JP3452787B2 - Structure of Inertial Supercharged Intake Manifold for Multi-Cylinder Internal Combustion Engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cylinder internal combustion engine, such as a four-cylinder engine, which is provided with a branch pipe independently connected to each of the cylinders. The present invention relates to a structure of an intake manifold which is connected to one surge tank on the downstream side so as to achieve supercharging of intake air by utilizing an inertial effect. 2. Description of the Related Art In general, in this type of inertia supercharged intake manifold for a multi-cylinder internal combustion engine, the length of each branch pipe from one surge tank to an intake port to each cylinder is made considerably long. By doing so, it is possible to obtain the supercharging of the intake air due to the inertia effect, so that the branch pipes for each of the cylinders are made considerably long, and the Must be configured so that each of the cylinders has substantially the same length. Therefore, conventionally, for example, Japanese Patent Application Laid-Open No.
As described in JP-A-8178 and JP-A-4-76263, each of the branch pipes having one end connected to a longitudinal side surface of a cylinder head in the internal combustion engine is made to have substantially the same length as each other, After being curved so as to extend along the longitudinal side in the above, the tip is connected to a surge tank arranged on the side of the internal combustion engine,
A throttle body provided with a throttle valve is attached to the intake inlet to the surge tank. [0004] However, it is not possible to make each of the branch pipes long so that each of the branch pipes extends along a longitudinal side surface of the internal combustion engine. The surge tank connected to the other end of each branch pipe is largely separated from the connecting portion of each branch pipe to the longitudinal side surface of the cylinder head, so that the total length of the intake manifold is longer than the length of each branch pipe. Therefore, there is a problem that the size of the entire internal combustion engine including the intake manifold becomes considerably large. Further, as described above, the surge tank having the heavy throttle body is largely separated from the connection of each branch pipe to the longitudinal side surface of the cylinder head. There is also a problem in that a large and sturdy bracket is required to support it, resulting in an increase in weight and cost. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a structure of an inertia supercharged intake manifold capable of reducing intake air flow resistance and improving workability. Is what you do. SUMMARY OF THE INVENTION In order to achieve the above technical object, the present invention provides a surge tank having an intake port connected to a throttle body, and from the surge tank to each cylinder in an internal combustion engine. In an intake manifold comprising a plurality of branch pipes extending independently and having one end connected to a longitudinal side surface of a cylinder head in an internal combustion engine, the surge tank is located at a position close to the longitudinal side surface of the cylinder head, and It is disposed at a substantially central portion of the longitudinal side of the cylinder head in the axial direction of the crankshaft, and on the lower surface thereof, each connection portion of each of the branch pipes to the surge tank is arranged in a substantially polygonal arrangement in plan view. On the other hand, when viewed from the axial direction of the crankshaft, each branch pipe is viewed from the longitudinal side of the cylinder head. A branch pipe extending from the cylinder located at the center of each of the branch pipes extends laterally through the upper side of the surge tank, curves downwardly outside the surge tank, and further upwardly curves below the surge tank. A branch pipe from an outer cylinder of the branch pipes is connected to a connection part of the connection pipe on a side farther from the internal combustion engine, among the connection parts, Out of the connection portions, the connection portion on the side remote from the internal combustion engine is outwardly inclined so that the axis thereof is obliquely outward toward the lower side than the axis of the connection portion on the side closer to the internal combustion engine in the connection portions. Tilt in the direction. " [Work]. While the surge tank is located at a position adjacent to the longitudinal side surface of the cylinder head, each branch pipe extends laterally from the longitudinal side surface of the cylinder head through the upper side of the surge tank as viewed from the axial direction of the crankshaft. By being curved downward on the outside of the surge tank and further curved upward on the underside of the surge tank and connected to each connection on the lower surface of the surge tank,
In a state where the surge tank is located at a position close to the longitudinal side surface of the cylinder head, each branch pipe having a long length for each cylinder can be disposed so as to substantially surround the outside of the surge tank. Therefore, the intake manifold can be made much more compact than before, and the entire internal combustion engine including this intake manifold can be made more compact. . Since the surge tank is located at a position close to the longitudinal side surface of the cylinder head, when the surge tank is supported on an internal combustion engine such as a cylinder head, its bracket is small, extremely simple and lightweight. The thing of the structure will be good. . A surge tank is disposed at a substantially central portion of the longitudinal side surface of the cylinder head in the axial direction of the crankshaft, and a connection portion of each of the branch pipes to the surge tank is formed on a lower surface thereof in a substantially polygonal shape in plan view. In this arrangement, the length of the surge tank along the axial direction of the crankshaft can be reduced. . Of the branch pipes, the branch pipe from the cylinder located at the center is provided on the lower surface of the surge tank. As described in detail in the following embodiments, the length of each branch pipe is set to be substantially equal for each branch pipe by being connected to the connection section farther from the internal combustion engine among the respective connection sections. Thus, it is possible to avoid an increase in the protrusion dimension from the longitudinal side surface of the cylinder head to the outer side surface of each branch pipe. . As described above, of the branch pipes from the cylinder located at the center of the branch pipes, the connection part on the side closer to the internal combustion engine among the connection parts provided on the lower surface of the surge tank,
When the branch pipes from the outer cylinder among the branch pipes are respectively connected to the connection parts farther from the internal combustion engine among the respective connection parts, the branch pipes from the cylinder located at the center are directed downward. The upwardly curved portion has a form that straddles the connection portion on the far side from the internal combustion engine among the connection portions on the lower surface of the surge tank, in other words, the tip of the branch pipe from the cylinder located outside, Of the branch pipes from the cylinder located in the center, the pipe is bent so as to enter inside the downwardly-upward bent section, and among the connection sections, the axis at the connection section farthest from the internal combustion engine and the vicinity of the internal combustion engine are close to each other. When the axis at the connection portion on the side is parallel or nearly parallel to each other, the cylinder located outside the connection portion on the side far from the internal combustion engine may To connect the branch pipe,
In the case of a metal branch pipe, since the downwardly curved portion of the branch pipe from the cylinder located on the outside must be bent with a smaller radius and a large bending angle. In the case of a branch pipe made of synthetic resin, the forming process becomes difficult, and the flow resistance of the intake air in the inside thereof increases. According to the present invention, the connecting portion on the side remote from the internal combustion engine among the connecting portions is arranged so that its axis is lower than the axis of the connecting portion on the side closer to the internal combustion engine among the connecting portions. It is inclined outwardly so as to be obliquely outward, whereby the connection part on the far side from the internal combustion engine is formed from the inside of the downwardly upward curved part of the branch pipe from the cylinder located in the center. Since the opening is formed so as to be inclined outward, when the tip of the branch pipe from the cylinder located on the outside is bent upward, the bending radius can be increased and the bending angle can be reduced. [0010] Accordingly, the present invention can reduce the size and weight of the intake manifold, and can avoid the overall increase in the size of the internal combustion engine including the intake manifold. Therefore, it is possible to reliably prevent an increase in weight and an increase in cost when supporting the surge tank with respect to the internal combustion engine, and furthermore, by the above, bending or forming of the branch pipe can be facilitated, and the intake This has the effect of reducing the flow resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the drawings when applied to a four-cylinder internal combustion engine.
In this figure, reference numeral 1 denotes four cylinders A1, A2, A
3 and A4 are arranged in series along the axial direction 1a of the crankshaft. A four-cylinder internal combustion engine is shown in FIG.
The intake ports 4, 5, 6, 7 to 2, A3, A4 are open. Reference numeral 8 denotes an intake manifold for the internal combustion engine 1. This intake manifold 8 includes a surge tank 9 made of a metal plate and four long branch metal branch pipes 10, 11, 12, and 13. One common flange 14 is fixed to one end of each of the branch pipes 10, 11, 12, and 13.
Each of the branch pipes 10, 11, 12, and 13 is disposed on each of the cylinders A with respect to the longitudinal side surface 3 of the cylinder head 2.
They are connected by a plurality of bolts 15 so as to communicate with intake ports 4, 5, 6, 7 to 1, A2, A3, and A4. As shown in FIG. 1 which is a plan view, the surge tank 9 in the intake manifold 8 is provided with a second one located at the center of the cylinders A1, A2, A3 and A4.
Disposed between the cylinder A2 and the third cylinder A3 and at a position close to the longitudinal side surface 3 of the cylinder head 2, and on the upper surface of the surge tank 9, an intake inlet pipe 16 is provided. A throttle body 17 provided with a throttle valve (not shown) is connected to an upper end of the intake port 16. On the lower surface of the surge tank 9, four connection portions 18, 19, 20, 21 for the respective branch pipes 10, 11, 12, 13 are provided, while the respective branch pipes 10, 11, 12, 12 are provided. , 13 are arranged at substantially the same length, and as shown in FIG. 3, which is a side view as viewed from the axial direction 1a of the crankshaft, the cylinder extends laterally from the longitudinal side surface 3 of the cylinder head 2 through the upper side of the surge tank 9. After that, it curves downwardly outside the surge tank 9, and further upwardly curves below the surge tank 9, so that each connection portion 18, 19, 2 on the lower surface of the surge tank 9 is formed.
0 and 21 respectively. In this case, the four connecting portions 18, 19, 20, 21 on the lower surface of the surge tank 9 are
As shown in FIG. 1 which is a plan view, each of the branches 18, 19, 20, 21 is connected to two branches 19, 20 on the side closer to the internal combustion engine 1. While connecting the branch pipes 11 and 12 from the second cylinder A2 and the third cylinder A3 located at the center of the pipes 10, 11, 12, and 13, the connection parts 18, 19, and
The branch pipes 10, 11, 1 are connected to two connecting portions 18, 21 on the side farther from the internal combustion engine 1, respectively.
The branch pipes 10 and 13 from the first cylinder A1 and the fourth cylinder A4 which are located outside of the cylinders 2 and 13 are connected. Further, each of the connecting parts 18, 19, 20, 2
1, two connecting portions 19, 20 on the side closer to the internal combustion engine 1.
As shown in FIG. 4, each of the connecting portions 18, 1 is configured such that its axis 19a, 20a is vertical.
As shown in FIG. 5, two connecting portions 18, 21 on the side remote from the internal combustion engine 1 are connected to the axis 18, 20, 21.
a, 21a is inclined outwardly so as to be obliquely outward at an appropriate angle θ toward a vertical line, that is, below the axes 19a, 20a at the two connecting portions 19, 20 on the side closer to the internal combustion engine. To As described above, while the surge tank 9 is disposed at a position close to the longitudinal side surface 3 of the cylinder head 2,
Each branch pipe 10, 11, 12, 13 connected to the longitudinal side surface 3 of the cylinder head 2 extends laterally from the longitudinal side surface 3 of the cylinder head 2 through the upper side of the surge tank 9 in a side view, and then the surge By curving downward on the outside of the tank 9 and further curving upward on the lower side of the surge tank 9 and connecting to each of the connecting portions 18, 19, 20 and 21 on the lower surface of the surge tank 9, With the surge tank 9 located at a position close to the longitudinal side surface 3 of the cylinder head 2, each of the branch pipes 10, 11, 12, 13 having a long length for each of the cylinders A1, A2, A3, A4 is removed. Since the air intake device can be disposed so as to substantially surround the outside of the surge tank 9, the intake device can be made much more compact than before. Further, since the surge tank 9 to which the heavy throttle body 17 is attached is located at a position close to the longitudinal side surface 3 of the cylinder head 2, this surge tank 9 can be used for an internal combustion engine such as the cylinder head 2. When supported, the bracket can be of a small, extremely simple and lightweight construction. Further, in addition to disposing the surge tank 9 in a substantially central portion of the longitudinal side surface of the cylinder head in the axial direction of the crankshaft in plan view, four connection portions on the lower surface of the surge tank 9 are provided. By arranging 18, 19, 20, 21 in a substantially square arrangement in plan view, the length of the surge tank 9 along the axis 1a of the crankshaft can be shortened. By the way, when the connecting portions 18, 19, 20, 21 on the lower surface of the surge tank 9 are arranged in a substantially square shape in plan view, the branch pipes 10, 11, 12, 13 are substantially mutually connected. With the same length, the branch pipes 10, 11, 12, 13 are respectively connected to the two connecting portions 19, 20 on the side closer to the internal combustion engine 1 among the connecting portions 18, 19, 20, 21. The branch pipes 10 and 13 from the first cylinder A1 and the fourth cylinder A4 located on the outer side are connected, while the connecting portions 18 and
The branch pipes 10, 1 are connected to two connecting portions 18, 21, which are farther from the internal combustion engine 1, among the connecting pipes 19, 20, 21.
When the branch pipes 11 and 12 from the second cylinder A2 and the third cylinder A3 located at the center of the first, second and third cylinders A1, 12 and 13 are connected, the connection from the second cylinder A2 and the third cylinder A3 located at the center is established. The outer surfaces 11a and 12a of the branch pipes 11 and 12 are arranged such that the length of the branch pipes 11 and 12 is substantially the same as that of the other branch pipes 10 and 13 from the outer surface of the surge tank 9. 18,
19, 20 and 21, which project from the internal combustion engine 1 by an amount connected to the two connecting portions 18 and 21 farther from the internal combustion engine 1;
The protruding dimension L up to 1a and 12a increases, and the intake manifold 8 becomes larger accordingly. As described above, each of the connecting portions 1
Each of the branch pipes 10, 1 is connected to two connecting portions 19, 20 on the side closer to the internal combustion engine 1 among 8, 19, 20, 21.
The branch pipes 11, 12 from the second cylinder A2 and the third cylinder A3, which are located at the center among the pipes 1, 12, 13 are connected, while the connecting portions 18, 19, 20, 21 are far from the internal combustion engine 1. Out of the branch pipes 10, 11, 12, and 13, the branch pipes 10, 13 from the first cylinder A1 and the fourth cylinder A4 located outside of the branch pipes 10, 11, 12, 13 are connected to the two connection portions 18, 21 on the side. Thereby, the second cylinder A2 and the third cylinder A3 located at the center
Outer surface 11 of branch pipes 11 and 12 from
a and 12a approach the surge tank 9 in a state where the lengths of the branch pipes 11 and 12 are substantially the same as those of the other branch pipes 10 and 13, and the longitudinal side surfaces 3 of the cylinder head 2 Thus, it is possible to avoid an increase in the protruding dimension L from the front side to the outer side surfaces 11a and 12a, so that the intake manifold 8 can be made more compact. Each of the branch pipes 10, 11,
The branch pipes 11, 12 from the cylinders A2, A3 located at the center of the cylinders 12, 13 are connected to the connection portions 18, 19, 20, 21 provided on the lower surface of the surge tank 9 on the side closer to the internal combustion engine 1. In parts 19 and 20, branch pipes 10 from outer cylinders A1 and A4 of the branch pipes are provided.
13 is connected to each of the connection portions 18 and 21 farthest from the internal combustion engine among the connection portions, the branch pipe 1 from the cylinders A2 and A3 located at the center.
Among the connecting portions on the lower surface of the surge tank 9, the connecting portions 18 and 19 farthest from the internal combustion engine of the connecting portions on the lower surface of the surge tank 9 have a configuration in which the curved portion from 1 to 12 extends upward.
In other words, the ends of the branch pipes 10 and 13 from the cylinders A1 and A4 located on the outside are connected to the cylinder A located at the center.
The branch pipes 11 and 12 from A2 and A3 are bent so as to enter the inside of the curved portion from downward to upward, and the axis 18a of the connecting portions 18 and 21 of the connecting portions farther from the internal combustion engine among the connecting portions. , 21a and the axes 19a, 20a at the connections 19, 20 on the side closer to the internal combustion engine.
Are parallel or nearly parallel to each other, to connect the branch pipes 10 and 13 from the cylinders A1 and A4 located outside to the connecting portions 18 and 21 far from the internal combustion engine, Of the branch pipes 10 and 13 from the cylinders A1 and A2 located on the outside, the curved portion from the downward direction to the upward direction must be bent at a smaller radius and at a larger bending angle. And the flow resistance of the intake air therein increases. In the present invention, as described above, the connecting portions 18, 21, 21 of the connecting portions 18, 19, 20, 21, which are farther from the internal combustion engine 1, have their axes 18 a, 21 a connected by the connecting portions 18, 21 a. Connecting portions 19 and 20 on the side closer to the internal combustion engine
Are tilted outward so as to be inclined obliquely outward by an appropriate angle θ below the axes 19a and 20a. With this configuration, the connecting portions 18 and 21 far from the internal combustion engine are connected to the bent portions of the branch pipes 11 and 12 from the cylinders A2 and A3 located at the center from downward to upward. The cylinders A1, A4 located outside are opened so as to be inclined outward from the inside.
When the distal ends of the branch pipes 10 and 13 are bent downward and upward, the bending radius can be increased and the bending angle can be reduced.
Can be easily bent and the flow resistance of the intake air can be reduced. Although the above-described embodiment has been applied to a four-cylinder internal combustion engine, the present invention is not limited to this, and a three-cylinder internal combustion engine (in this case, three connection portions on the lower surface of the surge tank are used) , One side is the axis 1 of the crankshaft
a is a parallel triangular arrangement) or a six-cylinder internal combustion engine (in this case, six connection portions on the lower surface of the surge tank are formed as a regular hexagon with one side parallel to the axis 1a of the crankshaft). It is needless to say that the same can be applied to the case where the intake manifold is made of synthetic resin.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing an embodiment of the present invention. FIG. 2 is a front view taken along the line II-II of FIG. FIG. 3 is a side view taken along the line III-III in FIG. 1; FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 3; FIG. 5 is an enlarged sectional view taken along line VV of FIG. 3; [Description of Signs] 1 Internal combustion engine A1, A2, A3, A4 Cylinder 2 Cylinder head 3 Longitudinal side surface 4, 5, 6, 7 of cylinder head Intake port 8 Intake manifold 9 Surge tank 10, 11, 12, 13 Branch pipe 14 Flange 16 Intake port 17 Throttle body 18, 19, 20, 21 Connection

Continuation of the front page (56) References JP-A-63-18178 (JP, A) JP-A-6-264837 (JP, A) JP-A-4-76263 (JP, A) JP-A-3-281920 (JP) U.S. Pat. No. 4,619,226 (US, A) EP 523028 (EP, A 2) EP 432919 (EP, A 1) EP 355 960 (EP, A 2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02M 35/10 F02B 27/00

Claims (1)

(1) A surge tank having an intake port connected to a throttle body, and independently extending from the surge tank toward each cylinder of the internal combustion engine, and having one end thereof connected to the internal combustion engine. Multiple connected to the longitudinal side of the cylinder head
An intake manifold comprising: a plurality of branch pipes; wherein the surge tank is disposed at a position adjacent to a longitudinal side surface of the cylinder head and at a substantially central portion of the longitudinal side surface of the cylinder head in an axial direction of a crankshaft. do it,
On the lower surface, each connection portion of each of the branch pipes to the surge tank is provided in a substantially polygonal arrangement in plan view, while each of the branch pipes is viewed from the axial direction of the crankshaft, and the longitudinal direction of the cylinder head. After extending laterally from the side through the upper side of the surge tank, it curves downwardly outside the surge tank, and further upwardly curves below the surge tank. The branch pipe is connected to the connection portion closer to the internal combustion engine among the connection portions, and the branch pipe from the outer cylinder is connected to the connection portion farther from the internal combustion engine among the connection portions. Connection, and furthermore, a connection part of the connection parts on the side remote from the internal combustion engine is connected to a connection part whose axis is closer to the internal combustion engine among the connection parts. Structure of inertia supercharged intake manifold in a multi-cylinder internal combustion engine, characterized in that inclined outwardly so as to obliquely outwardly downwardly of the axis.