JPS6043124A - Intake pot of internal-combustion engine - Google Patents

Abstract

PURPOSE:To produce strong swirl under a high volumetric efficiency, by selecting the connecting angle of an inlet portion and an outer portion of a swirl generating section at such an angle that main flow of intake air carried from the inlet portion to said outer portion of the swirl generating section is introduced between the peripheral surface of said outer portion and the peripheral surface of a valve shaft. CONSTITUTION:The axis of a cylindrical surface constituting the peripheral surface of an outer portion of a swirl generating section 16 is displaced toward the side of the peripheral surface of said outer portion 17 from the axis of an intake port 12, and the eccenticity is set at a value within the range of 2-50% of the diameter of the intake port 12. Further, the connecting angle of said outer portion 17 and an inlet portion 19 is selected at such an angle that main flow of intake air carried from the inlet portion 19 to the outer portion 17 is introduced between the peripheral surface of the outer portion 17 and that of a valve shaft 14. On the other hand, the distance from the axis of the intake port 12 to the center line of the inlet port 19 is selected to be within the range of 20-60% of the diameter of the intake port 12. Further, the inlet portion 19 is shaped to converge toward its top, and the minimum width of the inlet portion 19 is set at a value within the range of 25-85% of the diameter of the intake port 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake port for an internal combustion engine in which an intake hole is opened at a position eccentric from the center of an end face of a cylinder chamber, an intake valve is provided in the intake hole, and an intake passage is connected to the intake port.

In this type of intake port, the present inventor has previously developed an intake passage that communicates with the intake hole to create a vortex flow at the end of the passage surrounding the intake valve in order to generate a moderately stable vortex flow without reducing the volumetric efficiency. Consists of a starting part and an introduction part other than the end of this passage,
The width between the circumferential surface of the valve shaft of the intake valve and the surface of the vortex generating part facing the kneading is made wider at the outer part on the cylinder chamber side than the inner part on the center side of the cylinder chamber, and The height between the opening surface of the intake hole and the ceiling of the vortex generating section facing this is reduced from the wide outer part to the narrow inner part around the valve stem, and Average area l) Apply 7 turns around the valve stem to suck 9°C to 0% of the diameter of the hole.
As described above, we have invented an intake boat for an internal combustion engine in which the intake amount is set to 0.7 g% or less. Although this invention can achieve its purpose, it cannot be said that a strong vortex can be generated with high volumetric efficiency.

An object of the present invention is to improve the above-mentioned previous invention and provide an intake boat for an internal combustion engine that can generate a strong vortex flow with high volumetric efficiency.

In order to achieve the above object, the present invention limits various parts of the above conventional invention based on the results of experiments.

That is, the present invention, in the above-mentioned conventional invention, decenters the central axis of the cylindrical surface constituting the curved surface of the outer portion of the vortex generation portion from the central axis of the intake hole toward the circumferential surface of the outer portion. The core amount is set to 25 or more and 50% or less of the diameter of the intake hole, and the connection angle between the outer part and the introduction part is set so that the main flow of intake air from the introduction part to the outer part is between the peripheral surface of the outer part and the valve shaft. This is an intake boat for an internal combustion engine, characterized in that the intake boat is set at an angle that allows the intake air to flow between the phases.

In addition, this intake boat is characterized in that the distance from the center axis of the intake hole to the center line of the introduction part is set to 20% or more and 0% or less of the diameter of the intake hole, Further, the introduction part is formed into a tapered shape, and the minimum width of the introduction part is set to be 25% or more of the diameter of the intake hole and g5% or less.

The intake boat of the present invention can generate a stronger vortex flow with higher volumetric efficiency than is clear from the experimental results described below.

Next, examples of the present invention will be described.

As shown in Figs. 1 and 2, the intake boat of the internal combustion engine of this example has a circular intake hole Q in the circular end face of the cylinder chamber 0η from the center/U to the periphery (ti^ center position). Open the intake hole (14 with a poppet valve (1), connect the intake passage αQ, and connect the intake passage 09 with the intake hole 0).
A vortex generating portion 11 at the end of the passage that communicates with the pier and surrounds the intake valve
ii1 and an introduction part 09 other than this passage end, and the vortex generating part (1 (1) is formed by smoothly connecting two cylindrical surfaces facing the valve shaft 0→ aspect of the intake valve. 4, and the width between the circumferential surface of the valve shaft (14) and the circumferential surface of the vortex generating part OQ facing this is set to the outer 41111 portion 0 on the circumferential surface side of the cylinder chamber 01.
In η, it is made wider than the inner part 08) on the u side in the cylinder chamber, and gradually narrows around the valve shaft (14) from the outer part 0'h to the inner part 08), and the vortex generating part Qt9 is made wider. The wide outer part (171 has an introductory part 0 along its tangential direction)
9, and connect the wide outer part (from lη to the width The inner part of the narrow part is the same as 1111 up to the 0 mark, or gradually decreases, and the amount of decrease is 07g% of the intake hole diameter d per 7 degrees around the valve shaft 0 →
It is set within However, the central axis of the cylindrical surface that constitutes the circumferential surface of the inner part of the vortex generating part is located inside the intake hole α.
While aligning with the U axis, the central axis of the cylindrical surface constituting the surface of the outer part αη is eccentric from the intake hole 0 → middle IL) axis to the circumferential surface side of the outer part, and the eccentricity e is (2) diameter d
2% or more and 50% or less, and the connection angle between the outer part 0η and the introduction part 09, from the introduction part 09 to the outer part 07)
The angle is set such that the main flow of intake air flowing into the valve shaft flows between the circumferential surface of the outer portion and the circumferential surface of the valve shaft α→. Furthermore, inside IL of intake hole 02:? The distance l from the shaft to the middle line of the introduction part 0 is set to 20% or more and 60% or less of the diameter d of the intake hole, and the introduction part 0 flaw with a rectangular cross section is formed into a tapered shape. The minimum width W of the intake hole (12) is set to be 2S% or more and gS% or less of the diameter d of the intake hole (12).

In this intake boat, the intake air flowing through the intake passage 0.1 flows into the vortex generation part OQ from the introduction part (I), flows into the cylinder chamber 0η through the intake hole 0, and also flows into the cylinder chamber 0η through the intake hole 0. Flows from the center position 11t of the introduction part 09 to an intermediate position between the circumferential surface of the outer part αη of the vortex generating part and the circumferential surface of the valve shaft 0, and flows into the cylinder chamber (11) through the intake hole 0. A vortex flow flows in along the tangential direction of the portion of the surface near the intake hole and swirls along the surface of the cylinder chamber 0→.

A strong eddy current is generated under high volumetric efficiency.

Experiment/ In the intake port of the above example, the central axis of the cylindrical surface constituting the circumferential surface of the outer portion (l″I) of the vortex generating portion is eccentric from the central axis of the intake hole @ to the curved surface side of the outer portion 0η Re
is set at each position relative to the diameter d of the intake hole 0, and for each case, the strength of the vortex generated in the cylinder chamber 0), that is, the swirl ratio Sl't, and the pressure loss ΔP of the intake passage OQ are determined. As a result, I obtained the results as shown by the solid line in the diagram in Figure 3.It is clear from the upper and lower halves of the diagram that the dimensionless eccentricity e/d is 0.3. When it becomes larger, the swirl ratio 8R becomes smaller and the pressure loss Δ
P becomes larger. On the other hand, as the dimensionless eccentricity e/d becomes smaller than O/, the swirl ratio SR decreases and the pressure loss ΔP increases, and when the dimensionless eccentricity lie/d becomes smaller than O02, the swirl ratio 8R reduction device and pressure drop Δ
The amount of increase in P becomes large. Therefore, dimensionless eccentricity if e
When /d is 002 or more and 05 or less, the swirl ratio SR is large and the pressure loss ΔP is small. That is, a strong vortex flow occurs under high volumetric efficiency. In addition, the dimensionless eccentricity e
Even better performance can be obtained when /d is 0.03 or more and 03 or less.

Note that the connection angle between the outer part (17) and the inlet part is adjusted so that the main flow of intake air from the inlet part (In to the outer part 07) flows between the circumferential surface of the outer part and the circumferential surface of the valve shaft α. If it is set to an angle other than the angle, the performance will deteriorate in the region where the dimensionless eccentricity e/d is smaller than 0/, as shown by the broken line in the diagram in Figure 3, and the swirl ratio SR will decrease. As the pressure decreases rapidly, the pressure loss ΔP increases.

For each case, set the connection angle a between the outer part αη and the introduction part, and set the swirl ratio S for each case.
When we looked at R and the pressure loss ΔP, we obtained the results shown in the diagram in Figure 1I.

However, for convenience, the above connection angle α includes the connection line between the surface of the inner part 08) and the inner surface of the introduction part 09, and this connection line and the central axis of the intake hole 02, as shown in FIG. With respect to the connecting surface including the intersection line between the surface rotated 60 degrees from the surface to the outer portion Cl7) side with the central axis of the intake hole as the center axis and the peripheral surface of the outer portion 07) or the outer surface of the introduction part 0, Introduction part 0
This is the angle formed by the center line of 9.

As is clear from the upper and lower halves of the diagram in Fig. 1, when the connection angle α becomes larger than 735 degrees, the swirl ratio SI
(becomes very small - and the pressure loss ΔP becomes large η
Ru. That is, the main flow of intake air flowing from the introduction part 09 to the vortex generating part (IQ) collides with the valve shaft Oa, and the vortex becomes weaker. Therefore, when the connection angle α becomes 735 degrees or less,
The swirl ratio SR is large and the pressure loss ΔP is small. Note that even better performance can be obtained when the connection angle α is 710 degrees or less. On the other hand, as the connection angle α decreases by 15 degrees, the swirl ratio SR rapidly decreases and the pressure loss ΔP increases. That is, a part of the main flow of the intake air flowing from the introduction part 0 into the outer part a of the vortex generating part comes to collide with the surface of the outer part, and the vortex becomes weaker.

Therefore, if the connection angle α is set to an angle where the main flow of intake air from the introduction part 0 Samurai to the outer part α force flows between the circumferential surface of the outer part and the surface of the valve stem 04), the swirl ratio 8R will be large. Pressure loss ΔP becomes smaller.

Experimental In the intake port of the above example, the distance l from the center axis of the intake hole α force to the center line of the introduction part FIG is
When the swirl ratio SR and the pressure loss ΔP were determined for each case with respect to the diameter d, the results were obtained as shown in the diagram in Fig. S. As is clear from the upper and lower halves of the diagram, the dimensionless distance n/d
When becomes larger than O2 or smaller than 02, the swirl ratio SR becomes smaller and the pressure loss ΔP becomes larger. Therefore, when the dimensionless distance 1/d becomes 02 or more and 06 or less, the swirl ratio SR is large and the pressure loss ΔP is small.

In addition, the minimum width W of the tapered introduction part 01 was set to various degrees with respect to the diameter d of the intake hole 02, and the swirl ratio 8R and pressure loss ΔP were calculated for each case. The results shown in the diagram in the figure were obtained. As is clear from the upper and lower halves of the diagram, the dimensionless minimum width v
/ When d is larger than θg, then θ2SX
As v becomes smaller, the swirl ratio SR becomes smaller and the pressure loss ΔP becomes larger. Therefore, the dimensionless minimum width w/
When d is more than C2S and less than 0g5, the swirl ratio is 8R.
is large and pressure loss ΔP is small,

[Brief explanation of the drawing]

FIG. 1 is a plan view of an intake port according to an embodiment of the present invention. Fig. 2 is a sectional view taken along the line T in Fig. 1, Fig. 3 is a diagram showing the relationship between the swirl ratio SR1 pressure loss ΔP and the dimensionless eccentricity e/d at the same intake port, and Fig. Swirl ratio SR at the same intake port F. A diagram showing the relationship between pressure loss ΔP and connection angle α, Figure 5 is a diagram showing the relationship between swirl ratio SR at the same intake port, pressure loss ΔP and dimensionless distance 1/d, and Figure 6 is a diagram showing the relationship between the same intake port. It is a diagram showing the relationship between the swirl ratio SR1 pressure loss ΔP and the dimensionless minimum width v/d in FIG. 11 Niji cylinder chamber 12: Intake hole 13: Intake valve 14: Valve shaft 15: Intake passage 16: Vortex generating part 17: Outside part 18: Inside part 19: Introduction part

Claims (3)

[Claims] (1) The intake port of an internal combustion engine has an intake hole opened at a position eccentric from the center of the end face of the cylinder chamber, an intake valve is provided in the intake hole, and the intake passage is connected to the intake port, and the intake passage is communicated with the intake hole. The width between the circumferential surface of the valve shaft of the intake valve and the circumferential surface of the vortex generating section facing the intake valve is as follows:
The outer part on the side of the cylinder chamber is wider than the inner part on the center side of the cylinder chamber, and the introduction part is connected to the wide outer part of the vortex generating part, and the gap between the opening surface of the intake hole and the ceiling of the vortex generating part facing the kneading part is made. The height of the valve is reduced from the wide outer part to the narrow inner part around the valve stem, and the average reduction is 0.7 g at 0% or more of the diameter of the intake hole per 7 degrees around the valve stem.
% or less, the central axis of the cylindrical surface constituting the curve of the outer part of the vortex generating part is eccentric from the central axis of the intake hole toward the circumferential surface of the outer part, and the amount of eccentricity is calculated as the diameter of the intake hole. 50 for 2% or more
% or less, and set the connection angle between the outer part and the introduction part so that the main flow of intake air from the introduction part to the outer part. An intake port for an internal combustion engine, characterized in that the intake port is set at an angle such that the air flows between the circumferential surface of the outer portion and the circumferential surface of the valve shaft. (2) IL from the central axis of the intake hole to the middle of the introduction section: ? 2. The intake port for an internal combustion engine according to claim 1, wherein the distance to the line is set to 20% or more and 10% or less of the diameter of the intake hole. (3) The introduction part is formed into a tapered shape, and the minimum width of the introduction part is set to 25% or more of the diameter of the intake hole and g5% or less. intake port of an internal combustion engine.