JPH03955A - Cylinder liner for internal combustion engine - Google Patents

Abstract

PURPOSE:To mainly perform processings of decks with easiness and high accuracy by constituting a deck of a cylinder block to which a mid stop liner is fitted of an upper deck which seals a cooling water, and a lower deck which positions the liner. CONSTITUTION:At a cylinder block 1, respective upper and lower decks are privided. A stepped part 13, which is arranged at the center part of a cylinder liner 4, is abutted against the lower deck 3, which is used by the positioning deck. At the position which corresponds to the upper deck 2 of the cylinder liner 4, respective grooves 7,8 for receiving rings 5,6 for water and oil are formed, respectively. At the upper part of the upper deck 2, an water chamber 9 is formed so that cooling water is lead therein. Consequently, processing of the respective upper and lower decks 2,3 are performed easily and accurately, and it is possible to prevent corrosion.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a cylinder liner for an internal combustion engine.
It is particularly suitable for use in mid-stop liners in which the liner positioning collar is installed in the center of the liner.

(Prior Art) Fig. 2 shows a vertical cross-sectional view along the cylinder center line of a conventional example of an internal combustion engine using a midstop liner.
In the figure, a is the crankshaft.

b is a connecting rod, C is a piston, d is a cylinder block, and a midstop liner e is fitted into the cylinder pro, d and positioned at a deck g near the longitudinal center of the cylinder.

Since a cooling water chamber is formed between the liner e and the cylinder block d, the deck g functions as a cooling water seal as well as positioning the liner.

FIG. 3 shows part P in FIG. 2. This is a conventional example using a top stop liner, in which a liner k is fitted into a cylinder block j and positioned by a deck l at the top of the cylinder block j. There is. m is piston,
n is a cooling water chamber, and p is a cooling water seal. The mid-stop liner has the following advantages over the upper top-stop liner. That is, +11 Since the cooling water can be guided to a high position, the temperature of the piston ring can be reduced, and the piston ring can be made into a high top ring and its performance can be improved.

(2) In the top stop liner, the entire liner is suspended in a cantilever manner, but in the Minodoston liner, both ends are fixed, making it possible to improve liner susceptibility and reduce piston slap noise. .

FIG. 4 shows the Q portion in FIG. 2, and is a second specific example of the conventional type using a mid-stop liner (the one in FIG. 2 is the first specific example). In Fig. 4, the liner S is fitted into the cylinder block q and the spacer deck r above it, and the mid-stop liner S is positioned by the deck.
The water seal in the cooling water chamber (2) is indicated by W. U is a piston.

(Problems to be Solved by the Invention) In the first specific example of the conventional mid-stop liner shown in FIG.
It is necessary to process and form the liner, and a special water seal member is required due to the difficulty of ensuring precision.Also, if the fixed surface of the liner e faces the cooling water at the deck g, it will be corroded by water entering through the fine gaps on the surface. may occur.

Further, in the second conventional example shown in FIG. 4, a spacer deck r is required in addition to the cylinder block g, which increases the number of two parts, resulting in an increase in cost.

Furthermore, in the conventional mid-stop liner structure shown in Figures 2 and 4 above, the cooling area can be made small, but the degree of the three cantilevers is thick (or there is no sudden change to the non-cooled area). There was a major problem: this became a factor that hindered this.

(Means and effects for solving the problem) This invention has been made to solve the above problem, and is aimed at reducing the deck of the cylinder block into which the midstop liner is fitted.
It is constructed in stages, with the upper deck sealing the cooling water and the lower deck fixing the position of the liner.

(Example) Next, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal cross-sectional view along the cylinder center line of an internal combustion engine using the mid-stop liner according to the present invention, showing a main part thereof, and shows a portion corresponding to section Q in FIG. 2 above. . In Figure 1, 5 cylinder block l
Upper deck 2. and a lower deck 3 are provided, and a stepped portion 13 provided near the center of the cylinder liner 4 is connected to the lower deck 3.
By coming into contact with the lower deck 3, the lower deck 3 acts as a positioning deck, and a water ring 5. is placed in the liner 4 at a position corresponding to the upper deck 2. The top of the upper deck 2 forms a water chamber 9 as shown in the figure to guide cooling water, and between the upper deck 2 and the lower deck 3 there is a An oil chamber 10 is formed to guide lubricating oil for the engine. 11 is an oil hole, 12 is a head deck, and the cylinder liner 4 is connected to the head deck 12. Upper deck 2. It is held in three places on the lower deck 3, so 5
It has improved rigidity compared to conventional midstop liners.

(Effect of the invention) This invention is constructed as described above in detail.

It has the following excellent effects.

In other words, (1) the water seal is done with an O-ring fitted into the cylinder, just like the proven lower seal of conventional regular liners, and the fitting part is set higher than the conventional position;
It can be expected to improve machining accuracy.

(2) Cooling is done using both the ice chamber (temperature: approx. 100'C) and the oil chamber (temperature: approx. 120'C), which prevents sudden changes in liner wall temperature. (3) The oil seal on the positioning deck part leaked. However, since it falls into the crankcase, a rough surface accuracy is sufficient (as long as the height dimension is visible), so machining is easy.

(4) Since oil is guided to the pressure receiving surface of the positioning part, there is no risk of corrosion.

(5) Since the liner is held in three places, the rigidity is improved compared to conventional mint stop liners.

(6) Since the cylinder block has an intermediate deck surrounding the liner in the conventional water jacket throat section,
It also contributes to improving the rigidity of the block.

[Brief explanation of drawings]

Fig. 1 is an explanatory view of the main part of a longitudinal section along the cylinder center line of an internal combustion engine using a midstop liner according to the present invention, and Fig. 2 is a first specific example using a conventional Mindos 7 liner. 3 shows a conventional example using a top liner, and FIG. 4 shows a second example using a conventional midstop liner. 1...Cylinder block, 2...Upper deck. 3...Lower deck, 4...Cylinder liner 5...Water ring, 6...Oil ring. 13...Stepped part. Patent applicant: Komatsu Ltd. Representative (patent attorney): Osamu Matsuzawa

Claims (1)

[Claims] An internal combustion engine characterized in that the deck of the cylinder block into which the midstop liner of the cylinder of the internal combustion engine is fitted is composed of two stages: an upper deck for sealing cooling water and a lower deck for fixing the position of the liner. Engine cylinder liner.