JPH0712667Y2 - Engine structure with cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an engine structure with a cooling device.

[Conventional technology]

Conventionally, a cooling device for an adiabatic engine is, for example, the actual Kaisho 60-1
It is disclosed in Japanese Patent No. 5921. The cooling device for the adiabatic engine will be described with reference to FIG.

Regarding the cooling device for the adiabatic engine, cooling chambers 42 and 43 formed in at least two vertical stages in the vertical direction of the cylinder block 41 on the outer periphery of the lower portion of the cylinder liner, and the temperature of the refrigerant installed in each cooling chamber 42, 43 Temperature sensor for detecting 44,45
And a controller for transmitting a refrigerant flow velocity control signal corresponding to the detection signals of the temperature sensors 44, 45 to the refrigerant driving means 47.
46, and the controller 46 controls the flow velocity of the refrigerant in each of the cooling chambers 42, 43.

For insulated engines, the upper part 52 of the cylinder liner
A liner head 55 in which a cylinder head inner wall portion 49 and a cylinder liner upper portion 51 are integrally formed is fitted inside a cylinder head 50 integrally formed with. Cylinder head 50
A cooling chamber 53 is formed in the vicinity of. The cylinder block 41 and the cylinder head 50 are made of cast metal.
Liner head 55, cylinder liner 48 and piston head
54 is made of ceramics. In the figure, symbols A and B
Indicates the flow direction of cooling water.

[Problems to be solved by the device]

Generally, in a reciprocating engine, smooth reciprocating motion can be continued by cooling the cylinder head and the cylinder liner located on the outer circumference of the reciprocating piston with water or air.

By the way, the idea of providing a cooling system over the entire engine is gradually changing. For the most important heat generating part of the operation of a reciprocating engine, the top dead center (TD
After C), the pressure and temperature inside the cylinder are high up to about 70 ° at the crank angle, and the amount of heat radiation is large, but after that, it rapidly decreases and the amount of heat conduction is about 30% of the whole.

Therefore, the heat transfer amount of the reciprocating engine increases when the working gas pressure and temperature are high, but when it is low, it is noted that the heat transfer amount is not too large, and a water jacket is installed on the upper part of the cylinder liner and a part of the cylinder head. If it is provided and heat is efficiently radiated from the lower surface of the cylinder head to near the top dead center of the piston, and if the piston head is configured as a heat insulating structure, the heat conduction amount is cut off from the piston and the cylinder liner is fitted. The cylinder body does not need to be cooled by cooling water and the water jacket can be eliminated.

Therefore, as described above, when the water jacket is provided on the upper part of the cylinder liner and a part of the cylinder head, and the lower part of the cylinder liner and the piston head are constructed in a heat insulating structure to remove the water jacket from the cylinder body, Extremely effective by reducing the cooling to the minimum necessary, configuring the engine itself to be compact and improving the workability, reducing the weight and drastically reducing the cost, and smoothly flowing the cooling water to the required cooling area. The water pump can be cooled quickly and the water pump can be downsized.
There was a problem of how to arrange the oil cooler with respect to the engine.

The purpose of this device is to solve the above problems,
The lower surface of the cylinder head and the upper portion of each cylinder liner are integrally structured, and the water jacket is provided only on the outer peripheral portion on the upper side of each cylinder liner and the lower surface of the cylinder head, and the water jacket is excluded from the cylinder body forming the cylinder. At the same time, it is to provide an engine structure with a cooling device in which the lower portion of the cylinder liner and the piston head are formed into a heat insulating structure, and an oil cooler body is provided in the water jacket.

[Means for Solving the Problems]

The present invention is configured as follows to achieve the above object. That is, according to this invention, the piston head of each piston and the lower portion of each cylinder are constructed in a heat insulating structure, and the cylinder head and the upper portion of each cylinder liner are integrally formed. In order to cool the engine, a cooling water passage is formed only in the outer peripheral portion of the cylinder head and the upper portions of the respective cylinder liners, and an oil cooler main body is arranged in the cooling water passage. Regarding

Further, in this engine structure with a cooling device, the oil cooler body is disposed in the intake manifold side cooling water passage.

[Action]

The engine structure with the cooling device according to the present invention is configured as described above and operates as follows. That is, in this engine structure with a cooling device, the oil cooler main body is arranged in the cooling water passage only on the outer circumference of the cylinder head and the upper portion of each cylinder liner, so that the oil cooler main body can be effectively arranged in the water jacket, and the engine itself It can be made compact.

Further, the oil cooler body is arranged in the intake manifold side cooling water passage, or in a so-called Siamese type engine of the one-sided exhaust system, the oil cooler body can be arranged on the opposite side of the port, so that the cooling inside the water jacket is prevented. Since the water is not much affected by the heat of the exhaust manifold, the cooling of the oil can be effectively achieved.

〔Example〕

Hereinafter, embodiments of an engine structure with a cooling device according to the present invention will be described in detail with reference to the drawings.

1 and 2 show one embodiment of an engine structure with a cooling device according to the present invention. FIG. 1 is a sectional view showing an embodiment of a cooling device for an adiabatic engine according to the present invention, and FIG. 2 is an enlarged sectional view taken along line II-II in FIG.

This engine structure with a cooling device is an engine having a partially adiabatic structure in which a piston head and a lower portion of a cylinder liner are formed into an adiabatic structure, and mainly comprises a cylinder head 1 provided with a water jacket 2, a cylinder block 8 forming each cylinder, Each cylinder liner lower part 3 made of a ceramic material fitted to each cylinder of the cylinder block 8,
In addition, the piston head 4 made of a ceramic material is attached to the piston body 10 via the heat insulating layer 9, and the oil cooler body 15 is attached to the cylinder head 1.

Each cylinder liner upper portion 6 is located above each cylinder liner lower portion 3. In addition, each cylinder liner upper part 6,
Combustion chambers 11 are formed by each cylinder liner lower portion 3, cylinder head lower surface portion 7 and each piston head 4, and the cylinder head lower surface portion 7 on the side of each combustion chamber 11 is formed integrally with the cylinder head 1. The upper portion 6 of each cylinder liner and the lower surface portion 7 of the cylinder head are integrally formed.

The cylinder head lower surface portion 7 is provided with intake and exhaust ports of an intake port 13 and an exhaust port 12 in which intake and exhaust valves are arranged, and valve seats 19 are formed at these intake and exhaust ports.

The cylinder head 1 and the cylinder liner upper portion 6 are made of metal, for example, cast iron, but the outer peripheral portion of each cylinder liner upper portion 6 and a part of the cylinder head 1 extend over the cylinder head 1 and the cylinder liner upper portion 6. A water jacket 2 which is a cooling water passage is formed. In other words,
The water jacket 2 formed on the cylinder head 1 extends around the lower surface 7 of the cylinder head and the outer circumference of each cylinder liner upper portion 6.

Further, the water jacket is excluded from the cylinder block 8. Therefore, the water jacket 2 is configured to cool a portion facing each combustion chamber 11, particularly a high temperature portion from the cylinder head lower surface portion 7 to the vicinity of the top dead center of the piston 5, and the high temperature portion is cooled by the water. Cooling does not create any heat problems.

This engine structure with a cooling device is characterized in that the oil cooler is attached to the cylinder head 1 in the above-described configuration. That is, in the cooling water passage, that is, the water jacket 2 formed only in a part of the cylinder head 1 and the outer peripheral portion of each cylinder liner upper portion 6, the cylinder head 1
An oil cooler body 15 that penetrates through is disposed. The oil cooler body 15 is arranged on the side where the intake manifold is provided, that is, on the intake port 13 side.

Alternatively, although not shown, in the Siamese type engine, the oil cooler body is arranged on the opposite side of the port. The oil cooler main body 15 arranged in the water jacket 2 of the cylinder head 1 is formed by, for example, forming an oil passage 17 in the oil cooler main body 15 by superimposing uneven heat exchange plates 16 on each other and appropriately fixing them. As indicated by arrow C in
The oil passages 17 are provided in multiple stages and arranged along the water flow direction D. An oil pump 18 is provided at one end of the cylinder head 1 for circulating oil in the oil cooler body 15.

As described above, by providing the oil cooler main body 15 on the cylinder head 1, effective heat exchange is performed between the oil used for lubrication and the water for cooling the engine, and the oil is in a preferable state by the cooling water. Can be cooled to. Moreover, since the oil cooler body 15 is not arranged on the side of the exhaust port 12 where the heat of exhaust gas has a great influence, heat exchange with the oil can be achieved before the cooling water is affected by the heat of the exhaust port 12. Becomes Also, the oil cooler body
Since the 15 oil passages 17 are configured in multiple stages, the heat exchange efficiency between the cooling water and the oil becomes extremely good.

Further, as described above, since the water jacket 2 is provided only for a part of the cylinder head 1 and the cylinder liner upper portion 6, the shape of the water jacket 2 itself can be formed in an extremely simple structure, and the cooling water can be formed. The flow resistance can be reduced.

Therefore, the capacity of the cooling water pump for circulating the cooling water can be made small. Further, the cylinder liner 3 serving as a cylinder bore is closely fitted to the cylinder of the cylinder block 8.

That is, the lower portion 3 of the cylinder liner is cast into a cylinder block 8 made of cast metal, fitted by press fitting, shrink fitting, etc., and made of a ceramic material such as zirconia, silicon nitride, or silicon carbide. The piston 5 is configured to reciprocate in the lower cylinder liner 3, but since the high temperature and high pressure of the lower cylinder liner 3 is not so high, the lower cylinder liner 3 is made of silicon nitride.
If it is made of a ceramic material such as silicon carbide to improve seizure resistance, it is not necessary to provide a water jacket for the cylinder block 8 located on the outer periphery of the cylinder liner lower portion 3, and air-cooled fins are not required. It is not necessary to provide the above.

Therefore, when casting the cylinder block, the core for the water jacket can be eliminated, the workability becomes extremely easy, the weight can be reduced, and the cost can be largely reduced.

Regarding the piston 5, for example, the piston head 4 having a ceramic material whose combustion chamber 11 side is formed into a flat surface, that is, a flat surface is a ceramic piston ring.
The piston body 10 fitted with 14 is fixed by a metal flow or the like with a heat insulating layer 9 interposed. The ceramic material portion of the piston head 4 may be made thin with a ceramic material such as silicon nitride or silicon carbide, and the heat capacity of the portion may be reduced. The heat insulating layer 9 of the piston head portion can be manufactured from an air layer or a heat insulating material such as potassium titanate, potassium titanate whiskers, zirconia fibers, and alumina fibers.

[Effect of device]

The engine structure with the cooling device according to the present invention is configured as described above and has the following effects. That is,
In this engine structure with a cooling device, the piston head of each piston and the lower part of each cylinder are constructed as a heat insulating structure, and the cylinder head and the upper part of each cylinder liner are integrally formed, and the outer circumference of the cylinder head and the upper part of each cylinder liner is formed. Since the cooling water passage is formed only in the portion and the oil cooler main body is arranged in the cooling water passage, the oil cooler main body can be effectively arranged in the water jacket, and the engine itself can be made compact.

Further, by forming the water jacket only on the outer circumference of the upper part of the cylinder liner and a part of the cylinder head, the shape of the water jacket formed on the outer circumference of the combustion chamber that is most suitable for heat radiation, that is, the cooling water smoothly flows smoothly. It can be formed into a simple structure with a direct shape, and by circulating the cooling water and low resistance quickly and smoothly, the high temperature part of the combustion chamber can be cooled very effectively and quickly, and the gas pressure and temperature of the upper part of the cylinder head can be increased. It is possible to radiate heat from the portion, that is, the portion from the lower surface of the cylinder head to the vicinity of the top dead center of the piston.

Also, while improving the workability by simplifying the mold,
Since the engine itself can be made low in size and weight, and the water jacket can be made small, the amount of water and the flow resistance can be made small, the water pump for cooling water can also be made compact.

Further, since the oil cooler body is arranged in the intake manifold side cooling water passage, the cooling water in the water jacket is not yet affected by the heat of the exhaust manifold, so that the cooling of the oil can be effectively achieved. it can.

Further, in the so-called Siamese type engine of the one-sided intake / exhaust system, the oil cooler body can be arranged on the opposite side of the port, so that the cooling water in the water jacket is still affected by the heat of the exhaust manifold in the same manner as above. Therefore, the cooling of the oil can be effectively achieved.

Further, since the oil passage of the oil cooler body is formed by stacking uneven heat exchange plates, and the oil passages can be provided in multiple stages and arranged along the water flow direction, the flow resistance of the cooling water can be increased. There is no adverse effect on the capacity of the water pump due to the provision of the oil cooler body, and the heat exchange area can be increased, so that heat exchange between the cooling water and oil is achieved quickly and efficiently. can do.

Further, with the above structure, there is almost no heat conduction to the lower side of the cylinder liner, and the water jacket can be removed from the cylinder block. Therefore, when casting the cylinder block, the water jacket core can be eliminated, and the cylinder block Can be easily processed, the engine itself can be downsized, the weight can be reduced, and the manufacturing cost can be significantly reduced.

[Brief description of drawings]

1 is a sectional view showing an embodiment of an engine structure with a cooling device according to the present invention, FIG. 2 is an enlarged sectional view taken along line II-II of FIG. 1, and FIG. 3 is a conventional cooling device for an adiabatic engine. It is sectional drawing which shows an example. 1 ... Cylinder head, 2 ... Water jacket, 3 ... Cylinder liner, 4 ... Piston head, 5 ... Piston, 6 ... Cylinder line upper part, 7 ... Cylinder head lower surface part, 8 ... Cylinder block, 9 ... Insulation layer, 11 ...
... combustion chamber, 12 ... exhaust port, 13 ... intake port, 15 ...
… Oil cooler body, 16 …… heat exchange plate, 17 …… oil passage.

Claims (2)

[Scope of utility model registration request] 1. A piston head of each piston and a lower portion of each cylinder are formed into a heat insulating structure, and a cylinder head and an upper portion of each cylinder liner are integrally formed, and only the outer peripheral portion of the cylinder head and the upper portion of each cylinder liner is formed. An engine structure with a cooling device, wherein a cooling water passage is formed only in the outer peripheral portion of the cylinder head and an upper portion of each cylinder liner for cooling, and an oil cooler body is disposed in the cooling water passage. 2. The oil cooler body is disposed in a cooling water passage on the intake manifold side.
An engine structure with a cooling device according to.