# US 11,441,497 B2 · Internal combustion engine control method and internal combustion engine control device

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- Number: US 11,441,497 B2
- Document ID: US11441497B2
- Status: Granted
- Kind: B2
- Application number: 16/963,571
- Filed: 2018-01-23
- Published: 2021-02-25
- Granted: 2022-09-13
- Earliest claimed: 2018-01-23
- Assignees: Nissan Motor Co., Ltd.
- Applicants: Nissan Motor Co., Ltd.
- Inventors: Kengo Yonekura; Hirofumi Tsuchida
- Web page: https://patentgrep.com/patent/US11441497B2

## CPC

- F02D 41/0007: {for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12)}
- F02D 13/0234: {changing the valve timing only}
- F02D 41/1454: {the characteristics being an oxygen content or concentration or the air-fuel ratio}
- F02D 41/3029: {further comprising a homogeneous charge spark-ignited mode}
- F02D 41/307: {to avoid torque shocks}
- F02D 2041/002: {by simultaneous control of throttle and variable valve actuation}
- F02D 2200/101: Engine speed
- 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)

## Abstract

During a transient period, the opening degree of a throttle valve (throttle opening degree) is varied from a steady-period target throttle opening degree in a region A1 toward a valve closing side by a predetermined amount ΔP, and is thereafter controlled so as to become a steady-period target throttle opening degree in the region A1. The transient period is a transient period in which the operation state is shifted from a region B2 in which an air-fuel ratio in a supercharged state becomes a predetermined lean air-fuel ratio to a region A1 in which the air-fuel ratio in a non-supercharged state becomes a predetermined rich air-fuel ratio richer than the lean air-fuel ratio. In this transient period, by reducing the air amount in a cylinder, the combustion torque of an internal combustion engine is suppressed, and consequently; a torque overshoot can be suppressed.

## Claims

### Claim 1

A method for controlling an internal combustion engine including a throttle valve provided in an intake passage as an air amount controller configured to control an air amount in a cylinder, the method comprising:
controlling, during a transient period in which an operation state is shifted from a first operation state in which an air-fuel ratio in a turbocharged state becomes a predetermined lean air-fuel ratio to a second operation state in which the air-fuel ratio in a non-turbocharged state becomes a stoichiometric air-fuel ratio richer than the predetermined lean air-fuel ratio, the air amount in the cylinder so as to be an air amount smaller than an air amount realizing the stoichiometric air-fuel ratio by reducing the air amount in the cylinder,
controlling, during the transient period, a throttle opening degree of the throttle valve such that an intake pressure becomes lower than an exhaust pressure,
controlling, during the transient period, the throttle valve such that the throttle opening degree is varied toward a valve closing side further from a steady-time target throttle opening degree in the second operation state by a predetermined amount, and thereafter becomes the steady-time target throttle opening degree in the second operation state, and
setting the predetermined amount so as to be larger as a turbocharging pressure in the first operation state is higher.

### Claim 2 (depends on 1)

The method for controlling the internal combustion engine according to claim 1, wherein the predetermined amount is set so as to be smaller as an engine speed of the internal combustion engine in the first operation state is higher.

### Claim 3

A device for controlling an internal combustion engine, comprising:
a turbocharger;
a throttle valve provided in an intake passage as an air amount controller configured to control an air amount in a cylinder; and
a controller configured to control the air amount controller,
wherein during a transient period in which an operation state is shifted from a first operation state in which an air-fuel ratio in a turbocharged state becomes a predetermined lean air-fuel ratio to a second operation state in which the air-fuel ratio in a non-turbocharged state becomes a stoichiometric air-fuel ratio richer than the predetermined lean air-fuel ratio, the controller is configured to control the air amount controller such that the air amount in the cylinder becomes an air amount smaller than an air amount realizing the stoichiometric air-fuel ratio by reducing the air amount in the cylinder,
wherein during the transient period, a throttle opening degree of the throttle valve is controlled such that an intake pressure becomes lower than an exhaust pressure,
wherein during the transient period, the throttle valve is controlled such that the throttle opening degree is varied toward a valve closing side further from a steady-time target throttle opening degree in the second operation state by a predetermined amount, and thereafter becomes the steady-time target throttle opening degree in the second operation state, and
wherein the predetermined amount is set so as to be larger as a turbocharging pressure in the first operation state is higher.