Source: http://www.google.com/patents/US5230319?dq=7,190,101
Timestamp: 2014-10-02 05:18:18
Document Index: 158519880

Matched Legal Cases: ['art 14', 'art 15', 'art 14', 'art 16', 'art 15', 'art 180', 'art 17', 'art 180', 'art 17', 'art 180', 'art 16', 'art 14']

Patent US5230319 - Apparatus for detecting malfunction in evaporated fuel purge system - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA malfunction detection apparatus for detecting a malfunction in an evaporated fuel purge system in which fuel vapor from a fuel tank is adsorbed in an adsorbent in a canister and the adsorbed fuel vapor in the adsorbent is purged into an intake passage of an engine. The apparatus includes a detection...http://www.google.com/patents/US5230319?utm_source=gb-gplus-sharePatent US5230319 - Apparatus for detecting malfunction in evaporated fuel purge systemAdvanced Patent SearchPublication numberUS5230319 APublication typeGrantApplication numberUS 07/771,445Publication dateJul 27, 1993Filing dateOct 4, 1991Priority dateOct 5, 1990Fee statusLapsedAlso published asUS5313925Publication number07771445, 771445, US 5230319 A, US 5230319A, US-A-5230319, US5230319 A, US5230319AInventorsTakayuki Otsuka, Nobuaki Kayanuma, Kouichi Osawa, Hironori Okamizu, Chikao KunimasaOriginal AssigneeToyota Jidosha Kabushiki KaishaExport CitationBiBTeX, EndNote, RefManPatent Citations (16), Non-Patent Citations (4), Referenced by (22), Classifications (10), Legal Events (6) External Links: USPTO, USPTO Assignment, EspacenetApparatus for detecting malfunction in evaporated fuel purge systemUS 5230319 AAbstract A malfunction detection apparatus for detecting a malfunction in an evaporated fuel purge system in which fuel vapor from a fuel tank is adsorbed in an adsorbent in a canister and the adsorbed fuel vapor in the adsorbent is purged into an intake passage of an engine. The apparatus includes a detection part for detecting a concentration of fuel in the fuel vapor purged into the intake passage so that a change in the detected fuel concentration from a time when a purge cutting is performed to a time when a purging is performed after the purge cutting has been performed is detected, and a discrimination part for determining whether there is a malfunction in the system on the basis of the change in the detected fuel concentration by the detection part. The apparatus also includes a fuel vapor detection part for detecting a condition of fuel vapor in the fuel tank, and a purge cut time varying part for varying a purge cut time period for which the purge cutting is continuously performed, the purge cut time being varied by the purge cut time varying part in response to the detected fuel vapor condition by the fuel vapor detection part.
What is claimed is: 1. An apparatus for detecting a malfunction in an evaporated fuel purge system provided in an internal combustion engine, comprising:purge means for performing alternately a purging means and a purge cutting mode, fuel vapor from a fuel tank being absorbed in an adsorbent in a canister when said purge cutting mode is performed by said purge means, and when said purging mode is performed by said purge means the adsorbed fuel vapor in the adsorbent being purged into an intake passage of the internal combustion engine; detecting means for detecting a concentration of fuel in the fuel vapor purged into the intake passage so that a change in the detected fuel concentration from a time when the purge cutting mode is performed to a time when the purging mode is performed by said purge means immediately after said purge cutting mode has been performed is detected; malfunction discrimination means for determining whether there is a malfunction in the evaporated fuel purge system, by comparing said change in said detected fuel concentration detected by said detection means with a predetermined value; fuel vapor detection means for detecting conditions of fuel vapor in the fuel tank; and purge cut time varying means for determining a purge cut time, during which said purge cutting mode is continuously performed by said purge means, said purge cut time being varied by said purge cut time varying means in response to said fuel vapor conditions in the fuel tank detected by said fuel vapor detection means, wherein said malfunction discrimination means includes a first discrimination part for detecting tentatively whether there is a malfunction in the evaporated fuel purge system, and a second discrimination part for performing a malfunction discrimination after the purge cutting mode is performed continuously for the purge cut time varied by said purge cut time varying means, only when said first discrimination part has tentatively determined that there is a malfunction in the evaporated fuel purge system. 2. An apparatus for detecting a malfunction in an evaporated fuel purge system provided in an internal combustion engine, comprising:purge means for performing alternately a purging mode and a purge cutting mode, fuel vapor from a fuel tank being adsorbed in an adsorbent in a canister when said purge cutting mode is performed by said purge means, and when said purging mode is performed by said purge means the adsorbed fuel vapor in the adsorbent being purged into an intake passage of the internal combustion engine; detection means for detecting a concentration of fuel in the fuel vapor purged into the intake passage so that a change in the detected fuel concentration from a time when the purge cutting mode is performed to a time when the purging mode is performed by said purge means immediately after said purge cutting mode has been performed is detected; malfunction discrimination means for determining whether there is a malfunction in the evaporated fuel purge system, by comparing said change in said detected fuel concentration detected by said detection means with a predetermined value; fuel vapor detection means for detecting conditions of fuel vapor in the fuel tank, wherein said fuel vapor detection means includes a fuel gauge provided on the fuel tank; and purge cut time varying means for determining a purge cut time, during which said purge cutting mode is continuously performed by said purge means, said purge cut time being varied by said purge cut time varying means in response to said fuel vapor conditions in the fuel tank detected by said fuel vapor detection means, said purge cut time varying means calculating said purge cut time at least from a fuel amount correction factor and a fuel supply correction factor, said fuel amount correction factor and said fuel supply correction factor being determined in response to an output signal of said fuel gauge on the basis of a set of two-dimensional maps, stored in a memory part of a microcomputer, said set of two-dimensional maps defining respectively a relationship between the fuel amount correction factor and the detected fuel vapor condition and a relationship between the fuel supply correction factor and the detected fuel vapor condition. 3. The apparatus as claimed in claim 2, wherein said purge cut time varying means includes an intake air temperature sensor, said purge cut time being calculated by said purge cut time varying means from an intake air temperature correction factor determined in response to an intake air temperature indicated by an output signal of said intake air temperature sensor or the basis of a two-dimensional map, stored in said memory part of said microcomputer, said two-dimensional map defining a relationship between the intake air temperature correction factor and the indicated intake air temperature.
5. An apparatus for detecting a malfunction in an evaporated fuel purge system provided in an internal combustion engine, comprising:purge means for allowing fuel vapor evaporated in a fuel tank to be adsorbed in an adsorbent in a canister and for purging the adsorbed fuel vapor in said adsorbent in said canister into an intake passage of the internal combustion engine; concentration detection means for detecting a concentration of fuel in the purged fuel vapor by said purge means; malfunction discrimination means for performing a malfunction discrimination by determining that there is a malfunction in the evaporated fuel purge system, only when a change in the detected fuel concentration by said concentration detection means from a time for a purge cutting being performed to a time for a purging being performed by said purge means is not greater than a predetermined value; purge cutting means for performing a purge cutting by temporarily stopping the purging of the fuel vapor into the intake passage by said purge means when said malfunction discrimination means has determined that there is a malfunction; and malfunction process means for allowing said malfunction discrimination means to perform a second malfunction discrimination after the purge cutting has been performed by said purge cutting means, and for carrying out a malfunction process when said malfunction discrimination means has determined in said second malfunction discrimination that there is the malfunction. 6. The apparatus as claimed in claim 5, wherein said malfunction process means includes a malfunction warning lamp which is switched ON for giving a warning of the malfunction to a driver when said malfunction discrimination means has determined in said second malfunction discrimination that there is the malfunction.
SUMMARY OF THE INVENTION Accordingly, it is a general object of the present invention to provide an improved malfunction detection apparatus in which the above described problem of the conventional apparatus are eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram for explaining an embodiment of a malfunction detection apparatus according to the present invention;
DESCRIPTION OF THE PREFERRED EMBODIMENT First, a description will be given of a first embodiment of a malfunction detection apparatus according to the present invention, with reference to FIG. 1. In FIG. 1, this malfunction detection apparatus includes a purge part 14 for performing alternately a purge cutting mode and a purging mode, fuel vapor from a fuel tank 13 is adsorbed in an adsorbent in a canister when the purge cutting mode is performed, and the adsorbed fuel vapor in the adsorbent in the canister is purged into an intake passage 12 of an internal combustion engine 11 when the purging mode is performed. The malfunction detection apparatus also includes a concentration detecting part 15 for detecting a concentration of fuel in the purged fuel vapor into the intake passage 12 by the purge part 14 so that a change in the detected fuel concentration from a time when the purge cutting mode is performed to a time when the purging mode is performed immediately after the purge cutting mode is ended is detected, and a malfunction discriminating part 16 for determining whether there is a malfunction by comparing the change in the detected fuel concentration by the concentration detecting part 15 with a predetermined value. The malfunction detection apparatus also includes a fuel vapor detection part 180 for detecting a condition of fuel vapor in the fuel tank 13, and a purge cut time varying part 17 for varying a purge cut time, during which the purge cutting mode is performed and the purging of fuel vapor into the intake passage by the purge part is stopped, in response to the condition of fuel vapor in the fuel tank detected by the fuel vapor detection part 180. Generally speaking, the rate of evaporation of fuel in the fuel tank 13 is changed depending on the temperature of fuel in the fuel tank 13, the amount of fuel supply newly supplied and the amount of residual fuel in the fuel tank 13. The purge cut time varying part 17 of the present invention adjusts suitably the purge cut time on the basis of several factors related to the rate of evaporation of fuel in the fuel tank 13 which is detected by the fuel vapor detection part 180. Therefore, the necessary amount of fuel vapor for the malfunction discrimination can be adsorbed in the adsorbent in the canister during the purge cut time before a malfunction discrimination is made by the malfunction discriminating part 16. Also, it is possible to control the purge cut time, during which the purging of fuel vapor is stopped, to the least possible level, so that an appropriate amount of fuel vapor is always stored in the adsorbent in the canister.
[Purge Cut Time Calculation] FIGS. 8, 9 and 10 show, respectively, a fuel supply correction factor calculation routine, a purge cut time calculation routine and a fuel vapor storage routine, which are related to the purge cut time control procedure as the essential part of the present invention.
TN=30�KTHA�KTHW�KFUEL�KNFUEL
[Diagnosis Discrimination] FIGS. 12A through 12C show the diagnosis discrimination routine which is performed in the first embodiment of the present invention. This diagnosis discrimination routine is essentially the same as the tentative discrimination routine shown in FIGS. 4A through 4C. In the flow chart shown in FIG. 4A, a step 601 determines whether the flag FKDiAGPURGE is equal to "1" in order to check if it is tentatively determined in the step 125 shown in FIG. 4C that there is a malfunction. If the step 601 determines that the flag FKDiAGPURGE is equal to "138 , then a step 602 determines whether the flag FDiAGEND is equal to "1" in order to check if the diagnosis discrimination routine has been ended. If the step 601 determines that the flag FKDiAGPURGE is equal to "0" (which indicates that there is no malfunction), or if the step 602 determines that the flag FDiAGEND is equal to "1" (which indicates that the diagnosis discrimination is ended), then a step 632 shown in FIG. 12C sets the purge cutting mode flag XPURGE to zero " 0" and the routine is ended.
[VSV Control Routine] FIG. 13 shows the VSV control routine which is performed for controlling the flow of fuel vapor adsorbed in the adsorbent in the canister 44 into the intake passage of the engine by switching ON and OFF the VSV 46. The purge part 14 shown in FIG. 1 according to the present invention can be achieved by performing this VSV control routine. In the flow chart shown in FIG. 13, a step 701 determines whether the engine cooling water temperature THW indicated by an output signal of the water temperature sensor 39 is higher than 50 deg C. or not. If the step 701 determines that the engine cooling water temperature THW is higher than 50 deg C. (which indicates that the engine is in the warm-up condition), then a step 702 determines whether the purge cutting mode flag XKPURGE in the tentative discrimination routine is equal to "1". This flag XKPURGE is, in some cases, set to "1" in the step 108 in FIG. 4A, and in other cases the flag XKPURGE is set to "0" either in the step 109 in FIG. 4A or in the step 131 in FIG. 4C. If the step 702 determines that the flag XKPURGE is equal to "0", then a step 703 determines whether the purge cutting mode flag XPURGE in the diagnosis discrimination routine is equal to "1". This flag XPURGE is, in some cases, set to "1" in the step 609 in FIG. 12A, and in other cases the flag XPURGE is set to "0" either in the step 610 in FIG. 12A or in the step 632 in FIG. 12C.
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K.K.Abnormality diagnostic system for internal combustion enginesUS5465703 *Jun 23, 1993Nov 14, 1995Fuji Jukogyo Kabushiki KaishaControl method for purging fuel vapor of automotive engineUS5474050 *Jan 13, 1995Dec 12, 1995Siemens Electric LimitedLeak detection pump with integral vent sealUS5477837 *Mar 11, 1994Dec 26, 1995Mitsubishi Denki Kabushiki KaishaController for internal combustion engineUS5488936 *Sep 12, 1994Feb 6, 1996Ford Motor CompanyFor use in a motor vehicleUS5499614 *Nov 3, 1994Mar 19, 1996Siemens Electric LimitedAutomotive vehicleUS5560347 *Feb 27, 1995Oct 1, 1996General Motors CorporationMethod of diagnosing a fuel vapor handling systemUS5575267 *Sep 29, 1995Nov 19, 1996Mitsubishi Jidosha Kogyo Kabushiki KaishaFault diagnosis apparatus for a fuel evaporative emission suppressing systemUS5651349 *Dec 11, 1995Jul 29, 1997Chrysler CorporationFor evaporative emission control in a motor vehicleUS5666924 *Jul 6, 1995Sep 16, 1997Mitsubishi Denki Kabushiki KaishaMalfunction diagnosis device for fuel-evaporated-gas processing deviceUS5816223 *Dec 29, 1997Oct 6, 1998Ford Global Technologies, Inc.Evaporative emission control system for providing fuel to vapor to automotive engineUS7089920 *Aug 10, 2005Aug 15, 2006Fuji Jukogyo Kabushiki KaishaDiagnostic apparatus for evaporative emission control systemUS7316228 *Feb 15, 2007Jan 8, 2008Denso CorporationEvaporated fuel treatment system for internal combustion engineUS8155917 *Apr 23, 2009Apr 10, 2012Denso CorporationFlow diagnosis apparatus for fuel vapor purge system* Cited by examinerClassifications U.S. Classification123/520, 123/519, 123/198.00DInternational ClassificationF02B75/02, F02D41/22, F02D41/00, F02M25/08Cooperative ClassificationF02M25/0809, F02B2075/027European ClassificationF02M25/08BLegal EventsDateCodeEventDescriptionOct 2, 2001FPExpired due to failure to pay maintenance feeEffective date: 20010727Jul 29, 2001LAPSLapse for failure to pay maintenance feesFeb 20, 2001REMIMaintenance fee reminder mailedJan 13, 1997FPAYFee paymentYear of fee payment: 4Apr 19, 1994CCCertificate of correctionOct 4, 1991ASAssignmentOwner name: TOYOTA JIDOSHA KABUSHIKI KAISHA, A COMPANY OF JAPAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:OTSUKA, TAKAYUKI;KAYANUMA, NOBUAKI;OSAWA, KOUICHI;AND OTHERS;REEL/FRAME:005773/0418Effective date: 19910920RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google