# US 11,078,863 B2 · Abnormality determination apparatus for internal combustion engine

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- Number: US 11,078,863 B2
- Document ID: US11078863B2
- Status: Granted
- Kind: B2
- Application number: 16/783,759
- Filed: 2020-02-06
- Published: 2020-08-13
- Granted: 2021-08-03
- Earliest claimed: 2019-02-08
- Assignees: Honda Motor Co., Ltd.
- Applicants: Honda Motor Co., Ltd.
- Inventors: Toru Sekiguchi; Takashi Konomoto; Toshifumi Yoshida
- Web page: https://patentgrep.com/patent/US11078863B2

## CPC

- F02D 41/22: Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)}
- F01M 13/021: {of negative pressure}
- F01M 13/023: {Control valves in suction conduit}
- F02D 41/18: by measuring intake air flow
- F01M 2013/0077: {Engine parameters used for crankcase breather systems}
- F01M 2013/027: {with a turbo charger or compressor}
- F02D 2041/1432: {the system including a filter, e.g. a low pass or high pass filter}
- F02D 2200/0402: the parameter being determined by using a model of the engine intake or its components
- Y02T 10/40: Engine management systems
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An abnormality determination apparatus for an internal combustion engine in which an intake passage upstream of a supercharger and a crankcase are connected by a breather line includes: an intake flow rate detection unit that detects an intake flow rate in the intake passage; and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit accumulates a value calculated from a rotation second-order component of a fluctuation waveform of the intake flow rate over a predetermined period of time and determines the abnormality of the breather line when the accumulated value is less than a predetermined threshold.

## Claims

### Claim 1

An abnormality determination apparatus for an internal combustion engine in which a crankcase and an intake passage upstream of a forced-induction system are connected by a breather line, comprising:
an intake flow rate detection detector that detects an intake flow rate in the intake passage; and
an abnormality determination unit that determines abnormality of the breather line, wherein
the abnormality determination unit accumulates a value calculated from a rotation second-order component of a fluctuation waveform of the intake flow rate over a predetermined period of time to obtain an accumulated value and determines occurrence of the abnormality of the breather line when the accumulated value is less than a predetermined threshold.

### Claim 2 (depends on 1)

The abnormality determination apparatus for an internal combustion engine according to claim 1, wherein
the accumulated value is obtained by accumulating an absolute value of the rotation second-order component of the fluctuation waveform of the intake flow rate over the predetermined period of time.

### Claim 3 (depends on 1)

The abnormality determination apparatus for an internal combustion engine according to claim 1, wherein
the accumulated value is obtained by accumulating a difference in one cycle between a maximum value and a minimum value of the rotation second-order component of the fluctuation waveform of the intake flow rate over the predetermined period of time.

### Claim 4 (depends on 1)

The abnormality determination apparatus for an internal combustion engine according to claim 1, wherein
the rotation second-order component is calculated by multiplying the fluctuation waveform of the intake flow rate by a sine wave and a cosine wave corresponding to an angular velocity of a crank, followed by integration.

### Claim 5 (depends on 1)

The abnormality determination apparatus for an internal combustion engine according to claim 1, wherein
the rotation second-order component represents a rotation second-order fluctuation generated in an internal pressure of the crankcase.

### Claim 6

An abnormality determination method of an internal combustion engine in which a crankcase and an intake passage upstream of a forced-induction system are connected by a breather line, the method comprising steps of:
detecting by an intake flow rate detection detector an intake flow rate in the intake passage;
accumulating by a computer a value calculated from a rotation second-order component of a fluctuation waveform of the intake flow rate over a predetermined period of time to obtain an accumulated value; and
determining by the computer occurrence of the abnormality of the breather line when the accumulated value is less than a predetermined threshold.