# US 2018/0320642 A1 · Intake air temperature control device for engine

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- Number: US 2018/0320642 A1
- Document ID: US20180320642A1
- Status: Published application
- Kind: A1
- Application number: 15/772,552
- Filed: 2016-11-30
- Published: 2018-11-08
- Earliest claimed: 2016-01-26
- Assignees: Aisan Kogyo Kabushiki Kaisha
- Applicants: Aisan Kogyo Kabushiki Kaisha
- Inventors: Fumihito NAKATANI; Takahiko IWAKURA; Kazufumi ISHII
- Web page: https://patentgrep.com/patent/US20180320642A1

## CPC

- F02M 31/042: {Combustion air}
- F02D 35/027: {using knock sensors}
- F02D 37/02: one of the functions being ignition
- F02D 41/0002: {Controlling intake air}
- F02D 41/005: {according to engine operating conditions}
- F02D 45/00: Electrical control not provided for in groups F02D41/00 - F02D43/00
- F02M 31/08: the gases being exhaust gases {(adding exhaust gases to the air intake passage F02M26/00)}
- F02M 35/10: Air intakes; Induction systems
- F02P 5/045: {combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02)}
- F02P 5/1502: {using one central computing unit}
- F02P 5/152: dependent on pinking (detecting or indicating knocks in internal-combustion engines G01L23/22)
- G01L 23/221: {for detecting or indicating knocks in internal combustion engines}
- F02D 2200/021: Engine temperature
- F02D 2200/0414: Air temperature
- F02D 2200/1002: Output torque
- F02D 2200/101: Engine speed
- Y02T 10/12: Improving ICE efficiencies
- Y02T 10/40: Engine management systems
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- 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)
- F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00)
- G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An ECU controls a passage switch valve according to the operation state of an engine, to control the temperature of intake air introduced into the engine, by selectively causing outside air from an outside air inlet, high-temperature air from a high-temperature passage, or mixed air comprising the outside air and the high-temperature air to flow towards the downstream side of an intake passage. The ECU calculates the MBT ignition timing and the knock limit ignition timing based on detection results of sensors, and controls the passage switch valve such that, when the knock limit ignition timing is at a more advanced angle than the MBT ignition timing, the high-temperature air or the mixed air is introduced into the engine, and when the knock limit ignition timing is the same as or at a more delayed angle than the MBT ignition timing, the outside air is introduced into the engine.

## Claims

### Claim 1

An intake air temperature control device for an engine, comprising:
an intake passage for introducing intake air into the engine;
an unheated air passage for introducing unheated air which is free from heating into the intake passage;
a heated air passage for introducing heated air which has been heated into the intake passage;
a passage switch member for switching passages to selectively flow any one of the unheated air from the unheated air passage, the heated air from the heated air passage, and mixed air constituted of the unheated air and the heated air into a downstream side of the intake passage; and
a control unit for controlling the passage switch member according to an operation state of the engine,
the intake air temperature control device being configured to selectively flow any one of the unheated air, the heated air, and the mixed air constituted of the unheated air and the heated air to the downstream side of the intake passage to adjust the temperature of the intake air which is going to be introduced in the engine, wherein
the intake air temperature control device further comprises:
a fuel supply member for supplying fuel to the engine;
an ignition member for igniting combustible gas mixture constituted of the fuel supplied to the engine and the intake air introduced in the engine;
an intake property detection member for detecting property of the intake air which flows through the intake passage downstream of the passage switch member;
a rotational speed detection member for detecting rotational speed of the engine; and
a load detection member for detecting a load of the engine, and
the control unit is configured to calculate MBT ignition timing at which engine torque becomes maximum and knock limit ignition timing which is immediately before occurrence of knocking of the engine based on detection results obtained by the intake property detection member, the rotational speed detection member, and the load detection member, and to control the passage switch valve to introduce any one of the heated air and the mixed air as intake air to the engine when the knock limit ignition timing is advanced more than the MBT ignition timing and introduce the unheated air as the intake air into the engine when the knock limit ignition timing is equal to or delayed from the MBT ignition timing.

### Claim 2 (depends on 1)

The intake air temperature control device for the engine according to claim 1, wherein
the passage switch member is a passage switch valve which is constituted of a motor-operated valve, the passage switch valve including a valve element and a motor for driving the valve element, and the valve element is arranged switchable between a first position for introducing only the unheated air into the intake passage and a second position for introducing only the heated air into the intake passage and arranged to be held in any midway position between the first position and the second position;
the intake property detection member includes an intake air temperature sensor for detecting an intake air temperature as property of the intake air; and
the control unit is configured to control the passage switch valve so that the intake air temperature detected by the intake air temperature sensor reaches a target intake air temperature when the knock limit ignition timing is advanced more than the MBT ignition timing.