JPS6124650Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a liquid-cooled cooling device applied to diesel, gasoline, and gas-type meat combustion engines.

In a conventional internal combustion engine, as shown in FIG. 1, which is a partial vertical cross-sectional view, a cooling water chamber 2 formed around a cylinder liner 1 extends along almost the entire length of the liner 1 excluding the upper and lower ends, and the combustion chamber Upper liner half 5 close to 3
Since the lower half 6 of the liner, which is distant from the combustion chamber 3, receives the cooling effect to the same extent, the upper half 5 becomes hot and the lower half 6 becomes cold, resulting in the following problems. In other words, as the amount of thermal expansion of the upper half 5 increases, the gap between the upper half 5 and the piston 7 becomes too large, and the lubricating oil in the crank chamber 8 easily rises into the combustion chamber 3 through the gap, thereby providing lubrication. There are problems in that oil consumption increases, exhaust gas easily enters the crank chamber 8, that is, blow-by tends to occur, and the lower half 6 and piston 7
There is also a risk that the piston 7 may seize if the gap between them becomes too small. Moreover, since the amount of cooling water is large, the warm-up operation time becomes long, and under low-speed, low-output operating conditions, overcooling of the piston 7 causes combustion failure, causing problems such as blue-white smoke and strange odors in the exhaust gas. In order to prevent overcooling of the liner lower half 6 and shorten the warm-up operation time, it is possible to reduce the amount of cooling water circulated, but in that case, the cooling effect will be insufficient at high output, and the liner A problem arises in that the temperatures of the upper half 5 and the piston 7 become too high, reducing the durability of the liner 1 and the piston 7.

In order to solve the above-mentioned problems, the present invention cools the cylinder part on the cylinder head side and the cylinder part on the crank chamber side using separate cooling systems depending on the amount of heating in each part. The explanation will be as follows with reference to FIGS. 2 to 7.

In FIG. 2, which is a longitudinal section, the cylinder liner 10 is of a wet insertion type, and the upper and lower ends 11, 1
2 and intermediate part 13 are cylinder block 1
5, and between the liner 10 and the block 15, annular spaces 16 and 17 are formed above and below with the intermediate section 13 in between. The upper space 16 is a cooling water chamber filled with cooling water W, and the cooling water W circulates between the cooling water and the external radiator via a passage (not shown). A lubrication nozzle 18 fitted into a hole on the left side in the figure of the block 15 opens in the lower space.
The temperature control valve 2 is connected via an oil pipe 20 extending outside the temperature control valve 2
Connected to 1. The temperature control valve 21 is a valve with a built-in temperature sensor, and its opening degree increases as the temperature rises. It communicates with a lubricating oil passage 23 provided therein. Oil road 2
3 is for supplying lubricating oil to each part of the engine.
Lubricating oil from the oil pump (not shown) is supplied to oil path 2.
3 is constantly flowing. A large diameter hole 2 communicating with the upper part of the space 17 is located on the right side of the block 15 in the figure.
5 and the bottom of the space 17 are provided with a small diameter hole 26 that communicates with the bottom of the space 17. Both holes 25 and 26 are inclined downward as they move away from the liner 10, and the hole 25 opens toward the camshaft 27.

As shown in FIG. 3, which is a partial cross-sectional view taken along the line 2 in FIG. They are provided one by one. Lubricating nozzle 1
8 is opened generally in the tangential direction of the outer cylindrical surface of the liner 10, so that the lubricating oil from the nozzle 18 can easily flow inside the space 17 along the outer cylindrical surface of the liner 10. Note that, for example, one nozzle 18 and one small hole 26 in FIG. 2 are provided for each cylinder.

In low-speed, low-output operating conditions, the liner lower half 31 in FIG. 2 is far from the combustion chamber 30, so the degree of heating is low, and the temperature of the lower half 31 and the block portion 22 in its vicinity is not very high. No. Therefore, the temperature control valve 21 maintains a fully closed (or slightly opened) state in accordance with the temperature of the block portion 22, and no (or almost no) lubricating oil flows from the passage 23 into the space 17. In this manner, the lower half 31 of the liner is heated and cooled to a low degree, and is thus maintained at an appropriate temperature. Also, even at low speeds and low outputs, the upper half 32 of the liner is heated to a relatively high degree due to its proximity to the combustion chamber 30, but the upper half 32 is sufficiently cooled by the cooling water W circulating around it. The portion 32 is also kept at an appropriate temperature. Since the entire liner 10 is kept at an appropriate temperature in this way, the amount of thermal expansion of the liner 10 is made uniform to a predetermined value over the entire length, and the liner inner cylindrical surface 35
The gap between each part of the cylinder (inner cylindrical surface) and the piston (not shown) will not become too large or too small. Therefore, the lubricating oil in the crank chamber 36 is prevented from rising into the combustion chamber 30, the exhaust gas is prevented from entering the crank chamber 36 (blow-by), and seizure of the piston is also prevented as much as possible. In addition, at low speeds and low output, each part is forcibly cooled by only a relatively small amount of cooling water W filling the upper space 16, which shortens the warm-up time and prevents overcooling of each part and resulting poor combustion. This prevents blue-white smoke and strange odors from occurring in the exhaust gas.

When the engine shifts to a high speed, high output operating state, the amount of heating to the liner lower half 31 also becomes relatively large, and the temperatures of the lower half 31 and the block portion 22 rise (described later). The temperature control valve 21 detects a temperature rise in the block portion 22 and is, for example, fully opened, and a large amount of lubricating oil flows from the passage 23 through the valve 21, the pipe 20, and the nozzle 18 into the space 17. The inflowing lubricating oil flows along the outer cylindrical surface of the liner 10 and flows out from the hole 26. However, since the hole 26 has a small diameter and low discharge capacity, a portion of the lubricating oil accumulates in the space 17 and flows out from the hole 26. 25 toward the cam surface 28.
Since the lubricating oil cools the liner lower half 31 while flowing in the space 17, the temperature increase in the lower half 31 is very small, and the lower half 31 is kept at an appropriate temperature. If the cooling effect is too strong, the temperature of the lower half 31 will drop, but in that case, the temperature control valve 21 will detect the temperature drop and reduce the amount of lubricating oil, so the temperature will only drop a little and the lower half 31 will drop. The half portion 31 is kept at an appropriate temperature. At high speeds and high outputs, the liner upper half 32 is heated violently, but since the rotation speed of the cooling water pump (not shown) increases in accordance with the engine rotation speed, the cooling water W
The amount of circulation increases. Therefore, the upper half 32 is sufficiently cooled and maintained at an appropriate temperature. In this way, the entire liner 10 is kept at an appropriate temperature even at high speeds and high outputs, so the clearance between each part of the liner inner cylindrical surface 35 and the piston will not become too large or too small, which will prevent increased lubricating oil consumption and blow-by. , seizure of the piston is prevented as much as possible. Furthermore, since the liner 10 and the piston are not overheated, deterioration in durability is also prevented.

The above-mentioned operation will be explained below with reference to FIGS. 4 and 5. In FIG. 4, when the engine output reaches a predetermined value P or more, lubricating oil starts to be filled into the space 17 (FIG. 2), and thereafter the amount of lubricating oil increases in proportion to the increase in output. Therefore, the liner lower half 3
The degree of cooling relative to 1 also increases, and even if the output exceeds P as shown in FIG. 5, the piston temperature hardly increases. Note that the line a-b in FIG. 5 shows the case where the liner lower half 31 is not cooled with lubricating oil, and in that case, even if the output exceeds P, the piston temperature increases in proportion to the output.

As explained above, according to the present invention, the cylinder inner cylindrical surface (liner inner cylindrical surface 35) on which the piston slides
along the circumference of the cylinder head side space 16
and a space 17 on the crank chamber 36 side, the cylinder head side space 16 is used as a cooling water chamber in which cooling water is constantly circulated, and the space 17 on the crank chamber side is used as a lubricating oil chamber. An oil supply passage (oil supply pipe 20) is connected, and a lubricant control device (temperature control valve 21) is provided in the lubricant supply passage to increase the amount of lubricant supplied when the amount of heating to the cylinder increases. A lubricating oil passage (large diameter hole 26) that opens toward the camshaft 27 on the outside is provided in the wall of the cylinder block 15 surrounding the cylinder block 17, and the lubricating oil in the lubricating oil chamber is transferred to the camshaft 27 through the lubricating oil passage. It is designed to be discharged toward the cam surface 28.

In this way, in the present invention, the liner upper half 32 and the liner lower half 31 are cooled using cooling water and lubricating oil, respectively, depending on the amount of heating of each part, so the entire liner 10 is always kept at an appropriate temperature. It is possible to prevent or suppress various problems such as increased lubricating oil consumption, blow-by, piston seizure, and poor combustion.

Furthermore, the liner upper half 32 and lower half 31 are cooled by completely different cooling systems, that is, a cooling water system and a lubricating oil system. Cooling can be performed without being affected by the cooling state of the other, and both parts 31 and 32 can be cooled under optimal conditions.

Moreover, since the cam surface 28 of the camshaft 27 is lubricated using the lubricating oil in the lubricating oil chamber 17, the durability of the camshaft 27 and the tappet 29 can be increased. Further, since there is no need to provide an oil passage exclusively for the camshaft 27, the structure can be simplified.

In addition, when embodying the present invention, a variable opening type valve without a built-in temperature sensor is adopted in place of the temperature control valve 21, and a detection device that detects the rotation speed of the fuel pump and the position of the regulator handle is used. It is also possible to adjust the opening degree of the above-mentioned valve. In this case, the detection device indirectly detects the amount of heating to the liner 10 by detecting the speed and output of the engine, and controls the amount of oil supplied to the space 17.
It is also possible to divide the space 17 into two or more vertically adjacent chambers, and adjust the amount of oil applied to each chamber 17 for each chamber. Instead of the variable opening temperature control valve 21, a valve that only fully opens and closes can be used, and in that case, the amount of oil applied to the space 17 and the temperature change due to the oil cannot be precisely controlled. , the lower half 31 can be kept at approximately an appropriate temperature. The present invention can also be embodied as shown in FIG.

Fig. 6 shows the present invention applied to a cylinder having a press-fit type dry liner 41. The entire outer cylinder surface of the thin liner 41 is fitted into the cylinder block 42, and the two spaces 16 and 17 are closed to the cylinder block 42. It is formed within a wall thickness of 42 mm. Note that the oil supply system and oil drainage system for the space 17 are the same as in the case of FIG. 2.

Furthermore, the present invention is a cylinder without a liner,
That is, the present invention can also be applied to a cylinder in which a sliding surface is formed by thermal spraying or the like on the inner cylindrical surface of the cylinder block.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional partial view of the conventional example, Figures 2 and 6.
The drawings are partial vertical cross-sectional views of different embodiments, FIG. 3 is a cross-sectional view taken from the side shown in FIG. 2, and FIGS. 4 and 5 are graphs for explaining the cooling effect. 15... Cylinder block, 16, 17... Space, 20... Oil feed pipe (lubricating oil supply passage),
21...Temperature control valve (lubricating oil amount control device), 26...
Large diameter hole (lubricating oil passage) 27...Camshaft, 28...
Cam surface, 36...Crank chamber, W...Cooling water.

Claims (1)

[Scope of utility model registration request] A space on the cylinder head side and a space on the crank chamber side are formed along the periphery of the inner cylindrical surface of the cylinder on which the piston slides, and the space on the cylinder head side is used as a cooling water chamber in which cooling water is constantly circulated; A lubricating oil amount control device in which a space on the crank chamber side is used as a lubricating oil chamber, a lubricating oil supply passage is connected to the lubricating oil chamber, and the lubricating oil supply amount is increased when the amount of heating to the cylinder increases in the lubricating oil supply passage. A lubricating oil passage is provided in the wall of the cylinder block surrounding the lubricating oil chamber and opens toward the camshaft on the outside thereof, and the lubricating oil in the lubricating oil chamber is directed toward the cam surface of the camshaft through the lubricating oil passage. What is claimed is: 1. A cooling device for an internal combustion engine, characterized in that the cooling device discharges