Patent Abstract:
Disclosed herein is a reclining apparatus for a vehicle seat that is capable of improving coupling strength and entire durability and removing operation noise by removing a clearance between components at the time of a reclining operation and is capable of decreasing a cost and a weight by decreasing an entire size.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. national phase application, pursuant to 35 U.S.C. §371, of PCT/KR2013/001783, filed Mar. 6, 2013, designating the United States, which claims priority to Korean Application No. 10-2012-0022765, filed Mar. 6, 2012. The entire contents of the aforementioned patent applications are incorporated herein by this reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a reclining apparatus for a vehicle seat, and more particularly, to a technology associated with a reclining apparatus for a vehicle seat capable of improving strength and removing operation noise by removing a clearance between components at the time of a reclining operation (a locked state and a locked process). 
       BACKGROUND ART 
       [0003]    A seat provided in a vehicle is configured to include a seat back supporting an upper body of a passenger, a seat cushion supporting a lower body of the passenger such as hips, thighs, and the like, and a head rest supporting the back of a head of the passenger, wherein a reclining apparatus enabling adjustment of an angle of the seat back with respect to the seat cushion is mounted at a portion at which the seat back and the seat cushion are connected to each other. 
         [0004]    As the reclining apparatus, there are a manual type reclining apparatus adjusting an angle of the seat back by a lever manipulation by the passenger and a power type reclining apparatus automatically operated by power of a motor through a switch manipulation, and all of the reclining apparatuses should have strong coupling force between components at the time of a reclining operation in order to secure safety of the passenger regardless of an operation scheme. 
         [0005]    The reclining apparatus includes a component coupled to the seat back and a component coupled to the seat cushion, and these two components should show strong coupling force at the time of the reclining operation. When these two components have weak coupling force, an angle of the seat back is easily adjusted even by small impact. In this case, a change in the angle of the seat back is made in a state in which it is not desired by the passenger, such that the passenger is injured. 
         [0006]    In order for the reclining apparatus to have the strong coupling force when it is operated as described above, a clearance should not be generated between components engaged with each other if possible. 
         [0007]    In addition, it is preferable that the reclining apparatus, which is mounted at the portion at which the seat back and the seat cushion are connected to each other, is miniaturized and lightened. 
         [0008]    The contents described as the related art have been provided only for assisting in the understanding for the background of the present invention and should not be considered as corresponding to the related art known to those skilled in the art. 
       RELATED ART DOCUMENT 
     Patent Document 
       [0009]    (Patent Document 1) Korean Utility Model Laid-Open Publication No. 20-0330534 
       SUMMARY 
       [0010]    An object of the present invention is to provide a reclining apparatus for a vehicle seat that is capable of maintaining strong coupling force, improving strength, and removing operation noise by removing a clearance between components at the time of a reclining operation (a locked state and a locked process) and is capable of decreasing a cost by decreasing a size and a weight. 
         [0011]    According to an exemplary embodiment of the present invention, there is provided a reclining apparatus for a vehicle seat, including: a base plate installed so as to be connected to a seat cushion and having a circular operation space formed on one surface thereof; a mobile flange installed so as to be connected to a seat back, having an outer edge installed so as to be inserted into the operation space, and having an internal gear formed in a circumferential direction on an inner peripheral surface thereof; a central cam positioned at a central portion between the base plate and the mobile flange and installed so as to be rotatable together with an input shaft; and a locking device installed so as to be connected to the central cam to be engaged with or disengaged from the internal gear depending on a rotation direction of the central cam. 
         [0012]    The reclining apparatus for a vehicle seat may further include a spring member positioned in the operation space and having one end supported by the base plate and the other end supported by the central cam to provide elastic rotation restoring force to the central cam. 
         [0013]    The reclining apparatus for a vehicle seat may further include a retainer installed so as to enclose both of an outer edge of the base plate and one surface of the mobile flange to retain a coupled state between the base plate and the mobile flange. 
         [0014]    A cam groove into which the central cam may be rotatably inserted is formed at a central portion of the operation space, a pair of block supporting protrusions may be formed at outer side portions of the cam groove, a pair of gear supporting protrusions may be formed at positions bisecting a space between the block supporting protrusions, a pair of block moving grooves connected to the cam groove and directed toward the block supporting protrusions may be formed, spring insertion grooves connected to the cam groove may be formed, and two spaces positioned in any one diagonal line direction among spaces between the block supporting protrusions and the gear supporting protrusions may become first gear moving grooves, and the other two spaces positioned on another diagonal line direction may become second gear moving grooves. 
         [0015]    Both side surfaces of the block supporting protrusions and both side surfaces of the gear supporting protrusions may be formed as inclined surfaces so that outer side portions of the block supporting protrusions and the gear supporting protrusions have widths wider, in the circumferential direction of the base plate, than those of inner side portions thereof directed toward the center of the cam groove, and inclined angles of both side surfaces may be formed so as to be bilaterally symmetrical to each other with respect to each of the block supporting protrusions and the gear supporting protrusions. 
         [0016]    The locking device may include: a pair of cam blocks contacting the central cam and installed so as to be movable along the block moving grooves; a pair of first cam gears contacting the central cam, installed so as to be movable along the first gear moving grooves, and having first external gears formed on outer peripheral surfaces thereof and engaged with the internal gear; a pair of second cam gears contacting the central cam, installed so as to be movable along the second gear moving grooves, and having second external gears formed on outer peripheral surfaces thereof and engaged with the internal gear; and a control plate installed so as to be fitted into the central cam to be rotated together with the central cam and providing operation force so as to forcibly move the cam blocks and the first and second cam gears toward the center of the central cam in order to disengage the internal gear and the first and second external gears from each other by rotation of the central cam. 
         [0017]    Locking jaw parts limiting movement of the first and second cam gears toward the central cam, when the internal gear and the first and second external gears are disengaged from each other, may be formed integrally with both side surfaces of the gear supporting protrusions and one side surfaces of the first and second cam gears, respectively. 
         [0018]    An outer peripheral surface of the central cam may be provided with a pair of first cam protrusions supporting the cam blocks when the internal gear and the first and second external gears are engaged with each other, a pair of second and third cam protrusions each supporting the first and second cam gears when the internal gear and the first and second external gears are engaged with each other, and seating grooves into which the cam blocks are inserted when the internal gear and the first and second external gears are disengaged from each other, and the first and second cam gears may be each provided with gear protrusions contacting the second and third cam protrusions when the internal gear and the first and second external gears are engaged with each other. 
         [0019]    The cam blocks and the first and second cam gears may be provided with guide protrusions protruding therefrom, respectively, and the control plate may be provided with a plurality of guide holes into which the guide protrusions are inserted, respectively, the guide holes being slit holes formed in an arc shape in the circumferential direction of the control plate. 
         [0020]    One end and the other end of the guide hole may be formed in a shape in which a radius is gradually decreased from the center of the central cam, one end of the guide hole may be an end portion at which the guide protrusion is positioned when the internal gear and the first and second external gears are engaged with each other, and the other end of the guide hole may be an end portion at which the guide protrusion is positioned when the internal gear and the first and second external gears are disengaged from each other. 
         [0021]    The cam block may include: a fitted part installed so as to be fitted into the block moving groove; and a body part formed integrally with the fitted part and having an inner side surface contacting the first cam protrusion and both side surfaces contacting the first and second cam gears. 
         [0022]    Both side surfaces of the body part may be formed as inclined surfaces having a width that becomes narrow from an inner side toward the central cam toward an outer side, which is an opposite side to the inner side. 
         [0023]    The reclining apparatus according to an exemplary embodiment of the present invention may remove a clearance between components at the time of a reclining operation (a locked state and a locked process), thereby making it possible to improve strength and entire durability and remove operation noise. Particularly, an entire size of the reclining apparatus is decreased, such that a cost and a weight of the reclining apparatus may be decreased. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0024]      FIG. 1  is an exploded perspective view of a reclining apparatus according to an exemplary embodiment of the present invention; 
           [0025]      FIG. 2  is a side view of a coupled state of  FIG. 1 ; 
           [0026]      FIGS. 3 and 4  are, respectively, a left side view and a right side view of  FIG. 2 ; 
           [0027]      FIG. 5  is a front view of a base plate configuring the reclining apparatus according to an exemplary embodiment of the present invention; 
           [0028]      FIG. 6  is a view showing a locked state of the reclining apparatus according to an exemplary embodiment of the present invention; 
           [0029]      FIG. 7  is a view showing a state in which a control plate is removed in  FIG. 6 ; 
           [0030]      FIG. 8  is a perspective view of  FIG. 6 ; 
           [0031]      FIG. 9  is a view showing an unlocked state of the reclining apparatus according to an exemplary embodiment of the present invention; 
           [0032]      FIG. 10  is a view showing a state in which a control plate is removed in  FIG. 9 ; and 
           [0033]      FIG. 11  is a perspective view of a cam block configuring the reclining apparatus according to an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Hereinafter, a reclining apparatus for a vehicle seat according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. 
         [0035]    The reclining apparatus for a vehicle seat according to an exemplary embodiment of the present invention is configured to include a base plate  10  installed so as to be connected to a seat cushion and having a circular operation space  11  formed on one surface thereof, a mobile flange  20  installed so as to be connected to a seat back, having an outer edge installed so as to be inserted into the operation space  11 , and having an internal gear  21  formed in a circumferential direction on an inner peripheral surface thereof, a central cam  40  positioned at a central portion between the base plate  10  and the mobile flange  20  and installed so as to be rotatable together with an input shaft  30 , a locking device installed so as to be connected to the central cam  40  to be engaged with or disengaged from the internal gear  21  depending on a rotation direction of the central cam  40 , a spring member  50  positioned in the operation space  11  and having one end supported by the base plate  10  and the other end supported by the central cam  40  to provide elastic rotation restoring force to the central cam  40 , and a retainer  100  installed so as to enclose both of an outer edge of the base plate  10  and one surface of the mobile flange  20  to retain a coupled state between the base plate  10  and the mobile flange  20 , as shown in  FIGS. 1 to 11 . 
         [0036]    Here, the spring member  50 , which is a spiral spring, is installed in a structure in which an outer distal end thereof is supported by the base plate  10  and an inner distal end thereof is supported by the central cam  40 . 
         [0037]    A cam groove  12  into which the central cam  40  is rotatably inserted is formed at a central portion of the operation space  11  provided in the base plate  10 , a pair of block supporting protrusions  13  are formed symmetrically to each other at positions forming a phase of 180 degrees based on the cam groove  12 , a pair of gear supporting protrusions  14  are formed symmetrically to each other at positions bisecting a space between the block supporting protrusions  13 , a pair of block moving grooves  15  connected to the cam groove  12  and directed toward the block supporting protrusions  13  are formed symmetrically to each other, spring insertion grooves  16  connected to the cam groove  12  are formed, two spaces formed symmetrically to each other while forming a phase of 180 degrees among spaces between the block supporting protrusions  13  and the gear supporting protrusions  14  become first gear moving grooves  17 , and the other two spaces formed symmetrically to each other become second gear moving grooves  18 . 
         [0038]    Both side surfaces  13   a  of the block supporting protrusions  13  and both side surfaces  14   a  of the gear supporting protrusions  14  are formed as inclined surfaces so that outer side portions of the block supporting protrusions  13  and the gear supporting protrusions  14  have widths wider, in the circumferential direction of the base plate  10 , than those of inner side portions thereof directed toward the center of the cam groove  12 , and inclined angles of both side surfaces  13   a  and  14   a  are formed so as to be bilaterally symmetrical to each other with respect to each of the block supporting protrusions  13  and the gear supporting protrusions  14 . 
         [0039]    Meanwhile, the locking device is configured to include a pair of cam blocks  60  contacting the central cam  40  and installed so as to be movable along the block moving grooves  15 , a pair of first cam gears  70  contacting the central cam  40 , installed so as to be movable along the first gear moving grooves  17 , and having first external gears  71  formed on outer peripheral surfaces thereof and engaged with the internal gear  21 , a pair of second cam gears  80  contacting the central cam  40 , installed so as to be movable along the second gear moving grooves  18 , and having second external gears  81  formed on outer peripheral surfaces thereof and engaged with the internal gear  21 , and a control plate  90  installed so as to be fitted into the central cam  40  to be rotated together with the central cam  40  and providing operation force so as to forcibly move the cam blocks  60  and the first and second cam gears  70  and  80  toward the center of the central cam  40  in order to disengage the internal gear  21  and the first and second external gears  71  and  81  from each other by rotation of the central cam  40 . 
         [0040]    Locking jaw parts  111  and  113  limiting movement of the first and second cam gears  70  and  80  toward the central cam  40  when the internal gear  21  and the first and second external gears  71  and  81  are disengaged from each other are formed integrally with both side surfaces  14   a  of the gear supporting protrusions  14  and one side surfaces of the first and second cam gears  70  and  80 , respectively. 
         [0041]    An outer peripheral surface of the central cam  40  is provided with a pair of first cam protrusions  41  supporting the cam blocks  60  when the internal gear  21  and the first and second external gears  71  and  81  are engaged with each other, a pair of second and third cam protrusions  42  and  43  each supporting the first and second cam gears  70  and  80  when the internal gear  21  and the first and second external gears  71  and  81  are engaged with each other, and seating grooves  44  into which the cam blocks  60  are inserted when the internal gear  21  and the first and second external gears  71  and  81  are disengaged from each other; and the first and second cam gears  70  and  80  are each provided with gear protrusions  72  and  82  contacting the second and third cam protrusions  42  and  43  when the internal gear  21  and the first and second external gears  71  and  81  are engaged with each other. 
         [0042]    The cam blocks  60  and the first and second cam gears  70  and  80  are provided with guide protrusions  115  protruding integrally therewith, respectively, and the control plate  90  is provided with a plurality of guide holes  91  into which the guide protrusions  115  are inserted, respectively, wherein the guide holes  91  are slit holes formed in an arc shape in the circumferential direction of the control plate  90 . 
         [0043]    Here, one end and the other end of the guide hole  91  are formed in a shape in which a radius is gradually decreased from the center of the central cam  40 , one end of the guide hole  91  is an end portion at which the guide protrusion  115  is positioned when the internal gear  21  and the first and second external gears  71  and  81  are engaged with each other as shown in  FIG. 6 , and the other end of the guide hole  91  is an end portion at which the guide protrusion  91  is positioned when the internal gear  21  and the first and second external gears  71  and  81  are disengaged from each other as shown in  FIG. 9 . 
         [0044]    In addition, the cam block  60  is configured to include a fitted part  61  installed so as to be fitted into the block moving groove  15  and a body part  62  formed integrally with the fitted part  61  and having an inner side surface  62   a  contacting the first cam protrusion  41  and both side surfaces  62   b  contacting the first and second cam gears  70  and  80 . 
         [0045]    The body part  62  has the guide protrusion  115  protruding on an upper surface thereof. 
         [0046]    Both side surfaces  62   b  of the body part  62  are formed as inclined surfaces having a width that becomes narrow from an inner side toward the central cam  40  toward an outer side, which is an opposite side to the inner side. 
         [0047]    Hereinafter, an operation of the reclining apparatus according to an exemplary embodiment of the present invention will be described. 
         [0048]      FIGS. 6 to 8  show a state in which the internal gear  21  and the first and second external gears  71  and  81  are engaged with each other. In this case, the reclining apparatus is in a locked state. 
         [0049]    When the reclining apparatus is maintained in the locked state, the mobile flange  20  does not rotate with respect to the base plate  10 , such that adjustment of an angle of the seat back in front and rear directions is not made. 
         [0050]    In addition, when the reclining apparatus is maintained in the locked state, both side surfaces of the first and second cam gears  70  and  80  are completely closely adhered to the side surfaces of the block supporting protrusions  13  and the side surfaces of the gear supporting protrusions  14 , as shown in  FIG. 7 , thereby making it possible to prevent a clearance from being generated between components. Therefore, coupling force and strength of the reclining apparatus may be improved. 
         [0051]    Further, when the reclining apparatus is maintained in the locked state, the central cam  40  and the cam blocks  60  support the first and second cam gears  70  and  80 , such that the first and second external gears  71  and  81  included in the first and second cam gears  70  and  80  may be maintained in a state in which they are completely engaged with the internal gear  21  included in the mobile flange  20 . Therefore, the coupling force and the strength of the reclining apparatus may be improved. 
         [0052]    In addition, the reclining apparatus according to an exemplary embodiment of the present invention has a configuration in which it is maintained in the locked state by engaging the first and second cam gears  70  and  80 , of which the total number is four, with the mobile flange  20 . The coupling force and the strength of the reclining apparatus may be further improved due to the first and second cam gears  70  and  80  of which the total number is four, and an entire size of the reclining apparatus may be decreased, such that a cost and a weight of the reclining apparatus may be decreased. 
         [0053]      FIGS. 9 and 10  show a state in which the internal gear  21  and the first and second external gears  71  and  81  are disengaged from each other. In this case, the reclining apparatus is in an unlocked state. 
         [0054]    When the reclining apparatus is maintained in the unlocked state, the mobile flange  20  may smoothly rotate with respect to the base plate  10 , such that adjustment of an angle of the seat back in the front and rear directions may be made. 
         [0055]    When the input shaft  30 , the central cam  40 , and the control plate  90  rotate counterclockwise in the locked state as shown in  FIG. 6 , supporting force of the first and second cam gears  70  and  80  by the central cam  40  is released. At the same time, supporting force of the first and second cam gears  70  and  80  by the cam blocks  60  is released. At the same time, the guide holes  91  formed in the control plate  90  pull the guide protrusions  115  toward the central cam  40 . 
         [0056]    In this case, as shown in  FIG. 9 , the first and second external gears  71  and  81  formed in the first and second cam gears  70  and  80  are separated and spaced apart from the internal gear  21  formed in the mobile flange  20 , such that the mobile flange  20  is converted into a state in which it may smoothly rotate with respect to the base plate  10 . In this state, an angle of the seat back coupled to the mobile flange  20  may be adjusted in the front and rear directions. 
         [0057]    In addition, when force applied to the input shaft  30  is removed after the adjustment of the angle of the seat back is completed, the central cam  40  is converted from the state of  FIG. 9  into the state of  FIG. 6  by elastic restoring force of the spring member  50 . Finally, the first and second external gears  71  and  81  formed in the first and second cam gears  70  and  80  are again engaged with the internal gear  21  formed in the mobile flange  20 , such that the reclining apparatus is again converted into the locked state. 
         [0058]    As described above, the reclining apparatus according to an exemplary embodiment of the present invention may remove the clearance between the components at the time of the reclining operation (the locked state and the locked process), thereby making it possible to improve strength and entire durability and remove operation noise. Particularly, the entire size of the reclining apparatus is decreased, such that a cost and a weight of the reclining apparatus may be decreased. 
         [0059]    Although the present invention has been shown and described with respect to specific exemplary embodiments, it will be obvious to those skilled in the art that the present invention may be variously modified and altered without departing from the spirit and scope of the present invention as defined by the following claims. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 [Detailed Description of Main Elements] 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 10: base plate 
                  20: mobile flange 
               
               
                   
                 30: input shaft 
                  40: central cam 
               
               
                   
                 50: spring member 
                  60: cam block 
               
               
                   
                 70: first cam gear 
                  80: second cam gear 
               
               
                   
                 90: control plate 
                 100: retainer

Technology Classification (CPC): 1