Abstract:
A passage restricting member is attached to a corrugated tube. This corrugated tube includes a corrugated tube, a passage maintenance member, and an attachment member. The passage maintenance member is die-molded so as to maintain a shape in which at least a portion is curved in the longitudinal direction, and the transverse cross-section is arc shaped. The passage maintenance member has an opening penetrating to the internal peripheral side and the external peripheral side. The attachment member has an internal peripheral engaging part engaging with an internal peripheral portion of a slit in the corrugated tube, an external peripheral engaging part engaging with an external peripheral portion of the opening in the passage maintenance member, and a connecting part for connecting the internal peripheral engaging part and the external peripheral engaging part while disposed in the slit and the opening.

Description:
[0001]    This application is the national phase of PCT International Application No. PCT/JP2012/053596 that has an International filing date of Feb. 16, 2012 and designated the United States of America and claims priority to Japanese Patent App. No. JP 2011-191465 that was filed on Sep. 2, 2011. The disclosure of the prior applications is hereby incorporated by reference herein in their entirety. 
     
    
     BACKGROUND TECHNOLOGY 
       [0002]    As disclosed in patent references Japanese Published Utility Model Application 4-86022, Japanese Published Patent Application 2000-184551, Japanese Published Patent Application 2002-64917, Japanese Published Patent Application 2006-296166, technologies are known in which a wire harness arranged in a vehicle or the like is covered with a corrugated tube with good flexibility. 
       SUMMARY 
     Problems to be Resolved by the Invention 
       [0003]    However, because a corrugated tube itself has excellent flexibility, a passage of a wire harness cannot be constantly maintained. Because of this, the passage of the wire harness needs to be constantly maintained by fixing a clamp member that is mounted to the wire harness or the corrugated tube at a constant position of a vehicle. As the number of locations in which clamp members are fixed increases, there is a possibility that parts cost, mounting cost and the like may increase. 
         [0004]    Here, through a bucket-shaped resin molded product (or protector) that is three-dimensionally formed conforming to a location in which the wire harness is arranged, the wire harness can be protected, and the passage can be constantly maintained. 
         [0005]    However, in order to three-dimensionally form a resin molded product that can protect a wire harness, conforming to the location in which the wire harness is arranged, the molded shape becomes complex. Thus, the manufacturing cost increases. 
         [0006]    Thus, a structure is proposed in which a passage maintaining member that is die-molded so as to maintain a shape in which at least a portion is bent along a longitudinal direction is mounted to a corrugated tube, and the corrugated tube and a wire harness inside the corrugated tube are maintained in a specified bent shape. For a structure in which a passage maintaining member is mounted to a corrugated tube, a structure is suggested in which a pair of concave groove portions is formed in a passage maintaining member, and end peripheral portions at both sides of a slit of the corrugated tube fit into the pair of concave groove portions. 
         [0007]    However, the passage maintaining member is constituted so as to have a portion to be exposed to an outer circumferential side of the corrugated tube. Thus, the presence of the portion to be exposed becomes a hindrance to visual recognition, so it is difficult to visually recognize a position relationship between the end peripheral portions at both sides of the slit of the corrugated tube and the pair of concave groove portions. Because of this, operability of fitting the end peripheral portions of both sides of the slit of the corrugated tube into the pair of concave groove portions is poor. 
         [0008]    In particular, if a subject wire harness has a large diameter, it is necessary to increase rigidity of a passage restricting member so as to maintain the passage. Because of this, it is necessary to enlarge a cross section of the passage maintaining member, and the above-mentioned concave groove portions need to be made deep. Thus, the fitting operation becomes worse. 
         [0009]    Thus, an object is to make it easy to mount a passage restricting member to a corrugated tube by mounting a passage maintaining member to the corrugated tube when wires are covered and the passage is constantly maintained. 
       Means of Solving the Problem 
       [0010]    In order to solve the above-mentioned problem, in a first mode, there are provided: a corrugated tube in which annular convex portions and annular concave portions are alternately formed along a longitudinal direction and a slit is formed along the longitudinal direction; a passage maintaining member that is die-molded so as to maintain a shape at least part of which is curved along the longitudinal direction, the passage maintaining member having a horizontal cross section formed in an arc shape, an opening that goes through inner and outer circumferential sides of the passage maintaining member being formed along at least part of the longitudinal direction, the passage maintaining member being arranged along an outer circumference of the corrugated tube in a state in which the opening is arranged at the outer circumferential side of the slit; and a mounting member having (i) an inner circumferential-side engaging portion that can be engaged to an inner circumferential-side portion of the slit of the corrugated tube, (ii) an outer circumferential-side engaging portion that can be engaged to an outer circumferential-side portion of the opening of the passage maintaining member, and (iii) a connector that connects the inner and outer circumferential-side engaging portions that are arranged at the slit and the opening. 
         [0011]    A second mode is the corrugated tube with a passage maintaining member related to the first mode, in which the mounting member is a member that can be deformed according to the shape of the passage maintaining member in the longitudinal direction. 
         [0012]    A third mode is the corrugated tube with a passage maintaining member related to the first or second mode, in which the horizontal cross-sectional shape of the mounting member is formed in the same shape along the longitudinal direction of the mounting member. 
         [0013]    A fourth mode is the corrugated tube with a passage maintaining member related to the first or second mode, in which at least one of the inner and outer circumferential-side engaging portions is intermittently formed along the longitudinal direction of the mounting member. 
         [0014]    A fifth mode is the corrugated tube with a passage maintaining member related to any of the first through fourth modes, in which the passage maintaining member is divided into two divided parts at the opening. 
         [0015]    A sixth mode is the corrugated tube with a passage maintaining member related to any of the first through fourth modes, in which the opening is formed in the passage maintaining member so as to maintain both side portions of the passage maintaining member in a connected state. 
         [0016]    A wire harness related to a seventh mode is provided with the corrugated tube with a passage maintaining member as set forth in any of the first through sixth modes; and a wire harness main body portion that is provided with at least one wire and is inserted through the corrugated tube that has the passage maintaining member. 
       Effects 
       [0017]    According to the corrugated tube with a passage maintaining member related to the first mode, wires can be covered and protected by the corrugated tube, and the passage can be constantly maintained by the passage maintaining member. Additionally, in a state in which the passage maintaining member is arranged along the outer circumference of the corrugated tube, the inner circumferential-side engaging portion is engaged to the inner circumferential-side portion of the slit of the corrugated tube. At the same time, the outer circumferential-side engaging portion is engaged to the outer circumferential-side portion of the opening of the passage maintaining member. Thus, the passage maintaining member can be positioned and easily mounted with respect to the corrugated tube. 
         [0018]    According to the second mode, the mounting member can be used according to various shapes of the passage maintaining member in the longitudinal direction. Because of this, versatility of the mounting member is excellent. 
         [0019]    According to the third mode, the mounting member can be easily molded. 
         [0020]    According to the fourth mode, the material that forms the mounting member can be reduced. 
         [0021]    According to the fifth mode, the passage maintaining member is divided into two divided parts at the opening. Thus, the shape of each of the divided parts is simplified, and each divided part can be easily formed. 
         [0022]    According to the sixth mode, the passage maintaining member can be handled as one member. Because of this, parts management becomes easy. 
         [0023]    According to the wire harness related to the seventh mode, wires are covered with a corrugated tube, and the passage can be constantly maintained by the passage maintaining member. Additionally, in a state in which the passage maintaining member is arranged along the outer circumference of the corrugated tube, the inner circumferential-side engaging portion is engaged to the inner circumferential-side portion of the slit of the corrugated tube. At the same time, the outer circumferential-side engaging portion is engaged to the outer circumferential-side portion of the opening of the passage maintaining member. Thus, the passage maintaining member can be positioned and easily mounted with respect to the corrugated tube. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is a schematic perspective view showing a mounting portion of a corrugated tube of a wire harness. 
           [0025]      FIG. 2  is a plan view showing a passage maintaining member. 
           [0026]      FIG. 3  is a perspective view showing the corrugated tube and a mounting member. 
           [0027]      FIG. 4  is an explanatory view showing a step of mounting the passage maintaining member to the corrugated tube. 
           [0028]      FIG. 5  is an explanatory view showing a step of mounting the passage maintaining member to the corrugated tube. 
           [0029]      FIG. 6  is a plan view showing the passage maintaining member related to a first modified example. 
           [0030]      FIG. 7  is an explanatory view showing a step of mounting the passage maintaining member to the corrugated tube. 
           [0031]      FIG. 8  is a side view showing a mounting member related to a second modified example. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0032]    The following explains a corrugated tube with a passage maintaining member related to embodiments, and a corrugated tube with the passage maintaining member.  FIG. 1  is a schematic perspective view showing a mounting portion of a corrugated tube  20  of a wire harness  10 .  FIG. 2  is a plan view showing a passage maintaining member  30 .  FIG. 3  is a perspective view showing a corrugated tube  20  and a mounting member  40 .  FIGS. 4 and 5  are explanatory views showing a step of mounting the passage maintaining member  30  and the mounting member  40  to the corrugated tube  20 . 
         [0033]    The wire harness  10  is provided with a wire harness main body portion  12 , the corrugated tube  20 , the passage maintaining member  30 , and the mounting member  40 . 
         [0034]    The wire harness main body portion  12  is constituted such that a plurality of wires is bundled. More specifically, the wire harness main body portion  12  is constituted such that a plurality of wires are branched off and bundled according to the wiring configuration for a subject vehicle. The wire harness main body portion  12  does not necessarily need to be branched off, and may be constituted by a single wire. Furthermore, another optical cable or the like may be bundled to the wire harness main body portion  12 . 
         [0035]    When the wire harness main body portion  12  is arranged on a vehicle or the like, the wire harness main body portion  12  is bent according to the arrangement. In order to keep the wire harness main body portion  12  from interfering with a surrounding portion, the wire harness main body  12  may be maintained in a bent shape according to the arrangement. In such a case, a corrugated tube C with this passage maintaining member is mounted to the wire harness main body portion  12 . In other words, the wire harness main body portion  12  is inserted through the corrugated tube C with the passage maintaining member. By so doing, the wire harness main body portion  12  is maintained in a specific bent shape. Additionally, the portion over which the corrugated tube C with the passage maintaining member is mounted to the wire harness main body portion  12  may be at least part of the wire harness main body portion  12 . This may be part of the wire harness main body portion  12  or may be substantially the entire wire harness main body portion  12 . 
         [0036]    The corrugated tube  20  is a cylindrical member in which annular convex portions  21  and annular concave portions  22  are alternatively formed along a longitudinal direction (see  FIG. 3 ) and is formed of resin or the like. The corrugated tube  20  is easily elastically deformed by step portions or the like between the annular convex portions  21  and the annular concave portions  22 . Thus, the entire corrugated tube  20  has an easily deformable property. Normally, for the corrugated tube  20 , a tube is used that has an inner diameter larger than (usually slightly larger than) an outer diameter of the portion of the wire harness main body portion  12  to be mounted. 
         [0037]    Furthermore, on one side portion of the corrugated tube  20 , a slit  24  is formed along the longitudinal direction. Additionally, by splitting and opening the corrugated tube  20  with the slit  24 , the wire harness main body portion  12  can be easily arranged within the corrugated tube  20 . 
         [0038]    The passage maintaining member  30  is a long member that is die-molded so as to maintain a shape at least part of which is curved along a longitudinal direction and is formed of resin such as P.P. (polypropylene). In other words, the passage maintaining member  30  is formed in a shape at least part of which is curved at the time of die-molding. The curved shape of the passage maintaining member  30  is set in a shape corresponding to an arranging passage in which a portion of the wire harness main body portion  12  to be mounted is arranged. In the example shown in  FIG. 1 , an intermediate portion of the passage maintaining member  30  in the longitudinal direction is curved so as to form a moderate S shape, and both end portions of the passage maintaining member  30  are formed in a linear shape. Either the entire portion or part of the passage maintaining member  30  may be formed in a curved shape. Furthermore, the portion formed in a curved shape may be formed in a shape that is curved in a plane, or may be formed in a dimensionally (three-dimensionally) curved shape. 
         [0039]    Additionally, a horizontal cross section of the passage maintaining member  30  is formed in an arc shape. Here, in the width direction intermediate portion, the passage maintaining member  30  is divided into two divided parts  34  by an opening  32  formed over the entire longitudinal direction. Here, the horizontal cross-sectional shape of the passage maintaining member  30  forms a ½ arc shape as a whole, and a ¼ arc shape for each divided portion  34 . An inner circumferential shape of the horizontal cross section of the passage maintaining member  30  is formed in a shape corresponding to an outer circumferential shape of the corrugated tube  20 . In other words, the inner diameter of the passage maintaining member  30  is set to be the same as the outer diameter of the corrugated tube  20 . By so doing, in a state in which the passage maintaining member  30  is adhered to the outer circumference of the corrugated tube  20 , the passage maintaining member  30  can be arranged along the longitudinal direction of the corrugated tube  20 . 
         [0040]    The opening  32  is formed so as to go through the inner and outer circumferential sides of the passage maintaining member  30 . Furthermore, by arranging a gap between the pair of divided parts  34  and arranging the pair of divided parts  34  along the outer circumference of the corrugated tube  20  on both sides of the slit  24 , in state in which the opening  32  is arranged at the outer circumferential sides of the slit  24 , the passage maintaining member  30  is arranged along the outer circumference of the corrugated tube  20 . 
         [0041]    Additionally, the dimension of the passage maintaining member  30  in the circumferential direction is not limited to the above-mentioned example, but other arc shapes such as a ¼ arc shape may be formed. The pair of divided parts  34  does not need to equally divide the passage maintaining member  30  into two portions, and the pair of divided parts  34  may be provided with different circumferential direction dimensions, respectively. Furthermore, the thickness of the passage maintaining member  30  may be uniform or irregular in either the longitudinal or circumferential direction. 
         [0042]    The mounting member  40  is provided with an inner circumferential-side engaging portion  42 , an outer circumferential-side engaging portion  44 , and a connector  46 . 
         [0043]    The inner circumferential-side engaging portion  42  is constituted so as to be engageable to the inner circumferential-side portion of the slit  24  of the corrugated tube  20 . Additionally, the outer circumferential-side engaging portion  44  is constituted so as to be engageable to the outer circumferential-side portion of the opening  32  of the passage maintaining member  30 . The connector  46  is constituted so as to be arranged at the slit  24  and the opening  32 , and in that arrangement, to allow the inner circumferential-side engaging portion  42  and the outer circumferential-side engaging portion  44  to be connected to each other. Additionally, at both side portions of the mounting member  40 , a U-shaped groove  40   g  is formed, which is surrounded by the inner circumferential-side engaging portion  42 , the connector  46 , and the outer circumferential-side engaging portion  44 . Side peripheral portions of the slit  24  of the corrugated tube  20  and side peripheral portions of the opening  32  of the passage maintaining member  30  fit into the grooves  40   g.    
         [0044]    More specifically, the connector  46  is formed in a thin long plate that can be arranged at the slit  24  and the opening  32 . It is preferable that the thickness dimension of the connector  46  is set at a dimension that can be arranged in the slit  24  and the opening  32 , and that the thickness is as thin as possible within a range that can maintain a state in which the inner circumferential-side engaging portion  42  and the outer circumferential-side engaging portion  42  are connected to each other. It is preferable that the width dimension of the connector  46  (a dimension in an inside-to-outside direction in a state in which the corrugated tube  20  and the passage maintaining member  30  are mounted) is substantially the same as a sum of the thickness dimension of the corrugated tube  20  and the thickness dimension of the passage maintaining member  30 . 
         [0045]    The inner circumferential-side engaging portion  42  is formed in a thin, long plate shape having a width dimension larger than the thickness dimension of the connector  46 . This outer circumferential-side engaging portion  44  is arranged so as to protrude from one end portion (inside end portion) of the connector  46  to both sides. 
         [0046]    The outer circumferential-side engaging portion  44  is formed in a thin, long plate shape having a width dimension larger than the thickness dimension of the connector  46 . This outer circumferential-side engaging portion  44  is arranged so as to protrude from one end portion (outside end portion) of the connector  46  to both sides. Additionally, inclined surfaces  44   a  that are inwardly inclined in an outward direction are formed on both sides of the outward surface of the outer circumferential-side engaging portion  44 . Thus, while the outer circumferential-side engaging portion  44  is arranged along the outer circumference of the passage maintaining member  30  at the outside of the opening  32 , the protrusion shape with respect to the outer circumferential surface of the passage maintaining member  30  becomes as moderate as possible. 
         [0047]    In this embodiment, the inner circumferential-side engaging portion  42 , the outer circumferential-side engaging portion  44 , and the connector  46  are continuously formed along the longitudinal direction. That is, the horizontal cross-sectional shape of the mounting member  40  is formed in the same shape along the longitudinal direction. Because of this, the mounting member  40  can be easily formed by extrusion molding or the like. 
         [0048]    Additionally, the mounting member  40  is constituted so as to be deformable according to the shape of the passage maintaining member  30  in the longitudinal direction. The mounting member  40  can be formed by an elastomer such as rubber. 
         [0049]    A procedure is explained in which the passage maintaining member  30  and the mounting member  40  are mounted to the wire harness main body portion  12 . 
         [0050]    First, by opening the corrugated tube  20  at the slit  24 , the wire harness main body portion  12  is housed within the corrugated tube  20  (See  FIG. 4 ). 
         [0051]    Thereafter, while the corrugated tube  20  is opened at the slit  24 , and the inner circumferential-side engaging portion  42  is arranged within the corrugated tube  20 , the connector  46  is inserted at both side portions of the slit  24  of the corrugated tube  20  (see  FIG. 5 ). In this state, passages of the wire harness main body portion  12 , the corrugated tube  20 , and the mounting member  40  are not restricted, and all three can be bendingly deformed. 
         [0052]    Thereafter, the pair of divided parts  34  is arranged, with a distance therebetween, at both sides of the connector  46  protruding from the slit  24 . Then, while the wire harness main body portion  12 , the corrugated tube  20 , and the mounting member  40  are made to be deformed according to the curved shape of the pair of divided parts  34 , the inside end peripheral portions of the pair of divided parts  34  fit into gaps between outside portions of the slit  24  of the corrugated tube  20  and the outer circumferential-side engaging portion  44 . Thus, the pair of divided parts  34  is mounted in a state that suppresses shifting with respect to the corrugated tube  20  in the circumferential direction, and suppresses removal to the outer circumferential side. By so doing, the corrugated tube  20  can be integrated to the passage maintaining member  30  so as to be curved along the shape of the passage maintaining member  30 . Furthermore, the pair of divided parts  34  may be sequentially mounted. 
         [0053]    Thereafter, as needed, by winding a tie band, an adhesive tape  50 , or the like about the outer circumference of the corrugated tube  20 , a closed state of the corrugated tube  20  can be maintained. At the same time, integration of the corrugated tube  20  and the passage maintaining member  30  is maintained (see  FIG. 1 ). So-called “rough winding” or “tight winding” may be used for the structure of winding an adhesive tape. Additionally, an adhesive tape may be entirely or partially wound about the passage maintaining member  30  in the longitudinal direction. It is preferable that the adhesive tape  50  is also wound about the wire harness main body portion  12  that extends outward from the end portions of the corrugated tube  20 . By so doing, the corrugated tube  20  and the passage maintaining member  30  are positioned with respect to the wire harness main body portion  12 , and a state is constantly maintained in which bending is performed by the passage maintaining member  30  with respect to a branched end portion  12   a  of the wire harness main body portion  12  (see  FIG. 1 ). 
         [0054]    According to the corrugated tube C with a passage maintaining member that is thus constituted and the wire harness  10 , wires can be covered and protected by the corrugated tube  20 , and the passage can be constantly maintained by the passage maintaining member  30 . 
         [0055]    Additionally, in a state in which the passage maintaining member  30  is arranged along the outer circumference of the corrugated tube  20 , the inner circumferential-side engaging portion  42  is engaged to the inner circumferential-side portion of the slit  24  of the corrugated tube  20 , and the outer circumferential-side engaging portion  44  is formed at the outer circumferential-side portion of the opening  32  of the passage maintaining member  30 . Thus, the passage maintaining member  30  can be easily mounted so as to be positioned with respect to the corrugated tube  20 . 
         [0056]    In particular, in this embodiment, in a state in which the mounting member  40  is mounted to the corrugated tube  20 , a gap between the outside portion of the slit  24  of the corrugated tube  20  and the outer circumferential-side engaging portion  44  can be visually seen from outside. Because of this, while this gap is being visually recognized, the inside end peripheral portion of the divided parts  34  can easily fit in the gap. 
         [0057]    Additionally, when the passage of the wire harness main body portion  12 —whose diameter is relatively large—is restricted, a circumferential direction length of the passage maintaining member  30  may be made long, or the thickness may be made thick. Thus, there is no need for making the groove  40   g  of the mounting member  40  deep. Because of this, even when the passage of the wire harness main body portion  12  whose diameter is relatively large is restricted, an operation of mounting the passage maintaining member  30  can easily be performed. 
         [0058]    Additionally, the passage maintaining member  30  itself is a member having a horizontal cross-sectional arc shape. Thus, even if it is a relatively complex shape, such as a three-dimensional shape, it can be relatively easily die-molded. 
         [0059]    Additionally, in this embodiment, the passage maintaining member  30  is divided into two divided parts  34  at the opening  32 , so the shape of each of the divided parts  34  is simplified. Because of this, even if this is a relatively complex shape, such as a three-dimensional shape, it can be more easily die-molded. 
         [0060]    Furthermore, the slit  24  of the corrugated tube  20  is sealed by the mounting member  40 , so wires can be suppressed from falling from a middle portion of the corrugated tube  20  in the longitudinal direction. 
         [0061]    Furthermore, the mounting member  40  is constituted so as to be deformable according to the shape of the passage maintaining member  30  in the longitudinal direction. Thus, passage maintaining members  30  having various curved shapes can be used for mounting to the corrugated tube  20 . Because of this, versatility of the mounting member  40  is excellent. 
         [0062]    Of course, in the same manner as the passage maintaining member  30 , the mounting member  40  is a long member that is die-molded so as to maintain a shape at least part of which is curved along a longitudinal direction according to the arrangement passage in which the portion of the wire harness main body portion  12  to be mounted is arranged. In this case, the mounting member  40  may be formed of resin such as P.P. (polypropylene), which has rigidity to a certain degree. 
         [0063]    Furthermore, the horizontal cross-sectional shape of the mounting member  40  is formed in the same shape along the longitudinal direction. Thus, the mounting member  40  can be easily formed by extrusion molding or the like. 
         [0064]    Based on the above-mentioned embodiments, various modified examples will be explained. 
         [0065]    First, as described in the first modified example shown in  FIG. 6 , in a passage maintaining member  30 B corresponding to the passage maintaining member  30 , an opening  32 B may be formed so as to maintain both side portions in a connected state. Here, in a width-direction intermediate portion of the passage maintaining member  30 , the opening  32 B is formed along the longitudinal direction. At both end portions of the opening  32 B, both side portions of the passage maintaining member  30  are connected. That is, the opening  32 B is formed in an opening shape surrounded on all sides. It is preferable that the width dimension of the opening  32 B is approximately the same as the thickness dimension of the connector  46 . 
         [0066]    In this case, the passage maintaining member  30 B is mounted as follows. 
         [0067]    That is, as shown in  FIG. 7 , by opening the corrugated tube  20  at the slit  24 , the wire harness main body portion  12  is housed in the corrugated tube  20 . Furthermore, while the inner circumferential-side engaging portion  42  is arranged within the corrugated tube  20  by opening the corrugated tube  20  at the slit  24 , the connector  46  is inserted at both side portions of the slit  24  of the corrugated tube  20 . 
         [0068]    Then, while the wire harness main body portion  12  and the corrugated tube  20  are being bent according to the curved shape of the passage maintaining member  30 B, the passage maintaining member  30 B is arranged at the outside portion of the slit  24  of the corrugated tube  20 . At that time, when the connector  46  and the outer circumferential-side engaging portion  44  that protrude from the slit  24  are pushed into the opening  32 B, the opening  32 B is pushed against the inclined surfaces  44   a  and spread. Additionally, when the outer circumferential-side engaging portion  44  goes past the inside of the opening  32 B, the opening  32 B returns to its original width. By so doing, the outer circumferential-side engaging portion  44  is engaged to the passage maintaining member  30 B from the outer circumferential side of the opening  32 B, and the passage maintaining member  30 B is mounted so as to suppress shifting with respect to the corrugated tube  20  in the circumferential direction, and suppress removal to the outer circumferential side. 
         [0069]    Thereafter, as needed, by winding a tie band, an adhesive tape, or the like about the outer circumference of the corrugated tube  20 , integration of the corrugated tube  20  and the passage maintaining member  30  can be more reliably maintained. 
         [0070]    According to the first modified example, the passage maintaining member  30 B is not divided into two parts. Thus, the passage maintaining member  30 B can be handled as one member. Because of this, managing parts is simplified. 
         [0071]    Furthermore, in the same manner as in the second modified example shown in  FIG. 8 , in a mounting member  40 C corresponding to the mounting member  40 , an inner circumferential-side engaging portion  42 C may be formed to be a continuous long shape, and connectors  46 C and outer circumferential-side engaging portions  44 C may be intermittently formed along the longitudinal direction of the inner circumferential-side engaging portion  42 C, that is, may be partially formed with a distance therebetween. Additionally, horizontal cross-sectional shapes themselves of the connectors  46 C and the outer circumferential-side engaging portion  44 C may be in the same shape as the connector  46  and the outer circumferential-side engaging portion  44 . 
         [0072]    According to the second modified example, the material that forms the mounting member  40 C can be reduced. 
         [0073]    Furthermore, it is acceptable if only the outer circumferential-side engaging portion is intermittently formed along the longitudinal direction. Additionally, the outer circumferential-side engaging portion may be formed in a continuous long shape, and the inner circumferential-side engaging portion may be intermittently formed along the longitudinal direction of the outer circumferential-side engaging portion. Furthermore, the connector may be formed in a continuous long shape, and both of the inner and outer circumferential-side engaging portions may be intermittently formed along the longitudinal direction of the connector. That is, if at least one of the inner and outer circumferential-side engaging portions is intermittently formed along the longitudinal direction of the mounting member, the material can be reduced, and the passage maintaining member can be mounted. 
         [0074]    In this case, for the passage maintaining member, a member may be used that is constituted in the same manner as the passage maintaining members  30  and  30 B. Of course, the locations in which the openings  32  and  32 B of the passage maintaining members  30  and  30 B are formed may be intermittently formed according to the locations in which the connectors  46 C and the outer circumferential-side engaging portion  44 C are formed. That is, at at-least part of the passage maintaining member in the longitudinal direction, an opening may be formed that goes through the inner and outer circumferential sides. 
         [0075]    Additionally, each structure explained in the above embodiments and each modified example may be appropriately combined as long as they are not inconsistent with each other. 
         [0076]    This invention was explained in detail above, but the above explanation is an example in all aspects, and this invention is not limited to this. Countless modified examples that are not shown are not out of the scope of this invention and are construed to be within the scope of this invention.