JP2006329170A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further increase amount of intake air filled into a combustion chamber. <P>SOLUTION: Intake passage cross sections of two branched intake ports 11A (11B) are expanded and deformed so as to approach for each other when approaching the upstream side from each downstream end opening 50A (50B) while maintaining its each cross sectional area at the same area. Inclined faces 51A (51B) inclined toward an outer side in the direction of arrangement in parallel (X direction) of its both downstream end openings 50A (50B) as approaching its each downstream end opening 50A (50B) are formed on inner faces on adjacent branched intake port sides in each branched intake port 11B (11A). Intake air AG is guided by the inclined faces 51A (51B) to prevent intake air AGG flowing into the combustion chamber 4 from both branched intake ports 11A, 11B from colliding mutually on an inward side in X direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake device for an engine.

  In an engine intake device, it is preferable to sufficiently secure engine output by reducing intake resistance as much as possible and increasing intake charge amount. Patent Document 1 proposes a method in which intake air flow is lowered by gradually widening the intake port width from the upstream side to the downstream side of the intake valve shaft to suppress separation of the intake air in the intake valve shaft. Yes. According to this, generation | occurrence | production of wake itself (wake) itself can be suppressed, pressure resistance can be reduced, and, thereby, increase of intake resistance can be suppressed.

  Further, Patent Document 2 proposes an engine intake device provided with a control valve for deflecting the flow of intake air in an intake passage. In the engine intake device, an intake valve guide is provided to reduce intake resistance. An improved intake passage cross-sectional shape has been proposed.

By the way, in the engine intake device as described above, generally, as a valve body of the control valve, only a radially outer portion on one side in the radial direction with respect to the valve shaft is formed as a complete state, and the diameter with respect to the valve shaft as a reference. The outer part on the other side in the direction is formed in a state where all or a part thereof is cut out (see the drawing in Patent Document 2). During a predetermined operation such as low speed operation, the control valve is closed to generate a tumble flow in the combustion chamber, and intake air is passed only on the other radial side of the valve shaft. The valve is fully opened, and the combustion chamber is filled with more intake air than in the case of a predetermined operation such as a low speed operation.
JP 2004-308441 A Japanese Patent Laid-Open No. 2003-3071724

  However, in many intake devices including the intake device of the above engine, it is adjacent to the intake air taken into the combustion chamber from each intake port, although it is necessary to increase the intake charge amount as much as possible when the engine operates at high speed. Some of the intake ports face inwardly in the direction of arrangement, and the intake air from both intake ports collide with each other. For this reason, this is an obstacle to increasing the intake resistance and increasing the intake charge amount into the combustion chamber.

  The present invention has been made in view of the above circumstances, and a technical problem thereof is to provide an engine intake device capable of further increasing the intake charge amount into the combustion chamber.

In order to achieve the technical problem, in the present invention (the invention according to claim 1),
One common intake port is divided into two branch intake ports centering on the branch portion on the downstream side, and the downstream end openings of the two branch intake ports are arranged side by side. In the intake system of the engine that opens to the cylinder,
Among the cross-sections of the branch intake ports, the cross-sections of the intake passages that cross in the direction perpendicular to the extending direction of the branch intake ports maintain the same cross-sectional areas of the intake passages. It is set as the structure expanded and deformed so that it may mutually approach as it goes upstream from a downstream end opening. Preferred embodiments of the first aspect are as described in the second to sixth aspects.

According to the first aspect of the present invention, the intake passage cross section of each branch intake port is expanded and deformed so as to approach each other as it goes upstream from the downstream end opening of each branch intake port. The branch intake port forms an inclined surface that inclines toward the outer side in the juxtaposed direction of the downstream end openings in both branch intake ports toward the downstream end openings of the adjacent branch intake port side inner surfaces. Intake is guided using the inclined surface as a guide surface. The intake air flowing in the direction along the inclined surface has a momentum vector in that direction, and among these, the vector component toward the outside in the juxtaposed direction of the downstream end openings at both branch intake ports is the other intake air. Acts against. As a result, in the combustion chamber, it is possible to prevent a large amount of intake air from flowing toward the inner side in the direction in which the downstream end openings of both branch intake ports are juxtaposed, and the intake air from both branch intake ports collide with each other. Can be suppressed. For this reason, the intake resistance can be reduced, and the intake charge amount into the combustion chamber can be further increased.
Further, since the partial component of the momentum vector of the intake air flowing in the direction along the inclined surface acts on the outer side in the juxtaposed direction of the downstream end openings in both branch intake ports with respect to the other intake air, In the combustion chamber, most of the intake air can flow toward the wall surface of the combustion chamber and collide with the wall surface of the combustion chamber, and generation of a tumble flow in the combustion chamber can be suppressed. For this reason, it is possible to suppress the occurrence of abnormal combustion by reducing the combustion speed, particularly during high-speed operation.

  According to the second aspect of the present invention, since both the branch intake ports are connected to the common intake port in a state where the expansion deformation of the intake passage section is continued, the intake air is supplied from the common intake port to each branch intake port. After entering each port smoothly, the guiding action of the inclined surface in each branch intake port is received over the entire extending direction of each branch intake port, and the momentum of the intake air flowing in the direction along the inclined surface during that time The above-mentioned partial component of the vector acts toward the outside in the juxtaposed direction of the downstream end openings at both branch intake ports with respect to the other intake air. For this reason, each branch intake port can be used as effectively as possible, and the same effect as in the first aspect can be obtained accurately.

  According to the invention described in claim 3, at least the inner side in the juxtaposed direction of both branch intake ports as the cross section of the intake passage of each branch intake port goes upstream from the downstream end opening of each branch intake port. Therefore, in the downstream end opening of each branch intake port, the curvature is increased and finally becomes a general circular shape. Even if the passage vertical width of each branch intake port becomes narrower on the inner side of both branch intake ports, the passage vertical width of each branch intake port is secured as much as possible on the upstream side, and the area of the inclined surface Can be increased. Thereby, based on the intake air flowing in the direction along the inclined surface, it is possible to increase the flow of the other intake air toward the outside in the juxtaposed direction of the downstream end openings in both branch intake ports in the combustion chamber. The effect similar to that of the first aspect can be obtained more accurately.

  According to the fourth aspect of the present invention, the upper side surface in the vertical direction of the passage of each branch intake port is substantially perpendicular to the vertical direction of the passage over substantially the entire lateral direction of the passage of each branch intake port. Since the control valve for deflecting the intake air to the upper side in the vertical direction of the passage of the common intake port is provided in the common intake port, it is deflected by the control valve (valve closed). The intake air flow is guided to the flat surface (upper side surface in the vertical direction of the passage) of each branch intake port and flows into the combustion chamber. For this reason, a high tumble ratio can be achieved when the control valve is closed.

  According to the fifth aspect of the present invention, the intake valve valve seat having an opening larger than the downstream end opening is provided on the downstream side of the downstream end opening in each branch intake port, and the downstream of each branch intake port. Since the end opening is shifted to the upper side in the vertical width direction of the downstream end opening, on the lower side in the vertical width direction (outside in the radial direction of the cylinder) of the downstream end opening and on the downstream side of the downstream end opening, The intake passage is rapidly expanded based on the opening of the valve seat, and the intake air also flows in the expanded direction. For this reason, it is possible to cause a part of the flow of the intake air to collide toward the combustion chamber inner wall, thereby suppressing the generation of the tumble flow.

  According to the sixth aspect of the present invention, since the intake passage cross-sectional area of the intake passage cross section at each branch intake port is maintained the same, the intake flow rate flowing through each branch intake port is reduced more than before. In addition, the exclusive space can be made the same as before so as not to affect the surrounding members.

  FIG. 1 shows a case where the present invention is applied to a spark ignition type engine. 1 is a cylinder block, 2 is a cylinder head fixed to the upper surface of the cylinder head 1, and 3 is slid into a cylinder 1 a formed on the cylinder block 1. The piston is movably inserted, and the combustion chamber 4 is defined by these 1-3.

  As shown in FIG. 1, the cylinder head 2 is formed with an intake port 11 and an exhaust port 13 for each cylinder 1a. In the present embodiment, the intake port 11 is branched into two branched intake ports 11A and 11B branched by a partition wall 5 formed integrally with the cylinder head 2, and the two branched intake ports 11A and 11B. And a common intake port 11C in which they merge on the upstream side of the branching portion 5a (configured by the partition wall 5) serving as a branching point. The two branch intake ports 11A and 11B are opened in parallel to each other in the cylinder 1a, that is, in the combustion chamber 4, and an intake valve is provided on the downstream end opening 50A (50B) side of each branch intake port 11A (11B). 14 (one intake valve is not shown), and each intake port 11A (11B) is opened and closed independently by each intake valve 14.

  In this case, the valve shaft 14a of each intake valve 14 is guided by a valve guide 21, and a part of each valve guide 21 protrudes slightly into the branch intake port 11A (11B). Further, a valve seat on which each intake valve 14 is separated and attached is denoted by reference numeral 16, and the valve seat 16 portion substantially becomes an open end, that is, a throat portion of the intake port into the cylinder 1 a, and the valve seat 16 The opening area determined by the inner diameter of the throat portion is the opening cross-sectional area of the throat portion in the intake port 11. As another aspect, a cross section passing through the intersection of the axis line (extension line) of the common intake port 10 and the valve shaft 13a may be a minimum passage cross section, that is, a throat portion.

  As shown in FIG. 1, the common intake port 11 </ b> C is continuous so that its downstream end merges with the two branched intake ports 11 </ b> A (11 </ b> B), and its upstream end extends from the intake manifold mounting surface 2 a of the cylinder head 2. It is open to the outside.

  As shown in FIG. 1, two exhaust ports 13 are also provided in the present embodiment, and the two exhaust ports 13 (one exhaust port is not shown) are intake ports. In the same manner, the cylinders 1a are opened in parallel with each other. Each exhaust port 13 is individually provided with an exhaust valve 15 at the opening end on the combustion chamber side (one exhaust valve is not shown), and each exhaust port 13 is independently provided by each exhaust valve 15. It is to be opened and closed. The exhaust system including the exhaust port 13 will not be described further.

  An intake manifold 18 is fixed to the mounting surface 2 a of the cylinder head 2. The intake manifold 18 has a plurality of independent passages 18a (only one is shown), and each upstream end thereof is connected to a surge tank (not shown) as an intake collecting portion, and each downstream end thereof is One common intake port 11C among the intake ports 11 is connected. As a result, the independent passage 18a, the common intake port 11C and the branch intake port 11A (11B) of the intake manifold 18 constitute one intake passage.

  As shown in FIGS. 1 and 2, a control valve 40 is provided in each independent passage 18a of the intake manifold 18 on the upstream side of the mounting surface 2a. The control valve 40 generates a deflected flow of intake air in order to generate a tumble flow in the combustion chamber 4 in a predetermined operation region such as a low-speed operation region, and as its main components, a valve shaft 41, And a valve body 42 projecting radially outward from the valve shaft 41 with the valve shaft 41 as a reference. The valve shaft 41 crosses the independent passage 18a while maintaining a substantially horizontal state at a substantially central portion in the vertical direction of the independent passage 18a. The diameter of the valve shaft 41 is longer than the thickness of the valve body 42. . The valve body 42 is formed so that only the radially outer portion on the one side in the radial direction with respect to the valve shaft 41 is partially formed, and the outer portion on the other side in the radial direction on the basis of the valve shaft 41 is partially cut away. It is formed in a state. Then, during a predetermined operation such as a low speed operation, the intake valve passes only on the other radial side of the valve shaft 41 by closing the control valve 40 in order to generate a tumble flow in the combustion chamber 4 (see FIG. 2). During high-speed operation, the valve body 42 of the control valve 40 has a posture along the flow of intake air so that as much intake air as possible is filled into the combustion chamber 4 (FIG. 1). reference).

  A fuel injection valve 19 is attached to the upper part of the downstream end of the intake manifold 18. The fuel injection valve 19 is a four-hole type, and is divided into each branch intake port 11A, 11B for injection. The fuel injection valve is provided for each branch intake port 11A, 11B. Can also be provided.

  In this case, the opening cross-sectional area of the common intake port 11C on the mounting surface 2a side is slightly larger than the opening cross-sectional area of the intake manifold 18, and an escape recess 20 is formed on the upper inner wall of the common intake port 11C. Is formed. The escape recesses 20 are for preventing interference with the spray injected from the fuel injection valve 19, and are formed at the common intake port 11C portion corresponding to the branched intake ports 11A and 11B. However, they are not formed in the branch intake ports 11A and 11B. As shown by an arrow Y in FIG. 1, the spray directing direction center line from the fuel injection valve 19 is lower than the center of the intake valve 14 (closer to the lower inner wall side of the branch intake port 11).

  Next, based on FIG. 3 to FIG. 8, the intake passage section of each branch intake port 11A (11B) and the common intake port 11C in the vicinity of the branch portion 5a, that is, the branch intake port 11A (11B) or the common intake port 11C. A cross section that crosses in a direction perpendicular to the extending direction will be described. 3 to 8, the solid line shape indicates the content of the present case, and the broken line shape indicates a conventional existing configuration. Reference numeral 52 </ b> A (52 </ b> B) denotes a valve guide wall for guiding the valve guide 21.

  In the present embodiment, both branch intake ports 11A and 11B are arranged symmetrically with respect to the symmetry axis T. As shown in FIG. 6, both the branch intake ports 11A and 11B are expanded and deformed so as to approach each other from the downstream end opening 50A (50B) of the branch intake port 11A (11B) toward the upstream. The deformed state continues to the common intake port 11C. Cross sections D, C, and B in FIG. 3 show passage intake cross sections of the branch intake port 11A (11B) from the downstream end opening 50A (50B) side to the upstream side, and the cross section A is upstream of the cross section B. The cross section of the intake passage of the common intake port 11C is shown. In section D, the distance between both branched intake ports 11A, 11B is Ds, in section C, the distance between both branched intake ports 11A, 11B is Cs, and in section B, both branched intake air The interval between the ports 11A and 11B is Bs, and these intervals Ds, Cs, and Bs have a relationship of Bs <Cs <Ds.

  In other words, based on FIG. 9, it can also be explained by the axis (port center line) 11AL (11BL) of each branch intake port 11A (11B). Whereas the shaft center 11AL ′ (11BL ′) of each existing branch intake port (broken line) is on the extension of the shaft center of the valve shaft 14a of the intake valve 14 (see also FIG. 4), this In the embodiment, the downstream end openings 50A (50B) of both branched intake ports 11A (11B) are arranged so that the axial centers 11AL, 11BL of both branched intake ports 11A (11B) are directed upstream from the downstream end openings 50A (50B). In the juxtaposed direction (hereinafter referred to as the X direction).

  Thereby, as shown in FIG. 7, each branch intake port 11A (11B) is directed outward in the X direction toward the downstream end opening 50A (50B) on the inner surface of the adjacent branch intake port 11B (11A). Thus, the inclined surface 51A (51B) that is inclined is formed.

  As a result, the intake AG is guided using the inclined surface 51A (51B) as a guide surface, and the intake AG flowing in the direction along the inclined surface 51A (51B) has a component force toward the outside in the X direction with respect to other intake air. Thus, a large amount of intake air is prevented from flowing inward in the X direction in the combustion chamber 4. As a result, as shown in FIG. 8, it is possible to reduce the intake resistance by suppressing the intake AGGs from the downstream end openings 50A, 50B of the branched intake ports 11A, 11B from colliding with each other on the inner side in the X direction. Thus, the intake charge amount into the combustion chamber 4 can be further increased.

  Further, at this time, the intake air flowing in the direction along the inclined surface 51A (51B) causes the component force toward the outside in the X direction to act on the other intake air, as shown in FIG. Most of the flow is caused to flow toward the wall surface of the combustion chamber 4 and collide with the wall surface of the combustion chamber 4, and generation of a tumble flow in the combustion chamber 4 can be suppressed. Thereby, especially at the time of high-speed driving | operation, a combustion speed can be reduced and it can suppress that abnormal combustion generate | occur | produces.

  In this embodiment, the intake passage cross section of each branch intake port 11A (11B) is not only expanded and deformed so as to approach each other toward the upstream side, but also at least inward in the X direction as shown in FIG. On the side, the passage vertical width (length in the vertical direction in FIG. 6) in each branch intake port 11A (11B) is gradually expanded and deformed toward the upstream side. Specifically, in the cross section D, the passage vertical width is Dh, in the cross section C, the passage vertical width is Ch, and in the cross section B, the passage vertical width is Bh. These intervals Dh, Ch, Bh are Dh <Ch <Bh. Have the relationship. Thereby, regarding the inclined surface 51A (51B), the length in the direction perpendicular to the paper surface of FIG. 7 becomes longer from the downstream end opening 50A (50B) toward the upstream side, and the area of the inclined surface 51A (51B) is secured as much as possible. Is supposed to. As a result, based on the intake air flowing in the direction along the inclined surface 51A (51B), it is possible to increase the flow of other intake air toward the X direction outward side in the combustion chamber 4.

In the present embodiment, the cross-sectional area of the intake passage cross section (intake passage cross-sectional area) in each branch intake port 11A (11B) is maintained the same throughout with the same cross-sectional area as the conventional one. This is because the flow rate of intake air flowing through each branch intake port 11A (11B) is not reduced, and the exclusive space is made the same as before, so that the surrounding members are not affected.
For this reason, in this embodiment, as shown in FIGS. 6 and 7, the circular broken line shape showing the cross section of the conventional passage is expanded and deformed in the direction shown by the black arrow, and the intake passage according to this embodiment A cross section is formed. In this case, the upper side surface 53A (53B) in the passage vertical width direction (vertical direction in FIG. 6) in each branch intake port 11A (11B) is the passage width direction (in FIG. 6) in each branch intake port 11A (11B). A flat surface that is substantially perpendicular to the vertical direction of the passage is formed over substantially the whole (left-right direction). Thus, as shown in FIG. 2, when the control valve 42 is closed and the intake air is deflected and flowed upward in the vertical direction of the passage of the common intake port 11C, the intake air is supplied to each branch intake port 11A (11B). Therefore, the flat upper side surface 53A (53B) is guided and introduced into the combustion chamber 4, so that a high tumble ratio can be achieved in the combustion chamber 4.

  In the present embodiment, as shown in FIG. 10, the opening diameter d2 of the valve seat (valve seat) 16 is smaller than the opening diameter d1 of the downstream end opening 50A (50B) in each branch intake port 11A (11B). The axial center 11AL (11BL) of the downstream end opening 50A (50B) in each branch intake port 11A (11B) is in the vertical width direction of the downstream end opening 50A (50B) with respect to the axial center 16L of the toilet seat 6. It is shifted to the upper side (the diagonally upper left side in FIG. 10). As a result, the downstream side of the downstream end opening 50A (50B) is rapidly expanded based on the opening of the valve seat 16, and the intake AGG also flows in the expanded direction (combustion chamber 4 inner wall side). The intake AGG collides with the inner wall of the combustion chamber 4. For this reason, the production | generation of a tumble flow can be suppressed also by this.

Side surface sectional drawing which shows embodiment. Explanatory drawing explaining the deflection | deviation flow of the intake air produced | generated based on a control valve. Explanatory drawing explaining the shape of the intake port which concerns on embodiment from a side surface. Explanatory drawing explaining the intake port which concerns on FIG. 3 planarly. The figure which shows the state which looked at the intake port which concerns on FIG. 3 from the right side. Explanatory drawing of each cross section in FIG. The figure which shows the cross section F of FIG. The figure which shows the cross section E of FIG. The figure which shows the relationship of the axial center of the branch intake port which concerns on embodiment. Explanatory drawing which shows the relationship between the valve-seat opening for intake valves, and the downstream end opening in a branch intake port.

Explanation of symbols

1: Cylinder block 1a: Cylinder 2: Cylinder head 2a: Intake manifold mounting surface (upstream end of intake port)
5: Bulkhead 5a: Branch 10: Intake passage 11: Intake port 11A: Branch intake port 11B: Branch intake port 11C: Common intake port 40: Control valve 50A: Branch intake port Downstream end opening 50B: Branch end intake port downstream end opening 51A: Branch intake port inclined surface 51B: Branch intake port inclined surface 53A: Branch intake port upper side surface 53B: Branch intake port Top side

Claims (6)

One common intake port is divided into two branch intake ports centering on the branch portion on the downstream side, and the downstream end openings of the two branch intake ports are arranged in parallel and In the intake system of the engine that opens to the cylinder,
Among the cross-sections of the respective branch intake ports, the cross sections of the intake passages that cross in the direction perpendicular to the extending direction of the branch intake ports are closer to each other as they go upstream from the downstream end openings of the respective branch intake ports. Extended deformation,
An intake system for an engine characterized by that. In claim 1,
The two branched intake ports are connected to the common intake port in a state in which the expansion deformation of the intake passage section is continued.
An intake system for an engine characterized by that. In claim 1,
As the cross-section of the intake passage of each branch intake port goes upstream from the downstream end opening of each branch intake port, at least on the inner side in the juxtaposed direction of both branch intake ports, the passage vertical width of each branch intake port Is also set to expand and deform,
An intake system for an engine characterized by that. In claim 1,
The upper side surface in the vertical direction of the passage in each branch intake port forms a flat surface that is substantially perpendicular to the vertical direction of the passage over the entire width direction of the passage in each branch intake port.
The common intake port is provided with a control valve that deflects intake air upward in the vertical direction of the passage of the common intake port.
An intake system for an engine characterized by that. In claim 1,
On the downstream side of the downstream end opening in each branch intake port, an intake valve valve seat having an opening larger than the downstream end opening is provided,
The downstream end opening in each branch intake port is shifted to the upper side in the vertical width direction of the downstream end opening.
An intake system for an engine characterized by that. In any one of Claims 1-5,
The intake passage cross-sectional area of the intake passage cross section in each branch intake port is maintained the same,
An intake system for an engine characterized by that.

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