JPS6196133A - Suction device for engine - Google Patents

Abstract

PURPOSE:To aim at improvements in combustion with a simple structure, by installing a through hole, accelerating a suction air stream, in the specified position of a control valve installed in an engine suction passage, while feeding a combustion chamber directly with the high-speed suction air stream via this through hole in time of full close in the control valve. CONSTITUTION:A disklike control valve 8 is installed in an inlet pat of a suction port 6. And, a valve shaft 9 supported on a cylinder head 1 free of rotation so as to pierce through the suction port 6 comes into combinedly contact with an actuator and controls opening of the control valve 8 so as to cause it to be full-close in time of low speed or low load but full-open in time of high speed or high load, respectively. In addition, an almost circular through hole 10 is formed in the control valve centering on a pint crossed with a directional line A-A in time of the full-close. According to this method, in time of low speed or low load running when the control valve 8 is fully closed, suction air is concentrated on this through hole 10, increasing its flow velocity, and flows into a combustion chamber 2 directly along the directional line A-A. Therefore, a powerful swirl S is formed inside the combustion chamber 2, thus a good combustion state is securable.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention improves the air flow in the combustion chamber by changing the substantial passage shape or passage area near the suction boat of the AM intake passage according to the operating conditions. The present invention relates to an intake system for an internal combustion engine that optimally controls intake properties and combustion.

(Prior Art) Techniques have been proposed in which the intake air flow within a combustion chamber is variably controlled according to operating conditions, mainly for the purpose of preventing knocking in engines with large spark points, improving fuel efficiency, and improving drivability.

One of them is the intake nozzle or stool (
A relatively small-diameter auxiliary intake passage is formed from the intake manifold to the cylinder head to generate turbulence (hereinafter simply referred to as "intake turbulence"), and the ratio of intake air flow flL to this auxiliary intake passage under predetermined operating conditions is There are some systems that increase the intake air flow and supply a high-speed intake air flow to produce strong intake air turbulence. (For example, see Japanese Patent Laid-Open No. 54-74021, etc.) (Problem to be solved by the invention, α) However, in this type of intake device, a groove in which a sub-intake passage is provided in addition to the original intake passage As a result, the shape and structure of the cylinder head and intake manifold that form the sub-intake passages become more complex, resulting in increased machining and loss in the manufacturing process, resulting in lower production yields and other problems. A problem arises.

The present invention has been made in view of these problems, and provides an intake system that can perform appropriate intake control according to the operating conditions without providing a 111 intake passage or other auxiliary passages. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a control valve that opens and closes in the ffi intake passage depending on the operating state, and also allows the control valve to fully open. When the intake valve is in the state of The control valve was formed so that the cross section of the through hole was substantially perpendicular to the cross section.

(Operation) Generally, it is necessary to generate sufficient intake air turbulence during low-speed or low-load operation when the intake air flow rate and flow velocity decrease and the intake air flow within the combustion chamber tends to become inactive.

Now, when the control valve is fully opened in such an operating state, the intake air flowing through the intake boat is concentrated in the control valve's hole, increasing its flow velocity and increasing to lS! Heading to the Kanenfu combustion chamber.

At this time, if the opening area of the hole or the area ratio with the intake passage is set so that the necessary intake flow velocity is obtained in the flow 111X range in the low speed or low load region, the intake flow line when passing through the hole will be 6
Since the L deviation is small and the directionality of the intake flow after passing through the hole changes depending on the direction of the hole, the intake flow is directed in a direction almost perpendicular to the cross section of the hole, that is, with respect to the above-mentioned intake valve. Proceed along the direction line that maximizes the projected area of the closing part between it and the valve seat.

Therefore, the high-speed intake flow after passing through the through hole advances linearly through the closed part, and directly @ without reducing its flow velocity.
Enter the baking room.

Therefore, even during low-speed, low-load operation, a necessary and sufficient flow of 6L of intake air into the combustion chamber can be obtained.

In addition, during high-speed or high-load operation when the intake flow rate increases, by fully opening the control valve, the generation of excessive intake air flow is suppressed to obtain an appropriate combustion speed, and the intake resistance is reduced to achieve the desired output. performance can be ensured.

Next, embodiments of the present invention will be described based on the drawings.

(Example) In Figure 1 and Figures 1 and 2, 1 is the cylinder head of the internal combustion engine, 2 is the combustion chamber, 3 is the exhaust valve, 4 is the intake valve,
5 is a spark plug, 6 is an intake boat forming a part of the engine intake passage, and 7 is an intake manifold. The suction boat 6 basically has a shape that allows suitable intake properties to be obtained at high speed and high load.

8 is a circular plate-shaped control valve installed at the inlet of the suction boat 6; 9 is a valve shaft rotatably supported in the sill head 1 so as to pass through the suction boat 6; the valve shaft 9 is an actuator (not shown); For example, the control valve 8 is connected to the control valve 8 so as to be fully closed at low speed or low load, and fully open at high speed or high load.
The opening degree of the valve is controlled stepwise or continuously.

10 is applied to the control valve 8 in the direction MA-AC first at all times.
It is a substantially circular through hole formed centered at the point where it intersects with the (see figure). The direction MA-A is in this case the intake valve 4 as shown.
This is a line that passes approximately through the center of the closed portion 12 that is formed in ml with the valve 811 when the valve 811 is lifted almost to the maximum, and runs along the direction in which the projected area of the closed portion is maximized. That is, the through hole 10 is formed at a position where the area of the closed portion is largest when viewed from the control valve 8.

Further, the control valve 8 is designed so that the cross section of the through hole 10 is perpendicular to the direction #1A-A when the control valve 8 is fully closed.

In the above configuration, during low-speed or low-load operation when the control valve 8 is fully closed, the intake air concentrates at the vent 10, increases the flow velocity, and flows directly into the combustion chamber 2 along the direction MA-A, as described above. . In addition, in this case, when viewed from above, the intake air flows further along the tangential direction of the intake boat 6, which is slightly offset from the center of the combustion chamber 2, as shown in FIG. A strong stool occurs in the direction indicated by arrow S. Therefore, even in such an operating range where the intake air flow rate is low, a good combustion state can be ensured.

On the other hand, during high-speed or high-load operation where the intake flow rate increases, when the control valve 8 is set to all positions, the intake air flowing through the intake boat 6 is not throttled through the air hole 10, but depends on the shape of the intake boat 6. It flows into the combustion chamber 2 with directionality.

Therefore, there will be no reduction in intake light*, rate and output, and there will be no inconvenience such as excessive intake air flow of 6L resulting in increased combustion noise.

Next, another embodiment of the present invention is shown in FIG. 3 and subsequent figures.

Figure 3 shows the bottom surface of the suction boat 6A in order to increase the flow coefficient.
The curvature of the part connected to the intake valve seat 11 is reduced.In this case, the distance between the bottom surface and the direction line A-A becomes small and there is a risk of interference with the intake flow from the through hole 10. As shown in the figure, the interference is avoided by forming a smooth groove 6B in the bottom surface 6A along the direction line A-A. It goes without saying that by improving the flow coefficient of the suction boat 6 in this manner, the engine output when the control valve 8 is fully open is improved.

Further, FIG. 5 shows an example of application to a three-valve type Isoseki equipped with two intake valves 4A, 4B and a corresponding intake boat 6 having two boat parts 6A, 6B branching from the middle. The control valve 8 has an oval through hole that approximately matches the shape of the frontage between the intake valve 4A and its valve seat 11A with respect to the direction line A-A in one boat section 6A. 10 is provided. Further, the control valve 8 is rotatably supported on a Housong 15 sandwiched between the Schilling Radar 1 and the intake manifold old 7 via a valve shaft 9. Note that 16 is a notch formed in the control valve 8 so as not to obstruct the fuel flowing along the bottom surface of the boat 6 when the valve is fully closed. In order to allow fuel to flow along the wall of the boat 6, for example, a control valve 8 is required.
The outer diameter of the boat 6 may be made slightly smaller than the inner diameter of the boat to provide an annular gap, or a groove or notch may be formed in the wall of the boat 6 so as to bypass the control valve 8.

Except for the above points, both FIGS. 3 and 5 are similar to the first embodiment, so the same parts are given the same reference numerals and the explanation thereof will be omitted.

(Effects of the Invention) As explained above, in this invention, a through hole for accelerating the intake air flow is provided at a predetermined position of a control valve installed in an engine intake passage of a suction boat, etc. By supplying all the high-speed intake air directly to the combustion chamber, a strong 6L flow of intake air can be generated within the combustion chamber. That is,
According to this invention, there is no need for an auxiliary passage for promoting intake air flow (improvement of combustion can be achieved, and therefore, the structure of the cylinder head and intake manifold old can be relatively simplified and its productivity can be increased. This has the effect of being able to.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a bottom view thereof. PIS3 diagram is also a longitudinal cross-sectional view of another embodiment. The tjSA diagram is its BB sectional view. FIG. 5 is a bottom view of still another embodiment. 1... Schilling head of an internal combustion engine, 2... Combustion chamber,
4... Intake valve, 6... Intake boat, 7... Intake manifold, 8... $ control valve, 1o... Through hole, 11... Intake valve seat, 12 ...The opening between the intake valve and the valve seat. Figure 1 Figure 2

Claims (1)

[Claims] A control valve is installed in the engine intake passage that opens and closes depending on the operating condition, and when the control valve is fully closed, the projected area of the closed part that occurs between the valve seat and the valve seat when the intake valve is lifted. An internal combustion engine characterized in that a control valve is formed such that a through hole is formed centered at a point of intersection with a direction line where the direction line is approximately maximum, and the control valve is formed such that the direction line and the cross section of the through hole are approximately perpendicular to each other when fully closed. Intake device.