JPH0237111A - Variable swirl device - Google Patents

Abstract

PURPOSE:To excellently adjust swirl strength by communicating a helical port and subport at the middle of the helical port. CONSTITUTION:A helical port 3 is connected to a cylinder bore 7 to form suction swirl S. A subport 4 of another system is provided to communicate the helical port 3 and the subport 4 at the middle of the helical port 3 through a connecting port 6. Since while the subport is opened, a part of suction swirl S is introduced from the connecting port 6, suction swirl S is damped more than while the subport is closed. This enables swirl strength to be adjusted excellently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable swirl device that improves the combustion performance of an engine by varying the intensity of intake swirl.

[Prior Art] The present applicant's ``Variable Swirl Port Purifier'' (Utility Model Application Publication No. 114040/1983) was proposed to improve combustion performance by swirling and supplying combustion air into the combustion chamber. be.

This proposal, as shown in Fig. 7, opens an air passage to weaken the intake swirl S in the helical port a, and arranges a heating means d near the opening end C of the air passage. By opening and closing the air passage, the upstream end of the air passage and the upstream side of the helical port a can be configured to adjust the intake swirl S, or configured to be connected to an EGR device (not shown). Adjust the strength of the intake swirl S (if the engine speed is high, open the air passage and adjust the intake swirl strength weakly; if the engine speed is low, close the helical port b and adjust the intake swirl strength) On the other hand, the swirl strength adjustment function of the air passage is maintained constant by incinerating the oil mist and unburned materials that are adhering to and accumulating on the opening end C by the heating of the heating means d. That's what I do.

[Problems to be Solved by the Invention] In the proposal, since the intake swirl strength is selectively determined by opening and closing the air passage, it is necessary to adjust the intake swirl strength to match the engine. It is effective to change the cross-sectional area of the flow path. However, there are various restrictions in changing the cross-sectional area of the flow path due to the need to arrange the injector, glow plug, or spark plug in a narrow space like a small engine, and the need to form a water jacket. There is.

Furthermore, in recent years, there has been a desire for a proposal that would increase the number of stages for adjusting intake swirl strength and further adjust combustion performance.

[Means for Solving the Problems] The present invention aims to solve the above problems, and the present invention includes a helical pod that generates an intake swirl, a sub-port that introduces intake air and makes it counterflow with the intake swirl downstream. ,
A variable swirl device is constituted by a communication port that communicates these ports in the middle of the helical port.

[Function] When the sub-port is closed, part of the intake air that is being swirled in the helical port is introduced into the sub-port from the communication port, and the introduced intake air flow is directed against the intake swirl downstream of the helical port. Flow. Then, the intake swirl is attenuated.

When the sub-port is open, intake air is introduced into the sub-port and a portion of the intake swirl is introduced from the communication port, so the intake swirl is damped more effectively compared to when the sub-port is closed. .

[Embodiment] A preferred embodiment of the present invention will be described below based on the accompanying drawings.

As shown in FIG. 1, a helical port 3 is formed in the cylinder head 1, which opens from one side 2 of the cylinder head 1 and faces the inside of a cylinder bore 7 of a cylinder body (not shown). An intake swirl S that effectively mixes intake air and fuel gas within the cylinder bore 7 is generated at the helical port 3. In the embodiment, the helical port 3 is formed so that its flow path cross section (cross section perpendicular to the flow direction) is approximately rectangular. On the other hand, inside the cylinder head 1, at a position almost parallel to the helical port 3, there is a sub port 4 which is opened from one side 2 of the cylinder head 1 and introduces intake air from another system to the helical port 3. is formed. In the embodiment, the opening @5 is formed at a position where the introduced intake air flows counter-currently with the downstream intake swirl S supplied into the cylinder bore, thereby attenuating the intake swirl S. That is, with respect to the helical port 3, the sub-port 4 is separated from the helical port 3 on the upstream side of the intake swirl S, and successively approaches the helical port 3 on the downstream side, so that the intake air introduced individually at the most downstream side flows mutually. However, when attempting to supply intake air to the sub port 4 independently from the helical port 3, a valve (not shown) that opens and closes based on the engine speed and engine load, and a chamber (not shown) are provided. When the intake air is distributed to the auxiliary port 4 through the chamber, the air passage (not shown) that supplies intake air to the chamber is opened and closed by the valve.

If formed in this way, the intake air introduced from the sub port 4 when the valve is open will attenuate the intake swirl S generated by the helical port 3, but the intake swirl S cannot be attenuated when the valve is closed, so this embodiment In this case, at a downstream position where the helical port 3 and the sub-port 4 are close to each other, the helical port 3 and the sub-port 4 are overlapped with each other to form a communication port 6 for communicating with each other.

FIGS. 2, 3, 4, and 5 show cross-sections of the flow passages taken from the helical port and the sub-port 4 at regular intervals from upstream to downstream. In particular, FIG. 4 shows that the helical port 3 and the sub-port 4 are formed to communicate with each other via a communication port 6.

Next, the action will be explained.

When the sub port 4 and the communication port 6 have the same flow path cross-sectional area, when the sub port 4 is closed by the valve, a part of the intake swirl S in the helical port 3 is introduced from the communication port 6 into the sub port 4, The introduced intake flow flows counter-currently to the intake swirl S downstream of the helical portora, thereby attenuating the intake swirl S. However, this is a case where the cross-sectional area of the sub-port 4 and the communication port 6 are the same, so even if the sub-port 4 is closed, the damping efficiency of the intake swirl S can be improved depending on the selection of the opening area of the communication port 6. Can be done.

When the sub-port 4 is open, intake air is introduced into the sub-port 4 and a part of the intake swirl S is introduced from the communication port 6, so the amount of air flowing downstream of the helical port 3 is lower than when the sub-port 4 is closed. The intake swirl S of is more effectively damped.

In FIG. 6, a helical port 3 is formed with the same flow path cross section, and the intake swirl strength of this helical port 3 is adjusted only by the sub port 4 (valve closing is performed by AI).

(valve opening is A2) and intake swirl strength is auxiliary port 4.
When adjusting with communication port 6 (valve close is Bl).

A comparison of the damping performance with the valve opening B2) is shown.

As shown in the figure, it can be seen that the case where the adjustment is made using the sub-port 4 and the communication port 6 exhibits higher damping performance than the case where the adjustment is made only using the sub-port 4.

[Effects of the Invention] As is clear from the above explanation, the present invention exhibits the following excellent effects.

A variable swirl device is constructed from a helical port that generates an intake swirl, a sub-port that introduces intake air to flow counter-currently to the downstream intake swirl, and a communication port that connects these ports in the middle of the helical port, thereby increasing the intake swirl strength. can be adjusted well.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIG. 3 is a sectional view taken along FIG. 5 is a sectional view taken along line IV--■ in FIG. 1, FIG. 6 is a comparison diagram of intake swirl damping performance, and FIG. 7 is a sectional view showing a conventional example. In the figure, 2 is a helical port, 3 is a sub-port, and 6 is a communication port.

Claims (1)

[Claims] 1. A helical port that generates an intake swirl, and a sub-port that introduces intake air and causes it to flow counter-currently to the downstream intake swirl;
A variable swirl device characterized by comprising a communication port that communicates these ports in the middle of a helical port.