JP2009292442A - Duct - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a generation of a swirl flow near a bent portion of a duct body and to prevent an increase of a pressure loss. <P>SOLUTION: A first deformable wall 34 and a second deformable wall 36 bending inward and outward of the duct body 10 are provided on wall surfaces of an upstream side and a downstream side connected to a bending inner side 18A of a first bent portion 18 in the duct body 1. The first deformable wall 34 and the second deformable wall 36 form curved surfaces extending to the bending inner side 18A of the first bent portion 18, when they are expansively deformed into an air circulation space 26. A third deformable wall 38 and a fourth deformable wall 40 bending inward and outward of the duct body 10 are provided on wall surfaces of the upstream side and the downstream side connected to a bending inner side 20A of a second bent portion 20 in the duct body 1. The third deformable wall 38 and the fourth deformable wall 40 form curved surfaces extending to the bending inner side 20A of the second bent portion 20, when they are expansively deformed into the air circulation space 26. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a duct provided in a duct main body having an air circulation space therein, and having a bent portion that bends the air circulation space at a required angle.

  Ducts of various shapes and sizes have been proposed in order to distribute and guide various fluids such as gas and liquid. FIG. 12 shows a duct D1 disposed on the back side of the vehicle interior member IP assembled in the passenger compartment of the automobile and connecting the air conditioner unit AC installed on the vehicle body and the air outlet AO attached to the vehicle interior member IP. Illustrated.

On the back side of the vehicle interior member IP described above, a lot of in-vehicle devices and devices (not shown) are arranged. In order to avoid interference with these devices and devices, the duct body 10 constituting the duct D1 is complicated. In many cases, the outer shape is bent or bent in the middle. Accordingly, the duct D1 shown in FIG. 12 includes two bent portions 18 and 20 that bend the air circulation space at a required angle in the middle of the duct body 10 having an air circulation space inside. The first bent portion 18 and the second bent portion 20 are bellows that can be bent and deformed, and the air circulation space can be bent by bending and deforming the bent portions 18 and 20. In addition, the 1st bending part 18 and the 2nd bending part 20 can also be expanded-contracted, and the length adjustment of the duct main body 10 is possible. Such a duct is disclosed in Patent Documents 1 and 2, for example.
Japanese Utility Model Publication No. 6-78746 JP 2000-108637 A

  Incidentally, the duct disclosed in each patent document and the duct D1 shown in FIG. 12 are deformed when the first bent portion 18 and the second bent portion 20 which are bellows are bent at right angles or substantially right angles. , 20, the bending radius R of the bent inner side 18A, 20A becomes extremely small, and the bending of the air circulation space 26 at both the bent portions 18, 20 becomes steep. For this reason, the air does not flow smoothly in the bent portions 18 and 20, and a swirl flow (vortex) 28 is generated on the downstream side connected to the bent inner sides 18A and 20A of the bent portions 18 and 20, resulting in pressure loss. There was a problem that would increase.

  An object of this invention is to provide the duct which suppressed generation | occurrence | production of the swirling flow in the vicinity part of the bending part in a duct main body, and prevented that a pressure loss became large.

In order to solve the problem and achieve the intended purpose, the invention according to claim 1
In a duct provided with a bent portion that is provided in a duct body having an air circulation space therein and bends the air circulation space at a required angle,
Provided on at least one of the upstream and downstream wall surfaces connected to the bent inner side of the bent portion in the duct main body is a deformable wall portion that can be deformed in the inner and outer directions of the duct main body,
The gist of the present invention is that the deforming wall portion is held in a state of bulging and deforming into the air circulation space to form a curved surface that is continuous on the bent side of the bent portion.

  Therefore, according to the first aspect of the invention, at least one of the upstream and downstream wall surfaces connected to the bent portion of the duct body is provided with the deformed wall portion bulged into the air circulation space, By configuring a curved surface that is continuous inside the bent portion, the separation of the air flow inside the bent portion at the bent portion is reduced. Therefore, it is possible to prevent the swirling flow from occurring in the vicinity of the bent portion in the duct body, and to prevent the pressure loss from increasing. The deformed wall portion is deformed into a shape bulged into the air circulation space by being pressed from the outside of the duct after the duct body is molded, and is held in the bulged and deformed state.

The invention described in claim 2
The bent portion is a bellows having a plurality of protruding portions,
The gist is that a plurality of the deformed wall portions are provided in the circumferential direction of the duct body.
Therefore, according to the invention according to claim 2, since the bent portion can be bent in various directions, a plurality of forms of ducts having different bent directions can be formed, and the bent portion can be bent in any direction. In addition, by causing the deformation wall portion located inside the bent portion of the bent portion to bulge and deform into the air circulation space, separation of the air flow inside the bent portion at the bent portion is reduced.

  According to the duct according to the present invention, since the deformation wall portion provided in the duct body is bulged and deformed into the air circulation space, separation of the air flow inside the bending portion at the bending portion is reduced, so that the bending in the duct body is performed. The generation of the swirling flow in the vicinity of the portion is suppressed, and the pressure loss can be prevented from increasing.

  Next, a preferred embodiment of the duct according to the present invention will be described and described below with reference to the accompanying drawings. In the embodiment, similarly to the conventional duct D1 shown in FIG. 12, the air conditioner unit AC installed in the passenger compartment of the automobile and the air outlet AO arranged in the vehicle interior member IP installed in the passenger compartment, respectively. A duct D that is connected and guides the temperature-controlled air sent from the air conditioner unit AC to the air outlet AO is illustrated. Note that the same parts and members as those already shown in FIG. 12 are designated by the same reference numerals.

  As shown in FIGS. 1 and 2, the duct D according to the embodiment includes two bent portions 18 and 20 (hereinafter referred to as “first bent portion 18”) and a predetermined interval in the middle of the duct body 10 in the air flow direction. (Referred to as “second bent portion 20”). Thereby, the duct main body 10 is connected to the first main body portion 12 connected to the air conditioner unit AC, the second main body portion 14 located between the first bent portion 18 and the second bent portion 20, and the air outlet AO. The third main body 16 is divided. The duct main body 10 bends the second main body portion 14 at a right angle with respect to the first main body portion 12 by bending deformation of the first bent portion 18 on the upstream side, and bends deformation of the second bent portion 20 on the downstream side. As a result, an L crank shape in which the third main body portion 16 is bent at right angles to the second main body portion 14 is exhibited (FIG. 1). An air inlet 22 is formed at the end of the first body 12 and an air outlet 24 is formed at the end of the third body 16, and an air circulation space 26 is defined in the duct body 10. ing.

  The first bent portion 18 and the second bent portion 20 include a plurality of projecting portions 32 projecting outward of the duct body 10 and extending in the circumferential direction of the duct body 10 in the air circulation direction (15 in the embodiment). ) It is configured as a continuous bellows. As shown in FIGS. 6 to 8, the protruding portion 32 includes a first wall portion 44 and a second wall portion 46 that are connected to each other at the top portion 48 of the maximum diameter portion. In each protrusion 32 adjacent in the air flow direction, a first wall 44 and a second wall 46 are connected by a valley 50 having a minimum diameter. As shown in FIG. 8, the first wall portion 44 and the second wall portion 46 are formed so that the thickness gradually decreases from the valley portion 50 toward the top portion 48.

  As shown in FIG. 8, the first wall 44 is formed in a flat shape from the top 48 to the valley 50. The linear distance S1 from the top 48 to the valley 50 in the first wall 44 is set longer than the linear distance S2 from the top 48 to the valley 50 in the second wall 46.

  As shown in FIG. 8, the second wall portion 46 is curved so that the curve deformation base point 51 provided on the top portion 48 side and the valley portion 50 protrude toward the first wall portion 44 side connected by the top portion 48. Then, the first state (FIG. 6) in which the adjacent valley portions 50 are held close to each other, and the first wall portion 44 side where the curved deformation base point 51 and the valley portion 50 are connected by the valley portion 50. A second state in which it is curved so as to protrude (curved so as to protrude to the side opposite to the side of the first wall 44 connected at the top 48), and the adjacent valleys 50 are held apart (FIG. 7). It is designed to be transformed. In the embodiment, the bending deformation base point 51 of the second wall portion 46 is described above as the top portion 48 at a position in the vicinity of the top portion 48 and spaced from the top portion 48 at the same interval as the thickness of the second wall portion 46. It extends over the entire circumference of the second wall 46 while maintaining the interval. Therefore, the second wall portion 46 is deformed into the first state and the second state by bending the portion between the bending deformation base point 51 and the valley portion 50. Then, as shown in FIG. 7, the second wall portion 46 deformed to the second state has a curved surface shape that forms a part of a spherical surface having a radius M passing through the curved deformation base point 51 and the valley portion 50 at the same center.

  The bending deformation base point 51 is located on the inner side (in the radial direction center side of the duct body 10) from the top 48 in a state where the adjacent valley portions 50 are separated from each other (shown by a solid line in FIG. 8). As described above, the distance between the top portion 48 and the bending deformation base point 51 in the second wall portion 46 is approximately the same as the thickness of the second wall portion 46 in the vicinity of the bending deformation base point 51. Thus, the second wall portion 46 can be deformed into the first state and the second state without being affected by the first wall portion 44 connected at the top portion 48, and as shown by a two-dot chain line in FIG. The second wall 46 deformed to the first state is prevented from coming into strong contact with the first wall 44 connected at the top 48. Therefore, when the first bent portion 18 or the second bent portion 20 is bent, both the portion of the second wall portion 46 that is in the first state and the portion that is in the second state are held in that state, The first bent portion 18 or the second bent portion 20 is stably held in a bent state.

  The deformation of the second wall portion 46 from the first state to the second state and the deformation from the second state to the first state are performed by the first wall portion of the adjacent projecting portion 32 provided continuously through the valley portion 50. 44. That is, as shown in FIG. 6, when each projecting portion 32 is pushed from both sides in the air flow direction, the top portion 48 and the valley portion 50 overlap each other in the inside and outside directions of the duct body 10, and each valley portion 50 approaches. . At this time, the curved shape of the second wall portion 46 was continuously provided at the top portion 48 of the second wall portion 46 from the first wall portion 44 side continuously provided at the valley portion 50 of the second wall portion 46. It reverses (deforms) toward the first wall 44 side. Thus, if each 2nd wall part 46 is hold | maintained in a 1st state, each trough part 50 will be hold | maintained in the state which adjoined.

  On the other hand, as shown in FIG. 7, when the contracted projecting portions 32 are pulled to both sides in the air flow direction, the valley portions 50 are separated in the air flow direction. At this time, the curved shape of the second wall portion 46 was continuously provided at the valley portion 50 of the second wall portion 46 from the first wall portion 44 side continuously provided at the top portion 48 of the second wall portion 46. It reverses (deforms) toward the first wall 44 side. Thus, if each 2nd wall part 46 is hold | maintained in a 2nd state, each trough part 50 will be hold | maintained in the separated state.

  Accordingly, each projecting portion 32 has a valley portion in which the second wall portion 46 and the first wall portion 44 are adjacent to each other in a region where the second wall portion 46 is deformed to the first state in the circumferential direction of the duct body 10. 50 are held close to each other, and the portion of each projecting portion 32 is in a contracted state. Moreover, in the site | part where the 2nd wall part 46 deform | transformed into the 2nd state in the circumferential direction of the duct main body 10, the 2nd wall part 46 and the 1st wall part 44 are spaced apart, and the adjacent trough parts 50 are spaced apart The part of each protrusion 32 is in an expanded state. In addition, in the state where the top portion 48 is thin and the adjacent valley portions 50 are held apart from each other, the bending deformation base point 51 is set on the inner side of the top portion 48, so that each projecting portion 32. Is easily deformed into a contracted state and an expanded state, and it is difficult to develop a restoring force to the opposite state regardless of which state it is deformed, and is appropriately held in the deformed state.

  Accordingly, the first bent portion 18 and the second bent portion 20 have a portion facing the contracted position in the radial direction of the duct body 10 in the air flow direction with the same position in the circumferential direction of each protruding portion 32 as the center. When expanded (stretched), the first bent portion 18 and the second bent portion 20 are held in a state of being bent and deformed by 90 degrees in the air flow direction. Since the duct D of the embodiment in which the first bent portion 18 and the second bent portion 20 are provided in the duct main body 10 is held in a state where the bent portions 18 and 20 are bent at 90 degrees, the duct main body is maintained. 10 can be held in a folded state.

  Further, the first bent portion 18 and the second bent portion 20 can be expanded in the air flow direction at any position in the circumferential direction of each protruding portion 32. Therefore, the bent portions 18, 20 are shown in FIG. It can bend in any direction, not just the state. Therefore, the first main body portion 12 and the second main body portion 14, and the second main body portion 14 and the third main body portion 16 can be bent at 90 degrees in any direction with respect to each other. Further, since the first bent portion 18 and the second bent portion 20 can be deformed so as to expand in the air circulation direction over the entire circumference, the duct body 10 can be expanded and contracted linearly. It is. That is, the duct D of the embodiment can be expanded and contracted and bent in various shapes as well as the shape shown in FIG. 1, and can be used as a duct having a plurality of shapes and sizes.

  In the duct D of the embodiment, as shown in FIG. 1, the upstream and downstream wall surfaces connected to the bent inner sides 18A and 20A of the bent portions 18 and 20 in the duct body 10 bulge out to the air circulation space 26. Deformed wall portions 34, 36, 38, and 40 that are held in a deformed state are provided. That is, the first deformation wall portion 34 is provided on the wall surface portion of the first main body portion 12 that is connected to the bent inner side 18 </ b> A of the first bent portion 18, and is connected to the bent inner side 18 </ b> A of the first bent portion 18 of the second main body portion 14. A second deformation wall portion 36 is provided on the wall surface portion. Similarly, a third deformed wall portion 38 is provided on the wall surface portion connected to the bent inner side 20A of the second bent portion 20 in the second main body portion 14, and the bent inner side 20A of the second bent portion 20 in the third main body portion 16 is provided. The 4th deformation wall part 40 is provided in the wall surface part connected. These first to fourth deformed wall portions 34, 36, 38, and 40 are deformed into a state of bulging into the air circulation space 26 after the duct body 10 is molded, as will be described later.

  As shown in FIG. 1, each of the first to fourth deformed wall portions 34, 36, 38, and 40 has a maximum bulge portion in which a substantially middle portion in the air flow direction is bulged to the air flow space 26 to the maximum. 34A, 36A, 38A, 40A. And each deformation | transformation wall part 34,36,38,40 gradually increases the amount of swelling as it approaches the maximum bulging part 34A, 36A, 38A, 40A from the upstream side, and the maximum bulging part 34A, 36A, 38A. , 40A, the bulging amount gradually decreases as the distance from the downstream side increases, so-called streamline shape. Further, as is apparent from FIG. 1, the deformed wall portions 34, 36, 38, 40 are located between the adjacent first or second bent portions 18, 20 from the maximum bulging portions 34A, 36A, 38A, 40A. However, it has an arc shape or an approximate arc shape along the air flow direction.

  Accordingly, in the duct D of the embodiment, the upstream and downstream wall surfaces connected to the first bent portion 18 in the duct body 10 are bulged and deformed into the air circulation space 26, and the first deformed wall portion 34 and the second deformed wall. The portion 36 is formed into a gentle curved surface that is continuous with the bent inner side 18 </ b> A of the first bent portion 18 in the bending direction (air flow direction) of the first bent portion 18. In addition, the upstream and downstream wall surfaces connected to the second bent portion 20 in the duct body 10 are also swelled by the third deformation wall portion 38 and the fourth deformation wall portion 40 bulging and deformed into the air circulation space 26. In the bending direction of the bent portion 20 (air flow direction), it is formed in a gently curved surface that is continuous with the bent inner side 20A of the second bent portion 20. That is, the bent inner side 18 </ b> A of the first bent portion 18 is located in the middle of the gently curved surface formed by the first deformed wall portion 34 and the second deformed wall portion 36, and the bent inner side of the second bent portion 20. 20A is also located in the middle of the gently curved surface formed by the third deformation wall portion 38 and the fourth deformation wall portion 40.

  In the duct D of the above-described embodiment, the protruding portions 32 of the first bent portion 18 and the second bent portion 20 are expanded from a synthetic resin such as polyethylene (PE) or polypropylene (PP) by a molding die (not shown). Blow molding is performed in the state, and the shape shown in FIG. 3 is obtained by shrinking the bent portions 18 and 20 after blow molding. When the duct body 10 is blow-molded, as shown in FIGS. 2A and 3, the first to fourth deformed wall portions 34, 36, 38, and 40 are removed from the duct body 10. It is formed into a shape bulging out. Then, after the molding, as shown in FIGS. 2B and 3, the deformed wall portions 34, 36, 38, 40 bulging outward from the duct body 10 are moved from the outside of the duct by fingertips or tools. By pressing, each of the deformation wall portions 34, 36, 38, 40 is plastically deformed into the above-described shape bulging into the air circulation space 26.

  Further, as shown in FIGS. 2 (a) and 2 (b), bent lines 42 are extended around the deformed wall portions 34, 36, 38, 40 in the duct body 10. The bent line 42 is formed thinner than the deformed wall portions 34, 36, 38, 40 and the peripheral portions of the deformed wall portions 34, 36, 38, 40. Accordingly, the deformed wall portions 34, 36, 38, and 40 that bulge outward from the duct body 10 are bent along the folding line 42 so as to bulge toward the air circulation space 26. The deformation easily develops (FIGS. 2 (b) and 4), and is retained in the bulged shape after being deformed into the state of bulging toward the air circulation space 26 side.

  And as shown in FIG. 5, the duct D which deform | transformed each 1st-4th deformation | transformation wall part 34,36,38,40 in the state bulged to the air circulation space 26 side is the 1st deformation wall part. The second main body portion 14 is bent at a right angle with respect to the first main body portion 12 by bending and deforming the first bent portion 18 with the side where the 34 and the second deformable wall portion 36 are provided as the inner side. Further, the third body 16 is perpendicular to the second body 14 by bending and deforming the second bent portion 20 with the side on which the third deformed wall 38 and the fourth deformed wall 40 are provided as the inside. Bend to.

  In the duct D of the embodiment configured as described above, the upstream side and the downstream side connected to the bent inner side 18A of the first bent portion 18 bulge into the air circulation space 26 of the duct body 10 and are formed into a gently curved surface. Therefore, the air that has flowed into the first main body portion 12 of the duct main body 10 is gradually changed from the first deformable wall portion 34 along the second deformable wall portion 36, and then from the first main body portion 12 to the second main body portion 12. It smoothly circulates toward the main body 14. Therefore, the generation of a swirling flow in the vicinity of the bent inner side 18A of the first bent portion 18 in the duct body 10, that is, the portion where the second deformed wall portion 36 is provided is preferably suppressed. Similarly, the air that has flowed into the second main body portion 14 gradually changes from the third deformable wall portion 38 along the fourth deformable wall portion 40 to the third main body portion 16 from the second main body portion 14. Circulate smoothly toward Therefore, the generation of a swirling flow in the vicinity of the bending inner side 20A of the second bending portion 20 in the duct body 10, that is, the portion where the fourth deformation wall portion 40 is provided is preferably suppressed. Therefore, in the duct D of the embodiment, the generation of the swirling flow in the vicinity of both the bent portions 18 and 20 is suppressed, so that an increase in pressure loss can be prevented.

  And each 1st-4th deformation | transformation wall part 34,36,38,40 can be easily deform | transformed into the shape swelled to the air circulation space 26 only by pressing from the outside after shaping | molding of the duct main body 10. FIG. . Further, since the bent lines 42 are extended around the respective deformation wall portions 34, 36, 38, 40 in the duct main body 10, after the duct main body 10 is formed, the respective deformation wall portions 34, 36, 38, 40 are made to air. The deformed wall portions 34, 36, 38, and 40 that are easily bulged and deformed into the circulation space 26 and bulged and deformed into the air circulation space 26 are held in the bulged shape.

(Example of change)
FIG. 9 shows the duct D according to the modified example 1 connected to the air conditioner unit AC and the air outlet AO. The duct D according to the modified example 1 has a second deformed wall portion 36 bulging and deformed into the air circulation space 26 on the downstream wall surface portion connected to the bent inner sides 18A and 20A of the bent portions 18 and 20 in the duct body 10. And the 4th deformation wall part 40 is provided. The second deformation wall portion 36 and the fourth deformation wall portion 40 are configured in the same position and the same shape as the second deformation wall portion 36 and the fourth deformation wall portion 40 of the duct D of the embodiment shown in FIG. Yes. Therefore, the bent inner side 18A of the first bent portion 18 is located at the upstream end of the gently curved surface constituted by the second deformed wall portion 36, and the bent inner side 20A of the second bent portion 20 is also the fourth deformed shape. It is located at the upstream end of a gently curved surface formed by the wall 40. Thus, the air that has passed through the first bent portion 18 swells into the air circulation space 26 of the duct body 10 and smoothly circulates along the second deformation wall portion 36 that is formed in a gently curved surface. The air that has passed through the two bent portions 20 swells into the air circulation space 26 of the duct body 10 and smoothly flows along the fourth deformed wall portion 40 that is formed in a gently curved surface. Generation | occurrence | production of the swirl | vortex flow in the vicinity part of the parts 18 and 20 is suppressed, and it can prevent that a pressure loss becomes large.

  FIG. 10 shows the duct D according to the modified example 2 in a state where it is connected to the air conditioner unit AC and the air outlet AO. The duct D according to the modified example 2 includes a first deformed wall portion 34 bulged and deformed into the air circulation space 26 on the upstream wall surface portion connected to the bent inner sides 18A and 20A of the bent portions 18 and 20 in the duct body 10. And the 3rd deformation wall part 38 is provided. The first deformable wall portion 34 and the third deformable wall portion 38 are configured in the same position and in the same shape as the first deformable wall portion 34 and the third deformable wall portion 38 of the duct D of the embodiment shown in FIG. Yes. Accordingly, the bent inner side 18A of the first bent portion 18 is located at the downstream end of the gently curved surface constituted by the first deformed wall portion 34, and the bent inner side 20A of the second bent portion 20 is also third deformed. It is located at the downstream end of a gently curved surface formed by the wall portion 38. As a result, the air that has swelled into the air circulation space 26 of the duct body 10 and circulated along the first deformed wall portion 34 formed in a gently curved surface passes through the first bent portion 18 while turning. The air flowing along the third deforming wall portion 38 that is circulated to the air flow space 26 of the duct main body 10 and formed into a gently curved surface while flowing to the second main body portion 14 is secondly changed in direction. Since it passes through the deformed wall portion 36 and flows to the third main body portion 16, generation of swirling flow in the vicinity of both the bent portions 18 and 20 is suppressed, and pressure loss is prevented from increasing. obtain.

  FIG. 11A shows a plurality (here, two each) of the third deformation wall portion 38 and the fourth deformation wall portion 40 in the circumferential direction of the duct body 10 on the upstream side and the downstream side of the second bending portion 20. It is the fragmentary perspective view which showed the form provided in the position which opposes. The duct D of the embodiment can bend the first bent portion 18 and the second bent portion 20 that form a bellows in various directions in the circumferential direction of the duct main body 10, so that the second main body portion 14 can be bent with respect to the first main body portion 12. The bending direction and the bending direction of the third body part 16 with respect to the second body part 14 can be changed to a state other than the state shown in FIG. Therefore, as shown in FIG. 11B, when the third main body portion 16 is bent and deformed in the first direction, which is the upper side of the drawing, the third main body portion 16 is positioned on the inner side 20A of the bent second bent portion 20 ( The third deformation wall portion 38 and the fourth deformation wall portion 40 (located in the upper part of the figure) may be bulged and deformed into the air circulation space 26, respectively. Further, as shown in FIG. 11C, when the third main body 16 is bent and deformed in the second direction, which is the lower side of the figure, the third main body 16 is positioned on the inner side 20A of the bent second bent portion 20 ( The third deformation wall portion 38 and the fourth deformation wall portion 40 (located below the figure) may be bulged and deformed into the air circulation space 26, respectively. That is, even if the third main body portion 16 is bent and deformed in the first direction, it is possible to form a curved surface on the duct main body 10 that is gently continuous with the bent inner side 20A of the second bent portion 20, and the third main body portion. Even if 16 is bent and deformed in the second direction, it is possible to form a curved surface in the duct body 10 that is gently continuous with the bent inner side 20A of the second bent portion 20. Although not shown, the same effects can be obtained by providing a plurality of first deformable wall portions 34 and second deformable wall portions 36 in the circumferential direction of the duct body 10 in the first bent portion 18 as well.

The duct D targeted by the present application is not limited to the embodiment described above, and various modifications can be made.
(1) Each bending part 18 and 20 is not limited to the thing of the bellows shown in the Example and each modification. That is, it may be a so-called solid-type bent portion formed in a shape bent in advance at a required angle.
(2) When a plurality of deformation wall portions 34, 36, 38, 40 are provided in the circumferential direction of the duct body 10, the number is not limited to two as shown in FIG. Also good. For example, if a plurality of deformation wall portions 34, 36, 38, 40 are provided side by side over the entire circumference of the duct body 10, the first bent portion 18 and the second bent portion 20 are provided in the duct body. The deformed wall portions 34, 36, 38, 40 are positioned at the positions connected to the bent inner sides 18 A, 20 A of the bent portions 18, 20 that are bent and deformed even if they are bent and deformed in any of the ten circumferential directions. Thus, the wall surface portion connected to the bent inner sides 18A and 20A in the duct body 10 can be formed into a curved surface.
(3) The bent portions 18 and 20 are not limited to those that bend and deform at 90 degrees, and may be bent at 90 degrees or more or 90 degrees or less.
(4) The duct body 10 is not limited to a cylindrical shape, and may be a rectangular tube shape.
(5) The duct targeted by the present application is not limited to that disposed in an automobile, but is also disposed in other vehicles, buildings, and the like.
(6) In the embodiment, the first deformable wall portion 34 and the second deformable wall portion 36 provided on the upstream side and the downstream side with the first bent portion 18 interposed therebetween are symmetrical with respect to the first bent portion 18. At the same time, the third deformed wall portion 38 and the fourth deformed wall portion 40 provided on the upstream side and the downstream side with the second bent portion 20 interposed therebetween have a symmetrical shape with the second bent portion 20 interposed therebetween. The deformation wall portion 34 and the second deformation wall portion 36 and the third deformation wall portion 38 and the fourth deformation wall portion 40 do not have to be symmetrical. Further, the first deformation wall portion 34, the second deformation wall portion 36, the third deformation wall portion 38, and the fourth deformation wall portion 40 are configured to bulge and deform into the air circulation space 26 with different shapes and sizes. May be.

It is explanatory drawing which shows the duct of the Example bent at each bending part in the state connected with the air-conditioner unit and the air outlet, respectively. (a) Partial perspective view showing a deformed wall portion provided at a position adjacent to each bent portion of the duct body in a state where the duct body is molded, (b) is a view showing the deformed wall portion after the duct body is molded. It is a fragmentary perspective view which shows the state which pressed from the duct outer side and deform | transformed this deformation | transformation wall part into the shape swelled to the air circulation space. It is explanatory drawing shown in the state which shape | molded the duct main body, Comprising: It has shown that each deformation | transformation wall part is shape | molded in the state which bulged out of the duct main body from the duct main body. After the duct main body is formed, each deformation wall portion is pressed from the outside of the duct to form the deformation wall portion in a state of bulging into the duct main body (air circulation space). It is explanatory drawing which shows the state which bends and deforms each bending part and makes a duct main body bend. It is a fragmentary sectional view which shows that the 2nd wall part of each protrusion-shaped part which comprises a bending part deform | transforms into a 1st state, and the adjacent trough parts hold | maintain in the state which adjoined. It is a fragmentary sectional view which shows that the 2nd wall part of each protrusion-shaped part which comprises a bending part deform | transforms into a 2nd state, and the adjacent trough parts hold | maintained in the separated state. It is sectional drawing which expands and shows the form of the 1st wall part and 2nd wall part of a protruding part. It is explanatory drawing which shows the duct of the modification 1 which bent the duct main body in each bending part in the state connected with the air-conditioner unit and the air outlet, respectively. It is explanatory drawing which shows the duct of the modification 2 which bent the duct main body in each bending part in the state connected with the air-conditioner unit and the air outlet, respectively. (a) is explanatory drawing which shows the example of a change which provided the two deformation | transformation wall part in the site | part which opposes in the circumferential direction of a duct main body, (b) shows the state which bent the bending part to the 1st direction. (C) has shown the state which bent the bending part to the 2nd direction. It is explanatory drawing which showed the conventional duct bent by each bending part in the state connected with the air-conditioner unit and the air outlet, respectively, Comprising: Since a duct main body bends suddenly in a bending part, in the downstream of this bending part, It shows that a swirling flow (vortex) is generated and the pressure loss increases.

Explanation of symbols

10 duct body, 18 first bent portion, 18A bent inner side, 20 second bent portion 20A bent inner side, 26 air circulation space, 34 first deformed wall portion (deformed wall portion)
36 2nd deformation wall part (deformation wall part), 38 3rd deformation wall part (deformation wall part)
40 Fourth deformation wall (deformation wall)

Claims (2)

In a duct provided with a bent portion that is provided in a duct body having an air circulation space therein and bends the air circulation space at a required angle,
Provided on at least one of the upstream and downstream wall surfaces connected to the bent inner side of the bent portion in the duct main body is a deformable wall portion that can be deformed in the inner and outer directions of the duct main body,
The duct is characterized in that the deformed wall portion is held in a state of bulging and deforming into an air circulation space, and is formed so as to form a curved surface continuous on the bent inner side of the bent portion. The bent portion is a bellows having a plurality of protruding portions,
The duct according to claim 1, wherein a plurality of the deformation wall portions are provided in a circumferential direction of the duct body.

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