Abstract:
A mounting structure for an energy absorber includes an energy absorber having a mounting hole therein, a member having a mounting surface for receiving the energy absorber thereon and a rod projecting from the mounting surface to enter the mounting hole, and a cylindrical member. The cylindrical member includes a cylindrical portion to be disposed over and fixed to the rod and having axial ends, a first flanged portion extending outwardly from one axial end of the cylindrical portion and located above a peripheral portion of the mounting hole of the energy absorber, and a second flanged portion extending outwardly from the other end of the cylindrical portion and located in and surrounded by the energy absorber. The energy absorber is securely fixed to the member by the cylindrical member.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation application of PCT/JP00/02405 filed on Apr. 13, 2000 and is a continuation-in-part application of U.S. Ser. No. 09/709,508 filed on Nov. 13, 2000 now U.S. Pat. No. 6,345,420. 
    
    
     FIELD OF THE INVENTION AND RELATED ART STATEMENT 
     The present invention relates to mounting structure for an energy absorber and, more particularly, to the mounting structure for the energy absorber which can be suitably applied to a trim of an automobile. 
     For energy absorption in the event of a lateral collision, an energy absorber made of rigid urethane is mounted on a door trim of an automobile. As an example of method for mounting the energy absorber made of rigid urethane to the door trim, there is a method using caulking as shown in FIGS. 6 a  and  6   b . FIG. 6 b  is an enlarged view of a portion VIB of FIG. 6 a.    
     A trim (door trim)  1 ′ is provided with rods  2 ′ projecting from an inner surface of the trim  1 ′. The rods  2 ′ are inserted through mounting holes  4  formed in an energy absorber  3 ′ for the event of the lateral collision. After flat washers are fitted onto the rods  2 ′, the tops of the rods  2 ′ are caulked to form enlarged portions  2 ′ a . To prevent the backlash of the energy absorber  3 ′, hot-melt adhesives  6  are affixed on a corner between the side periphery of the energy absorber  3 ′ and the trim  1 ′. 
     Conventional structure as shown in FIGS. 6 a ,  6   b  requires a step of caulking the rods  2 ′ after the flat washers  5  are inserted and further a step of affixing the hot-melt adhesives  6 , taking plenty of time and labor for mounting the energy absorber. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide the mounting structure for an energy absorber for securely mounting an energy absorber to a member such as a trim without causing backlash and without using hot-melt adhesives. 
     In a first aspect of mounting structure for an energy absorber of the present invention, a rod projecting from a mounting surface of a member on which the energy absorber is mounted is inserted into a mounting hole of the energy absorber. A cylindrical member having a cylindrical portion and a flanged portion overhanging from the cylindrical portion is fitted onto the rod. The cylindrical portion is fitted into the mounting hole of the energy absorber and the flanged portion is overlapped with a peripheral portion about the mounting hole. 
     In the mounting structure for an energy absorber, the cylindrical portion of the cylindrical member is arranged between the inner surface of the mounting hole of the energy absorber and the outer surface of the rod, thereby preventing the backlash of the energy absorber in a direction along the mounting surface. The backlash of the energy absorber in a direction perpendicular to the mounting surface is prevented by the flanged portion of the cylindrical member which is overlapped with the peripheral portion about the mounting hole of the energy absorber. Therefore, the present invention allows the energy absorber to be mounted to the member such as a trim without using hot-melt adhesives. 
     In the present invention, the outer surface of the cylindrical portion is preferably in contact with the inner surface of the mounting hole of the energy absorber. As a result of this, the backlash of the energy absorber in the direction along the mounting surface can be further securely prevented. 
     In an embodiment of the present invention, the rod is provided with an enlarged portion at an end thereof whereby the cylindrical member is fastened to the rod. 
     In another embodiment of the present invention, the cylindrical portion is provided with slits extending from an end of the cylindrical portion, the cylindrical portion is provided with a pawl formed on an inner surface of a portion near the end of the cylindrical portion, the rod is provided with a concavity or convexity formed on an outer surface of the rod, and the pawl is engaged with the concavity or convexity whereby the cylindrical member is fastened to the rod. 
     A second aspect of mounting structure for an energy absorber of the present invention is for mounting an energy absorber to a member. The energy absorber has a mounting hole. The structure has an anchor projecting from a mounting surface of the member to enter the mounting hole, a pressing member having a flanged portion pressing the periphery of the mounting hole and a projection inserted into the mounting hole, a serrate portion provided to one of the anchor and the projection, and an engaging portion provided to the other of the anchor and the projection to engage with the serrate portion. 
     According to the mounting structure for an energy absorber of the second aspect, the backlash of the energy absorber in a direction perpendicular to the mounting surface is prevented by flanged portion of the pressing member which presses the periphery of the mounting hole of the energy absorber. The pressing member is designed so as to be in contact with the inner surface of the mounting hole of the energy absorber, thereby preventing the backlash of the energy absorber in a direction along the mounting surface. 
     According to the present invention, the cylindrical member may have a projection which is engaged with the energy absorber to prevent the rotation of the cylindrical member about the rod. The projection may be a pawl which cuts into the energy absorber. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view showing mounting structure for an energy absorber according to one embodiment of the present invention; 
     FIG. 2 is a perspective view of a cylindrical member employed in the embodiment; 
     FIG. 3 is a perspective view of another variation of the cylindrical member; 
     FIG. 4 is a perspective view of another variation of the cylindrical member; 
     FIG. 5 is a perspective view of another variation of the cylindrical member; 
     FIG. 6 a  is a sectional view showing a conventional mounting structure for an energy absorber to a door trim, and 
     FIG. 6 b  is an enlarged view of a portion VIB in FIG. 6 a;    
     FIG. 7 is a sectional view showing mounting structure for an energy absorber according to another embodiment of the present invention; 
     FIG. 8 a  is a perspective view of a cylindrical member employed in the embodiment of FIG. 7, and 
     FIG. 8 b  is a sectional perspective view of the cylindrical member of FIG. 8 a;    
     FIG. 9 is a sectional view showing mounting structure for an energy absorber according to further another embodiment of the present invention; 
     FIG. 10 is a sectional perspective view of a cylindrical member employed in the embodiment of FIG. 9; 
     FIG. 11 is a sectional view showing mounting structure for an energy absorber according to an embodiment of the present invention; 
     FIG. 12 a  is a perspective view of a cylindrical member employed in the embodiment of FIG. 11, and 
     FIG. 12 b  is a sectional perspective view of the cylindrical member; 
     FIG. 13 is a sectional view showing mounting structure for an energy absorber according to an embodiment of the present invention; 
     FIG. 14 is a perspective view of a cylindrical member employed in the embodiment of FIG. 13; 
     FIG. 15 is a sectional view of a pile of the cylindrical members of FIG. 11; 
     FIG. 16 is a sectional view showing mounting structure for an energy absorber according to an embodiment of the present invention; 
     FIG. 17 is a sectional view showing mounting structure for an energy absorber according to an embodiment of the present invention; 
     FIG. 18 is an exploded view showing the structure of FIG. 17; 
     FIG. 19 is a sectional view showing mounting structure for an energy absorber according to an embodiment of the present invention; 
     FIG. 20 is a sectional view showing mounting structure for an energy absorber according to an embodiment of the present invention; 
     FIG. 21 is a perspective view of a cylindrical member employed in the embodiment; and 
     FIG. 22 is a sectional view of an energy absorber provided with the cylindrical member of FIG.  21 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Hereinafter, embodiments will be described with reference to attached drawings. FIG. 1 is a sectional view showing mounting structure for an energy absorber according to the first embodiment and shows a section of a portion similar to a portion shown in FIG. 6 b . FIG. 2 is a perspective view of a cylindrical member employed in this embodiment. 
     In this embodiment, a trim  1  is provided with rods  2  which are inserted through mounting holes  4  formed in an energy absorber  3 , respectively, in the same manner as the conventional one. In this embodiment, a cylindrical member  7  is put on the rod  2 . The cylindrical member  7  comprises a cylindrical portion  7   a  and a flanged portion  7   b  formed integrally. The cylindrical portion  7   a  is fitted onto the rod  2  and the flanged portion  7   b  is overlapped with the peripheral portion about the mounting hole  4 . The cylindrical member  7  is put on the rod  2  in such a manner that the cylindrical portion  7   a  is fitted into the mounting hole  4  and the flanged portion  7   b  is laid on the energy absorber  3 . After that, the top end of the rod  2  is caulked or processed to form an enlarged portion  2   a.    
     As a result of this, the energy absorber  3  is mounted to the trim  1  without causing backlash. That is, the movement of the energy absorber  3  in a direction along the surface of the trim  1  is prevented by the respective cylindrical portions  7   a  arranged between the rods  2  and the inner surfaces of the mounting holes  4 . The movement of the energy absorber  3  in a direction perpendicular to the surface of the trim  1  is prevented by the flanged portions  7   b  of the cylindrical members  7 . Therefore, unlike the conventional one of FIGS. 6 a ,  6   b , hot-melt adhesives are not required, thereby facilitating the work of mounting the energy absorber  3 . In case of mounting the energy absorber to a car trim, the number of the rods or the mounting holes are preferably 2-6, more preferably 2-4 per one energy absorber. 
     The diameter (outer diameter) of the cylindrical portion  7   a  of the cylindrical member  7  is preferably ±1 mm, more preferably ±0.5 mm relative to the diameter (inner diameter) of the mounting hole  4  of the energy absorber  3  before the insertion of the cylindrical portion  7   a . The diameter (outer diameter) of the cylindrical portion  7   a  is preferably 5-12 mm, more preferably 5-10 mm. The diameter (inner diameter) of the cylindrical member  7  is preferably larger than the outer diameter of the rod  2  by 0.1-2.0 mm, more preferably by 0.5-1.0 mm. 
     The length of the cylindrical member  7  in the longitudinal direction is preferably 25-100%, more preferably 40-80% of the length of the mounting hole  4  in the longitudinal direction. In case of the energy absorber made of rigid urethane, the length of the mounting hole  4  in the longitudinal direction is preferably 4 mm or more, while the cylindrical portion  7   a  of the cylindrical member  7  in the axial direction thereof is preferably 3 mm or more, more preferably, 10-15 mm. 
     The diameter (outer diameter) of the flanged portion  7   b  is preferably larger than the diameter (inner diameter) of the mounting hole  4  by 8-15 mm. The thickness of the flanged portion  7   b  is preferably 0.5 mm or more, for example 0.5-2 mm. The material of the cylindrical member  7  is metal or synthetic resin. The synthetic resin may be polypropylene, ABS, or the like. 
     Though the flanged portion  7   b  of the cylindrical member  7  is formed in a disc-like configuration in FIGS. 1 and 2, the flanged portion  7   b  may be formed in a polygon such as square or hexagon, an ellipse, or a star-like configuration. 
     In the present invention, cylindrical members  8 ,  9 ,  10 ,  80  may be provided with projections  8   c ,  9   c ,  10   c  or  81  as shown in FIGS. 3 through 5 and FIGS. 21 and 22. The projections  8   c ,  9   c ,  81  cut into the inner surface of the mounting hole  4  while the projections  10   c  cut into the peripheral portion around the mounting hole  4 , thereby preventing the rotation of the cylindrical member  8 ,  9 ,  10 , or  80  about the rod  2 . Since the cylindrical member  8 ,  9 ,  10  or  80  is fixed to the energy absorber  3 , the cylindrical member  8 ,  9 ,  10  or  80  never rubs against the inner surface of the mounting hole  4  of the energy absorber  3 , thereby preventing the wear of the inner surface of the mounting hole  4 . 
     The projections  8   c  of FIG. 3 are each formed in a triangle and are disposed at the end of the cylindrical portion  8   a  in such a manner that the triangle has a steep-back angle toward the other end of the cylindrical portion  8   a  in order to allow the easy insertion of the cylindrical portion  8   a  into the mounting hole  4 . The projection  8   c  may be longer than that shown in FIG. 3 and, for example, may be a trapezoid extending to connect to the flanged portion  8   b . The cylindrical member  8  may have one projection  8   c  or three or more projections  8   c.    
     The cylindrical members  8 ,  9 ,  10 ,  80  can be made integral with the energy absorber  3  when the energy absorber  3  is produced by foaming as shown in FIG.  22 . The cylindrical member  80  has a cylindrical portion  82 , the projection  81  provided at one end of the cylindrical portion  80  and a projection  83  provided at the other end thereof. The projections  81  and  83  may have the same configuration. 
     The projections  9   c  of FIG. 4 are each formed in a triangle at the corner between the cylindrical portion  9   a  and the flanged portion  9   b . The projections  10   c  of FIG. 5 are formed to project from the peripheral edge of the flanged portion  10   b  in a direction along the axial direction of the cylindrical portion  10   a . Since each of the projections  10   c  has a sharp tip, the projections  10   c  can be easily cut into the peripheral portion about the mounting hole  4  of the energy absorber  3 . 
     According to the present invention, the enlarged portion  2   a  can be formed by deformation process such as a US caulking and a tapping-vis caulking. The method for forming the enlarged portion is not limited in particular. 
     FIG. 7 is a sectional view of mounting structure for an energy absorber according to another embodiment of the present invention, FIG. 8 a  is a perspective view of a cylindrical member employed in this embodiment, and FIG. 8 b  is a sectional perspective view of this cylindrical member. 
     In this embodiment, the cylindrical member  20  comprises a cylindrical portion  21  and a flanged portion  22  formed integrally. The cylindrical portion  21  is provided with a pawl  23  extending inwardly from the end of the cylindrical portion  21 . A rod  26  projecting from a trim  1  is provided with a concavity  27  formed in the outer surface thereof so that the pawl  23  engages with the concavity  27 . 
     The cylindrical portion  21  is formed with slits  24  extending from the end thereof in parallel with the axial direction of the cylindrical portion  21  so that the cylindrical portion  21  can elastically deform in the radial direction thereof. 
     To mount the energy absorber  3  to the trim  1 , the energy absorber  3  is arranged along the surface of the trim  1  in such a manner that the rods  26  are inserted into the mounting holes  4  of the energy absorber  3  and the cylindrical members  20  are then fitted and pressed onto the rods  26  to engage the pawls  23  with the concavities  27 . As a result of this, the flanged portions  22  press the peripheral portions about the mounting holes  4  of the energy absorber  3 . 
     The cylindrical portion  21  is formed in a tapered configuration, thereby facilitating the insertion of the cylindrical portion  21  into the mounting hole  4 . In a state that the cylindrical member  20  is fitted to the rod  26  (FIG.  7 ), the outer surface of the cylindrical portion  21  is in close contact with the inner surface of the mounting hole  4 . 
     The number of the slits  24  is preferably 4-6. 
     FIG. 9 is a sectional view of mounting structure of an energy absorber according to further another embodiment of the present invention and FIG. 10 is a sectional perspective view of a cylindrical member employed in this embodiment. 
     In this embodiment, the cylindrical member  30  comprises a cylindrical portion  31  and a flanged portion  32  formed integrally. The cylindrical portion  31  is provided with a concavity  35  circumferentially formed in the inner surface near the end of the cylindrical portion and with a pawl  33  inwardly extending from the end thereof. A rod  36  projecting from a trim  1  is provided with a convexity  37  circumferentially formed on the outer surface thereof so that the pawl  33  engages with the convexity  37 . 
     The cylindrical portion  31  is formed with about four to six slits  34  extending from the end thereof in parallel with the axial direction of the cylindrical portion  31  so that the cylindrical portion  31  can elastically deform in the radial direction thereof. 
     To mount the energy absorber  3  to the trim  1 , the energy absorber  3  is arranged along the surface of the trim  1  in such a manner that the rods  36  are inserted into the mounting holes  4  of the energy absorber  3  and the cylindrical members  30  are then fitted and pressed onto the rods  36  to engage the pawls  33  with the convexities  37 . As a result of this, the flanged portions  32  press the peripheral portions about the mounting holes  4  of the energy absorber  3 . 
     Though the cylindrical portion  31  is formed in a right circular cylinder shape in FIGS. 9 and 10, the cylindrical portion  31  may be formed in a tapered configuration similar to the cylindrical portion  21 . At least a portion of the outer surface of the cylindrical portion  31  is in contact with the inner surface of the mounting hole  4 . 
     In any of the embodiments of FIGS. 7 through 10 structured as described above, the energy absorber  3  can be mounted to the trim  1  without causing backlash. That is, the movement of the energy absorber  3  in a direction along the surface of the trim  1  is prevented by the respective cylindrical portions  21 ,  31  arranged between the rods  26 ,  36  and the inner surfaces of the mounting holes  4 . The movement of the energy absorber  3  in a direction perpendicular to the surface of the trim  1  is prevented by the flanged portions  22 ,  32  of the cylindrical members  20 ,  30 . 
     In the present invention, the cylindrical member may be completely perforated in the longitudinal direction thereof as shown in FIGS. 11 through 15. 
     A cylindrical member  20 A shown in FIGS. 11,  12  has the same structure as the cylindrical member  20  shown in FIGS. 7,  8  except that the cylindrical member  20 A is completely perforated in the longitudinal direction thereof. 
     A cylindrical member  30 A shown in FIGS. 13,  14  has the same structure as the cylindrical member  30  shown in FIGS. 9,  10  except that the cylindrical member  30 A is completely perforated in the longitudinal direction thereof. 
     Since a cylindrical potion  21  of the cylindrical member  20 A of the FIGS. 11,  12  has a tapered configuration, two or more cylindrical members  20 A can be compactly piled up by putting the nose thereof into the end of the cylindrical potion  21  of another one, so that the volume of the package thereof can be reduced. The pile of the cylindrical members  20 A is useful in the operation for mounting the energy absorber onto the trim by using it in a manner that the pile is coaxially pierced with a pole (not shown) so that the cylindrical member  20 A is delivered one by one by being guided with the pole. 
     The slits  21 ,  34  formed in the cylindrical potion as shown in FIGS. 7 through 14 may partially extend in the cylindrical potion. When the cylindrical member  20  or  30  is made up with an elastically deformable material such as the synthetic resin, the slits may be omitted. 
     FIGS. 16 through 20 show embodiments in which the energy absorber  3  is mounted to the trim  1  by fastening a pressing member to an anchor of the trim with a serrate portion. 
     In FIG. 16, an anchor  40  is provided to the trim  1  as an insert projecting from the trim  1 . A serrate portion  41  is formed around the anchor  40 . 
     A pressing member  44  has a flanged portion  45 , a cylindrical projection  46  having a tapered configuration which is inserted into the mounting hole  4 , and an engaging portion  47  which is inwardly projected from the front end of the projection  46 . 
     The pressing member  44  is inserted into the mounting hole  4  so that the flanged portion  45  presses the periphery of the mounting hole  4 . The anchor  40  enters the cylindrical projection  46  so that the engaging portion  47  engages with the serrate portion  41  whereby the pressing member  44  is prevented from slipping off, thereby preventing the energy absorber  3  from moving up and down in the figures. The projection  46  is in contact with the inner surface of the mounting hole  4 , thereby preventing the energy absorber  3  from moving sidewards in the figures. 
     In FIGS. 17,  18 , an anchor  50  projected from the trim  1  as an insert is provided with an engaging portion  51  projected from the outer surface thereof. A pressing member  54  is composed of a flanged portion  55 , a cylindrical projection  56  which is inserted into the mounting hole  4 , and a serrate portion  57  provided to the inner surface of the projection  56 . The pressing member  54  is pressed into the mounting hole  4  as the anchor  50  enters the cylindrical projection  56  to engage the serrate portion  57  with the engaging portion  51 ,  50  that the energy absorber  3  is fastened to the trim  1 . The flanged portion  55  presses the energy absorber  3  from above. The projection  56  is in contact with the inner surface of the mounting hole  4 , thereby preventing the energy absorber  3  from moving sidewards. 
     In FIG. 19, a pressing member  60  is composed of a flanged portion  63 , a projection  62  inserted into the mounting hole  4 , an insert  64  projecting from the projection  62  toward the trim  1 , and a serrate portion  65  provided to the outer surface of the insert  64 . An anchor  70  projecting from the trim  1  has an engaging portion  71  inwardly projecting from the nose thereof. 
     The pressing member  60  is inserted into the mounting hole  4  as the insert  64  enters the anchor  70  to engage the serrate portion  65  with the engaging portion  71 , thereby mounting the energy absorber  3  to the trim  1 . 
     A pressing member  60 A has an engaging portion  65 A on the outer surface of the nose of an insert  64 A. An anchor  70 A has a serrate portion  71 A on the inner surface thereof. The structure of the pressing member  60 A other than those described above is the same as that shown in FIG.  19 . The same numerals appearing in FIGS. 19 and 20 respectively denote the same portions. 
     In FIGS. 19 and 20, the flanged portion  63  presses the energy absorber  3  from above, and the projection  62  is in contact with the inner surface of the mounting hole  4  to keep the energy absorber  3  from moving sidewards. The projection  62  may have solid structure. 
     Therefore, a caulking apparatus is not required according to the embodiments of FIGS. 7 through 20, thereby facilitating the work of mounting the energy absorber  3 . 
     It should be noted that the cylindrical members of the embodiments of FIGS. 7-9 may be provided with projections for cutting into peripheral portions about the mounting holes  4  of the energy absorber just like the cylindrical members as shown in FIGS. 3-5. 
     In the embodiment of FIGS. 11-20, projections for cutting into the inner surface of the mounting holes  4  of the energy absorber may be provided to the cylindrical member or the pressing member. 
     The form of the serrate portion and engaging portion described above are not limitative to aforementioned embodiments so long as these portions can tightly engage with each other. The form of the cylindrical potion, rod and anchor are not especially limitative so long as these portions can press the energy absorber and keep the energy absorber from moving sidewards. 
     Though the above-described embodiments relate to the case that the energy absorber  3  for the event of a lateral collision is mounted to the door trim of a vehicle, the present invention can be applied to a case that an energy absorber made of rigid urethane for protecting the head or the like of a vehicle occupant is mounted to a vehicle member other than the door trim. The energy absorber may be made of any material having impact absorbing property such as synthetic resin other than rigid urethane. 
     As described above, the present invention allows the easy mounting of the energy absorber to a member such as a trim. According to the structure of the present invention, the energy absorber can be mounted to the member without causing backlash and without using hot-melt adhesives.