JPS597538Y2 - Internal combustion engine intake control device - Google Patents

Description

[Detailed description of the invention] An intake port of the engine body and a carburetor having a throttle valve are connected via an intake manifold, and a blockage in the intake passage downstream of the throttle valve is closed during low power operation in relation to the engine output. By providing a valve and opening the intake passage between the crest valve and the obstruction valve into the intake passage near the intake valve via a sub-intake passage with a small cross-sectional area, when the obstruction valve is closed, the sub-intake passage is closed. We have already proposed a device that introduces a high-speed intake air flow into the combustion chamber through the combustion chamber, creates an intake air vortex in the combustion chamber, and burns the intake air at high speed during the subsequent ignition stroke to improve the thermal efficiency of the engine. -137320).

However, in such an engine, the valve chamber of the shutoff valve is deformed due to the weight of the carburetor and intake manifold, or thermal distortion of the intake manifold or the engine body, and the valve stem of the butterfly-shaped shutoff valve is prevented from rotating smoothly. Something happened.

The present invention aims to eliminate such problems.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

1 in Figure 1 is the engine body, cylinder 2, piston 3
, has a combustion chamber 5 formed by a cylinder head 4.

6 and 7 are an intake passage and an exhaust passage leading to the combustion chamber, and are provided with an intake valve 8 and an exhaust valve 9.

A composite carburetor 14 having throttle valves 12 a and 12 b is connected to an intake port 11 opening on one side of the engine body 1 via an intake manifold 15 .

15a is a hot water riser that heats the manifold to vaporize fuel adhering to the inner surface of the intake passage.

16 is an insulator.

Reference numeral 17 denotes a closing valve, which is controlled in relation to the engine output, and when the output is low, the valve is fully closed or closes to a low opening close to it.

That is, the blockage valve 17 is of a so-called butterfly valve type and is rotatably supported in a valve chamber 19 by its support shaft 18.

It is connected by a link mechanism 21 to a diaphragm 22 responsive to intake negative pressure.

Of course, the technique of operating a diaphragm using intake negative pressure and extracting an output in relation to the engine output is well known in itself, so a detailed explanation will be omitted.

The intake passage 6a between the throttle valves 12a, 12b and the blockage valve 17 communicates with the intake passage 6 near the intake valve 8 via a sub-intake passage 23 having a small cross-sectional area about 1 times the cross-sectional area of the intake passage 6a. are doing.

As a result, when the blockage valve is closed, the intake air-fuel mixture that has been saved by the carburetor 14 bypasses the blockage valve and enters the auxiliary intake passage 23.
, and flows into the combustion chamber 5 through the intake passage 6 at high speed while the intake valve 8 is open, producing a high-speed vortex flow, so-called swirl.

As a result, when the air-fuel mixture is ignited, flame propagation occurs rapidly, improving the thermal efficiency of the engine.

24 is installed in the cylinder head 4 with a stud bolt, and passes through the valve chamber 19 and is attached to the manifold 15 by a nut 25 at the flange portion of the manifold 15.
The valve chamber 19 and cylinder head 4 are integrally fastened together.

As shown in FIGS. 2 and 3, at least two valve chambers 19 used for adjacent cylinders are metallurgically connected integrally by casting, and a common support shaft 18 is inserted through the valve chambers 19. Ru.

2 and 4 show a four-cylinder engine in which the valve chambers 19 of two left and right cylinders are integrated, and FIGS. 3 and 5 show a four-cylinder engine in which four valve chambers 19 are integrated. This shows an integrated structure of all 19 components.

The engine shown in FIGS. 2 and 4 has a common valve chamber 19 and a support shaft 18 for each of the two left intake passages 6, and the left and right support shafts 18a and 18b are connected to each other through an adjustment link 26. The left and right support shafts 18 a ,
18b can be corrected.

FIGS. 6 and 7 show a communication hole 23 in which the auxiliary intake passage 23 for each cylinder is formed by a groove and a valve chamber carved in the engine-side end of the intake manifold 15 at the joint surface thereof.
An example is shown in which they communicate with each other via a.

By the way, the valve chamber 19 and the engine body 1 are separate bodies, and it is difficult to match the positions of the main and sub-intake passages 6 and 23 between the two without causing errors.

In particular, when the main and auxiliary intake passages 6 and 23 are provided in the valve chamber 19 and attached to the engine body 1 as described above, the passage area fluctuation rate due to errors is smaller in the auxiliary intake passage 23 than in the main intake passage 6. This is large compared to the previous model, and has a large impact on the desired engine performance.

Therefore, when connecting the small-diameter sub-intake passages 23 with high accuracy, consideration must be given to reducing the influence of errors in the main intake passage 6.

For this reason, in this embodiment, as shown in FIGS. 1 and 6, a chamfered slope is formed on the end of the intake port 11 on the side of the engine body 1 facing the valve chamber 19, thereby increasing the resistance of the flow of intake air. It was designed to suppress the

Since the present invention is implemented as described above, even if the intake manifold 15 and the intake flange portion of the cylinder head 4 expand or contract in the cylinder arrangement direction depending on the engine temperature, the valve chambers 19 of the adjacent cylinders are Since at least two pieces are metallurgically made integrally, they are unlikely to fall over in the arrangement direction.

Therefore, there is no problem in which the concentricity between the support shaft holes 18y and 182 of the blockage valve 17 is impaired and the rotation of the support shaft 18 is hindered.

In addition, the intake manifold 15, the valve chamber 19, and the engine body 1 are connected to stud bolts 24 installed in the cylinder head.
Since the three parts are connected in one body, most of the weight of the carburetor 14 and the intake manifold 15 is directly borne by the engine body 1, so that the valve chamber 19 is not significantly deformed.

In this way, even if the valve chamber of the shutoff valve provided between the intake manifold and the engine body is subjected to thermal stress from the engine itself and from the riser of the intake manifold, the valve chamber is less deformed. .

Furthermore, since the weight of the carburetor and intake manifold is not directly applied to the valve chamber, there is little deformation due to this.

Therefore, when a butterfly-shaped blockage valve is installed in the intake passage downstream of the throttle valve, the concentricity of the shaft hole of the support shaft that supports the blockage valve will not deteriorate, and the operation of the blockage valve will not become unstable. be effective.

In addition, a chamfered slope is provided on the air outlet 11 of the engine body 1, so that the intake manifold 15, the valve chamber 19 and the engine body 1 are provided with a chamfered slope.
When these are connected in one piece, the fluctuation rate of the passage area due to the installation error of the main intake passage 6 due to the accurate connection of the small-diameter sub-intake passages 23 is minimized, and the increase in flow resistance is minimized. This has the effect of making it possible to avoid adverse effects on the desired engine performance.

As shown in FIGS. 6 and 7, when the auxiliary intake passages of each cylinder are communicated with each other, the intake air downstream of the blockage valve of the other cylinder is affected by the intake load of one valve during the intake stroke. The pressure inside the road is kept low.

As a result, high-speed auxiliary intake air flows into the combustion chamber through the auxiliary intake passage immediately at the beginning of another intake stroke, that is, when the intake valve opens, so that the vortex generated within the combustion chamber can be made even stronger. can.

In other words, if there is no such mechanism, when the intake valve opens, the intake air accumulated in the intake passage downstream of the blockage valve is first drawn into the combustion chamber, and then the auxiliary intake air is drawn into the combustion chamber through the auxiliary intake passage. As a result, the effect of creating a swirl in the thermal combustion chamber due to the sub-intake air flow is reduced.

Therefore, although the communication hole 23a is provided on the intake manifold side in the embodiment, it is preferable that the communication hole 23a be located closer to the intake valve 8.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a longitudinal cross-sectional side view of an internal combustion engine implementing the present invention, Fig. 2 is a plan view thereof,
FIG. 3 is a plan view showing another embodiment in which a part of FIG. 2 is modified. 4 is a sectional view taken along the line IV-TV in FIG. 2, and FIG. 5 is a sectional view taken along the line V--■ in FIG. 3. FIG. 6 is a longitudinal sectional side view of a main part showing still another embodiment, and FIG. 7 is a plan view thereof. 1...Engine, 6...Intake path, 11
...Intake port, 12a, 12b... Throttle valve, 14... Carburizer, 15... Intake manifold, 17... Closure valve , 18...
- Support shaft, 19... Valve chamber, 23... Sub-intake passage, 24... Stud bolt.

Claims (1)

[Scope of utility model registration request] An intake port of the engine body and a carburetor having a throttle valve are connected via an intake manifold, and a butterfly-shaped blockage valve that operates in relation to engine output is provided in the intake passage downstream of the throttle valve, and the throttle valve and blockage valve are provided in the intake passage downstream of the throttle valve. By opening the intake passage between the valve and the intake passage near the intake valve via a sub-intake passage with a small cross-sectional area, the intake passage can be opened to the intake passage near the intake valve, during relatively low-load operation of the engine when the blocking valve is in the fully open or low opening position. is an intake control device for a multi-cylinder internal combustion engine that generates a high-speed intake vortex in the combustion chamber.
A valve chamber of a blocking valve is interposed between the intake manifold and the engine body, and at least two adjacent valve chambers corresponding to each valve are metallurgically integrated, and a bolt passes through the valve chamber. An intake control device in which an intake manifold, a valve chamber, and an engine are integrally fastened together, and a chamfered slope is formed at the intake port end of the engine body facing the valve chamber.