JP2019073989A - Air intake duct - Google Patents

Abstract

To prevent an air intake duct from being recessed to an internal side in a simple structure.SOLUTION: A lower duct body 13b of a lower-side air intake duct 13 is formed in a flat cylindrical shape of which the length in a longitudinal direction is shorter than a length L2 in a vehicle width direction. At a lower side of a front-side opposite wall part 15, a front opening part 23 is provided for communicating a flow passage of sucked air inside of the lower duct body 13b with a flow passage of sucked air in a connection part 13c of the lower-side air intake duct 13 within the lower-side air intake duct 13. The front opening part 23 is connected to the side of an engine 3. In a rear-side opposite wall part 16, a protruding curved surface region 25 which protrudes in a spherical surface shape backwards in a substantially central part of the rear-side opposite wall part 16 is provided. The protruding curved surface region 25 is opposite to a portion of the front opening part 23 in the front-side opposite wall part 15.SELECTED DRAWING: Figure 6

Description

  The present disclosure relates to an intake duct that defines a flow path of intake air to the engine side.

  Patent Document 1 discloses an intake duct of a cab-over type vehicle. The intake duct includes a snorkel as an intake duct fixed to the rear wall of the cab, a bellows-like upper elastic cylinder made of rubber integrally coupled to the lower part of the snorkel, and a downward opening of the upper elastic cylinder. And a lower duct to be worn. The snorkel is a resin molded product and is in the form of a flat bulging container. The lower duct is a resin molded product and has a flat rectangular container shape, and the inflow opening is formed above the lower duct, and the side cylinder is extendedly formed on the forward facing wall. The side cylinder is connected to the engine side via an air cleaner or the like. The forward facing wall of the lower duct is formed with three inwardly directed projections, and the tips of the respective projections are integrally coupled to the inner wall surface of the rearward facing wall. Heads of bolts are embedded in connection portions between the respective projections and the rear facing wall, and fixing brackets are fixed to screw portions of the respective bolts projecting to the outside. The fixed bracket is integrally coupled to the horizontal support for the duct support. The horizontal base frame fixes the lower duct and the air cleaner, and attaches them to the side rails via the vertical base frame.

JP-A-9-144615

  As in the intake duct described in Patent Document 1, the intake duct is formed in a flat cylindrical shape, is provided with an opening on one side in the minor axis direction, and the opening is connected to the engine side. At the same time, when a negative pressure is generated inside the duct, the wall on the other side facing the opening on the one side may be recessed toward the inside of the duct, which may narrow the cross-sectional area of the intake flow path.

  In the air intake duct described in Patent Document 1, three inward projecting portions are formed on the forward facing wall of the lower duct, and the pointed end of each projecting portion is integrally coupled to the inner wall surface of the rearward facing wall; Since the fixing bracket is fixed to the bolt embedded in the joint portion of, the forward dent of the rear facing wall can be suppressed. However, in the air intake duct described in Patent Document 1 described above, since it is necessary to form an inward projection or embed a bolt, the structure of the air intake duct is complicated, and the formation of the air intake duct may be complicated. There is.

  Then, this indication aims at provision of the air intake duct which can prevent a dent to an inner side by simple structure.

  In order to solve the above-mentioned subject, the 1st mode of the present invention has a field formed in a flat cylinder shape which made a pair of opposing wall parts in alignment with a major axis direction space apart in the minor axis direction, and made it oppose each other. An intake duct for dividing a flow path of intake air to the engine side, comprising an opening and a projecting curved surface area. The opening is provided on the side of one of the pair of opposing walls, and is connected to the engine. The projecting curved surface area is provided on the other opposing wall side of the pair of opposing wall portions, and projects in a curved shape opposite to at least a part of the opening and outside.

  In the above configuration, the opening portion connected to the engine side is provided on one of the opposing wall portions of the pair of opposing wall portions along the major axis direction of the intake duct, and the opening portion is provided on the other opposing wall portion side. A projecting curved surface area facing at least a part is provided. For this reason, when a negative pressure is generated inside the intake duct at the time of intake, a force toward the opening acts on the projecting curved surface area of the other opposing wall. The projecting curved surface area of the other opposing wall portion projects in a curved shape toward the outside, so that the other opposing wall has an opening in the other opposing wall as compared with the case where the area opposing the opening is flat. When the force to the part side acts, the dent deformation (deformation to concave toward the opening) of the other opposing wall to the opening can be suppressed.

  In addition, it has a simple structure in which an opening is provided on one opposing wall side and a projecting curved surface area is provided on the other opposing wall side (a position facing to at least a part of the opening of the other opposing wall). Because of this, the intake duct can be easily formed.

  A second aspect of the present invention is the air intake duct according to the first aspect, wherein the projecting curved surface area on the other opposing wall side projects in a spherical shape outward.

  In the above configuration, since the projecting curved surface area on the other opposing wall side projects spherically to the outside, the sectional shape of the projecting curved surface area along the minor axis direction is a curved surface at any position of the projecting curved surface area It becomes. For this reason, it is possible to preferably suppress the dent deformation of the other opposing wall toward the opening when the force toward the opening acts on the other opposing wall.

  A third aspect of the present invention is the air intake duct according to the first aspect or the second aspect, comprising a rib. The rib is provided in at least a projecting curved surface area of the other opposing wall portion, and extends in a direction intersecting with the minor axis direction in a state of being recessed inward.

  In the above configuration, the other opposing wall portion is provided with a rib which is disposed at least in the projecting curved surface area and is recessed inward and extends in a direction intersecting with the short diameter direction. The rigidity of the opposing wall can be increased, and the deformation of the other opposing wall toward the opening can be suitably suppressed when the force toward the opening is applied to the other opposing wall.

  According to the present disclosure, it is possible to prevent the recess to the inside of the intake duct with a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic side view of the vehicle carrying the intake duct which concerns on one Embodiment of this invention, (a) shows a non-tilt state, (b) shows a tilt state, respectively. FIG. 1 is a schematic perspective view from the rear of a vehicle equipped with an intake duct according to an embodiment of the present invention. It is a perspective view of a lower side intake duct. It is the fragmentary sectional view seen from the side of the lower side intake duct. It is a bottom view of a lower side intake duct. It is a rear view of a lower side intake duct. It is explanatory drawing about shaping | molding of a lower side intake duct.

  Hereinafter, an embodiment of the present invention will be described based on the drawings. In each of the drawings, FR indicates the front of the vehicle, UP indicates the upper side, and IN indicates the inner side in the vehicle width direction. Further, in the following description, the left and right direction means the left and right direction in a state of facing the front of the vehicle.

  As shown in FIGS. 1 (a) and 1 (b), the vehicle 1 provided with the intake duct 10 according to the present embodiment is, for example, a cabover type vehicle 1 in which the cab 2 is disposed substantially above the engine 3. is there. From the non-tilt state (the state shown in FIG. 1A), the lower end of the front end of the cab 2 is rotatably supported with respect to the vehicle body frame 4 and the rear end side of the cab 2 is supported by the vehicle body frame 4. The rear end of the lens can be tilted forward and upward to be in a tilt state (the state shown in FIG. 1 (b)). The intake duct 10 defines a flow path of intake air to the engine 3 side. The intake air is guided to the air cleaner 5 by the intake duct 10 and supplied to the engine 3 through the air cleaner 5.

  As shown in FIGS. 1 (a), 1 (b) and 2, the intake duct 10 extends vertically in the rear of the cab 2, the lower end side is connected to the engine 3 side, and the intake port 10a on the upper end side The intake air (air) taken in is guided to the engine 3 side. The intake duct 10 is supported by an upper intake duct 11 extending along the back surface 2a of the cab 2 and fixed to the back surface 2a, a bellows duct 12 fixed to the upper intake duct 11, and the vehicle body frame 4 side. And a lower air intake duct 13. The intake duct 10 is disposed at the outer end of one side (the right side in the present embodiment) of the rear surface 2 a of the cab 2 in the vehicle width direction. The bellows duct 12 and the lower intake duct 13 are connected to each other so as to be separated from each other vertically. When the cab 2 is changed from the non-tilt state to the tilt state, the upper intake duct 11 and the bellows duct 12 separate from the lower intake duct 13 and tilt upward with the cab 2 and the lower intake duct 13 tilts. It is supported by the body frame 4 side. In the present embodiment, the intake duct 10 is disposed at the right end of the rear surface 2a of the cab 2 in the vehicle width direction outer end, but the present invention is not limited to this. It may be disposed at the left end in the vehicle width direction or at the center in the vehicle width direction of the rear surface 2 a of the cab 2.

  The upper intake duct 11 is a resin duct formed in a flat cylindrical shape whose length in the front-rear direction is shorter than the length in the vehicle width direction in order to suppress the amount of protrusion of the cab 2 rearward from the back surface 2a. It extends vertically and defines an intake flow path (not shown) inside. At the upper end portion of the upper intake duct 11, an intake port 10 a communicating the inside and the outside of the upper intake duct 11 is provided. A cover member 14 is attached to the intake port 10a. The cover member 14 is formed with a plurality of openings, and in the state covering the intake port 10a, suppresses the intrusion of rain water etc. from the outside to the inside of the upper intake duct 11, and from the outside to the inside of the upper intake duct 11. Allow inflow of air. The lower end portion of the upper intake duct 11 is disposed near the lower end portion of the back surface 2 a of the cab 2.

  The bellows duct 12 is a resin duct formed in a flat cylindrical shape whose length in the front-rear direction is shorter than the length in the vehicle width direction in order to reduce the amount of protrusion of the cab 2 rearward from the back surface 2a. The upper end side is fixed to the lower end of the upper intake duct 11. The bellows duct 12 is formed in a bellows-like shape and defines an air flow path (not shown) inside. The lower end opening (not shown) of the bellows duct 12 allows intrusion of the upper end of the lower intake duct 13 described later, and is connected to the upper end of the lower intake duct 13 in the non-tilted state. The bellows duct 12 connects the upper air intake duct 11 and the lower air intake duct 13 in a non-tilt state, and allows relative displacement between the upper air intake duct 11 and the lower air intake duct 13 due to vibration etc. Absorb.

  As shown in FIGS. 3 to 6, the lower intake duct 13 is a resin duct integrally molded by blow molding with substantially the same thickness and formed into an elbow shape bent substantially at a right angle, The intake air from the upper intake duct 11 side is guided to the front air cleaner 5. The lower intake duct 13 has a flat cylindrical insertion connecting portion 13a inserted into the bellows duct 12 and a flat cylindrical lower duct main body (flat cylindrical shape) extending continuously downward from the lower end of the insertion connecting portion 13a. The formed region 13b and a cylindrical connecting portion 13c extending forward from the lower end portion of the lower duct body 13b and connected to the air cleaner 5 (see FIG. 1A) are integrally formed. The insertion connection portion 13a and the lower duct main body 13b are formed in a flat cylindrical shape whose length in the front-rear direction is shorter than the length in the vehicle width direction in order to suppress the amount of protrusion of the cab 2 rearward from the back surface 2a. The bending angle of the lower air intake duct 13 is not limited to the substantially right angle.

  The insertion connecting portion 13 a of the lower air intake duct 13 has an elongated upper end opening 18 in the vehicle width direction. The guide member 19 is attached to the insertion connection part 13a. The guide member 19 has a flat cylindrical fixing portion 19a fixed to the insertion connecting portion 13a of the lower intake duct 13, and a guide portion 19b protruding upward from the fixing portion 19a. The fixing portion 19 a is fixed to the insertion connecting portion 13 a of the lower air intake duct 13 in a state of being disposed on the outer periphery of the insertion connecting portion 13 a of the lower air intake duct 13. The guide portion 19 b has a shape that protrudes so as to taper upward in a side view, is formed of a plurality of rods, and allows the flow of air in the vertical direction. When changing the cab 2 from the tilt state to the non-tilt state, the guide portion 19b does not shift the positions of the lower end opening of the bellows duct 12 which tilts downward with the cab 2 and the insertion connecting portion 13a of the lower intake duct 13 Then, the insertion connecting portion 13 a of the lower air intake duct 13 is guided into the lower end opening of the bellows duct 12.

  The lower duct main body 13b of the lower intake duct 13 is formed into a flat cylindrical shape in which the length L1 in the front-rear direction (short diameter direction) is shorter than the length L2 in the vehicle width direction (long diameter direction) It is exposed below the bellows duct 12 in a state where the side intake duct 13 is connected. The lower duct main body 13b includes front and rear opposing wall portions (one pair of opposing wall portions) 15 and 16 which are spaced apart in the front-rear direction so as to face each other, and left and right opposing wall portions 20 which are spaced apart and opposed in the vehicle width direction 21 and a bottom wall portion 22 disposed at a position facing the upper end opening 18 of the insertion connection portion 13a, and guides the intake air from above from below. The front and rear opposing wall portions 15 and 16 divide the front and rear of the intake flow path 17 (flow path on the rear side of the two-dot chain line 6 in FIG. 4) extending in the vertical direction. The left and right portions of the inspiratory flow path 17 define the lower side of the inspiratory flow path 17. In addition, the dashed-two dotted line 6 in FIG. 4 is an imaginary extension line which extended the opposing wall part 15 of the front side to linear shape below.

  The front facing wall portion (one facing wall portion) 15 is formed in a substantially flat plate shape, and extends long in the vehicle width direction in a state of intersecting with the front-rear direction below the insertion connecting portion 13a. A flow path 17 of the intake air inside the lower duct main body 13b in the lower intake duct 13 and a lower intake duct 13 in the lower side of the front facing wall portion 15 (the position shown by the two-dot chain line 6 in FIG. 4) A front opening (opening) 23 is provided to communicate the connection portion 13c with an intake flow path 24 described later. That is, the front opening 23 connected to the engine 3 is provided on the front opposite wall 15 side of the front and rear facing walls 15 and 16. The front opening 23 is formed in a substantially rectangular shape whose length in the vehicle width direction is longer than the length in the vertical direction. The upper end of the front opening 23 is divided by the lower end edge of the front opposite wall 15, and the lower end of the front opening 23 is divided by the front edge of the bottom wall 22 of the lower duct main body 13b. The left and right side ends are defined by the front end edges of the left and right facing wall portions 20, 21 of the lower duct body 13b.

  The rear opposite wall portion (the other opposite wall portion) 16 is formed in a substantially rectangular shape in a rear view, and extends in the vehicle width direction and the vertical direction in a state of intersecting with the front and rear direction. The rear facing wall portion 16 has a projecting curved surface area 25 projecting in a spherical shape rearward at a substantially central portion of the rear facing wall section 16 and a flat surface area 27 surrounding the periphery of the projecting curved surface area 25 Is provided. The projecting curved surface area 25 is a circular area in a rear view centering on the upper, lower, left, and right centers of the opposing wall 16 on the rear side, and faces a part of the front opening 23 of the opposing wall 15 on the front side. . The projecting curved surface region 25 projecting in a spherical shape to the rear has any cross-sectional shape (cross-sectional shape along the short diameter direction (front-rear direction)) as viewed from the direction (vertical direction or vehicle width direction) intersecting with the front-rear direction Also in the position, it becomes a curved surface of a substantially arc shape. The central portion of the projecting curved surface region 25 in the rear view is the portion that protrudes most to the rear, and is the rear end of the opposing wall 16 on the rear side. The upper end 25 a of the projecting curved surface area 25 is disposed above the upper end 23 a of the front opening 23 of the facing wall 15 on the front side. The lower end 25 b of the projecting curved region 25 is disposed slightly above the lower end 23 b of the front opening 23. The vehicle width direction inner end 25 c of the protruding curved surface area 25 is disposed outside the vehicle width direction inner end 23 c of the front opening 23 in the vehicle width direction and below the upper end 23 a of the front opening 23. The vehicle width direction outer end 25 d is disposed inward of the vehicle width direction outer end 23 d of the front opening 23 in the vehicle width direction and below the upper end 23 a of the front opening 23. A plurality of (four in the present embodiment) ribs 27a to 27d extending in the vertical direction are provided on the rear opposite wall portion 16 in a state of being recessed forward. Note that the projecting curved surface area 25 in the rear view circular shape includes not only the projecting curved surface area 25 that is completely circular in rear view, but also the projecting curved area 25 that is elliptical in rear view. In addition, the sectional shape (the cross sectional shape along the minor axis direction) of the spherical projecting curved surface area 25 viewed from the direction intersecting the minor axis direction (front-rear direction) is a substantially arc-shaped curved surface shape at any position The area of That is, the spherical projecting curved surface area 25 includes not only a completely spherical projecting curved surface area 25 projecting outward (in the present embodiment, rearward) but also a projecting curved surface area 25 in a state close to a spherical surface. 3 and 6, although the boundary between the flat region 27 and the protruding curved region 25 is illustrated for the sake of clarity, the boundary between the flat region 27 and the protruding curved region 25 recognizes the boundary. It may be as clear as possible, or may be in the form of a gently curved surface where the boundaries can not be recognized.

  The ribs 27a to 27d are spaced apart from each other in the vehicle width direction and disposed substantially parallel to each other, and extend rectilinearly in the vertical direction in a state of being recessed forward. The upper end portion and the lower end portion of the ribs 27a to 27d are disposed in the flat area 27 of the opposing wall 16 on the rear side, and the intermediate portion of the ribs 27a to 27d is disposed in the projecting curved area 25 of the opposing wall 16 on the rear Be done. That is, the area | region where rib 27a-27d is arrange | positioned among the plane area | regions 27 of the opposing wall part 16 of the rear side is dented ahead. Moreover, the area | region where rib 27a-27d is arrange | positioned among the projecting curved-surface area | regions 25 of the opposing wall part 16 on the back side is dented ahead. The depth of the ribs 27a to 27d (the length from the bottom surface 28 of the ribs 27a to 27d to the rear surface of the opposing wall 16 on the rear side) is the deepest at the central portion in the vertical direction of the projecting curved surface area 25.

  The left facing wall portion 20 of the lower duct main body 13b connects the inner end edges of the front and rear facing wall portions 15 and 16 in the vehicle width direction. The opposing wall portion 21 on the right side of the lower duct main body 13b connects the outer edges in the vehicle width direction of the opposing wall portions 15 and 16 on the front and rear sides. The bottom wall portion 22 of the lower duct body 13 b is gently curved and extended continuously downward from the lower end edge of the rear opposite wall portion 16 downward, and the upper surface of the front end edge is the lower end of the front opening 23 Section 23b.

  The connection portion 13 c of the lower intake duct 13 is formed in a tubular shape that divides the flow path 24 of the air supply extending forward from the front opening 23. A circular front end opening 29 connected to the air cleaner 5 is provided at the front end 26 of the connection portion 13 c. That is, the connecting portion 13 c becomes circular as it goes from the front opening 23 to the front, and communicates the substantially rectangular front opening 23 with the circular front end opening 29. The diameter (length in the height direction) L3 of the front end portion 26 of the connection portion 13c is longer than the length L1 of the lower duct main body 13b in the front-rear direction and shorter than the length L2 of the lower duct main body 13b in the vehicle width direction . Further, the diameter L3 of the front end portion 26 of the connection portion 13c is shorter than the length in the vertical direction of the projecting curved surface area 25 of the opposing wall portion 16 on the rear side and shorter than the length in the vertical direction of the front opening 23. The front end opening 29 of the connection portion 13c is disposed in the front opening 23 in a rear view, and a partial region of the front end opening 29 is opposed to the projecting curved surface region 25 of the opposing wall 16 on the rear side. The upper end 29a of the front end opening 29 of the connection portion 13c is below the upper end 25a of the projecting curved surface area 25 and the upper end 23a of the front opening 23, and above the height position of the vertically central portion of the projecting curved area 25. Be placed. The lower end 29b of the front end opening 29 of the connecting portion 13c is disposed at substantially the same height position as the lower end 23b of the front opening 23. That is, the lower end 29b of the front end opening 29 of the connecting portion 13c is the lower end of the projecting curved region 25. It is disposed slightly below 25b. The vehicle width direction inner end 29 c of the front end opening 29 of the connection portion 13 c is disposed outside the vehicle width direction inner end 25 c of the projecting curved region 25 in the vehicle width direction. The vehicle width direction outer end 29 d of the front end opening 29 of the connection portion 13 c is disposed on the inner side in the vehicle width direction than the vehicle width direction outer end 25 d of the projecting curved region 25.

  A drainage portion 31 projecting downward is formed at the center in the vehicle width direction of the lower surface portion 30 of the connection portion 13c. A drainage port (not shown) is formed at the bottom of the drainage portion 31, and the water droplets that have entered or generated in the intake duct 10 are drained from the drainage port of the drainage portion 31. The angle of the front wall 31a of the drainage 31 relative to the lower surface 30 forward of the drainage 31 (the angle in front of the front wall 31a) is the back wall of the drainage 31 relative to the lower surface 30 behind the drainage 31 The angle is larger than the angle of the portion 31 b (the angle behind the rear wall portion 31 b). As shown in FIG. 7, when the lower intake duct 13 is blow-molded using the mold 32, the corner from the lower duct main body 13 b and the connecting portion 13 c is directed downward from the mold 32 in a state in which the corners are downward. To be removed. The front wall portion 31a of the drainage portion 31 extends linearly along the removal direction (along the vertical direction in FIG. 7) when removing the blow-molded lower air intake duct 13 from the mold 32.

  In the lower duct main body 13b of the lower intake duct 13 of the intake duct 10 configured as described above, the length L1 in the front-rear direction (short diameter direction) is the length in the vehicle width direction (long diameter direction) of the lower duct main body 13b It is formed in a flat cylindrical shape shorter than the length L2, and the front opening 23 is provided in the facing wall 15 on the front side of the lower duct main body 13b. For this reason, when a negative pressure is generated inside the lower intake duct 13 of the intake duct 10 at the time of intake, a force to the front opening 23 side acts on the opposing wall 16 on the rear side. The rear facing wall portion 16 is provided with a projecting curved surface area 25 opposed to a part of the front opening 23 of the front opposing wall 15, and the projecting curved surface area 25 projects in a spherical shape to the rear. Compared with the case where the rear opposing wall 16 is formed flat without providing the projecting curved surface area 25 in the opposing wall 16 on the side, a frontward force is applied to the rear opposing wall 16 Depression deformation (depression deformation to the front opening 23 side) of the rear opposite wall portion 16 can be suppressed.

  Further, the front opening 23 is provided in the facing wall 15 on the front side of the lower duct main body 13 b formed in a flat cylindrical shape, and at a position facing at least a part of the front opening 23 in the rear facing wall 16. Because of the simple structure in which the projecting curved surface area 25 is provided, the lower intake duct 13 of the intake duct 10 can be easily formed.

  In addition, the projecting curved surface area 25 of the opposing wall portion 16 on the rear side protrudes in a spherical shape, and the sectional shape of the projecting curved surface area 25 viewed from the direction (vertical direction or vehicle width direction) intersecting with the front and rear direction is a substantially arc shaped curved surface It becomes a shape. That is, since the cross-sectional shape of the projecting curved surface area 25 along the front-back direction is a curved surface at any position of the projecting curved surface area 25, the rear side when a forward force is applied to the opposing wall 16 on the rear side The dent deformation of the opposite wall portion 16 can be suitably suppressed.

  In addition, since the ribs 27a to 27d extending along the vertical direction are provided on the rear facing wall portion 16 so as to be recessed forward, the rigidity of the rear facing wall portion 16 against the force in the front-rear direction is increased. . For this reason, it is possible to preferably suppress the dent deformation of the rear opposing wall portion 16 when a forward force acts on the rear opposing wall portion 16.

  Therefore, according to the present embodiment, the lower intake duct 13 of the intake duct 10 can be easily formed, and the concave toward the front of the rear opposite wall portion 16 of the lower intake duct 13 inward is It can be prevented.

  Also, the front wall 31a of the drainage portion 31 of the lower intake duct 13 is straight along the removal direction when removing the blow molded lower intake duct 13 from the mold 32 (along the vertical direction in FIG. 7) It is possible to prevent interference between the mold 31 and the front wall 31a of the drainage portion 31 when the blow molded lower intake duct 13 is removed upward from the mold 32. 13 can be removed from the mold 32 upwards. For this reason, unlike the case where the front wall 31a of the drainage portion 31 and the mold 32 interfere with each other, the mold 32 is positioned at a position corresponding to the front wall 31a of the drainage portion 31 relative to the lower intake duct 13. Since it is not necessary to provide the slide mold portion that can be removed from the mold 32 first, the mold 32 can have a simple structure by that amount, and the manufacturing cost of the mold 32 can be suppressed.

  Further, since the ribs 27a to 27d which are recessed forward are provided on the rear opposite wall portion 16, the amount of protrusion of the intake duct 10 to the rear can be suppressed unlike in the case of projecting to the rear.

  In the present embodiment, the intake duct 10 is configured by the upper intake duct 11, the bellows duct 12, and the lower intake duct 13, and when the cab 2 is in a tilt state, the bellows duct 12 and the lower intake duct 13 Although the ducts are separable above and below each other, the intake duct 10 is not limited to this. For example, the intake duct 10 may be configured such that the bellows duct 12 and the lower intake duct 13 are not separated from each other vertically, and the intake duct 10 may be applied to a vehicle that does not tilt.

  Further, in the present embodiment, the intake duct 10 is configured to be elongated in the vertical direction (predetermined direction) by the upper intake duct 11, the bellows duct 12 and the lower intake duct 13, but the shape of the intake duct is limited thereto For example, it may be an intake duct which is short in the vertical direction like the lower intake duct 13.

  In the present embodiment, the lower intake duct 13 of the intake duct 10 is a bent elbow duct, but the shape of the lower intake duct 13 is not limited to this, and, for example, the lower duct main body 13b is formed in a box shape in the form of a bottomed rectangular cylinder opening upward, and a circular opening (opening) is formed at a predetermined position (central portion etc.) of the opposing wall 15 on the front side of the lower duct main body 13b A duct having a connecting portion 13c extending from the opening to the side of the engine 3 may be used. That is, as in the present embodiment, in the opening provided in the facing wall 15 on the front side, a partial region of the outer edge of the opening is the front edge of the bottom wall 22 or the facing walls 20 and 21 on the left and right. The front opening 23 may be divided, or the whole area of the outer edge of the opening may be divided by the front facing wall 15 (a predetermined position of the front facing wall 15 (a central portion Etc.) may be formed.

  Further, in the present embodiment, the intake duct 10 constituted by the upper intake duct 11 and the bellows duct 12 extending vertically and the elbow-type lower intake duct 13 bent forward at the lower end of the intake duct 10 is exemplified. However, the intake duct is not limited to this. The intake duct may be an intake duct having a flat cylindrical region in which a pair of opposing wall portions along the major axis direction are separated in the minor axis direction to be opposed to each other. That is, the minor axis direction of the intake duct is not limited to the front-rear direction, the major axis direction of the intake duct is not limited to the vehicle width direction, and the direction in which the intake duct extends is not limited to the vertical direction. Further, the arrangement position of the intake duct is not limited to the rear of the cab 2.

  Further, in the present embodiment, the shape of the front opening 23 is a substantially rectangular shape whose length in the vehicle width direction is longer than the length in the vertical direction, but the shape of the front opening 23 is limited to this Instead, various shapes can be applied.

  Further, in the present embodiment, the protruding curved surface area 25 that protrudes in a spherical shape to the rear is provided in the opposing wall portion 16 on the rear side, but the shape of the protruding curved surface area 25 is not limited to the spherical shape. For example, the shape of the projecting curved surface area 25 may be a shape extending linearly in a direction (vertical direction, vehicle width direction, etc.) intersecting with the short diameter direction in a state of projecting in an arc shape (curved shape) to the outside.

  Moreover, in this embodiment, although the four ribs 27a-27d were provided in the opposing wall part 16 on the back side, the number of ribs is not limited to this. The rear opposing wall 16 may be provided with one or more ribs. Alternatively, no rib may be provided on the rear facing wall portion 16.

  Moreover, in this embodiment, although the some rib 27a-27d extended in the up-down direction was provided in the opposing wall part 16 on the back side, the direction which extends the ribs 27a-27d is not limited to this, and it is front and back It may be a direction intersecting with the direction (minor direction). For example, a rib extending along the vehicle width direction may be provided on the rear facing wall portion 16.

  Further, in the present embodiment, the lower intake duct 13 is integrally molded by blow molding, but is not limited to this. For example, after the lower duct main body 13b and the connecting portion 13c are separately molded, they are fixed to each other You may

  Further, although the intake duct 10 of the vehicle 1 has been described in the present embodiment, the intake duct may be applied other than the vehicle 1.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to the content of the said embodiment, Of course, it can change suitably in the range which does not deviate from this invention. That is, it is needless to say that other embodiments, examples, operation techniques and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

3: Engine 10: Intake duct 13: Lower intake duct 15: front opposing wall (one opposing wall of a pair of opposing walls)
16: back facing wall (the other facing wall of a pair of facing walls)
17: Intake flow path 23: Front opening (opening)
25: projecting curved surface area 27a to 27d: rib

Claims (3)

An air intake duct having at least a flat cylindrical region in which a pair of opposing wall portions along the major axis direction are separated in the minor axis direction to be opposed to each other, and which divides the flow path of intake air to the engine side,
An opening which is provided on one of the pair of opposing wall portions and is connected to the engine side;
A projecting curved surface area provided on the other of the pair of opposing wall sections and facing at least a part of the opening and projecting in a curved shape toward the outside; Characteristic intake duct. The air intake duct according to claim 1, wherein
An air intake duct characterized in that the projecting curved surface area on the side of the other opposing wall portion projects in a spherical shape to the outside. The air intake duct according to claim 1 or 2, wherein
An air intake duct comprising: a rib provided in at least the projecting curved surface area of the other opposing wall portion, and extending in a direction which intersects with the short diameter direction in a state of being dented inward.

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