JP3668446B2 - Intake device for multi-cylinder internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake device for a multi-cylinder internal combustion engine, and more particularly to an intake device for a multi-cylinder internal combustion engine having a resonance chamber that communicates with a surge tank through a communication pipe.
[0002]
[Prior art]
Conventionally, as disclosed in, for example, JP-A-11-50924, JP-A-11-117819, and the like, a surge tank connected to a resonance (resonance) chamber through a communication pipe is provided in an intake manifold of an intake device. The resonance chamber reduces the intake noise such as the intake noise, smoothes the pulsation of the intake air, removes the sound generated in the surge tank, and improves the torque of the internal combustion engine. ing. These include a structure in which a resonance chamber separate from the surge tank is connected to the surge tank through a communication pipe, and a structure in which the resonance chamber is formed integrally with the surge tank.
[0003]
[Problems to be solved by the invention]
However, for example, the one disclosed in Japanese Patent Laid-Open No. 11-50924 has a resonance chamber that is separate from the surge tank, but this structure increases the number of parts and assembly man-hours, and the manufacturing cost. There is also a problem of soaring. Further, since the communication path between the resonance chamber and the surge tank opens near the branch intake pipe farthest from the intake inlet, each branch intake pipe when reducing the intake noise generated in the surge tank by the resonance chamber is used. It is difficult to equalize the vibration frequency from
[0004]
On the other hand, what is disclosed in Japanese Patent Application Laid-Open No. 11-117819 is that a resonance chamber is integrated with a surge tank and each branch intake pipe, and a split surface is formed along each branch intake pipe in consideration of moldability. The two divided bodies (intake manifold parts 11 and 21) are joined together by abutting their welded parts together and vibration welded, reducing the number of parts and reducing the manufacturing cost. . However, this structure has a problem that it is difficult to ensure a uniform sealing property on the entire circumference because the welded portion formed on the dividing surface has a curved surface shape and a large welded area. Furthermore, since both the split bodies are not provided with positioning means for joining each other, at the time of welding, the two split bodies can be pressed directly by the welding jig, so that there is a problem that the alignment is difficult. is there.
[0005]
The present invention has been devised to solve the above-described problems of the prior art, and is a resonance chamber that is easy to manufacture and can easily ensure sealing performance, and can be expected to have a high resonance effect. It aims at providing the intake device of the multicylinder internal combustion engine which has this.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to claim 1 of the present invention , the partition member 13 provided with the communication pipe 18 is covered on the lower casing 12, and the branch intake pipes 2a, 2b, 2c, 2d of the respective cylinders are placed on the upper end surface portion. There covered with the upper casing 14 opening on the partition member, the lower casing 12, one 且sealed with substantially the same plane P and vibration-welded by overlapping outer edge portions of the partition member 13 and the upper casing 14 by integrating, defining a Les Zona Nsu chamber 16 between the partition member 13 and the lower casing 12, defining a sub Jitanku 15 between the partition member 13 and the upper casing 14, both these An intake device for a multi-cylinder internal combustion engine in which chambers are communicated with each other via the communication pipe, and a step portion 1 formed at an inner edge of the opening of the lower casing A step portion 13a formed on the outer periphery of the partition member is placed on a, and the lower casing and the partition member are positioned relative to each other, and a recess 14a formed over the entire outer periphery of the open end surface of the upper casing. The protruding members 13b formed over the entire circumference of the outer surface of the partition member facing the opening end surface are fitted to each other, and the partition member and the upper casing are mutually positioned, and the protruding members are used as welding ribs. It was characterized by vibration welding. If it does in this way, since each part can be positioned without using another positioning jig etc. at the time of welding, manufacture can be facilitated. In addition, since the welded portion fits between the stepped portions, or the ridge and the recess, and the ridge functions as a weld rib, it is easy to ensure uniform sealing performance over the entire circumference . Furthermore, in the invention of claim 2, the communication pipe 18 of the partition member 13 is opened facing the center of the opening 2a, 2b, 2c, 2d row of the branch intake pipe . Thereby , the vibration frequency from each branch intake pipe can be made uniform, the intake sound can be reduced evenly in each cylinder, and the pulsation of the intake air can be smoothed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0008]
FIG. 1 shows an entire intake system to which the present invention is applied. This intake system is provided on a surface facing forward in a state of being mounted on a vehicle body of a four-cylinder internal combustion engine (not shown), and an intake manifold 2 connected to an intake port (not shown) provided in the cylinder head. An intake chamber 3 with a resonator connected to the intake upstream end of the intake manifold 2, a throttle body 4 connected to an intake inlet opening on the upper surface of the right end of the intake chamber 3, and an anti-throttle body of the intake manifold 2 An EGR valve 6 for controlling the exhaust gas recirculation amount is provided at the end on the 4 side.
[0009]
The intake manifold 2 is formed, for example, by casting an aluminum alloy. As shown in FIG. 2, the intake manifold 2 has four elbow-shaped curves so as to connect the upper surface of the intake chamber 3 and the front surface of the cylinder head. It has branch intake pipes 2a, 2b, 2c and 2d.
[0010]
As shown in FIGS. 2 to 4, the intake chamber 3 of the intake device includes a lower casing 12 made of a thermoplastic resin having a large volume box-like container shape, and an elliptical hemispherical container placed on the lower casing 12. A partition member 13 made of a thermoplastic resin, and an upper casing 14 made of a thermoplastic resin having a substantially dome shape, which is put on the partition member. The edge of the lower casing 12, the edge of the partition member 13, and the edge of the upper casing 14 are overlapped, and the three members are joined by vibration welding and hermetically sealed in the same plane P. A resonance chamber 16 is defined between the partition member 13 and a surge tank 15 is defined between the partition member 13 and the upper casing 14.
[0011]
More specifically, the stepped portion 13a of the partition member 13 is placed on the stepped portion 12a formed at the inner edge of the lower casing 12, so that the both are positioned, and the entire circumference formed on the partition member 13 extends. The protrusions 13b are fitted into the recesses 14a of the upper casing 14, both are positioned, and the three members are positioned, and vibration welding (thermal welding) is performed, so that they are integrally joined. Here, the ridges 13b function not only as positioning but also as welding ribs.
[0012]
At the upper end of the upper casing 14, base ends of the branch intake pipes 2a, 2b, 2c, and 2d are formed so as to be connected to the intake manifold 2, and the branch intake pipes 2a, 2b, 2c, and 2d are formed. Openings 2aa, 2ba, 2ca and 2da are provided in series on the upper end surface of the upper casing 14. The partition member 13 is integrally formed with a communication pipe 18 having a predetermined diameter and length for communicating the surge tank 15 and the resonance chamber 16. The opening on the surge tank 15 side of the communication pipe 18 is provided to face the center of the opening 2aa, 2ba, 2ca, 2da row of each branch intake pipe 2a, 2b, 2c, 2d.
[0013]
In the above intake system, outside air is taken in from the air inlet, passes through an air duct and an air cleaner (both not shown), is supplied to the throttle body 4, and then led to the surge tank 15. The air introduced into the surge tank 15 is supplied to the combustion chamber of each cylinder from the branch air pipes 2a, 2b, 2c, and 2d.
[0014]
At that time, the throttle body 4 is mounted on the upstream side of the surge tank 15 with a downward opening, and the resonance chamber 16 is communicated with the opening below the surge tank 15, and the intake pressure wave inverted by the surge tank 15 including the resonance chamber 16. Is opposed to the flow of intake air flowing in through the throttle body 4 and is not directly affected by this. Thereby, the attenuation of the intake pressure wave in the surge tank 15 and each of the branch intake pipes 2a, 2b, 2c and 2d can be suppressed to the maximum, and the influence can be smoothly exerted on the other cylinders. The volumetric efficiency of intake air can be improved by the set resonance supercharging effect of intake air.
[0015]
In order to improve the volumetric efficiency due to the resonance supercharging effect when reducing the medium rotation speed of the internal combustion engine, the diameter or length of the communication pipe 18 may be changed based on the Helmholtz equation. The diameter and length of the communication pipe 18 can be easily changed, and the intake noise reduction frequency and the torque improvement frequency can be easily changed by changing them. Further, it is preferable to increase the length of the communication pipe 18 that enters the resonance chamber, so that the intake air flow in the surge tank can be prevented from being disturbed.
[0016]
Note that by changing the shape of the partition member 13, the volume of the surge tank 15 and the volume of the resonance chamber 16 can be changed without changing the upper casing 14 and the lower casing 12. As a result, it is possible to reduce intake sounds having different frequencies.
[0017]
In the above configuration, the intake device for a four-cylinder internal combustion engine has been described. However, the present invention is not limited to this, and it is needless to say that the present invention can be easily applied to other multi-cylinder internal combustion engines such as six cylinders.
[0018]
【The invention's effect】
As is apparent from the above description, according to the intake device for a multi-cylinder internal combustion engine according to the present invention described in claim 1 , another positioning treatment is performed at the time of welding of a plurality of members that define a surge tank and a resonance chamber. Since each member can be positioned relative to each other without using a tool or the like, a great effect can be achieved in facilitating manufacturing. In addition, since the welded portion fits between the stepped portions, or between the ridge and the recess, and the ridge functions as a weld rib, it is effective in facilitating ensuring uniform sealing performance over the entire circumference. According to the intake device for a multi-cylinder internal combustion engine according to the second aspect of the present invention, each branch intake is made by opening the communication pipe of the partition member so as to face the center of the opening row of the branch intake pipe. The vibration frequency from the pipe can be made uniform, the intake noise can be reduced evenly for each cylinder, and the pulsation of the intake air can be smoothed.
[Brief description of the drawings]
FIG. 1 is a perspective view of an intake system to which the present invention is applied.
FIG. 3 is an exploded cross-sectional view of a main part of the intake device of FIG.
4 is an enlarged view of a seal surface portion of FIG. 3;
[Explanation of symbols]
2 Intake manifolds 2a, 2b, 2c, 2d Branch intake pipe 3 Intake chamber 12 Lower casing 13 Partition member 14 Upper casing 15 Surge tank 16 Resonance chamber 18 Communication pipe

Claims (2)

A partition member provided with a communication pipe is placed on the lower casing, and an upper casing having an upper end surface where a branch intake pipe of each cylinder opens is placed on the partition member, and the outer periphery of the lower casing, the partition member, and the upper casing by integrating and sealed in substantially the same plane by vibration welding by overlapping edge portions to define a Les Zona Nsu chamber between the lower casing and the partition member, said upper casing and said partition member a suction device for a multi-cylinder internal combustion engine comprising so as to communicate with each other by defining a sub Jitanku, the communicating pipe both of these chambers in between,
Place the step formed on the outer periphery of the partition member on the step formed on the inner edge of the opening of the lower casing, and perform mutual positioning of the lower casing and the partition member,
A ridge formed over the entire circumference of the outer periphery of the surface facing the opening end surface of the partition member is fitted into the recess formed over the entire outer periphery of the opening end surface of the upper casing. Perform mutual positioning of the member and the upper casing,
An intake system for a multi-cylinder internal combustion engine, wherein the convex ribs are vibration welded as welding ribs .     2. The intake system for a multi-cylinder internal combustion engine according to claim 1, wherein the communication pipe of the partition member is opened facing a center of an opening row of the branch intake pipe.

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