JPS6034741Y2 - Coolant circulation system for liquid-cooled internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a coolant circulation system for a liquid-cooled internal combustion engine.

In conventional liquid-cooled internal engines of this type, the coolant flows sequentially through the radiator, circulation pump, oil cooler, cylinder block, and cylinder head, returns to the radiator via the outlet pipe, and is circulated through these paths. Also, when the coolant temperature is low, such as during start-up, the coolant is returned to the circulation pump from the thermostat in the outlet pipe.

In particular, since the coolant flowing through the cylinder block and having a high temperature and reduced pressure further flows to the cylinder head, the cylinder head is not sufficiently cooled, and cavitation is generated within the cylinder head. The cylinder head is becoming corroded.

The purpose of this invention is that it can be easily applied to existing internal combustion engines as well as newly built internal combustion engines, without changing the piping or pump installation, to maintain the coolant at a predetermined temperature and pressure. A coolant circulation system for a liquid-cooled internal combustion engine that prevents the induction of low-temperature boiling and cavitation, and also prevents corrosion of the cylinder block and cylinder head caused by cavitation and improves the cooling effect. On offer.

With these issues in mind, the coolant circulation system for a liquid-cooled internal combustion engine of this invention consists of a block-side coolant passage formed in the cylinder block, a head-side coolant passage formed in the cylinder head, and a radiator-side coolant passage formed in the cylinder block. a radiator inlet conduit, which is equipped with a coolant circulation pump and a thermostat, and which connects the outlet of the block side and head side coolant passages to the inlet of the radiator; and a radiator inlet conduit that connects the outlet of the radiator to the inlet of the coolant circulation pump. A high pressure side coolant supply conduit that connects the discharge port of the coolant circulation pump to the inlet of the head side coolant passage, and a high pressure side coolant supply conduit that connects the discharge port of the coolant circulation pump to the inlet of the block side coolant passage. a radiator bypass conduit connecting the thermostud to the suction port of the coolant circulation pump; and a connection point between the discharge port of the coolant circulation pump and the low pressure side coolant supply conduit; It consists of an orifice plate placed at the connection point.

Hereinafter, preferred specific examples of the coolant circulation system for a liquid-cooled internal combustion engine according to this invention will be described with reference to the drawings.

The figure shows a specific example 10 of the coolant circulation system of this invention applied to a diesel engine 40 mounted on a truck.

This coolant circulation system 10 includes a block side coolant passage 11 formed in a cylinder block 41 of a diesel engine, a head side coolant passage 12 formed in a cylinder head 42 of a diesel engine 40, and a radiator. 13, a coolant circulation pump 14 driven by a diesel engine 40, and a radiator connecting the outlet 23.25 of the block side and head side coolant passages 11.12 to the inlet of the radiator 13, that is, the upper tank 26. an inlet conduit 15, a thermo stud 20 provided in the radiator inlet conduit 15, and a radiator outlet conduit connecting the outlet of the radiator 13, that is, the lower tank 27, to the suction port 29 of the coolant circulation pump 14; 16, a high-pressure side coolant supply conduit 17 connecting the discharge port 30 of the coolant circulation pump 14 to the inlet 24 of the head side coolant passage 12, and a discharge port 30 of the coolant circulation pump 14.
a low-pressure side coolant supply conduit 18 that connects the thermostud 20 to the inlet 22 of the block side coolant passage 11; a radiator bypass conduit 19 that connects the thermostud 20 to the suction port 29 of the coolant circulation pump 14; 14 discharge ports 30 and the low-pressure side coolant supply conduit 18 are connected to each other.

The coolant circulation system 10 includes an oil cooler 31 in the low pressure side coolant supply conduit 18.

Since the coolant circulation system 10 is configured in this way and is filled with coolant, the engine 40 is now started.
If the coolant temperature is low, the engine 40
The coolant circulation pump 14 and the cooling fan 32 are driven, and the thermo stud 20 is connected to the radiator 1.
Since the port to the upper tank 26 of No. 3 is closed and the port to the radiator bypass conduit 19 is open, the coolant flows from the discharge port 30 of the pump 14 to the head side coolant via the high pressure side coolant supply conduit 17. It flows into the inlet 24 of the passage 12 and also flows from the outlet 30 of the pump 14 via the low pressure side coolant supply conduit 18 to the inlet 22 of the block side coolant passage 11.

In particular, as the coolant flows through the coolant supply conduit 18, it passes through the restriction 2.
1, which also cools the oil cooler 31.

As can be seen from the figure, the throttle 21 consists of an orifice plate and is arranged between the flanges of the outlet 30 of the pump 14 and the coolant supply conduit 18 which are flanged together, or Because it is located between the body of the pump 14 and the cylinder block 41, which communicates the outlet 30 with the coolant supply conduit 18, no changes are made to the piping or pump installation, and no cumbersome piping is required. This eliminates the need to change the design of the pump and the pump installation, and prevents changes in the manufacturing process associated with the design change.

Furthermore, one of the coolants flows in the block-side coolant passage 11, cooling the cylinder block 41 and passing from the outlet 23 to the suction port 29 of the pump 14 via the radiator inlet conduit 15 and the radiator bypass conduit 19. The other coolant flows in the head side coolant passage 12,
It cools the cylinder head 42 and flows from the outlet 25 to the suction port 29 of the pump 14 via the radiator inlet conduit 15 and the radiator bypass conduit 19.

In particular, since the orifice plate 21 is provided in the coolant supply conduit 18, the block side and head side coolant passages 1
1.12, the flow rates of the coolant at the outlets 23.24 of the cylinder block 4 are controlled to be substantially equal.
1 and the cylinder head 42 are effectively cooled and the coolant is brought up to temperature as quickly as possible.

As such, when the coolant is raised in temperature, the thermo stud 20 closes the port to the radiator bypass conduit 19 and opens the port to the upper tank 26 of the radiator 13, so that the coolant is transferred to the radiator inlet conduit. 15 to the upper tank 26 of the radiator 13 from the outlet 23.25 of the block-side and head-side coolant passages 11.12.

Further, in the radiator 13, the coolant flows down the fin tube 28 and from the upper tank 26 to the lower tank 27, where it is cooled by outside air taken in from the front grille of the truck by the cooling fan 32. .

The coolant flowing into the lower tank 27 flows through the radiator outlet conduit 16 to the suction port 29 of the pump 14, and is then returned to the radiator 13 via the aforementioned path and is recirculated.

According to this invention, the orifice plate is placed at the connection point between the discharge port of the coolant circulation pump and the low-pressure side coolant supply conduit, so there is no need to change the installation of the piping pump, and troublesome piping is avoided. This eliminates the need to change the design of the engine and pump installation, making it easy to apply to both existing and newly built internal combustion engines. It is now possible to flow low-pressure coolant into the side coolant passage, and high-pressure coolant can flow into the head side coolant passage, allowing the coolant to flow according to the cooling points of the internal combustion engine. temperature and pressure to prevent low-temperature boiling and cavitation, and to prevent cylinder damage caused by cavitation.
Corrosion of the block and cylinder head is alleviated, the cooling effect is improved, and furthermore, an increase in pump loss due to complicated piping is prevented.

[Brief explanation of drawings]

The figure is a schematic diagram of the coolant circulation system of this invention applied to a truck diesel engine. 10... Coolant circulation system, 11... Block side coolant passage, 12... Head side coolant passage, 13... Radiator, 14...・・・・・・
Coolant circulation pump, 15...Radiator inlet side conduit, 17...High pressure side cooling supply conduit, 18...
...low pressure side coolant supply conduit, 19...radiator bypass conduit, 20...thermo stud, 21...throttle, 26... Upper tank.

Claims (1)

[Claims for Utility Model Registration] A block-side coolant passage formed in the cylinder block, a head-side coolant passage formed in the cylinder head, a radiator, a coolant circulation pump, and a thermostat. , and a radiator inlet side conduit that connects the outlet of the block side and head side coolant passages to the radiator inlet, a radiator outlet side conduit that connects the radiator outlet to the suction port of the coolant circulation pump, and a coolant circulation pump. a high-pressure side coolant supply conduit that connects the outlet of the coolant circulation pump to the inlet of the head side coolant passage; a low-pressure side coolant supply conduit that connects the outlet of the coolant circulation pump to the inlet of the block side coolant passage; A liquid-cooled internal combustion engine comprising: a radiator bypass conduit connecting a stud to a suction port of a coolant circulation pump; and an orifice plate disposed at a connection between a discharge port of a coolant circulation pump and a low-pressure side coolant supply conduit. Coolant circulation system for.