JPS6033309Y2 - Crankcase liner cooling water passage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in liner cooling water passages in crankcases of internal combustion engines.

The structure of the liner cooling water passage in the crankcase of a conventional internal combustion engine is shown in FIGS. A cylindrical space through which cooling water passes is formed between the lower surface and the lower surface.

In order to increase the cooling effect of the cylinder liner a and prevent cavitation, a shelf is provided that connects the bosses C of adjacent cylinder head tightening bolts from the circumferential wall of the space and projects toward the cylinder liner a, so that cooling water can be Some devices increase the flow rate and pressure of cooling water by narrowing the passages.

However, this structure has the following drawbacks.

(1) Boss C of the cylinder head tightening bolt at the top of the shelf
Among the volumes A and B surrounded by
temperature distribution becomes uneven.

(2) Due to the stagnation of the cooling water, cavitation occurs near the cooling surface of the cylinder liner.

The purpose of this invention is to eliminate stagnation of cooling water, control the flow velocity, prevent uneven temperature distribution and cavitation in the cylinder liner, and improve the cooling effect of the crankcase by focusing on the above points. The purpose is to provide a water passage structure, and its feature is that only a part of the shelf in the area where there is no water hole to the cylinder head is eliminated from the volume between the bosses of adjacent cylinder head tightening bolts. That's true.

This allows the cooling water flow rate to be controlled and the cooling water to be circulated around the cylinder liner, eliminating uneven flow rates (particularly stagnation), increasing the cooling effect of the cylinder liner, and increasing the temperature of the cylinder liner due to uneven temperatures. distribution, and furthermore, cavitation is prevented from occurring.

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

FIG. 2a is a sectional view showing a liner cooling passage of a crankcase according to an embodiment of the present invention, and FIG.
It is an E arrow sectional view.

In the figure, 1 is a cylinder liner, and a cylindrical space through which cooling water passes is formed between an upper surface and a lower surface that seal the upper and lower ends of the outer circumferential surface of the cylinder liner.

Cooling water population 4 is opened at the bottom of the same space.

Numeral 3 denotes bosses of the cylinder head tightening bolts, which are connected to the upper surface from the circumferential wall of the space of the crankcase, protrude inward, and are arranged at intervals around one cylinder liner, and are connected to the top surface and the cylinder liner. A throttle passage is formed between the outer circumferential surface of 1 and the outer circumferential surface of 1.

Reference numeral 2 denotes a shelf of the crankcase, which protrudes from the peripheral wall of the space by connecting the lower ends of adjacent bosses 3, and forms a throttle passage between it and the outer peripheral surface of the cylinder liner 1.

That is, the boss 3 is approximately above the height of the shelf 2.

Reference numeral 5 denotes a water hole in the cylinder head, which is provided only on a selected upper surface of the upper surfaces between adjacent bosses 3.

Reference numeral 2a denotes a part of the shelf 2 that is removed, that is, a notched part, and is formed in a section between adjacent bosses 3 without a water hole 5 on the upper surface.

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

The cooling water entering from the cooling water port 4 first flows into the cylinder liner 1.
It goes around the entire outer circumference of the lower part of , then goes up in the part 2a where there is no shelf 2, the flow velocity is controlled by that area, and finally it is squeezed by the boss 3, and the water hole surrounded by the shelf 2 and the boss 3. Enter section 5.

Further, it is directly narrowed down to the shelf 2 and flows into the same section.

From the same section, water is introduced into the cylinder head via the water hole 5.

The present invention as described above has the following effects.

(1) The flow rate of the cooling water is controlled by the area of the portion 2a where there is no shelf 2, and the cooling effect is increased.

(2) Stagnation of cooling water is eliminated, and uneven temperature distribution in the cylinder liner 1 is prevented.

(3) Stagnation of cooling water is eliminated, and cavitation on the outer wall of the cylinder liner 1 is prevented.

[Brief explanation of the drawing]

FIG. 1a is a cross-sectional view showing a liner cooling water passage of a conventional crankcase; FIG. 1 is a cross-sectional view taken along the line D in FIG. 1a;
FIG. 2a is a sectional view showing one embodiment of the present invention, and FIG. 2a is a sectional view taken along the line E--E in FIG. 2a. 1...Cylinder liner, 2...Shelf, 2
a... Part without shelf, 3... Cylinder head tightening bolt boss, 4... Cooling water inlet,
5...Water hole to the cylinder head.

Claims (1)

[Scope of utility model registration request] A cylinder liner housing part of the crankcase that forms a cylindrical space through which cooling water passes between an upper surface and a lower surface that seal the upper and lower ends of the cylinder liner peripheral surface, a cooling water inlet that opens at the bottom of the space, and the space described above. bosses of a plurality of cylinder head tightening bolts protruding from the peripheral wall of the cylinder and connected to the upper surface and arranged around the cylinder liner; water holes for the cylinder head selectively provided on the upper surface between the adjacent bosses; In the liner cooling water passage of the crankcase, which has a shelf protruding from the peripheral wall of the space by connecting the lower end portions of the adjacent bosses, a notch is provided in the shelf between the adjacent bosses without the water hole. The crankcase liner cooling water passage is characterized by: