JP2009062949A - Internal combustion engine provided with air intake component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce influence of flow rate fluctuation of blow-by gas flowing in an intake air passage on an air flow meter, improve detection accuracy of the air flow meter and miniaturize an air intake component. <P>SOLUTION: Air passages 51, 61, 71 formed by ducts 50, 60, 70 communicating to a clean chamber 13 of an air cleaner includes a bent passage 61 at a downstream of an air flow meter 80, and a downstream passage 71 including a surrounding passage 76 surrounding the bent duct 60 forming the bent passage 61 and having a flow outlet 61o of the bent passage 61 open thereto. A blow-by gas introduction port 87 opens to the surrounding passage 76 which is an annular passage at an upstream of the flow outlet 61o. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine provided with an intake component that forms an air passage that constitutes an intake passage, and more specifically, includes an air flow meter that detects the flow rate of air flowing through the intake passage, and introduces blow-by gas into the intake component. The present invention relates to an internal combustion engine provided with a mouth.

2. Description of the Related Art An internal combustion engine having an air flow meter that detects the flow rate of air flowing through an intake passage is known in which a blow-by gas inlet is provided in an intake passage downstream of the air flow meter. (For example, see Patent Document 1)
JP 2003-278523 A

In the intake passage, when the blow-by gas inlet is provided downstream of the air flow meter, the flow rate variation (or pulsation of blow-by gas) of the blow-by gas flowing into the intake passage from the blow-by gas inlet with respect to the air flowing through the intake passage. There is a possibility that the detection accuracy of the air flow meter may be lowered by affecting the flow of air passing through the air flow meter.
Therefore, by disposing the blow-by gas introduction port away from the air flow meter, it is possible to suppress the influence of the flow rate fluctuation of the blow-by gas on the air flow meter, but it is an air passage that constitutes the intake passage and is downstream of the air flow meter. The length of the air passage becomes longer, the intake parts forming the air passage become larger, and the intake device becomes larger.

  The present invention has been made in view of such circumstances, and the invention according to claims 1 to 5 reduces the influence of the flow rate fluctuation of blow-by gas flowing into the intake passage on the air flow meter. The purpose is to improve the detection accuracy of the air intake and to reduce the size of the intake parts. The invention described in claim 2 is intended to further improve the uniformity of the mixing of air and blow-by gas in the intake component, and the invention described in claim 3 further improves the intake efficiency. When the curved duct is used as the downstream duct, the invention according to claim 4 further reduces the oil remaining in the blow-by gas by devising the arrangement of the low-by gas inlet. An object of the present invention is to make it easier to guide to the intake passage and to increase the utilization of the curved outer space of the curved duct, and an object of the present invention is to further reduce the number of parts and the cost of the intake parts.

The invention according to claim 1 is an internal combustion engine comprising an air flow meter for detecting a flow rate of air flowing through the intake passage and an intake part forming an air passage constituting the intake passage, wherein the air passage is the air flow meter. A first air passage downstream of the first air passage, and a second air passage having an enclosing passage that at least partially surrounds a downstream duct forming the first air passage in a circumferential direction and having an outlet of the first air passage opened. The blow-by gas introduction port through which the blow-by gas flows into the intake passage is an internal combustion engine that opens to the surrounding passage upstream of the outlet.
According to a second aspect of the present invention, in the internal combustion engine according to the first aspect, the surrounding passage is an annular passage that surrounds the downstream duct over the entire circumference.
According to a third aspect of the present invention, in the internal combustion engine according to the first or second aspect, an air flow direction at an inlet of the first air passage and an air flow direction at an outlet of the second air passage are The downstream duct is a curved duct curved so that the air flow at the outlet is directed to the outlet of the second air passage, and the first air passage is a curved passage. It is.
According to a fourth aspect of the present invention, in the internal combustion engine according to the third aspect, the blow-by gas introduction port is disposed on the curved inner side and on the upper side in the surrounding passage with respect to the passage center line of the curved duct. It is.
According to a fifth aspect of the present invention, in the internal combustion engine according to any one of the first to fourth aspects, the intake component includes an upstream duct to which the air flow meter is attached, the downstream duct, and the second air passage. A second downstream duct to be formed, and the downstream duct is a seal member that seals between the upstream duct and the second downstream duct.

According to the first aspect of the present invention, since the surrounding passage where the blow-by gas introduction port is opened is a passage surrounding the downstream duct, it is a passage with an extremely small air flow compared to the first air passage, and moreover, The gas flow fluctuation is attenuated in the surrounding passage. In addition, since the flow rate variation of the blow-by gas is transmitted from the outlet to the air in the first air passage after passing through the surrounding passage, the transmission path length when the flow rate variation is transmitted from the blow-by gas inlet to the air flow meter is The passage length of the first air passage is longer than the surrounding passage.
As a result, the influence of fluctuations in the flow rate of blow-by gas flowing into the intake passage on the detection of the air flow rate by the air flow meter is reduced, and the detection accuracy of the air flow meter is improved. In addition, since the transmission path length can be increased without increasing the length of the first air path by the surrounding passage, the intake parts can be reduced in size while reducing the influence of the flow rate variation of the blow-by gas on the air flow meter. Can be
According to the second aspect of the present invention, since the surrounding passage is an annular passage that surrounds the first downstream duct over the entire circumference, the volume of the surrounding passage is increased, and the flow fluctuation of the blow-by gas in the surrounding passage is changed. Since it further attenuates, it is possible to further reduce the influence of the flow rate variation of the blow-by gas on the flow rate detection of the air flow meter.
Moreover, since blow-by gas can flow out downstream from the outlet over a wide range in the circumferential direction, the uniformity of mixing of the air flowing out from the first downstream duct and the blow-by gas is improved.
According to the third aspect of the present invention, the air flowing through the first air passage even when the air flow direction at the inlet of the first air passage is different from the air flow direction at the outlet of the second air passage. Is smoothly guided toward the outlet by the curved duct and flows out from the outlet toward the outlet, so that the air flowing out from the first air passage is suppressed from becoming a turbulent flow in the second air passage, Intake efficiency is improved.
According to the fourth aspect of the present invention, the blow-by gas introduction port is opened in the surrounding passage in the surrounding passage and on the upper side of the passage center line of the bending duct, and thus remains in the blow-by gas. The remaining oil flowing in the surrounding passage flows toward the outlet along with the blow-by gas while falling in the surrounding passage, and is mixed into the air flowing through the curved passage. As a result, by effectively utilizing the space formed when the curved duct is used, it is possible to suppress the residual oil from staying in the lower portion of the surrounding passage, and to remove the residual oil downstream from the outlet. 2 It becomes easy to guide to the air passage.
In addition, the curved inner space formed on the curved inner side with respect to the passage center line of the curved duct is a narrow space compared to the outer curved space formed on the curved outer side with respect to the passage center line. By arranging the blow-by gas inlet that does not require space in the curved inner space, another member such as a part of the intake component or a peripheral component arranged around the intake component can be arranged in the outer curved space. This makes it possible to increase the utilization of the curved outer space. Further, by effectively utilizing the space formed when the curved duct is used, the degree of freedom of arrangement of the other member can be increased, and the intake component can be downsized, or the intake component and the It is possible to make the arrangement of peripheral parts compact.
According to the matter of Claim 5, a downstream duct serves as the sealing member which connects an upstream duct and a 2nd downstream duct airtightly. As a result, a separate sealing member is not required in addition to the upstream duct, the downstream duct, and the second downstream duct, so that the number of parts is reduced and the cost is reduced.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
Referring to FIGS. 1 to 3, an internal combustion engine E to which the present invention is applied is mounted on a front-wheel drive vehicle, and an intake device of the internal combustion engine E includes an air cleaner device A as an intake component including an air cleaner 10, and a throttle. A valve device 2 and an intake pipe device 4 are provided. The internal combustion engine E constitutes a power unit together with a transmission to which power generated by the internal combustion engine E is input, and the power unit is disposed in an engine room formed at the front portion of the vehicle body.

  The multi-cylinder four-stroke internal combustion engine E includes an engine body 1 including a cylinder block 1a in which a piston is fitted so as to be able to reciprocate, a cylinder head 1b coupled to the cylinder block 1a, and the like. The piston driven by the pressure of the combustion gas generated by the combustion of the air-fuel mixture in the combustion chamber provided in the engine body 1 rotates the crankshaft supported by the engine body 1.

The intake device forms an intake passage (hereinafter referred to as “intake passage”) that guides combustion air to a combustion chamber provided in the engine body 1, and the air cleaner device A constitutes at least a part of the intake passage. An air passage P (see FIGS. 5, 7, and 8) is formed.
The air flowing through the intake passage passes through an intake port provided in the cylinder head 1b and is driven by a valve operating device of the internal combustion engine E to open and close the intake port in synchronization with the engine rotational speed. Inhaled into the combustion chamber. Therefore, in the internal combustion engine E, intake pulsation occurs in the intake passage due to the opening / closing operation of the intake valve.

The vertical direction of the air cleaner apparatus A alone is divided into a dust chamber 12 formed below and a clean chamber 13 formed above the air cleaner chamber 11 with the cleaner element F interposed therebetween in the vertical direction. As an example of the vertical direction, the direction shown in FIGS. 2 and 5 is the vertical direction in this embodiment for convenience. As shown in FIGS. 1 and 7, directions orthogonal to each other on a horizontal plane that is a plane orthogonal to the vertical direction are defined as a front-rear direction as a first direction and a horizontal direction as a second direction.
Here, when one of the front and rear is one direction of the first direction, the other of the front and rear is the other direction of the first direction, and one of the left and right is one direction of the second direction. Sometimes, the other of the left side and the right side is the other direction of the second direction.

Therefore, when the internal combustion engine E including the air intake device to which the air cleaner device A is assembled is mounted on a vehicle as a machine, the vertical direction may substantially coincide with the vertical direction of the vehicle, but it does not necessarily coincide. There is no need.
As an example, when the internal combustion engine E is mounted on a vehicle, the air cleaner device A is configured so that the front-rear direction is substantially the same as the vertical direction of the vehicle so that the air cleaner device A is inclined slightly downward toward the front. It is attached to the power unit via a plurality of attachment portions (not shown), with the front-rear direction being substantially the left-right direction (or the vehicle width direction).
Note that the description including the expression modified by the term “almost” includes the description when not modified by the term “almost”.

1 to 4, the air cleaner apparatus A includes a plurality of passage forming members that form an air passage P, a cleaner element F, and a cover B7 as its constituent members. The plurality of passage forming members include first to fourth members B1 to B4, a duct B5, and a cover B6. The members B1 to B4, the duct B5, and the cover B6 are combined to form an air passage P. .
The first to fourth members B1 to B4 and the two covers B6 and B7 are each a single member molded from a synthetic resin, and the duct B5 is a single member molded from an elastomer, here rubber. It is.

  The air cleaner apparatus A includes an air cleaner 10, an introduction duct 20 and a lead-out duct 40 connected to the air cleaner 10, and a resonator 90. The air cleaner 10 is a downstream component arranged downstream of the introduction duct 20 and an upstream component arranged upstream of the outlet duct 40.

5 to 7, the air cleaner 10 removes dust contained in the air cleaner case C forming the air cleaner chamber 11 and the air disposed in the air cleaner chamber 11 and passing through the air cleaner chamber 11. And a cleaner element F which is a filtering member. The air cleaner chamber 11 includes a dust chamber 12 which is an upstream chamber formed below the cleaner element F in the vertical direction by a cleaner element F held by an air cleaner case C, and a downstream chamber formed above the dust chamber 12. It is divided into a clean room 13.
The introduction duct 20 forms an air introduction passage 21 that guides air taken from the outside of the internal combustion engine E to the dust chamber 12, and the lead-out duct 40 passes through the cleaner element F after flowing into the dust chamber 12 from the air introduction passage 21. An air outlet passage 41 (see also FIG. 8) for guiding clean air in the clean chamber 13 to the throttle valve device 2 is formed. Therefore, the air passage P is constituted by the air introduction passage 21, the air cleaner chamber 11, and the air outlet passage 41.
Here, “upstream” and “downstream” are used in relation to the flow of air flowing through the intake passage from the intake port 21 i of the air introduction passage 21 toward the combustion chamber. In addition, the air flow direction in the intake passage is simply referred to as “flow direction” in the following description.

  The resonator 90 is provided with a resonance chamber 93 and a resonance communication passage 94 that communicates the resonance chamber 93 with the air introduction passage 21. The resonator 90 has a function of reducing intake noise or an increase of torque of the internal combustion engine E as an intake silencer in a specific engine speed range.

The air cleaner case C is configured by sequentially laminating a plurality of case constituent members, in this embodiment, first to third cases C1 to C3 which are three case constituent members from below. The first and second cases C1 and C2 constitute a lower case as a bottom case and an intermediate case, respectively, and the third case C3 constitutes an upper case.
The cleaner element F is sandwiched between holding portions C2a and C3a provided in the second and third cases C2 and C3 and is held in an airtight state. When viewed from above and below (hereinafter referred to as “plan view”), the holding portions C2a and C3a are rectangular frames, and the cleaner element F is rectangular.

The chamber wall of the air cleaner chamber 11 includes a bottom wall 14 constituted by the first and second cases C2 and C3, a ceiling wall 15 constituted by the third case C3, and rising from the bottom wall 14 and the bottom wall 14 And side walls 16 and 17 surrounding the air cleaner chamber 11 between the ceiling wall 15. The bottom wall 14 and the ceiling wall 15 face the cleaner element F in the vertical direction. The side walls 16 and 17 constituted by the first to third cases C1 to C3 are seen from a pair of side walls 16a and 17a; It is referred to as “plan view”.) It is composed of a pair of side walls 16c, 17c; 16d, 17d facing in the left-right direction as a direction orthogonal to the facing direction D, and has a quadrangular shape in plan view. The pair of side walls 16a, 17a; 16b, 17b are first side walls 16a, 17a (also rear walls) to which the air introduction passage 21 and the air lead-out passage 41 are connected, and a direction D opposite to the side walls 16a, 17a. The second side walls 16b and 17b (also front walls) facing each other with the cleaner element F interposed therebetween. The side walls 16 and 17 are composed of a lower side wall 16 that is a side wall of the dust chamber 12 and an upper side wall 17 that is a side wall of the clean chamber 13.
Therefore, the chamber wall of the dust chamber 12 is composed of the bottom wall 14 and the four lower side walls 16a to 16d, and the chamber wall of the clean chamber 13 is composed of the ceiling wall 15 and the four upper side walls 17a to 17d. The cleaner element F has a rectangular peripheral edge Fa, Fb, Fc, Fd substantially in the same position as the pair of upper side walls 17a, 17b in the front-rear direction and substantially the same as the pair of upper side walls 17c, 17d in the left-right direction. The air cleaner case C is disposed so as to occupy the same position.

  The first and second cases C1 and C2 are coupled to each other by welding as coupling means at the coupling portions B1a and B2a, which are the edges of the first and second members B1 and B2, and the second and third cases C2 , C3 are coupled by a clamp (not shown) as coupling means for detachably coupling to each other for convenience of maintenance of the air cleaner 10 including replacement of the cleaner element F.

  The introduction duct 20 is connected to the lower side wall 16a connected so that the air introduction passage 21 communicates with the dust chamber 12. The air introduction passage 21 has an outside air inlet 21i and an outlet 21o that opens to the dust chamber 12 at the lower side wall 16a. The introduction duct 20 that is arranged side by side in the front-rear direction with respect to the air cleaner 10 extends rearward from the lower side wall 16a or the outlet 21o and has the outlet 21o and the lower side wall in order to reduce the size of the air cleaner device A in the front-rear direction. It is a curved duct that curves to the left from immediately upstream of 16a (see FIGS. 1 and 7), and therefore the air introduction passage 21 is also a curved passage.

  The introduction duct 20 includes a first duct portion 20a that is integrally formed and connected to the first case C1, and a second duct portion 20b that is integrally formed and connected to the second case C2. The first case C1 and the first duct portion 20a are constituted by the first member B1, and the second case C2 and the second duct portion 20b are constituted by the second member B2. The first and second duct portions 20a and 20b are coupled to each other by welding the coupling portions B1a and B2a. The introduction duct 20 has a straight portion 20s and a single curved portion 20c that is curved in an arc shape in plan view.

The air introduction passage 21 includes a straight passage 21s formed by a straight portion 20s and having a substantially straight passage center line on the upstream side, and a single curved passage 21c formed by the bending portion 20c and continuing downstream from the straight portion 20s. Have When the air introduction passage 21 is divided into an upstream passage and a downstream passage, the straight passage 21s extending obliquely downward from the intake 21i toward the downstream is the upstream passage having the intake 21i, and starts to bend. The curved passage 21c extending substantially horizontally from the portion toward the downstream is the downstream passage having the outlet 21o.
As shown in FIGS. 1 and 7, the curved passage 21 c is a left side that is a direction orthogonal to the opposing direction D in a direction intersecting with the front-rear direction toward the upstream in a plan view. The straight passage 21s extends to the left from the curved passage 21c to the left and extends substantially in parallel in the left-right direction.

Referring to FIGS. 2 and 4-7, the curved passage 21c is formed integrally with the first duct portion 20a, which is one of the two duct portions 20a and 20b, and extends along the passage center line of the curved portion 20c. By a rectifying plate 22 that is one or more curved, here as one partition wall, a predetermined number of branch paths that are plural in the left-right direction, the curved inner branch path 23 that is two branch paths in this embodiment, and the curved outer side Divided into branch roads 24. The rectifying plate 22 provided in the air introduction passage 21 is disposed downstream of the intake port 21i and in the curved passage 21c from the downstream end of the straight passage 21s to the outlet 21o. It should be noted that the gap between the rectifying plate 22 and the duct portion 20b in the vertical direction is preferably zero or smaller from the viewpoint of equalizing the air flow in both the branch paths 23 and 24.
Here, “curved inner side” and “curved outer side” mean that a curved member or curved part is located on the side closer to the center of curvature of the curve with respect to the reference portion, and the curvature of the curve, respectively. It means to be located on the side far from the center.

Therefore, the outlet 21o is divided into an outlet 23o of the curved inner branch path 23 and an outlet 24o of the curved outer branch path 24. The outlets 23o and 24o are at the same position in the vertical direction, and are on the same horizontal plane in plan view. In the direction intersecting with the front-rear direction, here in the left-right direction. Therefore, the outlet 21o is divided into the predetermined number, here two outlets 23o and 24o, in the left-right direction by the rectifying plate 22.
Further, the lower part of the outlet 20o of the introduction duct 20 forming the outlet 21o continues to the bottom wall 14 on substantially the same horizontal plane (see FIGS. 5 and 6). Therefore, the air from the curved inner branch path 23 and the curved outer branch path 24 is guided to the bottom wall 14 and flows in the dust chamber 12 immediately after flowing into the dust chamber 12 from the respective outlets 23o and 24o.

  The rectifying plate 22 disposed on the passage center line of the curved passage 21c in a plan view suppresses that a large amount of air flowing through the straight passage 21s flows into the curved outer branch passage 24 due to centrifugal force, and the curved inner branch passage 23 and The flow rate of air flowing through each curved outer branch path 24 is made uniform.

  Since the air introduction passage 21 has the curved passage 21c, the first passage length from the intake port 21i through the curved inner branch passage 23 to the outlet 23o reaches the outlet 24o from the intake port 21i through the curved outer branch passage 24. It is set shorter than the second passage length. For this reason, when air having pulsation flows through the air introduction passage 21, the air flowing through the curved inner branch passage 23 reaches the outlet 21o from the intake port 21i in a shorter time than the air flowing through the curved outer branch passage 24, Therefore, it flows into the dust chamber 12 earlier than the air flowing through the curved outer branch passage 24.

  5 to 7, in the dust chamber 12 where the air introduction passage 21 opens, the bottom wall 14 flows into the dust chamber 12 from the lower flat portion 30 connected to the outlet portion 20 o and the air introduction passage 21. The air guide portion 31 projecting upward with respect to the lower flat portion 30 to guide the air so as to uniformly hit the cleaner element F, and the water mixed into the air and separated by the cleaner element F gathers. Water collecting space 38 is provided.

  The air guide section 31 deflects the air flow separately flowing from the curved inner branch path 23 and the curved outer branch path 24 into the dust chamber 12 and guided to the lower flat section 30, respectively, so that the bottom wall Diffusion suppression that suppresses diffusion away from the cleaner element F, such as the deflection part 32 directed to the cleaner element F disposed above 14 and the air flow immediately after being deflected by the deflection part 32 downward. And an upper flat part 36 as a part. Both flat portions 30 and 36 are substantially parallel to the horizontal plane. In FIG. 5, the general flow of deflected air is indicated by white arrows.

The deflecting portion 32 provided integrally with the first case C1 constituting the bottom wall 14 is formed by a raised portion having an outer surface of the bottom wall 14 as a concave portion, and the raised portion is directed upward from the lower flat portion 30. Thus, it protrudes upward with respect to the lower flat portion 30. The deflecting portion 32 that is bent in a step shape between the pair of lower side walls 16c and 16d in a plan view and extends in the left-right direction includes the predetermined number of deflecting portions. In this embodiment, the deflecting section 32 is mainly composed of two deflecting sections, that is, a first deflecting section 33 that directs the flow of air flowing from the outlet 23o through the curved inner branch 23 to the cleaner element F. A second deflecting section 34 for directing the air flow flowing in from the outlet 24o through the curved outer branch path 24 toward the cleaner element F, and further connecting the first and second deflecting sections 33 and 34 in the front-rear direction. The first and second deflecting portions 33 and 34 have a connecting portion 35 that constitutes a stepped portion.
The air flowing into the dust chamber 12 from the air introduction passage 21 including the air deflected by the first and second deflecting portions 33 and 34 is an opening C2b (see FIG. 4) provided in the second case C2. See also) and head to the cleaner element F.

  The positions of the first and second deflecting portions 33 and 34 and the connecting portion 35 in the vertical direction are substantially the same, and the path widths of the branch paths 23 and 24 or the air introduction path 21 in the vertical direction are substantially the same. The position is 1/2, that is, substantially the same position as the central portion of each branch path 23,24. Accordingly, the first and second deflecting portions 33 and 34 and the connecting portion 35 occupy the same position as the lower half of both the branch paths 23 and 24 in the vertical direction. Further, the vertical distance between each of the first and second deflecting portions 33 and 34 and the connecting portion 35 and the cleaner element F is substantially equal.

  The first and second deflecting portions 33 and 34 are respectively directed from the lower flat portion 30 upward toward the cleaner element F toward the lower side wall 16a (or the deflecting portions 33 and 34 in the front-rear direction). The first and second guide surfaces 33a and 34a are curved in a convex shape (in the direction of the air flow toward).

  The first guide surface 33a and the outlet 23o, which are the guide surfaces of the deflecting unit 32, and the second guide surface 34a and the outlet 24o, which are the guide surfaces of the deflecting unit 32, are arranged at positions facing each other in the front-rear direction. With either one of the outlets 23o, 24o as a reference outlet, the distance from the reference outlet in the front-rear direction to the first and second guide surfaces 33a, 34a is different, and from the reference outlet to the first guide surface 33a Is longer than the distance from the reference outlet to the second guide surface 34a. In addition, the first guide surface 33a is located at substantially the center of the dust chamber 12 and the cleaner element F in the front-rear direction and at substantially the same position as an inlet 51i described later in the front-rear direction. On the other hand, the second guide surface 34a is located substantially at the center between the outlet 24o and the first guide surface 33a in the front-rear direction. Therefore, the second deflection unit 34 is located closer to the outlet 21o or the reference outlet than the first deflection unit 33 in the front-rear direction.

  The distance between the first deflector 33 and the second deflector 34 in the front-rear direction is the difference between the first passage length and the second passage length (in this embodiment, the passage length of the curved inner branch passage 23). And the length of the curved outer branch path 24). For this reason, most of the air in the curved inner branch path 23 and the curved outer branch path 24 hits the cleaner element F almost at the same time by the first and second deflecting portions 33 and 34, and the cleaner element F Misalignment of passing time is reduced. As a result, the air introduction passage 21 is divided into the curved inner branch passage 23 and the curved outer branch passage 24, so that the time when the air flow separated in the dust chamber 12 hits the cleaner element F is shifted. The deviation of the air flow in the chamber 13 and the air outlet passage 41 is suppressed.

  When the air flowing into the dust chamber 12 from the curved inner branch path 23 has a velocity component directed outward from the curved side, the connecting portion 35 located at the same position as the downstream end 22a of the rectifying plate 22 in the left-right direction Since the air flow is restrained from being deflected to the outside of the curve and guided so as to be deflected by the first guide surface 33a, it is promoted that the air in the dust chamber 12 uniformly strikes the cleaner element F.

  A flat plate-like upper flat part 36 provided integrally with the second case C2 is coupled to the tops of the deflecting parts 33, 34 by welding the coupling parts B1a, B2a. The upper flat part 36 is substantially at the same position as the central part of each branch path 23, 24 in the vertical direction, and extends forward from the deflection part 32 toward the lower side wall 16b in the front-rear direction. The upper flat portion 36 is provided with a reinforcing rib 37 that protrudes upward at the same position as the second deflecting portion 34 in the left-right direction and extends substantially parallel to the left-right direction. With the reinforcing rib 37 positioned farther away from the inlet 51i in the front-rear direction with respect to the outlet 21o, the air flowing toward the front immediately above the second deflecting portion 34 is quickly removed in the counter-exit side region Rb described later. Deflection to hit F.

  The water collecting space 38 is provided in the second case C2 and has an opening C2c (see also FIG. 4) positioned between the lower side wall 16b and the upper flat part 36 in the front-rear direction, and passes through the opening C2c. The water in the dust chamber 12 flows into the water collecting space 38. The water collecting space 38 is formed by the air guide portion 31 and a portion 14a of the bottom wall 14 that is integrally formed with the first case C1 and is continuous with the deflecting portion 32. Therefore, in the bottom wall 14, the lower flat portion 30 and the water collecting space 38 are formed with the deflecting portion 32 sandwiched in the front-rear direction, and the upper flat portion 36 becomes a ceiling wall of the water collecting space 38. The portion 14a and the lower flat portion 30 are provided with a drain portion 39 provided with a drain hole. As described above, the water collecting space 38 is formed by using the upper flat portion 36 of the air guide portion 31, so that the water collecting space 38 can be formed without complicating the structure of the bottom wall 14.

1 to 6 and 8, the lead-out duct 40 connects the air cleaner 10 and the throttle valve device 2. A throttle valve device 2 as a downstream intake part that is arranged downstream of the air cleaner device A and into which the air that has passed through the air cleaner device A flows in is a body that forms an air passage 3 through which the air that flows out of the air cleaner device A flows. A throttle body 2a and a throttle valve 2b disposed in the air passage 3 and controlling the flow rate of air are provided. The air outlet passage 41 guides the air in the clean chamber 13 to the air passage 3. The air flowing through the throttle valve device 2 flows through the air passage 5 formed by the intake pipe device 4 having the intake manifold, and then flows into the combustion chamber through the intake port.
Therefore, the intake passage is constituted by the air passage P, the air passage 3 and the air passage 5.

  The outlet duct 40 is connected to the upper side wall 17 connected so that the air outlet passage 41 communicates with the clean chamber 13. The lead-out duct 40 includes an upstream duct 50 connected to the upper side wall 17a which is the side wall on the same side as the lower side wall 16a in the facing direction D (or front-rear direction) in the chamber wall of the air cleaner chamber 11, and an upstream duct at the upstream connection portion 62. 50 and a downstream duct 42 connected to the throttle valve device 2 at the downstream connection portion 75.

  The air outlet passage 41 includes an upstream passage 51 formed by the upstream duct 50 and having an inlet 51i, and a downstream passage 43 formed by the downstream duct 42 and having an outlet 71o. An outlet 71o formed by the downstream connection portion 75 opens into the air passage 3 (see FIG. 1) of the throttle valve device 2. The upstream passage 51 is connected to the upper side wall 17a so as to communicate with the clean chamber 13, and has a passage center line L2 parallel to the front-rear direction. Therefore, in this embodiment, the direction of the passage center line L2 is the front-rear direction.

The upstream duct 50 includes an upstream portion 50c having an inlet portion 50i that forms an inlet 51i that opens into the clean chamber 13 and expands in a funnel shape, and a downstream connection portion 50d that forms an outlet 51o that opens into the downstream passage 61. It is a venturi duct having. The outflow port 51o allows the air flowing in from the inlet 51i to flow out into a curved passage 61 (described later), which is an air passage as the outside of the clean chamber 13. The downstream connection portion 50d connected to the downstream duct 42 has a flange portion 50e formed integrally with the upper side wall 17a and extends rearward from the upper side wall 17a to the outside of the clean chamber 13 in the front-rear direction.
The third case C3 and the upstream duct 50 are constituted by the third member B3, and the upstream duct 50 is integrally formed with the third case C3.

Referring also to FIG. 7, the upstream portion 50 c extends forward in the front-rear direction from the upper side wall 17 a toward the upper side wall 17 b in the clean chamber 13. The upstream passage 51 has an inlet 51i in the clean chamber 13 at a position away from the upper side wall 17a in the front-rear direction. The inlet 51i is substantially positioned on a plane H that is orthogonal to the front-rear direction and intersects the first deflection unit 33, and opens into the clean chamber 13. Therefore, the upstream duct 50 is connected to the side wall 17a in the clean chamber 13 of the first side walls 16a and 17a and extends in the front-rear direction in the clean chamber 13.
The air cleaner chamber 11 and the cleaner element F are arranged on the outlet side on the side close to the outlet 21o of the air introduction passage 21 in the front-rear direction with the plane H including the passage center line L2 of the upstream passage 51 at the inlet 51i as a boundary. Divided into a region Ra and a counter-exit side region Rb far from the exit 21o.

The guide surface 34a of the second deflecting portion 34 is located between the upper side wall 17a or the outlet 51o and the inlet 51i in the front-rear direction, substantially at the center or slightly closer to the outlet 21o than the center. Therefore, the guide surface 34a has an upstream portion 50c of the upstream duct 50, or the passage portion 51c formed by the upstream portion 50c of the upstream passage 51, or substantially at the center in the front-rear direction or slightly at the outlet 21o. Located closer.
At least a part of the first deflection part 33 and at least a part of the second deflection part 34 are located between the inlet 51i and the outlet 51o in the front-rear direction in plan view, and here, the inlet 51i in the front-rear direction. The entire guide surface 33a having the downstream end at substantially the same position and the entire guide surface 34a are located between the inlet 51i and the outlet 51o in the front-rear direction. The first deflection unit 33 is disposed closer to the inlet 51i in the front-rear direction in plan view, and the second deflection unit 34 is disposed closer to the outlet 51o in the front-rear direction in plan view.

The upstream portion 50c protrudes downward in the clean chamber 13 and serves as a part of the ceiling wall 15 and a lower duct portion 50a serving as a partition wall between the clean chamber 13 and the upstream passage 51, and a first ceiling wall described later. The upper duct portion 50b protrudes upward from 15c and 15d.
The first ceiling walls 15c and 15d, which are the portions of the ceiling wall 15 in the outlet side region Ra where the upstream portion 50c is located, are spaced apart from the cleaner element F in the vertical direction so that the ceiling wall 15 in the counter outlet side region Rb Is smaller than the second ceiling wall 15b. The pair of first ceiling walls 15c and 15d located across the upstream portion 50c in the left-right direction are substantially at the same position as the passage center line L2 of the upstream passage 51 in the up-down direction. The first ceiling walls 15c and 15d include air deflected by the second deflecting unit 34 as compared to the case where the first ceiling walls 15c and 15d are assumed to be in the same position as the second ceiling wall 15 in the vertical direction. The air that has passed through the cleaner element F can be quickly deflected toward the inlet 51i, and the occurrence of air stagnation between the first ceiling walls 15c, 15d and the cleaner element F in the vertical direction can be suppressed. Increases the effect.

  Referring to FIGS. 3 to 5 and 8, an air flow meter 80 (see also FIG. 1) for detecting the flow rate of the air flowing through the intake passage is attached to the upper duct portion 50b near the downstream connection portion 50d by screws. A mounting portion 81 is provided. A detection unit 80a of an air flow meter 80 that is provided in the internal combustion engine E and detects an intake air amount used for fuel amount control and ignition timing control is inserted into the upstream passage 51 through a through hole 81a provided in the attachment unit 81. Be placed.

  Referring to FIGS. 1 to 6 and 8, the downstream duct 42 includes a curved duct 60 that is a first downstream duct as an inner passage forming component connected to the downstream connection portion 50 d, and at least a part of the curved duct 60. And a second downstream duct 70 as an outer passage forming part surrounding the outer periphery. The downstream passage 43 formed by the curved duct 60 and the downstream duct 70 is an air passage downstream from the air flow meter 80 in the same manner as the passage portion 51d formed by the downstream connection portion 50d in the upstream passage 51. The downstream passage 43 is a curved passage 61 as a first downstream passage formed by the curved duct 60, and a second downstream passage that is also an air chamber formed by the downstream duct 70 and opening the outlet 61o of the curved passage 61. 71. Here, the passage portion 51 d and the curved passage 61 are first air passages downstream of the air flow meter 80, and the downstream passage 71 is a second air passage downstream of the air flow meter 80.

The second downstream duct 70 and the second downstream passage 71 are at least partly including the entirety of each of the curved duct 60 and the curved passage 61 in the direction (or the flow direction) along the passage center line L3 of the curved passage 61. Surrounding, in this embodiment, most of the majority of the curved duct 60 and the curved passage 61 are enclosed from the outside. Further, the downstream duct 70 and the downstream passage 71 at least partially surround the curved duct 60 and the curved passage 61 including the entire circumference in the circumferential direction, and in this embodiment, the curved duct 60 and the curved passage 61 are arranged around the entire circumference. It surrounds and surrounds the entire curved portion 63 and curved passage portion 65 described later in the circumferential direction.
For this reason, in the downstream duct 42, in the part where the downstream duct 70 surrounds the curved duct 60, the curved duct 60 serves as an inner tube, and the downstream duct 70 serves as an outer tube. In the embodiment, a double tube structure is provided over the entire circumference.

  The curved duct 60 constituted by the duct B5 having rubber-like elasticity is fitted to the outer periphery of the downstream connection portion 50d of the upstream duct 50 and is formed in an accordion shape and can be expanded and contracted in the flow direction, And a curved portion 63 connected downstream of the upstream connecting portion 62. In order to reduce the size of the air cleaner apparatus A in the front-rear direction, the curved duct 60 extends rearward from the upper side wall 17a or the outlet 51o and is curved to the right. Further, the upstream connecting portion 62 has a convex portion 62 b as a positioning portion that engages with the concave portion 74 b of the downstream duct 70.

  The curved passage 61 has a linear passage portion 64 formed by the upstream connection portion 62 and a curved passage portion 65 formed by the curved portion 63. The passage portion 64 has an inlet 61 i of the curved passage 61, and the curved passage portion 65 has an outlet 61 o of the curved passage 61.

  The upstream connection part 62 surrounds the downstream connection part 50d and is in close contact with the flange part 50e in the flow direction, and the seal part 68a is in close contact with the upstream connection part 74 of the downstream duct 70 in the flow direction and the radial direction. , 68b and a downstream seal portion 68. Here, regarding the curved duct 60 and the downstream duct 70, the radial direction is the radial direction of the curved duct 60 with respect to the passage center line L3.

  In a state where the air cleaner apparatus A is assembled, the upstream connection portion 62 is pressed and shortened in the flow direction by the flange portion 50e and the upstream connection portion 74, and an airtight state is established between the upstream duct 50 and the downstream duct 70. Therefore, the curved duct 60 having the upstream connection portion 62 is also a seal member that seals between the upstream duct 50 and the downstream duct 70.

  The curved portion 63 and the curved passage portion 65 intersect in the front-rear direction from the upstream connecting portion 62 and the passage portion 64 having the passage center line L3 that coincides with the passage center line L2 of the upstream passage 51 in a plan view. Direction, in this embodiment extends in a curved direction to the right in the left-right direction. And the outflow port 61o formed of the downstream end part 63d of the curved part 63 is opened substantially facing right. Therefore, the air flow direction at the inflow port 61i and the air flow direction at the outlet 71o are different from each other and intersect in a plan view. The air flow at the outlet 61o is directed toward the outlet 71o.

  The downstream duct 70 includes a concave case 72 that forms a space in which the curved duct 60 is accommodated and opens downward, and a plate-like cover B6. The case 72 and the cover B6 include a joint B4b (see FIG. 5) that is an edge of the bottom that is open in the case 72, and a joint B6a (see FIGS. 1 and 5) that is an edge of the cover B6. Are bonded by welding as a bonding means. The cover B6 is also a partition wall that partitions the downstream passage 71 and the resonance chamber 93.

  The downstream duct 70 has an upstream connecting portion 74 and surrounds the curved duct 60 over the entire circumference, and a downstream connecting portion 75 that is located downstream of the surrounding portion 73 and to which the throttle valve device 2 is connected. Have The upstream connection portion 74 has a concave portion 74b as a positioning portion that sets a relative position with respect to the curved duct 60 to be connected. The upstream connection portion 74 is closely fitted to the outer periphery of the downstream seal portion 68.

The downstream passage 71 is an annular passage formed by the surrounding portion 73 and surrounding the curved duct 60 over the entire circumference from the downstream seal portion 68, which is the downstream end portion of the upstream connection portion 62, to the downstream end portion 63d. A passage 76 and a linear passage 77 having an outlet 71o and positioned downstream of the surrounding passage 76 are provided.
The surrounding passage 76 formed between the bending duct 60 and the surrounding portion 73 in the radial direction of the bending duct 60 is connected to the upstream connecting portion 62 in an airtight state by the upstream connecting portion 74. The upstream end 76a of 76 is closed. The surrounding passage 76 is a space formed in the downstream passage 71 upstream from the outlet 61o.

  As shown in FIG. 8, the curved duct 60 and the curved passage 61 are arranged in a direction crossing the front-rear direction as they go upstream from the upstream connection portion 62 or the inflow port 61 i in a plan view. Is curved to the right, which is a direction perpendicular to the front-rear direction, and the passage 77 extends straight from the outlet 61 i of the curved passage 61 to the right in the left-right direction in a straight line.

  In assembling the air cleaner apparatus A, the first member integrated in the air cleaner 10 is obtained by welding the second member B2 and the fourth member B4 at the joints B2b and B4a (see FIG. 5) which are edges. After the downstream duct 70 is coupled to the second cases C1 and C2, the curved duct 60 is inserted into the downstream duct 70 through the upstream connecting portion 74. Next, in a state where the upstream connection portions 62 and 74 are connected to each other, the downstream connection portion 50d is inserted into the upstream connection portion 62, and the upstream duct 50 and the curved duct 60 press the upstream connection portion 62 in the flow direction. Thus, the third case C3 is coupled to the second case C2 by a clamp.

  Referring to FIGS. 1 to 3, 5, and 8, the internal combustion engine E includes a blow-by gas reduction device that reduces blow-by gas to the intake passage. The reduction device includes a gas-liquid separator that separates oil mixed in blow-by gas guided from a crank chamber formed by the engine body 1, and a return passage that guides blow-by gas after the oil is separated to an intake passage. A return pipe is formed. The return pipe is connected to the conduit 85 (see FIG. 6) for guiding the blow-by gas from the gas-liquid separator, and is provided in the outlet duct 40 so that the blow-by gas is disposed downstream of the air flow meter 80. And a grommet 86 as an introduction part that flows into the downstream passage 71 of the air outlet passage 41 of the intake passage at a position. A blow-by gas introduction port 87 that opens to the downstream passage 71 of the return passage is formed by a grommet 86.

The grommet 86 is attached to an attachment portion 72a that is a recess provided in the case 72 in a state of penetrating a through hole that is an opening provided in the attachment portion 72a. The blow-by gas introduction port 87 is in the direction perpendicular to the plane substantially including the passage center line L3 of the curved duct 60 (or the curved passage portion 65) in the upper portion of the surrounding passage 76, in the vicinity of the uppermost portion in this embodiment. In the embodiment, it corresponds to the vertical direction) (in this embodiment, it is a plan view), and is curved inside the curved duct 60 or the curved passage portion 65, and in this embodiment is curved with respect to the passage center line L3. Arranged inside.
Therefore, the blow-by gas introduction port 87 opens in the surrounding passage 76 or between the curved duct 60 and the surrounding portion 73 in the radial direction, and in a plan view, on the outside of the curve with the passage center line L3 as a boundary. It arrange | positions in the curved inner space which is a fan-shaped space small compared with the curved outer space which is the sector-shaped space formed.
In order to reduce the influence of the flow rate fluctuation (pulsation) of the blow-by gas flowing in from the blow-by gas inlet 87 on the detection accuracy of the air flow meter 80, the distance from the blow-by gas inlet 87 to the outlet 61o is increased. The blow-by gas introduction port 87 is preferably disposed at the upstream end portion 76a including the portion farthest from the outflow port 61o. Further, the blow-by gas introduction port 87 is configured so that the inflow direction of the blow-by gas from the blow-by gas introduction port 87 is almost opposite to the air flow direction at the outflow port 61o, that is, the left side in this embodiment. The direction of the through hole is set.

1 to 4, 6, and 7, a resonator 90 provided so as to partially surround the introduction duct 20 includes cases 91 and 92 constituted by second and fourth members B <b> 2 and B <b> 4, and a cover. And B7. The cover B7 has a pair of claws B7a inserted into a pair of attachment portions 92a provided on the case 92, and is coupled to the case 92 by screws.
The chamber wall of the resonance chamber 93 is configured by the cases 91 and 92 and the second duct portion 20b, and the communication path 94 that allows the resonance chamber 93 and the curved outer branch passage 24 to communicate with each other is connected to the first duct portion 20a. The passage forming portion 95a is integrally formed, and the tubular passage forming portion 95b is integrally formed with the second duct portion 20b.

Next, operations and effects of the embodiment configured as described above will be described.
When the internal combustion engine E is operated and the air that has flowed into the dust chamber 12 from the outside of the internal combustion engine E through the air introduction passage 21 is guided by the air guide 31 and deflected upward, Passes through and flows into the clean chamber 13. The air in the clean chamber 13 flows into the air passage 3 of the throttle valve device 2 through the air outlet passage 41, the flow rate is controlled by the throttle valve 2b, and then enters the combustion chamber through the air passage 5 of the intake pipe device 4. Inhaled.

  The air passage P formed by the air cleaner device A is a surrounding passage 76 that surrounds the curved passage 61 that is the first downstream passage downstream of the air flow meter 80 and the curved duct 60 that is the downstream duct forming the curved passage 61. And a second downstream passage 71 in which the outflow port 61o of the curved passage 61 opens, and the blowby gas introduction port 87 opens into the surrounding passage 76 upstream of the outflow port 61o. Since the surrounding passage 76 in which 87 is opened is a passage surrounding the curved duct 60, the flow of air is much less than that of the curved passage 61, and the flow rate variation of blow-by gas is attenuated in the surrounding passage 76. . In addition, since the flow rate fluctuation of the blow-by gas is transmitted from the outlet 61o to the air in the curved path 61 after passing through the surrounding passage 76, the flow rate fluctuation is transmitted to the air flow meter 80 from the blow-by gas introduction port 87. The transmission path length, which is the length, is longer than the path length of the curved path 61 by the amount of the surrounding path 76. As a result, the influence of the flow rate variation of the blow-by gas flowing into the downstream passage 71 of the air passage P on the detection of the air flow rate by the air flow meter 80 is reduced, and the detection accuracy of the air flow meter 80 is improved. In addition, since the surrounding passage 76 can increase the length of the transmission path without increasing the length of the curved path 61, the air cleaner apparatus A can reduce the influence of the flow rate variation of the blow-by gas on the air flow meter 80. Can be miniaturized.

  Since the surrounding passage 76 is an annular passage that surrounds the curved duct 60 over the entire circumference, the volume of the surrounding passage 76 is increased, and the flow fluctuation of the blow-by gas in the surrounding passage 76 is further attenuated. The influence of the flow-by fluctuation of blow-by gas on 80 flow rate detection can be further reduced. In addition, since the blow-by gas can flow out downstream from the outlet 61o over a wide range in the circumferential direction, the uniformity of the mixing of the intake air flowing out from the curved duct 60 and the blow-by gas is improved.

  The flow direction of air at the inlet 61i of the curved passage 61 and the flow direction of air at the outlet 71o of the downstream passage 71 are different from each other. The curved duct 60 is a flow of air at the outlet 61o of the curved passage 61. Is curved so as to be directed to the outlet 71o, so that the air flowing through the curved passage 61 is also bent by the curved duct 60 even when the air flow direction at the inlet 61i and the air flow direction at the outlet 71o are different. As a result, the air is smoothly guided toward the outlet 71o and flows out from the outlet 61o toward the outlet 71o, so that the air flowing out of the curved passage 61 is prevented from being disturbed in the passage 77 of the downstream passage 71. , Intake efficiency is improved.

The blow-by gas introduction port 87 is disposed on the curved inner side and in the upper portion of the surrounding passage 76 with respect to the passage center line L3 of the curved duct 60, so that the blow-by gas introduction port 87 is curved more than the passage center line L3. Since it opens to the surrounding passage 76 inside and at the top, the residual oil remaining in the blow-by gas flows toward the outlet 61o along with the blow-by gas while falling in the surrounding passage 76, and is curved. It mixes in the air flowing through the passage 61. As a result, by effectively utilizing the space formed when the curved duct 60 is used, it is possible to suppress the residual oil from staying in the lower portion of the surrounding passage 76, and to remove the residual oil from the outlet 61o. It becomes easy to guide to the downstream passage 77.
In addition, the curved inner space is narrower than the outer curved space, but by arranging the blow-by gas inlet 87 that does not require a large space for arrangement in the curved inner space, the outer curved space can be obtained. Since it becomes possible to arrange another member such as a part of the air cleaner apparatus A (for example, the cover B7 of the resonator 90) or a peripheral component arranged around the air cleaner apparatus A, the utilization of the curved outer space can be reduced. Can be increased. Further, by effectively utilizing the space formed when the curved duct 60 is used, the degree of freedom of arrangement of the another member can be increased, and the air cleaner apparatus A can be downsized or the air cleaner apparatus. A and the arrangement of the peripheral parts can be made compact.

  The air cleaner apparatus A includes an upstream duct 50 to which an air flow meter 80 is attached, a curved duct 60, and a second downstream duct 70 that forms a second downstream passage 71. The curved duct 60 includes the upstream duct 50 and the second downstream duct. By being a seal member that seals between the duct 70, the curved duct 60 also serves as a seal member that hermetically connects the upstream duct 50 and the second downstream duct 70. As a result, a separate sealing member is not required in addition to the upstream duct 50, the curved duct 60, and the second downstream duct 70, so that the number of parts is reduced and the cost is reduced.

The pair of side walls 16a and 16b of the dust chamber 12 of the air cleaner chamber 11 is opposite to the side wall 16a to which the air introduction passage 21 is connected and the side wall 16a opposite to the side wall 16a with the cleaner element F in the front-rear direction. The air introduction passage 21 has a curved passage 21c divided into a curved inner branch passage 23 and a curved outer branch passage 24 by a rectifying plate 22, and the curved inner passage branches from the intake port 21i by the curved passage 21c. The first passage length leading to the exit 21o via the path 23 is set shorter than the second passage length leading from the intake port 21i to the outlet 21o via the curved outer branch passage 24, and the curved passage 21c is located upstream in plan view. Curved in the left-right direction, which is a direction intersecting the front-rear direction, and flowed into the dust chamber 12 separately from the outlet 21o through the curved inner branch 23 and the curved outer branch 24 into the dust chamber 12. Air flow above each A first deflector 33 and a second deflector 34 that are deflected in the direction toward the cleaner element F are provided, and the second deflector 34 is closer to the outlet 21o than the first deflector 33 in the front-rear direction. As a result, the following effects are produced.
Since the air introduction passage 21 connected to the side wall 16a of the pair of side walls 16a and 16b facing each other with the cleaner element F sandwiched in the front-rear direction is curved in a direction crossing the front-rear direction in plan view, The air cleaner apparatus A can be reduced in size.
Further, since the air flow in the curved passage 21c is restricted from being deflected outward by the rectifying plate 22 that divides the curved passage 21c into the curved inner branch passage 23 and the curved outer branch passage 24, the curved passage 21c is provided. Since the flow of air flowing into the dust chamber 12 from the air introduction passage 21 is made uniform and the positions of the first and second deflecting portions 33 and 34 are different in the front-rear direction, Since the air flow can be directed to the cleaner element F over a wide range in the front-rear direction, from the air introduction passage 21 having the curved passage 21c in which the curved inner branch 23 and the curved outer branch 24 are formed by the rectifying plate 22. Air that has flowed into the dust chamber 12 is uniformly applied to the cleaner element F so that the cleaner element F can be used evenly, and the life of the cleaner element F can be extended.
Further, since the second deflection portion 34 is located closer to the outlet 21o than the first deflection portion 33, corresponding to the second passage length being longer than the first passage length, the curved inner branch passage 23 and the curved outer side Since the deviation of the time when the flow of the air flowing into the dust chamber 12 from the branch path 24 is deflected by the first and second deflecting portions 33 and 34 respectively decreases and the deviation of the timing when it hits the cleaner element F is reduced, The uneven flow of air in the clean chamber 13 and further in the air outlet passage 41 is suppressed, and the uniformity of the air flow in the air outlet passage 41 is improved. For this reason, the detection accuracy of the intake air amount by the air flow meter 80 arranged in the upstream passage 51 of the air outlet passage 41 is improved, and the mixture of the blow-by gas flowing into the downstream passage 71 from the blow-by gas introduction port 87 and the intake air is mixed. Improves uniformity.
The first and second deflecting portions 33 and 34 are arranged such that the distance in the front-rear direction between the first deflecting portion 33 and the second deflecting portion 34 is substantially equal to the difference between the first passage length and the second passage length. Since the distance between the first passage length and the second passage length is approximately equal, the flow of the air flowing into the dust chamber 12 from the curved inner branch passage 23 and the curved outer branch passage 24 is the first and second deflections. The deviation of the time deflected by each of the portions 33 and 34 is greatly reduced, and consequently the deviation of the time of contact with the cleaner element F is greatly reduced. Therefore, the air outlet passage 41 including the clean passage 13 and the upstream passage 51 is also included. The air flow unevenness in the air is further suppressed, and the air flow uniformity in the air outlet passage 41 is further improved.

  The air outlet passage 41 extends from the side wall 17a toward the side wall 17b in the clean chamber 13, and has an inlet 51i at a position away from the side wall 17a or the peripheral edge Fa of the cleaner element F. 34 is located between the side wall 17a or the peripheral edge Fa and the inlet 51i in the front-rear direction, so that the flow of air deflected by the second deflecting section 34 passes through the cleaner element F, and then in the clean chamber 13 Since it flows into the outlet side area Ra between the side wall 17a or the peripheral edge Fa and the inlet 51i in the front-rear direction and flows toward the inlet 51i, the occurrence of air stagnation in the outlet side area Ra of the clean chamber 13 occurs. The air flow in the clean chamber 13 is smoothed by being suppressed. As a result, the air in the dust chamber 12 can be uniformly applied to the cleaner element F even when the inlet 51i of the air outlet passage 41 is away from the first side wall 17a or the peripheral edge Fa.

  Each of the deflecting portions 33 and 34 is formed of a raised portion provided on the bottom wall 14 and raised upward, and has guide surfaces 33a and 34a that are curved. The air flowing into the chamber 12 and flowing along the bottom wall 14 in the vicinity of the bottom wall 14 is moved upward by the deflecting portions 33 and 34 constituted by the raised portions that rise upward from the bottom wall 14. Since the air is deflected toward the arranged cleaner element F, the air flow between the bottom wall 14 and the cleaner element F is more efficient due to the air flow deflected by the deflecting portions 33 and 34 from the vicinity of the bottom wall 14. Often directed to cleaner element F. As a result, it is possible to reduce the size of the deflection portions 33 and 34 for uniformly applying the air flowing in from the air introduction passage 21 to the cleaner element F, and the guide surfaces 33a and 34a of the deflection portions 33 and 34 Since the airflow is smoothly deflected, the airflow resistance in the dust chamber 12 is reduced and the intake efficiency is improved.

  The air outlet passage 41 has an upstream passage 51 having an inlet 51i and an outlet 51o through which the air flowing in from the inlet 51i flows out into the curved passage 61 outside the clean chamber 13, and the upstream passage 51 is The first deflection section 33 and the second deflection section 34 are formed by an upstream duct 50 connected to the sidewall 17a of the clean chamber 13 of the first sidewalls 16a and 17a and extending in the front-rear direction in the clean chamber 13. Is located between the inlet 51i and the outlet 51o in the front-rear direction when viewed from the vertical direction, so that the air in the flow deflected by the second deflecting unit 34 passes through the cleaner element F, and then the clean chamber 13, the air flows into the outlet side region Ra, which is a region between the inlet 51i and the outlet 51o of the upstream passage 51, and flows toward the inlet 51i, so that the air in the outlet side region Ra of the clean chamber 12 flows. The occurrence of stagnation is suppressed and emptying in the clean room 13 The flow of mind becomes smooth. As a result, even when the inlet 51i and the outlet 51o of the upstream passage 51 formed by the upstream duct 50 disposed in the clean chamber 13 are separated in the front-rear direction, the second deflection unit 34 causes the dust chamber to The air in 12 can be uniformly applied to the cleaner element F.

  In the first and second deflection units 33 and 34 disposed between the inlet 51i and the outlet 51o in the front-rear direction, the first deflection unit 33 is disposed closer to the inlet 51i in the front-rear direction, and the second deflection unit 34 is By being arranged closer to the outlet 51o in the front-rear direction, the air flowing in from the air introduction passage 21 in the dust chamber 12 is caused to flow upward and in the front-rear direction between the inlet 51i and the side wall 17b by the first deflection unit 33. Between the inlet 51i and the outlet 51o in the front and back direction by the second deflector 34 (hence the outlet side area Ra). Deflected towards As a result, the air in the dust chamber 12 can be uniformly applied to the cleaner element F. Further, since the interference between the air flows deflected by the first and second deflecting portions 33 and 34 can be reduced, the effect of uniformly applying the air to the cleaner element F is further enhanced.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The intake component may be a component constituting an intake device other than the air cleaner device A, for example, the throttle valve device 2 or the intake pipe device 4.
The curved passage 21c may be formed by a partition wall so that the curved inner branch path and the curved outer branch path are bifurcated with a gap therebetween.
The predetermined number may be 3 or more. In that case, the curved passage 21c is divided into three or more branch paths by two or more partition walls, and the present invention is applied to two adjacent branch paths.
At least a part of the plurality of deflecting portions of the deflecting portion may have a shape other than the raised portion, and may be provided on a portion other than the bottom wall in the air cleaner, for example, on the side wall.
The air introduction passage has a downstream straight passage that continues downstream of the curved passage, and the curved passage 21c and the downstream straight passage are separated by a partition wall from the curved inner branch passage and the downstream straight branch passage, and the curved outer branch passage. It may be divided into a path and a straight branch path downstream thereof.
The guide surfaces 33a and 34a may be configured by an inclined plane having a single inclination angle, and may be a composite such as a plurality of curved surfaces having different curvatures, a plurality of inclined planes having different inclination angles, or a combination of a curved surface and an inclined plane. You may comprise by a surface.
The second downstream duct 70 may be connected to the upstream duct 50 so as to surround the entire curved duct 60 and to surround a part of the upstream duct 50, for example, the downstream connection portion 50d. For example, the downstream connection 50d) becomes part of the downstream duct of the claims.
Even if the second downstream duct 70 partially surrounds the curved duct 60 in the circumferential direction instead of the entire circumference, the surrounding passage 76 is not an annular passage and the curved duct 60 is partially enclosed in the circumferential direction. Good.
The blow-by gas introduction port 87 may be opened at the lower part of the surrounding passage 76.
The internal combustion engine may be mounted on a machine other than the vehicle.

It is a principal part top view of the air cleaner apparatus of the internal combustion engine to which this invention was applied, and is the figure which simplified the component shown by FIG. It is II arrow directional view of FIG. It is a III arrow directional view of FIG. FIG. 2 is an exploded plan view of the air cleaner device of FIG. 1. It is the VV sectional view taken on the line of FIG. FIG. 6 is a sectional view taken along line VI-VI in FIGS. 3 and 5. It is a top view which shows a part in cross section in the state which removed a part of air cleaner apparatus of FIG. It is a top view which shows a part in cross section for the principal part of the air cleaner apparatus of FIG.

Explanation of symbols

10 ... Air cleaner, 11 ... Air cleaner chamber, 12 ... Dust chamber, 13 ... Clean chamber, 14 ... Bottom wall, 16, 17 ... Side wall, 21 ... Air introduction passage, 21i ... Inlet, 21o ... Outlet, 22 ... Rectifying plate, 23, 24 ... Branching path, 33, 34 ... Deflection part, 41 ... Air outlet passage, 50 ... Upstream duct, 51 ... Upstream passage, 60 ... Curved duct, 61 ... Curved path, 62 ... Upstream connecting part, 63 ... Curved , 64 ... passage part, 65 ... curved passage part, 70 ... downstream duct, 71 ... downstream passage, 73 ... surrounding part, 74 ... upstream connecting part, 76 ... surrounding passage, 80 ... air flow meter, 87 ... blow-by gas inlet ,
A: Air cleaner device, D: Opposing direction, F: Cleaner element.

Claims (5)

In an internal combustion engine comprising: an air flow meter that detects a flow rate of air flowing through an intake passage; and an intake part that forms an air passage constituting the intake passage.
The air passage has a first air passage downstream from the air flow meter and an enclosing passage that at least partially surrounds a downstream duct forming the first air passage in the circumferential direction, and an outlet of the first air passage Has a second air passage opening,
An internal combustion engine, wherein a blow-by gas inlet for allowing blow-by gas to flow into the intake passage opens into the surrounding passage upstream of the outlet.   The internal combustion engine according to claim 1, wherein the surrounding passage is an annular passage that surrounds the downstream duct over the entire circumference. The direction of air flow at the inlet of the first air passage and the direction of air flow at the outlet of the second air passage are different from each other.
The downstream duct is a curved duct that is curved so that an air flow at the outlet is directed to the outlet of the second air passage, and the first air passage is a curved passage. Item 3. The internal combustion engine according to Item 1 or 2.   4. The internal combustion engine according to claim 3, wherein the blow-by gas introduction port is arranged on the curved inner side and on the upper side in the surrounding passage with respect to a passage center line of the curved duct. The intake component includes an upstream duct to which the air flow meter is attached, the downstream duct, and a second downstream duct that forms the second air passage,
The internal combustion engine according to any one of claims 1 to 4, wherein the downstream duct is a seal member that seals between the upstream duct and the second downstream duct.

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