Patent Publication Number: US-9884607-B2

Title: Seat belt retractor and seat belt device

Description:
FIELD OF THE INVENTION 
     The present invention relates to a seatbelt retractor and a seatbelt device, and more particularly, to a seatbelt retractor having a lock mechanism engageable with a base plate and a seatbelt device including the seatbelt retractor. 
     BACKGROUND OF THE INVENTION 
     Vehicles, such as automobiles, are generally provided with a seatbelt device that restrains an occupant on a seat including a seat section on which the occupant sits and a backrest section located on the back of the occupant. Such a seatbelt device includes webbing that restrains the occupant, a seatbelt retractor that retracts the webbing, a guide anchor provided on a vehicle body to guide the webbing, a belt anchor that fixes the webbing to the vehicle body, a buckle disposed on a side surface of the seat, and a tongue disposed on the webbing. The occupant is restrained in the seat by the webbing by fitting the tongue in the buckle. 
     Such a seatbelt retractor often includes a spool that retracts the webbing, a base frame that houses the spool rotatably, a spring unit that applies retracting force to the spool, a vehicle sensor that detects rapid deceleration of the vehicle, a lock mechanism actuated by the vehicle sensor to engage the spool with the base frame, and a pretensioner that removes the slack of the webbing in an emergency such as a vehicle collision (see, for example, Japanese Unexamined Patent Application Publication No. 2014-80121 and Japanese Unexamined Patent Application Publication No. 2000-289571). 
     SUMMARY OF THE INVENTION 
     For example, as described in Japanese Unexamined Patent Application Publication No. 2000-289571, the above-described lock mechanism often includes a base lock (also referred to as a locking base) connected to an end portion of the spool, a lock plate (also referred to as a pawl) disposed movably outward in the radial direction relative to the base lock, and ratchet teeth (also referred to as engaging teeth) provided on an inner rim of an aperture provided in the base frame. 
     As described in Japanese Unexamined Patent Application Publication No. 2000-289571, the above-described lock plate (pawl) is disposed in a recess (receiving portion) provided in the lock base (locking base), and is retreated at a position such as not to engage with the ratchet teeth (engaging teeth) of the base frame in a normal state (an unlocked state). Since the lock plate (pawl) is structured to move outward in the radial direction relative to the base lock and to engage with the ratchet teeth (engaging teeth) of the base frame in an emergency such as a vehicle collision, it is loosely fitted in the receiving portion. Therefore, for example, when vibrations occur in the seatbelt retractor, the lock plate (pawl) hits a wall surface of the receiving portion, and this causes abnormal noise. 
     The present invention has been made in view of such a problem, and an object of the present invention is to provide a seatbelt retractor and a seatbelt device that can suppress the occurrence of abnormal noise. 
     The present invention provides a seatbelt retractor including a spool that retracts webbing configured to restrain an occupant, a base frame that houses the spool rotatably, and a lock mechanism that restricts rotation of the spool. The lock mechanism includes a locking base disposed in an end portion of the spool, a pawl disposed to protrude outward from an outer periphery of the locking base, a pawl spring that biases the pawl inward relative to the locking base, and a lock gear coaxially disposed to rotate relative to the locking base. The pawl includes a first restraint portion that restrains movement of the pawl in one rotating direction of the spool while being located inside the outer periphery of the locking base, and a second restraint portion that restrains the movement of the pawl in an opposite rotating direction of the spool while the movement of the pawl is retrained by the first restraint portion. 
     The present invention also provides a seatbelt device including webbing that restrains an occupant, a seatbelt retractor that retracts the webbing, a guide anchor provided on a vehicle body to guide the webbing, a belt anchor that fixes the webbing to the vehicle body, a buckle disposed on a side surface of a seat on which the occupant sits, and a tongue disposed on the webbing. The seatbelt retractor includes a spool that retracts the webbing, a base frame that houses the spool rotatably, and a lock mechanism that restricts rotation of the spool. The lock mechanism includes a locking base disposed in an end portion of the spool, a pawl disposed to protrude outward from an outer periphery of the locking base, a pawl spring that biases the pawl inward relative to the locking base, and a lock gear disposed coaxially with the locking base to rotate relative to the locking base. The pawl includes a first restraint portion that restrains movement of the pawl in one rotating direction of the spool while being located inside the outer periphery of the locking base, and a second restraint portion that restrains the movement of the pawl in an opposite rotating direction of the spool while the movement is retrained by the first restraint portion. 
     In the seatbelt retractor and the seatbelt device of the present invention described above, the pawl may be received in a recess provided in the spool or the locking base. 
     The first restraint portion may be a portion in contact with a component having the recess, and the second restraint portion may be a portion in contact with the component having the recess or the lock gear. 
     The first restraint portion may be a portion in contact with a component having the recess, the second restraint portion may be a portion in contact with the lock gear, and the first restraint portion and the second restraint portion may form a wedge shape with respect to the component having the recess and the lock gear. The lock gear may include an engaging portion engageable with the component having the recess in a state in which the movement of the pawl is restrained by the first restraint portion. 
     The first restraint portion and the second restraint portion may be portions in contact with the component having the recess, and the first restraint portion and the second restraint portion may form a wedge shape with respect to the component having the recess. 
     According to the seatbelt retractor and the seatbelt device of the present invention described above, when the pawl that constitutes the lock mechanism is received (in a non-operation state), the movement of the pawl can be restrained in both rotating directions of the spool by the first restraint portion and the second restraint portion, the movement relative to the locking base can be suppressed, and the occurrence of abnormal noise can be suppressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a component developed view of a seatbelt retractor according to an embodiment of the present invention. 
         FIGS. 2A and 2B  are explanatory views of a lock gear illustrated in  FIG. 1 ,  FIG. 2A  is a perspective view from the front side, and  FIG. 2B  is a perspective view from the back side. 
         FIGS. 3A and 3B  are explanatory views illustrating the operation of the seatbelt retractor illustrated in  FIG. 1 ,  FIG. 3A  illustrates a normal state, and  FIG. 3B  illustrates a lock mechanism operating state. 
         FIGS. 4A and 4B  are explanatory views of a modification of a seatbelt retractor,  FIG. 4A  illustrates a normal state, and  FIG. 4B  illustrates a lock mechanism operating state. 
         FIG. 5  is an overall configuration view of a seatbelt device according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will be described below with reference to  FIGS. 1 to 5 . Here,  FIG. 1  is a component developed view of a seatbelt retractor according to an embodiment of the present invention.  FIGS. 2A and 2B  are explanatory views of a lock gear illustrated in  FIG. 1 ,  FIG. 2A  is a perspective view from the front side, and  FIG. 2B  is a perspective view from the back side.  FIGS. 3A and 3B  are explanatory views illustrating the operation of the seatbelt retractor illustrated in  FIG. 1 ,  FIG. 3A  illustrates a normal state, and  FIG. 3B  illustrates a lock mechanism operating state. In  FIG. 1 , illustration of webbing is omitted for convenience of explanation. 
     As illustrated in  FIG. 1 , a seatbelt retractor  1  according to the embodiment of the present invention includes a spool  2  that retracts webbing for restraining the occupant, a base frame  3  that houses the spool  2  rotatably, and a lock mechanism  4  that restricts the rotation of the spool  2 . The lock mechanism  4  includes a locking base  41  disposed in an end portion of the spool  2 , a pawl  42  disposed on the locking base  41  and disposed to protrude outward from an outer periphery of the locking base  41 , a pawl spring  43  that biases the pawl  42  inward relative to the locking base  41 , and a lock gear  44  disposed coaxially with the locking base  41  to rotate relative to the locking base  41 . The pawl  42  includes a first restraint portion  42   a  that restrains the movement of the pawl  42  in one rotating direction of the spool  2  while being located on an inner side of the outer periphery of the locking base  41 , and a second restraint portion  42   b  that restrains the movement of the pawl  42  in an opposite rotating direction of the spool  2  while the movement is restrained by the first restraint portion  42   a.    
     The spool  2  is a winding drum for retracting the webbing. For example, the spool  2  is rotatably supported at one end by a spring unit  5 , and is connected at the other end to the locking base  41 . The locking base  41  is rotatably supported by a retainer cover  6  with a cap  61  being disposed therebetween. The spring unit  5  is a component that biases the spool  2  in a retracting direction, and contains a spiral spring. The retainer cover  6  is a component that receives the lock mechanism  4  and a vehicle sensor  7 . The spring unit  5  and the retainer cover  6  are directly or indirectly fixed to the base frame  3 . 
     The seatbelt retractor  1  may further include a pretensioner  8  that removes the slack of the webbing in an emergency such as a vehicle collision. In the embodiment, the pretensioner  8  is disposed inside the base frame  3  adjacent to the locking base  41 , and only a pipe  81  that discharges a mass body for rotating the spool  2  is illustrated in  FIG. 1 . The arrangement of the pretensioner  8  is not limited to the illustrated one. The pretensioner  8  may be disposed outside the base frame  3  adjacent to the locking base  41  or may be disposed inside the spring unit  5 . 
     For example, the base frame  3  is a frame structure having a substantially angular U-shaped cross section. A pair of wall members that form side surfaces are provided at opposite ends of a wall member that forms a rear surface. The pair of wall members that form the side surfaces have apertures  31  through which end portions of the spool  2  (including the locking base  41 ) are passed. A tie plate that forms a front surface may be connected to distal ends of the pair of wall members that form the side surfaces. As illustrated in  FIG. 1 , engaging teeth  32  are provided on inner rims of the apertures  31 . 
     The side surface of the base frame  3  may have an aperture  33  that retains the vehicle sensor  7 . For example, the vehicle sensor  7  includes a spherical mass body  71 , a sensor lever  72  to be swung by movement of the mass body  71 , and a sensor cover  73  that receives and retains the mass body  71  and the sensor lever  72  in the aperture  33 . According to this vehicle sensor  7 , when a deceleration or a tilt more than or equal to a predetermined value occurs in the vehicle body, the mass body  71  disturbs its balance and pushes the sensor lever  72  upward, and a distal end of the sensor lever  72  engages with the lock gear  44 , so that the rotation of the lock gear  44  is restricted. 
     For example, the lock mechanism  4  includes the locking base  41 , the pawl  42 , the pawl spring  43 , the lock gear  44 , a protect cover  45  that restricts movement of the pawl  42  in the axial direction of the spool  2 , a flywheel  46  swingably disposed on the lock gear  44 , and a hook spring  47  that biases a distal end of the flywheel  46  inward in the radial direction. 
     As illustrated in  FIG. 1 , the locking base  41  is inserted in the aperture  31  of the base frame  3  and is disposed so that an outer peripheral portion thereof is opposed to the engaging teeth  32 . The locking base  41  has enough thickness to form a receiving portion for the pawl  42 , and has, in a front surface, a recess  411  for receiving the pawl  42 . The locking base  41  includes a shaft portion  412  that forms a rotation shaft of the spool  2 , and a plurality of projections  413  that fixes the protect cover  45 . 
     For example, as illustrated in  FIG. 3A , the recess  411  includes a wide portion  411   a  provided along the outer periphery of the locking base  41  to extend wide to a portion near the shaft portion  412 , and a guide portion  411   b  extending from the wide portion  411   a  toward the opposite outer periphery around the shaft portion  412 . The wide portion  411   a  includes a first wall surface portion  411   c  provided on a side far from the guide portion  411   b  and a second wall surface portion  411   d  provided on a side close to the guide portion  411   b.    
     In  FIGS. 3A and 3B , for convenience of explanation, components of the lock gear  44  are shown by solid lines, and the engaging teeth  32  of the base frame  3 , the locking base  41 , the pawl  42 , and the pawl spring  43  are shown by one-dot chain lines. Surfaces of the locking base  41  and the pawl  42  are painted in gray. 
     The first wall surface portion  411   c  is provided opposed to one rotating direction of the spool  2  (clockwise direction in the figures). The second wall surface portion  411   d  is provided opposed to an opposite rotating direction of the spool  2  (counterclockwise direction in the figures). The distance between the first wall surface portion  411   c  and the second wall surface portion  411   d  may decrease from the outer periphery of the locking base  41  toward the center. 
     For example, the first wall surface portion  411   c  may be shaped to be convex in the opposite rotating direction of the spool  2  (counterclockwise direction in the figures). For example, the second wall surface portion  411   d  may be shaped to be concave in the opposite rotating direction of the spool  2  (counterclockwise direction in the figures). The second wall surface portion  411   d  may be provided to continue from a wall surface portion for forming the guide portion  411   b  with almost the same curvature. 
     For example, as illustrated in  FIG. 3A , the pawl  42  includes a head portion  421  received in the wide portion  411   a  that constitutes the recess  411  of the locking base  41  and a tail portion  422  received in the guide portion  411   b  that constitutes the recess  411  of the locking base  41 . As illustrated, the pawl  42  has substantially the same outer shape as that of the recess  411 , and is loosely fitted in the recess  411 . On the outer periphery of the head portion  421 , teeth portion  421   a  are provided along the outer periphery of the locking base  41 . 
     The head portion  421  has a first restraint portion  42   a  provided along the first wall surface portion  411   c  of the wide portion  411   a  to be in contact therewith. As illustrated, the first restraint portion  42   a  has a concave shape corresponding to the convex shape of the first wall surface portion  411   c . This shape allows the first restraint portion  42   a  to be movable toward the outer side of the outer periphery of the locking base  41  while being in contact with the first wall surface portion  411   c.    
     The tail portion  422  is disposed in the guide portion  411   b  to have the function of stabilizing the posture of the pawl  42  when the head portion  421  moves to the outer side or the inner side of the outer periphery of the locking base  41 . 
     As illustrated in  FIGS. 1 and 3A , the pawl  42  has a pawl pin  423  that is passed through an aperture (cam hole  44   e ) provided in the lock gear  44  and moves the pawl  42  when relative rotation occurs between the locking base  41  and the lock gear  44 . 
     The pawl  42  may be configured movable toward the outer side of the outer periphery of the locking base  41  by sliding, or may be configured movable toward the outer side of the outer periphery by turning. The shape of the recess  411  of the locking base  41  for receiving the pawl  42  is not limited to the illustrated shape, and can be appropriately changed according to the shape and structure of the pawl  42 . 
     While the locking base  41  is connected to the end portion of the spool  2  and the surface of the end portion has the recess  411  for receiving the pawl  42  in the embodiment, as described above, the present invention is not limited to such an embodiment. For example, when an annular locking base  41  is connected the outer periphery of the end portion of the spool  2  or when the spool  2  and the locking base  41  are integrally formed, the surface of the end portion of the spool  2  may have the recess  411  for receiving the pawl  42 . Therefore, in the embodiment “component having the recess  411 ” refers to the locking base  41  or the spool  2 . 
     For example, as illustrated in  FIGS. 1, 2A, and 2B , the lock gear  44  includes a disc portion  44   a  disposed opposed to the locking base  41  and an outer peripheral wall  44   b  standing outward along an outer rim of the disc portion  44   a . On an outer surface of the outer peripheral wall  44   b , engaging teeth  44   c  are provided to be engageable with the sensor lever  72  of the vehicle sensor  7 . 
     As illustrated in  FIG. 2A , the disc portion  44   a  has, for example, an insertion hole  44   d  through which the shaft portion  412  of the locking base  41  is passed, a substantially V-shaped cam hole  44   e  through which the pawl pin  423  is passed, a guide wall  44   f  standing outward along an outer periphery of the cam hole  44   e  to guide the pawl pin  423 , an aperture  44   g  that avoids interference with the pawl spring  43 , a support pin  44   h  that supports the flywheel  46  swingably, and a hook pin  44   i  that supports one end of the pawl spring  43 . 
     The cam hole  44   e  and the guide wall  44   f  constitute a cam mechanism that guides movement of the pawl  42 , and have the function of guiding the pawl  42  to push the pawl  42  to the outer side of the outer periphery of the locking base  41 . Further, to change the moving track of the pawl  42 , the cam hole  44   e  and the guide wall  44   f  have, for example, a first guide portion  441  provided in the substantially circumferential direction and a second guide portion  442  provided in the substantially radial direction. For example, the first guide portion  441  and the second guide portion  442  form a substantially V-shape to be convex toward the outer periphery. The shape of the guide portion for guiding the pawl  42  is not limited to the substantially V-shape, and may be, for example, a substantially U-shape, a substantially J-shape, or a substantially C-shape. 
     As illustrated in  FIG. 3A , the pawl spring  43  is retained at one end by the hook pin  44   i , is retained at the other end by the pawl pin  423 , and is disposed so that a coil part thereof can expand and contract within the aperture  44   g . In a normal state (a non-operation state of the lock mechanism  4 ), the pawl  42  is biased by the pawl spring  43  so that the first restraint portion  42   a  is pressed against the first wall surface portion  411   c , as illustrated. 
     As illustrated in  FIG. 2B , a projection-like engaging portion  44   j  is provided on a back surface of the disc portion  44   a  to be engageable with the locking base  41 . As illustrated in  FIGS. 1 and 3A , the front surface of the locking base  41  has a slot  414  in which the engaging portion  44   j  can be inserted. The slat  414  is provided along the rotating direction of the locking base  41 , has a first end surface  414   a  in the counterclockwise direction in the figures, and has a second end surface  414   b  in the clockwise direction in the figures. 
     As illustrated in  FIG. 3A , the engaging portion  44   j  and the first end surface  414   a  are provided to touch with each other before the pawl pin  423  touches a surface of the second guide portion  442  close to the first wall surface portion  411   c  in a state in which the first restraint portion  42   a  of the pawl  42  is pressed against the first wall surface portion  411   c . That is, when the pawl  42  is pulled inward by the pawl spring  43 , the first restraint portion  42   a  of the pawl  42  touches the first wall surface portion  411   c  of the locking base  41 , and the pawl  42  and the locking base  41  move in the clockwise direction in the figures. After that, the engaging portion  44   j  and the first end surface  414   a  touch with each other, and this restricts relative rotation between the locking base  41  and the lock gear  44 . Therefore, the lock gear  44  has the engaging portion  44   j  that can engage with the locking base  41  in a state in which the movement of the pawl  42  is restrained by the first restraint portion  42   a.    
     When the pawl  42  is further pulled inward by the pawl spring  43 , the pawl pin  423  moves in contact with the surface of the second guide portion  442  far from the first wall surface portion  411   c . This portion of the pawl pin  423  in contact with the second guide portion  442  forms the second restraint portion  42   b  of the pawl  42 . 
     Here, an extension of the portion where the first restraint portion  42   a  of the pawl  42  is in contact with the first wall surface portion  411   c  of the locking base  41  is taken as Lp 1 , and an extension of the portion where the second restraint portion  42   b  of the pawl  42  is in contact with the second guide portion  442  of the lock gear  44  is taken as Lp 2 . As illustrated in  FIG. 3A , the extension Lp 1  and the extension Lp 2  are provided to intersect near the shaft portion  412  of the locking base  41 . That is, the first restraint portion  42   a  is a portion in contact with the locking base  41 , and the second restraint portion  42   b  is a portion in contact with the lock gear  44 . The first restraint portion  42   a  and the second restraint portion  42   b  form a wedge shape with respect to the locking base  41  and the lock gear  44 . 
     By thus forming the first restraint portion  42   a  and the second restraint portion  42   b  that form the wedge shape in the pawl  42 , when the pawl  42  is received (non-operation state of the lock mechanism  4 ), it can be clamped from both sides by the locking base  41  and the lock gear  44 , and this can restrict the movement of the pawl  42  in both rotating directions of the spool  2  and can suppress the movement of the pawl  42  relative to the locking base  41 . Therefore, even when vibrations occur in the seatbelt retractor  1 , the movement of the pawl  42  can be restricted, and the occurrence of abnormal noise can be suppressed. 
     Besides apertures through which the shaft portion  412  and the projections  413  of the locking base  41  are passed, the protect cover  45  has a cutout  45   a  through Which the pawl pin  423  of the pawl  42  is passed and an aperture  45   b  through which the engaging portion  44   j  of the lock gear  44  is passed. 
     The retainer cover  6  has a substantially cylindrical projecting portion  62  that covers the outer periphery of the outer peripheral wall  44   b  of the lock gear  44 . Inside the projecting portion  62 , an inner peripheral wall (not illustrated) is provided on the inner side of the outer peripheral wall  44   b  of the lock gear  44 . Therefore, when the lock mechanism  4  is assembled, the outer peripheral wall  44   b  of the lock gear  44  is inserted between the inner peripheral wall and the projecting portion  62 , and the flywheel  46  is disposed on the inner side of the inner peripheral wall. An inner surface of the inner peripheral wall is provided with a claw (not illustrated) to be engageable with the distal end of the flywheel  46 . 
     According to the lock mechanism  4  having the above-described structure, in the normal state (when the withdraw acceleration of the webbing is less than or equal to a predetermined threshold value), the locking base  41  and the lock gear  44  rotate together along with the rotation of the spool  2 . Therefore, since the spool  2  (locking base  41 ) and the lock gear  44  do not rotate relative to each other in the normal state, the pawl  42  is kept in the state retreated at the position such as not to interfere with the engaging teeth  32  of the base frame  3 , as illustrated in  FIG. 3A . At this time, since the movement of the pawl  42  is restrained by the locking base  41  and the lock gear  44 , abnormal noise is not caused. 
     When the withdraw acceleration of the webbing is higher than the regular withdraw acceleration, that is, when the withdraw acceleration of the webbing exceeds the predetermined threshold value, the flywheel  46  swings and engages with the claw of the retainer cover  6  (not illustrated), and this restricts the rotation of the lock gear  44 . When the vehicle sensor  7  is actuated, the distal end of the sensor lever  72  engages with the engaging teeth  44   c  provided on the outer surface of the outer peripheral wall  44   b  of the lock gear  44 , and this also restricts the rotation of the lock gear  44 . 
     When the rotation of the lock gear  44  is thus restricted, relative rotation occurs between the spool  2  (locking base  41 ) and the lock gear  44 . Along with the relative rotation, the pawl  42  slides along the recess  411 , and the teeth portion  421   a  of the pawl  42  approaches and engages with the engaging teeth  32  provided on the inner rim of the aperture  31  of the base frame  3 , as illustrated in  FIG. 3B . As a result, the rotation of the locking base  41  (spool  2 ) is restricted, and withdraw of the webbing is restricted. 
     In the operating state of the lock mechanism  4  illustrated in  FIG. 3B , the engaging portion  44   j  of the lock gear  44  moves along the slot  414  provided in the locking base  41 . Therefore, the length of the slot  414  (distance in the rotating direction from the first end surface  414   a  to the second end surface  414   b ) is designed to be more than the amount of relative rotation caused between the locking base  41  and the lock gear  44  until the pawl  42  engages with the base frame  3 . 
     While the projection-like engaging portion  44   j  is provided on the back surface of the lock gear  44  and the slot  414  is provided in the front surface of the locking base  41  in the above-described embodiment, a projection may be provided on the front surface of the locking base  41  and a slot-like engaging portion may be provided in the back surface of the lock gear  44 . 
     Next, a modification of the above-described seatbelt retractor  1  will be described with reference to  FIGS. 4A and 4B . Here,  FIGS. 4A and 4B  are explanatory views of the modification of the seatbelt retractor,  FIG. 4A  illustrates a normal state, and  FIG. 4B  illustrates a lock mechanism operating state. The same components as those of the above-described embodiment are denoted by the same reference numerals, and redundant descriptions thereof are omitted. 
     In  FIGS. 4A and 4B , for convenience of explanation, components of a lock gear  44  are shown by solid lines, engaging teeth  32  of a base frame  3 , a locking base  41 , a pawl  42 , and a pawl spring  43  are shown by one-dot chain lines, and surfaces of the locking base  41  and the pawl  42  are filled in gray. 
     In the modification illustrated in  FIGS. 4A and 4B , the position of a second restraint portion  42   b  is changed. Specifically, in this modification, an inclined surface  411   e  inclined toward a shaft portion  412  is provided in a distal end portion of a second wall surface portion  411   d  that forms a recess  411  of the locking base  41 , and a projecting portion (second restraint portion  42   b ) to be in contact with the inclined surface  411   e  is provided in a head portion  421  of the pawl  42 . As illustrated, the second restraint portion  42   b  is provided on a side opposite from a first restraint portion  42   a , for example, near the boundary between the head portion  421  and a tail portion  422 . 
     In the modification, when the pawl  42  is pulled inward by the pawl spring  43 , the first restraint portion  42   a  of the pawl  42  touches a first wall surface portion  411   c  of the locking base  41 . After that, the pawl pin  423  touches a guide wall  44   f , and the lock gear  44  is thereby positioned. When the pawl  42  is further pulled inward by the pawl spring  43 , the second restraint portion  42   b  touches the inclined surface  411   e , and the pawl  42  is thereby positioned. 
     Here, an extension of a portion of the first restraint portion  42   a  of the pawl  42  that touches the first wall surface portion  411   c  of the locking base  41  is taken as Lp 1 , and an extension of a portion of the second restraint portion  42   b  of the pawl  42  that touches the inclined surface  411   e  of the locking base  41  is taken as Lp 2 . As illustrated in  FIG. 4A , the extension Lp 1  and the extension Lp 2  are provided to intersect near the shaft portion  412  of the locking base  41 . That is, the first restraint portion  42   a  and the second restraint portion  42   b  are portions in contact with the locking base  41 , and the first restraint portion  42   a  and the second restraint portion  42   b  form a wedge shape with respect to the locking base  41 . 
     According to this modification, in the received state of the pawl  42  (non-operation state of the lock mechanism  4 ), the pawl  42  can be clamped from both sides by the first wall surface portion  411   c  and the inclined surface  411   e  of the locking base  41 , the movement of the pawl  42  in both of the rotating directions of the spool  2  can be restrained by the first restraint portion  42   a  and the second restraint portion  42   b , and the movement of the pawl  42  relative to the locking base  41  can be suppressed. Therefore, even when vibrations occur in the seatbelt retractor  1 , the movement of the pawl  42  can be restricted, and this can suppress the occurrence of abnormal noise. 
     Next, a seatbelt device according to an embodiment of the present invention will be described with reference to  FIG. 5 . Here,  FIG. 5  is an overall configuration view of the seatbelt device according to the embodiment of the present invention. In  FIG. 5 , for convenience of explanation, components other than the seatbelt device are shown by one-dot chain lines. 
     A seatbelt device  100  of the embodiment illustrated in  FIG. 5  includes webbing W that restrains an occupant, a seatbelt retractor  1  that retracts the webbing W, a guide anchor  101  provided on the vehicle body to guide the webbing W, a belt anchor  102  that fixes the webbing W to the vehicle body, a buckle  103  disposed on a side surface of a seat S on which the occupant sits, and a tongue  104  disposed on the webbing W. For example, the seatbelt retractor  1  has the structures illustrated in  FIGS. 1 to 4B . 
     Components other than the seatbelt retractor  1  will be briefly described below. For example, the seat S includes a seat section S 1  on which the occupant sits, a backrest section S 2  located on the back of the occupant, and a headrest section S 3  that supports head of the occupant. For example, the seatbelt retractor  1  is built in a B-pillar P of the vehicle body. 
     In general, the buckle  103  is often disposed on a side surface of the seat section S 1 , and the belt anchor  102  is often disposed on a lower surface of the seat section S 1 . The guide anchor  101  is often disposed on the B-pillar P. The webbing W is connected at one end to the belt anchor  102 , and is connected at the other end to the seatbelt retractor  1  with the guide anchor  101  being disposed therebetween. 
     Therefore, when the tongue  104  is fitted in the buckle  103 , the webbing W is withdrawn from the seatbelt retractor  1  while sliding in an insertion hole of the guide anchor  101 . When the occupant wears the seatbelt or releases the seatbelt to get off the vehicle, the webbing W is retracted by the action of a spring unit  5  of the seatbelt retractor  1  until a fixed load is applied thereto. 
     While the above-described seatbelt device  100  is obtained by applying the seatbelt retractor  1  of the above embodiment to a normal seatbelt device at the front seat, for example, it may be applied to the rear seat without using the guide anchor  101 . 
     The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, for example, the present invention may, of course, be applied to a seatbelt device used in conveyances other than the vehicle.