JPS5913320Y2 - internal combustion engine cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to cylinders of diesel, gasoline, and gas internal combustion engines having wet-inserted cylinder liners, and is aimed at improving the cooling system to obtain optimum operating conditions.

In FIG. 1, which is a longitudinal cross-sectional partial view of a conventional vertical internal combustion engine, a warm insertion type cylinder liner 1 has an upper end portion 2 and a lower end portion 3.
is fitted into the cylinder block 5, and an annular cold water generating chamber 9 filled with cooling water W is formed between the cylinder block 5 and an intermediate portion 6 between both ends 2 and 3.

However, if the cooling water ice chamber 9 is made vertically long to reduce the weight of the cylinder as shown in FIG. Therefore, the lower half 7 that is away from the combustion chamber 10 is supercooled and the amount of thermal expansion becomes small, and the gap between the lower half 7 and the piston 11 becomes too small, which may cause seizure of the piston 11. be.

Also, since the upper half 8 becomes hotter than the lower half 7 and has a larger amount of thermal expansion, if the gap between the lower half 7 and the piston 11 is set large enough to prevent the above-mentioned seizure, the upper half The gap between the part 8 and the piston 11 becomes too large and the crank chamber 1
The lubricating oil in the combustion chamber 1 may easily rise from the gap to the combustion chamber 10, increasing the amount of lubricating oil consumed.
The problem is that the exhaust gas inside the engine enters the crank chamber 12.
In other words, a problem occurs in which blow-by occurs.

Moreover, since the amount of cooling water W is large, the warm-up time becomes longer, and in the case of a direct injection engine, the piston 11 is supercooled at low speed and low output conditions such as at the start of operation, resulting in poor combustion. There are problems with the generation of blue-white smoke and strange odors in the exhaust.

Cooling water W transmits sound more easily than air, etc., but in conventional products, the liner 1 is covered over a wide area with cooling water W, so the explosion sound inside the combustion chamber 10 is hardly attenuated and the liner 1, The cooling water W is transmitted to the outside via the block 5, and the impact sound of the piston 11 is caused by the piston 11 colliding with the inner cylinder surface of the liner 1 due to fluttering (oscillation) at the top dead center and bottom dead center. There is also the problem that the collision sound is hardly attenuated and is transmitted to the outside via the liner 1, the cooling water W, and the block 5, that is, the noise is large.

In order to solve the above conventional problems, this invention divides the space between the cylinder block and cylinder liner into a cylinder head side space and a crank chamber side space, and the cylinder head side space is used as a cooling water ice chamber. At the same time, the space on the crank chamber side is made into a soundproof layer, which will be explained with reference to FIG. 2 as follows.

In FIG. 2, which is a partial vertical cross-sectional view, the cylinder liner 1
5 is fitted into the cylinder block 20 at three locations: the upper end 16, the lower end 17, and the middle part 18, and the O-ring 2
1.22 is between the middle part 18 and the block 20 and the lower end part 1
7 and block 20.

Two (two types) annular spaces 23 and 24 are formed between the liner 15 and the block 20, sandwiching the intermediate part 18, and the upper space 23 (on the cylinder head side) is filled with cooling water W. , the lower space 24 (on the crank chamber 26 side) is empty.

The O-ring 21 prevents the cooling water W from flowing into the lower space 24, and the O-ring 22 prevents oil splashed in the crank chamber 26 from flowing into the space 24.

27.28 is a plug.

The thickness t of the liner upper half 30 is the thickness t of the liner lower half 31.
1 and the thickness t2 of the liner intermediate portion 6 in FIG. 1 (conventional product).

Although the liner upper half 30 is thin, as mentioned above, the liner 15 is supported by the block 20 at three locations, so it has the necessary strength to prevent explosions and pistons inside the combustion chamber 27. It can sufficiently withstand the impact caused by the fluttering of 35.

The cooling effect will be explained.

The lower half 31 of the liner is away from the combustion chamber 27 and is heated to a low degree, but since it is not covered with cooling water W and is covered with highly insulating air, it is not overcooled. Maintained at an appropriate temperature.

The upper half 30 is close to the combustion chamber 27 and is heated intensely;
Since it is in contact with the cooling water W, it is sufficiently cooled.

Therefore, the upper half 30 is kept at an appropriate temperature without being overheated.

Furthermore, since the thickness t of the upper half 30 is small, the heat applied to the inner cylinder surface of the upper half 30 is quickly transmitted to the cooling water W.

Therefore, in this respect as well, the upper part 30 is not heated and is kept at an appropriate temperature.

Since both the upper half 30 and the lower half 31 have an appropriate temperature in this way, the amount of thermal expansion is approximately constant over the entire liner 16, and the gap between the liner 16 and the piston 35 is also approximately equalized to a predetermined value, so that excessive or It will never be too small.

Therefore, the lubricating oil in the crank chamber 26 is prevented from rising to the combustion chamber 27, the exhaust gas is prevented from entering the crank chamber 26 (blow pie), and seizure of the piston 35 does not occur.

Since the amount of cooling water W is reduced by providing the space 24, the temperature of each part rises to a predetermined temperature in a single hour.

Therefore, the warm-up operation time is shortened, and the piston 35 is not overcooled and combustion defects do not occur during low-speed, low-output operation immediately after startup.

Since the liner lower half 31 is covered by the soundproof layer formed by the space 24, the noise generated inside the cylinder that is transmitted from the liner lower half 31 to the outside through the space 24 and the block 20 is significantly reduced. In particular, the noise generated in the lower half 31 of the liner, that is, the noise generated by the piston 35 at bottom dead center, is reduced.
The impact sound generated by the fluttering becomes difficult to be transmitted to the outside.

The liner 15 is subjected to an impact force due to the explosion within the combustion chamber 27 and the above-mentioned fluttering, and as a result, the liner 15 tries to vibrate in the direction of diameter expansion and diameter contraction, but the liner intermediate portion 18
is supported by the block 20, and the O
Since the ring 21 acts as a damper, the liner 15
Vibration is largely prevented, wear of the liner 15 and piston rings is reduced, and engine performance is improved.

As explained above, according to the present invention, the liner upper half 30
Since only the piston 35 is covered with the cooling water W, consumption of lubricating oil and blow piping can be suppressed, and seizing of the piston 35 can be prevented as much as possible.

It is possible to prevent overcooling of the piston 35, thereby preventing poor combustion at low speeds and low outputs, preventing generation of blue-white smoke and strange odors in the exhaust gas, and shortening the warm-up operation time.

Since the liner lower half 31 is covered with a soundproof layer, it is possible to significantly prevent noise from being transmitted to the outside.

The liner 15 has not only the upper and lower ends 16,17 but also the middle part 18.
is also supported by the block 20, so the liner upper half 3
It is possible to increase the cooling effect by reducing the thickness t of 0,
Furthermore, vibration of the liner 15 can be suppressed to reduce wear of various parts and improve engine performance.

Since the overall volume of the rain space portions 23 and 24 is approximately the same as the volume of the cooling water chamber 9 in Figure 1, the overall weight does not increase significantly compared to conventional products, and the weight is far reduced. are related.

Note that when embodying the present invention, a soundproof and heat insulating material made of glass wool, foamed resin, etc. may be placed in the space 24.

The annular space 24 can be divided into a plurality of partial annular spaces, and the space 24 can also be further divided into upper and lower parts by an annular partition wall.

[Brief explanation of drawings]

FIG. 1 is a partial vertical cross-sectional view of a conventional example, and FIG. 2 is a partial vertical cross-sectional view of an embodiment of the present invention. 15... Cylinder liner, 16... Upper end (cylinder head side end), 17... Lower end (crank chamber side end), 18...・Middle part, 2
0...Cylinder block, 23.24...
...Space section.

Claims (1)

[Scope of utility model registration request] The cylinder head side end of the cylinder liner, the crank chamber side end, and the intermediate portion between both ends are fitted into the inner cylindrical surface of the cylinder block, and the intermediate portion is sandwiched between the cylinder liner and the cylinder block. Forming two types of spaces,
A cylinder for an internal combustion engine, characterized in that a space on the cylinder head side is a cooling water ice chamber, and a space on the crank chamber side is a soundproof layer.