JP2526037Y2 - Cylinder head cooling structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cooling structure for a cylinder head in an insulated engine.

[Conventional technology]

Conventionally, a cooling device for an internal combustion engine is disclosed in, for example, Japanese Utility Model Laid-Open No. 55-76422. The cooling device for an internal combustion engine has a cylinder head of the engine, in which three members of an intake valve portion, an exhaust valve portion, and a fuel valve insertion portion are formed in a triangular arrangement, and a Y-shaped member is formed between the three members. A lubricating oil passage is formed, and a part of the lubricating oil of the engine passes through an oil cooler, first passes through a passage located in the inter-valve portion of the Y-shaped lubricating oil passage, and then branches off from the other two passages. In such a way as to flow along the course.

[Problems to be solved by the invention]

By the way, in an adiabatic engine, there are two main factors that cause a reduction in the suction efficiency in the suction process. One is that the intake air expands due to the heat received in the intake passage, that is, the intake port, and becomes difficult to be introduced into the combustion chamber. The other is that the air introduced by the heat reception from the inner wall of the cylinder, that is, the wall of the combustion chamber expands, and the air is not subsequently introduced.

In the adiabatic engine, when the cooling liquid jacket formed on the cylinder head is abolished and the outer wall of the exhaust port and the lower surface of the head of the cylinder head are configured to have an adiabatic structure, the temperature of the entire cylinder head in the insulated engine is generally Temperature of the cylinder head of a water-cooled engine with a water jacket formed on the typical cylinder head, the temperature of the intake port rises, and the air expands at the hot intake port and enters the combustion chamber. It becomes difficult to enter and the inhalation efficiency decreases. Therefore, in the heat-insulated engine, there is a problem how to configure the structure of the heat-insulated engine to improve the suction efficiency in the engine suction process.

The purpose of this invention is to solve the above-mentioned problems, and in an insulated engine, eliminate the cooling jacket formed on the cylinder head, eliminate the need for a core when casting the cylinder head, reduce the weight, simplify the structure, The manufacturing cost is reduced, and the wall of the exhaust port and the lower surface of the cylinder head are formed in an adiabatic structure to reduce the heat effect on the intake port and control the temperature rise of the intake port. Is formed by casting from a material such as normal FC, Al, etc., and intake / exhaust valves provided on the cylinder head, rocker arms that operate the intake / exhaust valves, and oil that lubricates sliding parts of various members such as camshafts are taken in by oil. Cylinder head in an insulated engine that cools the wall of the port, blocks intake air from receiving heat from the intake port, suppresses air expansion, and improves intake efficiency. To provide a cooling structure.

[Means for solving the problem]

This invention is configured as follows to achieve the above object. That is, the present invention does not provide a cooling jacket on the cylinder head, at least the lower surface of the head and the upper part of the cylinder liner are configured in a heat insulating structure, and cooling oil injection means is provided above the intake port and near the inlet of the intake port, Oil for lubricating sliding portions of various members disposed above the cylinder head is caused to flow down along the outer wall surface of the intake port to cool the intake port and to forcibly inject from the cooling oil injection means. A cooling mechanism for cooling the cylinder head in an adiabatic engine, wherein the cooling oil cools the intake port, and the oil flows down to an oil reservoir through an oil passage formed in the cylinder head and the cylinder block. About.

[Action]

The cylinder head cooling structure according to the present invention is configured as described above, and operates as follows. That is, the cooling structure of the cylinder head has a heat insulating structure at least on the lower surface of the head and the upper portion of the cylinder liner, and supplies oil for lubricating rocker arms, cams, intake and exhaust valves located above the cylinder head to the intake port of the cylinder head. Flow down along the outer wall of the intake port, the intake port can be cooled quickly, heat reception from the exhaust port can be eliminated, intake air can suppress heat reception from the intake port, and reduction in intake efficiency can be reduced. Does not happen.

After the cooling of the intake port, the oil flows from an oil passage inlet provided in the cylinder head into an oil passage formed in the cylinder head, and then flows through an oil passage formed in the cylinder block to an oil sump such as an oil pan. be able to.

Further, since the cooling oil injection means is provided above the intake port and near the inlet of the intake port, when the cooling state of the intake port is insufficient, the cooling oil injection means is operated to perform the cooling oil injection. The intake port can be forcibly cooled by the oil or the oil jet forcibly injected from the means, and the amount of heat received from the intake port by the intake air can be minimized, so that the intake efficiency can be improved.

〔Example〕

Hereinafter, an embodiment of a cooling structure for a cylinder head in an insulated engine according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a cooling structure for a cylinder head according to the present invention. In the cylinder head cooling structure according to the present invention, the cylinder head 10 is attached to the cylinder body or the cylinder block 1 in which the cylinder 11 is formed.
Is fixed, and the cylinder liner 3 is fitted to the inner peripheral surface of the cylinder 11 formed in the cylinder block 1. The cylinder block 1 is made of a casting such as aluminum or iron. The cylinder liner 3 is made of silicon nitride (Si
₃ N ₄ ) and ceramics such as silicon carbide (SiC).

Further, the cylinder liner 3 can be configured as a wet type, that is, a cooling liquid jacket 4 for the cylinder line 3 can be formed above the cylinder block 1.
The cooling liquid jacket 4 forms a liquid passage through which a liquid such as cooling water or cooling oil flows.

The cylinder head 10 does not include a cooling liquid jacket, and is provided so that the intake port 2 and the exhaust port 6 are provided upright. In other words, the intake port 2 and the exhaust port 6 are formed in a structure in which the air layer 34 exists between the intake port 2 and the upper surface of the cylinder head 10. Although not shown, when the engine is a diesel engine instead of a catholine engine, the cylinder head is, of course, formed with a combustion injection nozzle port for mounting a fuel injection nozzle.

The intake port 2 and the exhaust port 6 have an intake / exhaust valve 7
(Only the exhaust valve is shown in the figure), and the intake / exhaust valve 7 is provided so as to reciprocate the valve guide 19 of the cylinder head 10. A head cover 12 is attached to an upper portion of the cylinder head 10, and a plurality of cams 31 provided on a cam shaft 13, a rocker arm 14, and a space formed by the upper surface of the cylinder head 10 and the head cover 12.
A valve operating mechanism including a valve spring 16, a valve spring receiver 17, and the like is provided.

To constitute the valve operating mechanism, the intake and exhaust valve 7 is attached by a cotter 18, a valve spring receiver 17 and a valve spring 16 attached to the upper end of the valve stem of the intake and exhaust valve 7. These intake / exhaust valves 7 are provided with rocker arms 14 pivotally mounted on a cylinder head 10.
And reciprocating motion by the operation of the cam 31 for rocking the rocker arm 14.

In the cooling structure of the heat-insulating engine, at least the lower surface of the cylinder head 10 and the exhaust port 6 are formed in a heat-insulating structure. That is, a cylinder portion 29 is formed in the cylinder head 10, and a head liner 30 in which the head lower surface portion 8 and the cylinder liner upper portion 9 are integrally formed is provided on the cylinder portion 29. It is fitted via a heat insulating ring 21. Headliner 30 and cylinder head 10
A heat-insulating air layer 22 is formed between them. Headliner 30 constitutes a wall surface exposed to the fuel gas forms a combustion chamber 20, silicon nitride (Si ₃ N _4), and a ceramic such as silicon carbide (SiC). The exhaust port 6 is formed by attaching a liner 24 made of stainless steel exposed to exhaust gas to the cylinder head 10 with a heat insulating material 25 interposed.

The cylinder head cooling structure according to the present invention has the following features in the cylinder head 10 having the above structure. A valve operating mechanism including a cam 31, a rocker arm 14, a valve spring 16, a valve spring receiver 17, and the like provided on a cam shaft 13 provided above the cylinder head 10 includes a lubricating oil supply unit ( (Not shown). An oil passage inlet 27 is formed on an outer surface of the cylinder head 10, and an oil passage 5 communicating with the oil passage inlet 27 is formed on a lower surface of the cylinder head 10.

Further, an oil passage 15 communicating with the oil passage 5 of the cylinder head 10 is formed in the cylinder block 1. The oil passage 15 is opened at the lower end of the cylinder block 1, and the oil that has passed through the oil passage 15 flows down to an oil reservoir 28 such as an oil pan of a crankcase.

Further, in the cylinder head 10, cooling oil injection means 26 including an oil pump or the like is provided above the intake port 2 and near the inlet of the intake port 2. The oil outlet 33 of the cooling oil injection means 26 opens on the outer wall surface of the intake port 2. Although not shown, on the outer wall surface of the cylinder head 10 forming the intake port 2,
A guide plate or a fin for guiding oil is provided so that the oil flows down only on the outer wall surface of the intake port 2.

Further, the guide means such as the guide plate, the fins, and the oil passages have a function of causing the same cooling oil as the lubricating oil jetted from the cooling oil jetting means 26 to flow uniformly to the outer wall surface of the intake port 2. Of course, guide means such as guide plates and fins can perform a cooling function by contacting air. Normally, the amount of lubricating oil is about 1/3 of 50 l / min, but it goes without saying that the amount of oil can be appropriately adjusted.
The oil cooler that cools the lubricating oil is usually air-cooled.

Since the cooling structure of the cylinder head in the insulated engine according to the present invention is configured as described above, the lubricating oil that lubricates the valve operating mechanism provided above the cylinder head 10 flows along the outer wall surface of the intake port 2. The lubricating oil is directly and quickly cooled down, and the lubricating oil is introduced into the oil passage 5 of the cylinder head 10 from an oil passage inlet 27 formed in the cylinder head 10, and then the oil passage of the cylinder block 1 is cooled. It flows down to oil pool 28 such as an oil pan through 15. If the cooling of the intake port 2 with the lubricating oil is insufficient, the oil pump of the oil injection means 26 is operated to eject the same kind of oil as the lubricating oil, that is, the cooling oil. 2 to flow down along the outer wall surface, whereby the intake port 2 can be forcibly and quickly cooled.

[Effect of the invention]

The cooling structure of the cylinder head in the heat insulating engine according to the present invention is configured as described above, and has the following effects. In other words, the cooling structure of this cylinder head has at least the lower surface of the head and the upper portion of the cylinder liner in an adiabatic structure, and oil for lubricating sliding parts of various members disposed above the cylinder head is applied to the outer wall surface of the intake port. The intake port can be cooled quickly and directly because the oil flows down along the cylinder head and the oil passage through the passage formed in the cylinder block. In addition, since the intake port blocks the amount of heat received from the exhaust port and the like, and the wall surface of the intake port does not become hot, it is possible to prevent intake air from receiving heat from the intake port.

Therefore, there is no phenomenon that the intake air expands, and the intake efficiency does not decrease. The oil can flow through an oil passage formed in the cylinder head through an oil inlet provided in the cylinder head, and then flow down to an oil reservoir such as an oil pan through an oil passage formed in the cylinder block. Next, the oil is circulated again from the oil reservoir by a normal oil circulation system for lubricating the valve mechanism and cooling the intake port.

Further, since the cooling oil injection means is provided above the intake port above the cylinder head and near the inlet of the intake port, if the cooling state of the intake port by oil is insufficient, the cooling oil The oil pump of the injection means is operated, and the wall surface of the intake port can be quickly and forcibly cooled by the oil, that is, the oil jet, which is forcibly and quickly injected from the cooling oil injection means. The amount of heat received from the intake air can be minimized, and the expansion phenomenon of the intake air does not occur, so that the intake efficiency can be improved.

Further, since no liquid jacket is formed on the cylinder head, a core for forming the jacket is not required when casting the cylinder head, so that the cylinder head can be manufactured easily and at low cost. In addition, the structure of the cylinder head itself can be simply formed, and, for example, a guide plate, a fin, an oil passage, etc., for guiding the flow of oil on the cylinder head wall forming the intake port can be easily formed. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a cooling structure for a cylinder head in an insulated engine according to the present invention. 1 ... Cylinder block, 2 ... Intake port, 3 ... Cylinder liner, 5,15 ... Oil passageway, 8 ... Head lower part, 9 ... Cylinder liner upper part, 10 ... Cylinder head, 26 ... Oil Injection means, 28 ... Oil pool.

Claims (1)

(57) [Scope of request for utility model registration] 1. A cooling oil injection means, wherein at least a lower surface of a head and an upper portion of a cylinder liner are formed in a heat insulating structure without providing a cooling jacket for a cylinder head, and cooling oil injection means is provided above an intake port and near an inlet of the intake port. Oil for lubricating sliding portions of various members disposed above the cylinder head is caused to flow down along the outer wall surface of the intake port to cool the intake port, and is forcibly injected from the cooling oil injection means. A cooling structure for cooling the cylinder head in an adiabatic engine, wherein the intake port is cooled by oil, and the oil flows down to an oil reservoir through an oil passage formed in the cylinder head and the cylinder block.