JPH059474Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cylinder head structure for an engine, and particularly to one that prevents air from remaining in a water jacket.

(Conventional technology) Conventionally, as an engine cylinder head structure,
For example, as disclosed in Japanese Utility Model Application No. 60-72945, a water jacket is formed between the middle deck and the bottom deck of the cylinder head, and one end of the intake port or exhaust port of each cylinder is opened to the bottom deck. The other end is provided so as to open into the side wall of the cylinder head, and a push rod hole is provided near the exhaust port or intake port that communicates the upper surface of the middle deck with the lower surface of the bottom deck, and the intake port at the end of the bottom deck in the direction of the cylinder row is provided. A water hole for introducing cooling water into the water jacket is provided near the opening at one end of the port or exhaust port, and the intake port or exhaust port is cooled by the cooling water introduced from the water hole into the water jacket. something is known.

(Problem to be solved by the invention) However, in such a cylinder head structure, a water hole is provided near the opening at one end of the intake port or exhaust port (at the bore periphery) at the end of the bottom deck in the cylinder row direction. The cooling water introduced into the water jacket from the water hole flows in the cylinder row direction, but the flow rate of the cooling water is slow at the end of the water jacket in the cylinder row direction and on the side wall side of the cylinder head. Therefore, there is a problem in that air tends to accumulate at the end of the water jacket in the direction of the cylinder row and at the side wall of the cylinder head.

In particular, if a push rod hole is provided near the intake port or exhaust port,
Since the cooling water is blocked by the intake port or exhaust port and the push rod hole, the air that has accumulated on the end side of the water jacket in the cylinder row direction and on the side wall side of the cylinder head is It becomes difficult to get out. As a result, the cooling performance of the cylinder head becomes poor, and the air stagnant in the above part is released all at once when the engine operating conditions fluctuate and is sucked into the water pump, etc., resulting in a decrease in the reliability of the water pump, etc. There's a problem.

The present invention has been devised in view of these points, and its purpose is to prevent air from accumulating on the end side of the water jacket in the cylinder row direction and on the side wall side of the cylinder head. With the goal.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a structure in which the lower surface of the middle deck is located closer to the end of the water jacket than the intake port or the exhaust port in the direction of the cylinder row and to the side wall of the cylinder head. A sloped portion is provided to guide air remaining in the side portion toward the center of the cylinder.

Specifically, the solution taken by the present invention is that a water jacket is formed between the middle deck and the bottom deck of the cylinder head, and at least one of the intake port and exhaust port of the cylinder at the end in the cylinder row direction is provided. is provided so that one end thereof opens into the bottom deck and the other end opens into the side wall of the cylinder head, and the upper surface of the middle deck and the bottom deck are located near the at least one port and near the side wall of the cylinder head. A push rod hole is provided to communicate with the lower surface, and a water hole for introducing cooling water into the water jacket is provided near one end side opening of the at least one port at the end of the bottom deck in the cylinder row direction. Based on the cylinder head structure of the engine provided with the cylinder head structure, the water pipe is formed above the at least one port on the lower surface of the middle deck so as to be inclined upwardly from the side wall side of the cylinder head toward the center of the cylinder. The jacket is provided with an inclined portion that is closer to the end in the direction of the cylinder row than the at least one port and that guides air accumulated in the side wall side of the cylinder head toward the center of the cylinder. .

(Function) With the above configuration, at least one of the intake port and the exhaust port at the rear in the cylinder row direction on the lower surface of the middle deck is inclined upwardly from the side wall side of the cylinder head toward the cylinder center side. Because of the provision of the sloping portion formed to .

Therefore, even though the push rod hole is provided near at least one of the intake port and the exhaust port and near the side wall of the cylinder head where the at least one port opens, the water Air is less likely to accumulate in a portion of the jacket that is closer to the end in the cylinder row direction than the at least one port and is closer to the side wall of the cylinder head.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

Figures 1 to 3 relate to an embodiment of the present invention.
Shows the cylinder head of an OHV type engine.
The cylinder head has a substantially rectangular parallelepiped shape,
Reference numeral 1 denotes a middle deck constituting the upper wall, and 2 denotes a bottom deck constituting the lower wall. A water jacket 3 through which cooling water flows is formed between the middle deck 1 and the bottom deck 2.

Further, a plurality of cylinders 4, 4, . . . are arranged in series below the cylinder head, and the cylinder head is formed with an intake port 5 and an exhaust port 6 for each cylinder. Among these, in the cylinder 4 at the rear end in the cylinder row direction (the cylinder at the left end in FIG. 1), the intake port 5 is arranged on the front side, the exhaust port 6 is arranged on the rear side, and one end of both ports 5 and 6 is arranged on the front side. While it opens into the bottom deck 2, the other end of the intake port 5 opens into the left side 7 of the cylinder head, and the other end of the exhaust port 6 opens into the right side 8 of the cylinder head. Above the openings on the bottom deck side of the intake/exhaust ports 5, 6 in the middle deck 1, valve springs for biasing the intake/exhaust valves disposed in each opening in the closing direction are arranged. Exhaust valve spring bosses 9 and 10 are formed, and these valve spring bosses 9 and 10 are communicated with each other by a communication groove 11 that guides oil.

Furthermore, the middle deck 1 is located near the intake/exhaust ports 5 and 6 and the right side surface 8 of the cylinder head.
Push rod holes 12 and 13 for intake and exhaust are provided to communicate between the bottom deck 2 and the bottom deck 2.
The intake push rod hole 12 is located on the right side of the intake valve spring boss 9, and the exhaust push rod hole 13 is located on the right side of the exhaust valve spring boss 10, respectively, on the right side surface 8 of the cylinder head. It is provided integrally with the inner wall, and a push rod is inserted into the inside thereof. Further, an oil passage 14 recessed downward is provided between the intake valve spring boss 9 and the intake push rod hole 12 in the middle deck 1, and the oil passage 14 which is recessed downward is used to drain the oil accumulated in the valve spring bosses 9 and 10 to the intake air. The cylinder block is returned to the cylinder block through the push rod hole 12.

Water holes 15, 15 for introducing cooling water supplied from the cylinder block below the cylinder head into the water jacket 3 are provided near the rear side of the bottom deck side opening 6a of the exhaust port 6. Note that the location of the water hole 15 for introducing cooling water into the water jacket 3 is not shown in the drawings, but in addition to the above location, it is well known as shown in Japanese Utility Model Application No. 57-171122, etc. They are also provided below each exhaust port 6 in the bottom deck 2, as shown in FIG.

As a feature of this embodiment, an inclined portion 16 is formed above the rear end side exhaust port 6 on the lower surface of the middle deck 1, which slopes upward from the right side of the cylinder head toward the center of the cylinder. ing.

Next, to explain the operation of the above embodiment,
The air contained in the cooling water introduced into the water jacket 3 from the water holes 15, 15 reduces the flow rate of the cooling water on the right side of the rear end of the water jacket, and causes the air to flow between the exhaust port 6 and the exhaust push rod. hall 1
3 and the lower surface of the oil passage 14, the cooling water floats near the exhaust push rod hole 13 on the right side of the rear end of the water jacket 3, but this air flows into the inclined part. 16
After being guided to the center of the cylinder by
No air pocket is formed in the vicinity of the exhaust push rod hole 13, so that the cooling performance of the cylinder head can be maintained well, and the release of air pockets is prevented, thereby improving the reliability of the water pump, etc. I can do it.

(Effects of the Invention) As explained above, according to the engine cylinder head structure of the present invention, a port is provided above at least one of the intake port and the exhaust port on the lower surface of the middle deck from the side wall side of the cylinder head. By providing a sloped portion that slopes upward toward the center of the cylinder,
Air remaining in a portion of the water jacket closer to the end in the cylinder row direction than the at least one port and closer to the side wall of the cylinder head is guided toward the center of the cylinder. Therefore, even though the push rod hole is provided near at least one of the intake port and the exhaust port and near the side wall of the cylinder head where the at least one port opens, the water After the air in the portion of the jacket that is closer to the end in the cylinder row direction than the at least one port and that is closer to the side wall of the cylinder head is smoothly guided to the center of the cylinder without being obstructed by the push rod hole, The cooling water is quickly discharged to the outside of the water jacket along with the flow of high-velocity cooling water that flows in the cylinder row direction through the center of the cylinders in the water jacket.

Therefore, according to the present invention, since no air pocket is formed in the vicinity of the push rod hole, it is possible to maintain good cooling performance of the cylinder head and improve the reliability of the water pump and the like.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a plan view of the rear part of the cylinder head, FIG. 2 is a cross-sectional view taken along the line - - in FIG.
FIG. 1...middle deck, 2...bottom deck, 3
... Water jacket, 4 ... Cylinder, 6 ... Exhaust port, 8 ... Right side, 12, 13 ... Push rod hole, 15 ... Water hole, 16 ... Inclined part.

Claims (1)

[Scope of utility model registration request] A water jacket is formed between the middle deck and the bottom deck of the cylinder head, and one end of at least one of the intake port and exhaust port of the cylinder at the end in the cylinder row direction opens into the bottom deck, and the other end opens into the bottom deck. is provided to open in the side wall of the cylinder head, and a push rod hole is provided near the at least one port and near the side wall of the cylinder head to communicate the top surface of the middle deck with the bottom surface of the bottom deck. In the engine cylinder head structure, a water hole for introducing cooling water into the water jacket is provided in the vicinity of one end side opening of the at least one port at the end of the bottom deck in the cylinder row direction, A port is formed above the at least one port on the lower surface of the middle deck so as to be inclined upward from the side wall side of the cylinder head toward the cylinder center side, and is more inclined in the cylinder row direction than the at least one port in the water jacket. A cylinder head structure for an engine, characterized in that an inclined part is provided on the end side of the cylinder head and on the side wall side of the cylinder head to guide air staying in the cylinder head toward the center of the cylinder.