JP2543312Y2 - Intake device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an intake device for an internal combustion engine.

[Conventional technology]

In the Japanese Patent Application No. 2-65430, the present applicant connects a single cylinder with a swirl port and a straight port separated by a separating wall, and opens and closes the straight port in accordance with an engine operating state. An intake device for an internal combustion engine has been proposed in which an intake control valve is provided and fuel is injected from a fuel injection valve having two injection ports to a swirl port and a straight port.

[Problems to be solved by the invention]

By the way, in this intake device, a fuel injector is disposed in a separation wall, and a first injector for guiding fuel injected from the injection port to a straight port and a swirl port on a separation wall downstream and forward of the injection port of the injection valve. When the first port and the second injector port are formed, the first
The upstream end of the separation wall extending in a wedge shape from the downstream side to the upstream side between the injector port and the second injector port is connected to the swirl port and the straight port of the first injector port and the second injector port. When the intake control valve is located on the upstream side of the upstream end of the opening, the first port is closed when the intake control valve closes the straight port.
The intake air flows in the direction opposite to the fuel injection direction in the injector port. This causes a problem that the injected fuel is scattered and adheres to the inner wall surface of the injector port, and the atomization of the fuel is deteriorated. As a result, the fuel condition deteriorates.

[Means for solving the problem]

According to the present invention, in order to solve the above problem, a first cylinder is connected to a first intake port and a second intake port which are arranged substantially in parallel with a separation wall interposed therebetween. The intake port is provided with an intake control valve that opens and closes the second intake port in accordance with an engine operating state. The first intake port and the second intake port are provided on the separation wall downstream of the intake control valve. A fuel injection valve having an injection hole for injecting fuel obliquely downstream toward each of the ports is disposed, and the fuel injected from the injection hole is supplied to the first intake port downstream of the injection hole of the fuel injection valve. An injector port leading to each of the port and the second intake port, wherein the injector port is provided with a common injector port immediately downstream of the injection hole and a separate injector formed continuously downstream of the common injector port. The common injector port is formed by hollowing out a separation wall on the downstream side of the fuel injection valve so as to linearly communicate between the first intake port and the second intake port. Is formed on a flat surface facing the downstream end of the fuel injection valve where the injection hole is formed, and the separated injector port is located on the first intake port side of the downstream side wall surface of the common injector port. And an intake device for an internal combustion engine formed by cutting off the edge on the side of the second intake port and the edge on the downstream side diagonally outside.

[Operation] The downstream side wall surface of the common injector port is formed in a plane opposite to the end where the injection hole of the fuel injection valve is formed, and when the intake control valve is closed, the intake air flows in the direction opposite to the direction of fuel injection. Does not flow. Therefore, it is possible to prevent the fuel from adhering to the inner wall surface of the injector port.

〔Example〕

Hereinafter, the present invention will be described with reference to the accompanying drawings. Second
FIG. 1 is a schematic view showing an example of a configuration of an internal combustion engine employing an intake device according to the present invention.

In the figure, 10 is a cylinder block, 12 is a combustion chamber, 14
Indicates a spark plug, and 12a and 12b indicate intake ports, respectively. The intake port and the exhaust port are provided with two intake valves 16a and 16b and two exhaust valves 18a and 18b, respectively, and have a so-called four-valve configuration. The first intake port 12a is a swirl port configured to be convenient for forming the intake swirl.
The second intake port 12b is of a straight type.

An intake control valve 32 as a butterfly valve is provided in an intake passage following the straight type intake port 12b, and when the intake control valve 32 is in a closed state, the intake air is substantially introduced only from the swirl port 12a, and the cylinder is operated. Since a strong swirl (swirl flow) of intake air is generated in the inside, stable combustion of a lean air-fuel mixture becomes possible. When the intake control valve 32 is opened, air is introduced from both the intake ports 12a and 12b, and the intake amount increases. A lever 34 is attached to a valve shaft of the intake control valve 32 of each cylinder, and the lever 34 is connected to a negative pressure actuator 38 via a lot 36. The negative pressure actuator 38 includes a diaphragm 40 and a spring 41. When a negative pressure is not applied to the diaphragm 40, the diaphragm 41 is pushed to the left in the figure by the action of the spring 41,
The intake control valve 32 assumes the open position. When a negative pressure is applied to the diaphragm 40, the diaphragm 40 is pulled right against the spring 41, and the intake control valve 32 is moved to the intake port 12b.
Take the position to close.

The diaphragm 40 is connected to a negative pressure tank 45 via an electromagnetic three-way switching valve 44. The negative pressure tank 45 is connected via a check valve to a negative pressure outlet port 24 provided on the intake pipe 20 downstream of the throttle valve 22.

The check valve 46 holds a negative pressure applied to the diaphragm 40. The switching valve 44 has three ports 44a, 44b, and 44c. When electricity is removed, the ports 44a and 44b communicate with each other. The diaphragm 40 communicates with the negative pressure port 24. The diaphragm 40 is in communication with the atmosphere. The operation of the switching valve 44 is controlled by an electronic control unit (ECU) 50.

3 to 5 are views showing details of the swirl port 12a. In this embodiment, the intake passage following the swirl port
20a is substantially straight, and the intake valve 16a of the swirl port 12a
A triangular pyramid-shaped swirl generating projection 2 is provided on the upper wall surface on the side of the straight port 12b. The protruding portion 2 has a fuel injection valve 2 extending from a vertex 2c protruding into the intake passage 20a and a vertex 2c.
A ridge line 2d extending toward the sixth side and a first guide surface 2a and a second guide surface 2b contacting each other via the ridge line 2d are provided.
The first guide surface 2a is shaped so as to deflect the intake air flow toward the outer periphery of the cylinder and to give a swirl velocity component to the intake air flow by flowing the swirl port along the outer peripheral wall surface of the cylinder (see FIG. 4). The angle between the ridge line 2e connecting the guide surface 1 and the swirl port wall surface and the central axis of the intake passage 20a (in FIG. 4, α
Indicated by ) Is preferably 45 degrees or less in order to generate an appropriate swirling flow.

In addition, the second guide surface 2b is provided with a part of the intake air flow downward with the intake valve.
Angle to the horizontal plane to deflect toward 16a (5th
The angle θ is equal to or larger than the angle θ ₀ that the axis of the injection port on the swirl port side of the fuel injection valve forms with the horizontal plane in order to guide the injected fuel to the intake valve head.
Preferably, the height of the vertex 2c is set so that the second guide surface 2b is parallel to the axis of the injection port as shown in FIG.

6 and 7 show how the fuel injection valve 26 is mounted. Referring to FIGS. 6 and 7, a fuel injection valve 26 is disposed in a thick portion of the separation wall between the swirl port 12a and the straight port 12b.

In FIG. 7, the cross-hatched portion and the reference numeral 30a indicate the end of the separation wall 30 and the fuel injection valve.
26 is formed on a plane substantially facing the end. And
A common injector port 31 is formed between the end of the fuel injection valve 26 and the end 30a of the separation wall 30, and the common injector port 31 linearly communicates the swirl port 12a and the straight port 12b. I have.

In FIG. 7, a portion shown like an insect wing is a separation injector port formed by scraping off the separation wall 30. 29a is a first separate injector port directed to the swirl port 12a, and 29b is a second separate injector port 29b directed to the straight port 12b.

FIG. 1 shows a schematic view of the injector port section. First
In the figure, the upstream end of the separation wall is 30b as shown by the dashed line.
When the upstream end 30b is located upstream of the communication portion end 31a closest to the fuel injection valve (upstream side), the intake air when the intake control valve 32 is closed is The flow is largely curved in a U-shape as shown by a chain line P in FIG. 1 and flows in a direction opposite to the fuel injection direction. For this reason, the injected fuel is scattered and adheres to the wall surface of the separation wall, and the atomization of the fuel is deteriorated. As a result the cycle variability of the mixture is increased and the fuel state deteriorated NO _X, etc. there is a problem that occurs.

For this reason, in the present embodiment, as shown by a straight line in FIG. 1, the upstream end 30a of the separation wall is located downstream of the upstream end 31a of the communication portion 31. Therefore, when the intake control valve 32 is closed, the flow of the intake air does not flow in a greatly curved U-shape as shown by the solid line E in FIG. 1, and therefore flows in the direction opposite to the fuel injection direction. Absent. Therefore, it is possible to prevent the injected fuel from scattering and adhering to the wall surface of the separation wall. Further, atomization of the fuel injected into the straight port 12b is promoted by the flow of the intake air. Therefore, it is possible to air-fuel mixture in each cycle stable get good fuel is supplied, it is possible to prevent an increase in such NO _X.

[Effect of the invention]

Since the fuel does not adhere to the inner wall surface of the injector port, the fuel can be atomized, and thus good combustion can be obtained.

[Brief description of the drawings]

1 is a schematic plan view of an injector port portion, FIG. 2 is an overall view of an internal combustion engine, FIG. 3 is a perspective view of a swirl port, and FIGS. 4 and 5 show details of a protrusion of the swirl port. FIG. 6 is a side view of the injector port and the intake port, and FIG. 7 is a plan view of FIG. 12a: swirl port, 12b: straight port, 26: fuel injection valve, 29a: first separation injector port, 29b: second separation injector port, 30: separation wall, 31: common injector port, 32: intake control valve.

Claims (1)

(57) [Scope of request for utility model registration] A first intake port and a second intake port, which are arranged substantially in parallel with a separation wall interposed therebetween, are connected to a single cylinder, and an engine operation state is connected to the second intake port. According to the second
An intake control valve that opens and closes the intake port of the intake port;
A fuel injection valve having an injection hole for injecting fuel obliquely downstream toward each of the intake port and the second intake port, and injecting the fuel from the injection hole downstream of the injection hole of the fuel injection valve. Forming an injector port for guiding the fuel to each of the first intake port and the second intake port, wherein the injector port is provided at a common injector port immediately downstream of the injection hole and at a downstream side of the common injector port. The common injector port is formed by hollowing out a separation wall downstream of the fuel injection valve so as to linearly communicate between the first intake port and the second intake port. A downstream side wall surface of the common injector port is formed on a flat surface facing a downstream end of the fuel injection valve where the injection hole is formed; The internal combustion engine according to claim 1, wherein the separation injector port is formed by cutting off an edge of the downstream side wall surface of the common injector port on the first intake port side and an edge of the second intake port side on the obliquely downstream side. Engine intake device.