JPS6023455Y2 - Internal combustion engine exhaust manifold water cooling system - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of the exhaust manifold water cooling system for internal combustion engines, which allows for good water flow from the cylinder head to the exhaust manifold during engine operation, and improves the flow of water from the cylinder head to the exhaust manifold during engine operation. The aim is to improve drainage from the area.

By the way, when cooling the exhaust manifold with cooling water, a water hole is provided at the joint surface between the exhaust manifold and the cylinder head to communicate the cooling water jackets of both, so that the cooling water that has cooled the cylinder head flows to the exhaust manifold. It is now being supplied.

However, if only the water passage is considered, it is preferable that the water passage hole from the cylinder head to the exhaust manifold is located as high as possible, but if the cooling water extraction is considered,
It is advantageous to provide the exhaust manifold as low as possible because the cooling water remaining in the exhaust manifold can flow back toward the cylinder head and be extracted, and there is no need to provide a dedicated drain hole in the manifold.

The present invention takes into consideration the above-mentioned flexible shield for the water passage hole between the exhaust manifold cooling device and the cylinder head, and improves both the water passage to the exhaust manifold side and the drainage from the side. Therefore, the water passage hole is divided into two parts, upper and lower, and the passage cross-sectional area of the lower water passage hole is made smaller than the deflection of the upper water passage hole.

Hereinafter, an embodiment shown in the drawings will be described in detail.

In the figure, 1 is a cylinder head of an internal combustion engine, which has a cooling water jacket 2, and 3 is an exhaust manifold joined to the side surface of the head, which also has a cooling water jacket 4.
has.

On the joint surface between the cylinder head 1 and the exhaust manifold 3, in order to communicate the cooling water jackets 2 and 4 of both, there are multiple sets of water holes 5 and 6, each consisting of two upper and lower holes, as necessary. It is provided.

However, it is assumed that the passage area of the lower water passage hole 6 is smaller than that of the upper water passage hole 5.
For this purpose, it is not necessarily necessary to make the hole diameter of the water passage hole 5 small, and as long as it is substantially small, it is sufficient.

Therefore, when the cylinder head 1 and the exhaust manifold 3 are made of cast metal, the respective sand removal holes are connected to the above-mentioned water passage holes 5.
, 6, the diameter of the sand removal hole cannot be made very small, so for the lower water passage hole 6,
The following measures will be taken:

That is, the sand removal hole 6a on the cylinder head side and the sand removal hole 6b on the exhaust manifold side, which constitute the lower water passage hole 6, are formed in advance with their respective positions shifted, and the exhaust manifold 3 is joined to the cylinder head 1. 7. Both sand removal holes 6a,
Care is taken that the passage cross-sectional area of the water passage hole 6 constituted by 6b is much smaller than that of each trick hole.

Note that 7 in the figure indicates a plurality of exhaust gas inlets provided in the exhaust manifold 3, which communicate with an exhaust gas outlet 9 via an exhaust gas passage 8, and 10 indicates a cooling water jacket 4 and a cooling water jacket 4 in the exhaust manifold 3. The expansion tank is formed in series and generally has a cooling water outlet 11,12.

In the above configuration, if the internal combustion engine is currently being operated, the cooling water that has been supplied to the cooling water jacket 2 of the cylinder head 1 will flow from the jacket to the water passage hole 5.
, 6 into the cooling water jacket 4 of the exhaust manifold 3, cooling the manifold and collecting in the expansion tank 10.

However, in this case, the water flow between the jackets 2 and 4 is because the cross-sectional area of the lower water passage hole 6 is at least substantially smaller than that of the upper water passage hole 5. This is mainly carried out through the upper water passage hole 5.

Therefore, water can flow from the cylinder head 1 side to the exhaust manifold 3 side well, and highly concentrated cooling water does not stay in the upper part of the cooling water jacket 2 in the former case.

Additionally, if you open the drain hole (not shown) provided at the lowest point of the cooling water system to drain the cooling water from the entire internal combustion engine,
The cooling water remaining in the cooling water jacket 4 of the exhaust manifold 3 and the expansion tank 10 connected thereto is discharged through the outlet 12.
Although some of the water is also discharged from the cooling water jacket 2 of the cylinder head 1, most of it flows back into the cooling water jacket 2 of the cylinder head 1 and is discharged through the jacket.

However, since there is a lower water passage hole 6 between both jackets 2 and 4, even though the passage cross-sectional area is small, the above-mentioned backflow of cooling water is mainly performed through the lower water passage hole 6, and the exhaust gas is No cooling water remains on the manifold 3 side.

As described above, the present invention provides a pair of upper and lower water holes that communicate the cooling water jackets of both at the joint between the cylinder head and the exhaust manifold. According to the present invention, the cooling water jacket on the cylinder head side and the cooling water jacket on the exhaust manifold side are In between, it is possible not only to improve water flow from the former to the latter during engine operation, but also to improve drainage from the latter through the former when cooling water is removed, and especially to the exhaust manifold side. Effects such as no need to provide a drain hole can be expected.

[Brief explanation of drawings]

Fig. 1 is a cutaway plan view showing an embodiment of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is the same <B-B.
FIG. 4 is a sectional view taken along the line C--C in FIG. 2. 1... Cylinder head, 3... Exhaust manifold, 2, 4... Cooling water jacket, 5,
6... Water hole.

Claims (1)

[Scope of utility model registration request] At the joint between the cylinder head and the exhaust manifold, water holes are provided as a set of two (upper and lower) to communicate between the cooling water jackets of both of them, and the passage cross-sectional area of the lower water hole is higher than that of the upper one. An exhaust manifold water cooling device for an internal combustion engine, characterized in that the water cooling device is at least substantially smaller than the passage cross-sectional area of the water passage hole.