JPH03264721A - Block for heat insulating engine - Google Patents

Abstract

PURPOSE:To efficiently cool an engine by supplying cooling water to a water jacket surrounding the cylinder head side part of a cylinder liner, and dispersing oil mist in cavities surrounding the crank case side part of it. CONSTITUTION:The outer circumference of the cylinder head 5 side part of the cylinder liner 3 in a cylinder block 1 is surrounded with a water jacket 18. The part surrounding the cylinder head side part of the cylinder liner 3 is cooled by supplying cooling water from a water supply port 18a into the water jacket 18. Meanwhile, a plurality of cavities 20 opening their lower ends to a crank case 14 at necessary intervals in the circumferential direction are arranged in the cylinder block, so as to surround the outer circumference of the crank case side part of the cylinder line 3 in the cylinder block 1. Hence, by the use of cooling water in the water jacket 18 and oil mist in the cavities 20, cooling of the engine is efficiently performed.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a block for an adiabatic engine. [Prior Art] As a conventional adiabatic engine block, for example, there is one shown in FIG.
A water jacket 4 is provided so as to surround the outer periphery of the cylinder liner 3 that forms the cylinder chamber 2 over substantially the entire length in the axial direction.
Cooling water is supplied from a to cool the part surrounding the cylinder liner 3, and the cylinder head 5 includes a combustion chamber 6 and an intake lower and an exhaust lower which communicate with the combustion chamber 6. A water jacket 8 surrounding and communicating with the water jacket 4 is provided, and cooling water is supplied from the water jacket 4 to the water jacket 8 to surround the combustion chamber 6, the intake lower and the exhaust lower. The water is cooled and drained from the drain port 8a. In the figure, 9 is a camshaft located in the cam chamber 10, 11 is a valve rod that is raised and lowered by the rotation of the camshaft 9, and causes the intake valve 12 or the exhaust valve 12 to open and close the intake lower or the exhaust lower. A connecting rod whose one end is connected to the crankshaft in the crank chamber 14 and the other end is connected to the piston i5, and which slides the piston 15 along the inner wall of the cylinder liner 3 in the axial direction of the cylinder liner 3;
An oil pan 16 pools lubricating oil 17 injected onto the crankshaft, the bearings of the connecting rod 13, the bearings of the camshaft 9, the piston pin, the piston 15, the piston rings, and the like. Furthermore, as a block for an adiabatic engine other than the above-mentioned adiabatic engine block, for example, there is an adiabatic engine block as shown in FIG. 4, which is a partially improved adiabatic engine block shown in FIG. be. That is, the heat-insulating engine block shown in FIG. 4 surrounds the outer circumference of the cylinder head 5 side portion of the cylinder liner 3 with a water jacket 18 communicating with the water jacket 8 of the cylinder head 5, and also surrounds the outer periphery of the cylinder head 5 side portion of the cylinder liner 3 with a water jacket 18 communicating with the water jacket 8 of the cylinder head 5. The outer periphery of the side portion is surrounded by a cavity 19, and cooling water is supplied to the water jacket 18 from the water supply port 18a to cool the portion of the cylinder liner 3 surrounding the cylinder head 5 side portion. [Problems to be Solved by the Invention] However, in the case of an adiabatic engine block as shown in FIG. Since the cooling is done uniformly throughout the area, as shown by the solid line A in Fig. 5, the part where the fuel burns and becomes high temperature, that is, the part near the piston top dead center A of the cylinder liner 3 which is connected to the combustion chamber 6 of the cylinder head 5. can be cooled to below a predetermined temperature, but the portion of the cylinder liner 3 below the piston top dead center A, that is, the intermediate point B, does not need to be cooled that much.
The area near the bottom dead center C of the piston becomes too cold and becomes supercooled. When the part of the cylinder liner 3 below the piston top dead center A becomes supercooled, the temperature of this part decreases and the viscosity of the lubricating oil increases.As a result, the shear resistance when the piston 15 slides increases, increasing the efficiency of the engine. This causes a decrease in fuel consumption and an increase in fuel consumption. Furthermore, in the adiabatic engine block shown in FIG. 4, the drawbacks of the adiabatic engine block shown in FIG. Although the parts are cooled to a predetermined temperature or lower, the parts of the cylinder liner 3 below the piston top dead center A are not overcooled. However, in the case of an adiabatic engine block as shown in FIG. 4, the cylinder liner 3 as shown by the broken line in FIG.
The temperature of the portion below the piston top dead center A increases, especially the portion near the piston bottom dead center C. This temperature rise causes the viscosity of the lubricating oil to drop significantly at the portion near the piston bottom dead center C, and as a result, the cylinder Liner 3 and piston 15
The lubricating oil film between the piston 15 and the piston 15 is worn out, resulting in significant wear of the piston 15, and furthermore, since the temperature difference between the upper and lower parts of the cylinder block i itself is large, the bore deformation is large. The present invention was made in view of the above-mentioned circumstances, and it is possible to improve the efficiency and extend the life of the engine by allowing the piston to slide circularly between the piston top dead center and the piston bottom dead center of the cylinder liner. The purpose of this invention is to provide a heat insulating engine block. [Means for Solving the Problems] The present invention provides a cylinder head that includes a combustion chamber, an intake port and an exhaust port that communicate with the combustion chamber, and a water jacket that surrounds the combustion chamber, the intake port, and the exhaust port. In an insulated engine block, the cylinder block is provided with a cylinder liner at one end thereof, and the other end of the cylinder block is arranged in communication with a crank chamber provided with an oil pan. A block for an insulated engine, characterized in that a water jacket is provided to surround a portion of the cylinder liner on the side of the cylinder head, and a cavity is provided that opens into the crank chamber so as to surround the portion of the cylinder liner on the side of the crank chamber. It is something. [Function] The cylinder head side portion of the cylinder liner is cooled by supplying cooling water to the water jacket, and the crank chamber side portion of the cylinder liner is cooled by scattering oil mist into the cavity, so the piston of the cylinder liner is cooled. The temperature of the sliding part is neither too low nor too high.

【Example】

Embodiments of the present invention will be described based on the drawings. FIG. 1 shows one embodiment of the present invention, and the third
The same reference numerals as in the figures and FIG. 4 indicate the same parts. The outer periphery of the cylinder head 5 side portion of the cylinder liner 3 in the cylinder block l is surrounded by a water jacket 18, and the water supply port 18 is connected to the water jacket 18.
By supplying cooling water from a, the part surrounding the cylinder head 5 side of the cylinder liner 3 can be cooled, and the outer periphery of the crank chamber 14 side part of the cylinder liner 3 in the cylinder block area is surrounded. In addition, a plurality of cavities 20 are provided in the cylinder block l at required intervals in the circumferential direction of the cylinder liner 3, the lower ends of which are open to the crank chamber I4, and the cavities 20 face the cam chamber lO side.
has an integral structure with the cam chamber IO. As mentioned above, the cylinder liner 3 in the cylinder block 1 has a cylinder head 5 side portion (the upper portion where the temperature is high) 3
a1, that is, a portion of the cylinder liner 3 near the piston top dead center A, can be cooled to a predetermined temperature or lower by supplying cooling water to the water jacket 18 from the water supply port 18a. Further, the crank chamber 14 side portion (lower temperature lower portion) 3b1 of the cylinder liner 3 in the cylinder block l, that is, the lower portion 3b of the piston bottom dead center C of the cylinder liner 3 is surrounded by a plurality of cavities 20 at required intervals, and Since the lower ends of these cavities 20 open into the crank chamber 14, a part of the oil mist injected for cooling and lubricating the piston 15 by a ring jet from a sub-oil hole (not shown) flows from the lower side. It scatters into each cavity 2o and the cam chamber 10, and adheres to the wall surfaces of these cavities 2o and cam chamber lo. In this way, the crank chamber 14 side portion 3b of the cylinder liner 3 in the cylinder block l is appropriately cooled by the oil mist adhering to the wall surfaces of each cavity 20 and the cam chamber 10. Therefore, the temperature of the cylinder block l from the vicinity of the midpoint B of the cylinder rungs 3 to the vicinity of the piston bottom dead center C is as shown by the dotted chain line C in Figure 5, compared to the conventional adiabatic engine block shown in Figure 4. This prevents the temperature from rising and the viscosity of the lubricating oil from dropping significantly. As a result, the loss of the lubricating oil film between the cylinder liner 3 and the piston 15 can be eliminated, and the wear of the piston 15 due to the loss of the oil film can be eliminated, and the life of the engine can be extended. Also, compared to the conventional adiabatic engine block shown in Figure 3,
The temperature near the intermediate point B of the cylinder liner 3 in the cylinder block l and near the bottom dead center C of the piston is as follows:
It rises as shown in FIG. 5--dotted chain line C. Due to this temperature rise, the viscosity of the lubricating oil in the vicinity of the intermediate point B of the cylinder liner 3 and the area leading to the bottom dead center C of the piston is appropriately reduced, and the shear resistance to the oil film when the piston 15 slides can be reduced, and the engine Efficiency can be improved. Furthermore, the outer periphery of the cylinder head 5 side portion of the cylinder liner 3 in the cylinder block l is covered with a water jacket 1.
8 and cooled by cooling water, and the outer periphery of the crank chamber 14 side portion of the cylinder liner 3 is surrounded by the cavity 20 and cooled by oil mist, so that the upper and lower parts of the cylinder block l are Since the cylinder block 1 is cooled approximately evenly, deformation of the cylinder block 1 due to temperature differences can be prevented. Furthermore, a cavity 20 and a cam chamber l in the cylinder block 1
The oil mist scattered inside O absorbs heat from the cylinder liner 3, turns into oil droplets, travels along the walls of the cavity 20 and the cam chamber 10, falls, and is collected in the oil pan 16 as lubricating oil 17. Another embodiment of the present invention will be described based on FIG. This example is a horizontally placed insulated engine block,
The same reference numerals as in FIG. 1 indicate the same parts. The insulated engine block shown in FIG. 1 is placed horizontally and supported by a frame 21 via a support member 22, with a cavity 20 located above and a cavity (
An appropriate number (two in the drawing) of communication holes 23 communicating with the cam chamber 10 (in the drawing) are provided in the cylinder block 1. Therefore, the surrounding portion of the cylinder head 5 side portion 3a of the cylinder liner 3 in the cylinder block l (the right side portion in FIG. 2) is covered by the cooling water of the water jacket 18, and the surrounding portion of the crank chamber 14 side portion 3b of the cylinder liner 3 ( 2) are cooled by the oil mist in the cavity 20 and the cam chamber lO, so each part of the cylinder liner 3 is cooled as shown by the dotted chain line C in FIG. 5 in the same way as shown in FIG. 1. can do. Also, the cavity 20 and the cam chamber lO in the cylinder block l
The oil mist scattered inside absorbs heat from the cylinder liner 3 and becomes oil droplets, which flow down through the communication hole 23 from the upper cavity 20 to the lower cavity (cam chamber 10 in the drawing). The lubricating oil 17 is collected in the oil pan 16. Further, in the one shown in FIG. 2, the cavity 20 and the cam chamber I
The communication hole 23 is omitted by providing O in the cylinder block l so that the opening with the crank chamber 14 is on the lower side, and the cylinder head 5 side of the cylinder block l is closer to the crank chamber 14 side of the cylinder block l. It is optional to omit the communication hole 23 by arranging it at an angle so that it is on the upper side (upwards to the right in FIG. 2). The present invention is not limited to the illustrated and described embodiments, and may be applied to, for example, 2-cycle engines, 4-cycle engines, diesel engines, etc., and various modifications may be made without departing from the gist of the invention. Of course, other changes may be made. [Effects of the Invention] As described above, according to the insulated engine block of the present invention, the cylinder head side portion of the cylinder liner is heated by the cooling water of the water jacket, and the crank chamber side portion of the cylinder liner is heated by the oil mist in the cavity. Since the temperature of the cylinder liner where the piston slides is cooled, the temperature of the cylinder liner where the piston slides is prevented from dropping more than necessary and is also not too high. Therefore, the viscosity of the lubricating oil is reduced to an oil film of the lubricating oil when the piston slides. The shearing resistance against the piston can be appropriately reduced to improve engine efficiency and reduce fuel consumption, and the lubricating oil film does not run out, preventing piston wear and extending the life of the engine. Furthermore, since the injected oil mist is used for piston cooling and lubrication, it is economical and exhibits various excellent effects.

[Brief explanation of drawings]

1 and 2 are cutaway side views showing an embodiment of a block for an insulated engine according to the present invention, and FIGS. 3 and 4 are cutaway side views showing an embodiment of a conventional block for an insulated engine, respectively. FIG. 5 is a graph showing the relationship between the cylinder liner portion and surface temperature in the present invention and the conventional adiabatic engine block. In the figure, l is the cylinder block, 3 is the cylinder liner, 3a
is the cylinder liner part on the cylinder head side, 3b is the cylinder liner part on the crank chamber side, 5 is the cylinder head,
6 is a combustion chamber, 7 is an intake port, 7° is an exhaust port, 8 is a water jacket, 1o is a cam chamber, 14 is a crank chamber, 15
is the piston, 1B is the oil pan, 17 is the lubricating oil, 1
8 is a water jacket, 20 is a cavity, and 23 is a communicating hole.

Claims (1)

[Claims] 1) A cylinder head including a combustion chamber, an intake port and an exhaust port communicating with the combustion chamber, and a water jacket surrounding the combustion chamber, intake port, and exhaust port is attached to one end of a cylinder block that has a cylinder liner inside. In the insulated engine block, the cylinder block is arranged in communication with a crank chamber provided with an oil pan at the other end of the cylinder block, and the cylinder block is provided with water so as to surround a portion of the cylinder liner on the cylinder head side. A heat insulating engine block characterized in that it is provided with a jacket and a cavity that opens into the crank chamber so as to surround the crank chamber side portion of the cylinder liner.