JPS59213924A - Suction port for internal-combustion engine - Google Patents

Abstract

PURPOSE:To increase a swirl ratio, by specifying a stepped portion formed between a peripheral surface of a vortex flow generating portion in a suction passage and an opening edge of a suction port. CONSTITUTION:A peripheral surface and an inlet of a vortex flow generating portion 16 are arcuately rounded. A radius of curvature R1 at an outlet of a stepped portion 21 formed near a peripheral surface of a cylinder chamber 11 is larger than a radius of curvature R2 at an inlet of the stepped portion 21 formed at a distant from the peripheral surface of the cylinder chamber 11, so that the stepped portion 21 may be smoothly shaped in such a manner that the outlet is less angulated than the inlet. A reduced amount of a height between an opening surface of a suction port 12 and a top wall of the vortex flow generating portion 16 is set to be within 0.18% of a diameter (d) of the suction port per one degree about a valve shaft 14. A suction air flow in a suction passage 15 is induced through an induction portion 19, the vortex flow generating portion 16 and the suction port 12 to the cylinder chamber 11. A main flow of the suction air is induced from an axial position of the induction portion 19 to an intermediate position between a peripheral surface of an outside part 17 of the vortex flow generating portion and a peripheral surface of the valve shaft 14. Then, it is induced through the suction port 12 to the cylinder chamber 11, where forming a vortex flow along the periphery of the cylinder chamber 11.

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 in an end face of a cylinder chamber at a position eccentric from the center thereof, an intake valve is provided in the intake hole, and an intake passage is connected to the intake port. .

Previously, the inventor of the present invention has constructed an intake passage at the end of the passage that communicates with the intake hole and surrounds the intake valve in order to generate a moderately stable vortex flow without reducing the volumetric efficiency in the intake port of C. A groove is formed from the vortex generation part and the 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 circumferential surface of the vortex generating portion facing the intake valve is made wider at the outer portion on the side facing the cylinder chamber than the inner portion 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 the same from the wide outer part to the narrow inner part around the valve stem, or Invented an intake port for an internal combustion engine in which the average reduction is set within 2/J% of the intake hole diameter per 7 degrees around the valve shaft.

An object of the present invention is to improve the above-mentioned previous invention and provide an intake port for an internal combustion engine with a high swirl ratio.

In the present invention, in order to increase the swirl ratio, the step portion formed between the circumferential surface of the vortex generating portion of the intake passage and the opening edge of the pore is devised.

In the above-mentioned conventional invention, the present invention is such that the stepped portion between the circumferential surface of the vortex-generating portion of the intake passage and the opening edge of the intake hole is made smoother in a portion closer to the circumferential surface of the cylinder chamber than in a portion farther away. This is an intake port for an internal combustion engine that is characterized by a

In this intake port, as is clear from the experimental results described later, it is possible to generate a vortex flow with a swirl ratio of W'II. As shown in FIGS. 1 and 2, the intake port is located on the circular end surface of the cylinder chamber αυ from the inside IL
Open a circular intake hole (6) at a position eccentric to 11, provide an intake valve (opener) of a poppet valve in the intake hole @ and connect the intake passage a9, and connect the intake passage (10 to the intake hole o). The vortex generating portion Utt and 00 at the end of the passage that communicate with each other and surround the intake valve 0i
It consists of an introductory part OX4 outside the end of the passageway, and a vortex generating part (formed by slidingly connecting the circumferential surface of the cylindrical surface to a cylindrical surface facing the circumferential surface of the valve shaft of the intake valve, The cylinder chamber (
At 0 force, the outer part on the circumferential side of 1υ is wider than the inner part on the center side of the cylinder chamber, and the inner part (from the outside (III fa) around the valve tiIllll (141) to the inner part (l mark) is gradually narrowed. and the wide outside (1f
1 part Q7) along its tangential direction, and connect the intake hole (the opening surface of the part Q7) and the vortex generation M
ls (1 (the height between the ceilings of j is kept the same or gradually decreased from the wide outer part Q7 around the valve axis α) to the narrow inner 11111 part θ~, and the decreasing pattern is The times of the valve stem 04) V&ko/#: 07g% of the intake hole diameter d
Specifically, set it to 006%, and
As shown in the figure, the outer and inner corners of the stepped portion c2D formed between the circumferential surface of the vortex generating portion OQ and the opening edge of the intake hole u4 are rounded into arc shapes, and the outer corner of the stepped portion nυ is rounded. radius of curvature of hole 1
and the radius of curvature R2 of the large corner are made larger in the part near the cylinder chamber Ov surface than in the part far away, and the stepped part c2υ is made smooth so that the part near the circumference of the cylinder chamber 0υ is less angular than the part far away. Specifically, the curvature radius of the hole, and the hole, as shown by the solid line in the diagram of
It is changing against.

As shown in FIG. 2, the angle γ is an angle measured around the valve axis α→ of the intake valve from the V-V line cross section in the flow direction of the intake air flow.

In this intake port, the intake flow flowing through the intake passage (old) flows from the introduction part 01 into the vortex generation part (1 (9), passes through the intake hole a, and into the cylinder chamber Ql), and the intake flow The main flow flows from the introduction part OIO axis position to the intermediate position between the outer part of the vortex generating part α force and the circumferential surface of the valve shaft (141), and passes through the intake hole 04 to the cylinder chamber 01. It flows in along the tangential direction of the portion near the hole and becomes a vortex flow that swirls along the circumferential surface of the cylinder chamber (lυ).

In the intake port of this example, the flow rate Q of the intake air flowing through the intake passage 9 was set to 6 values, and the strength of the vortex generated in the cylinder chamber aυ, that is, the swirl ratio SR, was determined for each of the 6 values. However, we obtained experimental results as shown by the solid line in the diagram of FIG.

Also, for comparison, the radius of curvature of the protruding corner of the stepped portion (21) and the radius of curvature of the inlet corner 2'f: are changed as shown by broken lines in the diagram of FIG. 6 in the conventional case. When we similarly determined the swirl ratio Sli for the flow rate Q of the intake passage (1G), we obtained experimental results shown by the broken line in the diagram of FIG.

As is clear from these experimental results, the intake port of this example can generate a vortex flow with a high swirl ratio.

[Brief explanation of drawings]

1 is a schematic perspective view of an intake port according to an embodiment of the present invention, FIG. 2 is a cross-sectional plan view of the same intake port, and FIG. 3 is a partially omitted cross-sectional view taken along the line T in FIG. The figure is a partially omitted view of the cross section taken along the line IV-IV in Fig. 2, Fig. 5 is a partially omitted view of the cross section taken along the ■-v line of Fig. 2, and Fig. 6 is the protruding corner of the stepped portion of the same intake port. FIG. 7 is a diagram showing the relationship between the swirl ratio and the intake air flow at the same intake port. 11 Niji cylinder chamber 12: Intake element 113: Intake valve 14: Valve shaft 15: Intake curved path 1
6: Eddy current generating part 17: Outside fi11 f41i
18: Inner part 19: Praying part 21: Step
Figure 2 ■ Figure 3 Figure 4

Claims (1)

[Claims] In the intake port of an internal combustion engine, in which an intake hole is 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, the intake passage is communicated with the intake hole to intake air. It consists of a vortex generating part at the end of the passage surrounding the valve and an introduction part at the other end of the passage, and the width between the circumferential surface of the valve shaft of the intake valve and the circumferential surface of the vortex generating part facing it is equal to the width on the circumferential side of the cylinder chamber. The outer part is made wider than the inner part on the +L> side of the cylinder chamber, and the introduction part is connected to the wide outer part of the vortex generating part, and the height between the opening surface of the hole and the ceiling of the vortex generating part facing it is The width is the same or decreases from the wide outer part to the narrow inner part around the valve stem, and the average reduction is equal to O/Z% of the intake hole diameter per 7 degrees around the valve stem. An intake port for an internal combustion engine, characterized in that the step between the circumferential surface of the vortex generating part and the opening edge of the intake hole is made smooth so that the part closer to the cylinder chamber surface is less angular than the part farther away. .