Cooling system for internal combustion engines

• US 4,759,316 A
• Filed: 07/07/1987
• Issued: 07/26/1988
• Est. Priority Date: 07/07/1986
• Status: Expired due to Term

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Itakura, Masato
• Primary Examiner(s): Argenbright, Tony M.
• Application Number:
  US07/072,653
• Time in Patent Office: 385 Days
• Field of Search: 123/41.08, 123/41.09, 123/41.1, 123/41.44, 123/41.29, 123/41.82 R, 123/41.82 A, 123/41.72, 236/34.5
• US Class Current: 123/41.08
• CPC Class Codes: F01P 2003/027 Cooling cylinders and cylinder heads in parallel
• 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 2025/00 Measuring
• CPC Class Codes: F01P 2025/50 using two or more temperature sensors
• CPC Class Codes: F01P 2025/62 Load
• 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 cooling system for an internal combustion engine comprising independent head-side and block-side water jackets and a shared radiator and cooling fan. Further included are a first cooling water conduit connecting the outlet of the head-side jacket and the inlet of the radiator, a mixing valve having two water inlets and one water outlet, a second cooling water conduit connecting one water inlet and the outlet of the radiator, a third conduit connecting the water outlet of the block-side jacket and the other water inlet, a water pump connected between the outlet of the mixing valve and the block-side jacket, a fourth conduit branched from the second conduit and connected with the inlet of the head-side jacket, an auxiliary water pump disposed in the fourth conduit pumping water to said head-side jacket, a fifth conduit branched from the third conduit and connected with the first conduit, a one-way valve disposed in the fifth conduit allowing water to flow only from the third conduit to the first conduit, a one-way valve disposed in the second conduit between the branch point of the fourth conduit and the mixing valve allowing water to flow only from the branch point to the mixing valve, and a control unit controlling the mixing ratio of the mixing valve, the auxiliary water pump and the cooling fan.

Claims

1. A cooling system for an internal combustion engine, comprising:

a head-side water jacket and a block-side water jacket made independent of each other; and

a radiator and a cooling fan shared between said two water jackets,

wherein the improvement comprises;

a first cooling water conduit for connecting the outlet of said head-side water jacket and the inlet of said radiator;

a mixing valve having two water inlets and one water outlet;

a second cooling water conduit for connecting one of the water inlets of said mixing valve and the outlet of said radiator;

a third conduit for connecting the water outlet of said block-side water jacket and the remaining one of the water inlets of said mixing valve;

a water pump connected between the water outlet of said mixing valve and said block-side water jacket for pumping water to said block-side water jacket;

a fourth conduit branched midway from said second conduit and connected with the water inlet of said head-side water jacket;

an auxiliary water pump disposed midway of said fourth conduit for pumping water to said head-side water jacket;

a fifth conduit branched midway from said third conduit and connected with said first conduit;

a one-way valve disposed midway of said fifth conduit for allowing the water to flow only from said third conduit to said first conduit;

a one-way valve disposed midway of said second conduit and between the branch point of said fourth conduit and said mixing valve for allowing the water to flow only from said branch point to said mixing valve; and

a control unit for controlling the mixing ratio of said mixing valve, the displacement of said auxiliary water pump and the operation of said cooling fan.

2. A cooling system according to claim 1, further comprising:

a water temperature sensor for detecting the water temperature of said head-side water jacket;

a water temperature sensor for detecting the water temperature of said block-side water jacket; and

an intake pressure sensor for detecting the pressure in the intake manifold of said internal combustion engine,

wherein said control unit controls the mixing ratio of said mixing valve, the displacement of said auxiliary water pump and the operation of said cooling fan in accordance with detected signals of said water temperature sensors and said intake pressure sensor.

3. A cooling system according to claim 2, wherein the controls of said control unit are so performed that the water temperature of said head-side water jacket may be lower than that of said block-side water jacket.

4. A cooling system according to claim 1, further comprising an electric motor for driving said auxiliary water pump.