims
`
`Ind~endent Claims
`
`19 - 20 =
`
`01 - 3 =
`
`00
`
`00
`
`Multiple de~endent claim(s) (if applicable)
`
`X $ 22.00
`
`X $ 76.00
`
`+ $240.00
`
`TOTAL OF ABOVE CALCULATIONS =
`
`Reduction by 1/2 for filing by small entity, if applicable.
`Verified Small Entity statement must also be filed.
`(Note 37 CFR 1.9, 1.27 1.28).
`
`ATTORNEY DOCKET NO. P8017·5009
`
`DATE:
`
`June 6, 1995
`
`CALCULATIONS
`
`I PTO USE ONLY
`
`$980
`
`$00
`
`$00
`
`$00
`
`$00
`
`$980
`
`$00
`
`SUBTOTAL =
`
`$980
`
`Processing fee of $130.00 for furnishing the English translation later
`the_ 20 _ 30 months from the earliest claimed priority date (37 CFR
`1.492(f)).
`+
`
`Fee for recording the enclosed assignment (37 CFR 1.21(h)). The
`assignment must be accompanied by an appropriate cover sheet (37 CFR
`3.28 3.31). $40.00_per property
`
`+
`
`TOTAL NATIONAL FEE =
`
`$00
`
`$980
`
`$00
`
`TOTAL FEES ENCLOSED =
`
`$980
`
`Amount to be refunded
`
`Charged
`
`$
`
`$
`
`a. M A check in the amount of $2§Q to cover the above fees is enclosed.
`b. - ·Please charge my Deposit Account No.
`in the amount of $
`]4-]Q6Q
`A duplicate copy of this sheet is enclosed.
`c. M The Commis·sioner is hereby authorized to charge any additional fees which may be required, or credit
`any overpayment to Deposit Account No.
`]{t-]Q6Q •
`NOTE: ~here an appropriate time limit under 37 CFR 1.494 or 1.495 has not been met, a petition to revive (37 CFR
`1.137(a) or (b)) must be filed and granted to restore the application to pending status.
`
`to cover the above fees.
`
`,..
`NIKAIDO, MARMELSTEIN, MURRAY AND ORAM
`Metropolitan Square
`655 15th Street, N.~.
`Suite 330 - G Street Lobby
`~ashington, D.C. 20005-5701
`Telephone No. (202) 638·5000
`
`PRobert B. Murray
`Reg. No. 22,980
`
`-
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`SEND ALL CORRESPONDENCE TO: ~~
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`........
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`\
`
`(.__./
`
`Page 6 of 135
`
`

`

`wo 94117293
`
`08/446739
`
`PCT I A U94/00028
`
`; 0 6 JUN 1995
`~-_J;THOD OF OPERATING AN INTERNAL CQMBUSTIQN EN§INE
`This invention relates to a method of operating an internal
`
`combustion engine in _order to produce high exhaust gas temperatures and is
`particularly useful for internal combustion engines incorporating a catalytic
`
`5 treatment means in the exhaust system for treatment of the exhaust gases to
`reduce undesirable contaminants therein.
`
`Although catalytic treatment of gases to reduce the level of undesirable
`emissions therein is effective, the catalytic material or catalyst of the catalytic
`
`treatment means has a minimum operating temperature (generally referred to as
`
`10 the "light off" temperature and conventionally taken as the temperature at which
`
`the catalyst is 50 % efficient), and is relatively ineffective until this required
`
`operating
`
`temperature has been reached. Thus, during such periods,
`
`increased levels of undesirable emissions are likely to issue from the exhaust
`system. Normally, at engine startup, particularly after a period of non-operation,
`
`1 5 the catalytic material is below its light-off temperature and in order to reduce the
`time, and therefore the amount of emissions output until light-off of the catalyst, it
`
`may be desirable to raise the temperature of the exhaust gases delivered from
`the combustion chamber(s) of the engine to the exhaust system. However, at
`
`startup the engine typically will operate at a relatively low load and speed, such
`20 as is termed "engine idle", and therefore the amount of fuel being delivered to
`
`the engine is comparatively small and hence, only a relatively small amount of
`
`heat is available for raising the temperature of the exhaust gases and hence the
`
`temperature of the catalytic material to its "light-off" temperature.
`Further, after catalyst light-off, when the engine is allowed to idle or
`
`25 operate at a low load condition for a significant period of time, particularly in low
`
`· ambient temperature conditions, the exhaust gas temperature may drop to a
`
`value that is insufficient to maintain the catalytic material in the light-off condition
`and thus it will become ineffective in the treatment of contaminants and
`
`undesirable emissions in the exhaust gas.
`There have been proposals to heat the catalytic material by means of an
`
`30
`
`afterburner device placed upstream of the catalytic treatment means. In such an
`
`arrangement, the afterburner device ignites the remaining combustible mixture
`
`Page 7 of 135
`
`

`

`wo 94/17293
`
`PCT I A U94/00028
`
`2
`
`within the exhaust gases to raise the temperature of the catalytic material. This
`arrangement does however add significantly to the cost and complexity of the
`
`engine installation.
`It is therefore the object of the present invention to provide a method of
`
`5 operating an internal combustion engine which will assist in maintaining high
`exhaust gas temperatures and thus, where appropriate, achieve rapid light-off of
`
`the catalytic material in the exhaust system and maintain such a light-off
`condition whilst the engine is operating.
`
`With this object in view, there is provided a method of operating an
`10 internal combustion engine comprising retarding the ignition of a gas/fuel
`
`mixture within at least one cylinder of the engine to after top dead centre (ATDC)
`
`in respect of the combustion cycle of said at least one cylinder of the engine.
`
`While said ignition is so retarded, the fuelling rate of said at least one cylinder is
`
`preferably increased to a level higher than that required when the engine is
`
`15 operating normally.
`Conveniently, ignition can be retarded up to about -30° BTOC (i.e 30°
`
`ATDC) and is preferably of the order of -20°BTDC (i.e 20° ATDC). The ignition
`~etardation may alternatively be variable, preferably between 15° ATDC to 30°
`
`ATDC in the case of a multi cylinder engine such as a three cylinder engine.
`20 Preferably, the fuelling rate (measured in mg/cylinder/cycle) is greater than 50%
`
`of the fuelling rate at maximum load, and more preferably is up to about 80% of
`the fuelling rate at maximum load. However, if desired, the fuelling rate can be
`in excess of 100% of the fuelling rate at maximum engine load. However, the
`
`selected fuelling rate is conveniently the minimum rate which will ensure that the
`
`25 desired exhaust gas temperature is achieved. The fuel may be introduced to the
`combustion chamber before top dead centre (BTDC) and most preferably at 60°
`
`to 80° BTDC in the case of a direct injected engine.
`It is however also
`envisaged that the fuel be introduced to the cylinder after top dead centre
`
`(A TOG) under certain conditions or situations.
`
`30
`
`This method may conveniently be used in an engine including a catalytic
`
`treatment means provided in the exhaust system of the engine. A flame arrester
`
`may be placed between an exhaust port of the engine and the catalytic
`
`Page 8 of 135
`
`

`

`WO 94/17293
`
`PCT I A U94/00028
`
`3
`
`treatment means. This prevents the catalytic material held within the catalytic
`treatment means from directly contacting any flame that may arise as a resulting
`
`of any still burning exh~ust gases. Additional air may be introduced upstream of
`the catalytic treatment means. This additional air helps to promote the catalytic
`
`5 oxidation of the exhaust gases.
`
`The method can be operated during cold start of the engine. Alternatively
`
`or in addition, the method is operated when the temperature of the catalytic
`
`material is sensed or determined to be below a required operating temperature.
`
`The engine may conveniently be a two stroke internal combustion engine.
`1 0 The engine may preferably have piston operated exhaust ports.
`
`In the case of an air control system as disclosed in our copending
`Australian Patent Application No. 51065/90, the contents of which are hereby
`
`incorp.orated by reference, the by-pass air control valve under the control of the
`
`engine ·management system may be fully opened whilst the main manually
`
`15 controlled throttle valve remains in the closed position.
`The invention will be more readily understood from the following
`
`description of an exemplary embodiment of the method of operating an internal
`combustion engine according to the present invention as shown in the
`
`accompanying drawings.
`In the drawings:
`
`20
`
`Figure 1 is a graph showing the cylinder pressure-crankangle
`
`characteristics for a typical direct injected two-stroke internal combustion engine;
`
`and
`
`Figure 2
`
`is a graph showing the cylinder pressure-crankangle
`
`25 characteristics for a direct injected two-stroke internal combustion engine
`
`operated according to the method of the present inventionJt:-v
`The method according to the invention can be us~d on a two stroke
`internal combustion engine having piston controlled exhaust ports and the
`
`invention will be described in relation to this exemplary application.
`Referring initially to Figure 1, in a typical direct injected two-stroke internal
`
`30
`
`combustion engine, the fuel is introduced to the cylinder at approximately 60"
`
`before top dead centre (BTDC) with ignition within the cylinder occurring prior to
`
`Page 9 of 135
`
`

`

`wo 94/17293
`
`PCT/AU94/00028
`
`4
`
`top dead centre at approximately 35° BTDC. The solid curve of the graph of
`Figure 1 shows the cylinder pressure crankangle characteristics where ignition
`
`has occurred. The dashed curve shows the situation where ignition does not
`occur.
`
`5
`
`In the method according to the invention and as shown in an exemplary
`embodiment in Figure 2, while the fuel is introduced to the cylinder at between
`
`60° and 80° BTDC, the ignition within the cylinder is retarded and occurs at up to
`about -30° BTDC, ie. 30° after top dead centre (ATDC). The curve of the graph
`
`of Figure 2 shows the cylinder pressure crankangle characteristics where the
`1 0 fuel is introduced to the cylinder at 60° BTDC and ignition thereof occurs at -20°
`
`BTDC .
`. The fuelling rate can also be varied such that it is greater than 50% of the
`
`fuelling rate at maximum load, and preferably up to about 80% of the fuelling
`rate at maximum load.
`~;;.he method according to the present invention can be varied depending
`on the number of cylinders of the engine. For example, in a three cylinder
`
`15
`
`engine where only one or two cylinders are to be operated in accordance with
`said method, it is preferred that the fuelling rate thereto be kept constant and that
`
`the ignition be retarded a fixed amount, typically about 20° ATDC, for the
`20 cylinder(s) operating under ignition retard/high fuelling rate conditions. Under
`
`such operation, the other cylinder(s) still operates under normal conditions and
`the operation thereof may be such as to compensate for the temporary loss in
`
`torque while the other cylinder(s) operate(s) under said conditions. The
`cylinder(s) operating under normal conditions may also regulate the engine idle
`
`25 speed.
`
`By comparison, in a three cylinder engine where all cylinders are
`
`operating in accordance with said method it is preferred that a high fuelling rate
`be fixed for all of the cylinders and that all of the cylinders operate with retarded
`
`ignition. The degree of retardation for each of the cylinders may conveniently be
`30 the same during at least one combustion cycle of one light-off period.
`
`Further, it is preferable that the degree of ignition retard of the cylinders
`during the one light-off period be altered from cycle to cycle, typically between
`
`Page 10 of 135
`
`

`

`WO 94/17293
`
`PCT I A U94/00028
`
`5
`
`15° ATDC to 30° ATDC, to control the engine idle speed. However, it is also
`
`envisaged that the degree of ignition retard could alternatively or in addition be
`
`controlled to differ bet~een respective cylinders during the one light-off period.
`
`By virtue primarily of the retarded ignition and also to a lesser extent the
`
`5 high fuelling rate, the overall thermal efficiency (i.e the efficiency of conversion of
`energy provided by combustion of the fuel into useful work) is quite low. Thus
`
`there is a high level of thermal energy available to heat the catalytic treatment
`In addition, extra heat is
`means provided for treatment of the exhaust gases.
`
`released to the engine coolant thereby rapidly increasing the coolant
`
`10 temperature which results in a lower engine output of HC emissions thereby
`
`reducing the dependence on the catalytic treatment means to maintain the
`required HC emissions level.
`
`The combustion preferably occurs under rich conditions with the overall
`air/fuel ratio being close to the stoichiometric ratio. Because of the inefficient
`
`1 5 combustion conditions, gases with lower oxidation temperatures such as H and
`CO will be produced. These gases can react with the catalytic material to
`
`increase its temperature and therefore aid the catalytic material in achieving its
`
`light-off temperature.
`
`If desired, additional oxygen containing gas, such as air, may be
`20 introduced upstream of the catalytic treatment means provided in the exhaust
`
`system of the engine, for example, by use of an air pump, thus ensuring the
`introduction of excess oxygen to the exhaust system enabling catalytic
`
`In many cases, it will be
`conversion of any contaminants in the exhaust gas.
`desirable that the throttle or air control means for the air supply to the
`
`25 combustion chamber with retarded ignition be set at a "wide open" or near "wide
`open" value such as to maximise air supply to that combustion chamber, thus
`
`allowing higher fuelling rates to be used. However, in the case that the air
`control system serves more than one cylinder, then the air flow rate must be
`
`established such that the combustion efficiency of the combustion chamber(s)
`30 without retarded ignition is not adversely affected.
`
`It has been found that maintaining the retarded ignition and high fuelling
`rate conditions for a "light-off" period only of the order of 30 seconds from engine
`
`Page 11 of 135
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`

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`WO 94/17293
`
`PCT I A U94/00028
`
`6
`
`startup is sufficient to bring the catalytic treatment means up to temperature to
`establish light-off of the catalytic material in the treatment means.
`In some
`
`cases, the level of thermal energy available is even greater thus shortening the
`above period to 5 seconds or so. Furthermore, and particularly in the case of
`
`5 two stroke engines, there may be insufficient time between the commencement
`of ignition and the opening of the exhaust port for all of the fuel to be combusted
`
`within the combustion chamber. Thus, combustion may continue as the
`combustion gases flow from the combustion chamber into the exhaust system.
`
`In such a case, it may be beneficial to place a flameshield upstream of the
`10 catalytic treatment means to protect it from contact with any flames. Where
`
`necessary, and as alluded to hereinbefore, excess air may be introduced to the
`exhaust system to promote the catalytic oxidation of the exhaust gases.
`
`Further, it is to be understood that the high degree of retarding of the
`ignition resulting in the relatively short period between ignition and exhaust and
`
`15 the high fuelling rate may only produce a relatively low torque output.
`Accordingly, at engine idle, the high fuelling rate does not result in the engine
`
`rewing at a speed significantly different to the normal engine idle speed. In this
`regard, it may be preferable that in a multi-cylinder engine, only one or some of
`
`the cylinders are subjected to the highly retarded ignition and high fuelling rate
`20 thereby enabling the remaining cylinder(s) to provide the necessary control of
`
`engine idle speed as aluded to hereinbefore.
`It may be advantageous to "rotate" the cylinders such that each cylinder
`
`sequentially operates under the retarded ignition and high fuelling rate
`conditions. This rotation between cylinders may occur within a single light-off
`
`25 period. Alternatively, a different cylinder could be used for consecutive light-off
`periods. This helps to ensure that each cylinder is subjected to similar
`
`temperature and/or carbon formation conditions.
`The reduction in the time for the catalyst to reach its light-off temperature
`
`achieved by the use of the present invention also enables the catalytic treatment
`30 means to be located a greater distance downstream from the engine exhaust
`
`port than may otherwise be possible, thereby improving the durability of the
`catalytic treatment means.
`
`Page 12 of 135
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`WO 94/17293
`
`PCT I A U94/00028
`
`7
`
`It will be appreciated that where an engine start-up occurs after only a
`short period of time after shut-down of the engine, the catalytic treatment means
`
`may still be at a suff!ciently high temperature to immediately light-off on
`restarting the engine and hence it may be undesirable to further heat the
`
`5 catalytic treatment means by way of the present invention. However, this
`condition can be determined by appropriate sensing of other engine parameters
`
`such as the temperature of the engine in general, cooling water temperature or
`the temperature of the exhaust system in the vicinity of the catalytic treatment
`
`means. Accordingly, sensing of these and/or other engine parameters may be
`1 0 effected and the specific ignition retarding and high fuelling rate conditions only
`
`implemented if for example, the sensed temperature condition of the engine
`
`and/or exhaust system indicates that the temperature of the catalytic treatment
`
`means .is at a level which would necessitate assistance in achieving prompt
`
`light-off thereof.
`
`15
`
`Further, wher~ the engine is left idling for a considerable time, and
`particularly in low ambient temperature conditions, the exhaust system and
`
`particularly the catalytic treatment means may fall in temperature to a level at
`which the catalytic treatment means is below the light-off temperature. Similarly,
`
`appropriate sensors can be provided to detect this condition and the engine
`20 management system can be arranged to respond to the sensing of such
`
`conditions to implement the ignition retard and high fuelling rate conditions to
`
`restore or maintain the catalytic treatment means in an acceptable operational
`
`condition.
`When the appropriate sensor or sensors detect that the engine
`
`25 parameter, for example the exhaust system temperature, is again above the
`acceptable value, the engine management system may then cease to effect the
`
`ignition retard and high fuelling rate conditions and return the cylinder to normal
`ignition timing and fuelling rates. Where more than one cylinder has been
`
`operating with retarded ignition and a high fuelling rate, the return to normal
`30 operation is preferably sequential, that is, one cylinder at a time is returned to
`
`normal operation and stabilised. This is particularly useful in the case where
`switching from a high to a lower fuelling rate causes fuel "hangup", that is,
`
`Page 13 of 135
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`

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`wo 94/17293
`
`PCT I A U94/00018
`
`8
`
`retention of fuel within the means used to deliver fuel to the cylinder, in which
`case the transient response of the engine may not be precise. However, if
`
`multiple cylinders are operating with retarded ignition and a high fuelling rate,
`they may be returned to normal operation simultaneously if there is a substantial
`
`5 increase in operator demand. The method of operating the engine according to
`
`the present invention can therefore be initiated, both during cold start of the
`
`engine, and when the temperature of catalytic material is sensed or determined
`to be below the required light-off operating temperature any time during the
`
`running of the engine.
`While the method of the present invention is particularly suitable for two-
`
`1 0
`
`stroke engines, preferably those engines which are directly injected, the
`
`invention is not limited in its applicability to such engines. In a two-stroke three
`
`cylinder 1.2 litre direct injected engine, the anticipated fuel per cycle at normal
`engine idle is 3 mg/cylinder/cycle whereas when retarded ignition and a high
`
`1 5 fuelling rate is enabled in accordance with the method of the present invention,
`
`the increased fuelling rate may be as high as 18 to 25 mg/cylinder/cycle, i.e 85
`
`% to 115 % of the fuelling rate at maximum engine load.
`In an air-assisted direct injected 2-stroke engine as described, for
`
`example, in the applicant's US Patent No. 4693224, it may be convenient to
`
`20 control the speed of the engine by controlling the fuelling rate to the cylinders
`
`that are running under normal settings and by controlling the ignition timing of
`
`those cylinders that are operating with retarded ignition and increased fuelling
`
`rate according to the invention as described herein.
`It will be appreciated that the invention is particularly beneficial for
`25 bringing the engine catalytic treatment means rapidly to its light-off temperature,
`and few if any additional components are required. This results in little to no
`
`additional costs to the piece price of the engine.
`
`Page 14 of 135
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`

`

`- - - - - - - - - - - - - - - - - - - - - - - - - - - -
`
`WO 94/17293
`
`PCT I A U94/00028
`
`THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:
`
`9
`
`A method of qperating an
`the ignition of a gas/fuel mixture within at least one cylinder of the
`
`internal combustion engine comprising
`
`engine to
`
`er top dead centre (ATDC) in respect of the combustion cycle of said
`
`at least one c · der of the engine.
`
`A method according to claim 1 wherein, while said ignition is so retarded,
`
`that required
`
`f said at least one cylinder is increased to a level higher than
`tfl
`
`•
`. A method according to claim.,l'wherein the fuelling rate is greater than
`1/7
`50% of the fuelling rate at maximum load.
`
`'V
`A method according to claim )t, wherein the fuelling rate is about 80% of
`the fuelling rate at maximum load.
`
`I
`A method according to claim~wherein the fuelling rate is greater than
`
`100% of the fuelling rate at maximum load.
`
`/
`
`~0~ M. J
`II) j.
`A method according to4any one of tile p1eceding claim! wherein the
`ignition is retarded up to about 30° ATDC.
`
`A method according to claim~ wherein the ignition is retarded to about
`~ /
`20° ATDC.
`
`/
`
`~ i
`
`A method according t*'~r~11e of the ~reeeeliA9 .:laims...wherein the
`
`degree of ignition retardation differs between each of the cylinders of a multi(cid:173)
`
`cylinder engine.
`
`~ J.
`
`A method according to claim'} wherein the degree of ignition retardation
`differs between 15° ATDC and 30° ATDC.
`
`Page 15 of 135
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`

`wo 94/17293
`
`PCT I A U94/00028
`
`10
`
`q . /
`
`c.lct~ tn I
`A method according tOd&r•y oue of tire preceding elairn-s wherein the fuel
`
`yu.
`is introduced at between 60° to 80° BTDC.
`
`c.loJ~
`A method according to(. any one of tl=1e pr eceditlg claims wherein the
`engine includes in an exhaust system thereof a catalytic treatment means
`
`supporting a catalytic material therein.
`
`tO
`A method according to claim';( wherein a flame arrester is inserted
`
`\\~.
`between an engine exhaust port and the catalytic treatment means.
`
`upstream of the catalytic treatment means.
`
`l ~ A method according to claim~~~ wherein additional air is introduced
`u \ 10
`\'?;L A method according tCl\a~' ~e~f elaiffls 11 to 13 wherein the engine is
`
`operated according to said method during cold start of the engine.
`~l ~
`\~}6. A method according to.<._any~f'le ef elaims 11 te 14 wherein the engine is
`operated according to said method when the temperature of the catalytic
`
`,\
`
`material is sensed or determined to be below a required operating temperature.
`eJ ct\ m. l
`A method accordinQ\-a:Ay one of the I' I ecedir rg clair~•s-.wherein the engine
`
`\~ L
`)'ti.
`
`has piston controlled exhaust ports.
`
`"· \
`\
`(.)\ G\.A IV\ '
`A method according toJ\any one of the ptecedir1g clain~ wherein the
`
`engine is a two stroke internal combustion engine.
`
`\'\£.
`
`~~a.,\ lY\ \
`A method according to~~y one ot the precedin~ claimS" wherein the
`
`engine is a multi-cylinder engine and at least one of said cylinders is operated
`without ignition timing retarded to after top dead centre.
`
`Page 16 of 135
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`

`

`wo 94/17293
`
`PCT I A U94/00028
`
`& ;4. A method according t~ylV\ote of the Jlreeedirrg~leims, wherein after a
`
`1 1
`
`predetermined operating condition has been sensed or determined, said engine
`
`reverts back to normal _operation.
`
`' ..
`
`i'
`
`'
`
`Page 17 of 135
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`

`

`NIKAIDO, M
`N, M. M &