Abstract:
A seal structure includes: a longitudinal member; and an elastic member having an insertion part into which the longitudinal member is inserted and which is brought into close contact with the outer circumference of the longitudinal member. The insertion part includes: a tubular part having openings on both ends; an insertion hole which is connected to both of the openings and through which the longitudinal member is inserted; and a seal part for sealing the longitudinal member in the inner wall of the insertion hole. The seal part has: first projections that can closely contact, in the circumferential direction, the longitudinal member inserted into the insertion hole; and second projections that can contact, on the outer circumference of the longitudinal member, the longitudinal member inserted into the insertion hole.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a technique for a seal structure to seal a long member at an inner wall of an insertion hole. 
       BACKGROUND ART 
       [0002]    Grommets through which control cables are inserted have been known (see, e.g., Patent Literature (hereinafter, referred to “PTL”) 1). Such a grommet is provided with a seal portion that seals against moisture such as rain water at an inner wall of an insertion hole. However, when protruding portions to be provided at the seal portion for the purpose of making insertion of a control cable easier are placed at intervals, there may be a case where the shape of the seal portion cannot conform to a curve shape of the control cable when the control cable curves and a gap is generated between the control cable and the protruding portions, causing a decrease in seal efficiency. 
       CITATION LIST 
     Patent Literature 
       [0000]    
       
         PTL 1 
         Japanese Patent Application Laid-Open No. 2009-68518 
       
     
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    It is therefore an object of the present invention to provide a technique for a seal structure which allows easy insertion of a long member and does not cause a decrease in seal efficiency even when the long member curves. 
       SOLUTION TO PROBLEM 
       [0006]    A problem to be solved by the present invention is as described above, and a means for solving the problem will be described, next. 
         [0007]    More specifically, according to the present invention, a seal structure is provided, including: a long member; and an elastic member including an insertion portion through which the long member is inserted and which comes into close contact with an outer periphery of the long member, in which: the insertion portion includes: a cylindrical portion including openings at both ends of the cylindrical portion, an insertion hole which communicates with the openings and through which the long member is inserted, and a seal portion configured to seal the long member at an inner wall of the insertion hole, in which: the seal portion includes: a first protruding portion formed to be capable of circumferentially coming into close contact with the long member inserted through the insertion hole, and a second protruding portion formed to be capable of coming into contact with the outer periphery of the long member for the long member inserted through the insertion hole. 
         [0008]    According to the present invention, in the above seal structure: a plurality of the first protruding portions are disposed with an interval that allows the long member to be inserted through the insertion hole, and the second protruding portion is disposed between the first protruding portions. 
         [0009]    According to the present invention, in the above seal structure: the second protruding portion is formed so that the second protruding portion is annular in a circumferential direction of the insertion hole and that an inner diameter of a top portion of the second protruding portion is substantially identical to an outer diameter of the long member, and the first protruding portion is formed so that first protruding portion is annular in the circumferential direction of the insertion hole and that an inner diameter of a top portion of the first protruding portion is smaller than the outer diameter of the long member and smaller than the inner diameter of the second protruding portion. 
         [0010]    According to the present invention, in any one of the above seal structures, an inner diameter of a top portion of the second protruding portion is between 100 percent and 92 percent of an outer diameter of the long member. 
       ADVANTAGEOUS EFFECTS OF INVENTION 
       [0011]    As an effect of the present invention, the following effect will be brought about. 
         [0012]    According to the present invention, a seal structure which allows easy insertion of a long member and does not cause a decrease in seal efficiency even when the long member curves is achieved. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]      FIG. 1  is a top view illustrating a grommet according to a first embodiment of the present invention; 
           [0014]      FIG. 2  is a partially enlarged cross-sectional view of an insertion portion along A-A cross section of  FIG. 1 ; 
           [0015]      FIG. 3  is a partially enlarged cross-sectional view of the insertion portion of the grommet in the cross section of  FIG. 2 ; 
           [0016]      FIG. 4  is an explanatory diagram illustrating unevenness provided in a seal portion of  FIG. 3 ; 
           [0017]      FIGS. 5A and 5B  are partially enlarged explanatory diagrams respectively illustrating the insertion portions before and after insertion of a control cable; 
           [0018]      FIGS. 6A and 6B  are explanatory diagrams respectively illustrating regions Ra and Rb in  FIG. 5B  in an enlarged manner; 
           [0019]      FIGS. 7A and 7B  are diagrams illustrating respectively the insertion portions before and after the control cable curves in a state where the control cable is inserted through the grommet of  FIG. 1 ; 
           [0020]      FIGS. 8A and 8B  are diagrams respectively illustrating regions Rc and Rd in  FIG. 7B  in an enlarged manner; 
           [0021]      FIGS. 9A through 9D  are each a diagram illustrating a shape of a protruding portion of a grommet according to another embodiment; and 
           [0022]      FIGS. 10A and 10B  are diagrams each illustrating unevenness provided in a seal portion of a grommet according to another embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0023]    A technical idea of the present invention is applicable to any elastic member through which a long member is inserted. In this application, a description will be given while the long member and the elastic member are referred to as “control cable  1 ” and “grommet  2 ,” respectively. 
         [0024]      FIG. 1  illustrates grommet  2  according to a first embodiment.  FIG. 2  illustrates A-A cross-section in  FIG. 1 . Note that, alternate long and two short dashes lines in the drawings represent control cable  1 . 
         [0025]    Control cable  1  will be briefly described, first. 
         [0026]    As described above, the long member in this application refers to control cable  1 , in particular, outer casing  1   o . Control cable  1  is composed of inner cable  1   i  and outer casing  1   o  covering this inner cable  1   i.  However, the long member is not limited to any particular configuration and may be inner cable  1   i , a power transmission line, a communication line, and/or the like, for example. As for the long member, it is possible to employ a member having a predetermined length and disposed to pass through inner and outer sides such as the inside and outside of a vehicle, and it is preferable that an outer peripheral surface of this member be a smooth and flat surface. 
         [0027]    Grommet  2  will be described, next. 
         [0028]    Grommet  2  according to this embodiment is configured to hold control cable  1  in a state of being attached to a chassis panel or the like of an automobile. Grommet  2  is composed of body portion  21  and insertion portion  22  provided at this body portion  21 . Note that, grommet  2  is formed of an elastic material (such as ethylene-propylene-diene (EPDM) rubber). However, the material of grommet  2  is not limited to any particular material, and may be, for example, nitrile rubber (NBR) or chloroprene rubber (CR) or the like. In addition, a material obtained by incorporating an elastic material into some part of a non-elastic material may be adopted. In this case, one that is obtained by attaching insertion portion  22  formed of rubber to body portion  21  formed of metal, for example, by baking may be adopted. As an elastic member, any member may be used as long as the member has an elastic function so that the member can come into close contact with outer casing  1   o  which is the long member, and control cable  1  is inserted by covering an outer periphery of the long member, and thus, a seal structure can be formed. 
         [0029]    Body portion  21  refers to a flat and broad portion of grommet  2 . Body portion  21  is formed in a polygonal shape and covers a cable hole provided in the chassis panel. In addition, body portion  21  is provided with two bolt holes  21   h  and fixed to the chassis panel by bolts passed through these two bolt holes  21   h.    
         [0030]    Insertion portion  22  is a portion where the long member is inserted through, and in this embodiment, insertion portion  22  includes a portion where cylindrical portion  23  is formed in grommet  2 . Cylindrical portion  23  includes insertion hole  23   h  formed at a center of cylindrical portion  23  and has a predetermined thickness that allows holding of the long member and thus holds control cable  1  arranged up to the cable hole. In addition, insertion hole  23   h  includes seal portion  24  provided at an inner wall of insertion hole  23   h  and seals control cable  1  by seal portion  24 . More specifically, insertion hole  23   h  includes seal portion  24  at the inner wall of insertion hole  23   h  and seals an outer periphery of outer casing  1   o  by unevenness of seal portion  24 . 
         [0031]    Hereinafter, insertion portion  22  will be described in detail. 
         [0032]      FIG. 3  illustrates insertion portion  22  of grommet  2 .  FIG. 4  illustrates unevenness provided at seal portion  24 . 
         [0033]    As described above, insertion portion  22  includes a portion where cylindrical portion  23  is formed in grommet  2 . Cylindrical portion  23  includes openings  23   o  at both ends thereof (see  FIG. 2 ). Openings  23   o  are each formed to have a size that allows control cable  1  to be inserted, and in this embodiment, each opening  23   o  is formed in a circular shape although it is not limited to any particular shape. In addition, insertion hole  23   h  is formed so as to communicate with both openings  23   o . More specifically, cylindrical portion  23  has a shape in which insertion hole  23   h  is formed to penetrate from one of openings  23   o  to the other one of openings  23   o.  Insertion hole  23   h  is provided with seal portion  24  at the inner wall thereof and seals an outer periphery of outer casing  1   o  by the unevenness of seal portion  24 . Seal portion  24  is provided in such a way that the unevenness are axially apart from each other, and seals the outer periphery of outer casing  1   o  so that moisture is prevented from moving along the outer periphery of outer casing  1   o  to an inner side, thereby making it possible to exert waterproofing performance. Note that, how insertion hole  23   h  is provided is not limited to any particular way as long as insertion hole  23   h  is provided to allow control cable  1  to be routed through the inside and outside of a vehicle, and in this embodiment, insertion hole  23   h  is formed in a cylindrical shape. 
         [0034]    In this grommet  2 , recess portions  24   c  of the unevenness are formed annularly about center axis L of insertion hole  23   h . All recess portions  24   c  have an identical depth. Meanwhile, protruding portions  24   p  of the unevenness are formed annularly about center axis L of insertion hole  23   h . However, not all protruding portions  24   p  have an identical height. More specifically, protruding portions  24   p  in grommet  2  include two kinds of protruding portions  24   p , which are one with a higher height and the other with a lower height. In this application, protruding portion  24   p  with a higher height is defined as “first protruding portion  25 ” and protruding portion  24   p  with a lower height is defined as “second protruding portion  26 .” 
         [0035]    First protruding portions  25  are each configured to come into close contact with control cable  1  and to seal control cable  1 . More specifically, first protruding portion  25  comes into close contact with outer casing  1   o  of control cable  1 , thereby sealing against moisture such as rain water moving along outer casing  1   o . First protruding portion  25  may have resistance to insertion that does not deteriorate the insertion property of outer casing  1   o  which is the long member, and may be configured to have a shape capable of coming into close contact with an outer shape of outer casing  1   o . Note that, the term “come into close contact with” means a state where first protruding portion  25  having elastically deformed presses hard against an outer periphery of outer casing  1   o , so that the pressure of the contact portion increases. In terms of functionality, this term means a state where it is possible to surely seal against moisture such as rain water. Note that, since first protruding portions  25  have a role of sealing against moisture such as rain water, first protruding portions  25  are always circumferentially annular and do not include a spiral. 
         [0036]    In first protruding portion  25 , a cross-sectional shape of base portion  25   b  is substantially rectangular. Furthermore, top portion  25   a  has a substantially wedge shape in which top portion  25   a  is tapered as a cross-sectional shape of top portion  25   a  nears center line L. More specifically, the cross-sectional shape of first protruding portion  25  extends perpendicularly toward center line L from a bottom of recess portion  24   c  and is tapered starting from a predetermined height. This shape is adopted for the purpose of adequately keeping rigidity of a root portion and of reducing a contact area with control cable  1 . This increases flexibility of first protruding portion  25  and simultaneously achieves an improvement in the sealing function. Meanwhile, the flexibility of first protruding portion  25  can be increased by forming recess portion  24   c  with a greater depth. Note that, inner diameter φx of top portion  25   a  of first protruding portion  25  is between 99% and 65% of outer diameter φc of control cable  1  (see  FIGS. 5A and 5B ). The numerical value of inner diameter φx is calculated by the following expression. 
         [0000]      Expression: φ x/φc× 100=99 to 65(%)
 
         [0037]    A ratio of inner diameter φx to outer diameter φc can be practically within a range of 65% to 99% both inclusive. However, in order to improve workability while securing the seal efficiency, the ratio is preferably within a range of 87% to 95% both inclusive. Note that, the term “top portion” means a portion around a top of first protruding portion  25 , which is closest to an axis side in a portion of first protruding portion  25  protruding in the axial direction of insertion hole  23   h . This portion is a portion which comes into contact with the outer periphery of outer casing  1   o  and where elastic deformation of first protruding portion  25  occurs at the time of insertion of control cable  1 . In this embodiment, as described above, this portion is configured to have a protruding shape, and in cases of first protruding portions  25  as well as second protruding portions  26  to be described hereinafter, the inner diameter is defined with reference to a leading end of the protruding portion. 
         [0038]    Second protruding portions  26  are each configured to come into contact with control cable  1  and to seal control cable  1 . More specifically, second protruding portion  26  comes into contact with outer casing  1   o  of control cable  1 , thereby sealing against moisture such as rain water moving along outer casing  1   o . Note that, the term “come into contact with” means a state where second protruding portion  26  having elastically deformed lightly presses against the outer periphery of outer casing  1   o , so that the pressure of the contact portion somewhat increases. In terms of functionality, this term means a state where it is possible to auxiliary seal against moisture such as rain water while insertion of control cable  1  is made easy. Note that, since second protruding portions  26  have a role of sealing against moisture such as rain water, second protruding portions  26  are preferentially circumferentially annular about center axis L of insertion hole  23   h . However, as long as first protruding portions  25  can secure the sealing function, second protruding portions  26  are not necessarily annular. 
         [0039]    In second protruding portion  26 , a cross-sectional shape of base portion  26   b  is substantially rectangular. Furthermore, top portion  26   a  has a substantially wedge shape in which top portion  26   a  is tapered as a cross-sectional shape of top portion  26   a  nears center line L. More specifically, the cross-sectional shape of second protruding portion  26  extends perpendicularly toward center axis L from a bottom of recess portion  24   c  and is tapered starting from a predetermined height. This shape is adopted for the purpose of adequately keeping rigidity of a root portion and of reducing the contact area with control cable  1 . This increases flexibility of second protruding portion  26  and simultaneously achieves an improvement in the sealing function. Meanwhile, the flexibility of second protruding portion  26  can be increased by forming recess portion  24   c  with a greater depth. Regarding the height of second protruding portion  26  from the bottom of recess portion  24   c  of second protruding portion  26 , second protruding portion  26  is configured to have a height that allows second protruding portion  26  to come into contact with the outer periphery of outer casing  1   o  which is a direct sealing target and configured not to generate resistance to insertion and not to elastically deform at the time of insertion of control cable  1  by setting inner diameter φy of second protruding portion  26  to be larger than inner diameter φx of first protruding portion  25 . Note that, inner diameter φy of top portion  26   a  of second protruding portion  26  is between 100 percent and 92 percent of outer diameter φc of control cable  1  (see  FIGS. 5A and 5B ). This numerical value of the inner diameter φy is calculated by the following expression. 
         [0000]      Expression: φ y/φc× 100=100 to 92(%)
 
         [0040]    In this embodiment, while outer diameter φc of outer casing  1   o  is 7.1 mm, inner diameter φx of first protruding portion  25  is set to 6.4 mm, and inner diameter φy of second protruding portion  26  is set to 6.8 mm. 
         [0041]    Next, first and second protruding portions  25  and  26  will be described in more detail. 
         [0042]      FIGS. 5A and 5B  respectively illustrate insertion portions  22  before and after insertion of control cable  1 .  FIGS. 6A and 6B  are diagrams respectively illustrating regions Ra and Rb in  FIG. 5B  in an enlarged manner.  FIGS. 7A and 7B  respectively illustrate insertion portions  22  before and after control cable  1  curves.  FIGS. 8A and 8B  are diagrams respectively illustrating regions Rc and Rd in  FIG. 7B  in an enlarged manner. Note that, the arrows illustrated in  FIGS. 6A, 6B, 8A and 8B  represent directions in which first protruding portion  25  or second protruding portion  26  deform. 
         [0043]    In grommet  2 , inner diameter cm of top portion  25   a  of first protruding portion  25  is smaller than outer diameter φc of control cable  1 . Meanwhile, inner diameter φy of top portion  26   a  of second protruding portion  26  is substantially identical to outer diameter φc of control cable  1 . Accordingly, first protruding portion  25  deforms due to insertion of control cable  1  and second protruding portion  26  hardly deforms. For this reason, first protruding portion  25  serves as resistance at the time of insertion of control cable  1  but second protruding portion  26  hardly serves as resistance. 
         [0044]    In this regard, first and second protruding portions  25  and  26  in grommet  2  are alternately provided, and first protruding portions  25  are each disposed with an appropriate interval from adjacent one of second protruding portions  26 . For this reason, even when first protruding portion  25  deforms due to insertion of control cable  1 , first protruding portion  25  does not interfere with adjacent second protruding portion  26 . More specifically, even when first protruding portion  25  deforms due to insertion of control cable  1  and thus expands and/or bend in the axial direction of insertion hole  23   h , first protruding portion  25  does not come to contact with adjacent second protruding portion  26 . Accordingly, first protruding portion  25  easily deforms at the time of insertion of control cable  1  and does not become a large resistance that hinders an insertion operation. In this application, an interval with which first and second protruding portions  25  and  26  do not interfere with each other even when first protruding portion  25  deforms at the time of insertion of control cable  1  is defined as “interval that allows the long member (control cable  1 ) to be inserted through insertion hole  23   h .” Note that, when first protruding portions  25  are provided in an overcrowded manner, the resistance to insertion of control cable  1  may increase. Therefore, intervals may be adjusted appropriately in accordance with inner diameter φx of first protruding portions  25 . 
         [0045]    Moreover, since the amount of deformation of first protruding portion  25  before and after insertion of control cable  1  is large, first protruding portion  25  comes into close contact with outer casing  1   o  of control cable  1 . In addition, since the amount of deformation of first protruding portion  25  before and after insertion of control cable  1  is large, first protruding portion  25  has large room for extension, and a gap is unlikely to be generated even when control cable  1  curves. In other words, first protruding portion  25  flexibly deforms in accordance with a curve shape of control cable  1  and always comes into close contact with outer casing  1   o  of control cable  1 . More specifically, it can be seen that first protruding portion  25  in region Rc extends in accordance with the curve of control cable  1  and is kept in a state of coming into close contact with control cable  1 . 
         [0046]    Meanwhile, since the amount of deformation of second protruding portion  26  before and after insertion of control cable  1  is small, second protruding portion  26  comes into contact with outer casing  1   o  of control cable  1 . In addition, since the amount of deformation of second protruding portion  26  before and after insertion of control cable  1  is small, second protruding portion  26  has large room for contraction, and a gap is unlikely to be generated even when control cable  1  curves. More specifically, second protruding portion  26  flexibly deforms in accordance with a curve shape of control cable  1  and always comes into contact with outer casing  1   o  of control cable  1 . More specifically, it can be seen that second protruding portion  26  in region Rd contracts in accordance with the curve of control cable  1  and is kept in a state of coming into contact with control cable  1 . 
         [0047]    As described above, the characteristics of grommet  2  are summarized as follows. 
         [0048]    As a first characteristic, grommet  2  has insertion portion  22 . Insertion portion  22  includes: cylindrical portion  23  provided with openings  23   o  at both ends thereof; insertion hole  23   h  which communicates with both openings  23   o  and through which control cable  1  is inserted; and seal portion  24  which seals control cable  1  at an inner wall of insertion hole  23   h . Moreover, seal portion  24  includes: first protruding portions  25  formed so as to be capable of circumferentially coming into close contact with control cable  1  inserted through insertion hole  23   h ; and second protruding portions  26  formed so as to be capable of coming into contact with the outer periphery of control cable  1  for control cable  1  inserted through insertion hole  23   h . 
         [0049]    As a second characteristic, first protruding portions  25  are disposed with intervals that allow control cable  1  to be inserted through insertion hole  23   h . Moreover, second protruding portions  26  are each disposed between first protruding portions  25 . 
         [0050]    As a third characteristic, second protruding portions  26  are formed so that second protruding portions  26  are each annular in a circumferential direction of insertion hole  23   h  and that inner diameter φy of top portion  26   a  is substantially identical to outer diameter φc of control cable  1 . Meanwhile, first protruding portions  25  are formed so that first protruding portions  25  are each annular in a circumferential direction of insertion hole  23   h  and that inner diameter φx of top portion  25   a  is smaller than outer diameter φc of control cable  1  and is also smaller than the inner diameter of second protruding portion  26 . 
         [0051]    As a fourth characteristic, inner diameter φy of second protruding portion  26  of top portion  26   a  is between 100 percent and 92 percent of the outer diameter of control cable  1 . 
         [0052]    According to the characteristics described above, grommet  2  allows easy insertion of control cable  1  and does not cause a decrease in seal efficiency even when control cable  1  curves. More specifically, use of the technical idea of the present invention makes it possible to achieve a seal structure which allows easy insertion of a long member and does not cause a decrease in seal efficiency even when the long member curves. 
         [0053]    Next, grommet  2  according to another embodiment will be described. 
         [0054]      FIGS. 9A through 9D  each illustrate a shape of protruding portion  24   p  of grommet  2  according to another embodiment. Hereinafter, for simplicity of the drawings, the shapes of first protruding portion  25  and second protruding portion  26  are expressed as single protruding portion  24   p . 
         [0055]    In first protruding portion  25  of grommet  2  according to the first embodiment, the cross-sectional shape of base portion  25   b  is substantially rectangular (see  FIG. 4 ). This shape is adopted for the purpose of adequately keeping the rigidity of the root portion and of increasing flexibility. However, in the present application, the cross-sectional shape of base portion  25   b  is not limited to be substantially rectangular. For example, as illustrated in  FIG. 9A , a substantially wedge shape in which base portion  25   b  is tapered as the cross-sectional shape thereof nears center line L may be adopted. 
         [0056]    Furthermore, as described above, in first protruding portion  25  of grommet  2  according to the first embodiment, top portion  25   a  has a substantially wedge shape in which top portion  25   a  is tapered as the cross-sectional shape thereof nears center line L (see  FIG. 4 ). However, in this application, the cross-sectional shape of top portion  25   a  is not limited to the substantially wedge shape. For example, as illustrated in  FIG. 9B , it is possible to adopt a substantially rectangular shape. In addition, a substantially circular-arc shape may be adopted as illustrated in  FIG. 9C . Furthermore, a substantially trapezoidal shape may be adopted as illustrated in  FIG. 9D . Note that, in a case where a substantially trapezoidal shape is adopted as illustrated in  FIG. 9D , the insertion operation of control cable  1  is made easy by inserting control cable  1  from a lower side to an upper side of an inclined surface. 
         [0057]    In second protruding portion  26  of grommet  2  according to the first embodiment, the cross-sectional shape of base portion  26   b  is substantially rectangular (see  FIG. 4 ). This shape is adopted for the purpose of adequately keeping the rigidity of the root portion and of increasing flexibility. However, in this application, the cross-sectional shape of base portion  26   b  is not limited to be substantially rectangular. For example, as illustrated in  FIG. 9A , a substantially wedge shape in which base portion  26   b  is tapered as the cross-sectional shape thereof nears center line L may be adopted. 
         [0058]    Moreover, as described above, in second protruding portion  26  of grommet  2  according to the first embodiment, top portion  26   a  has a substantially wedge shape in which top portion  26   a  is tapered as the cross-sectional shape of top portion  26   a  nears center line L (see  FIG. 4 ). However, in this application, the cross-sectional shape of top portion  26   a  is not limited to the substantially wedge shape. For example, as illustrated in  FIG. 9B , it is possible to adopt a substantially rectangular shape. In addition, a circular-arc shape may be adopted as illustrated in  FIG. 9C . Furthermore, a substantially trapezoidal shape may be adopted as illustrated in  FIG. 9D . Note that, in a case where a substantially trapezoidal shape is adopted as illustrated in  FIG. 9D , the insertion operation of control cable  1  is made easy by inserting control cable  1  from a lower side to an upper side of an inclined surface. 
         [0059]    Furthermore, grommet  2  according to another embodiment will be described. 
         [0060]      FIGS. 10A and 10B  each illustrate unevenness provided in seal portion  24  of grommet  2  according to another embodiment. 
         [0061]    First and second protruding portions  25  and  26  of grommet  2  according to the first embodiment are alternately provided (see  FIG. 4 ). This configuration is adopted for exerting a stable function in all first and second protruding portions  25  and  26 . However, in this application, how first and second protruding portions  25  and  26  are provided is not limited to the configuration in which first and second protruding portions  25  and  26  are alternately provided. For example, as illustrated in  FIG. 10A , first protruding portions  25  may be provided next to each other. Moreover, as illustrated in  FIG. 10B , second protruding portions  26  may be provided next to each other. Furthermore, first and second protruding portions  25  and  26  may be provided in a way other than the ways illustrated in  FIGS. 10A and 10B . More specifically, in the present invention, as long as second protruding portions  26  are provided so as to exert an auxiliary sealing function, first protruding portions  25  may be provided with second protruding portion  26  interposed therebetween or first and second protruding portions  25  may be separated from each other while first protruding portions  25  are provided next to each other and second protruding portions  26  are also provided next to each other, and it is also possible to appropriately adopt a configuration in such a way that second protruding portions  26  do not hinder elastic deformation of first protruding portions  25 . 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  Control cable (long member) 
           1   i  Inner cable 
           1   o  Outer casing 
           2  Grommet (elastic member) 
           21  Body portion 
           22  Insertion portion 
           23  Cylindrical portion 
           23   h  Insertion hole 
           24  Seal portion 
           24   c  Recess portion 
           24   p  Protruding portion 
           25  First protruding portion 
           26  Second protruding portion 
         φx Inner diameter of top portion of first protruding portion 
         φy Inner diameter of top portion of second protruding portion 
         φc Outer diameter of control cable