JP2006070864A - Intake device for multi-cylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device compatibly establishing improvement of output performance and tone of intake sound. <P>SOLUTION: This device is provided with a pair of intake collectors 3a, 3b mutually facing at one side surfaces 6, one end side common line part 10 connected to an intake port 13 of an engine main body 2, intake passages 5 independent for each cylinder which consists of short branch line part 11 and long branch line part 12 in another end side branched in two ways and connected to intake collectors 3a, 3b respectively. Each short branch line part 11 is connected to one side surface of the intake collector 3 and each long branch line part 12 is connected toward roughly center in cylinder train direction at an upper part of the suction collector 3. Each suction collector 3, 3 have intake air introduction opening 7 introducing intake air formed at roughly center of the cylinder train direction of another side surface 8 facing one side surface 6 having the short branch line part 11 connected to. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intake device for a multi-cylinder internal combustion engine.

Patent Document 1 discloses a first and a second intake collector to which a first cylinder group and a second cylinder group having different intake valve opening timings are connected, and a combustion chamber of each cylinder group from the first and second intake collectors. Between a first intake collector and a second intake collector in a communication path communicating with a relatively long main intake pipe and a short bypass intake pipe provided in an intake passage for supplying intake air to the first and second intake collectors And an on-off valve arranged to be able to cut off communication, and a pipe length switching valve for opening and closing the bypass intake pipe, and the length and diameter of the main intake pipe is an intake inertia effect when the engine speed is a predetermined speed in the middle speed range Is set so that the intake air intake effect is maximized at a predetermined engine speed in the high speed region of the engine, and the length and diameter of the resonance tube are Volume of the second intake collector Intake system for a multi-cylinder engine is disclosed that the intake inertia effect when the predetermined rotational speed is set to the maximum, both in the low-speed range of the engine. In Patent Document 1, by switching between the main intake pipe and the bypass intake pipe by the pipe length switching valve, an intake inertia effect can be obtained in the engine speed region corresponding to each, and the output can be improved. ing.
Japanese Patent Laid-Open No. 5-98968

  However, in this patent document 1, since the passage length from the throttle valve to the intake valve is greatly different for each cylinder, although the engine output is improved, the tone of the intake sound is deteriorated. There is a fear. In addition, since the resonance tube needs to be set to a sufficiently long length in order to utilize the resonance effect in the low speed range, the layout of the intake system may be restricted, and the intake resistance in the high speed range may be reduced. There is a risk of deteriorating output performance.

  Therefore, the present invention provides a pair of intake collectors whose one side faces each other, a common pipe section on one end connected to the intake port of the engine body, and a bifurcated branch connected to different intake collectors. In the intake system of a multi-cylinder internal combustion engine, each of the short branch pipe sections is provided with an independent intake passage for each cylinder composed of the short branch pipe section and the long branch pipe section on the other end side. Connected to one side of the intake collector, each long branch pipe section is connected toward the center in the cylinder row direction above the intake collector, and each intake collector faces one side face to which the short branch pipe section is connected An intake inlet for introducing intake air is formed in the center of the other side surface in the cylinder row direction.

  According to the present invention, it is possible to reduce the variation of the intake flow path length from the opening of the long branch pipe section to the intake inlet between the cylinders, so that the intake air is evenly distributed to each cylinder. The output performance can be improved by distributing. In addition, the variation in the intake flow path length from the intake inlet to the intake valve has been improved between the cylinders, so the output performance is improved, and the basic order of the intake noise for each cylinder is coordinated. The tone can be improved.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 show an intake device for a multi-cylinder internal combustion engine in a first embodiment applied to a V-type 8-cylinder engine.

  An intake device 1 mounted on a vehicle is roughly composed of a pair of intake collectors 3a and 3b located above an engine body 2 and an intake manifold 4 connected to the intake collectors 3a and 3b.

  The intake manifold 4 is integrally formed with an independent intake passage 5 for each cylinder, one end of which is connected to the intake port 13 of the engine body 2 and the other end is bifurcated to be connected to the intake collector 3a and the intake collector 3b. Molded. That is, the eight intake passages 5a to 5h are respectively connected to different intake collectors 3 with the other end branching into a bifurcated shape.

  The intake collectors 3a and 3b have a substantially box shape elongated along the cylinder row direction, and are arranged so that one side surface 6a of the intake collector 3a and one side surface 6b of the intake collector 3b face each other.

  Each of the intake collectors 3a and 3b is formed with intake inlets 7a and 7b for introducing intake air at substantially the center in the cylinder row direction (the vertical direction in the drawing in FIG. 1 and the left and right direction in FIG. 2). The intake inlets 7a and 7b are formed on the other side surfaces 8a and 8b of the intake collectors 3a and 3b. A throttle valve 9 is adjacent to the intake inlets 7a and 7b and upstream of the intake air. Is provided. Further, one side surface 6 and the other side surface 8 of the intake collector 3 are formed so as to be substantially opposed to each other. Each of the intake collectors 3a and 3b is divided into one side where the intake manifold 4 is connected and the other side where the intake inlet 7 is formed by diagonally dividing surfaces P and P along the cylinder row direction. These are configured to be split into two along the cylinder row direction.

  The intake passage 5 includes a common pipe section 10 on one end side, a short branch pipe section 11 on the other end side, and the other end side having a relatively longer pipe length than the short branch pipe section 11. And a long branch pipe section 12. That is, in the intake manifold 4, a short branch is formed by the common pipe part 10 and the short branch pipe part 11, and the common pipe part 10 and the long branch pipe part 12 make the intake flow path more than the short branch. A long branch is formed.

  Each of the common pipe portions 10a to 10h is formed so as to be curved as a whole, and is connected to the intake port 13 of the corresponding cylinder at the upper part of the engine body 2.

  Each of the short branch pipe portions 11a to 11h has a straight line shape and is connected to one side surface 6 of the corresponding intake collector 3. More specifically, an intake passage 5a corresponding to the # 1 cylinder, an intake passage 5c corresponding to the # 3 cylinder, an intake passage 5e corresponding to the # 5 cylinder, and an intake passage 5g corresponding to the # 7 cylinder have their short branch pipes. Portions 11a, 11c, 11e, and 11g are connected to one side surface 6a of the intake collector 3a, an intake passage 5b corresponding to the # 2 cylinder, an intake passage 5d corresponding to the # 4 cylinder, an intake passage 5f corresponding to the # 6 cylinder, and The intake passage 5h corresponding to the # 8 cylinder has short branch pipe portions 11b, 11d, 11f, and 11h connected to one side surface 6b of the intake collector 3b. On the other end of each of the short branch pipe sections 11a to 11h, that is, in the vicinity of the connection portion between the short branch pipe section 11 and the intake collector 3, an on-off valve 14 that is controlled to open and close according to the engine speed. Are intervened. The on-off valve 14 is a so-called butterfly valve. As shown in FIG. 3, each on-off valve 14 is controlled to be fully closed when the engine speed is low and medium speed and fully open when the engine speed is high speed. The on-off valve 14 may be controlled to open and close according to the engine speed and the vehicle load.

  The long branch pipe sections 12a,..., 12h are positioned above the corresponding short branch pipe sections 11, and one end side of each long branch pipe section 12a,. From the upper side in the vertical direction (the vertical direction on the paper surface in FIG. 1 and the vertical direction on the paper surface in FIG. 2), one end on the downstream side of the opening / closing valve 14 of the corresponding short branch pipe portion 11, that is, the corresponding short branch pipe portion 11 And the other end side of each long branch pipe section 12a to 12h connected to the intake upstream end is connected toward the center of the corresponding intake collector 3 in the cylinder row direction. Yes. Furthermore, the long branch pipe sections 12a to 12h are respectively connected obliquely to the upper part on the side surface 6 side of the corresponding intake collector 3. More specifically, the long branch pipe line portion 12 has an obtuse angle α formed by the surface Q including the opening 15 and one side surface 6 of the intake collector 3 at the connection portion with the intake collector 3. The upper part of the corresponding intake collector 3 is connected obliquely. Note that the intake passage 5a corresponding to the # 1 cylinder, the intake passage 5c corresponding to the # 3 cylinder, the intake passage 5e corresponding to the # 5 cylinder, and the intake passage 5g corresponding to the # 7 cylinder have the long branch pipe portion 12a. , 12c, 12e, and 12g are obliquely connected to an upper portion of one side surface 6b of the intake collector 3b, and an intake passage 5b corresponding to the # 2 cylinder, an intake passage 5d corresponding to the # 4 cylinder, and an intake air corresponding to the # 6 cylinder In the intake passage 5h corresponding to the passage 5f and the # 8 cylinder, the long branch pipe sections 12b, 12d, 12f, and 12h are obliquely connected to the upper portion on the side surface 6a side of the intake collector 3a.

  The lengths of the long branch pipe sections 12 are set so that a so-called inertia supercharging tuning point exists in the low and medium speed rotation range of the engine. That is, the lengths of the long branches described above are set so that the inertia supercharging tuning point exists in the low and medium engine speed range.

  In FIG. 1, 16 is a flange portion of the intake manifold 4 fixed to the upper portion of the engine body, 17 is a fuel injection valve attached to the common conduit portion, and 18 is a fuel supply to the fuel injection valve 17. A fuel tube 19 is an intake valve.

  In the intake device 1 of the first embodiment described above, each long branch pipe section 12 is connected to the intake collector 3 in which the intake inlet 7 is formed in the center of the other side surface 8 in the cylinder row direction. Since the upper part of the collector 3 is connected toward the center in the cylinder row direction, the difference in the distance from the opening 15 of the long branch pipe section 12 to the intake inlet 7 can be reduced between the cylinders. That is, the variation in the intake flow path length from the throttle valve 9 to the intake valve 19 between the cylinders can be reduced, so that the output performance is improved by evenly distributing the intake air to each cylinder. can do.

  Further, since the variation in the intake flow path length from the intake inlet 7 to the intake valve 19 is improved among the cylinders, the basic order of the intake sound for each cylinder is coordinated to improve the tone of the intake sound. be able to. FIG. 4 shows the correlation between the timbre improvement allowance that is an index of the tone of the intake sound and the equality that is an index of variation between the cylinders of the intake flow path length from the throttle valve 19 to the intake valve 9. It is. As shown in FIG. 4, the smaller the isometric distance between the cylinders (the smaller the variation in the intake flow path length), the better the timbre improvement allowance, that is, the clearer timbre intake sound can be obtained and the timbre is improved. The

  Since the long branch conduit portion 12 is obliquely connected to the upper portion of the intake collector 3, intake air can be smoothly introduced from the intake collector 3 to the long branch conduit portion 12. Further, while ensuring the capacity of each intake collector 3a, 3b, the space above the intake collector 3 occupied by the long branch conduit section 12, in other words, the long branch conduit section 12 protruding above the intake collector 3 is provided. The height in the vertical direction of the engine body 2 can be made relatively small, and the intake device 1 can be made compact as a whole.

  Further, when the engine speed is low and medium speed, each on-off valve 14 is closed, and intake air is introduced into the combustion chamber (not shown) of each cylinder only from the corresponding long branch pipe section 12. Therefore, the intake inertia effect using the long branch can be utilized to the maximum. When the engine speed is high speed, each on-off valve 14 is opened, and the intake collector 3a and the intake collector 3b communicate with each other via the short branch pipe portion 11. Therefore, the intake collectors 3a and 3b The generated intake pulsations in opposite phases cancel each other out, and the intake density is averaged to improve the output performance. In addition, since intake air is introduced into the combustion chamber (not shown) of each cylinder from both the corresponding short branch pipe portion 11 and the long branch pipe portion 12, The diameter is increased, the intake resistance is decreased, and the output performance can be improved.

  Further, each intake collector 3a, 3b is configured so as to be divided into two along the cylinder row direction by the oblique dividing planes P, P, so that the connection work between the intake manifold 4 and the engine body 2 is performed. The on-off valve 14 can be easily installed in each of the short branch pipe sections 11a to 11h, and the fuel such as the fuel injection valve 17 and the fuel tube 18 adjacent to the intake manifold 4 can be easily provided. Assembly work of the system members can be facilitated.

  And since each long branch pipe part 12a, ..., 12h is connected to the end of the corresponding straight short branch pipe part 11 on the intake downstream side, each short branch pipe part 11a, ..., In a low / medium speed rotation region where each on-off valve 14 in 11h is closed, a so-called dead volume in the intake passage 5 can be reduced as much as possible, and the intake inertia effect of the long branch can be efficiently exhibited. Further, each on-off valve 14 is installed at the end of each short branch pipe section 11a to 11h on the intake upstream side in the vicinity of the connection portion between the short branch pipe section 11 and the intake collector 3. In the high-speed rotation range where each on-off valve 14 is opened, the on-off valve 14 is in response to the flow of intake air from the long branch pipe section 12 at the connection portion between the short branch pipe section 11 and the long branch pipe section 12. There is no interference.

  Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the same component as 1st Embodiment mentioned above, and the overlapping description is abbreviate | omitted.

  The intake device 30 of the second embodiment shown in FIG. 5 has substantially the same configuration as the intake device 1 of the first embodiment described above, but the most in the vertical direction of the intake collector 3 (vertical direction in FIG. 5). The lower portion and each common conduit portion 10 located below the intake collector 3 are configured to communicate with each other via an oil dropping passage 31. In other words, the vertical direction of the intake collector 3 (vertical direction in FIG. 5) via the oil dropping passage 31 in a portion of the common duct section 10 that is close to the intake collector 3 and vertically below the intake collector 3. ) In which oil staying at the bottom is introduced.

  In such a second embodiment, the oil in the intake collector 3 is sucked into the common conduit portions 10a to 10h from the oil drop passages 31 so that the oil generated in the intake collector 3 is absorbed. Generation of white smoke due to accumulation can be prevented.

  The technical idea of the present invention that can be grasped from the above embodiment will be listed together with the effects thereof.

  (1) Located above the engine body, one side faces each other, a pair of elongated intake collectors along the cylinder row direction, one end side is connected to the intake port of the engine body, and the other end side is bifurcated. In each of the intake devices of a multi-cylinder internal combustion engine, each intake passage is connected to one end side. A common branch section, a short branch pipe section on the other end side in which an opening / closing valve controlled to open and close according to the engine speed is installed, and a pipe length relative to the short branch pipe section. Each of the short branch pipe sections is connected to one side of the intake collector, and each long branch pipe section is a cylinder row above the intake collector. Touch toward the center of the direction Are, each intake collector, intake air introduction port short branch pipe portion is introduced into the cylinder row direction substantially intake at the center of the other side surface opposite to the connected one side are formed. As a result, it is possible to reduce the variation of the intake flow path length from the opening of the long branch pipe section to the intake inlet between the cylinders, so that the intake air is evenly distributed to each cylinder. Can improve output performance. In addition, the variation in the intake flow path length from the intake inlet to the intake valve has been improved between the cylinders, so the output performance is improved, and the basic order of the intake noise for each cylinder is coordinated. The tone can be improved.

  (2) More specifically, the multi-cylinder internal combustion engine intake device described in (1) is provided with a throttle valve adjacent to the intake inlet.

  (3) In the intake system for a multi-cylinder internal combustion engine described in (1) or (2) above, each long branch pipe line portion is obliquely connected to the upper portion of the intake collector. Thereby, the intake air can be smoothly introduced from the intake air collector to the long branch pipe line portion. In addition, while ensuring the capacity of each intake collector, the space above the intake collector occupied by the long branch pipe portion can be made relatively small, and the intake device can be made compact as a whole.

  (4) In the intake system for a multi-cylinder internal combustion engine according to any one of (1) to (3), when the engine speed is low and medium speed, the on-off valve is closed and only from the long branch pipe section Intake air is introduced into each cylinder, and when the engine speed is high, the on-off valve is opened and intake air is introduced into each cylinder from both the short branch pipe section and the long branch pipe section. As a result, when the engine speed is low and medium, the intake inertia effect utilizing the long branch can be utilized to the maximum. Also, when the engine speed is high, the pair of intake collectors communicate with each other via the short branch pipe section, so that the intake pulsations in opposite phases generated by the pair of intake collectors cancel each other out. The density is averaged to improve the output performance, and the substantial intake passage diameter is increased, the intake resistance is reduced, and the output performance can be improved.

  (5) In the intake device for a multi-cylinder internal combustion engine according to any one of (1) to (4) above, each common pipe section is formed to be curved as a whole, and each short branch pipe section is It is formed in a straight line, and the corresponding long branch pipe part is connected to the downstream end of the straight short branch pipe part. As a result, the so-called dead volume of the intake passage 5 can be minimized.

  (6) In the intake device for a multi-cylinder internal combustion engine according to any one of (1) to (5) above, each intake collector is connected to the short branch pipe section and the long branch pipe section by an oblique dividing surface. The one side surface formed and the other side surface on which the intake inlet is formed can be divided. As a result, the connection work between the intake manifold and the engine body can be facilitated, and the open / close valve can be easily installed in each short branch pipe section, and the fuel system member adjacent to the intake manifold can be assembled. Work can be facilitated.

  (7) In the intake system for a multi-cylinder internal combustion engine according to any one of (1) to (6), the multi-cylinder internal combustion engine is a V-type multi-cylinder internal combustion engine.

  (8) In the intake system for a multi-cylinder internal combustion engine described in (7) above, each common conduit portion is configured to communicate with the lowest portion of the intake collector in the vertical direction via an oil drain passage. Yes. As a result, it is possible to prevent the generation of white smoke due to the oil pool generated in each intake collector.

The front view in 1st Embodiment of the intake device of the multicylinder internal combustion engine which concerns on this invention. The top view in 1st Embodiment of the intake device of the multicylinder internal combustion engine which concerns on this invention. Explanatory drawing which shows the control characteristic of an on-off valve. Explanatory drawing which shows the correlation of a timbre improvement allowance and equal length. The front view in 2nd Embodiment of the intake device of the multicylinder internal combustion engine which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Intake device 2 ... Engine body 3 ... Intake collector 4 ... Intake manifold 5 ... Intake passage 6 ... One side surface 7 ... Intake inlet 10 ... Common pipe part 11 ... Short branch pipe part 12 ... Long branch pipe part

Claims (8)

Located above the engine body, one side faces each other, a pair of elongated intake collectors along the cylinder row direction, and one end side is connected to the intake port of the engine body and the other end side is bifurcated to be different from each other In an intake device of a multi-cylinder internal combustion engine, comprising an independent intake passage for each cylinder connected to an intake collector, and an intake manifold comprising these intake passages,
Each intake passage includes a common pipe section on one end side, a short branch pipe section on the other end side in which an on-off valve controlled to open and close according to the engine speed is interposed, and a short branch pipe line A long branch pipe portion which is the other end side having a relatively longer pipe length than the portion, and
Each short branch line is connected to one side of the intake collector,
Each long branch pipe section is connected toward the center of the cylinder direction in the upper part of the intake collector,
The multi-cylinder internal combustion engine, wherein each intake collector is formed with an intake introduction port for introducing intake air at a substantially central position in the cylinder row direction on the other side surface facing the one side surface to which the short branch pipe line portion is connected. Inhalation device.   2. An intake system for a multi-cylinder internal combustion engine according to claim 1, wherein a throttle valve is provided adjacent to the intake inlet.   3. The intake system for a multi-cylinder internal combustion engine according to claim 1, wherein each long branch pipe line portion is obliquely connected to an upper portion of the intake collector.   When the engine speed is low and medium speed, the on-off valve is closed and intake air is introduced into each cylinder only from the long branch pipe line. When the engine speed is high, the on-off valve is opened and the intake valve is opened. The intake device for a multi-cylinder internal combustion engine according to any one of claims 1 to 3, wherein intake air is introduced into each cylinder from both the branch pipeline portion and the long branch pipeline portion.   Each common pipe section is formed so as to be curved as a whole, and each short branch pipe section is formed in a straight line, and a corresponding long branch is provided at the downstream end of the straight short branch pipe section. The intake system for a multi-cylinder internal combustion engine according to any one of claims 1 to 4, wherein the pipe sections are connected to each other.   Each intake collector is formed by an oblique dividing surface so that it can be divided into one side where the short branch pipe part and the long branch pipe part are connected and the other side where the intake inlet is formed. The intake device for a multi-cylinder internal combustion engine according to any one of claims 1 to 5.   The multi-cylinder internal combustion engine according to any one of claims 1 to 6, wherein the multi-cylinder internal combustion engine is a V-type multi-cylinder internal combustion engine. 8. The intake system for a multi-cylinder internal combustion engine according to claim 7, wherein each common conduit portion is configured to communicate with a lowermost portion of the intake collector in the vertical direction via an oil dropping passage. .

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