JPS59201929A - internal combustion engine intake port - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an air intake system for an internal combustion engine in which an intake hole is opened in the end face of a cylinder chamber at a position offset from the center U, an intake valve is provided in the intake hole, and an intake passage is connected to the intake hole. Regarding ports.

The inventor of the present invention has previously proposed that, in an intake port of type C, in order to generate a moderately stable vortex flow without reducing the volumetric efficiency, the intake passage was connected to the intake hole at the end of the passage surrounding the intake valve. Consists of a vortex generating 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 opposite surface of the vortex generating part is made wider at the outer part on the cylinder chamber circumferential side and the inner part on the center side of the cylinder chamber, and the wider outer part of the vortex generating part The height between the opening surface of the intake hole and the ceiling of the vortex generation part facing the C groove is the same from the wide outer part to the narrow inner part around the valve stem. The present invention has invented an intake port for an internal combustion engine in which the average reduction amount is set within 07g% of the diameter of the intake hole per 7 degrees around the valve stem.

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, various improvements have been made to the arrangement position of the intake hole opening at the end face of the cylinder chamber.

That is, in the first invention, in the above-mentioned previous invention, the line connecting the center of the intake hole Iu and the center of the end surface of the cylinder chamber is different from the line connecting the centers of the end surfaces of the cylinder chambers arranged in series. This is an intake port for an internal combustion engine, characterized in that the angle formed is set within 70 degrees. In this intake port, a vortex flow with a high swirl ratio can be generated, as is clear from the experimental results described later.

Further, a second invention is an intake air intake of an internal combustion engine according to the above-mentioned previous invention, characterized in that the distance between the centers of the inner and outer ends of the intake hole and the end face of the cylinder chamber is set to within 30% of the diameter of the cylinder chamber. It is a port. In this intake hoard, it is possible to generate a vortex flow with a high swirl ratio, as is clear from the experimental results described later.

Next, examples of the present invention will be described.

As shown in FIGS. 1 and 2, the intake port of the internal combustion engine of this example has a circular intake hole θ steeply opened at a position eccentric from the center toward the periphery in the circular end face of the cylinder chamber αυ. An intake valve (L3) of a poppet valve is provided in the intake hole (6) and an intake passage is connected to the intake passage αQ, and the intake passage αQ is connected to the vortex flow generating portion αQ at the end of the passage surrounding the intake valve Q3. The introduction section (11) other than this passage end is formed by smoothly connecting the circumferential surface of the vortex generating section QQ with two cylindrical surfaces facing the circumferential surface of the valve shaft (14) of the intake valve. The width between the circumferential surface of the axis α → and the circumferential surface of the vortex generating part QfjO facing C is made wider evenly in the outer part α on the cylinder chamber 0υ circumferential side than the inner part α in the cylinder chamber and on the D side. Then, it is gradually narrowed around the valve axis α from the outer part (17) to the inner part (to),
The introduction part OCJ is connected to the wide outer part Oη of the vortex generating part Oη along its tangential direction, and the height between the opening surface of the intake hole @ and the ceiling of the vortex generating part Q facing it is determined as the valve axis. (1
4) from the wide outer part αη to the narrow inner part (
(to) or gradually decreases, and the amount of decrease is set to 07 of the intake hole diameter d per 7 degrees around the valve stem (14).
g%, specifically set to 00%%, and as shown in Figure 3, multiple lines connecting the center of the intake hole (2) and the inside/U of the end face of the cylinder chamber 0υ are connected in series. The angle θ formed with the line connecting the center of the end surface of the cylinder chamber + L) is set within 70 degrees, specifically 6 degrees, and as shown in Figure 2, the angle θ of the intake hole 0 The distance r between the center and the end face of the cylinder chamber 0υ is set within 30%, specifically 25%, of the diameter of the cylinder chamber 01).

In this intake port, the intake air flow flowing through the intake passage a9 flows from the introduction part 01 into the vortex generation part 049, flows into the cylinder chamber 0υ via the intake hole (2), and the main flow of the interrupted intake air flow is as follows: The flow flows from the axial center position of the introduction part 01 to an intermediate position between the circumferential surface of the outer part 0η of the vortex generating part and the phase of the valve axis α→, passes through the intake hole 0, and enters the cylinder chamber 0υ in the vicinity of the intake hole of that phase. flows along the tangential direction of the cylinder chamber (I)
) becomes a vortex that swirls along the circumferential surface.

In the intake port of this example, the line connecting the center of the intake hole @ and the center of the end face of the cylinder chamber 01) is made with respect to the line connecting the center of the end face of a plurality of cylinder chambers (11) arranged in series. When the angle θ was set at various positions and the strength of the vortex generated in the cylinder chamber (l), that is, the swirl ratio SR, and the volumetric efficiency VB of the cylinder chamber αυ were determined for each position, the line diagram shown in Fig. The experimental results shown are obtained. In addition, in the same drawing M, the sign of the above-mentioned arrangement angle θ indicates that the center I of the intake hole (6) is located in the intake passage with respect to the line connecting the center and U of the end faces of the cylinder chambers 0υ arranged in series. It is positive when the introduction part Ql is located at 911, and the introduction part OI
It is considered negative when it is located on the opposite side. As is clear from the upper part of the diagram, the swirl ratio 8R decreases rapidly when the arrangement angle θ exceeds 70 degrees, and reaches a very high value within 75 degrees. As is clear from the lower part of the diagram, the volumetric efficiency VE does not change significantly depending on the magnitude of the arrangement angle θ. Therefore, if the arrangement angle θ is set within 70 degrees, the swirl ratio can be increased without reducing the volumetric efficiency, and if the arrangement angle θ is set within 75 degrees, the swirl ratio can be made very high. can.

In addition, in the intake port of this example, the intake hole @ middle JL)
The distance 1111r between the centers of the end faces of the cylinder chamber αυ and the center of the end face of the cylinder chamber αυ is set at each position relative to the diameter of the cylinder chamber (1υ), and each position r
Swirl ratio SR and volumetric efficiency VE for /1), respectively.
When we tried to find this, we obtained experimental results as shown in the diagram in Figure 5. As is clear from the upper part of the diagram, the swirl ratio SR decreases rapidly when the above value, that is, the dimensionless arrangement distance r/D exceeds 03, and becomes extremely It becomes a high value. As is clear from the bottom of the diagram, the volumetric efficiency VE is determined by the dimensionless arrangement distance r/D
It does not change much depending on the size of the Therefore, if the dimensionless arrangement distance r/D is set within 30%, the swirl ratio can be increased without reducing the volumetric efficiency, and the dimensionless arrangement distance r/D can be set to 75% or more and 26% or less. When set, the swirl ratio can be made very high.

[Brief Description of the Drawings] Fig. 1 is a schematic oblique view of an intake port according to an embodiment of the present invention, Fig. 2 is a plan view of the intake boat, and Fig. 3 is a schematic diagram showing the arrangement of the intake boats. Figure 1 is a diagram showing the relationship between the intake hole arrangement angle and swirl ratio or volumetric efficiency in the same intake boat, and Figure S is a diagram showing the relationship between the intake hole arrangement distance and the swirl ratio or volume in the same intake boat. FIG. 3 is a diagram showing the relationship between efficiency. 11 Nijiring chamber 12: Intake hole 13: Intake valve 14: Valve Shaft 15: Intake passage
16: Eddy current generating part 17: Outside part 18:
Inner part 19: Introduction part θ: Arrangement angle of intake hole r: Arrangement distance of intake hole D Diameter of cylinder chamber Fig. 3

Claims (1)

[Scope of Claims] (1) In an intake port of 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 IL), an intake valve is provided in the intake hole, and an intake passage is connected to the intake port, The intake passage is composed of a vortex generating part at the end of the passage that communicates with the intake hole and surrounds the intake valve, and an introduction part other than the end of the passage, and includes a circumferential surface of the valve shaft of the intake valve and a circumferential surface of the vortex generating part facing it. The width between
The outer part on the side of the cylinder chamber is made wider than the inner part on the ID side of the cylinder chamber, and the introduction part is connected to the wide outer part of the vortex generating part, and the opening surface of the intake hole and the ceiling of the vortex generating part facing this are made. the height between the valve stem turning from the wide outer part to the narrow inner part, the height being the same or decreasing;
The average decrease is 0 for the diameter of the intake hole per 7 degrees around the valve stem.
Set within 7g%, and set the angle between the line connecting the center of the end surface of the cylinder chamber and Iu inside the intake hole to the line connecting the inside U of the end surface of multiple cylinder chambers arranged in series within 70 degrees. An intake port of an internal combustion engine characterized by being set to . (2) An intake port of an internal combustion engine according to claim 1, characterized in that the angle is set within 75 degrees. The intake port of an internal combustion engine according to claim 1 or 2, characterized in that the distance is set within 30% of the diameter of the cylinder chamber. In an intake port of an internal combustion engine in which an intake port is opened at a position where an intake port is opened, an intake valve is provided in the intake port, and an intake passage is connected, the intake passage is connected to a vortex flow generating portion at the end of the passage that communicates with the intake hole and surrounds the intake valve. 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 determined by the width between the circumferential surface of the valve shaft of the intake valve and the circumferential surface of the vortex generating section facing it. The introduction part is connected to the wide outer part of the vortex generating part, and the height between the opening surface of the intake hole and the ceiling of the vortex generating part facing this is made wider than the inner part, and the wide outer part is connected around the valve stem. from the inner part to the narrow inner part, and the average reduction is 07g% of the intake hole diameter per 7 degrees around the valve stem.
An intake port for an internal combustion engine, characterized in that the distance between the middle ju of the end face of the cylinder chamber and the middle U of the intake hole is set within 30% of the diameter of the cylinder chamber. (5) The intake port of an internal combustion engine according to claim 4, wherein the distance is set to be 75% or more and 26% or less of the diameter of the cylinder chamber.