Cooling device for internal combustion engine, and cooling method for internal combustion engine

Patent metadata

Field	Value
Publication number	US-2016160739-A1
Application number	US-201414902211-A
Country	US
Kind code	A1
Filing date	May 19, 2014
Priority date	Jul 1, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

A control unit stores a correlation between a temperature difference ΔT between an inlet temperature and an outlet temperature of a heat exchanger for cooling of cooling water, and the amount of thermal deformation occurring in the heat exchanger. At the time when the cooling water is supplied to the heat-exchanging flow path having the heat exchanger, the control unit refers to the temperature difference ΔT and the correlation to obtain the volume of flow of the cooling water supplied to the heat-exchanging flow path so that the amount of thermal deformation is less than or equal to a threshold amount of thermal deformation set in advance.

First claim

1 . A cooling device for an internal combustion engine, comprising:
a cooling-water flow path through which cooling water for cooling an internal combustion engine passes therethrough; a switching unit provided on an outlet side of the cooling-water flow path, and configured to branch the cooling-water flow path into either a heat-exchanging flow path having a heat exchanger for cooling the cooling water disposed therein or a bypass flow path without the heat exchanger, or both; a circulation pump that delivers, to the cooling-water flow path, cooling water passing through the heat-exchanging flow path and the bypass flow path; an inlet temperature detector that detects a temperature of the cooling water supplied to the heat exchanger; an outlet temperature detector that detects a temperature of the cooling water discharged from the heat exchanger; and a controller that controls distribution, in the switching unit, of a volume of flow of the cooling water to the heat-exchanging flow path and the bypass flow path, wherein the controller includes a storage unit that stores a correlation between the amount of thermal deformation occurring in the heat exchanger and a temperature difference between a first cooling water temperature detected by the inlet temperature detector and a second cooling water temperature detected by the outlet temperature detector, and wherein, when the cooling water is supplied to the heat-exchanging flow path, the controller refers to the temperature difference and the correlation to obtain a volume of flow of the cooling water supplied to the heat-exchanging flow path so that the amount of thermal deformation is less than or equal to a threshold amount of thermal deformation set in advance, and controls distribution, by the switching unit, of the volume of flow of the cooling water to achieve the obtained volume of flow of the cooling water.

2 . The cooling device for an internal combustion engine according to claim 1 ,
wherein the controller sets, to the correlation, a boundary line that separates an area where the amount of thermal deformation exceeds the threshold amount of thermal deformation from an area where the amount of thermal deformation does not exceed the threshold amount of thermal deformation, and sets, along this boundary line, the volume of flow of the cooling water flowing through the heat-exchanging flow path.

3 . The cooling device for an internal combustion engine according to claim 1 ,
wherein the switching unit is capable of bringing, into a fully closed state, an opening of the switching unit on the heat-exchanging flow path side and an opening of the switching unit on the bypass flow path side, and wherein the inlet temperature detector is provided in a vicinity of the outlet side of the cooling-water flow path on an upstream side of the switching unit.

4 . A cooling method for an internal combustion engine, comprising:
causing cooling water to flow through a cooling-water flow path for cooling an internal combustion engine when the internal combustion engine is started; switching a flow path of the cooling water at a time of reducing an elevated cooling water temperature that is raised due to the cooling water passing through the cooling-water flow path, the switching being performed so as to cause at least part of the cooling water to flow through a heat-exchanging flow path having a heat exchanger disposed therein, and to cause a remainder of the cooling water to flow through a bypass flow path; obtaining a temperature difference between a first cooling water temperature detected by an inlet temperature detector provided at an inlet of the heat exchanger on the heat-exchanging flow path, and a second cooling water temperature detected by an outlet temperature detector provided at an outlet of the heat exchanger on the heat-exchanging flow path; and referring to a correlation between the temperature difference and the amount of thermal deformation occurring in the heat exchanger to obtain a volume of flow of the cooling water flowing through the heat-exchanging flow path so that the amount of thermal deformation occurring in the heat exchanger is less than or equal to a threshold amount of thermal deformation set in advance, and controlling distribution of the volume of flow of the cooling water flowing through the heat-exchanging flow path and the bypass flow path, so as to achieve the obtained volume of flow of the cooling water.

5 . The cooling device for an internal combustion engine according to claim 2 ,
wherein the switching unit is capable of bringing, into a fully closed state, an opening of the switching unit on the heat-exchanging flow path side and an opening of the switching unit on the bypass flow path side, and wherein the inlet temperature detector is provided in a vicinity of the outlet side of the cooling-water flow path on an upstream side of the switching unit.

Assignees

• Nissan Motor

Inventors

• Ichihara Takayoshi
• Kawamoto Aiko
• Oko Yoshimi

Classifications

• F01P2025/50

  using two or more temperature sensors · CPC title

• F01P7/16 Primary

  by thermostatic control · CPC title

• B60K11/02

  with liquid cooling · CPC title

• F01P2025/36

  Heat exchanger mixed fluid temperature · CPC title

• F01P2007/146

  using valves · CPC title