JPS6218650Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cooling system for a water-cooled internal combustion engine, and is a cooling system for an internal combustion engine with a new structure that improves engine cooling efficiency and makes it possible to reduce the size and weight of the engine. The purpose is to provide

Hereinafter, a cooling device for a water-cooled internal combustion engine according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 and 2 show a cooling system for a vertical water-cooled diesel engine, which is an embodiment of the present invention.

In the figure, numeral 1 is the engine body, 2 and 3 are the cylinder block and cylinder head that make up the engine body 1, 4 is the piston, 5 is the crankshaft which is the engine shaft, and 6 is the engine shaft that is pivoted to one end of the crankshaft 5. 7 is a recoil starter disposed outside the centrifugal fan 6, and 8 is a fan case attached to the side of the engine body 1 to surround the outer periphery of the centrifugal fan 6. It shows.

The centrifugal fan 6 includes blowing blades 9, 9...
It is pivotally mounted on the crankshaft 5 with the engine body 1 facing toward the engine body 1 side.

The inside of the fan case 8 is divided into a lower fan chamber 10 and an upper radiator chamber 11 by a partition wall 15 and a deflection rib 16. Note that the space between the partition wall 15 and the deflection rib 16 is an outlet 17 of the centrifugal fan 6.

The fan case 8 includes an inner case 8a attached to the cylinder block 2 side and the inner case 8.
It is divided into an outer case 8b that covers the outer opening of the cylinder block 2, and is attached by bolts 12 with the inner case 8a facing closely to the side wall of the cylinder block 2. At this time, a gap S communicating with the outside is formed between the side wall of the cylinder block 2 and the inner case 8a. The cavity S acts as an intake air passage for the centrifugal fan 6, and is connected to the crankshaft insertion hole 1 of the inner case 8a.
A substantially annular suction port 14 is formed at the third peripheral edge.

Reference numeral 18 denotes a cooling fin that is protruded from a fan case mounting portion of the crankcase 19 at the bottom of the cylinder block 2.

The bolt 12 is attached to a bolt receiving portion 20 formed on the outer peripheral edge of the suction port 14 in the inner case 8a.
and a mounting seat 21 formed on the crankcase 19 are fastened and fixed via anti-vibration rubber 22. In this way, the bolt receiving part 20 is connected to the suction port 14 with low rigidity.
If formed on the outer peripheral edge of the recoil starter 7
Even during operation, the fan case 8 is relatively firmly fixed without tilting significantly. Reference numeral 23 denotes a wire mesh provided at the suction port 13 to prevent foreign matter from entering.

Furthermore, a recoil starter mounting hole 24 is formed in the outer case 8b at a position corresponding to the axis of the crankshaft 5.

Note that the gap between the inner circumferential surface of the recoil starter mounting hole 24 and the outer circumferential surface of the rope pulley 25 of the recoil starter 7 is narrow enough that the two do not come into contact, since there is no need for cooling air to flow in as in the conventional case. It is said to be a gap.

On the other hand, in the radiator chamber 11 in the fan case 8 , a radiator device 26 for cooling the engine is arranged at a position close to the outlet 17 of the centrifugal fan 6 .

The radiator device 26 includes a radiator body 27
An upper tank 28 and a lower tank 29 are attached to the upper and lower parts of the tank, respectively.

This radiator device 26 has an upper tank 28 placed close to the inner wall side of the inner case 8a, which is the inner wall of the fan case 8 on the side of the engine body 1 (in other words, to the cylinder head 3), and the lower tank 29 is placed close to the cylinder block 2. The cooling air passage area from the lower end to the upper end of the radiator device 26 is gradually narrowed. There is. This means that the centrifugal fan 6
It functions to allow the cooling air A from the radiator device 26 to flow evenly through the radiator device 26.

The upper tank 28 is connected to the water jacket 31 in the cylinder head 3 via the cooling water return pipe 30, while the lower tank 29 is connected to the water jacket 33 in the cylinder block 2 via the cooling water outlet pipe 32. is connected to.

Note that the reference numeral 34 is a vibration isolating member interposed between the fan case 8 and the radiator device 26,
It also acts as a sealing member for the cooling air A.
Reference numeral 35 indicates a cooling air outlet formed at the upper part of the outer case 8b, 36 a radiator grill attached to the cooling air outlet 35, 37 a water supply port, and 38 an overflow pipe.

Next, the operation of the illustrated cooling system for a water-cooled internal combustion engine will be explained.

When the engine body 1 is operated and the centrifugal fan 6 rotates, cooling air flows from the gap S formed between the side wall of the cylinder block 2 and the inner case 8a to the suction port of the inner case 8a, as shown by arrow A. The air is sucked into the fan case 8 through the centrifugal fan 6 , is further increased in pressure by the centrifugal fan 6 , is blown out from the air outlet 17 while being deflected by the deflection ribs 16 , and is then evenly passed through the radiator body 27 . The cooling air is discharged to the outside from the cooling air outlet 35. At this time, the cooling air A cools the lubricating oil in the crankcase 19 by exchanging heat with the cooling fins 18 while passing through the gap S, and also cools the cooling water W while passing through the radiator body 27. It works like this.

On the other hand, as shown by arrow W, the cooling water flows from the radiator device 26 through the cooling water outlet pipe 32, the water jacket 33 of the cylinder block 2, the water jacket 31 of the cylinder head 3, and the cooling water return pipe 30. The water is returned to the radiator device 26, during which time the cylinder block 2 and cylinder head 3 are cooled. This cooling water W is caused to undergo natural convection due to the temperature difference between the engine body 1 side and the radiator device 26 side.

Furthermore, since the upper tank 28 and the cylinder head 3 are close to each other, the amount of high-temperature cooling water W that accumulates between them is reduced.
Since the cylinder block 9 and the cylinder block 2 are located far apart from each other, a large amount of cooling water W accumulates between them. Therefore, the downward action of the cooling water W, which has been cooled by the radiator main body 27 and has increased in specific gravity, becomes stronger.

Next, the effects of the cooling device for a water-cooled internal combustion engine of the present invention will be listed below.

That is, according to the present invention, (1) the radiator chamber 11 is formed above the fan chamber 10 in the fan case 8, and the radiator device 26 is installed in the radiator chamber 11 against the inner wall of the fan case 8 on the side of the engine body 1; Since the cooling air passage area from the lower end of the radiator device 26 to the upper end of the radiator device 26 is gradually narrowed, the cooling air can be distributed evenly to the radiator device 26. (2) The upper tank 28 is attached to the cylinder head 3 against the inner wall of the fan case 8 on the engine body 1 side.
Since the radiator device 26 is arranged in an inclined state so that the lower tank 29 is close to the cylinder block 2 and away from the cylinder block 2, the upper tank 29
Since the amount of high temperature cooling water that accumulates between the cylinder head 8 and the cylinder head 3 is small, and the amount of cooling water that accumulates between the lower tank 29 and the cylinder block 2 increases, it is cooled by the radiator body 27 and its specific gravity increases. As a result, the downward action of the cooling water becomes stronger and the amount of water increases, the cooling effect of the engine is significantly improved, and the cooling device can be made smaller accordingly, which is a practical effect.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of a main part of a water-cooled internal combustion engine equipped with a cooling device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line XX in FIG. 1... Engine body, 2... Cylinder block, 3
...Cylinder head, 6...Centrifugal fan, 8...
Fan case, 10...Fan chamber, 11...Radiator chamber, 26...Radiator device, 27...Radiator body, 28...Upper tank, 29...Lower tank.

Claims (1)

[Scope of utility model registration request] Inside the fan case 8 attached to the side wall of the engine body 1, there are a fan chamber 10 at the bottom and a radiator chamber 1 at the top.
A centrifugal fan 6 is disposed in the fan chamber 10, while an upper tank 28 communicating with a water jacket 31 in the cylinder head 3 and a cylinder block 2 are disposed in the radiator chamber 11. A lower tank 29 that communicates with the water jacket 33 inside, and both tanks 28,
A radiator device 26 including a radiator main body 27 connecting a radiator 29 is arranged so that the upper tank 28 is close to the cylinder head 3 and the lower tank 29 is connected to the inner wall of the engine main body 1 side of the fan case 8. A cooling device for a water-cooled internal combustion engine, characterized in that the cooling air passage area is gradually narrowed from the lower end side to the upper end side of the radiator device 26 by slanting it away from the radiator device 26. .