Patent Publication Number: US-2006010773-A1

Title: Guide roller of slide door for vehicle

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a guide roller which rolls along a rail provided on a vehicle body side, and is rotatably supported by a support member connected to a slide door.  
      2. Description of the Prior Art  
      In a slide door of a vehicle, an upper guide roller provided in an upper portion of a front end of the slide door, a center guide roller provided in a central portion of a rear end in a height direction, and a lower guide roller provided in a lower portion of the front end are rollably engaged with an upper rail provided in an upper edge portion of a vehicle body opening, a center rail provided in a central portion in the height direction of a side wall of a vehicle body rear part adjacent to the vehicle body opening, and a lower rail provided in a lower edge part of the vehicle body opening, so that to the slide door is slidably supported along the vehicle body side wall and thereby the slide door can be opened and closed by the slide of this slide door.  
      As a guide roller of a slide door, a bearing type of roller in which synthetic resin is coated on an outer periphery of an outer ring is used as shown in JP-A-2003-176661 (especially see  FIG. 3 ), for example. The reason that the bearing type of guide roller is used like so is that if a guide roller which is constructed as a roller of a resin solid type with a small number of components is used, there is the disadvantage that the resin solid roller is partially worn due to the load of the slide door to disturb smooth rotation, and in the worst case, the resin solid roller is broken, so that the slide door falls off (runs off) the vehicle body. In the case of the bearing type of guide roller, at least a structure body of the roller is an outer ring made of a metal (bearing steel), and therefore, there are the advantages that the roller itself is difficult to break and, even if the resin part is broken, the slide door is difficult to fall off the vehicle body.  
     BRIEF SUMMARY OF THE INVENTION  
      However, in the case of the guide roller shown in JP-A-2003-176661, since an outer peripheral surface and an upper end surface of the outer ring are coated with a resin part, when the resin part is broken, it is difficult to say that the guide roller is reliably prevented from falling from a rail even if the structure body of the roller is the outer ring. Since the resin part also covers the upper end surface of a support shaft, it is difficult to adopt relatively easy fastening structure such as caulking when fixing the support shaft to the support member, and there is the possibility that the fastening structure becomes complicated. Further, in the case of the guide roller shown in JP-A-2003-176661, there are the problems that an effective countermeasure is not taken against the wear of a track recessed part of the outer ring of the roller which is adapted to abut on a plurality of bearings, and a track recessed part of the support shaft, and that a portion which has been contacted with the guide rail at a temperature during ED (electro diptation) performed as the slide door is mounted to the vehicle remains as a flat surface on the covering member of the synthetic resin, so that the smooth movement of the slide door is inhibited at the time of use. The present invention is made in view of the above described circumstances, and an object thereof is to provide a bearing type of guide roller capable of being prevented from falling off a rail more reliably.  
      A solving means which is adopted by the present invention with reference to the drawings will be explained. As shown in  FIGS. 1 and 3 , the invention according to claim  1  is characterized in that, in a guide roller  20  which rolls along a center rail  3  (guide rail) provided on a vehicle body outer plate  1  (vehicle body side) and is rotatably supported by a support member  10  connected to a slide door  9 , the above described guide roller  20  is configured from a support shaft  21  fixed to the above described support member  10  by caulking, a ring-shaped outer ring  28  made of bearing steel disposed to surround an outer periphery of the support shaft  21  via a plurality of bearings  26 , and a covering member  32  made of synthetic resin covering an outer peripheral surface of the outer ring  28 , and the above-described support shaft  21  has an upper end projecting from an upper end surface of the above described ring-shaped outer ring.  
      The invention according to claim  2  is characterized in that, in the guide roller  20  according to claim  1 , the above described flange part is also formed on a lower end of the outer peripheral surface of the above described ring-shaped outer ring  28 .  
      The invention according to claim  3  is characterized in that, in the guide roller  20  according to claim  1  or claim  2 , induction hardening treatment is applied to a track recessed part  23  on which the above described bearing  26  of the above described support shaft  21  abuts.  
      Further, the invention according to claim  4  is characterized in that, in the guide roller  20  according to any one of claims  1  to claim  3 , the above described covering member  32  is made of a fiber reinforced type of synthetic resin which includes  46  nylon having a high softening temperature as a main component and is mixed with special fibers. As the special fibers mixed into the covering member  32 , aramid fibers and carbon fibers are cited.  
      In the invention according to claim  1 , since the flange part  29  is formed at the upper end of the outer peripheral surface of the outer ring  28 , even if the covering member  32  is broken, the flange part  29  interferes with the rail, and therefore, it is possible to prevent the guide roller  20  from falling off the rail more reliably as compared with the prior art. Also, since the upper end of the support shaft  21  projects from the upper end surface of the outer ring  28 , caulking can be applied to fixing structure of the support shaft  21  against the support member  10 , and therefore, the support shaft  21  can be fixed to the support member  10  easily and at low cost, as compared with the prior art.  
      In the invention according to claim  2 , since the flange part  29  is formed also at the lower end of the outer peripheral surface of the outer ring  28  to hold the covering member  32  with the flange part  29 , the covering member  32  can be prevented from falling off the outer ring  28 .  
      In the invention according to claim  3 , since the induction hardening treatment is applied to the track recessed part  23  of the support shaft  21 , wear of the guide roller  20  and the bearing  26  can be suppressed while ensuring the fixing structure by caulking.  
      In the invention according to claim  4 , since the covering member  32  is made of a fiber reinforced type of synthetic resin in which the 46 nylon, as a main component, having a high softening temperature is mixed with the special fibers, the strength can be enhanced, and the portion of the covering member  23  made of the synthetic resin, which portion has abutted on the rail, does not become a flat surface due to the temperature at the time of ED, and therefore, it is possible to maintain smooth rolling of the guide roller with respect to the rail. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       FIG. 1  is a sectional view of a center rail part to which a guide roller  20  according to the present embodiment is applied;  
       FIGS. 2A, 2B  and  2 C are a front view, a plane view and a right side view, respectively, showing an outline of a center guide roller mechanism to which the guide roller  20  is applied; and  
       FIG. 3  is a partially cutaway front view showing the internal structure of the guide roller. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Hereinafter, one embodiment of a guide roller of a slide door for a vehicle according to the present invention will be explained with reference to FIGS.  1  to  3 .  FIG. 1  is a sectional view of a center rail part to which a guide roller  20  according to the present embodiment is applied,  FIGS. 2A, 2B  and  2 C are respectively a front view, a plane view and a right side view, respectively, showing an outline of a center guide roller mechanism  10  to which the guide roller  20  is applied, and  FIG. 3  is a partially cutaway front view showing the internal structure of the guide roller  20 .  
      As described in the above, the slide door for the vehicle is adapted to able to be opened and closed by a slide of this slide door by rollably engaging an upper guide roller provided in an upper part of a front end of the slide door, a center guide roller provided in a central part in a height direction of a rear end, and a lower guide roller provided in a lower part of the front end with an upper rail provided in an upper edge part of a vehicle body opening, a center rail provided in a central part in the height direction of a side wall in a rear part of the vehicle body adjacent to the vehicle body opening and a lower rail provided in a lower edge part of the vehicle body opening, respectively, to slidably support the slide door along the vehicle body side wall. The embodiment shown in the drawings shows one in which the guide roller according to the present invention applied to the above described center guide roller mechanism  10 .  
      As shown in  FIG. 1 , a center rail  3  is attached in a recessed part  2  having a substantially horseshoe-shaped section, of which an opening is opened sideward on a side wall of a rear part of a vehicle body outer plate  1 . The center rail  3  is formed so that a guide roller chamber  4  in which the guide roller  20  is housed in its upper position and a support roller chamber  5  in which a support roller  15  is housed are vertically communicated with each other. A partition projection piece  6  is provided so as to project inward from one side wall which partitions off the guide roller chamber  4  and the support roller chamber  5 . This partition projection piece  6  is provided for preventing the guide roller  20  from falling off the center rail  3 , and thereby preventing the slide door  9  from falling off. The recessed part  2  is covered with a detachable center rail cover  7 , while a space holding member  8  which is in contact with the center rail  3  to hold the space is fixed to an inside of a lower end of the center rail cover  7 .  
      The support roller  15  and the guide roller  20  of the center guide roller mechanism  10  are rollably engaged with the center rail  3  constructed as described above, and connected to the slide door  9  via a support member  11  of the center guide roller mechanism  10 . Here, the center guide roller mechanism  10  will be explained with reference to  FIGS. 1 and 2 .  
      The center guide roller mechanism  10  is constituted from the support member  11  formed into a crank shape, and the support roller  15  and the guide roller  20  which are rotatably mounted to a support roller mounting piece  12  and a guide roller mounting piece  13  which are formed in an upper part of one end of the support member  11 . More specifically, one end side (upper end side) of the support member  11  is raised in the vertical direction, and a center portion of that raised part is the support roller mounting piece  12 . Both left and right sides of the raised part are further projected in the horizontal direction to be the guide roller mounting pieces  13 . A support shaft  14  rotatably supporting the support roller  15  is fixed to the support roller mounting piece  12  by caulking. Also, a support shaft  21  rotatably supporting the guide roller  20  is fixed to the guide roller mounting piece  13  by caulking. Meanwhile, the other end side of the support member  11  forms a mounting piece which is suspended downward to be connected to the slide door  9 .  
      In the center guide roller mechanism  10  constructed as describe above, the support roller  15  is housed in the support roller chamber  5  of the center rail  3  and rolls while abutting on a bottom surface of the support roller chamber  5  in accordance with sliding movement of the slide door  9 , and the guide roller  20  is housed in the guide roller chamber  4  of the center rail  3  and rolls while abutting on left and right side surfaces of the guide roller chamber  4  in accordance with the sliding movement of the slide door  9 . While the support roller  15  is configured from a bearing type of roller of which an outer periphery is coated with a covering member made of synthetic resin or rubber, the support roller  15  may have the same structure as the guide roller  20  which constitutes the gist of the present invention.  
      Next, a detailed construction of the guide roller  20  will be explained with reference mainly to  FIG. 3 . The guide roller  20  is configured from the support shaft  21  fixed to the guide roller mounting piece  13  of the above described support member  11  by caulking, a ring-shaped outer ring  28  disposed to surround an outer periphery of the support shaft  21  via a plurality of bearings  26 , and a covering member  32  made of synthetic resin covering an outer peripheral surface of the outer ring  28 .  
      The support shaft  21  is formed from a columnar member made of medium carbon steel (S35C, for example), and has a clamp holding projection  22  formed in its substantially middle portion, which projection abuts on the guide roller mounting piece  13  when fixed by caulking, and recessed parts  24  and  25  for caulking formed on its upper and lower end surfaces, into which recessed parts a pressing member for caulking is to be charged. Further, an arc-shaped track recessed part  23  on which the bearing  26  abuts is formed in an upper portion of the support shaft  21 . This region of the track recessed part  23  is subjected to induction hardening treatment. By constructing the support shaft  21  using medium carbon steel, the support shaft  21  is easily fixed to the above described guide roller mounting piece  13  by caulking, and by performing induction hardening for the track recessed part  23  of which wear is calculated, durability is provided against frictional wear caused by the bearing  26 . As a result of performing the induction hardening treatment, the hardness of the track recessed part  23  becomes Hv 700 or more. Further, rustproofing treatment using manganese phosphate is performed for the entire support shaft  21 .  
      A plurality of bearings  26  are adapted to be equidistantly disposed by a retainer  27  between the above described support shaft  21  and the outer ring  28 . Grease is applied between the bearings  26 . Further, in the ring-shaped outer ring  28  disposed to surround the outer periphery of the support shaft  21 , a flange part  29  is integrally formed at an upper end of the outer peripheral surface thereof, and an arc-shaped track recessed part  30  on which the above described bearing  26  abuts is formed on its inner peripheral surface. Furthermore, falling-off prevention recessed parts  31  which engage with the covering member  32  are formed in two upper and lower locations on an outer peripheral surface of the ring-shaped outer ring  28 . The outer ring  28  is constructed by bearing steel (SUJ-2, for example), and vacuum hardening treatment is performed for the entire outer ring  28 . By performing the vacuum hardening treatment for the entire outer ring  28  like this, the hardness of the track recessed part  30  becomes HRc 58 to 65, and therefore, the outer ring  28  has the durability against the friction wear by the bearing  26 .  
      The covering member  32  made of synthetic resin is composed of a fiber reinforced type of synthetic resin in which 46 nylon having a softening temperature higher than that of nylon 66 is included as a main component, and special fibers such as aramid fibers and carbon fibers are mixed by 10 wt % or less (desirably 2 to 6 wt %) therewith. This covering member  32  is provided to cover the outer peripheral surface of the outer ring  28  by insert molding. When the covering member is covered, an upper end of the covering member  32  is hooked at the flange part  29  of the outer ring  28  and the covering member  32  engages with the falling-off prevention recessed parts  31 . Therefore, the covering member  32  made of the synthetic resin does not fall off the outer ring  28 . Further, since the covering member  32  made of the synthetic resin is made of the fiber reinforcement type of synthetic resin in which the 46 nylon having a high softening temperature is included as the main component and the special fibers are mixed therewith, strength can be enhanced, and the portion of the covering member  32  made of the synthetic resin which portion has abutted on the guide rail does not become a flat surface due to the temperature at the time of ED. Therefore, smooth movement of the slide door  9  can be maintained. Also, by an embodiment in which the flange part  29  is also formed at the lower end of the outer ring  28  and the covering member  32  is held with the flange parts  29 , the covering member  32  made of the synthetic resin can be prevented from falling off the outer ring  28 .  
      Further the flange part  29  formed at the upper end of the outer peripheral surface of the outer ring  28  is not covered with the covering member  28 , and is able to contact with the left and right side surfaces of the guide roller chamber  4 . Therefore, even if the covering member  32  is broken, the guide roller  20  is prevented from falling off the guide roller chamber  4  more reliably as a result that the flange part  29  which is difficult to wear by the vacuum hardening treatment interferes with the left and right side surfaces, and the center guide roller mechanism  10  is prevented from falling off the center rail  3  to cause the slide door to fall off the vehicle body ultimately.  
      In the assembled state of the guide roller  20  shown in  FIG. 3 , the upper end of the support shaft  21  protrudes upward (upward in  FIG. 3 ) from the upper end surface of the outer ring  28 . In this case, when mounting the guide roller  20  to the guide roller mounting piece  13 , it is possible to hold the support shaft  21  by a jig or the like, while locating the outer ring  28  on the support shaft  21 . Thereby, the support shaft  21  can be fixed to the guide roller mounting piece  13  by caulking, and the guide roller  20  can be mounted to the guide roller mounting piece  13  by using relatively easy fixing structure.  
      In the guide roller  20  consisting of the support shaft  21 , the bearing  26 , the outer ring  28  and the covering member  32  as described above, the upper surface and the lower surface of the outer ring  28  are sealed with seal rings  33  when the support shaft  21  is assembled into the outer ring  28  so that a foreign matter does not enter the inside thereof.  
      In the embodiment explained above, the case where the guide roller  20  is assembled into the center guide roller mechanism  10  is explained, but the present invention can be applied to the guide roller which is assembled into the upper guide roller mechanism or the lower guide roller mechanism.