JP2016188035A - Seat belt retractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat belt retractor on which an acceleration sensor can be assembled easily without interference between a sensor lever and a steering wheel.SOLUTION: A steering wheel 60 includes a plurality of inclined surfaces 68a, 68b inclined to a circumferential direction along the circumferential direction on an end surface in an axial direction of an annular part 67 on a system cover side. In mounting an acceleration sensor 80 on a frame 11, a sensor lever 84 of the acceleration sensor 80 rotates in a direction separating from the steering wheel 60 by the inclined surfaces 68a, 68b formed on the annular part 67 when the sensor lever 84 in a rotating state is assembled in a position in which the sensor lever 84 interferes with the annular part 67 of the steering wheel 60.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a seat belt retractor, and more particularly, to a seat belt retractor to which an acceleration sensor can be easily assembled.

  A seatbelt device mounted on a vehicle restrains an occupant seated on a seat by a seatbelt pulled out from a seatbelt retractor to protect the occupant in a vehicle collision or the like. The seatbelt retractor detects the acceleration with an acceleration sensor and activates the seatbelt locking mechanism when an acceleration greater than a predetermined value is applied in the horizontal direction during a vehicle collision, etc., thereby making it impossible to pull out the seatbelt. To do.

  As shown in FIG. 6, a retractor 100 for a seat belt described in Patent Document 1 includes a spindle (not shown) around which a webbing 101 is wound, and a steering wheel supported on one shaft portion 102 of the spindle so as to be relatively rotatable. 103, a WS lever 105 that is rotatably fitted to the convex shaft 104 of the steering wheel 103, and an acceleration sensor 120 that detects the horizontal acceleration of the vehicle. A plurality of engaging claws 106 are provided on the outer periphery of the steering wheel 103. The WS lever 105 is urged counterclockwise in the figure by a WS spring 108 disposed between the protrusion 107 of the steering wheel 103. The acceleration sensor 120 includes a sensor holder 121, a ball 123 movably disposed in the recess 122 of the sensor holder 121, and a shaft support hole (not shown) provided in the sensor holder 121 that covers the ball 123 from above. ), And a sensor lever 125 supported so as to be swingable in the vertical direction about a horizontal shaft 124 fitted thereto. A claw 126 that can engage with the engaging claw 106 of the steering wheel 103 is provided at the tip of the sensor lever 125.

  When the steering wheel 103 rotates beyond a predetermined acceleration by pulling out the webbing 101, the WS lever 105 rotates clockwise while compressing the WS spring 108, and one end 105a of the WS lever 105 is moved to the system cover. The steering wheel 103 is locked by the inner teeth 111 formed on the inner periphery of the 110 to prevent the steering wheel 103 from rotating.

  When the acceleration of the vehicle exceeds a predetermined acceleration due to sudden braking or a collision, the ball 123 moves on the sensor holder 121 by the inertial force, and the sensor lever 125 is rotated clockwise about the horizontal axis 124. . As a result, the claw 126 of the sensor lever 125 meshes with the engagement claw 106 of the steering wheel 103 to prevent the steering wheel 103 from rotating.

  When the spindle further rotates while the rotation of the steering wheel 103 is locked by the WS lever 105 or the sensor lever 125, a lock dog (not shown) in which the cam pin 113 is fitted in the cam hole 109 of the steering wheel 103 is radially outward. The lock pawl engaging claws engage with internal teeth of the frame (both not shown) to lock the rotation of the spindle.

JP 2014-177268 A

  In the seatbelt retractor 100 described in Patent Document 1, the acceleration sensor 120 is attached to the frame in a state of being housed in a system cover 110 that covers the outside of the emergency lock mechanism. The sensor lever 125 is rotatable about the horizontal axis 124, and its position is not restricted when assembled to the frame. For this reason, when the acceleration sensor 120 is approached from the side of the steering wheel 103 together with the system cover 110 in a state shown by a broken line in FIG. Interferes with the annular portion 103 a of the steering wheel 103. If the acceleration sensor 120 is attached to the frame in this state, the sensor lever 125 and the steering wheel 103 may be damaged, and the function of the acceleration sensor 120 may be impaired. In particular, since the acceleration sensor 120 is covered with the system cover 110 during assembly, the state of the sensor lever 125 inside the system cover may not be visually confirmed. There was a problem that the assembly man-hours increased.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a seat belt retractor in which an acceleration sensor can be easily assembled without interference between a sensor lever and a steering wheel. .

The above object of the present invention can be achieved by the following constitution.
(1) A spindle that is rotatably supported by a frame and on which a webbing is wound, an emergency lock mechanism that locks rotation of the spindle in the webbing pull-out direction, and a winding that biases the spindle in the winding direction of the webbing A seat belt retractor comprising:
The emergency locking mechanism is
A locking member engaged with the frame;
A steering wheel that is rotatably supported by the spindle and that operates the lock member by causing a rotation delay with respect to the spindle;
An acceleration sensor having a sensor lever which can be engaged with an engaging claw formed on the outer peripheral surface of the steering wheel, and detecting a sudden deceleration state of the vehicle and preventing rotation of the spindle in the webbing pull-out direction;
A system cover that houses the acceleration sensor and is fixed to the frame and covers the emergency locking mechanism;
With
In the annular portion of the steering wheel in which the engagement claw is formed, a plurality of inclined surfaces that are inclined with respect to the circumferential direction are formed along the circumferential direction on the axial end surface on the system cover side. Features a seat belt retractor.
(2) The inclined surface has one inclined surface inclined from the valley portion toward the mountain portion and the other inclined surface inclined from the valley portion toward the other mountain portion, and the one inclination surface. The seatbelt retractor according to (1), wherein an inclination angle of the surface and the other inclined surface with respect to the circumferential direction is different from each other.
(3) The seat belt retractor according to (1) or (2), wherein at least one inclined surface is formed between the adjacent engaging claws.
(4) The seat belt retractor according to any one of (1) to (3), wherein the inclined surface includes at least one of a flat surface and a curved surface.
(5) The seat belt retractor according to any one of (1) to (4), wherein a ridge angle extending in a longitudinal direction of the inclined surface is chamfered.
(6) The valley portion of the inclined surface when the seat belt retractor is assembled is such that the sensor lever of the acceleration sensor rotates and the claw of the sensor lever is viewed from the annular portion of the steering wheel from the axial direction. The seatbelt retractor according to any one of (1) to (5), wherein the seatbelt retractor is located at a position deviating from an interfering phase.

  According to the seat belt retractor of the present invention, the steering wheel constituting the emergency lock mechanism has a plurality of inclining with respect to the circumferential direction on the axial end surface on the system cover side of the annular portion where the engaging claws are formed. An inclined surface is provided along the circumferential direction. Thus, when the acceleration sensor is attached to the frame, even if the sensor lever of the acceleration sensor is assembled in a state where it is rotated to a position where it interferes with the annular portion of the steering wheel, the sensor lever can be It can be rotated in a direction away from the steering wheel. Accordingly, the acceleration sensor can be easily assembled without considering the position of the sensor lever.

It is a front view which shows the external appearance of a seatbelt retractor. It is a disassembled perspective view of the seatbelt retractor shown in FIG. (A) is an enlarged perspective view of the steering wheel, (b) is a partial front view of the steering wheel, and (c) is an enlarged view of the main part of (a). It is a side view which shows the steering wheel periphery of the seatbelt retractor seen from the one side plate side of a frame in the state which removed the system cover. It is a partial front view corresponding to FIG.3 (b) of the steering wheel which concerns on the modification of this invention. It is a side view which shows the steering wheel periphery of the conventional seatbelt retractor.

  Hereinafter, an embodiment of a seat belt retractor according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an external view of a seat belt retractor according to the present invention, and FIG. 2 is an exploded perspective view of the seat belt retractor shown in FIG. As shown in FIGS. 1 and 2, the seat belt retractor 10 is made of a metal (for example, aluminum alloy) spindle 20 around which a webbing (not shown) is wound, and a metal that rotatably supports the spindle 20. A U-shaped frame 11, an emergency lock mechanism 14 that mechanically locks the webbing drawer, and an outer side of the other side plate 11 </ b> B of the frame 11. And a spring type winding device 30 that urges 20 to rotate in the webbing winding direction.

  The pair of side plates 11 </ b> A and 11 </ b> B of the frame 11 oppose each other across the central portion of the spindle 20 in the axial direction. In addition, a large number of internal teeth 12 that mesh with claws 51 of a lock dog 50 described later are formed on the inner periphery of the circular opening of the side plate 11A of the frame 11.

  The spindle 20 includes a body portion 27 around which the webbing is wound, and a pair of shaft portions 21 and 25 extending outward in the axial direction from a pair of flange portions 22 provided on both sides of the body portion 27 in the axial direction. . Further, on one end face side of the spindle 20, a substantially disk-shaped side wall portion 23 having a predetermined thickness is provided between the flange portion 22 and the shaft portion 21. The lock dog 50 is slidably accommodated in a lock dog accommodation space 24 in which the side wall 23 is partially cut out in a substantially fan shape.

  The emergency lock mechanism 14 detects a sudden pull-out of the webbing by detecting a sudden pull-out of the web 20 by using a metal (for example, iron) lock dog 50 as a lock member, a resin steering wheel 60, and the rotation of the spindle 20 in the webbing pull-out direction. A WS lever 71 and a WS spring 75 that constitute the webbing acceleration sensing means 70, and an acceleration sensor 80 as a vehicle body acceleration sensing means that senses a sudden deceleration state of the vehicle and prevents rotation of the spindle 20 in the webbing pull-out direction. And is covered with a system cover 90 fixed to one side plate 11A of the frame 11.

  The system cover 90 houses a resin bush 55 and a latch spring 59 interposed between the steering wheel 60 and the bush 55. The bush 55 has a cap-shaped portion 57 that covers the shaft portion 21 of the spindle 20 that passes through the center hole 61 of the steering wheel 60, and rotates integrally with the spindle 20. Further, the bush 55 is provided with a spring support portion 56 that extends in a radial direction from the cap-shaped portion 57 and supports one end of the latch spring 59.

  The steering wheel 60 is supported by the spindle 20 so as to be relatively rotatable, and operates the lock dog 50 by causing a rotation delay with respect to the spindle 20. As shown in FIGS. 3 and 4, the steering wheel 60 includes a spring receiving portion 62 that supports one end of the latch spring 59, a cam hole 63 that engages the cam pin 52 of the lock dog 50, and a shaft hole of the WS lever 71. A plurality of engagements formed on the outer peripheral surface of the convex shaft 64 that swingably supports the WS lever 71 by being fitted to 72, the projecting piece 65 that supports one end of the WS spring 75, and the outer annular portion 67. The claw 66 has a plurality of inclined surfaces 68 a and 68 b formed on the end surface in the axial direction of the annular portion 67 on the system cover side.

The inclined surfaces 68a and 68b are formed with crests 69a at positions (side surfaces) corresponding to the respective engaging claws 66, and the inclination angle α is loose with respect to the circumferential direction from the crests 69a toward the troughs 69b. An inclined surface 68a is formed, and an inclined surface 68b having a steep inclination angle β with respect to the circumferential direction is formed from the peak portion 69a toward the other valley portion 69b. That is, the inclined surfaces 68 a and 68 b are formed one by one between the adjacent engaging claws 66.
In addition, the inclined surfaces 68a and 68b may be configured by planes, may be configured by curved surfaces, or may be configured by a plurality of planes, a plurality of curved surfaces, or a combination of planes and curved surfaces.
A ridge angle extending in the longitudinal direction of the axial end surface of the annular portion 67 is chamfered on the outer diameter side. That is, in this embodiment, as shown in FIG. 3C, the inclined surfaces 68 a and 68 b are provided on the inner diameter side with a plane portion 88 along the substantially radial direction, and the outer periphery of the plane portion 88 and the annular portion 67. And an inclined surface portion 89 that is inclined so that the axial length of the annular portion 67 decreases from the inner diameter side toward the outer diameter side.

  Further, the spring receiving portion 62, the convex shaft 64, and the protruding piece 65 are formed on the side surface of the steering wheel 60 on the side facing the system cover 90.

  A latch spring 59 is mounted between the spring receiving portion 62 and the spring support portion 56 of the bush 55 to urge the steering wheel 60 counterclockwise with respect to the spindle 20.

  Therefore, the lock dog 50 in which the cam pin 52 is inserted into the cam hole 63 is held in the unlocking direction in which the pawl 51 is separated from the internal teeth 12 by the urging force of the latch spring 59. Further, when the steering wheel 60 rotates clockwise relative to the spindle 20 against the urging force of the latch spring 59 (actually, the spindle 20 rotates), the cam pin 52 enters the cam hole 63. And the claw 51 is moved outward in the radial direction. Then, by engaging the claw 51 that has advanced outward in the radial direction with the internal teeth 12 of the frame 11, the spindle 20 is locked to the internal teeth 12 of the frame 11, and the rotation in the webbing pull-out direction is mechanically locked.

  The system cover 90 has a cylindrical wall (not shown) protruding inside the side plate portion 91, and an inner tooth 93 (see FIG. 4) that can mesh with the WS lever 71 is provided on the inner periphery of the cylindrical wall. ing.

  The WS lever 71 is made of metal so that it also has a function as an inertial body. The WS lever 71 includes a claw 73 that can be engaged with the internal teeth 93 of the system cover 90 and is fitted to the convex shaft 64 of the steering wheel 60. ing. A WS spring 75 is mounted between the arm 74 on the opposite side of the claw 73 with respect to the shaft hole 72 and the protruding piece 65 of the steering wheel 60 to retract the claw 73 inward (inside of the system cover 90). The WS lever 71 is urged to rotate in a direction away from the teeth 93. Therefore, at normal times, the pawl 73 is held in a non-operating position where it does not engage with the internal teeth 93 of the system cover 90.

  As a result, when the webbing is guided by the webbing guide 13 and pulled out due to a sudden movement of the occupant, the WS lever 71 is rotated by the inertial force, and the claw 73 of the WS lever 71 is projected outward, and the system cover 90 Mesh with the inner teeth 93. Therefore, the webbing acceleration sensing means 70 prevents the steering wheel 60 from rotating in the webbing pull-out direction.

  As shown in FIG. 2, the acceleration sensor 80 includes a sensor holder 81, a ball cover 82 attached to the sensor holder 81, a ball 83 that is stored in the ball cover 82 and is displaced according to horizontal acceleration, and a support The shaft 86 includes a sensor lever 84 supported by a ball cover 82 so as to be rotatable in the horizontal direction, and is accommodated in the sensor cover 94 of the system cover 90.

  Then, when the ball 83 moves in accordance with the vehicle body acceleration, the sensor lever 84 swings and the claw 85 is lifted and engaged with the engagement claw 66 provided on the outer periphery of the steering wheel 60, and the steering wheel 60. Prevents rotation in the webbing pull-out direction.

  Also, the system cover 90 is provided with a boss 95 that forms a support hole (not shown) that rotatably supports the cap-shaped portion 57 of the bush 55 so as to protrude from the side plate portion 91 outward in the axial direction.

  Between the boss 95 and the side plate portion 91, a plurality of ribs 99 for reinforcing the strength are formed to reinforce the rigidity of the boss 95. Thereby, the thrust load loaded by the shaft portion 21 on one end side of the spindle 20 can be reliably received.

  As shown in FIG. 2, the winding device 30 includes a spring core 32 as a retainer formed in a cylindrical shape, a winding spring 33, and a spring cassette 34. The spring cassette 34 includes a spring housing 35 that supports the spring core 32, and a spring case 31 that is fixed to the other side plate 11B of the frame 11 so as to cover the spring housing 35 from the axial direction and the radial direction. The spring core 32 and the take-up spring 33 are held.

  A support hole 36 that rotatably supports the shaft portion 25 is formed on the inner wall surface of the spring case 31 at a position facing the shaft portion 25 on the other end side of the spindle 20.

  The spring core 32 includes a cylindrical spring fixing portion 41 and a flange portion 42 that is formed to protrude radially outward from one axial end portion of the spring fixing portion 41. The shaft portion 25 on the other end side of the spindle 20 is fitted to the spring fixing portion 41 so as to be integrally rotatable.

  The winding spring 33 is formed by winding a strip-shaped spring material in a spiral shape. The outer peripheral end 33 a is fixed to the spring housing 35, and the inner peripheral end 33 b is a spring fixing portion 41 of the spring core 32. The spindle 20 is constantly urged in the winding direction.

  Hereinafter, the operation of the seat belt retractor 10 of the present embodiment will be described. In the seat belt retractor 10 of the present embodiment, when the webbing is pulled out through the webbing guide 13 at a normal speed, the spindle 20 on which the shaft portions 21 and 25 at both ends are supported by the system cover 90 and the spring case 31 rotates. To allow the wound webbing to be pulled out.

  When the webbing is pulled out from the seat belt retractor 10 at a speed higher than a predetermined speed, the WS lever 71 rotating together with the steering wheel 60 causes the elastic force of the WS spring 75 by inertial force as shown in FIG. 4, the claw 73 of the WS lever 71 meshes with the internal teeth 93 of the system cover 90 to prevent the steering wheel 60 from rotating in the webbing pull-out direction.

  When the webbing is further pulled out while the steering wheel 60 is stopped and the spindle 20 rotates relative to the steering wheel 60, the lock dog 50 in which the cam pin 52 is fitted in the cam hole 63 of the steering wheel 60 is The claw 51 is pushed outward, meshed with the inner teeth 12 of the frame 11, the rotation of the spindle 20 is locked, and the webbing is prevented from being pulled out to protect the occupant.

  Further, when a large acceleration acts on the vehicle due to a collision or the like, the ball 83 stored in the ball cover 82 moves to swing the sensor lever 84 and the claw 85 engages with the engagement claw 66 of the steering wheel 60. Thus, the rotation of the steering wheel 60 in the webbing pull-out direction is prevented. When the spindle 20 rotates relative to the steering wheel 60 by pulling out the webbing, the claw 51 of the lock dog 50 meshes with the inner teeth 12 of the frame 11 and the rotation of the spindle 20 is locked, as described above. , Webbing withdrawal is blocked.

  Next, assembly of the acceleration sensor 80 will be described. The acceleration sensor 80 is accommodated in the sensor cover 94 of the system cover 90 in a state where the sensor holder 81, the ball cover 82, the ball 83, and the sensor lever 84 are assembled, and the system cover 90 is one side plate of the frame 11. 11A is fixed and assembled.

  The acceleration sensor 80 is assembled from the side of the steering wheel 60 together with the system cover 90. However, the sensor lever 84 that can be rotated around the support shaft 86 is not limited in the rotation range, and rotates in the clockwise direction. Thus, there is a possibility of interfering with the annular portion 67 of the steering wheel 60.

  Here, in the seat belt retractor 10 of the present embodiment, since the inclined surfaces 68 a and 68 b are formed on the axial end surface of the annular portion 67 of the steering wheel 60 on the system cover side, the acceleration sensor 80 is steered together with the system cover 90. Even when approaching from the side of the wheel 60 and the claws 85 of the sensor lever 84 interfere with the inclined surfaces 68a and 68b, the sensor lever 84 moves along the inclined surfaces 68a and 68b as it moves in the direction approaching the steering wheel 60. Rotate clockwise. Thereby, the interference between the sensor lever 84 and the steering wheel 60 can be automatically prevented by simply bringing the acceleration sensor 80 close to the side of the steering wheel 60 and can be easily assembled.

  As described above, according to the seatbelt retractor 10 of the present embodiment, the steering wheel 60 has a plurality of inclined surfaces 68a inclined to the circumferential direction on the axial end surface of the annular portion 67 on the system cover side. 68b is provided, when the acceleration sensor 80 is attached to the frame 11, the claw 85 of the sensor lever 84 of the acceleration sensor 80 is assembled in a state of being rotated to a position where it interferes with the annular portion 67 of the steering wheel 60. In addition, the sensor lever 84 can be rotated clockwise, that is, in a direction away from the steering wheel 60 by the inclined surfaces 68 a and 68 b formed on the side surface of the annular portion 67. Thereby, the acceleration sensor 80 can be easily assembled without considering the position of the sensor lever 84.

  In addition, the inclination angles α and β with respect to the circumferential direction of the one inclined surface 68b and the other inclined surface 68b are made different from each other so that the sensor lever 84 of the acceleration sensor 80 interferes with the annular portion 67 of the steering wheel 60. The valley portion 69b of the annular portion 67 is not positioned. Here, since the spindle 20 is attached with the same phase by a jig during assembly, the phase of the steering wheel 60 is always constant when the system cover 90 having the acceleration sensor 80 is assembled. Accordingly, the inclination angles α and β are made different from each other, and the trough portion 69b of the annular portion 67 is set to be out of the phase where the claw 85 of the sensor lever 84 interferes with the annular portion 67 when viewed in the axial direction. The sensor lever 84 can be rotated more reliably.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
The shape of the inclined surface of the present invention is not limited to that of the present embodiment, and can be rotated and separated even if the sensor lever 84 of the acceleration sensor 80 interferes with the annular portion 67 of the steering wheel 60. For example, the two inclined surfaces 68a and 68b may have the same inclination angle, or as shown in FIG. 5, the inclined surface 68a extending from the peak portion 69a toward the valley portion 69b, and the shaft You may form in the shape of a saw with which the surface 68c along a direction continues continuously.

  Further, it is sufficient that at least one inclined surface of the present invention is formed between adjacent engaging claws, and inclined surfaces 68a and 68b are arranged between adjacent engaging claws 66 as in the present embodiment. By being formed one by one, the space between the engaging claws 66 becomes a uniform shape and can be easily processed or molded.

DESCRIPTION OF SYMBOLS 10 Seat belt retractor 11 Frame 14 Emergency lock mechanism 20 Spindle 30 Winding device 50 Lock dog (lock member)
60 Steering wheel 66 Engaging claw 67 Annular part 68a, 68b Inclined surface 69a Mountain part 69b Valley part 80 Acceleration sensor 84 Sensor lever 90 System cover

Claims (6)

A spindle that is rotatably supported by the frame and on which the webbing is wound, an emergency lock mechanism that locks rotation of the spindle in the webbing pull-out direction, and a winding device that biases the spindle in the winding direction of the webbing A seat belt retractor comprising:
The emergency locking mechanism is
A locking member engaged with the frame;
A steering wheel that is rotatably supported by the spindle and that operates the lock member by causing a rotation delay with respect to the spindle;
An acceleration sensor having a sensor lever which can be engaged with an engaging claw formed on the outer peripheral surface of the steering wheel, and detecting a sudden deceleration state of the vehicle and preventing rotation of the spindle in the webbing pull-out direction;
A system cover that houses the acceleration sensor and is fixed to the frame and covers the emergency locking mechanism;
With
In the annular portion of the steering wheel in which the engagement claw is formed, a plurality of inclined surfaces that are inclined with respect to the circumferential direction are formed along the circumferential direction on the axial end surface on the system cover side. Features a seat belt retractor.   The inclined surface has one inclined surface inclined from the valley portion toward the mountain portion, and the other inclined surface inclined from the valley portion toward the other mountain portion, the one inclined surface and the The seat belt retractor according to claim 1, wherein the inclination angles of the other inclined surfaces with respect to the circumferential direction are different from each other.   The seat belt retractor according to claim 1 or 2, wherein at least one of the inclined surfaces is formed between the adjacent engaging claws.   The seat belt retractor according to any one of claims 1 to 3, wherein the inclined surface includes at least one of a flat surface and a curved surface.   The seat belt retractor according to any one of claims 1 to 4, wherein a ridge angle extending in a longitudinal direction of the inclined surface is chamfered.   The trough portion of the inclined surface when the seat belt retractor is assembled is from a phase in which the sensor lever of the acceleration sensor rotates and the pawl of the sensor lever interferes with the annular portion of the steering wheel when viewed from the axial direction. The seatbelt retractor according to any one of claims 1 to 5, wherein the seatbelt retractor is in a disengaged position.

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