JPS587076Y2 - internal combustion engine cylinder head - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to improvements in cylinder heads for internal combustion engines.

Conventionally, the intake valve seat installed in the cylinder head to send intake air from the intake port into the combustion chamber of an internal combustion engine is subject to extremely high wear, so a special metal valve seat is fitted or cast into the cylinder head. Some have a lubricating device installed on the suction valve seat, but all have the disadvantage of increasing manufacturing costs.

On the other hand, in recent years, nitrogen oxide NOx, which is generated when the combustion gas temperature of internal combustion engines is high, causes pollution such as smog, so in order to reduce the concentration of NOx generated, a part of the engine's exhaust gas is pumped into the intake air. Some use a method of reducing the combustion temperature of the engine by reducing it and re-burning it in the combustion chamber with fresh intake air.

That is, as a method similar to the above, in conventional petroleum engines,
There is an idea to provide a communication hole that communicates from the exhaust port side of the cylinder head to the intake port side, but in this idea, the exhaust port side is opened along the exhaust gas flow, but the intake port side is opened along the intake air flow. It opens to face the.

Furthermore, since the purpose of this invention is to mix a portion of the exhaust gas from the petroleum engine into the intake air at a certain appropriate time to increase the intake air temperature, nozzles are required at both ends of the communication hole.

Therefore, it is difficult to attach and support the nozzle to the cylinder head and to process the communication holes, which increases manufacturing costs and reduces productivity. The disadvantage is that there is a risk of it falling off.

Also, since the exhaust gas is passed through the communication hole, it is inevitable that unburned wood particles will adhere to the inside of the communication hole, so it is necessary to clean the communication hole at an appropriate time, but due to its structure, cleaning cannot be done easily. There are also maintenance problems.

Also, since the nozzle protrudes from both ends of the communication hole, suction and
It has the disadvantage that it acts as a resistance to the exhaust flow, causing noise, and that it requires a complicated arrangement because there are intake and exhaust valves, etc. around it.

There is also an idea in which a control valve is disposed in a communication hole that communicates the intake passage and the exhaust hole, but this has the disadvantage that the control valve is installed in a narrow space, which reduces productivity and increases manufacturing costs.

Furthermore, since the communication hole is orthogonal to the intake passage and the exhaust hole, it cannot be bored from the direction of the intake passage or the outlet of the intake hole, and its machining is troublesome.

Further, oil in the exhaust gas tends to adhere to the wall surface of the intake passage, and there is a drawback that it is difficult to apply the oil to the intake valve seat.

The object of the present invention is to provide a cylinder head for an internal combustion engine that does not have the above-mentioned drawbacks.

That is, the present invention provides a cylinder head for an internal combustion engine in which an intake port and an exhaust port are communicated through a communication hole.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings, in which the communication hole is formed by an inclined linear hole extending from the outlet of the exhaust port to the valve seat opening of the intake port.

Fig. 1 is a vertical cross-sectional view of the main part of the cylinder head in Embodiment 1 of the present invention, Fig. 2 is a cross-sectional view of a part of the main part of the cylinder head in Fig. FIG. 4 is a longitudinal sectional view of the main part of the cylinder head in the second embodiment, and FIG. 4 is a longitudinal sectional view of the main part of the cylinder head in the third embodiment.

First, as shown in FIG. 1, a communication hole 4 is provided between the intake port 1 and the exhaust port 2 in the cylinder head 6.

The opening end of the communication hole 4 on the intake port 1 side is provided along the flow A of intake air, and the opening end on the exhaust port 2 side is provided along the flow B of exhaust gas.

In this case, the communication hole 4 is provided obliquely with respect to the axial direction of the cylinder head 6 so that it can be bored from the valve seat opening 7 of the intake port 1 or the gas outlet 5 of the exhaust port 2.

Therefore, part of the exhaust gas in the exhaust port and the exhaust silencer that passes through the communication hole 4 during intake flows toward the intake valve seat, thereby applying oil in the exhaust gas to the intake valve seat.

Furthermore, since the exhaust gas is mixed into the combustion mixture, the combustion temperature decreases and the concentration of NOx decreases.

On the other hand, during exhaust, part of the fresh air passing through the communication hole 4 is mixed into the exhaust gas, reducing the concentration of black smoke.

Moreover, the communication hole 4 is cleaned by the fresh air, and the adhesion of oil, etc. is prevented.

Note that in the case where the exhaust port is insulated, a portion of the fresh air from the intake port is mixed into the exhaust gas, causing the exhaust gas to be re-burned and the amount of unburned products to be reduced.

Next, as shown in the cross-sectional view of part of the cylinder head in Fig. 2, the bosses of the communication holes 4 are used to connect the valves of the intake port 1 and the exhaust port 2 so that the area between the valves does not become over-walled. The communication hole 4 is installed away from the center line.

This is effective in preventing overheating of the portion between the valves in the cylinder head 6.

In this case, the communication hole 4 may be provided either on the side closer to or farther from the combustion chamber boss 3 from the center line connecting the two valves.

In Embodiment 2 shown in FIG. 3, the same parts as in Embodiment 1 shown in FIG. In order to facilitate the drilling in the case of drilling from the outside, a seat 8 is provided on the main body of the cylinder head 6 at the opening portion of the communication hole 4 on the exhaust port 2 side.

At the exhaust port 2, this seat 8 does not act as a resistance to the flow of exhaust gas.

Furthermore, in the third embodiment shown in FIG. 4, the first embodiment shown in FIG.
The same parts are indicated by the same part numbers, but the difference is that a cooling water hole 9 is provided below the communication hole 4.

By providing the cooling water holes 9, the installation of the communication holes 4 can be prevented from interfering with cooling the area between the valves.

As described above, the present invention provides a cylinder head for an internal combustion engine in which an intake port and an exhaust port are communicated with each other through a communication hole, and the communication hole is formed in an inclined straight line from the outlet of the exhaust port to the valve seat opening of the intake port. Since the communicating hole is formed by drilling, the manufacturing process is very easy because the communicating hole can be formed by drilling from the outlet side of the exhaust port side toward the valve seat opening side of the intake port.

Furthermore, since special devices and parts such as valves are not required, the structure is extremely simple and maintenance and inspection are easy.

Furthermore, since the communication hole opens on the inner wall surface of the intake port and faces the valve seat opening, the oil contained in the exhaust gas can be applied to the intake valve seat without increasing the resistance of intake air. be able to.

Note that, if desired, the communication hole may be formed from the valve seat opening of the intake port to the outlet of the exhaust port.

Also, by tapering one or both of the opening ends of the exhaust port and intake port of the communication hole, when actively guiding exhaust gas, fresh air can be actively mixed into the exhaust gas. It has the advantage that it can be freely adjusted depending on the purpose, such as when

Furthermore, compared to similar conventional designs, the present invention has a simpler structure, does not require special equipment or parts, and is easier to process, resulting in lower manufacturing costs, increased productivity, and improved reliability. It has the advantage that it is not only effective, but also easy to maintain and does not cause noise as there are no protrusions in the fluid.

The present invention is mainly effective for cylinder heads of internal combustion engines having intake and exhaust valves.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a vertical sectional view of the main part of the cylinder head in Embodiment 1 of the present invention, and Fig. 2 is a partial I-I of the main part of the cylinder head in Fig. 1 above. The sectional view, FIGS. 3 and 4 are longitudinal sectional views of the main parts of the cylinder head in another embodiment. 1...Intake port, 2...Exhaust port, 4...Communication hole, 6...Cylinder head, 7. Bend/valve seat opening, 8 ...Seat, 9...Water hole between valve.

Claims (1)

[Scope of utility model registration request] A cylinder head for an internal combustion engine in which an intake port and an exhaust port communicate with each other through a communication hole, characterized in that the communication hole is formed by an inclined linear hole extending from the outlet of the exhaust port to the valve seat opening of the intake port. cylinder head of an internal combustion engine.