JP3617679B2 - V-type multi-cylinder engine intake system - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an intake device for a multi-cylinder engine.
[0002]
[Prior art]
In many cases, an intake device of a multi-cylinder engine employs a structure in which a throttle valve is disposed at one end of a surge tank and an intake port of each intake pipe (intake passage) of the intake manifold is opened in the surge tank.
[0003]
By the way, in the multi-cylinder engine, the intake radiated sound generated from the vicinity of the intake port of the intake pipe is one of the causes of unpleasant noise of muddy sound quality that penetrates into the passenger compartment particularly during vehicle acceleration, so-called rambling noise. It is supposed to be. In particular, it is considered that the rambling noise increases when a throttle valve is disposed at one end of the surge tank as in the conventional intake device.
[0004]
Therefore, as an intake device that can be expected to reduce the rambling noise, the intake port of each intake pipe of the intake manifold is connected to a surge tank, and each intake pipe is divided into two groups, and a throttle valve is arranged between the two groups. By installing the throttle valve, a throttle valve connected to the central portion of the surge tank in the cam shaft direction has been proposed.
[0005]
[Problems to be solved by the invention]
When the throttle valve is arranged in the center of the surge tank, it is considered that the rambling noise can be reduced because the equivalent pipe length of the intake pipe is substantially equal on both sides of the throttle valve. However, since this intake system employs a structure that divides the intake pipe into two groups and secures the arrangement space of the throttle valve between them, the intake pipe has a curved shape that bypasses the throttle valve. Since the flow of intake air in each of the intake pipes connected to the intake port is forcibly bent, the intake resistance increases accordingly, and as a result, there is a concern that the maximum intake amount decreases and the engine output decreases.
[0006]
The present invention has been made in view of the above-described conventional situation, and an object thereof is to provide an intake device for a multi-cylinder engine that can avoid a decrease in the maximum intake amount while reducing a rambling noise.
[0007]
[Means for Solving the Problems]
The present invention provides an intake device for a V-type multi-cylinder engine in which a throttle valve is disposed upstream of a surge tank and the surge tank and an intake port connected to an intake valve opening are connected by an intake passage. Formed in a box shape extending in the direction of the crankshaft, disposed in the V bank in parallel with the crankshaft, and further positioned on the far side from the bottom of the V bank and the first chamber located near the bottom of the V bank by the wall. A throttle valve is disposed at one end of the first chamber in the crankshaft direction, and an opening for communicating the first and second chambers is formed at the approximate center of the wall in the crankshaft direction. and, the intake passage, a plurality of intake passages for cylinders of one side of the V-bank, composed of a plurality of intake passages for the other side of the cylinders of the V-bank, the one side cylinders Each intake passage extends from one side of the V bank in parallel with each other in a direction substantially perpendicular to the crankshaft in plan view, and its upstream end is inserted from the upper surface into a portion near the cylinder on the other side of the second chamber. Similarly, the intake passages for the other cylinders extend from the other side of the V bank in parallel to each other in a direction substantially perpendicular to the crankshaft in a plan view, and their upstream ends are on one side of the second chamber. The cylinder intake passages are inserted from the upper side into the cylinder, and the intake passages for the cylinders on the one side and the other side are provided one by one per cylinder, are formed in a generally downward U shape, and are alternately arranged. Further, an extension pipe is disposed in the second chamber so as to communicate with the upstream end of each intake passage, and the first and second chambers are provided on one side of the V bank and on the other side of the cylinder. It is characterized in that has become a common volume to
[0008]
According to a second aspect of the present invention, in the first aspect, the cylinder intake passages at both ends in the crankshaft direction of the intake passage are slightly bent inward in the crankshaft at a rising portion on the downstream end connected to the intake port. After that, it is characterized by extending linearly in a direction substantially perpendicular to the crankshaft direction.
[0010]
[Action]
According to the invention of claim 1, the surge tank is defined in the first and second chambers having a sufficient volume by the wall, the intake passage is connected to one of them, and the throttle valve is arranged on the other, Since the opening that communicates the first and second chambers is provided at the center of the wall in the crankshaft direction, the portion from the throttle valve to the intake port of the intake passage functions as a capacity, not as a passage. The equivalent pipe lengths from the throttle valve to each of the suction ports are substantially the same, and the effect of reducing rambling noise can be obtained.
[0011]
On the other hand, in the present invention, it is not necessary to bend the intake passages as in the above-mentioned conventional device, which divides the intake passages into two groups and secures a throttle valve arrangement space between the two groups. It is possible to set to an increasing shape, and therefore, it is possible to avoid the problem of a decrease in the maximum intake air amount caused by taking measures against rumble noise.
[0012]
In addition , the surge tank is disposed in the V bank, the intake passage is connected to the second chamber located on the side far from the bottom of the V bank, and the throttle valve is connected to the end of the first chamber located on the side close to the bottom of the V bank. Since the opening is formed in the wall between the two chambers, it is possible to avoid a decrease in the maximum intake amount while taking the above-mentioned countermeasure against the rambling noise in the V-type multi-cylinder engine.
[0013]
According to the second aspect of the invention, the cylinder intake passages at both ends of the crankshaft are slightly bent in the crankshaft direction at the rising portion on the downstream end side connected to the intake port and then extended in the direction perpendicular to the crankshaft. Therefore, all intake passages can be positioned within the vertical projection plane of the surge tank while minimizing the intake resistance, and the entire intake unit can be made compact.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 4 are views for explaining an intake device of a V-type 8-cylinder engine according to an embodiment of the present invention. FIG. 1 is a schematic front view of an engine equipped with this embodiment device. 3 and 4 are a cross-sectional front view, a cross-sectional side view, and a plan view, respectively, of the embodiment apparatus.
[0015]
In these drawings, reference numeral 1 denotes a water-cooled four-cycle V-type 8-cylinder engine. The engine 1 is an oil pan that forms a lower crank chamber on the lower side of a skirt portion 2a that forms an upper crank chamber of a cylinder block 2. 3 and the left and right cylinder heads 4 and 5 are connected to the mating surfaces of the left and right cylinder portions 2b and 2c forming the V bank of the cylinder block 2 with head bolts. 5, left and right head covers 6 and 7 are mounted on the upper mating surface.
[0016]
The left and right cylinder portions 2b and 2c each have four cylinder bores 2d formed in parallel, and pistons 8 slidably inserted into the cylinder bores 2d are cranked via connecting rods 9, respectively. It is connected to the shaft 10.
[0017]
Each of the left and right cylinder heads 4 and 5 has four combustion recesses each forming a combustion chamber on the block side mating surface. The three intake valve openings 11 and the two exhaust valve openings 12 opened in the respective combustion recesses are opened and closed respectively, and the intake and exhaust valves 13 and 14 are respectively formed by intake and exhaust camshafts 15 and 16. It is opened and closed.
[0018]
The intake valve opening 11 and the exhaust valve opening 12 are led out to the inner wall and the outer wall of the V bank by an intake port 18 and an exhaust port 17, respectively, and an exhaust manifold 17a is connected to an external connection port of the exhaust port 17.
[0019]
An intake unit 19 is connected to the external connection port 18 a of the intake port 18. The intake unit 19 is set in such a shape as to fill the V bank space A formed by the left and right cylinder portions 2b and 2c, the left and right cylinder heads 4 and 5, and the left and right head covers 6 and 7. Yes. The intake unit 19 includes left and right valve bodies 20a and 20b connected to the external connection port 18a, and an intake passage block 21 disposed in an arch shape between the valve bodies 20a and 20b. 21 and a surge tank 22 disposed below the intake passage blocks 21 and 21.
[0020]
The connecting surfaces of the external connection ports 18a of the left and right cylinder heads 4 and 5 are formed flush with each other and parallel to the crankshaft 10, and the valve bodies 20a and 20b are cast products made of an aluminum alloy. It has a flat plate shape. In the left and right valve bodies 20a and 20b, there is disposed a switching valve 23 in which one valve plate 23b is fixed to each valve shaft 23a extending in parallel with the crankshaft 10 for each cylinder. Yes. The valve plate 23b is formed with a notch 23c that is located on the top wall 18b side of the intake port 18 and at the cam shaft direction end when the valve plate 23b is rotated to the closed position. Therefore, when the intake port 18 is closed by the valve plate 23b, the intake air is biased toward the top wall 18b side of the intake port 18 and toward the cam shaft end, and the direction from the intake valve opening at the cam shaft end to the cylinder axial direction. In addition, a so-called oblique swirl that flows along the inner peripheral surface and flows in the axial direction is easily generated in the cylinder.
[0021]
The valve bodies 20a and 20b are provided with one fuel injection valve 24 for each cylinder so as to be substantially vertical, and this is located between the switching valve 23 and the intake camshaft 15. ing. Each fuel injection valve 24 is positioned on a substantially center line of the intake port 18 when viewed from above, and its fuel injection port is directed to each intake valve opening 11.
[0022]
The intake passage blocks 21 consists of two pairs of those for cylinders one and the other side for the cylinders of one side of the V-bank, generally U a flange 21a fixed to the respective valve body 20a, 20b The downstream end of each cylinder-shaped intake pipe (intake passage) 21b is fixed by welding. Of course, the flange and the intake pipe may be integrally cast. Although the valve bodies 20a and 20b and the intake block 21 can be formed integrally, the valve body and the intake passage block 21 are separately formed in this embodiment to simplify the mold structure. Because.
[0023]
The upstream end 21c of each intake pipe 21b is inserted and fixed by welding at a portion closer to the opposing cylinder side of the lid 22b of the surge tank 22. Therefore, the two sets of intake passage blocks 21 and 21 are integrated into one block by the lid 22b.
[0024]
As shown in FIGS. 1 and 2, an outside air flow passage B extending in the crankshaft direction is formed by the upstream end 21c portions of the one and the other cylinder intake pipes 21b and the lid body 22b. The outside air flow passage B communicates with the external space in the crankshaft direction, so that the outside air flows in the crankshaft direction through the passage B, thereby suppressing an increase in intake air temperature due to hot air.
[0025]
The surge tank 22 is a substantially rectangular parallelepiped box, and includes a tank main body 22a and the lid body 22b that closes a rectangular opening of the main body, and both are coupled by a bolt 22c inserted from the bottom side. Yes. Therefore, the surge tank 22 of this embodiment is suspended from the intake passage block 21. The lid body 22b has a flat plate shape, and the upper surface thereof is flat. An extension pipe 25 communicating with the upstream end 21c of each intake pipe 21b is bolted to the inner surface of the lid body 22b via a flange 25a. It is fixed by.
[0026]
The tank body 22a is positioned on the side closer to the V bank bottom surface (side closer to the engine outer wall) and on the side farther from the V bank bottom surface (side far from the engine outer wall) by the wall 22d. Each cylinder intake pipe 21b is opened to the second chamber 22f through the extension pipe 25. The wall 22d is provided with an opening 22i that communicates the first and second chambers 22e and 22f. The opening 22i is located at the approximate center in the crankshaft direction.
[0027]
Here, the surge tank 22 needs to be set large enough to function as a volume (volume) rather than as a passage for the first and second chambers 22e and 22f. Therefore, in the present embodiment, the surge tank 22 is set to a size that substantially fills the V-bank space A.
In this embodiment, functioning as a volume rather than as a passage is defined as functioning as a passage when, for example, a negative pressure wave generated by opening an intake valve is propagated upstream, and the negative pressure wave is large. The case where the pressure is released to about atmospheric pressure is defined as functioning as a volume.
[0028]
Reference numeral 22g denotes a recess for mounting the knock sensor 27, which is formed by expanding the side wall of the second chamber 22f toward the inside of the chamber, and is formed as a pair of left and right. Since the recess 22g is formed in the chamber side wall in this way, there is no restriction on the position where the knock sensor 27 is disposed.
[0029]
One end of the first chamber 22e in the crank shaft direction extends to the outside of the V bank, and a throttle seat 22h is formed at the extended end. Mounted on the throttle seat 22h is a throttle valve 26 in which a pair of valve plates 26b are rotatably disposed around rotation axes parallel to each other in a throttle body 26a.
[0030]
Here, as shown in a plan view in FIG. 4, the axis of the eight intake pipes 21b extends linearly in a direction substantially perpendicular to the crankshaft, thereby smoothing the flow of intake air from the surge tank 22. The intake resistance is minimized. Of the intake pipes 21b, the four intake pipes 21b 'for the cylinders at both ends in the crankshaft direction are slightly bent inward in the crankshaft direction at the rising portion (see axis a), and It extends linearly in a substantially perpendicular direction (see axis b). This is because the entire intake unit is made compact by positioning all the intake pipes 21b in the vertical projection plane of the surge tank 22 while minimizing the intake resistance.
[0031]
Next, the function and effect of this embodiment will be described.
In the engine 1 of this embodiment, the intake air is introduced from the throttle valve 26 into the first chamber 22e of the surge tank 22, and is introduced into the second chamber 22f through the opening 22i formed at the center in the crankshaft direction. The air is drawn into the cylinder from the extension pipe 25, the intake pipe 21b, and the valve body 21a or 21b through the intake port 18.
[0032]
When the engine is operating at a low speed such as low speed and low load, the switching valve 23 is rotated to the closed position, and the intake air is on the top wall 18b side of the intake port 18 and at the end in the camshaft direction. The air flows toward the opening, is directed in the cylinder axial direction from the intake valve opening at the end, and is introduced into the cylinder, so-called oblique swirl is generated in the cylinder.
[0033]
Here, the flow of intake air in the surge tank 22 will be described in more detail. In this embodiment, the surge tank 22 is defined by the first and second chambers 22e and 22f having a sufficient volume, and the throttle valve 26 is connected to one end of the first chamber 22e. The subsequent first and second chambers 22e and 22f function not as passages but as volumes, and through the openings 22i, intake air flows into the second chamber 22f from the center in the crankshaft direction. Accordingly, it can be considered that the equivalent pipe length from the throttle valve 26 to the suction port of each intake passage, that is, the extension pipe 25 of each cylinder intake pipe 21b, is substantially the same, and as a result, the above-mentioned rambling noise reduction effect is achieved. can get.
[0034]
On the other hand, in the present embodiment, the surge tank 22 is defined in the first and second chambers 22e and 22f, and the opening 22i that communicates both is formed in the center in the clan axial direction, so that the intake air is cranked in the second chamber 22f. While being configured to be introduced from the center in the axial direction, there is no restriction on the position, shape, etc. of each cylinder intake pipe 21b. Therefore, in this embodiment, all the intake pipes 21b can be formed linearly. For example, the intake pipe is divided into two groups, and the intake resistance is compared with a case where a throttle body is arranged between the two groups. Can be reduced and the maximum intake volume can be secured. Therefore, in this embodiment, there is no reduction in output due to measures against rumble noise.
[0035]
In the above embodiment, the throttle valve 26 is directly attached to the upstream end of the first chamber 22e. However, the throttle valve 26 may be attached further upstream. In the above embodiment, the intake device for the V-type multi-cylinder engine has been described. However, the present invention can also be applied to an intake device for an in-line multi-cylinder engine. In this case, the surge tank is arranged on the side of the cylinder head in parallel with the crankshaft, and the surge tank is divided into a first chamber located closer to the intake port and a second chamber located farther from the wall. The suction port of the intake passage is connected to the first chamber, and a throttle valve is disposed at one end in the crankshaft direction of the second chamber. Also in the case of this in-line multi-cylinder engine, the rambling noise can be reduced and the reduction of the maximum intake amount can be avoided.
[0036]
【The invention's effect】
According to the first aspect of the present invention, the surge tank is defined in the first and second chambers having a sufficient volume by the wall, and the two chambers are communicated with each other through the opening located substantially in the center in the crankshaft direction. Since the intake passage is connected to the chamber, and the throttle valve is disposed in the other chamber, the portion from the throttle valve to the intake passage suction port acts as a volume, not as an intake passage, and therefore, the throttle valve is connected to the intake passage. The equivalent pipe length to the suction port is approximately the same, which has the effect of reducing rambling noise.
[0037]
In addition, it is not necessary to curve the intake passage as in the case where the intake passage is divided into two groups and a throttle body arrangement space is secured between the two groups, the intake passage has the minimum intake resistance, and the maximum intake amount increases. Therefore, it is possible to avoid the problem of a decrease in the maximum intake air amount caused by taking measures against rumble noise.
[0038]
In addition , the surge tank is arranged in the V bank, the intake passage is connected to the second chamber outside the V bank, the throttle valve is connected to the end of the first chamber inside the bank, and the wall between the two chambers is connected Since the opening is formed, in the V-type multi-cylinder engine, there is an effect that a reduction in the maximum intake amount can be avoided while taking the above-mentioned countermeasure against the rambling noise.
[0039]
According to invention of Claim 2 , there exists an effect which can make the whole intake unit compact .
[Brief description of the drawings]
FIG. 1 is a schematic front view of a V-type 8-cylinder engine equipped with an intake device according to an embodiment of the present invention.
FIG. 2 is a sectional front view of the apparatus of the first embodiment.
FIG. 3 is a sectional side view of the apparatus of the first embodiment.
FIG. 4 is a plan view of the apparatus according to the embodiment.
[Explanation of symbols]
1 V-type 8-cylinder engine 10 Crankshaft 11 Intake valve opening 18 Intake port 21b Intake pipe (intake passage)
22 Surge tank 22d Drawing wall 22e 1st chamber 22f 2nd chamber 22i Opening 25 Extension pipe (suction port of intake passage)
26 Throttle valve

Claims (2)

In the intake device of a V-type multi-cylinder engine in which a throttle valve is disposed upstream of the surge tank and the surge tank and an intake port connected to the intake valve opening are connected by an intake passage, the surge tank is disposed in the crankshaft direction. A first chamber that is formed in an extending box shape and is disposed in parallel with the crankshaft in the V bank, and is located on the side closer to the bottom surface of the V bank and a second chamber located on the far side from the bottom surface of the V bank. A throttle valve is disposed at one end of the first chamber in the crankshaft direction, and an opening for communicating the first and second chambers is formed substantially at the center of the wall in the crankshaft direction. The passage includes a plurality of intake passages for cylinders on one side of the V bank and a plurality of intake passages for cylinders on the other side of the V bank. Are extended from one side of the V bank in parallel with each other in a direction substantially perpendicular to the crankshaft in a plan view, and their upstream ends are inserted from the upper surface into a portion near the cylinder on the other side of the second chamber. The intake passages for the other cylinders extend from the other side of the V bank in parallel to each other in a direction substantially perpendicular to the crankshaft in plan view, and their upstream ends are close to the cylinders on one side of the second chamber. Each of the intake passages for the cylinders on the one side and the other side is inserted into the portion from the upper side, provided one per cylinder, formed in a generally downward U-shape, and alternately arranged. An extension pipe is disposed in the two chambers so as to communicate with the upstream ends of the intake passages, and the first and second chambers are common to the one side cylinder and the other side cylinder of the V bank. V-type multi-cylinder engine characterized by its volume Down of the intake system. In Claim 1, among the intake passages, the intake passages for the cylinders at both ends in the crankshaft direction are slightly bent inward in the crankshaft direction at the rising portion on the downstream end side connected to the intake port, An intake device for a V-type multi-cylinder engine, which extends linearly in a substantially perpendicular direction.

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