Apparatus for detecting malfunction in evaporated fuel purge system used in internal combustion ...

58 Pages·2013·3.42 MB·English

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USO05295472A
United States Patent {191 [11] Patent Number: 5,295,472
Otsuka et a1. [45] Date of Patent: Mar. 22, 1994
[54] APPARATUS FOR DETECTING 17169 2/1991 Japan .
26862 2/1991 Japan.
MALFUNCI‘ION IN EVAPORATED FUEL
249364 11/1991 Japan .
PURGE SYSTEM USED IN INTERNAL
503844 7/1992 Japan .
COMBUSTION ENGINE
OTHER PUBLICATIONS
[75] Inventors: Takayuki Otsuka; Kouichi Osawa,
both of Susono; Tatsumasa Ser. No. 895,102 ?led Jun. 8, 1992 -copending applica
Sugiyama, Kariya; Katsulriko tion.
Teraoka, Aichi; Nobuyuki Kobayashi;
(List continued on next page.)
Koji Okawa, both of Toyota, all of
Japan Primary EJcaminer-E. Rollins. Cross .
Assistant Examiner-Thomas Moulis
[73] Assignee: Toyota Jidosha Kabushiki Kaisha,
Attorney, Agent, or Firm—Kenyon & Kenyon
Aichi, Japan
[57] ABSTRACT
[21] Appl. No.2 998,191
A malfunction detecting apparatus for an evaporated
[22] Filed: Dec. 29, 1992
fuel purge system includes a ?rst control ,valve for con
[30] Foreign Application Priority Data trolling a ?ow of fuel vapor in a purge passage between
a canister and an intake passage, a second control valve
Jan. 6, 1992 [JP] Japan ............................... .._. 4-000288
for controlling a ?ow of air from the atmosphere to the
Jan. 6, 1992 [JP] Japan ................................ .. 4-000289
canister via an air inlet opening of the canister, a ?rst
Jan. 6, 1992 [JP]
control part for turning OFF the second control valve
Feb. 10, 1992 [JP]
and for turning ON the ?rst control valve during a ?rst
Feb. 14, 1992 [JP]
time period, so as to subject the purge passage, the
Mar. 5, 1992 [JP]
canister, and a vapor passage to a negative pressure of
Jul. 9, 1992 [JP]
the intake passage during the ?rst time period, and a
Jul. 23, 1992 [JP]
Aug. 31, 1992 [JP] ?rst discriminator for detecting whether or not a mal
Aug. 31, 1992 [JP] function has occurred in the system, in accordance with
Sep. 28, 1992 [JP] a pressure change rate derived from pressures of the
Sep. 28, 1992 [JP] system sensed at a start of the ?rst time period and at an
Dec. 25, 1992 [JP] end thereof. The apparatus further includes a second
control part for detecting whether or not a pressure of
[51] Int. Cl.5 ........................................... .. F02M 33/02 the system reaches a prescribed negative pressure after‘
[52] U.S. Cl. ....................... .. 123/520; 123/198 D it is detected that no malfunction has occurred in the
[58] Field of Search ............. .. 123/516, 518, 519, 520, system, and for turning OFF the ?rst and second con
123/521, 198 D
trol valves during a second time period after the pre
[56] References Cited scribed negative pressure is reached, and a second dis
criminator for detecting whether or not a malfunction
U.S. PATENT DOCUMENTS
has occurred in the system, in accordance with a pres
_4,949,695 8/ 1990 Uranishi et al. ................... .. 123/520 sure change rate derived from pressures of the system
sensed at a start of the second time period and at an end
(List continued on next page.)
thereof.
FOREIGN PATENT DOCUMENTS
102360 4/1990 Japan.
32 Claims, 33 Drawing Sheets
130255 5/1990 Japan.
5 mm: PASSAE u
1mm 1 2o
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5,295,472
Page 2
us. PAH-5,1311: OTHER PUBLICATIONS
5,027,780 Uranishi C! a]. ................ ..-... Ser_ No_ Oct 10’ 1991_c°pcnding applica
5,123,459 6/1992 TOShihil'O ....... .. 123/520" “on
5,143,035 9/1992 Kayanuma .. 123/520 ‘ . ‘
5,146,902 9/1992 Cook et a1. .. 123/520 Ser No. 777,757 ?led Oct. 10, 1991-copend1ng apphca
5,158,054 10/1992 01611116 ........ .. 123/520 11611.w _
we": Ser.No. 867,148 11166 Apr. 10, l992-c0pcnding applica
s,193,s11 3/1993 Fujino ........... ......... .. 123/520 mm- 2
5,193,512 3/1993 Steinbrenneretal. .... .. 123/520 '
5,197,442 3/1993 Blumenstock et a]. ........... .. 123/520 W0 9112426 (PCT) Aug- 1991
5229898 6/1993 KidOkOrO 61 a1. ................ .. 123/520 W0 9116216 (PCT) 091- 1991

US. Patent Mar. 22, 1994 Sheet 2 of 33 5,295,472
I_NT...
(Agmmmwkmi?
MM04883115

US. Patent _ Mar.~22, 1994 Sheet 4 of 33 5,295,472
FIG. 4A
EXECUTION FLAG 0N?
PRESSURE FLAG ON?
NO
/ vsv 36 OFF (2ND CONTROL VALVE 1s (am/V104
, I
/ vsv as 0N (1ST CONTROL VALVE 15 ON) #105
STORE PM W110 ‘
1 <35)
CGVPUTHPQFPSO/X ~H1
5,295,472
US. Patent Mar. 22, 1994 Sheet 5 of 33
FIG. 4B
/ vsv 38 OFF (1ST comm VALVE 15 om?ns
116
2ND TIME CUJNT B=0?
NO
120‘
NO
INCREMENT B N118
~121 SET DETECTION FLAG ~119
I
CUIIPUTE(P,2-Ps2)/X N122
123
N O (NCRMAL)
(PQZ'PSQ/YZRZ
YES
WARNING LAMP UII
I
STCRE FAIL CEDE
/ vsv as on (2ND comRoL VALVE 1e om/wzs
RESET TILE CCUNTS A AND B W127
I
SET EXECUTIGI FLAG ~128
I
RESET DETECTIGI AND N129
PRESSURE FLAGS
I
END
US. Patent Mar. 22, 1994 Sheet 6 of 33 5,295,472
FIG.5
VALVE I5 ON
1
VALVE l5 OFF
VALVE IS ON ]
VALVE 16 OFF
TANK
INTERNAL
PRESSURE
NEGATIVE
ATMOSPHERIC I
(P0)
1| 12 1314 15
--r-TIME (sec)
US. Patent Mar. 22, 199-4 Sheet 7 of 33 5,295,472
FIG. 6
STEPS 101-126
(FIGS. 4A-4B)
130
TANK PRESSUREZPO
I 5131 YES
DISALLOW VSV 38 TO RESET TIME CGJNTS ~12‘!
BE TURNED (N 1
SET EXECUTKN FLAG ~128
]
RESET DETECTIW ~129
AND PRESSURE FLAGS
END
US. Patent 5,295,472
Mar. 22, 1994 Sheet 8 of 33
FIG. 7
(START)
STEPS 101-115
(FIGS. 4A-4B)
YES ,
TANK PRESSURE 2 P1
5146
NO (NORMAL)
WARNING LAMP ON
STEPS 116*126
5147
(FIG. 4B)
STORE FAIL CODE
1
(VSV 36)
INCREMENT C N141
V
VSV 36 ON ~148
NARNI NG LAMP ON ~149
STORE FAIL CODE ~150
(VSV 38)
7 YES (NORMAL)
RESET TINE CGJNTS
SET EXECUTIW FLAG
~129
RESET DETECTION 1
mo PRESSURE FLAGS
Claw