JPS6335128Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a cylinder head for an internal combustion engine.

[Prior art]

In the case of a cylinder head of an internal combustion engine, for example, a counterflow type cylinder head in which the intake/exhaust boat opens on the peripheral side end face of the cylinder head, a blow-by gas relief port is opened on the peripheral edge on the side where the intake/exhaust manifold is connected. There is. An oil return port is further opened on the top surface of such a cylinder head for returning oil to the oil pan after lubricating the cylinder head mounting hole, valve mechanism, etc.

Some of these cylinder heads are designed to prevent oil from flowing into the blow-by gas relief port and preventing the flow of oil and blow-by gas from interfering with each other as much as possible. Some devices have a partition wall protruding from the top surface that surrounds the blow-by gas vent.

[The problem that the idea attempts to solve]

However, even with this partition wall, when a large amount of oil circulates, such as during high-speed, high-load operation, or when oil return is poor, such as immediately after a cold start, the oil may overflow the partition wall and flow into the blow-by gas relief port. Conventionally, the height of the upper end face of the partition wall surrounding the blow-by gas relief port was the same over its entire periphery, so that the oil flows over almost the entire periphery of the partition wall into the blow-by gas relief port and tries to flow down along almost the entire periphery of the inner wall, which makes the effective opening area of the blow-by gas relief port extremely small, and this tends to hinder the smooth return of oil and the smooth discharge of blow-by gas.

In particular, when oil flows into the blow-by gas relief port from almost the entire circumference of the partition wall, the oil must directly collide with the blow-by gas and flow into the relief port. The height will be much higher than the height of the partition wall. If the oil level above the cylinder head becomes higher, the amount of oil splashed here will increase, resulting in an increase in the amount of oil carried away.Also, the amount of oil in the oil pan will decrease, causing air This can cause various problems such as suction of water.

[Means to solve the problem]

In order to solve the above problems, the present invention has a blow-by gas relief port opened on the top surface of the cylinder head, and a partition wall that protrudes from the top surface of the cylinder head and surrounds the blow-by gas relief port. In the cylinder head of an internal combustion engine, the partition wall is formed with a low part lower than the partition wall and protruding from the upper surface of the cylinder head in a part of the circumferential direction for regulating the direction of oil inflow. be.

[Effect]

With this configuration, the oil flowing from the blow-by gas vent flows only from the lower part of the partition wall surrounding the blow-by gas vent, and the amount of oil flowing in is regulated.

The oil flowing only from the lower part flows down the wall surface of the blow-by gas vent and does not block the blow-by gas vent.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 is a cylinder head, and in the embodiment, an intake port 2 and an exhaust port 3 are shown.
This is for a counterflow type inline 4-cylinder engine in which the cylinders are opened on the same side end face. A projecting edge 1a is formed on the peripheral edge of this cylinder head 1,
Oil that has been used to lubricate a valve train (not shown) and the like is stored on the cylinder head 1 at a certain height.

One blow-by gas escape port 5 and two oil return ports 6 are opened on the upper surface of the cylinder head 1 along the direction in which the combustion chambers 4 are arranged, each near the end surface 1b on the intake/exhaust manifold connection side. A total of ten cylinder head mounting holes 7 are opened on the upper surface of the cylinder head 1, five of which are located on the side facing the intake/exhaust manifold and spaced apart in the direction in which the combustion chambers 4 are arranged. The remaining five are located on the end face 1c side opposite to the intake/exhaust manifold connecting end face and are spaced apart in the arrangement direction of the combustion chambers 4.

One of the cylinder head mounting holes 7 located on the intake/exhaust manifold connection end surface 1b side 7A
is provided at a position inward of and close to the blow-by gas relief port 5. This blow-by gas relief port 5 is surrounded by a partition wall 8 that projects from the upper surface of the cylinder head on the outer side of the cylinder head mounting hole 7A. and,
As shown in FIG. 3, in some embodiments of the circumferential direction, this partition wall 8 has a part that is lower than the partition wall 8 and protrudes from the upper surface of the cylinder head 1 at a position facing the combustion chamber 4 side. A low-lying portion 8a is formed. That is, by providing the low part 8a,
A notch 9 corresponding to the low portion 8a is formed in the partition wall 8.

In the present invention configured as described above, the low portion 8a serves as a kind of dam. That is, oil is normally returned from the oil return port 6, but a large amount of oil is temporarily trapped on the upper surface of the cylinder head 1, that is, its height is lower than the lower part 8a.
When the temperature rises slightly higher than , the oil passes over the low portion 8a, flows into the blow-by gas relief port 5, and flows down into the oil pan (inside the crankcase). Since this oil flows down only a part of the inner wall surface of the blow-by gas relief port 5 in the circumferential direction (a position corresponding to the low point 8a), the blow-by gas relief port 5 Therefore, the opening area will not be significantly reduced. Therefore, oil is returned smoothly and blow-by gas is smoothly discharged.

Figure 4 shows another embodiment of the present invention, in which the engine is installed in a vehicle at an angle (vertical line
The angle of inclination with respect to the height is indicated by Θ), and a low portion 8a is provided at the lowest position. In the case of this embodiment, the height of the oil level on the cylinder head 1 can be kept lower, and the oil can be more reliably flowed down through only a part of the inner wall of the blow-by gas relief port 5 due to gravity. maintained.

FIG. 5 shows yet another embodiment of the present invention. In this embodiment, the partition wall 8 is extended further toward the combustion chamber 4 side than in the previous embodiment, and corresponding to this extension, the low portion 8a and the blowby A stepped portion 10 having an intermediate height is formed between the gas relief port 5 and the gas relief port 5. This stepped portion 10
By providing this, the oil is hardly subjected to discharge pressure from the blow-by gas relief port 5 in the low portion 8a, and the oil is dispersed and flows down the wall surface of the blow-by gas relief port 5. Therefore, the height difference H ₁ of the oil surface with respect to the low part 8a can be made smaller than the height differences H ₂ and H ₃ in the cases shown in FIGS. 3 and 4.

FIG. 6 shows still another embodiment of the present invention. In the embodiment shown in FIG.
0 has a cylinder head mounting hole 7A opened. Note that 11 in FIG. 6 is a mounting bolt.

[Effect of idea]

As detailed above, according to the present invention, a partition wall is provided to surround the blow-by gas vent, and a low-lying part is provided in a part of the partition wall, which is lower than the partition wall and protrudes from the upper surface of the cylinder head. Because of this provision, this low-lying portion serves as a kind of dam for the blow-by gas vent.

As a result, in normal cases, blowby gas is discharged without oil flowing into the blowby gas relief port, and even if the amount of oil increases and oil flows into the blowby gas relief port from a low place, the Since the inflow amount is regulated, the inflowing oil will not flow down the wall of the blow-by gas vent and cause blockage.

Furthermore, due to the inflow from the lower part, the liquid level of the oil accumulated on the upper surface of the cylinder head is lowered, which has the effect of reducing the amount of oil carried away.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a cylinder head showing an embodiment of the present invention, Fig. 2 is a view of the cylinder head shown in Fig. 1 viewed from the combustion chamber side, and Fig. 3 is a sectional view of the main part of Fig. 1. , and FIGS. 4 to 6 are sectional views of main parts showing other embodiments of the present invention. 1...Cylinder head, 5...Blowby gas vent, 8...Partition wall, 8a...Low part.

Claims (1)

[Scope of utility model registration request] In a cylinder head for an internal combustion engine, a blow-by gas relief port is opened at the top surface of the cylinder head, and a partition wall is provided so as to surround the blow-by gas relief port by a partition wall that projects from the top surface of the cylinder head. A cylinder head for an internal combustion engine, comprising a low part for regulating the direction of oil inflow, which is lower than the partition wall and protrudes from the upper surface of the cylinder head in a part of the cylinder head in the circumferential direction.