JPH076383B2 - V-type internal combustion engine cooling device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled cooling device for a V-type internal combustion engine, and more particularly to an improvement of a cooling device configured to perform forced circulation of cooling water mainly through a water jacket on the cylinder head side. .

BACKGROUND ART Generally, in an internal combustion engine, in order to prevent abnormal combustion such as knocking, the temperature on the cylinder head side is made relatively low, and in order to reduce friction due to the viscosity of lubricating oil, the temperature on the cylinder block side is reduced. Is desired to be kept relatively high.

Therefore, the forced circulation of the cooling water by the water pump is performed through the inside of the water jacket on the cylinder head side so that the natural convection due to the temperature difference between the water jacket on the cylinder block side and the water jacket on the cylinder head side is performed. A cooling device for such an internal combustion engine has been proposed (see Japanese Patent Application Laid-Open No. 61-122322, etc.).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above cooling device, since the flow of cooling water in the water jacket on the cylinder block side is very small, vapor bubbles may be generated inside depending on the operating conditions. Therefore, if this cooling device is applied to a V-type internal combustion engine as it is, there is a possibility that a considerably large amount of vapor bubbles may remain in the innermost portion of the V bank at the top of the cylinder block side water jacket due to the inclination of each bank. It is possible to cause partial cooling failure, resulting in knocking and excessive thermal deformation.

Therefore, according to the present invention, in a V-type internal combustion engine in which a water jacket is formed over both a cylinder block and a cylinder head, a side portion outside each V bank of each cylinder head is provided. The cooling water introduction passages are formed along the engine front-rear direction, the cooling water discharge passages are formed on the inner side of the V bank along the engine front-rear direction, and both cooling water introduction passages are formed on the water pump. It is characterized in that the cooling water is connected to the discharge side, and the cooling water supplied to the cooling water introduction passage is discharged across the inside of the cylinder head to the cooling water discharge passage.

Function In the above configuration, the cooling water pumped by the water pond flows into the periphery of each cylinder of the cylinder head through the cooling water introduction passage on the side of the cylinder head, and traverses the inside of the cylinder head to the outside from the cooling water discharge passage. Taken out. Here, since the cooling water introduction passage is located below the cooling water discharge passage due to the inclination of each bank, the cooling water flows from the lower side to the upper side through the inside of the cylinder head side water jacket. A part of the cooling water also flows upward through the upper end of the water jacket on the cylinder block side. Therefore, the vapor bubbles generated inside the water jacket are quickly discharged.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a cooling device for a V-type 6-cylinder internal combustion engine having a bank angle of 60 °, for example.

In the figure, 1 is a cylinder block in which three cylinders 2 are arranged in each of the left and right banks, 3 is a cylinder head fixed to the top of the cylinder block 1 to form the left and right banks, and 4 is inserted into each cylinder 2. It is a filled piston.

A water jacket 5 is formed on the cylinder block 1 so as to mainly surround the circumference of the cylinder 2.

The pair of left and right cylinder heads 3 are basically formed in a substantially symmetrical shape in the right bank, and an exhaust port 6 is formed toward the outside of the V bank, and an intake port 7 is formed inside the V bank. Has been formed. The intake port 7 has a shape that rises relatively upward, and the tip flange surface 7a is located on a horizontal plane, that is, on the left and right cylinder heads 3 on the same plane. 8 is an exhaust valve, 9
Is an intake valve.

Further, inside the cylinder head 3, a water jacket 11 is integrally and continuously formed as a whole so as to surround the exhaust port 6 and the intake port 7 and the upper part of the combustion chamber 10.
Are formed. The water jacket 11 on the cylinder head side is the water jacket 5 on the cylinder block side.
And the cylinder head gasket 12 through a communication hole 13 (see FIG. 2).

Further, a cooling water discharge passage 14 is cast integrally with the cylinder head 3 on the side of the cylinder head 3 inside the V bank, specifically, on the lower side of the intake port 7. The cooling water discharge passage 14 is formed from the front end to the rear end of the cylinder head 3 along the longitudinal direction of the engine (crankshaft axis direction), and a plurality of cooling water discharge passages 14 are provided at appropriate positions such as the lower portion of the intake port 7. Water jacket on the cylinder head side through the 15 communicating holes
It communicates with 11. The rear end is closed and the front end is connected to a water outlet 16 described later.

On the other hand, a cooling water introducing passage 17 is formed on the side of the cylinder head 3 outside the V bank, specifically, on the lower side of the exhaust port 6. The cooling water introducing passage 17 is composed of a gallery member 18 having a rectangular cross section which is cast separately from the cylinder head 3, and is fixed to the lower surface of the side portion of the cylinder head 3 by a bolt 19. Like the cooling water discharge passage 14, the cooling water introduction passage 17 is formed along the longitudinal direction of the engine, and communicates with the lower portion of the water jacket 11 on the cylinder head side through a plurality of the communication 20 on the upper surface. The rear end is closed and the front end is connected to the discharge port of the water pump 21. Cylinder head gasket
As shown in FIG. 2, a rectangular communicating hole 22 corresponding to the communicating hole 20 is intermittently provided in the hole 12.

FIG. 3 shows the structure of the front end of the engine for circulating the cooling water between the cooling water introduction passage 17 and the cooling water discharge passage 14. As described above, the water outlet 16 uses the stud bolts 23 to form a pair of cylinders. It is fixed so as to straddle the head 3. The water outlet 16 has an inverted Y-shaped flow path, and a pair of lower inlets are connected to the cooling water discharge passage 14 via a connector 24, respectively. The branch pipe 25 is connected to the flange portion 16a having a single outlet, and one of the outlet flange portions 25a is connected to the bypass side flange portion 26a of the thermostat housing 26. Further, a radiator inlet passage (not shown) is connected to the other outlet pipe 25b, and the tip of the radiator outlet passage (not shown) is connected to the radiator side flange portion 26b of the thermostat housing 26. Further, the housing 27 of the water pump 21 is integrated with the thermostat housing 26, and a pair of outlet pipes 27a, 27b extending from the left and right thereof are connected to the front end of the cooling water introduction passage 17 via a connector 28. .

Note that, in FIG. 3, the O-rings, nuts, and the like of each connecting portion are not shown.

That is, when the temperature of the cooling water is sufficiently high, a thermostat valve (not shown) causes the suction port of the water pump 21 to communicate with the radiator outlet passage, so that the cooling water exiting the pair of cooling water discharge passages 14 is discharged at the water outlet 16. After merging into one, they are guided by the radiator, sucked by the water pump 21 from here, and circulated and supplied again to each cooling water introduction passage 17. When the temperature of the cooling water is low, the thermostat valve (not shown) switches to the bypass passage side, so the cooling water that exits the water outlet 16 is immediately discharged from the water pump.
It is sucked into 21 and is circulated and supplied to each cooling water introduction passage 17.

On the other hand, inside the internal combustion engine, cooling water flows into the water jacket 11 on the cylinder head side from the cooling water introduction passage 17 located relatively downward, and traverses the water jacket 11 to the upper cooling water discharge passage 14. Flowing. A part of the cooling water is used in the water jacket 5 on the cylinder block side.
Flows through the upper end of the same. Here, when steam bubbles are generated in the water jacket 5 on the cylinder block side, they try to stay at the uppermost part, especially on the side of the intake port 7 which is the upper part due to the inclination of the bank, but as described above, the cooling water flows from the lower part to the upper part. As a result of flowing in, vapor bubbles are effectively discharged. Therefore, it is possible to reliably prevent local cooling failure at the upper end of the cylinder 2 or the like due to retention of vapor bubbles.

Next, in the embodiment shown in FIGS. 4 to 6, the communication hole on the side of the exhaust port 6 located at the periphery of the communication hole 13 of the cylinder head gasket 12, particularly the position for receiving the cooling water flowing from the cooling water introduction passage 17. A water guide 31 is provided upright on the inner peripheral edge of 13 to project into the water jacket 11 on the cylinder head side. The water guide 31 has its upper surface and both ends closed with only one outer peripheral surface opened (see FIG. 5).

Therefore, in this embodiment, a part of the cooling water flowing into the cylinder head side water jacket 11 from the cooling water introduction passage 17 is captured by the water guide 31 and is forcibly guided to the cylinder block side. Therefore, the cooling water more reliably flows through the upper end portion of the water jacket 5 on the cylinder block side, and the retention of steam bubbles can be prevented. A communication hole on the exhaust port 7 side is provided so that the cooling water flowing into the water jacket 5 on the cylinder block side along the water guide 31 does not immediately return to the cylinder head side.
13 is reduced as shown in FIG.

EFFECTS OF THE INVENTION As is clear from the above description, according to the cooling device for a V-type internal combustion engine according to the present invention, the cooling water introduction passage on the outside of the V bank, which is located relatively below, is located relatively above. Since the cooling water is configured to flow to the cooling water discharge passage inside the V bank, it is possible to prevent vapor bubbles from staying at the uppermost portion of the water jacket on the cylinder block side, and reliably prevent local cooling failure. Further, since the flow of cooling water in the water jacket on the cylinder block side is relatively small, the original action of actively cooling the cylinder head side while keeping the temperature of the cylinder block relatively high is lost. Never.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the essential parts of a V-type internal combustion engine showing an embodiment of the cooling device according to the present invention, FIG. 2 is a perspective view of the essential parts of the cylinder head gasket thereof, and FIG. 3 is the front part of the internal combustion engine. FIG. 4 is an exploded perspective view, FIG. 4 is a sectional view of a V-type internal combustion engine main part showing a different embodiment of the present invention, FIG. 5 is an enlarged sectional view of the same main part, and FIG. 6 is a perspective view of the cylinder head gasket main part. It is a figure. 1 ... Cylinder block, 3 ... Cylinder head, 5 ...
… Cylinder block side water jacket, 11 …… Cylinder block side water jacket, 14 …… Cooling water discharge passage, 17 …… Cooling water introduction passage, 21 …… Water pump.

Claims (1)

[Claims] 1. In a V-type internal combustion engine having a water jacket formed over both a cylinder block and a cylinder head, cooling water along the longitudinal direction of the engine is provided on the side of each cylinder head outside the V bank. The cooling water discharge passages are formed along the longitudinal direction of the engine at the side portions on the inner side of the V bank, and the cooling water discharge passages are connected to the discharge side of the water pump. A cooling device for a V-type internal combustion engine, wherein the cooling water supplied to the water introduction passage is configured to be discharged to the cooling water discharge passage across the inside of the cylinder head.