United States Patent
`Tabata et at.
`
`[19]
`
`[54] HYBRID VElllCLE DRIVE SYSTEM HAVING
`A DRIVE MODE USING BOTH ENGINE AND
`ELECTRIC MOTOR
`
`[75]
`
`Inventors: Atsushi Thbnta, Okazaki; Yutaka
`Taga, Aichi-kcn; Ryuji Ibaraki,
`Toyota; Thuyoshi Mikami, Toyota;
`Hiroshi Hata, Toyota, all of Japan
`
`[73] Assignee; Toyota Jidosha Kabushiki Kaisha,
`Toyota, Japan
`
`[21]
`
`[22]
`
`[30J
`
`Appl. No : 805,164
`
`Filed:
`
`Feb. 24, 1997
`
`Foreign Application Priority Data
`
`Feb. 29, 1996
`May 27, 1996
`[51J Int. CI.'
`[52] U.S. CI.
`
`[JP]
`[lPl
`
`Japan
`Japan
`
`....... 8-042943
`8-132105
`
`.
`
`H02P 9/04
`............. 290/40 C; 180/65.4; 290/16;
`290/27; 3181143; 322/16
`290/11,16,27,
`Field of Search
`290/40 C; 180/65.1, 65.4; 318/139, 143;
`322/14. 15, 16
`
`[58]
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`5,176,213
`5,343.970
`5,545,928
`5,550,445
`5,588,498
`
`1/1993
`9/1994
`8/1996
`R/1996
`12/1996
`
`Kawai et aL
`Sevcrinsky .
`Kotani
`Nii
`Kilada
`
`.
`
`180(243
`180/65.2
`290/40 C
`3t8/153
`180/65.4
`
`22r'
`
`I11111111111111111111111111111111111111111111111111111111 1l1li1111111111111
`US005841201A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,841,201
`Nov. 24, 1998
`
`5,621,304
`5,650,931
`5,656,921
`5,698,955
`5,722,911
`5,751;137
`
`411997
`7/1997
`8/1997
`12/1997
`3/1998
`511998
`
`Kiuchi ct al.
`Nii
`FarraH
`Nii
`Ibaraki et al.
`IGuchi et al.
`
`..
`
`322/18
`364/424.026
`322/40
`318/139
`477/3
`322/14
`
`..
`
`FOREIGN PATENT DOCUMENTS
`
`A-3-121928
`A-6-80048
`
`511991
`3/1994
`
`Japan.
`Japan.
`
`Primary Examiner-Steven L Stephan
`Assistant Examiner-Nicholas Ponomarenko
`Attorney, Agent) or Firm--Dliff & Berridge, PLC
`
`[57]
`
`ABSTRACT
`
`A hybrid drive system for a motor vehicle, having a power
`drive state in which there is available a power drive mode in
`which an enginc and an electric motor arc both operated as
`a drivc powcr source for driving the vehicle, and wherein a
`manually operated power drive selector is provided for
`selecting the power drive mode, and a power drive restrict(cid:173)
`ing device is provided to inhibit
`the vehicle from being
`driven in the power drive state and therefore in the power
`drive mode if the power drive selector is nol manually
`operated. TIle hybrid drive system may have an engine assist
`drive mode in which the electric motor is operated as an
`auxiliary drive power source,
`together with the engine
`operated as a primary drive power source, according to a
`selected one of dilTerent drivability modes of the vehicle
`selected by a manually operated drivability performance
`selector.
`
`12 Claims, 21 Drawing Sheets
`
`)0
`
`r 24
`
`ENGINE
`CONTROLLER
`I
`INTERNAL
`COMBUSTION
`ENGINE
`
`12.
`
`OUTPUT DEVICE I
`\...18
`
`ELECTRIC
`ENERGY
`STORAGE
`DEVICE
`T,
`r20
`MOTOR/'
`r?' GENERATOR
`CONTROLLER
`t
`ELECTRIC
`MOTOR
`
`14..1
`
`r 16
`ITRANSMISSION
`26, T
`
`SOC
`
`CONTROL
`DEVICE
`
`TE, TM, BA
`NE, NM, No
`
`9
`EXHIBIT
`WIT: N: ;j11,,~e IffINl/?
`'1- 10 -20105-
`DATE:
`JANET A, HAMILTON, ADA
`
`Page 1 of43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 1 of 21
`
`5,841,201
`
`22
`
`/
`
`ELECTRIC
`ENERGY
`STORAGE
`DEVICE
`
`t
`,20
`MOTOR/'
`r7 GENERATOR
`CONTROLLER
`t
`
`ELECTRIC
`MOTOR
`
`14./
`
`SOC
`
`/16
`ITRANSMISSION:
`t
`26,
`
`~
`
`CONTROL
`DEVICE
`
`I'
`
`TE, TM, 8A
`NE, NM, No
`
`) 0
`
`/24
`
`ENGINE
`CONTROLLER
`I
`INTERNAL
`COMBUSTION
`ENGINE
`
`/12.
`
`: OUTPUT DEVICE I
`\...18
`
`FIG. 1
`
`Page 2 of43
`
`FORD 1245
`
`

`

`'""
`"'"" ~
`
`No"
`
`.,I;;.
`
`Q
`~O
`
`til
`
`FIG.2
`
`116
`
`~24126)
`
`,122
`
`120
`
`\
`
`112
`
`108
`
`~106
`
`104
`
`~
`
`114
`
`rJ).
`
`."'"
`
`>-'
`
`~
`
`z~ N
`
`==-
`~(cid:173)~
`
`"'0
`F1.
`
`d•r
`
`..
`:4
`if
`
`-'
`
`
`
`No.N>
`
`I
`
`.,-
`
`110
`
`(
`
`L.IL.II
`
`.L
`
`.L
`
`82
`
`81
`
`~32
`
`118a
`
`CONBUSTION
`
`ENGINE
`INTERNAL
`
`12
`
`100
`
`c
`
`MOTOR
`ELECTRIC
`
`14
`
`Wo-"
`
`'"w
`
`(I)
`to
`113
`"tl
`
`FORD 1245
`
`

`

`U.S. Patent
`
`Nov. 24, 1998
`
`Sheet 3 of 21
`
`5,841,201
`
`32\
`
`SP
`
`soc
`
`(40
`
`/"42
`,
`
`~
`
`POWER DRIVE
`RESTRICTING
`MEANS
`
`POWER DRIVE
`MODE INHIBITING
`MEANS
`
`SD
`
`44\
`,
`
`POWER-
`NORMAL
`SWITCHING
`MEANS
`I
`
`NORMAL
`DRIVE
`CONTROL
`MEANS
`
`'-34
`
`I,
`POWER
`DRIVE
`CONTROL
`MEANS
`'-36
`
`FIG.3
`
`ENGINE
`DRIVE
`&CHARGING
`MODE
`CONTROL
`MEANS
`,-.
`38
`
`Page 4 of 43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 4 of 21
`
`5,841,201
`
`34
`46 ~
`
`/'"
`
`,-:
`50
`Ilt
`COMPARING
`MEANS
`11
`
`,....52
`
`MEMORY
`MEANS
`
`FIRST
`CALCULATING
`MEANS
`
`4
`
`SECOND
`CALCULATING
`MEANS
`
`\.:.
`
`48
`
`FIG.4
`
`Page 5 of 43
`
`FORD 1245
`
`

`

`U.S. Patent
`
`Nov. 24, 1998
`
`Sheet 5 of 21
`
`5,841,201
`
`81
`
`READING INPUT SIGNALS
`SP, TE' TM' eA' NE' NM' NO, SOC, ETC.
`
`FIG.5
`
`NO
`
`NO
`
`x
`
`YES
`
`NO
`
`89
`CALCULATING
`Mlcm AND Mice
`
`810
`
`YES
`
`811
`MOTOR DRIVE
`MODE
`SUB·ROUTINE
`
`NO
`
`812
`ENGINE DRIVE
`MODE
`SUB-ROUTINE
`
`YES
`
`83
`,----C' 80C > A
`NO
`?
`
`84
`
`YES
`
`YES
`
`86
`POWER DRIVE
`MODE OFF
`INDICATOR 30
`TURNED ON
`
`I?--fx
`
`87
`ENGINE DRIVE
`& CHARGING
`MODE
`SUB-ROUTINE
`
`85
`ENGINE'MOTOR
`DRIVE MODE
`SUB-ROUTINE
`
`RETURN
`
`Page 6 of43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 6 of 21
`
`5,841,201
`
`FIG. 6
`
`(
`
`)
`
`ENGINE DRIVE &CHARGING MODE SUB-ROUTINE
`_1-,
`PICE = PL IN 1ST CYCLE
`PICE = PICE +llPICE
`IN 2ND AND SUBSEQUENT
`CYCLES
`
`R1
`
`I
`CALCULATING 1JICE
`1
`CALCULATING AND
`STORING 1JT
`1
`PICE> PE?
`
`R4
`
`TYES
`
`NO
`
`SELECTING PICE WHOSE
`1JT IS MAXIMUM
`I
`OPERATING ENGINE WITH
`PICE AND SETTING PGEN
`1
`END
`
`)
`
`(
`
`R2
`
`R3
`
`R5
`
`R6
`
`Page 7 of 43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 7 of 21
`
`5,841,201
`
`FIG.7
`
`7JICEmax
`
`ENGINE SPEED NE
`
`FIG.8
`
`7JMOTmax
`
`MOTOR SPEED NM
`
`o
`
`o
`
`wf
`
`(cid:173)W~aa
`
`:2w:
`
`z:
`CJ:z:
`w
`
`~f
`
`(cid:173)W~aa
`
`f(cid:173)
`
`:o
`a:5:::;;:
`
`Page 8 of 43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 8 of 21
`
`5,841,201
`
`FIG.9
`
`( PICE - PL)
`
`PICE
`
`PL
`
`o
`
`ENGINE SPEED NE
`
`LU
`I-
`
`w:
`
`:::>aa:
`
`0
`I-
`z
`Cl
`:z:
`w
`
`w:
`
`Page 9 of 43
`
`FORD 1245
`
`

`

`~No~
`
`e
`~o
`
`,l:;;o.
`
`01
`
`...
`""o...,
`i4
`if
`r.F:J
`
`N.
`
`""""QO
`~....
`
`zo:
`' N.
`
`~(cid:173)l'll :=-
`
`""0
`Fl .
`
`d•C
`
`10
`
`FIG.
`
`219
`
`~\
`l~I.V---r-trl
`
`238F2
`
`236
`
`234
`.-=::;/C-.--ijt.....l
`
`"
`
`I
`
`1
`
`I
`
`C2
`
`1
`
`218~
`232
`_._/
`rF
`I~:::jlJdJ.)-,J~L)
`
`)22~FO
`
`216
`
`r
`I
`
`',,-224
`
`230~.I
`
`1111'I'nilII(LrrI1I
`
`+-
`B4
`
`210
`
`/
`
`83
`
`,/
`
`222
`
`,
`
`8
`
`S,
`
`220
`
`(
`
`,
`
`0
`
`~E2C~r'8
`
`214
`
`E/G
`
`212
`
`228
`
`-Ilo
`....
`CD....o
`
`o.
`
`W
`
`to
`III
`"'0
`
`FORD 1245
`
`

`

`-'
`
`NoI
`~
`
`I-'
`,j;;;,.
`Oe
`01
`
`....
`
`Q"-(cid:173)N.
`
`.....
`
`en=(cid:173) '"~
`
`.....
`.....
`
`z":
`' N
`
`~
`
`"'t:le.~=-
`
`F.J. .
`
`d•\
`
`LL
`SL1ISL2SLS!SL41su.iTSL-iTSLN
`
`J
`
`214
`
`)
`
`2;8
`
`-1---252
`
`I
`~
`
`TIMING
`IGNITION
`
`t
`
`:n
`CJ
`CJ
`:IJ
`o:J
`-<
`:c
`
`<m
`00Z
`
`0
`
`n
`m:
`
`r-
`r-
`:n
`---i
`
`:noo Z
`m--
`~cn---l
`0(1»>
`:n:s:;::s:;:
`---i(l)o
`ZZ---i
`o::t>c
`0:n::t>
`
`---i
`
`/210
`
`2(4
`
`112(2
`
`FUELINJECTION
`
`AMOUNT
`
`t
`
`0J
`
`11'
`
`2~0
`
`NE
`TM
`NM
`(JAC
`
`ENGINESPEEDSENSOR
`
`MOTORAMMETER
`
`MOTORSPEEDSENSOR
`ACCELERATORSENSOR
`
`FIG.11
`
`L-...
`L'::;
`
`jNrll
`
`n
`
`SHIFT-DOWNSWITCH
`
`SHIFT-UPSWITCH
`
`+-
`-INPUTSHAFTSPEEDSENSOR
`
`MANUALMODESWITCH
`
`SELECTORSWITCH
`
`SHIFTPATIERN
`
`SHIFTPOSITIONSENSOR
`
`BRAKESWITCH
`
`+-
`
`+-
`
`243
`242
`24
`276
`
`278
`
`274
`
`272
`
`No(V)
`TE
`
`VEHICLESPEEDSENSOR
`
`THROTILESENSOR
`
`-
`-
`
`27
`26
`
`
`
`----
`
`
`
`
`
`266
`265
`264
`262
`
`o-"
`
`'"w
`(I).... ....
`
`(Q
`III
`"'0
`
`FORD 1245
`
`

`

`t=- ~:
`~ ~ '
`~1
`
`....
`..... ~
`,j;;;,.
`00
`01
`
`No.
`
`~
`
`....
`<0...,
`,....
`
`N,
`
`'JJ=(cid:173) '"'"... ,....
`
`Xl
`
`~<
`
`.... ,....
`
`'N
`
`"':I
`
`0.753
`
`1.000
`
`1.424
`
`2.180
`
`3.357
`
`-3.431
`
`-4.550
`
`-
`
`RATIO
`SPEED
`
`0
`
`0
`
`00
`
`•0
`
`0
`
`0
`
`00
`
`0
`
`000
`
`0
`
`•0
`
`0
`
`000
`00
`
`•0
`
`00
`
`00
`
`0
`
`0
`
`0
`
`CoC1C2BoB1B2B3B4FaF1F2
`CLUTCHES
`ONE-WAY
`
`CLUTCHES
`
`BRAKES
`FIG.12
`
`5th
`
`4th
`
`3rd
`
`2nd
`
`151
`
`Rev2
`
`Rev1
`
`DRIVE
`
`REVERSE
`
`N
`
`NEUTRAL
`
`TRANSMISSION
`
`LEVER
`SHIFT
`
`""Co)
`...
`CD....
`
`I\J
`
`o.
`
`(Q
`III
`"'0
`
`FORD 1245
`
`

`

`-/0
`
`No1
`
`1-/0
`.&;;..
`
`e
`~o
`
`!.Jl
`
`'"'
`
`N"
`
`."
`
`o,
`
`"'"' N
`
`en=(cid:173) '"'"~
`
`"'"'~
`....
`
`~;
`< N
`
`00
`
`~(cid:173)~=-
`
`"tI
`:.n •
`cj
`
`•r
`
`~
`
`~
`
`""421p
`
`421
`
`-b---I--406
`
`82
`
`404
`
`403
`
`412
`
`~=
`~=
`
`~~
`
`377
`
`SLU
`
`=
`
`(83
`
`SLU
`
`P
`
`410
`
`u
`
`---=
`
`83
`'-411
`
`~3
`
`.-z.384n
`
`378----------
`
`=
`
`382
`
`....---376
`
`385
`
`12.2-3
`
`J<345
`
`400
`
`'>t------!:::1'--;;:il:J,!ll;
`
`EX
`
`399
`
`FIG.13
`
`423
`
`Ii
`
`.
`
`Ii
`
`.
`
`I1I1
`
`415
`
`387
`
`417
`
`394
`
`Co)
`
`418
`375
`
`\.395
`
`1.2
`<~
`
`~--"'---
`
`EX
`
`~
`
`393
`419
`
`:,=
`
`389
`420401"
`
`413
`
`C2
`
`402
`
`~372387
`
`SL3
`
`416
`
`EX
`
`386
`
`EX
`
`374
`
`,--371
`
`370
`
`~3
`
`EX
`
`"'"w
`....
`(1)....w
`II) co
`"tI
`
`o.
`
`FORD 1245
`
`

`

`U.S. Patent
`
`Nov. 24, 1998
`
`Sheet 13 of 21
`
`5,841,201
`
`256\
`
`MOTOR/
`GENERATOR
`CONTROLLER
`
`250
`
`(
`
`I
`
`cr:
`w
`-'
`-'
`r:
`I-
`:z
`0
`<.:)
`
`0c
`
`w>
`
`cr:
`
`00
`
`cr:
`In
`>-
`I
`
`Page 14 of 43
`
`ENERGY
`STORAGE
`DEVICE
`
`CE1\
`
`: FIRST CLUTCH
`
`CE2~
`
`>1 SECOND CLUTCH I
`
`FIG. 14
`
`214\
`
`-
`
`MOTOR/
`GENERATOR
`
`c-
`
`258\
`
`!L ELECTRIC
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 14 of 21
`
`5,841,201
`
`OPERATION MODE DETERMINING SUB-ROUTINE FIG. 15
`
`YES
`81.......-:::ENGINE
`,-_STARTING >----------------;
`REQUIRED?
`82 ~S-EL....JEC-T-ING.....,
`.---~
`MODE 9
`NO
`
`NO
`
`83
`
`BRAKING
`YES
`REQUIRED?
`YES
`~ 85 SELECTING
`87 VEHICLE START YES
`MODE 8
`< BY ENGINE~ ~
`A 8s
`REQUIRED?
`NO
`ACCELERATOR NO
`<-DEPRESSED ?>-----~
`810 SELECTING
`YES '------------,
`MODE 7
`
`SELECTING 86
`MODE 6
`
`NO
`
`89 SELECTING
`MODE 5
`
`815
`<P1<Pd<P2?
`
`NO
`
`NO
`
`YES
`
`YES
`
`YES
`
`813
`
`SELECTING
`MODE 1
`
`YES
`
`817
`i-S-EL....JEC-TI---'-NG-'
`MODE 2
`
`814
`SELECTING
`MODE 3
`
`SELECTING 819
`MODE 4
`
`Page 15 of 43
`
`FORD 1245
`
`

`

`..
`rJJ=(cid:173) '"~
`
`'Jl
`>-'
`
`N>
`C.
`
`-'
`
`>-'
`.J;,.
`
`O
`
`~Q
`
`zc:
`" N
`
`==-
`~(cid:173)~
`
`"":l
`F.J.
`
`d•\
`
`MOTORDRIVE
`
`DISCHARGED
`
`OFF
`
`MODENOMENCLATURE
`
`STORAGEDEVICE58
`
`ENGINE12
`
`FIG.16
`
`0"'"~
`
`No~
`
`~0
`
`ENGINESTARTING
`
`DISCHARGED
`
`START
`
`(h
`
`ENGINEBRAKING
`
`NOENG.CSMD
`
`ELECTRICNEUTRALITY
`
`NOENG.CSMD
`
`REGENERATIVEBRAKING
`
`VEHICLESTARTBYENGINE
`
`CHARGED
`
`CHARGED
`
`ENGINE'MOTORDRIVE
`
`DISCHARGED
`
`ENGINEDRIVE+CHARGING
`
`CHARGED
`
`ENGINEDRIVE
`
`NOENG.CSMD
`
`OFF
`
`ON
`
`OFF
`
`ON
`
`ON
`
`ON
`
`ON
`
`ON
`
`ON
`
`OFF
`
`ON
`
`ON
`
`ON
`
`ON
`
`OFF
`
`OFF
`
`ON
`
`ON
`
`ON
`
`ON
`
`CE2
`
`ON
`
`ON
`
`.
`
`ON
`
`ON
`
`OFF
`
`CE1
`
`CLUTCHES
`
`1
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`8
`
`9
`
`MODE
`
`"'"w
`...
`(!)....
`
`0)
`
`o.
`
`CO
`III
`"'0
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 16 of 21
`
`5,841,201
`
`VEHICLE
`REAR
`
`RIGHT
`
`LEFT
`
`VEHICLE
`FRONT
`
`(
`
`240
`
`243
`
`FIG. 17
`
`Page 17 of 43
`
`FORD 1245
`
`

`

`U.S. Patent
`
`Nov. 24, 1998
`
`Sheet 17 of 21
`
`5,841,201
`
`VEHICLE
`FRONT
`
`p)
`
`R
`
`~
`
`N I
`
`3-- 0 - OM
`
`FIG. 18
`
`~
`
`L
`
`I2
`
`(258
`r------+-'
`ELECTRIC
`ENERGY
`STORAGE
`DEVICE
`
`(242
`
`FIG. 19
`
`252
`
`AUTOMATIC
`TRANSMISSION
`CONTROLLER
`
`"'-243
`
`Page 18 of 43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 18 of 21
`
`5,841,201
`
`ENGINE ASSIST CONTROL SUB-ROUTINE
`
`SA1
`----NORMAL DRIVE
`~---> POWER DRIVE?
`
`NO
`
`YESI<E----<
`YES
`
`o ---> OM
`?
`
`NO
`SA3
`----POWER DRIVE
`<-...---> NORMAL DRIVE?
`
`SA? NO ~-----,
`
`ENGINE ASSIST
`CONTROL
`OF MOTOR
`DEFERRED
`
`SA8
`
`'-------71 YES
`SAg
`ENGINE ASSIST
`CONTROL
`OF MOTOR
`INITIATED
`
`RETURN
`
`Page 19 of 43
`
`FIG. 20
`
`NO
`
`DM - 0
`?
`
`NO
`
`SA15
`
`SM
`YESI<E-_---<:
`YES
`
`~_...l.-_-..,
`
`~Hf~tHp~~t~~E~E~~bMVTEED'YES
`
`OR SHIFT LEVER PLACED
`IN MANUAL DRIVE
`POSITION "DM" ?
`
`SA11
`
`TO SAg
`
`NO
`
`NO
`
`eAC2;;;' ea
`?
`,----~YES
`SA12
`TERMINATION OF
`ENGINE ASSIST
`CONTROL
`DEFERRED
`
`SA13
`
`YES I<E-------.J
`
`SA14
`ENGINE ASSIST
`CONTROL
`OF MOTOR
`TERMINATED
`
`FORD 1245
`
`

`

`U.S. Patent
`
`Nov. 24, 1998
`
`Sheet 19 of 21
`
`5,841,201
`
`III
`
`---
`
`FIG. 21
`
`ACCELERATOR PEDAL
`OPERATION AMOUNT BAC
`
`w:
`
`::>a
`
`0:
`
`2w:
`
`>
`0:o
`
`Page 20 of 43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 20 of 21
`
`5,841,201
`
`Q)
`
`~N
`
`C\J
`Il..
`
`co
`C')
`N
`
`<0
`C')
`
`N '
`
`<t
`C')
`N
`
`C\J
`
`('I')
`U <0
`C\J
`•
`N CJ
`-
`LL
`
`N
`
`~
`
`Il..
`
`<0
`N
`
`~
`
`=-11....1 ..,
`
`"
`co
`~~1
`
`g~
`N
`
`~n
`U
`
`0
`
`~
`
`co
`
`C\J
`
`co
`
`W
`
`'<t
`
`NN
`
`~'
`
`C\J
`
`U0
`WU,H]
`~y.
`
`N
`\J
`
`~C
`
`(!J
`
`--W
`
`C\J
`
`co
`C\J
`C\J
`
`0
`L!)
`'<t
`
`~
`
`Page 21 of 43
`
`FORD 1245
`
`

`

`u.s. Patent
`
`Nov. 24, 1998
`
`Sheet 21 of 21
`
`5,841,201
`
`~
`
`0
`co
`'"
`
`0
`
`.,.
`'"
`":
`
`~
`
`0
`
`0
`
`•
`
`0
`
`1'.'
`'"
`
`0
`a
`~
`
`~
`
`0
`
`0
`0
`
`-
`.c
`.,.
`
`0
`
`>
`'"
`a:
`
`W
`(f)
`cr:.
`w
`>
`W
`a:
`
`0
`
`0
`
`1iJ
`
`~
`
`"0
`c
`<OJ
`
`W
`>
`a:
`Cl
`
`°0
`w-
`wI-
`a..-eX:
`(f)cr:.
`
`I
`
`0
`
`'"
`'"
`'"
`I
`
`r--
`LD
`'"
`coi
`
`0
`
`0 •
`
`>-~
`-eX:::r:
`So
`'I-w:::>
`Z-l
`0 0
`
`(f)
`w
`Y:
`-eX:
`cr:.
`co
`
`(f)
`w
`::r:
`<..)
`I-
`:::>
`-l
`<..)
`
`'"
`
`LL
`
`~
`
`LL
`..,.
`CO
`'"
`CO
`
`N
`CO
`
`~
`
`CO
`'"
`
`0
`
`~
`
`0
`
`CJ-LL
`
`Z
`
`:z
`
`0(
`
`f)
`(f)
`::2
`(f)
`
`Z-
`
`eX:
`cr:.
`I-
`
`-l
`-eX:
`I-cr:.
`cr:.
`LLW
`-> I-
`::r: w
`:::>
`(f)-l
`w
`Z
`
`Page 22 of 43
`
`FORD 1245
`
`

`

`5,841,201
`
`1
`HYBRID VEHICLE DRIVE SYSTEM HAVING
`A DRIVE MODE USING BOTH ENGINE AND
`ELECTRIC MOTOR
`
`This application is based on Japanese Patent Applications
`No. 8-42943 filed Feb. 29, 1996 and No. 8-132105 filed May
`27, 1996, the contents of which are incorporated hereinto by
`reference.
`
`CROSS REfERENCE TO RELATED
`APPLICATIONS
`
`U.S. patent application SeI. No. 08/685,102 filed .luI. 22,
`1996
`
`BACKGROUND OF THE INVENTION
`
`2
`this type of hybrid drive system is disclosed in lP-A-3(cid:173)
`121928. In this system, the engine is normally operated as
`the drive power source for driving the vehicle, and the
`electric motor is also operated to assist the engine only when
`5 the engine load (as represented by the amount of operation
`of the accelerator pedal) exceeds a given upper limit. This
`system assures desired drivability of the vehicle while
`reducing the amount of fuel consumption and the amount of
`exhaust gas emission.
`In the above hybrid drive system haVing the engine assist
`function, however, the electric motor is necessarily operated
`as long as the engine load is higher than the predetermined
`upper limit. This arrangement tends to suffer from relatively
`high frequency of operation of the electric motor and
`15 relatively large amount of consumption of the electric
`energy, reqUiring the electric energy storage device to have
`a comparatively large capacity and to be charged relatively
`frequently by the engine.
`
`10
`
`1. Field of the Invention
`The present invention relates in general to a hybrid drive
`system for driving a motor vehicle, and more particularly to
`such a hybrid vehicle drive system having a power drive 20
`state in which the vehicle is driven by both an engine and an
`electric motor, or an engine as..<;ist drive mode in which the
`electric motor cooperates with the engine to serve as a drive
`power source.
`2. Discussion of the Related Art
`For driving a motor vehicle, there is known a hybrid drive
`system which includes, as drive power sources, an engine
`operated by combustion of a fuel, and an electric motor
`operated by ao electric energy stored io ao electric energy 30
`storage device. Such a hybrid drive system has an engine
`drive mode in which the engine is operated to drive the
`vehicle, and a motor drive mode in which the electric motor
`is operated to drive the vehicle. The engine drive mode and
`the motor drive mode are selectively established depending 35
`upon the running condition of the vehicle, so as to reduce the
`amount of consumption of the fuel and the amount of
`exhaust gas emission from the engine. For further reducing
`the fuel consumption and the exhaust gas emission, there is
`proposed a hybrid drive system which has a so-called 40
`"power drive mode" in which the engine and the electric
`motor are both operated to drive the vehicle so as to restrict
`the maximum output of the engine. This power drive mode
`is established when a load acting on the vehicle is relatively
`high, for example, during running of the vehicle on an uphill 45
`road. An example of this type of hybrid drive system is
`disclosed in lP-A-6-80048, wherein the power drive state is
`established when the accelerator pedal is operated by a
`relatively large amount by the vehicle operator, namely,
`when the vehicle load is relatively high.
`However, the conventional hybrid drive system described
`above may suffer from an insufficient drive force in the
`power drive mode, due to a reduced amount of the electric
`energy stored in the electric energy storage device, which
`causes a reduced output of the electric motor even when the 55
`amouot of operation of the accelerator pedal by the vehicle
`operator is relatively large. 'Ibis tendency gives a discomfort
`to the vehicle operator who expects a sufficient drive force
`upon depression of the accelerator pedal by a relatively large
`amounL In other words,
`the conventional hybrid drive GO
`system tends to suffer from a variation in the drive force in
`the power drive mode, due to a varying amount of the stored
`electric energy, even when the running condition of the
`vehicle is substantially constant.
`There is also known achybrid drive system wherein the 65
`electric motor is operated as needed, to assist the engine
`during running of the vehicle by the engine. An example of
`
`SUMMARY 01' TIlE INVENTION
`
`It is therefore a first object of the present invention to
`provide a hybrid drive system for a motor vehicle, which
`does not give a discomfort to the vehicle operator even when
`the operation of the electric motor is limited due to reduced
`25 amount of the electric energy stored in the electric energy
`storage device.
`It is a second object of the invention to provide a hybrid
`drive system which is adapted to reduce the frequency of
`operation of the electric motor and minimize the amount of
`consumption of the electric energy by the electric motor,
`while permitting the motor vehicle to be driven with driv(cid:173)
`ability performance or drive force as desired by the vehicle
`operator.
`The first object may be achieved according to the first
`aspect of the present invention, which provides a hybrid
`drive system for a motor vehicle, comprising: (a) an engine
`operated by combustion of a fuel; (b) an electric energy
`storage device for storing an electric energy; (c) an electric
`motor operated with the electric energy stored in the electric
`energy storage device; (d) nonnal drive control means for
`controlling the engine and the electric motor so as to
`establish a normal drive state in which One of the engine and
`the electric motor is operated as a drive power source to
`drive the motor vehicle; (e) power drive control means for
`controlling the engine and the electric motor so as to
`establish a power drive state in which there is available a
`power drive mode in which both of the engine and the
`electric motor are operated as the drive power source to
`50 drive the motor vehicle; (1) power drive selecting means
`manually operated by an operator of the motor vehicle when
`the operator desires to drive the motor vehicle in the power
`drive mode; and (g) power drive restricting means for
`permitting the power drive control means to establish the
`power drive state if the power drive selecting means is
`operated, and inhibiting the power drive control means from
`establishing the power drive state,
`to thereby inhibit the
`motor vehicle from being driven in said power drive mode,
`if the power drive selecting means is not manually operated.
`In the hybrid drive system for a motor vehicle, the power
`drive mode is available in the power drive state. However,
`the power drive state is not established when the power drive
`selecting means is not manually operated. 'lberefore, when
`the power drive selecting means is not operated, the vehicle
`is not driven in the power drive mode in which the engine
`and the electric motor are both operated as the drive power
`source for driving the vehicle. In other words, the vehicle is
`
`Page 23 of 43
`
`FORD 1245
`
`

`

`5,841,201
`
`3
`driven by only the engine or the electric motor when the
`power drive selecting means is nol manually operated. If the
`electric motor cannot be operated to provide a sufficient
`drive force due to reduction of the electric energy amount
`stored in the electric energy storage device while the power 5
`drive selecting meaDS is not operated, the vehicle is driven
`by the engine used as the drive power source. In this case
`where the manually operable power drive selecting means is
`not operated, the vehicle operator recognizes tbat the power
`drive mode is not available, and does not feel that the vehicle 10
`drive force is unexpectedly small. When the power drive
`selecting means is manually operated, the vehicle is driven
`in the power drive mode with the engine and the electric
`motor if the appropriate condition is satisfied, for example,
`the stored electric energy is sufficient to operate the electric 15
`motor. Thus, only when excessive reduction of the stored
`electric energy occurs while the power drive selecting means
`is operated, the vehicle driver may feel that the vehicle drive
`force is smaller than expected upon depression of the
`accelerator pedal with the power drive selecting means 20
`being operated to select the power drive mode.
`The principle of the first aspect of the present invention is
`applicable to various types of hybrid drive system equipped
`with the engine and the electric motor as the drive power
`source for driving the motor vehicle. One or both of the 25
`engine and the electric motor may be used as the drive power
`source, by selective connection and disconnection of appro(cid:173)
`priate power transmission paths by selective engagement
`and disengagement of clutches, or by a synthesizer and
`distributor mechanism such as a planetary gear mechanism 30
`for synthesizing or distributing the outputs of the engine and
`electric motor, or by suitable means for using the electric
`motor as an auxiliary drive power source to assist the engine
`as a primary power source. In any case, the hybrid drive
`system has the normal drive state in which tbe vehicle is 35
`driven by only one of the engine or the electric motor, and
`the power drive state in which the vehicle can be driven in
`the power drive mode using both of the engine and the
`electric motor. The electric motor may be provided for each
`of the drive wheels of the motor vehicle.
`In the normal drive state established by the normal drive
`control means, the vehicle may be driven in an engine drive
`mode using the engine as the drive power source, or in a
`motor drive mode using the electric motor as the drive power
`source. Preferably, the engine drive mode and the motor 45
`drive mode are selectively established depending upon the
`running condition of the vehicle, so as to reduce the amount
`of exhaust gas emission. However, the engine is always used
`as a primary power source, with the electric motor being
`used as an auxiliary power source which is operated when 50
`needed. In the power drive state established by the power
`drive control means when the power drive selecting means
`is operated, at least the power drive mode is available for
`driving the vehicle with bolh of the engine and the electric
`motor. This power drive mode may be established irrespec- 55
`tive of the running condition of the vehicle, as long as the
`power drive selecting means is operated. For reducing the
`amount of exhaust gas emission, however, it is desirable that
`the power drive mode be established only when the prcde~
`termined condition is satisfied while the power drive select- 60
`ing means is operated.
`The power drive selecting means is operated by the
`vehicle Dperator according to the desire of the vehicle
`operator regarding the drive force produced by the hybrid
`drive system. The power drive selecting means may com- 65
`prise a selector switch provided on an instrument panel of
`the vehicle, or on a pushbutton provided on a grip of a shift
`
`40
`
`4
`lever for shifting a transmission provided on the vehicle. The
`power drive sclecting means may be provided as one of the
`operating positions of a transmission shift lever.
`According to one preferred form of this invention, the
`power drive restricting means is adapted to command the
`normal drive control means to establish the normal drive
`state if the power drive selecting means is not manually
`operated.
`According to another preferred form of the invention, the
`(h) power drive
`hybrid drive system further comprises:
`mode inhibiting means for inhibiting the power drive control
`means from establishing the power drive mode and for
`operating only the engine as the drive power source for
`driving the motor vehicle, if an amount of the electric energy
`stored in the electric energy storage device is smaller than a
`predetermined lower limit, even when the power drive
`selecting means is manually operated; and (i) indicating
`means for informing the operator of the motor vehicle that
`the motor vehicle is inhibited from being driven in the power
`drive mode, when the power drive control means is inhibited
`by the power drive mode inhibiting means from establishing
`the power drive mode.
`In the above preferred form of the invention, the running
`of the vehicle in the power drive mode is inhibited when the
`stored electric energy amount is smaller than the lower limit,
`even when the power drive selecting means is operated. This
`arrangement is effective to prevent damaging of the electric
`energy storage device, and excessive reduction of the charg"
`ing and discharging efficienci~<; of the storage device.
`Further, the indicating means provides an indication that the
`power drive mode is not available when the stored electric
`energy amount is smaller than the lower limit. This arrange(cid:173)
`the
`ment permits the vehicle operator to recognize that
`vehicle is driven by only the engine even though the vehicle
`operator has manipulated the power drive selecting means to
`select the power drive mode. This arrangement does not give
`a discomfort to the vehicle operator even if the vehicle drive
`force as felt by the vehicle drive is smaller than expected.
`The lower limit of the stored electric energy amount
`below which the running of the vehicle in the power drive
`mode is inhibited by the power drive mode inhibiting means
`is determined to prevent excessive deterioration of the
`charging and discharging efficiencies of the electric energy
`storage device due to excessive reduction of the stored
`electric energy amount, which may result in damaging the
`storage device. The power drive mode inhibiting means may
`be operable only when the power drive state is established
`by the power drive control means. However, the power drive
`mode inhibiting means may be operable in both of the
`normal drive state and the power drive state. In this case, the
`electric motor is inhibited from operating or stopped, and the
`vehicle is driven by only the engine, if the stored electric
`energy amount falls below the lower limit, irrespective of
`whether the hybrid drive system is in the normal drive state
`or in the power drive state. The indicating means may be an
`indicator disposed on the vehicle instrument panel, for
`providing a visual or audible indication. The indicating
`means may be activated as long as the running of the vehicle
`in the power drive mode is inhibited. However, the indicat(cid:173)
`ing means may be activated only when the power mode
`selecting means is manually Dperated and the running of the
`vehicle in the power drive mode is inhibited by the power
`drive mode inhibiting means.
`The second object
`indicated above may be achieved
`according to a second aspect of this invention, which pro(cid:173)
`vides a hybrid drive system for a motor vehicle, comprising:
`
`Page 24 of 43
`
`FORD 1245
`
`

`

`5,841,201
`
`5
`(a) an engine operated by combustion of a fuel; (b) an
`electric motor operated by an electric energy; (c) engine
`assist control means operable io an engine assist mode, for
`controlling the electric motor such that the electric motor is
`operated as needed, as an auxiliary drive power source,
`together with the engine, to "--"isist the engine to drive the
`motor vehicle, during running of the motor vehicle with the
`engine operated as a primary drive power source; and Cd)
`drivability performance selecting means manually operated
`by an operator of the motor vehicle, for selecting one of a 10
`plurality of drivability modes of the motor vehicle, and
`wherein the engine assist control means includes assist
`torque changing means for changing an amount of an assist
`torque which is produced by the electric motor and which is
`added to a torque of the engine in the engine assist mode. 15
`The assist torque changing means changing the amount of
`the assist
`torque according to tbe one of the drivability
`modes of the motor vehicle selected by the drivability
`performance selecting means.
`In the hybrid drive system according to the second aspect 20
`of this invention constructed as described above, the amount
`of the assist torque produced by the electric motor and added
`to the torque of the engine in the engine assist drive mode
`is changed by the assist torque changing means of the engine
`assist control means, according to or depending upon the 25
`selected one of the drivability modes of the motor vehicle
`which is selected by the vehicle operator by the drivability
`performance selecting means. Thus, the present hybrid drive
`system assures reduced frequency of operation of the elec(cid:173)
`tric motor and reduced amount of consumption of the 30
`electric energy by the electric motor, while permitting the
`vehicle to be driven with drivability performance or drive
`force as desired by the vehicle operator.
`The principle of the above second aspect of the present
`invention is applicable to various types of hybrid drive 35
`system which are equipped with the engine and the electric
`motor as the drive power source for driving the motor
`vehicle and which are adapted such that one or both of the
`engine and the electric motor may be used as the drive power
`source, by selective connection and disconnection of appro- 40
`priate power transmission paths by selective engagement
`and disengagement of clutches, or by a synthesizer and
`distributor mechanism such as a planetary gear mechanism
`for synthesizing or distributing the outputs of the engine and
`electric motor. In any case, the hybrid drive system has the 45
`engine assist drive mode in which the electric motor is
`operated a.<; an auxiliary drive power source, together with
`the engine, to assist the engine to drive the motor vehicle,
`during running of the motor vehicle with the engine operated
`as a primary drive power source. The electric motor may be 50
`provided for each of the drive wheels of the motor vehicle.
`The hybrid drive system according to the second aspect of
`the invention should have the engine assist drive mode in
`which the electric motor is used as the auxiliary drive power
`source to assist the engine which serves as the primary drive 55
`power source. However, the present hybrid drive system
`may have other drive modes such as an engine drive mode
`in which only the engine is operated to drive the vehicle. In
`this case, one of the drive modes is selected depending upon
`the running condition of the vehicle, such as the operation 60
`amount of the accelerator pedal,
`running speed of the
`vehicle, and amount of electric energy stored in an electric
`energy storage device. The engine may preferably use a
`throttle valve whose opening angle is electrically controlled
`according to-the operation amount of the accelerator pedal. 65
`Where the engine is always used as the drive power source,
`however,
`the engine may use a throttle valve which is
`
`6
`mechanically connected to the accelerator pedal so that the
`opening angle of the throttle valve is changed as the accel(cid:173)
`erator pedal is operated. In either case, the opening angle of
`the throttle valve, which represents the engine output cur(cid:173)
`rently required by the vehicle operator, generally has a given
`relationship with the operation amount of the accelerator
`pedal. Therefore, the currently required output of the engine
`may be represented by the opening angle of the throttle
`valve, or an intake air quantity of the engine.
`The total vehicle drive force in the engine assist drive
`mode is a sum of the assist torque produced by the electric
`motor and the torque produced by the engine. The engine
`assist control means is adapted to control the electric motor
`in the engine a.-;sist drive mode such that the total vehicle
`drive force continuously smoothly increases with an
`increase in the currently required output of the engine as
`represented by the operation amount of the accelerator
`pedal, over substantially the entire range of the operation
`amount of the accelerator pedal, for example. The pattern of
`change of the assist torque produced by the engine with
`respect
`to the currently required output of the engine is
`determined with the output characteristics of the engine
`taken into account. Usually, the engine output substantially
`linearly increases with the engine load when the engine load
`is relatively low. When the engine load is relatively high, the
`rate of increase of the engine output is reduced, and the
`engine output does not substantially linearly increase with
`the engine load. In the light of this fact, the electric motor is
`not operated as the auxiliary drive power source to assist the
`engine while the engine load is relatively low, that is, while
`the currently required output of the engine is relatively
`small. When the engine load is relatively high, the engine
`assist control means operates the electric motor to assist the
`engine in the engine assist drive mode such that the total
`vehicle drive torque continuously smoothly increases with
`an increase in the engine load, namely, with an increase in
`the currently required output of the engine. In particular, the
`assist torque changing means is adapted to increase the assist
`torque so that the total vehicle drive force smoothly increase
`with the engine load.
`The drivability performance selecting means may be a
`selector switch exclusively provided for selecting a desired
`one of the two or more drivability modes of the vehicle.
`However, the drivability performance selecting means may
`be a shift pattern s