JPS6029653Y2 - 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 vertical cross-sectional partial view of a conventional vertical internal combustion engine, a wet 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 cooling water chamber 9 filled with cooling water W is formed between the cylinder block 5 and the intermediate portion 6 between both ends 2.3.

However, according to the cylinder shown in FIG. 1, since the cooling water W exerts a cooling effect on the lower half 7 of the intermediate section 6 to the same extent as on the upper half 8, the lower half 7 away from the combustion chamber 10 is overheated. When cooled, the amount of thermal expansion becomes smaller, and the gap between the lower half 7 and the piston 11 becomes too small, which may cause the piston 11 to seize.

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 lubricating oil in the crank chamber 12 tends to rise from the gap to the combustion chamber 10, resulting in problems such as increased lubricant consumption and exhaust gas in the combustion chamber 10. A problem occurs in which the oil enters the crank chamber 12, that is, a blow pie 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.

In order to solve the above-mentioned conventional problems, the present invention is designed to fill the portion of the cooling water ice compartment space on the crank chamber side with a filler material, and is constructed as follows.

That is, in the present invention, the cylinder head side end and the crank chamber side end of the cylinder liner are removably fitted to the inner cylindrical surface of the cylinder block toward the cylinder head, and the middle part between the above-mentioned both ends of the cylinder liner and the cylinder block are connected. A space for a cooling water ice chamber is formed in between, and an annular lightweight filler is fitted into the crank chamber side of the space, and the filler has enough elasticity to be attached to and removed from the space. A main body part formed of a flexible molded body and fitted into both the cylinder block and cylinder liner as a filler to close the space, and an extension extending from the main body part along the inner cylindrical surface of the cylinder block toward the cylinder head side. The extension part is fitted into the cylinder block to form a heat radiation regulating layer from the cylinder block, and the extension part is separated from the cylinder liner to leave a space between the extension part and the cylinder liner. There is.

Next, an embodiment will be described with reference to FIGS. 2 to 4.

In FIG. 2, which is a partial vertical cross-sectional view, the outer cylindrical surface of the upper end 17 of the cylinder liner 16 that fits into the cylinder block 15 forms a stepped portion 18 with a small diameter D□ on the lower side, and the liner 16 is It is in a state where it cannot be moved below a predetermined position.

A cylinder head 20 is fixed to the upper surface of the cylinder block 15 by bolts (not shown) that are screwed into bolt holes 19, and the head 20 prevents the liner 16 from moving upward.

The liner lower end 21 that fits into the cylinder block 15 has a constant outer diameter D3 except for the lowermost end 22 (non-fitting part), and the outer diameter D3 is smaller than (or the same as) the outer diameter D1. .

The lowermost end 22 has an outer diameter smaller than the outer diameter D3.

24 is an O-ring. The intermediate portion 23 between the upper and lower end portions 17.21 of the liner has an outer diameter D2 smaller than the outer diameter D3, and an annular space 25 is formed between the intermediate portion 23 and the cylinder block 15.

An annular filler 26 is fitted into the lower half of the space 25, so that the cooling water W mainly circulates only in the upper half of the space 25.

The filler 26 is made of an elastic, flexible and lightweight material, such as a single rubber material or a combination of foam particles and a rubber material (binder), and is shown in FIG. 2 and ■-■ in FIG.
The liner 16 and the block 1 are shown in FIG.
It is in close contact with 5 due to its elasticity.

As shown in FIG. 2, the upper surface 27 of the filler 26 is tapered and is shaped so that it occupies an upper position as it goes radially outward (to the left in FIG. 3), into which the filler 26 fits. Of the liner outer cylindrical surface portion 28 and the block inner cylindrical surface portion 29,
The vertical length 1° of the inner cylindrical surface portion 29 is longer than the vertical length 11 of the outer cylindrical surface portion 28.

That is, the inner cylindrical surface portion 29 extends upwardly more than the outer cylindrical surface portion 28.

As shown in FIG. 4, which is a longitudinal cross-sectional view of the filler 26, a slit 36 or a hole for draining the cooling water W (FIG. 2) is opened at the lowest part (inner periphery) of the upper surface 27 of the filler. 36 communicates with a water drain hole 37 (FIG. 4) of the cylinder block 15 (FIG. 2) at its lower end.

Block portion 3 into which the upper edge of the filler 26 shown in FIG. 2 fits
4 protrudes slightly toward the liner 16, so that the filler 26 does not move upward due to vibration or the like, and the passage for the cooling water W is always maintained at a predetermined size and shape.

The cooling effect during operation will be explained.

The lower half 31 of the liner is remote from the combustion chamber 33 and is heated to a low degree, but because it is covered with the filler 26, it receives little or no cooling effect from the cooling water W.

Therefore, the lower half 31 is kept at an appropriate temperature without being overcooled.

The upper half 30 is close to the combustion chamber 33 and is heated intensely, but
Since it is in contact with the cooling water W and has a thin wall, it is intensely cooled.

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

Since both the upper half 30 and the lower half 31 are at an appropriate temperature in this way, the amount of thermal expansion is approximately constant over the entire liner 16, and the gap between it and the piston ring 13 (Fig. 1) is approximately at a predetermined value. Equalized and not too large or too small.

Therefore, the lubricating oil in the crank chamber 35 is prevented from rising to the combustion chamber 33, and the exhaust gas is prevented from entering the crank chamber 35 (blow pie), and seizure of the piston does not occur.

Since the amount of cooling water W is reduced by the volume of the filler 26,
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 is not overcooled and combustion defects do not occur in low-speed, low-output operating conditions immediately after starting.

In addition, the length 13 of the inner cylindrical surface portion 29 is longer than the outer cylindrical surface portion 11, and the block 15 is covered over a wide area with the filler 26 (heat insulating material), so that the heat transferred to the cooling water W is transferred to the block 15. It is largely prevented from being released into the atmosphere from the outside, and in this respect too, the warm-up time is shortened and overcooling of various parts is prevented.

Note that in high-speed, high-output conditions, the amount of circulation of the cooling water W increases, so the heat transferred to the cooling water W is quickly sent to the radiator (not shown) together with the cooling water W and released to the outside, thereby discharging the heat from each part. is never overheated.

When assembling each part, the cylinder block 15 is assembled by temporarily elastically deforming the filler material 26 that has been molded externally in advance.
It is inserted into the block 15 and tightly fitted into the block 15 due to its elasticity.

Next, the cylinder liner 16 is inserted into the block 15 from above.

In that case, the lower end 21 of the liner hits the filler 26, but
Since the filler 26 is elastically deformed, the liner 16 can be inserted without any problem, and when the insertion is completed, the filler 26 is tightly attached to the liner 16 due to its elasticity.

Even when the liner 16 is pulled upward, the filler 26 elastically deforms to allow the liner 16 to be pulled out.

As explained above, according to the present invention, the filler 26 is provided in the lower half of the space 25 (the part opposite to the cylinder head 20).
This reduces lubricant consumption and blow piping, prevents piston seizure as much as possible, shortens warm-up time, and prevents overcooling of the piston during low-speed, low-output operation. It is possible to prevent poor combustion of the fuel and to prevent the generation of blue-white smoke and strange odors in the exhaust gas.

Moreover, since the block inner cylindrical surface portion 29 into which the filler 26 fits is extended upward (toward the cylinder head 20 side), the heat retention effect on the cooling water W can be enhanced, and in this respect, the warm-up operation time can also be shortened. , it is possible to prevent poor combustion at low speeds and low outputs.

Also, the liner outer cylinder surface portion 28 into which the filler 26 fits is short;
Since the filler upper surface 27 is tapered, the block 15
Even though the fitting length is 1° long, the required amount of cooling water W can be secured and overheating can be prevented.

By simply changing the amount and material of the filler 26, it is possible to easily obtain the optimum cooling effect according to the output specifications of the engine.

That is, for example, in an engine with high output specifications, the cooling effect can be enhanced by increasing the amount of cooling water W by simply reducing the amount of the filler 26, and if the filler 26 is a foam with open cells, By simply changing the material of the foam and increasing the amount of open cells, the amount of cooling water that permeates into the foam can be increased and the cooling effect on the lower half 31 can be enhanced.

Furthermore, in the present invention, since the filler 26 is a flexible elastic body,
The filler 26 can be manufactured externally and then incorporated into the block 15, and since the filler 26 can be manufactured externally in this way, it becomes easier to foam and mold the filler 26.

Since the filler 26 is made of foam etc., the block 15
It is lighter than other materials, and therefore the overall weight does not increase significantly compared to conventional products, making it possible to achieve a distant relative of weight reduction.

The effect of preventing proper cooling, etc. will be explained from another perspective as follows.

That is, cooling elements for the liner 16 generally include cooling by cooling water W and cooling from the outer surface of the cylinder block 15.

The amount of circulating water W changes depending on the engine speed, and the amount of heat generated by the engine (the degree to which cooling is required)
changes depending on the engine speed.

Therefore, the degree of cooling by the cooling water W changes depending on the amount of heat generated by the engine.

As is clear from the above explanation, it is generally desirable to cool the engine mainly with the cooling water W, and if the heat radiation from the cylinder block 15 accounts for a large proportion as a cooling element, the amount of heat generated by the engine and the degree of cooling will change. An imbalance occurs between the two, leading to problems such as overcooling.

In contrast, in the present invention, heat radiation from the cylinder block 15 is restricted by the extension part (part that fits only into the block 15) of the filler 26 having the tapered upper surface 27.
The engine can be mainly cooled only by the cooling water W, and the amount of heat generated and the degree of cooling can be balanced.

The portion of the liner 16 adjacent the tapered top surface 27 requires cooling, but to a lesser extent than the portion closer to the head 20.

In the present invention, by providing the extension, the volume of the space (cooling water passage) facing the tapered upper surface 27 is narrowed.

Therefore, the degree to which the liner 16 portion adjacent to the tapered upper surface 27 is actually cooled corresponds to the degree to which cooling is required, and unbalanced cooling is also prevented in this respect.

In addition, when embodying the present invention, the outer diameter D2 of the liner intermediate section 23 can be made larger than (or the same as) the outer diameter D3 of the lower end section 21, so that the lower end section 21 is filled when the liner 16 is inserted. Since it does not get caught (or gets caught) on the material 26, the insertion work becomes easier.

However, if D2≧D3, the thickness of the intermediate portion 23 increases, so that the cooling effect on the upper half portion 30 is somewhat reduced.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical cross-sectional view of the conventional example, FIG. 2 is a partial vertical cross-sectional view of the embodiment of the present invention, and FIG. 3 is a partial partial cross-sectional view taken along the line ■-■ of FIG.
FIG. 4 is a longitudinal sectional view of the filler. 15... Cylinder block, 16...
Cylinder liner, 17... Upper end (cylinder head side end), 20... Cylinder head, 21
・Curved bottom end (crank chamber side end), 23...
Middle part, 25...Concave space part, 26...Filling material,
28...Outer cylindrical surface portion, 29...Inner cylindrical surface portion, 35.Curve/crank chamber.

Claims (1)

[Scope of utility model registration request] The cylinder head side end and the crank chamber side end of the cylinder liner are removably fitted to the inner cylindrical surface of the cylinder block toward the cylinder head, and cooled between the intermediate part between the above two ends of the cylinder liner and the cylinder block. A flexible molded body that forms a space for a water ice compartment, fits an annular lightweight filler into the crank chamber side portion of the space, and has sufficient elasticity to allow the filler to be attached to and removed from the space. The main body portion is shaped like a filler and fits into both the cylinder block and the cylinder liner to close the space, and the extension portion extends from the main body portion toward the cylinder head side along the inner cylindrical surface of the cylinder block. and the extension portion is fitted to the cylinder block to form a heat radiation regulating layer from the cylinder block,
A cylinder for an internal combustion engine, characterized in that an extension part is separated from a cylinder liner to leave a space between the extension part and the cylinder liner.