JP2013245620A - Duct fitting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smooth the operation of fitting a divided air intake duct 1 in a cylindrical mounting part 12 of an air cleaner case 2.SOLUTION: An air intake duct 1 is divided into a first duct half part 3 and a second duct half part 4 and integrally assembled by a locking claw 5. An end 11 inserted into a cylindrical mounting part 12 has a projection 31 comprising a first projection half part 32 and a second projection half part 33 and the part projecting from the end edge 17 has guide faces 37 and 38. The cylindrical mounting part 12 is formed of a cut part 41 corresponding to the projection 31. When inserted, the projection 31 precedes to enter the cut part 41 and both the duct half parts 3 and 4 contact with each other closely so that smooth insertion is possible even if there is a warp or the like on the duct half parts 3 and 4.

Description

  The present invention relates to a duct fitting structure in which an end portion of a synthetic resin duct is fitted into a cylindrical mounting portion of a mating member such as a synthetic resin air cleaner case, and in particular, the duct end portion is halved. The present invention relates to a duct fitting structure in the case of a structure.

  As disclosed in Patent Document 1, for example, a synthetic resin duct is halved as an intake duct of an automobile, and the first duct half and the second duct half are molded by injection molding or the like. Then, the structure which combined both by mechanical engagement structures, such as a latching claw of a side edge, is known.

  Further, in Patent Document 2, a pair of duct halves formed in a half structure is provided with strip-shaped flanges along side edges, and these flanges are butted against each other to be welded to form a cylindrical intake duct. It is disclosed that. The end portion of the intake duct thus formed in a cylindrical shape is inserted inside the cylindrical duct on the air cleaner case side and is in a state of being fitted to each other, but in order to avoid interference with the flange, the end portion on the air cleaner case side A slit corresponding to the length of the flange is formed in the duct.

JP 2011-202508 A JP 2003-247465 A

  In the duct that is integrated with the locking claw as a half structure as in Patent Document 1 above, when the end portion is fitted inside the cylindrical mounting portion of another duct or air cleaner case, In general, a pair of duct halves are not fixed to each other at the duct end inserted into the cylindrical mounting portion. That is, the two duct halves are fixed by the locking claw on the side edge at a portion that does not overlap with the cylindrical mounting portion, and the end of the duct has a simple cylindrical shape without a locking claw or the like.

  Therefore, due to slight warping or molding error of each duct half due to injection molding, etc., the two duct halves are slightly separated at the end of the duct, that is, slightly lifted across the dividing line. There is. In such a case, it may become impossible to insert into the cylindrical mounting portion of the counterpart member, or the insertion may be difficult, which may cause deterioration in workability.

  In Patent Document 2, welding is performed by extending the flange to the vicinity of the end of the duct. However, a larger flange is necessary for vibration welding or the like, and two duct halves are welded to each other up to the end of the duct. Not realistic.

In this invention, a first duct half and a second duct half made of synthetic resin each molded into a half structure are combined with each other to form a cylindrical duct, and the end of this duct is the cylinder of the mating member. In the fitting structure of the duct that is fitted in the shaped mounting part,
On the outer peripheral surface of the duct end, provided with protrusions respectively provided at two parting line portions of the first duct half and the second duct half,
The mounting portion has a pair of cutout portions each having a shape corresponding to the protruding portion,
The protrusion comprises a first protrusion half integrally formed with the first duct half, and a second protrusion half integrally formed with the second duct half, In a state of being combined with each other, it forms a substantially rectangular shape with a pair of side edges parallel to the axial direction of the duct, and a part thereof protrudes in the axial direction from the leading edge of the duct end,
The notch includes a pair of parallel notch side edges closely contacting the pair of side edges,
The tip of the protruding portion or the opening edge of the notch is inclined with respect to the axial direction so that the first protrusion half and the second protrusion half receive a force in close contact with each other during insertion. The guide surface is formed.

  In said structure, if the duct which combines the 1st duct half part and the 2nd duct half part is inserted in a cylindrical attachment part to an axial direction, the protrusion part which protrudes in the axial direction from the duct front end edge First tries to enter the notch. At this time, since the guide surface is provided at either the tip of the protruding portion of the protruding portion or the opening edge of the cutout portion receiving the protruding portion, the first protruding half and the second protruding half are mutually connected. Even if they are lifted, they are tightened in the direction in which they are in close contact with each other. Accordingly, the two projection halves are inserted into the cutout portion smoothly as one projection portion in close contact with each other, and the side edge outside the projection portion is in close contact with the cutout side edge of the cutout portion. Along with this, the leading edge of each half of the duct, which has a semicircular shape, is continuous as a single circle with no gap, and the duct end fits smoothly into the cylindrical mounting portion.

  The guide surface can be provided on the protrusion side as a straight or curved shape so that the protruding portion of the protrusion is tapered, and at least one of the first protrusion half and the second protrusion half It is enough to provide it. In a preferred embodiment, the guide surface is provided on both the first projection half and the second projection half at the tip of the protruding portion. Thus, the two projection halves are pushed from both sides.

  Further, the guide surface may be on the side of the notch, and in this case, the protrusion can be a simple rectangular shape. The guide surface on the notch portion side can be provided as a straight or curved shape so that the opening width of the notch portion gradually increases along the axial direction, and one side of the pair of notch side edges. Alternatively, it can be provided on both sides.

  According to this invention, even when the first duct half and the second duct half are lifted from each other at the end of the duct end inserted into the cylindrical mounting portion of the counterpart member, the protrusion and the notch The end of the duct can be smoothly inserted into the cylindrical mounting portion by the interaction with the portion, and workability is improved.

The perspective view which shows the principal part of an intake duct provided with the fitting structure which concerns on this invention, and an air cleaner case. The exploded perspective view of an air intake duct. The side view which shows the shape of a projection part and a notch part. The side view which shows the other example of the shape of a projection part and a notch part. The side view which shows the further another example of the shape of a projection part and a notch part. The side view which shows the Example which provided the guide surface in the notch part side.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a fitting structure for attaching an intake duct 1 of an internal combustion engine for an automobile to an air cleaner case 2 as an embodiment of the present invention. The intake duct 1 has a halved structure that is divided into a first duct half 3 and a second duct half 4 along a dividing plane that passes through the central axis in the longitudinal direction. , 4 are molded so as to have a semicircular cross-sectional shape by injection molding of hard synthetic resin. And the locking claw 5 is provided in the side edge of the 1st duct half part 3 in the several places of a longitudinal direction, and the side edge of the 2nd duct half part 4 corresponding to this locking claw 5 A slit-like engagement hole 6 (see FIG. 2) is formed in the first duct half part 3 and the second duct half part 4 by integration of both.

  Specifically, as shown in FIG. 2, a flange portion 8 is formed along the side edge of the first duct half 3, and the locking claw 5 extends from the flange portion 8 along the tangential direction of the outer peripheral surface. It protrudes. The locking claw 5 includes a hook portion 5a at the tip. Further, a flange portion 9 is formed along the side edge of the second duct half portion 4, and a part of the flange portion 9 is wide, and an engagement hole 6 is formed through this portion. In the portions other than the locking claws 5 and the engaging holes 6, a cover portion 10 extends from the outer edge of the flange portion 8 of the first duct half portion 3 so as to form an L-shaped cross section, and the second portion The outer surface of the flange portion 9 of the duct half 4 is covered. In other words, the cover portion 10 is relatively loosely fitted to the outer surface of the flange portion 9.

  One end portion 11 of the cylindrical intake duct 1 formed by combining the two duct halves 3 and 4 as described above is simply fitted to the inner peripheral surface of the cylindrical mounting portion 12 of the air cleaner case 2. It has a cylindrical shape. That is, in the region of the end portion 11, the flange portions 8 and 9, the locking claws 5 and the engagement holes 6 are not provided. Note that, in the dividing line PL between the first duct half 3 and the second duct half 4, the region of the end 11 in order to constrain the position of the side edges of both the duct halves 3, 4 in the radial direction. Are provided with stepped portions 13 and 14 that mesh with each other. That is, the side edge of the first duct half 3 has a step 13 extending along the outer peripheral surface of the intake duct 1, and the side edge of the second duct half 4 is the inner periphery of the intake duct 1. A step portion 14 extending along the surface is provided, and these step portions 13 and 14 are engaged with each other. In the illustrated example, the step portions 13 and 14 are provided only in the region of the end portion 11. However, the step portions 13 and 14 are not limited thereto, and are along the dividing line PL between the first duct half portion 3 and the second duct half portion 4. May be provided continuously.

  Further, the first duct half 3 and the second duct half 4 are defined so as to define the insertion limit when the end 11 of the intake duct 1 is inserted into the cylindrical mounting portion 12 on the air cleaner case 2 side. The stopper parts 15 and 16 which protruded circularly from the outer peripheral surface of the intake duct 1 are formed in each. Further, the front end edge 17 of the intake duct 1 is engaged with a not-shown recess or notch of the cylindrical attachment portion 12 when inserted into the cylindrical attachment portion 12 to prevent the intake duct 1 from being pulled out. The locking portion 19 is also formed in a shape protruding in an arc shape from the outer peripheral surface of the intake duct 1. In the illustrated example, the locking portion 19 is provided only at one location of the first duct half 3, but the locking portion 19 may be provided at a plurality of locations, for example, two locations separated by 180 °. Further, a portion that becomes a boundary between the general portion of the intake duct 1 and the end portion 11, that is, a position adjacent to the stopper portions 15 and 16, is in contact with the tip edge 42 of the cylindrical mounting portion 12 relatively closely. An annular portion 22 having a diameter slightly larger than the outer peripheral surface of the end portion 11 is provided.

  As described above, the end portion 11 of the intake duct 1 inserted into the cylindrical mounting portion 12 has a cylindrical shape with a perfectly circular cross section, but the other portion of the intake duct 1, that is, the middle in the longitudinal direction. The portion does not necessarily have a perfect circular shape in cross section, and may have an appropriate curved shape as shown in FIG.

  In the intake duct 1 having the basic configuration as described above, in the present invention, protrusions 31 protruding outward from the outer peripheral surface are further provided at two positions on the tip side of the end portion 11. These protrusions 31 are provided at the position of the dividing line PL between the first duct half 3 and the second duct half 4, and as shown in FIG. A substantially rectangular first protrusion half part 32 formed integrally with the half part 3 and a substantially rectangular second protrusion half part 33 formed integrally with the second duct half part 4 are formed. Yes. That is, in a state where both are combined, the protrusion 31 has a substantially rectangular shape as a whole, and this is divided into two along the dividing line PL.

  In a state where both are combined, the protrusion 31 includes a pair of side edges 34 and 35 parallel to the axial direction of the end 11 of the intake duct 1. Further, a tip edge 36 is provided along a plane orthogonal to the axial direction, and a part of the protrusion 31 including the tip edge 36 is formed from the tip edge 17 forming the circular shape of the end portion 11 of the intake duct 1. Projects in the axial direction. The tip edge 36 is actually constituted by both the first protrusion half 32 and the second protrusion half 33. In addition, guide surfaces 37 and 38 that are inclined with respect to the axial direction are provided so as to be continuous from the tip edge 36 to the side edges 34 and 35, respectively. In the illustrated example, the guide surfaces 37 and 38 are linearly inclined surfaces extending over the entire range protruding from the front end edge 17 of the intake duct 1 and are formed symmetrically with respect to the dividing line PL. ing. That is, the protruding portion of the protruding portion 31 extending in the axial direction from the leading edge 17 of the end portion 11 has a symmetrical tapered shape.

  On the other hand, the air cleaner case 2 is also made of a hard synthetic resin with respect to the intake duct 1 as described above, and a cylindrical mounting portion 12 is integrally formed on a part of the side surface thereof. In the illustrated example, the cylindrical mounting portion 12 is formed so as to protrude cylindrically from the outer surface of the air cleaner case 2, but a part or all of its length is located inside the air cleaner case 2. It is also possible to configure as described above. The cylindrical mounting portion 12 is integrally formed in a cylindrical shape continuous in the circumferential direction, and an inner diameter corresponding to the outer diameter of the end portion 11 so that the end portion 11 of the intake duct 1 can be fitted. have.

  At the tip of the cylindrical mounting portion 12 (the end on the side facing the end 11 of the air intake duct 1), there are cutout portions that have a shape corresponding to the protrusion 31 at two locations that are 180 ° apart. 41 are formed. The notch 41 has a shape cut rearward from the front edge 42 of the cylindrical wall constituting the cylindrical mounting portion 12, and has a pair of notch side edges 43, 44 parallel to the axial direction, and the protrusion An axial edge 45 corresponding to the tip edge 36 of the portion 31 and inclined edges 46 and 47 corresponding to the guide surfaces 37 and 38 are provided. The distance between the pair of cutout side edges 43 and 44 is the width between the side edges 34 and 35 of the projection 31 in a state where the first projection half 32 and the second projection half 33 are closely combined. Is substantially equal to Since the protrusion 31 protrudes in the axial direction from the front end edge 17 of the intake duct 1 as described above, the notch 41 has a shape obtained by further extending the outer shape of the protrusion 31 in the axial direction. There is no.

  In the configuration as described above, the end portion 11 of the intake duct 1 is assembled into the cylindrical mounting portion 12 by manual operation, for example. Here, when the leading edges 17 of the intake duct 1 composed of the first duct half 3 and the second duct half 4 are slightly separated from each other along the dividing line PL due to warpage, molding error, or the like. The first projection half 32 and the second projection half 33 constituting the projection 31 are fitted into the notch 41 of the cylindrical mounting portion 12 via the guide surfaces 37 and 38, whereby both the duct halfs are formed. The parts 3 and 4 are pressed against each other, and a close state is obtained. That is, since the protrusion 31 protrudes in the axial direction from the front end edge 17 of the intake duct 1, before the front end edge 17 of the intake duct 1 contacts the front end edge 42 of the cylindrical mounting portion 12, the notch portion is preceded. 41. And since the front end side of the protrusion part 31 is equipped with the inclined guide surfaces 37 and 38, each guide surface 37 and the pair of opening edge 48 (refer FIG. 3) which makes the substantially right angle of the notch part 41 are provided. 38 and the intake duct 1 is pushed in the axial direction, a force is generated in a direction in which the first projection half 32 and the second projection half 33 are brought into close contact with each other.

  Therefore, even if the front end edge 17 of the intake duct 1 is slightly opened along the dividing line PL, when the front end edge 17 of the intake duct 1 reaches the front end edge 42 of the cylindrical mounting portion 12, the first duct half 3 And the second duct half 4 are in close contact with each other, and can be smoothly inserted into the cylindrical mounting portion 12. And in the state finally fitted in the predetermined position, the protrusion 31 is located in the notch 41, and the side edges 34 and 35 of the protrusion 31 are in close contact with the notch side edges 43 and 44 of the notch 41. It becomes.

  In the above embodiment, both the first protrusion half 32 and the second protrusion half 33 have the guide surfaces 37 and 38 symmetrically, and the protrusion halves 32 and 33 are seen from both sides when the intake duct 1 is inserted. However, in the present invention, the first protrusion half 32 and the second protrusion half 33 do not necessarily have to be symmetrical. Furthermore, the structure which provided the guide surface 37 only in any one, for example, as shown in FIG. 4 only in the 1st protrusion half part 32 is also possible.

  FIG. 5 shows an embodiment in which the guide surfaces 37 and 38 are arcuate surfaces instead of the linear guide surfaces 37 and 38 described above. Even with such arcuate guide surfaces 37 and 38, the same action can be obtained. In this case as well, the guide surfaces 37 and 38 may be provided on only one of the first protrusion half 32 and the second protrusion half 33.

  Next, FIG. 6 shows an embodiment in which a guide surface is provided on the notch 41 side. In this embodiment, the first protrusion half 32 and the second protrusion half 33 constituting the protrusion 31 have a simple quadrilateral shape, and the guide surfaces 37 and 38 are not provided. The cutout portion 41 provided on the cylindrical attachment portion 12 side with respect to the projection portion 31 has a long and narrow rectangular shape as a basic shape, but the opening edge on both sides of the tip edge 42 of the cylindrical attachment portion 12. Are cut off obliquely, and are linear guide surfaces 51 and 52 that are inclined with respect to the insertion direction of the intake duct 1 (the axial direction of the end portion 11).

  Therefore, in this embodiment, when the first duct half 3 and the second duct half 4 are separated when the intake duct 1 is inserted, the first projection half 32 and the second projection half are separated. The corner portions 53 and 54 of the portion 33 come into contact with the guide surfaces 51 and 52 in advance, and a force is generated in the direction in which both the duct half portions 3 and 4 are brought into close contact with each other as in the above-described embodiment. Thereby, the end portion 11 of the intake duct 1 is smoothly fitted into the cylindrical mounting portion 12.

  As in the embodiment shown in FIG. 4, the guide surfaces 51 and 52 on the notch 41 side may be only one of them, and the guide surface 51 as in the embodiment shown in FIG. , 52 can be arcuate surfaces.

  In any of the embodiments, the first duct half 3 and the second duct half 4 to be injection-molded have a simple substantially rectangular shape at the side edge of each of the duct halves 3 and 4 having a semicircular cross section. Since the projection halves 32 and 33 protrude sideways along the dividing surface, the forming of the duct halves 3 and 4 is not complicated. That is, even the duct halves 3 and 4 having the projection halves 32 and 33 can be injection-molded with the upper and lower core molds and the cavity mold without using the slide core.

  As mentioned above, although one Example of this invention was described in detail, this invention is not limited to the said Example, A various change is possible. For example, in the above-described embodiment, the first duct half 3 and the second duct half 4 are coupled by the engagement of the locking claw 5 and the engagement hole 6. The present invention can be similarly applied to an intake duct in which both are welded or bonded. In the above embodiment, the fitting structure for connecting the intake duct 1 to the air cleaner case 2 has been described as an example. However, the present invention can also be applied to a place where a divided structure is connected to another duct.

DESCRIPTION OF SYMBOLS 1 ... Air intake duct 2 ... Air cleaner case 3 ... 1st duct half part 4 ... 2nd duct half part 5 ... Locking claw 11 ... End part 12 ... Cylindrical attachment part 31 ... Projection part 32 ... 1st projection half Part 33 ... Second protrusion half part 34, 35 ... Side edge 37, 38 ... Guide surface 41 ... Notch part 43, 44 ... Notch side edge 51, 52 ... Guide surface

Claims (2)

A first duct half and a second duct half made of synthetic resin each molded into a half structure are combined with each other to form a cylindrical duct, and the end of this duct is placed in the cylindrical mounting portion of the mating member. In the fitting structure of the duct to be fitted,
On the outer peripheral surface of the duct end, provided with protrusions respectively provided at two parting line portions of the first duct half and the second duct half,
The mounting portion has a pair of cutout portions each having a shape corresponding to the protruding portion,
The protrusion comprises a first protrusion half integrally formed with the first duct half, and a second protrusion half integrally formed with the second duct half, In a state of being combined with each other, it forms a substantially rectangular shape with a pair of side edges parallel to the axial direction of the duct, and a part thereof protrudes in the axial direction from the leading edge of the duct end,
The notch includes a pair of parallel notch side edges closely contacting the pair of side edges,
The tip of the protruding portion or the opening edge of the notch is inclined with respect to the axial direction so that the first protrusion half and the second protrusion half receive a force in close contact with each other during insertion. A duct fitting structure characterized in that a guide surface is formed.   2. The duct fitting structure according to claim 1, wherein the guide surfaces are provided on both the first protrusion half and the second protrusion half, respectively. 3.

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