INTERNAL COMBUSTION ENGINE COOLING SYSTEM

Abstract

A check valve having a thermostat function is provided between an engine and a thermal storage tank that stores a portion of the coolant circulating in the engine. The check valve restricts the flow of the coolant from the engine to the thermal storage tank, and loosens the restriction when the temperature of the coolant increases. Through such operation of the check valve, the warm coolant is collected in the thermal storage tank and engine preheating may be performed before engine start. Thus, by providing between the engine and the thermal storage tank the check valve that operates in response to the temperature of the coolant, engine preheating can be accomplished with a simple structure and at a low cost, without using a three-way valve and performing an electrical valve switching control.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and further objects, features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:

FIG. 1 is a circuit diagram illustrating one example of a cooling system according to the invention;

FIG. 2 is a vertical sectional view showing the structure of a check valve, which also serves as a thermostat, used in the cooling system shown in FIG. 1;

FIG. 3 is a diagram showing the operation of the cooling system shown in FIG. 1 during the preheating period;

FIG. 4 is a diagram showing the operation of the cooling system shown in FIG. 1 during the warm-up period of an engine;

FIG. 5 is a diagram showing the operation of the cooling system shown in FIG. 1 after the warm-up of the engine;

FIG. 6A and FIG. 6B are diagrams showing other embodiments of the cooling system according to the invention;

FIG. 7A and FIG. 7B are diagrams showing other embodiments of the cooling system according to the invention; and FIG. 8 is a circuit diagram showing one example of a cooling system according to a related art.

Claims

1. A cooling device of an internal combustion engine, comprising: a thermal storage device that stores a part of a coolant circulating in an internal combustion engine while keeping the stored coolant warm; anda valve device that is provided between the thermal storage device and the internal combustion engine and controls the flow of the coolant, whereinthe valve device restricts the flow of the coolant from the internal combustion engine to the thermal storage device and loosens the restriction on the flow of the coolant when the temperature of the coolant increases.

2. The cooling device of an internal combustion engine according to claim 1, wherein the valve device includes a temperature-sensing portion that opens a valve body of the valve device when the temperature of the coolant in contact with the temperature-sensing portion increases, thereby reducing the restriction on the flow of the coolant.

3. The cooling device of an internal combustion engine according to claim 2, wherein the valve body is opened by a displacement of the valve body itself, the displacement being caused by a expansion of the temperature-sensing portion in response to an increase in the temperature of the coolant in contact with the temperature-sensing portion.

4. The cooling device of an internal combustion engine according to claim 2, wherein the valve device is structured to bring the temperature-sensing portion into contact with the coolant flowing from the internal combustion engine by diverting the coolant within the valve device when the valve device is restricting the flow of the coolant.

5. The cooling device of an internal combustion engine according to claim 2, wherein a pipe, which communicates with a flow passage within the valve device where the temperature-sensing portion is located, is provided through which the coolant flows when the valve device restricts the flow of the coolant, to bring the temperature-sensing portion into contact with the coolant flowing from the internal combustion engine.

6. The cooling device of an internal combustion engine according to claim 2, wherein the valve device contacts a main body of the internal combustion engine.

7. The cooling device of an internal combustion engine according to claim 6, wherein the valve device is incorporated in the main body of the internal combustion engine.

8. The cooling device of an internal combustion engine according to claim 6, wherein the valve device is disposed outside of the main body of the internal combustion engine.