UNITED STATES PATENT AND TRADEMARK OFFICE
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`FORD MOTOR COMPANY
`
`Petitioner,
`
`V.
`
`PAICE LLC & ABELL FOUNDATION, INC.
`
`Patent Owner.
`
`DECLARATION OF WALT JOHNSON
`
`1, Walt Johnson, hereby declare as follows:
`
`1.
`
`I am presently employed as the Patent and Trademark Resource Center (PTRC)
`
`Librarian at the Minneapolis Central Library. The Minneapolis Central Library is a PTRC
`
`located in Minneapolis, Minnesota. I have personal knowledge of the matters stated below. I am
`
`over 18 years of age, and I am competent to testify regarding the following.
`
`2.
`
`It is the normal course of business for the library services to index and catalog
`
`technical reference materials for incorporation into our facility in order to provide access to
`
`intellectual property information. Once received, a reference stamped with the date of receipt and
`
`placed on the shelf within a few days.
`
`3.
`
`Attached as Exhibit A to my declaration is a true and accurate copy of a
`
`technical article titled “A High-Expansion-Ratio Gasoline Engine for the Toyota Hybrid System”
`
`that was authored by T. Takaoka, K. Hirose, T. Ueda, Y. Nouno, H. Tada, and H. Kanai.
`
`
`
`Page 1 of 11 '
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`4.
`
`The first page of Exhibit A includes an imprint of the Minneapolis Public
`
`Library and Information Center’s, which is now called the Minneapolis Central Library after a
`
`merger with the Hennepin County Library system, property stamp together with a stamped date
`
`of “May 2_, 1998.” The second digit of the date stamp is not clear; however, it is clear that the
`
`stamped date is between May 21-29, 1998. Therefore, I understand that the stamped date is May
`
`29, 1998 at the latest. This property stamp and date would have been placed on the volume at the
`
`time it was being processed by the library services at
`
`the Minneapolis Public Library and
`
`Information Center.
`
`5.
`
`l have knowledge that there existed no time between the processing date of
`
`around May 29, 1998 and December 23, 2014 when the technical reference attached as Exhibit A
`
`was not publically available at the Minneapolis Public Library and Information Center or the
`
`Minneapolis Central Library, except between August 2002 and May 20, 2006 while the library
`was in a smaller, temporary location during the contstruction of the new Minneapolis Central
`
`Library. Older issues of most magazines were not available to staff or public during this period.
`
`6.
`
`The technical reference attached as Exhibit A would therefore have been
`
`indexed and searchable by the general public since around May 29, 1998.
`
`7.
`
`The technical reference attached as Exhibit A would have been indexed and
`
`searchable by the general public well before September 1998.
`
`I declare under the penalty of perjury that the foregoing is true and accurate to
`
`the best of my knowledge.
`
`:23 Dam. am»:
`
`Date
`
`
`um
`Walt Johnso
`
`
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`EXHIBIT A
`
`EXHIBIT A
`
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`MINNEAPJLIS PUBLIC ,LI RAF’Y‘.
`
`
`
`q Vol. 47 No.
`Special Edition
`
`\
`
`Prevention of
`Global Warmin
`‘f"
`.
`I
`__
`39121 Reduction
`
`”7' a9;
`
`FORD 1127
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`
`
`Contents
`
`9 Special Edition for Prevention of Global Warming ~COz Reduction-
`. Not Only as a Businessman, but as a Citizen
`.......By AkioMatsubara 4
`. CO: Reduction in Automotive Development
`--‘----By Naoto Kushi .................................................................................................................................................................
`. Fuel Efficiency Improvement of Gasoline Engine Vehicle
`
`6
`
`- Development of Fuel Economy 5W-20 Gasoline Engine Oil
`
`.......By Kenyu Akiyama/ Hiromi Kawai/ ShinichiSuglyama" 18
`. Contributions of Automatic Transmission to Fuel Economy
`.......By Sinya Nakamuraf Masahim Kojjma/ KatsumiKohno 23
`- Development of D-4 Engine
`-
`
`.......By Zonichiro Mashild/ Souichi Matsushita/ Takeshi GOHI‘IO
`- Electric Vehicle "FIAV4 EV"
`I
`
`29
`
`-
`
`.......By MaSao KinoshitaJ‘SadahiroKlmura 36
`introduction of EV Commuter "e-co'm"
`-
`I
`.
`.1
`I
`'
`_
`__
`-------By Makoto Yamada/ Keiji Kogakil Toshiyukj Sekimori/ Tetsuhiro Ish1kawa 43
`- A Development of Toyota Hybrid System
`‘
`------- By Shinichi Abel Takeshi Kotani/ Ryuji Ibaraki/ Kazuo Tojirnaf Sumjkazu Shamoto/ Akita Sakai
`- A High-Expansion-Ratio Gasoline Engine for the TOYOTA Hybrid System
`m-mBy Toshifumi Takaokal Katsuhiko Hirose/ Tatehito Ueda/ Yasushi Nouno/ Hiroshi Tada/ Hiroshi Kanai ----------------
`- Production Engineering Development for EV, HV Units
`"nu-By Ken Tanoue/ Hiroshi Miyazaki/ Yasutomo Kawabata/ Toshiaki Yamamoto/ Takao Hirose/ Hajime Nakagawa----------
`- Development of Electric Vehicle Powered by Fuel Cell
`"'"“By Yasuhiro Nonobe/ YoshioKlmura 67
`- C02 Reduction Activities in TMC Production Process
`
`47
`
`53
`
`61
`
`....... By Hidehiro 0110/ Wataru Sato/ Tomoki Nakagaki/ TakeoSakal 73
`
`
`DTechnical Paper
`- An Automatic Offsetting Method of Composite Surfaces
`------- By Hiroyuki Kawabata/ Yukitaka Fujitani/ Junji Ishida/ HirorniMorlsakj 79
`- Development of TOYOTA New BEAMS 1UZ-FE Engine
`'
`
`-------By Kenji Watanabe/ Tetsuji Asahi/ Minoru Iwamuro/ Kunihiko Satou/ Tsutomu Hiyoshi/ Shigeo Kikori """"""""""""
`- A Development of Easy-Column Shift
`-------By Yoshitaka Sato/ Harumi Minoshima/ Minoru Makjguchi
`' Development of Catalyst for Diesel Engine
`------- By Hideakj Ueno/ Toshinobu Furutani/ Tetsuo Nagami/ Norihiko Aono/ Hideyukj Goshima/ Kouichi Kasahara
`. Molecular-Level-Anaiysis on Water Behavior Concerned to Degradation of Paint Film
`.......By Nobuflki Takazawa/ Yoshihiro Yamamura/ Ryuji Shlmflzakl 104
`- Construction and Implementation of Internal Management System for Hazardous Substances
`.......By Kengo Andol Yoshihisa Nakagawaj Yuj1ijono/Chikashi0gura 111
`
`85
`
`92
`
`98
`
`DTechnicaI Award News .............................................................................................................................................................
`
`[>Recent Publications by Toyota Authors (January _ June, 1997)
`
`125
`
`129
`
`135
`
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`
`1998
`
`
`Editorial Staff
`
`
`
`Eisaku Akutsu
`Yoshihai‘u Kanamori
`
`Future PIOJECtDiV- I
`Vehicle Engineering Div.
`
`N0rihi1’o-Suzuki
`
`Himakj Tanaka
`_
`Tetsuo Morita
`
`Hikaru Aoyagi
`Masayuki Kotani
`..
`Nobuo Fullta
`Takasi Nagase
`Siro Miyazaki
`
`Mikio Sato
`
`Masaharu Yuasa
`
`Secretariat
`
`Engine Engineering Div.
`
`Chassis System Development Div.
`.
`.
`.
`.
`Elf??? Evaluam“ 8‘ Engmeenng
`'
`Material Engineering DiV- 1
`Electronics Engineering Div. I
`
`Elecmc and Hybrid VBhiCIB Div.
`Production Engineering Development
`DIV.
`Plant Engineering Div.
`
`Mammary Engineering Adminimfltion
`Dw'
`Information Systems Div. I
`
`
`
`
`
`
`
`
`
`
`
`
`
`*Chisato Niki
`Technical Administration Div.
`Norie Kishimoto
`Technical Administration Div.
`
`
` Kumiko Tsuji
`
`Technical Administration Div.
`
`
`
`
`
`
`
`
`
`‘
`
`53'
`f.
`
`if
`
`.‘ii
`
`ii
`I!::
`I
`E
`Ir;
`!55
`i:
`
`This No.2 issue of TOYOTA Technical Review Vol.47 is being pub~
`lished in the winter when the evening breeze blows very cold.
`Many of our readers may wonder what the TOYOTA ECO PROJECT
`which has been positively promoted at Toyota since early 1998 is all
`about.
`
`We would be happy if you would include “Prevention of Global
`Warming -COz Reduction-” featured in this TTR issue as a part of the
`TOYOTA ECO PROJECT.
`
`Technological advancement has been accelerated year by year, and
`vehicles which were once dreams are now a reality. In our daily jobs,
`desk-top personal computers have been used since the late autumn of
`1996. Electronic mail has become the communication means for ex-
`changing meeting agendas with people outside the company using the
`e-mail addresses written on name cards so often that they are felt to be
`more closer than people in the company. It will not be long before the
`TTR is published electronically without any copyright or duplication
`pmblems‘
`(Akutsu)
`Six months have passed since I was unexpectedly assigned to the Eco
`proiect as a member for technological development. Through this issue,
`I have renewed my awareness of the quick progress in technological
`development that is taking place in many diverse fields concerning en-
`vironmental protection and conservation.
`I have been very stimulated by the activities of rival engineers, cause
`ing me to renew my enthusiasm in order to display my full potential.
`(Kanamori)
`
`_
`,
`.
`.
`.
`EnVironmental issues are being discussed almost every day in the
`press as we approach the end of the 20th century. Although we have
`been making efforts to ensure more efficient use of precious global re-
`sources, various kinds of waste result from their consumption. Coming
`up with ways to restore nature is the goal of almost every industrial
`field. Great advancements are expected in this regard through the appli-
`cation of human wisdom.
`
`In the automotive field, these same efforts are being made every day
`and the image of vehicles for the let century is about to be formed.
`(Fujita)
`
`
`
`.
`
`'
`
`i
`i
`
`I
`|
`I
`
`
`
`*Chairman of the Editorial Committee
`
`TOYOTA Technical Review Vol. 47 No. 2
`
`© 1998 TOYOTA MOTOR CORPORATION, Printed in Japan
`Copyrights of all articles published in the TOYOTA Technical Review are the proper«
`ty of TOYOTA MOTOR CORPORATION.
`For permission to reproduce articles in quality or for use in other printed material, con-
`tact the chairman of the Editorial Committee.
`
`Publisher's
`Office
`
`,
`
`Technical Administration Div.
`TOYOTA MOTOR CORPORATION
`l Toyota-eye, Toyota, Aichi, 471—8572 Japan
`Tel. (565) 28—2121
`Fax. (565) 23—5744
`
`Publisher
`
`Editor
`
`Printer
`
`Eishi Ohno
`
`-
`
`Chisato Niki
`
`CMC Co., Ltd.
`1-1-19 Heiwa, Nakaku, Nagoya, Aichi, 460-0021 Japan
`
`Printed
`
`'
`
`Apr. 1998
`
`Page 6 of 11
`
`Printed on recycle paper
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`

`Power performance
`
`Passing acceleration
`(20 —> EOkm/h)
`
`_
`_
`Passmg acceleration
`(40 —> 70km/hl
`
`THS vehicle
`
`— |:] 1.5rliter Corolla
`with automatic
`transmission
`
`A High-Expansion-Ratio Gasoline
`
`Engine for the TOYOTA Hybrid System
`
`Toshifumi Takaoka** Yasushi Nouno**
`Katsuhiko Hirose*
`Hiroshi Tada**
`Tatehito Ueda*
`Hiroshi Kanai*
`
`o
`
`5
`
`(seconds)
`
`(In-house test)
`
`Abstract
`
`2.7.3 Engine and Motor Drive Power Control
`
`The power performance of the THS vehicle is the sum total of the
`engine's direct drive power and the drive power of the motor, which
`comes simultaneously from electricity generated by the generator
`using the engine‘s power, and from electricity supplied by the battery.
`The drive power configuration is such that the lower the vehicle
`
`speed, the more motor drive is used. With the power split device
`functioning like a continuously variable transmission, the vehicle
`achieves smoother acceleration and deceleration performance than a
`vehicle with a conventional engine.
`
`3. THS Vehicle Performance
`
`3.1 Fuel Economy
`
`In in-house driving tests in the 10 . 15 mode, the THS vehicle
`achieved approximately twice the fuel economy of a vehicle with a
`conventional engine and automatic transmission, or 28 km/liter.
`
`3.2 Exhaust Emissions
`
`Fig. 13 Passing Acceleration Performance
`
`4. Conclusion
`
`In January of 1997, Toyota announced the promotion of the
`"Toyota Eco-Project”. Among the goals of the project, particularly
`with respect to reducing C02 emissions to prevent global warming, is
`the development of a hybrid vehicle with twice the fuel economy of
`conventional vehicles. The authors firmly believe that the completion
`of the Toyota Hybrid System is a major contribution toward the
`achievement of this objective.
`This paper has been based upon information released to the press in
`the spring of 1997.
`
`
`
`
`
`The THS vehicle emits only half as much C02 as a gasoline engine
`
`I Authors
`
`vehicle, and its emissions of carb0n monoxide, hydrocarbons, and ni-
`trogen oxides have been reduced to approximately one-tenth of their
`regulation standard levels.
`
`3.3 Acceleration
`
`The passing acceleration of the THS vehicle matches or exceeds
`that of a vehicle with a conventional engine and automatic transmis-
`sion, and its acceleration is smoother, without any kickudown.
`Fuel economy (10 - 15 model
`
`THS vehicle
`
`1.5-liter Corolla with
`automatic transmission
`
`0
`
`1D
`
`20
`
`Fig. 11 10. 15 Made Fuel Economy
`
`Emissions (10 - 15 modeilnehouse test)
`.
`_
`Exhaust emrssrons
`
`Regulation
`standards lg/km)
`
`at?
`
`T. KOTANI
`
`.
`
`-
`
`ir‘
`as
`Kl
`
`I i
`
`A 50% reduction in 002 and fuel consumption in comparison with a vehicle with the same engine displace-
`ment has been achieved by the newly developed gasoline engine for the Toyota Hybrid System. This is
`achieved by a combination of an electric motor and an internal-combustion engine that
`is optimized in
`terms of its displacement and heat cycle. Delaying the closing of the intake valve effectively separates the
`compression ratio and expansion ratio, so that the expansion ratio, which is normally set to 9:1 to 10:1 to
`suppress knocking, can be set to 13.5:1. Motor-assisted quick start, improved catalyst warm-up, and the
`elimination of light-load firing allow the system to achieve emissions levels that are only one-tenth of the
`current Japanese standard values.
`
`Keywords: hybrid, low fuel consumption, low emissions, low friction, variable valve timing
`
`engine output and the motor output by means of a planetary gear sys-
`tem to control the power split. One notable feature is that because the
`drive power is the combined power of the engine and the motor, the
`engine output can be set to a relatively low value without reducing ve-
`hicle performance.
`
`1.
`
`Introduction
`
`The earth's remaining reserves of fossil fuels are said to total approx-
`imately two—trillion barrels, or about a 50-year supply. The electric ve-
`hicle, because of its zero emissions level and the diversity of sources to
`supply electrical energy, is regarded as a promising automobile for the
`future. On the other hand, the energy limitations of on-board batteries,
`
`which is to say, their inferior energy density in comparison with fossil
`fuels, has meant that the electric vehicle has remained no more than just
`one future technology. The internal-combustion/electric hybrid system
`is promoted as a technology that compensates for this shortcoming of
`the electric vehicle, but it is also the object of attention as a system that
`eliminates the problems of the internal—combustion engine.
`Because the drive energy of the hybrid system comes either from
`electrical generation by the internal-combustion engine or from the en-
`gine's direct drive of the axle, the efficiency of the engine, the primary
`power source, strongly influences the efficiency of the entire System.
`In the development of the Toyota Hybrid System, a new gasoline en-
`gine was developed with more emphasis on thermal efficiency than on
`Specific output. Because priority was given to the total efficiency of
`the entire system, it was decided that a high-expansion-ratio cycle
`would be used, and the engine displacement and maximum output
`were chosen to reduce friction loss. This paper describes the inves-
`
`tigative process and the results that were obtained“
`
`
`
`
`
`
`
`
`
`power path
`
`Electric
`path
`. —
`Mechanical
`
`Reduction
`gears
`
`Hybrid transmission
`
`Fig. 1 Toyota Hybrid System Configuration
`
`Fig. 2 shows the relationship between output and efficiency. One
`issue for the engine was how to raise the net thermal efficiency from
`point A to point B.
`
`2.2 Engine Specifications
`
`In order to achieve the thermal efficiency objective, the engine for
`the hybrid vehicle was planned with the following three points in
`mind:
`
`(1) The only restriction to be placed on the choice of engine displace-
`ment would be that it be within a range that satisfies the engine
`output and installability requirements. This makes it possible to
`use a high-expansion—ratio cycle with delayed intake valve clos—
`
`
`
`
`
`50
`Compared to regulation standards
`
`100
`
`Fig. 12 10- 15 Mode Emissions
`
`52
`
`K. TOJIMA
`
`S. SHAMOTO
`
`A. SAKAI
`
`2. Hybrid System and Engine Specifications
`
`2.1 Hybrid System
`
`The configuration of THS is shown in Fig. 1. The system links the
`
`* Engine Engineering Div. II
`** Power Train Engineering Div. 11
`
`I i Page 7 of 11
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`
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`

`A High-Expansion-Fiatio Gasoline Engine for the TOYOTA Hybrid System
`
`
`
`3.2 Relationship of Mechanical Compression Ratio,
`
`Valve Timing, and Brake Thermal Efficiency
`
`Before a prototype of the high—expansion-ratio engine was built, the ef-
`fects of the mechanical compression ratio and valve timing on brake ther-
`mal efficiency were studied. An in-line four-cylinder, 2164scc Toyota SS-
`FE engine was used in the experiments.
`Fig. 9 shows the changes in thermal efficiency with different combina-
`tions of expansion ratio and valve timing. If the expansion ratio is in-
`creased and intake valve closing is delayed, brake thermal efficiency rises,
`but it reaches a limit at an expansion ratio of 14.7:1. Also, the maximum
`value of the brake mean effective pressure drops as the delay in intake
`valve closing increases.
`
`2400mm
`
`
`
`36
`
`32
`
`28
`
`24
`
`20
`
`0.2
`
`0.4
`
`0.5
`
`0.8
`
`1
`
`Brake mean effective pressure Prne (MPal
`
`0:“
`>-
`(JI:
`.2
`.E-l
`%_
`
`W E0
`
`:
`E.
`g
`i!no
`
`Fig. 9 Expansion Ratio and Thermal Efficiency
`
`Fig. 10 shows the relationship between brake thermal efficiency
`and brake mean effective pressure under full load. As the expansion
`ratio increases, the timing advance becomes slower due to knocking,
`and the brake thermal efficiency drops, but if the intake valve closing
`35
`
`34
`
`1%) BrakethermalefficiencyWei
`
`
`
`1600
`
`1800
`
`
`
`improvement
`
`1000
`
`1200
`
`1400
`
`
`
`Fueleconomy
`
`
`
`
`
`
`
`
`
`Netthermalefficiency
`
`THS vehicle
`
`B: improved engine efficiency
`
`0%
`improvement
`
`Conventional
`Vehicle
`
`A: Optimized engine operating range
`
`Engine output
`
`Fig. 2 Relationship of Engine Output and Efficiency
`
`ing, as well as to reduce friction loss by lowering the engine
`speed.
`
`(2) In order to achieve a major reduction in emissions, the engine
`would operate with 7L = 1 over its entire range, and the exhaust
`system would use a 3eway catalyst.
`(3) Active measures would be taken to reduce weight and increase ef—
`ficiency.
`
`Fig. 3 shows the relationship between the SN ratio (the ratio of
`combustion chamber surface area to combustion chamber volume) and
`
`the indicated mean effective pressure. The smaller the SN ratio, the
`
`less heat is dissipated into the cooiant, raising the indicated mean ef-
`fective pressure. Since the SN ratio tends to decrease as the displace-
`ment per cylinder increases, this also raises the indicated mean effec-
`tive pressure.
`Fig. 4 shows the relationship between displacement and friction
`loss in two engines designed to have identical output. Because the
`maximum engine speed can be set lower as the displacement increas-
`
`es, it is possible to reduce friction loss by reducing both the load on
`the valve system springs and the tensile strength of the piston rings
`while maintaining the same output.
`Based on these considerations, the relationship between displace-
`
`ment and fuel consumption was calculated. The results are shown in
`Fig. 5 and Fig. 6. From Fig. 5 it can be seen that in the high-output
`
`range, thermal efficiency rises as the displacement becomes larger, but
`in the low-output range, thermal efficiency is higher with a small-dis-
`placement engine. Both the indicated thermal efficiency and the me—
`chanical efficiency (friction loss) improve as displacement becomes
`larger, but in the low-output range, because of the effect of the pump-
`ing loss that results from the shift to a partial load, thermal efficiency
`is better with a smalladisplacernent engine.
`Fig. 6 shows the relationship between displacement and fuel con—
`sumption. For the reasons cited above, 1500 cc was deemed the opti-
`mum engine displacement, given the curb weight of the THS vehicle.
`
`Frictionloss
`
`
`
`(Nmi
`
`Output (kW)
`
`Fig. 4 Relationship of Displacement and Friction
`
`Pe: Brake mean effective pressure
`Pi*=Pe+me+pr me: Friction mean effective pressure
`pr: Pumping mean effective pressure
`
`1.40
`
`4:.o
`
`r".
`
`Displacement (cc)
`
`Fig. 6 Displacement and Fuel Economy
`
`3. Improving Efficiency by Means of High Expansion Ratio
`
`3.1 Principle
`
`The theoretical thermal efficiency of an equivalent charge Cycle is
`improved by raising the compression ratio. But if the compression
`ratio is raised in a gasoline engine, the compression end temperature
`rises, and knocking OCCurS. To prevent knocking in the high-expan-
`sion-ratio engine, the timing of intake valve closing was delayed con-
`siderably, thus lowering the effective compression ratio and raising the
`expansion ratio, which essentially controls the thermal efficiency.
`Fig. 7 is a pressure-volume (p-V) diagram comparing the high-expan-
`sion-ratio cycle with the conventional cycle when the charging effi-
`ciencies of the two are equal. Fig. 8 shows the same sort of comparir
`son when the compression end pressures are equal. When the
`charging efficiency is identical, delaying the closing of the intake
`valve raises the maximum pressure and increases the positive work,
`and also reduces pumping loss. With identical compression end pres-
`sure, increasing the expansion ratio raises the theoretical efficien-
`Cy-l|ll1)(3ll4il51161l7)(8)t9)
`
`10000
`
`30
`
`Intake vaalve
`closing delay
`
`33
`
`32
`
`31
`
`1.1
`1
`0.9
`0.8
`0.7
`Brake mean effective pressure under full load (MPai
`
`g
`Z0C
`.9
`.2
`fi
`Tu
`.3
`E.u:x
`E
`to
`
`E{
`
`10
`
`100
`
`1000
`
`Cylinder volume (cc)
`
`_
`High—expansmn-
`
`ratio cycle
`Conventionai
`
`Otto
`
`
`
`10
`
`100 ‘ 1000
`
`
`
`Pressure(kPa)
`
`1000
`
`100
`
`10
`
`Cylinder volume ice)
`
`Fig. 7 p-V Diagrams with
`Equivalent
`Charging Efficiency
`
`Fig. 8 p-V Diagrams with
`Equivalent
`Compression End
`Pressure
`
`TOYOTA Technical Review Vol. 47 No. 2 Apr. 1998
`
`Fig. 10 Relationship of Brake Mean Effective Pressure
`and Thermal Efficiency as Expansion Ratio and
`Compression Ratio Change
`
`55
`
`FORD 1127
`
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`
`
`
`
`
`
`all-f
`
`Cumulative
`
`”Md:
`Ln ,
`iillliililln......
`tiara”
`1111! [ll
`
`0
`
`20
`
`180000
`1500cc
`1300cc
`
`1000cc
`
`30
`
`100
`
`50
`
`.
`
`40
`
`
`
`
`
`
`
`n.
`E
`EU
`r:
`2?:o.
`
`1.35
`
`1.30
`
`1.25
`0.2
`
`0.22
`
`0.24
`
`0.25
`
`0.28
`
`SN ratio (11mm)
`
`
`
`
`
`
`
`30
`
`20
`
`.
`
`.4
`-/
`.1
`
`Urban mode
`EBubUrban m
`
`ode
`
`12%) CumulativeBrakethermalefficiency frequency(sec)
`
`Fig. 3 Relationship of SIV Ratio and Indicated Mean
`Effective Pressure
`
`Fig. 5 Displacement and Engine Efficiency
`
`Engine output (kW)
`
`54
`
`Page 8 of 11
`
`Page 8 of 11
`
`FORD 1127
`
`

`

`A High-Expansion—Raiio Gasoline Engine for the TOYOTA Hybrid System
`
`combustion chamber volume and the adhesion of deposits in the com—
`bustion chamber, in order to leave a margin for pro-ignition.
`
`ventional engines and that the objective of reducing friction loss was
`achieved.
`
`1000 rpm
`
`Black points are trace knock
`
`80
`
`120
`
`80
`lg/kWh} 220
`BSFC
`
`Intake valve
`A closing
`Intake valve
`I] closing
`
`9
`so Aeoc
`0
`
`90
`
`ABDC
`
`260
`
`240
`
`100
`
`
`
`Torquelel
`
`Expansion ratio
`
`70
`
`60
`280
`
`260
`
`240
`
`220
`
`E.
`
`2.
`g
`E"
`,9
`
`E E
`
`2"
`L)
`
`a
`no
`
`4.2 Engine Structure
`
`Fig. 12 is a transverse sectional view of the high-expansion-ratio
`engine. An aluminum—alloy cylinder block, offset crankshaftfl‘” and
`ladder-frame structure are used. The crankshaft has been made thin-
`
`ner and lighter, and the load on the valve system springs has been re-
`duced, as has the tensile strength of the piston rings. The connecting
`rod/stroke ratio has been increased, and the intake inertia effect has
`
`been reduced by using a small intake manifold. The engine also uses
`a slant squish combustion chamber. All of these features combine to
`achieve lighter weight, lower friction, and improved combustion.
`
`
`
`Conventionai
`1.5-liter engine
`
`Ignition advance (degrees BTDC)
`
`1000
`
`2000
`
`3000
`
`4000
`
`Fig. 13 Relationship of Ignition Timing and BSFC
`
`Engine speed (rpml
`
`Fig. 15 Torque Improvement Effect of VVT-i
`
`THS engine
`
`
`
`40
`
`is delayed at the same time, knocking gradually diminishes and effie
`ciency improves. Therefore, if the brake mean effective pressure is al-
`lowed to fall, the combination of high expansion ratio and delayed in-
`take valve closing achieves high efficiency. Fig. 11 is an indicator
`diagram of actual measured results showing that the heat cycle illus-
`trated in Fig. 7 and Fig. 8 was achieved.
`
`10000
`
`1000
`
`100
`
`10
`
`E
`5
`9D(I)(0
`2a.
`
`Conventional Otto
`cycle
`
`High-expansion- ratio cycle 1
`
`10
`
`100
`
`1000
`
`Cylinder volume (cc)
`
`Fig. 11 Indicator Diagram of Actual Measurements
`
`4. High-expansion-ratio THS Engine
`
`
`
`
`
`
`
`
`
`
`Table 1 shows the main specifications for the high-expansion-ratio
`engine. The mechanical compression ratio is set to 13.5:1, but the ef-
`fective compression ratio is suppressed to the range of 4.8:1 to 9.3:1
`by using intelligent variable valve timing (VVT-i) to time the intake
`valve closing between 80° and 120° after bottom dead center (ABDC).
`The ratio of 4.8:1 is obtained by the maximum delay of VVT-i and is
`used to counter vibration during engine restart, as explained below.
`
`Table 1 Design Specifications
`
`Engine model
`
`1Nz—FXE
`
`o75>< 84.7
`
`1497
`
`Displacement (cc)
` Borax stroke
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`56
`
`
`
`
`
`
`
`Frictionloss(MPal
`
`THS engine
`
`0
`
`1500
`
`3200
`
`4800
`
`6400
`
`Engine speed (rpm)
`
`Fig. 16 Comparison of Friction Loss
`
`5.4 Reduction of Exhaust Emissions
`
`The advantages and disadvantages of the hybrid vehicle with re-
`
`spect to cleaner exhaust emissions are summarized below.
`Advantages
`
`(1) By using the supplementary drive power of the electric motor, the
`system eliminates the light-load range, where concentrations of
`hydrocarbons in the emissions are high and the exhaust tempera-
`ture is low.
`
`57
`
`
`
`35
`
`30
`
`0
`
`10
`
`20
`
`30
`
`40
`
`50
`
`Engine output (kW)
`
`g
`>-UC
`.9
`.2
`s:a:
`TD
`13
`5.OJA:
`Eto
`
`E2
`
`Fig. 14 Expansion Ratio and Brake Thermal Efficiency
`
`5.2 Torque Improvement by VVT—i
`
`Full-load torque was adjusted using VVT-i. The results are shown
`in Fig. 15. An improvement in torque of 10% or more was made pos-
`sible by advancing the intake valve closing by 10°.
`In THS, the en-
`gine is controlled so that intake valve closing is advanced when the
`load requirements are high.
`
`5.3 Friction Loss
`
`As stated previously, the engine speed was lowered in an attempt to
`reduce friction loss. The measured results are shown in Fig. 16.
`It
`
`can be seen that the friction loss for the hightexpansion-ratio engine is
`
`at a consistently lower level than the cluster of points plotted for con-
`
`TOYOTA Technical Review Vol. 47 No. 2 Apr. 1998
`
`This section summarizes the results of experiments conducted on
`the 1.5—1iter high—expansion-ratio engine and some considerations con-
`cerning them.
`
`5.1 Relationship of Expansion Ratio and Brake Thermal
`Efficiency
`
`Fig. 13 shows the relationship of ignition timing to torque and to
`
`brake specific fuel consumption (BSFC). Expansion ratios of 13:1,
`14:1, and 15:1 were compared, and it can be seen that as the expan-
`sion ratio increases, the trace knock ignition timing is delayed. With a
`15 :1 expansion ratio, the efficiency improves at the point of minimum
`
`spark advance for best torque (MET), but the expansion ratio is re-
`stricted by the knocking that occurs due to the high effective compres-
`sion ratio. The best results in terms of torque and BSFC were ob-
`tained with an expansion ratio of 14: 1.
`Fig. 14 shows the results of a study of thermal efficiency versus
`
`engine output. A 14:1 expansion ratio showed the best results over
`the entire output range. Ultimately, an expansion ratio of 13.5:1 was
`chosen, taking into account such factors as the allowable variation in
`
`4.1 Basic Specifications
`
`5. Experimental Results and Considerations
`
`Fig. 12 Transverse Section of High-expansion-ratio Engine
`
`Page 9 of 11
`
`
`FORD 1127
`
`Page 9 of 11
`
`FORD 1127
`
`

`

`
`
`A High-Expansion-Ra’tio Gasoline Engine for the TOYOTA Hybrid System
`
`N...
`
`Intake valve
`
`closing 90°
`
`ABDC
`
`Hih
`VIIIIII"
`i
`
`"
`
`.l
`
`Intake valve
`
`closing 120°
`ABDC
`
`0
`
`0.2
`
`0.4
`Time Isec.)
`
`0.6
`
`0.8
`
`1
`
`3‘5
`E
`S
`.33
`2
`
`g
`<1
`
`
`
`
`
`Cylinderpressure(MPaI
`
`Intake valve closing timing
`90”
`ABDC
`1 14°
`125°
`78°
`
`Intake valve
`
`closing 120“
`
`0
`
`400
`
`800
`
`1200
`
`Engine speed (rpm)
`
`(2) By allocating a portion of the load to the electric motor, the system
`is able to reduce engine load fluctuation under conditions such as
`rapid acceleration. This makes it possible to reduce quick transients
`in engine load so that the air—fuel ratio can be stabilized easily.
`Disadvantages
`(1) Because the engine is used in the high-efficiency range, the ex-
`haust temperatures are lower than for a conventional vehicle.
`(2) There is concern that the more the engine is stopped and restarted,
`the more unburned fuel will enter the exhaust system and the more
`the catalyst bed temperature will drop.
`Fig. 17 shows the exhaust temperature distribution for the high-ex-
`pansion-ratio engine. Although the exhaust temperatures are lower
`than for a conventional engine, a minimum temperature of 400°C is
`ensured for the engine operating range shown in the diagram. This is
`a temperature that can maintain the catalyst in an activated state.
`
`Fig. 18 shows the change in the catalyst bed temperature after the
`vehicle stops.
`In a conventional vehicle, where the engine continues
`to idle, the catalyst bed temperature slowly drops. But in the THS ve—
`hicle, the influx of low-temperature exhaust gases can be avoided by
`stopping the engine, making it possible to sustain a comparatively
`gradual decline in temperature.
`Fig. 19 shows the levels of exhaust gases at the catalyst inlet.
`Hydrocarbons are at the same level as a conventional vehicle, which is
`
`(”Cl
`Catalystbedtemperature
`
`
`Engine stopped
`
`Idling at 1000 rpm
`
`200
`
`Time Imin.)
`
`Fig. 18 Change in Catalyst Bed Temperature with
`Engine Stopped
`
`10 - 15 mode
`
`g
`
`C
`.9
`d.)
`
`10
`
`0
`
`E
`«5
`g -10
`0
`4
`
`E
`3 1000
`
`'6CI)OJQin
`
`3
`.5)
`E
`
`0
`-0.2
`
`
`
`Conventional
`
`1.2
`
`0.8
`
`0.4
`
`HCCONOX(g/kml HC
`
`
`Fig. 20 Vibration When Engine Starts
`
`Fig. 21 Relationship of Engine Speed and Cylinder
`Pressure
`
`5.6 Low-temperature Starting
`
`.p.o
`
`Brakethermalefficiency(%I
`
`NOX
`
`
`
`
`
`
`
`
`
`
`
`thought to be due to the smaller volume and higher S/V ratio of the
`combustion chamber. However, as explained previously, the catalyst
`is maintained in an activated state that is sufficient to ensure a high
`rate of catalytic conversion.
`Exploiting the advantages cited above based on these results,
`Toyota optimized the system to achieve the voluntary emissions target
`of one-tenth of the current standard values.
`
`120
`
`100
`
`80
`
`60
`
`::
`
`Torque
`
`[le
`
`THS engine operating range
`
`K
`
`5_°°\\\\\
`
`Exhaust temperature (“Cl
`
`300
`
`1600
`
`2400
`
`3200
`
`4000
`
`Engine speed (rpml
`
`Fig. 17 Exhaust Temperature Map
`
`58
`
`Page 10 of11
`
`
`Fig. 19 Comparison of Emissions at Catalyst Inlet
`
`5.5 Vibration Countermeasures When Starting and
`Stopping
`
`Stopping the engine when the vehicle stops contributes greatly to
`fuel economy, realizing a 20% improvement in the 10-15 mode. On
`
`the other hand, problems have been raised with vibration as the engine
`speed passes through the resonance point of the drive train, as well as
`
`vibration due to the brief continuation of the compression and expan
`sion cycle when the engine stops. The drive train resonance problem
`is solved by using the motor to raise the engine speed in a shorter
`time.
`It was thought that the compression and expansion cycle could
`be moderated by reducing the volume of air when the engine is shut
`off. The VVT-i function is used to reduce the volume of the intake air.
`
`Fig. 20 shows floor vibration when the engine starts. The large am—
`plitude of acceleration seen in area A in the diagram is due to the come
`
`pression reaction force. This amplitude can be reduced considerably, as
`shown in area A', by using VVT—i to set the timing of intake valve close
`
`ing to 120° ABDC. The vibration seen in area B arises from the rapid
`increase in engine torque after the engine starts firing. This is eliminatr
`
`ed by controlling the ignition timing delay, as shown in area B'.
`
`In the THS system, the generator is used as a starter motor to start
`the engine turning. For this purpose, the generator uses the large—ca—
`pacity nickel-metal hydride battery as a power supply. However, as
`the temperature drops, the battery power also drops, reducing the
`cranking speed. On the other hand, the significant delay in intake
`valve closing in the high—expansion-ratio engine reduces the compres-
`sion end pressure (the maximum pressure within the cylinder) during
`cranking. The relationship between cylinder pressure and engine
`speed is shown in Fig. 21, using intake valve closing timing as a para-
`meter. Given the combustion characteristics of the engine, the maxi-
`mum pressure at which ignition is possible is approximately 0.85
`MPa. In the THS system, th