Abstract:
A bush for holding first and second member includes a shaft portion having two ends, and a flange integrally formed on one of the two ends of the shaft portion to extend radially outwardly therefrom. The flange has at least one first pressing portion capable of deforming in an axial direction of the shaft portion for elastically pressing one of the two second member toward the other.

Description:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT  
       [0001]     The present invention relates to a bush to be provided on an axial portion for connecting two members to be relatively rotatable.  
         [0002]     In an automobile, a glove box, a center console, and the like are provided as a glove compartment that can be used by an occupant in a driver seat or a passenger seat. In such a glove compartment, there is a structure in which a lid member is rotatably fixed to a storage member. Japanese Patent Publication (Kokai) No. 09-169245 has disclosed such a structure in which a storage member has a box shape and an open face, and a side plate projecting from an inner face of a lid member is overlapped with an outer surface of a sidewall of the storage member. A synthetic resin bush with a flange is screwed into the sidewall of the storage member from the outside of the side plate of the lid member.  
         [0003]     In such a glove compartment of an automobile, it is difficult to adjust a gap of a relative rotational connected portion between the storage member and the lid member. When the gap is too large, since the automobile always vibrates, a chattering sound is produced. When the storage member is attached to the lid member too tightly in order to prevent the chattering sound, it is difficult to smoothly open and close the lid member. In other words, in the conventional structure in which the bush is provided on the axial portion of the storage member and the lid member, it is difficult to balance the chattering sound and the smooth operation.  
         [0004]     There has been known a method for adjusting a pressure force between the sidewall of the storage member and the side plate of the lid member, in which a disc spring is fitted in a rotational axis. However, it is necessary to provide the disc spring separately, thereby making part management troublesome and increasing the number of assembly steps.  
         [0005]     In view of the problem, an object of the invention is to provide a synthetic bush for a glove compartment wherein a chattering sound is decreased and a smooth operation can be made without increasing the number of parts or assembly steps.  
         [0006]     Further objects and advantages of the invention will be apparent from the following description of the invention.  
       SUMMARY OF INVENTION  
       [0007]     In order to attain the objects described above, according to a first aspect of the present invention, a synthetic resin bush is provided for holding first and second members to be relatively rotatable around an axial portion thereof. The synthetic resin bush includes a flange for holding the second member (for example, a side plate of a lid) between the flange and the first member (for example, a sidewall of a storage member), and a pressing portion (for example, a cantilever portion) integrated with the flange and capable of elastically deforming in an axial direction for applying a pressing force to the second member.  
         [0008]     According to a second aspect of the present invention, a depressed portion (for example, a depression) may be formed in the second member for receiving the flange. Further, another pressing portion (for example, an arc-shaped elastic portion) is integrated with an outer circumference of the flange and capable of elastically deforming in a radial direction for applying a pressing force to an inner circumferential surface of the depressed portion.  
         [0009]     In the first aspect of the present invention, it is not necessary to provide an additional member such as a disc spring for applying a contacting force between the first and second members in the axial direction, thereby reducing the number of parts or assembly steps. Also, is it possible to form the synthetic resin bush accuracy and uniformity with an injection molding, thereby obtaining a stable contacting force.  
         [0010]     In the second aspect of the invention, the pressing portion of the flange elastically deforms in the radius direction and abuts against the depression receiving the flange. Accordingly, it is possible to improve accuracy of the central position of the bush, and eliminate wobbling in the radius direction. In the invention, it is possible to balance a chattering sound and smooth operation without increasing the number of parts or assembly steps. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a vertical sectional view of a mounted part of a bush according to an embodiment of the present invention;  
         [0012]      FIG. 2  is a perspective view of the bush according to the embodiment of the present invention;  
         [0013]      FIG. 3  is a plan view of the bush according to the embodiment of the present invention;  
         [0014]      FIG. 4  is a bottom view of the bush according to the embodiment of the present invention;  
         [0015]      FIG. 5  is a front view of the bush according to the embodiment of the present invention;  
         [0016]      FIG. 6  is a left side view of the bush according to the embodiment of the present invention;  
         [0017]      FIG. 7  is a cross sectional view taken along line  7 - 7  in  FIG. 3 ; and  
         [0018]      FIG. 8  is a cross sectional view taken along line  8 - 8  in  FIG. 3 . 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0019]     Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.  FIG. 1  shows a portion connected between a storage member wherein the present invention is applied and a lid. In  FIG. 1 , a sidewall  1  of the storage member, i.e. a first member, is attached to a side plate  2  provided on an inner face of the lid, i.e. a second member, to be rotatable through a bush  3 .  
         [0020]     A cylinder portion  4  with a relatively short height in an axial direction projects from an outer surface of the sidewall  1  of the storage member. A columnar boss  5  with a tip projecting slightly above an end surface of the cylinder portions  4  in the axial direction is formed at the center of the cylinder portion  4 . An inner circumferential surface of the cylinder portion  4  and an outer circumferential surface of the boss  5  are connected with radial ribs  6  having a height about half of the depth of the cylinder portion  4  at a position dividing the circumference into two.  
         [0021]     The bush  3  is integrally formed of a synthetic resin (for example, POM) with injection molding, and comprises a cylindrical shaft portion  7  contacting the outer circumference of the boss  5 ; a flange  8  formed on an outer end of the shaft portion  7 ; and a pair of detent projections  9  formed on an inner end of the shaft portion  7 . A flat cylinder-shaped depression  10  for receiving the flange  8  formed on the outer end of the bush  3  in the axial direction, and a hole  11  penetrating through the center of the depression  10  are formed in the side plate  2  provided on the inner face of the lid member.  
         [0022]     The side plate  2  of the lid is placed on the outer. surface of the sidewall  1  of the storage member, and the shaft portion  7  inserted through the penetrating hole  11  from the outside of the side plate  2  is fitted into the boss  5  projecting toward the outer surface of the sidewall  1  of the storage member. As a result, the bush  3  regulates the rotational center of the lid relative to the storage member. Then, a tapping screw  12  is screwed in the center of the boss  5  from the outer end of the bush  3  in the axial direction through a penetrating hole  7   a  provided in the base end side of the shaft portion  7 . Accordingly, the sidewall  1  of the storage member is integrally attached to the side plate  2  of the lid in a state that the side plate  2  of the lid is clamped between the sidewall  1  of the storage member and the flange  8  of the bush  3 . Also, the bush  3  is fixed to the sidewall  1  of the storage member when a pair of the detent projections  9  engages the radial rib  6  formed on the bottom of the cylinder portion  4 .  
         [0023]     As shown in  FIG. 2 , cut portions  13  are formed in the flange  8  of the bush  3  in a radius direction to form three cantilever portions  14  and three fan-shaped portions  15 . Circumferential strips  16  and  17  having a semicircular cross section are formed at outer circumferential portions of the cantilever portions  14  and the fan-shaped portions  15  facing the bottom face of the depression  10 . The strips  16  of the cantilever portions  14  and the strips  17  of the fan-shaped portions  15  are shifted in an axial direction so that the strips  16  of the cantilever portions  14  are located closer to the bottom face of the depression  10 .  
         [0024]     Arc-shaped slits  18  are formed at outer circumferential portions of two of the three fan-shaped portions  15 , so that arc-shaped elastic portions  19  capable of deforming inwardly in the radius direction are formed. A face  20  parallel to a tangential line is formed on the remaining one of the three fan-shaped portions  15 , and a part of an outer circumferential surface thereof is cut off. Axial directional strips  21  with a semicircular cross section are formed on both ends of the face  20  parallel to the tangential line and on the centers of the outer circumferential surfaces of the arc-shaped elastic portions  19 .  
         [0025]     With the structure described above, when the tapping screw  12  is screwed in the center of the boss  5  from the outer end of the bush  3  in the axial direction, the strips  16  of the cantilever portions  14  contact the bottom surface of the depression  10  before the strips  17  of the fan-shaped portions  15  due to the shifted position in the axial direction. When the tapping screw  12  is screwed in and the strips  17  of the fan-shaped portions  15  contact the bottom surface of each depression  10 , the cantilever portions  14  bend outwardly in the axial direction. The cantilever portions  14  elastically deform in the axial direction to generate repulsion force, so that the side plate  2  of the lid is pressed in the axial direction against the cylinder portions  4  of the sidewall  1  of the storage portion.  
         [0026]     The pressing force of the cantilever portions  14  in the axial direction is determined by a bending amount of the cantilever portions  14 . It is possible to set an early bending amount of the cantilever portions  14  when the tapping screw  12  is fully fastened by adjusting a size of the boss  5  projecting from the cylinder portion  4 . Also, it is possible to properly and stably set the repulsion force of the cantilever portions  14  by adjusting a thickness or a radial size of the cantilever portion  14 , a height of the strip  16 , and the like.  
         [0027]     The circumferential strips  16  of the cantilever portions  14  have a semicircular cross section so that the lid is opened and closed smoothly without an influence of the resistance of the axial directional pressing force of the cantilever portions  14 . Accordingly, combined with the selection of POM for the molding material, it is possible to reduce a sliding resistance and obtain the smooth operation when the lid is opened and closed.  
         [0028]     The arc-shaped elastic portions  19  are provided on the outer circumferential side of the flange  8 , and the axial directional strips  21  are provided. Further, a distance between the tip of the strip  21  and the inner circumference of the depression  10  is set to be tight. Accordingly, when the strips  21  abut against the inner circumferential surface of the depression  10 , the arc-shaped elastic portions  19  divided with the arc-like slits  18  elastically deform inwardly, thereby eliminating wobbling in the radius direction of the lid.  
         [0029]     According to the present invention, the synthetic resin bush reduces the chattering sound and provides smooth operation without increasing the number of the parts or assembly steps. Also, the bush is universally applicable on an axial portion of two members relatively rotatably connected together.  
         [0030]     The disclosure as disclosed in Japanese Patent Application No. 2003-293305 filed on Aug. 14, 2003 is incorporated herein.  
         [0031]     While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.