JPS6214340Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to the engine cylinder head.
The main purpose is to sufficiently cool the comparatively thick portion of the wall facing the combustion chamber of the cylinder head that stores a large amount of heat, thereby eliminating the occurrence of thermal strain, thermal cracks, etc.

For example, in a forced water-cooled diesel engine having an auxiliary combustion chamber, the auxiliary combustion chamber 1 and both intake and exhaust ports 2 and 3 are arranged in a triangle with respect to the main combustion chamber 4, as shown in FIG. , the respective peripheral walls gather near the center of the three to form a thick wall portion. Conventionally, in order to cool this thick part, a three-pronged waterway 5 was used.
was established. However, in this case, since the water channel 5 is narrow, it is not possible to allow the necessary and sufficient amount of cooling water to pass through it, and as time passes, water scales and the like adhere to the water channel 5, resulting in a reduction in cooling capacity.

This idea solves the above problems by making it possible to sufficiently cool the thick heat storage section.The heat pipe has high heat conduction efficiency and can transfer large amounts of heat. It is characterized by sufficient heat dissipation.

Examples of this invention will be described below based on the drawings.

FIG. 2 is a longitudinal cross-sectional view of a main part of the forced water-cooled diesel engine, and FIG. 3 is a cross-sectional view taken along the line shown in FIG. 2.
In the figure, a cylinder jacket 12 is formed inside a crankcase 10 so as to surround a cylinder 11, and a radiator 13 is disposed so as to close the upper opening of the cylinder jacket 12. Further, inside the cylinder head 14 mounted on the side wall of the crankcase 10, a head jacket (cooling fluid passage) 15 is formed which communicates with the cylinder jacket 12 described above. 16
1 is a piston, 17 is a valve train, and 18 is a fuel injection nozzle.

As shown in FIG. 3, inside the cylinder head 14, an intake port (chamber) 21 and an exhaust port (chamber) 22, which are opened and closed by an intake valve 19 and an exhaust valve 20, are arranged on the left and right sides, and there are An auxiliary combustion chamber (chamber) 23 is arranged at the upper center of the combustion chamber. The partition walls 21a, 22a, 23a which partition the intake and exhaust ports 21, 22 and the auxiliary combustion chamber 23, respectively, are assembled at adjacent portions to form a trident-shaped thick wall. .

This thick wall, that is, the heat storage part H has a groove 3 for guiding cooling water on the inlet 29 side of the cooling water passage 15.
1 is recessed, and the cooling water near the heat storage section H is guided to the exit 30 side of the cooling water passage 15 by this groove 31. Further, a heat pipe P is provided in the groove 31 so as to extend between the inside of the wall of the heat storage section H and the cooling water passage 15. As shown in FIG. 4, the heat pipe P has a stainless steel airtight container 24 lined with a metal felt wick 25.
This wick 25 is impregnated with a working fluid such as ammonia or methanol. One end of the heat receiving part 26 is located within the wall of the heat storage part H, and the other end of the heat radiating part 27 faces the head jacket 15.

As described above, when the heat pipe P is embedded in the heat storage section H, the heat of the heat storage section H is transferred from the heat receiving section 26 into the heat pipe P, and the working fluid is evaporated. Then, this steam moves at high speed within the closed container 24 toward the heat radiating section 27, condenses there, becomes liquefied, and is returned to the heat receiving section 26 by the capillary action of the wick 25. In this operation cycle, the latent heat absorbed by the working fluid during evaporation is radiated from the heat radiating section 27 to the cooling water during condensation, so that the heat storage section H is sufficiently cooled and the occurrence of thermal strain and thermal cracks can be eliminated.

Note that two or more heat pipes P may be arranged in the heat storage section H.

As explained above, in this invention, a heat pipe is provided in the groove recessed in the heat storage part of the cylinder head, and the heat dissipation part of this heat pipe is made to protrude toward the entrance of the cooling water passage. The heat dissipating section of the heat pipe can be powerfully cooled by the low-temperature cooling water that enters from the inlet, and the heat dissipating section of the heat pipe can also be powerfully cooled while a large amount of cooling water is collected in the grooves and flowing.

Therefore, the large amount of heat transferred from the combustion chamber to the heat storage section can be efficiently radiated from the heat radiating section of the heat pipe, and moreover, using a large amount of cooling water.
The heat storage section is sufficiently cooled. This makes it possible to reduce the temperature gradient between the heat storage section and other parts, eliminating the occurrence of thermal distortion and thermal cracking, and also increasing the thermal load on the cylinder head, allowing the engine to run at higher speeds and with higher compression ratios. can be realized, and its output performance can be further improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a cylinder head showing a conventional example, Figs. 2 to 5 show an embodiment of this invention, Fig. 2 is a longitudinal sectional view of an engine, and Fig.
FIG. 4 is a sectional view showing a schematic structure of a heat pipe. 14...Cylinder head, 15...Cooling fluid passage (head jacket), 21...Intake port,
22...Exhaust port, 23...Sub-combustion chamber, 21
a, 22a, 23a... section walls of 21, 22, 23, H... heat storage section, P... heat pipe, 26...
...Heat receiving section, 27... Heat dissipating section.

Claims (1)

[Scope of utility model registration request] An intake port 21, an exhaust port 22, and an auxiliary combustion chamber 23 are arranged in a triangular shape within the cylinder head 14,
The wall facing the main fuel chamber 28 of the cylinder head 14 and the partition walls of the above-mentioned chambers that are continuous with this wall form a trifurcated thick-walled heat storage section H, and a cooling water passage 15 formed in the cylinder head 14 is formed. The heat storage part H between the intake port 21 and the exhaust port 22 is connected to the inlet 2 of the cooling water passage 15.
At the same time, a groove 31 for guiding cooling water is provided in the heat storage section H, and the heat pipe P is inserted into the groove 31 across the wall of the heat storage section H and the cooling water passage 15. The heat receiving part 26 of the heat pipe P
A cylinder head of an engine, which is located in a heat storage part H and has a heat radiation part 27 protruding toward an inlet 29 of a cooling water passage 15.