Loading patent…
AssigneesNippon Soken, Inc., Denso Corporation
InventorsNoriyasu Amano, Hideaki Itakura, Naoya Kato, Masao Kano
Estimating the term…
An apparatus detects leak in a fuel vapor treatment system which is referred to as an evaporation system. The apparatus measures a required time T2 that is required for decreasing pressure in the evaporation system from P0 to P1 while opening a base leak hole that provides known amount of leak. Then, a required time T1 that is required for decreasing pressure from P0 to P1 is measured while closing the base leak hole. The apparatus compares the required times T1 and T2 in order to detect a leak other than the base leak hole. In this process, a specified coefficient that is defined in accordance with the base leak hole is taken into consideration. It is possible to detect the leak of the evaporation system with high accuracy even when the amount of remaining fuel is extremely large.
A failure diagnosis method for diagnosing an evaporated fuel treating unit provided with a canister receiving an absorbent for absorbing evaporated fuel, a purge passage for introducing the evaporated fuel separated from the absorbent into an intake pipe of an internal combustion engine, and a purge control valve for controlling a flow rate of the evaporated fuel in the purge passage, the method comprising the steps of:
A failure diagnosis method for diagnosing an evaporated fuel treating unit provided with a canister receiving an absorbent for absorbing evaporated fuel, a purge passage for introducing the evaporated fuel separated from the absorbent into an intake pipe of an internal combustion engine, and a purge control valve for controlling a flow rate of the evaporated fuel in the purge passage, the method comprising the steps of:
A failure diagnosis device for diagnosing an evaporated fuel treating unit provided with a canister receiving an absorbent for absorbing evaporated fuel, a purge passage for introducing the evaporated fuel separated from the absorbent into an intake pipe of an internal combustion engine, and a purge control valve for controlling a flow rate of the evaporated fuel in the purge passage, the device comprising:
A failure diagnosis device for diagnosing an evaporated fuel treating unit provided with a canister receiving an absorbent for absorbing evaporated fuel, a purge passage for introducing the evaporated fuel separated from the absorbent into an intake pipe of an internal combustion engine, and a purge control valve for controlling a flow rate of the evaporated fuel in the purge passage, the device comprising:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Backward citations are indexed for grants only.
Drawings are temporarily unavailable. Open the PDF at USPTO
Adding fuel vapours drawn from engine fuel reservoir: judging failure of purge control system
Supplying combustion engines in general with combustible mixtures or constituents thereof
Term end not estimated
This application is based on Japanese Patent Applications No. 2002-109172 filed on Apr. 11, 2002 and No. 2003-24353 filed on Jan. 31, 2003 the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a failure diagnosis method and failure diagnosis device for an evaporated fuel treating unit and in particular, to a technology for making a determination on the leak of fuel vapor.
Features and advantages of embodiments will be appreciated, as well as methods of operation and the function of the related parts, from a study of the following detailed description, the appended claims, and the drawings, all of which form a part of this application. In the drawings:
FIG. 1 is a block diagram showing the construction of an evaporated fuel treating unit in accordance with a first embodiment of the invention.
FIG. 2 is a flowchart in accordance with the first embodiment.
First Embodiment
The construction of a failure diagnosis device of an evaporated fuel processing unit of a first embodiment of the present invention is shown in FIG. 1. In this embodiment, the invention is applied to an automobile mounted with an internal combustion engine (engine) 1. A fuel tank 6 of the engine 1 is connected to a canister 8 through an introduction passage 7 and always communicates with the canister 8. The canister 8 is filled with an absorbent 9 and fuel evaporated in the fuel tank 6 is temporarily absorbed by the absorbent 9. The canister 8 is connected to an intake pipe 2 of the engine 1 through a purge passage 10. The purge passage 10 is provided with a purge valve 11 that is a purge control valve and when the purge valve 11 is opened, the canister 8 is made to communicate with the intake pipe 2. A solenoid valve is used as the purge valve 11.
The purge valve 11 is controlled by an electronic control unit (hereinafter referred to as ECU) 18 for controlling parts of the engine 1. The ECU 18 has a basic construction used for a general engine. The ECU 18 controls such parts as an injector 4 that is mounted in the intake pipe 2 and injects fuel, a throttle 5 that adjusts the amount of intake air, and the like based on the amount of intake air by an air flow sensor 19 mounted in the intake pipe 2, a fuel-air ratio detected by a fuel-air ratio sensor 20 fixed to an exhaust pipe 3, an ignition signal, an engine speed, the temperature of engine cooling water, an accelerator position, and the like to provide a suitable amount of fuel injected and a suitable throttle opening. The opening of the purge valve 11 is controlled by a duty control or the like by the ECU 18 when the engine is operated. The purge valve 11 controls a flow rate of evaporated fuel in the purge passage 10. The evaporated fuel separated from the absorbent 9 is purged into the intake pipe 2 by a negative pressure and is burned with the fuel injected by the injector 4.