Patent Publication Number: US-2011073350-A1

Title: Grommet

Description:
FIELD OF THE INVENTION 
     This invention relates to a grommet and more particularly relates to a grommet that is mounted on a wire harness to be wired in a motor vehicle and is attached to a through-hole in a vehicle body panel to protect, waterproof, and dustproof a portion of the wire harness inserted in the through-hole. 
     BACKGROUND OF THE INVENTION 
     Heretofore, a wire harness to be wired from an engine room in a motor vehicle to passenger room mounts a grommet, and the grommet is attached to a through-hole provided in a vehicle body panel for partitioning a vehicle body of the motor vehicle into the engine room and the passenger room so as to protect the wire harness passing the through-hole and to waterproof, dustproof, and sound-insulate, from an engine room side to a passenger room side. 
     The present applicant has proposed a so-called one-motion type grommet in which a vehicle body latch recess provided on an outer peripheral surface is engaged with an peripheral edge around the through-hole merely by pushing the grommet into the through-hole in the vehicle body panel from a one side. 
     As shown in  FIG. 10 , an one-motion type grommet  100  disclosed in JP 2002-171644 A (Patent Document 1) is mounted on a wire harness W/H, the grommet  100  is attached to a through-hole  3  in a vehicle body panel  2  that partitions a vehicle body into an engine room X and a passenger room Y merely by pushing the wire harness into the through-hole  3 , and the wire harness W/H is drawn out from the engine room X to the passenger room Y. That is, a side of the engine room X across the panel  2  defines a pushing-in side P 1  for the wire harness W/H while a side of the passenger room Y across the panel  2  defines a drawing-out side P 2  for the wire harness W/H. 
     As shown in  FIG. 10 , the grommet  100  includes a smaller diameter tubular section  103  through which the wire harness W/H passes in a close contact manner, and an enlarging diameter tubular section  104  provided on a pushing-in side end of the section  103 . A smaller diameter end  104   a  of the diameter enlarging section  104  is contiguous with the pushing-in side end of the smaller diameter tubular section  103 . A vehicle body latch recess  101  is provided on an outer peripheral surface of an enlarging diameter end  104   b  of the section  104 . When the grommet  100  is inserted into and attached to the through-hole  3  in the vehicle body panel  2 , the smaller diameter tubular section  103  is inserted into the through-hole  3 , the wire harness W/H is pushed into the drawing-out side P 2  from the pushing-in side P 1 . Then, the enlarging diameter tubular section  104  is deflected inward and a peripheral edge around the through-hole  3  falls down in the vehicle body latch recess  101 . Consequently, the grommet  100  is engaged with the vehicle body panel  2 . 
     At this time, in order to reduce an inserting force of the grommet  100  into the through-hole  3  in the vehicle body panel  2 , the grommet  100  is provided on its outer peripheral surface with projecting ribs  105 . This can reduce a contact area between the grommet  100  and the through-hole  3 . 
     The above one-motion type grommet  100  can be mounted on the through-hole  3  in the vehicle body panel  2  merely by pushing the grommet  100  from the engine room side. In addition, since the enlarging diameter tubular section  104  is provided on the outer peripheral surface with the projecting ribs  105 , there is an advantage for reducing the inserting force of the grommet  100 . 
     Currently, a wiring space for the wire harness has been decreased in association with an drastic increase of electrical equipments to be installed in a motor vehicle. Consequently, as shown in  FIG. 11A , the wire harness W/H that passes the through-hole  3  in the vehicle body panel  2  will interfere with an electrical equipment D, if the wire harness W/H is arranged straightly. In particular, since electrical equipments to be installed in an instrument panel, from which the wire harness is drawn out, has been increased significantly, there will be a possibility that the wire harness W/H is bent at an angle of 90 (ninety) degrees, as shown in  FIG. 11A . Similarly, there will be a possibility that the wire harness may be bent at the angle of 90 degrees in the engine room. 
     If the wire harness W/H is bent at the angle of 90 degrees, as shown in  FIG. 11A , the smaller diameter tubular section  103  closely mounted on the wire harness W/H is also bent. The enlarging diameter tubular section  104  contiguous with the smaller diameter tubular section  103  is pulled in a bending direction, and the vehicle body latch recess  101  provided on the enlarging diameter tubular section  104  is also pulled. Consequently, as shown in  FIG. 11B , a slant wall side surface  101   a  of the vehicle body latch recess  101  is deformed to float up. Thus, there is a possibility that any deleterious effect will occur in a sealing function between the inner peripheral surface of the through-hole  3  and the recess  101 . Since the enlarging diameter tubular section  104  is designed to be easily deflected inward upon insertion into the through-hole  3  in the one-motion type grommet, the enlarging diameter tubular section  104  follows the pulling action in the bending direction. This will be susceptible to improvement.
     Patent Document 1: JP 2002-171644 A   

     SUMMARY OF THE INVENTION 
     Problems that the Invention is to Solve 
     In view of the above problems, an object of the present invention is to provide a grommet that does not lower a sealing function even if a wire harness is bent in arrangement after the wire harness passes a through-hole in a vehicle body panel. 
     Means for Solving the Problems 
     In order to achieve the above object, the present invention is directed to a grommet that is mounted on a wire harness, is engaged with a through-hole in a vehicle body, and is made of an elastic material. The grommet includes: an inner tube having a smaller diameter and passing electrical cables in the wire harness in a close contact manner; an annular coupling section protruding from an outer peripheral surface of an intermediate part between both ends of the inner tube at a pushing-in side and a drawing-out side in a longitudinal direction; and an outer tube having a larger diameter, contiguous with an outer peripheral surface of the annular coupling section, and coaxially disposed around the inner tube through a space. The outer tube is provided with a slant wall section that reduces a diameter from a larger thickness portion at a coupling position with the annular coupling section to the drawing-out side. The outer tube is provided with a vehicle body latch recess between the larger thickness portion and the slant wall section in an annular manner. An inner peripheral surface at a smaller diameter end side of the slant wall section is spaced through a given clearance apart from an outer peripheral surface of the inner tube. Both ends of the inner tube protrude outward from the outer tube at the pushing-in side and the drawing-out side. 
     As described above, in the grommet of the present invention, the inner tube that passes the wire harness in the close contact manner and the outer tube provided with the vehicle body recess are separated through a great clearance apart from each other at the drawing-out side of the wire harness. Thus, even if the wire harness drawn out from the grommet and arranged in the passenger room side is bent sharply by an angle of about 90 degrees and the inner tube is bent, the deformation of the inner tube is not transmitted directly to the outer tube. Also, since the inner tube is coupled to the outer tube through the annular coupling section from the intermediate position of the inner tube spaced apart from the drawing-out side of the inner tube in the longitudinal direction, the deformation of the inner tube can be absorbed even in the annular coupling section, thereby preventing the deformation from being transmitted to the vehicle body latch recess provided on the larger diameter end of the outer tube. Thus, since the vehicle body latch recess is prevented from floating up on account of deformation even if the wire harness is bent sharply, it is possible to maintain the seal function between the vehicle body latch recess and the inner peripheral surface of the through-hole. 
     Preferably, the slant wall section of the outer tube is provided on a smaller diameter end with a drawing-out distal end side tubular portion that extends in parallel to an axial direction of the inner tube, and the clearance is defined between an inner peripheral surface of the drawing-out distal end side tubular portion and the outer peripheral surface of the inner tube. 
     Thus, since the slant wall section of the outer tube is provided on the smaller diameter end with the drawing-out distal end side tubular portion, it is possible to enhance contour-keeping strength of the outer tube and it is possible to restrain the deformation effect from affecting the slant wall section when the inner tube is deformed by the bending of the wire harness so that the inner tube contacts with the drawing-out distal end side tubular portion. 
     The inner peripheral surface of the smaller diameter end side of the slant wall section may be separated through a clearance apart from the outer peripheral surface of the inner tube without providing the drawing-out distal end side tubular portion on the slant wall section. 
     Preferably, a dimension of the clearance in a radial direction is set to be ½ to 3/2 (one-half to three-halves) of a radius of the inner tube. When the wire harness protruding from a drawing-out side distal end of the inner tube is bent at an angle of less than 90 degrees, the slant wall section is spaced apart from the inner tube by the clearance so that the slant wall is not deformed. 
     A length of the clearance is variable in accordance with an outer diameter of the inner tube. However, it is preferable that the length is 5 to 15 mm (five to fifteen millimeters). 
     Preferably, the slant wall section of the outer tube is provided on a smaller diameter end with a drawing-out distal end side tubular portion that extends in parallel to an axial direction of the inner tube, and the clearance is defined between an inner peripheral surface of the drawing-out distal end side tubular portion and the outer peripheral surface of the inner tube. 
     As described above, since the slant wall section is provided on the outer peripheral surface with the projecting ribs that are spaced apart from one another in the peripheral direction, it is possible to decrease a contact area between the inner peripheral surface of the through-hole in the vehicle panel and the slant wall section and also to lower the inserting force of the grommet. 
     It is possible to carry out stable insertion by forming each of the projecting ribs into a stepped configuration with a flat surface on its top portion. Preferably, the number of projecting ribs is 4 to 8 (four to eight), and more preferably, 6 (six). 
     The distal end at the larger diameter side of each projecting rib is disposed at the distal end of the side surface of the vehicle body latch recess. Preferably, the smaller diameter end of each projecting rib is contiguous with the drawing-out distal end side tubular portion. If the distal end of each projecting rib contiguous with the distal end of the side surface of the vehicle body latch recess is formed into a configuration in which the top surface and both side surfaces are cut away at three sides, when the peripheral edge around the through-hole falls down into and engages the vehicle body latch recess, the edge can smoothly engages the recess without causing the projecting ribs to interfere with the edge around the through-hole. 
     A thickness of the annular coupling section is smaller than thicknesses of the inner and outer tubes. The annular coupling section protrudes slant toward an opposite side from the slant wall section beyond a coupling point with the inner tube. A pushing rib protrudes from a slant portion of the annular coupling section toward an inner peripheral surface of the slant wall section. 
     When the grommet is inserted into the through-hole in the vehicle body panel, a working person holds the wire harness at the pushing-in side of the inner tube and pushes the wire harness into the through-hole. Since the outer tube is coupled through the annular coupling section to the inner tube, the pushing force is hardly transmitted to the slant wall section at the drawing-out side of the outer tube. Accordingly, the annular coupling section is provided with the pushing rib, the pushing rib is pressed onto the inner peripheral surface at the drawing-out side of the slant wall section, and the pressing force is transmitted through the pushing rib to the slant wall section. This can enhance workability in insertion of the grommet. 
     Since the annular coupling section has the smaller thickness and protrudes slant without protruding directly in the radial direction, when the inner tube is deformed on account of the bending of the wire harness, the annular coupling section absorbs the deformation of the inner tube, thereby avoiding the deformation of the outer tube. Thus, even if the wire harness is sharply bent in the engine room, the annular coupling section absorbs the deformation and the vehicle body latch recess of the outer tube is not deformed. 
     Preferably, the annular coupling section is bent in a V-shape between the inner and outer tubes. This V-shape can increase an amount of absorbing the deformation at the annular coupling section, when the inner tube is deformed on account of the bending of the wire harness. 
     Preferably, the pushing rib is provided on a whole periphery of the annular coupling section in a peripheral direction of the annular coupling section, since this will uniform the pushing force to the slant wall section. 
     In the case where the wire members such as the opener cable and the feed water hose are inserted into the grommet, the pushing rib is divided in the peripheral direction at the inserting positions of the wire members. 
     A thickness of the pushing rib is 2 to 4 (two to four) times of that of the annular coupling section and is larger than a thickness of the slant wall section. 
     Thus, if the thickness of the pushing rib is great, it is possible to increase the pushing force to the slant wall section. 
     A projecting end of the pushing rib contacts with an inner surface of the slant wall section with the grommet being mounted on a vehicle body. The pushing rib, outer tube, inner tube, and annular coupling section surround an interior of the grommet to define a sound insulation space. 
     If the sound insulation space is provided by utilizing the pushing rib, it is possible to restrain noises caused in the engine room from transmitting to the passenger room, thereby keeping the passenger room in a silent condition. 
     If the pushing rib is formed into a continuous annular configuration in the peripheral direction, it is possible to define the sound insulation space as the closed space, thereby enhancing the sound insulation function. 
     Preferably, an intermediate part of the annular coupling section is bent toward the slant wall section, and the pushing rib protrudes from the bent intermediate part. 
     Thus, since the pushing rib is directed to the inner surface of the slant wall section, the pushing force is smoothly transmitted from the inner tube through the pushing rib to the annular coupling section. 
     Preferably, the outer tube is provided on an inner peripheral surface opposed to the pushing rib with a stopper projection, and the stopper projection serves to prevent the pushing rib from shifting from a pushing position. 
     Thus, since the outer tube is provided with the stopper projection, the projecting end that is pressed onto the inner peripheral surface of the slant wall section slides on the slant surface of the slant wall section, thereby preventing the projecting end from moving out from the slant wall section. 
     In the case where the wire members such as the opener cable and the feed water hose are inserted into the grommet, the through-apertures are provided in the slant wall section, outer guide pipes are provided on the peripheral edges around the through-apertures, and inner guide pipes are provided in the grommet. Preferably, these inner and outer guide pipes are provided with smaller diameter portions to seal and support the wire members at two positions. 
     EFFECTS OF THE INVENTION 
     As described above, according to the present invention, in the case where the wire harness inserted in the grommet is bent sharply, the grommet of the present invention has a construction in which the vehicle body latch recess is not deformed, thereby obtaining a good sealing function. 
     That is, the outer tube provided with the vehicle body latch recess is separated through a space apart from the inner tube that is likely to be deformed by the wire harness, and the deformation of the inner tube is not transmitted directly to the outer tube. Accordingly, it is possible to prevent the vehicle body latch recess from floating up and to obtain a good sealing function. 
    
    
     
       BRIEF EXPLANATION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a grommet of the present invention taken from a drawing-out side.  FIG. 1B  is a perspective view of the grommet of the present invention taken from a pushing-in side. 
         FIG. 2  is a plan view of the grommet shown in  FIG. 1 , illustrating the grommet taken from the drawing-out side. 
         FIG. 3  is a longitudinal section view of the grommet taken along lines in  FIG. 2 . 
         FIG. 4  is a longitudinal section view of the grommet taken along lines IV-IV in  FIG. 2 . 
         FIG. 5  is a longitudinal section view of the grommet taken along line V-V in  FIG. 2 . 
         FIG. 6  is a cross section view of the grommet taken along lines VI-VI in  FIG. 4 . 
         FIG. 7  is a longitudinal section view of the grommet into which a wire harness is inserted and that is attached to a vehicle body. 
         FIG. 8A  is a side elevation view of the grommet in the case where the wire harness is bent at the drawing-out side of the grommet.  FIG. 8B  is a side elevation view of the grommet in the case where the wire harness is bent at the pushing-in side of the grommet. 
         FIG. 9  is a longitudinal section view of a main part of a modified grommet of the present invention. 
         FIG. 10  is a longitudinal section view of a prior art grommet. 
         FIGS. 11A and 11B  are explanatory views illustrating problems in the prior art grommet. 
     
    
    
     EXPLANATION OF SIGNS 
     
         
           1 : grommet 
           2 : vehicle body panel 
           3 : through-hole 
           5 : inner tube 
           6 : annular coupling section 
           8 : outer tube 
           9 : larger thickness portion 
           10 : vehicle body latch recess 
           11 : slant wall section 
           12 : drawing-out distal end side tubular section 
           12   a:  stopper projection 
           15 : projecting rib 
           18 : pushing rib 
           19 : smaller thickness portion 
       
    
     PREFERRED ASPECTS OF EMBODYING THE INVENTION 
     Referring now to the drawings, embodiments of a grommet in accordance with the present invention will be described below. 
       FIGS. 1A to 8B  show an embodiment of a grommet in accordance with the present invention. 
     A grommet  1  is mounted on a wire harness W/H arranged from an engine room X in a vehicle motor via a through-hole  3  in a vehicle body panel  2  to a passenger room Y, as is the case with the prior art grommet shown in  FIGS. 10 to 11B . The grommet  1  is engaged with a peripheral edge around the through-hole  3  to be attached to the vehicle body. The grommet  1  is a one-motion type grommet that is inserted into the through-hole  3  from an engine room X so as to be attached to the vehicle body. The one end of the grommet  1  defines a pushing-in side P 1  while the other end defines a drawing-out side P 2 . 
     The grommet  1  is molded from rubber or elastomer. 
     The grommet  1  includes an inner tube  5  having a smaller diameter and permitting a set of electrical cables in the wire harness W/H to pass, an annular coupling section  6  that protrudes from an outer peripheral surface  5   a  on an intermediate part of the inner tube  5  between a pushing-in end  5 P 1  at the pushing-in side P 1  and a drawing-out end  5 P 2  at the drawing-out side P 2  in a longitudinal direction of the inner tube  5 , and an outer tube  8  having a larger diameter and contiguous with an outer peripheral surface of the annular coupling section  6 . 
     The outer tube  8  is coaxial with the inner tube  5  and is disposed through a space on an intermediate part of the inner tube  5  in its longitudinal direction. The inner tube  5  protrudes from opposite ends of the outer tube  8  at the pushing-in side P 1  and the drawing-out side P 2  in the longitudinal direction. 
     The outer tube  8  extends to the drawing-out side P 2  from a connecting part between the outer tube  8  and an outer peripheral surface of the annular coupling section  6 . A larger thickness portion  9  formed on the connecting part is provided on an outer peripheral surface with an annular vehicle body latch recess  10 . A slant wall section  11  is contiguous with the larger thickness portion  9  and extends to the drawing-out side P 2  to reduce a diameter of the portion  11  in the axial direction. The slant wall section  11  is provided on its distal end with a drawing-out distal end side tubular portion  12  that extends in parallel to the axial direction of the inner tube  5 . 
     An annular clearance S ( FIG. 3 ) is defined between an inner peripheral surface of the drawing-out distal end side tubular portion  12  and the outer peripheral surface  5   a  of the inner tube  5  to separate the portion  12  apart from the inner tube  5 . That is, a smaller diameter end of the outer tube  8  surrounds the outer peripheral surface of the inner tube  5  through the annular clearance S and the drawing-out side end  5 P 2  protrudes outward from the outer tube  8 . 
     As shown in  FIGS. 2 to 6 , a radial distance d 1  ( FIG. 3 ) of the annular clearance S is set to be ½ to 3/2 (one-half to three-halves) of a radius d 2  ( FIG. 3 ) of the inner tube  5 . It is preferable in the present embodiment that the radial distance d 1  is ¾ (three quarters) of the radius d 2 . A length L 1  ( FIG. 3 ) of the drawing-out distal end side tubular portion  12  that extends through the annular clearance S in parallel to the outer peripheral surface  5   a  of the inner tube  5  may be altered in accordance with a size of the grommet  1 . It is preferable in the present embodiment that the length L 1  is 5 to 15 mm (five to fifteen millimeters). 
     As shown in  FIGS. 3 and 4 , the larger thickness portion  9  of the outer tube  8  protrudes slightly toward the pushing-in side P 1  from the connecting part between the larger thickness portion  9  and an outer peripheral end  6   a  of the annular coupling section  6 . The pushing-in side distal end surface  9   a  defines an orthogonal surface to an axis O. The larger thickness portion  9  is provided on its outer peripheral surface with an annular vehicle body latch recess  10 . A distal end of a drawing-out side surface  10   b  that stands up from a bottom surface  10   a  of the vehicle body latch recess  10  is contiguous with a larger diameter end  11   a  of the slant wall section  11 . A smaller diameter end  11   b  of the slant wall section  11  is contiguous with the drawing-out distal end side tubular portion  12 . A curved portion  11   c  is provided between the larger diameter end lie and the smaller diameter end  11   b  so as to change an inclined angle of the outer peripheral surface of the slant wall section  11 . 
     The slant wall section  11  is provided on the outer peripheral surface that changes the inclined angle with axially stepped projecting ribs  15  that extend from the larger diameter end  11   a  of the distal end of the drawing-out side surface  10   b  on the vehicle body latch recess  10  to the smaller diameter end  11   b  and are spaced apart from one another in the peripheral direction. An imaginary circle created by continuing the stepped projecting ribs  15  in the peripheral direction of the curved portion  11   c  is set to be equal to an inner diameter of the through-hole  3  in the vehicle body panel  2 . In the present embodiment, the number of the stepped projecting ribs  15  is six (6) and the pitches of the ribs are sixty (60) degrees. A total peripheral length of top surfaces  15   a  ( FIG. 2 ) on the six stepped projecting ribs  15  is set to be 20 to 40% (twenty to forty percent) of the outer peripheral surface on the curved portion  11   c.    
     The stepped projecting ribs  15  couple their smaller diameter side end surfaces  15   b  to the outer peripheral surface of the drawing-out distal end side tubular portion  12 . 
     As shown in  FIGS. 1A and 1B , each stepped projecting rib  15  is provided on its larger diameter end side at the distal end of the drawing-out side surface  10   b  of the vehicle body latch recess  10  with slant surfaces  15   c  that incline the top surface  15   a  of the stepped projecting rib  15  downward to the drawing-out side surface  10   b.  Both side surfaces  15   d  and  15   e  of each stepped projecting rib  15  at their distal end sides across the slant surface  15   c  define slant surfaces  15   f  and  15   g  that approach to each other. That is, each stepped projecting rib  15  is provided on its larger diameter end with the slant surfaces  15 ,  15   f,  and  15   g  that are cut at three sides. Thus, since the distal end surface of each stepped projecting rib  15  is cut at the three sides to eliminate edges, the stepped projecting ribs  15  are not caught by the peripheral edge around the through-hole  3  when the peripheral edge around the through-hole  3  in the vehicle body panel  2  drops down into the vehicle body latch recess  10 . 
     An inner peripheral surface of the outer tube  8  is parallel to the axial direction O from a position corresponding to the vehicle body latch recess  10  to a position corresponding to the curved portion  11   c  of the slant wall section  11 . A thickness t 1  ( FIG. 3 ) of the outer tube  8  is set to be small from the curved portion  11   c  to the drawing-out distal end side tubular portion  12 . A thickness t 2  ( FIG. 3 ) of the drawing-out distal end side tubular portion  12  is set to be larger than the thickness t 1 . 
     Furthermore, as shown in  FIG. 6 , each stepped projecting rib  15  of the slant wall section  11  is provided in its inner peripheral surface with a groove  15   h  to reduce stiffness of each stepped projecting rib  15 , thereby easily deflecting the stepped projecting ribs  15  inward when the stepped projecting ribs  15  are pressed onto the inner peripheral surface around the through-hole  3 . Further, as shown in  FIG. 2 , the slant wall section  11  is provided with axial grooves  15   k  and  15   i  on its outer surface at proximal ends of each projecting rib  15  and on each central parts between the adjacent projecting ribs  15 , respectively, thereby facilitating to deflect the slant wall section  11 . 
     As shown in  FIGS. 3 and 4 , the annular coupling section  6  that interconnects the outer tube  8  and inner tube  5  protrudes in a V-shaped configuration from an inner peripheral end  6   b  contiguous with the outer peripheral surface  5   a  of the inner tube  5  to the pushing-in side P 1 . The outer peripheral end  6   a  of the annular coupling section  6  is disposed at the pushing-in side P 1  beyond the inner peripheral end  6   b  and is contiguous with the larger thickness portion  9  of the outer tube  8 . 
     That is, although the smaller diameter side of the enlarging diameter tubular section is contiguous with the smaller diameter tubular section in the prior art one-motion type grommet  100  shown in  FIG. 10 , the larger diameter side of the outer tube  8  (corresponding to the enlarging diameter tubular section) is connected through the annular coupling section  6  to the inner tube  5  in the grommet  1  of the present invention. 
     As shown in  FIG. 1B , the annular coupling section  6  includes flat surfaces  6   e  and  6   f  extending in the radial direction at two positions opposed to each other in the orthogonal directions and provided with inserting ports  31  and  32  for wire members  20  mentioned after. The annular coupling section  6  is not bent in a V-shape at the two positions. 
     A thickness t 3  ( FIG. 3 ) of the annular coupling section  6  is set to be substantially equal to or less than a thickness t 4  ( FIG. 3 ) of the inner tube  5  so as to be deflectable. An angle θ of the annular coupling section  6  that is slant coupled to the outer peripheral surface of the inner tube  5  is set to be 20 to 30 (twenty to thirty) degrees. Thus, the inner tube  5  and outer tube  8  are not interconnected to each other directly in the radial direction but interconnected to each other through the V-shaped annular coupling section  6 . Thus, when the inner tube  5  is deformed in connection with bending of the wire harness W/H, the annular coupling section  6  absorbs the deformation of the inner tube  5 , so that the deformation of the inner tube  5  is not transmitted to the outer tube  8 . This serves as a release portion. 
     The annular coupling section  6  is provided on its inclined portion between an inner peripheral end  6   b  and a V-shaped projecting end  6   c  with a bent portion  6   d  that is bent toward the slant wall section  11 . A pushing rib  18  having a larger thickness protrudes from the bent portion  6   d  toward the slant wall section  11 . As shown in  FIG. 6 , the pushing rib  18  is continuous in its peripheral direction but it is divided at positions corresponding to guide inner tubes  28  and  29  for wire members  20  mentioned after. 
     A thickness t 5  ( FIG. 3 ) of the pushing rib  18  is large enough to be 2 to 4 (two to four) times of the thickness t 3  of the annular coupling section  6 , is larger than the thickness t 1  of the slant wall section  11 , and is substantially the same as the thickness of the larger thickness portion  9 . 
     The reason why the pushing rib  18  is a larger thickness is ascribable to the fact that, when the grommet  1  is inserted into the through-hole  3  in the vehicle body panel  2 , a projecting end  18   a  of the pushing rib  18  contacts with the inner peripheral surface of the slant wall section  11  to permit the pushing force to be transmitted to the outer tube  8 . When the grommet  1  is attached to the vehicle body panel  2 , the projecting end  18   a  of the pushing rib  18  is disposed near the slant wall section  11  so that they can contact with each other. Thus, a sound-insulating space B ( FIG. 3 ) is defined among the pushing rib  18 , the inner tube  5 , the annular coupling section  6 , and the outer tube  8 . 
     As shown in  FIGS. 3 and 4 , the pushing rib  18  protrudes slightly slant in its outer diametrical direction. The projecting end  18   a  is opposed to the smaller diameter end of the slant wall section  11  contiguous with the drawing-out distal end side tubular portion  12 . The drawing-out distal end side tubular portion  12  is provided with a stopper projection  12   a,  which protrudes inward from the slant wall section  11 , at a side of the slant wall section  11  with which the pushing rib  18  contacts. Since the stopper projection  12   a  is provided on the drawing-out distal end side tubular portion  12 , it is possible to prevent the projecting end  18   a  of the pushing rib  18  from slipping down into the drawing-out distal end side tubular portion  12  and to surely bring the pushing rib  18  into contact with the slant wall section  11  so as to transmit the pushing force to the slant wall section  11 . 
     Furthermore, the slant wall section  11  is provided with an annular shallow recess in an inner surface from an outer diameter side, with which the projecting end  18   a  of the pushing rib  18  contacts, to the bent portion  11   c.  Thus, the slant wall section  11  is provided with a smaller thickness portion  19  having a smaller thickness t 6 . Since the slant wall section  11  is provided with a smaller thickness portion  19  on the curved portion  11   c  at the smaller diameter side, the smaller thickness portion  19  serves as a stress absorbing portion when the drawing-out distal end side tubular portion  12  is deformed on account of the bending of the wire harness. That is, a bending stress is concentrated in the smaller thickness portion  19 , so that the drawing-out distal end side tubular portion  12  is hard to transmit its deformation to the vehicle body latch recess  10 . The thickness t 6  of the smaller thickness portion  19  is smaller than the thickness t 3  of the annular coupling section  6 . 
     Two wire members  20  ( FIG. 5 ) including an opener cable  21  for releasing a bonnet and a feed water hose  22  for a washer penetrate the grommet  1  and are arranged from the engine room X to the passenger room Y. The wire members  20  extend from the pushing-in side P 1  to the drawing-out side P 2 . 
     As shown in  FIG. 5 , the slant wall section  11  is provided with a through-aperture  24  in order to cause the opener cable  21  to penetrate the grommet  1 , while the slant wall section  11  is provided with a through-aperture  25  in order to cause the feed water feed hose  22  to penetrate the grommet  1 . The through-apertures  24  and  25  are disposed on a diametrical direction of the grommet  1 . 
     Outer guide pipes  26  and  27  protrude outward from peripheral edges around the through-apertures  24  and  25 . The outer guide pipes  26  and  27  are provided on their distal ends with closing end portions  26   a  and  27   a.  When the wire members  20  penetrate the grommet  1 , the closing end portions  26   a  and  27   a  are cut away to open the outer guide pipes  26  and  27 . In the case where the wire members  20  do not penetrate the grommet  1 , the closing end portions  26   a  and  27   a  are left on the outer guide pipes  26  and  27 . Inner guide pipes  28  and  29  protrude into an interior of the grommet  1  from the peripheral edges around the through-apertures  24  and  25 . 
     The outer guide pipe  26  of the opener cable  21  is provided on a protruding side with a smaller diameter portion  26   c  that has the same inner diameter as an outer diameter of the opener cable  21 . A cut-away line  26   b  is provided on the smaller diameter portion  26   c  at its distal end side. When the distal end of the smaller diameter portion  26   c  is cut away from the outer guide pipe  26 , the smaller diameter portion  26   c  closely contacts with an outer peripheral surface of the opener cable  21  to seal and guide the opener cable  21 . 
     An inner diameter d 4  ( FIG. 5 ) of the inner guide pipe  28  is set to be larger than an outer diameter d 3  ( FIG. 5 ) of the opener cable  21 . The inner guide pipe  28  is provided on an inner peripheral surface with a seal wall  28  having a through-aperture  28   a  with an inner diameter d 3  ( FIG. 5 ). Thus, the opener cable  21  is sealed and supported by the seal wall  28   b  in the grommet  1 . Further, the opener cable  21  is sealed and supported by the smaller diameter portion  26   c  of the outer guide pipe  26  of the grommet  1 . 
     On the other hand, at the side of the feed water hose  22 , the outer guide pipe  27  is provided with a smaller diameter portion  27   c  and a cut-away line  27   b  at the distal end side. The smaller diameter portion  27   c  closely contacts with an outer peripheral surface of the feed water hose  22  to seal it. An inner guide pipe  29  is provided on its inner periphery with two smaller diameter portions  29   a  and  29   b.  The inner peripheral surfaces of the smaller diameter portions  29   a  and  29   b  closely contact with the outer peripheral surface of the feed water hose  22  to seal it. 
     The annular coupling section  6  is provided on its engine room side surface in the diametrical direction with inserting ports  31  and  32  for the opener cable  21  and the feed water hose  22 . The annular coupling section  6  is not bent in the V-shape at the inserting ports  31  and  32  to form the flat surfaces  6   e  and  6   f  extending in the diametrical direction, as described above. 
     The smaller diameter inner tube  5 , through which the wire harness W/H passes, protrudes from the opposite ends of the outer tube  8  in the longitudinal direction. The inner tube  5  is provided on an inner peripheral surface of each protruding end portion from the outer tube  8  with three waterproofing lips  33 . 
     As shown in  FIG. 7 , since the through-hole  3  in the vehicle body panel  2  for receiving the grommet  1  is an aperture with a burr  3   b  that protrudes from the peripheral edge  3   a  around the through-hole  3  to the pushing-in side P 1 , the vehicle body latch recess  10  in the outer tube  8  has a configuration corresponding to the burr  3   b.    
     That is, as shown in  FIG. 5 , the vehicle body latch recess  10  is provided on a central part of its bottom surface  10   a  with a seal lip  10   c  to contact with the burr  3   b.  A drawing-out side surface  10   b  of the vehicle body latch recess  10  at the side of the slant wall section  11  inclines a distal end of the surface  10   b  inward. In addition, a side surface  10   d  opposed to the side surface  10   b  is provided with a depression  10   e  contiguous with the bottom surface  10   a  to contain a distal end of the burr  3   b.  A vertical surface  10   f  stands up from the depression  10   e  so that an upper end of the vertical surface  10   f  extends upward over the drawing-out side surface  10   b.    
     A process for attaching the wire harness W/H to the grommet  1  is carried out by inserting the electrical wires in the wire harness W/H while enlarging the inner peripheral surface of the inner tube  5  by a jig (not shown). After inserting the wire harness W/H into the inner tube  5 , the wire harness W/H drawn out from the opposite ends  5 P 1  and  5 P 2  of the inner tube  5  and the opposite ends  5 P 1  and  5 P 2  are secured to one another by winding adhesive tapes  40  around them. 
     Varying sizes in diameter of the wire harness W/H are absorbed in the annular coupling section  6 , so that the outer tube  8  connected through the annular coupling section  6  to the inner tube  5  is not subject to affections caused by the varying sizes. Accordingly, it is possible to maintain the outer diameter of the outer tube in a designed size. That is, since the annular coupling section  6  has a smaller thickness enough to be deformed and is formed into the V-shape, the annular coupling section  6  can respond to the varying sizes in diameter merely by changing the bending angle. 
     As shown in  FIG. 7 , the grommet  1  mounted on the wire harness W/H is inserted into and attached to the through-hole  3  with the burr  3   b  in the vehicle body panel  2  that partitions a vehicle body into the engine room X and the passenger room Y. 
     A working of inserting the grommet  1  into the through-hole  3  is carried out by inserting the drawing-out end  5 P 2  of the inner tube  5  into the through-hole  3  from the engine room X, and then pushing the grommet  1  into the through-hole by a working person in the engine room X while holding the wire harness W/H with the grommet  1  by the working person. The grommet  1  is latched in the through-hole  3  by a one-motion operation in which a pushing-in action is effected at one time from the one side. 
     Specifically, since the smaller diameter side of the slant wall section  11  of the outer tube  8  is smaller than the inner diameter of the through-hole  3 , the grommet  1  can be readily inserted into the through-hole  3 . When the bent portion  11   c  of the slant wall section  11  reaches the inner peripheral surface  3   a  of the through-hole  3 , the stepped projecting ribs  15  of the slant wall section  11  contact with the inner peripheral surface  3   a,  thereby causing an inserting resistance. Then, the outer tube  8  cannot be further pushed into the through-hole  3  easily from the inner peripheral surface  3   a.    
     However, if the working person holds and pushes the wire harness W/H to be drawn out from the pushing-in side P 1  of the inner tube  5 , the inner tube  5  that closely contacts with the wire harness W/H is advanced to the drawing-out side P 2  in the drawing-out direction. The pushing rib  18  of the annular coupling section  6  connected to the inner tube  5  is also advanced to the inner surface of the slant wall section  11  of the outer tube  8  by the movement of the inner tube  5  and the projecting end  18   a  of the pushing rib  18  bumps onto the inner peripheral surface of the slant wall section  11 . Thus, since the slant wall section  11  is pushed and moved forward by the pushing rib  18 , the outer tube  8  with the slant wall section  11  passes through the through-hole  3  to the passenger room Y. 
     When the pushing rib  18  pushes the slant wall section  11 , the stopper projection  12   a  can prevent the projecting end  18   a  of the pushing rib  18  from sliding down into the drawing-out distal end side tubular portion  12 . Thus, it is possible to surely hold the projecting end  18   a  of the pushing rib  18  on the inner peripheral surface of the slant wall section  11  and to transmit the pushing force from the pushing rib  18  to the slant wall section  11 . 
     Since the slant wall section  11  is provided on the outer peripheral surface with the stepped projecting ribs  15 , only the top surfaces  15   a  of the stepped projections contact with the inner peripheral surface  3   a  of the through-hole  3  and the inner peripheral surface of the burr  3   b,  when the pushing rib  18  is inserted into the through-hole  3 . Consequently, a contact area is reduced and an inserting force is lowered. Each stepped projecting rib  15  is provided in the inner peripheral surface with a groove  15   h  to facilitate to cause the stepped projecting rib  15  to be deflected. The smaller thickness portion between the adjacent stepped projecting ribs  15  can be easily deflected by the grooves  15   k  provided on the both proximal ends of each stepped projecting rib  15  and the central groove  15   i  in the smaller thickness portion. The slant wall section  11  of the outer tube  8  can be pushed into the through-hole  3  by pressing the pushing rib  18  onto the inner peripheral surface of the slant wall section  11  and the pushing force can be reduced. 
     The pushing rib  18  presses the slant wall section  11  and the distal ends of the stepped projecting ribs  15  reach the inner peripheral surface  3   a  of the through-hole  3 . Since each stepped projecting rib  15  is provided on the distal end with slant surfaces  15   c,    15   f,  and  15   g  in three cut-away sides, the inner peripheral surface  3   a  of the through-hole  3  and the burr  3   b  fall down into the vehicle body latch recess  10  as if the stepped projecting ribs  15  fall down into the through-hole  3 , and the grommet  1  can be secured to the vehicle body panel  2 . 
     As described above, after the grommet  1  is secured to the vehicle body panel  2 , as shown in  FIG. 8A , the wire harness W/H drawn out into the passenger room Y is sharply bent downward (or upward, rightward, or leftward) by an angle of 90 (ninety) degrees in many cases. 
     In the case where the wire harness W/H is bent downward by the angle of 90 degrees, the conventional grommet is pulled down at its upper part and the vehicle body latch recess floats up at the distal end side, so that a sealing function is hard to obtain. 
     On the contrary, since the grommet  1  of the present invention is constructed above, it is possible to prevent the vehicle body latch recess  10  from floating up and to obtain a sealing function. 
     That is, the wire harness W/H can closely contact with and pass through the through-hole  3 , the inner tube  5  secured to the wire harness W/H by the adhesive tapes  40  follows the bending angle of the wire harness W/H, and the inner tube  5  is bent downward at the drawing-out end  5 P 2 . 
     However, even if the drawing-out end  5 P 2  is bent downward, the outer tube  8  is not coupled to the inner tube  5  at the drawing-out end  5 P 2  and the great clearance S exists between the drawing-out distal end tube  12  of the outer tube  8  and the inner tube  5 . Thus, since the inner tube  5  is merely bent in the clearance S between the inner tube  5  and the outer tube  8 , the outer tube  8  is not bent at the drawing-out side P 2 . 
     In the case where the inner tube  5  is greatly bent by the bending of the wire harness W/H, the bending will be transmitted through the annular coupling section  6  connected to the inner tube  5  to the outer tube  8 . Even in this case, the V-shaped thin annular coupling section  6  will absorb the deformation of the inner tube  5 , and the outer tube  8  is not deformed by the bending of the wire harness W/H. Consequently, the vehicle body latch recess  10  of the outer tube  8  is not deformed and floats up from the inner peripheral surface  3   a  of the through-hole  3  or the inner peripheral surface of the burr  3   b,  thereby obtaining the sealing function. 
     Even if the wire harness W/H is bent greatly and the inner tube  5  contacts with the drawing-out distal end tube  12  of the outer tube  8  to deform the outer tube  8 , since the slant wall section  11  is provided on the smaller diameter side with the smaller thickness portion  19 , a stress is concentrated in the smaller thickness portion  19  upon deformation. Accordingly, only the smaller thickness portion  19  is deformed and the vehicle body latch recess  10  at the larger diameter end side of the slant wall section  11  is not deformed. 
     Thus, even if the wire harness W/H drawn out from the grommet  1  is bent perpendicularly, since the inner tube  5  and outer tube  8  are spaced through the great clearance S from each other at the drawing-out side P 2  and an intermediate part of the inner tube  5  is coupled through the V-shaped thin annular coupling portion  6  to the outer tube  8 , the deformation effect of the inner tube  5  is not applied to the vehicle body latch recess  10  of the outer tube  8 . 
     As shown in  FIG. 8B , there is a case where the wire harness W/H inserted in the grommet  1  is bent at an angle of 90 degrees in the engine room X. 
     In this case, the inner tube  5  is bent in connection with the bending of the wire harness W/H. However, since the annular coupling section  6  connected to the inner tube  5  is formed into the V-shape and a smaller thickness, the annular coupling section  6  is deformed to absorb the deformation of the inner tube  5  and the bending effect of the wire harness W/H is not applied to the vehicle body latch recess  10  of the outer tube  8 , thereby obtaining the good sealing function. 
     As described above, in the case where the opener cable  21  and feed water hose  22  pass through the grommet  1  mounted in the through-hole  3  in the vehicle body panel  2 , the closing ends of the outer guide pipes  26  and  27  are cut away. Then, the opener cable  21  and feed water hose  22  are inserted through the inserting apertures  31  and  32  in the annular coupling section  6  into the inner guide pipes  28  and  29 , are inserted into the through-apertures  24  and  25 , and are further inserted into the outer guide tubes  26  and  27  to keep the cable  21  and hose  22  straightly. 
     At this time, the opener cable  21  and feed water hose  22  are sealed and supported by the inner guide pipe  28 ,  29  and outer guide pipe  26 ,  27  protruding from the outer tube  8 . Accordingly, even if the inner tube  5  is bent, since the opener cable  21  and feed water hose  22  are inserted into the outer tube  8  and are positively supported by the inner and outer guide pipes  28 ,  29  and  26 ,  27 , the bending effect of the inner tube  5  is not applied to the opener cable  21  and feed water hose  22 . 
     It should be noted that the grommet of the present invention is not limited to the above embodiment. For example, as shown in  FIG. 9 , the vertical side surface  10   d  of the vehicle body latch recess  10  may be provided on its distal end with a waterproofing rib  50  that contacts with the vehicle body panel  2 . 
     The slant wall section of the outer tube may not be provided on the smaller diameter distal end with the drawing-out distal end side tubular portion to define a terminal end. An inner peripheral surface of the terminal end may be greatly spaced apart from the outer peripheral surface of the outer tube through a great clearance. 
     In the case where the opener cable  21  and feed water hose  22  do not pass the grommet, it is preferable that the pushing rib is not divided in its peripheral direction to be formed into a continuous annular configuration. 
     Furthermore, eight stepped projections may be provided on the slant wall section. The bent portion may not be provided on the annular coupling section from which the pushing rib protrudes. 
     Thus, the present invention can include various aspects without departing from the gist of the present invention.