JPS5813077Y2 - Intake pipe of two-valve direct injection internal combustion engine - Google Patents

Description

[Detailed description of the invention] The present invention is a two-valve direct injection internal combustion engine that is equipped with an intake inertia pipe having a shape that maintains the optimum swirl ratio necessary for combustion. It concerns the intake pipe.

In the intake pipe of the conventional two-valve direct injection internal combustion engine shown in FIGS. 1 and 2, the helical intake port 2 is different from the exhaust port 5, and the intake valve 4 and the intake port 2
Since it is formed asymmetrically with respect to the inlet part of the intake inertia pipe 1, the intake flow shown by the arrow F, which is uniformly drawn in at the position A having a circular cross section of the inlet [-] part of the intake inertia pipe 1, is drawn by a simple center line. When reaching position B, which has an oval cross section of the curved pipe represented by the curvature R, the inertial force of the intake flow F pushes the intake port 2 in the cylinder head 6 against the left inner wall in FIG. At a position having a rectangular cross section, the intake air flow F is biased toward the left side.

For this reason, the swirl S when it flows into the cylinder 3 becomes weak and deviates from the optimum value, causing poor combustion even if the amount of intake air increases, resulting in the disadvantage that high output of the engine cannot be achieved.

Here, the inflow distribution of the intake flow F in the intake inertial pipe 1 is calculated as follows: It is desired to have a uniform flow similar to the distribution.

Therefore, in order to eliminate the above-mentioned conventional drawbacks, the present invention makes the intake air inflow distribution in the intake inertial pipe a uniform flow even in the cross section of the intake port, and maintains the swirl value when the intake air flows into the cylinder at an optimal value. The purpose is to achieve good combustion and increase the output of the engine.

That is, the present invention provides an intake inertia pipe which is installed at an angle with respect to the side surface of the cylinder head, and whose center line is constructed of a straight line that matches the angle of the inclination and a straight line that is approximately perpendicular to the side surface of the cylinder head. In this configuration, a wall portion is formed on the inner surface of the intake inertia pipe on the side opposite to the intake port on the side opposite to the cylinder head, and a flat wall portion connected to the intake port side of the convex wall portion is formed.

Embodiments of the present invention will be described below with reference to the drawings.
Components that are the same as those in the conventional example shown in FIGS.

In the first embodiment of the present invention shown in FIGS. 3 and 4,
The intake inertia pipe 1 is installed so as to communicate with the intake ports 1-2 of the cylinder head 6 at an inclination angle of α with respect to the side surface of the cylinder head 6. and a center line approximately perpendicular to the side surface of the cylinder head 6, indicated by the length 12 in FIG. With respect to the intersection point X of the line on the opposite side of the side surface of the cylinder ped 6 in the intake inertia pipe 1 and the parallel line with the above-mentioned inclination angle α, the third In the figure, a convex wall portion 1a is formed with a perpendicular length 11 and a parallel length 14 connected to the side surface of the cylinder head 6, respectively, and a flat wall portion 1b with a length 11 is formed, and the inner wall of the intake inertia pipe 1, The convex wall portion 1a and the flat wall surface portion 1b are formed so as to be connected by smooth convex walls having curvatures R1 and R2, respectively.

On the other hand, the opposite side of the convex wall portion 1a, which is fixed to the intake port 2, forms a smooth convex wall portion 1C with a curvature R3.

Note that the cross section of the intake inertial tube 1 at the position E is formed into a rectangular shape.

By forming the intake inertia pipe 1 as described above, the intake flow F taken in from the circular cross section at position A passes through the circular cross section position B, and then passes through the convex wall portion formed at position E having a rectangular cross section. 1a due to its inertial force, a portion of the intake flow F is further reflected by the flat wall portion 1b, and collides with other intake flows F, resulting in a gap between position C and position where the intake port 2 has a rectangular cross section. The intake air flow F becomes almost uniform, and the swirl characteristic shown by S is maintained within the cylinder 3.

Next, in Embodiment 2 of the present invention shown in FIGS. 4 and 5, the intake inertia pipe 1 is sucked from below the cylinder head 6 in the direction of the inclination angle α, and FIGS. The same parts as in the first embodiment shown in FIG. 4 are indicated by the same part numbers and perform the same functions.

Therefore, the direction of inclination when the intake inertia pipe 1 is installed in the cylinder head 6 may be opposite to that in Embodiments 1 and 2, and the direction is not particularly restricted.

Further, the lengths of the convex wall portion 1a and the flat wall portion 1b formed in the intake inertial pipe 1 in the present invention are not particularly limited, and they act to make the intake air flow, ftF, in the intake port 2 uniform. Any length is valid as long as it is such a length.

One of the features of the intake inertia pipe 1 of the present invention is that the space around the side of the intake inertia pipe 1 adjacent to the cylinder head 6, indicated by Y in Figures 3 and 6, is wider than that of the conventional one. be.

Therefore, in a two-valve direct injection internal combustion engine to which the intake pipe of the present invention is applied, the amount of intake air is increased due to the intake inertia effect, and a uniform intake flow is obtained within the cross section of the intake port of the cylinder head. Since the optimum swirl ratio required for combustion is maintained when flowing into the combustion engine, the internal combustion engine has the effect of increasing output while maintaining low combustion costs.

In particular, the intake inertia pipe of the present invention has a shape that increases the space around the side adjacent to the cylinder head, so it is easy to insert the intake pipe mounting bolt, and this part can also be used to connect the fuel for the adjacent cylinder. There is also the advantage that high pressure pipes can be inserted and arranged.

Note that the present invention is effective for general two-valve direct injection internal combustion engines.

[Brief explanation of the drawing]

1 and 2 are a plan sectional view and a side sectional view taken along the line II in FIG. A plan sectional view and an I-I side sectional view of FIG. 3, respectively, of the main parts of the intake pipe of the engine,
5 and 6 are a plan cross-sectional view of the main part of the intake pipe of an internal combustion engine in Embodiment 2 of the present invention, and an I--
FIG. 1... Intake inertia pipe, 1a... Convex wall part,
1b: Flat wall portion, 1C: Convex wall portion, 2: Intake port, 6: Cylinder head, F: Intake Flow, S...
Swirl, α...Inclination angle.

Claims (1)

[Scope of utility model registration request] In the intake inertia pipe installed at an angle with respect to the side surface of the cylinder head, the center line of the intake inertia pipe is composed of a straight line that matches the angle of the inclination and a straight line that is approximately perpendicular to the side surface of the cylinder head. An intake pipe for a two-valve direct injection internal combustion engine, which has a convex wall part formed on the inner surface of the inertia pipe near the intake port on the side opposite to the cylinder head, and a flat wall part connected to the intake port side of the convex wall part. .