JPS6065224A - Steam manifold in multi-cylinder internal-combustion engine of boiling-cooling type - Google Patents

Abstract

PURPOSE:To enable steam to be smoothly derived from a water jacket, by mounting a steam manifold to independently communicate its respective inlet port in each cylinder to the upper position of its water jacket and guiding the inlet port to an outlet port through a steam collector, in the case of an engine of boiling-cooling type. CONSTITUTION:A steam manifold 30 is mounted to the side end face of a cylinder head 11 through a mounting flange 31, and a respective inlet port 32 provided in each cylinder is independently communicated to a communication port part 17A in the upper position of an outer wall 16 of a main combustion chamber 15 and in a gas-phase refrigerant space in the upper of a water jacket 17 of the cylinder head 11. Then the inlet port 32, having a smooth curved wall, is communicated to a steam collector 33 in the upper position. Further an outlet port 35 is provided in an upper part in the vicinity of an almost central upper end in a longitudinal direction of the steam collector 33.

Description

[Detailed Description of the Invention] Technical Field> The present invention relates to a so-called boiling-cooled multi-cylinder internal combustion engine that uses the latent heat of vaporization of a refrigerant to cool cylinders and the outer wall of a combustion chamber. This invention relates to a steam manifold that guides boiling steam to the outside.

<Background Art> A boiling-cooled internal combustion engine is disclosed in Japanese Patent Publication No. 57-57608, for example, and will be explained with reference to FIG.

That is, the water jacket 2 of the engine 1 is filled with a liquid-phase refrigerant that occupies most of its volume, and the liquid-phase refrigerant is heat exchanged with the cylinders and boiled and vaporized to form steam (vapor). A phase refrigerant V) is generated.

After the generated steam is collected in the upper space within the cylinder head of the water jacket 2, it is led to the condenser 4 via the steam passage 3, where it is radiated heat, condensed, and returned to liquid refrigerant.

The liquefied refrigerant is passed through the refrigerant passage 5 to the feed pump 6
The water is then refluxed into the water jacket 2 again.

Such boiling cooling systems use the latent heat of vaporization of the refrigerant to cool the engine, so they have high cooling efficiency, and the condenser has excellent heat dissipation effects because it exchanges heat with the large temperature difference between high-temperature steam and the outside air. ing. Further, since the boiling of the refrigerant starts from the portions that are easily exposed to high temperatures, such as the walls of the combustion chamber, uniform cooling can be achieved.

For these reasons, boiling cooling allows the wall temperature of the combustion chamber to be as high as possible within a range that does not affect the durability and knock resistance of the material, resulting in extremely favorable results in terms of thermal efficiency. can be obtained.

By the way, in the refrigerant cycle of the evaporative cooling system that has such a characteristic effect, the steam passage 3 is pipe-shaped and is simply connected to the end of the cylinder head in the cylinder row direction, as shown in the figure. The actual situation is that the volume occupied by the vapor phase refrigerant is relatively small because it is configured to cover the wall that draws vapor to the outside from the outermost end of the seven layers of phase refrigerant and the wall of the combustion chamber.

Therefore, the steam generated from the water jacket part around the cylinder near the steam outlet is smoothly drawn into the condenser 4, but conversely, the steam generated in the water jacket part at the opposite end far from the steam outlet is transferred to the vapor phase refrigerant. 7 It becomes easy to stagnate in the 7th layer, and the heat dissipation of the stagnant steam cannot be done smoothly, resulting in cylinders that locally become hot.Especially when the diameter of the pipe for steam clearance is small, the synergistic effect of passage resistance Otherwise, there is a risk that parts of the water jacket 2 such as the exhaust port wall and the combustion chamber wall may become locally overheated.

<Objective of the Invention> In view of the above, an object of the present invention is to enable steam to be smoothly led out from the water jacket section for all cylinders.

<Structure of the Invention> In order to achieve the above object, the present invention provides a dedicated steam manifold, and allows the steam above the water jackets to stagnate through inlet boats formed to communicate independently above the water jackets of each cylinder. The steam manifold is configured so that the steam is smoothly guided and collected in a steam collector having a large capacity and therefore low passage resistance without any trouble, and the steam is smoothly guided to the outside from an outlet boat provided at the upper part of the steam collector.

<Example> Examples of the present invention will be described below based on FIGS. 2 to 4.

FIGS. 2(A) to 2(D) show the present invention applied to a multi-cylinder diesel engine, in which a cylinder head 11 is formed with an auxiliary combustion chamber 12 facing a glow plug and an injection valve, and the auxiliary combustion chamber The fuel injected into the cylinder head 12 is ignited by the compression action of the piston 13, and a flame enters the main combustion chamber 15 from the nozzle 14. The water jacket 17 in the cylinder head facing the outer wall 16 of the unburned chamber 15 passes through the communication passage 1B. It communicates with a water jacket 21 surrounding each cylinder wall 20 of the cylinder block 19 via the cylinder block 19 . The liquid phase refrigerant then fills the water jacket 21 of the cylinder block 19 and further flows through the lower part of the cylinder head 11. This covers the cylinder remains 20 and the outer walls 16 of each combustion chamber 15.degree. 12, which absorbs heat and boils and vaporizes. The boiling vapor collects in the gas phase refrigerant space above the water jacket 17. 26 in the figure
is the injection nozzle mounting hole, 27 is the glow plug mounting hole, 28
29 is an intake manifold, and 29 is an exhaust manifold.

On the other hand, on the side end surface of the cylinder head 11, a steam manifold 30 according to the present invention, which is cast at Atsube, is mounted on a mounting flange 31.
It is attached by fixing means such as bolting. A communication port portion 17A that is a phase refrigerant space in the steam manifold 30 and located above the outer wall 16 of the main combustion chamber 15
communicate with each other independently. The communication boat section 17A guides the steam in the gas phase refrigerant space of the water jacket 17 directly above, and then connects it to the inlet boat 3 of the steam manifold 30 to the clean car.
Each inlet boat 32 has an equal passage area and communicates with a steam collector 33 located at a higher level than the inlet boat 32 by a smooth convex wall.

Therefore, the steam in the water jacket 17 can be smoothly guided into the higher steam collector 33 in an approximately equal amount for each cylinder independently, so that the vapor phase refrigerant space above the water jacket 1f can be ventilated. It is effective to improve the properties and create a stagnation of steam.

In particular, since the steam collector 33 is located at a higher level than the inlet port 32, it provides a draining effect that causes droplets condensed in the steam collector 33 to flow through the inlet port 32 into the water jacket 17.

The steam collector 33 is formed of a generally cylindrical body extending parallel to the cylinder row, and both ends thereof are closed by Welch plugs 34. Therefore, its shape is compact, manufacturing is extremely easy, and furthermore, it is easy to layout near the intake manifold 28. An outlet port 35 is connected to the upper part of the steam collector 33, such as near the upper end in the center in the longitudinal direction. The passage area of the outlet boat 35 and the steam collector 330 is set to be sufficiently large.
The steam flows flowing in from each inlet port 32 are prevented from interfering with each other and causing steam to locally stagnate in the water jacket 17. The steam smoothly guided in this way passes through the outlet port 35 (not shown).
(see figure) is sent to the capacitor.

A water inlet 36 is provided at a portion of the upper end of the steam collector 33. For this reason, the steam manifold 30 is at the highest position in the cooling system, and the end face of the flange 37 from the water inlet 36 at its upper end is provided with a ring groove 38 for installing a sealing structure using an NO ring. Sealing performance can be ensured even if manufacturing precision is reduced, and air can be prevented from entering when the insides of the water jacket 17 and steam manifold 30 become negative pressure.

In the above embodiment, the outlet boat 35 is located approximately at the center of the steam collector 33 in the longitudinal direction. As a result, there is no need for a long distance from each inlet port 32 as in the prior art, that is, the ventilation resistance is averaged, and a substantially equal amount of steam can be extracted from each cylinder to the outside.

In that sense, from each inlet port 32 to the outlet boat 35
If it is necessary to further equalize the passage resistance leading to this, the longer the distance from the inlet port 32 to the outlet boat 35, the greater the passage area of the inlet port 32 or the shorter its length. An example thereof is shown in FIG. In this embodiment, the outlet port 35A is provided at the longitudinal end of the steam collector 33, but the inlet boat 32 and the outlet port 35A are
An example is shown in which the length of the inlet port 32 is shortened as the distance from the inlet port 32 is longer.

Furthermore, in the steam collector 33, increasing the passage cross-sectional area according to the steam flow rate reduces passage resistance. Therefore, as shown in FIG. 4, the cross-sectional area of the steam collector section through which the steam led only from a single inlet port 32B flows, is also different from the cross-sectional area of the steam collector section through which the steam led only from the single inlet port 32B flows, and the steam led from the other inlet port 32b in addition to the above steam flow joins. If the top wall of the steam collector 33A is inclined by α toward the outlet port 35 in order to increase the cross-sectional area of the steam collector portion, it is possible to equalize the steam flow flowing through the inlet ports 32a and 32b. In this case, smooth flow of steam along the ceiling wall can be promoted.

<Effects of the Invention> As described above, according to the present invention, each cylinder has a plurality of inlet boats each independently communicating with the gas phase cooling space above the water jacket, and a plurality of inlet boats arranged at a higher position. A steam manifold is provided, which includes a steam collector that collects steam flowing in from the inlet boat, and an outlet boat that guides the steam to the outside from the upper part of the steam collector. It is possible to prevent local stagnation of steam by drawing an equal amount of steam to the outside. This makes it possible to generate vapor from the liquid phase refrigerant uniformly in each cylinder, preventing local overheating of the cylinder wall and combustion chamber wall, and preventing thermal deformation and damage to the cylinder head. In addition to this, together with the smooth induction of steam, the cooling performance of the engine can be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic system diagram showing a conventional example of a boiling-cooled multi-cylinder internal combustion engine, Fig. 2 shows an embodiment of the present invention, (A) is a longitudinal cross-sectional view, and (B) is the same as that used in the above. A side view of the steam manifold alone, (C) is a cross-sectional view taken along the line C-C in (B), (D) is a cross-sectional view of the outlet port section in (B), Figures 3 and 4.
Each figure is a side view of a single steam manifold showing other embodiments of the present invention. 11...Cylinder head 17.21...Walker 35,35A...Proport patent applicant Fujio Sasashima, patent attorney representing Nissan Motor Co., Ltd.

Claims (1)

[Claims] A steam manifold that is connected to the cylinder head of a boiling-cooled multi-cylinder internal combustion engine and draws boiling vapor of refrigerant to the outside from above the water jacket, and is connected to the above water jacket of each cylinder independently according to the number of cylinders. It is characterized by having an inlet boat, a steam collector that communicates with the inlet port and is arranged at a higher level than the inlet port to collect steam, and an outlet port that guides the steam to the outside from the upper part of the steam collector. Steam manifold of boiling-cooled multi-cylinder internal combustion engine.