JP2007107481A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compact an engine intake device 1 and reduce intake noise. <P>SOLUTION: Intake system elements such as an upstream intake passage part 3, an intake collecting part 4 and branch passage parts 5-8 are laid out to hold a resonance chamber 9 in an engine 1 side by the intake system elements, and the upstream intake passage part 3, the intake collecting part 4, the branch passage parts 5-8 and the resonance chamber 9 are integrated by common bulkheads 15-17. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

    The present invention relates to an intake device for an in-line multi-cylinder engine.

    An in-line multi-cylinder engine intake system includes an upstream intake passage portion that introduces intake air, an intake manifold portion that follows the upstream intake passage portion, and a plurality of intake air that branches from the intake manifold portion and supplies intake air to each cylinder of the engine A branch passage portion is provided as a basic component. With regard to the layout of these three elements, various devices have been devised for compactly accommodating the intake device in the engine room of the vehicle. For example, an intake collecting portion is arranged on one side of the engine, the upstream intake passage portion is extended in the cylinder row direction of the engine and the downstream end thereof is connected to the lower portion of the intake collecting portion, and the plurality of branch passage portions are arranged in the cylinder row direction. A layout is adopted in which the engine is raised from the upper part of the intake air collecting portion, curved upward toward the engine side, and connected to the engine with each downstream side portion facing obliquely downward.

By the way, in an engine, there exists a tendency which produces a trough in output torque in a specific rotation area. This appears as a negative effect when a so-called resonance supercharging effect is obtained in which the intake pulsation generated in each branch passage is resonated in the entire intake system to increase intake charging efficiency. As a countermeasure, in order to appropriately reverse the pressure wave of the intake air in the intake air collecting portion, a resonance chamber is connected to the intake air collecting portion by a communication passage, and the capacity of the resonance chamber, the inner diameter of the communication passage, and the passage length are tuned. Things have been done. For example, Patent Document 1 describes that a rigid resin-made resonance chamber (resonator) is coupled to one end of an intake manifold portion that is elongated in the cylinder row direction by a coupling member.
JP-A-10-18849

    In order to reduce the size of the intake device including the resonance chamber as described above, it is necessary to devise the arrangement of the resonance chamber. In addition, if the intake device is made of resin from the viewpoint of weight reduction and cost reduction, radiation sound from the outer wall due to intake vibration, that is, intake noise may be a problem, but the whole including the resonance chamber is made of resin. In some cases, the walls of the resonance chamber can also be a source of noise.

    Therefore, the present invention has an object to make the entire intake device compact, to suppress intake noise as much as possible, and to increase the rigidity of the entire intake device when providing the resonance chamber in the resin intake device.

    In order to solve such a problem, the present invention provides an intake system in which the resonance chamber is held in the engine side by an intake air collecting portion, an upstream intake passage portion, and a plurality of branch passage portions. The elements were laid out, and the walls constituting the intake air collecting portion, the upstream intake passage portion, and the branch passage portion were also used as the walls constituting the resonance chamber.

The invention according to claim 1 supplies the intake air to each cylinder of the in-line multi-cylinder engine branched from the upstream intake passage portion for introducing intake air, the intake manifold portion following the upstream intake passage portion, and the intake manifold portion. A plurality of branch passage portions and a resonance chamber;
The intake assembly is disposed on one side of the engine,
The upstream intake passage portion extends in the cylinder row direction of the engine, and a downstream end thereof is connected to a lower portion of the intake manifold portion,
The plurality of branch passages are arranged along a cylinder row of the engine, and each includes a rising portion extending upward from an upper portion of the intake manifold portion and a curved portion curved toward the engine side following the rising portion. In an engine intake system having
The upstream intake passage portion has a downstream portion extending along an engine side wall of the intake manifold portion, and a downstream end thereof connected to an intermediate portion in the cylinder row direction below the intake manifold portion,
The resonance chamber is disposed between a portion extending from an upper portion of the intake air collecting portion to a rising portion of the plurality of branch passage portions and the engine,
The engine-side wall above the intake manifold portion, the upper-side wall of the upstream intake passage portion, and the engine-side wall of the plurality of branch passage portions are respectively an intake manifold portion, an upstream intake passage portion, and a branch passage portion. And the resonance chamber are shared by each other as a partition wall,
A communication portion is formed in the partition wall of the intake air collecting portion and the resonance chamber so as to communicate the internal spaces of the both.
The upstream intake passage portion, the intake manifold portion, the plurality of branch passage portions, and the resonance chamber are formed by joining a plurality of resin parts to each other.

    That is, the downstream portion of the upstream intake passage portion extends along the engine-side wall of the intake manifold portion, and the downstream end is connected to an intermediate portion in the cylinder row direction at the lower portion of the intake manifold portion, and a plurality of branch passage portions are the intake manifold portions. It is curved to the engine side when it rises from the top, which means that the intake collecting portion, the upstream intake passage portion, and the plurality of branch passage portions are arranged in a form along one side of the engine. is there. Moreover, on one side of the engine, the lower part is the downstream part of the upstream intake passage part, the upper part is the curved part of the plurality of branch passage parts, and the intermediate part is the upper part of the intake manifold part and the rising part of the plurality of branch passage parts It means that you can create an enclosed space.

    In such a layout, the space generated on one side of the engine as described above is used, and the resonance chamber is disposed there. Therefore, the space utilization efficiency is increased, and the place where the intake device occupies beside the engine. However, it does not spread from the engine to the side and does not spread in the cylinder row direction, and the intake device becomes compact.

    Thus, the resonance chamber includes the engine-side wall at the top of the intake manifold, the upper-side wall of the upstream intake passage, and the engine-side wall of the plurality of branch passages as walls that form the resonance chamber. Since it is shared with the three elements of the intake system, the exposed wall surface is reduced and the generation of radiation noise due to intake vibration is reduced. This is true not only for the resonance chamber but also for the intake air collecting portion, the upstream intake passage portion, and the branch passage portion. By sharing the above-mentioned wall, the radiated sound from these three intake system elements is also reduced. It will be.

    In addition, the use of the above-mentioned walls makes it possible to reduce the weight and reduce the material cost.In addition, the intake air collecting portion, the upstream intake passage portion, and the branch passage portion are connected to each other via a resonance chamber, so that the entire intake device is a single block (a block). ) Since it becomes a structure, the rigidity of the entire intake device is increased. That is, although the intake device is formed by joining a plurality of resin parts, it is easy to ensure the strength.

The invention according to claim 2 is the invention according to claim 1,
The plurality of branch passage portions include a connection flange for connecting to the engine at a downstream end extending obliquely downward from the curved portion,
A working space is formed between the rising portions of at least one adjacent branch passage portion so that the operation of connecting the connection flange to the engine can be performed from the outside of the rising portion,
On the upper surface of the resonance chamber, there is formed a groove-like recess extending from the working space toward the engine side and opening in the engine side wall of the resonance chamber so as to enable the operation. Features.

    Due to the layout and the formation of the common wall as described above, the resonance chamber has fewer wall surfaces exposed to the outside. However, the engine side wall of the resonance chamber is not shared with other intake system elements, and is an open wall that is relatively widely exposed to the outside. Therefore, in the present invention, a groove-shaped recess that can be used for flange connection work is positively formed on the upper surface of the resonance chamber, and the surface rigidity is increased by forming a bay portion around the open wall by the groove-shaped recess. This makes it difficult for the open wall to vibrate and become a noise source. Further, the formation of the groove-like concave portion simultaneously increases the surface rigidity of the upper surface wall of the resonance chamber, so that the vibration is suppressed and it is advantageous for preventing radiation sound from the upper surface wall.

    More specifically, since the connecting flange at the downstream end of the branch passage portion is provided at the tip further extending obliquely downward from the curved portion, when the engine is viewed from the outside of the branch passage portion, The positional relationship overlaps with the connecting flange. Therefore, in order to fasten the connection flange to the engine from the outside of the branch passage portion, a working space (a hole or a gap opened upward) for inserting a fastener and a tool between the rising portions of adjacent branch passage portions is provided. It is necessary to provide it. In this case, when the upper edge of the resonance chamber is located near the curved portion of the branch passage portion, a tool or the like interferes with the resonance chamber. Accordingly, as described above, a groove-like recess is formed on the upper surface of the resonance chamber. Accordingly, the fastening operation of the connection flange to the engine can be performed without any trouble from the outside of the branch passage portion, and the wall on the engine side of the resonance chamber can be prevented from becoming a noise source.

The invention according to claim 3 is the invention according to claim 1 or 2,
The connection port of the downstream end of the upstream intake passage portion to the intake manifold portion is widened and opened so as to be offset from the central portion of the intake manifold portion in the cylinder row direction to the upstream side of the upstream intake passage portion. And

    That is, generally, when the downstream end of the upstream intake passage portion is opened at the center of the intake manifold portion in the cylinder row direction, the distribution balance of intake air from the intake manifold portion to each branch passage portion is good. However, when the downstream portion of the upstream intake passage portion extends along the engine side wall of the intake manifold portion and is connected to the intake manifold portion as described above, the intake air is upstream of the intake manifold portion due to its inertia. It flows in the direction opposite to the part, making it difficult to achieve the above distribution balance. Therefore, in the present invention, the inlet port of the upstream intake passage portion downstream end is opened so as to be offset from the central portion of the intake manifold portion toward the upstream side of the upstream intake passage portion, whereby the intake air flows upstream of the intake manifold portion. It is easy to flow in to the side and improves the distribution balance of intake air.

    Moreover, even if the opening of the intake air collecting portion is increased as described above, the intake air collecting portion is connected to the resonance chamber by the shared partition wall, and further, the resonance chamber is also connected to the upstream intake passage portion by the shared partition wall. These adjacent resonance chambers and upstream intake passage portions can compensate for a decrease in strength of the intake air collecting portion due to the expansion of the opening, making it easy to secure the strength.

    As described above, according to the first aspect of the invention, on one side of the engine, the lower side is the upstream intake passage portion, the upper side is the curved portion of the plurality of branch passage portions, and the intermediate portion is the upper portion of the intake manifold portion and the plurality of A resonance chamber is arranged in this space so that a space surrounded by the rising portion of the branch passage portion is formed, and a wall on the engine side at the upper portion of the intake manifold portion, a wall on the upper surface side of the upstream intake passage portion, and a plurality of Since the engine side wall of the branch passage is shared by each of the three elements of the intake system and the resonance chamber as a partition wall, the intake device becomes compact and the resonance chamber is externally connected to the resonance chamber. The exposed wall is reduced and the generation of radiated noise due to intake vibration is suppressed. At the same time, the radiated sound from the three elements of the intake system is also suppressed. Stiffness is increased even resin intake device, the securing strength is facilitated.

    According to the second aspect of the present invention, the working space for connecting the connection flange at the downstream end of the branch passage portion to the engine is formed between the rising portions of at least one adjacent branch passage portion, and the resonance chamber is formed. Since a groove-like recess extending toward the engine side is formed on the upper surface of the connecting flange, the fastening operation of the connection flange to the engine can be performed from the outside of the branch passage portion without any trouble. Further, it is possible to prevent the engine-side wall and the top wall of the resonance chamber from becoming noise sources.

    According to the invention of claim 3, the connection port to the intake manifold portion at the downstream end of the upstream intake passage portion is further offset from the central portion in the cylinder row direction of the intake manifold portion to the upstream side of the upstream intake passage portion. Since the opening is widened, the distribution balance of the intake air is improved, and the shared partition is provided between the intake air collecting portion and the upstream intake passage portion and the resonance chamber as described above. The strength reduction of the intake air collecting portion due to the opening expansion is compensated, and the strength can be easily secured.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Embodiment 1>
In FIG. 1, reference numeral 1 denotes an intake device (intake manifold) of an in-line multi-cylinder (4 cylinders in this example) engine 2 of an automobile. The intake device 1 supplies an intake air to each cylinder of the engine 2 by branching from an upstream intake passage portion 3 for introducing intake air, an intake air collecting portion 4 following the upstream intake air passage portion 3, and the intake air collecting portion 4. The first to fourth branch passage portions 5 to 8 are provided, and a resonance chamber 9 is further provided as shown in FIG. 2 (a rear view seen from the engine side). In addition, the intake device 1 is formed by joining a plurality of parts each formed of a synthetic resin. This point will be described in detail later.

    The intake air collecting portion 4 is disposed at a substantially central position in the cylinder row direction on one side of the engine 2 and extends in the cylinder row direction as indicated by a broken line in FIG.

    The upstream intake passage portion 3 is inclined downward from the upstream end toward the downstream end and extends in the cylinder row direction. As shown in FIG. 2, the downstream portion of the upstream intake passage 3 extends along the engine-side wall of the intake manifold 4, and its downstream end is at the intermediate portion in the cylinder row direction below the intake manifold 4. It is connected. As shown in FIG. 3, the connection port 11 to the intake manifold portion 4 at the downstream end of the upstream intake passage portion 3 is further offset from the central portion in the cylinder row direction of the intake manifold portion 4 to the upstream side of the upstream intake passage portion 3. Open to open. “Upstream” means the direction in which intake air flows, and “downstream” means the direction in which intake air flows down.

    As shown in FIG. 1, the branch passage portions 5 to 8 are arranged along the cylinder row of the engine 2, and rising portions 5 a to 8 a extending upward from the upstream ends connected to the upper portions of the intake air collecting portions 4. Then, following the rising portions 5a to 8a, there are curved portions 5b to 8b curved to the engine side as shown in FIGS. The rising portions 5a to 8a spread in a fan shape so that the interval between the rising portions adjacent to each other increases in the upward direction.

    As shown in FIG. 5, the downstream end side of each branch passage portion 5-8 extends obliquely downward from the curved portions 5a-8a, and a connection flange 12 for connecting to the engine 2 is provided at the tip, that is, the downstream end. It has been. As shown in FIG. 2, the connection flange 12 is a flange common to the four branch passage portions that spread in the cylinder row direction so as to connect the branch passage portions 5 to 8.

    Due to the layout of the upstream intake passage portion 3, the intake manifold portion 4 and the branch passage portions 5 to 8 as described above, as shown in FIG. 5, the lower side is the downstream portion of the upstream intake passage portion 3 on one side of the engine 2, The upper side is a curved portion of the branch passage portions 5 to 8 and the middle portion is a space surrounded by the upper portion of the intake manifold portion 4 and the rising portions 5a to 8a of the branch passage portions 5 to 8. Further, this space is closed on one side in the cylinder row direction by an inclined upstream portion of the upstream intake passage portion 3.

    Thus, a resonance chamber 9 is disposed in a space on one side of the engine surrounded by the three intake system elements 3, 4, 5-8. That is, the resonance chamber 9 is disposed between the engine 2 and a portion extending from the upper portion of the intake air collecting portion 4 to the rising portions 5 a to 8 a of the branch passage portions 5 to 8. As shown in FIG. 2, the engine-side wall of the resonance chamber 9 is an open wall that is exposed to the outside over the entire surface. However, a part of the wall on the lower surface side and the wall on the opposite side of the engine is shared. It is a partition wall.

    That is, as shown in sectional views in FIGS. 5 to 7, the upper surface side wall 15 of the upstream intake passage portion 3, the engine side wall 16 above the intake air collection portion 4, and the engine of the branch passage portion rising portions 5 a to 8 a. The side wall 17 is shared as a partition wall that partitions the intake air collecting portion 4, the upstream intake passage portion 7, the branch passage portions 5 to 8, and the resonance chamber 9. Further, as shown in FIGS. 5 and 7, the wall 18 at the downstream end portion of the branch passage portions 5 to 8 is also used as a partition wall that partitions the partition passage portions 5 to 8 and the resonance chamber 9. As shown in FIGS. 3 and 6, a communication hole 19 is formed in the partition wall 16 shared by the intake air collecting portion 4 and the resonance chamber 9, as shown in FIGS. 3 and 6.

    In addition, as shown in FIG. 3, the resonance chamber 9 extends in a fan shape so that the upper side is widened, and a groove-shaped recess 21 is formed in the central portion of the upper surface wall 20. The concave groove 21 is provided for connecting the connection flange 12 to the engine 2 and is provided to increase the surface rigidity of the open wall on the engine side of the resonance chamber 9.

    That is, as described above, the connection flange 12 is provided at a point that is inclined obliquely below the curved portions 5b to 8b of the branch passage portions 5 to 8. Therefore, as shown in FIG. 1, when the connection flange 12 is viewed from the outside of the intake device 1 (opposite to the engine), the rising portions 5a to 8a of the branch passage portions 5 to 8 and the connection flange 12 overlap. It becomes a positional relationship. Therefore, in order to fasten the connection flange 12 to the engine 2, a working space (hole) for inserting a fastener (bolt) and a fastening tool between the rising portions 5 a to 8 a of the adjacent branch passage portions 5 to 8. Or a gap opened upward).

    In the present embodiment, as shown in FIG. 2, fastening holes (bolt insertion holes) 22 are disposed at positions outside the branch passage portions 5 to 8 at both ends of the connection flange 12 extending in the cylinder row direction. The three fastening holes 22 are arranged in a staggered manner between the rising portions of the adjacent branch passage portions 5 to 8. The fastening hole 22 between the first branch passage portion 5 and the second branch passage portion 6 and the fastening hole 22 between the third branch passage portion 7 and the fourth branch passage portion 8 are both of the connection flange 12. It arrange | positions at the upper edge side, and as shown in FIG. 1, it faces the clearance gap (working space) opened upward between each branch passage part. Therefore, the connection flange 12 can be fastened to the engine 2 by inserting a fastener and a tool from the gap and applying the fastener and tool to the fastening hole 22.

    On the other hand, a central fastening hole 22 existing between the second branch passage portion 6 and the third branch passage portion 7 is disposed on the lower edge side of the connection flange 12. A connecting wall 23 is provided between the branch passage portions 6 and 7 to connect the branch passage portions 6 and 7. Accordingly, a working hole (working space) 24 corresponding to the fastening hole 22 is formed in the connecting wall 23. Thus, a groove-like recess 21 extending linearly from the work hole 24 to the engine side wall surface is formed at the center of the upper surface wall 20 of the resonance chamber 9 so as to correspond to the work hole 24. ing. Therefore, the connection flange 12 can be fastened to the engine 2 by applying a fastener and a tool to the central fastening hole 22 through the work hole 24 and the groove-shaped recess 21.

    Note that the four openings arranged in a straight line in the cylinder row direction of the connection flange 12 are connection ports 26 connected to the intake ports of the cylinders of the cylinder head, and a circular opening provided at one end of the connection flange 12. Is a gas inlet 27 for EGR (exhaust gas recirculation).

    As shown in FIG. 2, the stay 28 extends downward from the engine side wall of the intake air collecting portion 4. The lower end of the stay 28 is fastened to the engine 2.

    As shown in FIGS. 3 and 6, a vacuum chamber 29 serving as a negative pressure source of the negative pressure responsive actuator is formed between the curved portions 6 b and 7 b of the second branch passage portion 6 and the third branch passage portion 7. .

    Next, resin parts constituting the intake device 1 will be described. As shown in FIGS. 5 to 7, the intake device 1 includes a first resin part 31 on the engine side, a third resin part 33 on the side opposite to the engine (meaning opposite to the engine side), and an intermediate first resin part 33. It is formed by joining two resin parts 32.

    The first resin component 31 includes an engine side portion of the upstream intake passage portion 3, a downstream portion extending obliquely downward following the curved portions 5 b to 8 b of the branch passage portions 5 to 8 and the connection flange 12, and the resonance chamber 9. The engine side portion and the stay 28 are configured. That is, the engine side portion of the upstream intake passage portion 3, the downstream portion of the branch passage portions 5 to 8, and the connection flange 12 are connected so as to be integrated at the engine side portion of the resonance chamber 9. The first resin component 31 is provided with a part of the shared partition wall 15 for the upstream intake passage portion 3 and the resonance chamber 9, and the shared partition wall 18 for the downstream end portions of the branch passage portions 5 to 8 and the resonance chamber 9. ing.

    The second resin component 32 includes the upstream-side intake passage portion 3 on the side opposite to the engine, the intake-side assembly portion 4 on the engine-side portion, the branch passage portions 5 to 8 on the engine-side wall 17 and the curved portion. The downstream part of 5b-8b and the anti-engine side part of the resonance chamber 9 are comprised. That is, the non-engine side portion of the upstream intake passage portion 3 and the subsequent engine side portion of the intake air collecting portion 4 and the downstream portion of the curved portions 5 b to 8 b are connected to the non-engine side including the common partition wall 17 of the resonance chamber 9. It is a part that is connected so as to be united with each other. The second resin component 32 includes a remaining portion of the shared partition 15 between the upstream intake passage portion 3 and the resonance chamber 9, a shared partition 16 between the intake assembly portion 4 and the resonance chamber 9, the rising portions 5a to 8a, and the resonance chamber. 9 and a common partition wall 17 are provided.

    The third resin component 33 is a portion extending from the anti-engine side portion of the intake manifold portion 4 and the rising portions 5a to 8a (excluding the shared partition wall 17) of the branch passage portions 5 to 8 to the upstream portion of the curved portions 5b to 8b. And make up.

    Then, the 1st-3rd resin components 31-33 are provided with the recessed part and convex part which mutually fit in a mutual mating surface, and the mating surface is joined by welding.

    As shown in FIG. 1, reinforcing ribs 35 formed in a lattice shape are provided on the wall of the intake air collecting portion 4 on the side opposite to the engine to increase the surface rigidity. Further, as shown in FIG. 2, the engine-side wall of the resonance chamber 9 is provided with reinforcing ribs 36 formed in a lattice shape so as to increase the surface rigidity.

    As described above, according to the engine intake device according to the present embodiment, the resonance chamber 9 is disposed in the space surrounded by the upstream intake passage portion 3, the intake manifold portion 4, the branch passage portions 5-8 and the engine 2. Therefore, the space can be effectively used and the intake device 1 is compactly arranged on one side of the engine 2. Therefore, it becomes easy to lay out the intake device 1 and other engine-related parts without interfering with each other in the engine room of the automobile.

    Thus, the resonance chamber 9 has a part of the wall on the lower surface side thereof formed by the shared partition wall 15 with the upstream intake passage portion 3, and a part of the wall on the opposite engine side with the intake air collecting portion 4. And a common partition wall 17 with the branch passage portions 5 to 8. Therefore, the upstream intake passage portion 3, the intake manifold portion 4, and the branch passage portion rising portions 5a to 5b reinforce the walls on the lower surface side of the resonance chamber 9 and the walls on the engine side. The vibration of the wall due to the intake vibration inside, that is, the generation of radiated sound is prevented, or the radiated sound is blocked by the upstream intake passage portion 3, the intake collecting portion 4 and the branch passage portion rising portions 5a to 8b. The noise is reduced. Further, the formation of the shared partition walls 15 to 17 also reduces radiated sound from the upstream intake passage portion 3, the intake air collecting portion 4, and the branch passage portion rising portions 5a to 8b.

    On the other hand, with respect to the wall 20 on the upper surface side of the resonance chamber 9, the surface rigidity is increased by the formation of the groove-shaped recess 21, and the shared partition wall 18 is formed between the downstream end portions of the branch passage portions 5 to 8. Because it is provided, it is difficult to generate radiated sound.

    Further, the engine-side wall 30 of the resonance chamber 9 is also an open wall that is relatively widely exposed to the outside. However, the groove-shaped recess 21 allows the upper edge to enter the bay toward the inside (downward). Since the bay entrance is formed, the surface rigidity is higher than when there is no such bay entrance and it simply spreads around. That is, the peripheral portion of the open wall 30 serves as a restraint portion that restricts vibration of the open wall 30, but the restraint portion is located inside the open wall 30 at the center in the cylinder row direction by the groove-shaped recess 21. Since it is in the bay, surface rigidity is increased. In other words, since the open wall 30 has a narrower vertical width at the center part in the cylinder row direction due to the bay portion, the center part becomes a node that is less likely to cause surface vibration, and is divided into two vibration region parts with small areas on both sides. It becomes the shape that was made. And since a wall becomes difficult to vibrate, so that an area becomes small, generation | occurrence | production of the radiation sound by an internal intake vibration will be suppressed.

    Further, by forming the shared partition walls 15 to 18, the upstream intake passage portion 3, the intake manifold portion 4, and the branch passage portions 5 to 8 are connected to each other via the resonance chamber 9, so that the entire intake device has a single block structure. Since it becomes a body, the rigidity of the whole intake device is increased. That is, although the intake device is formed by joining a plurality of resin parts 31 to 33, it is easy to ensure the strength. In addition, such sharing of the walls can reduce the weight of the intake device 1 and reduce the material cost.

    Further, since the downstream portion of the upstream intake passage portion 3 extends along the engine side wall of the intake air collecting portion 4, the intake air introduced into the intake air collecting portion 4 is separated from the upstream intake passage portion 3 by its inertia. Is going toward the first branch passage portion 5 located on the opposite side. However, since the connection port 11 of the upstream intake passage portion 3 to the intake manifold portion 4 is widened and opened toward the upstream side of the upstream intake passage portion 3, the intake air is on the upstream intake passage 3 side of the intake manifold portion 4. It is easy to flow into the fourth branch passage portion 8 side in a short circuit.

    Therefore, regardless of the adoption of a structure in which the downstream side portion of the upstream intake passage portion 3 is extended along the engine side wall of the intake air collecting portion 4 (which is advantageous for the compactness of the intake device 1 and the formation of the shared partition wall 15). The distribution characteristics of the intake air to the first to fourth branch passage portions 5 to 8 are improved.

    In addition, the intake air collecting portion 4 is connected to the resonance chamber 9 by the shared partition wall 16, and the resonance chamber 9 is also connected to the upstream intake passage portion 3 by the shared partition wall 15. The passage portion 3 compensates for the strength reduction of the intake air collecting portion 4 due to the enlargement of the connection port 11 and facilitates securing the strength.

<Embodiment 2>
Only the principal part of this embodiment is shown in FIG. That is, the resonance chamber 9 is provided in order to make the resonance supercharging effect appropriate as described at the beginning of this specification. For this purpose, the capacity of the resonance chamber 9 is set to the engine 2 and the branch passage section 5. Tuning is necessary according to the capacity of the intake manifold 4. This embodiment is a case where the resonance chamber 9 has a smaller capacity than the first embodiment.

    In this case, as shown in FIG. 8, a groove-like recess 21 is provided in the center of the upper surface wall 20 of the resonance chamber 9 in the cylinder row direction, and both side portions of the groove-like recess 21 become lower toward both ends. What is necessary is just to form so that it may become the square shape of the downward inclination. As a result, the capacity of the resonance chamber 9 can be reduced, and similar effects such as reduction of radiated sound using the shared partition wall and the groove-shaped recess 21 and the downsizing of the intake device 1 can be obtained as in the first embodiment. .

    In the first and second embodiments, the communication hole 19 between the intake air collecting portion 4 and the resonance chamber 9 is arranged at the center of the intake air collecting portion 4 in the cylinder row direction. You may make it do.

1 is a front view of an engine intake device according to Embodiment 1. FIG. It is the same rear view. It is the sectional view on the AA line of FIG. It is a side view of the same intake device. It is the BB sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG. It is the DD sectional view taken on the line of FIG. FIG. 4 is a view similar to FIG. 3 relating to an engine intake device according to Embodiment 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intake device 2 Engine 3 Upstream intake passage part 4 Intake collection part 5-8 Branch passage part 5a-8a Rising part 5b-8b Curved part 9 Resonance chamber 11 Connection port 12 Connection flange 15-18 Shared partition 19 Communication hole (communication part) )
20 upper surface wall 21 groove-shaped recess 24 work hole (work space)
31-33 Resin parts

Claims (3)

An upstream intake passage portion for introducing intake air, an intake manifold portion following the upstream intake passage portion, a plurality of branch passage portions that branch from the intake manifold portion and supply intake air to each cylinder of the in-line multi-cylinder engine, and resonance A chamber,
The intake assembly is disposed on one side of the engine,
The upstream intake passage portion extends in the cylinder row direction of the engine, and a downstream end thereof is connected to a lower portion of the intake manifold portion,
The plurality of branch passages are arranged along a cylinder row of the engine, and each includes a rising portion extending upward from an upper portion of the intake manifold portion and a curved portion curved toward the engine side following the rising portion. In an engine intake system having
The upstream intake passage portion has a downstream portion extending along an engine side wall of the intake manifold portion, and a downstream end thereof connected to an intermediate portion in the cylinder row direction below the intake manifold portion,
The resonance chamber is disposed between a portion extending from an upper portion of the intake air collecting portion to a rising portion of the plurality of branch passage portions and the engine,
The engine-side wall above the intake manifold portion, the upper-side wall of the upstream intake passage portion, and the engine-side wall of the plurality of branch passage portions are respectively an intake manifold portion, an upstream intake passage portion, and a branch passage portion. And the resonance chamber are shared by each other as a partition wall,
A communication portion is formed in the partition wall of the intake air collecting portion and the resonance chamber so as to communicate the internal spaces of the both.
An intake system for an engine, wherein the upstream intake passage portion, the intake manifold portion, the plurality of branch passage portions, and the resonance chamber are formed by joining a plurality of resin parts to each other. In claim 1,
The plurality of branch passage portions include a connection flange for connecting to the engine at a downstream end extending obliquely downward from the curved portion,
A working space is formed between the rising portions of at least one adjacent branch passage portion so that the operation of connecting the connection flange to the engine can be performed from the outside of the rising portion,
On the upper surface of the resonance chamber, there is formed a groove-like recess extending from the working space toward the engine side and opening in the engine side wall of the resonance chamber so as to enable the operation. A featured engine intake system. In claim 1 or 2,
The connection port of the downstream end of the upstream intake passage portion to the intake manifold portion is widened and opened so as to be offset from the central portion of the intake manifold portion in the cylinder row direction to the upstream side of the upstream intake passage portion. The engine intake system.

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