Evaporative fuel-processing system for internal combustion engines

• US 5,355,864 A
• Filed: 12/27/1993
• Issued: 10/18/1994
• Est. Priority Date: 01/20/1992
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Maruyama, Hiroshi, Iwata, Yoichi, Yamanaka, Masayoshi, Takizawa, Tsuyoshi, Kuroda, Shigetaka, Sawamura, Kazutomo
• Primary Examiner(s): Cross, E. Rollins
• Assistant Examiner(s): Moulis, Thomas N.
• Application Number:
  US08/173,055
• Time in Patent Office: 295 Days
• Field of Search: 123/516, 123/518, 123/519, 123/520, 123/198 D
• US Class Current: 123/520
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system

Abstract

An evaporative fuel-processing system for an internal combustion engine, in which a first control valve is arranged across an evaporative fuel-guiding passage extending from a fuel tank to a canister, a second control valve across a purging passage extending from the canister to the intake system of the engine, and a third control valve at an air inlet port of the canister, respectively. An ECU generates operation command signals to the first to third control valves for closing or opening the same. The ECU is responsive to an output from a tank internal pressure sensor which detects pressure within the fuel tank and the operation command signals, for detecting an abnormality in operation of a predetermined one of the first to third control valves.

Claims

1. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage, said first control valve being controllable to be opened or closed for detection of an abnormality of said evaporative fuel-processing system;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

tank internal pressure detecting means for detecting pressure within said fuel tank;

control means for supplying operation command signals to said first to third control valves at the same time for closing or opening the same; and

abnormality detecting means responsive to an output from said tank internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves.

2. An evaporative fuel-processing system as claimed in claim 1, wherein said abnormality detecting means determines that operation of said third control valve is abnormal when said pressure within said fuel tank detected by said tank internal pressure detecting means lowers by a predetermined amount or more while said control means is supplying said operation command signals for opening said first control valve, opening said second control valve, and opening said third control valve.

3. An evaporative fuel-processing system as claimed in claim 1, wherein said abnormality detecting means determines that operation of said third control valve is abnormal when said pressure within said fuel tank detected by said tank internal pressure detecting means lowers below a predetermined value while said control means is supplying said operation command signals for opening said first control valve, opening said second control valve, and opening said third control valve.

4. An evaporative fuel-processing system as claimed in claim 3, wherein said control means causes said second control valve to be closed when said control means determines that operation of said third control valve is abnormal.

5. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

tank internal pressure detecting means for detecting pressure within said fuel tank;

control means for supplying operation command signals to said first to third control valves for closing or opening the same; and

abnormality detecting means responsive to an output from said tank internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves, wherein said abnormality detecting means determines that operation of said first control valve is abnormal when said pressure within said fuel tank detected by said tank internal pressure detecting means lowers by a predetermined amount or more while said controlled means is supplying said operation command signals for closing said first control valve, closing said third control valve and opening said second control valve.

6. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

tank internal pressure detecting means for detecting pressure within said fuel tank;

control means for supplying operation command signals to said first to third control valves for closing or opening the same; and

abnormality detecting means responsive to an output from said tank internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves, wherein said abnormality detecting means determines that operation of said first control valve is abnormal when said pressure within said fuel tank detected by said tank internal pressure detecting means rises above a predetermined value while said control means is supplying said operation command signals for opening said first control valve, opening said second control valve, and opening said third control valve.

7. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

tank internal pressure detecting means for detecting pressure within said fuel tank;

control means for supplying operation command signals to said first to third control valves for closing or opening the same; and

abnormality detecting means responsive to an output from said tank internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves, wherein said abnormality detecting means determines that operation of said second control valve is abnormal when said pressure within said fuel tank detected by said tank internal pressure detecting means lowers by a predetermined amount or more while said control means is supplying said operation command signals for opening said first control valve, closing said second control valve, and closing said third control valve.

8. An evaporative fuel-processing system as claimed in claim 7, wherein said control means causes said first control valve to be closed when said control means determines that operation of said second control valve is abnormal.

9. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage, said first control valve being controllable to be opened or closed for detection of an abnormality of said evaporative fuel-processing system;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

system internal pressure detecting means arranged at a location in a part of said evaporative fuel-processing system upstream of said first control valve for detecting pressure within said part of said evaporative fuel-processing system;

control means for supplying operation command signals to said first to third control valves at the same time for closing or opening the same; and

abnormality detecting means responsive to an output from said system internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves.

10. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

system internal pressure detecting means arranged at a location in a part of said evaporative fuel-processing system upstream of said first control valve for detecting pressure within said part of said evaporative fuel-processing system;

control means for supplying operation command signals to said first to third control valves for closing or opening the same; and

abnormality detecting means responsive to an output from said system internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves, wherein said abnormality detecting means determines that operation of said first control valve is abnormal when said pressure within said part of said evaporative fuel-processing system upstream of said first control valve detected by said system internal pressure detecting means lowers by a predetermined amount or more while said controlled means is supplying said operation command signals for closing said first control valve, closing said third control valve and opening said second control valve.

11. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

system internal pressure detecting means arranged at a location in a part of said evaporative fuel-processing system upstream of said first control valve for detecting pressure within said part of said evaporative fuel-processing system;

control means for supplying operation command signals to said first to third control valves for closing or opening the same; and

abnormality detecting means responsive to an output from said system internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves, wherein said abnormality detecting means determines that operation of said first control valve is abnormal when said pressure within said part of said evaporative fuel-processing system upstream of said first control valve detected by said system internal pressure detecting means rises above a predetermined value while said control means is supplying said operation command signals for opening said first control valve, opening said second control valve, and opening said third control valve.

12. An evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, comprising:

a canister having an air inlet port provided therein;

an evaporative fuel-guiding passage extending from said fuel tank to said canister;

a first control valve arranged across said evaporative fuel-guiding passage;

a purging passage extending from said canister to said intake system of said engine;

a second control valve arranged across said purging passage;

a third control valve arranged at said air inlet port of said canister for establishing and interrupting communication between the interior of said canister and the atmosphere;

system internal pressure detecting means arranged at a location in a part of said evaporative fuel-processing system upstream of said first control valve for detecting pressure within said part of said evaporative fuel-processing system;

control means for supplying operation command signals to said first to third control valves for closing or opening the same; and

abnormality detecting means responsive to an output from said system internal pressure detecting means and said operation command signals, for detecting an abnormality in operation of a predetermined one of said first to third control valves, wherein said abnormality detecting means determines that operation of said second control valve is abnormal when said pressure within said part of said evaporative fuel-processing system upstream of said first control valve detected by said system internal pressure detecting means lowers by a predetermined amount or more while said control means is supplying said operation command signals for opening said first control valve, closing said second control valve, and closing said third control valve.