JP2010203357A - Intake device of multi-cylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To equally distribute intake by an auxiliary intake passage to each cylinder, to improve an air-fuel ratio variation among cylinders, and to improve the exhaust gas performance of an internal combustion engine. <P>SOLUTION: A swirl flow generating means (an inner wall 61A of a circular arc face and restriction by a step 68) generating swirl flow around a suction air intake port 62 is formed in a terminating part 61 where an aggregate passage 60 communicates with the suction air intake port 62 of an auxiliary intake chamber 58. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an intake device for a multi-cylinder internal combustion engine, and more particularly to an intake device having an auxiliary intake system.

  As an intake device of a multi-cylinder internal combustion engine, a main intake passage for supplying intake air to each of a plurality of cylinders, a main throttle valve provided in the main intake passage, and the main intake air downstream of the main throttle valve An intake device having an auxiliary intake passage that supplies intake air to the passage is known (for example, Patent Document 1).

  The auxiliary intake passage may be called an auxiliary intake passage or a bypass intake passage. In addition, since idle control is performed by the intake air flowing through the auxiliary intake passage, the auxiliary intake passage is called a primary intake passage, and the main intake passage provided with the main throttle valve is sometimes called a secondary intake passage. In the specification, the secondary intake passage is called a main intake passage, and the primary intake passage is called a sub intake passage.

JP 2003-328882 A

  In the intake device as described above, the distribution characteristic of the intake air between the cylinders by the auxiliary intake passage affects the air-fuel ratio variation between the cylinders. For this reason, in order to reduce the variation in the air-fuel ratio among the cylinders, the intake air from the auxiliary intake passage must be evenly distributed and supplied to each cylinder.

  The problem to be solved by the present invention is to improve the distribution characteristic between the cylinders of the intake air by the auxiliary intake passage, and to improve the exhaust gas performance of the internal combustion engine by suppressing the air-fuel ratio variation between the cylinders.

  An intake apparatus for a multi-cylinder internal combustion engine according to the present invention includes a plurality of main intake passages provided for each of a plurality of cylinders for supplying intake air to each cylinder, a main throttle valve provided for each of the main intake passages, An intake system for a multi-cylinder internal combustion engine having an auxiliary intake passage for supplying intake air to the main intake passage on the intake downstream side of the main throttle valve, wherein the auxiliary intake passage is provided for each of the cylinders. A plurality of branch passages that communicate with the intake passage, an intake chamber that is connected to the plurality of branch passages and has one intake intake opening, and communicates with the intake intake with a terminal end upstream of the intake intake. And an eddy current generating means for generating an eddy current around the intake intake port in the collective passage.

  According to this configuration, when the intake air flows from the collecting passage through the intake port to the intake chamber, a vortex flow around the intake port is generated in the intake air by the vortex generating means. As a result, the intake air flows evenly from the entire circumference of the intake air intake to the intake chamber, and the intake air does not flow into the intake chamber with directivity with respect to a specific branch passage, and the intake air is evenly distributed to the branch passages of each cylinder. Is done.

  In the intake system for a multi-cylinder internal combustion engine according to the present invention, preferably, the intake inlet communicates and connects the intake chamber and the collecting passage with a circular or elliptical through hole, and the intake intake is The intake chamber and the collective passage are connected in communication with each other with a circular or elliptical through-hole, and the vortex generating means is seen in a cross section of the passage perpendicular to the flow direction of the intake air flowing through the collective passage. One side of the end portion in the passage width direction has a smaller passage cross-sectional area than the other side, and the one side serves as a throttle portion.

  According to this configuration, when the intake air flowing from the collecting passage to the intake port flows into the terminal portion, the throttle portion receives a throttle action on one side of the passage and is given a flow resistance difference in the passage width direction of the terminal portion. . Due to this flow path resistance difference, an intake speed difference and a flow rate difference are produced in the passage width direction of the end portion, and by these, a swirl flow (swirl flow) swirling around the speed difference intake port is generated.

  In the intake device for a multi-cylinder internal combustion engine according to the present invention, preferably, an opening direction of the intake port with respect to the intake chamber is different from an opening direction of the inlet of the branch passage formed in the intake chamber with respect to the intake chamber. ing. Since the opening direction of the intake intake with respect to the intake chamber is different from the opening direction of the branch passage inlet, the intake air does not flow directly into the intake chamber from the intake intake with respect to a specific branch passage. In addition, the even distribution performance for each cylinder of intake air is improved.

  In the intake system for a multi-cylinder internal combustion engine according to the present invention, preferably, the intake chamber is long in a cylinder row direction of the multi-cylinder internal combustion engine, and the intake chamber is provided with a branch passage of each cylinder at intervals in the cylinder row direction. The inlet is open, and the ignition sequence of the multi-cylinder internal combustion engine is reversed in the cylinder row direction. The intake intake port opens into the intake chamber at a position corresponding to an intermediate position when viewed in the cylinder row direction.

  According to this configuration, the branch passage that sucks in the intake air from the intake chamber changes depending on the ignition order, so that the intake air flows into the intake chamber from the intake intake into the central region where the intake air in the intake chamber is swung in the cylinder row direction. This also improves the even distribution performance of the intake air to each cylinder.

  According to the intake system for a multi-cylinder internal combustion engine according to the present invention, when the intake air flows from the collecting passage to the intake chamber through the intake air intake, a vortex flow around the intake intake is generated in the intake air by the vortex generating means, It flows uniformly from the entire circumference of the intake port to the intake chamber. As a result, the intake air does not flow into the intake chamber with directivity with respect to the specific branch passage, and the intake air is evenly distributed to the branch passages of the respective cylinders, thereby suppressing variations in the air-fuel ratio among the cylinders.

1 is a cross-sectional view showing one embodiment of a V-type multi-cylinder internal combustion engine to which an intake device according to the present invention is applied. The figure which shows typically one Example of the intake device of the multicylinder internal combustion engine by this invention. The plane sectional view of the air intake device by this example. The longitudinal cross-sectional view of the principal part of the intake device by a present Example. Sectional drawing along line VV of FIG. Sectional drawing along line VI-VI of FIG. Explanatory drawing for showing the appropriate position of the intake port in the intake device of the multi-cylinder internal combustion engine according to the present invention.

  An embodiment of an intake device for a multi-cylinder internal combustion engine according to the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the multi-cylinder internal combustion engine (engine) of the present embodiment is a V-type multi-cylinder engine, and a cylinder bore 16 is provided in each of the right bank portion 12 and the left bank portion 14 of the cylinder block 10. Is formed. A plurality of cylinder bores 16 are provided in a direction orthogonal to the plane of FIG. 1. In the case of a 10-cylinder V-type engine, five cylinder bores 16 are formed by the right bank portion 12 and the left bank portion 14, respectively.

  A cylinder head 18 is attached to each of the right bank portion 12 and the left bank portion 14 of the cylinder block 10 so as to close the upper end of the cylinder bore 16. A piston 20 is provided in the cylinder bore 16 so as to be able to reciprocate. The piston 20 defines a combustion chamber 22 (# 1 to # 5 cylinder) with the cylinder head 18.

  The cylinder head 18 of each bank has an intake port 24 and an exhaust port 26 for each combustion chamber 22. The intake port 24 and the exhaust port 26 are opened and closed at the open end (downstream end) with respect to the combustion chamber 22 by an intake valve 28 and an exhaust valve 30, respectively.

  An intake body 40 is attached to an intake connection surface portion (surface portion where the upstream end of the intake port 24 is opened) of the cylinder head 18 of each bank. The intake body 40 is also referred to as an injector base member, and includes a plurality of main intake passages 42 that individually communicate with the intake ports 24, and injector mounting holes 44 that are opened in the plurality of main intake passages 42 (see FIG. 3). ) And formed. The main intake passage 42 is provided for each cylinder and individually supplies intake air to each cylinder. An injector (fuel injection valve) 32 is attached to the injector attachment hole 44. The injector 32 is provided for each cylinder and injects fuel toward the intake port 24 communicating with the main intake passage 42.

  A throttle body 70 is attached to the intake upstream side of the intake body 40. The throttle body 70 has a plurality of throttle passages 72 that individually communicate with the main intake passages 42. The throttle passage 72 is individually provided for each cylinder. A main throttle valve 74 is provided in each of the plurality of throttle passages 72. The main throttle valve 74 is a multiple type provided individually for each cylinder, that is, for each main intake passage 42, and is a butterfly valve that is rotatably supported by the throttle body 70 by a common valve shaft 76. It is. The main throttle valves 74 of the cylinders are simultaneously opened and closed by a valve shaft 76 to quantitatively adjust (measure) the flow rate of intake air (intake air amount) taken into the combustion chambers 22 through the main intake passage 42.

  Such a throttle mechanism is called a cylinder-by-cylinder throttle or a multiple throttle, and in this multiple throttle, the intake passage length from each throttle valve to the combustion chamber of each cylinder can be set short, so that the throttle opening change Responsiveness of actual intake air amount change due to.

  A main intake chamber 80 forming a collecting pipe portion of the intake manifold is connected to the intake upstream side of the throttle body 70.

  Next, details of the auxiliary intake system of the intake device according to the present embodiment will be described with reference to FIGS. Since the intake device of the right bank portion 12 and the left bank portion 14 have the same configuration of symmetrical arrangement, the one of the bank portion will be described. Further, the five cylinders in the bank portion on one side are referred to as # 1 cylinder, # 2 cylinder, # 3 cylinder, # 4 cylinder, and # 5 cylinder in order from the left one in FIG.

  In the intake body 40, as auxiliary intake passages, there are branches corresponding to the number of cylinders that extend around the outer periphery of each main intake passage 42 so as to be curved and communicate with the main intake passage 42 downstream of the main throttle valve 74. A passage 46, a sub-intake chamber 58 connected to the branch passage 46 of each cylinder, and a collective passage 60 upstream of the sub-intake chamber 58 are formed.

  The auxiliary intake chamber 58 is long in the cylinder row direction (left and right direction as viewed in FIG. 3) of the multi-cylinder internal combustion engine, and is formed on the vertical side wall of the auxiliary intake chamber 58 at the entrance of the branch passage 46 of each cylinder at intervals in the cylinder row direction. 48 is open.

  As shown in FIG. 4, the collecting passage 60 is a passage separated from the auxiliary intake chamber 58 by the ceiling wall 40 </ b> A of the auxiliary intake chamber 58. A single intake intake 62 communicating with the end portion 61 of the collecting passage 60 and the auxiliary intake chamber 58 is opened in the ceiling wall 40A. The intake air intake 62 is a circular through hole, and the opening direction of the intake air intake 62 with respect to the auxiliary intake chamber 58 is perpendicular to the inlet 48 of the branch passage 46 formed in the auxiliary intake chamber 58. The opening direction with respect to the auxiliary intake chamber 58 is a horizontal direction, and the opening directions are different from each other.

  In FIG. 2, the opening direction of the intake intake 62 and the opening direction of the inlet 48 are the same, but in FIG. 2, the entire auxiliary intake passage is shown in a plan view. Actually, the direction is different as shown in FIG.

  The intake air intake 62 is a cylinder arrangement of the inlets 48 of the branch passage 46 corresponding to two cylinders whose ignition order is continuous between adjacent cylinders after the ignition order of the multi-cylinder internal combustion engine is reversed in the cylinder row direction. The auxiliary intake chamber 58 opens at an arrangement position A (see FIG. 3) corresponding to an intermediate position in the direction when viewed in the cylinder row direction.

  As shown in FIG. 7A, the ignition sequence of the five-cylinder internal combustion engine is ignited when the order is # 1 cylinder → # 5 cylinder → # 2 cylinder → # 3 cylinder → # 4 cylinder → # 1 cylinder. The two cylinders whose ignition sequence is continuous between adjacent cylinders after the order is reversed in the cylinder row direction are the # 2 cylinder and the # 3 cylinder, and the arrangement position A of the intake intake 62 in the cylinder row direction is The intermediate position in the cylinder arrangement direction between the inlet 48 of the branch passage 46 corresponding to the # 2 cylinder and the inlet 48 of the branch passage 46 corresponding to the # 3 cylinder corresponds to the position in the cylinder row direction.

  As another example, in the case of a four-cylinder internal combustion engine, as shown in FIG. 7B, the ignition sequence is # 1 cylinder → # 4 cylinder → # 2 cylinder → # 3 cylinder → In the case of the # 1 cylinder, the arrangement position A of the intake intake 62 is in the cylinder row direction at an intermediate position in the cylinder arrangement direction between the inlet of the branch passage corresponding to the # 2 cylinder and the inlet of the branch passage corresponding to the # 3 cylinder. It becomes the position corresponding to see. In the case of a three-cylinder internal combustion engine, as shown in FIG. 7C, if the ignition order is # 1 cylinder → # 3 cylinder → # 2 cylinder → # 1 cylinder, Arrangement position A corresponds to an intermediate position in the cylinder arrangement direction between the entrance of the branch passage corresponding to the # 2 cylinder and the entrance of the branch passage corresponding to the # 3 cylinder in the cylinder row direction.

  Since the intake intake port 62 is formed by casting in the cast intake body 40, a core extraction hole 40 </ b> C is formed at a portion where the bottom of the auxiliary intake chamber 58 corresponds to the intake intake port 62. The surface of the core hole 40 </ b> C exposed in the auxiliary air intake chamber 58 is closed by a spherical plug member 59.

  The collecting passage 60 is a roll-over L-shaped passage composed of a horizontal passage 63 that extends in the horizontal direction and reaches the end portion 61 and a vertical passage 64 that is connected to the intake upstream side of the horizontal passage 63. In this embodiment, the cross-sectional shape of the vertical passage 64 is circular, whereas the cross-sectional shape of the horizontal passage 63 is a flat quadrangle.

  The collecting passage 60 reaching the end portion 61 is a horizontal passage 63, and the extending direction of the horizontal passage 63 is horizontal and intersects at right angles to the penetration direction (vertical direction) of the intake air inlet 62. In other words, the intake intake 62 opens at the bottom surface of the end portion 61.

  The end portion 61 serves as an eddy current generating means, and an inner wall 61A at the end of the end portion is an arc surface that follows the outer peripheral edge shape of the intake air inlet 62, in this embodiment, a semicircular surface concentric with the intake air inlet 62, When viewed in a cross section of the passage perpendicular to the flow direction of the intake air flowing through the collecting passage 60 (the cross section shown in FIG. 6), one side of the end portion 61 in the passage width direction is compared with the other side. Is small, and the one side is an aperture 61C. The narrowed portion 61C is formed by a recess 40D formed in the ceiling wall 40B when viewed from the outside of the ceiling wall 40B of the horizontal passage 63.

  An additional gas introduction port 66 for introducing an additional gas such as a purge gas of a charcoal calister into the collecting passage 60 is opened on the inner peripheral side of the bent portion 65 formed by the connection portion between the horizontal passage 63 and the vertical passage 64. Yes. At the upper end portion of the vertical passage 64, a turbulent flow generation projection 67 is formed to protrude. The turbulent flow generating projection 67 is configured as a ridge extending horizontally along the circumferential direction on the inner wall of the vertical passage 64.

  A throttle bore 101 of the sub-throttle body 100 is connected to the intake inlet formed by the upper end of the vertical passage 64. The throttle bore 101 is provided with a sub-throttle valve 103 that is a butterfly valve that quantitatively sets the intake air flow rate flowing through the sub-intake passage.

  As shown in FIG. 1, the position of the sub throttle valve 103 is higher than the position of the main throttle valve 74. As a result, a space constituting the auxiliary intake chamber 58 can be secured below the auxiliary throttle valve 103. Further, the main throttle valve 74 can be disposed at a position close to the cylinder head 18, and the effect of improving the response is increased.

Next, the operation of the auxiliary intake system configured as described above will be described.
The intake air that is sucked into the combustion chamber 22 of each cylinder through the auxiliary intake passage is first measured in flow rate by the auxiliary throttle valve 103 and then flows in the vertical passage 64, the bent portion 65, and the horizontal passage 63 of the collecting passage 60 in order. .

  In the intake flow of the collecting passage 60, when the intake air passes through the turbulent flow generation convex portion 67, a part of the intake air collides with the turbulent flow generation convex portion 67. This causes turbulence (turbulent flow). When this turbulent flow flows through the bent portion 65, the turbulent flow range is expanded by the deflection of the intake flow.

  An additional gas such as a purge gas is introduced from the additional gas introduction port 66 into the turbulent flow atmosphere of the bent portion 65. As a result, the intake air and the additional gas are mixed well, the intake air and the additional gas are mixed well, and the homogenization of the air-fuel mixture of the intake air and the additional gas is promoted.

  Thereafter, an air-fuel mixture of intake air and additional gas (hereinafter referred to as auxiliary intake air) flows through the relatively long horizontal passage 63 and is rectified in the process of flowing through the horizontal passage 63. When the auxiliary intake air reaches the end portion 61 on the intake downstream side of the collecting passage 60, the sub intake air is subjected to a throttle action on one side of the passage by the restricting portion 61C, and is given a flow resistance difference in the passage width direction of the end portion 61. The Since the restricting portion 61C has a larger flow path resistance than the non-restricted portion 61B, the auxiliary intake air flows biased toward the non-restricted portion 61B, and the intake air speed difference and flow rate in the passage width direction of the end portion 61 There is a difference.

  This sub-intake is combined with the speed difference and flow rate difference in the passage width direction of the end portion 61 and the fact that the sub-intake flows along the inner wall 61A that is a semicircular surface concentric with the intake intake 62. A swirl flow (vortex flow) around the intake port 62, that is, a swirl flow, flows from the entire circumference of the intake port 62 to the auxiliary intake chamber 58 evenly.

  Thus, the auxiliary intake air is prevented from flowing into the auxiliary intake chamber 58 with directivity with respect to the specific branch passage 46. As a result, the auxiliary intake air is not distributed evenly to the branch passages 46 of the specific cylinders, but is evenly distributed to the branch passages 46 of the respective cylinders. As a result, the air-fuel ratio variation among the cylinders can be suppressed.

  The opening direction of the intake air inlet 62 with respect to the auxiliary intake chamber 58 is vertical, whereas the opening direction of the inlet 48 of the branch passage 46 formed in the auxiliary intake chamber 58 with respect to the auxiliary intake chamber 58 is horizontal. Since the opening directions are different from each other, the auxiliary intake air flowing into the auxiliary intake chamber 58 from the intake intake port 62 does not go directly to the inlet 48 of the branch passage 46 of the specific cylinder. This also prevents the auxiliary intake air from being distributed unevenly to the branch passage 46 of the specific combustion chamber 22 (cylinder) and suppresses variations in air-fuel ratio among the cylinders. Further, the uniform diffusivity in the auxiliary intake chamber 58 is also improved when the auxiliary intake air that has entered the auxiliary intake chamber 58 from the intake port 62 collides with the spherical surface of the plug member 59 exposed on the bottom surface in the auxiliary intake chamber 58.

  Further, the intake intake 62 is provided at the inlet 48 of the branch passage 46 corresponding to two cylinders whose ignition sequence is continuous between adjacent cylinders after the ignition sequence of the multi-cylinder internal combustion engine is reversed in the cylinder row direction. At the arrangement position A corresponding to the intermediate position in the cylinder arrangement direction when viewed in the cylinder row direction, the auxiliary intake chamber 58 is opened, so that the branch passage 46 for taking in the auxiliary intake air from the auxiliary intake chamber 58 changes depending on the ignition sequence. As a result, the auxiliary intake air flows into the auxiliary intake chamber 58 from the intake intake 62 into the central region where the auxiliary intake air in the auxiliary intake chamber 58 is swung in the cylinder row direction. This also improves the even distribution performance of the intake air to each cylinder and suppresses air-fuel ratio variation among the cylinders.

  The intake device according to the present invention is not limited to the above-described embodiments, and can be changed without departing from the spirit of the present invention. For example, the intake port 62 may be an oval opening.

DESCRIPTION OF SYMBOLS 22 Combustion chamber 40 Intake body 42 Main intake passage 46 Branch passage 48 Inlet 58 Sub intake chamber 60 Collecting passage 61 End portion 61A Inner wall 61C Restriction portion 62 Intake intake 63 Horizontal passage 64 Vertical passage 66 Additional gas introduction port 74 Main throttle valve 80 Main intake chamber 103 Sub throttle valve

Claims (4)

A plurality of main intake passages provided for each of the plurality of cylinders for supplying intake air to the respective cylinders, a main throttle valve provided for each of the main intake passages, and the main intake air downstream of the main throttle valve An intake device for a multi-cylinder internal combustion engine having a sub-intake passage for supplying intake air to the passage,
The sub-intake passage is provided for each cylinder and communicates with the main intake passage, a plurality of branch passages, an intake chamber that is connected to the plurality of branch passages and has one intake intake opening, and a termination A collecting passage that communicates with the intake intake and forms an intake passage on the intake upstream side of the intake intake,
An intake device for a multi-cylinder internal combustion engine, wherein vortex generating means for generating vortex around the central axis of the intake intake is provided in the collecting passage. The intake intake is a communication connection between the intake chamber and the collecting passage having a circular or elliptical through hole;
The eddy current generating means has a passage cross-sectional area in which one side in the radial direction of the intake air inlet of the terminal portion is compared with the other side when viewed in a passage transverse section perpendicular to the flow direction of the intake air flowing through the collecting passage. 2. The intake device for a multi-cylinder internal combustion engine according to claim 1, wherein the intake device is configured to be small and the one side is a throttle portion.   The multi-cylinder internal combustion engine according to claim 1 or 2, wherein an opening direction of the intake air inlet with respect to the intake chamber and an opening direction of the inlet of the branch passage formed in the intake chamber with respect to the intake chamber are different from each other. Intake device. The intake chamber is long in the cylinder row direction of the multi-cylinder internal combustion engine, and the intake chamber has openings in the branch passages of the cylinders at intervals in the cylinder row direction.
Cylinders are positioned at intermediate positions in the cylinder arrangement direction of the inlets of the branch passages corresponding to two cylinders that are consecutive between adjacent cylinders after the ignition order of the multi-cylinder internal combustion engine is reversed in the cylinder row direction. The intake device for a multi-cylinder internal combustion engine according to any one of claims 1 to 3, wherein the intake port is open to the intake chamber at a position corresponding to the row direction.

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