JP2015127174A - Retractor for seat belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retractor for a seat belt which inhibits axial backlash of a spindle, prevents vibration sound and abnormal noise which are generated by vibration during traveling and the like, and stably operates without being affected by external factors.SOLUTION: A take-up device 30 includes: a spring core 32 coaxially provided at a spindle 20; and a spring cassette 34 which stores a take-up spring 33 and a spring core 32 and is fixed to a frame 11. A plate spring 46 formed in a flange part 42 of the spring core 32 is disposed between the spring cassette 34 and the spindle 20. The spindle 20 is biased in an axial direction by an elastic force of the plate spring 46.

Description

  The present invention relates to a seat belt retractor, and more particularly to an improvement of a seat belt retractor provided with a lock mechanism.

  Conventionally, there has been disclosed a safety belt winding device in which journals provided at both ends of a spindle around which a webbing is wound are rotatably supported by bearings coupled to elastically deformable elements (for example, Patent Documents). 1). In this safety belt winding device, a bearing that rotatably supports the spindle is coupled to an elastic element disposed outside the frame, so that the spindle is rotatable and perpendicular to the axis. Movement is freely supported. Therefore, when the vehicle decelerates at a deceleration exceeding a predetermined value or the webbing is pulled out rapidly, the spindle is displaced in a direction perpendicular to the axis, and the spindle external teeth and the frame internal teeth Meshes with each other to restrain the rotation of the spindle and prevent the webbing from being pulled out.

Japanese Unexamined Patent Publication No. 64-78950

  By the way, in the safety belt winding device described in Patent Document 1, the spindle is preloaded from the outside of the frame by the elastic element, but the pressure and impact acting on the cover during transportation and handling, and the external heat It is easily affected by external factors such as deformation caused by the above, and there is a possibility that the operation of the retractor becomes unstable, so there is room for improvement.

  The present invention has been made in view of the above-described problems, and its purpose is to suppress the axial backlash of the spindle, prevent vibration noise and abnormal noise generated by vibration during traveling, and external factors. It is an object of the present invention to provide a seat belt retractor that can operate stably without being affected by the above.

In order to achieve the above-described object, the seatbelt retractor according to the present invention is characterized by the following (1) to (8).
(1) a spindle that is rotatably supported by a frame and on which a webbing is wound;
An emergency lock mechanism for locking the rotation of the spindle in the webbing pull-out direction;
A winding device for urging the spindle in the winding direction of the webbing;
A seat belt retractor comprising:
The winding device
A winding spring;
A spring fixing portion that fixes one end of the winding spring; and a flange portion that protrudes radially outward from the spring fixing portion, is provided coaxially with the spindle, and rotates integrally with the spindle. A retainer to
A spring cassette fixed to the frame and holding the take-up spring and the retainer;
With
The retractor for a seat belt according to claim 1, wherein the flange portion of the retainer includes an elastic member that urges the spring cassette and the spindle in an axial direction.
(2) The retractor for a seat belt according to (1), wherein the retainer is formed in a cylindrical shape.
(3) The retractor for a seat belt according to (1), wherein the elastic member of the flange portion protrudes from a plane of one axial end portion of the spring fixing portion.
(4) The retractor for a seat belt according to any one of (1) to (3), wherein the elastic member is a leaf spring integrally formed with the flange portion of the retainer.
(5) The spring cassette includes a spring housing that supports the retainer, and a spring case that is fixed to the frame so as to cover the spring housing,
The retainer urges the spindle in an axial direction by the spring fixing portion by bringing the elastic member into contact with the spring housing, according to any one of (1) to (4), Seat belt retractor.
(6) The emergency lock mechanism includes a lock member that engages with the frame and a steering wheel that is rotatably supported by the spindle and operates the lock member by causing a rotation delay with respect to the spindle. And comprising
The shaft portion of the spindle opposite to the side on which the retainer is disposed is rotatably supported by a cover member that covers the steering wheel, and is positioned in the axial direction by the cover member. The retractor for seatbelts in any one of (1)-(5).
(7) The shaft portion of the spindle is rotatably supported by the cover member via a bush fitted to the end portion of the shaft portion,
The sheet according to (6), wherein an axial end surface of the bush and the axial end surface of the cover member that are opposed to each other are in contact with each other by a protruding portion that is provided in one of them and protrudes in the axial direction. Belt retractor.

  According to the seat belt retractor of the present invention, the take-up device includes a retainer provided coaxially with the spindle, and a take-up spring and a spring cassette that houses the retainer and is fixed to the frame. Since the elastic member formed on the shaft urges the spring cassette and the spindle in the axial direction, the axial backlash of the spindle can be suppressed, and vibration noise and abnormal noise generated during traveling can be prevented, and It is possible to operate stably without being affected by external factors.

It is a front view which shows the external appearance of the retractor for seatbelts. It is a disassembled perspective view of the retractor for seatbelts shown in FIG. It is a principal part expanded sectional view of the retractor for seatbelts of the one side board side of a flame | frame. It is a principal part expanded sectional view of the retractor for seatbelts of the other side-plate side of a flame | frame. It is a side view which shows the steering wheel periphery of the retractor for seatbelts seen from the one side plate side of a frame in the state which removed the system cover. (A) is a left side view of the spring core, (b) is a front view, and (c) is a right side view. It is a perspective view which shows the assembly | attachment procedure of a winding apparatus. It is a perspective view which shows the procedure which pre-winds and assembles a winding spring.

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

  FIG. 1 is an external view of a seatbelt retractor according to the present invention, and FIG. 2 is an exploded perspective view of the seatbelt 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 of the frame 11. A spring-type winding device 30 that urges the spindle 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 in the axial direction of the body portion 27. (See FIGS. 3 and 4). 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 by a system cover 90 fixed to 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 (see FIG. 5).

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 FIG. 5, the steering wheel 60 is fitted into 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 72 of the WS lever 71. As a result, it has a convex shaft 64 that supports the WS lever 71 in a swingable manner, a projecting piece 65 that supports one end of the WS spring 75, and a plurality of engaging claws 66 formed on the outer peripheral surface. .
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.

  As shown in FIG. 3, the system cover 90 has a cylindrical wall 92 protruding from the inside of the side plate portion 91, and an inner tooth 93 that can mesh with the WS lever 71 is provided on the inner periphery of the cylindrical wall 92. It has been.

  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. As a result, 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 stored in the ball cover 82 and displaced according to horizontal acceleration, And a sensor lever 84, which is housed in a sensor cover 94 of the system cover 90.

  When the ball 83 moves in accordance with the vehicle body acceleration, the acceleration sensor lever 84 swings and the claw 85 is lifted up, and engages with the engagement claw 66 provided on the outer periphery of the steering wheel 60, so that the steering wheel The rotation of the webbing 60 in the pulling direction is prevented.

  As shown in FIG. 3, the system cover 90 is provided with a boss 95 that protrudes outward in the axial direction from the side plate portion 91 and forms a support hole 96. The bush 55 is rotatably supported with respect to the boss 95 by fitting the cap-shaped portion 57 into the support hole 96 of the boss 95.

  Further, on the inner wall surface 97 of the side plate portion 91 of the system cover 90, a protruding portion 98 that protrudes toward the bush 55 is provided at a position in the support hole 96 where the axial end surface 57a of the cap-shaped portion 57 of the bush 55 faces. Is formed. When the spindle 20 is urged in the axial direction by a spring core 32 to be described later, the protrusion 98 abuts against the axial end surface 57a of the bush 55 to position the spindle 20 in the axial direction.

  Further, a plurality of ribs 99 for reinforcing the strength are formed between the boss 95 and the side plate portion 91 to enhance 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 FIGS. 2 and 4, 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.

  As shown in FIG. 6, 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 spring fixing portion 41 has a non-circular hole 43 formed at the center thereof and fitted into a non-circular shaft portion 26 having two planes formed on the base side of the shaft portion 25, and an inner peripheral end of the winding spring 33. A fixing groove 44 for fixing the portion 33a, and a pin hole 45 for restraining the rotation of the spring core 32 against the elastic force of the winding spring 33 when pre-winding the winding spring 33 described later. , Is provided.

  Three leaf springs 46, which are elastic members extending in the circumferential direction like a cantilever, are formed integrally with the flange 42 in the middle in the radial direction of the flange 42. A middle portion in the longitudinal direction (circumferential direction) of the leaf spring 46 protrudes toward the spring fixing portion 41 and is curved.

  The winding spring 33 is formed by winding a strip-shaped spring material in a spiral shape. The outer peripheral end is fixed to the spring housing 35 and the inner peripheral end 33 a is fixed to the fixing groove 44 of the spring core 32. And is accommodated in the spring housing 35, and always urges the spindle 20 in the winding direction.

  The spring housing 35 has a cylindrical portion 37 and an annular wall portion 38 provided in the middle of the cylindrical portion 37 in the axial direction, and a through hole 38 a is formed at the center of the wall portion 38. In addition, three locking portions 40 for fixing the spring core 32 are provided in the circumferential direction on the periphery of the through hole 38a.

  As shown in FIGS. 4 and 7, in the winding device 30, after the winding spring 33 is accommodated in the cylindrical portion 37 of the spring housing 35, the spring fixing portion 41 of the spring core 32 is inserted into the through hole 38a. . Then, the inner peripheral end portion 33a of the winding spring 33 is inserted into the fixing groove 44 of the spring core 32, and the outer peripheral edge of the flange portion 42 is locked by the three locking portions 40, whereby the spring core 32 is fixed to the spring housing. Assemble to 35.

  Next, the cylindrical portion 37 of the spring housing 35 is covered with a spring case 31, and the winding spring 33 is pre-wound so as to apply tension to the webbing, and the other part of the spindle 20 is inserted into the non-circular hole 43 of the spring core 32. The non-circular shaft portion 26 on the end side is fitted. Thereby, the spring core 32 is coaxial with the spindle 20 and rotates integrally with the spindle 20.

  In addition, in order to apply tension in the winding direction to the webbing, the pre-winding applied to the winding spring 33 is to rotate the spring core 32 with the winding device 30 assembled as shown in FIG. After a predetermined amount of torsion is applied to the take-up spring 33, the fixing pin 100 is inserted from the work hole 31a provided in the spring case 31 and engaged with the pin hole 45 of the spring core 32 to take up the take-up spring 33. The torsion of the spring 33 is prevented from returning.

  The take-up device 30 on which the take-up spring 33 is pre-wound is formed on the shaft portion 25 and the non-circular shaft portion 26 on the other end side of the spindle 20, and the support hole 36 of the spring case 31 and the non-spring shaft 32. The circular hole 43 is fitted, and the spring case 31 is fixed to the side plate 11B of the frame 11. Thereby, prewinding is performed in the state in which the winding device 30 was assembled.

  When the spring case 31 is fixed to the side plate 11B of the frame 11, the spring fixing portion 41 of the spring core 32 and the side surface of the spindle 20 come into contact with each other. At this time, the three leaf springs 46 of the spring core 32 contacting the wall portion 38 of the spring housing 35 are elastically deformed, and the spindle 20 is pressed in the axial direction (rightward in FIG. 4) by this elastic force. As a result, the axial end surface 57a of the cap-shaped portion 57 of the bush 55 fitted to the shaft portion 21 on one end side of the spindle 20 comes into contact with the protrusion 98 provided on the inner wall surface 97 of the system cover 90, and the spindle Twenty axial backlashes are absorbed and positioned axially (see FIG. 3).

  The spindle 20 is rotated in a state where the axial end surface 57a of the cap-shaped portion 57 is in contact with the protruding portion 98 of the inner wall surface 97. The contact area between the axial end surface 57a and the protruding portion 98 is as follows. Since it is small, the operating torque is also small.

  Hereinafter, the operation of the seatbelt retractor 10 of the present embodiment will be described. In the seatbelt retractor 10 of the present embodiment, when the webbing is pulled out through the webbing guide 13 at a normal speed, the spindle 20 supported by the system cover 90 and the spring case 31 rotates to wind the wound webbing. Allow withdrawal.

  Further, as shown in FIG. 5, 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 elasticity of the WS spring 75 by inertial force. 5, 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, the webbing is prevented from being pulled out, and the occupant is protected.

  When a large acceleration is applied to the vehicle, the ball 83 stored in the ball cover 82 moves to swing the acceleration sensor lever 84 and the claw 85 engages with the engagement claw 66 of the steering wheel 60. 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 the webbing withdrawal, the claw 51 of the lock dog 50 meshes with the inner teeth 12 of the frame 11 and the webbing withdrawal is prevented, as described above. .

  Here, since the leaf spring 46 of the spring core 32 urges the spindle 20 in the axial direction regardless of whether the webbing acceleration sensing means 70 and the acceleration sensor 80 are operated, the spindle 20 Axial backlash is suppressed, and the generation of vibration noise and abnormal noise accompanying traveling of the vehicle is prevented. Further, the spindle 20 operates stably without being affected by external factors.

  As described above, according to the seatbelt retractor 10 of the present embodiment, the winding device 30 includes the winding spring 33, the spring core 32 provided coaxially with the spindle 20, the winding spring 33, and the spring. A spring cassette 34 that holds the core 32 and is fixed to the frame 11, and a leaf spring 46 formed on the flange 42 of the spring core 32 urges the spring cassette 34 and the spindle 20 in the axial direction. The backlash in the axial direction of the spindle 20 can always be suppressed, vibration noise and abnormal noise generated during traveling can be prevented, and stable operation can be performed without being affected by external factors. .

  Further, since the leaf spring 46 of the flange portion 42 is disposed on the plane of one axial end portion of the spring core 32, the spring core 32 can be efficiently accommodated in the narrow space of the spring housing 35.

  Further, since the elastic member is a leaf spring 46 formed integrally with the flange portion 42 of the spring core 32, the axial length of the winding device 30 can be shortened, and the seat belt retractor 10 can be downsized. The

  Further, the shaft portion 21 on one end side of the spindle 20 is rotatably supported by the system cover 90 via a fitting bush 55, and the elasticity of the leaf spring 46 formed integrally with the flange portion 42 of the spring core 32. The axial end surface 57a of the cap-shaped portion 57 of the bush 55 and the projection 98 of the inner wall surface 97 of the system cover 90 are brought into contact with each other by force. At this time, since the contact area between the axial end surface 57a of the cap-shaped portion 57 and the projection 98 of the inner wall surface 97 is small, the spindle 20 is positioned in the axial direction while reducing the operating torque during rotation of the spindle 20. be able to.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
For example, the elastic member of the spring core 32 is not limited to the leaf spring 46 but may be a coil spring or the like.
Moreover, in the said embodiment, although the spring fixing | fixed part of the spring core 32 is formed in the cylindrical shape, it can also be formed in prismatic shapes, such as a quadrangle and a pentagon.
Furthermore, in the said embodiment, although the collar part 42 of the spring core 32 protrudes from the axial direction one end part of the spring fixing | fixed part 41, you may protrude from not only this but an axial direction intermediate part.

DESCRIPTION OF SYMBOLS 10 Seat belt retractor 11 Frame 20 Spindle 21, 25 Shaft part 30 Winding device 31 Spring case 32 Spring core (retainer)
33 Winding spring 33a Inner peripheral end (one end of winding spring)
34 Spring cassette 35 Spring housing 41 Spring fixing part 42 Eaves part 46 Leaf spring (elastic member)
55 Bush 56 Spring Support 57a Axial End Surface 59 Latch Spring 50 Lock Dog (Lock Member)
60 Steering wheel 70 Webbing acceleration sensing means 71 WS lever (locking means)
90 System cover (cover member)
97 Inner wall surface (Axial end surface of cover member)
98 Protrusion

Claims (7)

A spindle that is rotatably supported by the frame and on which the webbing is wound,
An emergency locking mechanism that has a lock member that engages with the frame and locks rotation of the spindle in the webbing pull-out direction;
A winding device for urging the spindle in the winding direction of the webbing;
A seat belt retractor comprising:
The winding device
A winding spring;
A spring fixing portion that fixes one end of the winding spring; and a flange portion that protrudes radially outward from the spring fixing portion, is provided coaxially with the spindle, and rotates integrally with the spindle. A retainer to
A spring cassette fixed to the frame and holding the take-up spring and the retainer;
With
The retractor for a seat belt according to claim 1, wherein the flange portion of the retainer includes an elastic member that urges the spring cassette and the spindle in an axial direction.   The seat belt retractor according to claim 1, wherein the retainer is formed in a cylindrical shape.   The retractor for a seat belt according to claim 1, wherein the elastic member of the flange portion protrudes from a plane of one axial end portion of the spring fixing portion.   The retractor for a seat belt according to any one of claims 1 to 3, wherein the elastic member is a leaf spring formed integrally with the flange portion of the retainer. The spring cassette includes a spring housing that supports the retainer, and a spring case that is fixed to the frame so as to cover the spring housing,
The seat belt according to any one of claims 1 to 4, wherein the retainer urges the spindle in the axial direction by the spring fixing portion by bringing the elastic member into contact with the spring housing. For retractor. The emergency lock mechanism includes: a lock member that engages with the frame; and 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. Prepared,
The shaft portion of the spindle opposite to the side on which the retainer is disposed is rotatably supported by a cover member that covers the steering wheel, and is positioned in the axial direction by the cover member. The retractor for seatbelts in any one of Claims 1-5. The shaft portion of the spindle is rotatably supported by the cover member via a bush fitted to the end portion of the shaft portion,
The sheet according to claim 6, wherein the axial end surface of the bush and the axial end surface of the cover member that are opposed to each other are in contact with each other by an axially projecting portion provided on one of them. Belt retractor.

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