WO2013172192A1

WO2013172192A1 - Air intake device for internal combustion engine

Info

Publication number: WO2013172192A1
Application number: PCT/JP2013/062543
Authority: WO
Inventors: 濱本　高行; 杉山　孝伸; 高生伊藤; 賢午米倉
Original assignee: 日産自動車株式会社
Priority date: 2012-05-18
Filing date: 2013-04-30
Publication date: 2013-11-21

Abstract

A collector (21) is provided with a collector partition plate (213) for dividing the inner space of the collector into two parts. A resonance pipe (22) is provided with a resonance pipe partition plate (223) for dividing the inner space of the resonance pipe into two parts. A first air intake branch pipe (231) and a fourth air intake branch pipe (234), which are located at both ends of a row of cylinders, are connected to one collector chamber (211) separated by the collector partition plate. A second air intake branch pipe (232) and a third air intake branch pipe (233), which are located at the center of the row of cylinders, extend toward the collector from the same direction as the first air intake branch pipe and the fourth air intake branch pipe, pass through between the collector and the resonance pipe, and are connected to the other collector chamber (212).

Description

Intake device for internal combustion engine

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

The four cylinders of the in-line four-cylinder internal combustion engine are divided into two cylinder groups in which the intake strokes are not continuous with each other (ignition order is first cylinder → third cylinder → fourth cylinder → second cylinder), and first to fourth intake passages Are arranged such that one of the first resonance chamber and the second resonance chamber that merges in each of the two cylinder groups is elongated in a direction perpendicular to the cylinder arrangement direction, and the other is long in a direction parallel to the cylinder arrangement direction. An intake manifold arranged as a long shape has been proposed (Patent Document 1).

In this intake manifold, the downstream side of the first resonance passage extending upstream from the first resonance chamber and the downstream side of the second resonance passage extending upstream from the second resonance chamber extend in parallel to the cylinder arrangement direction, The first to third intake passages are curved in an inverted U shape, the first intake passage is connected to the upper surface of the first resonance chamber, the second and third intake passages are connected to the upper surface of the second resonance chamber, The fourth intake passage is connected to the side surface of the first resonance chamber through the space below the first to third intake passages along the side surface of the second resonance chamber.

JP-A-10-73024

However, in the conventional intake manifold, since the first resonance chamber and the second resonance chamber are arranged vertically and horizontally on the side of the internal combustion engine, the resonance passage extends from the resonance chamber to the upstream side and extends from the resonance chamber to the downstream side. There is a problem that it is difficult to make the length of the independent intake passage compact, and that it is difficult to lay out compactly while realizing a resonance supercharging effect or an inertial supercharging effect.

The problem to be solved by the present invention is to provide an intake device for an internal combustion engine capable of achieving both a resonance supercharging effect or an inertial supercharging effect and a compact layout.

According to the present invention, a resonance tube partition plate that divides the internal space of the resonance tube into two along the extending direction is provided inside the resonance tube, and the two are connected to two collector chambers partitioned by the collector partition plate. Of the four intake branch pipes, the first intake branch pipe and the fourth intake branch pipe at both ends of the cylinder row are connected to one collector chamber partitioned by the collector partition plate, and the center of the remaining cylinder rows is connected. The second intake branch pipe and the third intake branch pipe extend from the same direction as the first intake branch pipe and the fourth intake branch pipe toward the collector, and pass between the collector and the resonance pipe and pass through the other The above-mentioned problem is solved by connecting to the collector chamber.

According to the present invention, it is possible to achieve both a resonance supercharging effect or an inertial supercharging effect and a compact layout.

1 is a perspective view showing an internal combustion engine to which an embodiment of the present invention is applied. It is a side view of FIG. 1A. It is a top view (2A arrow line view of FIG. 1A and FIG. 1B) which shows the intake device which concerns on one embodiment of this invention. FIG. 2B is a side view of FIG. It is sectional drawing which follows the 2C-2C line | wire of FIG. 2A. It is sectional drawing which follows the 2D-2D line | wire of FIG. 2A. It is a top view which shows the inside of the collector of FIG. 2A. It is sectional drawing which follows the 3B-3B line | wire of FIG. 3A. It is a graph which shows the relationship of the amount of intake air with respect to the rotational speed of the internal combustion engine to which the intake device of FIG. 2A is applied with a comparative example. It is a top view (2A arrow line view of FIG. 1A and FIG. 1B) which shows the intake device which concerns on other embodiment of this invention. FIG. 5B is a side view of FIG. 5A (viewed in the direction of arrow 5B in FIG. 5A, partially broken). It is a top view (2A arrow directional view of FIG. 1A and FIG. 1B) which shows the intake device which concerns on other embodiment of this invention. FIG. 6B is a sectional view taken along line 6B-6B in FIG. 6A.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1A and 1B are a perspective view and a side view showing an internal combustion engine 1 to which an intake device 2 according to an embodiment of the present invention is applied. The present invention is applied to a horizontal type in-line four-cylinder internal combustion engine 1. The present invention will be described in the embodiment. However, the intake device of the present invention may be an in-line four-cylinder internal combustion engine, and can be applied to a drive system such as an FF vehicle or an FR vehicle in addition to a vertically installed in-line four-cylinder internal combustion engine. .

As shown in FIGS. 1A and 1B, the internal combustion engine 1 is mounted horizontally in the engine room of the vehicle body so that the arrangement direction of the four cylinders is along the left-right direction of the vehicle body. The exhaust device 3 is disposed on the rear side of the vehicle body. From the viewpoint of collision safety, the shape of the restriction surface 4 from the vehicle hood for the purpose of protecting pedestrians and the securing of a space for protecting the pedestrian are considered, but they do not interfere with the restriction surface 4 from the vehicle hood. Thus, in order to mount the internal combustion engine 1, the structure and layout of the intake device 2 and the exhaust device 3 are important. In the internal combustion engine 1 of this example, the intake device 2 is arranged on the front side of the vehicle in relation to such hood line regulation (see FIG. 1B), but the front and rear space of the vehicle as viewed from the internal combustion engine 1 is very narrow. In this narrow space, the output performance is higher than that of the current car. At the same time, the low load range uses the intake resonance supercharging effect to reduce the residual gas in the cylinder by increasing the intake pressure, improving knock and reducing the size. To achieve both.

FIG. 2A is a plan view showing the intake device 2 according to one embodiment of the present invention, and is a view taken in the direction of arrow 2A in FIGS. 1A and 1B. The intake device 2 of this example includes a collector 21, a resonance tube 22, and an intake branch tube 23. As indicated by a two-dot chain line in the figure, the four cylinders of the internal combustion engine 1, that is, the first cylinder 11, the second cylinder 12, the third cylinder 13 and the fourth cylinder 14 from the right side to the left side of the vehicle are the left and right sides of the vehicle. The first cylinder 11 ⇒ the third cylinder 13 ⇒ the fourth cylinder 14 ⇒ the second cylinder 12 are ignited in this order. The arrangement direction of the four cylinders 11 to 14 (the left-right direction of the vehicle in this example) is also referred to as the cylinder arrangement direction.

The collector 21 has a long and substantially cylindrical shape (or a substantially rectangular tube shape or box shape), and is disposed along the cylinder arrangement direction on the side portion (front side of the vehicle) of the internal combustion engine 1 via a throttle valve 24. The collected air is collected and discharged to the cylinders 11 to 14 through the intake branch pipe 23. 3A is a plan view showing the inside of the collector 21 of this example, and FIG. 3B is a cross-sectional view taken along line 3B-3B of FIG. 3A. Inside the collector 21 of this example, a collector partition plate 213 is provided along the extending direction thereof, whereby the internal space of the collector 21 is partitioned into a first collector chamber 211 and a second collector chamber 212. .

Further, an opening is formed in a part of the collector partition plate 213, and a plate-like opening / closing valve 214 similar to the collector partition plate 213 is provided in the opening. The on-off valve 214 is rotated by a valve actuator between an open position indicated by a solid line in FIG. 3B and a closed position indicated by a two-dot chain line. Accordingly, when the opening / closing valve 214 is operated to the open position, the first collector chamber 211 and the second collector chamber 212 are connected to form one collector chamber, while when the opening / closing valve 214 is operated to the closed position, The first collector chamber 211 and the second collector chamber 212 are isolated (not connected) to form two collector chambers. The valve actuator 215 is operated by a control signal from an engine control unit (not shown), details of which will be described later.

As shown in FIG. 2A, the resonance tube 22 of the present example has a long and substantially cylindrical shape, and is located farther from the side of the internal combustion engine 1 than the collector 21 (front side of the vehicle from the collector 21). 21 extends from one end side in the extending direction to the other end side. The downstream end of the resonance tube 22 is connected to one end of the collector 22, and the upstream end is connected to the throttle valve 24. 1A, 1B and 2A, the throttle valve 24 is supported above the internal combustion engine 1 and the collector 21 is supported below the internal combustion engine 1. . The upstream end of the resonance tube 22 starts from above the internal combustion engine 1, turns along the side of the internal combustion engine 1 while being gently bent or curved with a large curvature, reaches the lower side of the internal combustion engine 1, and reaches the downstream side. It is connected to the collector 21 at the end on the side.

In the resonance tube 22 of this example, a resonance tube partition plate 223 is provided along the extending direction thereof, so that the internal space of the resonance tube 22 is partitioned into the first resonance passage 221 and the second resonance passage 222. It has been. A portion indicated by reference numeral 224 in FIG. 2A is a starting point of the resonance tube partition plate 223, and extends from here to a connection portion with the collector 21 toward the downstream side. 2C is a cross-sectional view taken along the line 2C-2C in FIG. 2A and shows a general cross section in which the resonance tube partition plate 223 is provided. A resonance pipe partition plate 223 is provided so that the cross-sectional areas of the first resonance path 221 and the second resonance path 222 are equal.

FIG. 2D is a cross-sectional view taken along line 2D-2D of FIG. 2A, and is a cross-sectional view showing a connection portion between the downstream end of the resonance tube 22 and one end of the collector 21. As shown in the figure, in the connection portion, the collector partition plate 213 of the collector 21 and the resonance tube partition plate 223 of the resonance tube 22 are connected in the same direction. That is, the first resonance passage 221 of the resonance tube 22 communicates only with the first collector chamber 211 of the collector 21, while the second resonance passage 222 of the resonance tube 22 communicates only with the second collector chamber 212 of the collector 21. The collector partition plate 213 and the resonance tube partition plate 223 are connected to each other. The shape of the resonance tube 22 is curved substantially along a surface obtained by extending the collector partition plate 213 (see FIG. 2D). Accordingly, the first resonance passage 221 and the second resonance passage 222 partitioned by the resonance tube partition plate 223 are configured to have substantially the same length. As a result, the equal lengths of the first resonance passage 221 and the second resonance passage 222 are improved, and the resonance supercharging effect can be improved.

Of the four intake branch pipes 23 in this example, the first intake branch pipe 231 and the fourth intake branch pipe 234 at both ends of the cylinder row are connected to the first collector chamber 211 partitioned by the collector partition plate 213. Of the two intake branch pipes 23, the second intake branch pipe 232 and the third intake branch pipe 233 in the center of the cylinder row are connected to a second collector chamber 212 partitioned by a collector partition plate 213. That is, since the ignition sequence of the internal combustion engine 1 of this example is first cylinder 11⇒third cylinder 13⇒fourth cylinder 14⇒second cylinder 12, intake branch pipes connected to cylinders whose intake strokes do not overlap each other. 23, that is, the first intake branch pipe 231 and the fourth intake branch pipe 234, and the second intake branch pipe 232 and the third intake branch pipe 233 are connected to

different collector chambers

211 and 212, respectively.

Further, the first intake branch pipe 231 and the fourth intake branch pipe 234 at both ends of the cylinder row are reverse U-shaped upward from the cylinder of the internal combustion engine 1 toward the side surface of the collector 21, as shown in the side view of FIG. It is formed in a curved shape. In particular, in the space indicated by the dotted line 15 in FIG. 2A, the drive motor for the alternator and the hybrid vehicle is disposed (see also FIG. 1A), so the first intake branch pipe 231 is located on the upper side or side of the alternator and the drive motor. In order not to interfere with the portion, the curved portion is formed in an inverted U shape so as to cover them.

In contrast, the second intake branch pipe 232 and the third intake branch pipe 233 in the center of the cylinder row extend toward the collector 21 from the same direction as the first intake branch pipe 231 and the fourth intake branch pipe. 2A passes through the gap between the collector 21 and the resonance tube 22 in a plan view, and surrounds the side surface of the collector 21 and is connected to the second collector chamber 212 below the collector 21.

When the four intake branch pipes 23 are connected to the collector 21 shorter than the lengths of the four cylinders 11 to 14 as shown in FIG. 2A, the

intake branch pipes

231 and 234 at both ends are the central intake branch pipes 232. , 233, the pipe length must be long. However, as in this example, the central second intake branch pipe 232 and the third intake branch pipe 233 are surrounded by the side of the collector 21 and below the collector 21. By connecting to the second collector chamber 212, the lengths of the first intake branch pipe 231 and the fourth intake branch pipe 234 at both ends can be made equal, and the inertia supercharging effect can be enhanced.

Incidentally, as shown in FIG. 2B, the lower surfaces of the first intake branch pipe 231 and the fourth intake branch pipe 234, which are curved in an inverted U shape upward, the second intake branch pipe 232, A gap S may be formed between the upper surface of the three intake branch pipes 233. 5A and 5B are a plan view and a side view showing an example in which a blow-by gas recirculation pipe 25 for recirculating blow-by gas in the crank chamber of the internal combustion engine 1 to the intake system is arranged in the gap S.

The blow-by gas recirculation pipe 25 is routed along a side surface of the internal combustion engine 1 from a crank chamber (not shown), and is arranged from the fourth intake branch pipe 234 side toward the first intake branch pipe 231 as shown in FIG. 5A. ing. At this time, as shown in FIG. 5B, the gap is formed between the lower surfaces of the first intake branch pipe 231 and the fourth intake branch pipe 234 and the upper surfaces of the second intake branch pipe 232 and the third intake branch pipe 233. It can be routed so as to pass through the gap S. Then, the communication holes 251 are formed in the contact portions with the first intake branch pipe 231 to the fourth intake branch pipe 234, so that the blow-by gas in the crank chamber passes through the communication holes 251 as shown in FIG. Thus, the air is returned to each of the first intake branch pipe 231 to the fourth intake branch pipe 234. Although the conventional blow-by gas recirculation pipe is routed in front of the resonance pipe 22 (the outer peripheral surface of the internal combustion engine 1), the internal combustion engine 1 can be made more compact by passing the gap S as in this example. it can.

Further, when the collector 21 is arranged, as shown by a white arrow in FIG. 6A, the collector 21 may be arranged inclining with the front of the internal combustion engine 1 (the vehicle right direction in the figure) as a downward direction. Alternatively, or in addition to this, a contact portion 26 that contacts the upper surface of the resonance tube 22 is formed on the lowermost surfaces of the second intake branch pipe 232 and the third intake branch pipe 233 in the vertical direction. Alternatively, a communication hole 261 of about φ3 that allows the second intake branch pipe 232 and the third intake branch pipe 233 and the resonance pipe 22 to communicate with each other may be formed.

The collector 21 is disposed so as to be inclined as shown in the figure, and / or a communication hole is formed in the contact portion 26 between the bottom surface of the second intake branch pipe 232 and the third intake branch pipe 233 in the vertical direction and the resonance pipe 22. By forming 261, the lubricating oil and moisture accumulated in the collector 21 or in the second intake branch pipe 232 and the third intake branch pipe 233 can be guided to the resonance pipe 22 far from the cylinders 11-14. As a result, it is possible to prevent misfire caused by white smoke or moisture mixed in the cylinder.

FIG. 4 is a graph showing the relationship between the intake air amount and the rotational speed of the internal combustion engine 1 to which the intake device 2 of the present example is applied together with a comparative example. The solid line indicates this example, and the dotted line indicates a comparative example in which the intake branch pipe is longer than this example. In this example, in the low speed rotation region (low load region of the internal combustion engine 1), the opening / closing valve 214 is closed to partition the collector 21 into a first collector chamber 211 and a second collector chamber 212 (the volume of the collector chamber is reduced). Small), while realizing the resonance supercharging effect, in the middle to high speed rotation range (medium load range to high load range of the internal combustion engine 1), the open / close valve 214 is opened and one collector chamber is formed in the collector 21. (Collector chamber volume is large) to achieve inertial supercharging effect.

In contrast to the inertial intake system of the comparative example having a long intake branch pipe, the collector 21 constitutes two

collector chambers

211 and 212 in the low-speed rotation region, so that the intake pressure can be increased by the resonance supercharging effect. Thus, the torque characteristics in the low speed rotation range can be improved. In addition, the increase in intake pressure reduces residual gas in the low-speed rotation region, contributing to improvement in knock performance. On the other hand, the collector 21 constitutes one collector chamber in the medium speed to high speed rotation range, and the inertial supercharging effect works due to the equalized intake branch pipe 23, which is a higher load range than the comparative example. The amount of intake air increases at.

As described above, according to the intake device of the present example, the first resonance chamber 221 and the second resonance passage 222 partitioned by the resonance tube partition plate 223 are separated from the first collector chamber 211 partitioned by the collector partition plate 213. The first collector branch pipe 231 and the fourth intake branch pipe 234 at both ends of the cylinder row of the four intake branch pipes are communicated with the second collector chamber 212, respectively. The second intake branch pipe 232 and the third intake branch pipe 233 in the center of the remaining cylinder rows are connected to the chamber 211 and are directed from the same direction as the first intake branch pipe 231 and the fourth intake branch pipe 234 toward the collector 21. In addition to being extended and passing between the collector 21 and the resonance tube 22 and connected to the other collector chamber 212, the resonance supercharging effect or the And realization of supercharging effect, it is possible to achieve both the compact layout properties.

Further, the second intake branch pipe 232 and the third intake branch pipe 233 are routed so as to pass through the portion of the resonance pipe 22 near the internal combustion engine 1, that is, between the collector 21 and the resonance pipe 22. The pipe length can be suppressed from becoming extremely long, and the first intake branch pipe 231 and the fourth intake branch pipe 234 can be easily configured to have the same length. If the second intake branch pipe 232 and the third intake branch pipe 233 are routed outside the resonance pipe 22, the pipe length becomes too long and is equal to the pipe lengths of the first intake branch pipe 231 and the fourth intake branch pipe 234. In order to achieve this, the first intake branch pipe 231 and the fourth intake branch pipe 234 must be lengthened. As a result, the amount of protrusion of the first intake branch pipe 231 and the fourth intake branch pipe 234 increases, and the internal combustion Although the engine 1 itself becomes large, the intake device 2 of this example can set the four intake branch pipes 231 to 234 to have the same length without causing such a problem.

In addition, since the resonance pipe 22 is disposed so as to surround the second intake branch pipe 232 and the third intake branch pipe 233, the bending R of the resonance pipe 22 having a larger flow rate than the intake branch pipe 23 is extremely reduced. The reduction in size is suppressed, and the intake resistance can be reduced.

Further, according to the intake device 2 of the present example, since there is no intake branch pipe 23 passing between the collector 21 and the resonance pipe 22 at the connection end of the collector 21 with the resonance pipe 22, the resonance pipe 22 on the connection side. Can be bent gently in an arc toward the throttle valve 24 supported by the internal combustion engine 1, can form a smooth (large bending R) resonance tube 22, and reduce intake resistance Can do. Further, by drawing a gentle arc, a sufficient length is secured from the throttle valve 24 to the collector 21. As a result, it is easy to realize the resonance supercharging effect.

Further, according to the intake device 2 of the present example, the resonance tube 22 having the resonance partition plate 223 is provided along substantially one plane so that the direction of the resonance tube partition plate 223 is aligned with the direction of the collector partition plate 213. The resonance pipe 22 connected to the collector 21 from the lower side of the internal combustion engine 1 once goes from the collector 21 toward the upstream side of the intake flow toward the lower side of the internal combustion engine 1, and then remains on the same plane as the throttle valve above the internal combustion engine. 24 can be formed. Further, the amount of protrusion of the resonance tube 22 to the side of the internal combustion engine can be reduced, and the intake device 2 can be configured compactly.

Further, according to the intake device 2 of the present example, the alternator and the driving motor disposed in the space 15 below the first intake branch pipe 231 are increased, and thereby the first intake branch pipe 231 has a long shape. In addition, since the second intake branch pipe 232 and the third intake branch pipe 233 are configured to surround the collector 21, the pipe lengths of the first intake branch pipe 231, the second intake branch pipe 232, and the third intake branch pipe 233 are the same. Can be made equal in length. In the FF vehicle, the motor fan on the vehicle side is arranged on the side surface of the internal combustion engine 1, but according to the intake device 2 of this example, the motor fan can be avoided and mounted on a more compact vehicle. Can do.

Further, according to the intake device 2 of the present example, the lower surfaces of the first intake branch pipe 231 and the fourth intake branch pipe 234 that are curved in an inverted U shape upward, and the second intake branch pipe 232 are formed. And a blow-by gas recirculation pipe 25 that recirculates the blow-by gas in the crank chamber of the internal combustion engine 1 to the intake system is disposed in this gap S. The gas reflux pipe 25 becomes compact without protruding from the intake device 2, and at the same time, the blow-by gas reflux pipe 25 contributes to improving the rigidity of the intake device 2 itself.

Further, according to the intake device 2 of the present example, the collector 21 is disposed so as to be inclined with the front of the internal combustion engine 1 as a downward direction, or the second intake branch pipe 232 and the third intake branch pipe 233 are arranged in the vertical direction. Since the lower surface has a contact portion 26 in contact with the upper surface of the resonance tube 22, a communication hole 261 for communicating the second intake branch tube 232 and the third intake branch tube 233 with the resonance tube 22 is formed in the contact portion 26. In addition, it is possible to prevent a large amount of water or oil generated by blow-by gas or EGR (exhaust gas recirculation) from being introduced into the internal combustion engine 1, and as a result, it is possible to prevent the occurrence of problems such as white smoke and misfire. .

The first collector chamber 211 corresponds to one collector chamber according to the present invention, and the second collector chamber 212 corresponds to the other collector chamber according to the present invention.

1 ... Internal combustion engine 11-14 ... Cylinder 15 ... Alternator and drive motor space)
2 ... Intake device 21 ... Collector 211 ... First collector chamber (one collector chamber)
212 ... Second collector chamber (the other collector chamber)
213 ... Collector partition plate 214 ... Open / close valve 215 ... Valve actuator 22 ... Resonance tube 221 ... First resonance passage 222 ... Second resonance passage 223 ... Resonance tube partition plate 224 ... Resonance tube partition plate starting point 23 ... Intake branch tube 231 ... the first intake branch pipe 232 ... the second intake branch pipe 233 ... the third intake branch pipe 234 ... the fourth intake branch pipe 24 ... the throttle valve 25 ... the blowby gas recirculation pipe 251 ... the communication hole 26 ... the contact portion 261 ... the communication hole 3 ... exhaust device 4 ... hood

Claims

A collector extending along the cylinder arrangement direction at the side of the in-line four-cylinder internal combustion engine;
A resonance tube extending from one end side in the extending direction of the collector to the other end side at a position farther from the side of the internal combustion engine than the collector, and connected to one end side of the collector;
An intake branch pipe connecting the collector and each cylinder,
The collector is provided inside the collector, and includes a collector partition plate that divides the internal space of the collector into two along the extending direction thereof,
The resonance tube is provided inside the resonance tube, divides the internal space of the resonance tube into two along the extending direction, and at least the collector partition plate so as to be continuous with the collector partition plate. A resonance pipe partition plate formed so that the connection portion is in the same direction as the collector partition plate,
Of the four intake branch pipes, the first intake branch pipe and the fourth intake branch pipe at both ends of the cylinder row are connected to one collector chamber partitioned by the collector partition plate,
Of the four intake branch pipes, the second intake branch pipe and the third intake branch pipe in the center of the cylinder row extend from the same direction as the first intake branch pipe and the fourth intake branch pipe toward the collector. And an intake device for an internal combustion engine that passes between the collector and the resonance tube and is connected to the other collector chamber.
The intake device for an internal combustion engine according to claim 1, wherein one end of the resonance pipe is connected to a throttle valve supported by the internal combustion engine.
The one collector chamber is disposed farther from the side surface of the internal combustion engine than the other collector chamber,
The intake device for an internal combustion engine according to claim 2, wherein the resonance pipe is connected to the collector from below the internal combustion engine, and the throttle valve is provided above the internal combustion engine.
The collector has an open / close valve that switches the one collector chamber and the other collector chamber to a communication state or a non-communication state;
The open / close valve switches the one collector chamber and the other collector chamber to a non-communication state in a low load region of the internal combustion engine, and the one of the one and the other collector chambers in a medium load region to a high load region of the internal combustion engine. The intake device for an internal combustion engine according to any one of claims 1 to 3, wherein the collector chamber and the other collector chamber can be switched to a communication state.
The first intake branch pipe is curved in an inverted U shape so as to cover an upper part or a side part of an alternator or a driving motor arranged in a lower part of the first intake branch pipe. Intake device for internal combustion engine.
The first intake branch pipe and the fourth intake branch pipe are connected to a side surface of the collector;
The intake device for an internal combustion engine according to any one of claims 1 to 5, wherein the second intake branch pipe and the third intake branch pipe surround the side surface of the collector and are connected from below.
When the internal combustion engine is viewed from the side in the cylinder arrangement direction, it is between the lower surfaces of the first intake branch pipe and the fourth intake branch pipe and the upper surfaces of the second intake branch pipe and the third intake branch pipe. The internal combustion engine intake device according to any one of claims 1 to 6, wherein a gap is formed in the gap, and a blow-by gas recirculation pipe of the internal combustion engine is inserted into the gap.
The intake device for an internal combustion engine according to any one of claims 1 to 7, wherein the collector is disposed so as to be inclined with a front side of the internal combustion engine as a downward direction.
The second intake branch pipe and the third intake branch pipe have a contact portion in contact with the upper surface of the resonance pipe at the lowermost surface in the vertical direction,
9. The intake device for an internal combustion engine according to claim 1, wherein a communication hole for communicating the second intake branch pipe, the third intake branch pipe, and the resonance pipe is formed in the contact portion.