JPH0643458Y2 - Engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an intake device for an engine, and more particularly to an improvement of an intake air intake supercharger.

(Prior Art) Conventionally, as an intake device for an engine of this type, as disclosed in, for example, Japanese Patent Laid-Open No. 59-25071, a main intake passage for supplying intake air to each cylinder of the engine has a predetermined volume. By providing a surge tank that is a capacity part and connecting a branch intake passage communicating with each cylinder to the surge tank, the intake air supplied from the main intake passage is evenly distributed from the surge tank to each branch intake passage. In addition, it is known that an intake inertia effect using the pulsation of intake air is obtained while preventing intake interference between the branch intake passages.

(Problems to be solved by the invention) By the way, in such an engine intake device,
The surge tank is formed in a simple square tube shape, and the main intake passage is connected to the intake inflow side wall and the branch intake passage is connected to the intake outflow side wall.

However, in this case, since the main intake passage is positioned substantially perpendicular to the side wall of the surge tank facing the main intake passage, the flow of intake air from the main intake passage strikes the facing side wall from the front, so that in the surge tank. There is a problem that the flow of intake air is disturbed, intake resistance increases, and charging efficiency becomes low.

In view of the above, it is an object of the present invention to smooth the flow of intake air and improve the effect of intake inertia.

(Means for Solving the Problems) In order to achieve the above object, the present invention specifies the shape of the surge tank, the shape of the connection between the surge tank and the branch intake passage, and the shape of the branch intake passage. Specifically, specifically, a main intake passage that introduces intake air, a branch intake passage for each cylinder that supplies intake air to each cylinder, and a cylinder row direction provided between the main intake passage and the branch intake passage. Assuming an engine intake device including a rectangular tubular surge tank extending to a side wall, the surge tank has an intake inflow side wall and an intake outflow side wall facing each other in parallel with each other and having a relative length. Have different long side walls and short side walls, and the main intake passage is connected to a central portion in the cylinder row direction on the intake inflow side wall of the surge tank,
The axial line of the main intake passage near the surge tank and the long side wall of the surge tank are formed so that the intake air flowing into the surge tank from the main intake passage strikes the long side wall obliquely. The angle is set to an obtuse angle, and each of the branch intake passages is formed in a shape that is curved in a U shape and has an opening width in the direction orthogonal to the cylinder row direction that gradually decreases from the upstream end side to the downstream end side. The branch intake passages are connected to the side wall of the surge tank on the intake / outflow side so that the intervals between the upstream ends of the branch intake passages are smaller than the intervals between the downstream ends. The connection portion of the branch intake passage with the surge tank has an opening width in the direction orthogonal to the cylinder row direction larger than the opening width in the cylinder row direction, and a wall portion outside the connection portion is the surge tank. Inner wall of the side sidewalls and continuous to and the connection portion is to a configuration that is formed in a shape continuous with the short side walls of the surge tank.

(Operation) With the above configuration, the main intake passage is connected to the center of the side wall of the surge tank in the cylinder column direction on the intake inflow side wall, and the main intake passage has an axis near the surge tank and the long side of the surge tank. Since the angle formed by the side wall is set to an obtuse angle, the intake air that has flowed into the surge tank from the main intake passage spreads to both sides of the surge tank in the longitudinal direction and strikes the long side wall obliquely. The flow of intake air flowing into the surge tank from becomes smooth.

Since each branch intake passage is formed in a shape in which the opening width in the direction orthogonal to the cylinder row direction gradually decreases from the upstream end side to the downstream end side, the flow of intake air from the surge tank to each branch intake passage is smooth. In addition, the pressure wave transmitted from each branch intake passage to the surge tank is not easily attenuated.

Each branch intake passage is connected to the intake / outflow side wall of the surge tank so that the distance between the upstream ends of each branch intake passage is smaller than the distance between the downstream ends, so the main intake passage is a surge tank. In combination with the configuration that it is connected to the central part of the side wall of the intake inflow side, the flow of intake air flowing from the main intake passage to each branch intake passage through the surge tank becomes smooth, and Since the upstream openings are close to each other, the pressure wave transmitted from one branch intake passage to the surge tank is smoothly transmitted to the other branch intake passage.

In the connection portion of each branch intake passage with the surge tank, the opening width in the direction orthogonal to the cylinder row direction is larger than the opening width in the cylinder row direction, and the outer wall portion is continuous with the long side wall of the surge tank. In addition, since the inner wall portion has a shape that is continuous with the short side wall of the surge tank, intake air smoothly flows from the surge tank to each branch intake passage, thereby reducing intake resistance and also from one branch intake passage to the surge tank. Of the pressure wave to and from the surge tank to the other branch intake passage is smooth.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show an intake system for an engine according to an embodiment of the present invention. FIG. 1 is a front view thereof, FIG. 2 is a plan view, and FIG. 3 is a side view. In the figure, 1 is a series 4
This is a cylinder engine, and four first to fourth cylinders 2a to 2d are arranged in the engine 1 in the longitudinal direction thereof. A main intake passage 3 for supplying intake air to each of the cylinders 2a to 2d is provided above the engine 1 so as to extend in a direction orthogonal to the cylinder row. Further, on the diagonally upper side of the engine 1, there is disposed a volume portion 4 provided in the main intake passage 3 and serving as a surge tank for introducing intake air of the main intake passage 3. Further, the volume portion 4 is provided with a vertically long, substantially elliptical branch intake passage 5 for each cylinder, thereby forming the cylinders 2a to 2d.
The intake air sucked into the main intake passage 3 is stored in the volume portion 4 to relieve its dynamic pressure and then evenly distributed to the respective branch intake passages 5. The engine is supercharged by utilizing the intake inertia effect according to the equivalent pipe length of each branch intake passage 5.

Further, the volume portion 4 is formed in a rectangular tube shape and arranged in parallel with the cylinder row, and the vertical wall 6 as an inflow side wall to which the main intake passage 3 is connected is seen from FIG. It is provided substantially vertically, and the main intake passage 3 is connected to the central portion of the vertical wall 6 in the cylinder row direction. The outer wall 7a as a long side wall facing the main intake passage 3 is formed obliquely downward with respect to the intake air inflow direction into the volume 4, that is, the direction of the main intake passage 3. Each of the branch intake passages 5 has an outer wall 7a and an inner wall 7b as a short side wall formed in parallel with the outer wall 7a and below the intake intake 3a.
Are connected continuously in the same direction as the both side walls 7a, 7b along with, as shown in FIG. 1, the intake air inflow direction to the volume section 4 and the cylinders 2a to 2d from the volume section 4 The angle θ formed between the intake air flow direction and the intake air flow direction is formed as an obtuse angle.

As shown in FIG. 1, each branch intake passage 5 is formed in a U-shaped curve from the volume portion 4 to the engine 1, and has an opening width in the direction orthogonal to the cylinder row direction on the upstream end side. To the downstream end side, the shape is gradually reduced. Further, in the connection portion of each branch intake passage 5 with the volume portion 5, the opening width in the direction orthogonal to the cylinder row direction becomes larger than the opening width in the cylinder row direction, and the wall portion outside the branch intake passage 5 is formed. Is continuous with the outer wall 7a of the volume 4 and the inner wall of each branch intake passage 5 is the inner wall 7b of the volume 4.
Is formed in a continuous shape.

Further, as shown in FIG. 2, in each branch intake passage 5, the distance between the upstream end portions of each branch intake passage 5 is smaller than the distance between the downstream end portions on the inner wall 7b of the volume portion 5. It is connected.

Therefore, in the above embodiment, the dynamic pressure of the intake air sucked into the main intake passage 3 in the volume chamber 5 is relieved, so that the intake air can be evenly distributed to the respective branch intake passages 5.

Further, since the intake air inflow direction from the main intake passage 3 to the volume portion 4 and the intake air outflow direction from the volume portion 4 to each branch intake passage 5 form an obtuse angle, the flow of intake air becomes smooth and the intake resistance decreases. The filling efficiency is high. Moreover, since each branch intake passage 5 formed by the volume portion 4 is formed in an oval cross section having a major axis that substantially matches the width of the volume portion 4, the branch intake passages 5 can be arranged in close contact with each other. It is possible to shorten the length of the volume part in the cylinder arrangement direction,
The even distribution effect can be further enhanced.

Further, by providing ribs on the outer side from the vertical wall 6 of the volume part 4 to the inner side wall, the rigidity thereof is enhanced.

(Effect of the Invention) As described above, according to the engine intake system of the present invention, the main intake passage is connected to the central portion of the surge tank on the intake inflow side wall in the cylinder column direction, and The angle between the axis near the surge tank and the long side wall of the surge tank is set to an obtuse angle, so the flow of intake air flowing from the main intake passage into the surge tank becomes smooth, and the intake resistance decreases. .

Further, since each branch intake passage is formed in such a shape that the opening width in the direction orthogonal to the cylinder row direction becomes gradually smaller from the upstream end side to the downstream end side, intake air from the surge tank to each branch intake passage is intaken. As the resistance decreases,
Since the pressure wave transmitted from each branch intake passage to the surge tank is not easily attenuated, the pulsation effect of intake air is improved.

Further, each branch intake passage is connected to the intake-outlet side wall of the surge tank so that the interval between the upstream end portions of each branch intake passage is smaller than the interval between the downstream end portions,
The flow of intake air from the surge tank to each branch intake passage becomes smooth, and the pressure wave transmitted from one branch intake passage to the surge tank is smoothly transmitted to the other branch intake passage. Since it is smoothly propagated to other branch intake passages, the pulsation effect of intake air is improved.

Further, in the connection portion of each branch intake passage with the surge tank, the opening width in the direction orthogonal to the cylinder row direction becomes larger than the opening width in the intake row direction, and the outer wall portion is the long side wall of the surge tank. Since the inner wall portion is continuous with the short side wall of the surge tank, the intake resistance of the intake air flowing from the surge tank to each branch intake passage is reduced, and at the same time, one branch of the pressure wave Since the propagation from the passage to the other branch intake passage via the surge tank becomes smooth, the pulsation effect of intake air is improved.

Therefore, according to the present invention, the intake resistance of the intake air flowing from the main intake passage through the surge tank to each branch intake passage is reduced, and at the same time, it is propagated from one branch intake passage to the other branch intake passage through the surge tank. Since the attenuation of the pressure wave generated is reduced, the dynamic effect of intake air is significantly improved and engine performance is greatly improved.

[Brief description of drawings]

The drawings show an intake system for an engine according to an embodiment of the present invention. FIG. 1 is a front view, FIG. 2 is a plan view, and FIG. 3 is a side view. 1 ... Engine, 2a-2d ... Cylinder, 3 ... Main intake passage,
4 ... Volume (surge tank) 5 ... Branch intake passage, 7a
…… Outside wall (long side wall), 7b …… Inner wall (short side wall).

Claims (1)

[Scope of utility model registration request] 1. A main intake passage for introducing intake air, a branch intake passage for each cylinder that supplies intake air to each cylinder, and an angle extending in the cylinder row direction provided between the main intake passage and the branch intake passage. An intake system for an engine, comprising: a cylindrical surge tank, wherein the surge tank has a pair of intake inflow side walls and an intake outflow side wall facing each other in parallel with each other and having different relative lengths. A side wall and a short side wall, and the main intake passage is connected to a center portion of the intake tank inflow side wall of the surge tank in the cylinder column direction, and the intake air flowing into the surge tank from the main intake passage. The angle formed by the axis of the surge tank vicinity portion in the main intake passage and the long side wall of the surge tank is set to an obtuse angle so that it hits the long side wall obliquely. The branch intake passage is formed in a U-shape and has an opening width in the direction orthogonal to the cylinder row direction that gradually decreases from the upstream end side to the downstream end side. The branch intake passages are connected such that the distance between the upstream ends thereof is smaller than the distance between the downstream ends thereof, and the connection portion of each of the branch intake passages with the surge tank is in a direction orthogonal to the cylinder row direction. The opening width is larger than the opening width in the cylinder row direction, the outer wall portion of the connection portion is continuous with the long side wall of the surge tank, and the inner wall portion of the connection portion is the short side of the surge tank. An intake device for an engine, which is formed in a shape that is continuous with a side wall.