# US 9,752,487 B2 · Failure detection device for fuel addition valve

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- Number: US 9,752,487 B2
- Document ID: US9752487B2
- Status: Granted
- Kind: B2
- Application number: 14/784,209
- Filed: 2014-07-08
- Published: 2016-02-25
- Granted: 2017-09-05
- Earliest claimed: 2013-07-10
- Assignees: Hino Motors, Ltd.
- Applicants: Hino Motors, Ltd.
- Inventors: Munechika Tsutsumi
- Web page: https://patentgrep.com/patent/US9752487B2

## CPC

- F01N 11/00: Monitoring or diagnostic devices for exhaust-gas treatment apparatus
- F01N 3/0253: {adding fuel to exhaust gases}
- F01N 3/36: Arrangements for supply of additional fuel
- F01N 9/002: {of filter regeneration}
- F01N 2550/04: Filtering activity of particulate filters
- F01N 2550/05: Systems for adding substances into exhaust
- F01N 2610/03: the substance being hydrocarbons, e.g. engine fuel
- F01N 2900/1808: Pressure
- Y02T 10/40: Engine management systems
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A controller recognizes that fuel is and is not actually injected when an amplitude of fuel pressure fluctuations detected by a pressure sensor is not less than and is less than a pressure threshold α, respectively, to obtain a number N of actual fuel injections and determines that a fuel addition valve operates normally and has malfunction when a ratio (N/S) of the obtained numbers N of the actual fuel injections to a number S of the fuel injection commands is not less than and is less than a number ratio threshold β, respectively.

## Claims

### Claim 1

A device for detecting failure of a fuel addition valve which injects fuel from a fuel pump through a fuel addition pipe to exhaust gas flowing through an exhaust pipe, the device comprising:
a pressure sensor incorporated in said fuel addition pipe for detecting fuel pressure fluctuations upon injection of the fuel by said fuel addition valve; and
a controller
for recognizing that the fuel is actually injected when an amplitude of the fuel pressure fluctuations detected by said pressure sensor is not less than a pressure threshold and that the fuel is not actually injected when the amplitude of the fuel pressure fluctuations detected by said pressure sensor is less than the pressure threshold to thereby obtain a number of actual fuel injections, and
for determining that said fuel addition valve operates normally when a ratio of said number of actual fuel injections to a number of fuel injection commands is not less than a number ratio threshold and that said fuel addition valve has a malfunction when the ratio of said number of actual fuel injections to the number of fuel injection commands is less than the number ratio threshold,
wherein the controller sets the number ratio threshold to satisfy an inequation:
0<β<1
where β is said number ratio threshold.

### Claim 2 (depends on 1)

The device for detecting failure of the fuel addition valve as claimed in claim 1, wherein the pressure threshold is a predetermined amplitude of the fuel pressure fluctuations.

### Claim 3 (depends on 1)

The device for detecting failure of the fuel addition valve as claimed in claim 1, the number of actual fuel injections is equal to a number of times the amplitude of the fuel pressure fluctuations detected by said pressure sensor is not less than the pressure threshold over a period of time in which the number of fuel injection commands are output by the controller.