Abstract:
In order to provide a guide roller which can be readily mounted on a support member and readily adjusted in position without reducing strength of a support shaft, according to the invention, when inserting a screw part of the shaft through a long hole of the support member and fixing the shaft by a nut on a back side, the screw part is inserted while contacting notched planes with contact parts, and an insertion position of the screw part is made adjustable in the long hole. It is possible, without necessity to form an engaging part for calking in the columnar shaped support shaft, to prevent reduction in strength of the guide roller, to position the guide roller with respect to a rail only by screwing the guide roller to the support member after previously fixing the support member to the slide door, and to make the operation efficient.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a guide roller which rolls along a rail provided on a vehicle body side and is rotatably and pivotally supported by a support member connected to a slide door.  
         [0003]     2. Description of the Prior Art  
         [0004]     In a slide door for a vehicle, the slide door is slidably supported along a vehicle body side wall by rollably engaging an upper guide roller provided in a front end upper portion of the slide door, a center guide roller provided in a central portion in a height direction of a rear end, and a lower guide roller provided in a front end lower portion 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 in a vehicle body rear portion adjacent to the vehicle opening, and a lower rail provided in a lower edge portion of the vehicle opening, respectively, so that the slide door can be opened and closed.  
         [0005]     As a guide roller of a slide door, there has been used a bearing type roller in which an outer peripheral surface and a top surface of an outer ring are covered with a synthetic resin as shown in JP-A-2003-176661 (see FIGS. 3 and 8), for example. The reason why the bearing type guide roller is used like this is that when a roller constructed as a resin solid roller with the small number of components is used, there arises the disadvantage that the resin solid roller is asymmetrically worn due to a load of the slide door and prevented from smoothly rotating, and thereby the resin solid roller breaks and falls off from a vehicle body in the worst case. The bearing type guide roller has the advantage that the roller itself is difficult to break and hardly falls off from the vehicle body even if the resin part breaks because at least a structure body of the roller is an outer ring made of metal (bearing steel).  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     However, in the guide roller shown in FIG. 3 of the above described JP-A-2003-176661, since the outer peripheral surface and the top surface of the outer ring are covered with a resin part, and the fixing structure to a bracket which is a support member is calking structure, an engaging part having a recessed groove shape is formed in a middle portion of the support shaft for fitting a calking jig. Therefore, since the diameter of the support shaft becomes thin in a portion of the engaging part having the recessed groove shape, there are the problems of reducing in strength and being complicated in shape to increase machining cost. Further, in the guide roller shown in FIG. 8 of the above described JP-A-2003-176661, the guide roller having the structure in which mounting to the bracket is made by screw fixing, instead of by calking fixing, without forming the above described engaging part having the recessed groove shape is disclosed. Although the mounting structure of the guide roller to the bracket is not disclosed in detail, if the mounting structure is the same mounting structure as the guide roller shown in FIG. 3, the guide roller can be fixed to only a predetermined position with respect to the bracket, and therefore, positioning of the guide roller has to be performed between the bracket and the slide door, which resultantly causes the problem that a part for adjusting a position becomes heavy which makes it difficult to perform fine adjustment. Therefore, there has been a guide roller in which notched planes are formed at screw parts, however since a screw portion of the shaft does not extend on the entire periphery, there has been the case that fastening strength with a nut can not be sufficiently secured.  
         [0007]     The present invention is made in view of the above circumstances, and an object of the present invention is to provide a guide roller capable of readily mounting it to a support member and readily adjusting its position without reducing strength of a support shaft.  
         [0008]     The solution which is adopted by the present invention is explained with reference to the drawings. The invention according to claim  1  is, as shown in FIGS.  1  to  3 , a guide roller  20  which rolls along an upper rail  3  (guide rail) provided at vehicle body outer plates  1   a  to  1   d  (on a vehicle body side), and is rotatably and pivotally supported by a support member  11  connected to a slide door  6 , and which guide roller  20  is constructed by a support shaft  21  having a columnar shape fixed to the support member  11  by a screw, a ring-shaped outer ring  28  consisting of bearing steel disposed via a plurality of bearings  26  to surround an outer periphery of the support shaft  21 , and a covering member  32  made of a synthetic resin covering an outer peripheral surface and a top surface of the outer ring  28 , and is characterized in that: in the above described support shaft  21 , a whirl-stop seat  33  which enhances the strength of a screw part  23  is provided at an upper end circumference of the screw part  23  formed below the columnar shape, and a flange part  22  for preventing falling down is provided at an upper end circumference of the whirl-stop seat  33 ; notched planes  34  are formed by cutting in a vertical direction at opposed positions of an outer periphery of the whirl-stop seat  33 ; a long hole  15  having contact parts  15   a  which contact the notched planes  34  is formed in the support member  11 ; and when the screw part  23  of the support shaft  21  is inserted through the long hole  15  of the support member  11  and fixed with a nut  16  on a back side, the screw part  23  is inserted through there while contacting the notched planes  34  of the whirl-stop seat  33  with the contact parts  15   a , and an insertion position of the support shaft  21  with respect to the long hole  15  is made adjustable.  
         [0009]     Further, the invention according to claim  2  is the guide roller  20  according to claim  1 , which is characterized in that after quench-and-temper treatment is performed for the support shaft  21 , nitriding treatment is performed.  
         [0010]     Further, the invention according to claim  3  is the guide roller  20  according to claim  1  or claim  2 , which is characterized in that the covering member  32  is made of a fiber reinforced synthetic resin in which 46 nylon or aromatic polyamide of which softening temperature is high is contained as a main component, and in which special fiber is mixed. Further, as special fiber mixed in the covering member  32 , aramid fiber and carbon fiber are raised.  
         [0011]     Further, the invention according to claim  4  is the guide roller  20  according to any one of claims  1  to  3 , which is characterized in that grinding working is performed for one of or both of a surface of a track recessed part of the support shaft which contacts the bearings, and a surface of a track recessed part of the outer ring which contacts the bearings.  
         [0012]     Further, the invention according to claim  5  is the guide roller  20  according to any one of claims  1  to  4 , which is characterized in that a phosphate film having a thickness of 10 to 30 μm is formed on the bearing.  
         [0013]     Further, the invention according to claim  6  is the guide roller  20  according to any one of claims  1  to  5 , which is characterized in that a flange part contact surface of the flange part, which contacts the support member, is formed into a concave-and-convex shape.  
         [0014]     In the invention according to claim  1 , since the support shaft  21  is fixed to the support member  11  by the screw, it is not necessary to form an engaging part for calking at the support shaft  21  having the columnar shape, so that reduction in strength of the guide roller  20  can be prevented.  
         [0015]     Further, since the whirl-stop seat  33  is formed at the upper end circumference of the screw part  23 , a root portion of the screw part  33  becomes large, and strength against fastening of the screw part  23  can be enhanced.  
         [0016]     Further, when the screw part  23  of the support shaft  21  is inserted through the long hole  15  of the support member  11  and fixed with the nut  16  on the back side, the screw part  23  is inserted through there while contacting the notched planes  34  formed with the whirl-stop seat  33  on the contact parts  15   a  of the long hole  15  and the insertion position of the support shaft  21  with respect to the long hole  15  is made adjustable, and therefore, positioning of the guide roller  20  with respect to the rail  3  can be performed only by screwing the guide roller  20  to the support member  11  after the support member  11  is previously fixed to the slide door  6 , and thereby the operation can be made efficient.  
         [0017]     Further, since the notched planes  34  formed on the whirl-stop seat  33  are made to contact the contact parts  15   a  of the long hole  15 , the support shaft  21  does not rotate with respect to the support member  11 , whereby loosening of the nut  16  with respect to the screw part  23  can be prevented.  
         [0018]     Further, since the notched planes  34  which contact the contact parts  15   a  of the long hole  15  are formed in the whirl-stop seat  33  as described above, a screw part area does not decrease as in the case where the notched planes  34  are formed on the screw part  23 , and the fastening force with respect to the screw part  23  is not reduced.  
         [0019]     Furthermore, when the notched planes  34  are formed on the screw part  23 , those have to be formed by cutting working after forming the screw part  23 , but formation of the notched planes  34  in the whirl-stop seat  33  can be performed by molding with a metallic mold, which is less expensive than the case where the notched planes  34  are formed on the screw part  23 , and thereby, reduction in cost of the guide roller  20  can be achieved.  
         [0020]     In the invention according to claim  2 , after the quench-and-temper treatment is performed for the support shaft  21 , the nitriding treatment is performed, and therefore, wear of the guide roller  20  and the bearings  26  can be suppressed without deteriorating elongation of the support shaft  21 .  
         [0021]     In the invention according to claim  3 , since the covering member  32  is made of the fiber reinforced synthetic resin in which 46 nylon or aromatic polyamide of which softening temperature is high is contained as a main component and in which the special fiber is mixed, strength can be enhanced, and since the portion of the covering member  32  made of the synthetic resin, which contacts the rail, does not become flat surface due to temperature at the time of ED coating, smooth rolling of the guide roller  20  with respect to the rail  3  can be maintained.  
         [0022]     In the invention according to claim  4 , since the grinding working is performed for one of or both of the surface of the track recessed part  25  of the support shaft  21 , and the surface of the track recessed part  30  of the outer ring  28 , smooth rolling of the bearing can be maintained by improving profiled irregularity of the track recessed parts  25  and  30 , and occurrence of abnormal noise can be prevented.  
         [0023]     In the invention according to claim  5 , since the phosphate film having the thickness of 10 to 30 μm is formed on the bearings  26 , friction between the bearings  26 , and the track recessed part  25  of the support shaft  21  and the track recessed part  30  of the outer ring  28  is reduced, and adhesion is suppressed by interposition of the different material, whereby occurrence of fretting on the surfaces of the bearings  26  due to vibration of the vehicle body can be prevented.  
         [0024]     In the invention according to claim  6 , since the flange part contact surface  22   a  which contacts the support member  11  of the flange part  22  is formed into the concave-and-convex shape, the support shaft  21  is difficult to slip with respect to the support member  11 , whereby loosening of the nut  16  against the screw part  23  can be prevented.  
         [0025]     Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0026]      FIG. 1  is a sectional view of an upper rail part to which a guide roller according to this embodiment is applied;  
         [0027]      FIG. 2  is an exploded perspective view of an upper guide roller mechanism to which the guide roller is applied;  
         [0028]      FIG. 3  is a partial cutaway front view showing internal structure of the guide roller; and  
         [0029]      FIG. 4  is a bottom view of the guide roller. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     Hereinafter, one embodiment of a guide roller of a vehicle slide door according to the present invention will be described with reference to FIGS.  1  to  4 .  FIG. 1  is a sectional view of an upper rail part to which a guide roller  20  according to the embodiment is applied,  FIG. 2  is an exploded perspective view of an upper guide roller mechanism  10  to which the guide roller  20  is applied,  FIG. 3  is a partial cutaway front view showing internal structure of the guide roller  20 , and  FIG. 4  is a bottom view of the guide roller  20 .  
         [0031]     As described above, an upper guide roller provided in a front end upper portion of the slide door, a center guide roller provided in a central portion in a height direction of a rear end, and a lower guide roller provided in a front end lower portion 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 a height direction of a vehicle body rear portion side wall adjacent to the vehicle body opening, and a lower rail provided in a lower edge portion of the vehicle body opening, respectively, so that the slide door is slidably supported along the vehicle body side wall, and the slide door of the vehicle can be opened and closed by sliding this slide door. The embodiment shown in the drawings shows a guide roller according to the present invention which is applied to the above described upper guide roller mechanism  10 .  
         [0032]     As shown in  FIG. 1 , an upper rail  3  is mounted in a recessed part  2  for laying a rail which is formed by assembling a plurality of vehicle body outer plates  1   a  to  1   d  by welding to have a substantially U-shaped section and an opening opened sideway. The upper rail  3  is formed into an inversed U-shape with an opening opened downward so as to form a guide roller chamber  4  in which a guide roller  20  is housed. A rubber packing  5  for securing fitting between the slide opening and the slide door  6  when the slide door  6  is closed is fitted to a lower end portion of the recessed part  2 .  
         [0033]     The guide roller  20  of the upper guide roller mechanism  10  is rollably engaged with the upper rail  3  which is constructed as described above, and the upper rail  3  is connected to the slide door  6  via a support member  11  of the upper guide roller mechanism  10 . Here, the upper guide roller mechanism  10  will be described with reference to  FIGS. 1 and 2 .  
         [0034]     The upper guide roller mechanism  10  is constructed by the support member  11  formed in an inversed L shape in the plane view, and the guide roller  20  which is rotatably mounted on a guide roller mounting piece part  14  forming one end side of the support member  11 . In more detail, the one end side of the support member  11  formed in the inversed L shape is formed as a door mounting piece part  12  which hangs in a vertical direction, and door mounting holes  13   a  and  13   b  are provided at positions separated in a left and right direction of the door mounting piece part  12  as shown in  FIG. 2 . The door mounting holes  13   a  and  13   b  are the mounting holes for mounting the support member  11  to an inner side of the upper end portion of the slide door  6  with bolts  18  as shown in  FIG. 1 .  
         [0035]     Meanwhile, the other end side of the support member  11  formed in the inversed L shape is formed as the guide roller mounting piece part  14  extending in an orthogonal direction from the above described door mounting piece part  12 , and a long hole  15  having a track shape is provided near a tip end of its top surface. A support shaft  21  of the guide roller  20  is inserted through the long hole  15  and fastened with a nut  16  from a back surface. An inner periphery in a longitudinal direction of the long hole  15  forms linear contact parts  15   a  which contact notched planes  34  formed in a whirl-stop seat  33  of the support shaft  21 . A guide projection  17  which engages in an engaging groove (not shown) formed on the vehicle body side when the slide door  6  is closed is projectingly provided on a front surface side of an L-shaped corner portion of the support member  11  to perform positioning of a final closing position of the slide door  6 .  
         [0036]     In the upper guide roller mechanism  10  constructed as described above, the guide roller  20  is housed in the guide roller chamber  4  of the upper rail  3  so as to roll there while contacting left and right side surfaces of the guide roller chamber  4  in connection with slide movement of the slide door  6 .  
         [0037]     Next, the construction of the guide roller  20  will be described in detail, mainly with reference to  FIGS. 3 and 4 . The guide roller  20  is constructed by the columnar support shaft  21  which is fixed to the guide roller mounting piece part  14  of the above described support member  11  by screwing, a ring-shaped outer ring  28  made of bearing steel and disposed via a plurality of bearings  26  to surround an outer periphery of the support shaft  21 , and a covering member  32  made of a synthetic resin which covers an outer peripheral surface and a top surface of the outer ring  28 .  
         [0038]     The support shaft  21  is formed by a column member of medium carbon steel (S35C or S45C, for example). A flange part  22  for preventing falling down is circumferentially provided just below a substantially intermediate portion of the support shaft  21 , the whirl-stop seat  33  which enhances the strength of a screw part  23  is formed below the flange part  22 , and further, a portion below the whirl-stop seat  33  is the screw part  23 . A flange part contact surface  22   a  of the flange part  22  which contacts the support member  11  is formed in a concave and convex shape (or an uneven shape). The concave and convex shape is the shape which is formed in, for example, a lattice shape, a corrugated shape, or the like.  
         [0039]     The whirl-stop seat  33  is formed into a shape which is cut off in a vertical direction in opposed positions of the outer periphery of the cylinder, and cut off portions are formed as notched planes  34 . The notched planes  34  are adapted to contact the contact parts  15   a  when the screw part  23  of the support shaft  21  is inserted through the long hole  15  of the support member  11  as described above. The notched planes  34  are formed in the whirl-stop seat  33  as described above, and therefore, those can be formed by molding processing by a metallic mold. Therefore, those do not have to be formed by cutting processing after formation of the screw part  23  as in the case of forming the notched planes  34  in the screw part  23 , and those are made at lower cost than the case of forming the notched planes  34  in the screw part  23 , whereby cost of the guide roller  20  can be reduced.  
         [0040]     Since the whirl-stop seat  33  is formed on an upper end circumference of the screw part  23 , the diameter of a root portion of the screw part  23  becomes large, and thus its strength against the fastening of the screw part  23  can be enhanced.  
         [0041]     Since the dimension in the longitudinal direction of the long hole  15  is larger than the diameter of the arc portion of the whirl-stop seat  33 , the fastening position of the support shaft  21  can be moved in the long hole  15 . Further, an arc-shaped track recessed part  25  which contacts the bearing  26  is formed in an upper portion of the support shaft  21 . Since grinding processing is performed for a surface of the track recessed part  25 , profile irregularity is improved, whereby smooth rolling of the bearing can be maintained, and occurrence of abnormal noise can be prevented.  
         [0042]     On the other hand, the support shaft  21  is required to have contradicting performances, namely, hardness for improving wear resistance of the track recessed part  25  which is a track of the bearing  26 , and softness (elongation) for resisting twist at the time of fastening a screw against the screw part  23 . In order to ensure the contradicting performances, induction hardening is sometimes performed only for the track recessed part  25  made of medium carbon steel, but there has been the disadvantage that operability is not good because the hardened portion is limited. Therefore, the support shaft  21  according to this embodiment is also given proper hardness without inhibiting elongation by performing quench-and-temper treatment for the entire support shaft  21  made of medium carbon steel, and operability can be enhanced. Further, by performing nitriding treatment for the support shaft  21 , sliding characteristics (wear resistance, low frictional property) of the track recessed part  25  is enhanced, and anti-corrosive property can be enhanced.  
         [0043]     Further, a plurality of bearings  26  are disposed at regular intervals by a retainer  27  between the above described support shaft  21  and the outer ring  28 . Grease is applied between the bearings  26 . 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 a lower end of an outer peripheral surface, and an arc-shaped track recessed part  30  which contacts the above described bearings  26  is formed on its inner peripheral surface. The outer ring  28  is constructed by bearing steel (for example, SUJ-2), and vacuum hardening treatment is performed for the entire outer ring  28 . As a result of 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  is constructed to have durability against frictional wear with respect to the bearings  26 . Since grinding working is performed for a surface of the track recessed part  30  of the outer ring  28  like the track recessed part  25  of the above described support shaft  21 , profile irregularity is improved, whereby smooth rolling of the bearings  26  can be maintained, and occurrence of abnormal noise can be prevented.  
         [0044]     Further, since a phosphate film of a thickness of 10 to 30 μm is formed on the above described bearings  26 , friction between the bearings  26 , and the track recessed part  25  of the support shaft  21  and the track recessed part  30  of the outer ring  28  is reduced, and since adhesion is suppressed by interposition of the different material, occurrence of fretting on the surfaces of the bearings  26  due to vibration of the vehicle body can be prevented. As a phosphate film, zinc phosphate, manganese phosphate, calcium phosphate, ferric phosphate and the like are raised, for example. In the case that the thickness of the phosphate film is less than 10 μm, however, the phosphate film will wear at the time of initial wear for conformity. When the thickness of the phosphate film exceeds 30 μm, the phosphate film strength reduces, and peeling will occur in the film layer. Accordingly, the effect of prevention of occurrence of fretting can be provided in the range of the thickness of the phosphate film of 10 μm to 30 μm.  
         [0045]     The covering member  32  of a synthetic resin is constructed by a fiber reinforced synthetic resin in which 46 nylon or aromatic polyamide of which softening temperature is higher than 66 nylon is contained as a main component and in which not more than 10 wt % (preferably, 2 to 6 wt %) of special fiber such as aramid fiber and carbon fiber is mixed. The covering member  32  is provided to cover the outer peripheral surface and the top surface of the outer ring  28  by insert molding, and when the covering member  32  is provided, a lower end of the covering member  32  is engaged with and fastened to the flange part  29  of the outer ring  28 , and therefore, the covering member  32  of the synthetic resin does not fall off from the outer ring  28 . Further, since the covering member  32  made of the synthetic resin is the fiber reinforced synthetic resin in which 46 nylon or aromatic polyamide (of which softening temperature is high) is contained as a main component and in which the special fiber is mixed therein, strength can be enhanced, and the portion of the covering member  32  made of the synthetic resin which contacts the guide rail does not become a flat surface due to the temperature at the time of ED coating. Therefore, smooth movement of the slide door  6  can be maintained. In the guide roller  20  constructed by the support shaft  21 , the outer ring  28 , the bearing  26  and the covering member  32  as described above, foreign substances do not enter the inside in the state where the support shaft  21  is assembled to the outer ring  28  since its undersurface is sealed with the seal ring  31 .  
         [0046]     In order to mount the guide roller  20  having the above described structure on the support member  11 , the screw part  23  of the guide roller  20  is inserted through the long hole  15  of the guide roller mounting piece part  14 , and the flange part contact surface  22   a  of the flange part  22  is made to contact the top surface of the guide roller mounting piece part  14 . When the screw part  23  is inserted through the long hole  15 , the screw part  23  is inserted while contacting the notched planes  34  of the whirl-stop seat  33  with the contact parts  15   a  of the long hole  15 . Thereafter, the nut  16  is fastened from the back surface of the guide roller mounting piece part  14 . At the time of this fastening, the notched planes  34  are in the state that those contact and are held by the contact parts  15   a , which provides the whirl-stop function, and fastening operation of the nut  16  to the screw part  23  is facilitated. However, at the time of the fastening, it is suitable to fasten the nut  16  loosely enough for the support shaft  21  to move with respect to the long hole  15 .  
         [0047]     Further, in the state where the upper guide roller mechanism  10  of which the guide roller  20  is screwed and fixed to the support member  11  as described above is firmly fixed to the inner side of the upper end portion of the slide door  6  by the bolt  18 , in order to mount the entire slide door  6  on the upper rail  3 , the guide roller  20  is firstly inserted into the guide roller chamber  4  of the upper rail  3 , final position adjustment of the guide roller  20  is performed, and then the nut  16  is firmly fastened. The flange part  22  contacts the top surface of the support member  11  by the final fastening of the nut  16 , and therefore, even if it is used for long periods, deformation such as inclination of the support shaft  21  or the like can be prevented.  
         [0048]     Besides, as described above, the flange contact surface  22   a  of the flange part  22  is formed in the convex-and-concave shape, and looseness-prevention-projections  19  are projectingly provided all over the circumference on a surface of the nut  16   a , which surface is formed on the nut  16   a  and contacts the support member  11  of the flange, as shown in  FIG. 2 . Therefore, when the nub  16  is finally fixed, the support shaft  21  and the nut  16  are difficult to slip with respect to the support member  11 , and therefore, looseness of the nut  16  with respect to the screw part  23  can be prevented. As described above, since the notched planes  34  which are formed on the whirl-stop seat  33  are in contact with the contact parts  15   a  of the long hole  15 , the support shaft  21  does not rotate with respect to the support member  11 , whereby looseness of the nut  16  with respect to the screw part  23  can be also prevented.  
         [0049]     Further, since the notched planes  34  which are adapted to contact the contact parts  15   a  of the long hole  15  are formed on the whirl-stop seat  33  as described above, the screw part area does not decrease as in the case where the notched planes  34  are formed in the screw part  23 , and thus fastening force with respect to the screw part  23  is not reduced.  
         [0050]     In the embodiment described above, the case where the guide roller  20  is assembled to the upper guide roller mechanism  10  is described, but the present invention can be also applied to a guide roller which is assembled to a center guide roller mechanism or a lower guide roller mechanism.  
         [0051]     It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.