JP2639720B2 - Intake control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an intake control device employed in a two-intake-valve internal combustion engine, in an air-fuel mixture passage from an intake manifold to a combustion chamber via an intake port. , Forming a swirl generating side groove with a swirl control valve (hereinafter referred to as SCV) to increase swirl generation and air-fuel mixture flow rate, improve combustion in low speed, low load range, and improve output and fuel efficiency. To an intake control device for an internal combustion engine.

[Conventional technology]

Generally, in the intake system of a vehicle engine, a swirl generating means such as a partition wall or a throttle valve is provided in a mixture passage in order to improve intake efficiency and combustion at low speeds and low loads where the intake air amount is small. Many intake control devices that improve the swirl effect have been proposed.

Therefore, conventionally, as described in Japanese Patent Application Laid-Open No. 55-35177, for example, the air-fuel mixture is deflected by a gap formed between the throttle valve and the intake pipe at a low load, so The gas is introduced into the port and is swirled in the combustion chamber to improve combustion, or as shown in Japanese Utility Model Laid-Open Publication No. 55-39363, the upper wall of the air-fuel mixture passage is located downstream of the throttle (swirl control) valve. Prior art is known, such as one in which a long groove for guiding a turbulent air-fuel mixture is formed along.

[Problems to be solved by the invention]

By the way, in the former prior art, the gap formed between the throttle valve and the suction pipe has a small gap around the throttle valve even if the opening area is small, and the convergence effect of the air-fuel mixture is insufficient. Becomes That is, if an attempt is made to generate a drift due to a slight opening between the normally-shaped intake pipe and the butterfly valve, the drift effect as expected due to leakage of the air-fuel mixture from around the butterfly valve cannot be obtained. Further, in the latter prior art, since the long groove for guiding the mixed air-flow mixture is formed only along the upper wall surface of the air-fuel mixture passage only in the intake port downstream of the throttle valve, a sufficient swirl effect cannot be obtained, and Since the long groove is arranged along the direction of the air-fuel mixture flow of the throttle valve, even if the air-fuel mixture is introduced into the long groove by a small opening between the intake pipe and the throttle valve at a low load, the vicinity of the throttle valve and the intake pipe are Leakage of the air-fuel mixture from the minute gap occurs, so that the air-fuel mixture cannot be guided sufficiently to the long groove, the effect of converging the air-fuel mixture to the long groove is poor, and the flow velocity is low, so that combustion is not stable.

The present invention has been proposed to solve the above-described problems. In a two-intake-valve internal combustion engine, a swirl control valve is installed at an inlet port of an intake port through which an air-fuel mixture flows from an intake manifold. Forming a side groove for guiding the air-fuel mixture from the upstream intake manifold to the upstream of the intake valve of one of the intake ports to increase swirl generation and the air-fuel mixture flow rate,
It is an object of the present invention to provide an intake control device for an internal combustion engine capable of improving combustion in a low engine speed and low load region and improving output and fuel efficiency.

[Means for solving the problem]

In order to achieve the above object, an intake control device for an internal combustion engine according to the present invention provides a two-intake valve type internal combustion engine having a butterfly swirl control valve installed in a mixture passage for introducing a mixture into a combustion chamber of the internal combustion engine. In the intake control device of the engine, from the intake manifold on the upstream side of the swirl control valve to just upstream of the intake valve hole on one side of the intake port, a spiral side groove for guiding the air-fuel mixture bypassing the swirl control valve is formed. The swirl control valve is disposed at a predetermined inclination angle so that the upper edge of the swirl control valve on the side groove side in the fully closed state is located upstream of the upper edge on the side opposite to the side groove side, The opening of the swirl control valve is operated by the intake pipe negative pressure that changes depending on the engine load. It is characterized in that it has configured to control via the actuator.

[Action]

In such a configuration, according to the present invention, at the time of idling and low load of the two-intake-valve internal combustion engine, the swirl control valve does not close the intake manifold via the actuator operated by the intake pipe negative pressure,
The air-fuel mixture flowing in the intake manifold flows along a side groove formed from a side groove of the intake manifold upstream of the swirl control valve to a position immediately upstream of the intake valve hole of one intake port, and flows into the combustion chamber from the intake valve hole. . At this time, the inclination angle of the upper end edge of the swirl control valve is disposed in a direction for removing the flow of the air-fuel mixture, and the side groove of the intake port is formed in a spiral shape.
By increasing the swirl of the air-fuel mixture and the flow rate of the air-fuel mixture, it is possible to improve combustion during low-speed, low-load operation.

Further, when the engine load becomes medium or high, the negative pressure of the intake pipe for operating the swirl control valve becomes small to open the swirl control valve, and the air-fuel mixture flows into the combustion chamber from the two intake valve holes. At this time, the passage cross-sectional area from the intake manifold to the intake port is sufficiently ensured, and the air-fuel mixture flowing from the intake port into the combustion chamber is turbulent in the combustion chamber because the side flow forms a wall flow. A flow is generated, and combustion is promoted, so that output and fuel efficiency are improved.

Furthermore, in the side groove formed from the intake manifold on the upstream side of the swirl control valve to the upstream of the intake valve of one intake port, a partition wall is formed only between the side groove and the intake port on the intake port side.
The swirl effect of the air-fuel mixture is further enhanced, and combustion is promoted in all regions from a low load to a high load.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing an intake system of a two-intake valve type horizontally opposed four-cylinder engine to which the present invention is applied. In the figure, reference numeral 1 denotes a main body of the engine, and a crankcase 2
The combustion chambers 5,5 are provided in the cylinder heads 4,4 of the right and left banks 3,3, and the combustion chambers 5,5 have two intake valve holes 6'a, 6'b as shown in FIG. Exhaust valves 7a, 7b are provided in the intake valves 6a, 6b and the two exhaust valve holes 7'a, 7'b, and a spark plug mounting hole 8 is formed substantially in the center of the combustion chambers 5,5.

The two intake valve holes 6'a and 6'b communicate with bifurcated intake ports 9a and 9b, and the two exhaust valve holes 7'a and 7'b communicate with an exhaust port 10. 6a, 6b and the exhaust valves 7a, 7b are respectively connected to the intake system valve mechanism 11, 11 and the exhaust system valve mechanism 12,
The opening / closing operation is performed at a predetermined timing according to FIG.

Next, the intake system will be described. As shown in FIG. 3, a swirl control valve 1 is provided in intake ports 9a, 9b formed in the cylinder heads 4, 4 on the left and right banks 3, 3, respectively.
Swirl control valve body with 3,13 installed 14,1
An intake manifold 15 having a curved length is connected to the intake manifold 15 via an intake pipe 4, and an intake pipe 16 for introducing air sucked from an air cleaner (not shown) is connected to a substantially central portion of the intake manifold 15. The intake pipe 16 is provided with a fuel injector 17 and a throttle valve 18 for controlling the amount of intake air.

Hereinafter, the right bank 3 will be described because the left and right banks 3 are symmetrical.

First, the swirl control valve body 14 is
Flange connected to cylinder head 4 of engine body 1
14a, which is connected with the flange 15a of the intake manifold 15 via a spacer 19 and gaskets 19a, 19b.

A swirl control valve shaft 20 to which the butterfly swirl control valve 13 is fixed is installed in the swirl control valve body 14, and the swirl control valve shaft 20 is arranged as shown in FIG. The diaphragm-type actuator 21 can rotate through an operation rod 21b and a link 22.

An intake pipe negative pressure in the intake manifold 15 is introduced into the diaphragm chamber 21a of the actuator 21 through the negative pressure passage 23, and the operating rod 21b is moved up and down by the intake pipe negative pressure that changes according to an operation state. The opening degree of the swirl control valve 13 is controlled. As shown in FIGS. 4 to 6, the fully open position and the fully closed position in the operating angle range of the swirl control valve 13 are regulated by stoppers 24a and 24b, respectively. Is done.

Furthermore, the above-mentioned shaft for the swirl control valve
Numeral 20 corresponds to the two cylinders arranged on the right bank 3 side as shown in FIG. 5, and the swirl control valves 13 and 13 in the swirl control valve body 14.
Are linked together.

On the other hand, as shown in FIGS. 2 and 7, the swirl control valve 13 installed in the swirl control valve body 14 has a tilt angle set in a range of 5 degrees to 30 degrees in a fully closed state, and A twist angle (30 degrees to 45 degrees) is formed along the upper wall surface of the air-fuel mixture passage in a direction in which the flow of the air-fuel mixture is swept by the upper edge of the swirl control valve 13.
The side groove 30 having a degree (degree) is formed.

As shown in FIGS. 1 and 3, the swirl control valve body 14 has an intake manifold 15 connected to the upstream side of the swirl control valve body 14 and one intake port 9a of the cylinder head 4 connected to the downstream side. The side grooves 31 and 32 are formed so as to communicate with the side grooves 30 formed in the valve body 14 and do not hinder the flow of the air-fuel mixture.

That is, the side groove 31 formed along the upper wall surface of the mixture passage of the intake manifold 15 is extended to an appropriate length in the upstream intake manifold 15 of the swirl control valve 13, and is formed in the intake port 9a. The side groove 32 extends to a position immediately upstream of the intake valve hole 6'a in the intake valve 6a.

Further, the side groove 32 of the intake port 9a is formed in a slightly spiral state as shown in FIGS. 3 and 8, and the immediately upstream portion of the intake valve hole 6'a faces the tangential direction of the combustion chamber 5. ,
Swirl is generated in the air-fuel mixture flowing through the side groove 32.

In the drawing, reference numeral 35 denotes a water jacket through which cooling water flows in the cylinder head 4, and reference numeral 36 denotes a cooling water passage for preheating intake air in the intake manifold 15.

Further, the embodiment according to the present invention is a single point injection type in which an injector 17 is installed in an intake pipe 16, but a multi-point injection type in which an injector is installed immediately upstream of a side groove 31, 31 corresponding to each cylinder from the intake manifold 15. It can be a point injection type, and the description is omitted.

Next, the operation of the intake control device for an internal combustion engine thus configured will be described.

First, during low-load operation including the idling state, a negative pressure is introduced into the diaphragm chamber 21a of the actuator 21 by the intake pipe negative pressure of the intake manifold 15, and the operating rod 21b
, The swirl control valve 13 is closed in the swirl control valve body 14. At this time, the air-fuel mixture is guided to the side groove 31 of the intake manifold 15 and is drawn into the side groove of the swirl control valve body 14.
While passing through 30, the air flows along the side groove 32 of the intake port 9a, and is introduced into the combustion chamber 5 by opening the intake valve 6a.

The flow of the air-fuel mixture in the side groove 31 of the intake manifold 15 is
Since the air-fuel mixture is removed by the swirl control valve 13, the air-fuel mixture passing through the spiral side groove 32 of the intake port 9 a flows in a layered manner, and the swirl ratio rises, and at the end of the compression stroke, the turbulence converted from the swirl flows into the combustion chamber 5. Therefore, combustion is favorably performed.

On the other hand, when the engine load is increased and the operation becomes medium or high load, the negative pressure of the intake pipe for operating the swirl control valve 13 is reduced, and the operating rod 21b of the actuator 21 is operated.
Is lowered to open the swirl control valve 13, and the air-fuel mixture is introduced into the combustion chamber 5 through the intake ports 9a and 9b. At this time, a wall flow is generated by the side groove 32 in the air-fuel mixture flowing from the intake port 9a, and turbulence is generated in the combustion chamber 5 to promote combustion.

FIGS. 9 and 10 show another embodiment according to the present invention, in which a partition wall 33 is provided so as to surround the side groove 32 only in a side groove 32 formed in one of the intake ports 9a on the cylinder head 4 side, and a low load state is provided. In addition, the swirl ratio is further increased by the drift effect of the air-fuel mixture flowing through the side groove 32 of the intake port 9a when the load is medium and high.

〔The invention's effect〕

As described above, according to the present invention, in the two-intake-valve engine, the swirl control valve is installed at the inlet of the intake port through which the air-fuel mixture flows from the intake manifold, and the swirl control valve is provided with the swirl control valve from the upstream intake manifold. A helical gutter that guides the air-fuel mixture immediately upstream of the intake valve hole at one intake port increases swirl due to drift and increases the air-fuel mixture flow rate at low load, resulting in the mixing and combustion of the air-fuel mixture. The combustion is improved in the practical use range of the engine.

Further, at the time of medium and high loads, effective combustion is performed due to the turbulence effect of the air-fuel mixture, so that output and fuel efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic structural view showing an intake system of a two-intake valve type horizontally opposed four-cylinder engine according to the present invention, FIG. 2 is a front view showing an intake port inlet of a cylinder head, and FIG.
III-III sectional view, FIG. 4 is a partially cutaway front view showing the actuator, FIG. 5 is a VV sectional view of FIG. 1, FIG. 6 is a VI-VI sectional view of FIG. FIG. 8 is a sectional view taken along line VII-VII of FIG. 2, FIG. 8 is an explanatory view showing a sectional shape at each position of the intake port according to the present invention, FIG. 9 is an explanatory view showing another embodiment of the intake port, FIG. The figure is a view as viewed in the direction of the arrow Z in FIG. 1 ... engine body, 4 ... cylinder head, 5 ... combustion chamber, 6a, 6b ... intake valves, 6'a, 6'b ... intake valve holes, 9
a, 9b …… Intake port, 13… Swirl control valve, 14 …… Swirl control valve body, 20 ……
Shaft for swirl control valve, 21 ... Actuator, 30 ... Side groove, 31, 32 ... Side groove.

Claims (2)

(57) [Claims] An intake control device for a two-intake valve type internal combustion engine, comprising a butterfly type swirl control valve installed in an air-fuel mixture passage for introducing an air-fuel mixture into a combustion chamber of the internal combustion engine, wherein an upstream side of the swirl control valve is provided. From the intake manifold to just upstream of the intake valve hole on one side of the intake port, a spiral groove is formed to guide the air-fuel mixture by bypassing the upstream swirl control valve, and the swirl control valve is fully closed in the side groove side. The swirl control valve is disposed at a predetermined inclination angle such that the upper edge of the swirl control valve is located upstream of the upper edge opposite to the side groove side, and the opening degree of the swirl control valve is changed depending on the engine load. That it is controlled via an actuator operated by the negative pressure of the intake pipe Intake air control system for an internal combustion engine according to symptoms. 2. A two-intake-valve internal combustion engine in which a side groove for bypassing the swirl control valve and guiding an air-fuel mixture is formed from an upstream intake manifold of the swirl control valve to a position immediately upstream of one intake valve hole of an intake port. The intake control device for an internal combustion engine according to claim 1, wherein a partition wall is formed between the side groove and the intake port only on the intake port side.