Liquid-cooling device for internal combustion engine

• US 20060096553A1
• Filed: 11/09/2005
• Published: 05/11/2006
• Est. Priority Date: 11/11/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Takahashi, Eizo
• Granted Patent: US 7,243,620 B2
• Time in Patent Office: Days
• US Class Current: 123/41.1
• CPC Class Codes: F01P 2003/021 Cooling cylinders
• CPC Class Codes: F01P 2003/024 Cooling cylinder heads
• CPC Class Codes: F01P 2005/105 Using two or more pumps
• CPC Class Codes: F01P 2005/125 Driving auxiliary pumps electrically
• CPC Class Codes: F01P 2060/08 Cabin heater
• CPC Class Codes: F01P 3/02 Arrangements for cooling cylinders or cylinder heads
• CPC Class Codes: F01P 7/165 characterised by systems with two or more loops
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed

Abstract

A head cooling path diverges from a backflow path at a position between a radiator and a thermostat and is connected with a cylinder head of an engine by bypassing a cylinder block of the engine. A pump circulates the cooling water through the head cooling path, to the cylinder head, when the engine is operated at a high load and/or a vehicle is in a rapid acceleration, so that sufficiently cooled cooling water is supplied directly to the cylinder head.

Claims

1. A liquid-cooling device for an internal combustion engine, comprising:

a radiator for cooling down cooling liquid for a liquid-cooling type internal combustion engine, by means of heat exchange between the cooling liquid and air;

an inflow path for guiding the cooling liquid from a cylinder head of the engine into the radiator;

a backflow path for guiding the cooling liquid cooled down by the radiator into a cylinder block of the engine;

a bypass connected with the inflow path and the backflow path, for making the cooling liquid bypass the radiator;

a liquid temperature controlling means installed at a junction of the bypass and the backflow path, for controlling temperature of the cooling liquid entering the cylinder block by adjusting a ratio between amounts of flows of the cooling liquid from the backflow path and from the bypass;

a first circulation means installed at a downstream of the liquid temperature controlling means for circulating the cooling liquid in accordance with a revolution of the engine;

a controller for controlling an operation of the engine;

a head cooling path diverging from the backflow path at a position between the radiator and the liquid temperature controlling means, for guiding the cooling liquid into the cylinder head; and

a second circulation means independently operated of the first circulation means and circulating the cooling liquid through the head cooling path, wherein

the controller controls the operation of the second circulation means.

2. The liquid-cooling device according to claim 1, wherein the controller activates the second circulation means when a load of the engine is heavier than a load threshold.

3. The liquid-cooling device according to claim 1, wherein the controller activates the second circulation means when an acceleration of the engine is larger than an acceleration threshold.

4. The liquid-cooling device according to claim 1, wherein the controller increases an amount of the air passing through the radiator in conjunction with the operation of the second circulation means.

5. The liquid-cooling device according to claim 1, wherein the liquid temperature controlling means controls the temperature of the cooling liquid flowing back to the cylinder block at a value higher than a temperature, at which the cooling liquid flowing back into the cylinder block is normally controlled.

6. The liquid-cooling device according to claim 1, wherein the first circulation means is replaced with an electrically operated circulation device installed at the position downstream of the liquid temperature controlling means, for circulating the cooling liquid independently of a revolution of the engine, wherein the controller controls the operation of the electrically operated circulation device.

7. The liquid-cooling device according to claim 1, further comprising:

a liquid storage tank installed at a position where the head cooling path diverges from the backflow path, for storing the cooling liquid from the radiator.

8. The liquid-cooling device according to claim 7, wherein the liquid storage tank and a lower tank of the radiator is made as one unit.

9. The liquid-cooling device according to claim 7, wherein the second circulation means is installed at the liquid storage tank.

10. A liquid-cooling device for an internal combustion engine, comprising:

a radiator for cooling down cooling liquid for a liquid-cooling type internal combustion engine, by means of heat exchange between the cooling liquid and air;

an inflow path for guiding the cooling liquid from a cylinder head of the engine into the radiator;

a backflow path for guiding the cooling liquid cooled down by the radiator into a cylinder block of the engine;

a head cooling path diverging from the backflow path, for guiding the cooling liquid into the cylinder head by bypassing the cylinder block; and

a circulation means for circulating the cooling liquid in a first circuit comprising the cylinder block, the cylinder head, the inflow path, the radiator, and the backflow path,

the circulation means further circulating the cooling liquid in a second circuit comprising the cylinder head, the inflow path, the radiator, and the head cooling path, depending on an operational condition of the engine.