JPH0768896B2 - Liquid cooling overhead valve engine cooling fluid path - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling liquid passage for a liquid-cooled engine, and more particularly, between an engine that does not liquid-cool a cylinder head and an engine that liquid-cools at least a part of the cylinder head. It relates to a cooling liquid passage for a liquid-cooled engine, which enables common use of the cylinder block in the same manner, and simplifies the communication structure between the pressure feed passage and the return passage formed in the cylinder block so that it can be manufactured at low cost. is there.

<Prior art> For example, in a liquid-cooled engine in which a part of the lubricating oil pumped up from an oil pan is used as a cooling liquid to cool the engine, only the high temperature part of the cylinder block is oil-cooled, and the relatively low temperature of the cylinder block Not only the part for air-cooling the part and the cylinder head, but also the high temperature part of the cylinder block as well as the high temperature part of the cylinder head, for example, around the sub chamber of the sub chamber type diesel engine or around the spark plug of the spark ignition engine. Some are liquid cooled.

Conventionally, different cylinder blocks and cylinder heads are used between liquid-cooled engines having different parts to be liquid-cooled as described above, depending on the type of the engine.

<Problems to be Solved by the Invention> As described above, it is disadvantageous to use a cylinder block having a different shape depending on the type of the liquid cooling portion in order to reduce the cost due to mass production.

The present invention has been made in view of the above circumstances, in which a cylinder block is shared between a liquid-cooled engine that liquid-cools at least a part of a cylinder head and a liquid-cooled engine that does not liquid-cool the cylinder head. Cooling of a liquid-cooled engine that enables cost reduction due to mass production, and that a communication passage that connects the cooling liquid pressure feed passage and the return passage formed in the cylinder block can be easily and inexpensively formed. The purpose is to provide a liquid channel.

<Means for Solving Problems> In the cooling liquid passage of the liquid cooling engine according to the present invention, in order to achieve the above object in the liquid cooling engine, for example, the first
As shown in FIGS. 4 and 5, a cooling liquid pressure feed passage 4 and a cooling liquid return passage 5 are formed in the cylinder block 2 of the liquid cooling engine 1, and the cooling liquid pressure feed passage 4 is formed in the upper end surface 6 of the cylinder block 2.
A groove 10 formed in the lower surface of the cylinder head 3 to form a communication passage 9 that opens the end 7 of the return passage 5 and the end 7 of the return passage 5, and connects the end 7 of the cooling liquid pressure feed passage 4 and the start end 8 of the return passage 5.
And at least one of the gasket removal space 12 formed by removing a part of the head gasket 11.

<Operation> According to the present invention, as described above, the end 7 of the cooling liquid pressure feed passage 4 and the start end 8 of the return passage 5 are opened at positions close to each other on the upper end surface 6 of the cylinder block 2. As shown in FIG. 4, the cooling liquid introduction port 37 of the cylinder head 3 of the engine 1 for liquid cooling at least a part of the cylinder head 3
At least a portion of the cylinder head 3 is liquid-cooled by opening the lower end surface of the cylinder head 3 by facing the end 7 of the cooling liquid pressure feed passage 4 and the start end 8 of the return passage 5 with the cooling liquid outlet 38. The cylinder block 2 can be shared between the engine 1 and the liquid-cooled engine 1 in which the cylinder head 3 is not liquid-cooled.

A gasket 10 formed by removing a part of the head gasket 11 and a groove 10 formed on the lower surface of the cylinder head 3 is provided with a communication passage 9 that connects the end 7 of the cooling liquid pressure feed passage 4 and the start end 8 of the return passage 5. Since it is formed in at least one of the removal spaces, the communication passage 9 can be formed easily and inexpensively.

<Examples> Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a rear view of an oil-cooled engine according to an embodiment of the present invention in which a main part is longitudinally cut, FIG. 2 is a rear view thereof, and FIG. 3 is a side view thereof.

In this engine 1, the cylinder block 2 is cast and formed integrally with the crankcase 12, and the oil storage chamber 13 is formed in the lower portion of the crankcase 12.

An oil strainer 15 that removes solid impurities from the lubricating oil pumped from the oil pan 13 is attached to the lower portion of the rear end cover 14 that covers the rear surface of the crankcase 12, and the rear end cover 14 has an intermediate height portion. A lubricating oil pump 16 including, for example, a trochoid pump is incorporated. In the rear end cover 14, a lubricating oil supply path 19 from the oil strainer 15 to a bearing portion 18 that rotatably supports the rear end of the crankshaft 17 via a lubricating oil pump 16 is provided.
A pressure setting valve 21 connected to a middle portion of the lubricating oil supply passage 19 via a branch passage 20 is provided above the rear end cover 14.

On one side of the cylinder block 2, a cooling hydraulic pressure passage 4 and a push rod insertion chamber 22 are formed side by side inside and outside when viewed from the center of the cylinder 24. A part of the push rod insertion chamber 22 is divided by a partition wall 23 and returned. The path 5 is formed.

The starting end portion 24 of the pressure feeding path 4 is communicated with the drain chamber 25 of the pressure setting valve 21 via the connection hole 26, and the terminal end 7 is opened at the upper end surface 6 of the cylinder block 2. Further, the start end 8 of the return passage 5 is opened to the upper end surface 6 of the cylinder block 2 adjacent to the end 7 of the pressure feeding passage 4. On the lower surface of the cylinder head 3,
From the portion of the pumping path 4 facing the end 7 to the beginning 8 of the return path 5
The groove 10 is formed over the portion facing the. A head gasket 11 is inserted between the cylinder block 2 and the cylinder head 3, and a gasket removal space (not shown) formed by removing a portion of the head gasket 11 facing the communication passage 9 and the groove 10 are provided. A communication passage 9 that connects the end 7 of the pressure feed passage 4 and the start end 8 of the return passage 5 is formed.

The end 27 of the return path 5 is communicated with the crank chamber 30 in the crankcase 12 above the fuel cam 29 that drives the fuel injection pump 28. The fuel cam 29 is formed on the circumferential surface of a cam shaft 32 which is common to the valve operating cam 31.

A cooling fan 33 fixed to the front end of the crankshaft 17 is arranged on the front side of the crankcase 12 of the engine 1,
The cooling air generated by this cooling fan 33 is applied to the cylinder block 2
A wind guide case 34 for guiding the head block 3 is fixed to the front portion of the engine 1.

In the above configuration, the lubricating oil in the oil storage chamber 13 is pumped up by the lubricating oil pump 16 via the oil strainer 15, and the crankshaft is set at the pressure set by the pressure setting valve 21.
While being supplied to the bearing portion 18 of 17, the lubricating oil is partially fed from the drain chamber 25 of the pressure setting valve 21 through the connection hole 26.
Is supplied to. Then, while ascending in the pressure feeding path 4 toward the terminal end 7, the portion of the cylinder block 2 on the side of the push rod insertion chamber 23, which tends to reach a particularly high temperature, is oil-cooled, and then the communication path 9
It is made to flow to the return path 5 through. A part of the lubricating oil that flows down from the end 27 of the return path 5 to the crank room 30 is a fuel cam.
It adheres to the surface of 29 and lubricates the sliding contact portion between the fuel cam 29 and the fuel injection pump 28.

The cooling air generated by the cooling fan 33 is guided to the cylinder block 2 and the cylinder head 3 by the air guide case 34, and heat is taken from the surfaces of the cylinder block 2 and the cylinder head 3 to cool them.

FIG. 4 is a rear view in which a main part of an oil-cooled engine in which the cylinder head 3 partially cooled with oil is assembled instead of the cylinder head 3 not oil-cooled as described above is longitudinally cut.

In the cylinder head 3 of the engine 1, an oil jacket (not shown) and an introduction path 35 for supplying cooling oil to the oil jacket, and an outlet path 36 for returning the lubricating oil from the oil jacket to the return path 5 via an oil cooler (not shown). And are formed. The inlet 37 of the introduction passage 35 is opened at the lower end surface of the cylinder head 3 so as to face the terminal end 7 of the pressure feeding passage 4, and the outlet 38 of the outlet passage 36 faces the start end 8 of the return passage 5. It is opened at the lower end surface of.

In this way, the cooling oil introduction port 13 and the cooling oil return port 14 of the cylinder head 3 are opened at the lower end surface of the cylinder head 3 so as to face the end 7 of the cooling hydraulic pressure passage 4 and the start 8 of the return passage 5. As a result, the cylinder block 2 can be shared between the engine 1 that oil-cools at least a part of the cylinder head 3 and the oil-cooled engine 1 that does not oil-cool the cylinder head 3.

<Effects of the Invention> As described above, according to the present invention, since the end of the cooling liquid pressure feed passage and the start of the return passage are opened at positions close to each other on the upper end surface of the cylinder block, at least a part of the cylinder head is provided. The cooling liquid inlet and the cooling liquid outlet of the cylinder head of the engine for liquid cooling are made to face the end of the cooling liquid pressure feed path and the start end of the return path and open at the lower end surface of the cylinder head. A cylinder block can be shared between an engine that liquid-cools at least a part and a liquid-cooled engine that does not liquid-cool a cylinder head, and cost reduction can be achieved by mass production.

Further, at least one of a groove formed on the lower surface of the cylinder head and a gasket removing space formed by removing a part of the head gasket, the communicating passage communicating the end of the cooling liquid pressure feed passage and the beginning of the return passage. Since it is formed by, the communication passage can be easily formed at low cost.

[Brief description of drawings]

FIG. 1 is a rear view of a liquid-cooled engine according to an embodiment of the present invention in which a main part is longitudinally cut, FIG. 2 is a rear view thereof, FIG. 3 is a side view thereof, and FIG. 4 is a cylinder head 3 which is not liquid-cooled. FIG. 6 is a rear view in which a main part of a liquid-cooled engine in which a cylinder head 3 in which a part is liquid-cooled is assembled instead is vertically cut. 1 ... Engine, 2 ... Cylinder block, 3 ... Cylinder head, 4 ... Pressure feed path, 5 ... Return path, 6 ... Upper end surface of cylinder block 2, 7 ... End of pressure feed path 4, 8 ...
… Starting end of return path 5, 9 …… communicating passage, 10 …… groove, 11 …… head gasket.

Claims (1)

[Claims] 1. A liquid cooling overhead valve engine (1) having a cylinder block (2) formed with a cooling liquid pressure feed passage (4) and a cooling liquid return passage (5), the upper end surface of the cylinder block (2) ( The end (7) of the cooling liquid pressure feed passage (4) and the starting end (8) of the cooling liquid return passage (5) are opened at positions close to each other in (6), and the end (7) of these cooling liquid pressure feed passages (4) is opened. And the starting end (8) of the coolant return path (5) are communicated with each other through the communication path (9), and the groove (10) formed on the lower surface of the cylinder head (3),
A cooling liquid passage for a liquid cooling overhead valve engine, characterized in that the communication passage (9) is formed in at least one of a gasket removal space formed by removing a part of the head gasket (11).