JP2510100Y2 - Internal combustion engine intake system - Google Patents

Description

The present invention relates to an intake device for an internal combustion engine, and more particularly to an intake device for an internal combustion engine in which the shape of an intake intake opening of a throttle body is changed.

[Conventional technology]

In some intake systems for internal combustion engines, a throttle body provided with a throttle valve is interposed between an air cleaner and an intake manifold. As such an intake device, the shape of the upstream opening is determined to reduce the intake resistance of intake air and increase the opening area in a limited shape.
For example, as shown in FIGS. 8 and 9, an intake intake opening 36 that is an upstream side opening of the body intake passage 34 of the throttle body 32.
Some are formed in a mortar shape. The intake system shown in FIGS. 8 and 9 includes a fuel injection valve 16 upstream of the throttle valve 14.
It is so-called single point injection with the attached. That is, as shown in FIGS. 8 to 10, in the conventional intake system, the throttle body 32 having the throttle valve 14 in the body intake passage 34 is provided between the cylindrical air cleaner 4 and the intake manifold 6 for multiple cylinders. The shaft center Z of the body air intake passage 34 is interposed and the air cleaner 4 of the air cleaner 4 is provided.
Are arranged substantially orthogonal to the axis C of the intake hole 20, and the axis B of the manifold intake passage 24 of the branch pipe 26 of the intake manifold 6 is arranged substantially orthogonal to the axis Z of the body intake passage 34. Is provided so that the axis C of the suction hole intersects the central axis O of the air cleaner 4, and the air-fuel mixture is distributed to each cylinder of a multi-cylinder internal combustion engine (not shown) on the downstream side of the throttle body 32. are doing.

Further, as an intake device for an internal combustion engine, for example
-167561. The one described in this publication is provided with a surge tank in a cylindrical space in the middle of the intake passage, and an outlet provided at the center of the surge tank so as to open in the axial direction thereof is connected to the intake manifold, and also in the surge tank. An air cleaner is connected to an inlet provided in the connecting direction.

[Problems to be solved by the invention]

By the way, in single-point injection, the cylinder distribution of the fuel, that is, the air-fuel mixture supplied to the internal combustion engine is one of the major problems, but the shape of the body intake passage formed by the throttle body takes this into consideration. There wasn't.

For this reason, in the conventional throttle body shape, the distribution of the air-fuel mixture in the cylinder is particularly poor when the throttle valve is fully opened, that is, as shown by the alternate long and short dash line in FIG. 6 branch pipes 26, 26
There is a disadvantage that the manifold intake passages 24, 24 are not evenly distributed, and as a result, knocking easily occurs.

In order to eliminate this inconvenience, it is conceivable to retard the ignition timing. However, retarding the ignition timing causes the inconvenience that the engine output decreases, and it is possible to thicken the air-fuel ratio. However, if the air-fuel ratio is increased, there is an inconvenience that fuel efficiency is deteriorated, and improvement has been desired.

[Purpose of device]

Therefore, in order to eliminate the above-mentioned inconvenience, the object of the present invention is to form the intake intake opening of the throttle body in an elliptical shape and to make the major axis of the intake intake opening in a direction substantially orthogonal to the intake flow flowing into the air cleaner. When the throttle valve is fully opened, the cylinder distribution of the air-fuel mixture can be improved and knocking can be avoided, thereby advancing the ignition timing and improving the engine output. ,
An object is to realize an intake system for an internal combustion engine that can reduce fuel consumption by reducing the air-fuel ratio.

[Means for solving problems]

In order to achieve this object, the present invention has a throttle body provided with a throttle valve in the body intake passage and is provided between a cylindrical air cleaner and an intake manifold for multiple cylinders.
The axis of the body intake passage is arranged substantially orthogonal to the axis of the intake hole of the air cleaner of the air cleaner,
The axis of the manifold intake passage of the branch pipe of the intake manifold is disposed substantially orthogonal to the axis of the body intake passage,
An intake device for a multi-cylinder internal combustion engine, wherein the intake hole has an axial center intersecting a central axis of the air cleaner, and a mixture is distributed to each cylinder on a downstream side of the throttle body. The intake intake opening is formed in an oval shape, and the long axis of the intake intake opening is oriented substantially orthogonal to the intake flow flowing into the air cleaner.

[Action]

According to the configuration of this invention, since the intake air to the air cleaner flows in substantially perpendicular to the long axis of the intake intake opening of the throttle body, the intake flow is directed in the axial direction of the throttle body in the throttle body. As a result, the intake air is evenly distributed at the branch portion of the intake manifold, and therefore, a substantially uniform air-fuel mixture is supplied to each cylinder, so that knocking can be avoided.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below with reference to the drawings.

1 to 7 show an embodiment of the present invention.
In the figure, 2 is an internal combustion engine for multiple cylinders (for example, 4 cylinders), 4 is a cylindrical air cleaner, 6 is an intake manifold for multiple cylinders, and 8 is an exhaust manifold. A throttle body 10 is provided between the air cleaner 4 and the intake manifold 6 (see FIG. 3).

Body intake passage formed in this throttle body 10
Inside 12, a throttle valve 14 is provided. Further, in the body intake passage 12, one fuel injection valve 16 is provided upstream of the throttle valve 14. That is, the internal combustion engine 2 is provided with a single point injection having one fuel injection valve 16 in the body intake passage 12.

The intake intake opening 18, which is the upstream side opening of the body intake passage 12, is formed in an oval shape, as is apparent from the plan views of FIGS. The major axis X of the intake intake opening 18 is substantially orthogonal to the axial center C of the air cleaner nanose 22 having the intake hole 20 of length L so as to be directed in a direction substantially orthogonal to the intake air flow flowing into the air cleaner 4. In this embodiment, they are arranged orthogonally (90 °) to the axis C.
The short axis Y of the intake intake opening 18 is the air cleaner
It is located on the same line as the axis C of 22.

Reference numerals 24 and 24 are manifold intake passages formed in the branch pipes 26 and 26 of the intake manifold, and Z is the body intake passage 12
Is the axis center of. The axis Z of the body intake passage 12 coincides with the central axis O of the air cleaner 4.

 Next, the operation of this embodiment will be described.

When the throttle valve 14 is fully opened, as shown in FIG. 5, the intake air flowing into the throttle body 10 side from the intake hole 20 of the air cleaners 22 has an ellipse, the long axis X of the intake intake opening 18 being the axis center. Since it is orthogonal to C, the directionality of the flow due to the intake inertia is suppressed, and it flows in substantially parallel to the axis Z of the body intake passage 12 of the throttle body 10. Then, this intake air mixes well with the fuel injected from the fuel injection valve 16 located approximately on the axis Z of the body intake passage 12.

Next, this air-fuel mixture is separated from the intake manifold 6 at the branch point S.
Since it is evenly distributed to the manifold intake passages 24, 24 (shown by the one-dot chain line in FIG. 5), the performance of distributing the air-fuel mixture to each cylinder is improved. That is, in this embodiment, in the internal combustion engine 2 having the intake passage bent in the layout of the auxiliary machine,
To rectify the air-fuel mixture before the intake manifold 6 in order to distribute the air-fuel mixture to each cylinder in a good and even manner,
The shape of the intake intake opening 18 of the throttle body 10 installed on the upstream side of the intake manifold 6 is changed to an ellipse, whereby a wide opening area is secured and the flow rate of the air-fuel mixture is increased to shorten the intake passage. With the length, the air-fuel mixture is effectively rectified (flow direction, velocity distribution, flow stabilization).

As a result, as shown in FIG. 6, the variation of the air-fuel ratio in each cylinder with the conventional throttle body shape (shown by the broken line).
Although the difference between the minimum value and the maximum value of Δ1A / F was Δ1A / F, the difference between the minimum value and the maximum value of the fluctuation of the air-fuel ratio (shown by the solid line) in each cylinder in the shape of the throttle body 10 in this embodiment is , Δ2A / F, which is smaller than the conventional difference Δ1A / F.

Further, as shown in FIG. 7, even in the engine speed state, the difference between the maximum value and the minimum value of the fluctuation of the air-fuel ratio (shown by the solid line) in this embodiment is shown by the fluctuation of the conventional air-fuel ratio (shown by the broken line). It is possible to reduce the difference between the maximum value and the minimum value of), and the operating state of the internal combustion engine 2 can be favorably maintained over the entire operating range.

Therefore, knocking of the internal combustion engine 2 can be efficiently avoided.

Since it is possible to avoid the occurrence of knocking of the internal combustion engine 2 in this way, it is possible to advance the ignition timing,
The engine output can be improved, and the air-fuel ratio can be set to the lean side, so that the fuel consumption can be improved.

The shape of the intake intake opening 18 of the throttle body 10 is not limited to the above-mentioned shape, and it goes without saying that another shape may be used as long as it is an ellipse.

[Effect of device]

As is apparent from the above detailed description, according to the present invention, the intake intake opening of the throttle body is formed in an oval shape, and the major axis of the intake intake opening is in a direction substantially orthogonal to the intake flow flowing into the air cleaner. Since it is possible to prevent the occurrence of knocking by making the cylinder distribution of the air-fuel mixture good when the throttle valve is fully opened, it is not necessary to retard the ignition timing, and the ignition timing is advanced. In addition to improving the engine output, it is not necessary to set a rich air-fuel ratio, and the air-fuel ratio can be set on the lean side to improve fuel efficiency.

[Brief description of drawings]

1 to 7 show an embodiment of the present invention, FIG. 1 is a schematic view of an internal combustion engine and an intake device, and FIG. 2 is a plan view for explaining the relationship between an air cleaner and an intake intake opening of a throttle body. FIG. 3 is a side view of the intake device, FIG. 4 is a plan view of the intake device, FIG. 5 is an explanatory view of a supply state of intake air, and FIG. 6 is a view illustrating a variation state of the air-fuel ratio in each cylinder, FIG. 7 is a diagram showing the relationship between the engine speed and the magnitude difference of the air-fuel ratio. 8 to 10 show a conventional intake device, FIG. 8 is a side view of the intake device, FIG. 9 is a plan view of the intake device, and FIG. 10 is an explanatory view of a supply state of intake air. In the figure, 2 is an internal combustion engine, 4 is an air cleaner, 6 is an intake manifold, 10 is a throttle body, 12 is a body intake passage, 14 is a throttle valve, 16 is a fuel injection valve, 18 is an intake intake opening, and 20 is intake. Holes, 22 are air cleaners, and 24 are manifold intake passages.

Claims (1)

(57) [Scope of utility model registration request] 1. A throttle body having a throttle valve provided in a body intake passage is provided between a cylindrical air cleaner and an intake manifold for multiple cylinders, and an axial center of the body intake passage is an air cleaner of the air cleaner. The intake manifold is disposed substantially orthogonal to the axial center of the intake manifold, and the manifold intake passage axial center of the branch pipe of the intake manifold is disposed substantially orthogonal to the body intake passage axial center of the intake hole. In an intake device for a multi-cylinder internal combustion engine, the axis of which is disposed so as to intersect the center axis of the air cleaner and which distributes a mixture to each cylinder on the downstream side of the throttle body, an intake intake opening of the throttle body. The intake portion of the internal combustion engine is characterized in that the portion is formed in an elliptical shape and the major axis of the intake intake opening is oriented substantially orthogonal to the intake flow flowing into the air cleaner. Apparatus.