JPS6233423B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a cooling device for a high foot portion of a water-cooled cylinder cover.

A conventional cylinder cover of this kind is schematically shown in FIG. 1, and a cross section of the high leg portion of the same cylinder cover is shown in FIG. 2. In the figure, 1 is a cylinder cover, 2 is an exhaust valve, 3 is a cylinder liner, 4 is a cylinder jacket, 5 is a combustion chamber, 6 is a piston, and 9 is a cooling hole, which are spaced apart in the circumferential direction in the cylinder cover 1. A large number of them are formed.

The cooling water that has cooled the cylinder liner 3 enters the annular cooling chamber 8 from the inlet passage 10 of the water chamber hardware 7.
After cooling the high foot part 1a formed at the lower part of the cylinder cover, the upper part 1b of the combustion chamber wall is cooled through the cooling hole 9.
is cooled and flows outside.

However, the above method has the following drawbacks.

The high foot portion 1a is cooled only by the cooling water in the cooling chamber 8, but since only the outer peripheral side of the high foot portion 1a is cooled, the inner peripheral side, that is, the combustion chamber surface 1c side is not sufficiently cooled.

An object of the present invention is to focus on the above points and provide a cylinder cover that improves the cooling effect of the high foot part.The main feature of the present invention is that, in a water-cooled cylinder cover, the cylinder cover is formed at the lower part of the cylinder cover. An annular upper cooling chamber and a lower cooling chamber provided on the outer circumferential side of the cylindrical high foot part, and a plurality of annular cooling chambers each formed in a single straight line inside the high foot part with both ends opening into the cooling chambers. It is equipped with cooling holes.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a cross-sectional view showing the high foot part of one embodiment of the present invention, FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 5 is a cross-sectional view taken along the line B-B in FIG. 4. It is.

In the figure, 5 is the combustion chamber, 9 is the cooling hole, and the second
Shows the same thing as the figure.

11 is a cylinder cover, 11a is a high leg portion of the cylinder cover 11, and 12 is water chamber hardware.

14 is an annular lower cooling chamber, and 15 is an annular upper cooling chamber, both of which are formed between the outer periphery of the high leg portion 11a and the inner periphery of the water chamber hardware 12.

Reference numeral 13 denotes a cooling hole, which is bored obliquely upward θ from the lower cooling chamber 14 toward the upper cooling chamber 15, and communicates the two chambers 14 and 15 with each other. A plurality of cooling holes 13 are provided, and each cooling hole 13 is formed in a single straight line that does not intersect, that is, does not connect to each other in the middle (for example, 13a and 13b), and is arranged at constant intervals on the circumference. ing.

The operation in the case of the above configuration will be described.

The cooling water that enters the lower cooling chamber 14 from the inlet passage 10 flows into the cooling hole 13 while circulating inside the cooling chamber 14, and flows out into the upper cooling chamber 15 while cooling the high foot portion 11a.

The coolant in the upper cooling chamber 15 enters the cooling hole 9, cools the upper part 11b of the combustion chamber wall of the cylinder cover, and is then sent to the exhaust valve cooling section and the like.

Due to the above, the high leg portion 11a of the cylinder cover 11
And the upper part 11b of the combustion chamber wall is sufficiently cooled.

The above case has the following effects.

(1) Since the cooling hole is provided inside the high foot part, the cooling hole can be close to the wall surface of the combustion chamber. Therefore, the high foot portion can be sufficiently cooled.

(2) Since the cooling holes do not intersect within the high foot section, stress concentration is reduced, and thermal stress and mechanical stress are reduced.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view schematically showing a cylinder cover of a diesel engine, Fig. 2 is a cross-sectional view showing a high foot part of the cylinder cover of Fig. 1, and Fig. 3 is a cross-sectional view showing a high foot part of an embodiment of the present invention. 4 is a sectional view taken along line AA in FIG. 3, and FIG. 5 is a sectional view taken along line BB in FIG. 4. 11... Cylinder cover, 11a... High foot part, 12
...Water chamber hardware, 13...Cooling holes, 14...Lower cooling chamber,
15...Upper cooling chamber.

Claims (1)

[Claims] 1. In a water-cooled cylinder cover, an annular upper cooling chamber and a lower cooling chamber are respectively provided on the outer circumferential side of a cylindrical high leg formed at the bottom of the cylinder cover, and a single straight line is provided inside the high leg. What is claimed is: 1. A cylinder cover comprising a plurality of cooling holes formed in a shape with both ends opening into the cooling chambers, the cooling holes being formed so as not to intersect inside the high foot portion.